906 files changed, 46925 insertions, 34190 deletions

diff --git a/deps/v8/src/DEPS b/deps/v8/src/DEPS
index 90cfd737f2..99873803c9 100644
--- a/deps/v8/src/DEPS
+++ b/deps/v8/src/DEPS
@@ -13,6 +13,7 @@ include_rules = [
   "+src/heap/heap.h",
   "+src/heap/heap-inl.h",
   "+src/heap/heap-write-barrier-inl.h",
+  "+src/heap/heap-write-barrier.h",
   "-src/inspector",
   "-src/interpreter",
   "+src/interpreter/bytecode-array-accessor.h",
@@ -30,6 +31,7 @@ include_rules = [
   "+testing/gtest/include/gtest/gtest_prod.h",
   "-src/libplatform",
   "-include/libplatform",
+  "+builtins-generated",
   "+torque-generated"
 ]
 
diff --git a/deps/v8/src/accessors.cc b/deps/v8/src/accessors.cc
index da935f3652..226178394d 100644
--- a/deps/v8/src/accessors.cc
+++ b/deps/v8/src/accessors.cc
@@ -31,7 +31,8 @@ Handle<AccessorInfo> Accessors::MakeAccessor(
   info->set_is_special_data_property(true);
   info->set_is_sloppy(false);
   info->set_replace_on_access(false);
-  info->set_has_no_side_effect(false);
+  info->set_getter_side_effect_type(SideEffectType::kHasSideEffect);
+  info->set_setter_side_effect_type(SideEffectType::kHasSideEffect);
   name = factory->InternalizeName(name);
   info->set_name(*name);
   Handle<Object> get = v8::FromCData(isolate, getter);
@@ -70,7 +71,7 @@ bool Accessors::IsJSObjectFieldAccessor(Isolate* isolate, Handle<Map> map,
     default:
       if (map->instance_type() < FIRST_NONSTRING_TYPE) {
         return CheckForName(isolate, name, isolate->factory()->length_string(),
-                            String::kLengthOffset, FieldIndex::kTagged, index);
+                            String::kLengthOffset, FieldIndex::kWord32, index);
       }
 
       return false;
diff --git a/deps/v8/src/accessors.h b/deps/v8/src/accessors.h
index 69fdbbb74e..15c4773ec3 100644
--- a/deps/v8/src/accessors.h
+++ b/deps/v8/src/accessors.h
@@ -22,27 +22,28 @@ class JavaScriptFrame;
 
 // The list of accessor descriptors. This is a second-order macro
 // taking a macro to be applied to all accessor descriptor names.
-#define ACCESSOR_INFO_LIST(V)                                       \
-  V(arguments_iterator, ArgumentsIterator)                          \
-  V(array_length, ArrayLength)                                      \
-  V(bound_function_length, BoundFunctionLength)                     \
-  V(bound_function_name, BoundFunctionName)                         \
-  V(error_stack, ErrorStack)                                        \
-  V(function_arguments, FunctionArguments)                          \
-  V(function_caller, FunctionCaller)                                \
-  V(function_name, FunctionName)                                    \
-  V(function_length, FunctionLength)                                \
-  V(function_prototype, FunctionPrototype)                          \
-  V(string_length, StringLength)
-
-#define SIDE_EFFECT_FREE_ACCESSOR_INFO_LIST(V) \
-  V(ArrayLength)                               \
-  V(BoundFunctionLength)                       \
-  V(BoundFunctionName)                         \
-  V(FunctionName)                              \
-  V(FunctionLength)                            \
-  V(FunctionPrototype)                         \
-  V(StringLength)
+// V(accessor_name, AccessorName, GetterSideEffectType, SetterSideEffectType)
+#define ACCESSOR_INFO_LIST_GENERATOR(V, _)                                    \
+  V(_, arguments_iterator, ArgumentsIterator, kHasNoSideEffect,               \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, array_length, ArrayLength, kHasNoSideEffect, kHasSideEffectToReceiver) \
+  V(_, bound_function_length, BoundFunctionLength, kHasNoSideEffect,          \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, bound_function_name, BoundFunctionName, kHasNoSideEffect,              \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, error_stack, ErrorStack, kHasSideEffectToReceiver,                     \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, function_arguments, FunctionArguments, kHasNoSideEffect,               \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, function_caller, FunctionCaller, kHasNoSideEffect,                     \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, function_name, FunctionName, kHasNoSideEffect,                         \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, function_length, FunctionLength, kHasNoSideEffect,                     \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, function_prototype, FunctionPrototype, kHasNoSideEffect,               \
+    kHasSideEffectToReceiver)                                                 \
+  V(_, string_length, StringLength, kHasNoSideEffect, kHasSideEffectToReceiver)
 
 #define ACCESSOR_SETTER_LIST(V) \
   V(ArrayLengthSetter)          \
@@ -55,11 +56,11 @@ class JavaScriptFrame;
 
 class Accessors : public AllStatic {
  public:
-#define ACCESSOR_GETTER_DECLARATION(accessor_name, AccessorName) \
-  static void AccessorName##Getter(                              \
-      v8::Local<v8::Name> name,                                  \
+#define ACCESSOR_GETTER_DECLARATION(_, accessor_name, AccessorName, ...) \
+  static void AccessorName##Getter(                                      \
+      v8::Local<v8::Name> name,                                          \
       const v8::PropertyCallbackInfo<v8::Value>& info);
-  ACCESSOR_INFO_LIST(ACCESSOR_GETTER_DECLARATION)
+  ACCESSOR_INFO_LIST_GENERATOR(ACCESSOR_GETTER_DECLARATION, /* not used */)
 #undef ACCESSOR_GETTER_DECLARATION
 
 #define ACCESSOR_SETTER_DECLARATION(accessor_name)          \
@@ -71,7 +72,7 @@ class Accessors : public AllStatic {
 
   static constexpr int kAccessorInfoCount =
 #define COUNT_ACCESSOR(...) +1
-      ACCESSOR_INFO_LIST(COUNT_ACCESSOR);
+      ACCESSOR_INFO_LIST_GENERATOR(COUNT_ACCESSOR, /* not used */);
 #undef COUNT_ACCESSOR
 
   static constexpr int kAccessorSetterCount =
@@ -118,9 +119,9 @@ class Accessors : public AllStatic {
       AccessorNameBooleanSetterCallback setter);
 
  private:
-#define ACCESSOR_INFO_DECLARATION(accessor_name, AccessorName) \
+#define ACCESSOR_INFO_DECLARATION(_, accessor_name, AccessorName, ...) \
   static Handle<AccessorInfo> Make##AccessorName##Info(Isolate* isolate);
-  ACCESSOR_INFO_LIST(ACCESSOR_INFO_DECLARATION)
+  ACCESSOR_INFO_LIST_GENERATOR(ACCESSOR_INFO_DECLARATION, /* not used */)
 #undef ACCESSOR_INFO_DECLARATION
 
   friend class Heap;
diff --git a/deps/v8/src/address-map.cc b/deps/v8/src/address-map.cc
index 2b0bf727e5..ad71a25a99 100644
--- a/deps/v8/src/address-map.cc
+++ b/deps/v8/src/address-map.cc
@@ -14,8 +14,8 @@ RootIndexMap::RootIndexMap(Isolate* isolate) {
   map_ = isolate->root_index_map();
   if (map_ != nullptr) return;
   map_ = new HeapObjectToIndexHashMap();
-  for (uint32_t i = 0; i < Heap::kStrongRootListLength; i++) {
-    Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(i);
+  for (RootIndex root_index = RootIndex::kFirstStrongRoot;
+       root_index <= RootIndex::kLastStrongRoot; ++root_index) {
     Object* root = isolate->heap()->root(root_index);
     if (!root->IsHeapObject()) continue;
     // Omit root entries that can be written after initialization. They must
@@ -25,11 +25,12 @@ RootIndexMap::RootIndexMap(Isolate* isolate) {
     if (isolate->heap()->RootCanBeTreatedAsConstant(root_index)) {
       HeapObject* heap_object = HeapObject::cast(root);
       Maybe<uint32_t> maybe_index = map_->Get(heap_object);
+      uint32_t index = static_cast<uint32_t>(root_index);
       if (maybe_index.IsJust()) {
         // Some are initialized to a previous value in the root list.
-        DCHECK_LT(maybe_index.FromJust(), i);
+        DCHECK_LT(maybe_index.FromJust(), index);
       } else {
-        map_->Set(heap_object, i);
+        map_->Set(heap_object, index);
       }
     } else {
       // Immortal immovable root objects are constant and allocated on the first
diff --git a/deps/v8/src/address-map.h b/deps/v8/src/address-map.h
index 599e44724a..f7a1cc2ad9 100644
--- a/deps/v8/src/address-map.h
+++ b/deps/v8/src/address-map.h
@@ -56,11 +56,14 @@ class RootIndexMap {
  public:
   explicit RootIndexMap(Isolate* isolate);
 
-  static const int kInvalidRootIndex = -1;
-
-  int Lookup(HeapObject* obj) {
+  // Returns true on successful lookup and sets *|out_root_list|.
+  bool Lookup(HeapObject* obj, RootIndex* out_root_list) {
     Maybe<uint32_t> maybe_index = map_->Get(obj);
-    return maybe_index.IsJust() ? maybe_index.FromJust() : kInvalidRootIndex;
+    if (maybe_index.IsJust()) {
+      *out_root_list = static_cast<RootIndex>(maybe_index.FromJust());
+      return true;
+    }
+    return false;
   }
 
  private:
diff --git a/deps/v8/src/allocation-site-scopes-inl.h b/deps/v8/src/allocation-site-scopes-inl.h
new file mode 100644
index 0000000000..e114bb3885
--- /dev/null
+++ b/deps/v8/src/allocation-site-scopes-inl.h
@@ -0,0 +1,52 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_ALLOCATION_SITE_SCOPES_INL_H_
+#define V8_ALLOCATION_SITE_SCOPES_INL_H_
+
+#include "src/allocation-site-scopes.h"
+
+#include "src/objects/allocation-site-inl.h"
+
+namespace v8 {
+namespace internal {
+
+Handle<AllocationSite> AllocationSiteUsageContext::EnterNewScope() {
+  if (top().is_null()) {
+    InitializeTraversal(top_site_);
+  } else {
+    // Advance current site
+    Object* nested_site = current()->nested_site();
+    // Something is wrong if we advance to the end of the list here.
+    update_current_site(AllocationSite::cast(nested_site));
+  }
+  return Handle<AllocationSite>(*current(), isolate());
+}
+
+void AllocationSiteUsageContext::ExitScope(Handle<AllocationSite> scope_site,
+                                           Handle<JSObject> object) {
+  // This assert ensures that we are pointing at the right sub-object in a
+  // recursive walk of a nested literal.
+  DCHECK(object.is_null() || *object == scope_site->boilerplate());
+}
+
+bool AllocationSiteUsageContext::ShouldCreateMemento(Handle<JSObject> object) {
+  if (activated_ && AllocationSite::CanTrack(object->map()->instance_type())) {
+    if (FLAG_allocation_site_pretenuring ||
+        AllocationSite::ShouldTrack(object->GetElementsKind())) {
+      if (FLAG_trace_creation_allocation_sites) {
+        PrintF("*** Creating Memento for %s %p\n",
+               object->IsJSArray() ? "JSArray" : "JSObject",
+               static_cast<void*>(*object));
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_ALLOCATION_SITE_SCOPES_INL_H_
diff --git a/deps/v8/src/allocation-site-scopes.h b/deps/v8/src/allocation-site-scopes.h
index 60614c5e01..0a729948db 100644
--- a/deps/v8/src/allocation-site-scopes.h
+++ b/deps/v8/src/allocation-site-scopes.h
@@ -56,40 +56,12 @@ class AllocationSiteUsageContext : public AllocationSiteContext {
         top_site_(site),
         activated_(activated) { }
 
-  inline Handle<AllocationSite> EnterNewScope() {
-    if (top().is_null()) {
-      InitializeTraversal(top_site_);
-    } else {
-      // Advance current site
-      Object* nested_site = current()->nested_site();
-      // Something is wrong if we advance to the end of the list here.
-      update_current_site(AllocationSite::cast(nested_site));
-    }
-    return Handle<AllocationSite>(*current(), isolate());
-  }
+  inline Handle<AllocationSite> EnterNewScope();
 
   inline void ExitScope(Handle<AllocationSite> scope_site,
-                        Handle<JSObject> object) {
-    // This assert ensures that we are pointing at the right sub-object in a
-    // recursive walk of a nested literal.
-    DCHECK(object.is_null() || *object == scope_site->boilerplate());
-  }
+                        Handle<JSObject> object);
 
-  bool ShouldCreateMemento(Handle<JSObject> object) {
-    if (activated_ &&
-        AllocationSite::CanTrack(object->map()->instance_type())) {
-      if (FLAG_allocation_site_pretenuring ||
-          AllocationSite::ShouldTrack(object->GetElementsKind())) {
-        if (FLAG_trace_creation_allocation_sites) {
-          PrintF("*** Creating Memento for %s %p\n",
-                 object->IsJSArray() ? "JSArray" : "JSObject",
-                 static_cast<void*>(*object));
-        }
-        return true;
-      }
-    }
-    return false;
-  }
+  inline bool ShouldCreateMemento(Handle<JSObject> object);
 
   static const bool kCopying = true;
 
diff --git a/deps/v8/src/allocation.cc b/deps/v8/src/allocation.cc
index 55c68dea89..6327a9c965 100644
--- a/deps/v8/src/allocation.cc
+++ b/deps/v8/src/allocation.cc
@@ -8,6 +8,7 @@
 #include "src/base/bits.h"
 #include "src/base/lazy-instance.h"
 #include "src/base/logging.h"
+#include "src/base/lsan-page-allocator.h"
 #include "src/base/page-allocator.h"
 #include "src/base/platform/platform.h"
 #include "src/utils.h"
@@ -17,10 +18,6 @@
 #include <malloc.h>  // NOLINT
 #endif
 
-#if defined(LEAK_SANITIZER)
-#include <sanitizer/lsan_interface.h>
-#endif
-
 namespace v8 {
 namespace internal {
 
@@ -51,21 +48,29 @@ struct InitializePageAllocator {
       static v8::base::PageAllocator default_allocator;
       page_allocator = &default_allocator;
     }
+#if defined(LEAK_SANITIZER)
+    {
+      static v8::base::LsanPageAllocator lsan_allocator(page_allocator);
+      page_allocator = &lsan_allocator;
+    }
+#endif
     *page_allocator_ptr = page_allocator;
   }
 };
 
 static base::LazyInstance<v8::PageAllocator*, InitializePageAllocator>::type
     page_allocator = LAZY_INSTANCE_INITIALIZER;
-
-v8::PageAllocator* GetPageAllocator() { return page_allocator.Get(); }
-
 // We will attempt allocation this many times. After each failure, we call
 // OnCriticalMemoryPressure to try to free some memory.
 const int kAllocationTries = 2;
 
 }  // namespace
 
+v8::PageAllocator* GetPlatformPageAllocator() {
+  DCHECK_NOT_NULL(page_allocator.Get());
+  return page_allocator.Get();
+}
+
 void* Malloced::New(size_t size) {
   void* result = AllocWithRetry(size);
   if (result == nullptr) {
@@ -131,68 +136,62 @@ void AlignedFree(void *ptr) {
 #endif
 }
 
-size_t AllocatePageSize() { return GetPageAllocator()->AllocatePageSize(); }
+size_t AllocatePageSize() {
+  return GetPlatformPageAllocator()->AllocatePageSize();
+}
 
-size_t CommitPageSize() { return GetPageAllocator()->CommitPageSize(); }
+size_t CommitPageSize() { return GetPlatformPageAllocator()->CommitPageSize(); }
 
 void SetRandomMmapSeed(int64_t seed) {
-  GetPageAllocator()->SetRandomMmapSeed(seed);
+  GetPlatformPageAllocator()->SetRandomMmapSeed(seed);
 }
 
-void* GetRandomMmapAddr() { return GetPageAllocator()->GetRandomMmapAddr(); }
+void* GetRandomMmapAddr() {
+  return GetPlatformPageAllocator()->GetRandomMmapAddr();
+}
 
-void* AllocatePages(void* address, size_t size, size_t alignment,
+void* AllocatePages(v8::PageAllocator* page_allocator, void* address,
+                    size_t size, size_t alignment,
                     PageAllocator::Permission access) {
+  DCHECK_NOT_NULL(page_allocator);
   DCHECK_EQ(address, AlignedAddress(address, alignment));
-  DCHECK_EQ(0UL, size & (GetPageAllocator()->AllocatePageSize() - 1));
+  DCHECK_EQ(0UL, size & (page_allocator->AllocatePageSize() - 1));
   void* result = nullptr;
   for (int i = 0; i < kAllocationTries; ++i) {
-    result =
-        GetPageAllocator()->AllocatePages(address, size, alignment, access);
+    result = page_allocator->AllocatePages(address, size, alignment, access);
     if (result != nullptr) break;
-    size_t request_size = size + alignment - AllocatePageSize();
+    size_t request_size = size + alignment - page_allocator->AllocatePageSize();
     if (!OnCriticalMemoryPressure(request_size)) break;
   }
-#if defined(LEAK_SANITIZER)
-  if (result != nullptr) {
-    __lsan_register_root_region(result, size);
-  }
-#endif
   return result;
 }
 
-bool FreePages(void* address, const size_t size) {
-  DCHECK_EQ(0UL, size & (GetPageAllocator()->AllocatePageSize() - 1));
-  bool result = GetPageAllocator()->FreePages(address, size);
-#if defined(LEAK_SANITIZER)
-  if (result) {
-    __lsan_unregister_root_region(address, size);
-  }
-#endif
-  return result;
+bool FreePages(v8::PageAllocator* page_allocator, void* address,
+               const size_t size) {
+  DCHECK_NOT_NULL(page_allocator);
+  DCHECK_EQ(0UL, size & (page_allocator->AllocatePageSize() - 1));
+  return page_allocator->FreePages(address, size);
 }
 
-bool ReleasePages(void* address, size_t size, size_t new_size) {
+bool ReleasePages(v8::PageAllocator* page_allocator, void* address, size_t size,
+                  size_t new_size) {
+  DCHECK_NOT_NULL(page_allocator);
   DCHECK_LT(new_size, size);
-  bool result = GetPageAllocator()->ReleasePages(address, size, new_size);
-#if defined(LEAK_SANITIZER)
-  if (result) {
-    __lsan_unregister_root_region(address, size);
-    __lsan_register_root_region(address, new_size);
-  }
-#endif
-  return result;
+  return page_allocator->ReleasePages(address, size, new_size);
 }
 
-bool SetPermissions(void* address, size_t size,
-                    PageAllocator::Permission access) {
-  return GetPageAllocator()->SetPermissions(address, size, access);
+bool SetPermissions(v8::PageAllocator* page_allocator, void* address,
+                    size_t size, PageAllocator::Permission access) {
+  DCHECK_NOT_NULL(page_allocator);
+  return page_allocator->SetPermissions(address, size, access);
 }
 
-byte* AllocatePage(void* address, size_t* allocated) {
-  size_t page_size = AllocatePageSize();
-  void* result =
-      AllocatePages(address, page_size, page_size, PageAllocator::kReadWrite);
+byte* AllocatePage(v8::PageAllocator* page_allocator, void* address,
+                   size_t* allocated) {
+  DCHECK_NOT_NULL(page_allocator);
+  size_t page_size = page_allocator->AllocatePageSize();
+  void* result = AllocatePages(page_allocator, address, page_size, page_size,
+                               PageAllocator::kReadWrite);
   if (result != nullptr) *allocated = page_size;
   return static_cast<byte*>(result);
 }
@@ -206,16 +205,17 @@ bool OnCriticalMemoryPressure(size_t length) {
   return true;
 }
 
-VirtualMemory::VirtualMemory() : address_(kNullAddress), size_(0) {}
-
-VirtualMemory::VirtualMemory(size_t size, void* hint, size_t alignment)
-    : address_(kNullAddress), size_(0) {
-  size_t page_size = AllocatePageSize();
-  size_t alloc_size = RoundUp(size, page_size);
-  address_ = reinterpret_cast<Address>(
-      AllocatePages(hint, alloc_size, alignment, PageAllocator::kNoAccess));
-  if (address_ != kNullAddress) {
-    size_ = alloc_size;
+VirtualMemory::VirtualMemory(v8::PageAllocator* page_allocator, size_t size,
+                             void* hint, size_t alignment)
+    : page_allocator_(page_allocator) {
+  DCHECK_NOT_NULL(page_allocator);
+  size_t page_size = page_allocator_->AllocatePageSize();
+  alignment = RoundUp(alignment, page_size);
+  size = RoundUp(size, page_size);
+  Address address = reinterpret_cast<Address>(AllocatePages(
+      page_allocator_, hint, size, alignment, PageAllocator::kNoAccess));
+  if (address != kNullAddress) {
+    region_ = base::AddressRegion(address, size);
   }
 }
 
@@ -226,30 +226,31 @@ VirtualMemory::~VirtualMemory() {
 }
 
 void VirtualMemory::Reset() {
-  address_ = kNullAddress;
-  size_ = 0;
+  page_allocator_ = nullptr;
+  region_ = base::AddressRegion();
 }
 
 bool VirtualMemory::SetPermissions(Address address, size_t size,
                                    PageAllocator::Permission access) {
   CHECK(InVM(address, size));
-  bool result = v8::internal::SetPermissions(address, size, access);
+  bool result =
+      v8::internal::SetPermissions(page_allocator_, address, size, access);
   DCHECK(result);
   return result;
 }
 
 size_t VirtualMemory::Release(Address free_start) {
   DCHECK(IsReserved());
-  DCHECK(IsAddressAligned(free_start, CommitPageSize()));
+  DCHECK(IsAddressAligned(free_start, page_allocator_->CommitPageSize()));
   // Notice: Order is important here. The VirtualMemory object might live
   // inside the allocated region.
-  const size_t free_size = size_ - (free_start - address_);
+
+  const size_t old_size = region_.size();
+  const size_t free_size = old_size - (free_start - region_.begin());
   CHECK(InVM(free_start, free_size));
-  DCHECK_LT(address_, free_start);
-  DCHECK_LT(free_start, address_ + size_);
-  CHECK(ReleasePages(reinterpret_cast<void*>(address_), size_,
-                     size_ - free_size));
-  size_ -= free_size;
+  region_.set_size(old_size - free_size);
+  CHECK(ReleasePages(page_allocator_, reinterpret_cast<void*>(region_.begin()),
+                     old_size, region_.size()));
   return free_size;
 }
 
@@ -257,41 +258,21 @@ void VirtualMemory::Free() {
   DCHECK(IsReserved());
   // Notice: Order is important here. The VirtualMemory object might live
   // inside the allocated region.
-  Address address = address_;
-  size_t size = size_;
-  CHECK(InVM(address, size));
+  v8::PageAllocator* page_allocator = page_allocator_;
+  base::AddressRegion region = region_;
   Reset();
-  // FreePages expects size to be aligned to allocation granularity. Trimming
-  // may leave size at only commit granularity. Align it here.
-  CHECK(FreePages(reinterpret_cast<void*>(address),
-                  RoundUp(size, AllocatePageSize())));
+  // FreePages expects size to be aligned to allocation granularity however
+  // ReleasePages may leave size at only commit granularity. Align it here.
+  CHECK(FreePages(page_allocator, reinterpret_cast<void*>(region.begin()),
+                  RoundUp(region.size(), page_allocator->AllocatePageSize())));
 }
 
 void VirtualMemory::TakeControl(VirtualMemory* from) {
   DCHECK(!IsReserved());
-  address_ = from->address_;
-  size_ = from->size_;
+  page_allocator_ = from->page_allocator_;
+  region_ = from->region_;
   from->Reset();
 }
 
-bool AllocVirtualMemory(size_t size, void* hint, VirtualMemory* result) {
-  VirtualMemory vm(size, hint);
-  if (vm.IsReserved()) {
-    result->TakeControl(&vm);
-    return true;
-  }
-  return false;
-}
-
-bool AlignedAllocVirtualMemory(size_t size, size_t alignment, void* hint,
-                               VirtualMemory* result) {
-  VirtualMemory vm(size, hint, alignment);
-  if (vm.IsReserved()) {
-    result->TakeControl(&vm);
-    return true;
-  }
-  return false;
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/allocation.h b/deps/v8/src/allocation.h
index 8e17a35514..3a21310af8 100644
--- a/deps/v8/src/allocation.h
+++ b/deps/v8/src/allocation.h
@@ -6,6 +6,7 @@
 #define V8_ALLOCATION_H_
 
 #include "include/v8-platform.h"
+#include "src/base/address-region.h"
 #include "src/base/compiler-specific.h"
 #include "src/base/platform/platform.h"
 #include "src/globals.h"
@@ -82,6 +83,9 @@ void* AllocWithRetry(size_t size);
 void* AlignedAlloc(size_t size, size_t alignment);
 void AlignedFree(void *ptr);
 
+// Returns platfrom page allocator instance. Guaranteed to be a valid pointer.
+V8_EXPORT_PRIVATE v8::PageAllocator* GetPlatformPageAllocator();
+
 // Gets the page granularity for AllocatePages and FreePages. Addresses returned
 // by AllocatePages and AllocatePage are aligned to this size.
 V8_EXPORT_PRIVATE size_t AllocatePageSize();
@@ -101,14 +105,16 @@ V8_EXPORT_PRIVATE void* GetRandomMmapAddr();
 // AllocatePageSize(). Returns the address of the allocated memory, with the
 // specified size and alignment, or nullptr on failure.
 V8_EXPORT_PRIVATE
-V8_WARN_UNUSED_RESULT void* AllocatePages(void* address, size_t size,
+V8_WARN_UNUSED_RESULT void* AllocatePages(v8::PageAllocator* page_allocator,
+                                          void* address, size_t size,
                                           size_t alignment,
                                           PageAllocator::Permission access);
 
 // Frees memory allocated by a call to AllocatePages. |address| and |size| must
 // be multiples of AllocatePageSize(). Returns true on success, otherwise false.
 V8_EXPORT_PRIVATE
-V8_WARN_UNUSED_RESULT bool FreePages(void* address, const size_t size);
+V8_WARN_UNUSED_RESULT bool FreePages(v8::PageAllocator* page_allocator,
+                                     void* address, const size_t size);
 
 // Releases memory that is no longer needed. The range specified by |address|
 // and |size| must be an allocated memory region. |size| and |new_size| must be
@@ -116,7 +122,8 @@ V8_WARN_UNUSED_RESULT bool FreePages(void* address, const size_t size);
 // Released memory is left in an undefined state, so it should not be accessed.
 // Returns true on success, otherwise false.
 V8_EXPORT_PRIVATE
-V8_WARN_UNUSED_RESULT bool ReleasePages(void* address, size_t size,
+V8_WARN_UNUSED_RESULT bool ReleasePages(v8::PageAllocator* page_allocator,
+                                        void* address, size_t size,
                                         size_t new_size);
 
 // Sets permissions according to |access|. |address| and |size| must be
@@ -124,18 +131,21 @@ V8_WARN_UNUSED_RESULT bool ReleasePages(void* address, size_t size,
 // cause the memory contents to be lost. Returns true on success, otherwise
 // false.
 V8_EXPORT_PRIVATE
-V8_WARN_UNUSED_RESULT bool SetPermissions(void* address, size_t size,
+V8_WARN_UNUSED_RESULT bool SetPermissions(v8::PageAllocator* page_allocator,
+                                          void* address, size_t size,
                                           PageAllocator::Permission access);
-inline bool SetPermissions(Address address, size_t size,
-                           PageAllocator::Permission access) {
-  return SetPermissions(reinterpret_cast<void*>(address), size, access);
+inline bool SetPermissions(v8::PageAllocator* page_allocator, Address address,
+                           size_t size, PageAllocator::Permission access) {
+  return SetPermissions(page_allocator, reinterpret_cast<void*>(address), size,
+                        access);
 }
 
 // Convenience function that allocates a single system page with read and write
 // permissions. |address| is a hint. Returns the base address of the memory and
 // the page size via |allocated| on success. Returns nullptr on failure.
 V8_EXPORT_PRIVATE
-V8_WARN_UNUSED_RESULT byte* AllocatePage(void* address, size_t* allocated);
+V8_WARN_UNUSED_RESULT byte* AllocatePage(v8::PageAllocator* page_allocator,
+                                         void* address, size_t* allocated);
 
 // Function that may release reserved memory regions to allow failed allocations
 // to succeed. |length| is the amount of memory needed. Returns |true| if memory
@@ -143,50 +153,67 @@ V8_WARN_UNUSED_RESULT byte* AllocatePage(void* address, size_t* allocated);
 V8_EXPORT_PRIVATE bool OnCriticalMemoryPressure(size_t length);
 
 // Represents and controls an area of reserved memory.
-class V8_EXPORT_PRIVATE VirtualMemory {
+class V8_EXPORT_PRIVATE VirtualMemory final {
  public:
   // Empty VirtualMemory object, controlling no reserved memory.
-  VirtualMemory();
+  VirtualMemory() = default;
 
   // Reserves virtual memory containing an area of the given size that is
-  // aligned per alignment. This may not be at the position returned by
-  // address().
-  VirtualMemory(size_t size, void* hint, size_t alignment = AllocatePageSize());
+  // aligned per |alignment| rounded up to the |page_allocator|'s allocate page
+  // size.
+  // This may not be at the position returned by address().
+  VirtualMemory(v8::PageAllocator* page_allocator, size_t size, void* hint,
+                size_t alignment = 1);
 
   // Construct a virtual memory by assigning it some already mapped address
   // and size.
-  VirtualMemory(Address address, size_t size)
-      : address_(address), size_(size) {}
+  VirtualMemory(v8::PageAllocator* page_allocator, Address address, size_t size)
+      : page_allocator_(page_allocator), region_(address, size) {
+    DCHECK_NOT_NULL(page_allocator);
+  }
 
   // Releases the reserved memory, if any, controlled by this VirtualMemory
   // object.
   ~VirtualMemory();
 
+  // Move constructor.
+  VirtualMemory(VirtualMemory&& other) V8_NOEXCEPT { TakeControl(&other); }
+
+  // Move assignment operator.
+  VirtualMemory& operator=(VirtualMemory&& other) V8_NOEXCEPT {
+    TakeControl(&other);
+    return *this;
+  }
+
   // Returns whether the memory has been reserved.
-  bool IsReserved() const { return address_ != kNullAddress; }
+  bool IsReserved() const { return region_.begin() != kNullAddress; }
 
   // Initialize or resets an embedded VirtualMemory object.
   void Reset();
 
+  v8::PageAllocator* page_allocator() { return page_allocator_; }
+
+  const base::AddressRegion& region() const { return region_; }
+
   // Returns the start address of the reserved memory.
   // If the memory was reserved with an alignment, this address is not
   // necessarily aligned. The user might need to round it up to a multiple of
   // the alignment to get the start of the aligned block.
   Address address() const {
     DCHECK(IsReserved());
-    return address_;
+    return region_.begin();
   }
 
   Address end() const {
     DCHECK(IsReserved());
-    return address_ + size_;
+    return region_.end();
   }
 
   // Returns the size of the reserved memory. The returned value is only
   // meaningful when IsReserved() returns true.
   // If the memory was reserved with an alignment, this size may be larger
   // than the requested size.
-  size_t size() const { return size_; }
+  size_t size() const { return region_.size(); }
 
   // Sets permissions according to the access argument. address and size must be
   // multiples of CommitPageSize(). Returns true on success, otherwise false.
@@ -204,17 +231,16 @@ class V8_EXPORT_PRIVATE VirtualMemory {
   void TakeControl(VirtualMemory* from);
 
   bool InVM(Address address, size_t size) {
-    return (address_ <= address) && ((address_ + size_) >= (address + size));
+    return region_.contains(address, size);
   }
 
  private:
-  Address address_;  // Start address of the virtual memory.
-  size_t size_;    // Size of the virtual memory.
-};
+  // Page allocator that controls the virtual memory.
+  v8::PageAllocator* page_allocator_ = nullptr;
+  base::AddressRegion region_;
 
-bool AllocVirtualMemory(size_t size, void* hint, VirtualMemory* result);
-bool AlignedAllocVirtualMemory(size_t size, size_t alignment, void* hint,
-                               VirtualMemory* result);
+  DISALLOW_COPY_AND_ASSIGN(VirtualMemory);
+};
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/api-arguments-inl.h b/deps/v8/src/api-arguments-inl.h
index 89f606ed41..1e5d6b2aaa 100644
--- a/deps/v8/src/api-arguments-inl.h
+++ b/deps/v8/src/api-arguments-inl.h
@@ -8,6 +8,7 @@
 #include "src/api-arguments.h"
 
 #include "src/api-inl.h"
+#include "src/debug/debug.h"
 #include "src/objects/api-callbacks.h"
 #include "src/tracing/trace-event.h"
 #include "src/vm-state-inl.h"
@@ -34,6 +35,10 @@ inline JSObject* PropertyCallbackArguments::holder() {
   return JSObject::cast(this->begin()[T::kHolderIndex]);
 }
 
+inline Object* PropertyCallbackArguments::receiver() {
+  return Object::cast(this->begin()[T::kThisIndex]);
+}
+
 inline JSObject* FunctionCallbackArguments::holder() {
   return JSObject::cast(this->begin()[T::kHolderIndex]);
 }
@@ -47,14 +52,24 @@ inline JSObject* FunctionCallbackArguments::holder() {
   DCHECK(!name->IsPrivate());                     \
   DCHECK_IMPLIES(name->IsSymbol(), interceptor->can_intercept_symbols());
 
-#define PREPARE_CALLBACK_INFO(ISOLATE, F, RETURN_VALUE, API_RETURN_TYPE,     \
-                              CALLBACK_INFO)                                 \
-  if (ISOLATE->debug_execution_mode() == DebugInfo::kSideEffects &&          \
-      !ISOLATE->debug()->PerformSideEffectCheckForCallback(CALLBACK_INFO)) { \
-    return RETURN_VALUE();                                                   \
-  }                                                                          \
-  VMState<EXTERNAL> state(ISOLATE);                                          \
-  ExternalCallbackScope call_scope(ISOLATE, FUNCTION_ADDR(F));               \
+#define PREPARE_CALLBACK_INFO(ISOLATE, F, RETURN_VALUE, API_RETURN_TYPE, \
+                              CALLBACK_INFO, RECEIVER, ACCESSOR_KIND)    \
+  if (ISOLATE->debug_execution_mode() == DebugInfo::kSideEffects &&      \
+      !ISOLATE->debug()->PerformSideEffectCheckForCallback(              \
+          CALLBACK_INFO, RECEIVER, Debug::k##ACCESSOR_KIND)) {           \
+    return RETURN_VALUE();                                               \
+  }                                                                      \
+  VMState<EXTERNAL> state(ISOLATE);                                      \
+  ExternalCallbackScope call_scope(ISOLATE, FUNCTION_ADDR(F));           \
+  PropertyCallbackInfo<API_RETURN_TYPE> callback_info(begin());
+
+#define PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(ISOLATE, F, RETURN_VALUE, \
+                                                     API_RETURN_TYPE)          \
+  if (ISOLATE->debug_execution_mode() == DebugInfo::kSideEffects) {            \
+    return RETURN_VALUE();                                                     \
+  }                                                                            \
+  VMState<EXTERNAL> state(ISOLATE);                                            \
+  ExternalCallbackScope call_scope(ISOLATE, FUNCTION_ADDR(F));                 \
   PropertyCallbackInfo<API_RETURN_TYPE> callback_info(begin());
 
 #define CREATE_NAMED_CALLBACK(FUNCTION, TYPE, RETURN_TYPE, API_RETURN_TYPE,   \
@@ -65,11 +80,13 @@ inline JSObject* FunctionCallbackArguments::holder() {
     Isolate* isolate = this->isolate();                                       \
     RuntimeCallTimerScope timer(                                              \
         isolate, RuntimeCallCounterId::kNamed##FUNCTION##Callback);           \
+    Handle<Object> receiver_check_unsupported;                                \
     GenericNamedProperty##FUNCTION##Callback f =                              \
         ToCData<GenericNamedProperty##FUNCTION##Callback>(                    \
             interceptor->TYPE());                                             \
     PREPARE_CALLBACK_INFO(isolate, f, Handle<RETURN_TYPE>, API_RETURN_TYPE,   \
-                          INFO_FOR_SIDE_EFFECT);                              \
+                          INFO_FOR_SIDE_EFFECT, receiver_check_unsupported,   \
+                          NotAccessor);                                       \
     LOG(isolate,                                                              \
         ApiNamedPropertyAccess("interceptor-named-" #TYPE, holder(), *name)); \
     f(v8::Utils::ToLocal(name), callback_info);                               \
@@ -87,10 +104,12 @@ FOR_EACH_CALLBACK(CREATE_NAMED_CALLBACK)
     Isolate* isolate = this->isolate();                                       \
     RuntimeCallTimerScope timer(                                              \
         isolate, RuntimeCallCounterId::kIndexed##FUNCTION##Callback);         \
+    Handle<Object> receiver_check_unsupported;                                \
     IndexedProperty##FUNCTION##Callback f =                                   \
         ToCData<IndexedProperty##FUNCTION##Callback>(interceptor->TYPE());    \
     PREPARE_CALLBACK_INFO(isolate, f, Handle<RETURN_TYPE>, API_RETURN_TYPE,   \
-                          INFO_FOR_SIDE_EFFECT);                              \
+                          INFO_FOR_SIDE_EFFECT, receiver_check_unsupported,   \
+                          NotAccessor);                                       \
     LOG(isolate, ApiIndexedPropertyAccess("interceptor-indexed-" #TYPE,       \
                                           holder(), index));                  \
     f(index, callback_info);                                                  \
@@ -108,9 +127,11 @@ Handle<Object> FunctionCallbackArguments::Call(CallHandlerInfo* handler) {
   RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kFunctionCallback);
   v8::FunctionCallback f =
       v8::ToCData<v8::FunctionCallback>(handler->callback());
+  Handle<Object> receiver_check_unsupported;
   if (isolate->debug_execution_mode() == DebugInfo::kSideEffects &&
       !isolate->debug()->PerformSideEffectCheckForCallback(
-          handle(handler, isolate))) {
+          handle(handler, isolate), receiver_check_unsupported,
+          Debug::kNotAccessor)) {
     return Handle<Object>();
   }
   VMState<EXTERNAL> state(isolate);
@@ -167,10 +188,11 @@ Handle<Object> PropertyCallbackArguments::CallNamedDescriptor(
 
 Handle<Object> PropertyCallbackArguments::BasicCallNamedGetterCallback(
     GenericNamedPropertyGetterCallback f, Handle<Name> name,
-    Handle<Object> info) {
+    Handle<Object> info, Handle<Object> receiver) {
   DCHECK(!name->IsPrivate());
   Isolate* isolate = this->isolate();
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value, info);
+  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value, info, receiver,
+                        Getter);
   f(v8::Utils::ToLocal(name), callback_info);
   return GetReturnValue<Object>(isolate);
 }
@@ -184,9 +206,8 @@ Handle<Object> PropertyCallbackArguments::CallNamedSetter(
   Isolate* isolate = this->isolate();
   RuntimeCallTimerScope timer(isolate,
                               RuntimeCallCounterId::kNamedSetterCallback);
-  Handle<Object> side_effect_check_not_supported;
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value,
-                        side_effect_check_not_supported);
+  PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
+                                               v8::Value);
   LOG(isolate,
       ApiNamedPropertyAccess("interceptor-named-set", holder(), *name));
   f(v8::Utils::ToLocal(name), v8::Utils::ToLocal(value), callback_info);
@@ -202,9 +223,8 @@ Handle<Object> PropertyCallbackArguments::CallNamedDefiner(
                               RuntimeCallCounterId::kNamedDefinerCallback);
   GenericNamedPropertyDefinerCallback f =
       ToCData<GenericNamedPropertyDefinerCallback>(interceptor->definer());
-  Handle<Object> side_effect_check_not_supported;
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value,
-                        side_effect_check_not_supported);
+  PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
+                                               v8::Value);
   LOG(isolate,
       ApiNamedPropertyAccess("interceptor-named-define", holder(), *name));
   f(v8::Utils::ToLocal(name), desc, callback_info);
@@ -219,9 +239,8 @@ Handle<Object> PropertyCallbackArguments::CallIndexedSetter(
                               RuntimeCallCounterId::kIndexedSetterCallback);
   IndexedPropertySetterCallback f =
       ToCData<IndexedPropertySetterCallback>(interceptor->setter());
-  Handle<Object> side_effect_check_not_supported;
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value,
-                        side_effect_check_not_supported);
+  PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
+                                               v8::Value);
   LOG(isolate,
       ApiIndexedPropertyAccess("interceptor-indexed-set", holder(), index));
   f(index, v8::Utils::ToLocal(value), callback_info);
@@ -237,9 +256,8 @@ Handle<Object> PropertyCallbackArguments::CallIndexedDefiner(
                               RuntimeCallCounterId::kIndexedDefinerCallback);
   IndexedPropertyDefinerCallback f =
       ToCData<IndexedPropertyDefinerCallback>(interceptor->definer());
-  Handle<Object> side_effect_check_not_supported;
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value,
-                        side_effect_check_not_supported);
+  PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
+                                               v8::Value);
   LOG(isolate,
       ApiIndexedPropertyAccess("interceptor-indexed-define", holder(), index));
   f(index, desc, callback_info);
@@ -275,7 +293,9 @@ Handle<Object> PropertyCallbackArguments::CallIndexedDescriptor(
 Handle<Object> PropertyCallbackArguments::BasicCallIndexedGetterCallback(
     IndexedPropertyGetterCallback f, uint32_t index, Handle<Object> info) {
   Isolate* isolate = this->isolate();
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value, info);
+  Handle<Object> receiver_check_unsupported;
+  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, v8::Value, info,
+                        receiver_check_unsupported, Getter);
   f(index, callback_info);
   return GetReturnValue<Object>(isolate);
 }
@@ -287,7 +307,9 @@ Handle<JSObject> PropertyCallbackArguments::CallPropertyEnumerator(
       v8::ToCData<IndexedPropertyEnumeratorCallback>(interceptor->enumerator());
   // TODO(cbruni): assert same type for indexed and named callback.
   Isolate* isolate = this->isolate();
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<JSObject>, v8::Array, interceptor);
+  Handle<Object> receiver_check_unsupported;
+  PREPARE_CALLBACK_INFO(isolate, f, Handle<JSObject>, v8::Array, interceptor,
+                        receiver_check_unsupported, NotAccessor);
   f(callback_info);
   return GetReturnValue<JSObject>(isolate);
 }
@@ -303,7 +325,8 @@ Handle<Object> PropertyCallbackArguments::CallAccessorGetter(
   LOG(isolate, ApiNamedPropertyAccess("accessor-getter", holder(), *name));
   AccessorNameGetterCallback f =
       ToCData<AccessorNameGetterCallback>(info->getter());
-  return BasicCallNamedGetterCallback(f, name, info);
+  return BasicCallNamedGetterCallback(f, name, info,
+                                      handle(receiver(), isolate));
 }
 
 Handle<Object> PropertyCallbackArguments::CallAccessorSetter(
@@ -314,15 +337,15 @@ Handle<Object> PropertyCallbackArguments::CallAccessorSetter(
                               RuntimeCallCounterId::kAccessorSetterCallback);
   AccessorNameSetterCallback f =
       ToCData<AccessorNameSetterCallback>(accessor_info->setter());
-  Handle<Object> side_effect_check_not_supported;
-  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, void,
-                        side_effect_check_not_supported);
+  PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, void, accessor_info,
+                        handle(receiver(), isolate), Setter);
   LOG(isolate, ApiNamedPropertyAccess("accessor-setter", holder(), *name));
   f(v8::Utils::ToLocal(name), v8::Utils::ToLocal(value), callback_info);
   return GetReturnValue<Object>(isolate);
 }
 
 #undef PREPARE_CALLBACK_INFO
+#undef PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/api-arguments.h b/deps/v8/src/api-arguments.h
index 0a0a7362c7..d8fc2b49ab 100644
--- a/deps/v8/src/api-arguments.h
+++ b/deps/v8/src/api-arguments.h
@@ -26,12 +26,12 @@ class CustomArguments : public CustomArgumentsBase {
  public:
   static const int kReturnValueOffset = T::kReturnValueIndex;
 
-  ~CustomArguments() {
+  ~CustomArguments() override {
     this->begin()[kReturnValueOffset] =
         reinterpret_cast<Object*>(kHandleZapValue);
   }
 
-  virtual inline void IterateInstance(RootVisitor* v) {
+  inline void IterateInstance(RootVisitor* v) override {
     v->VisitRootPointers(Root::kRelocatable, nullptr, values_,
                          values_ + T::kArgsLength);
   }
@@ -133,9 +133,10 @@ class PropertyCallbackArguments
       IndexedPropertyGetterCallback f, uint32_t index, Handle<Object> info);
   inline Handle<Object> BasicCallNamedGetterCallback(
       GenericNamedPropertyGetterCallback f, Handle<Name> name,
-      Handle<Object> info);
+      Handle<Object> info, Handle<Object> receiver = Handle<Object>());
 
   inline JSObject* holder();
+  inline Object* receiver();
 
   // Don't copy PropertyCallbackArguments, because they would both have the
   // same prev_ pointer.
diff --git a/deps/v8/src/api-inl.h b/deps/v8/src/api-inl.h
index 50586814d8..5758729dd3 100644
--- a/deps/v8/src/api-inl.h
+++ b/deps/v8/src/api-inl.h
@@ -7,6 +7,7 @@
 
 #include "src/api.h"
 #include "src/objects-inl.h"
+#include "src/objects/stack-frame-info.h"
 
 namespace v8 {
 
diff --git a/deps/v8/src/api-natives.cc b/deps/v8/src/api-natives.cc
index 977d6cdafc..11b63d56d8 100644
--- a/deps/v8/src/api-natives.cc
+++ b/deps/v8/src/api-natives.cc
@@ -114,9 +114,8 @@ MaybeHandle<Object> DefineDataProperty(Isolate* isolate,
   }
 #endif
 
-  MAYBE_RETURN_NULL(
-      Object::AddDataProperty(&it, value, attributes, kThrowOnError,
-                              Object::CERTAINLY_NOT_STORE_FROM_KEYED));
+  MAYBE_RETURN_NULL(Object::AddDataProperty(
+      &it, value, attributes, kThrowOnError, StoreOrigin::kNamed));
   return value;
 }
 
@@ -403,8 +402,10 @@ MaybeHandle<JSObject> InstantiateObject(Isolate* isolate,
   }
 
   Handle<JSObject> object;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, object,
-                             JSObject::New(constructor, new_target), JSObject);
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, object,
+      JSObject::New(constructor, new_target, Handle<AllocationSite>::null()),
+      JSObject);
 
   if (is_prototype) JSObject::OptimizeAsPrototype(object);
 
@@ -495,8 +496,15 @@ MaybeHandle<JSFunction> InstantiateFunction(Isolate* isolate,
                                   parent_prototype);
     }
   }
+  InstanceType function_type =
+      (!data->needs_access_check() &&
+       data->named_property_handler()->IsUndefined(isolate) &&
+       data->indexed_property_handler()->IsUndefined(isolate))
+          ? JS_API_OBJECT_TYPE
+          : JS_SPECIAL_API_OBJECT_TYPE;
+
   Handle<JSFunction> function = ApiNatives::CreateApiFunction(
-      isolate, data, prototype, ApiNatives::JavaScriptObjectType, maybe_name);
+      isolate, data, prototype, function_type, maybe_name);
   if (serial_number) {
     // Cache the function.
     CacheTemplateInstantiation(isolate, serial_number, CachingMode::kUnlimited,
@@ -625,8 +633,7 @@ void ApiNatives::AddNativeDataProperty(Isolate* isolate,
 
 Handle<JSFunction> ApiNatives::CreateApiFunction(
     Isolate* isolate, Handle<FunctionTemplateInfo> obj,
-    Handle<Object> prototype, ApiInstanceType instance_type,
-    MaybeHandle<Name> maybe_name) {
+    Handle<Object> prototype, InstanceType type, MaybeHandle<Name> maybe_name) {
   Handle<SharedFunctionInfo> shared =
       FunctionTemplateInfo::GetOrCreateSharedFunctionInfo(isolate, obj,
                                                           maybe_name);
@@ -670,33 +677,10 @@ Handle<JSFunction> ApiNatives::CreateApiFunction(
     immutable_proto = instance_template->immutable_proto();
   }
 
-  // TODO(svenpanne) Kill ApiInstanceType and refactor things by generalizing
-  // JSObject::GetHeaderSize.
-  int instance_size = kPointerSize * embedder_field_count;
-  InstanceType type;
-  switch (instance_type) {
-    case JavaScriptObjectType:
-      if (!obj->needs_access_check() &&
-          obj->named_property_handler()->IsUndefined(isolate) &&
-          obj->indexed_property_handler()->IsUndefined(isolate)) {
-        type = JS_API_OBJECT_TYPE;
-      } else {
-        type = JS_SPECIAL_API_OBJECT_TYPE;
-      }
-      instance_size += JSObject::kHeaderSize;
-      break;
-    case GlobalObjectType:
-      type = JS_GLOBAL_OBJECT_TYPE;
-      instance_size += JSGlobalObject::kSize;
-      break;
-    case GlobalProxyType:
-      type = JS_GLOBAL_PROXY_TYPE;
-      instance_size += JSGlobalProxy::kSize;
-      break;
-    default:
-      UNREACHABLE();
-      break;
-  }
+  // JS_FUNCTION_TYPE requires information about the prototype slot.
+  DCHECK_NE(JS_FUNCTION_TYPE, type);
+  int instance_size =
+      JSObject::GetHeaderSize(type) + kPointerSize * embedder_field_count;
 
   Handle<Map> map = isolate->factory()->NewMap(type, instance_size,
                                                TERMINAL_FAST_ELEMENTS_KIND);
diff --git a/deps/v8/src/api-natives.h b/deps/v8/src/api-natives.h
index e8bb32d40a..ff6cdc6c86 100644
--- a/deps/v8/src/api-natives.h
+++ b/deps/v8/src/api-natives.h
@@ -9,6 +9,7 @@
 #include "src/base/macros.h"
 #include "src/handles.h"
 #include "src/maybe-handles.h"
+#include "src/objects.h"
 #include "src/property-details.h"
 
 namespace v8 {
@@ -33,15 +34,9 @@ class ApiNatives {
   V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> InstantiateRemoteObject(
       Handle<ObjectTemplateInfo> data);
 
-  enum ApiInstanceType {
-    JavaScriptObjectType,
-    GlobalObjectType,
-    GlobalProxyType
-  };
-
   static Handle<JSFunction> CreateApiFunction(
       Isolate* isolate, Handle<FunctionTemplateInfo> obj,
-      Handle<Object> prototype, ApiInstanceType instance_type,
+      Handle<Object> prototype, InstanceType type,
       MaybeHandle<Name> name = MaybeHandle<Name>());
 
   static void AddDataProperty(Isolate* isolate, Handle<TemplateInfo> info,
diff --git a/deps/v8/src/api.cc b/deps/v8/src/api.cc
index 5ac9aec047..3f62a23d43 100644
--- a/deps/v8/src/api.cc
+++ b/deps/v8/src/api.cc
@@ -58,7 +58,9 @@
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/ordered-hash-table-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/objects/templates.h"
+#include "src/parsing/parse-info.h"
 #include "src/parsing/parser.h"
 #include "src/parsing/scanner-character-streams.h"
 #include "src/pending-compilation-error-handler.h"
@@ -834,6 +836,7 @@ StartupData SnapshotCreator::CreateBlob(
   }
   data->created_ = true;
 
+  DCHECK(i::Snapshot::VerifyChecksum(&result));
   return result;
 }
 
@@ -876,12 +879,12 @@ void RegisteredExtension::UnregisterAll() {
 namespace {
 class ExtensionResource : public String::ExternalOneByteStringResource {
  public:
-  ExtensionResource() : data_(0), length_(0) {}
+  ExtensionResource() : data_(nullptr), length_(0) {}
   ExtensionResource(const char* data, size_t length)
       : data_(data), length_(length) {}
-  const char* data() const { return data_; }
-  size_t length() const { return length_; }
-  virtual void Dispose() {}
+  const char* data() const override { return data_; }
+  size_t length() const override { return length_; }
+  void Dispose() override {}
 
  private:
   const char* data_;
@@ -1391,7 +1394,7 @@ static Local<FunctionTemplate> FunctionTemplateNew(
     next_serial_number = isolate->heap()->GetNextTemplateSerialNumber();
   }
   obj->set_serial_number(i::Smi::FromInt(next_serial_number));
-  if (callback != 0) {
+  if (callback != nullptr) {
     Utils::ToLocal(obj)->SetCallHandler(callback, data, side_effect_type);
   }
   obj->set_length(length);
@@ -1676,7 +1679,8 @@ static void TemplateSetAccessor(
     Template* template_obj, v8::Local<Name> name, Getter getter, Setter setter,
     Data data, AccessControl settings, PropertyAttribute attribute,
     v8::Local<AccessorSignature> signature, bool is_special_data_property,
-    bool replace_on_access, SideEffectType getter_side_effect_type) {
+    bool replace_on_access, SideEffectType getter_side_effect_type,
+    SideEffectType setter_side_effect_type) {
   auto info = Utils::OpenHandle(template_obj);
   auto isolate = info->GetIsolate();
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
@@ -1686,8 +1690,8 @@ static void TemplateSetAccessor(
                        is_special_data_property, replace_on_access);
   accessor_info->set_initial_property_attributes(
       static_cast<i::PropertyAttributes>(attribute));
-  accessor_info->set_has_no_side_effect(getter_side_effect_type ==
-                                        SideEffectType::kHasNoSideEffect);
+  accessor_info->set_getter_side_effect_type(getter_side_effect_type);
+  accessor_info->set_setter_side_effect_type(setter_side_effect_type);
   i::ApiNatives::AddNativeDataProperty(isolate, info, accessor_info);
 }
 
@@ -1695,29 +1699,34 @@ void Template::SetNativeDataProperty(
     v8::Local<String> name, AccessorGetterCallback getter,
     AccessorSetterCallback setter, v8::Local<Value> data,
     PropertyAttribute attribute, v8::Local<AccessorSignature> signature,
-    AccessControl settings, SideEffectType getter_side_effect_type) {
+    AccessControl settings, SideEffectType getter_side_effect_type,
+    SideEffectType setter_side_effect_type) {
   TemplateSetAccessor(this, name, getter, setter, data, settings, attribute,
-                      signature, true, false, getter_side_effect_type);
+                      signature, true, false, getter_side_effect_type,
+                      setter_side_effect_type);
 }
 
 void Template::SetNativeDataProperty(
     v8::Local<Name> name, AccessorNameGetterCallback getter,
     AccessorNameSetterCallback setter, v8::Local<Value> data,
     PropertyAttribute attribute, v8::Local<AccessorSignature> signature,
-    AccessControl settings, SideEffectType getter_side_effect_type) {
+    AccessControl settings, SideEffectType getter_side_effect_type,
+    SideEffectType setter_side_effect_type) {
   TemplateSetAccessor(this, name, getter, setter, data, settings, attribute,
-                      signature, true, false, getter_side_effect_type);
+                      signature, true, false, getter_side_effect_type,
+                      setter_side_effect_type);
 }
 
 void Template::SetLazyDataProperty(v8::Local<Name> name,
                                    AccessorNameGetterCallback getter,
                                    v8::Local<Value> data,
                                    PropertyAttribute attribute,
-                                   SideEffectType getter_side_effect_type) {
+                                   SideEffectType getter_side_effect_type,
+                                   SideEffectType setter_side_effect_type) {
   TemplateSetAccessor(this, name, getter,
                       static_cast<AccessorNameSetterCallback>(nullptr), data,
                       DEFAULT, attribute, Local<AccessorSignature>(), true,
-                      true, getter_side_effect_type);
+                      true, getter_side_effect_type, setter_side_effect_type);
 }
 
 void Template::SetIntrinsicDataProperty(Local<Name> name, Intrinsic intrinsic,
@@ -1737,10 +1746,11 @@ void ObjectTemplate::SetAccessor(v8::Local<String> name,
                                  v8::Local<Value> data, AccessControl settings,
                                  PropertyAttribute attribute,
                                  v8::Local<AccessorSignature> signature,
-                                 SideEffectType getter_side_effect_type) {
+                                 SideEffectType getter_side_effect_type,
+                                 SideEffectType setter_side_effect_type) {
   TemplateSetAccessor(this, name, getter, setter, data, settings, attribute,
                       signature, i::FLAG_disable_old_api_accessors, false,
-                      getter_side_effect_type);
+                      getter_side_effect_type, setter_side_effect_type);
 }
 
 void ObjectTemplate::SetAccessor(v8::Local<Name> name,
@@ -1749,10 +1759,11 @@ void ObjectTemplate::SetAccessor(v8::Local<Name> name,
                                  v8::Local<Value> data, AccessControl settings,
                                  PropertyAttribute attribute,
                                  v8::Local<AccessorSignature> signature,
-                                 SideEffectType getter_side_effect_type) {
+                                 SideEffectType getter_side_effect_type,
+                                 SideEffectType setter_side_effect_type) {
   TemplateSetAccessor(this, name, getter, setter, data, settings, attribute,
                       signature, i::FLAG_disable_old_api_accessors, false,
-                      getter_side_effect_type);
+                      getter_side_effect_type, setter_side_effect_type);
 }
 
 template <typename Getter, typename Setter, typename Query, typename Descriptor,
@@ -1765,15 +1776,15 @@ static i::Handle<i::InterceptorInfo> CreateInterceptorInfo(
       isolate->factory()->NewStruct(i::INTERCEPTOR_INFO_TYPE, i::TENURED));
   obj->set_flags(0);
 
-  if (getter != 0) SET_FIELD_WRAPPED(isolate, obj, set_getter, getter);
-  if (setter != 0) SET_FIELD_WRAPPED(isolate, obj, set_setter, setter);
-  if (query != 0) SET_FIELD_WRAPPED(isolate, obj, set_query, query);
-  if (descriptor != 0)
+  if (getter != nullptr) SET_FIELD_WRAPPED(isolate, obj, set_getter, getter);
+  if (setter != nullptr) SET_FIELD_WRAPPED(isolate, obj, set_setter, setter);
+  if (query != nullptr) SET_FIELD_WRAPPED(isolate, obj, set_query, query);
+  if (descriptor != nullptr)
     SET_FIELD_WRAPPED(isolate, obj, set_descriptor, descriptor);
-  if (remover != 0) SET_FIELD_WRAPPED(isolate, obj, set_deleter, remover);
-  if (enumerator != 0)
+  if (remover != nullptr) SET_FIELD_WRAPPED(isolate, obj, set_deleter, remover);
+  if (enumerator != nullptr)
     SET_FIELD_WRAPPED(isolate, obj, set_enumerator, enumerator);
-  if (definer != 0) SET_FIELD_WRAPPED(isolate, obj, set_definer, definer);
+  if (definer != nullptr) SET_FIELD_WRAPPED(isolate, obj, set_definer, definer);
   obj->set_can_intercept_symbols(
       !(static_cast<int>(flags) &
         static_cast<int>(PropertyHandlerFlags::kOnlyInterceptStrings)));
@@ -2001,24 +2012,15 @@ ScriptCompiler::CachedData::~CachedData() {
   }
 }
 
-
 bool ScriptCompiler::ExternalSourceStream::SetBookmark() { return false; }
 
-
 void ScriptCompiler::ExternalSourceStream::ResetToBookmark() { UNREACHABLE(); }
 
 ScriptCompiler::StreamedSource::StreamedSource(ExternalSourceStream* stream,
                                                Encoding encoding)
     : impl_(new i::ScriptStreamingData(stream, encoding)) {}
 
-ScriptCompiler::StreamedSource::~StreamedSource() { delete impl_; }
-
-
-const ScriptCompiler::CachedData*
-ScriptCompiler::StreamedSource::GetCachedData() const {
-  return impl_->cached_data.get();
-}
-
+ScriptCompiler::StreamedSource::~StreamedSource() = default;
 
 Local<Script> UnboundScript::BindToCurrentContext() {
   auto function_info =
@@ -2030,7 +2032,6 @@ Local<Script> UnboundScript::BindToCurrentContext() {
   return ToApiHandle<Script>(function);
 }
 
-
 int UnboundScript::GetId() {
   auto function_info =
       i::Handle<i::SharedFunctionInfo>::cast(Utils::OpenHandle(this));
@@ -2157,10 +2158,6 @@ int PrimitiveArray::Length() const {
   return array->length();
 }
 
-void PrimitiveArray::Set(int index, Local<Primitive> item) {
-  return Set(Isolate::GetCurrent(), index, item);
-}
-
 void PrimitiveArray::Set(Isolate* v8_isolate, int index,
                          Local<Primitive> item) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
@@ -2174,10 +2171,6 @@ void PrimitiveArray::Set(Isolate* v8_isolate, int index,
   array->set(index, *i_item);
 }
 
-Local<Primitive> PrimitiveArray::Get(int index) {
-  return Get(Isolate::GetCurrent(), index);
-}
-
 Local<Primitive> PrimitiveArray::Get(Isolate* v8_isolate, int index) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   i::Handle<i::FixedArray> array = Utils::OpenHandle(this);
@@ -2534,6 +2527,7 @@ MaybeLocal<Function> ScriptCompiler::CompileFunctionInContext(
   RETURN_ESCAPED(Utils::CallableToLocal(result));
 }
 
+void ScriptCompiler::ScriptStreamingTask::Run() { data_->task->Run(); }
 
 ScriptCompiler::ScriptStreamingTask* ScriptCompiler::StartStreamingScript(
     Isolate* v8_isolate, StreamedSource* source, CompileOptions options) {
@@ -2544,10 +2538,13 @@ ScriptCompiler::ScriptStreamingTask* ScriptCompiler::StartStreamingScript(
   // TODO(rmcilroy): remove CompileOptions from the API.
   CHECK(options == ScriptCompiler::kNoCompileOptions);
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
-  return i::Compiler::NewBackgroundCompileTask(source->impl(), isolate);
+  i::ScriptStreamingData* data = source->impl();
+  std::unique_ptr<i::BackgroundCompileTask> task =
+      base::make_unique<i::BackgroundCompileTask>(data, isolate);
+  data->task = std::move(task);
+  return new ScriptCompiler::ScriptStreamingTask(data);
 }
 
-
 MaybeLocal<Script> ScriptCompiler::Compile(Local<Context> context,
                                            StreamedSource* v8_source,
                                            Local<String> full_source_string,
@@ -2562,11 +2559,11 @@ MaybeLocal<Script> ScriptCompiler::Compile(Local<Context> context,
       isolate, origin.ResourceName(), origin.ResourceLineOffset(),
       origin.ResourceColumnOffset(), origin.SourceMapUrl(),
       origin.HostDefinedOptions());
-  i::ScriptStreamingData* streaming_data = v8_source->impl();
+  i::ScriptStreamingData* data = v8_source->impl();
 
   i::MaybeHandle<i::SharedFunctionInfo> maybe_function_info =
       i::Compiler::GetSharedFunctionInfoForStreamedScript(
-          isolate, str, script_details, origin.Options(), streaming_data);
+          isolate, str, script_details, origin.Options(), data);
 
   i::Handle<i::SharedFunctionInfo> result;
   has_pending_exception = !maybe_function_info.ToHandle(&result);
@@ -2908,10 +2905,6 @@ void Message::PrintCurrentStackTrace(Isolate* isolate, FILE* out) {
 
 // --- S t a c k T r a c e ---
 
-Local<StackFrame> StackTrace::GetFrame(uint32_t index) const {
-  return GetFrame(Isolate::GetCurrent(), index);
-}
-
 Local<StackFrame> StackTrace::GetFrame(Isolate* v8_isolate,
                                        uint32_t index) const {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
@@ -3572,17 +3565,20 @@ MaybeLocal<BigInt> Value::ToBigInt(Local<Context> context) const {
   RETURN_ESCAPED(result);
 }
 
+bool Value::BooleanValue(Isolate* v8_isolate) const {
+  return Utils::OpenHandle(this)->BooleanValue(
+      reinterpret_cast<i::Isolate*>(v8_isolate));
+}
+
 MaybeLocal<Boolean> Value::ToBoolean(Local<Context> context) const {
-  auto obj = Utils::OpenHandle(this);
-  if (obj->IsBoolean()) return ToApiHandle<Boolean>(obj);
-  auto isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
-  auto val = isolate->factory()->ToBoolean(obj->BooleanValue(isolate));
-  return ToApiHandle<Boolean>(val);
+  return ToBoolean(context->GetIsolate());
 }
 
 
 Local<Boolean> Value::ToBoolean(Isolate* v8_isolate) const {
-  return ToBoolean(v8_isolate->GetCurrentContext()).ToLocalChecked();
+  auto isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  return ToApiHandle<Boolean>(
+      isolate->factory()->ToBoolean(BooleanValue(v8_isolate)));
 }
 
 
@@ -3888,36 +3884,6 @@ void v8::RegExp::CheckCast(v8::Value* that) {
 }
 
 
-bool Value::BooleanValue() const {
-  return BooleanValue(Isolate::GetCurrent()->GetCurrentContext())
-      .FromJust();
-}
-
-
-double Value::NumberValue() const {
-  return NumberValue(Isolate::GetCurrent()->GetCurrentContext())
-      .FromMaybe(std::numeric_limits<double>::quiet_NaN());
-}
-
-
-int64_t Value::IntegerValue() const {
-  return IntegerValue(Isolate::GetCurrent()->GetCurrentContext())
-      .FromMaybe(0);
-}
-
-
-uint32_t Value::Uint32Value() const {
-  return Uint32Value(Isolate::GetCurrent()->GetCurrentContext())
-      .FromMaybe(0);
-}
-
-
-int32_t Value::Int32Value() const {
-  return Int32Value(Isolate::GetCurrent()->GetCurrentContext())
-      .FromMaybe(0);
-}
-
-
 Maybe<bool> Value::BooleanValue(Local<Context> context) const {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
   return Just(Utils::OpenHandle(this)->BooleanValue(isolate));
@@ -4006,12 +3972,6 @@ MaybeLocal<Uint32> Value::ToArrayIndex(Local<Context> context) const {
 }
 
 
-bool Value::Equals(Local<Value> that) const {
-  return Equals(Isolate::GetCurrent()->GetCurrentContext(), that)
-      .FromMaybe(false);
-}
-
-
 Maybe<bool> Value::Equals(Local<Context> context, Local<Value> that) const {
   i::Isolate* isolate = Utils::OpenHandle(*context)->GetIsolate();
   auto self = Utils::OpenHandle(this);
@@ -4063,7 +4023,8 @@ Maybe<bool> v8::Object::Set(v8::Local<v8::Context> context,
   auto value_obj = Utils::OpenHandle(*value);
   has_pending_exception =
       i::Runtime::SetObjectProperty(isolate, self, key_obj, value_obj,
-                                    i::LanguageMode::kSloppy)
+                                    i::LanguageMode::kSloppy,
+                                    i::StoreOrigin::kMaybeKeyed)
           .is_null();
   RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
   return Just(true);
@@ -4617,8 +4578,8 @@ static Maybe<bool> ObjectSetAccessor(
     Local<Context> context, Object* self, Local<Name> name, Getter getter,
     Setter setter, Data data, AccessControl settings,
     PropertyAttribute attributes, bool is_special_data_property,
-    bool replace_on_access,
-    SideEffectType getter_side_effect_type = SideEffectType::kHasSideEffect) {
+    bool replace_on_access, SideEffectType getter_side_effect_type,
+    SideEffectType setter_side_effect_type) {
   auto isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
   ENTER_V8_NO_SCRIPT(isolate, context, Object, SetAccessor, Nothing<bool>(),
                      i::HandleScope);
@@ -4629,8 +4590,8 @@ static Maybe<bool> ObjectSetAccessor(
   i::Handle<i::AccessorInfo> info =
       MakeAccessorInfo(isolate, name, getter, setter, data, settings, signature,
                        is_special_data_property, replace_on_access);
-  info->set_has_no_side_effect(getter_side_effect_type ==
-                               SideEffectType::kHasNoSideEffect);
+  info->set_getter_side_effect_type(getter_side_effect_type);
+  info->set_setter_side_effect_type(setter_side_effect_type);
   if (info.is_null()) return Nothing<bool>();
   bool fast = obj->HasFastProperties();
   i::Handle<i::Object> result;
@@ -4653,11 +4614,12 @@ Maybe<bool> Object::SetAccessor(Local<Context> context, Local<Name> name,
                                 AccessorNameSetterCallback setter,
                                 MaybeLocal<Value> data, AccessControl settings,
                                 PropertyAttribute attribute,
-                                SideEffectType getter_side_effect_type) {
+                                SideEffectType getter_side_effect_type,
+                                SideEffectType setter_side_effect_type) {
   return ObjectSetAccessor(context, this, name, getter, setter,
                            data.FromMaybe(Local<Value>()), settings, attribute,
                            i::FLAG_disable_old_api_accessors, false,
-                           getter_side_effect_type);
+                           getter_side_effect_type, setter_side_effect_type);
 }
 
 
@@ -4684,19 +4646,22 @@ Maybe<bool> Object::SetNativeDataProperty(
     v8::Local<v8::Context> context, v8::Local<Name> name,
     AccessorNameGetterCallback getter, AccessorNameSetterCallback setter,
     v8::Local<Value> data, PropertyAttribute attributes,
-    SideEffectType getter_side_effect_type) {
+    SideEffectType getter_side_effect_type,
+    SideEffectType setter_side_effect_type) {
   return ObjectSetAccessor(context, this, name, getter, setter, data, DEFAULT,
-                           attributes, true, false, getter_side_effect_type);
+                           attributes, true, false, getter_side_effect_type,
+                           setter_side_effect_type);
 }
 
 Maybe<bool> Object::SetLazyDataProperty(
     v8::Local<v8::Context> context, v8::Local<Name> name,
     AccessorNameGetterCallback getter, v8::Local<Value> data,
-    PropertyAttribute attributes, SideEffectType getter_side_effect_type) {
+    PropertyAttribute attributes, SideEffectType getter_side_effect_type,
+    SideEffectType setter_side_effect_type) {
   return ObjectSetAccessor(context, this, name, getter,
                            static_cast<AccessorNameSetterCallback>(nullptr),
                            data, DEFAULT, attributes, true, true,
-                           getter_side_effect_type);
+                           getter_side_effect_type, setter_side_effect_type);
 }
 
 Maybe<bool> v8::Object::HasOwnProperty(Local<Context> context,
@@ -5343,10 +5308,6 @@ bool String::ContainsOnlyOneByte() const {
   return helper.Check(*str);
 }
 
-int String::Utf8Length() const {
-  return Utf8Length(Isolate::GetCurrent());
-}
-
 int String::Utf8Length(Isolate* isolate) const {
   i::Handle<i::String> str = Utils::OpenHandle(this);
   str = i::String::Flatten(reinterpret_cast<i::Isolate*>(isolate), str);
@@ -5570,14 +5531,6 @@ static bool RecursivelySerializeToUtf8(i::String* current,
   return true;
 }
 
-
-int String::WriteUtf8(char* buffer, int capacity,
-                      int* nchars_ref, int options) const {
-  return WriteUtf8(Isolate::GetCurrent(),
-                   buffer, capacity, nchars_ref, options);
-}
-
-
 int String::WriteUtf8(Isolate* v8_isolate, char* buffer, int capacity,
                       int* nchars_ref, int options) const {
   i::Handle<i::String> str = Utils::OpenHandle(this);
@@ -5645,18 +5598,6 @@ static inline int WriteHelper(i::Isolate* isolate, const String* string,
 }
 
 
-int String::WriteOneByte(uint8_t* buffer, int start,
-                         int length, int options) const {
-  return WriteOneByte(Isolate::GetCurrent(), buffer, start, length, options);
-}
-
-
-int String::Write(uint16_t* buffer, int start, int length,
-                  int options) const {
-  return Write(Isolate::GetCurrent(), buffer, start, length, options);
-}
-
-
 int String::WriteOneByte(Isolate* isolate, uint8_t* buffer, int start,
                          int length, int options) const {
   return WriteHelper(reinterpret_cast<i::Isolate*>(isolate), this, buffer,
@@ -6010,16 +5951,16 @@ HeapStatistics::HeapStatistics()
       malloced_memory_(0),
       external_memory_(0),
       peak_malloced_memory_(0),
-      does_zap_garbage_(0),
+      does_zap_garbage_(false),
       number_of_native_contexts_(0),
       number_of_detached_contexts_(0) {}
 
-HeapSpaceStatistics::HeapSpaceStatistics(): space_name_(0),
-                                            space_size_(0),
-                                            space_used_size_(0),
-                                            space_available_size_(0),
-                                            physical_space_size_(0) { }
-
+HeapSpaceStatistics::HeapSpaceStatistics()
+    : space_name_(nullptr),
+      space_size_(0),
+      space_used_size_(0),
+      space_available_size_(0),
+      physical_space_size_(0) {}
 
 HeapObjectStatistics::HeapObjectStatistics()
     : object_type_(nullptr),
@@ -6604,11 +6545,6 @@ MaybeLocal<String> String::NewFromTwoByte(Isolate* isolate,
   return result;
 }
 
-Local<String> v8::String::Concat(Local<String> left,
-                                 Local<String> right) {
-  return Concat(Isolate::GetCurrent(), left, right);
-}
-
 Local<String> v8::String::Concat(Isolate* v8_isolate, Local<String> left,
                                  Local<String> right) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
@@ -6793,7 +6729,6 @@ double v8::NumberObject::ValueOf() const {
 }
 
 Local<v8::Value> v8::BigIntObject::New(Isolate* isolate, int64_t value) {
-  CHECK(i::FLAG_harmony_bigint);
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, BigIntObject, New);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
@@ -6835,11 +6770,6 @@ bool v8::BooleanObject::ValueOf() const {
 }
 
 
-Local<v8::Value> v8::StringObject::New(Local<String> value) {
-  return New(Isolate::GetCurrent(), value);
-}
-
-
 Local<v8::Value> v8::StringObject::New(Isolate* v8_isolate,
                                        Local<String> value) {
   i::Handle<i::String> string = Utils::OpenHandle(*value);
@@ -6981,23 +6911,6 @@ Local<v8::Array> v8::Array::New(Isolate* isolate, int length) {
   return Utils::ToLocal(obj);
 }
 
-Local<v8::Array> v8::Array::New(Isolate* isolate, Local<Value>* elements,
-                                size_t length) {
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i::Factory* factory = i_isolate->factory();
-  LOG_API(i_isolate, Array, New);
-  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
-  int len = static_cast<int>(length);
-
-  i::Handle<i::FixedArray> result = factory->NewFixedArray(len);
-  for (int i = 0; i < len; i++) {
-    i::Handle<i::Object> element = Utils::OpenHandle(*elements[i]);
-    result->set(i, *element);
-  }
-
-  return Utils::ToLocal(
-      factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS, len));
-}
 
 uint32_t v8::Array::Length() const {
   i::Handle<i::JSArray> obj = Utils::OpenHandle(this);
@@ -7103,30 +7016,30 @@ i::Handle<i::JSArray> MapAsArray(i::Isolate* isolate, i::Object* table_obj,
   i::Factory* factory = isolate->factory();
   i::Handle<i::OrderedHashMap> table(i::OrderedHashMap::cast(table_obj),
                                      isolate);
-  const bool collect_keys =
-      kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kKeys;
-  const bool collect_values =
-      kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kValues;
-  int capacity = table->UsedCapacity();
-  int max_length =
-      (capacity - offset) * ((collect_keys && collect_values) ? 2 : 1);
-  i::Handle<i::FixedArray> result = factory->NewFixedArray(max_length);
+  if (offset >= table->NumberOfElements()) return factory->NewJSArray(0);
+  int length = (table->NumberOfElements() - offset) *
+               (kind == MapAsArrayKind::kEntries ? 2 : 1);
+  i::Handle<i::FixedArray> result = factory->NewFixedArray(length);
   int result_index = 0;
   {
     i::DisallowHeapAllocation no_gc;
+    int capacity = table->UsedCapacity();
     i::Oddball* the_hole = i::ReadOnlyRoots(isolate).the_hole_value();
-    for (int i = offset; i < capacity; ++i) {
+    for (int i = 0; i < capacity; ++i) {
       i::Object* key = table->KeyAt(i);
       if (key == the_hole) continue;
-      if (collect_keys) result->set(result_index++, key);
-      if (collect_values) result->set(result_index++, table->ValueAt(i));
+      if (offset-- > 0) continue;
+      if (kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kKeys) {
+        result->set(result_index++, key);
+      }
+      if (kind == MapAsArrayKind::kEntries || kind == MapAsArrayKind::kValues) {
+        result->set(result_index++, table->ValueAt(i));
+      }
     }
   }
-  DCHECK_GE(max_length, result_index);
-  if (result_index == 0) return factory->NewJSArray(0);
-  result->Shrink(isolate, result_index);
-  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS,
-                                         result_index);
+  DCHECK_EQ(result_index, result->length());
+  DCHECK_EQ(result_index, length);
+  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS, length);
 }
 
 }  // namespace
@@ -7211,26 +7124,24 @@ i::Handle<i::JSArray> SetAsArray(i::Isolate* isolate, i::Object* table_obj,
   i::Factory* factory = isolate->factory();
   i::Handle<i::OrderedHashSet> table(i::OrderedHashSet::cast(table_obj),
                                      isolate);
-  // Elements skipped by |offset| may already be deleted.
-  int capacity = table->UsedCapacity();
-  int max_length = capacity - offset;
-  if (max_length == 0) return factory->NewJSArray(0);
-  i::Handle<i::FixedArray> result = factory->NewFixedArray(max_length);
+  int length = table->NumberOfElements() - offset;
+  if (length <= 0) return factory->NewJSArray(0);
+  i::Handle<i::FixedArray> result = factory->NewFixedArray(length);
   int result_index = 0;
   {
     i::DisallowHeapAllocation no_gc;
+    int capacity = table->UsedCapacity();
     i::Oddball* the_hole = i::ReadOnlyRoots(isolate).the_hole_value();
-    for (int i = offset; i < capacity; ++i) {
+    for (int i = 0; i < capacity; ++i) {
       i::Object* key = table->KeyAt(i);
       if (key == the_hole) continue;
+      if (offset-- > 0) continue;
       result->set(result_index++, key);
     }
   }
-  DCHECK_GE(max_length, result_index);
-  if (result_index == 0) return factory->NewJSArray(0);
-  result->Shrink(isolate, result_index);
-  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS,
-                                         result_index);
+  DCHECK_EQ(result_index, result->length());
+  DCHECK_EQ(result_index, length);
+  return factory->NewJSArrayWithElements(result, i::PACKED_ELEMENTS, length);
 }
 }  // namespace
 
@@ -7501,7 +7412,7 @@ class AsyncCompilationResolver : public i::wasm::CompilationResultResolver {
             reinterpret_cast<i::Isolate*>(isolate)->global_handles()->Create(
                 *Utils::OpenHandle(*promise))) {}
 
-  ~AsyncCompilationResolver() {
+  ~AsyncCompilationResolver() override {
     i::GlobalHandles::Destroy(i::Handle<i::Object>::cast(promise_).location());
   }
 
@@ -7540,9 +7451,6 @@ void WasmModuleObjectBuilderStreaming::Finish() {
 void WasmModuleObjectBuilderStreaming::Abort(MaybeLocal<Value> exception) {
 }
 
-WasmModuleObjectBuilderStreaming::~WasmModuleObjectBuilderStreaming() {
-}
-
 // static
 v8::ArrayBuffer::Allocator* v8::ArrayBuffer::Allocator::NewDefaultAllocator() {
   return new ArrayBufferAllocator();
@@ -7602,9 +7510,8 @@ void ArrayBufferDeleter(void* buffer, size_t length, void* info) {
 
 v8::ArrayBuffer::Contents v8::ArrayBuffer::GetContents() {
   i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
-  size_t byte_length = static_cast<size_t>(self->byte_length()->Number());
   Contents contents(
-      self->backing_store(), byte_length, self->allocation_base(),
+      self->backing_store(), self->byte_length(), self->allocation_base(),
       self->allocation_length(),
       self->is_wasm_memory() ? Allocator::AllocationMode::kReservation
                              : Allocator::AllocationMode::kNormal,
@@ -7632,7 +7539,7 @@ void v8::ArrayBuffer::Neuter() {
 
 size_t v8::ArrayBuffer::ByteLength() const {
   i::Handle<i::JSArrayBuffer> obj = Utils::OpenHandle(this);
-  return static_cast<size_t>(obj->byte_length()->Number());
+  return obj->byte_length();
 }
 
 
@@ -7656,6 +7563,7 @@ Local<ArrayBuffer> v8::ArrayBuffer::New(Isolate* isolate, void* data,
                                         ArrayBufferCreationMode mode) {
   // Embedders must guarantee that the external backing store is valid.
   CHECK(byte_length == 0 || data != nullptr);
+  CHECK_LE(byte_length, i::JSArrayBuffer::kMaxByteLength);
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, ArrayBuffer, New);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
@@ -7687,9 +7595,8 @@ Local<ArrayBuffer> v8::ArrayBufferView::Buffer() {
 
 size_t v8::ArrayBufferView::CopyContents(void* dest, size_t byte_length) {
   i::Handle<i::JSArrayBufferView> self = Utils::OpenHandle(this);
-  size_t byte_offset = i::NumberToSize(self->byte_offset());
-  size_t bytes_to_copy =
-      i::Min(byte_length, i::NumberToSize(self->byte_length()));
+  size_t byte_offset = self->byte_offset();
+  size_t bytes_to_copy = i::Min(byte_length, self->byte_length());
   if (bytes_to_copy) {
     i::DisallowHeapAllocation no_gc;
     i::Isolate* isolate = self->GetIsolate();
@@ -7720,19 +7627,19 @@ bool v8::ArrayBufferView::HasBuffer() const {
 
 size_t v8::ArrayBufferView::ByteOffset() {
   i::Handle<i::JSArrayBufferView> obj = Utils::OpenHandle(this);
-  return static_cast<size_t>(obj->byte_offset()->Number());
+  return obj->WasNeutered() ? 0 : obj->byte_offset();
 }
 
 
 size_t v8::ArrayBufferView::ByteLength() {
   i::Handle<i::JSArrayBufferView> obj = Utils::OpenHandle(this);
-  return static_cast<size_t>(obj->byte_length()->Number());
+  return obj->WasNeutered() ? 0 : obj->byte_length();
 }
 
 
 size_t v8::TypedArray::Length() {
   i::Handle<i::JSTypedArray> obj = Utils::OpenHandle(this);
-  return obj->length_value();
+  return obj->WasNeutered() ? 0 : obj->length_value();
 }
 
 static_assert(v8::TypedArray::kMaxLength == i::Smi::kMaxValue,
@@ -7840,9 +7747,8 @@ v8::SharedArrayBuffer::Contents::Contents(
 
 v8::SharedArrayBuffer::Contents v8::SharedArrayBuffer::GetContents() {
   i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
-  size_t byte_length = static_cast<size_t>(self->byte_length()->Number());
   Contents contents(
-      self->backing_store(), byte_length, self->allocation_base(),
+      self->backing_store(), self->byte_length(), self->allocation_base(),
       self->allocation_length(),
       self->is_wasm_memory()
           ? ArrayBuffer::Allocator::AllocationMode::kReservation
@@ -7858,7 +7764,7 @@ v8::SharedArrayBuffer::Contents v8::SharedArrayBuffer::GetContents() {
 
 size_t v8::SharedArrayBuffer::ByteLength() const {
   i::Handle<i::JSArrayBuffer> obj = Utils::OpenHandle(this);
-  return static_cast<size_t>(obj->byte_length()->Number());
+  return obj->byte_length();
 }
 
 Local<SharedArrayBuffer> v8::SharedArrayBuffer::New(Isolate* isolate,
@@ -7912,8 +7818,8 @@ Local<Symbol> v8::Symbol::New(Isolate* isolate, Local<String> name) {
 Local<Symbol> v8::Symbol::For(Isolate* isolate, Local<String> name) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   i::Handle<i::String> i_name = Utils::OpenHandle(*name);
-  return Utils::ToLocal(i_isolate->SymbolFor(
-      i::Heap::kPublicSymbolTableRootIndex, i_name, false));
+  return Utils::ToLocal(
+      i_isolate->SymbolFor(i::RootIndex::kPublicSymbolTable, i_name, false));
 }
 
 
@@ -7921,10 +7827,11 @@ Local<Symbol> v8::Symbol::ForApi(Isolate* isolate, Local<String> name) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   i::Handle<i::String> i_name = Utils::OpenHandle(*name);
   return Utils::ToLocal(
-      i_isolate->SymbolFor(i::Heap::kApiSymbolTableRootIndex, i_name, false));
+      i_isolate->SymbolFor(i::RootIndex::kApiSymbolTable, i_name, false));
 }
 
 #define WELL_KNOWN_SYMBOLS(V)                 \
+  V(AsyncIterator, async_iterator)            \
   V(HasInstance, has_instance)                \
   V(IsConcatSpreadable, is_concat_spreadable) \
   V(Iterator, iterator)                       \
@@ -7961,8 +7868,8 @@ Local<Private> v8::Private::New(Isolate* isolate, Local<String> name) {
 Local<Private> v8::Private::ForApi(Isolate* isolate, Local<String> name) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   i::Handle<i::String> i_name = Utils::OpenHandle(*name);
-  Local<Symbol> result = Utils::ToLocal(i_isolate->SymbolFor(
-      i::Heap::kApiPrivateSymbolTableRootIndex, i_name, true));
+  Local<Symbol> result = Utils::ToLocal(
+      i_isolate->SymbolFor(i::RootIndex::kApiPrivateSymbolTable, i_name, true));
   return v8::Local<Private>(reinterpret_cast<Private*>(*result));
 }
 
@@ -8003,7 +7910,6 @@ Local<Integer> v8::Integer::NewFromUnsigned(Isolate* isolate, uint32_t value) {
 }
 
 Local<BigInt> v8::BigInt::New(Isolate* isolate, int64_t value) {
-  CHECK(i::FLAG_harmony_bigint);
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(internal_isolate);
   i::Handle<i::BigInt> result = i::BigInt::FromInt64(internal_isolate, value);
@@ -8011,7 +7917,6 @@ Local<BigInt> v8::BigInt::New(Isolate* isolate, int64_t value) {
 }
 
 Local<BigInt> v8::BigInt::NewFromUnsigned(Isolate* isolate, uint64_t value) {
-  CHECK(i::FLAG_harmony_bigint);
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(internal_isolate);
   i::Handle<i::BigInt> result = i::BigInt::FromUint64(internal_isolate, value);
@@ -8021,7 +7926,6 @@ Local<BigInt> v8::BigInt::NewFromUnsigned(Isolate* isolate, uint64_t value) {
 MaybeLocal<BigInt> v8::BigInt::NewFromWords(Local<Context> context,
                                             int sign_bit, int word_count,
                                             const uint64_t* words) {
-  CHECK(i::FLAG_harmony_bigint);
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
   ENTER_V8_NO_SCRIPT(isolate, context, BigInt, NewFromWords,
                      MaybeLocal<BigInt>(), InternalEscapableScope);
@@ -8186,6 +8090,11 @@ void Isolate::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) {
   isolate->heap()->SetEmbedderHeapTracer(tracer);
 }
 
+EmbedderHeapTracer* Isolate::GetEmbedderHeapTracer() {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  return isolate->heap()->GetEmbedderHeapTracer();
+}
+
 void Isolate::SetGetExternallyAllocatedMemoryInBytesCallback(
     GetExternallyAllocatedMemoryInBytesCallback callback) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
@@ -8225,9 +8134,9 @@ void Isolate::RequestGarbageCollectionForTesting(GarbageCollectionType type) {
         kGCCallbackFlagForced);
   } else {
     DCHECK_EQ(kFullGarbageCollection, type);
-    reinterpret_cast<i::Isolate*>(this)->heap()->CollectAllGarbage(
-        i::Heap::kAbortIncrementalMarkingMask,
-        i::GarbageCollectionReason::kTesting, kGCCallbackFlagForced);
+    reinterpret_cast<i::Isolate*>(this)->heap()->PreciseCollectAllGarbage(
+        i::Heap::kNoGCFlags, i::GarbageCollectionReason::kTesting,
+        kGCCallbackFlagForced);
   }
 }
 
@@ -8296,7 +8205,11 @@ void Isolate::Initialize(Isolate* isolate,
   if (params.entry_hook || !i::Snapshot::Initialize(i_isolate)) {
     // If snapshot data was provided and we failed to deserialize it must
     // have been corrupted.
-    CHECK_NULL(i_isolate->snapshot_blob());
+    if (i_isolate->snapshot_blob() != nullptr) {
+      FATAL(
+          "Failed to deserialize the V8 snapshot blob. This can mean that the "
+          "snapshot blob file is corrupted or missing.");
+    }
     base::ElapsedTimer timer;
     if (i::FLAG_profile_deserialization) timer.Start();
     i_isolate->Init(nullptr);
@@ -8366,6 +8279,11 @@ void Isolate::SetHostInitializeImportMetaObjectCallback(
   isolate->SetHostInitializeImportMetaObjectCallback(callback);
 }
 
+void Isolate::SetPrepareStackTraceCallback(PrepareStackTraceCallback callback) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->SetPrepareStackTraceCallback(callback);
+}
+
 Isolate::DisallowJavascriptExecutionScope::DisallowJavascriptExecutionScope(
     Isolate* isolate,
     Isolate::DisallowJavascriptExecutionScope::OnFailure on_failure)
@@ -8791,17 +8709,17 @@ void Isolate::SetStackLimit(uintptr_t stack_limit) {
 
 void Isolate::GetCodeRange(void** start, size_t* length_in_bytes) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
-  if (isolate->heap()->memory_allocator()->code_range()->valid()) {
-    *start = reinterpret_cast<void*>(
-        isolate->heap()->memory_allocator()->code_range()->start());
-    *length_in_bytes =
-        isolate->heap()->memory_allocator()->code_range()->size();
-  } else {
-    *start = nullptr;
-    *length_in_bytes = 0;
-  }
+  const base::AddressRegion& code_range =
+      isolate->heap()->memory_allocator()->code_range();
+  *start = reinterpret_cast<void*>(code_range.begin());
+  *length_in_bytes = code_range.size();
 }
 
+MemoryRange Isolate::GetEmbeddedCodeRange() {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  return {reinterpret_cast<const void*>(isolate->embedded_blob()),
+          isolate->embedded_blob_size()};
+}
 
 #define CALLBACK_SETTER(ExternalName, Type, InternalName)      \
   void Isolate::Set##ExternalName(Type callback) {             \
@@ -8986,9 +8904,6 @@ bool MicrotasksScope::IsRunningMicrotasks(Isolate* v8Isolate) {
   return isolate->IsRunningMicrotasks();
 }
 
-String::Utf8Value::Utf8Value(v8::Local<v8::Value> obj)
-  : Utf8Value(Isolate::GetCurrent(), obj) {}
-
 String::Utf8Value::Utf8Value(v8::Isolate* isolate, v8::Local<v8::Value> obj)
     : str_(nullptr), length_(0) {
   if (obj.IsEmpty()) return;
@@ -9008,9 +8923,6 @@ String::Utf8Value::~Utf8Value() {
   i::DeleteArray(str_);
 }
 
-String::Value::Value(v8::Local<v8::Value> obj)
-  : Value(Isolate::GetCurrent(), obj) {}
-
 String::Value::Value(v8::Isolate* isolate, v8::Local<v8::Value> obj)
     : str_(nullptr), length_(0) {
   if (obj.IsEmpty()) return;
@@ -9192,7 +9104,10 @@ int debug::Script::ColumnOffset() const {
 
 std::vector<int> debug::Script::LineEnds() const {
   i::Handle<i::Script> script = Utils::OpenHandle(this);
-  if (script->type() == i::Script::TYPE_WASM) return std::vector<int>();
+  if (script->type() == i::Script::TYPE_WASM &&
+      this->SourceMappingURL().IsEmpty()) {
+    return std::vector<int>();
+  }
   i::Isolate* isolate = script->GetIsolate();
   i::HandleScope scope(isolate);
   i::Script::InitLineEnds(script);
@@ -9281,7 +9196,8 @@ bool debug::Script::GetPossibleBreakpoints(
     std::vector<debug::BreakLocation>* locations) const {
   CHECK(!start.IsEmpty());
   i::Handle<i::Script> script = Utils::OpenHandle(this);
-  if (script->type() == i::Script::TYPE_WASM) {
+  if (script->type() == i::Script::TYPE_WASM &&
+      this->SourceMappingURL().IsEmpty()) {
     i::WasmModuleObject* module_object =
         i::WasmModuleObject::cast(script->wasm_module_object());
     return module_object->GetPossibleBreakpoints(start, end, locations);
@@ -9332,9 +9248,13 @@ bool debug::Script::GetPossibleBreakpoints(
 int debug::Script::GetSourceOffset(const debug::Location& location) const {
   i::Handle<i::Script> script = Utils::OpenHandle(this);
   if (script->type() == i::Script::TYPE_WASM) {
-    return i::WasmModuleObject::cast(script->wasm_module_object())
-               ->GetFunctionOffset(location.GetLineNumber()) +
-           location.GetColumnNumber();
+    if (this->SourceMappingURL().IsEmpty()) {
+      return i::WasmModuleObject::cast(script->wasm_module_object())
+                 ->GetFunctionOffset(location.GetLineNumber()) +
+             location.GetColumnNumber();
+    }
+    DCHECK_EQ(0, location.GetLineNumber());
+    return location.GetColumnNumber();
   }
 
   int line = std::max(location.GetLineNumber() - script->line_offset(), 0);
@@ -9777,10 +9697,10 @@ int debug::GetNativeAccessorDescriptor(v8::Local<v8::Context> context,
   }
   auto isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
   int result = 0;
-#define IS_BUILTIN_ACESSOR(name, _)                         \
+#define IS_BUILTIN_ACESSOR(_, name, ...)                    \
   if (*structure == *isolate->factory()->name##_accessor()) \
     result |= static_cast<int>(debug::NativeAccessorType::IsBuiltin);
-  ACCESSOR_INFO_LIST(IS_BUILTIN_ACESSOR)
+  ACCESSOR_INFO_LIST_GENERATOR(IS_BUILTIN_ACESSOR, /* not used */)
 #undef IS_BUILTIN_ACESSOR
   i::Handle<i::AccessorInfo> accessor_info =
       i::Handle<i::AccessorInfo>::cast(structure);
@@ -9826,7 +9746,7 @@ debug::PostponeInterruptsScope::PostponeInterruptsScope(v8::Isolate* isolate)
           new i::PostponeInterruptsScope(reinterpret_cast<i::Isolate*>(isolate),
                                          i::StackGuard::API_INTERRUPT)) {}
 
-debug::PostponeInterruptsScope::~PostponeInterruptsScope() {}
+debug::PostponeInterruptsScope::~PostponeInterruptsScope() = default;
 
 Local<String> CpuProfileNode::GetFunctionName() const {
   const i::ProfileNode* node = reinterpret_cast<const i::ProfileNode*>(this);
@@ -9950,6 +9870,47 @@ debug::TypeProfile::ScriptData debug::TypeProfile::GetScriptData(
   return ScriptData(i, type_profile_);
 }
 
+v8::MaybeLocal<v8::Value> debug::WeakMap::Get(v8::Local<v8::Context> context,
+                                              v8::Local<v8::Value> key) {
+  PREPARE_FOR_EXECUTION(context, WeakMap, Get, Value);
+  auto self = Utils::OpenHandle(this);
+  Local<Value> result;
+  i::Handle<i::Object> argv[] = {Utils::OpenHandle(*key)};
+  has_pending_exception =
+      !ToLocal<Value>(i::Execution::Call(isolate, isolate->weakmap_get(), self,
+                                         arraysize(argv), argv),
+                      &result);
+  RETURN_ON_FAILED_EXECUTION(Value);
+  RETURN_ESCAPED(result);
+}
+
+v8::MaybeLocal<debug::WeakMap> debug::WeakMap::Set(
+    v8::Local<v8::Context> context, v8::Local<v8::Value> key,
+    v8::Local<v8::Value> value) {
+  PREPARE_FOR_EXECUTION(context, WeakMap, Set, WeakMap);
+  auto self = Utils::OpenHandle(this);
+  i::Handle<i::Object> result;
+  i::Handle<i::Object> argv[] = {Utils::OpenHandle(*key),
+                                 Utils::OpenHandle(*value)};
+  has_pending_exception = !i::Execution::Call(isolate, isolate->weakmap_set(),
+                                              self, arraysize(argv), argv)
+                               .ToHandle(&result);
+  RETURN_ON_FAILED_EXECUTION(WeakMap);
+  RETURN_ESCAPED(Local<WeakMap>::Cast(Utils::ToLocal(result)));
+}
+
+Local<debug::WeakMap> debug::WeakMap::New(v8::Isolate* isolate) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  LOG_API(i_isolate, WeakMap, New);
+  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
+  i::Handle<i::JSWeakMap> obj = i_isolate->factory()->NewJSWeakMap();
+  return ToApiHandle<debug::WeakMap>(obj);
+}
+
+debug::WeakMap* debug::WeakMap::Cast(v8::Value* value) {
+  return static_cast<debug::WeakMap*>(value);
+}
+
 const char* CpuProfileNode::GetFunctionNameStr() const {
   const i::ProfileNode* node = reinterpret_cast<const i::ProfileNode*>(this);
   return node->entry()->name();
@@ -10134,11 +10095,6 @@ void CpuProfiler::SetIdle(bool is_idle) {
   isolate->SetIdle(is_idle);
 }
 
-void CpuProfiler::UseDetailedSourcePositionsForProfiling(Isolate* isolate) {
-  reinterpret_cast<i::Isolate*>(isolate)
-      ->set_detailed_source_positions_for_profiling(true);
-}
-
 uintptr_t CodeEvent::GetCodeStartAddress() {
   return reinterpret_cast<i::CodeEvent*>(this)->code_start_address;
 }
@@ -10546,9 +10502,9 @@ void EmbedderHeapTracer::GarbageCollectionForTesting(
   CHECK(i::FLAG_expose_gc);
   i::Heap* const heap = reinterpret_cast<i::Isolate*>(isolate_)->heap();
   heap->SetEmbedderStackStateForNextFinalizaton(stack_state);
-  heap->CollectAllGarbage(i::Heap::kAbortIncrementalMarkingMask,
-                          i::GarbageCollectionReason::kTesting,
-                          kGCCallbackFlagForced);
+  heap->PreciseCollectAllGarbage(i::Heap::kNoGCFlags,
+                                 i::GarbageCollectionReason::kTesting,
+                                 kGCCallbackFlagForced);
 }
 
 bool EmbedderHeapTracer::AdvanceTracing(double deadline_in_ms) {
diff --git a/deps/v8/src/api.h b/deps/v8/src/api.h
index ae0ce350a4..e5f5c7da70 100644
--- a/deps/v8/src/api.h
+++ b/deps/v8/src/api.h
@@ -116,6 +116,7 @@ class RegisteredExtension {
   V(Proxy, JSProxy)                            \
   V(debug::GeneratorObject, JSGeneratorObject) \
   V(debug::Script, Script)                     \
+  V(debug::WeakMap, JSWeakMap)                 \
   V(Promise, JSPromise)                        \
   V(Primitive, Object)                         \
   V(PrimitiveArray, FixedArray)                \
diff --git a/deps/v8/src/arguments.h b/deps/v8/src/arguments.h
index 0bfdd770f5..db1ee5467c 100644
--- a/deps/v8/src/arguments.h
+++ b/deps/v8/src/arguments.h
@@ -27,7 +27,7 @@ namespace internal {
 // Note that length_ (whose value is in the integer range) is defined
 // as intptr_t to provide endian-neutrality on 64-bit archs.
 
-class Arguments BASE_EMBEDDED {
+class Arguments {
  public:
   Arguments(int length, Object** arguments)
       : length_(length), arguments_(arguments) {
diff --git a/deps/v8/src/arm/assembler-arm.cc b/deps/v8/src/arm/assembler-arm.cc
index 163fa4c219..758fcd1a68 100644
--- a/deps/v8/src/arm/assembler-arm.cc
+++ b/deps/v8/src/arm/assembler-arm.cc
@@ -46,6 +46,7 @@
 #include "src/deoptimizer.h"
 #include "src/macro-assembler.h"
 #include "src/objects-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -417,6 +418,13 @@ Operand Operand::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rn, int32_t offset, AddrMode am)
     : rn_(rn), rm_(no_reg), offset_(offset), am_(am) {
   // Accesses below the stack pointer are not safe, and are prohibited by the
@@ -472,6 +480,7 @@ void NeonMemOperand::SetAlignment(int align) {
 }
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     switch (request.kind()) {
@@ -483,6 +492,12 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         request.code_stub()->set_isolate(isolate);
         object = request.code_stub()->GetCode();
         break;
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        object = str->AllocateStringConstant(isolate);
+        break;
+      }
     }
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     Memory<Address>(constant_pool_entry_address(pc, 0 /* unused */)) =
@@ -1418,7 +1433,7 @@ int Assembler::branch_offset(Label* L) {
 
 // Branch instructions.
 void Assembler::b(int branch_offset, Condition cond, RelocInfo::Mode rmode) {
-  RecordRelocInfo(rmode);
+  if (!RelocInfo::IsNone(rmode)) RecordRelocInfo(rmode);
   DCHECK_EQ(branch_offset & 3, 0);
   int imm24 = branch_offset >> 2;
   const bool b_imm_check = is_int24(imm24);
@@ -1432,7 +1447,7 @@ void Assembler::b(int branch_offset, Condition cond, RelocInfo::Mode rmode) {
 }
 
 void Assembler::bl(int branch_offset, Condition cond, RelocInfo::Mode rmode) {
-  RecordRelocInfo(rmode);
+  if (!RelocInfo::IsNone(rmode)) RecordRelocInfo(rmode);
   DCHECK_EQ(branch_offset & 3, 0);
   int imm24 = branch_offset >> 2;
   const bool bl_imm_check = is_int24(imm24);
@@ -5103,13 +5118,7 @@ void Assembler::dq(uint64_t value) {
 }
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
-  if (options().disable_reloc_info_for_patching) return;
-  if (RelocInfo::IsNone(rmode) ||
-      // Don't record external references unless the heap will be serialized.
-      (RelocInfo::IsOnlyForSerializer(rmode) &&
-       !options().record_reloc_info_for_serialization && !emit_debug_code())) {
-    return;
-  }
+  if (!ShouldRecordRelocInfo(rmode)) return;
   DCHECK_GE(buffer_space(), kMaxRelocSize);  // too late to grow buffer here
   RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
   reloc_info_writer.Write(&rinfo);
diff --git a/deps/v8/src/arm/assembler-arm.h b/deps/v8/src/arm/assembler-arm.h
index fb36702882..1bfa58b853 100644
--- a/deps/v8/src/arm/assembler-arm.h
+++ b/deps/v8/src/arm/assembler-arm.h
@@ -393,7 +393,7 @@ enum Coprocessor {
 // Machine instruction Operands
 
 // Class Operand represents a shifter operand in data processing instructions
-class Operand BASE_EMBEDDED {
+class Operand {
  public:
   // immediate
   V8_INLINE explicit Operand(int32_t immediate,
@@ -425,6 +425,7 @@ class Operand BASE_EMBEDDED {
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Operand EmbeddedCode(CodeStub* stub);
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Return true if this is a register operand.
   bool IsRegister() const {
@@ -498,7 +499,7 @@ class Operand BASE_EMBEDDED {
 
 
 // Class MemOperand represents a memory operand in load and store instructions
-class MemOperand BASE_EMBEDDED {
+class MemOperand {
  public:
   // [rn +/- offset]      Offset/NegOffset
   // [rn +/- offset]!     PreIndex/NegPreIndex
@@ -557,7 +558,7 @@ class MemOperand BASE_EMBEDDED {
 
 // Class NeonMemOperand represents a memory operand in load and
 // store NEON instructions
-class NeonMemOperand BASE_EMBEDDED {
+class NeonMemOperand {
  public:
   // [rn {:align}]       Offset
   // [rn {:align}]!      PostIndex
@@ -580,7 +581,7 @@ class NeonMemOperand BASE_EMBEDDED {
 
 
 // Class NeonListOperand represents a list of NEON registers
-class NeonListOperand BASE_EMBEDDED {
+class NeonListOperand {
  public:
   explicit NeonListOperand(DoubleRegister base, int register_count = 1)
     : base_(base), register_count_(register_count) {}
@@ -1693,7 +1694,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   friend class UseScratchRegisterScope;
 };
 
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   V8_INLINE explicit EnsureSpace(Assembler* assembler);
 };
diff --git a/deps/v8/src/arm/code-stubs-arm.cc b/deps/v8/src/arm/code-stubs-arm.cc
index bb5becefb8..c7eaef1325 100644
--- a/deps/v8/src/arm/code-stubs-arm.cc
+++ b/deps/v8/src/arm/code-stubs-arm.cc
@@ -131,7 +131,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
                IsolateAddressId::kPendingExceptionAddress, isolate())));
   }
   __ str(r0, MemOperand(scratch));
-  __ LoadRoot(r0, Heap::kExceptionRootIndex);
+  __ LoadRoot(r0, RootIndex::kException);
   __ b(&exit);
 
   // Invoke: Link this frame into the handler chain.
@@ -418,7 +418,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ LeaveExitFrame(false, r4, stack_space_operand != nullptr);
 
   // Check if the function scheduled an exception.
-  __ LoadRoot(r4, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(r4, RootIndex::kTheHoleValue);
   __ Move(r6, ExternalReference::scheduled_exception_address(isolate));
   __ ldr(r5, MemOperand(r6));
   __ cmp(r4, r5);
@@ -469,14 +469,14 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data
   __ push(call_data);
 
   Register scratch0 = call_data;
   Register scratch1 = r5;
-  __ LoadRoot(scratch0, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch0, RootIndex::kUndefinedValue);
   // return value
   __ push(scratch0);
   // return value default
@@ -549,7 +549,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // Push data from AccessorInfo.
   __ ldr(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
   __ push(scratch);
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   __ Push(scratch, scratch);
   __ Move(scratch, ExternalReference::isolate_address(isolate()));
   __ Push(scratch, holder);
diff --git a/deps/v8/src/arm/codegen-arm.cc b/deps/v8/src/arm/codegen-arm.cc
index 39f756d152..7dc4ced321 100644
--- a/deps/v8/src/arm/codegen-arm.cc
+++ b/deps/v8/src/arm/codegen-arm.cc
@@ -9,7 +9,6 @@
 #include "src/arm/assembler-arm-inl.h"
 #include "src/arm/simulator-arm.h"
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 
 namespace v8 {
@@ -19,17 +18,17 @@ namespace internal {
 
 #if defined(V8_HOST_ARCH_ARM)
 
-MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
-                                                MemCopyUint8Function stub) {
+MemCopyUint8Function CreateMemCopyUint8Function(MemCopyUint8Function stub) {
 #if defined(USE_SIMULATOR)
   return stub;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return stub;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   Register dest = r0;
   Register src = r1;
@@ -166,11 +165,12 @@ MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
   return FUNCTION_CAST<MemCopyUint8Function>(buffer);
 #endif
 }
@@ -178,16 +178,17 @@ MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
 
 // Convert 8 to 16. The number of character to copy must be at least 8.
 MemCopyUint16Uint8Function CreateMemCopyUint16Uint8Function(
-    Isolate* isolate, MemCopyUint16Uint8Function stub) {
+    MemCopyUint16Uint8Function stub) {
 #if defined(USE_SIMULATOR)
   return stub;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return stub;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   Register dest = r0;
   Register src = r1;
@@ -256,25 +257,27 @@ MemCopyUint16Uint8Function CreateMemCopyUint16Uint8Function(
   }
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
   return FUNCTION_CAST<MemCopyUint16Uint8Function>(buffer);
 #endif
 }
 #endif
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
 #if defined(USE_SIMULATOR)
   return nullptr;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   __ MovFromFloatParameter(d0);
   __ vsqrt(d0, d0);
@@ -282,12 +285,13 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 #endif
 }
 
diff --git a/deps/v8/src/arm/interface-descriptors-arm.cc b/deps/v8/src/arm/interface-descriptors-arm.cc
index 8af455fc6e..f3be7a7c4a 100644
--- a/deps/v8/src/arm/interface-descriptors-arm.cc
+++ b/deps/v8/src/arm/interface-descriptors-arm.cc
@@ -88,9 +88,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // r0 : number of arguments (on the stack, not including receiver)
   // r1 : the target to call
-  // r2 : arguments list (FixedArray)
   // r4 : arguments list length (untagged)
-  Register registers[] = {r1, r0, r2, r4};
+  // r2 : arguments list (FixedArray)
+  Register registers[] = {r1, r0, r4, r2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -125,9 +125,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // r0 : number of arguments (on the stack, not including receiver)
   // r1 : the target to call
   // r3 : the new target
-  // r2 : arguments list (FixedArray)
   // r4 : arguments list length (untagged)
-  Register registers[] = {r1, r3, r0, r2, r4};
+  // r2 : arguments list (FixedArray)
+  Register registers[] = {r1, r3, r0, r4, r2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -193,7 +193,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r1,  // JSFunction
@@ -237,10 +237,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r0,  // argument count (not including receiver)
-      r3,  // new target
+      r4,  // address of the first argument
       r1,  // constructor to call
+      r3,  // new target
       r2,  // allocation site feedback if available, undefined otherwise
-      r4   // address of the first argument
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/arm/macro-assembler-arm.cc b/deps/v8/src/arm/macro-assembler-arm.cc
index 09db465d59..cdf9dad1d9 100644
--- a/deps/v8/src/arm/macro-assembler-arm.cc
+++ b/deps/v8/src/arm/macro-assembler-arm.cc
@@ -130,7 +130,7 @@ int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
+      RootIndex::kBuiltinsConstantsTable));
 
   // The ldr call below could end up clobbering ip when the offset does not fit
   // into 12 bits (and thus needs to be loaded from the constant pool). In that
@@ -147,7 +147,7 @@ void TurboAssembler::LoadFromConstantsTable(Register destination,
     reg = r7;
   }
 
-  LoadRoot(reg, Heap::kBuiltinsConstantsTableRootIndex);
+  LoadRoot(reg, RootIndex::kBuiltinsConstantsTable);
   ldr(destination, MemOperand(reg, offset));
 
   if (could_clobber_ip) {
@@ -527,7 +527,7 @@ void MacroAssembler::Store(Register src,
   }
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index,
+void TurboAssembler::LoadRoot(Register destination, RootIndex index,
                               Condition cond) {
   ldr(destination, MemOperand(kRootRegister, RootRegisterOffset(index)), cond);
 }
@@ -615,8 +615,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -628,7 +626,6 @@ void TurboAssembler::CallRecordWriteStub(
   Pop(slot_parameter);
   Pop(object_parameter);
 
-  Move(isolate_parameter, ExternalReference::isolate_address(isolate()));
   Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -1520,7 +1517,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(r3, Heap::kUndefinedValueRootIndex);
+    LoadRoot(r3, RootIndex::kUndefinedValue);
   }
 
   Label done;
@@ -1642,9 +1639,7 @@ void MacroAssembler::CompareInstanceType(Register map,
   cmp(type_reg, Operand(type));
 }
 
-
-void MacroAssembler::CompareRoot(Register obj,
-                                 Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(Register obj, RootIndex index) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
   DCHECK(obj != scratch);
@@ -2053,7 +2048,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
   if (emit_debug_code()) {
     Label done_checking;
     AssertNotSmi(object);
-    CompareRoot(object, Heap::kUndefinedValueRootIndex);
+    CompareRoot(object, RootIndex::kUndefinedValue);
     b(eq, &done_checking);
     ldr(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
     CompareInstanceType(scratch, scratch, ALLOCATION_SITE_TYPE);
diff --git a/deps/v8/src/arm/macro-assembler-arm.h b/deps/v8/src/arm/macro-assembler-arm.h
index 055b6e6fbc..ef75c3fe4c 100644
--- a/deps/v8/src/arm/macro-assembler-arm.h
+++ b/deps/v8/src/arm/macro-assembler-arm.h
@@ -71,6 +71,9 @@ enum TargetAddressStorageMode {
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -481,11 +484,10 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   }
 
   // Load an object from the root table.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override {
+  void LoadRoot(Register destination, RootIndex index) override {
     LoadRoot(destination, index, al);
   }
-  void LoadRoot(Register destination, Heap::RootListIndex index,
-                Condition cond);
+  void LoadRoot(Register destination, RootIndex index, Condition cond);
 
   // Jump if the register contains a smi.
   void JumpIfSmi(Register value, Label* smi_label);
@@ -566,10 +568,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -713,8 +719,8 @@ class MacroAssembler : public TurboAssembler {
 
   // Compare the object in a register to a value from the root list.
   // Acquires a scratch register.
-  void CompareRoot(Register obj, Heap::RootListIndex index);
-  void PushRoot(Heap::RootListIndex index) {
+  void CompareRoot(Register obj, RootIndex index);
+  void PushRoot(RootIndex index) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
@@ -722,14 +728,13 @@ class MacroAssembler : public TurboAssembler {
   }
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal) {
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal) {
     CompareRoot(with, index);
     b(eq, if_equal);
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal) {
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal) {
     CompareRoot(with, index);
     b(ne, if_not_equal);
   }
diff --git a/deps/v8/src/arm/simulator-arm.cc b/deps/v8/src/arm/simulator-arm.cc
index b1e8421876..e9d74104d3 100644
--- a/deps/v8/src/arm/simulator-arm.cc
+++ b/deps/v8/src/arm/simulator-arm.cc
@@ -3212,15 +3212,15 @@ void Simulator::DecodeTypeVFP(Instruction* instr) {
         DecodeVCMP(instr);
       } else if (((instr->Opc2Value() == 0x1)) && (instr->Opc3Value() == 0x3)) {
         // vsqrt
-        lazily_initialize_fast_sqrt(isolate_);
+        lazily_initialize_fast_sqrt();
         if (instr->SzValue() == 0x1) {
           double dm_value = get_double_from_d_register(vm).get_scalar();
-          double dd_value = fast_sqrt(dm_value, isolate_);
+          double dd_value = fast_sqrt(dm_value);
           dd_value = canonicalizeNaN(dd_value);
           set_d_register_from_double(vd, dd_value);
         } else {
           float sm_value = get_float_from_s_register(m).get_scalar();
-          float sd_value = fast_sqrt(sm_value, isolate_);
+          float sd_value = fast_sqrt(sm_value);
           sd_value = canonicalizeNaN(sd_value);
           set_s_register_from_float(d, sd_value);
         }
@@ -5282,10 +5282,10 @@ void Simulator::DecodeSpecialCondition(Instruction* instr) {
               src[i] = bit_cast<uint32_t>(result);
             }
           } else {
-            lazily_initialize_fast_sqrt(isolate_);
+            lazily_initialize_fast_sqrt();
             for (int i = 0; i < 4; i++) {
               float radicand = bit_cast<float>(src[i]);
-              float result = 1.0f / fast_sqrt(radicand, isolate_);
+              float result = 1.0f / fast_sqrt(radicand);
               result = canonicalizeNaN(result);
               src[i] = bit_cast<uint32_t>(result);
             }
diff --git a/deps/v8/src/arm64/assembler-arm64-inl.h b/deps/v8/src/arm64/assembler-arm64-inl.h
index 52df8143ef..5a163b06fd 100644
--- a/deps/v8/src/arm64/assembler-arm64-inl.h
+++ b/deps/v8/src/arm64/assembler-arm64-inl.h
@@ -341,7 +341,9 @@ Immediate Operand::immediate_for_heap_object_request() const {
   DCHECK((heap_object_request().kind() == HeapObjectRequest::kHeapNumber &&
           immediate_.rmode() == RelocInfo::EMBEDDED_OBJECT) ||
          (heap_object_request().kind() == HeapObjectRequest::kCodeStub &&
-          immediate_.rmode() == RelocInfo::CODE_TARGET));
+          immediate_.rmode() == RelocInfo::CODE_TARGET) ||
+         (heap_object_request().kind() == HeapObjectRequest::kStringConstant &&
+          immediate_.rmode() == RelocInfo::EMBEDDED_OBJECT));
   return immediate_;
 }
 
diff --git a/deps/v8/src/arm64/assembler-arm64.cc b/deps/v8/src/arm64/assembler-arm64.cc
index d41b1a7d7f..eb581b472b 100644
--- a/deps/v8/src/arm64/assembler-arm64.cc
+++ b/deps/v8/src/arm64/assembler-arm64.cc
@@ -36,6 +36,7 @@
 #include "src/code-stubs.h"
 #include "src/frame-constants.h"
 #include "src/register-configuration.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -583,6 +584,7 @@ void Assembler::Reset() {
 }
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     switch (request.kind()) {
@@ -601,6 +603,13 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
                          request.code_stub()->GetCode());
         break;
       }
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        set_target_address_at(pc, 0 /* unused */,
+                              str->AllocateStringConstant(isolate).address());
+        break;
+      }
     }
   }
 }
@@ -1717,6 +1726,13 @@ Operand Operand::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.heap_object_request_.emplace(str);
+  DCHECK(result.IsHeapObjectRequest());
+  return result;
+}
+
 void Assembler::ldr(const CPURegister& rt, const Operand& operand) {
   if (operand.IsHeapObjectRequest()) {
     RequestHeapObject(operand.heap_object_request());
@@ -4751,14 +4767,6 @@ void Assembler::GrowBuffer() {
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data,
                                 ConstantPoolMode constant_pool_mode) {
-  // Non-relocatable constants should not end up in the literal pool.
-  DCHECK(!RelocInfo::IsNone(rmode));
-  if (options().disable_reloc_info_for_patching) return;
-
-  // We do not try to reuse pool constants.
-  RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
-  bool write_reloc_info = true;
-
   if ((rmode == RelocInfo::COMMENT) ||
       (rmode == RelocInfo::INTERNAL_REFERENCE) ||
       (rmode == RelocInfo::CONST_POOL) || (rmode == RelocInfo::VENEER_POOL) ||
@@ -4772,23 +4780,22 @@ void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data,
            RelocInfo::IsConstPool(rmode) || RelocInfo::IsVeneerPool(rmode));
     // These modes do not need an entry in the constant pool.
   } else if (constant_pool_mode == NEEDS_POOL_ENTRY) {
-    write_reloc_info = constpool_.RecordEntry(data, rmode);
+    bool new_constpool_entry = constpool_.RecordEntry(data, rmode);
     // Make sure the constant pool is not emitted in place of the next
     // instruction for which we just recorded relocation info.
     BlockConstPoolFor(1);
+    if (!new_constpool_entry) return;
   }
   // For modes that cannot use the constant pool, a different sequence of
   // instructions will be emitted by this function's caller.
 
-  if (write_reloc_info) {
-    // Don't record external references unless the heap will be serialized.
-    if (RelocInfo::IsOnlyForSerializer(rmode) &&
-        !options().record_reloc_info_for_serialization && !emit_debug_code()) {
-      return;
-    }
-    DCHECK_GE(buffer_space(), kMaxRelocSize);  // too late to grow buffer here
-    reloc_info_writer.Write(&rinfo);
-  }
+  if (!ShouldRecordRelocInfo(rmode)) return;
+
+  // We do not try to reuse pool constants.
+  RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
+
+  DCHECK_GE(buffer_space(), kMaxRelocSize);  // too late to grow buffer here
+  reloc_info_writer.Write(&rinfo);
 }
 
 void Assembler::near_jump(int offset, RelocInfo::Mode rmode) {
diff --git a/deps/v8/src/arm64/assembler-arm64.h b/deps/v8/src/arm64/assembler-arm64.h
index b42b80f9ca..0432708fd1 100644
--- a/deps/v8/src/arm64/assembler-arm64.h
+++ b/deps/v8/src/arm64/assembler-arm64.h
@@ -718,6 +718,7 @@ class Operand {
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Operand EmbeddedCode(CodeStub* stub);
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   inline bool IsHeapObjectRequest() const;
   inline HeapObjectRequest heap_object_request() const;
@@ -3624,8 +3625,7 @@ class PatchingAssembler : public Assembler {
   void PatchSubSp(uint32_t immediate);
 };
 
-
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBufferSpace();
diff --git a/deps/v8/src/arm64/code-stubs-arm64.cc b/deps/v8/src/arm64/code-stubs-arm64.cc
index 328983f42c..9b8114c9bf 100644
--- a/deps/v8/src/arm64/code-stubs-arm64.cc
+++ b/deps/v8/src/arm64/code-stubs-arm64.cc
@@ -124,7 +124,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
                     IsolateAddressId::kPendingExceptionAddress, isolate())));
   }
   __ Str(code_entry, MemOperand(x10));
-  __ LoadRoot(x0, Heap::kExceptionRootIndex);
+  __ LoadRoot(x0, RootIndex::kException);
   __ B(&exit);
 
   // Invoke: Link this frame into the handler chain.
@@ -434,8 +434,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   // Check if the function scheduled an exception.
   __ Mov(x5, ExternalReference::scheduled_exception_address(isolate));
   __ Ldr(x5, MemOperand(x5));
-  __ JumpIfNotRoot(x5, Heap::kTheHoleValueRootIndex,
-                   &promote_scheduled_exception);
+  __ JumpIfNotRoot(x5, RootIndex::kTheHoleValue, &promote_scheduled_exception);
 
   __ DropSlots(stack_space);
   __ Ret();
@@ -484,7 +483,7 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
 
   Register undef = x7;
-  __ LoadRoot(undef, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undef, RootIndex::kUndefinedValue);
 
   // Push new target, call data.
   __ Push(undef, call_data);
@@ -562,7 +561,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
                      name));
 
   __ Ldr(data, FieldMemOperand(callback, AccessorInfo::kDataOffset));
-  __ LoadRoot(undef, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undef, RootIndex::kUndefinedValue);
   __ Mov(isolate_address, ExternalReference::isolate_address(isolate()));
   __ Ldr(name, FieldMemOperand(callback, AccessorInfo::kNameOffset));
 
diff --git a/deps/v8/src/arm64/codegen-arm64.cc b/deps/v8/src/arm64/codegen-arm64.cc
index ad77033280..180e3f54b7 100644
--- a/deps/v8/src/arm64/codegen-arm64.cc
+++ b/deps/v8/src/arm64/codegen-arm64.cc
@@ -8,7 +8,6 @@
 #include "src/arm64/macro-assembler-arm64-inl.h"
 #include "src/arm64/simulator-arm64.h"
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 
 namespace v8 {
@@ -16,9 +15,7 @@ namespace internal {
 
 #define __ ACCESS_MASM(masm)
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
-  return nullptr;
-}
+UnaryMathFunction CreateSqrtFunction() { return nullptr; }
 
 #undef __
 
diff --git a/deps/v8/src/arm64/constants-arm64.h b/deps/v8/src/arm64/constants-arm64.h
index 389f4818d5..1d238e2d32 100644
--- a/deps/v8/src/arm64/constants-arm64.h
+++ b/deps/v8/src/arm64/constants-arm64.h
@@ -291,10 +291,8 @@ M_(FPCR, AHP_mask | DN_mask | FZ_mask | RMode_mask)
   const uint32_t Name##_mask = ((1 << Name##_width) - 1) << LowBit;
 #define DECLARE_INSTRUCTION_FIELDS_OFFSETS(Name, HighBit, LowBit, unused_1)    \
   DECLARE_FIELDS_OFFSETS(Name, HighBit, LowBit, unused_1, unused_2)
-#define NOTHING(A, B)
 INSTRUCTION_FIELDS_LIST(DECLARE_INSTRUCTION_FIELDS_OFFSETS)
 SYSTEM_REGISTER_FIELDS_LIST(DECLARE_FIELDS_OFFSETS, NOTHING)
-#undef NOTHING
 #undef DECLARE_FIELDS_OFFSETS
 #undef DECLARE_INSTRUCTION_FIELDS_OFFSETS
 
diff --git a/deps/v8/src/arm64/interface-descriptors-arm64.cc b/deps/v8/src/arm64/interface-descriptors-arm64.cc
index bb1c22aff5..905cc51a57 100644
--- a/deps/v8/src/arm64/interface-descriptors-arm64.cc
+++ b/deps/v8/src/arm64/interface-descriptors-arm64.cc
@@ -89,9 +89,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // x0 : number of arguments (on the stack, not including receiver)
   // x1 : the target to call
-  // x2 : arguments list (FixedArray)
   // x4 : arguments list length (untagged)
-  Register registers[] = {x1, x0, x2, x4};
+  // x2 : arguments list (FixedArray)
+  Register registers[] = {x1, x0, x4, x2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -126,9 +126,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // x0 : number of arguments (on the stack, not including receiver)
   // x1 : the target to call
   // x3 : the new target
-  // x2 : arguments list (FixedArray)
   // x4 : arguments list length (untagged)
-  Register registers[] = {x1, x3, x0, x2, x4};
+  // x2 : arguments list (FixedArray)
+  Register registers[] = {x1, x3, x0, x4, x2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -198,7 +198,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       x1,  // JSFunction
@@ -242,10 +242,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       x0,  // argument count (not including receiver)
-      x3,  // new target
+      x4,  // address of the first argument
       x1,  // constructor to call
+      x3,  // new target
       x2,  // allocation site feedback if available, undefined otherwise
-      x4   // address of the first argument
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/arm64/macro-assembler-arm64.cc b/deps/v8/src/arm64/macro-assembler-arm64.cc
index b15ab47473..97a75e5758 100644
--- a/deps/v8/src/arm64/macro-assembler-arm64.cc
+++ b/deps/v8/src/arm64/macro-assembler-arm64.cc
@@ -1516,7 +1516,7 @@ void TurboAssembler::CanonicalizeNaN(const VRegister& dst,
   Fsub(dst, src, fp_zero);
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
+void TurboAssembler::LoadRoot(Register destination, RootIndex index) {
   // TODO(jbramley): Most root values are constants, and can be synthesized
   // without a load. Refer to the ARM back end for details.
   Ldr(destination, MemOperand(kRootRegister, RootRegisterOffset(index)));
@@ -1646,7 +1646,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
     Register scratch = temps.AcquireX();
     Label done_checking;
     AssertNotSmi(object);
-    JumpIfRoot(object, Heap::kUndefinedValueRootIndex, &done_checking);
+    JumpIfRoot(object, RootIndex::kUndefinedValue, &done_checking);
     Ldr(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
     CompareInstanceType(scratch, scratch, ALLOCATION_SITE_TYPE);
     Assert(eq, AbortReason::kExpectedUndefinedOrCell);
@@ -1727,7 +1727,7 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
 }
 
 void MacroAssembler::JumpToInstructionStream(Address entry) {
-  Mov(kOffHeapTrampolineRegister, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
+  Ldr(kOffHeapTrampolineRegister, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
   Br(kOffHeapTrampolineRegister);
 }
 
@@ -1806,8 +1806,8 @@ void TurboAssembler::CallCFunction(Register function, int num_of_reg_args,
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+      RootIndex::kBuiltinsConstantsTable));
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   Ldr(destination,
       FieldMemOperand(destination,
                       FixedArray::kHeaderSize + constant_index * kPointerSize));
@@ -1905,7 +1905,7 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
         Register scratch = temps.AcquireX();
         EmbeddedData d = EmbeddedData::FromBlob();
         Address entry = d.InstructionStartOfBuiltin(builtin_index);
-        Mov(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
+        Ldr(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
         Jump(scratch, cond);
         return;
       }
@@ -1963,7 +1963,7 @@ void TurboAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode) {
         Register scratch = temps.AcquireX();
         EmbeddedData d = EmbeddedData::FromBlob();
         Address entry = d.InstructionStartOfBuiltin(builtin_index);
-        Mov(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
+        Ldr(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
         Call(scratch);
         return;
       }
@@ -2225,7 +2225,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(x3, Heap::kUndefinedValueRootIndex);
+    LoadRoot(x3, RootIndex::kUndefinedValue);
   }
 
   Label done;
@@ -2597,8 +2597,7 @@ void MacroAssembler::LoadElementsKindFromMap(Register result, Register map) {
   DecodeField<Map::ElementsKindBits>(result);
 }
 
-void MacroAssembler::CompareRoot(const Register& obj,
-                                 Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(const Register& obj, RootIndex index) {
   UseScratchRegisterScope temps(this);
   Register temp = temps.AcquireX();
   DCHECK(!AreAliased(obj, temp));
@@ -2606,17 +2605,13 @@ void MacroAssembler::CompareRoot(const Register& obj,
   Cmp(obj, temp);
 }
 
-
-void MacroAssembler::JumpIfRoot(const Register& obj,
-                                Heap::RootListIndex index,
+void MacroAssembler::JumpIfRoot(const Register& obj, RootIndex index,
                                 Label* if_equal) {
   CompareRoot(obj, index);
   B(eq, if_equal);
 }
 
-
-void MacroAssembler::JumpIfNotRoot(const Register& obj,
-                                   Heap::RootListIndex index,
+void MacroAssembler::JumpIfNotRoot(const Register& obj, RootIndex index,
                                    Label* if_not_equal) {
   CompareRoot(obj, index);
   B(ne, if_not_equal);
@@ -2823,8 +2818,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -2834,7 +2827,6 @@ void TurboAssembler::CallRecordWriteStub(
 
   Pop(slot_parameter, object_parameter);
 
-  Mov(isolate_parameter, ExternalReference::isolate_address(isolate()));
   Mov(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Mov(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -2915,8 +2907,7 @@ void TurboAssembler::AssertUnreachable(AbortReason reason) {
   if (emit_debug_code()) Abort(reason);
 }
 
-void MacroAssembler::AssertRegisterIsRoot(Register reg,
-                                          Heap::RootListIndex index,
+void MacroAssembler::AssertRegisterIsRoot(Register reg, RootIndex index,
                                           AbortReason reason) {
   if (emit_debug_code()) {
     CompareRoot(reg, index);
diff --git a/deps/v8/src/arm64/macro-assembler-arm64.h b/deps/v8/src/arm64/macro-assembler-arm64.h
index a2862748a6..8648ff0439 100644
--- a/deps/v8/src/arm64/macro-assembler-arm64.h
+++ b/deps/v8/src/arm64/macro-assembler-arm64.h
@@ -180,6 +180,9 @@ enum PreShiftImmMode {
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -1126,7 +1129,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 #undef DECLARE_FUNCTION
 
   // Load an object from the root table.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override;
+  void LoadRoot(Register destination, RootIndex index) override;
 
   inline void Ret(const Register& xn = lr);
 
@@ -1262,10 +1265,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -1821,17 +1828,13 @@ class MacroAssembler : public TurboAssembler {
   void LoadElementsKindFromMap(Register result, Register map);
 
   // Compare the object in a register to a value from the root list.
-  void CompareRoot(const Register& obj, Heap::RootListIndex index);
+  void CompareRoot(const Register& obj, RootIndex index);
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(const Register& obj,
-                  Heap::RootListIndex index,
-                  Label* if_equal);
+  void JumpIfRoot(const Register& obj, RootIndex index, Label* if_equal);
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(const Register& obj,
-                     Heap::RootListIndex index,
-                     Label* if_not_equal);
+  void JumpIfNotRoot(const Register& obj, RootIndex index, Label* if_not_equal);
 
   // Compare the contents of a register with an operand, and branch to true,
   // false or fall through, depending on condition.
@@ -1944,7 +1947,7 @@ class MacroAssembler : public TurboAssembler {
   // Debugging.
 
   void AssertRegisterIsRoot(
-      Register reg, Heap::RootListIndex index,
+      Register reg, RootIndex index,
       AbortReason reason = AbortReason::kRegisterDidNotMatchExpectedRoot);
 
   // Abort if the specified register contains the invalid color bit pattern.
@@ -2025,7 +2028,7 @@ class MacroAssembler : public TurboAssembler {
 // instructions. This scope prevents the MacroAssembler from being called and
 // literal pools from being emitted. It also asserts the number of instructions
 // emitted is what you specified when creating the scope.
-class InstructionAccurateScope BASE_EMBEDDED {
+class InstructionAccurateScope {
  public:
   explicit InstructionAccurateScope(TurboAssembler* tasm, size_t count = 0)
       : tasm_(tasm)
diff --git a/deps/v8/src/asmjs/asm-js.cc b/deps/v8/src/asmjs/asm-js.cc
index fd973c8a36..aea4c0a21b 100644
--- a/deps/v8/src/asmjs/asm-js.cc
+++ b/deps/v8/src/asmjs/asm-js.cc
@@ -391,7 +391,7 @@ MaybeHandle<Object> AsmJs::InstantiateAsmWasm(Isolate* isolate,
       return MaybeHandle<Object>();
     }
     memory->set_is_growable(false);
-    size_t size = NumberToSize(memory->byte_length());
+    size_t size = memory->byte_length();
     // Check the asm.js heap size against the valid limits.
     if (!IsValidAsmjsMemorySize(size)) {
       ReportInstantiationFailure(script, position, "Invalid heap size");
diff --git a/deps/v8/src/assembler.cc b/deps/v8/src/assembler.cc
index 0f216052f3..2037a0ec8f 100644
--- a/deps/v8/src/assembler.cc
+++ b/deps/v8/src/assembler.cc
@@ -44,10 +44,24 @@
 #include "src/simulator.h"  // For flushing instruction cache.
 #include "src/snapshot/serializer-common.h"
 #include "src/snapshot/snapshot.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
 
+AssemblerOptions AssemblerOptions::EnableV8AgnosticCode() const {
+  AssemblerOptions options = *this;
+  options.v8_agnostic_code = true;
+  options.record_reloc_info_for_serialization = false;
+  options.enable_root_array_delta_access = false;
+  // Inherit |enable_simulator_code| value.
+  options.isolate_independent_code = false;
+  options.inline_offheap_trampolines = false;
+  // Inherit |code_range_start| value.
+  // Inherit |use_pc_relative_calls_and_jumps| value.
+  return options;
+}
+
 AssemblerOptions AssemblerOptions::Default(
     Isolate* isolate, bool explicitly_support_serialization) {
   AssemblerOptions options;
@@ -61,9 +75,12 @@ AssemblerOptions AssemblerOptions::Default(
   options.enable_simulator_code = !serializer;
 #endif
   options.inline_offheap_trampolines = !serializer;
+
 #if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
-  options.code_range_start =
-      isolate->heap()->memory_allocator()->code_range()->start();
+  const base::AddressRegion& code_range =
+      isolate->heap()->memory_allocator()->code_range();
+  DCHECK_IMPLIES(code_range.begin() != kNullAddress, !code_range.is_empty());
+  options.code_range_start = code_range.begin();
 #endif
   return options;
 }
@@ -355,6 +372,13 @@ HeapObjectRequest::HeapObjectRequest(CodeStub* code_stub, int offset)
   DCHECK_NOT_NULL(value_.code_stub);
 }
 
+HeapObjectRequest::HeapObjectRequest(const StringConstantBase* string,
+                                     int offset)
+    : kind_(kStringConstant), offset_(offset) {
+  value_.string = string;
+  DCHECK_NOT_NULL(value_.string);
+}
+
 // Platform specific but identical code for all the platforms.
 
 void Assembler::RecordDeoptReason(DeoptimizeReason reason,
@@ -381,11 +405,13 @@ void Assembler::DataAlign(int m) {
 }
 
 void AssemblerBase::RequestHeapObject(HeapObjectRequest request) {
+  DCHECK(!options().v8_agnostic_code);
   request.set_offset(pc_offset());
   heap_object_requests_.push_front(request);
 }
 
 int AssemblerBase::AddCodeTarget(Handle<Code> target) {
+  DCHECK(!options().v8_agnostic_code);
   int current = static_cast<int>(code_targets_.size());
   if (current > 0 && !target.is_null() &&
       code_targets_.back().address() == target.address()) {
@@ -398,6 +424,7 @@ int AssemblerBase::AddCodeTarget(Handle<Code> target) {
 }
 
 Handle<Code> AssemblerBase::GetCodeTarget(intptr_t code_target_index) const {
+  DCHECK(!options().v8_agnostic_code);
   DCHECK_LE(0, code_target_index);
   DCHECK_LT(code_target_index, code_targets_.size());
   return code_targets_[code_target_index];
@@ -405,6 +432,7 @@ Handle<Code> AssemblerBase::GetCodeTarget(intptr_t code_target_index) const {
 
 void AssemblerBase::UpdateCodeTarget(intptr_t code_target_index,
                                      Handle<Code> code) {
+  DCHECK(!options().v8_agnostic_code);
   DCHECK_LE(0, code_target_index);
   DCHECK_LT(code_target_index, code_targets_.size());
   code_targets_[code_target_index] = code;
diff --git a/deps/v8/src/assembler.h b/deps/v8/src/assembler.h
index b108c5dfff..a2a1c73191 100644
--- a/deps/v8/src/assembler.h
+++ b/deps/v8/src/assembler.h
@@ -67,6 +67,7 @@ class Isolate;
 class SCTableReference;
 class SourcePosition;
 class StatsCounter;
+class StringConstantBase;
 
 // -----------------------------------------------------------------------------
 // Optimization for far-jmp like instructions that can be replaced by shorter.
@@ -97,8 +98,9 @@ class HeapObjectRequest {
  public:
   explicit HeapObjectRequest(double heap_number, int offset = -1);
   explicit HeapObjectRequest(CodeStub* code_stub, int offset = -1);
+  explicit HeapObjectRequest(const StringConstantBase* string, int offset = -1);
 
-  enum Kind { kHeapNumber, kCodeStub };
+  enum Kind { kHeapNumber, kCodeStub, kStringConstant };
   Kind kind() const { return kind_; }
 
   double heap_number() const {
@@ -111,6 +113,11 @@ class HeapObjectRequest {
     return value_.code_stub;
   }
 
+  const StringConstantBase* string() const {
+    DCHECK_EQ(kind(), kStringConstant);
+    return value_.string;
+  }
+
   // The code buffer offset at the time of the request.
   int offset() const {
     DCHECK_GE(offset_, 0);
@@ -128,6 +135,7 @@ class HeapObjectRequest {
   union {
     double heap_number;
     CodeStub* code_stub;
+    const StringConstantBase* string;
   } value_;
 
   int offset_;
@@ -139,6 +147,9 @@ class HeapObjectRequest {
 enum class CodeObjectRequired { kNo, kYes };
 
 struct V8_EXPORT_PRIVATE AssemblerOptions {
+  // Prohibits using any V8-specific features of assembler like (isolates,
+  // heap objects, external references, etc.).
+  bool v8_agnostic_code = false;
   // Recording reloc info for external references and off-heap targets is
   // needed whenever code is serialized, e.g. into the snapshot or as a WASM
   // module. This flag allows this reloc info to be disabled for code that
@@ -168,6 +179,9 @@ struct V8_EXPORT_PRIVATE AssemblerOptions {
   // the instruction immediates.
   bool use_pc_relative_calls_and_jumps = false;
 
+  // Constructs V8-agnostic set of options from current state.
+  AssemblerOptions EnableV8AgnosticCode() const;
+
   static AssemblerOptions Default(
       Isolate* isolate, bool explicitly_support_serialization = false);
 };
@@ -268,13 +282,23 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
     }
   }
 
-  // {RequestHeapObject} records the need for a future heap number allocation or
-  // code stub generation. After code assembly, each platform's
-  // {Assembler::AllocateAndInstallRequestedHeapObjects} will allocate these
-  // objects and place them where they are expected (determined by the pc offset
-  // associated with each request).
+  // {RequestHeapObject} records the need for a future heap number allocation,
+  // code stub generation or string allocation. After code assembly, each
+  // platform's {Assembler::AllocateAndInstallRequestedHeapObjects} will
+  // allocate these objects and place them where they are expected (determined
+  // by the pc offset associated with each request).
   void RequestHeapObject(HeapObjectRequest request);
 
+  bool ShouldRecordRelocInfo(RelocInfo::Mode rmode) const {
+    DCHECK(!RelocInfo::IsNone(rmode));
+    if (options().disable_reloc_info_for_patching) return false;
+    if (RelocInfo::IsOnlyForSerializer(rmode) &&
+        !options().record_reloc_info_for_serialization && !emit_debug_code()) {
+      return false;
+    }
+    return true;
+  }
+
  private:
   // Before we copy code into the code space, we sometimes cannot encode
   // call/jump code targets as we normally would, as the difference between the
@@ -301,7 +325,7 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
 };
 
 // Avoids emitting debug code during the lifetime of this scope object.
-class DontEmitDebugCodeScope BASE_EMBEDDED {
+class DontEmitDebugCodeScope {
  public:
   explicit DontEmitDebugCodeScope(AssemblerBase* assembler)
       : assembler_(assembler), old_value_(assembler->emit_debug_code()) {
@@ -332,7 +356,7 @@ class PredictableCodeSizeScope {
 
 
 // Enable a specified feature within a scope.
-class CpuFeatureScope BASE_EMBEDDED {
+class CpuFeatureScope {
  public:
   enum CheckPolicy {
     kCheckSupported,
@@ -350,12 +374,12 @@ class CpuFeatureScope BASE_EMBEDDED {
 #else
   CpuFeatureScope(AssemblerBase* assembler, CpuFeature f,
                   CheckPolicy check = kCheckSupported) {}
-  // Define a destructor to avoid unused variable warnings.
-  ~CpuFeatureScope() {}
+  ~CpuFeatureScope() {  // NOLINT (modernize-use-equals-default)
+    // Define a destructor to avoid unused variable warnings.
+  }
 #endif
 };
 
-
 // CpuFeatures keeps track of which features are supported by the target CPU.
 // Supported features must be enabled by a CpuFeatureScope before use.
 // Example:
@@ -420,7 +444,7 @@ class CpuFeatures : public AllStatic {
 // Utility functions
 
 // Computes pow(x, y) with the special cases in the spec for Math.pow.
-double power_helper(Isolate* isolate, double x, double y);
+double power_helper(double x, double y);
 double power_double_int(double x, int y);
 double power_double_double(double x, double y);
 
@@ -430,7 +454,7 @@ double power_double_double(double x, double y);
 
 class ConstantPoolEntry {
  public:
-  ConstantPoolEntry() {}
+  ConstantPoolEntry() = default;
   ConstantPoolEntry(int position, intptr_t value, bool sharing_ok,
                     RelocInfo::Mode rmode = RelocInfo::NONE)
       : position_(position),
@@ -447,7 +471,7 @@ class ConstantPoolEntry {
   int position() const { return position_; }
   bool sharing_ok() const { return merged_index_ != SHARING_PROHIBITED; }
   bool is_merged() const { return merged_index_ >= 0; }
-  int merged_index(void) const {
+  int merged_index() const {
     DCHECK(is_merged());
     return merged_index_;
   }
@@ -456,7 +480,7 @@ class ConstantPoolEntry {
     merged_index_ = index;
     DCHECK(is_merged());
   }
-  int offset(void) const {
+  int offset() const {
     DCHECK_GE(merged_index_, 0);
     return merged_index_;
   }
@@ -493,7 +517,7 @@ class ConstantPoolEntry {
 // -----------------------------------------------------------------------------
 // Embedded constant pool support
 
-class ConstantPoolBuilder BASE_EMBEDDED {
+class ConstantPoolBuilder {
  public:
   ConstantPoolBuilder(int ptr_reach_bits, int double_reach_bits);
 
diff --git a/deps/v8/src/assert-scope.h b/deps/v8/src/assert-scope.h
index acf7649792..b64f95dfa5 100644
--- a/deps/v8/src/assert-scope.h
+++ b/deps/v8/src/assert-scope.h
@@ -77,7 +77,9 @@ class PerThreadAssertScopeDebugOnly : public
 #else
 class PerThreadAssertScopeDebugOnly {
  public:
-  PerThreadAssertScopeDebugOnly() { }
+  PerThreadAssertScopeDebugOnly() {  // NOLINT (modernize-use-equals-default)
+    // Define a constructor to avoid unused variable warnings.
+  }
   void Release() {}
 #endif
 };
diff --git a/deps/v8/src/ast/ast-function-literal-id-reindexer.cc b/deps/v8/src/ast/ast-function-literal-id-reindexer.cc
index 5cb1e87d23..7e3a25890b 100644
--- a/deps/v8/src/ast/ast-function-literal-id-reindexer.cc
+++ b/deps/v8/src/ast/ast-function-literal-id-reindexer.cc
@@ -14,7 +14,7 @@ AstFunctionLiteralIdReindexer::AstFunctionLiteralIdReindexer(size_t stack_limit,
                                                              int delta)
     : AstTraversalVisitor(stack_limit), delta_(delta) {}
 
-AstFunctionLiteralIdReindexer::~AstFunctionLiteralIdReindexer() {}
+AstFunctionLiteralIdReindexer::~AstFunctionLiteralIdReindexer() = default;
 
 void AstFunctionLiteralIdReindexer::Reindex(Expression* pattern) {
   Visit(pattern);
diff --git a/deps/v8/src/ast/ast-source-ranges.h b/deps/v8/src/ast/ast-source-ranges.h
index cf7bab53da..60222a4035 100644
--- a/deps/v8/src/ast/ast-source-ranges.h
+++ b/deps/v8/src/ast/ast-source-ranges.h
@@ -21,8 +21,9 @@ struct SourceRange {
   static SourceRange OpenEnded(int32_t start) {
     return SourceRange(start, kNoSourcePosition);
   }
-  static SourceRange ContinuationOf(const SourceRange& that) {
-    return that.IsEmpty() ? Empty() : OpenEnded(that.end);
+  static SourceRange ContinuationOf(const SourceRange& that,
+                                    int end = kNoSourcePosition) {
+    return that.IsEmpty() ? Empty() : SourceRange(that.end, end);
   }
   int32_t start, end;
 };
@@ -56,7 +57,7 @@ enum class SourceRangeKind {
 
 class AstNodeSourceRanges : public ZoneObject {
  public:
-  virtual ~AstNodeSourceRanges() {}
+  virtual ~AstNodeSourceRanges() = default;
   virtual SourceRange GetRange(SourceRangeKind kind) = 0;
 };
 
@@ -65,7 +66,7 @@ class BinaryOperationSourceRanges final : public AstNodeSourceRanges {
   explicit BinaryOperationSourceRanges(const SourceRange& right_range)
       : right_range_(right_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     DCHECK_EQ(kind, SourceRangeKind::kRight);
     return right_range_;
   }
@@ -79,7 +80,7 @@ class ContinuationSourceRanges : public AstNodeSourceRanges {
   explicit ContinuationSourceRanges(int32_t continuation_position)
       : continuation_position_(continuation_position) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     DCHECK_EQ(kind, SourceRangeKind::kContinuation);
     return SourceRange::OpenEnded(continuation_position_);
   }
@@ -99,7 +100,7 @@ class CaseClauseSourceRanges final : public AstNodeSourceRanges {
   explicit CaseClauseSourceRanges(const SourceRange& body_range)
       : body_range_(body_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     DCHECK_EQ(kind, SourceRangeKind::kBody);
     return body_range_;
   }
@@ -114,7 +115,7 @@ class ConditionalSourceRanges final : public AstNodeSourceRanges {
                                    const SourceRange& else_range)
       : then_range_(then_range), else_range_(else_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     switch (kind) {
       case SourceRangeKind::kThen:
         return then_range_;
@@ -136,7 +137,7 @@ class IfStatementSourceRanges final : public AstNodeSourceRanges {
                                    const SourceRange& else_range)
       : then_range_(then_range), else_range_(else_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     switch (kind) {
       case SourceRangeKind::kElse:
         return else_range_;
@@ -162,7 +163,7 @@ class IterationStatementSourceRanges final : public AstNodeSourceRanges {
   explicit IterationStatementSourceRanges(const SourceRange& body_range)
       : body_range_(body_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     switch (kind) {
       case SourceRangeKind::kBody:
         return body_range_;
@@ -198,7 +199,7 @@ class NaryOperationSourceRanges final : public AstNodeSourceRanges {
   void AddRange(const SourceRange& range) { ranges_.push_back(range); }
   size_t RangeCount() const { return ranges_.size(); }
 
-  SourceRange GetRange(SourceRangeKind kind) { UNREACHABLE(); }
+  SourceRange GetRange(SourceRangeKind kind) override { UNREACHABLE(); }
 
  private:
   ZoneVector<SourceRange> ranges_;
@@ -227,7 +228,7 @@ class TryCatchStatementSourceRanges final : public AstNodeSourceRanges {
   explicit TryCatchStatementSourceRanges(const SourceRange& catch_range)
       : catch_range_(catch_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     switch (kind) {
       case SourceRangeKind::kCatch:
         return catch_range_;
@@ -247,7 +248,7 @@ class TryFinallyStatementSourceRanges final : public AstNodeSourceRanges {
   explicit TryFinallyStatementSourceRanges(const SourceRange& finally_range)
       : finally_range_(finally_range) {}
 
-  SourceRange GetRange(SourceRangeKind kind) {
+  SourceRange GetRange(SourceRangeKind kind) override {
     switch (kind) {
       case SourceRangeKind::kFinally:
         return finally_range_;
diff --git a/deps/v8/src/ast/ast-value-factory.cc b/deps/v8/src/ast/ast-value-factory.cc
index 8cf81b24a5..67ea77bfbf 100644
--- a/deps/v8/src/ast/ast-value-factory.cc
+++ b/deps/v8/src/ast/ast-value-factory.cc
@@ -242,6 +242,17 @@ const AstRawString* AstValueFactory::GetString(Handle<String> literal) {
   return result;
 }
 
+const AstRawString* AstValueFactory::CloneFromOtherFactory(
+    const AstRawString* raw_string) {
+  const AstRawString* result = GetString(
+      raw_string->hash_field(), raw_string->is_one_byte(),
+      Vector<const byte>(raw_string->raw_data(), raw_string->byte_length()));
+  // Check we weren't trying to clone a string that was already in this
+  // ast-value-factory.
+  DCHECK_NE(result, raw_string);
+  return result;
+}
+
 AstConsString* AstValueFactory::NewConsString() {
   AstConsString* new_string = new (zone_) AstConsString;
   DCHECK_NOT_NULL(new_string);
diff --git a/deps/v8/src/ast/ast-value-factory.h b/deps/v8/src/ast/ast-value-factory.h
index e85b0675bf..726d961362 100644
--- a/deps/v8/src/ast/ast-value-factory.h
+++ b/deps/v8/src/ast/ast-value-factory.h
@@ -194,48 +194,49 @@ class AstBigInt {
 };
 
 // For generating constants.
-#define AST_STRING_CONSTANTS(F)                                      \
-  F(anonymous_function, "(anonymous function)")                      \
-  F(arguments, "arguments")                                          \
-  F(async, "async")                                                  \
-  F(await, "await")                                                  \
-  F(bigint, "bigint")                                                \
-  F(boolean, "boolean")                                              \
-  F(constructor, "constructor")                                      \
-  F(default, "default")                                              \
-  F(done, "done")                                                    \
-  F(dot, ".")                                                        \
-  F(dot_for, ".for")                                                 \
-  F(dot_generator_object, ".generator_object")                       \
-  F(dot_iterator, ".iterator")                                       \
-  F(dot_result, ".result")                                           \
-  F(dot_switch_tag, ".switch_tag")                                   \
-  F(dot_catch, ".catch")                                             \
-  F(empty, "")                                                       \
-  F(eval, "eval")                                                    \
-  F(function, "function")                                            \
-  F(get_space, "get ")                                               \
-  F(length, "length")                                                \
-  F(let, "let")                                                      \
-  F(name, "name")                                                    \
-  F(native, "native")                                                \
-  F(new_target, ".new.target")                                       \
-  F(next, "next")                                                    \
-  F(number, "number")                                                \
-  F(object, "object")                                                \
-  F(proto, "__proto__")                                              \
-  F(prototype, "prototype")                                          \
-  F(return, "return")                                                \
-  F(set_space, "set ")                                               \
-  F(star_default_star, "*default*")                                  \
-  F(string, "string")                                                \
-  F(symbol, "symbol")                                                \
-  F(this, "this")                                                    \
-  F(this_function, ".this_function")                                 \
-  F(throw, "throw")                                                  \
-  F(undefined, "undefined")                                          \
-  F(use_asm, "use asm")                                              \
-  F(use_strict, "use strict")                                        \
+#define AST_STRING_CONSTANTS(F)                 \
+  F(anonymous_function, "(anonymous function)") \
+  F(arguments, "arguments")                     \
+  F(async, "async")                             \
+  F(await, "await")                             \
+  F(bigint, "bigint")                           \
+  F(boolean, "boolean")                         \
+  F(constructor, "constructor")                 \
+  F(default, "default")                         \
+  F(done, "done")                               \
+  F(dot, ".")                                   \
+  F(dot_for, ".for")                            \
+  F(dot_generator_object, ".generator_object")  \
+  F(dot_iterator, ".iterator")                  \
+  F(dot_promise, ".promise")                    \
+  F(dot_result, ".result")                      \
+  F(dot_switch_tag, ".switch_tag")              \
+  F(dot_catch, ".catch")                        \
+  F(empty, "")                                  \
+  F(eval, "eval")                               \
+  F(function, "function")                       \
+  F(get_space, "get ")                          \
+  F(length, "length")                           \
+  F(let, "let")                                 \
+  F(name, "name")                               \
+  F(native, "native")                           \
+  F(new_target, ".new.target")                  \
+  F(next, "next")                               \
+  F(number, "number")                           \
+  F(object, "object")                           \
+  F(proto, "__proto__")                         \
+  F(prototype, "prototype")                     \
+  F(return, "return")                           \
+  F(set_space, "set ")                          \
+  F(star_default_star, "*default*")             \
+  F(string, "string")                           \
+  F(symbol, "symbol")                           \
+  F(this, "this")                               \
+  F(this_function, ".this_function")            \
+  F(throw, "throw")                             \
+  F(undefined, "undefined")                     \
+  F(use_asm, "use asm")                         \
+  F(use_strict, "use strict")                   \
   F(value, "value")
 
 class AstStringConstants final {
@@ -297,10 +298,15 @@ class AstValueFactory {
     return GetTwoByteStringInternal(literal);
   }
   const AstRawString* GetString(Handle<String> literal);
+
+  // Clones an AstRawString from another ast value factory, adding it to this
+  // factory and returning the clone.
+  const AstRawString* CloneFromOtherFactory(const AstRawString* raw_string);
+
   V8_EXPORT_PRIVATE AstConsString* NewConsString();
-  AstConsString* NewConsString(const AstRawString* str);
-  AstConsString* NewConsString(const AstRawString* str1,
-                               const AstRawString* str2);
+  V8_EXPORT_PRIVATE AstConsString* NewConsString(const AstRawString* str);
+  V8_EXPORT_PRIVATE AstConsString* NewConsString(const AstRawString* str1,
+                                                 const AstRawString* str2);
 
   V8_EXPORT_PRIVATE void Internalize(Isolate* isolate);
 
diff --git a/deps/v8/src/ast/ast.cc b/deps/v8/src/ast/ast.cc
index 5a4add6039..617a26b937 100644
--- a/deps/v8/src/ast/ast.cc
+++ b/deps/v8/src/ast/ast.cc
@@ -551,12 +551,6 @@ bool ObjectLiteral::IsFastCloningSupported() const {
              ConstructorBuiltins::kMaximumClonedShallowObjectProperties;
 }
 
-bool ArrayLiteral::is_empty() const {
-  DCHECK(is_initialized());
-  return values()->is_empty() && (boilerplate_description().is_null() ||
-                                  boilerplate_description()->is_empty());
-}
-
 int ArrayLiteral::InitDepthAndFlags() {
   if (is_initialized()) return depth();
 
diff --git a/deps/v8/src/ast/ast.h b/deps/v8/src/ast/ast.h
index 6c1e989d30..6cc2cbc8ec 100644
--- a/deps/v8/src/ast/ast.h
+++ b/deps/v8/src/ast/ast.h
@@ -383,7 +383,7 @@ class DoExpression final : public Expression {
 
 class Declaration : public AstNode {
  public:
-  typedef ThreadedList<Declaration> List;
+  typedef base::ThreadedList<Declaration> List;
 
   VariableProxy* proxy() const { return proxy_; }
 
@@ -397,6 +397,7 @@ class Declaration : public AstNode {
   Declaration** next() { return &next_; }
   Declaration* next_;
   friend List;
+  friend base::ThreadedListTraits<Declaration>;
 };
 
 class VariableDeclaration : public Declaration {
@@ -1477,8 +1478,6 @@ class ArrayLiteral final : public AggregateLiteral {
 
   int first_spread_index() const { return first_spread_index_; }
 
-  bool is_empty() const;
-
   // Populate the depth field and flags, returns the depth.
   int InitDepthAndFlags();
 
@@ -1578,8 +1577,15 @@ class VariableProxy final : public Expression {
   // Bind this proxy to the variable var.
   void BindTo(Variable* var);
 
-  void set_next_unresolved(VariableProxy* next) { next_unresolved_ = next; }
-  VariableProxy* next_unresolved() { return next_unresolved_; }
+  V8_INLINE VariableProxy* next_unresolved() { return next_unresolved_; }
+
+  // Provides an access type for the ThreadedList used by the PreParsers
+  // expressions, lists, and formal parameters.
+  struct PreParserNext {
+    static VariableProxy** next(VariableProxy* t) {
+      return t->pre_parser_expr_next();
+    }
+  };
 
  private:
   friend class AstNodeFactory;
@@ -1590,7 +1596,8 @@ class VariableProxy final : public Expression {
                 int start_position)
       : Expression(start_position, kVariableProxy),
         raw_name_(name),
-        next_unresolved_(nullptr) {
+        next_unresolved_(nullptr),
+        pre_parser_expr_next_(nullptr) {
     bit_field_ |= IsThisField::encode(variable_kind == THIS_VARIABLE) |
                   IsAssignedField::encode(false) |
                   IsResolvedField::encode(false) |
@@ -1613,9 +1620,15 @@ class VariableProxy final : public Expression {
     const AstRawString* raw_name_;  // if !is_resolved_
     Variable* var_;                 // if is_resolved_
   };
+
+  V8_INLINE VariableProxy** next() { return &next_unresolved_; }
   VariableProxy* next_unresolved_;
-};
 
+  VariableProxy** pre_parser_expr_next() { return &pre_parser_expr_next_; }
+  VariableProxy* pre_parser_expr_next_;
+
+  friend base::ThreadedListTraits<VariableProxy>;
+};
 
 // Left-hand side can only be a property, a global or a (parameter or local)
 // slot.
@@ -2248,7 +2261,7 @@ class FunctionLiteral final : public Expression {
 
   void mark_as_iife() { bit_field_ = IIFEBit::update(bit_field_, true); }
   bool is_iife() const { return IIFEBit::decode(bit_field_); }
-  bool is_top_level() const {
+  bool is_toplevel() const {
     return function_literal_id() == FunctionLiteral::kIdTypeTopLevel;
   }
   bool is_wrapped() const { return function_type() == kWrapped; }
@@ -2308,7 +2321,7 @@ class FunctionLiteral final : public Expression {
   // - (function() { ... })();
   // - var x = function() { ... }();
   bool ShouldEagerCompile() const;
-  void SetShouldEagerCompile();
+  V8_EXPORT_PRIVATE void SetShouldEagerCompile();
 
   FunctionType function_type() const {
     return FunctionTypeBits::decode(bit_field_);
@@ -2736,7 +2749,7 @@ class TemplateLiteral final : public Expression {
 //   class SpecificVisitor : public AstVisitor<SpecificVisitor> { ... }
 
 template <class Subclass>
-class AstVisitor BASE_EMBEDDED {
+class AstVisitor {
  public:
   void Visit(AstNode* node) { impl()->Visit(node); }
 
@@ -2823,7 +2836,7 @@ class AstVisitor BASE_EMBEDDED {
 // ----------------------------------------------------------------------------
 // AstNode factory
 
-class AstNodeFactory final BASE_EMBEDDED {
+class AstNodeFactory final {
  public:
   AstNodeFactory(AstValueFactory* ast_value_factory, Zone* zone)
       : zone_(zone), ast_value_factory_(ast_value_factory) {}
@@ -3330,7 +3343,6 @@ class AstNodeFactory final BASE_EMBEDDED {
   }
 
   Zone* zone() const { return zone_; }
-  void set_zone(Zone* zone) { zone_ = zone; }
 
  private:
   // This zone may be deallocated upon returning from parsing a function body
diff --git a/deps/v8/src/ast/prettyprinter.cc b/deps/v8/src/ast/prettyprinter.cc
index d2e56a9335..f9c2243099 100644
--- a/deps/v8/src/ast/prettyprinter.cc
+++ b/deps/v8/src/ast/prettyprinter.cc
@@ -31,7 +31,7 @@ CallPrinter::CallPrinter(Isolate* isolate, bool is_user_js)
   InitializeAstVisitor(isolate);
 }
 
-CallPrinter::~CallPrinter() {}
+CallPrinter::~CallPrinter() = default;
 
 CallPrinter::ErrorHint CallPrinter::GetErrorHint() const {
   if (is_call_error_) {
@@ -666,7 +666,7 @@ void AstPrinter::PrintLiteral(const AstConsString* value, bool quote) {
 
 //-----------------------------------------------------------------------------
 
-class IndentedScope BASE_EMBEDDED {
+class IndentedScope {
  public:
   IndentedScope(AstPrinter* printer, const char* txt)
       : ast_printer_(printer) {
diff --git a/deps/v8/src/ast/scopes-inl.h b/deps/v8/src/ast/scopes-inl.h
new file mode 100644
index 0000000000..a70166c5ca
--- /dev/null
+++ b/deps/v8/src/ast/scopes-inl.h
@@ -0,0 +1,66 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_AST_SCOPES_INL_H_
+#define V8_AST_SCOPES_INL_H_
+
+#include "src/ast/scopes.h"
+
+namespace v8 {
+namespace internal {
+
+template <typename T>
+void Scope::ResolveScopesThenForEachVariable(DeclarationScope* max_outer_scope,
+                                             T variable_proxy_stackvisitor,
+                                             ParseInfo* info) {
+  // Module variables must be allocated before variable resolution
+  // to ensure that UpdateNeedsHoleCheck() can detect import variables.
+  if (info != nullptr && is_module_scope()) {
+    AsModuleScope()->AllocateModuleVariables();
+  }
+  // Lazy parsed declaration scopes are already partially analyzed. If there are
+  // unresolved references remaining, they just need to be resolved in outer
+  // scopes.
+  Scope* lookup =
+      is_declaration_scope() && AsDeclarationScope()->was_lazily_parsed()
+          ? outer_scope()
+          : this;
+
+  for (VariableProxy *proxy = unresolved_list_.first(), *next = nullptr;
+       proxy != nullptr; proxy = next) {
+    next = proxy->next_unresolved();
+
+    DCHECK(!proxy->is_resolved());
+    Variable* var =
+        lookup->LookupRecursive(info, proxy, max_outer_scope->outer_scope());
+    if (var == nullptr) {
+      variable_proxy_stackvisitor(proxy);
+    } else if (var != Scope::kDummyPreParserVariable &&
+               var != Scope::kDummyPreParserLexicalVariable) {
+      if (info != nullptr) {
+        // In this case we need to leave scopes in a way that they can be
+        // allocated. If we resolved variables from lazy parsed scopes, we need
+        // to context allocate the var.
+        ResolveTo(info, proxy, var);
+        if (!var->is_dynamic() && lookup != this) var->ForceContextAllocation();
+      } else {
+        var->set_is_used();
+        if (proxy->is_assigned()) var->set_maybe_assigned();
+      }
+    }
+  }
+
+  // Clear unresolved_list_ as it's in an inconsistent state.
+  unresolved_list_.Clear();
+
+  for (Scope* scope = inner_scope_; scope != nullptr; scope = scope->sibling_) {
+    scope->ResolveScopesThenForEachVariable(max_outer_scope,
+                                            variable_proxy_stackvisitor, info);
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_AST_SCOPES_INL_H_
diff --git a/deps/v8/src/ast/scopes.cc b/deps/v8/src/ast/scopes.cc
index 74d50c44de..e9fb195609 100644
--- a/deps/v8/src/ast/scopes.cc
+++ b/deps/v8/src/ast/scopes.cc
@@ -8,6 +8,7 @@
 
 #include "src/accessors.h"
 #include "src/ast/ast.h"
+#include "src/ast/scopes-inl.h"
 #include "src/base/optional.h"
 #include "src/bootstrapper.h"
 #include "src/counters.h"
@@ -23,15 +24,11 @@ namespace v8 {
 namespace internal {
 
 namespace {
-void* kDummyPreParserVariable = reinterpret_cast<void*>(0x1);
-void* kDummyPreParserLexicalVariable = reinterpret_cast<void*>(0x2);
-
 bool IsLexical(Variable* variable) {
-  if (variable == kDummyPreParserLexicalVariable) return true;
-  if (variable == kDummyPreParserVariable) return false;
+  if (variable == Scope::kDummyPreParserLexicalVariable) return true;
+  if (variable == Scope::kDummyPreParserVariable) return false;
   return IsLexicalVariableMode(variable->mode());
 }
-
 }  // namespace
 
 // ----------------------------------------------------------------------------
@@ -76,8 +73,9 @@ Variable* VariableMap::DeclareName(Zone* zone, const AstRawString* name,
   if (p->value == nullptr) {
     // The variable has not been declared yet -> insert it.
     DCHECK_EQ(name, p->key);
-    p->value = mode == VariableMode::kVar ? kDummyPreParserVariable
-                                          : kDummyPreParserLexicalVariable;
+    p->value = mode == VariableMode::kVar
+                   ? Scope::kDummyPreParserVariable
+                   : Scope::kDummyPreParserLexicalVariable;
   }
   return reinterpret_cast<Variable*>(p->value);
 }
@@ -154,7 +152,7 @@ Scope::Scope(Zone* zone, Scope* outer_scope, ScopeType scope_type)
 Scope::Snapshot::Snapshot(Scope* scope)
     : outer_scope_(scope),
       top_inner_scope_(scope->inner_scope_),
-      top_unresolved_(scope->unresolved_),
+      top_unresolved_(scope->unresolved_list_.first()),
       top_local_(scope->GetClosureScope()->locals_.end()),
       top_decl_(scope->GetClosureScope()->decls_.end()),
       outer_scope_calls_eval_(scope->scope_calls_eval_) {
@@ -310,6 +308,8 @@ void DeclarationScope::SetDefaults() {
   has_arguments_parameter_ = false;
   scope_uses_super_property_ = false;
   has_rest_ = false;
+  has_promise_ = false;
+  has_generator_object_ = false;
   sloppy_block_function_map_ = nullptr;
   receiver_ = nullptr;
   new_target_ = nullptr;
@@ -319,7 +319,7 @@ void DeclarationScope::SetDefaults() {
   should_eager_compile_ = false;
   was_lazily_parsed_ = false;
   is_skipped_function_ = false;
-  produced_preparsed_scope_data_ = nullptr;
+  preparsed_scope_data_builder_ = nullptr;
 #ifdef DEBUG
   DeclarationScope* outer_declaration_scope =
       outer_scope_ ? outer_scope_->GetDeclarationScope() : nullptr;
@@ -337,7 +337,7 @@ void Scope::SetDefaults() {
 #endif
   inner_scope_ = nullptr;
   sibling_ = nullptr;
-  unresolved_ = nullptr;
+  unresolved_list_.Clear();
 
   start_position_ = kNoSourcePosition;
   end_position_ = kNoSourcePosition;
@@ -779,6 +779,7 @@ Variable* DeclarationScope::DeclareGeneratorObjectVar(
   Variable* result = EnsureRareData()->generator_object =
       NewTemporary(name, kNotAssigned);
   result->set_is_used();
+  has_generator_object_ = true;
   return result;
 }
 
@@ -787,6 +788,7 @@ Variable* DeclarationScope::DeclarePromiseVar(const AstRawString* name) {
   DCHECK_NULL(promise_var());
   Variable* result = EnsureRareData()->promise = NewTemporary(name);
   result->set_is_used();
+  has_promise_ = true;
   return result;
 }
 
@@ -834,16 +836,9 @@ Scope* Scope::FinalizeBlockScope() {
   }
 
   // Move unresolved variables
-  if (unresolved_ != nullptr) {
-    if (outer_scope()->unresolved_ != nullptr) {
-      VariableProxy* unresolved = unresolved_;
-      while (unresolved->next_unresolved() != nullptr) {
-        unresolved = unresolved->next_unresolved();
-      }
-      unresolved->set_next_unresolved(outer_scope()->unresolved_);
-    }
-    outer_scope()->unresolved_ = unresolved_;
-    unresolved_ = nullptr;
+  if (!unresolved_list_.is_empty()) {
+    outer_scope()->unresolved_list_.Prepend(std::move(unresolved_list_));
+    unresolved_list_.Clear();
   }
 
   if (inner_scope_calls_eval_) outer_scope()->inner_scope_calls_eval_ = true;
@@ -887,7 +882,7 @@ void Scope::Snapshot::Reparent(DeclarationScope* new_parent) const {
   DCHECK_EQ(new_parent->outer_scope_, outer_scope_);
   DCHECK_EQ(new_parent, new_parent->GetClosureScope());
   DCHECK_NULL(new_parent->inner_scope_);
-  DCHECK_NULL(new_parent->unresolved_);
+  DCHECK(new_parent->unresolved_list_.is_empty());
   DCHECK(new_parent->locals_.is_empty());
   Scope* inner_scope = new_parent->sibling_;
   if (inner_scope != top_inner_scope_) {
@@ -910,14 +905,21 @@ void Scope::Snapshot::Reparent(DeclarationScope* new_parent) const {
     new_parent->sibling_ = top_inner_scope_;
   }
 
-  if (outer_scope_->unresolved_ != top_unresolved_) {
-    VariableProxy* last = outer_scope_->unresolved_;
-    while (last->next_unresolved() != top_unresolved_) {
-      last = last->next_unresolved();
+  if (outer_scope_->unresolved_list_.first() != top_unresolved_) {
+    // If the marked VariableProxy (snapshoted) is not the first, we need to
+    // find it and move all VariableProxys up to that point into the new_parent,
+    // then we restore the snapshoted state by reinitializing the outer_scope
+    // list.
+    {
+      auto iter = outer_scope_->unresolved_list_.begin();
+      while (*iter != top_unresolved_) {
+        ++iter;
+      }
+      outer_scope_->unresolved_list_.Rewind(iter);
     }
-    last->set_next_unresolved(nullptr);
-    new_parent->unresolved_ = outer_scope_->unresolved_;
-    outer_scope_->unresolved_ = top_unresolved_;
+
+    new_parent->unresolved_list_ = std::move(outer_scope_->unresolved_list_);
+    outer_scope_->unresolved_list_.ReinitializeHead(top_unresolved_);
   }
 
   // TODO(verwaest): This currently only moves do-expression declared variables
@@ -1261,8 +1263,7 @@ void Scope::DeclareCatchVariableName(const AstRawString* name) {
 void Scope::AddUnresolved(VariableProxy* proxy) {
   DCHECK(!already_resolved_);
   DCHECK(!proxy->is_resolved());
-  proxy->set_next_unresolved(unresolved_);
-  unresolved_ = proxy;
+  unresolved_list_.AddFront(proxy);
 }
 
 Variable* DeclarationScope::DeclareDynamicGlobal(const AstRawString* name,
@@ -1274,22 +1275,7 @@ Variable* DeclarationScope::DeclareDynamicGlobal(const AstRawString* name,
 }
 
 bool Scope::RemoveUnresolved(VariableProxy* var) {
-  if (unresolved_ == var) {
-    unresolved_ = var->next_unresolved();
-    var->set_next_unresolved(nullptr);
-    return true;
-  }
-  VariableProxy* current = unresolved_;
-  while (current != nullptr) {
-    VariableProxy* next = current->next_unresolved();
-    if (var == next) {
-      current->set_next_unresolved(next->next_unresolved());
-      var->set_next_unresolved(nullptr);
-      return true;
-    }
-    current = next;
-  }
-  return false;
+  return unresolved_list_.Remove(var);
 }
 
 Variable* Scope::NewTemporary(const AstRawString* name) {
@@ -1483,11 +1469,12 @@ Scope* Scope::GetOuterScopeWithContext() {
 
 Handle<StringSet> DeclarationScope::CollectNonLocals(
     Isolate* isolate, ParseInfo* info, Handle<StringSet> non_locals) {
-  VariableProxy* free_variables = FetchFreeVariables(this, info);
-  for (VariableProxy* proxy = free_variables; proxy != nullptr;
-       proxy = proxy->next_unresolved()) {
-    non_locals = StringSet::Add(isolate, non_locals, proxy->name());
-  }
+  ResolveScopesThenForEachVariable(this,
+                                   [=, &non_locals](VariableProxy* proxy) {
+                                     non_locals = StringSet::Add(
+                                         isolate, non_locals, proxy->name());
+                                   },
+                                   info);
   return non_locals;
 }
 
@@ -1504,10 +1491,15 @@ void DeclarationScope::ResetAfterPreparsing(AstValueFactory* ast_value_factory,
   decls_.Clear();
   locals_.Clear();
   inner_scope_ = nullptr;
-  unresolved_ = nullptr;
+  unresolved_list_.Clear();
   sloppy_block_function_map_ = nullptr;
   rare_data_ = nullptr;
   has_rest_ = false;
+  has_promise_ = false;
+  has_generator_object_ = false;
+
+  DCHECK_NE(zone_, ast_value_factory->zone());
+  zone_->ReleaseMemory();
 
   if (aborted) {
     // Prepare scope for use in the outer zone.
@@ -1532,7 +1524,7 @@ void DeclarationScope::ResetAfterPreparsing(AstValueFactory* ast_value_factory,
 
 void Scope::SavePreParsedScopeData() {
   DCHECK(FLAG_preparser_scope_analysis);
-  if (ProducedPreParsedScopeData::ScopeIsSkippableFunctionScope(this)) {
+  if (PreParsedScopeDataBuilder::ScopeIsSkippableFunctionScope(this)) {
     AsDeclarationScope()->SavePreParsedScopeDataForDeclarationScope();
   }
 
@@ -1542,30 +1534,33 @@ void Scope::SavePreParsedScopeData() {
 }
 
 void DeclarationScope::SavePreParsedScopeDataForDeclarationScope() {
-  if (produced_preparsed_scope_data_ != nullptr) {
+  if (preparsed_scope_data_builder_ != nullptr) {
     DCHECK(FLAG_preparser_scope_analysis);
-    produced_preparsed_scope_data_->SaveScopeAllocationData(this);
+    preparsed_scope_data_builder_->SaveScopeAllocationData(this);
   }
 }
 
 void DeclarationScope::AnalyzePartially(AstNodeFactory* ast_node_factory) {
   DCHECK(!force_eager_compilation_);
-  VariableProxy* unresolved = nullptr;
-
-  if (!outer_scope_->is_script_scope() ||
-      (FLAG_preparser_scope_analysis &&
-       produced_preparsed_scope_data_ != nullptr &&
-       produced_preparsed_scope_data_->ContainsInnerFunctions())) {
+  base::ThreadedList<VariableProxy> new_unresolved_list;
+  if (!IsArrowFunction(function_kind_) &&
+      (!outer_scope_->is_script_scope() ||
+       (FLAG_preparser_scope_analysis &&
+        preparsed_scope_data_builder_ != nullptr &&
+        preparsed_scope_data_builder_->ContainsInnerFunctions()))) {
     // Try to resolve unresolved variables for this Scope and migrate those
     // which cannot be resolved inside. It doesn't make sense to try to resolve
     // them in the outer Scopes here, because they are incomplete.
-    for (VariableProxy* proxy = FetchFreeVariables(this); proxy != nullptr;
-         proxy = proxy->next_unresolved()) {
-      DCHECK(!proxy->is_resolved());
-      VariableProxy* copy = ast_node_factory->CopyVariableProxy(proxy);
-      copy->set_next_unresolved(unresolved);
-      unresolved = copy;
-    }
+    ResolveScopesThenForEachVariable(
+        this, [=, &new_unresolved_list](VariableProxy* proxy) {
+          // Don't copy unresolved references to the script scope, unless it's a
+          // reference to a private field. In that case keep it so we can fail
+          // later.
+          if (!outer_scope_->is_script_scope() || proxy->is_private_field()) {
+            VariableProxy* copy = ast_node_factory->CopyVariableProxy(proxy);
+            new_unresolved_list.AddFront(copy);
+          }
+        });
 
     // Migrate function_ to the right Zone.
     if (function_ != nullptr) {
@@ -1586,7 +1581,7 @@ void DeclarationScope::AnalyzePartially(AstNodeFactory* ast_node_factory) {
 
   ResetAfterPreparsing(ast_node_factory->ast_value_factory(), false);
 
-  unresolved_ = unresolved;
+  unresolved_list_ = std::move(new_unresolved_list);
 }
 
 #ifdef DEBUG
@@ -1673,8 +1668,8 @@ void PrintMap(int indent, const char* label, VariableMap* map, bool locals,
   for (VariableMap::Entry* p = map->Start(); p != nullptr; p = map->Next(p)) {
     Variable* var = reinterpret_cast<Variable*>(p->value);
     if (var == function_var) continue;
-    if (var == kDummyPreParserVariable ||
-        var == kDummyPreParserLexicalVariable) {
+    if (var == Scope::kDummyPreParserVariable ||
+        var == Scope::kDummyPreParserLexicalVariable) {
       continue;
     }
     bool local = !IsDynamicVariableMode(var->mode());
@@ -2045,8 +2040,7 @@ bool Scope::ResolveVariablesRecursively(ParseInfo* info) {
   // scopes.
   if (is_declaration_scope() && AsDeclarationScope()->was_lazily_parsed()) {
     DCHECK_EQ(variables_.occupancy(), 0);
-    for (VariableProxy* proxy = unresolved_; proxy != nullptr;
-         proxy = proxy->next_unresolved()) {
+    for (VariableProxy* proxy : unresolved_list_) {
       Variable* var = outer_scope()->LookupRecursive(info, proxy, nullptr);
       if (var == nullptr) {
         DCHECK(proxy->is_private_field());
@@ -2060,8 +2054,7 @@ bool Scope::ResolveVariablesRecursively(ParseInfo* info) {
     }
   } else {
     // Resolve unresolved variables for this scope.
-    for (VariableProxy* proxy = unresolved_; proxy != nullptr;
-         proxy = proxy->next_unresolved()) {
+    for (VariableProxy* proxy : unresolved_list_) {
       if (!ResolveVariable(info, proxy)) return false;
     }
 
@@ -2074,57 +2067,6 @@ bool Scope::ResolveVariablesRecursively(ParseInfo* info) {
   return true;
 }
 
-VariableProxy* Scope::FetchFreeVariables(DeclarationScope* max_outer_scope,
-                                         ParseInfo* info,
-                                         VariableProxy* stack) {
-  // Module variables must be allocated before variable resolution
-  // to ensure that UpdateNeedsHoleCheck() can detect import variables.
-  if (info != nullptr && is_module_scope()) {
-    AsModuleScope()->AllocateModuleVariables();
-  }
-  // Lazy parsed declaration scopes are already partially analyzed. If there are
-  // unresolved references remaining, they just need to be resolved in outer
-  // scopes.
-  Scope* lookup =
-      is_declaration_scope() && AsDeclarationScope()->was_lazily_parsed()
-          ? outer_scope()
-          : this;
-  for (VariableProxy *proxy = unresolved_, *next = nullptr; proxy != nullptr;
-       proxy = next) {
-    next = proxy->next_unresolved();
-    DCHECK(!proxy->is_resolved());
-    Variable* var =
-        lookup->LookupRecursive(info, proxy, max_outer_scope->outer_scope());
-    if (var == nullptr) {
-      proxy->set_next_unresolved(stack);
-      stack = proxy;
-    } else if (var != kDummyPreParserVariable &&
-               var != kDummyPreParserLexicalVariable) {
-      if (info != nullptr) {
-        // In this case we need to leave scopes in a way that they can be
-        // allocated. If we resolved variables from lazy parsed scopes, we need
-        // to context allocate the var.
-        ResolveTo(info, proxy, var);
-        if (!var->is_dynamic() && lookup != this) var->ForceContextAllocation();
-      } else {
-        var->set_is_used();
-        if (proxy->is_assigned()) {
-          var->set_maybe_assigned();
-        }
-      }
-    }
-  }
-
-  // Clear unresolved_ as it's in an inconsistent state.
-  unresolved_ = nullptr;
-
-  for (Scope* scope = inner_scope_; scope != nullptr; scope = scope->sibling_) {
-    stack = scope->FetchFreeVariables(max_outer_scope, info, stack);
-  }
-
-  return stack;
-}
-
 bool Scope::MustAllocate(Variable* var) {
   if (var == kDummyPreParserLexicalVariable || var == kDummyPreParserVariable) {
     return true;
@@ -2236,6 +2178,24 @@ void DeclarationScope::AllocateReceiver() {
   AllocateParameter(receiver(), -1);
 }
 
+void DeclarationScope::AllocatePromise() {
+  if (!has_promise_) return;
+  DCHECK_NOT_NULL(promise_var());
+  DCHECK_EQ(this, promise_var()->scope());
+  AllocateStackSlot(promise_var());
+  DCHECK_EQ(VariableLocation::LOCAL, promise_var()->location());
+  DCHECK_EQ(kPromiseVarIndex, promise_var()->index());
+}
+
+void DeclarationScope::AllocateGeneratorObject() {
+  if (!has_generator_object_) return;
+  DCHECK_NOT_NULL(generator_object_var());
+  DCHECK_EQ(this, generator_object_var()->scope());
+  AllocateStackSlot(generator_object_var());
+  DCHECK_EQ(VariableLocation::LOCAL, generator_object_var()->location());
+  DCHECK_EQ(kGeneratorObjectVarIndex, generator_object_var()->index());
+}
+
 void Scope::AllocateNonParameterLocal(Variable* var) {
   DCHECK(var->scope() == this);
   if (var->IsUnallocated() && MustAllocate(var)) {
@@ -2304,6 +2264,19 @@ void Scope::AllocateVariablesRecursively() {
     return;
   }
 
+  // Make sure to allocate the .promise (for async functions) or
+  // .generator_object (for async generators) first, so that it
+  // get's the required stack slot 0 in case it's needed. See
+  // http://bit.ly/v8-zero-cost-async-stack-traces for details.
+  if (is_function_scope()) {
+    FunctionKind kind = GetClosureScope()->function_kind();
+    if (IsAsyncGeneratorFunction(kind)) {
+      AsDeclarationScope()->AllocateGeneratorObject();
+    } else if (IsAsyncFunction(kind)) {
+      AsDeclarationScope()->AllocatePromise();
+    }
+  }
+
   // Allocate variables for inner scopes.
   for (Scope* scope = inner_scope_; scope != nullptr; scope = scope->sibling_) {
     scope->AllocateVariablesRecursively();
@@ -2410,5 +2383,9 @@ int Scope::ContextLocalCount() const {
          (is_function_var_in_context ? 1 : 0);
 }
 
+void* const Scope::kDummyPreParserVariable = reinterpret_cast<void*>(0x1);
+void* const Scope::kDummyPreParserLexicalVariable =
+    reinterpret_cast<void*>(0x2);
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/ast/scopes.h b/deps/v8/src/ast/scopes.h
index f43761af58..0b88cc027c 100644
--- a/deps/v8/src/ast/scopes.h
+++ b/deps/v8/src/ast/scopes.h
@@ -20,8 +20,7 @@ class AstValueFactory;
 class AstRawString;
 class Declaration;
 class ParseInfo;
-class PreParsedScopeData;
-class ProducedPreParsedScopeData;
+class PreParsedScopeDataBuilder;
 class SloppyBlockFunctionStatement;
 class Statement;
 class StringSet;
@@ -103,7 +102,6 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   void SetScopeName(const AstRawString* scope_name) {
     scope_name_ = scope_name;
   }
-  void set_needs_migration() { needs_migration_ = true; }
 #endif
 
   // TODO(verwaest): Is this needed on Scope?
@@ -114,7 +112,7 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   ModuleScope* AsModuleScope();
   const ModuleScope* AsModuleScope() const;
 
-  class Snapshot final BASE_EMBEDDED {
+  class Snapshot final {
    public:
     explicit Snapshot(Scope* scope);
     ~Snapshot();
@@ -125,8 +123,8 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
     Scope* outer_scope_;
     Scope* top_inner_scope_;
     VariableProxy* top_unresolved_;
-    ThreadedList<Variable>::Iterator top_local_;
-    ThreadedList<Declaration>::Iterator top_decl_;
+    base::ThreadedList<Variable>::Iterator top_local_;
+    base::ThreadedList<Declaration>::Iterator top_decl_;
     const bool outer_scope_calls_eval_;
   };
 
@@ -203,9 +201,9 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   void DeclareCatchVariableName(const AstRawString* name);
 
   // Declarations list.
-  ThreadedList<Declaration>* declarations() { return &decls_; }
+  base::ThreadedList<Declaration>* declarations() { return &decls_; }
 
-  ThreadedList<Variable>* locals() { return &locals_; }
+  base::ThreadedList<Variable>* locals() { return &locals_; }
 
   // Create a new unresolved variable.
   VariableProxy* NewUnresolved(AstNodeFactory* factory,
@@ -218,8 +216,7 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
     DCHECK(!already_resolved_);
     DCHECK_EQ(factory->zone(), zone());
     VariableProxy* proxy = factory->NewVariableProxy(name, kind, start_pos);
-    proxy->set_next_unresolved(unresolved_);
-    unresolved_ = proxy;
+    AddUnresolved(proxy);
     return proxy;
   }
 
@@ -480,6 +477,9 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
     return false;
   }
 
+  static void* const kDummyPreParserVariable;
+  static void* const kDummyPreParserLexicalVariable;
+
  protected:
   explicit Scope(Zone* zone);
 
@@ -522,12 +522,12 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   VariableMap variables_;
   // In case of non-scopeinfo-backed scopes, this contains the variables of the
   // map above in order of addition.
-  ThreadedList<Variable> locals_;
+  base::ThreadedList<Variable> locals_;
   // Unresolved variables referred to from this scope. The proxies themselves
   // form a linked list of all unresolved proxies.
-  VariableProxy* unresolved_;
+  base::ThreadedList<VariableProxy> unresolved_list_;
   // Declarations.
-  ThreadedList<Declaration> decls_;
+  base::ThreadedList<Declaration> decls_;
 
   // Serialized scope info support.
   Handle<ScopeInfo> scope_info_;
@@ -597,9 +597,10 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   // Finds free variables of this scope. This mutates the unresolved variables
   // list along the way, so full resolution cannot be done afterwards.
   // If a ParseInfo* is passed, non-free variables will be resolved.
-  VariableProxy* FetchFreeVariables(DeclarationScope* max_outer_scope,
-                                    ParseInfo* info = nullptr,
-                                    VariableProxy* stack = nullptr);
+  template <typename T>
+  void ResolveScopesThenForEachVariable(DeclarationScope* max_outer_scope,
+                                        T variable_proxy_stackvisitor,
+                                        ParseInfo* info = nullptr);
 
   // Predicates.
   bool MustAllocate(Variable* var);
@@ -682,6 +683,12 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
   }
   bool is_being_lazily_parsed() const { return is_being_lazily_parsed_; }
 #endif
+  void set_zone(Zone* zone) {
+#ifdef DEBUG
+    needs_migration_ = true;
+#endif
+    zone_ = zone;
+  }
 
   bool ShouldEagerCompile() const;
   void set_should_eager_compile();
@@ -759,11 +766,22 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
   // literals, or nullptr.  Only valid for function scopes.
   Variable* function_var() const { return function_; }
 
+  // The variable holding the JSGeneratorObject for generator, async
+  // and async generator functions, and modules. Only valid for
+  // function and module scopes.
   Variable* generator_object_var() const {
     DCHECK(is_function_scope() || is_module_scope());
     return GetRareVariable(RareVariable::kGeneratorObject);
   }
 
+  // For async generators, the .generator_object variable is always
+  // allocated to a fixed stack slot, such that the stack trace
+  // construction logic can access it.
+  static constexpr int kGeneratorObjectVarIndex = 0;
+
+  // The variable holding the promise returned from async functions.
+  // Only valid for function scopes in async functions (i.e. not
+  // for async generators).
   Variable* promise_var() const {
     DCHECK(is_function_scope());
     DCHECK(IsAsyncFunction(function_kind_));
@@ -771,6 +789,11 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
     return GetRareVariable(RareVariable::kPromise);
   }
 
+  // For async functions, the .promise variable is always allocated
+  // to a fixed stack slot, such that the stack trace construction
+  // logic can access it.
+  static constexpr int kPromiseVarIndex = 0;
+
   // Parameters. The left-most parameter has index 0.
   // Only valid for function and module scopes.
   Variable* parameter(int index) const {
@@ -898,6 +921,8 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
   void AllocateLocals();
   void AllocateParameterLocals();
   void AllocateReceiver();
+  void AllocatePromise();
+  void AllocateGeneratorObject();
 
   void ResetAfterPreparsing(AstValueFactory* ast_value_factory, bool aborted);
 
@@ -919,13 +944,13 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
   // saved in produced_preparsed_scope_data_.
   void SavePreParsedScopeDataForDeclarationScope();
 
-  void set_produced_preparsed_scope_data(
-      ProducedPreParsedScopeData* produced_preparsed_scope_data) {
-    produced_preparsed_scope_data_ = produced_preparsed_scope_data;
+  void set_preparsed_scope_data_builder(
+      PreParsedScopeDataBuilder* preparsed_scope_data_builder) {
+    preparsed_scope_data_builder_ = preparsed_scope_data_builder;
   }
 
-  ProducedPreParsedScopeData* produced_preparsed_scope_data() const {
-    return produced_preparsed_scope_data_;
+  PreParsedScopeDataBuilder* preparsed_scope_data_builder() const {
+    return preparsed_scope_data_builder_;
   }
 
  private:
@@ -954,6 +979,10 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
   bool force_eager_compilation_ : 1;
   // This function scope has a rest parameter.
   bool has_rest_ : 1;
+  // This function scope has a .promise variable.
+  bool has_promise_ : 1;
+  // This function scope has a .generator_object variable.
+  bool has_generator_object_ : 1;
   // This scope has a parameter called "arguments".
   bool has_arguments_parameter_ : 1;
   // This scope uses "super" property ('super.foo').
@@ -981,7 +1010,7 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
   Variable* arguments_;
 
   // For producing the scope allocation data during preparsing.
-  ProducedPreParsedScopeData* produced_preparsed_scope_data_;
+  PreParsedScopeDataBuilder* preparsed_scope_data_builder_;
 
   struct RareData : public ZoneObject {
     // Convenience variable; Subclass constructor only
diff --git a/deps/v8/src/ast/variables.h b/deps/v8/src/ast/variables.h
index 10ac5c48a5..d33062973b 100644
--- a/deps/v8/src/ast/variables.h
+++ b/deps/v8/src/ast/variables.h
@@ -181,7 +181,7 @@ class Variable final : public ZoneObject {
                                       : kNeedsInitialization;
   }
 
-  typedef ThreadedList<Variable> List;
+  typedef base::ThreadedList<Variable> List;
 
  private:
   Scope* scope_;
@@ -215,6 +215,7 @@ class Variable final : public ZoneObject {
                           ForceHoleInitializationField::kNext, 1> {};
   Variable** next() { return &next_; }
   friend List;
+  friend base::ThreadedListTraits<Variable>;
 };
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/base/address-region.h b/deps/v8/src/base/address-region.h
new file mode 100644
index 0000000000..6b733cfe4d
--- /dev/null
+++ b/deps/v8/src/base/address-region.h
@@ -0,0 +1,70 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_ADDRESS_REGION_H_
+#define V8_BASE_ADDRESS_REGION_H_
+
+#include <iostream>
+
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace base {
+
+// Helper class representing an address region of certain size.
+class AddressRegion {
+ public:
+  typedef uintptr_t Address;
+
+  AddressRegion() = default;
+
+  AddressRegion(Address address, size_t size)
+      : address_(address), size_(size) {}
+
+  Address begin() const { return address_; }
+  Address end() const { return address_ + size_; }
+
+  size_t size() const { return size_; }
+  void set_size(size_t size) { size_ = size; }
+
+  bool is_empty() const { return size_ == 0; }
+
+  bool contains(Address address) const {
+    STATIC_ASSERT(std::is_unsigned<Address>::value);
+    return (address - begin()) < size();
+  }
+
+  bool contains(Address address, size_t size) const {
+    STATIC_ASSERT(std::is_unsigned<Address>::value);
+    Address offset = address - begin();
+    return (offset < size_) && (offset + size <= size_);
+  }
+
+  bool contains(AddressRegion region) const {
+    return contains(region.address_, region.size_);
+  }
+
+  bool operator==(AddressRegion other) const {
+    return address_ == other.address_ && size_ == other.size_;
+  }
+
+  bool operator!=(AddressRegion other) const {
+    return address_ != other.address_ || size_ != other.size_;
+  }
+
+ private:
+  Address address_ = 0;
+  size_t size_ = 0;
+};
+ASSERT_TRIVIALLY_COPYABLE(AddressRegion);
+
+inline std::ostream& operator<<(std::ostream& out, AddressRegion region) {
+  return out << "[" << reinterpret_cast<void*>(region.begin()) << "+"
+             << region.size() << "]";
+}
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_ADDRESS_REGION_H_
diff --git a/deps/v8/src/base/atomic-utils.h b/deps/v8/src/base/atomic-utils.h
index d81c537e57..90681b8a35 100644
--- a/deps/v8/src/base/atomic-utils.h
+++ b/deps/v8/src/base/atomic-utils.h
@@ -377,6 +377,22 @@ class AtomicElement {
   T value_;
 };
 
+template <typename T,
+          typename = typename std::enable_if<std::is_unsigned<T>::value>::type>
+inline void CheckedIncrement(std::atomic<T>* number, T amount) {
+  const T old = number->fetch_add(amount);
+  DCHECK_GE(old + amount, old);
+  USE(old);
+}
+
+template <typename T,
+          typename = typename std::enable_if<std::is_unsigned<T>::value>::type>
+inline void CheckedDecrement(std::atomic<T>* number, T amount) {
+  const T old = number->fetch_sub(amount);
+  DCHECK_GE(old, amount);
+  USE(old);
+}
+
 }  // namespace base
 }  // namespace v8
 
diff --git a/deps/v8/src/base/bits.h b/deps/v8/src/base/bits.h
index 731a7181d7..147a1730b2 100644
--- a/deps/v8/src/base/bits.h
+++ b/deps/v8/src/base/bits.h
@@ -146,6 +146,14 @@ constexpr inline bool IsPowerOfTwo(T value) {
 V8_BASE_EXPORT uint32_t RoundUpToPowerOfTwo32(uint32_t value);
 // Same for 64 bit integers. |value| must be <= 2^63
 V8_BASE_EXPORT uint64_t RoundUpToPowerOfTwo64(uint64_t value);
+// Same for size_t integers.
+inline size_t RoundUpToPowerOfTwo(size_t value) {
+  if (sizeof(size_t) == sizeof(uint64_t)) {
+    return RoundUpToPowerOfTwo64(value);
+  } else {
+    return RoundUpToPowerOfTwo32(value);
+  }
+}
 
 // RoundDownToPowerOfTwo32(value) returns the greatest power of two which is
 // less than or equal to |value|. If you pass in a |value| that is already a
diff --git a/deps/v8/src/base/bounded-page-allocator.cc b/deps/v8/src/base/bounded-page-allocator.cc
new file mode 100644
index 0000000000..ca9dde25f7
--- /dev/null
+++ b/deps/v8/src/base/bounded-page-allocator.cc
@@ -0,0 +1,101 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/base/bounded-page-allocator.h"
+
+namespace v8 {
+namespace base {
+
+BoundedPageAllocator::BoundedPageAllocator(v8::PageAllocator* page_allocator,
+                                           Address start, size_t size,
+                                           size_t allocate_page_size)
+    : allocate_page_size_(allocate_page_size),
+      commit_page_size_(page_allocator->CommitPageSize()),
+      page_allocator_(page_allocator),
+      region_allocator_(start, size, allocate_page_size_) {
+  CHECK_NOT_NULL(page_allocator);
+  CHECK(IsAligned(allocate_page_size, page_allocator->AllocatePageSize()));
+  CHECK(IsAligned(allocate_page_size_, commit_page_size_));
+}
+
+BoundedPageAllocator::Address BoundedPageAllocator::begin() const {
+  return region_allocator_.begin();
+}
+
+size_t BoundedPageAllocator::size() const { return region_allocator_.size(); }
+
+void* BoundedPageAllocator::AllocatePages(void* hint, size_t size,
+                                          size_t alignment,
+                                          PageAllocator::Permission access) {
+  LockGuard<Mutex> guard(&mutex_);
+  CHECK(IsAligned(alignment, region_allocator_.page_size()));
+
+  // Region allocator does not support alignments bigger than it's own
+  // allocation alignment.
+  CHECK_LE(alignment, allocate_page_size_);
+
+  // TODO(ishell): Consider using randomized version here.
+  Address address = region_allocator_.AllocateRegion(size);
+  if (address == RegionAllocator::kAllocationFailure) {
+    return nullptr;
+  }
+  CHECK(page_allocator_->SetPermissions(reinterpret_cast<void*>(address), size,
+                                        access));
+  return reinterpret_cast<void*>(address);
+}
+
+bool BoundedPageAllocator::FreePages(void* raw_address, size_t size) {
+  LockGuard<Mutex> guard(&mutex_);
+
+  Address address = reinterpret_cast<Address>(raw_address);
+  size_t freed_size = region_allocator_.FreeRegion(address);
+  if (freed_size != size) return false;
+  CHECK(page_allocator_->SetPermissions(raw_address, size,
+                                        PageAllocator::kNoAccess));
+  return true;
+}
+
+bool BoundedPageAllocator::ReleasePages(void* raw_address, size_t size,
+                                        size_t new_size) {
+  Address address = reinterpret_cast<Address>(raw_address);
+  CHECK(IsAligned(address, allocate_page_size_));
+
+  DCHECK_LT(new_size, size);
+  DCHECK(IsAligned(size - new_size, commit_page_size_));
+
+  // Check if we freed any allocatable pages by this release.
+  size_t allocated_size = RoundUp(size, allocate_page_size_);
+  size_t new_allocated_size = RoundUp(new_size, allocate_page_size_);
+
+#ifdef DEBUG
+  {
+    // There must be an allocated region at given |address| of a size not
+    // smaller than |size|.
+    LockGuard<Mutex> guard(&mutex_);
+    CHECK_EQ(allocated_size, region_allocator_.CheckRegion(address));
+  }
+#endif
+
+  if (new_allocated_size < allocated_size) {
+    LockGuard<Mutex> guard(&mutex_);
+    region_allocator_.TrimRegion(address, new_allocated_size);
+  }
+
+  // Keep the region in "used" state just uncommit some pages.
+  Address free_address = address + new_size;
+  size_t free_size = size - new_size;
+  return page_allocator_->SetPermissions(reinterpret_cast<void*>(free_address),
+                                         free_size, PageAllocator::kNoAccess);
+}
+
+bool BoundedPageAllocator::SetPermissions(void* address, size_t size,
+                                          PageAllocator::Permission access) {
+  DCHECK(IsAligned(reinterpret_cast<Address>(address), commit_page_size_));
+  DCHECK(IsAligned(size, commit_page_size_));
+  DCHECK(region_allocator_.contains(reinterpret_cast<Address>(address), size));
+  return page_allocator_->SetPermissions(address, size, access);
+}
+
+}  // namespace base
+}  // namespace v8
diff --git a/deps/v8/src/base/bounded-page-allocator.h b/deps/v8/src/base/bounded-page-allocator.h
new file mode 100644
index 0000000000..e3d928618b
--- /dev/null
+++ b/deps/v8/src/base/bounded-page-allocator.h
@@ -0,0 +1,79 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_BOUNDED_PAGE_ALLOCATOR_H_
+#define V8_BASE_BOUNDED_PAGE_ALLOCATOR_H_
+
+#include "include/v8-platform.h"
+#include "src/base/platform/mutex.h"
+#include "src/base/region-allocator.h"
+
+namespace v8 {
+namespace base {
+
+// This is a v8::PageAllocator implementation that allocates pages within the
+// pre-reserved region of virtual space. This class requires the virtual space
+// to be kept reserved during the lifetime of this object.
+// The main application of bounded page allocator are
+//  - V8 heap pointer compression which requires the whole V8 heap to be
+//    allocated within a contiguous range of virtual address space,
+//  - executable page allocation, which allows to use PC-relative 32-bit code
+//    displacement on certain 64-bit platforms.
+// Bounded page allocator uses other page allocator instance for doing actual
+// page allocations.
+// The implementation is thread-safe.
+class V8_BASE_EXPORT BoundedPageAllocator : public v8::PageAllocator {
+ public:
+  typedef uintptr_t Address;
+
+  BoundedPageAllocator(v8::PageAllocator* page_allocator, Address start,
+                       size_t size, size_t allocate_page_size);
+  ~BoundedPageAllocator() override = default;
+
+  // These functions are not inlined to avoid https://crbug.com/v8/8275.
+  Address begin() const;
+  size_t size() const;
+
+  // Returns true if given address is in the range controlled by the bounded
+  // page allocator instance.
+  bool contains(Address address) const {
+    return region_allocator_.contains(address);
+  }
+
+  size_t AllocatePageSize() override { return allocate_page_size_; }
+
+  size_t CommitPageSize() override { return commit_page_size_; }
+
+  void SetRandomMmapSeed(int64_t seed) override {
+    page_allocator_->SetRandomMmapSeed(seed);
+  }
+
+  void* GetRandomMmapAddr() override {
+    return page_allocator_->GetRandomMmapAddr();
+  }
+
+  void* AllocatePages(void* address, size_t size, size_t alignment,
+                      PageAllocator::Permission access) override;
+
+  bool FreePages(void* address, size_t size) override;
+
+  bool ReleasePages(void* address, size_t size, size_t new_size) override;
+
+  bool SetPermissions(void* address, size_t size,
+                      PageAllocator::Permission access) override;
+
+ private:
+  v8::base::Mutex mutex_;
+  const size_t allocate_page_size_;
+  const size_t commit_page_size_;
+  v8::PageAllocator* const page_allocator_;
+  v8::base::RegionAllocator region_allocator_;
+
+  DISALLOW_COPY_AND_ASSIGN(BoundedPageAllocator);
+};
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_BOUNDED_PAGE_ALLOCATOR_H_
diff --git a/deps/v8/src/base/build_config.h b/deps/v8/src/base/build_config.h
index df0d1110a5..695e67a618 100644
--- a/deps/v8/src/base/build_config.h
+++ b/deps/v8/src/base/build_config.h
@@ -196,9 +196,9 @@
 #endif
 
 #if defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_X64)
-#define V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK 1
+#define V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK true
 #else
-#define V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK 0
+#define V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK false
 #endif
 
 // Number of bits to represent the page size for paged spaces. The value of 19
diff --git a/deps/v8/src/base/debug/stack_trace.cc b/deps/v8/src/base/debug/stack_trace.cc
index 2a3fb87a19..cbf00ad17c 100644
--- a/deps/v8/src/base/debug/stack_trace.cc
+++ b/deps/v8/src/base/debug/stack_trace.cc
@@ -21,7 +21,7 @@ StackTrace::StackTrace(const void* const* trace, size_t count) {
   count_ = count;
 }
 
-StackTrace::~StackTrace() {}
+StackTrace::~StackTrace() = default;
 
 const void* const* StackTrace::Addresses(size_t* count) const {
   *count = count_;
diff --git a/deps/v8/src/base/debug/stack_trace_posix.cc b/deps/v8/src/base/debug/stack_trace_posix.cc
index 51b821bdd1..ed602af547 100644
--- a/deps/v8/src/base/debug/stack_trace_posix.cc
+++ b/deps/v8/src/base/debug/stack_trace_posix.cc
@@ -61,7 +61,7 @@ char* itoa_r(intptr_t i, char* buf, size_t sz, int base, size_t padding);
 namespace {
 
 volatile sig_atomic_t in_signal_handler = 0;
-bool dump_stack_in_signal_handler = 1;
+bool dump_stack_in_signal_handler = true;
 
 // The prefix used for mangled symbols, per the Itanium C++ ABI:
 // http://www.codesourcery.com/cxx-abi/abi.html#mangling
@@ -104,7 +104,7 @@ void DemangleSymbols(std::string* text) {
     // Try to demangle the mangled symbol candidate.
     int status = 0;
     std::unique_ptr<char, FreeDeleter> demangled_symbol(
-        abi::__cxa_demangle(mangled_symbol.c_str(), nullptr, 0, &status));
+        abi::__cxa_demangle(mangled_symbol.c_str(), nullptr, nullptr, &status));
     if (status == 0) {  // Demangling is successful.
       // Remove the mangled symbol.
       text->erase(mangled_start, mangled_end - mangled_start);
@@ -125,7 +125,7 @@ class BacktraceOutputHandler {
   virtual void HandleOutput(const char* output) = 0;
 
  protected:
-  virtual ~BacktraceOutputHandler() {}
+  virtual ~BacktraceOutputHandler() = default;
 };
 
 #if HAVE_EXECINFO_H
@@ -266,7 +266,7 @@ void StackDumpSignalHandler(int signal, siginfo_t* info, void* void_context) {
 
 class PrintBacktraceOutputHandler : public BacktraceOutputHandler {
  public:
-  PrintBacktraceOutputHandler() {}
+  PrintBacktraceOutputHandler() = default;
 
   void HandleOutput(const char* output) override {
     // NOTE: This code MUST be async-signal safe (it's used by in-process
diff --git a/deps/v8/src/base/debug/stack_trace_win.cc b/deps/v8/src/base/debug/stack_trace_win.cc
index 3fe66d97ad..6b22131233 100644
--- a/deps/v8/src/base/debug/stack_trace_win.cc
+++ b/deps/v8/src/base/debug/stack_trace_win.cc
@@ -7,13 +7,6 @@
 
 #include "src/base/debug/stack_trace.h"
 
-// This file can't use "src/base/win32-headers.h" because it defines symbols
-// that lead to compilation errors. But `NOMINMAX` should be defined to disable
-// defining of the `min` and `max` MACROS.
-#ifndef NOMINMAX
-#define NOMINMAX
-#endif
-
 #include <windows.h>
 #include <dbghelp.h>
 #include <Shlwapi.h>
diff --git a/deps/v8/src/base/ieee754.cc b/deps/v8/src/base/ieee754.cc
index 7a1cc175cb..8c5641569d 100644
--- a/deps/v8/src/base/ieee754.cc
+++ b/deps/v8/src/base/ieee754.cc
@@ -90,7 +90,7 @@ typedef union {
     ew_u.value = (d);              \
     (ix0) = ew_u.parts.msw;        \
     (ix1) = ew_u.parts.lsw;        \
-  } while (0)
+  } while (false)
 
 /* Get a 64-bit int from a double. */
 #define EXTRACT_WORD64(ix, d)    \
@@ -98,7 +98,7 @@ typedef union {
     ieee_double_shape_type ew_u; \
     ew_u.value = (d);            \
     (ix) = ew_u.xparts.w;        \
-  } while (0)
+  } while (false)
 
 /* Get the more significant 32 bit int from a double.  */
 
@@ -107,7 +107,7 @@ typedef union {
     ieee_double_shape_type gh_u; \
     gh_u.value = (d);            \
     (i) = gh_u.parts.msw;        \
-  } while (0)
+  } while (false)
 
 /* Get the less significant 32 bit int from a double.  */
 
@@ -116,7 +116,7 @@ typedef union {
     ieee_double_shape_type gl_u; \
     gl_u.value = (d);            \
     (i) = gl_u.parts.lsw;        \
-  } while (0)
+  } while (false)
 
 /* Set a double from two 32 bit ints.  */
 
@@ -126,7 +126,7 @@ typedef union {
     iw_u.parts.msw = (ix0);       \
     iw_u.parts.lsw = (ix1);       \
     (d) = iw_u.value;             \
-  } while (0)
+  } while (false)
 
 /* Set a double from a 64-bit int. */
 #define INSERT_WORD64(d, ix)     \
@@ -134,7 +134,7 @@ typedef union {
     ieee_double_shape_type iw_u; \
     iw_u.xparts.w = (ix);        \
     (d) = iw_u.value;            \
-  } while (0)
+  } while (false)
 
 /* Set the more significant 32 bits of a double from an int.  */
 
@@ -144,7 +144,7 @@ typedef union {
     sh_u.value = (d);            \
     sh_u.parts.msw = (v);        \
     (d) = sh_u.value;            \
-  } while (0)
+  } while (false)
 
 /* Set the less significant 32 bits of a double from an int.  */
 
@@ -154,7 +154,7 @@ typedef union {
     sl_u.value = (d);            \
     sl_u.parts.lsw = (v);        \
     (d) = sl_u.value;            \
-  } while (0)
+  } while (false)
 
 /* Support macro. */
 
@@ -1210,9 +1210,9 @@ double atan(double x) {
     if (ix > 0x7FF00000 || (ix == 0x7FF00000 && (low != 0)))
       return x + x; /* NaN */
     if (hx > 0)
-      return atanhi[3] + *(volatile double *)&atanlo[3];
+      return atanhi[3] + *const_cast<volatile double*>(&atanlo[3]);
     else
-      return -atanhi[3] - *(volatile double *)&atanlo[3];
+      return -atanhi[3] - *const_cast<volatile double*>(&atanlo[3]);
   }
   if (ix < 0x3FDC0000) {            /* |x| < 0.4375 */
     if (ix < 0x3E400000) {          /* |x| < 2^-27 */
diff --git a/deps/v8/src/base/logging.h b/deps/v8/src/base/logging.h
index baf6b12ccb..9a9538d065 100644
--- a/deps/v8/src/base/logging.h
+++ b/deps/v8/src/base/logging.h
@@ -49,7 +49,7 @@ V8_BASE_EXPORT void SetDcheckFunction(void (*dcheck_Function)(const char*, int,
     if (V8_UNLIKELY(!(condition))) {       \
       FATAL("Check failed: %s.", message); \
     }                                      \
-  } while (0)
+  } while (false)
 #define CHECK(condition) CHECK_WITH_MSG(condition, #condition)
 
 #ifdef DEBUG
@@ -59,7 +59,7 @@ V8_BASE_EXPORT void SetDcheckFunction(void (*dcheck_Function)(const char*, int,
     if (V8_UNLIKELY(!(condition))) {          \
       V8_Dcheck(__FILE__, __LINE__, message); \
     }                                         \
-  } while (0)
+  } while (false)
 #define DCHECK(condition) DCHECK_WITH_MSG(condition, #condition)
 
 // Helper macro for binary operators.
@@ -73,7 +73,7 @@ V8_BASE_EXPORT void SetDcheckFunction(void (*dcheck_Function)(const char*, int,
       FATAL("Check failed: %s.", _msg->c_str());                          \
       delete _msg;                                                        \
     }                                                                     \
-  } while (0)
+  } while (false)
 
 #define DCHECK_OP(name, op, lhs, rhs)                                     \
   do {                                                                    \
@@ -84,7 +84,7 @@ V8_BASE_EXPORT void SetDcheckFunction(void (*dcheck_Function)(const char*, int,
       V8_Dcheck(__FILE__, __LINE__, _msg->c_str());                       \
       delete _msg;                                                        \
     }                                                                     \
-  } while (0)
+  } while (false)
 
 #else
 
@@ -98,7 +98,7 @@ V8_BASE_EXPORT void SetDcheckFunction(void (*dcheck_Function)(const char*, int,
         typename ::v8::base::pass_value_or_ref<decltype(rhs)>::type>((lhs),  \
                                                                      (rhs)); \
     CHECK_WITH_MSG(_cmp, #lhs " " #op " " #rhs);                             \
-  } while (0)
+  } while (false)
 
 #define DCHECK_WITH_MSG(condition, msg) void(0);
 
diff --git a/deps/v8/src/base/lsan-page-allocator.cc b/deps/v8/src/base/lsan-page-allocator.cc
new file mode 100644
index 0000000000..4840c7ea80
--- /dev/null
+++ b/deps/v8/src/base/lsan-page-allocator.cc
@@ -0,0 +1,59 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/base/lsan-page-allocator.h"
+
+#include "src/base/logging.h"
+
+#if defined(LEAK_SANITIZER)
+#include <sanitizer/lsan_interface.h>
+#endif
+
+namespace v8 {
+namespace base {
+
+LsanPageAllocator::LsanPageAllocator(v8::PageAllocator* page_allocator)
+    : page_allocator_(page_allocator),
+      allocate_page_size_(page_allocator_->AllocatePageSize()),
+      commit_page_size_(page_allocator_->CommitPageSize()) {
+  DCHECK_NOT_NULL(page_allocator);
+}
+
+void* LsanPageAllocator::AllocatePages(void* address, size_t size,
+                                       size_t alignment,
+                                       PageAllocator::Permission access) {
+  void* result =
+      page_allocator_->AllocatePages(address, size, alignment, access);
+#if defined(LEAK_SANITIZER)
+  if (result != nullptr) {
+    __lsan_register_root_region(result, size);
+  }
+#endif
+  return result;
+}
+
+bool LsanPageAllocator::FreePages(void* address, size_t size) {
+  bool result = page_allocator_->FreePages(address, size);
+#if defined(LEAK_SANITIZER)
+  if (result) {
+    __lsan_unregister_root_region(address, size);
+  }
+#endif
+  return result;
+}
+
+bool LsanPageAllocator::ReleasePages(void* address, size_t size,
+                                     size_t new_size) {
+  bool result = page_allocator_->ReleasePages(address, size, new_size);
+#if defined(LEAK_SANITIZER)
+  if (result) {
+    __lsan_unregister_root_region(address, size);
+    __lsan_register_root_region(address, new_size);
+  }
+#endif
+  return result;
+}
+
+}  // namespace base
+}  // namespace v8
diff --git a/deps/v8/src/base/lsan-page-allocator.h b/deps/v8/src/base/lsan-page-allocator.h
new file mode 100644
index 0000000000..d95c7fbf1e
--- /dev/null
+++ b/deps/v8/src/base/lsan-page-allocator.h
@@ -0,0 +1,56 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_LSAN_PAGE_ALLOCATOR_H_
+#define V8_BASE_LSAN_PAGE_ALLOCATOR_H_
+
+#include "include/v8-platform.h"
+#include "src/base/base-export.h"
+#include "src/base/compiler-specific.h"
+
+namespace v8 {
+namespace base {
+
+// This is a v8::PageAllocator implementation that decorates provided page
+// allocator object with leak sanitizer notifications when LEAK_SANITIZER
+// is defined.
+class V8_BASE_EXPORT LsanPageAllocator
+    : public NON_EXPORTED_BASE(::v8::PageAllocator) {
+ public:
+  LsanPageAllocator(v8::PageAllocator* page_allocator);
+  ~LsanPageAllocator() override = default;
+
+  size_t AllocatePageSize() override { return allocate_page_size_; }
+
+  size_t CommitPageSize() override { return commit_page_size_; }
+
+  void SetRandomMmapSeed(int64_t seed) override {
+    return page_allocator_->SetRandomMmapSeed(seed);
+  }
+
+  void* GetRandomMmapAddr() override {
+    return page_allocator_->GetRandomMmapAddr();
+  }
+
+  void* AllocatePages(void* address, size_t size, size_t alignment,
+                      PageAllocator::Permission access) override;
+
+  bool FreePages(void* address, size_t size) override;
+
+  bool ReleasePages(void* address, size_t size, size_t new_size) override;
+
+  bool SetPermissions(void* address, size_t size,
+                      PageAllocator::Permission access) override {
+    return page_allocator_->SetPermissions(address, size, access);
+  }
+
+ private:
+  v8::PageAllocator* const page_allocator_;
+  const size_t allocate_page_size_;
+  const size_t commit_page_size_;
+};
+
+}  // namespace base
+}  // namespace v8
+#endif  // V8_BASE_LSAN_PAGE_ALLOCATOR_H_
diff --git a/deps/v8/src/base/macros.h b/deps/v8/src/base/macros.h
index 081018cc2e..8a2efe61a9 100644
--- a/deps/v8/src/base/macros.h
+++ b/deps/v8/src/base/macros.h
@@ -14,6 +14,9 @@
 // No-op macro which is used to work around MSVC's funky VA_ARGS support.
 #define EXPAND(x) x
 
+// This macro does nothing. That's all.
+#define NOTHING(...)
+
 // TODO(all) Replace all uses of this macro with C++'s offsetof. To do that, we
 // have to make sure that only standard-layout types and simple field
 // designators are used.
@@ -195,8 +198,9 @@ V8_INLINE Dest bit_cast(Source const& source) {
 #define V8_IMMEDIATE_CRASH() ((void(*)())0)()
 #endif
 
-
-// TODO(all) Replace all uses of this macro with static_assert, remove macro.
+// A convenience wrapper around static_assert without a string message argument.
+// Once C++17 becomes the default, this macro can be removed in favor of the
+// new static_assert(condition) overload.
 #define STATIC_ASSERT(test) static_assert(test, #test)
 
 namespace v8 {
@@ -276,6 +280,12 @@ struct Use {
     (void)unused_tmp_array_for_use_macro;                          \
   } while (false)
 
+// Evaluate the instantiations of an expression with parameter packs.
+// Since USE has left-to-right evaluation order of it's arguments,
+// the parameter pack is iterated from left to right and side effects
+// have defined behavior.
+#define ITERATE_PACK(...) USE(0, ((__VA_ARGS__), 0)...)
+
 }  // namespace base
 }  // namespace v8
 
@@ -346,47 +356,37 @@ V8_INLINE A implicit_cast(A x) {
 //      write V8_2PART_UINT64_C(0x12345678,90123456);
 #define V8_2PART_UINT64_C(a, b) (((static_cast<uint64_t>(a) << 32) + 0x##b##u))
 
-
-// Compute the 0-relative offset of some absolute value x of type T.
-// This allows conversion of Addresses and integral types into
-// 0-relative int offsets.
-template <typename T>
-constexpr inline intptr_t OffsetFrom(T x) {
-  return x - static_cast<T>(0);
-}
-
-
-// Compute the absolute value of type T for some 0-relative offset x.
-// This allows conversion of 0-relative int offsets into Addresses and
-// integral types.
-template <typename T>
-constexpr inline T AddressFrom(intptr_t x) {
-  return static_cast<T>(static_cast<T>(0) + x);
-}
-
-
 // Return the largest multiple of m which is <= x.
 template <typename T>
 inline T RoundDown(T x, intptr_t m) {
+  STATIC_ASSERT(std::is_integral<T>::value);
   // m must be a power of two.
   DCHECK(m != 0 && ((m & (m - 1)) == 0));
-  return AddressFrom<T>(OffsetFrom(x) & -m);
+  return x & -m;
 }
 template <intptr_t m, typename T>
 constexpr inline T RoundDown(T x) {
+  STATIC_ASSERT(std::is_integral<T>::value);
   // m must be a power of two.
   STATIC_ASSERT(m != 0 && ((m & (m - 1)) == 0));
-  return AddressFrom<T>(OffsetFrom(x) & -m);
+  return x & -m;
 }
 
 // Return the smallest multiple of m which is >= x.
 template <typename T>
 inline T RoundUp(T x, intptr_t m) {
+  STATIC_ASSERT(std::is_integral<T>::value);
   return RoundDown<T>(static_cast<T>(x + m - 1), m);
 }
 template <intptr_t m, typename T>
 constexpr inline T RoundUp(T x) {
-  return RoundDown<m, T>(static_cast<T>(x + m - 1));
+  STATIC_ASSERT(std::is_integral<T>::value);
+  return RoundDown<m, T>(static_cast<T>(x + (m - 1)));
+}
+
+template <typename T, typename U>
+inline bool IsAligned(T value, U alignment) {
+  return (value & (alignment - 1)) == 0;
 }
 
 inline void* AlignedAddress(void* address, size_t alignment) {
diff --git a/deps/v8/src/base/optional.h b/deps/v8/src/base/optional.h
index 6f5276843d..7dfef2d31f 100644
--- a/deps/v8/src/base/optional.h
+++ b/deps/v8/src/base/optional.h
@@ -123,7 +123,7 @@ class Optional {
  public:
   using value_type = T;
 
-  constexpr Optional() {}
+  constexpr Optional() = default;
 
   constexpr Optional(base::nullopt_t) {}  // NOLINT(runtime/explicit)
 
diff --git a/deps/v8/src/base/page-allocator.cc b/deps/v8/src/base/page-allocator.cc
index 25ee2e4721..c25104739d 100644
--- a/deps/v8/src/base/page-allocator.cc
+++ b/deps/v8/src/base/page-allocator.cc
@@ -24,11 +24,9 @@ STATIC_ASSERT_ENUM(PageAllocator::kReadExecute,
 
 #undef STATIC_ASSERT_ENUM
 
-size_t PageAllocator::AllocatePageSize() {
-  return base::OS::AllocatePageSize();
-}
-
-size_t PageAllocator::CommitPageSize() { return base::OS::CommitPageSize(); }
+PageAllocator::PageAllocator()
+    : allocate_page_size_(base::OS::AllocatePageSize()),
+      commit_page_size_(base::OS::CommitPageSize()) {}
 
 void PageAllocator::SetRandomMmapSeed(int64_t seed) {
   base::OS::SetRandomMmapSeed(seed);
diff --git a/deps/v8/src/base/page-allocator.h b/deps/v8/src/base/page-allocator.h
index ff817cdba2..68e17db494 100644
--- a/deps/v8/src/base/page-allocator.h
+++ b/deps/v8/src/base/page-allocator.h
@@ -15,11 +15,12 @@ namespace base {
 class V8_BASE_EXPORT PageAllocator
     : public NON_EXPORTED_BASE(::v8::PageAllocator) {
  public:
-  virtual ~PageAllocator() = default;
+  PageAllocator();
+  ~PageAllocator() override = default;
 
-  size_t AllocatePageSize() override;
+  size_t AllocatePageSize() override { return allocate_page_size_; }
 
-  size_t CommitPageSize() override;
+  size_t CommitPageSize() override { return commit_page_size_; }
 
   void SetRandomMmapSeed(int64_t seed) override;
 
@@ -34,6 +35,10 @@ class V8_BASE_EXPORT PageAllocator
 
   bool SetPermissions(void* address, size_t size,
                       PageAllocator::Permission access) override;
+
+ private:
+  const size_t allocate_page_size_;
+  const size_t commit_page_size_;
 };
 
 }  // namespace base
diff --git a/deps/v8/src/base/platform/OWNERS b/deps/v8/src/base/platform/OWNERS
index 5deaa67ce7..cbaed6105d 100644
--- a/deps/v8/src/base/platform/OWNERS
+++ b/deps/v8/src/base/platform/OWNERS
@@ -3,4 +3,6 @@ set noparent
 hpayer@chromium.org
 mlippautz@chromium.org
 
+per-file platform-fuchsia.cc=wez@chromium.org
+
 # COMPONENT: Blink>JavaScript
diff --git a/deps/v8/src/base/platform/platform-fuchsia.cc b/deps/v8/src/base/platform/platform-fuchsia.cc
index d1979fb9d8..713ee404bd 100644
--- a/deps/v8/src/base/platform/platform-fuchsia.cc
+++ b/deps/v8/src/base/platform/platform-fuchsia.cc
@@ -57,8 +57,8 @@ void* OS::Allocate(void* address, size_t size, size_t alignment,
                          strlen(kVirtualMemoryName));
   uintptr_t reservation;
   uint32_t prot = GetProtectionFromMemoryPermission(access);
-  zx_status_t status = zx_vmar_map_old(zx_vmar_root_self(), 0, vmo, 0,
-                                       request_size, prot, &reservation);
+  zx_status_t status = zx_vmar_map(zx_vmar_root_self(), prot, 0, vmo, 0,
+                                   request_size, &reservation);
   // Either the vmo is now referenced by the vmar, or we failed and are bailing,
   // so close the vmo either way.
   zx_handle_close(vmo);
@@ -67,7 +67,8 @@ void* OS::Allocate(void* address, size_t size, size_t alignment,
   }
 
   uint8_t* base = reinterpret_cast<uint8_t*>(reservation);
-  uint8_t* aligned_base = RoundUp(base, alignment);
+  uint8_t* aligned_base = reinterpret_cast<uint8_t*>(
+      RoundUp(reinterpret_cast<uintptr_t>(base), alignment));
 
   // Unmap extra memory reserved before and after the desired block.
   if (aligned_base != base) {
@@ -114,9 +115,8 @@ bool OS::SetPermissions(void* address, size_t size, MemoryPermission access) {
   DCHECK_EQ(0, reinterpret_cast<uintptr_t>(address) % CommitPageSize());
   DCHECK_EQ(0, size % CommitPageSize());
   uint32_t prot = GetProtectionFromMemoryPermission(access);
-  return zx_vmar_protect_old(zx_vmar_root_self(),
-                             reinterpret_cast<uintptr_t>(address), size,
-                             prot) == ZX_OK;
+  return zx_vmar_protect(zx_vmar_root_self(), prot,
+                         reinterpret_cast<uintptr_t>(address), size) == ZX_OK;
 }
 
 // static
diff --git a/deps/v8/src/base/platform/platform-linux.cc b/deps/v8/src/base/platform/platform-linux.cc
index 725ad0c6eb..10815f29c5 100644
--- a/deps/v8/src/base/platform/platform-linux.cc
+++ b/deps/v8/src/base/platform/platform-linux.cc
@@ -27,14 +27,6 @@
 #include <sys/types.h>  // mmap & munmap
 #include <unistd.h>     // sysconf
 
-// GLibc on ARM defines mcontext_t has a typedef for 'struct sigcontext'.
-// Old versions of the C library <signal.h> didn't define the type.
-#if defined(__ANDROID__) && !defined(__BIONIC_HAVE_UCONTEXT_T) && \
-    (defined(__arm__) || defined(__aarch64__)) &&                 \
-    !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT)
-#include <asm/sigcontext.h>  // NOLINT
-#endif
-
 #include <cmath>
 
 #undef MAP_TYPE
diff --git a/deps/v8/src/base/platform/platform-posix-time.h b/deps/v8/src/base/platform/platform-posix-time.h
index 4d3373715b..7814296b83 100644
--- a/deps/v8/src/base/platform/platform-posix-time.h
+++ b/deps/v8/src/base/platform/platform-posix-time.h
@@ -15,7 +15,7 @@ class PosixDefaultTimezoneCache : public PosixTimezoneCache {
   const char* LocalTimezone(double time_ms) override;
   double LocalTimeOffset(double time_ms, bool is_utc) override;
 
-  ~PosixDefaultTimezoneCache() override {}
+  ~PosixDefaultTimezoneCache() override = default;
 };
 
 }  // namespace base
diff --git a/deps/v8/src/base/platform/platform-posix.cc b/deps/v8/src/base/platform/platform-posix.cc
index cb25196970..c93974bcfc 100644
--- a/deps/v8/src/base/platform/platform-posix.cc
+++ b/deps/v8/src/base/platform/platform-posix.cc
@@ -86,7 +86,7 @@ namespace base {
 namespace {
 
 // 0 is never a valid thread id.
-const pthread_t kNoThread = (pthread_t) 0;
+const pthread_t kNoThread = static_cast<pthread_t>(0);
 
 bool g_hard_abort = false;
 
@@ -254,10 +254,6 @@ void* OS::GetRandomMmapAddr() {
   // Little-endian Linux: 46 bits of virtual addressing.
   raw_addr &= uint64_t{0x3FFFFFFF0000};
 #endif
-#elif V8_TARGET_ARCH_MIPS64
-  // We allocate code in 256 MB aligned segments because of optimizations using
-  // J instruction that require that all code is within a single 256 MB segment
-  raw_addr &= uint64_t{0x3FFFE0000000};
 #elif V8_TARGET_ARCH_S390X
   // Linux on Z uses bits 22-32 for Region Indexing, which translates to 42 bits
   // of virtual addressing.  Truncate to 40 bits to allow kernel chance to
@@ -267,6 +263,10 @@ void* OS::GetRandomMmapAddr() {
   // 31 bits of virtual addressing.  Truncate to 29 bits to allow kernel chance
   // to fulfill request.
   raw_addr &= 0x1FFFF000;
+#elif V8_TARGET_ARCH_MIPS64
+  // 42 bits of virtual addressing. Truncate to 40 bits to allow kernel chance
+  // to fulfill request.
+  raw_addr &= uint64_t{0xFFFFFF0000};
 #else
   raw_addr &= 0x3FFFF000;
 
@@ -313,7 +313,8 @@ void* OS::Allocate(void* address, size_t size, size_t alignment,
 
   // Unmap memory allocated before the aligned base address.
   uint8_t* base = static_cast<uint8_t*>(result);
-  uint8_t* aligned_base = RoundUp(base, alignment);
+  uint8_t* aligned_base = reinterpret_cast<uint8_t*>(
+      RoundUp(reinterpret_cast<uintptr_t>(base), alignment));
   if (aligned_base != base) {
     DCHECK_LT(base, aligned_base);
     size_t prefix_size = static_cast<size_t>(aligned_base - base);
diff --git a/deps/v8/src/base/platform/platform-posix.h b/deps/v8/src/base/platform/platform-posix.h
index 55861bc9ac..8cf5e54604 100644
--- a/deps/v8/src/base/platform/platform-posix.h
+++ b/deps/v8/src/base/platform/platform-posix.h
@@ -15,7 +15,7 @@ class PosixTimezoneCache : public TimezoneCache {
  public:
   double DaylightSavingsOffset(double time_ms) override;
   void Clear() override {}
-  ~PosixTimezoneCache() override {}
+  ~PosixTimezoneCache() override = default;
 
  protected:
   static const int msPerSecond = 1000;
diff --git a/deps/v8/src/base/platform/platform-win32.cc b/deps/v8/src/base/platform/platform-win32.cc
index 2e56ac5df1..11a008e6c6 100644
--- a/deps/v8/src/base/platform/platform-win32.cc
+++ b/deps/v8/src/base/platform/platform-win32.cc
@@ -822,7 +822,8 @@ void* OS::Allocate(void* address, size_t size, size_t alignment,
   if (base == nullptr) return nullptr;  // Can't allocate, we're OOM.
 
   // If address is suitably aligned, we're done.
-  uint8_t* aligned_base = RoundUp(base, alignment);
+  uint8_t* aligned_base = reinterpret_cast<uint8_t*>(
+      RoundUp(reinterpret_cast<uintptr_t>(base), alignment));
   if (base == aligned_base) return reinterpret_cast<void*>(base);
 
   // Otherwise, free it and try a larger allocation.
@@ -843,7 +844,8 @@ void* OS::Allocate(void* address, size_t size, size_t alignment,
     // Try to trim the allocation by freeing the padded allocation and then
     // calling VirtualAlloc at the aligned base.
     CHECK(Free(base, padded_size));
-    aligned_base = RoundUp(base, alignment);
+    aligned_base = reinterpret_cast<uint8_t*>(
+        RoundUp(reinterpret_cast<uintptr_t>(base), alignment));
     base = reinterpret_cast<uint8_t*>(
         VirtualAlloc(aligned_base, size, flags, protect));
     // We might not get the reduced allocation due to a race. In that case,
diff --git a/deps/v8/src/base/platform/platform.h b/deps/v8/src/base/platform/platform.h
index 51b6014821..f9d01edf00 100644
--- a/deps/v8/src/base/platform/platform.h
+++ b/deps/v8/src/base/platform/platform.h
@@ -188,7 +188,7 @@ class V8_BASE_EXPORT OS {
 
   class V8_BASE_EXPORT MemoryMappedFile {
    public:
-    virtual ~MemoryMappedFile() {}
+    virtual ~MemoryMappedFile() = default;
     virtual void* memory() const = 0;
     virtual size_t size() const = 0;
 
diff --git a/deps/v8/src/base/platform/semaphore.cc b/deps/v8/src/base/platform/semaphore.cc
index 5950664523..a7e50f5880 100644
--- a/deps/v8/src/base/platform/semaphore.cc
+++ b/deps/v8/src/base/platform/semaphore.cc
@@ -91,7 +91,9 @@ void Semaphore::Signal() {
   // This check may fail with <libc-2.21, which we use on the try bots, if the
   // semaphore is destroyed while sem_post is still executed. A work around is
   // to extend the lifetime of the semaphore.
-  CHECK_EQ(0, result);
+  if (result != 0) {
+    FATAL("Error when signaling semaphore, errno: %d", errno);
+  }
 }
 
 
diff --git a/deps/v8/src/base/platform/time.h b/deps/v8/src/base/platform/time.h
index 161092ad8b..9e99166487 100644
--- a/deps/v8/src/base/platform/time.h
+++ b/deps/v8/src/base/platform/time.h
@@ -105,10 +105,7 @@ class V8_BASE_EXPORT TimeDelta final {
   static TimeDelta FromTimespec(struct timespec ts);
   struct timespec ToTimespec() const;
 
-  TimeDelta& operator=(const TimeDelta& other) {
-    delta_ = other.delta_;
-    return *this;
-  }
+  TimeDelta& operator=(const TimeDelta& other) = default;
 
   // Computations with other deltas.
   TimeDelta operator+(const TimeDelta& other) const {
diff --git a/deps/v8/src/base/region-allocator.cc b/deps/v8/src/base/region-allocator.cc
new file mode 100644
index 0000000000..46ceca1857
--- /dev/null
+++ b/deps/v8/src/base/region-allocator.cc
@@ -0,0 +1,291 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/base/region-allocator.h"
+#include "src/base/bits.h"
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace base {
+
+// If |free_size| < |region_size| * |kMaxLoadFactorForRandomization| stop trying
+// to randomize region allocation.
+constexpr double kMaxLoadFactorForRandomization = 0.40;
+
+// Max number of attempts to allocate page at random address.
+constexpr int kMaxRandomizationAttempts = 3;
+
+RegionAllocator::RegionAllocator(Address memory_region_begin,
+                                 size_t memory_region_size, size_t page_size)
+    : whole_region_(memory_region_begin, memory_region_size, false),
+      region_size_in_pages_(size() / page_size),
+      max_load_for_randomization_(
+          static_cast<size_t>(size() * kMaxLoadFactorForRandomization)),
+      free_size_(0),
+      page_size_(page_size) {
+  CHECK_LT(begin(), end());
+  CHECK(base::bits::IsPowerOfTwo(page_size_));
+  CHECK(IsAligned(size(), page_size_));
+  CHECK(IsAligned(begin(), page_size_));
+
+  // Initial region.
+  Region* region = new Region(whole_region_);
+
+  all_regions_.insert(region);
+
+  FreeListAddRegion(region);
+}
+
+RegionAllocator::~RegionAllocator() {
+  for (Region* region : all_regions_) {
+    delete region;
+  }
+}
+
+RegionAllocator::AllRegionsSet::iterator RegionAllocator::FindRegion(
+    Address address) {
+  if (!whole_region_.contains(address)) return all_regions_.end();
+
+  Region key(address, 0, false);
+  AllRegionsSet::iterator iter = all_regions_.upper_bound(&key);
+  // Regions in |all_regions_| are compared by end() values and key's end()
+  // points exactly to the address we are querying, so the upper_bound will
+  // find the region whose |end()| is greater than the requested address.
+  DCHECK_NE(iter, all_regions_.end());
+  DCHECK((*iter)->contains(address));
+  return iter;
+}
+
+void RegionAllocator::FreeListAddRegion(Region* region) {
+  free_size_ += region->size();
+  free_regions_.insert(region);
+}
+
+RegionAllocator::Region* RegionAllocator::FreeListFindRegion(size_t size) {
+  Region key(0, size, false);
+  auto iter = free_regions_.lower_bound(&key);
+  return iter == free_regions_.end() ? nullptr : *iter;
+}
+
+void RegionAllocator::FreeListRemoveRegion(Region* region) {
+  DCHECK(!region->is_used());
+  auto iter = free_regions_.find(region);
+  DCHECK_NE(iter, free_regions_.end());
+  DCHECK_EQ(region, *iter);
+  DCHECK_LE(region->size(), free_size_);
+  free_size_ -= region->size();
+  free_regions_.erase(iter);
+}
+
+RegionAllocator::Region* RegionAllocator::Split(Region* region,
+                                                size_t new_size) {
+  DCHECK(IsAligned(new_size, page_size_));
+  DCHECK_NE(new_size, 0);
+  DCHECK_GT(region->size(), new_size);
+
+  // Create new region and put it to the lists after the |region|.
+  bool used = region->is_used();
+  Region* new_region =
+      new Region(region->begin() + new_size, region->size() - new_size, used);
+  if (!used) {
+    // Remove region from the free list before updating it's size.
+    FreeListRemoveRegion(region);
+  }
+  region->set_size(new_size);
+
+  all_regions_.insert(new_region);
+
+  if (!used) {
+    FreeListAddRegion(region);
+    FreeListAddRegion(new_region);
+  }
+  return new_region;
+}
+
+void RegionAllocator::Merge(AllRegionsSet::iterator prev_iter,
+                            AllRegionsSet::iterator next_iter) {
+  Region* prev = *prev_iter;
+  Region* next = *next_iter;
+  DCHECK_EQ(prev->end(), next->begin());
+  prev->set_size(prev->size() + next->size());
+
+  all_regions_.erase(next_iter);  // prev_iter stays valid.
+
+  // The |next| region must already not be in the free list.
+  DCHECK_EQ(free_regions_.find(next), free_regions_.end());
+  delete next;
+}
+
+RegionAllocator::Address RegionAllocator::AllocateRegion(size_t size) {
+  DCHECK_NE(size, 0);
+  DCHECK(IsAligned(size, page_size_));
+
+  Region* region = FreeListFindRegion(size);
+  if (region == nullptr) return kAllocationFailure;
+
+  if (region->size() != size) {
+    Split(region, size);
+  }
+  DCHECK(IsAligned(region->begin(), page_size_));
+  DCHECK_EQ(region->size(), size);
+
+  // Mark region as used.
+  FreeListRemoveRegion(region);
+  region->set_is_used(true);
+  return region->begin();
+}
+
+RegionAllocator::Address RegionAllocator::AllocateRegion(
+    RandomNumberGenerator* rng, size_t size) {
+  if (free_size() >= max_load_for_randomization_) {
+    // There is enough free space for trying to randomize the address.
+    size_t random = 0;
+
+    for (int i = 0; i < kMaxRandomizationAttempts; i++) {
+      rng->NextBytes(&random, sizeof(random));
+      size_t random_offset = page_size_ * (random % region_size_in_pages_);
+      Address address = begin() + random_offset;
+      if (AllocateRegionAt(address, size)) {
+        return address;
+      }
+    }
+    // Fall back to free list allocation.
+  }
+  return AllocateRegion(size);
+}
+
+bool RegionAllocator::AllocateRegionAt(Address requested_address, size_t size) {
+  DCHECK(IsAligned(requested_address, page_size_));
+  DCHECK_NE(size, 0);
+  DCHECK(IsAligned(size, page_size_));
+
+  Address requested_end = requested_address + size;
+  DCHECK_LE(requested_end, end());
+
+  Region* region;
+  {
+    AllRegionsSet::iterator region_iter = FindRegion(requested_address);
+    if (region_iter == all_regions_.end()) {
+      return false;
+    }
+    region = *region_iter;
+  }
+  if (region->is_used() || region->end() < requested_end) {
+    return false;
+  }
+  // Found free region that includes the requested one.
+  if (region->begin() != requested_address) {
+    // Split the region at the |requested_address| boundary.
+    size_t new_size = requested_address - region->begin();
+    DCHECK(IsAligned(new_size, page_size_));
+    region = Split(region, new_size);
+  }
+  if (region->end() != requested_end) {
+    // Split the region at the |requested_end| boundary.
+    Split(region, size);
+  }
+  DCHECK_EQ(region->begin(), requested_address);
+  DCHECK_EQ(region->size(), size);
+
+  // Mark region as used.
+  FreeListRemoveRegion(region);
+  region->set_is_used(true);
+  return true;
+}
+
+size_t RegionAllocator::TrimRegion(Address address, size_t new_size) {
+  DCHECK(IsAligned(new_size, page_size_));
+
+  AllRegionsSet::iterator region_iter = FindRegion(address);
+  if (region_iter == all_regions_.end()) {
+    return 0;
+  }
+  Region* region = *region_iter;
+  if (region->begin() != address || !region->is_used()) {
+    return 0;
+  }
+
+  // The region must not be in the free list.
+  DCHECK_EQ(free_regions_.find(*region_iter), free_regions_.end());
+
+  if (new_size > 0) {
+    region = Split(region, new_size);
+    ++region_iter;
+  }
+  size_t size = region->size();
+  region->set_is_used(false);
+
+  // Merge current region with the surrounding ones if they are free.
+  if (region->end() != whole_region_.end()) {
+    // There must be a range after the current one.
+    AllRegionsSet::iterator next_iter = std::next(region_iter);
+    DCHECK_NE(next_iter, all_regions_.end());
+    if (!(*next_iter)->is_used()) {
+      // |next| region object will be deleted during merge, remove it from
+      // the free list.
+      FreeListRemoveRegion(*next_iter);
+      Merge(region_iter, next_iter);
+    }
+  }
+  if (new_size == 0 && region->begin() != whole_region_.begin()) {
+    // There must be a range before the current one.
+    AllRegionsSet::iterator prev_iter = std::prev(region_iter);
+    DCHECK_NE(prev_iter, all_regions_.end());
+    if (!(*prev_iter)->is_used()) {
+      // |prev| region's size will change, we'll have to re-insert it into
+      // the proper place of the free list.
+      FreeListRemoveRegion(*prev_iter);
+      Merge(prev_iter, region_iter);
+      // |prev| region becomes the current region.
+      region_iter = prev_iter;
+      region = *region_iter;
+    }
+  }
+  FreeListAddRegion(region);
+  return size;
+}
+
+size_t RegionAllocator::CheckRegion(Address address) {
+  AllRegionsSet::iterator region_iter = FindRegion(address);
+  if (region_iter == all_regions_.end()) {
+    return 0;
+  }
+  Region* region = *region_iter;
+  if (region->begin() != address || !region->is_used()) {
+    return 0;
+  }
+  return region->size();
+}
+
+void RegionAllocator::Region::Print(std::ostream& os) const {
+  std::ios::fmtflags flags = os.flags(std::ios::hex | std::ios::showbase);
+  os << "[" << begin() << ", " << end() << "), size: " << size();
+  os << ", " << (is_used() ? "used" : "free");
+  os.flags(flags);
+}
+
+void RegionAllocator::Print(std::ostream& os) const {
+  std::ios::fmtflags flags = os.flags(std::ios::hex | std::ios::showbase);
+  os << "RegionAllocator: [" << begin() << ", " << end() << ")";
+  os << "\nsize: " << size();
+  os << "\nfree_size: " << free_size();
+  os << "\npage_size: " << page_size_;
+
+  os << "\nall regions: ";
+  for (const Region* region : all_regions_) {
+    os << "\n  ";
+    region->Print(os);
+  }
+
+  os << "\nfree regions: ";
+  for (const Region* region : free_regions_) {
+    os << "\n  ";
+    region->Print(os);
+  }
+  os << "\n";
+  os.flags(flags);
+}
+
+}  // namespace base
+}  // namespace v8
diff --git a/deps/v8/src/base/region-allocator.h b/deps/v8/src/base/region-allocator.h
new file mode 100644
index 0000000000..fb51472fa9
--- /dev/null
+++ b/deps/v8/src/base/region-allocator.h
@@ -0,0 +1,164 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_REGION_ALLOCATOR_H_
+#define V8_BASE_REGION_ALLOCATOR_H_
+
+#include <set>
+
+#include "src/base/address-region.h"
+#include "src/base/utils/random-number-generator.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"  // nogncheck
+
+namespace v8 {
+namespace base {
+
+// Helper class for managing used/free regions within [address, address+size)
+// region. Minimum allocation unit is |page_size|. Requested allocation size
+// is rounded up to |page_size|.
+// The region allocation algorithm implements best-fit with coalescing strategy:
+// it tries to find a smallest suitable free region upon allocation and tries
+// to merge region with its neighbors upon freeing.
+//
+// This class does not perform any actual region reservation.
+// Not thread-safe.
+class V8_BASE_EXPORT RegionAllocator final {
+ public:
+  typedef uintptr_t Address;
+
+  static constexpr Address kAllocationFailure = static_cast<Address>(-1);
+
+  RegionAllocator(Address address, size_t size, size_t page_size);
+  ~RegionAllocator();
+
+  // Allocates region of |size| (must be |page_size|-aligned). Returns
+  // the address of the region on success or kAllocationFailure.
+  Address AllocateRegion(size_t size);
+  // Same as above but tries to randomize the region displacement.
+  Address AllocateRegion(RandomNumberGenerator* rng, size_t size);
+
+  // Allocates region of |size| at |requested_address| if it's free. Both the
+  // address and the size must be |page_size|-aligned. On success returns
+  // true.
+  // This kind of allocation is supposed to be used during setup phase to mark
+  // certain regions as used or for randomizing regions displacement.
+  bool AllocateRegionAt(Address requested_address, size_t size);
+
+  // Frees region at given |address|, returns the size of the region.
+  // There must be a used region starting at given address otherwise nothing
+  // will be freed and 0 will be returned.
+  size_t FreeRegion(Address address) { return TrimRegion(address, 0); }
+
+  // Decreases size of the previously allocated region at |address|, returns
+  // freed size. |new_size| must be |page_size|-aligned and
+  // less than or equal to current region's size. Setting new size to zero
+  // frees the region.
+  size_t TrimRegion(Address address, size_t new_size);
+
+  // If there is a used region starting at given address returns its size
+  // otherwise 0.
+  size_t CheckRegion(Address address);
+
+  Address begin() const { return whole_region_.begin(); }
+  Address end() const { return whole_region_.end(); }
+  size_t size() const { return whole_region_.size(); }
+
+  bool contains(Address address) const {
+    return whole_region_.contains(address);
+  }
+
+  bool contains(Address address, size_t size) const {
+    return whole_region_.contains(address, size);
+  }
+
+  // Total size of not yet aquired regions.
+  size_t free_size() const { return free_size_; }
+
+  // The alignment of the allocated region's addresses and granularity of
+  // the allocated region's sizes.
+  size_t page_size() const { return page_size_; }
+
+  void Print(std::ostream& os) const;
+
+ private:
+  class Region : public AddressRegion {
+   public:
+    Region(Address address, size_t size, bool is_used)
+        : AddressRegion(address, size), is_used_(is_used) {}
+
+    bool is_used() const { return is_used_; }
+    void set_is_used(bool used) { is_used_ = used; }
+
+    void Print(std::ostream& os) const;
+
+   private:
+    bool is_used_;
+  };
+
+  // The whole region.
+  const Region whole_region_;
+
+  // Number of |page_size_| in the whole region.
+  const size_t region_size_in_pages_;
+
+  // If the free size is less than this value - stop trying to randomize the
+  // allocation addresses.
+  const size_t max_load_for_randomization_;
+
+  // Size of all free regions.
+  size_t free_size_;
+
+  // Minimum region size. Must be a pow of 2.
+  const size_t page_size_;
+
+  struct AddressEndOrder {
+    bool operator()(const Region* a, const Region* b) const {
+      return a->end() < b->end();
+    }
+  };
+  // All regions ordered by addresses.
+  typedef std::set<Region*, AddressEndOrder> AllRegionsSet;
+  AllRegionsSet all_regions_;
+
+  struct SizeAddressOrder {
+    bool operator()(const Region* a, const Region* b) const {
+      if (a->size() != b->size()) return a->size() < b->size();
+      return a->begin() < b->begin();
+    }
+  };
+  // Free regions ordered by sizes and addresses.
+  std::set<Region*, SizeAddressOrder> free_regions_;
+
+  // Returns region containing given address or nullptr.
+  AllRegionsSet::iterator FindRegion(Address address);
+
+  // Adds given region to the set of free regions.
+  void FreeListAddRegion(Region* region);
+
+  // Finds best-fit free region for given size.
+  Region* FreeListFindRegion(size_t size);
+
+  // Removes given region from the set of free regions.
+  void FreeListRemoveRegion(Region* region);
+
+  // Splits given |region| into two: one of |new_size| size and a new one
+  // having the rest. The new region is returned.
+  Region* Split(Region* region, size_t new_size);
+
+  // For two coalescing regions merges |next| to |prev| and deletes |next|.
+  void Merge(AllRegionsSet::iterator prev_iter,
+             AllRegionsSet::iterator next_iter);
+
+  FRIEND_TEST(RegionAllocatorTest, AllocateRegionRandom);
+  FRIEND_TEST(RegionAllocatorTest, Fragmentation);
+  FRIEND_TEST(RegionAllocatorTest, FindRegion);
+  FRIEND_TEST(RegionAllocatorTest, Contains);
+
+  DISALLOW_COPY_AND_ASSIGN(RegionAllocator);
+};
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_REGION_ALLOCATOR_H_
diff --git a/deps/v8/src/base/safe_math.h b/deps/v8/src/base/safe_math.h
index 62a2f723f2..700bc3387f 100644
--- a/deps/v8/src/base/safe_math.h
+++ b/deps/v8/src/base/safe_math.h
@@ -49,7 +49,7 @@ class CheckedNumeric {
  public:
   typedef T type;
 
-  CheckedNumeric() {}
+  CheckedNumeric() = default;
 
   // Copy constructor.
   template <typename Src>
diff --git a/deps/v8/src/base/threaded-list.h b/deps/v8/src/base/threaded-list.h
new file mode 100644
index 0000000000..d54bcb8f70
--- /dev/null
+++ b/deps/v8/src/base/threaded-list.h
@@ -0,0 +1,267 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_THREADED_LIST_H_
+#define V8_BASE_THREADED_LIST_H_
+
+#include <iterator>
+
+#include "src/base/compiler-specific.h"
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace base {
+
+template <typename T>
+struct ThreadedListTraits {
+  static T** next(T* t) { return t->next(); }
+};
+
+// Represents a linked list that threads through the nodes in the linked list.
+// Entries in the list are pointers to nodes. By default nodes need to have a
+// T** next() method that returns the location where the next value is stored.
+// The default can be overwritten by providing a ThreadedTraits class.
+template <typename T, typename BaseClass,
+          typename TLTraits = ThreadedListTraits<T>>
+class ThreadedListBase final : public BaseClass {
+ public:
+  ThreadedListBase() : head_(nullptr), tail_(&head_) {}
+  void Add(T* v) {
+    DCHECK_NULL(*tail_);
+    DCHECK_NULL(*TLTraits::next(v));
+    *tail_ = v;
+    tail_ = TLTraits::next(v);
+  }
+
+  void AddFront(T* v) {
+    DCHECK_NULL(*TLTraits::next(v));
+    DCHECK_NOT_NULL(v);
+    T** const next = TLTraits::next(v);
+
+    *next = head_;
+    if (head_ == nullptr) tail_ = next;
+    head_ = v;
+  }
+
+  // Reinitializing the head to a new node, this costs O(n).
+  void ReinitializeHead(T* v) {
+    head_ = v;
+    T* current = v;
+    if (current != nullptr) {  // Find tail
+      T* tmp;
+      while ((tmp = *TLTraits::next(current))) {
+        current = tmp;
+      }
+      tail_ = TLTraits::next(current);
+    } else {
+      tail_ = &head_;
+    }
+  }
+
+  void DropHead() {
+    DCHECK_NOT_NULL(head_);
+
+    T* old_head = head_;
+    head_ = *TLTraits::next(head_);
+    if (head_ == nullptr) tail_ = &head_;
+    *TLTraits::next(old_head) = nullptr;
+  }
+
+  void Append(ThreadedListBase&& list) {
+    *tail_ = list.head_;
+    tail_ = list.tail_;
+    list.Clear();
+  }
+
+  void Prepend(ThreadedListBase&& list) {
+    if (list.head_ == nullptr) return;
+
+    T* new_head = list.head_;
+    *list.tail_ = head_;
+    if (head_ == nullptr) {
+      tail_ = list.tail_;
+    }
+    head_ = new_head;
+    list.Clear();
+  }
+
+  void Clear() {
+    head_ = nullptr;
+    tail_ = &head_;
+  }
+
+  ThreadedListBase& operator=(ThreadedListBase&& other) V8_NOEXCEPT {
+    head_ = other.head_;
+    tail_ = other.head_ ? other.tail_ : &head_;
+#ifdef DEBUG
+    other.Clear();
+#endif
+    return *this;
+  }
+
+  ThreadedListBase(ThreadedListBase&& other) V8_NOEXCEPT
+      : head_(other.head_),
+        tail_(other.head_ ? other.tail_ : &head_) {
+#ifdef DEBUG
+    other.Clear();
+#endif
+  }
+
+  bool Remove(T* v) {
+    T* current = first();
+    if (current == v) {
+      DropHead();
+      return true;
+    }
+
+    while (current != nullptr) {
+      T* next = *TLTraits::next(current);
+      if (next == v) {
+        *TLTraits::next(current) = *TLTraits::next(next);
+        *TLTraits::next(next) = nullptr;
+
+        if (TLTraits::next(next) == tail_) {
+          tail_ = TLTraits::next(current);
+        }
+        return true;
+      }
+      current = next;
+    }
+    return false;
+  }
+
+  class Iterator final {
+   public:
+    using iterator_category = std::forward_iterator_tag;
+    using difference_type = std::ptrdiff_t;
+    using value_type = T*;
+    using reference = value_type;
+    using pointer = value_type*;
+
+   public:
+    Iterator& operator++() {
+      entry_ = TLTraits::next(*entry_);
+      return *this;
+    }
+    bool operator==(const Iterator& other) const {
+      return entry_ == other.entry_;
+    }
+    bool operator!=(const Iterator& other) const {
+      return entry_ != other.entry_;
+    }
+    T* operator*() { return *entry_; }
+    T* operator->() { return *entry_; }
+    Iterator& operator=(T* entry) {
+      T* next = *TLTraits::next(*entry_);
+      *TLTraits::next(entry) = next;
+      *entry_ = entry;
+      return *this;
+    }
+
+   private:
+    explicit Iterator(T** entry) : entry_(entry) {}
+
+    T** entry_;
+
+    friend class ThreadedListBase;
+  };
+
+  class ConstIterator final {
+   public:
+    using iterator_category = std::forward_iterator_tag;
+    using difference_type = std::ptrdiff_t;
+    using value_type = T*;
+    using reference = const value_type;
+    using pointer = const value_type*;
+
+   public:
+    ConstIterator& operator++() {
+      entry_ = TLTraits::next(*entry_);
+      return *this;
+    }
+    bool operator==(const ConstIterator& other) const {
+      return entry_ == other.entry_;
+    }
+    bool operator!=(const ConstIterator& other) const {
+      return entry_ != other.entry_;
+    }
+    const T* operator*() const { return *entry_; }
+
+   private:
+    explicit ConstIterator(T* const* entry) : entry_(entry) {}
+
+    T* const* entry_;
+
+    friend class ThreadedListBase;
+  };
+
+  Iterator begin() { return Iterator(&head_); }
+  Iterator end() { return Iterator(tail_); }
+
+  ConstIterator begin() const { return ConstIterator(&head_); }
+  ConstIterator end() const { return ConstIterator(tail_); }
+
+  // Rewinds the list's tail to the reset point, i.e., cutting of the rest of
+  // the list, including the reset_point.
+  void Rewind(Iterator reset_point) {
+    tail_ = reset_point.entry_;
+    *tail_ = nullptr;
+  }
+
+  // Moves the tail of the from_list, starting at the from_location, to the end
+  // of this list.
+  void MoveTail(ThreadedListBase* from_list, Iterator from_location) {
+    if (from_list->end() != from_location) {
+      DCHECK_NULL(*tail_);
+      *tail_ = *from_location;
+      tail_ = from_list->tail_;
+      from_list->Rewind(from_location);
+    }
+  }
+
+  bool is_empty() const { return head_ == nullptr; }
+
+  T* first() const { return head_; }
+
+  // Slow. For testing purposes.
+  int LengthForTest() {
+    int result = 0;
+    for (Iterator t = begin(); t != end(); ++t) ++result;
+    return result;
+  }
+
+  T* AtForTest(int i) {
+    Iterator t = begin();
+    while (i-- > 0) ++t;
+    return *t;
+  }
+
+  bool Verify() {
+    T* last = this->first();
+    if (last == nullptr) {
+      CHECK_EQ(&head_, tail_);
+    } else {
+      while (*TLTraits::next(last) != nullptr) {
+        last = *TLTraits::next(last);
+      }
+      CHECK_EQ(TLTraits::next(last), tail_);
+    }
+    return true;
+  }
+
+ private:
+  T* head_;
+  T** tail_;
+  DISALLOW_COPY_AND_ASSIGN(ThreadedListBase);
+};
+
+struct EmptyBase {};
+
+template <typename T, typename TLTraits = ThreadedListTraits<T>>
+using ThreadedList = ThreadedListBase<T, EmptyBase, TLTraits>;
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_THREADED_LIST_H_
diff --git a/deps/v8/src/base/timezone-cache.h b/deps/v8/src/base/timezone-cache.h
index 96ad7bb41f..3d97eee126 100644
--- a/deps/v8/src/base/timezone-cache.h
+++ b/deps/v8/src/base/timezone-cache.h
@@ -27,7 +27,7 @@ class TimezoneCache {
   virtual void Clear() = 0;
 
   // Called when tearing down the isolate
-  virtual ~TimezoneCache() {}
+  virtual ~TimezoneCache() = default;
 };
 
 }  // namespace base
diff --git a/deps/v8/src/base/utils/random-number-generator.cc b/deps/v8/src/base/utils/random-number-generator.cc
index afe5a1f098..a3313f4e88 100644
--- a/deps/v8/src/base/utils/random-number-generator.cc
+++ b/deps/v8/src/base/utils/random-number-generator.cc
@@ -99,7 +99,7 @@ int RandomNumberGenerator::NextInt(int max) {
 
 double RandomNumberGenerator::NextDouble() {
   XorShift128(&state0_, &state1_);
-  return ToDouble(state0_, state1_);
+  return ToDouble(state0_);
 }
 
 
diff --git a/deps/v8/src/base/utils/random-number-generator.h b/deps/v8/src/base/utils/random-number-generator.h
index b4b67970c7..45ec259305 100644
--- a/deps/v8/src/base/utils/random-number-generator.h
+++ b/deps/v8/src/base/utils/random-number-generator.h
@@ -108,11 +108,10 @@ class V8_BASE_EXPORT RandomNumberGenerator final {
   int64_t initial_seed() const { return initial_seed_; }
 
   // Static and exposed for external use.
-  static inline double ToDouble(uint64_t state0, uint64_t state1) {
+  static inline double ToDouble(uint64_t state0) {
     // Exponent for double values for [1.0 .. 2.0)
     static const uint64_t kExponentBits = uint64_t{0x3FF0000000000000};
-    static const uint64_t kMantissaMask = uint64_t{0x000FFFFFFFFFFFFF};
-    uint64_t random = ((state0 + state1) & kMantissaMask) | kExponentBits;
+    uint64_t random = (state0 >> 12) | kExponentBits;
     return bit_cast<double>(random) - 1;
   }
 
@@ -128,6 +127,8 @@ class V8_BASE_EXPORT RandomNumberGenerator final {
     *state1 = s1;
   }
 
+  static uint64_t MurmurHash3(uint64_t);
+
  private:
   static const int64_t kMultiplier = V8_2PART_UINT64_C(0x5, deece66d);
   static const int64_t kAddend = 0xb;
@@ -135,8 +136,6 @@ class V8_BASE_EXPORT RandomNumberGenerator final {
 
   int Next(int bits) V8_WARN_UNUSED_RESULT;
 
-  static uint64_t MurmurHash3(uint64_t);
-
   int64_t initial_seed_;
   uint64_t state0_;
   uint64_t state1_;
diff --git a/deps/v8/src/basic-block-profiler.cc b/deps/v8/src/basic-block-profiler.cc
index eaecd5dc68..d79dbcdfa8 100644
--- a/deps/v8/src/basic-block-profiler.cc
+++ b/deps/v8/src/basic-block-profiler.cc
@@ -27,9 +27,6 @@ BasicBlockProfiler::Data::Data(size_t n_blocks)
       block_rpo_numbers_(n_blocks_),
       counts_(n_blocks_, 0) {}
 
-BasicBlockProfiler::Data::~Data() {}
-
-
 static void InsertIntoString(std::ostringstream* os, std::string* string) {
   string->insert(0, os->str());
 }
@@ -68,10 +65,6 @@ void BasicBlockProfiler::Data::ResetCounts() {
   }
 }
 
-
-BasicBlockProfiler::BasicBlockProfiler() {}
-
-
 BasicBlockProfiler::Data* BasicBlockProfiler::NewData(size_t n_blocks) {
   base::LockGuard<base::Mutex> lock(&data_list_mutex_);
   Data* data = new Data(n_blocks);
diff --git a/deps/v8/src/basic-block-profiler.h b/deps/v8/src/basic-block-profiler.h
index 975840e46e..835dda5356 100644
--- a/deps/v8/src/basic-block-profiler.h
+++ b/deps/v8/src/basic-block-profiler.h
@@ -36,7 +36,7 @@ class BasicBlockProfiler {
                                     const BasicBlockProfiler::Data& s);
 
     explicit Data(size_t n_blocks);
-    ~Data();
+    ~Data() = default;
 
     void ResetCounts();
 
@@ -51,7 +51,7 @@ class BasicBlockProfiler {
 
   typedef std::list<Data*> DataList;
 
-  BasicBlockProfiler();
+  BasicBlockProfiler() = default;
   ~BasicBlockProfiler();
 
   V8_EXPORT_PRIVATE static BasicBlockProfiler* Get();
diff --git a/deps/v8/src/bit-vector.h b/deps/v8/src/bit-vector.h
index ef87600753..5be3198cc6 100644
--- a/deps/v8/src/bit-vector.h
+++ b/deps/v8/src/bit-vector.h
@@ -21,7 +21,7 @@ class BitVector : public ZoneObject {
   };
 
   // Iterator for the elements of this BitVector.
-  class Iterator BASE_EMBEDDED {
+  class Iterator {
    public:
     explicit Iterator(BitVector* target)
         : target_(target),
@@ -31,7 +31,7 @@ class BitVector : public ZoneObject {
           current_(-1) {
       Advance();
     }
-    ~Iterator() {}
+    ~Iterator() = default;
 
     bool Done() const { return current_index_ >= target_->data_length_; }
     void Advance();
@@ -305,10 +305,9 @@ class BitVector : public ZoneObject {
   DISALLOW_COPY_AND_ASSIGN(BitVector);
 };
 
-
-class GrowableBitVector BASE_EMBEDDED {
+class GrowableBitVector {
  public:
-  class Iterator BASE_EMBEDDED {
+  class Iterator {
    public:
     Iterator(const GrowableBitVector* target, Zone* zone)
         : it_(target->bits_ == nullptr ? new (zone) BitVector(1, zone)
diff --git a/deps/v8/src/bootstrapper.cc b/deps/v8/src/bootstrapper.cc
index 30450b133b..d9104863aa 100644
--- a/deps/v8/src/bootstrapper.cc
+++ b/deps/v8/src/bootstrapper.cc
@@ -19,22 +19,30 @@
 #include "src/extensions/trigger-failure-extension.h"
 #include "src/heap/heap.h"
 #include "src/isolate-inl.h"
+#include "src/math-random.h"
 #include "src/objects/api-callbacks.h"
 #include "src/objects/arguments.h"
+#include "src/objects/builtin-function-id.h"
 #include "src/objects/hash-table-inl.h"
 #ifdef V8_INTL_SUPPORT
 #include "src/objects/intl-objects.h"
+#endif  // V8_INTL_SUPPORT
+#include "src/objects/js-array-buffer-inl.h"
+#include "src/objects/js-array-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/js-break-iterator.h"
 #include "src/objects/js-collator.h"
+#include "src/objects/js-date-time-format.h"
 #include "src/objects/js-list-format.h"
 #include "src/objects/js-locale.h"
+#include "src/objects/js-number-format.h"
+#include "src/objects/js-plural-rules.h"
 #endif  // V8_INTL_SUPPORT
-#include "src/objects/js-array-buffer-inl.h"
-#include "src/objects/js-array-inl.h"
 #include "src/objects/js-regexp-string-iterator.h"
 #include "src/objects/js-regexp.h"
 #ifdef V8_INTL_SUPPORT
-#include "src/objects/js-plural-rules.h"
 #include "src/objects/js-relative-time-format.h"
+#include "src/objects/js-segmenter.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/templates.h"
 #include "src/snapshot/natives.h"
@@ -89,7 +97,7 @@ Handle<String> Bootstrapper::GetNativeSource(NativeType type, int index) {
       new NativesExternalStringResource(type, index);
   Handle<ExternalOneByteString> source_code =
       isolate_->factory()->NewNativeSourceString(resource);
-  DCHECK(source_code->is_short());
+  DCHECK(source_code->is_uncached());
   return source_code;
 }
 
@@ -146,8 +154,7 @@ void Bootstrapper::TearDown() {
   extensions_cache_.Initialize(isolate_, false);  // Yes, symmetrical
 }
 
-
-class Genesis BASE_EMBEDDED {
+class Genesis {
  public:
   Genesis(Isolate* isolate, MaybeHandle<JSGlobalProxy> maybe_global_proxy,
           v8::Local<v8::ObjectTemplate> global_proxy_template,
@@ -156,7 +163,7 @@ class Genesis BASE_EMBEDDED {
           GlobalContextType context_type);
   Genesis(Isolate* isolate, MaybeHandle<JSGlobalProxy> maybe_global_proxy,
           v8::Local<v8::ObjectTemplate> global_proxy_template);
-  ~Genesis() { }
+  ~Genesis() = default;
 
   Isolate* isolate() const { return isolate_; }
   Factory* factory() const { return isolate_->factory(); }
@@ -503,10 +510,9 @@ V8_NOINLINE Handle<JSFunction> SimpleInstallFunction(
     const char* function_name, Builtins::Name call, int len, bool adapt,
     PropertyAttributes attrs = DONT_ENUM,
     BuiltinFunctionId id = BuiltinFunctionId::kInvalidBuiltinFunctionId) {
-  // Function name does not have to be internalized.
   return SimpleInstallFunction(
       isolate, base, property_name,
-      isolate->factory()->NewStringFromAsciiChecked(function_name), call, len,
+      isolate->factory()->InternalizeUtf8String(function_name), call, len,
       adapt, attrs, id);
 }
 
@@ -587,8 +593,7 @@ V8_NOINLINE Handle<JSFunction> SimpleInstallGetter(
 V8_NOINLINE void InstallConstant(Isolate* isolate, Handle<JSObject> holder,
                                  const char* name, Handle<Object> value) {
   JSObject::AddProperty(
-      isolate, holder, isolate->factory()->NewStringFromAsciiChecked(name),
-      value,
+      isolate, holder, isolate->factory()->InternalizeUtf8String(name), value,
       static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
 }
 
@@ -855,11 +860,10 @@ void Genesis::CreateIteratorMaps(Handle<JSFunction> empty) {
       factory()->NewJSObject(isolate()->object_function(), TENURED);
   JSObject::ForceSetPrototype(generator_function_prototype, empty);
 
-  JSObject::AddProperty(
-      isolate(), generator_function_prototype,
-      factory()->to_string_tag_symbol(),
-      factory()->NewStringFromAsciiChecked("GeneratorFunction"),
-      static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
+  JSObject::AddProperty(isolate(), generator_function_prototype,
+                        factory()->to_string_tag_symbol(),
+                        factory()->InternalizeUtf8String("GeneratorFunction"),
+                        static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   JSObject::AddProperty(isolate(), generator_function_prototype,
                         factory()->prototype_string(),
                         generator_object_prototype,
@@ -871,7 +875,7 @@ void Genesis::CreateIteratorMaps(Handle<JSFunction> empty) {
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   JSObject::AddProperty(isolate(), generator_object_prototype,
                         factory()->to_string_tag_symbol(),
-                        factory()->NewStringFromAsciiChecked("Generator"),
+                        factory()->InternalizeUtf8String("Generator"),
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   SimpleInstallFunction(isolate(), generator_object_prototype, "next",
                         Builtins::kGeneratorPrototypeNext, 1, false);
@@ -951,7 +955,7 @@ void Genesis::CreateAsyncIteratorMaps(Handle<JSFunction> empty) {
   JSObject::AddProperty(
       isolate(), async_from_sync_iterator_prototype,
       factory()->to_string_tag_symbol(),
-      factory()->NewStringFromAsciiChecked("Async-from-Sync Iterator"),
+      factory()->InternalizeUtf8String("Async-from-Sync Iterator"),
       static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
   JSObject::ForceSetPrototype(async_from_sync_iterator_prototype,
@@ -1001,7 +1005,7 @@ void Genesis::CreateAsyncIteratorMaps(Handle<JSFunction> empty) {
 
   JSObject::AddProperty(isolate(), async_generator_object_prototype,
                         factory()->to_string_tag_symbol(),
-                        factory()->NewStringFromAsciiChecked("AsyncGenerator"),
+                        factory()->InternalizeUtf8String("AsyncGenerator"),
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   SimpleInstallFunction(isolate(), async_generator_object_prototype, "next",
                         Builtins::kAsyncGeneratorPrototypeNext, 1, false);
@@ -1056,7 +1060,7 @@ void Genesis::CreateAsyncFunctionMaps(Handle<JSFunction> empty) {
 
   JSObject::AddProperty(isolate(), async_function_prototype,
                         factory()->to_string_tag_symbol(),
-                        factory()->NewStringFromAsciiChecked("AsyncFunction"),
+                        factory()->InternalizeUtf8String("AsyncFunction"),
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
   Handle<Map> map;
@@ -1263,7 +1267,7 @@ Handle<JSGlobalObject> Genesis::CreateNewGlobals(
         isolate());
     js_global_object_function = ApiNatives::CreateApiFunction(
         isolate(), js_global_object_constructor, factory()->the_hole_value(),
-        ApiNatives::GlobalObjectType);
+        JS_GLOBAL_OBJECT_TYPE);
   }
 
   js_global_object_function->initial_map()->set_is_prototype_map(true);
@@ -1289,7 +1293,7 @@ Handle<JSGlobalObject> Genesis::CreateNewGlobals(
         FunctionTemplateInfo::cast(data->constructor()), isolate());
     global_proxy_function = ApiNatives::CreateApiFunction(
         isolate(), global_constructor, factory()->the_hole_value(),
-        ApiNatives::GlobalProxyType);
+        JS_GLOBAL_PROXY_TYPE);
   }
   global_proxy_function->initial_map()->set_is_access_check_needed(true);
   global_proxy_function->initial_map()->set_has_hidden_prototype(true);
@@ -1731,6 +1735,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kArrayPrototypeFind, 1, false);
     SimpleInstallFunction(isolate_, proto, "findIndex",
                           Builtins::kArrayPrototypeFindIndex, 1, false);
+    SimpleInstallFunction(isolate_, proto, "lastIndexOf",
+                          Builtins::kArrayPrototypeLastIndexOf, 1, false);
     SimpleInstallFunction(isolate_, proto, "pop", Builtins::kArrayPrototypePop,
                           0, false);
     SimpleInstallFunction(isolate_, proto, "push",
@@ -1739,19 +1745,14 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kArrayPrototypeReverse, 0, false);
     SimpleInstallFunction(isolate_, proto, "shift",
                           Builtins::kArrayPrototypeShift, 0, false);
-    SimpleInstallFunction(isolate_, proto, "unshift", Builtins::kArrayUnshift,
-                          1, false);
+    SimpleInstallFunction(isolate_, proto, "unshift",
+                          Builtins::kArrayPrototypeUnshift, 1, false);
     SimpleInstallFunction(isolate_, proto, "slice",
                           Builtins::kArrayPrototypeSlice, 2, false);
     SimpleInstallFunction(isolate_, proto, "sort",
                           Builtins::kArrayPrototypeSort, 1, false);
-    if (FLAG_enable_experimental_builtins) {
-      SimpleInstallFunction(isolate_, proto, "splice",
-                            Builtins::kArraySpliceTorque, 2, false);
-    } else {
-      SimpleInstallFunction(isolate_, proto, "splice", Builtins::kArraySplice,
-                            2, false);
-    }
+    SimpleInstallFunction(isolate_, proto, "splice", Builtins::kArraySplice, 2,
+                          false);
     SimpleInstallFunction(isolate_, proto, "includes", Builtins::kArrayIncludes,
                           1, false);
     SimpleInstallFunction(isolate_, proto, "indexOf", Builtins::kArrayIndexOf,
@@ -1861,14 +1862,14 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         SimpleInstallFunction(isolate_, number_fun, "parseFloat",
                               Builtins::kNumberParseFloat, 1, true);
     JSObject::AddProperty(isolate_, global_object,
-                          factory->NewStringFromAsciiChecked("parseFloat"),
+                          factory->InternalizeUtf8String("parseFloat"),
                           parse_float_fun, DONT_ENUM);
 
     // Install Number.parseInt and Global.parseInt.
     Handle<JSFunction> parse_int_fun = SimpleInstallFunction(
         isolate_, number_fun, "parseInt", Builtins::kNumberParseInt, 2, true);
     JSObject::AddProperty(isolate_, global_object,
-                          factory->NewStringFromAsciiChecked("parseInt"),
+                          factory->InternalizeUtf8String("parseInt"),
                           parse_int_fun, DONT_ENUM);
 
     // Install Number constants
@@ -1879,14 +1880,14 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     Handle<Object> infinity = factory->infinity_value();
     Handle<Object> nan = factory->nan_value();
-    Handle<String> nan_name = factory->NewStringFromAsciiChecked("NaN");
+    Handle<String> nan_name = factory->InternalizeUtf8String("NaN");
 
     JSObject::AddProperty(
-        isolate_, number_fun, factory->NewStringFromAsciiChecked("MAX_VALUE"),
+        isolate_, number_fun, factory->InternalizeUtf8String("MAX_VALUE"),
         factory->NewNumber(kMaxValue),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
-        isolate_, number_fun, factory->NewStringFromAsciiChecked("MIN_VALUE"),
+        isolate_, number_fun, factory->InternalizeUtf8String("MIN_VALUE"),
         factory->NewNumber(kMinValue),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
@@ -1894,37 +1895,36 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
         isolate_, number_fun,
-        factory->NewStringFromAsciiChecked("NEGATIVE_INFINITY"),
+        factory->InternalizeUtf8String("NEGATIVE_INFINITY"),
         factory->NewNumber(-V8_INFINITY),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
         isolate_, number_fun,
-        factory->NewStringFromAsciiChecked("POSITIVE_INFINITY"), infinity,
+        factory->InternalizeUtf8String("POSITIVE_INFINITY"), infinity,
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
         isolate_, number_fun,
-        factory->NewStringFromAsciiChecked("MAX_SAFE_INTEGER"),
+        factory->InternalizeUtf8String("MAX_SAFE_INTEGER"),
         factory->NewNumber(kMaxSafeInteger),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
         isolate_, number_fun,
-        factory->NewStringFromAsciiChecked("MIN_SAFE_INTEGER"),
+        factory->InternalizeUtf8String("MIN_SAFE_INTEGER"),
         factory->NewNumber(kMinSafeInteger),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
-        isolate_, number_fun, factory->NewStringFromAsciiChecked("EPSILON"),
+        isolate_, number_fun, factory->InternalizeUtf8String("EPSILON"),
         factory->NewNumber(kEPS),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
 
     JSObject::AddProperty(
-        isolate_, global, factory->NewStringFromAsciiChecked("Infinity"),
-        infinity,
+        isolate_, global, factory->InternalizeUtf8String("Infinity"), infinity,
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
         isolate_, global, nan_name, nan,
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
     JSObject::AddProperty(
-        isolate_, global, factory->NewStringFromAsciiChecked("undefined"),
+        isolate_, global, factory->InternalizeUtf8String("undefined"),
         factory->undefined_value(),
         static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM | READ_ONLY));
   }
@@ -2086,10 +2086,23 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kStringPrototypeToString, 0, true);
     SimpleInstallFunction(isolate_, prototype, "trim",
                           Builtins::kStringPrototypeTrim, 0, false);
-    SimpleInstallFunction(isolate_, prototype, "trimLeft",
-                          Builtins::kStringPrototypeTrimStart, 0, false);
-    SimpleInstallFunction(isolate_, prototype, "trimRight",
-                          Builtins::kStringPrototypeTrimEnd, 0, false);
+
+    // Install `String.prototype.trimStart` with `trimLeft` alias.
+    Handle<JSFunction> trim_start_fun =
+        SimpleInstallFunction(isolate_, prototype, "trimStart",
+                              Builtins::kStringPrototypeTrimStart, 0, false);
+    JSObject::AddProperty(isolate_, prototype,
+                          factory->InternalizeUtf8String("trimLeft"),
+                          trim_start_fun, DONT_ENUM);
+
+    // Install `String.prototype.trimEnd` with `trimRight` alias.
+    Handle<JSFunction> trim_end_fun =
+        SimpleInstallFunction(isolate_, prototype, "trimEnd",
+                              Builtins::kStringPrototypeTrimEnd, 0, false);
+    JSObject::AddProperty(isolate_, prototype,
+                          factory->InternalizeUtf8String("trimRight"),
+                          trim_end_fun, DONT_ENUM);
+
     SimpleInstallFunction(isolate_, prototype, "toLocaleLowerCase",
                           Builtins::kStringPrototypeToLocaleLowerCase, 0,
                           false);
@@ -2126,7 +2139,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     JSObject::AddProperty(
         isolate_, string_iterator_prototype, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("String Iterator"),
+        factory->InternalizeUtf8String("String Iterator"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     SimpleInstallFunction(isolate_, string_iterator_prototype, "next",
@@ -2134,12 +2147,14 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           BuiltinFunctionId::kStringIteratorNext);
 
     Handle<JSFunction> string_iterator_function = CreateFunction(
-        isolate_, factory->NewStringFromAsciiChecked("StringIterator"),
+        isolate_, factory->InternalizeUtf8String("StringIterator"),
         JS_STRING_ITERATOR_TYPE, JSStringIterator::kSize, 0,
         string_iterator_prototype, Builtins::kIllegal);
     string_iterator_function->shared()->set_native(false);
-    native_context()->set_string_iterator_map(
+    native_context()->set_initial_string_iterator_map(
         string_iterator_function->initial_map());
+    native_context()->set_initial_string_iterator_prototype(
+        *string_iterator_prototype);
   }
 
   {  // --- S y m b o l ---
@@ -2186,14 +2201,16 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     // Install the @@toStringTag property on the {prototype}.
     JSObject::AddProperty(
         isolate_, prototype, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("Symbol"),
+        factory->InternalizeUtf8String("Symbol"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     // Install the Symbol.prototype methods.
     SimpleInstallFunction(isolate_, prototype, "toString",
-                          Builtins::kSymbolPrototypeToString, 0, true);
+                          Builtins::kSymbolPrototypeToString, 0, true,
+                          BuiltinFunctionId::kSymbolPrototypeToString);
     SimpleInstallFunction(isolate_, prototype, "valueOf",
-                          Builtins::kSymbolPrototypeValueOf, 0, true);
+                          Builtins::kSymbolPrototypeValueOf, 0, true,
+                          BuiltinFunctionId::kSymbolPrototypeValueOf);
 
     // Install the @@toPrimitive function.
     Handle<JSFunction> to_primitive = InstallFunction(
@@ -2319,6 +2336,14 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     SimpleInstallFunction(isolate_, prototype, "toJSON",
                           Builtins::kDatePrototypeToJson, 1, false);
 
+#ifdef V8_INTL_SUPPORT
+    SimpleInstallFunction(isolate_, prototype, "toLocaleString",
+                          Builtins::kDatePrototypeToLocaleString, 0, false);
+    SimpleInstallFunction(isolate_, prototype, "toLocaleDateString",
+                          Builtins::kDatePrototypeToLocaleDateString, 0, false);
+    SimpleInstallFunction(isolate_, prototype, "toLocaleTimeString",
+                          Builtins::kDatePrototypeToLocaleTimeString, 0, false);
+#else
     // Install Intl fallback functions.
     SimpleInstallFunction(isolate_, prototype, "toLocaleString",
                           Builtins::kDatePrototypeToString, 0, false);
@@ -2326,6 +2351,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kDatePrototypeToDateString, 0, false);
     SimpleInstallFunction(isolate_, prototype, "toLocaleTimeString",
                           Builtins::kDatePrototypeToTimeString, 0, false);
+#endif  // V8_INTL_SUPPORT
 
     // Install the @@toPrimitive function.
     Handle<JSFunction> to_primitive = InstallFunction(
@@ -2734,7 +2760,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kJsonStringify, 3, true);
     JSObject::AddProperty(
         isolate_, json_object, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("JSON"),
+        factory->InternalizeUtf8String("JSON"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   }
 
@@ -2815,7 +2841,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                     factory->NewNumber(std::sqrt(2.0)));
     JSObject::AddProperty(
         isolate_, math, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("Math"),
+        factory->InternalizeUtf8String("Math"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   }
 
@@ -2869,6 +2895,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kConsoleProfileEnd, 1, false, NONE);
     SimpleInstallFunction(isolate_, console, "time", Builtins::kConsoleTime, 1,
                           false, NONE);
+    SimpleInstallFunction(isolate_, console, "timeLog",
+                          Builtins::kConsoleTimeLog, 1, false, NONE);
     SimpleInstallFunction(isolate_, console, "timeEnd",
                           Builtins::kConsoleTimeEnd, 1, false, NONE);
     SimpleInstallFunction(isolate_, console, "timeStamp",
@@ -2877,7 +2905,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kConsoleContext, 1, true, NONE);
     JSObject::AddProperty(
         isolate_, console, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("Object"),
+        factory->InternalizeUtf8String("Object"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
   }
 
@@ -2890,11 +2918,22 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     {
       Handle<JSFunction> date_time_format_constructor = InstallFunction(
-          isolate_, intl, "DateTimeFormat", JS_OBJECT_TYPE, DateFormat::kSize,
-          0, factory->the_hole_value(), Builtins::kIllegal);
+          isolate_, intl, "DateTimeFormat", JS_INTL_DATE_TIME_FORMAT_TYPE,
+          JSDateTimeFormat::kSize, 0, factory->the_hole_value(),
+          Builtins::kDateTimeFormatConstructor);
+      date_time_format_constructor->shared()->set_length(0);
+      date_time_format_constructor->shared()->DontAdaptArguments();
+      InstallWithIntrinsicDefaultProto(
+          isolate_, date_time_format_constructor,
+          Context::INTL_DATE_TIME_FORMAT_FUNCTION_INDEX);
+
       native_context()->set_intl_date_time_format_function(
           *date_time_format_constructor);
 
+      SimpleInstallFunction(
+          isolate(), date_time_format_constructor, "supportedLocalesOf",
+          Builtins::kDateTimeFormatSupportedLocalesOf, 1, false);
+
       Handle<JSObject> prototype(
           JSObject::cast(date_time_format_constructor->prototype()), isolate_);
 
@@ -2904,6 +2943,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           factory->Object_string(),
           static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
+      SimpleInstallFunction(isolate_, prototype, "resolvedOptions",
+                            Builtins::kDateTimeFormatPrototypeResolvedOptions,
+                            0, false);
+
       SimpleInstallFunction(isolate_, prototype, "formatToParts",
                             Builtins::kDateTimeFormatPrototypeFormatToParts, 1,
                             false);
@@ -2911,21 +2954,22 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
       SimpleInstallGetter(isolate_, prototype,
                           factory->InternalizeUtf8String("format"),
                           Builtins::kDateTimeFormatPrototypeFormat, false);
-
-      {
-        Handle<SharedFunctionInfo> info = SimpleCreateBuiltinSharedFunctionInfo(
-            isolate_, Builtins::kDateTimeFormatInternalFormat,
-            factory->empty_string(), 1);
-        native_context()->set_date_format_internal_format_shared_fun(*info);
-      }
     }
 
     {
       Handle<JSFunction> number_format_constructor = InstallFunction(
-          isolate_, intl, "NumberFormat", JS_OBJECT_TYPE, NumberFormat::kSize,
-          0, factory->the_hole_value(), Builtins::kIllegal);
-      native_context()->set_intl_number_format_function(
-          *number_format_constructor);
+          isolate_, intl, "NumberFormat", JS_INTL_NUMBER_FORMAT_TYPE,
+          JSNumberFormat::kSize, 0, factory->the_hole_value(),
+          Builtins::kNumberFormatConstructor);
+      number_format_constructor->shared()->set_length(0);
+      number_format_constructor->shared()->DontAdaptArguments();
+      InstallWithIntrinsicDefaultProto(
+          isolate_, number_format_constructor,
+          Context::INTL_NUMBER_FORMAT_FUNCTION_INDEX);
+
+      SimpleInstallFunction(
+          isolate(), number_format_constructor, "supportedLocalesOf",
+          Builtins::kNumberFormatSupportedLocalesOf, 1, false);
 
       Handle<JSObject> prototype(
           JSObject::cast(number_format_constructor->prototype()), isolate_);
@@ -2936,20 +2980,16 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           factory->Object_string(),
           static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
+      SimpleInstallFunction(isolate_, prototype, "resolvedOptions",
+                            Builtins::kNumberFormatPrototypeResolvedOptions, 0,
+                            false);
+
       SimpleInstallFunction(isolate_, prototype, "formatToParts",
                             Builtins::kNumberFormatPrototypeFormatToParts, 1,
                             false);
       SimpleInstallGetter(isolate_, prototype,
                           factory->InternalizeUtf8String("format"),
                           Builtins::kNumberFormatPrototypeFormatNumber, false);
-
-      {
-        Handle<SharedFunctionInfo> info = SimpleCreateBuiltinSharedFunctionInfo(
-            isolate_, Builtins::kNumberFormatInternalFormatNumber,
-            factory->empty_string(), 1);
-        native_context()->set_number_format_internal_format_number_shared_fun(
-            *info);
-      }
     }
 
     {
@@ -2960,6 +3000,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
       InstallWithIntrinsicDefaultProto(isolate_, collator_constructor,
                                        Context::INTL_COLLATOR_FUNCTION_INDEX);
 
+      SimpleInstallFunction(isolate(), collator_constructor,
+                            "supportedLocalesOf",
+                            Builtins::kCollatorSupportedLocalesOf, 1, false);
+
       Handle<JSObject> prototype(
           JSObject::cast(collator_constructor->prototype()), isolate_);
 
@@ -2969,25 +3013,28 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           factory->Object_string(),
           static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
+      SimpleInstallFunction(isolate_, prototype, "resolvedOptions",
+                            Builtins::kCollatorPrototypeResolvedOptions, 0,
+                            false);
+
       SimpleInstallGetter(isolate_, prototype,
                           factory->InternalizeUtf8String("compare"),
                           Builtins::kCollatorPrototypeCompare, false);
-
-      {
-        Handle<SharedFunctionInfo> info = SimpleCreateBuiltinSharedFunctionInfo(
-            isolate_, Builtins::kCollatorInternalCompare,
-            factory->empty_string(), 2);
-        native_context()->set_collator_internal_compare_shared_fun(*info);
-      }
     }
 
     {
-      Handle<JSFunction> v8_break_iterator_constructor =
-          InstallFunction(isolate_, intl, "v8BreakIterator", JS_OBJECT_TYPE,
-                          V8BreakIterator::kSize, 0, factory->the_hole_value(),
-                          Builtins::kIllegal);
-      native_context()->set_intl_v8_break_iterator_function(
-          *v8_break_iterator_constructor);
+      Handle<JSFunction> v8_break_iterator_constructor = InstallFunction(
+          isolate_, intl, "v8BreakIterator", JS_INTL_V8_BREAK_ITERATOR_TYPE,
+          JSV8BreakIterator::kSize, 0, factory->the_hole_value(),
+          Builtins::kV8BreakIteratorConstructor);
+      v8_break_iterator_constructor->shared()->DontAdaptArguments();
+      InstallWithIntrinsicDefaultProto(
+          isolate_, v8_break_iterator_constructor,
+          Context::INTL_V8_BREAK_ITERATOR_FUNCTION_INDEX);
+
+      SimpleInstallFunction(
+          isolate_, v8_break_iterator_constructor, "supportedLocalesOf",
+          Builtins::kV8BreakIteratorSupportedLocalesOf, 1, false);
 
       Handle<JSObject> prototype(
           JSObject::cast(v8_break_iterator_constructor->prototype()), isolate_);
@@ -2998,17 +3045,29 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           factory->Object_string(),
           static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
+      SimpleInstallFunction(isolate_, prototype, "resolvedOptions",
+                            Builtins::kV8BreakIteratorPrototypeResolvedOptions,
+                            0, false);
+
       SimpleInstallGetter(isolate_, prototype,
                           factory->InternalizeUtf8String("adoptText"),
-                          Builtins::kBreakIteratorPrototypeAdoptText, false);
+                          Builtins::kV8BreakIteratorPrototypeAdoptText, false);
 
-      {
-        Handle<SharedFunctionInfo> info = SimpleCreateBuiltinSharedFunctionInfo(
-            isolate_, Builtins::kBreakIteratorInternalAdoptText,
-            factory->empty_string(), 1);
-        native_context()->set_break_iterator_internal_adopt_text_shared_fun(
-            *info);
-      }
+      SimpleInstallGetter(isolate_, prototype,
+                          factory->InternalizeUtf8String("first"),
+                          Builtins::kV8BreakIteratorPrototypeFirst, false);
+
+      SimpleInstallGetter(isolate_, prototype,
+                          factory->InternalizeUtf8String("next"),
+                          Builtins::kV8BreakIteratorPrototypeNext, false);
+
+      SimpleInstallGetter(isolate_, prototype,
+                          factory->InternalizeUtf8String("current"),
+                          Builtins::kV8BreakIteratorPrototypeCurrent, false);
+
+      SimpleInstallGetter(isolate_, prototype,
+                          factory->InternalizeUtf8String("breakType"),
+                          Builtins::kV8BreakIteratorPrototypeBreakType, false);
     }
 
     {
@@ -3021,6 +3080,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           isolate_, plural_rules_constructor,
           Context::INTL_PLURAL_RULES_FUNCTION_INDEX);
 
+      SimpleInstallFunction(isolate(), plural_rules_constructor,
+                            "supportedLocalesOf",
+                            Builtins::kPluralRulesSupportedLocalesOf, 1, false);
+
       Handle<JSObject> prototype(
           JSObject::cast(plural_rules_constructor->prototype()), isolate_);
 
@@ -3029,6 +3092,13 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           isolate_, prototype, factory->to_string_tag_symbol(),
           factory->Object_string(),
           static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
+
+      SimpleInstallFunction(isolate_, prototype, "resolvedOptions",
+                            Builtins::kPluralRulesPrototypeResolvedOptions, 0,
+                            false);
+
+      SimpleInstallFunction(isolate_, prototype, "select",
+                            Builtins::kPluralRulesPrototypeSelect, 1, false);
     }
   }
 #endif  // V8_INTL_SUPPORT
@@ -3043,7 +3113,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     Handle<JSFunction> array_buffer_noinit_fun = SimpleCreateFunction(
         isolate_,
-        factory->NewStringFromAsciiChecked(
+        factory->InternalizeUtf8String(
             "arrayBufferConstructor_DoNotInitialize"),
         Builtins::kArrayBufferConstructor_DoNotInitialize, 1, false);
     native_context()->set_array_buffer_noinit_fun(*array_buffer_noinit_fun);
@@ -3088,7 +3158,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     SimpleInstallFunction(isolate_, atomics_object, "wake",
                           Builtins::kAtomicsWake, 3, true);
     SimpleInstallFunction(isolate_, atomics_object, "notify",
-                          Builtins::kAtomicsWake, 3, true);
+                          Builtins::kAtomicsNotify, 3, true);
   }
 
   {  // -- T y p e d A r r a y
@@ -3213,7 +3283,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     // Install the @@toStringTag property on the {prototype}.
     JSObject::AddProperty(
         isolate_, prototype, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("DataView"),
+        factory->InternalizeUtf8String("DataView"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     // Install the "buffer", "byteOffset" and "byteLength" getters
@@ -3260,6 +3330,14 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kDataViewPrototypeGetFloat64, 1, false);
     SimpleInstallFunction(isolate_, prototype, "setFloat64",
                           Builtins::kDataViewPrototypeSetFloat64, 2, false);
+    SimpleInstallFunction(isolate_, prototype, "getBigInt64",
+                          Builtins::kDataViewPrototypeGetBigInt64, 1, false);
+    SimpleInstallFunction(isolate_, prototype, "setBigInt64",
+                          Builtins::kDataViewPrototypeSetBigInt64, 2, false);
+    SimpleInstallFunction(isolate_, prototype, "getBigUint64",
+                          Builtins::kDataViewPrototypeGetBigUint64, 1, false);
+    SimpleInstallFunction(isolate_, prototype, "setBigUint64",
+                          Builtins::kDataViewPrototypeSetBigUint64, 2, false);
   }
 
   {  // -- M a p
@@ -3321,6 +3399,48 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     InstallSpeciesGetter(isolate_, js_map_fun);
   }
 
+  {  // -- B i g I n t
+    Handle<JSFunction> bigint_fun = InstallFunction(
+        isolate_, global, "BigInt", JS_VALUE_TYPE, JSValue::kSize, 0,
+        factory->the_hole_value(), Builtins::kBigIntConstructor);
+    bigint_fun->shared()->set_builtin_function_id(
+        BuiltinFunctionId::kBigIntConstructor);
+    bigint_fun->shared()->DontAdaptArguments();
+    bigint_fun->shared()->set_length(1);
+    InstallWithIntrinsicDefaultProto(isolate_, bigint_fun,
+                                     Context::BIGINT_FUNCTION_INDEX);
+
+    // Install the properties of the BigInt constructor.
+    // asUintN(bits, bigint)
+    SimpleInstallFunction(isolate_, bigint_fun, "asUintN",
+                          Builtins::kBigIntAsUintN, 2, false);
+    // asIntN(bits, bigint)
+    SimpleInstallFunction(isolate_, bigint_fun, "asIntN",
+                          Builtins::kBigIntAsIntN, 2, false);
+
+    // Set up the %BigIntPrototype%.
+    Handle<JSObject> prototype(JSObject::cast(bigint_fun->instance_prototype()),
+                               isolate_);
+    JSFunction::SetPrototype(bigint_fun, prototype);
+
+    // Install the properties of the BigInt.prototype.
+    // "constructor" is created implicitly by InstallFunction() above.
+    // toLocaleString([reserved1 [, reserved2]])
+    SimpleInstallFunction(isolate_, prototype, "toLocaleString",
+                          Builtins::kBigIntPrototypeToLocaleString, 0, false);
+    // toString([radix])
+    SimpleInstallFunction(isolate_, prototype, "toString",
+                          Builtins::kBigIntPrototypeToString, 0, false);
+    // valueOf()
+    SimpleInstallFunction(isolate_, prototype, "valueOf",
+                          Builtins::kBigIntPrototypeValueOf, 0, false);
+    // @@toStringTag
+    JSObject::AddProperty(
+        isolate_, prototype, factory->to_string_tag_symbol(),
+        factory->BigInt_string(),
+        static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
+  }
+
   {  // -- S e t
     Handle<JSFunction> js_set_fun =
         InstallFunction(isolate_, global, "Set", JS_SET_TYPE, JSSet::kSize, 0,
@@ -3435,8 +3555,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     SimpleInstallFunction(isolate_, prototype, "delete",
                           Builtins::kWeakMapPrototypeDelete, 1, true);
-    SimpleInstallFunction(isolate_, prototype, "get", Builtins::kWeakMapGet, 1,
-                          true);
+    Handle<JSFunction> weakmap_get = SimpleInstallFunction(
+        isolate_, prototype, "get", Builtins::kWeakMapGet, 1, true);
+    native_context()->set_weakmap_get(*weakmap_get);
     SimpleInstallFunction(isolate_, prototype, "has", Builtins::kWeakMapHas, 1,
                           true);
     Handle<JSFunction> weakmap_set = SimpleInstallFunction(
@@ -3445,7 +3566,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     JSObject::AddProperty(
         isolate_, prototype, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("WeakMap"),
+        factory->InternalizeUtf8String("WeakMap"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     native_context()->set_initial_weakmap_prototype_map(prototype->map());
@@ -3476,7 +3597,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     JSObject::AddProperty(
         isolate_, prototype, factory->to_string_tag_symbol(),
-        factory->NewStringFromAsciiChecked("WeakSet"),
+        factory->InternalizeUtf8String("WeakSet"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     native_context()->set_initial_weakset_prototype_map(prototype->map());
@@ -3852,8 +3973,7 @@ bool Bootstrapper::CompileNative(Isolate* isolate, Vector<const char> name,
 bool Genesis::CallUtilsFunction(Isolate* isolate, const char* name) {
   Handle<JSObject> utils =
       Handle<JSObject>::cast(isolate->natives_utils_object());
-  Handle<String> name_string =
-      isolate->factory()->NewStringFromAsciiChecked(name);
+  Handle<String> name_string = isolate->factory()->InternalizeUtf8String(name);
   Handle<Object> fun = JSObject::GetDataProperty(utils, name_string);
   Handle<Object> receiver = isolate->factory()->undefined_value();
   Handle<Object> args[] = {utils};
@@ -3975,17 +4095,17 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
   Factory* factory = isolate->factory();
   HandleScope scope(isolate);
   Handle<NativeContext> native_context = isolate->native_context();
-#define EXPORT_PRIVATE_SYMBOL(NAME)                                       \
-  Handle<String> NAME##_name = factory->NewStringFromAsciiChecked(#NAME); \
+#define EXPORT_PRIVATE_SYMBOL(_, NAME)                                \
+  Handle<String> NAME##_name = factory->InternalizeUtf8String(#NAME); \
   JSObject::AddProperty(isolate, container, NAME##_name, factory->NAME(), NONE);
-  PRIVATE_SYMBOL_LIST(EXPORT_PRIVATE_SYMBOL)
+  PRIVATE_SYMBOL_LIST_GENERATOR(EXPORT_PRIVATE_SYMBOL, /* not used */)
 #undef EXPORT_PRIVATE_SYMBOL
 
-#define EXPORT_PUBLIC_SYMBOL(NAME, DESCRIPTION)                           \
-  Handle<String> NAME##_name = factory->NewStringFromAsciiChecked(#NAME); \
+#define EXPORT_PUBLIC_SYMBOL(_, NAME, DESCRIPTION)                    \
+  Handle<String> NAME##_name = factory->InternalizeUtf8String(#NAME); \
   JSObject::AddProperty(isolate, container, NAME##_name, factory->NAME(), NONE);
-  PUBLIC_SYMBOL_LIST(EXPORT_PUBLIC_SYMBOL)
-  WELL_KNOWN_SYMBOL_LIST(EXPORT_PUBLIC_SYMBOL)
+  PUBLIC_SYMBOL_LIST_GENERATOR(EXPORT_PUBLIC_SYMBOL, /* not used */)
+  WELL_KNOWN_SYMBOL_LIST_GENERATOR(EXPORT_PUBLIC_SYMBOL, /* not used */)
 #undef EXPORT_PUBLIC_SYMBOL
 
   Handle<JSObject> iterator_prototype(
@@ -4238,6 +4358,7 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
            Builtins::kCallSitePrototypeGetScriptNameOrSourceURL},
           {"getThis", Builtins::kCallSitePrototypeGetThis},
           {"getTypeName", Builtins::kCallSitePrototypeGetTypeName},
+          {"isAsync", Builtins::kCallSitePrototypeIsAsync},
           {"isConstructor", Builtins::kCallSitePrototypeIsConstructor},
           {"isEval", Builtins::kCallSitePrototypeIsEval},
           {"isNative", Builtins::kCallSitePrototypeIsNative},
@@ -4261,7 +4382,6 @@ void Bootstrapper::ExportFromRuntime(Isolate* isolate,
   void Genesis::InitializeGlobal_##id() {}
 
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_do_expressions)
-EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_function_tostring)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_public_fields)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_private_fields)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_static_fields)
@@ -4269,6 +4389,9 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_class_fields)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_dynamic_import)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_import_meta)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_numeric_separator)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_json_stringify)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_sequence)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_await_optimization)
 
 #undef EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE
 
@@ -4305,40 +4428,6 @@ void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {
   }
 }
 
-void Genesis::InitializeGlobal_harmony_string_trimming() {
-  if (!FLAG_harmony_string_trimming) return;
-
-  Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
-  Factory* factory = isolate()->factory();
-
-  Handle<JSObject> string_prototype(
-      native_context()->initial_string_prototype(), isolate());
-
-  {
-    Handle<String> trim_left_name = factory->InternalizeUtf8String("trimLeft");
-    Handle<String> trim_start_name =
-        factory->InternalizeUtf8String("trimStart");
-    Handle<JSFunction> trim_left_fun = Handle<JSFunction>::cast(
-        JSObject::GetProperty(isolate_, string_prototype, trim_left_name)
-            .ToHandleChecked());
-    JSObject::AddProperty(isolate_, string_prototype, trim_start_name,
-                          trim_left_fun, DONT_ENUM);
-    trim_left_fun->shared()->SetName(*trim_start_name);
-  }
-
-  {
-    Handle<String> trim_right_name =
-        factory->InternalizeUtf8String("trimRight");
-    Handle<String> trim_end_name = factory->InternalizeUtf8String("trimEnd");
-    Handle<JSFunction> trim_right_fun = Handle<JSFunction>::cast(
-        JSObject::GetProperty(isolate_, string_prototype, trim_right_name)
-            .ToHandleChecked());
-    JSObject::AddProperty(isolate_, string_prototype, trim_end_name,
-                          trim_right_fun, DONT_ENUM);
-    trim_right_fun->shared()->SetName(*trim_end_name);
-  }
-}
-
 void Genesis::InitializeGlobal_harmony_array_prototype_values() {
   if (!FLAG_harmony_array_prototype_values) return;
   Handle<JSFunction> array_constructor(native_context()->array_function(),
@@ -4425,7 +4514,7 @@ void Genesis::InitializeGlobal_harmony_string_matchall() {
     JSObject::AddProperty(
         isolate(), regexp_string_iterator_prototype,
         factory()->to_string_tag_symbol(),
-        factory()->NewStringFromAsciiChecked("RegExp String Iterator"),
+        factory()->InternalizeUtf8String("RegExp String Iterator"),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     SimpleInstallFunction(isolate(), regexp_string_iterator_prototype, "next",
@@ -4433,7 +4522,7 @@ void Genesis::InitializeGlobal_harmony_string_matchall() {
                           true);
 
     Handle<JSFunction> regexp_string_iterator_function = CreateFunction(
-        isolate(), factory()->NewStringFromAsciiChecked("RegExpStringIterator"),
+        isolate(), factory()->InternalizeUtf8String("RegExpStringIterator"),
         JS_REGEXP_STRING_ITERATOR_TYPE, JSRegExpStringIterator::kSize, 0,
         regexp_string_iterator_prototype, Builtins::kIllegal);
     regexp_string_iterator_function->shared()->set_native(false);
@@ -4449,126 +4538,6 @@ void Genesis::InitializeGlobal_harmony_string_matchall() {
   }
 }
 
-void Genesis::InitializeGlobal_harmony_bigint() {
-  Factory* factory = isolate()->factory();
-  Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
-  if (!FLAG_harmony_bigint) {
-    // Typed arrays are installed by default; remove them if the flag is off.
-    CHECK(JSObject::DeleteProperty(
-              global, factory->InternalizeUtf8String("BigInt64Array"))
-              .ToChecked());
-    CHECK(JSObject::DeleteProperty(
-              global, factory->InternalizeUtf8String("BigUint64Array"))
-              .ToChecked());
-    return;
-  }
-
-  Handle<JSFunction> bigint_fun = InstallFunction(
-      isolate(), global, "BigInt", JS_VALUE_TYPE, JSValue::kSize, 0,
-      factory->the_hole_value(), Builtins::kBigIntConstructor);
-  bigint_fun->shared()->set_builtin_function_id(
-      BuiltinFunctionId::kBigIntConstructor);
-  bigint_fun->shared()->DontAdaptArguments();
-  bigint_fun->shared()->set_length(1);
-  InstallWithIntrinsicDefaultProto(isolate(), bigint_fun,
-                                   Context::BIGINT_FUNCTION_INDEX);
-
-  // Install the properties of the BigInt constructor.
-  // asUintN(bits, bigint)
-  SimpleInstallFunction(isolate(), bigint_fun, "asUintN",
-                        Builtins::kBigIntAsUintN, 2, false);
-  // asIntN(bits, bigint)
-  SimpleInstallFunction(isolate(), bigint_fun, "asIntN",
-                        Builtins::kBigIntAsIntN, 2, false);
-
-  // Set up the %BigIntPrototype%.
-  Handle<JSObject> prototype(JSObject::cast(bigint_fun->instance_prototype()),
-                             isolate());
-  JSFunction::SetPrototype(bigint_fun, prototype);
-
-  // Install the properties of the BigInt.prototype.
-  // "constructor" is created implicitly by InstallFunction() above.
-  // toLocaleString([reserved1 [, reserved2]])
-  SimpleInstallFunction(isolate(), prototype, "toLocaleString",
-                        Builtins::kBigIntPrototypeToLocaleString, 0, false);
-  // toString([radix])
-  SimpleInstallFunction(isolate(), prototype, "toString",
-                        Builtins::kBigIntPrototypeToString, 0, false);
-  // valueOf()
-  SimpleInstallFunction(isolate(), prototype, "valueOf",
-                        Builtins::kBigIntPrototypeValueOf, 0, false);
-  // @@toStringTag
-  JSObject::AddProperty(isolate(), prototype, factory->to_string_tag_symbol(),
-                        factory->BigInt_string(),
-                        static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
-
-  // Install 64-bit DataView accessors.
-  // TODO(jkummerow): Move these to the "DataView" section when dropping the
-  // FLAG_harmony_bigint.
-  Handle<JSObject> dataview_prototype(
-      JSObject::cast(native_context()->data_view_fun()->instance_prototype()),
-      isolate());
-  SimpleInstallFunction(isolate(), dataview_prototype, "getBigInt64",
-                        Builtins::kDataViewPrototypeGetBigInt64, 1, false);
-  SimpleInstallFunction(isolate(), dataview_prototype, "setBigInt64",
-                        Builtins::kDataViewPrototypeSetBigInt64, 2, false);
-  SimpleInstallFunction(isolate(), dataview_prototype, "getBigUint64",
-                        Builtins::kDataViewPrototypeGetBigUint64, 1, false);
-  SimpleInstallFunction(isolate(), dataview_prototype, "setBigUint64",
-                        Builtins::kDataViewPrototypeSetBigUint64, 2, false);
-}
-
-void Genesis::InitializeGlobal_harmony_await_optimization() {
-  if (!FLAG_harmony_await_optimization) return;
-
-  // async/await
-  Handle<JSFunction> await_caught_function = SimpleCreateFunction(
-      isolate(), factory()->empty_string(),
-      Builtins::kAsyncFunctionAwaitCaughtOptimized, 2, false);
-  native_context()->set_async_function_await_caught(*await_caught_function);
-
-  Handle<JSFunction> await_uncaught_function = SimpleCreateFunction(
-      isolate(), factory()->empty_string(),
-      Builtins::kAsyncFunctionAwaitUncaughtOptimized, 2, false);
-  native_context()->set_async_function_await_uncaught(*await_uncaught_function);
-
-  // async generators
-  Handle<JSObject> async_iterator_prototype =
-      factory()->NewJSObject(isolate()->object_function(), TENURED);
-
-  SimpleInstallFunction(
-      isolate(), async_iterator_prototype, factory()->async_iterator_symbol(),
-      "[Symbol.asyncIterator]", Builtins::kReturnReceiver, 0, true);
-
-  Handle<JSObject> async_from_sync_iterator_prototype =
-      factory()->NewJSObject(isolate()->object_function(), TENURED);
-  SimpleInstallFunction(
-      isolate(), async_from_sync_iterator_prototype, factory()->next_string(),
-      Builtins::kAsyncFromSyncIteratorPrototypeNextOptimized, 1, true);
-  SimpleInstallFunction(
-      isolate(), async_from_sync_iterator_prototype, factory()->return_string(),
-      Builtins::kAsyncFromSyncIteratorPrototypeReturnOptimized, 1, true);
-  SimpleInstallFunction(
-      isolate(), async_from_sync_iterator_prototype, factory()->throw_string(),
-      Builtins::kAsyncFromSyncIteratorPrototypeThrowOptimized, 1, true);
-
-  JSObject::AddProperty(
-      isolate(), async_from_sync_iterator_prototype,
-      factory()->to_string_tag_symbol(),
-      factory()->NewStringFromAsciiChecked("Async-from-Sync Iterator"),
-      static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
-
-  JSObject::ForceSetPrototype(async_from_sync_iterator_prototype,
-                              async_iterator_prototype);
-
-  Handle<Map> async_from_sync_iterator_map = factory()->NewMap(
-      JS_ASYNC_FROM_SYNC_ITERATOR_TYPE, JSAsyncFromSyncIterator::kSize);
-  Map::SetPrototype(isolate(), async_from_sync_iterator_map,
-                    async_from_sync_iterator_prototype);
-  native_context()->set_async_from_sync_iterator_map(
-      *async_from_sync_iterator_map);
-}
-
 #ifdef V8_INTL_SUPPORT
 void Genesis::InitializeGlobal_harmony_intl_list_format() {
   if (!FLAG_harmony_intl_list_format) return;
@@ -4586,13 +4555,16 @@ void Genesis::InitializeGlobal_harmony_intl_list_format() {
   list_format_fun->shared()->set_length(0);
   list_format_fun->shared()->DontAdaptArguments();
 
+  SimpleInstallFunction(isolate(), list_format_fun, "supportedLocalesOf",
+                        Builtins::kListFormatSupportedLocalesOf, 1, false);
+
   // Setup %ListFormatPrototype%.
   Handle<JSObject> prototype(
       JSObject::cast(list_format_fun->instance_prototype()), isolate());
 
   // Install the @@toStringTag property on the {prototype}.
   JSObject::AddProperty(isolate(), prototype, factory()->to_string_tag_symbol(),
-                        factory()->NewStringFromStaticChars("Intl.ListFormat"),
+                        factory()->InternalizeUtf8String("Intl.ListFormat"),
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
   SimpleInstallFunction(isolate(), prototype, "resolvedOptions",
@@ -4628,7 +4600,7 @@ void Genesis::InitializeGlobal_harmony_locale() {
 
   // Install the @@toStringTag property on the {prototype}.
   JSObject::AddProperty(isolate(), prototype, factory()->to_string_tag_symbol(),
-                        factory()->NewStringFromAsciiChecked("Locale"),
+                        factory()->InternalizeUtf8String("Intl.Locale"),
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
   SimpleInstallFunction(isolate(), prototype, "toString",
@@ -4687,6 +4659,10 @@ void Genesis::InitializeGlobal_harmony_intl_relative_time_format() {
   relative_time_format_fun->shared()->set_length(0);
   relative_time_format_fun->shared()->DontAdaptArguments();
 
+  SimpleInstallFunction(
+      isolate(), relative_time_format_fun, "supportedLocalesOf",
+      Builtins::kRelativeTimeFormatSupportedLocalesOf, 1, false);
+
   // Setup %RelativeTimeFormatPrototype%.
   Handle<JSObject> prototype(
       JSObject::cast(relative_time_format_fun->instance_prototype()),
@@ -4695,7 +4671,7 @@ void Genesis::InitializeGlobal_harmony_intl_relative_time_format() {
   // Install the @@toStringTag property on the {prototype}.
   JSObject::AddProperty(
       isolate(), prototype, factory()->to_string_tag_symbol(),
-      factory()->NewStringFromStaticChars("Intl.RelativeTimeFormat"),
+      factory()->InternalizeUtf8String("Intl.RelativeTimeFormat"),
       static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
   SimpleInstallFunction(isolate(), prototype, "resolvedOptions",
@@ -4708,6 +4684,37 @@ void Genesis::InitializeGlobal_harmony_intl_relative_time_format() {
                         false);
 }
 
+void Genesis::InitializeGlobal_harmony_intl_segmenter() {
+  if (!FLAG_harmony_intl_segmenter) return;
+  Handle<JSObject> intl = Handle<JSObject>::cast(
+      JSReceiver::GetProperty(
+          isolate(),
+          Handle<JSReceiver>(native_context()->global_object(), isolate()),
+          factory()->InternalizeUtf8String("Intl"))
+          .ToHandleChecked());
+
+  Handle<JSFunction> segmenter_fun = InstallFunction(
+      isolate(), intl, "Segmenter", JS_INTL_SEGMENTER_TYPE, JSSegmenter::kSize,
+      0, factory()->the_hole_value(), Builtins::kSegmenterConstructor);
+  segmenter_fun->shared()->set_length(0);
+  segmenter_fun->shared()->DontAdaptArguments();
+
+  SimpleInstallFunction(isolate(), segmenter_fun, "supportedLocalesOf",
+                        Builtins::kSegmenterSupportedLocalesOf, 1, false);
+
+  // Setup %SegmenterPrototype%.
+  Handle<JSObject> prototype(
+      JSObject::cast(segmenter_fun->instance_prototype()), isolate());
+
+  // Install the @@toStringTag property on the {prototype}.
+  JSObject::AddProperty(isolate(), prototype, factory()->to_string_tag_symbol(),
+                        factory()->NewStringFromStaticChars("Intl.Segmenter"),
+                        static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
+
+  SimpleInstallFunction(isolate(), prototype, "resolvedOptions",
+                        Builtins::kSegmenterPrototypeResolvedOptions, 0, false);
+}
+
 #endif  // V8_INTL_SUPPORT
 
 Handle<JSFunction> Genesis::CreateArrayBuffer(
@@ -4826,7 +4833,7 @@ bool Genesis::InstallNatives(GlobalContextType context_type) {
                            Builtins::kPromiseInternalConstructor, 1, true);
   promise_internal_constructor->shared()->set_native(false);
   InstallFunction(isolate(), extras_utils, promise_internal_constructor,
-                  factory()->NewStringFromAsciiChecked("createPromise"));
+                  factory()->InternalizeUtf8String("createPromise"));
 
   // v8.rejectPromise(promise, reason)
   Handle<JSFunction> promise_internal_reject =
@@ -4834,7 +4841,7 @@ bool Genesis::InstallNatives(GlobalContextType context_type) {
                            Builtins::kPromiseInternalReject, 2, true);
   promise_internal_reject->shared()->set_native(false);
   InstallFunction(isolate(), extras_utils, promise_internal_reject,
-                  factory()->NewStringFromAsciiChecked("rejectPromise"));
+                  factory()->InternalizeUtf8String("rejectPromise"));
 
   // v8.resolvePromise(promise, resolution)
   Handle<JSFunction> promise_internal_resolve =
@@ -4842,10 +4849,10 @@ bool Genesis::InstallNatives(GlobalContextType context_type) {
                            Builtins::kPromiseInternalResolve, 2, true);
   promise_internal_resolve->shared()->set_native(false);
   InstallFunction(isolate(), extras_utils, promise_internal_resolve,
-                  factory()->NewStringFromAsciiChecked("resolvePromise"));
+                  factory()->InternalizeUtf8String("resolvePromise"));
 
   InstallFunction(isolate(), extras_utils, isolate()->is_promise(),
-                  factory()->NewStringFromAsciiChecked("isPromise"));
+                  factory()->InternalizeUtf8String("isPromise"));
 
   int builtin_index = Natives::GetDebuggerCount();
   // Only run prologue.js at this point.
@@ -5708,6 +5715,7 @@ Genesis::Genesis(
     DCHECK_EQ(0u, context_snapshot_index);
     // We get here if there was no context snapshot.
     CreateRoots();
+    MathRandom::InitializeContext(isolate, native_context());
     Handle<JSFunction> empty_function = CreateEmptyFunction();
     CreateSloppyModeFunctionMaps(empty_function);
     CreateStrictModeFunctionMaps(empty_function);
diff --git a/deps/v8/src/bootstrapper.h b/deps/v8/src/bootstrapper.h
index e3ba8c06f2..4ad02eb836 100644
--- a/deps/v8/src/bootstrapper.h
+++ b/deps/v8/src/bootstrapper.h
@@ -18,7 +18,7 @@ namespace internal {
 // (array.js, etc.) to precompiled functions. Instead of mapping
 // names to functions it might make sense to let the JS2C tool
 // generate an index for each native JS file.
-class SourceCodeCache final BASE_EMBEDDED {
+class SourceCodeCache final {
  public:
   explicit SourceCodeCache(Script::Type type) : type_(type), cache_(nullptr) {}
 
@@ -122,8 +122,7 @@ class Bootstrapper final {
   DISALLOW_COPY_AND_ASSIGN(Bootstrapper);
 };
 
-
-class BootstrapperActive final BASE_EMBEDDED {
+class BootstrapperActive final {
  public:
   explicit BootstrapperActive(Bootstrapper* bootstrapper)
       : bootstrapper_(bootstrapper) {
diff --git a/deps/v8/src/builtins/arm/builtins-arm.cc b/deps/v8/src/builtins/arm/builtins-arm.cc
index c18811a4b6..92cb6df45d 100644
--- a/deps/v8/src/builtins/arm/builtins-arm.cc
+++ b/deps/v8/src/builtins/arm/builtins-arm.cc
@@ -60,8 +60,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  // tail call a stub
-  __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -122,7 +120,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ SmiUntag(r0);
 
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
 
     // Set up pointer to last argument.
     __ add(r4, fp, Operand(StandardFrameConstants::kCallerSPOffset));
@@ -169,6 +167,20 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
   __ Jump(lr);
 }
 
+void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
+                                 Register scratch, Label* stack_overflow) {
+  // Check the stack for overflow. We are not trying to catch
+  // interruptions (e.g. debug break and preemption) here, so the "real stack
+  // limit" is checked.
+  __ LoadRoot(scratch, RootIndex::kRealStackLimit);
+  // Make scratch the space we have left. The stack might already be overflowed
+  // here which will cause scratch to become negative.
+  __ sub(scratch, sp, scratch);
+  // Check if the arguments will overflow the stack.
+  __ cmp(scratch, Operand(num_args, LSL, kPointerSizeLog2));
+  __ b(le, stack_overflow);  // Signed comparison.
+}
+
 }  // namespace
 
 // The construct stub for ES5 constructor functions and ES6 class constructors.
@@ -188,7 +200,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label post_instantiation_deopt_entry, not_create_implicit_receiver;
 
     // Preserve the incoming parameters on the stack.
-    __ LoadRoot(r4, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(r4, RootIndex::kTheHoleValue);
     __ SmiTag(r0);
     __ Push(cp, r0, r1, r4, r3);
 
@@ -214,7 +226,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(r0, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(r0, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                          r0: receiver
@@ -253,6 +265,19 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Set up pointer to last argument.
     __ add(r4, fp, Operand(StandardFrameConstants::kCallerSPOffset));
 
+    Label enough_stack_space, stack_overflow;
+    Generate_StackOverflowCheck(masm, r0, r5, &stack_overflow);
+    __ b(&enough_stack_space);
+
+    __ bind(&stack_overflow);
+    // Restore the context from the frame.
+    __ ldr(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
+    __ CallRuntime(Runtime::kThrowStackOverflow);
+    // Unreachable code.
+    __ bkpt(0);
+
+    __ bind(&enough_stack_space);
+
     // Copy arguments and receiver to the expression stack.
     Label loop, entry;
     __ mov(r5, r0);
@@ -303,7 +328,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(r0, Heap::kUndefinedValueRootIndex, &use_receiver);
+    __ JumpIfRoot(r0, RootIndex::kUndefinedValue, &use_receiver);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -325,7 +350,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ ldr(r0, MemOperand(sp, 0 * kPointerSize));
-    __ JumpIfRoot(r0, Heap::kTheHoleValueRootIndex, &do_throw);
+    __ JumpIfRoot(r0, RootIndex::kTheHoleValue, &do_throw);
 
     __ bind(&leave_frame);
     // Restore smi-tagged arguments count from the frame.
@@ -399,7 +424,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+  __ CompareRoot(sp, RootIndex::kRealStackLimit);
   __ b(lo, &stack_overflow);
 
   // Push receiver.
@@ -466,7 +491,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
     __ Push(r1, r4);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(r1);
     __ ldr(r4, FieldMemOperand(r1, JSGeneratorObject::kFunctionOffset));
@@ -497,21 +522,6 @@ void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
   __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
 }
 
-static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
-                                        Register scratch,
-                                        Label* stack_overflow) {
-  // Check the stack for overflow. We are not trying to catch
-  // interruptions (e.g. debug break and preemption) here, so the "real stack
-  // limit" is checked.
-  __ LoadRoot(scratch, Heap::kRealStackLimitRootIndex);
-  // Make scratch the space we have left. The stack might already be overflowed
-  // here which will cause scratch to become negative.
-  __ sub(scratch, sp, scratch);
-  // Check if the arguments will overflow the stack.
-  __ cmp(scratch, Operand(num_args, LSL, kPointerSizeLog2));
-  __ b(le, stack_overflow);  // Signed comparison.
-}
-
 static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                              bool is_construct) {
   // Called from Generate_JS_Entry
@@ -573,7 +583,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
 
     // Initialize all JavaScript callee-saved registers, since they will be seen
     // by the garbage collector as part of handlers.
-    __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r4, RootIndex::kUndefinedValue);
     __ mov(r5, Operand(r4));
     __ mov(r6, Operand(r4));
     __ mov(r8, Operand(r4));
@@ -878,7 +888,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ sub(r9, sp, Operand(r4));
-    __ LoadRoot(r2, Heap::kRealStackLimitRootIndex);
+    __ LoadRoot(r2, RootIndex::kRealStackLimit);
     __ cmp(r9, Operand(r2));
     __ b(hs, &ok);
     __ CallRuntime(Runtime::kThrowStackOverflow);
@@ -887,7 +897,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // If ok, push undefined as the initial value for all register file entries.
     Label loop_header;
     Label loop_check;
-    __ LoadRoot(r9, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r9, RootIndex::kUndefinedValue);
     __ b(&loop_check, al);
     __ bind(&loop_header);
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
@@ -907,7 +917,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ str(r3, MemOperand(fp, r9, LSL, kPointerSizeLog2), ne);
 
   // Load accumulator with undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
@@ -987,7 +997,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ mov(r3, r0);  // Argument count is correct.
   }
 
@@ -1201,7 +1211,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
         __ push(r4);
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done);
@@ -1302,15 +1312,10 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Ret();
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ ldr(r0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-    __ ldr(r0, MemOperand(r0, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ ldr(r0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ ldr(r0, MemOperand(r0, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
@@ -1327,11 +1332,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
 
   __ bind(&skip);
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ LeaveFrame(StackFrame::STUB);
-  }
+  __ LeaveFrame(StackFrame::STUB);
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
@@ -1354,14 +1357,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   }
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -1375,7 +1370,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // arguments from the stack (including the receiver), and push thisArg (if
   // present) instead.
   {
-    __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r5, RootIndex::kUndefinedValue);
     __ mov(r2, r5);
     __ ldr(r1, MemOperand(sp, r0, LSL, kPointerSizeLog2));  // receiver
     __ sub(r4, r0, Operand(1), SetCC);
@@ -1398,8 +1393,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(r2, Heap::kNullValueRootIndex, &no_arguments);
-  __ JumpIfRoot(r2, Heap::kUndefinedValueRootIndex, &no_arguments);
+  __ JumpIfRoot(r2, RootIndex::kNullValue, &no_arguments);
+  __ JumpIfRoot(r2, RootIndex::kUndefinedValue, &no_arguments);
 
   // 4a. Apply the receiver to the given argArray.
   __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
@@ -1422,7 +1417,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     Label done;
     __ cmp(r0, Operand::Zero());
     __ b(ne, &done);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ add(r0, r0, Operand(1));
     __ bind(&done);
   }
@@ -1471,7 +1466,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   // remove all arguments from the stack (including the receiver), and push
   // thisArgument (if present) instead.
   {
-    __ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r1, RootIndex::kUndefinedValue);
     __ mov(r5, r1);
     __ mov(r2, r1);
     __ sub(r4, r0, Operand(1), SetCC);
@@ -1513,7 +1508,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   // arguments from the stack (including the receiver), and push thisArgument
   // (if present) instead.
   {
-    __ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r1, RootIndex::kUndefinedValue);
     __ mov(r2, r1);
     __ str(r2, MemOperand(sp, r0, LSL, kPointerSizeLog2));  // receiver
     __ sub(r4, r0, Operand(1), SetCC);
@@ -1600,26 +1595,13 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ bind(&ok);
   }
 
-  // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(scratch, Heap::kRealStackLimitRootIndex);
-    // The stack might already be overflowed here which will cause 'scratch' to
-    // become negative.
-    __ sub(scratch, sp, scratch);
-    // Check if the arguments will overflow the stack.
-    __ cmp(scratch, Operand(r4, LSL, kPointerSizeLog2));
-    __ b(gt, &done);  // Signed comparison.
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, r4, scratch, &stack_overflow);
 
   // Push arguments onto the stack (thisArgument is already on the stack).
   {
     __ mov(r6, Operand(0));
-    __ LoadRoot(r5, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(r5, RootIndex::kTheHoleValue);
     Label done, loop;
     __ bind(&loop);
     __ cmp(r6, r4);
@@ -1627,7 +1609,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ add(scratch, r2, Operand(r6, LSL, kPointerSizeLog2));
     __ ldr(scratch, FieldMemOperand(scratch, FixedArray::kHeaderSize));
     __ cmp(scratch, r5);
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex, eq);
+    __ LoadRoot(scratch, RootIndex::kUndefinedValue, eq);
     __ Push(scratch);
     __ add(r6, r6, Operand(1));
     __ b(&loop);
@@ -1637,6 +1619,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -1771,9 +1756,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ b(hs, &done_convert);
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(r3, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy);
-        __ JumpIfNotRoot(r3, Heap::kNullValueRootIndex, &convert_to_object);
+        __ JumpIfRoot(r3, RootIndex::kUndefinedValue, &convert_global_proxy);
+        __ JumpIfNotRoot(r3, RootIndex::kNullValue, &convert_to_object);
         __ bind(&convert_global_proxy);
         {
           // Patch receiver to global proxy.
@@ -1859,8 +1843,8 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
-      __ b(gt, &done);  // Signed comparison.
+      __ CompareRoot(sp, RootIndex::kRealStackLimit);
+      __ b(hs, &done);
       // Restore the stack pointer.
       __ add(sp, sp, Operand(r4, LSL, kPointerSizeLog2));
       {
@@ -1987,7 +1971,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // r2 to contain either an AllocationSite or undefined.
-  __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(r2, RootIndex::kUndefinedValue);
 
   Label call_generic_stub;
 
@@ -2165,7 +2149,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // r1: function
     // r2: expected number of arguments
     // r3: new target (passed through to callee)
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
     __ sub(r4, fp, Operand(r2, LSL, kPointerSizeLog2));
     // Adjust for frame.
     __ sub(r4, r4,
@@ -2331,7 +2315,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ CompareRoot(r0, Heap::kExceptionRootIndex);
+  __ CompareRoot(r0, RootIndex::kException);
   __ b(eq, &exception_returned);
 
   // Check that there is no pending exception, otherwise we
@@ -2342,7 +2326,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
         IsolateAddressId::kPendingExceptionAddress, masm->isolate());
     __ Move(r3, pending_exception_address);
     __ ldr(r3, MemOperand(r3));
-    __ CompareRoot(r3, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(r3, RootIndex::kTheHoleValue);
     // Cannot use check here as it attempts to generate call into runtime.
     __ b(eq, &okay);
     __ stop("Unexpected pending exception");
@@ -2401,9 +2385,9 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ str(cp, MemOperand(fp, StandardFrameConstants::kContextOffset), ne);
 
   // Reset the masking register. This is done independent of the underlying
-  // feature flag {FLAG_branch_load_poisoning} to make the snapshot work with
-  // both configurations. It is safe to always do this, because the underlying
-  // register is caller-saved and can be arbitrarily clobbered.
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
   __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
@@ -2585,6 +2569,10 @@ namespace {
 
 void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
                                           ElementsKind kind) {
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
+
   __ cmp(r0, Operand(1));
 
   __ Jump(CodeFactory::InternalArrayNoArgumentConstructor(masm->isolate(), kind)
diff --git a/deps/v8/src/builtins/arm64/builtins-arm64.cc b/deps/v8/src/builtins/arm64/builtins-arm64.cc
index 61fee9013b..0d51d9decf 100644
--- a/deps/v8/src/builtins/arm64/builtins-arm64.cc
+++ b/deps/v8/src/builtins/arm64/builtins-arm64.cc
@@ -55,7 +55,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -129,7 +128,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ Claim(slot_count);
 
     // Preserve the incoming parameters on the stack.
-    __ LoadRoot(x10, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(x10, RootIndex::kTheHoleValue);
 
     // Compute a pointer to the slot immediately above the location on the
     // stack to which arguments will be later copied.
@@ -195,6 +194,24 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
   __ Ret();
 }
 
+static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
+                                        Label* stack_overflow) {
+  UseScratchRegisterScope temps(masm);
+  Register scratch = temps.AcquireX();
+
+  // Check the stack for overflow.
+  // We are not trying to catch interruptions (e.g. debug break and
+  // preemption) here, so the "real stack limit" is checked.
+  Label enough_stack_space;
+  __ LoadRoot(scratch, RootIndex::kRealStackLimit);
+  // Make scratch the space we have left. The stack might already be overflowed
+  // here which will cause scratch to become negative.
+  __ Sub(scratch, sp, scratch);
+  // Check if the arguments will overflow the stack.
+  __ Cmp(scratch, Operand(num_args, LSL, kPointerSizeLog2));
+  __ B(le, stack_overflow);
+}
+
 }  // namespace
 
 // The construct stub for ES5 constructor functions and ES6 class constructors.
@@ -249,7 +266,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ Bind(&not_create_implicit_receiver);
-    __ LoadRoot(x0, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(x0, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                          x0: receiver
@@ -303,6 +320,19 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // slots for the arguments. If the number of arguments was odd, the last
     // argument will overwrite one of the receivers pushed above.
     __ Bic(x10, x12, 1);
+
+    // Check if we have enough stack space to push all arguments.
+    Label enough_stack_space, stack_overflow;
+    Generate_StackOverflowCheck(masm, x10, &stack_overflow);
+    __ B(&enough_stack_space);
+
+    __ Bind(&stack_overflow);
+    // Restore the context from the frame.
+    __ Ldr(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
+    __ CallRuntime(Runtime::kThrowStackOverflow);
+    __ Unreachable();
+
+    __ Bind(&enough_stack_space);
     __ Claim(x10);
 
     // Copy the arguments.
@@ -342,7 +372,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ CompareRoot(x0, Heap::kUndefinedValueRootIndex);
+    __ CompareRoot(x0, RootIndex::kUndefinedValue);
     __ B(eq, &use_receiver);
 
     // Otherwise we do a smi check and fall through to check if the return value
@@ -364,7 +394,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ Bind(&use_receiver);
     __ Peek(x0, 0 * kPointerSize);
-    __ CompareRoot(x0, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(x0, RootIndex::kTheHoleValue);
     __ B(eq, &do_throw);
 
     __ Bind(&leave_frame);
@@ -425,7 +455,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+  __ CompareRoot(sp, RootIndex::kRealStackLimit);
   __ B(lo, &stack_overflow);
 
   // Get number of arguments for generator function.
@@ -508,7 +538,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     // Push hole as receiver since we do not use it for stepping.
-    __ LoadRoot(x5, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(x5, RootIndex::kTheHoleValue);
     __ Push(x1, padreg, x4, x5);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(padreg, x1);
@@ -534,24 +564,6 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   }
 }
 
-static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
-                                        Label* stack_overflow) {
-  UseScratchRegisterScope temps(masm);
-  Register scratch = temps.AcquireX();
-
-  // Check the stack for overflow.
-  // We are not trying to catch interruptions (e.g. debug break and
-  // preemption) here, so the "real stack limit" is checked.
-  Label enough_stack_space;
-  __ LoadRoot(scratch, Heap::kRealStackLimitRootIndex);
-  // Make scratch the space we have left. The stack might already be overflowed
-  // here which will cause scratch to become negative.
-  __ Sub(scratch, sp, scratch);
-  // Check if the arguments will overflow the stack.
-  __ Cmp(scratch, Operand(num_args, LSL, kPointerSizeLog2));
-  __ B(le, stack_overflow);
-}
-
 // Input:
 //   x0: new.target.
 //   x1: function.
@@ -639,7 +651,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     // Initialize all JavaScript callee-saved registers, since they will be seen
     // by the garbage collector as part of handlers.
     // The original values have been saved in JSEntryStub::GenerateBody().
-    __ LoadRoot(x19, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(x19, RootIndex::kUndefinedValue);
     __ Mov(x20, x19);
     __ Mov(x21, x19);
     __ Mov(x22, x19);
@@ -957,7 +969,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ Sub(x10, sp, Operand(x11));
-    __ CompareRoot(x10, Heap::kRealStackLimitRootIndex);
+    __ CompareRoot(x10, RootIndex::kRealStackLimit);
     __ B(hs, &ok);
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ Bind(&ok);
@@ -966,7 +978,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Note: there should always be at least one stack slot for the return
     // register in the register file.
     Label loop_header;
-    __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(x10, RootIndex::kUndefinedValue);
     __ Lsr(x11, x11, kPointerSizeLog2);
     // Round up the number of registers to a multiple of 2, to align the stack
     // to 16 bytes.
@@ -988,7 +1000,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator with undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
@@ -1081,7 +1093,7 @@ static void Generate_InterpreterPushArgs(MacroAssembler* masm,
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
     // Store "undefined" as the receiver arg if we need to.
     Register receiver = x14;
-    __ LoadRoot(receiver, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(receiver, RootIndex::kUndefinedValue);
     __ SlotAddress(stack_addr, num_args);
     __ Str(receiver, MemOperand(stack_addr));
     __ Mov(slots_to_copy, num_args);
@@ -1300,7 +1312,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
     Register scratch1 = x12;
     Register scratch2 = x13;
     Register scratch3 = x14;
-    __ LoadRoot(undef, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(undef, RootIndex::kUndefinedValue);
 
     Label at_least_one_arg;
     Label three_args;
@@ -1452,15 +1464,10 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Ret();
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ Ldr(x0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-    __ Ldr(x0, MemOperand(x0, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ Ldr(x0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ Ldr(x0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ Ldr(x0, MemOperand(x0, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -1476,11 +1483,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
 
   __ Bind(&skip);
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ LeaveFrame(StackFrame::STUB);
-  }
+  __ LeaveFrame(StackFrame::STUB);
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
@@ -1501,14 +1506,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   __ Ret();
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -1526,8 +1523,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   Register undefined_value = x3;
   Register null_value = x4;
 
-  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
-  __ LoadRoot(null_value, Heap::kNullValueRootIndex);
+  __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
+  __ LoadRoot(null_value, RootIndex::kNullValue);
 
   // 1. Load receiver into x1, argArray into x2 (if present), remove all
   // arguments from the stack (including the receiver), and push thisArg (if
@@ -1609,7 +1606,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     Label non_zero;
     Register scratch = x10;
     __ Cbnz(argc, &non_zero);
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
     // Overwrite receiver with undefined, which will be the new receiver.
     // We do not need to overwrite the padding slot above it with anything.
     __ Poke(scratch, 0);
@@ -1666,7 +1663,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   Register this_argument = x4;
   Register undefined_value = x3;
 
-  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
 
   // 1. Load target into x1 (if present), argumentsList into x2 (if present),
   // remove all arguments from the stack (including the receiver), and push
@@ -1743,7 +1740,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   Register new_target = x3;
   Register undefined_value = x4;
 
-  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
 
   // 1. Load target into x1 (if present), argumentsList into x2 (if present),
   // new.target into x3 (if present, otherwise use target), remove all
@@ -1933,21 +1930,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   Register argc = x0;
   Register len = x4;
 
-  // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(x10, Heap::kRealStackLimitRootIndex);
-    // Make x10 the space we have left. The stack might already be overflowed
-    // here which will cause x10 to become negative.
-    __ Sub(x10, sp, x10);
-    // Check if the arguments will overflow the stack.
-    __ Cmp(x10, Operand(len, LSL, kPointerSizeLog2));
-    __ B(gt, &done);  // Signed comparison.
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ Bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, len, &stack_overflow);
 
   // Skip argument setup if we don't need to push any varargs.
   Label done;
@@ -1963,8 +1947,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     Register undefined_value = x12;
     Register scratch = x13;
     __ Add(src, arguments_list, FixedArray::kHeaderSize - kHeapObjectTag);
-    __ LoadRoot(the_hole_value, Heap::kTheHoleValueRootIndex);
-    __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(the_hole_value, RootIndex::kTheHoleValue);
+    __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
     // We do not use the CompareRoot macro as it would do a LoadRoot behind the
     // scenes and we want to avoid that in a loop.
     // TODO(all): Consider using Ldp and Stp.
@@ -1980,6 +1964,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -2121,9 +2108,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ B(hs, &done_convert);
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(x3, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy);
-        __ JumpIfNotRoot(x3, Heap::kNullValueRootIndex, &convert_to_object);
+        __ JumpIfRoot(x3, RootIndex::kUndefinedValue, &convert_global_proxy);
+        __ JumpIfNotRoot(x3, RootIndex::kNullValue, &convert_to_object);
         __ Bind(&convert_global_proxy);
         {
           // Patch receiver to global proxy.
@@ -2211,13 +2197,13 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
       Label done;
-      __ LoadRoot(x10, Heap::kRealStackLimitRootIndex);
+      __ LoadRoot(x10, RootIndex::kRealStackLimit);
       // Make x10 the space we have left. The stack might already be overflowed
       // here which will cause x10 to become negative.
       __ Sub(x10, sp, x10);
       // Check if the arguments will overflow the stack.
       __ Cmp(x10, Operand(bound_argc, LSL, kPointerSizeLog2));
-      __ B(gt, &done);  // Signed comparison.
+      __ B(hs, &done);
       __ TailCallRuntime(Runtime::kThrowStackOverflow);
       __ Bind(&done);
     }
@@ -2379,7 +2365,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // x2 to contain either an AllocationSite or undefined.
-  __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(x2, RootIndex::kUndefinedValue);
 
   Label call_generic_stub;
 
@@ -2586,7 +2572,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // Fill the remaining expected arguments with undefined.
   __ RecordComment("-- Fill slots with undefined --");
   __ Sub(copy_end, copy_to, Operand(scratch1, LSL, kPointerSizeLog2));
-  __ LoadRoot(scratch1, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch1, RootIndex::kUndefinedValue);
 
   Label fill;
   __ Bind(&fill);
@@ -2856,7 +2842,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ CompareRoot(result, Heap::kExceptionRootIndex);
+  __ CompareRoot(result, RootIndex::kException);
   __ B(eq, &exception_returned);
 
   // The call succeeded, so unwind the stack and return.
@@ -2922,9 +2908,9 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ Bind(&not_js_frame);
 
   // Reset the masking register. This is done independent of the underlying
-  // feature flag {FLAG_branch_load_poisoning} to make the snapshot work with
-  // both configurations. It is safe to always do this, because the underlying
-  // register is caller-saved and can be arbitrarily clobbered.
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
   __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
@@ -3131,6 +3117,9 @@ void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
 
   __ Bind(&n_case);
   // N arguments.
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
   Handle<Code> code = BUILTIN_CODE(masm->isolate(), ArrayNArgumentsConstructor);
   __ Jump(code, RelocInfo::CODE_TARGET);
 }
diff --git a/deps/v8/src/builtins/array-copywithin.tq b/deps/v8/src/builtins/array-copywithin.tq
index 8406123b20..6b9ba934a4 100644
--- a/deps/v8/src/builtins/array-copywithin.tq
+++ b/deps/v8/src/builtins/array-copywithin.tq
@@ -4,7 +4,7 @@
 
 module array {
   macro ConvertToRelativeIndex(index: Number, length: Number): Number {
-    return index < 0 ? max(index + length, 0) : min(index, length);
+    return index < 0 ? Max(index + length, 0) : Min(index, length);
   }
 
   // https://tc39.github.io/ecma262/#sec-array.prototype.copyWithin
@@ -17,32 +17,32 @@ module array {
     const length: Number = GetLengthProperty(context, object);
 
     // 3. Let relativeTarget be ? ToInteger(target).
-    const relative_target: Number = ToInteger_Inline(context, arguments[0]);
+    const relativeTarget: Number = ToInteger_Inline(context, arguments[0]);
 
     // 4. If relativeTarget < 0, let to be max((len + relativeTarget), 0);
     //    else let to be min(relativeTarget, len).
-    let to: Number = ConvertToRelativeIndex(relative_target, length);
+    let to: Number = ConvertToRelativeIndex(relativeTarget, length);
 
     // 5. Let relativeStart be ? ToInteger(start).
-    const relative_start: Number = ToInteger_Inline(context, arguments[1]);
+    const relativeStart: Number = ToInteger_Inline(context, arguments[1]);
 
     // 6. If relativeStart < 0, let from be max((len + relativeStart), 0);
     //    else let from be min(relativeStart, len).
-    let from: Number = ConvertToRelativeIndex(relative_start, length);
+    let from: Number = ConvertToRelativeIndex(relativeStart, length);
 
     // 7. If end is undefined, let relativeEnd be len;
     //    else let relativeEnd be ? ToInteger(end).
-    let relative_end: Number = length;
+    let relativeEnd: Number = length;
     if (arguments[2] != Undefined) {
-      relative_end = ToInteger_Inline(context, arguments[2]);
+      relativeEnd = ToInteger_Inline(context, arguments[2]);
     }
 
     // 8. If relativeEnd < 0, let final be max((len + relativeEnd), 0);
     //    else let final be min(relativeEnd, len).
-    const final: Number = ConvertToRelativeIndex(relative_end, length);
+    const final: Number = ConvertToRelativeIndex(relativeEnd, length);
 
     // 9. Let count be min(final-from, len-to).
-    let count: Number = min(final - from, length - to);
+    let count: Number = Min(final - from, length - to);
 
     // 10. If from<to and to<from+count, then.
     let direction: Number = 1;
@@ -63,15 +63,15 @@ module array {
       // a. Let fromKey be ! ToString(from).
       // b. Let toKey be ! ToString(to).
       // c. Let fromPresent be ? HasProperty(O, fromKey).
-      const from_present: Boolean = HasProperty(context, object, from);
+      const fromPresent: Boolean = HasProperty(context, object, from);
 
       // d. If fromPresent is true, then.
-      if (from_present == True) {
+      if (fromPresent == True) {
         // i. Let fromVal be ? Get(O, fromKey).
-        const from_val: Object = GetProperty(context, object, from);
+        const fromVal: Object = GetProperty(context, object, from);
 
         // ii. Perform ? Set(O, toKey, fromVal, true).
-        SetProperty(context, object, to, from_val);
+        SetProperty(context, object, to, fromVal);
       } else {
         // i. Perform ? DeletePropertyOrThrow(O, toKey).
         DeleteProperty(context, object, to, kStrict);
diff --git a/deps/v8/src/builtins/array-foreach.tq b/deps/v8/src/builtins/array-foreach.tq
index c0e19c0803..5a189a517f 100644
--- a/deps/v8/src/builtins/array-foreach.tq
+++ b/deps/v8/src/builtins/array-foreach.tq
@@ -5,20 +5,21 @@
 module array {
   macro ArrayForEachTorqueContinuation(
       context: Context, o: JSReceiver, len: Number, callbackfn: Callable,
-      thisArg: Object, initial_k: Smi): Object {
+      thisArg: Object, initialK: Number): Object {
     // 5. Let k be 0.
     // 6. Repeat, while k < len
-    for (let k: Smi = initial_k; k < len; k = k + 1) {
+    for (let k: Number = initialK; k < len; k = k + 1) {
       // 6a. Let Pk be ! ToString(k).
-      const pK: String = ToString_Inline(context, k);
+      // k is guaranteed to be a positive integer, hence ToString is
+      // side-effect free and HasProperty/GetProperty do the conversion inline.
 
       // 6b. Let kPresent be ? HasProperty(O, Pk).
-      const kPresent: Boolean = HasProperty(context, o, pK);
+      const kPresent: Boolean = HasProperty_Inline(context, o, k);
 
       // 6c. If kPresent is true, then
       if (kPresent == True) {
         // 6c. i. Let kValue be ? Get(O, Pk).
-        const kValue: Object = GetProperty(context, o, pK);
+        const kValue: Object = GetProperty(context, o, k);
 
         // 6c. ii. Perform ? Call(callbackfn, T, <kValue, k, O>).
         Call(context, callbackfn, thisArg, kValue, k, o);
@@ -32,10 +33,10 @@ module array {
   javascript builtin ArrayForEachLoopEagerDeoptContinuation(
       context: Context, receiver: Object, callback: Object, thisArg: Object,
       initialK: Object, length: Object): Object {
-    // The unsafe cast is safe because all continuation points in forEach are
+    // The unsafe Cast is safe because all continuation points in forEach are
     // after the ToObject(O) call that ensures we are dealing with a
     // JSReceiver.
-    const jsreceiver: JSReceiver = unsafe_cast<JSReceiver>(receiver);
+    const jsreceiver: JSReceiver = UnsafeCast<JSReceiver>(receiver);
     return ArrayForEachLoopContinuation(
         context, jsreceiver, callback, thisArg, Undefined, jsreceiver, initialK,
         length, Undefined);
@@ -44,10 +45,10 @@ module array {
   javascript builtin ArrayForEachLoopLazyDeoptContinuation(
       context: Context, receiver: Object, callback: Object, thisArg: Object,
       initialK: Object, length: Object, result: Object): Object {
-    // The unsafe cast is safe because all continuation points in forEach are
+    // The unsafe Cast is safe because all continuation points in forEach are
     // after the ToObject(O) call that ensures we are dealing with a
     // JSReceiver.
-    const jsreceiver: JSReceiver = unsafe_cast<JSReceiver>(receiver);
+    const jsreceiver: JSReceiver = UnsafeCast<JSReceiver>(receiver);
     return ArrayForEachLoopContinuation(
         context, jsreceiver, callback, thisArg, Undefined, jsreceiver, initialK,
         length, Undefined);
@@ -59,22 +60,22 @@ module array {
       to: Object): Object {
     try {
       const callbackfn: Callable =
-          cast<Callable>(callback) otherwise Unexpected;
-      const k: Smi = cast<Smi>(initialK) otherwise Unexpected;
-      const number_length: Number = cast<Number>(length) otherwise Unexpected;
+          Cast<Callable>(callback) otherwise Unexpected;
+      const k: Number = Cast<Number>(initialK) otherwise Unexpected;
+      const numberLength: Number = Cast<Number>(length) otherwise Unexpected;
 
       return ArrayForEachTorqueContinuation(
-          context, receiver, number_length, callbackfn, thisArg, k);
+          context, receiver, numberLength, callbackfn, thisArg, k);
     }
-    label Unexpected {
+    label Unexpected deferred {
       unreachable;
     }
   }
 
-  macro VisitAllElements<FixedArrayType : type>(
+  macro VisitAllElements<FixedArrayType: type>(
       context: Context, a: JSArray, len: Smi, callbackfn: Callable,
-      thisArg: Object): void labels
-  Bailout(Smi) {
+      thisArg: Object): void
+      labels Bailout(Smi) {
     let k: Smi = 0;
     const map: Map = a.map;
 
@@ -100,19 +101,19 @@ module array {
         }
       }
     }
-    label Slow {
+    label Slow deferred {
       goto Bailout(k);
     }
   }
 
   macro FastArrayForEach(
       context: Context, o: JSReceiver, len: Number, callbackfn: Callable,
-      thisArg: Object): Object labels
-  Bailout(Smi) {
+      thisArg: Object): Object
+      labels Bailout(Smi) {
     let k: Smi = 0;
     try {
-      const smi_len: Smi = cast<Smi>(len) otherwise Slow;
-      const a: JSArray = cast<JSArray>(o) otherwise Slow;
+      const smiLen: Smi = Cast<Smi>(len) otherwise Slow;
+      const a: JSArray = Cast<JSArray>(o) otherwise Slow;
       const map: Map = a.map;
 
       if (!IsPrototypeInitialArrayPrototype(context, map)) goto Slow;
@@ -121,14 +122,14 @@ module array {
 
       if (IsElementsKindGreaterThan(elementsKind, HOLEY_ELEMENTS)) {
         VisitAllElements<FixedDoubleArray>(
-            context, a, smi_len, callbackfn, thisArg)
-        otherwise Bailout;
+            context, a, smiLen, callbackfn, thisArg)
+            otherwise Bailout;
       } else {
-        VisitAllElements<FixedArray>(context, a, smi_len, callbackfn, thisArg)
-        otherwise Bailout;
+        VisitAllElements<FixedArray>(context, a, smiLen, callbackfn, thisArg)
+            otherwise Bailout;
       }
     }
-    label Slow {
+    label Slow deferred {
       goto Bailout(k);
     }
     return Undefined;
@@ -153,28 +154,28 @@ module array {
         goto TypeError;
       }
       const callbackfn: Callable =
-          cast<Callable>(arguments[0]) otherwise TypeError;
+          Cast<Callable>(arguments[0]) otherwise TypeError;
 
       // 4. If thisArg is present, let T be thisArg; else let T be undefined.
       const thisArg: Object = arguments.length > 1 ? arguments[1] : Undefined;
 
       // Special cases.
-      let k: Smi = 0;
+      let k: Number = 0;
       try {
         return FastArrayForEach(context, o, len, callbackfn, thisArg)
-        otherwise Bailout;
+            otherwise Bailout;
       }
-      label Bailout(k_value: Smi) {
-        k = k_value;
+      label Bailout(kValue: Smi) deferred {
+        k = kValue;
       }
 
       return ArrayForEachTorqueContinuation(
           context, o, len, callbackfn, thisArg, k);
     }
-    label TypeError {
+    label TypeError deferred {
       ThrowTypeError(context, kCalledNonCallable, arguments[0]);
     }
-    label NullOrUndefinedError {
+    label NullOrUndefinedError deferred {
       ThrowTypeError(
           context, kCalledOnNullOrUndefined, 'Array.prototype.forEach');
     }
diff --git a/deps/v8/src/builtins/array-lastindexof.tq b/deps/v8/src/builtins/array-lastindexof.tq
new file mode 100644
index 0000000000..056220092e
--- /dev/null
+++ b/deps/v8/src/builtins/array-lastindexof.tq
@@ -0,0 +1,159 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module array {
+  macro LoadWithHoleCheck<Elements: type>(
+      elements: FixedArrayBase, index: Smi): Object
+      labels IfHole;
+
+  LoadWithHoleCheck<FixedArray>(elements: FixedArrayBase, index: Smi): Object
+      labels IfHole {
+    const elements: FixedArray = UnsafeCast<FixedArray>(elements);
+    const element: Object = elements[index];
+    if (element == Hole) goto IfHole;
+    return element;
+  }
+
+  LoadWithHoleCheck<FixedDoubleArray>(elements: FixedArrayBase, index: Smi):
+      Object
+      labels IfHole {
+    const elements: FixedDoubleArray = UnsafeCast<FixedDoubleArray>(elements);
+    const element: float64 = LoadDoubleWithHoleCheck(elements, index)
+        otherwise IfHole;
+    return AllocateHeapNumberWithValue(element);
+  }
+
+  macro FastArrayLastIndexOf<Elements: type>(
+      context: Context, array: JSArray, from: Smi, searchElement: Object): Smi {
+    const elements: FixedArrayBase = array.elements;
+    let k: Smi = from;
+
+    // Bug(898785): Due to side-effects in the evaluation of `fromIndex`
+    // the {from} can be out-of-bounds here, so we need to clamp {k} to
+    // the {elements} length. We might be reading holes / hole NaNs still
+    // due to that, but those will be ignored below.
+    if (k >= elements.length) {
+      k = elements.length - 1;
+    }
+
+    while (k >= 0) {
+      try {
+        const element: Object = LoadWithHoleCheck<Elements>(elements, k)
+            otherwise Hole;
+
+        const same: Boolean = StrictEqual(searchElement, element);
+        if (same == True) {
+          assert(IsFastJSArray(array, context));
+          return k;
+        }
+      }
+      label Hole {}  // Do nothing for holes.
+
+      --k;
+    }
+
+    assert(IsFastJSArray(array, context));
+    return -1;
+  }
+
+  macro GetFromIndex(
+      context: Context, length: Number,
+      arguments: constexpr Arguments): Number {
+    // 4. If fromIndex is present, let n be ? ToInteger(fromIndex);
+    //    else let n be len - 1.
+    const n: Number = arguments.length < 2 ?
+        length - 1 :
+        ToInteger_Inline(context, arguments[1], kTruncateMinusZero);
+
+    // 5. If n >= 0, then.
+    let k: Number = SmiConstant(0);
+    if (n >= 0) {
+      // a. If n is -0, let k be +0; else let k be min(n, len - 1).
+      // If n was -0 it got truncated to 0.0, so taking the minimum is fine.
+      k = Min(n, length - 1);
+    } else {
+      // a. Let k be len + n.
+      k = length + n;
+    }
+    return k;
+  }
+
+  macro TryFastArrayLastIndexOf(
+      context: Context, receiver: JSReceiver, searchElement: Object,
+      from: Number): Object
+      labels Slow {
+    EnsureFastJSArray(context, receiver) otherwise Slow;
+    const array: JSArray = UnsafeCast<JSArray>(receiver);
+
+    const length: Smi = array.length_fast;
+    if (length == 0) return SmiConstant(-1);
+
+    const fromSmi: Smi = Cast<Smi>(from) otherwise Slow;
+    const kind: ElementsKind = array.map.elements_kind;
+    if (IsFastSmiOrTaggedElementsKind(kind)) {
+      return FastArrayLastIndexOf<FixedArray>(
+          context, array, fromSmi, searchElement);
+    }
+    assert(IsDoubleElementsKind(kind));
+    return FastArrayLastIndexOf<FixedDoubleArray>(
+        context, array, fromSmi, searchElement);
+  }
+
+  macro GenericArrayLastIndexOf(
+      context: Context, object: JSReceiver, searchElement: Object,
+      from: Number): Object {
+    let k: Number = from;
+
+    // 7. Repeat, while k >= 0.
+    while (k >= 0) {
+      // a. Let kPresent be ? HasProperty(O, ! ToString(k)).
+      const kPresent: Boolean = HasProperty(context, object, k);
+
+      // b. If kPresent is true, then.
+      if (kPresent == True) {
+        // i. Let elementK be ? Get(O, ! ToString(k)).
+        const element: Object = GetProperty(context, object, k);
+
+        // ii. Let same be the result of performing Strict Equality Comparison
+        //     searchElement === elementK.
+        const same: Boolean = StrictEqual(searchElement, element);
+
+        // iii. If same is true, return k.
+        if (same == True) return k;
+      }
+
+      // c. Decrease k by 1.
+      --k;
+    }
+
+    // 8. Return -1.
+    return SmiConstant(-1);
+  }
+
+  // https://tc39.github.io/ecma262/#sec-array.prototype.lastIndexOf
+  javascript builtin ArrayPrototypeLastIndexOf(
+      context: Context, receiver: Object, ...arguments): Object {
+    // 1. Let O be ? ToObject(this value).
+    const object: JSReceiver = ToObject_Inline(context, receiver);
+
+    // 2. Let len be ? ToLength(? Get(O, "length")).
+    const length: Number = GetLengthProperty(context, object);
+
+    // 3. If len is 0, return -1.
+    if (length == SmiConstant(0)) return SmiConstant(-1);
+
+    // Step 4 - 6.
+    const from: Number = GetFromIndex(context, length, arguments);
+
+    const searchElement: Object = arguments[0];
+
+    try {
+      return TryFastArrayLastIndexOf(context, object, searchElement, from)
+          otherwise Baseline;
+    }
+    label Baseline {
+      return GenericArrayLastIndexOf(context, object, searchElement, from);
+    }
+  }
+}
diff --git a/deps/v8/src/builtins/array-reverse.tq b/deps/v8/src/builtins/array-reverse.tq
index 8db542ddef..327ef12402 100644
--- a/deps/v8/src/builtins/array-reverse.tq
+++ b/deps/v8/src/builtins/array-reverse.tq
@@ -3,25 +3,25 @@
 // found in the LICENSE file.
 
 module array {
-  macro LoadElement<ElementsAccessor : type, T : type>(
+  macro LoadElement<ElementsAccessor: type, T: type>(
       elements: FixedArrayBase, index: Smi): T;
 
   LoadElement<FastPackedSmiElements, Smi>(
       elements: FixedArrayBase, index: Smi): Smi {
-    const elems: FixedArray = unsafe_cast<FixedArray>(elements);
-    return unsafe_cast<Smi>(elems[index]);
+    const elems: FixedArray = UnsafeCast<FixedArray>(elements);
+    return UnsafeCast<Smi>(elems[index]);
   }
 
   LoadElement<FastPackedObjectElements, Object>(
       elements: FixedArrayBase, index: Smi): Object {
-    const elems: FixedArray = unsafe_cast<FixedArray>(elements);
+    const elems: FixedArray = UnsafeCast<FixedArray>(elements);
     return elems[index];
   }
 
   LoadElement<FastPackedDoubleElements, float64>(
       elements: FixedArrayBase, index: Smi): float64 {
     try {
-      const elems: FixedDoubleArray = unsafe_cast<FixedDoubleArray>(elements);
+      const elems: FixedDoubleArray = UnsafeCast<FixedDoubleArray>(elements);
       return LoadDoubleWithHoleCheck(elems, index) otherwise Hole;
     }
     label Hole {
@@ -31,24 +31,24 @@ module array {
     }
   }
 
-  macro StoreElement<ElementsAccessor : type, T : type>(
+  macro StoreElement<ElementsAccessor: type, T: type>(
       elements: FixedArrayBase, index: Smi, value: T);
 
   StoreElement<FastPackedSmiElements, Smi>(
       elements: FixedArrayBase, index: Smi, value: Smi) {
-    const elems: FixedArray = unsafe_cast<FixedArray>(elements);
+    const elems: FixedArray = UnsafeCast<FixedArray>(elements);
     StoreFixedArrayElementSmi(elems, index, value, SKIP_WRITE_BARRIER);
   }
 
   StoreElement<FastPackedObjectElements, Object>(
       elements: FixedArrayBase, index: Smi, value: Object) {
-    const elems: FixedArray = unsafe_cast<FixedArray>(elements);
+    const elems: FixedArray = UnsafeCast<FixedArray>(elements);
     elems[index] = value;
   }
 
   StoreElement<FastPackedDoubleElements, float64>(
       elements: FixedArrayBase, index: Smi, value: float64) {
-    const elems: FixedDoubleArray = unsafe_cast<FixedDoubleArray>(elements);
+    const elems: FixedDoubleArray = UnsafeCast<FixedDoubleArray>(elements);
 
     assert(value == Float64SilenceNaN(value));
     StoreFixedDoubleArrayElementWithSmiIndex(elems, index, value);
@@ -57,16 +57,16 @@ module array {
   // Fast-path for all PACKED_* elements kinds. These do not need to check
   // whether a property is present, so we can simply swap them using fast
   // FixedArray loads/stores.
-  macro FastPackedArrayReverse<Accessor : type, T : type>(
+  macro FastPackedArrayReverse<Accessor: type, T: type>(
       elements: FixedArrayBase, length: Smi) {
     let lower: Smi = 0;
     let upper: Smi = length - 1;
 
     while (lower < upper) {
-      const lower_value: T = LoadElement<Accessor, T>(elements, lower);
-      const upper_value: T = LoadElement<Accessor, T>(elements, upper);
-      StoreElement<Accessor, T>(elements, lower, upper_value);
-      StoreElement<Accessor, T>(elements, upper, lower_value);
+      const lowerValue: T = LoadElement<Accessor, T>(elements, lower);
+      const upperValue: T = LoadElement<Accessor, T>(elements, upper);
+      StoreElement<Accessor, T>(elements, lower, upperValue);
+      StoreElement<Accessor, T>(elements, upper, lowerValue);
       ++lower;
       --upper;
     }
@@ -90,48 +90,48 @@ module array {
     let upper: Number = length - 1;
 
     while (lower < upper) {
-      let lower_value: Object = Undefined;
-      let upper_value: Object = Undefined;
+      let lowerValue: Object = Undefined;
+      let upperValue: Object = Undefined;
 
       // b. Let upperP be ! ToString(upper).
       // c. Let lowerP be ! ToString(lower).
       // d. Let lowerExists be ? HasProperty(O, lowerP).
-      const lower_exists: Boolean = HasProperty(context, object, lower);
+      const lowerExists: Boolean = HasProperty(context, object, lower);
 
       // e. If lowerExists is true, then.
-      if (lower_exists == True) {
+      if (lowerExists == True) {
         // i. Let lowerValue be ? Get(O, lowerP).
-        lower_value = GetProperty(context, object, lower);
+        lowerValue = GetProperty(context, object, lower);
       }
 
       // f. Let upperExists be ? HasProperty(O, upperP).
-      const upper_exists: Boolean = HasProperty(context, object, upper);
+      const upperExists: Boolean = HasProperty(context, object, upper);
 
       // g. If upperExists is true, then.
-      if (upper_exists == True) {
+      if (upperExists == True) {
         // i. Let upperValue be ? Get(O, upperP).
-        upper_value = GetProperty(context, object, upper);
+        upperValue = GetProperty(context, object, upper);
       }
 
       // h. If lowerExists is true and upperExists is true, then
-      if (lower_exists == True && upper_exists == True) {
+      if (lowerExists == True && upperExists == True) {
         // i. Perform ? Set(O, lowerP, upperValue, true).
-        SetProperty(context, object, lower, upper_value);
+        SetProperty(context, object, lower, upperValue);
 
         // ii. Perform ? Set(O, upperP, lowerValue, true).
-        SetProperty(context, object, upper, lower_value);
-      } else if (lower_exists == False && upper_exists == True) {
+        SetProperty(context, object, upper, lowerValue);
+      } else if (lowerExists == False && upperExists == True) {
         // i. Perform ? Set(O, lowerP, upperValue, true).
-        SetProperty(context, object, lower, upper_value);
+        SetProperty(context, object, lower, upperValue);
 
         // ii. Perform ? DeletePropertyOrThrow(O, upperP).
         DeleteProperty(context, object, upper, kStrict);
-      } else if (lower_exists == True && upper_exists == False) {
+      } else if (lowerExists == True && upperExists == False) {
         // i. Perform ? DeletePropertyOrThrow(O, lowerP).
         DeleteProperty(context, object, lower, kStrict);
 
         // ii. Perform ? Set(O, upperP, lowerValue, true).
-        SetProperty(context, object, upper, lower_value);
+        SetProperty(context, object, upper, lowerValue);
       }
 
       // l. Increase lower by 1.
@@ -143,29 +143,16 @@ module array {
     return object;
   }
 
-  macro EnsureWriteableFastElements(array: JSArray) {
-    const elements: FixedArrayBase = array.elements;
-    if (elements.map != kCOWMap) return;
-
-    // There are no COW *_DOUBLE_ELEMENTS arrays, so we are allowed to always
-    // extract FixedArrays and don't have to worry about FixedDoubleArrays.
-    assert(IsFastSmiOrTaggedElementsKind(array.map.elements_kind));
-
-    const length: Smi = array.length_fast;
-    array.elements = ExtractFixedArray(
-        unsafe_cast<FixedArray>(elements), 0, length, length, kFixedArrays);
-  }
-
   macro TryFastPackedArrayReverse(receiver: Object) labels Slow {
-    const array: JSArray = cast<JSArray>(receiver) otherwise Slow;
-    EnsureWriteableFastElements(array);
-    assert(array.elements.map != kCOWMap);
+    const array: JSArray = Cast<JSArray>(receiver) otherwise Slow;
 
     const kind: ElementsKind = array.map.elements_kind;
     if (kind == PACKED_SMI_ELEMENTS) {
+      EnsureWriteableFastElements(array);
       FastPackedArrayReverse<FastPackedSmiElements, Smi>(
           array.elements, array.length_fast);
     } else if (kind == PACKED_ELEMENTS) {
+      EnsureWriteableFastElements(array);
       FastPackedArrayReverse<FastPackedObjectElements, Object>(
           array.elements, array.length_fast);
     } else if (kind == PACKED_DOUBLE_ELEMENTS) {
diff --git a/deps/v8/src/builtins/array-splice.tq b/deps/v8/src/builtins/array-splice.tq
new file mode 100644
index 0000000000..16a192d2c0
--- /dev/null
+++ b/deps/v8/src/builtins/array-splice.tq
@@ -0,0 +1,395 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module array {
+  // Given {elements}, we want to create a non-zero length array of type
+  // FixedArrayType. Most of this behavior is outsourced to ExtractFixedArray(),
+  // but the special case of wanting to have a FixedDoubleArray when given a
+  // zero-length input FixedArray is handled here.
+  macro Extract<FixedArrayType: type>(
+      elements: FixedArrayBase, first: Smi, count: Smi,
+      capacity: Smi): FixedArrayType {
+    return UnsafeCast<FixedArrayType>(
+        ExtractFixedArray(elements, first, count, capacity));
+  }
+
+  Extract<FixedDoubleArray>(
+      elements: FixedArrayBase, first: Smi, count: Smi,
+      capacity: Smi): FixedDoubleArray {
+    if (elements == kEmptyFixedArray) {
+      return AllocateZeroedFixedDoubleArray(Convert<intptr>(capacity));
+    }
+    return UnsafeCast<FixedDoubleArray>(
+        ExtractFixedArray(elements, first, count, capacity));
+  }
+
+  macro FastSplice<FixedArrayType: type, ElementType: type>(
+      args: constexpr Arguments, a: JSArray, length: Smi, newLength: Smi,
+      lengthDelta: Smi, actualStart: Smi, insertCount: Smi,
+      actualDeleteCount: Smi): void
+      labels Bailout {
+    const elements: FixedArrayBase = a.elements;
+    const elementsMap: Map = elements.map;
+
+    // If the spliced array is larger then the
+    // source array, then allocate a new FixedArrayType to hold the result.
+    let newElements: FixedArrayBase = elements;
+    if (elementsMap == kCOWMap || lengthDelta > 0) {
+      newElements =
+          Extract<FixedArrayType>(elements, 0, actualStart, newLength);
+      if (elementsMap == kCOWMap) {
+        newElements.map = elementsMap;
+      }
+      a.elements = newElements;
+    }
+
+    // Copy over inserted elements.
+    let k: Smi = actualStart;
+    if (insertCount > 0) {
+      const typedNewElements: FixedArrayType =
+          UnsafeCast<FixedArrayType>(newElements);
+      for (let e: Object of args [2: ]) {
+        // The argument elements were already validated to be an appropriate
+        // {ElementType} to store in {FixedArrayType}.
+        typedNewElements[k++] = UnsafeCast<ElementType>(e);
+      }
+    }
+
+    // Copy over elements after deleted elements.
+    let count: Smi = length - actualStart - actualDeleteCount;
+    while (count > 0) {
+      const typedElements: FixedArrayType =
+          UnsafeCast<FixedArrayType>(elements);
+      const typedNewElements: FixedArrayType =
+          UnsafeCast<FixedArrayType>(newElements);
+      CopyArrayElement(typedElements, typedNewElements, k - lengthDelta, k);
+      k++;
+      count--;
+    }
+
+    // Fill rest of spliced FixedArray with the hole, but only if the
+    // destination FixedArray is the original array's, since otherwise the array
+    // is pre-filled with holes.
+    if (elements == newElements) {
+      const typedNewElements: FixedArrayType =
+          UnsafeCast<FixedArrayType>(newElements);
+      const limit: Smi = elements.length;
+      while (k < limit) {
+        StoreArrayHole(typedNewElements, k);
+        k++;
+      }
+    }
+
+    // Update the array's length after all the FixedArray shuffling is done.
+    a.length = newLength;
+  }
+
+  macro FastArraySplice(
+      context: Context, args: constexpr Arguments, o: JSReceiver,
+      originalLengthNumber: Number, actualStartNumber: Number, insertCount: Smi,
+      actualDeleteCountNumber: Number): Object
+      labels Bailout {
+    const originalLength: Smi =
+        Cast<Smi>(originalLengthNumber) otherwise Bailout;
+    const actualStart: Smi = Cast<Smi>(actualStartNumber) otherwise Bailout;
+    const actualDeleteCount: Smi =
+        Cast<Smi>(actualDeleteCountNumber) otherwise Bailout;
+    const lengthDelta: Smi = insertCount - actualDeleteCount;
+    const newLength: Smi = originalLength + lengthDelta;
+
+    const a: JSArray = Cast<JSArray>(o) otherwise Bailout;
+
+    const map: Map = a.map;
+    if (!IsPrototypeInitialArrayPrototype(context, map)) goto Bailout;
+    if (IsNoElementsProtectorCellInvalid()) goto Bailout;
+    if (IsArraySpeciesProtectorCellInvalid()) goto Bailout;
+
+    // Fast path only works on fast elements kind and with writable length.
+    let elementsKind: ElementsKind = EnsureArrayPushable(map) otherwise Bailout;
+    if (!IsFastElementsKind(elementsKind)) goto Bailout;
+
+    const oldElementsKind: ElementsKind = elementsKind;
+    for (let e: Object of args [2: ]) {
+      if (IsFastSmiElementsKind(elementsKind)) {
+        if (TaggedIsNotSmi(e)) {
+          const heapObject: HeapObject = UnsafeCast<HeapObject>(e);
+          elementsKind = IsHeapNumber(heapObject) ?
+              AllowDoubleElements(elementsKind) :
+              AllowNonNumberElements(elementsKind);
+        }
+      } else if (IsDoubleElementsKind(elementsKind)) {
+        if (!IsNumber(e)) {
+          elementsKind = AllowNonNumberElements(elementsKind);
+        }
+      }
+    }
+
+    if (elementsKind != oldElementsKind) {
+      const smiElementsKind: Smi = Convert<Smi>(Convert<int32>(elementsKind));
+      TransitionElementsKindWithKind(context, a, smiElementsKind);
+    }
+
+    // Make sure that the length hasn't been changed by side-effect.
+    const length: Smi = Cast<Smi>(a.length) otherwise Bailout;
+    if (originalLength != length) goto Bailout;
+
+    const deletedResult: JSArray =
+        ExtractFastJSArray(context, a, actualStart, actualDeleteCount);
+
+    if (newLength == 0) {
+      a.elements = kEmptyFixedArray;
+      a.length = 0;
+      return deletedResult;
+    }
+
+    if (IsFastSmiOrTaggedElementsKind(elementsKind)) {
+      FastSplice<FixedArray, Object>(
+          args, a, length, newLength, lengthDelta, actualStart, insertCount,
+          actualDeleteCount) otherwise Bailout;
+    } else {
+      FastSplice<FixedDoubleArray, Number>(
+          args, a, length, newLength, lengthDelta, actualStart, insertCount,
+          actualDeleteCount) otherwise Bailout;
+    }
+
+    return deletedResult;
+  }
+
+  macro FillDeletedElementsArray(
+      context: Context, o: JSReceiver, actualStart: Number,
+      actualDeleteCount: Number, a: JSReceiver): Object {
+    // 10. Let k be 0.
+    let k: Number = 0;
+
+    // 11. Repeat, while k < actualDeleteCount
+    while (k < actualDeleteCount) {
+      // a. Let from be ! ToString(actualStart + k).
+      const from: Number = actualStart + k;
+
+      // b. Let fromPresent be ? HasProperty(O, from).
+      const fromPresent: Boolean = HasProperty(context, o, from);
+
+      // c. If fromPresent is true, then
+      if (fromPresent == True) {
+        // i. Let fromValue be ? Get(O, from).
+        const fromValue: Object = GetProperty(context, o, from);
+
+        // ii. Perform ? CreateDataPropertyOrThrow(A, ! ToString(k), fromValue).
+        CreateDataProperty(context, a, k, fromValue);
+      }
+
+      // d. Increment k by 1.
+      k++;
+    }
+    // 12. Perform ? Set(A, "length", actualDeleteCount, true).
+    SetProperty(context, a, kLengthString, actualDeleteCount);
+    return a;
+  }
+
+  // HandleForwardCase implements step 15. "If itemCount < actualDeleteCount,
+  // then...""
+  macro HandleForwardCase(
+      context: Context, o: JSReceiver, len: Number, itemCount: Number,
+      actualStart: Number, actualDeleteCount: Number): void {
+    // 15. If itemCount < actualDeleteCount, then
+    // a. Let k be actualStart.
+    let k: Number = actualStart;
+
+    // b. Repeat, while k < (len - actualDeleteCount)
+    while (k < (len - actualDeleteCount)) {
+      // i. Let from be ! ToString(k + actualDeleteCount).
+      const from: Number = k + actualDeleteCount;
+      // ii. Let to be ! ToString(k + itemCount).
+      const to: Number = k + itemCount;
+
+      // iii. Let fromPresent be ? HasProperty(O, from).
+      const fromPresent: Boolean = HasProperty(context, o, from);
+
+      // iv. If fromPresent is true, then
+      if (fromPresent == True) {
+        // 1. Let fromValue be ? Get(O, from).
+        const fromValue: Object = GetProperty(context, o, from);
+
+        // 2. Perform ? Set(O, to, fromValue, true).
+        SetProperty(context, o, to, fromValue);
+
+        // v. Else fromPresent is false,
+      } else {
+        // 1. Perform ? DeletePropertyOrThrow(O, to).
+        DeleteProperty(context, o, to, kStrict);
+      }
+      // vi. Increase k by 1.
+      k++;
+    }
+
+    // c. Let k be len.
+    k = len;
+
+    // d. Repeat, while k > (len - actualDeleteCount + itemCount)
+    while (k > (len - actualDeleteCount + itemCount)) {
+      // i. Perform ? DeletePropertyOrThrow(O, ! ToString(k - 1)).
+      DeleteProperty(context, o, k - 1, kStrict);
+      // ii. Decrease k by 1.
+      k--;
+    }
+  }
+
+  // HandleBackwardCase implements step 16. "Else if itemCount >
+  // actualDeleteCount, then..."
+  macro HandleBackwardCase(
+      context: Context, o: JSReceiver, len: Number, itemCount: Number,
+      actualStart: Number, actualDeleteCount: Number): void {
+    // 16. Else if itemCount > actualDeleteCount, then
+    // a. Let k be (len - actualDeleteCount).
+    let k: Number = len - actualDeleteCount;
+
+    // b. Repeat, while k > actualStart
+    while (k > actualStart) {
+      // i. Let from be ! ToString(k + actualDeleteCount - 1).
+      const from: Number = k + actualDeleteCount - 1;
+
+      // ii. Let to be ! ToString(k + itemCount - 1).
+      const to: Number = k + itemCount - 1;
+
+      // iii. Let fromPresent be ? HasProperty(O, from).
+      const fromPresent: Boolean = HasProperty(context, o, from);
+
+      // iv. If fromPresent is true, then
+      if (fromPresent == True) {
+        // 1. Let fromValue be ? Get(O, from).
+        const fromValue: Object = GetProperty(context, o, from);
+
+        // 2. Perform ? Set(O, to, fromValue, true).
+        SetProperty(context, o, to, fromValue);
+
+        // v. Else fromPresent is false,
+      } else {
+        // 1. Perform ? DeletePropertyOrThrow(O, to).
+        DeleteProperty(context, o, to, kStrict);
+      }
+
+      // vi. Decrease k by 1.
+      k--;
+    }
+  }
+
+  macro SlowSplice(
+      context: Context, arguments: constexpr Arguments, o: JSReceiver,
+      len: Number, actualStart: Number, insertCount: Smi,
+      actualDeleteCount: Number): Object {
+    const affected: Number = len - actualStart - actualDeleteCount;
+
+    // 9. Let A be ? ArraySpeciesCreate(O, actualDeleteCount).
+    const a: JSReceiver = ArraySpeciesCreate(context, o, actualDeleteCount);
+    const itemCount: Number = insertCount;
+
+    // Steps 9 through 12: creating the array of deleted elements.
+    FillDeletedElementsArray(context, o, actualStart, actualDeleteCount, a);
+
+    // 13. Let items be a List whose elements are, in left-to-right order,
+    //     the portion of the actual argument list starting with the third
+    //     argument. The list is empty if fewer than three arguments were
+    //     passed.
+    // 14. Let itemCount be the Number of elements in items.
+    // (done above).
+
+    // 15. If itemCount < actualDeleteCount, then
+    if (itemCount < actualDeleteCount) {
+      HandleForwardCase(
+          context, o, len, itemCount, actualStart, actualDeleteCount);
+      // 16. Else if itemCount > actualDeleteCount, then
+    } else if (itemCount > actualDeleteCount) {
+      HandleBackwardCase(
+          context, o, len, itemCount, actualStart, actualDeleteCount);
+    }
+
+    // 17. Let k be actualStart.
+    let k: Number = actualStart;
+
+    // 18. Repeat, while items is not empty
+    //   a. Remove the first element from items and let E be the value of that
+    //   element.
+    if (arguments.length > 2) {
+      for (let e: Object of arguments [2: ]) {
+        // b. Perform ? Set(O, ! ToString(k), E, true).
+        SetProperty(context, o, k, e);
+
+        // c. Increase k by 1.
+        k = k + 1;
+      }
+    }
+
+    // 19. Perform ? Set(O, "length", len - actualDeleteCount + itemCount,
+    // true).
+    SetProperty(context, o, kLengthString, len - actualDeleteCount + itemCount);
+
+    return a;
+  }
+
+  // https://tc39.github.io/ecma262/#sec-array.prototype.splice
+  javascript builtin ArraySplice(
+      context: Context, receiver: Object, ...arguments): Object {
+    // 1. Let O be ? ToObject(this value).
+    const o: JSReceiver = ToObject(context, receiver);
+
+    // 2. Let len be ? ToLength(? Get(O, "length")).
+    const len: Number = GetLengthProperty(context, o);
+
+    // 3. Let relativeStart be ? ToInteger(start).
+    const start: Object = arguments[0];
+    const relativeStart: Number = ToInteger_Inline(context, start);
+
+    // 4. If relativeStart < 0, let actualStart be max((len + relativeStart),
+    // 0);
+    //    else let actualStart be min(relativeStart, len).
+    const actualStart: Number = relativeStart < 0 ?
+        Max((len + relativeStart), 0) :
+        Min(relativeStart, len);
+
+    let insertCount: Smi;
+    let actualDeleteCount: Number;
+    // 5. If the Number of actual arguments is 0, then
+    if (arguments.length == 0) {
+      // a. Let insertCount be 0.
+      insertCount = 0;
+      // b. Let actualDeleteCount be 0.
+      actualDeleteCount = 0;
+      // 6. Else if the Number of actual arguments is 1, then
+    } else if (arguments.length == 1) {
+      // a. Let insertCount be 0.
+      insertCount = 0;
+      // b. Let actualDeleteCount be len - actualStart.
+      actualDeleteCount = len - actualStart;
+      // 7. Else,
+    } else {
+      // a. Let insertCount be the Number of actual arguments minus 2.
+      insertCount = Convert<Smi>(arguments.length) - 2;
+      // b. Let dc be ? ToInteger(deleteCount).
+      const deleteCount: Object = arguments[1];
+      const dc: Number = ToInteger_Inline(context, deleteCount);
+      // c. Let actualDeleteCount be min(max(dc, 0), len - actualStart).
+      actualDeleteCount = Min(Max(dc, 0), len - actualStart);
+    }
+
+    // 8. If len + insertCount - actualDeleteCount > 2^53-1, throw a
+    //    Bailout exception.
+    const newLength: Number = len + insertCount - actualDeleteCount;
+    if (newLength > kMaxSafeInteger) {
+      ThrowTypeError(context, kInvalidArrayLength, start);
+    }
+
+    try {
+      return FastArraySplice(
+          context, arguments, o, len, actualStart, insertCount,
+          actualDeleteCount) otherwise Bailout;
+    }
+    label Bailout {}
+
+    // If the fast case fails, just continue with the slow, correct,
+    // spec-compliant case.
+    return SlowSplice(
+        context, arguments, o, len, actualStart, insertCount,
+        actualDeleteCount);
+  }
+}
diff --git a/deps/v8/src/builtins/array-unshift.tq b/deps/v8/src/builtins/array-unshift.tq
new file mode 100644
index 0000000000..3595b139a4
--- /dev/null
+++ b/deps/v8/src/builtins/array-unshift.tq
@@ -0,0 +1,107 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module array {
+  extern builtin ArrayUnshift(Context, JSFunction, Object, int32);
+
+  macro TryFastArrayUnshift(
+      context: Context, receiver: Object, arguments: constexpr Arguments):
+      never
+      labels Slow {
+    EnsureFastJSArray(context, receiver) otherwise Slow;
+    const array: JSArray = UnsafeCast<JSArray>(receiver);
+    EnsureWriteableFastElements(array);
+
+    const map: Map = array.map;
+    if (!IsExtensibleMap(map)) goto Slow;
+    EnsureArrayLengthWritable(map) otherwise Slow;
+
+    tail ArrayUnshift(
+        context, LoadTargetFromFrame(), Undefined,
+        Convert<int32>(arguments.length));
+  }
+
+  macro GenericArrayUnshift(
+      context: Context, receiver: Object,
+      arguments: constexpr Arguments): Number {
+    // 1. Let O be ? ToObject(this value).
+    const object: JSReceiver = ToObject_Inline(context, receiver);
+
+    // 2. Let len be ? ToLength(? Get(O, "length")).
+    const length: Number = GetLengthProperty(context, object);
+
+    // 3. Let argCount be the number of actual arguments.
+    const argCount: Smi = Convert<Smi>(arguments.length);
+
+    // 4. If argCount > 0, then.
+    if (argCount > 0) {
+      // a. If len + argCount > 2**53 - 1, throw a TypeError exception.
+      if (length + argCount > kMaxSafeInteger) {
+        ThrowTypeError(context, kInvalidArrayLength);
+      }
+
+      // b. Let k be len.
+      let k: Number = length;
+
+      // c. Repeat, while k > 0.
+      while (k > 0) {
+        // i. Let from be ! ToString(k - 1).
+        const from: Number = k - 1;
+
+        // ii. Let to be ! ToString(k + argCount - 1).
+        const to: Number = k + argCount - 1;
+
+        // iii. Let fromPresent be ? HasProperty(O, from).
+        const fromPresent: Boolean = HasProperty(context, object, from);
+
+        // iv. If fromPresent is true, then
+        if (fromPresent == True) {
+          // 1. Let fromValue be ? Get(O, from).
+          const fromValue: Object = GetProperty(context, object, from);
+
+          // 2. Perform ? Set(O, to, fromValue, true).
+          SetProperty(context, object, to, fromValue);
+        } else {
+          // 1. Perform ? DeletePropertyOrThrow(O, to).
+          DeleteProperty(context, object, to, kStrict);
+        }
+
+        // vi. Decrease k by 1.
+        --k;
+      }
+
+      // d. Let j be 0.
+      let j: Smi = 0;
+
+      // e. Let items be a List whose elements are, in left to right order,
+      //    the arguments that were passed to this function invocation.
+      // f. Repeat, while items is not empty
+      while (j < argCount) {
+        // ii .Perform ? Set(O, ! ToString(j), E, true).
+        SetProperty(context, object, j, arguments[Convert<intptr>(j)]);
+
+        // iii. Increase j by 1.
+        ++j;
+      }
+    }
+
+    // 5. Perform ? Set(O, "length", len + argCount, true).
+    const newLength: Number = length + argCount;
+    SetProperty(context, object, kLengthString, newLength);
+
+    // 6. Return length + argCount.
+    return newLength;
+  }
+
+  // https://tc39.github.io/ecma262/#sec-array.prototype.unshift
+  javascript builtin ArrayPrototypeUnshift(
+      context: Context, receiver: Object, ...arguments): Object {
+    try {
+      TryFastArrayUnshift(context, receiver, arguments) otherwise Baseline;
+    }
+    label Baseline {
+      return GenericArrayUnshift(context, receiver, arguments);
+    }
+  }
+}
diff --git a/deps/v8/src/builtins/array.tq b/deps/v8/src/builtins/array.tq
index 590947dd44..df4387878d 100644
--- a/deps/v8/src/builtins/array.tq
+++ b/deps/v8/src/builtins/array.tq
@@ -14,303 +14,56 @@ module array {
   type FastDoubleElements;
   type DictionaryElements;
 
-  macro GetLengthProperty(context: Context, o: Object): Number {
-    if (BranchIfFastJSArray(o, context)) {
-      let a: JSArray = unsafe_cast<JSArray>(o);
-      return a.length_fast;
-    } else
-      deferred {
-        return ToLength_Inline(context, GetProperty(context, o, 'length'));
-      }
-  }
-
-  macro FastArraySplice(
-      context: Context, args: constexpr Arguments, o: Object,
-      originalLengthNumber: Number, actualStartNumber: Number, insertCount: Smi,
-      actualDeleteCountNumber: Number): Object
-  labels Bailout {
-    let originalLength: Smi = cast<Smi>(originalLengthNumber) otherwise Bailout;
-    let actualStart: Smi = cast<Smi>(actualStartNumber) otherwise Bailout;
-    let actualDeleteCount: Smi =
-        cast<Smi>(actualDeleteCountNumber) otherwise Bailout;
-    let lengthDelta: Smi = insertCount - actualDeleteCount;
-    let newLength: Smi = originalLength + lengthDelta;
-
-    let a: JSArray = cast<JSArray>(o) otherwise Bailout;
-
-    let map: Map = a.map;
-    if (!IsPrototypeInitialArrayPrototype(context, map)) goto Bailout;
-    if (IsNoElementsProtectorCellInvalid()) goto Bailout;
-    if (IsArraySpeciesProtectorCellInvalid()) goto Bailout;
-
-    // Fast path only works on fast elements kind and with writable length.
-    let elementsKind: ElementsKind = EnsureArrayPushable(map) otherwise Bailout;
-    if (!IsFastElementsKind(elementsKind)) goto Bailout;
-
-    // For now, only support non-double fast elements
-    if (!IsFastSmiOrTaggedElementsKind(elementsKind)) goto Bailout;
-
-    if (IsFastSmiElementsKind(elementsKind)) {
-      for (let e: Object of args [2: ]) {
-        if (TaggedIsNotSmi(e)) goto Bailout;
-      }
-    }
-
-    // Make sure that the length hasn't been changed by side-effect.
-    let length: Smi = cast<Smi>(a.length) otherwise Bailout;
-    if (originalLength != length) goto Bailout;
-
-    let deletedResult: JSArray =
-        ExtractFastJSArray(context, a, actualStart, actualDeleteCount);
-
-    if (newLength == 0) {
-      a.elements = kEmptyFixedArray;
-      a.length = 0;
-      return deletedResult;
-    }
-
-    let elements: FixedArray = cast<FixedArray>(a.elements) otherwise Bailout;
-    let elementsMap: Map = elements.map;
-
-    // If the source is a COW array or the spliced array is larger then the
-    // source array, then allocate a new FixedArray to hold the result.
-    let newElements: FixedArray = elements;
-    if ((elementsMap == kCOWMap) || (lengthDelta > 0)) {
-      newElements = ExtractFixedArray(
-          elements, 0, actualStart, newLength, kAllFixedArrays);
-      newElements.map = elementsMap;
-      a.elements = newElements;
-    }
+  macro EnsureWriteableFastElements(array: JSArray) {
+    assert(IsFastElementsKind(array.map.elements_kind));
 
-    // Double check that the array is still in fast elements mode
-    assert(IsFastSmiElementsKind(a.map.elements_kind));
+    const elements: FixedArrayBase = array.elements;
+    if (elements.map != kCOWMap) return;
 
-    // Copy over inserted elements.
-    let k: Smi = actualStart;
-    if (insertCount > 0) {
-      for (let e: Object of args [2: ]) {
-        newElements[k++] = e;
-      }
-    }
-
-    // Copy over elements after deleted elements.
-    let count: Smi = length - actualStart - actualDeleteCount;
-    while (count > 0) {
-      let e: Object = elements[k - lengthDelta];
-      newElements[k++] = e;
-      count--;
-    }
-
-    // Fill rest of spliced FixedArray with the hole, but only if the
-    // destination FixedArray is the original array's, since otherwise the array
-    // is pre-filled with holes.
-    if (elements == newElements) {
-      let limit: Smi = elements.length;
-      while (k < limit) {
-        newElements[k++] = Hole;
-      }
-    }
-
-    // Update the array's length after all the FixedArray shuffling is done.
-    a.length = newLength;
+    // There are no COW *_DOUBLE_ELEMENTS arrays, so we are allowed to always
+    // extract FixedArrays and don't have to worry about FixedDoubleArrays.
+    assert(IsFastSmiOrTaggedElementsKind(array.map.elements_kind));
 
-    return deletedResult;
+    const length: Smi = array.length_fast;
+    array.elements =
+        ExtractFixedArray(elements, 0, length, length, kFixedArrays);
+    assert(array.elements.map != kCOWMap);
   }
 
-  // https://tc39.github.io/ecma262/#sec-array.prototype.splice
-  javascript builtin ArraySpliceTorque(
-      context: Context, receiver: Object, ...arguments): Object {
-    // 1. Let O be ? ToObject(this value).
-    let o: JSReceiver = ToObject(context, receiver);
-
-    // 2. Let len be ? ToLength(? Get(O, "length")).
-    let len: Number = GetLengthProperty(context, o);
-
-    // 3. Let relativeStart be ? ToInteger(start).
-    let start: Object = arguments[0];
-    let relativeStart: Number = ToInteger_Inline(context, start);
-
-    // 4. If relativeStart < 0, let actualStart be max((len + relativeStart),
-    // 0);
-    //    else let actualStart be min(relativeStart, len).
-    let actualStart: Number = relativeStart < 0 ?
-        max((len + relativeStart), 0) :
-        min(relativeStart, len);
-
-    let insertCount: Smi;
-    let actualDeleteCount: Number;
-    // 5. If the Number of actual arguments is 0, then
-    if (arguments.length == 0) {
-      // a. Let insertCount be 0.
-      insertCount = 0;
-      // b. Let actualDeleteCount be 0.
-      actualDeleteCount = 0;
-      // 6. Else if the Number of actual arguments is 1, then
-    } else if (arguments.length == 1) {
-      // a. Let insertCount be 0.
-      insertCount = 0;
-      // b. Let actualDeleteCount be len - actualStart.
-      actualDeleteCount = len - actualStart;
-      // 7. Else,
-    } else {
-      // a. Let insertCount be the Number of actual arguments minus 2.
-      insertCount = convert<Smi>(arguments.length) - 2;
-      // b. Let dc be ? ToInteger(deleteCount).
-      let deleteCount: Object = arguments[1];
-      let dc: Number = ToInteger_Inline(context, deleteCount);
-      // c. Let actualDeleteCount be min(max(dc, 0), len - actualStart).
-      actualDeleteCount = min(max(dc, 0), len - actualStart);
-    }
-
-    // 8. If len + insertCount - actualDeleteCount > 2^53-1, throw a
-    //    Bailout exception.
-    if (len + insertCount - actualDeleteCount > kMaxSafeInteger) {
-      ThrowRangeError(context, kInvalidArrayLength);
-    }
-
+  macro IsJSArray(o: Object): bool {
     try {
-      return FastArraySplice(
-          context, arguments, o, len, actualStart, insertCount,
-          actualDeleteCount) otherwise Bailout;
+      const array: JSArray = Cast<JSArray>(o) otherwise NotArray;
+      return true;
     }
-    label Bailout {}
-    // If the fast case fails, just continue with the slow, correct,
-    // spec-compliant case.
-
-    // 9. Let A be ? ArraySpeciesCreate(O, actualDeleteCount).
-    let a: Object = ArraySpeciesCreate(context, o, actualDeleteCount);
-
-    // 10. Let k be 0.
-    let k: Number = 0;
-
-    // 11. Repeat, while k < actualDeleteCount
-    while (k < actualDeleteCount) {
-      // a. Let from be ! ToString(actualStart + k).
-      let from: String = ToString_Inline(context, actualStart + k);
-
-      // b. Let fromPresent be ? HasProperty(O, from).
-      let fromPresent: Oddball = HasProperty(context, o, from);
-
-      // c. If fromPresent is true, then
-      if (fromPresent == True) {
-        // i. Let fromValue be ? Get(O, from).
-        let fromValue: Object = GetProperty(context, o, from);
-
-        // ii. Perform ? CreateDataPropertyOrThrow(A, ! ToString(k), fromValue).
-        CreateDataProperty(context, a, ToString_Inline(context, k), fromValue);
-      }
-
-      // d. Increment k by 1.
-      k = k + 1;
+    label NotArray {
+      return false;
     }
+  }
 
-    // 12. Perform ? Set(A, "length", actualDeleteCount, true).
-    SetProperty(context, a, 'length', actualDeleteCount);
-
-    // 13. Let items be a List whose elements are, in left-to-right order,
-    //     the portion of the actual argument list starting with the third
-    //     argument. The list is empty if fewer than three arguments were
-    //     passed.
-    // 14. Let itemCount be the Number of elements in items.
-    let itemCount: Number = insertCount;
-
-    // 15. If itemCount < actualDeleteCount, then
-    if (itemCount < actualDeleteCount) {
-      // a. Let k be actualStart.
-      let k: Number = actualStart;
-
-      // b. Repeat, while k < (len - actualDeleteCount)
-      while (k < (len - actualDeleteCount)) {
-        // i. Let from be ! ToString(k + actualDeleteCount).
-        let from: String = ToString_Inline(context, k + actualDeleteCount);
-        // ii. Let to be ! ToString(k + itemCount).
-        let to: String = ToString_Inline(context, k + itemCount);
-
-        // iii. Let fromPresent be ? HasProperty(O, from).
-        let fromPresent: Oddball = HasProperty(context, o, from);
-
-        // iv. If fromPresent is true, then
-        if (fromPresent == True) {
-          // 1. Let fromValue be ? Get(O, from).
-          let fromValue: Object = GetProperty(context, o, from);
-
-          // 2. Perform ? Set(O, to, fromValue, true).
-          SetProperty(context, o, to, fromValue);
-
-          // v. Else fromPresent is false,
-        } else {
-          // 1. Perform ? DeletePropertyOrThrow(O, to).
-          DeleteProperty(context, o, to, kStrict);
-        }
-        // vi. Increase k by 1.
-        k = k + 1;
-      }
-
-      // c. Let k be len.
-      k = len;
-      // d. Repeat, while k > (len - actualDeleteCount + itemCount)
-      while (k > (len - actualDeleteCount + itemCount)) {
-        // i. Perform ? DeletePropertyOrThrow(O, ! ToString(k - 1)).
-        DeleteProperty(context, o, ToString_Inline(context, k - 1), kStrict);
-
-        // ii. Decrease k by 1.
-        k = k - 1;
-      }
-      // 16. Else if itemCount > actualDeleteCount, then
-    } else if (itemCount > actualDeleteCount) {
-      // a. Let k be (len - actualDeleteCount).
-      let k: Number = len - actualDeleteCount;
-
-      // b. Repeat, while k > actualStart
-      while (k > actualStart) {
-        // i. Let from be ! ToString(k + actualDeleteCount - 1).
-        let from: String = ToString_Inline(context, k + actualDeleteCount - 1);
-
-        // ii. Let to be ! ToString(k + itemCount - 1).
-        let to: String = ToString_Inline(context, k + itemCount - 1);
-
-        // iii. Let fromPresent be ? HasProperty(O, from).
-        let fromPresent: Oddball = HasProperty(context, o, from);
-
-        // iv. If fromPresent is true, then
-        if (fromPresent == True) {
-          // 1. Let fromValue be ? Get(O, from).
-          let fromValue: Object = GetProperty(context, o, from);
+  macro StoreArrayHole(elements: FixedDoubleArray, k: Smi): void {
+    StoreFixedDoubleArrayHoleSmi(elements, k);
+  }
 
-          // 2. Perform ? Set(O, to, fromValue, true).
-          SetProperty(context, o, to, fromValue);
+  macro StoreArrayHole(elements: FixedArray, k: Smi): void {
+    elements[k] = Hole;
+  }
 
-          // v. Else fromPresent is false,
-        } else {
-          // 1. Perform ? DeletePropertyOrThrow(O, to).
-          DeleteProperty(context, o, to, kStrict);
-        }
+  macro CopyArrayElement(
+      elements: FixedArray, newElements: FixedArray, from: Smi, to: Smi): void {
+    const e: Object = elements[from];
+    newElements[to] = e;
+  }
 
-        // vi. Decrease k by 1.
-        k = k - 1;
-      }
+  macro CopyArrayElement(
+      elements: FixedDoubleArray, newElements: FixedDoubleArray, from: Smi,
+      to: Smi): void {
+    try {
+      const floatValue: float64 = LoadDoubleWithHoleCheck(elements, from)
+          otherwise FoundHole;
+      newElements[to] = floatValue;
     }
-
-    // 17. Let k be actualStart.
-    k = actualStart;
-
-    // 18. Repeat, while items is not empty
-    //   a. Remove the first element from items and let E be the value of that
-    //   element.
-    if (arguments.length > 2) {
-      for (let e: Object of arguments [2: ]) {
-        // b. Perform ? Set(O, ! ToString(k), E, true).
-        SetProperty(context, o, ToString_Inline(context, k), e);
-
-        // c. Increase k by 1.
-        k = k + 1;
-      }
+    label FoundHole {
+      StoreArrayHole(newElements, to);
     }
-
-    // 19. Perform ? Set(O, "length", len - actualDeleteCount + itemCount,
-    // true).
-    SetProperty(context, o, 'length', len - actualDeleteCount + itemCount);
-
-    return a;
   }
 }
diff --git a/deps/v8/src/builtins/base.tq b/deps/v8/src/builtins/base.tq
index 1b9d577f10..20c4f4b9e0 100644
--- a/deps/v8/src/builtins/base.tq
+++ b/deps/v8/src/builtins/base.tq
@@ -26,6 +26,7 @@ type AbstractCode extends HeapObject generates 'TNode<AbstractCode>';
 type Code extends AbstractCode generates 'TNode<Code>';
 type JSReceiver extends HeapObject generates 'TNode<JSReceiver>';
 type Context extends HeapObject generates 'TNode<Context>';
+type NativeContext extends Context generates 'TNode<Context>';
 type String extends HeapObject generates 'TNode<String>';
 type Oddball extends HeapObject generates 'TNode<Oddball>';
 type HeapNumber extends HeapObject generates 'TNode<HeapNumber>';
@@ -35,34 +36,56 @@ type Numeric = Number|BigInt;
 type Boolean extends Oddball generates 'TNode<Oddball>';
 type JSProxy extends JSReceiver generates 'TNode<JSProxy>';
 type JSObject extends JSReceiver generates 'TNode<JSObject>';
-type JSArray extends JSObject generates 'TNode<JSArray>';
+type JSArgumentsObjectWithLength extends JSObject
+    generates 'TNode<JSArgumentsObjectWithLength>';
+type JSArray extends JSArgumentsObjectWithLength
+    generates 'TNode<JSArray>';
 type JSFunction extends JSObject generates 'TNode<JSFunction>';
 type JSBoundFunction extends JSObject generates 'TNode<JSBoundFunction>';
 type Callable = JSFunction|JSBoundFunction|JSProxy;
 type Map extends HeapObject generates 'TNode<Map>';
 type FixedArrayBase extends HeapObject generates 'TNode<FixedArrayBase>';
 type FixedArray extends FixedArrayBase generates 'TNode<FixedArray>';
-type FixedDoubleArray extends FixedArrayBase generates
-'TNode<FixedDoubleArray>';
-type FixedTypedArrayBase extends FixedArrayBase generates
-'TNode<FixedTypedArrayBase>';
-type FixedTypedArray extends FixedTypedArrayBase generates
-'TNode<FixedTypedArray>';
-type NumberDictionary extends HeapObject generates 'TNode<NumberDictionary>';
+type FixedDoubleArray extends FixedArrayBase
+    generates 'TNode<FixedDoubleArray>';
+type FixedTypedArrayBase extends FixedArrayBase
+    generates 'TNode<FixedTypedArrayBase>';
+type FixedTypedArray extends FixedTypedArrayBase
+    generates 'TNode<FixedTypedArray>';
+type NumberDictionary extends HeapObject
+    generates 'TNode<NumberDictionary>';
+
+type NativeContextSlot generates 'TNode<IntPtrT>' constexpr 'int32_t';
+const FAST_ALIASED_ARGUMENTS_MAP_INDEX: constexpr NativeContextSlot
+    generates 'Context::FAST_ALIASED_ARGUMENTS_MAP_INDEX';
+const SLOW_ALIASED_ARGUMENTS_MAP_INDEX: constexpr NativeContextSlot
+    generates 'Context::SLOW_ALIASED_ARGUMENTS_MAP_INDEX';
+const STRICT_ARGUMENTS_MAP_INDEX: constexpr NativeContextSlot
+    generates 'Context::STRICT_ARGUMENTS_MAP_INDEX';
+const SLOPPY_ARGUMENTS_MAP_INDEX: constexpr NativeContextSlot
+    generates 'Context::SLOPPY_ARGUMENTS_MAP_INDEX';
+extern operator '[]' macro LoadContextElement(
+    NativeContext, NativeContextSlot): Object;
+
+extern operator '[]' macro LoadContextElement(Context, intptr): Object;
+extern operator '[]' macro LoadContextElement(Context, Smi): Object;
 
 type JSArrayBuffer extends JSObject generates 'TNode<JSArrayBuffer>';
-type JSArrayBufferView extends JSObject generates 'TNode<JSArrayBufferView>';
-type JSTypedArray extends JSArrayBufferView generates 'TNode<JSTypedArray>';
+type JSArrayBufferView extends JSObject
+    generates 'TNode<JSArrayBufferView>';
+type JSTypedArray extends JSArrayBufferView
+    generates 'TNode<JSTypedArray>';
 type JSDataView extends JSArrayBufferView generates 'TNode<JSDataView>';
 
 type InstanceType generates 'TNode<Int32T>' constexpr 'InstanceType';
 type ElementsKind generates 'TNode<Int32T>' constexpr 'ElementsKind';
 type LanguageMode generates 'TNode<Smi>' constexpr 'LanguageMode';
-type ExtractFixedArrayFlags generates
-'TNode<Smi>' constexpr 'ExtractFixedArrayFlags';
+type ExtractFixedArrayFlags
+    generates 'TNode<Smi>' constexpr 'ExtractFixedArrayFlags';
 type ParameterMode generates 'TNode<Int32T>' constexpr 'ParameterMode';
-type RootListIndex generates 'TNode<Int32T>' constexpr 'Heap::RootListIndex';
-type WriteBarrierMode generates 'TNode<Int32T>' constexpr 'WriteBarrierMode';
+type RootIndex generates 'TNode<Int32T>' constexpr 'RootIndex';
+type WriteBarrierMode
+    generates 'TNode<Int32T>' constexpr 'WriteBarrierMode';
 
 type MessageTemplate constexpr 'MessageTemplate::Template';
 
@@ -70,30 +93,38 @@ type ToIntegerTruncationMode constexpr 'ToIntegerTruncationMode';
 
 const NO_ELEMENTS: constexpr ElementsKind generates 'NO_ELEMENTS';
 
-const PACKED_SMI_ELEMENTS: constexpr ElementsKind generates
-'PACKED_SMI_ELEMENTS';
-const HOLEY_SMI_ELEMENTS: constexpr ElementsKind generates 'HOLEY_SMI_ELEMENTS';
-const PACKED_ELEMENTS: constexpr ElementsKind generates 'PACKED_ELEMENTS';
+const PACKED_SMI_ELEMENTS:
+    constexpr ElementsKind generates 'PACKED_SMI_ELEMENTS';
+const HOLEY_SMI_ELEMENTS:
+    constexpr ElementsKind generates 'HOLEY_SMI_ELEMENTS';
+const PACKED_ELEMENTS:
+    constexpr ElementsKind generates 'PACKED_ELEMENTS';
 const HOLEY_ELEMENTS: constexpr ElementsKind generates 'HOLEY_ELEMENTS';
-const PACKED_DOUBLE_ELEMENTS: constexpr ElementsKind generates
-'PACKED_DOUBLE_ELEMENTS';
-const HOLEY_DOUBLE_ELEMENTS: constexpr ElementsKind generates
-'HOLEY_DOUBLE_ELEMENTS';
-const DICTIONARY_ELEMENTS: constexpr ElementsKind generates
-'DICTIONARY_ELEMENTS';
+const PACKED_DOUBLE_ELEMENTS:
+    constexpr ElementsKind generates 'PACKED_DOUBLE_ELEMENTS';
+const HOLEY_DOUBLE_ELEMENTS:
+    constexpr ElementsKind generates 'HOLEY_DOUBLE_ELEMENTS';
+const DICTIONARY_ELEMENTS:
+    constexpr ElementsKind generates 'DICTIONARY_ELEMENTS';
 
 const UINT8_ELEMENTS: constexpr ElementsKind generates 'UINT8_ELEMENTS';
 const INT8_ELEMENTS: constexpr ElementsKind generates 'INT8_ELEMENTS';
-const UINT16_ELEMENTS: constexpr ElementsKind generates 'UINT16_ELEMENTS';
+const UINT16_ELEMENTS:
+    constexpr ElementsKind generates 'UINT16_ELEMENTS';
 const INT16_ELEMENTS: constexpr ElementsKind generates 'INT16_ELEMENTS';
-const UINT32_ELEMENTS: constexpr ElementsKind generates 'UINT32_ELEMENTS';
+const UINT32_ELEMENTS:
+    constexpr ElementsKind generates 'UINT32_ELEMENTS';
 const INT32_ELEMENTS: constexpr ElementsKind generates 'INT32_ELEMENTS';
-const FLOAT32_ELEMENTS: constexpr ElementsKind generates 'FLOAT32_ELEMENTS';
-const FLOAT64_ELEMENTS: constexpr ElementsKind generates 'FLOAT64_ELEMENTS';
-const UINT8_CLAMPED_ELEMENTS: constexpr ElementsKind generates
-'UINT8_CLAMPED_ELEMENTS';
-const BIGUINT64_ELEMENTS: constexpr ElementsKind generates 'BIGUINT64_ELEMENTS';
-const BIGINT64_ELEMENTS: constexpr ElementsKind generates 'BIGINT64_ELEMENTS';
+const FLOAT32_ELEMENTS:
+    constexpr ElementsKind generates 'FLOAT32_ELEMENTS';
+const FLOAT64_ELEMENTS:
+    constexpr ElementsKind generates 'FLOAT64_ELEMENTS';
+const UINT8_CLAMPED_ELEMENTS:
+    constexpr ElementsKind generates 'UINT8_CLAMPED_ELEMENTS';
+const BIGUINT64_ELEMENTS:
+    constexpr ElementsKind generates 'BIGUINT64_ELEMENTS';
+const BIGINT64_ELEMENTS:
+    constexpr ElementsKind generates 'BIGINT64_ELEMENTS';
 
 type FixedUint8Array extends FixedTypedArray;
 type FixedInt8Array extends FixedTypedArray;
@@ -107,40 +138,42 @@ type FixedUint8ClampedArray extends FixedTypedArray;
 type FixedBigUint64Array extends FixedTypedArray;
 type FixedBigInt64Array extends FixedTypedArray;
 
-const kAllFixedArrays: constexpr ExtractFixedArrayFlags generates
-'ExtractFixedArrayFlag::kAllFixedArrays';
-const kFixedArrays: constexpr ExtractFixedArrayFlags generates
-'ExtractFixedArrayFlag::kFixedArrays';
-
-const kFixedCOWArrayMapRootIndex: constexpr RootListIndex generates
-'Heap::kFixedCOWArrayMapRootIndex';
-const kEmptyFixedArrayRootIndex: constexpr RootListIndex generates
-'Heap::kEmptyFixedArrayRootIndex';
-
-const kInvalidArrayLength: constexpr MessageTemplate generates
-'MessageTemplate::kInvalidArrayLength';
-const kCalledNonCallable: constexpr MessageTemplate generates
-'MessageTemplate::kCalledNonCallable';
-const kCalledOnNullOrUndefined: constexpr MessageTemplate generates
-'MessageTemplate::kCalledOnNullOrUndefined';
+const kFixedDoubleArrays: constexpr ExtractFixedArrayFlags
+    generates 'ExtractFixedArrayFlag::kFixedDoubleArrays';
+const kAllFixedArrays: constexpr ExtractFixedArrayFlags
+    generates 'ExtractFixedArrayFlag::kAllFixedArrays';
+const kFixedArrays: constexpr ExtractFixedArrayFlags
+    generates 'ExtractFixedArrayFlag::kFixedArrays';
+
+const kFixedCOWArrayMapRootIndex:
+    constexpr RootIndex generates 'RootIndex::kFixedCOWArrayMap';
+const kEmptyFixedArrayRootIndex:
+    constexpr RootIndex generates 'RootIndex::kEmptyFixedArray';
+
+const kInvalidArrayLength: constexpr MessageTemplate
+    generates 'MessageTemplate::kInvalidArrayLength';
+const kCalledNonCallable: constexpr MessageTemplate
+    generates 'MessageTemplate::kCalledNonCallable';
+const kCalledOnNullOrUndefined: constexpr MessageTemplate
+    generates 'MessageTemplate::kCalledOnNullOrUndefined';
 
 const kMaxSafeInteger: constexpr float64 generates 'kMaxSafeInteger';
 
-const kTruncateMinusZero: constexpr ToIntegerTruncationMode generates
-'ToIntegerTruncationMode::kTruncateMinusZero';
-
-const kNotTypedArray: constexpr MessageTemplate generates
-'MessageTemplate::kNotTypedArray';
-const kDetachedOperation: constexpr MessageTemplate generates
-'MessageTemplate::kDetachedOperation';
-const kBadSortComparisonFunction: constexpr MessageTemplate generates
-'MessageTemplate::kBadSortComparisonFunction';
-const kIncompatibleMethodReceiver: constexpr MessageTemplate generates
-'MessageTemplate::kIncompatibleMethodReceiver';
-const kInvalidDataViewAccessorOffset: constexpr MessageTemplate generates
-'MessageTemplate::kInvalidDataViewAccessorOffset';
-const kStrictReadOnlyProperty: constexpr MessageTemplate generates
-'MessageTemplate::kStrictReadOnlyProperty';
+const kTruncateMinusZero: constexpr ToIntegerTruncationMode
+    generates 'ToIntegerTruncationMode::kTruncateMinusZero';
+
+const kNotTypedArray: constexpr MessageTemplate
+    generates 'MessageTemplate::kNotTypedArray';
+const kDetachedOperation: constexpr MessageTemplate
+    generates 'MessageTemplate::kDetachedOperation';
+const kBadSortComparisonFunction: constexpr MessageTemplate
+    generates 'MessageTemplate::kBadSortComparisonFunction';
+const kIncompatibleMethodReceiver: constexpr MessageTemplate
+    generates 'MessageTemplate::kIncompatibleMethodReceiver';
+const kInvalidDataViewAccessorOffset: constexpr MessageTemplate
+    generates 'MessageTemplate::kInvalidDataViewAccessorOffset';
+const kStrictReadOnlyProperty: constexpr MessageTemplate
+    generates 'MessageTemplate::kStrictReadOnlyProperty';
 
 extern macro TheHoleConstant(): Oddball;
 extern macro NullConstant(): Oddball;
@@ -149,12 +182,14 @@ extern macro TrueConstant(): Boolean;
 extern macro FalseConstant(): Boolean;
 extern macro Int32TrueConstant(): bool;
 extern macro Int32FalseConstant(): bool;
+extern macro LengthStringConstant(): String;
 
 const Hole: Oddball = TheHoleConstant();
 const Null: Oddball = NullConstant();
 const Undefined: Oddball = UndefinedConstant();
 const True: Boolean = TrueConstant();
 const False: Boolean = FalseConstant();
+const kLengthString: String = LengthStringConstant();
 
 const true: constexpr bool generates 'true';
 const false: constexpr bool generates 'false';
@@ -163,11 +198,11 @@ const kStrict: constexpr LanguageMode generates 'LanguageMode::kStrict';
 const kSloppy: constexpr LanguageMode generates 'LanguageMode::kSloppy';
 
 const SMI_PARAMETERS: constexpr ParameterMode generates 'SMI_PARAMETERS';
-const INTPTR_PARAMETERS: constexpr ParameterMode generates 'INTPTR_PARAMETERS';
-
+const INTPTR_PARAMETERS:
+    constexpr ParameterMode generates 'INTPTR_PARAMETERS';
 
-const SKIP_WRITE_BARRIER: constexpr WriteBarrierMode
-    generates 'SKIP_WRITE_BARRIER';
+const SKIP_WRITE_BARRIER:
+    constexpr WriteBarrierMode generates 'SKIP_WRITE_BARRIER';
 
 extern macro Is64(): constexpr bool;
 
@@ -175,6 +210,7 @@ extern macro SelectBooleanConstant(bool): Boolean;
 
 extern macro Print(constexpr string);
 extern macro Print(constexpr string, Object);
+extern macro Comment(constexpr string);
 extern macro Print(Object);
 extern macro DebugBreak();
 extern macro ToInteger_Inline(Context, Object): Number;
@@ -187,14 +223,18 @@ extern macro GetProperty(Context, Object, Object): Object;
 extern builtin SetProperty(Context, Object, Object, Object);
 extern builtin DeleteProperty(Context, Object, Object, LanguageMode);
 extern builtin HasProperty(Context, JSReceiver, Object): Boolean;
+extern macro HasProperty_Inline(Context, JSReceiver, Object): Boolean;
 
 extern macro ThrowRangeError(Context, constexpr MessageTemplate): never;
 extern macro ThrowTypeError(Context, constexpr MessageTemplate): never;
 extern macro ThrowTypeError(Context, constexpr MessageTemplate, Object): never;
 extern macro ThrowTypeError(
     Context, constexpr MessageTemplate, Object, Object, Object): never;
-extern macro ArraySpeciesCreate(Context, Object, Number): Object;
-extern macro EnsureArrayPushable(Map): ElementsKind labels Bailout;
+extern macro ArraySpeciesCreate(Context, Object, Number): JSReceiver;
+extern macro InternalArrayCreate(Context, Number): JSArray;
+extern macro EnsureArrayPushable(Map): ElementsKind
+    labels Bailout;
+extern macro EnsureArrayLengthWritable(Map) labels Bailout;
 
 extern builtin ToObject(Context, Object): JSReceiver;
 extern macro ToObject_Inline(Context, Object): JSReceiver;
@@ -203,17 +243,19 @@ extern macro IsTheHole(Object): bool;
 extern macro IsString(HeapObject): bool;
 extern builtin ToString(Context, Object): String;
 
-extern runtime CreateDataProperty(Context, Object, Object, Object);
+extern runtime NormalizeElements(Context, JSObject);
+extern runtime TransitionElementsKindWithKind(Context, JSObject, Smi);
+extern runtime CreateDataProperty(Context, JSReceiver, Object, Object);
 
-extern macro LoadRoot(constexpr RootListIndex): Object;
-extern macro StoreRoot(constexpr RootListIndex, Object): Object;
-extern macro LoadAndUntagToWord32Root(constexpr RootListIndex): int32;
+extern macro LoadRoot(constexpr RootIndex): Object;
+extern macro StoreRoot(constexpr RootIndex, Object): Object;
+extern macro LoadAndUntagToWord32Root(constexpr RootIndex): int32;
 
 extern runtime StringEqual(Context, String, String): Oddball;
 extern builtin StringLessThan(Context, String, String): Boolean;
 
 extern macro StrictEqual(Object, Object): Boolean;
-extern runtime SmiLexicographicCompare(Context, Object, Object): Number;
+extern macro SmiLexicographicCompare(Smi, Smi): Smi;
 
 extern operator '<' macro Int32LessThan(int32, int32): bool;
 extern operator '>' macro Int32GreaterThan(int32, int32): bool;
@@ -230,6 +272,10 @@ extern operator '>=' macro SmiGreaterThanOrEqual(Smi, Smi): bool;
 extern operator '==' macro ElementsKindEqual(
     constexpr ElementsKind, constexpr ElementsKind): constexpr bool;
 extern operator '==' macro ElementsKindEqual(ElementsKind, ElementsKind): bool;
+operator '!=' macro ElementsKindNotEqual(
+    k1: ElementsKind, k2: ElementsKind): bool {
+  return !ElementsKindEqual(k1, k2);
+}
 extern macro IsFastElementsKind(constexpr ElementsKind): constexpr bool;
 extern macro IsDoubleElementsKind(constexpr ElementsKind): constexpr bool;
 
@@ -243,22 +289,25 @@ extern operator '<' macro IntPtrLessThan(intptr, intptr): bool;
 extern operator '>' macro IntPtrGreaterThan(intptr, intptr): bool;
 extern operator '<=' macro IntPtrLessThanOrEqual(intptr, intptr): bool;
 extern operator '>=' macro IntPtrGreaterThanOrEqual(intptr, intptr): bool;
+extern operator '>' macro UintPtrGreaterThan(uintptr, uintptr): bool;
 extern operator '>=' macro UintPtrGreaterThanOrEqual(uintptr, uintptr): bool;
 
 extern operator '==' macro Float64Equal(float64, float64): bool;
 extern operator '!=' macro Float64NotEqual(float64, float64): bool;
+extern operator '>' macro Float64GreaterThan(float64, float64): bool;
+
+extern operator '==' macro BranchIfNumberEqual(Number, Number): never
+    labels Taken, NotTaken;
+extern operator '<' macro BranchIfNumberLessThan(Number, Number): never
+    labels Taken, NotTaken;
+extern operator '<=' macro BranchIfNumberLessThanOrEqual(Number, Number): never
+    labels Taken, NotTaken;
 
-extern operator
-'<' macro BranchIfNumberLessThan(Number, Number): never labels Taken, NotTaken;
-extern operator
-'<=' macro BranchIfNumberLessThanOrEqual(Number, Number): never labels Taken,
-    NotTaken;
-extern operator
-'>' macro BranchIfNumberGreaterThan(Number, Number): never labels Taken,
-    NotTaken;
+extern operator '>' macro BranchIfNumberGreaterThan(Number, Number): never
+    labels Taken, NotTaken;
 extern operator '>=' macro BranchIfNumberGreaterThanOrEqual(Number, Number):
-    never labels Taken,
-    NotTaken;
+    never
+    labels Taken, NotTaken;
 
 extern operator '==' macro WordEqual(Object, Object): bool;
 extern operator '!=' macro WordNotEqual(Object, Object): bool;
@@ -271,6 +320,7 @@ extern operator '>>>' macro SmiShr(Smi, constexpr int31): Smi;
 extern operator '<<' macro SmiShl(Smi, constexpr int31): Smi;
 
 extern operator '+' macro IntPtrAdd(intptr, intptr): intptr;
+extern operator '+' macro UintPtrAdd(uintptr, uintptr): uintptr;
 extern operator '-' macro IntPtrSub(intptr, intptr): intptr;
 extern operator '>>>' macro WordShr(uintptr, uintptr): uintptr;
 extern operator '<<' macro WordShl(intptr, intptr): intptr;
@@ -296,14 +346,16 @@ extern operator '<<' macro Word32Shl(uint32, uint32): uint32;
 extern operator '|' macro Word32Or(int32, int32): int32;
 extern operator '|' macro Word32Or(uint32, uint32): uint32;
 
+extern operator '+' macro Float64Add(float64, float64): float64;
+
 extern operator '+' macro NumberAdd(Number, Number): Number;
 extern operator '-' macro NumberSub(Number, Number): Number;
 extern macro NumberMin(Number, Number): Number;
 extern macro NumberMax(Number, Number): Number;
-macro min(x: Number, y: Number): Number {
+macro Min(x: Number, y: Number): Number {
   return NumberMin(x, y);
 }
-macro max(x: Number, y: Number): Number {
+macro Max(x: Number, y: Number): Number {
   return NumberMax(x, y);
 }
 
@@ -316,68 +368,89 @@ extern operator '!' macro IsFalse(Boolean): bool;
 
 extern operator '.map' macro LoadMap(HeapObject): Map;
 extern operator '.map=' macro StoreMap(HeapObject, Map);
-extern operator
-'.instanceType' macro LoadInstanceType(HeapObject): InstanceType;
+extern operator '.instanceType' macro LoadInstanceType(HeapObject):
+    InstanceType;
 
 extern operator '.length' macro LoadStringLengthAsWord(String): intptr;
 
 extern operator '.length' macro GetArgumentsLength(constexpr Arguments): intptr;
-extern operator
-'[]' macro GetArgumentValue(constexpr Arguments, intptr): Object;
+extern operator '[]' macro GetArgumentValue(
+    constexpr Arguments, intptr): Object;
 
-extern operator 'is<Smi>' macro TaggedIsSmi(Object): bool;
-extern operator 'isnt<Smi>' macro TaggedIsNotSmi(Object): bool;
+extern macro TaggedIsSmi(Object): bool;
+extern macro TaggedIsNotSmi(Object): bool;
 extern macro TaggedIsPositiveSmi(Object): bool;
 
-extern macro HeapObjectToJSDataView(HeapObject): JSDataView labels CastError;
-extern macro TaggedToHeapObject(Object): HeapObject labels CastError;
-extern macro TaggedToSmi(Object): Smi labels CastError;
-extern macro HeapObjectToJSArray(HeapObject): JSArray labels CastError;
-extern macro HeapObjectToCallable(HeapObject): Callable labels CastError;
-extern macro HeapObjectToFixedArray(HeapObject):
-    FixedArray labels CastError;
-extern macro HeapObjectToFixedDoubleArray(HeapObject):
-    FixedDoubleArray labels CastError;
-extern macro TaggedToNumber(Object): Number labels CastError;
-
-macro cast_HeapObject<A : type>(o : HeapObject) : A labels CastError;
-cast_HeapObject<HeapObject>(o : HeapObject) : HeapObject labels CastError { return o; }
-cast_HeapObject<FixedArray>(o: HeapObject): FixedArray labels CastError {
+extern macro HeapObjectToJSDataView(HeapObject): JSDataView
+    labels CastError;
+extern macro TaggedToHeapObject(Object): HeapObject
+    labels CastError;
+extern macro TaggedToSmi(Object): Smi
+    labels CastError;
+extern macro HeapObjectToJSArray(HeapObject): JSArray
+    labels CastError;
+extern macro HeapObjectToCallable(HeapObject): Callable
+    labels CastError;
+extern macro HeapObjectToFixedArray(HeapObject): FixedArray
+    labels CastError;
+extern macro HeapObjectToFixedDoubleArray(HeapObject): FixedDoubleArray
+    labels CastError;
+extern macro TaggedToNumber(Object): Number
+    labels CastError;
+
+macro CastHeapObject<A: type>(o: HeapObject): A
+    labels CastError;
+CastHeapObject<HeapObject>(o: HeapObject): HeapObject
+    labels CastError {
+  return o;
+}
+CastHeapObject<FixedArray>(o: HeapObject): FixedArray
+    labels CastError {
   return HeapObjectToFixedArray(o) otherwise CastError;
 }
-cast_HeapObject<FixedDoubleArray>(o: HeapObject): FixedDoubleArray labels CastError {
+CastHeapObject<FixedDoubleArray>(o: HeapObject): FixedDoubleArray
+    labels CastError {
   return HeapObjectToFixedDoubleArray(o) otherwise CastError;
 }
-cast_HeapObject<JSDataView>(o: HeapObject): JSDataView labels CastError {
+CastHeapObject<JSDataView>(o: HeapObject): JSDataView
+    labels CastError {
   return HeapObjectToJSDataView(o) otherwise CastError;
 }
-cast_HeapObject<Callable>(o: HeapObject): Callable labels CastError {
+CastHeapObject<Callable>(o: HeapObject): Callable
+    labels CastError {
   return HeapObjectToCallable(o) otherwise CastError;
 }
-cast_HeapObject<JSArray>(o: HeapObject): JSArray labels CastError {
+CastHeapObject<JSArray>(o: HeapObject): JSArray
+    labels CastError {
   return HeapObjectToJSArray(o) otherwise CastError;
 }
 
-macro cast<A : type>(o: HeapObject): A labels CastError {
-  return cast_HeapObject<A>(o) otherwise CastError;
+macro Cast<A: type>(o: HeapObject): A
+    labels CastError {
+  return CastHeapObject<A>(o) otherwise CastError;
 }
 
-// cast_HeapObject allows this default-implementation to be non-recursive.
+// CastHeapObject allows this default-implementation to be non-recursive.
 // Otherwise the generated CSA code might run into infinite recursion.
-macro cast<A : type>(o: Object): A labels CastError {
-  return cast_HeapObject<A>(
-    TaggedToHeapObject(o) otherwise CastError) otherwise CastError;
+macro Cast<A: type>(o: Object): A
+    labels CastError {
+  return CastHeapObject<A>(TaggedToHeapObject(o) otherwise CastError)
+      otherwise CastError;
 }
-cast<Smi>(o: Object): Smi labels CastError {
+Cast<Smi>(o: Object): Smi
+    labels CastError {
   return TaggedToSmi(o) otherwise CastError;
 }
-cast<Number>(o: Object): Number labels CastError {
+Cast<Number>(o: Object): Number
+    labels CastError {
   return TaggedToNumber(o) otherwise CastError;
 }
 
 extern macro AllocateHeapNumberWithValue(float64): HeapNumber;
 extern macro ChangeInt32ToTagged(int32): Number;
 extern macro ChangeUint32ToTagged(uint32): Number;
+extern macro ChangeUintPtrToFloat64(uintptr): float64;
+extern macro ChangeUintPtrToTagged(uintptr): Number;
 extern macro Unsigned(int32): uint32;
 extern macro Unsigned(intptr): uintptr;
 extern macro Unsigned(RawPtr): uintptr;
@@ -396,6 +469,8 @@ extern macro ChangeNumberToFloat64(Number): float64;
 extern macro ChangeFloat64ToUintPtr(float64): uintptr;
 extern macro ChangeInt32ToIntPtr(int32): intptr;   // Sign-extends.
 extern macro ChangeUint32ToWord(uint32): uintptr;  // Doesn't sign-extend.
+extern macro LoadNativeContext(Context): NativeContext;
+extern macro LoadJSArrayElementsMap(constexpr ElementsKind, Context): Map;
 
 extern macro NumberConstant(constexpr float64): Number;
 extern macro NumberConstant(constexpr int32): Number;
@@ -409,137 +484,157 @@ extern macro BoolConstant(constexpr bool): bool;
 extern macro StringConstant(constexpr string): String;
 extern macro LanguageModeConstant(constexpr LanguageMode): LanguageMode;
 extern macro Int32Constant(constexpr ElementsKind): ElementsKind;
+extern macro IntPtrConstant(constexpr NativeContextSlot): NativeContextSlot;
 
-macro from_constexpr<A : type>(o: constexpr int31): A;
-from_constexpr<intptr>(i: constexpr int31): intptr {
+macro FromConstexpr<A: type>(o: constexpr int31): A;
+FromConstexpr<intptr>(i: constexpr int31): intptr {
   return IntPtrConstant(i);
 }
-from_constexpr<int31>(i: constexpr int31): int31 {
+FromConstexpr<int31>(i: constexpr int31): int31 {
   return Int32Constant(i);
 }
-from_constexpr<int32>(i: constexpr int31): int32 {
+FromConstexpr<int32>(i: constexpr int31): int32 {
   return Int32Constant(i);
 }
-from_constexpr<uint32>(i: constexpr int31): uint32 {
+FromConstexpr<uint32>(i: constexpr int31): uint32 {
   return Unsigned(Int32Constant(i));
 }
-from_constexpr<uintptr>(i: constexpr int31): uintptr {
+FromConstexpr<uintptr>(i: constexpr int31): uintptr {
   return ChangeUint32ToWord(i);
 }
-from_constexpr<Smi>(i: constexpr int31): Smi {
+FromConstexpr<Smi>(i: constexpr int31): Smi {
   return SmiConstant(i);
 }
-from_constexpr<Number>(i: constexpr int31): Number {
+FromConstexpr<Number>(i: constexpr int31): Number {
   return SmiConstant(i);
 }
-from_constexpr<float64>(i: constexpr int31): float64 {
+FromConstexpr<float64>(i: constexpr int31): float64 {
   return Float64Constant(i);
 }
-macro from_constexpr<A : type>(o: constexpr int32): A;
-from_constexpr<intptr>(i: constexpr int32): intptr {
+macro FromConstexpr<A: type>(o: constexpr int32): A;
+FromConstexpr<intptr>(i: constexpr int32): intptr {
   return IntPtrConstant(i);
 }
-from_constexpr<int32>(i: constexpr int32): int32 {
+FromConstexpr<int32>(i: constexpr int32): int32 {
   return Int32Constant(i);
 }
-from_constexpr<Number>(i: constexpr int32): Number {
+FromConstexpr<Number>(i: constexpr int32): Number {
   return NumberConstant(i);
 }
-macro from_constexpr<A : type>(o: constexpr float64): A;
-from_constexpr<Number>(f: constexpr float64): Number {
+macro FromConstexpr<A: type>(o: constexpr float64): A;
+FromConstexpr<Number>(f: constexpr float64): Number {
   return NumberConstant(f);
 }
-macro from_constexpr<A : type>(b: constexpr bool): A;
-from_constexpr<bool>(b: constexpr bool): bool {
+macro FromConstexpr<A: type>(b: constexpr bool): A;
+FromConstexpr<bool>(b: constexpr bool): bool {
   return BoolConstant(b);
 }
-macro from_constexpr<A : type>(l: constexpr LanguageMode): A;
-from_constexpr<LanguageMode>(b: constexpr LanguageMode): LanguageMode {
+macro FromConstexpr<A: type>(l: constexpr LanguageMode): A;
+FromConstexpr<LanguageMode>(b: constexpr LanguageMode): LanguageMode {
   return LanguageModeConstant(b);
 }
-macro from_constexpr<A : type>(e: constexpr ElementsKind): A;
-from_constexpr<ElementsKind>(e: constexpr ElementsKind): ElementsKind {
+macro FromConstexpr<A: type>(e: constexpr ElementsKind): A;
+FromConstexpr<ElementsKind>(e: constexpr ElementsKind): ElementsKind {
   return Int32Constant(e);
 }
-macro from_constexpr<A : type>(s: constexpr string): A;
-from_constexpr<String>(s: constexpr string): String {
+macro FromConstexpr<A: type>(s: constexpr string): A;
+FromConstexpr<String>(s: constexpr string): String {
   return StringConstant(s);
 }
-from_constexpr<Object>(s: constexpr string): Object {
+FromConstexpr<Object>(s: constexpr string): Object {
   return StringConstant(s);
 }
+macro FromConstexpr<A: type>(e: constexpr NativeContextSlot): A;
+FromConstexpr<NativeContextSlot>(c: constexpr NativeContextSlot):
+    NativeContextSlot {
+  return IntPtrConstant(c);
+}
 
-macro convert<A : type>(i: constexpr int31): A {
+macro Convert<A: type>(i: constexpr int31): A {
   return i;
 }
-macro convert<A : type>(i: int32): A;
-convert<Number>(i: int32): Number {
+extern macro ConvertElementsKindToInt(ElementsKind): int32;
+
+macro Convert<A: type>(elementsKind: ElementsKind): A;
+Convert<int32>(elementsKind: ElementsKind): int32 {
+  return ConvertElementsKindToInt(elementsKind);
+}
+
+macro Convert<A: type>(i: int32): A;
+Convert<Number>(i: int32): Number {
   return ChangeInt32ToTagged(i);
 }
-convert<intptr>(i: int32): intptr {
+Convert<intptr>(i: int32): intptr {
   return ChangeInt32ToIntPtr(i);
 }
-convert<Smi>(i: int32): Smi {
+Convert<Smi>(i: int32): Smi {
   return SmiFromInt32(i);
 }
-macro convert<A : type>(ui: uint32): A;
-convert<Number>(ui: uint32): Number {
+macro Convert<A: type>(ui: uint32): A;
+Convert<Number>(ui: uint32): Number {
   return ChangeUint32ToTagged(ui);
 }
-convert<Smi>(ui: uint32): Smi {
+Convert<Smi>(ui: uint32): Smi {
   return SmiFromInt32(Signed(ui));
 }
-convert<uintptr>(ui: uint32): uintptr {
+Convert<uintptr>(ui: uint32): uintptr {
   return ChangeUint32ToWord(ui);
 }
-macro convert<A : type>(i: intptr): A;
-convert<int32>(i: intptr): int32 {
+macro Convert<A: type>(i: intptr): A;
+Convert<int32>(i: intptr): int32 {
   return TruncateIntPtrToInt32(i);
 }
-convert<Smi>(i: intptr): Smi {
+Convert<Smi>(i: intptr): Smi {
   return SmiTag(i);
 }
-macro convert<A : type>(ui: uintptr): A;
-convert<uint32>(ui: uintptr): uint32 {
+macro Convert<A: type>(ui: uintptr): A;
+Convert<uint32>(ui: uintptr): uint32 {
   return Unsigned(TruncateIntPtrToInt32(Signed(ui)));
 }
-macro convert<A : type>(s: Smi): A;
-convert<intptr>(s: Smi): intptr {
+macro Convert<A: type>(s: Smi): A;
+Convert<intptr>(s: Smi): intptr {
   return SmiUntag(s);
 }
-convert<int32>(s: Smi): int32 {
+Convert<int32>(s: Smi): int32 {
   return SmiToInt32(s);
 }
-macro convert<A : type>(h: HeapNumber): A;
-convert<float64>(h: HeapNumber): float64 {
+macro Convert<A: type>(h: HeapNumber): A;
+Convert<float64>(h: HeapNumber): float64 {
   return LoadHeapNumberValue(h);
 }
-macro convert<A : type>(n: Number): A;
-convert<float64>(n: Number): float64 {
+macro Convert<A: type>(n: Number): A;
+Convert<float64>(n: Number): float64 {
   return ChangeNumberToFloat64(n);
 }
-macro convert<A : type>(f: float32): A;
-convert<float64>(f: float32): float64 {
+macro Convert<A: type>(f: float32): A;
+Convert<float64>(f: float32): float64 {
   return ChangeFloat32ToFloat64(f);
 }
-macro convert<A : type>(d: float64): A;
-convert<Number>(d: float64): Number {
+macro Convert<A: type>(d: float64): A;
+Convert<Number>(d: float64): Number {
   return AllocateHeapNumberWithValue(d);
 }
-convert<uintptr>(d: float64): uintptr {
+Convert<float64>(ui: uintptr): float64 {
+  return ChangeUintPtrToFloat64(ui);
+}
+Convert<Number>(ui: uintptr): Number {
+  return ChangeUintPtrToTagged(ui);
+}
+Convert<uintptr>(d: float64): uintptr {
   return ChangeFloat64ToUintPtr(d);
 }
-macro convert<A : type>(r: RawPtr): A;
-convert<uintptr>(r: RawPtr): uintptr {
+macro Convert<A: type>(r: RawPtr): A;
+Convert<uintptr>(r: RawPtr): uintptr {
   return Unsigned(r);
 }
-convert<intptr>(r: RawPtr): intptr {
+Convert<intptr>(r: RawPtr): intptr {
   return Signed(r);
 }
 
 extern macro UnsafeCastNumberToHeapNumber(Number): HeapNumber;
 extern macro UnsafeCastObjectToFixedArrayBase(Object): FixedArrayBase;
 extern macro UnsafeCastObjectToFixedArray(Object): FixedArray;
+extern macro UnsafeCastObjectToContext(Object): Context;
 extern macro UnsafeCastObjectToFixedDoubleArray(Object): FixedDoubleArray;
 extern macro UnsafeCastObjectToHeapNumber(Object): HeapNumber;
 extern macro UnsafeCastObjectToCallable(Object): Callable;
@@ -553,61 +648,109 @@ extern macro UnsafeCastObjectToJSReceiver(Object): JSReceiver;
 extern macro UnsafeCastObjectToJSObject(Object): JSObject;
 extern macro UnsafeCastObjectToMap(Object): Map;
 
-macro unsafe_cast<A : type>(n: Number): A;
-unsafe_cast<HeapNumber>(n: Number): HeapNumber {
+macro UnsafeCast<A: type>(n: Number): A;
+UnsafeCast<HeapNumber>(n: Number): HeapNumber {
   return UnsafeCastNumberToHeapNumber(n);
 }
-macro unsafe_cast<A : type>(o: Object): A;
-unsafe_cast<FixedArray>(o: Object): FixedArray {
+macro UnsafeCast<A: type>(o: Object): A;
+UnsafeCast<Object>(o: Object): Object {
+  return o;
+}
+UnsafeCast<FixedArray>(o: Object): FixedArray {
   return UnsafeCastObjectToFixedArray(o);
 }
-unsafe_cast<FixedDoubleArray>(o: Object): FixedDoubleArray {
+UnsafeCast<FixedDoubleArray>(o: Object): FixedDoubleArray {
   return UnsafeCastObjectToFixedDoubleArray(o);
 }
-unsafe_cast<HeapNumber>(o: Object): HeapNumber {
+UnsafeCast<HeapNumber>(o: Object): HeapNumber {
   return UnsafeCastObjectToHeapNumber(o);
 }
-unsafe_cast<Callable>(o: Object): Callable {
+UnsafeCast<Callable>(o: Object): Callable {
   return UnsafeCastObjectToCallable(o);
 }
-unsafe_cast<Smi>(o: Object): Smi {
+UnsafeCast<Smi>(o: Object): Smi {
   return UnsafeCastObjectToSmi(o);
 }
-unsafe_cast<Number>(o: Object): Number {
+UnsafeCast<Number>(o: Object): Number {
   return UnsafeCastObjectToNumber(o);
 }
-unsafe_cast<HeapObject>(o: Object): HeapObject {
+UnsafeCast<HeapObject>(o: Object): HeapObject {
   return UnsafeCastObjectToHeapObject(o);
 }
-unsafe_cast<JSArray>(o: Object): JSArray {
+UnsafeCast<JSArray>(o: Object): JSArray {
   return UnsafeCastObjectToJSArray(o);
 }
-unsafe_cast<FixedTypedArrayBase>(o: Object): FixedTypedArrayBase {
+UnsafeCast<FixedTypedArrayBase>(o: Object): FixedTypedArrayBase {
   return UnsafeCastObjectToFixedTypedArrayBase(o);
 }
-unsafe_cast<NumberDictionary>(o: Object): NumberDictionary {
+UnsafeCast<NumberDictionary>(o: Object): NumberDictionary {
   return UnsafeCastObjectToNumberDictionary(o);
 }
-unsafe_cast<JSReceiver>(o: Object): JSReceiver {
+UnsafeCast<JSReceiver>(o: Object): JSReceiver {
   return UnsafeCastObjectToJSReceiver(o);
 }
-unsafe_cast<JSObject>(o: Object): JSObject {
+UnsafeCast<JSObject>(o: Object): JSObject {
   return UnsafeCastObjectToJSObject(o);
 }
-unsafe_cast<Map>(o: Object): Map {
+UnsafeCast<Map>(o: Object): Map {
   return UnsafeCastObjectToMap(o);
 }
-unsafe_cast<FixedArrayBase>(o: Object): FixedArrayBase {
+UnsafeCast<FixedArrayBase>(o: Object): FixedArrayBase {
   return UnsafeCastObjectToFixedArrayBase(o);
 }
+UnsafeCast<Context>(o: Object): Context {
+  return UnsafeCastObjectToContext(o);
+}
+
+// RawCasts should *never* be used anywhere in Torque code except for
+// in Torque-based UnsafeCast operators preceeded by an appropriate
+// type check().
+extern macro RawCastObjectToJSArgumentsObjectWithLength(Object):
+    JSArgumentsObjectWithLength;
+
+macro BranchIfJSArgumentsObjectWithLength(context: Context, o: Object): never
+    labels True, False {
+  const heapObject: HeapObject = Cast<HeapObject>(o) otherwise False;
+  const map: Map = heapObject.map;
+  const nativeContext: NativeContext = LoadNativeContext(context);
+  if (map == nativeContext[FAST_ALIASED_ARGUMENTS_MAP_INDEX]) goto True;
+  if (map == nativeContext[SLOW_ALIASED_ARGUMENTS_MAP_INDEX]) goto True;
+  if (map == nativeContext[STRICT_ARGUMENTS_MAP_INDEX]) goto True;
+  if (map != nativeContext[SLOPPY_ARGUMENTS_MAP_INDEX]) goto False;
+  goto True;
+}
+
+macro UnsafeCast<A: type>(context: Context, o: Object): A;
+UnsafeCast<JSArgumentsObjectWithLength>(
+    context: Context, o: Object): JSArgumentsObjectWithLength {
+  assert(BranchIfJSArgumentsObjectWithLength(context, o));
+  return RawCastObjectToJSArgumentsObjectWithLength(o);
+}
+
+macro Cast<A: type>(context: Context, o: Object): A
+    labels CastError;
+Cast<JSArgumentsObjectWithLength>(context: Context, o: Object):
+    JSArgumentsObjectWithLength
+    labels CastError {
+  if (BranchIfJSArgumentsObjectWithLength(context, o)) {
+    return UnsafeCast<JSArgumentsObjectWithLength>(context, o);
+  } else {
+    goto CastError;
+  }
+}
 
-const kCOWMap: Map = unsafe_cast<Map>(LoadRoot(kFixedCOWArrayMapRootIndex));
+const kCOWMap: Map = UnsafeCast<Map>(LoadRoot(kFixedCOWArrayMapRootIndex));
 const kEmptyFixedArray: FixedArrayBase =
-    unsafe_cast<FixedArrayBase>(LoadRoot(kEmptyFixedArrayRootIndex));
+    UnsafeCast<FixedArrayBase>(LoadRoot(kEmptyFixedArrayRootIndex));
 
-extern macro BranchIfFastJSArray(Object, Context): never labels Taken, NotTaken;
-extern macro BranchIfNotFastJSArray(Object, Context): never labels Taken,
-    NotTaken;
+extern macro BranchIfFastJSArray(Object, Context): never
+    labels Taken, NotTaken;
+extern macro BranchIfNotFastJSArray(Object, Context): never
+    labels Taken, NotTaken;
+
+macro EnsureFastJSArray(context: Context, object: Object) labels Bailout {
+  if (BranchIfNotFastJSArray(object, context)) goto Bailout;
+}
 
 extern macro IsPrototypeInitialArrayPrototype(Context, Map): bool;
 extern macro IsNoElementsProtectorCellInvalid(): bool;
@@ -615,38 +758,43 @@ extern macro IsArraySpeciesProtectorCellInvalid(): bool;
 extern macro IsTypedArraySpeciesProtectorCellInvalid(): bool;
 extern macro IsPromiseSpeciesProtectorCellInvalid(): bool;
 
-extern operator
-'.buffer' macro LoadTypedArrayBuffer(JSTypedArray): JSArrayBuffer;
+extern operator '.buffer' macro LoadTypedArrayBuffer(JSTypedArray):
+    JSArrayBuffer;
 
 extern operator '.data_ptr' macro LoadDataPtr(JSTypedArray): RawPtr;
 
 extern operator '.elements_kind' macro LoadMapElementsKind(Map): ElementsKind;
-extern operator
-'.elements_kind' macro LoadElementsKind(JSTypedArray): ElementsKind;
+extern operator '.elements_kind' macro LoadElementsKind(JSTypedArray):
+    ElementsKind;
 
 extern operator '.elements' macro LoadElements(JSObject): FixedArrayBase;
 extern operator '.elements=' macro StoreElements(JSObject, FixedArrayBase);
 
-extern operator '.length' macro LoadTypedArrayLength(JSTypedArray): Smi;
+extern operator '.length' macro LoadJSTypedArrayLength(JSTypedArray): Smi;
 extern operator '.length' macro LoadJSArrayLength(JSArray): Number;
+extern operator '.length' macro LoadJSArgumentsObjectWithLength(
+    JSArgumentsObjectWithLength): Object;
 extern operator '.length_fast' macro LoadFastJSArrayLength(JSArray): Smi;
 extern operator '.length=' macro StoreJSArrayLength(JSArray, Smi);
 
 extern operator '.length' macro LoadFixedArrayBaseLength(FixedArrayBase): Smi;
 extern operator '[]' macro LoadFixedArrayElement(FixedArray, intptr): Object;
 extern operator '[]' macro LoadFixedArrayElement(FixedArray, Smi): Object;
-extern operator
-'[]' macro LoadFixedArrayElement(FixedArray, constexpr int31): Object;
-extern operator
-'[]=' macro StoreFixedArrayElement(FixedArray, intptr, Object): void;
-extern operator
-'[]=' macro StoreFixedArrayElement(
+extern operator '[]' macro LoadFixedArrayElement(
+    FixedArray, constexpr int31): Object;
+extern operator '[]=' macro StoreFixedArrayElement(
+    FixedArray, intptr, Object): void;
+extern operator '[]=' macro StoreFixedArrayElement(
     FixedArray, constexpr int31, Object): void;
-extern operator
-'[]=' macro StoreFixedArrayElementSmi(FixedArray, Smi, Object): void;
+extern operator '[]=' macro StoreFixedArrayElementSmi(
+    FixedArray, Smi, Object): void;
+operator '[]=' macro StoreFixedDoubleArrayNumber(
+    a: FixedDoubleArray, index: Smi, value: Number): void {
+  a[index] = Convert<float64>(value);
+}
 
-extern macro StoreFixedArrayElementSmi(FixedArray, Smi, Object,
-  constexpr WriteBarrierMode): void;
+extern macro StoreFixedArrayElementSmi(
+    FixedArray, Smi, Object, constexpr WriteBarrierMode): void;
 
 extern operator '.instance_type' macro LoadMapInstanceType(Map): int32;
 
@@ -660,9 +808,8 @@ macro StoreFixedDoubleArrayElementWithSmiIndex(
   StoreFixedDoubleArrayElement(array, index, value, SMI_PARAMETERS);
 }
 
-extern macro BasicLoadNumberDictionaryElement(NumberDictionary, intptr):
-    Object labels NotData,
-    IfHole;
+extern macro BasicLoadNumberDictionaryElement(NumberDictionary, intptr): Object
+    labels NotData, IfHole;
 extern macro BasicStoreNumberDictionaryElement(NumberDictionary, intptr, Object)
 labels NotData, IfHole, ReadOnly;
 
@@ -672,6 +819,28 @@ extern macro IsFastSmiOrTaggedElementsKind(ElementsKind): bool;
 extern macro IsFastSmiElementsKind(ElementsKind): bool;
 extern macro IsHoleyFastElementsKind(ElementsKind): bool;
 
+macro AllowDoubleElements(kind: ElementsKind): ElementsKind {
+  if (kind == PACKED_SMI_ELEMENTS) {
+    return PACKED_DOUBLE_ELEMENTS;
+  } else if (kind == HOLEY_SMI_ELEMENTS) {
+    return HOLEY_DOUBLE_ELEMENTS;
+  }
+  return kind;
+}
+
+macro AllowNonNumberElements(kind: ElementsKind): ElementsKind {
+  if (kind == PACKED_SMI_ELEMENTS) {
+    return PACKED_ELEMENTS;
+  } else if (kind == HOLEY_SMI_ELEMENTS) {
+    return HOLEY_ELEMENTS;
+  } else if (kind == PACKED_DOUBLE_ELEMENTS) {
+    return PACKED_ELEMENTS;
+  } else if (kind == HOLEY_DOUBLE_ELEMENTS) {
+    return HOLEY_ELEMENTS;
+  }
+  return kind;
+}
+
 extern macro AllocateZeroedFixedArray(intptr): FixedArray;
 extern macro AllocateZeroedFixedDoubleArray(intptr): FixedDoubleArray;
 
@@ -687,8 +856,12 @@ extern macro AllocateJSArray(constexpr ElementsKind, Map, Smi, Smi): JSArray;
 extern macro IsElementsKindGreaterThan(
     ElementsKind, constexpr ElementsKind): bool;
 
+extern operator '[]=' macro StoreFixedDoubleArrayElementSmi(
+    FixedDoubleArray, Smi, float64): void;
+
 extern macro LoadDoubleWithHoleCheck(FixedDoubleArray, Smi): float64
-labels IfHole;
+    labels IfHole;
+extern macro StoreFixedDoubleArrayHoleSmi(FixedDoubleArray, Smi): void;
 
 extern macro Call(Context, Callable, Object): Object;
 extern macro Call(Context, Callable, Object, Object): Object;
@@ -699,18 +872,21 @@ extern macro Call(
 extern macro Call(
     Context, Callable, Object, Object, Object, Object, Object, Object): Object;
 
+extern macro ExtractFixedArray(FixedArrayBase, Smi, Smi, Smi): FixedArrayBase;
 extern macro ExtractFixedArray(
-    FixedArray, Smi, Smi, Smi, constexpr ExtractFixedArrayFlags): FixedArray;
+    FixedArrayBase, Smi, Smi, Smi,
+    constexpr ExtractFixedArrayFlags): FixedArrayBase;
 
 extern builtin ExtractFastJSArray(Context, JSArray, Smi, Smi): JSArray;
 
-macro LoadElementNoHole<T : type>(a: JSArray, index: Smi): Object labels IfHole;
+macro LoadElementNoHole<T: type>(a: JSArray, index: Smi): Object
+    labels IfHole;
 
 LoadElementNoHole<FixedArray>(a: JSArray, index: Smi): Object
-labels IfHole {
+    labels IfHole {
   try {
     let elements: FixedArray =
-        cast<FixedArray>(a.elements) otherwise Unexpected;
+        Cast<FixedArray>(a.elements) otherwise Unexpected;
     let e: Object = elements[index];
     if (e == Hole) {
       goto IfHole;
@@ -723,10 +899,10 @@ labels IfHole {
 }
 
 LoadElementNoHole<FixedDoubleArray>(a: JSArray, index: Smi): Object
-labels IfHole {
+    labels IfHole {
   try {
     let elements: FixedDoubleArray =
-        cast<FixedDoubleArray>(a.elements) otherwise Unexpected;
+        Cast<FixedDoubleArray>(a.elements) otherwise Unexpected;
     let e: float64 = LoadDoubleWithHoleCheck(elements, index) otherwise IfHole;
     return AllocateHeapNumberWithValue(e);
   }
@@ -735,29 +911,39 @@ labels IfHole {
   }
 }
 
+extern macro TransitionElementsKind(JSObject, Map, ElementsKind, ElementsKind):
+    void
+    labels Bailout;
+
 extern macro IsCallable(HeapObject): bool;
 extern macro IsJSArray(HeapObject): bool;
+extern macro IsJSReceiver(HeapObject): bool;
 extern macro TaggedIsCallable(Object): bool;
 extern macro IsDetachedBuffer(JSArrayBuffer): bool;
 extern macro IsHeapNumber(HeapObject): bool;
 extern macro IsFixedArray(HeapObject): bool;
+extern macro IsNumber(Object): bool;
 extern macro IsExtensibleMap(Map): bool;
 extern macro IsCustomElementsReceiverInstanceType(int32): bool;
+extern macro IsFastJSArray(Object, Context): bool;
 extern macro Typeof(Object): Object;
+extern macro LoadTargetFromFrame(): JSFunction;
 
 // Return true iff number is NaN.
 macro NumberIsNaN(number: Number): bool {
-  typeswitch(number) {
-    case (Smi) {
+  typeswitch (number) {
+    case (Smi): {
       return false;
-    } case (hn : HeapNumber) {
-      let value: float64 = convert<float64>(hn);
+    }
+    case (hn: HeapNumber): {
+      let value: float64 = Convert<float64>(hn);
       return value != value;
     }
   }
 }
 
-extern macro BranchIfToBooleanIsTrue(Object): never labels Taken, NotTaken;
+extern macro BranchIfToBooleanIsTrue(Object): never
+    labels Taken, NotTaken;
 
 macro ToBoolean(obj: Object): bool {
   if (BranchIfToBooleanIsTrue(obj)) {
@@ -767,7 +953,8 @@ macro ToBoolean(obj: Object): bool {
   }
 }
 
-macro ToIndex(input: Object, context: Context): Number labels RangeError {
+macro ToIndex(input: Object, context: Context): Number
+    labels RangeError {
   if (input == Undefined) {
     return 0;
   }
@@ -779,3 +966,21 @@ macro ToIndex(input: Object, context: Context): Number labels RangeError {
 
   return value;
 }
+
+macro GetLengthProperty(context: Context, o: Object): Number {
+  try {
+    return (Cast<JSArray>(o) otherwise CheckArgs).length;
+  }
+  label CheckArgs {
+    const a: JSArgumentsObjectWithLength =
+        Cast<JSArgumentsObjectWithLength>(context, o) otherwise Slow;
+    const length: Object = a.length;
+    return Cast<Smi>(length) otherwise goto ToLength(length);
+  }
+  label Slow deferred {
+    goto ToLength(GetProperty(context, o, kLengthString));
+  }
+  label ToLength(length: Object) deferred {
+    return ToLength_Inline(context, length);
+  }
+}
diff --git a/deps/v8/src/builtins/builtins-api.cc b/deps/v8/src/builtins/builtins-api.cc
index 95f5f2ebbd..8bc5c0b5ac 100644
--- a/deps/v8/src/builtins/builtins-api.cc
+++ b/deps/v8/src/builtins/builtins-api.cc
@@ -149,7 +149,7 @@ class RelocatableArguments : public BuiltinArguments, public Relocatable {
   RelocatableArguments(Isolate* isolate, int length, Object** arguments)
       : BuiltinArguments(length, arguments), Relocatable(isolate) {}
 
-  virtual inline void IterateInstance(RootVisitor* v) {
+  inline void IterateInstance(RootVisitor* v) override {
     if (length() == 0) return;
     v->VisitRootPointers(Root::kRelocatable, nullptr, lowest_address(),
                          highest_address() + 1);
diff --git a/deps/v8/src/builtins/builtins-arguments-gen.cc b/deps/v8/src/builtins/builtins-arguments-gen.cc
index c82cef3919..0e22db2598 100644
--- a/deps/v8/src/builtins/builtins-arguments-gen.cc
+++ b/deps/v8/src/builtins/builtins-arguments-gen.cc
@@ -89,7 +89,7 @@ ArgumentsBuiltinsAssembler::AllocateArgumentsObject(Node* map,
   Node* result = Allocate(size);
   Comment("Initialize arguments object");
   StoreMapNoWriteBarrier(result, map);
-  Node* empty_fixed_array = LoadRoot(Heap::kEmptyFixedArrayRootIndex);
+  Node* empty_fixed_array = LoadRoot(RootIndex::kEmptyFixedArray);
   StoreObjectField(result, JSArray::kPropertiesOrHashOffset, empty_fixed_array);
   Node* smi_arguments_count = ParameterToTagged(arguments_count, mode);
   StoreObjectFieldNoWriteBarrier(result, JSArray::kLengthOffset,
@@ -99,7 +99,7 @@ ArgumentsBuiltinsAssembler::AllocateArgumentsObject(Node* map,
     arguments = InnerAllocate(result, elements_offset);
     StoreObjectFieldNoWriteBarrier(arguments, FixedArray::kLengthOffset,
                                    smi_arguments_count);
-    Node* fixed_array_map = LoadRoot(Heap::kFixedArrayMapRootIndex);
+    Node* fixed_array_map = LoadRoot(RootIndex::kFixedArrayMap);
     StoreMapNoWriteBarrier(arguments, fixed_array_map);
   }
   Node* parameter_map = nullptr;
@@ -110,7 +110,7 @@ ArgumentsBuiltinsAssembler::AllocateArgumentsObject(Node* map,
     StoreObjectFieldNoWriteBarrier(result, JSArray::kElementsOffset,
                                    parameter_map);
     Node* sloppy_elements_map =
-        LoadRoot(Heap::kSloppyArgumentsElementsMapRootIndex);
+        LoadRoot(RootIndex::kSloppyArgumentsElementsMap);
     StoreMapNoWriteBarrier(parameter_map, sloppy_elements_map);
     parameter_map_count = ParameterToTagged(parameter_map_count, mode);
     StoreObjectFieldNoWriteBarrier(parameter_map, FixedArray::kLengthOffset,
diff --git a/deps/v8/src/builtins/builtins-array-gen.cc b/deps/v8/src/builtins/builtins-array-gen.cc
index d61a516422..4aebe2e02b 100644
--- a/deps/v8/src/builtins/builtins-array-gen.cc
+++ b/deps/v8/src/builtins/builtins-array-gen.cc
@@ -212,7 +212,7 @@ Node* ArrayBuiltinsAssembler::FindProcessor(Node* k_value, Node* k) {
         context(), original_array, length, method_name);
     // In the Spec and our current implementation, the length check is already
     // performed in TypedArraySpeciesCreate.
-    CSA_ASSERT(this, SmiLessThanOrEqual(CAST(len_), LoadTypedArrayLength(a)));
+    CSA_ASSERT(this, SmiLessThanOrEqual(CAST(len_), LoadJSTypedArrayLength(a)));
     fast_typed_array_target_ =
         Word32Equal(LoadInstanceType(LoadElements(original_array)),
                     LoadInstanceType(LoadElements(a)));
@@ -530,10 +530,11 @@ Node* ArrayBuiltinsAssembler::FindProcessor(Node* k_value, Node* k) {
     TNode<JSTypedArray> typed_array = CAST(receiver_);
     o_ = typed_array;
 
-    TNode<JSArrayBuffer> array_buffer = LoadArrayBufferViewBuffer(typed_array);
+    TNode<JSArrayBuffer> array_buffer =
+        LoadJSArrayBufferViewBuffer(typed_array);
     ThrowIfArrayBufferIsDetached(context_, array_buffer, name_);
 
-    len_ = LoadTypedArrayLength(typed_array);
+    len_ = LoadJSTypedArrayLength(typed_array);
 
     Label throw_not_callable(this, Label::kDeferred);
     Label distinguish_types(this);
@@ -964,8 +965,7 @@ TF_BUILTIN(ArrayPrototypePop, CodeStubAssembler) {
 
     // 3) Check that the elements backing store isn't copy-on-write.
     Node* elements = LoadElements(array_receiver);
-    GotoIf(WordEqual(LoadMap(elements),
-                     LoadRoot(Heap::kFixedCOWArrayMapRootIndex)),
+    GotoIf(WordEqual(LoadMap(elements), LoadRoot(RootIndex::kFixedCOWArrayMap)),
            &runtime);
 
     Node* new_length = IntPtrSub(length, IntPtrConstant(1));
@@ -1378,8 +1378,8 @@ TF_BUILTIN(ArrayPrototypeSlice, ArrayPrototypeSliceCodeStubAssembler) {
   Goto(&generic_length);
 
   BIND(&load_arguments_length);
-  Node* arguments_length =
-      LoadObjectField(array_receiver, JSArgumentsObject::kLengthOffset);
+  Node* arguments_length = LoadObjectField(
+      array_receiver, JSArgumentsObjectWithLength::kLengthOffset);
   GotoIf(TaggedIsNotSmi(arguments_length), &generic_length);
   o = CAST(receiver);
   len.Bind(arguments_length);
@@ -1524,19 +1524,23 @@ TF_BUILTIN(ArrayPrototypeShift, CodeStubAssembler) {
   {
     TNode<JSArray> array_receiver = CAST(receiver);
     CSA_ASSERT(this, TaggedIsPositiveSmi(LoadJSArrayLength(array_receiver)));
+
+    // 2) Ensure that the length is writable.
+    //    This check needs to happen before the check for length zero.
+    //    The spec requires a "SetProperty(array, 'length', 0)" call when
+    //    the length is zero. This must throw an exception in the case of a
+    //    read-only length.
+    EnsureArrayLengthWritable(LoadMap(array_receiver), &runtime);
+
     Node* length =
         LoadAndUntagObjectField(array_receiver, JSArray::kLengthOffset);
     Label return_undefined(this), fast_elements_tagged(this),
         fast_elements_smi(this);
     GotoIf(IntPtrEqual(length, IntPtrConstant(0)), &return_undefined);
 
-    // 2) Ensure that the length is writable.
-    EnsureArrayLengthWritable(LoadMap(array_receiver), &runtime);
-
     // 3) Check that the elements backing store isn't copy-on-write.
     Node* elements = LoadElements(array_receiver);
-    GotoIf(WordEqual(LoadMap(elements),
-                     LoadRoot(Heap::kFixedCOWArrayMapRootIndex)),
+    GotoIf(WordEqual(LoadMap(elements), LoadRoot(RootIndex::kFixedCOWArrayMap)),
            &runtime);
 
     Node* new_length = IntPtrSub(length, IntPtrConstant(1));
@@ -1679,15 +1683,38 @@ TF_BUILTIN(ExtractFastJSArray, ArrayBuiltinsAssembler) {
 
 TF_BUILTIN(CloneFastJSArray, ArrayBuiltinsAssembler) {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-  Node* array = Parameter(Descriptor::kSource);
+  TNode<JSArray> array = CAST(Parameter(Descriptor::kSource));
 
-  CSA_ASSERT(this, IsJSArray(array));
-  CSA_ASSERT(this, Word32BinaryNot(IsNoElementsProtectorCellInvalid()));
+  CSA_ASSERT(this,
+             Word32Or(Word32BinaryNot(IsHoleyFastElementsKind(
+                          LoadMapElementsKind(LoadMap(array)))),
+                      Word32BinaryNot(IsNoElementsProtectorCellInvalid())));
 
   ParameterMode mode = OptimalParameterMode();
   Return(CloneFastJSArray(context, array, mode));
 }
 
+// This builtin copies the backing store of fast arrays, while converting any
+// holes to undefined.
+// - If there are no holes in the source, its ElementsKind will be preserved. In
+// that case, this builtin should perform as fast as CloneFastJSArray. (In fact,
+// for fast packed arrays, the behavior is equivalent to CloneFastJSArray.)
+// - If there are holes in the source, the ElementsKind of the "copy" will be
+// PACKED_ELEMENTS (such that undefined can be stored).
+TF_BUILTIN(CloneFastJSArrayFillingHoles, ArrayBuiltinsAssembler) {
+  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
+  TNode<JSArray> array = CAST(Parameter(Descriptor::kSource));
+
+  CSA_ASSERT(this,
+             Word32Or(Word32BinaryNot(IsHoleyFastElementsKind(
+                          LoadMapElementsKind(LoadMap(array)))),
+                      Word32BinaryNot(IsNoElementsProtectorCellInvalid())));
+
+  ParameterMode mode = OptimalParameterMode();
+  Return(CloneFastJSArray(context, array, mode, nullptr,
+                          HoleConversionMode::kConvertToUndefined));
+}
+
 TF_BUILTIN(ArrayFindLoopContinuation, ArrayBuiltinsAssembler) {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
@@ -3582,6 +3609,8 @@ TF_BUILTIN(ArrayIteratorPrototypeNext, CodeStubAssembler) {
     BIND(&if_hole);
     {
       GotoIf(IsNoElementsProtectorCellInvalid(), &if_generic);
+      GotoIfNot(IsPrototypeInitialArrayPrototype(context, array_map),
+                &if_generic);
       var_value.Bind(UndefinedConstant());
       Goto(&allocate_entry_if_needed);
     }
@@ -3654,7 +3683,7 @@ TF_BUILTIN(ArrayIteratorPrototypeNext, CodeStubAssembler) {
     // [[ArrayIteratorNextIndex]] anymore, since a JSTypedArray's
     // length cannot change anymore, so this {iterator} will never
     // produce values again anyways.
-    TNode<Smi> length = LoadTypedArrayLength(CAST(array));
+    TNode<Smi> length = LoadJSTypedArrayLength(CAST(array));
     GotoIfNot(SmiBelow(CAST(index), length), &allocate_iterator_result);
     StoreObjectFieldNoWriteBarrier(iterator, JSArrayIterator::kNextIndexOffset,
                                    SmiInc(CAST(index)));
@@ -3701,8 +3730,6 @@ TF_BUILTIN(ArrayIteratorPrototypeNext, CodeStubAssembler) {
   }
 }
 
-namespace {
-
 class ArrayFlattenAssembler : public CodeStubAssembler {
  public:
   explicit ArrayFlattenAssembler(compiler::CodeAssemblerState* state)
@@ -3843,8 +3870,6 @@ class ArrayFlattenAssembler : public CodeStubAssembler {
   }
 };
 
-}  // namespace
-
 // https://tc39.github.io/proposal-flatMap/#sec-FlattenIntoArray
 TF_BUILTIN(FlattenIntoArray, ArrayFlattenAssembler) {
   Node* const context = Parameter(Descriptor::kContext);
diff --git a/deps/v8/src/builtins/builtins-array.cc b/deps/v8/src/builtins/builtins-array.cc
index ceeee5f37d..1e9de3dbe3 100644
--- a/deps/v8/src/builtins/builtins-array.cc
+++ b/deps/v8/src/builtins/builtins-array.cc
@@ -23,34 +23,6 @@ namespace internal {
 
 namespace {
 
-inline bool ClampedToInteger(Isolate* isolate, Object* object, int* out) {
-  // This is an extended version of ECMA-262 7.1.11 handling signed values
-  // Try to convert object to a number and clamp values to [kMinInt, kMaxInt]
-  if (object->IsSmi()) {
-    *out = Smi::ToInt(object);
-    return true;
-  } else if (object->IsHeapNumber()) {
-    double value = HeapNumber::cast(object)->value();
-    if (std::isnan(value)) {
-      *out = 0;
-    } else if (value > kMaxInt) {
-      *out = kMaxInt;
-    } else if (value < kMinInt) {
-      *out = kMinInt;
-    } else {
-      *out = static_cast<int>(value);
-    }
-    return true;
-  } else if (object->IsNullOrUndefined(isolate)) {
-    *out = 0;
-    return true;
-  } else if (object->IsBoolean()) {
-    *out = object->IsTrue(isolate);
-    return true;
-  }
-  return false;
-}
-
 inline bool IsJSArrayFastElementMovingAllowed(Isolate* isolate,
                                               JSArray* receiver) {
   return JSObject::PrototypeHasNoElements(isolate, receiver);
@@ -79,36 +51,20 @@ inline bool HasOnlySimpleElements(Isolate* isolate, JSReceiver* receiver) {
   return true;
 }
 
-// Returns |false| if not applicable.
-// TODO(szuend): Refactor this function because it is getting hard to
-//               understand what each call-site actually checks.
-V8_WARN_UNUSED_RESULT
-inline bool EnsureJSArrayWithWritableFastElements(Isolate* isolate,
-                                                  Handle<Object> receiver,
-                                                  BuiltinArguments* args,
-                                                  int first_arg_index,
-                                                  int num_arguments) {
-  if (!receiver->IsJSArray()) return false;
-  Handle<JSArray> array = Handle<JSArray>::cast(receiver);
-  ElementsKind origin_kind = array->GetElementsKind();
-  if (IsDictionaryElementsKind(origin_kind)) return false;
-  if (!array->map()->is_extensible()) return false;
-  if (args == nullptr) return true;
-
-  // If there may be elements accessors in the prototype chain, the fast path
-  // cannot be used if there arguments to add to the array.
-  if (!IsJSArrayFastElementMovingAllowed(isolate, *array)) return false;
+// This method may transition the elements kind of the JSArray once, to make
+// sure that all elements provided as arguments in the specified range can be
+// added without further elements kinds transitions.
+void MatchArrayElementsKindToArguments(Isolate* isolate, Handle<JSArray> array,
+                                       BuiltinArguments* args,
+                                       int first_arg_index, int num_arguments) {
+  int args_length = args->length();
+  if (first_arg_index >= args_length) return;
 
-  // Adding elements to the array prototype would break code that makes sure
-  // it has no elements. Handle that elsewhere.
-  if (isolate->IsAnyInitialArrayPrototype(array)) return false;
+  ElementsKind origin_kind = array->GetElementsKind();
 
-  // Need to ensure that the arguments passed in args can be contained in
-  // the array.
-  int args_length = args->length();
-  if (first_arg_index >= args_length) return true;
+  // We do not need to transition for PACKED/HOLEY_ELEMENTS.
+  if (IsObjectElementsKind(origin_kind)) return;
 
-  if (IsObjectElementsKind(origin_kind)) return true;
   ElementsKind target_kind = origin_kind;
   {
     DisallowHeapAllocation no_gc;
@@ -131,20 +87,37 @@ inline bool EnsureJSArrayWithWritableFastElements(Isolate* isolate,
     HandleScope scope(isolate);
     JSObject::TransitionElementsKind(array, target_kind);
   }
-  return true;
 }
 
-V8_WARN_UNUSED_RESULT static Object* CallJsIntrinsic(
-    Isolate* isolate, Handle<JSFunction> function, BuiltinArguments args) {
-  HandleScope handleScope(isolate);
-  int argc = args.length() - 1;
-  ScopedVector<Handle<Object>> argv(argc);
-  for (int i = 0; i < argc; ++i) {
-    argv[i] = args.at(i + 1);
-  }
-  RETURN_RESULT_OR_FAILURE(
-      isolate,
-      Execution::Call(isolate, function, args.receiver(), argc, argv.start()));
+// Returns |false| if not applicable.
+// TODO(szuend): Refactor this function because it is getting hard to
+//               understand what each call-site actually checks.
+V8_WARN_UNUSED_RESULT
+inline bool EnsureJSArrayWithWritableFastElements(Isolate* isolate,
+                                                  Handle<Object> receiver,
+                                                  BuiltinArguments* args,
+                                                  int first_arg_index,
+                                                  int num_arguments) {
+  if (!receiver->IsJSArray()) return false;
+  Handle<JSArray> array = Handle<JSArray>::cast(receiver);
+  ElementsKind origin_kind = array->GetElementsKind();
+  if (IsDictionaryElementsKind(origin_kind)) return false;
+  if (!array->map()->is_extensible()) return false;
+  if (args == nullptr) return true;
+
+  // If there may be elements accessors in the prototype chain, the fast path
+  // cannot be used if there arguments to add to the array.
+  if (!IsJSArrayFastElementMovingAllowed(isolate, *array)) return false;
+
+  // Adding elements to the array prototype would break code that makes sure
+  // it has no elements. Handle that elsewhere.
+  if (isolate->IsAnyInitialArrayPrototype(array)) return false;
+
+  // Need to ensure that the arguments passed in args can be contained in
+  // the array.
+  MatchArrayElementsKindToArguments(isolate, array, args, first_arg_index,
+                                    num_arguments);
+  return true;
 }
 
 // If |index| is Undefined, returns init_if_undefined.
@@ -189,6 +162,24 @@ V8_WARN_UNUSED_RESULT Maybe<double> GetLengthProperty(
   return Just(raw_length_number->Number());
 }
 
+// Set "length" property, has "fast-path" for JSArrays.
+// Returns Nothing if something went wrong.
+V8_WARN_UNUSED_RESULT MaybeHandle<Object> SetLengthProperty(
+    Isolate* isolate, Handle<JSReceiver> receiver, double length) {
+  if (receiver->IsJSArray()) {
+    Handle<JSArray> array = Handle<JSArray>::cast(receiver);
+    if (!JSArray::HasReadOnlyLength(array)) {
+      DCHECK_LE(length, kMaxUInt32);
+      JSArray::SetLength(array, static_cast<uint32_t>(length));
+      return receiver;
+    }
+  }
+
+  return Object::SetProperty(
+      isolate, receiver, isolate->factory()->length_string(),
+      isolate->factory()->NewNumber(length), LanguageMode::kStrict);
+}
+
 V8_WARN_UNUSED_RESULT Object* GenericArrayFill(Isolate* isolate,
                                                Handle<JSReceiver> receiver,
                                                Handle<Object> value,
@@ -350,7 +341,7 @@ V8_WARN_UNUSED_RESULT Object* GenericArrayPush(Isolate* isolate,
       // Must succeed since we always pass a valid key.
       DCHECK(success);
       MAYBE_RETURN(Object::SetProperty(&it, element, LanguageMode::kStrict,
-                                       Object::MAY_BE_STORE_FROM_KEYED),
+                                       StoreOrigin::kMaybeKeyed),
                    ReadOnlyRoots(isolate).exception());
     }
 
@@ -485,110 +476,141 @@ BUILTIN(ArrayPop) {
   return *result;
 }
 
-BUILTIN(ArrayShift) {
-  HandleScope scope(isolate);
-  Heap* heap = isolate->heap();
-  Handle<Object> receiver = args.receiver();
+namespace {
+
+// Returns true, iff we can use ElementsAccessor for shifting.
+V8_WARN_UNUSED_RESULT bool CanUseFastArrayShift(Isolate* isolate,
+                                                Handle<JSReceiver> receiver) {
   if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, nullptr, 0,
                                              0) ||
       !IsJSArrayFastElementMovingAllowed(isolate, JSArray::cast(*receiver))) {
-    return CallJsIntrinsic(isolate, isolate->array_shift(), args);
+    return false;
   }
+
   Handle<JSArray> array = Handle<JSArray>::cast(receiver);
+  return !JSArray::HasReadOnlyLength(array);
+}
 
-  int len = Smi::ToInt(array->length());
-  if (len == 0) return ReadOnlyRoots(heap).undefined_value();
+V8_WARN_UNUSED_RESULT Object* GenericArrayShift(Isolate* isolate,
+                                                Handle<JSReceiver> receiver,
+                                                double length) {
+  // 4. Let first be ? Get(O, "0").
+  Handle<Object> first;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, first,
+                                     Object::GetElement(isolate, receiver, 0));
+
+  // 5. Let k be 1.
+  double k = 1;
+
+  // 6. Repeat, while k < len.
+  while (k < length) {
+    // a. Let from be ! ToString(k).
+    Handle<String> from =
+        isolate->factory()->NumberToString(isolate->factory()->NewNumber(k));
+
+    // b. Let to be ! ToString(k-1).
+    Handle<String> to = isolate->factory()->NumberToString(
+        isolate->factory()->NewNumber(k - 1));
+
+    // c. Let fromPresent be ? HasProperty(O, from).
+    bool from_present;
+    MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, from_present, JSReceiver::HasProperty(receiver, from));
+
+    // d. If fromPresent is true, then.
+    if (from_present) {
+      // i. Let fromVal be ? Get(O, from).
+      Handle<Object> from_val;
+      ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+          isolate, from_val,
+          Object::GetPropertyOrElement(isolate, receiver, from));
+
+      // ii. Perform ? Set(O, to, fromVal, true).
+      RETURN_FAILURE_ON_EXCEPTION(
+          isolate, Object::SetPropertyOrElement(isolate, receiver, to, from_val,
+                                                LanguageMode::kStrict));
+    } else {  // e. Else fromPresent is false,
+      // i. Perform ? DeletePropertyOrThrow(O, to).
+      MAYBE_RETURN(JSReceiver::DeletePropertyOrElement(receiver, to,
+                                                       LanguageMode::kStrict),
+                   ReadOnlyRoots(isolate).exception());
+    }
 
-  if (JSArray::HasReadOnlyLength(array)) {
-    return CallJsIntrinsic(isolate, isolate->array_shift(), args);
+    // f. Increase k by 1.
+    ++k;
   }
 
-  Handle<Object> first = array->GetElementsAccessor()->Shift(array);
+  // 7. Perform ? DeletePropertyOrThrow(O, ! ToString(len-1)).
+  Handle<String> new_length = isolate->factory()->NumberToString(
+      isolate->factory()->NewNumber(length - 1));
+  MAYBE_RETURN(JSReceiver::DeletePropertyOrElement(receiver, new_length,
+                                                   LanguageMode::kStrict),
+               ReadOnlyRoots(isolate).exception());
+
+  // 8. Perform ? Set(O, "length", len-1, true).
+  RETURN_FAILURE_ON_EXCEPTION(isolate,
+                              SetLengthProperty(isolate, receiver, length - 1));
+
+  // 9. Return first.
   return *first;
 }
+}  // namespace
 
-BUILTIN(ArrayUnshift) {
+BUILTIN(ArrayShift) {
   HandleScope scope(isolate);
-  Handle<Object> receiver = args.receiver();
-  if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, &args, 1,
-                                             args.length() - 1)) {
-    return CallJsIntrinsic(isolate, isolate->array_unshift(), args);
-  }
-  Handle<JSArray> array = Handle<JSArray>::cast(receiver);
-  int to_add = args.length() - 1;
-  if (to_add == 0) return array->length();
 
-  // Currently fixed arrays cannot grow too big, so we should never hit this.
-  DCHECK_LE(to_add, Smi::kMaxValue - Smi::ToInt(array->length()));
+  // 1. Let O be ? ToObject(this value).
+  Handle<JSReceiver> receiver;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, receiver, Object::ToObject(isolate, args.receiver()));
 
-  if (JSArray::HasReadOnlyLength(array)) {
-    return CallJsIntrinsic(isolate, isolate->array_unshift(), args);
+  // 2. Let len be ? ToLength(? Get(O, "length")).
+  double length;
+  MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, length, GetLengthProperty(isolate, receiver));
+
+  // 3. If len is zero, then.
+  if (length == 0) {
+    // a. Perform ? Set(O, "length", 0, true).
+    RETURN_FAILURE_ON_EXCEPTION(isolate,
+                                SetLengthProperty(isolate, receiver, length));
+
+    // b. Return undefined.
+    return ReadOnlyRoots(isolate).undefined_value();
   }
 
-  ElementsAccessor* accessor = array->GetElementsAccessor();
-  int new_length = accessor->Unshift(array, &args, to_add);
-  return Smi::FromInt(new_length);
+  if (CanUseFastArrayShift(isolate, receiver)) {
+    Handle<JSArray> array = Handle<JSArray>::cast(receiver);
+    return *array->GetElementsAccessor()->Shift(array);
+  }
+
+  return GenericArrayShift(isolate, receiver, length);
 }
 
-BUILTIN(ArraySplice) {
+BUILTIN(ArrayUnshift) {
   HandleScope scope(isolate);
-  Handle<Object> receiver = args.receiver();
-  if (V8_UNLIKELY(
-          !EnsureJSArrayWithWritableFastElements(isolate, receiver, &args, 3,
-                                                 args.length() - 3) ||
-          // If this is a subclass of Array, then call out to JS.
-          !Handle<JSArray>::cast(receiver)->HasArrayPrototype(isolate) ||
-          // If anything with @@species has been messed with, call out to JS.
-          !isolate->IsArraySpeciesLookupChainIntact())) {
-    return CallJsIntrinsic(isolate, isolate->array_splice(), args);
-  }
-  Handle<JSArray> array = Handle<JSArray>::cast(receiver);
+  DCHECK(args.receiver()->IsJSArray());
+  Handle<JSArray> array = Handle<JSArray>::cast(args.receiver());
 
-  int argument_count = args.length() - 1;
-  int relative_start = 0;
-  if (argument_count > 0) {
-    DisallowHeapAllocation no_gc;
-    if (!ClampedToInteger(isolate, args[1], &relative_start)) {
-      AllowHeapAllocation allow_allocation;
-      return CallJsIntrinsic(isolate, isolate->array_splice(), args);
-    }
-  }
-  int len = Smi::ToInt(array->length());
-  // clip relative start to [0, len]
-  int actual_start = (relative_start < 0) ? Max(len + relative_start, 0)
-                                          : Min(relative_start, len);
-
-  int actual_delete_count;
-  if (argument_count == 1) {
-    // SpiderMonkey, TraceMonkey and JSC treat the case where no delete count is
-    // given as a request to delete all the elements from the start.
-    // And it differs from the case of undefined delete count.
-    // This does not follow ECMA-262, but we do the same for compatibility.
-    DCHECK_GE(len - actual_start, 0);
-    actual_delete_count = len - actual_start;
-  } else {
-    int delete_count = 0;
-    DisallowHeapAllocation no_gc;
-    if (argument_count > 1) {
-      if (!ClampedToInteger(isolate, args[2], &delete_count)) {
-        AllowHeapAllocation allow_allocation;
-        return CallJsIntrinsic(isolate, isolate->array_splice(), args);
-      }
-    }
-    actual_delete_count = Min(Max(delete_count, 0), len - actual_start);
-  }
+  // These are checked in the Torque builtin.
+  DCHECK(array->map()->is_extensible());
+  DCHECK(!IsDictionaryElementsKind(array->GetElementsKind()));
+  DCHECK(IsJSArrayFastElementMovingAllowed(isolate, *array));
+  DCHECK(!isolate->IsAnyInitialArrayPrototype(array));
 
-  int add_count = (argument_count > 1) ? (argument_count - 2) : 0;
-  int new_length = len - actual_delete_count + add_count;
+  MatchArrayElementsKindToArguments(isolate, array, &args, 1,
+                                    args.length() - 1);
+
+  int to_add = args.length() - 1;
+  if (to_add == 0) return array->length();
+
+  // Currently fixed arrays cannot grow too big, so we should never hit this.
+  DCHECK_LE(to_add, Smi::kMaxValue - Smi::ToInt(array->length()));
+  DCHECK(!JSArray::HasReadOnlyLength(array));
 
-  if (new_length != len && JSArray::HasReadOnlyLength(array)) {
-    AllowHeapAllocation allow_allocation;
-    return CallJsIntrinsic(isolate, isolate->array_splice(), args);
-  }
   ElementsAccessor* accessor = array->GetElementsAccessor();
-  Handle<JSArray> result_array = accessor->Splice(
-      array, actual_start, actual_delete_count, &args, add_count);
-  return *result_array;
+  int new_length = accessor->Unshift(array, &args, to_add);
+  return Smi::FromInt(new_length);
 }
 
 // Array Concat -------------------------------------------------------------
diff --git a/deps/v8/src/builtins/builtins-arraybuffer.cc b/deps/v8/src/builtins/builtins-arraybuffer.cc
index 808c34e43b..a4de98eb97 100644
--- a/deps/v8/src/builtins/builtins-arraybuffer.cc
+++ b/deps/v8/src/builtins/builtins-arraybuffer.cc
@@ -31,10 +31,12 @@ Object* ConstructBuffer(Isolate* isolate, Handle<JSFunction> target,
                         Handle<JSReceiver> new_target, Handle<Object> length,
                         bool initialize) {
   Handle<JSObject> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   size_t byte_length;
-  if (!TryNumberToSize(*length, &byte_length)) {
+  if (!TryNumberToSize(*length, &byte_length) ||
+      byte_length > JSArrayBuffer::kMaxByteLength) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
   }
@@ -98,7 +100,7 @@ BUILTIN(ArrayBufferPrototypeGetByteLength) {
   CHECK_SHARED(false, array_buffer, kMethodName);
   // TODO(franzih): According to the ES6 spec, we should throw a TypeError
   // here if the JSArrayBuffer is detached.
-  return array_buffer->byte_length();
+  return *isolate->factory()->NewNumberFromSize(array_buffer->byte_length());
 }
 
 // ES7 sharedmem 6.3.4.1 get SharedArrayBuffer.prototype.byteLength
@@ -108,7 +110,7 @@ BUILTIN(SharedArrayBufferPrototypeGetByteLength) {
   CHECK_RECEIVER(JSArrayBuffer, array_buffer,
                  "get SharedArrayBuffer.prototype.byteLength");
   CHECK_SHARED(true, array_buffer, kMethodName);
-  return array_buffer->byte_length();
+  return *isolate->factory()->NewNumberFromSize(array_buffer->byte_length());
 }
 
 // ES6 section 24.1.3.1 ArrayBuffer.isView ( arg )
@@ -143,7 +145,7 @@ static Object* SliceHelper(BuiltinArguments args, Isolate* isolate,
 
   // * [AB] Let len be O.[[ArrayBufferByteLength]].
   // * [SAB] Let len be O.[[ArrayBufferByteLength]].
-  double const len = array_buffer->byte_length()->Number();
+  double const len = array_buffer->byte_length();
 
   // * Let relativeStart be ? ToInteger(start).
   Handle<Object> relative_start;
@@ -242,7 +244,7 @@ static Object* SliceHelper(BuiltinArguments args, Isolate* isolate,
   }
 
   // * If new.[[ArrayBufferByteLength]] < newLen, throw a TypeError exception.
-  if (new_array_buffer->byte_length()->Number() < new_len) {
+  if (new_array_buffer->byte_length() < new_len) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate,
         NewTypeError(is_shared ? MessageTemplate::kSharedArrayBufferTooShort
@@ -264,10 +266,10 @@ static Object* SliceHelper(BuiltinArguments args, Isolate* isolate,
   size_t first_size = 0, new_len_size = 0;
   CHECK(TryNumberToSize(*first_obj, &first_size));
   CHECK(TryNumberToSize(*new_len_obj, &new_len_size));
-  DCHECK(NumberToSize(new_array_buffer->byte_length()) >= new_len_size);
+  DCHECK(new_array_buffer->byte_length() >= new_len_size);
 
   if (new_len_size != 0) {
-    size_t from_byte_length = NumberToSize(array_buffer->byte_length());
+    size_t from_byte_length = array_buffer->byte_length();
     USE(from_byte_length);
     DCHECK(first_size <= from_byte_length);
     DCHECK(from_byte_length - first_size >= new_len_size);
diff --git a/deps/v8/src/builtins/builtins-async-function-gen.cc b/deps/v8/src/builtins/builtins-async-function-gen.cc
index cf5e18f6a0..74d6077764 100644
--- a/deps/v8/src/builtins/builtins-async-function-gen.cc
+++ b/deps/v8/src/builtins/builtins-async-function-gen.cc
@@ -21,36 +21,19 @@ class AsyncFunctionBuiltinsAssembler : public AsyncBuiltinsAssembler {
   void AsyncFunctionAwait(Node* const context, Node* const generator,
                           Node* const awaited, Node* const outer_promise,
                           const bool is_predicted_as_caught);
-  void AsyncFunctionAwaitOptimized(Node* const context, Node* const generator,
-                                   Node* const awaited,
-                                   Node* const outer_promise,
-                                   const bool is_predicted_as_caught);
 
   void AsyncFunctionAwaitResumeClosure(
       Node* const context, Node* const sent_value,
       JSGeneratorObject::ResumeMode resume_mode);
 };
 
-namespace {
-
-// Describe fields of Context associated with AsyncFunctionAwait resume
-// closures.
-// TODO(jgruber): Refactor to reuse code for upcoming async-generators.
-class AwaitContext {
- public:
-  enum Fields { kGeneratorSlot = Context::MIN_CONTEXT_SLOTS, kLength };
-};
-
-}  // anonymous namespace
-
 void AsyncFunctionBuiltinsAssembler::AsyncFunctionAwaitResumeClosure(
     Node* context, Node* sent_value,
     JSGeneratorObject::ResumeMode resume_mode) {
   DCHECK(resume_mode == JSGeneratorObject::kNext ||
          resume_mode == JSGeneratorObject::kThrow);
 
-  Node* const generator =
-      LoadContextElement(context, AwaitContext::kGeneratorSlot);
+  Node* const generator = LoadContextElement(context, Context::EXTENSION_INDEX);
   CSA_SLOW_ASSERT(this, HasInstanceType(generator, JS_GENERATOR_OBJECT_TYPE));
 
   // Inline version of GeneratorPrototypeNext / GeneratorPrototypeReturn with
@@ -113,11 +96,6 @@ void AsyncFunctionBuiltinsAssembler::AsyncFunctionAwait(
   CSA_SLOW_ASSERT(this, HasInstanceType(generator, JS_GENERATOR_OBJECT_TYPE));
   CSA_SLOW_ASSERT(this, HasInstanceType(outer_promise, JS_PROMISE_TYPE));
 
-  ContextInitializer init_closure_context = [&](Node* context) {
-    StoreContextElementNoWriteBarrier(context, AwaitContext::kGeneratorSlot,
-                                      generator);
-  };
-
   // TODO(jgruber): AsyncBuiltinsAssembler::Await currently does not reuse
   // the awaited promise if it is already a promise. Reuse is non-spec compliant
   // but part of our old behavior gives us a couple of percent
@@ -130,8 +108,8 @@ void AsyncFunctionBuiltinsAssembler::AsyncFunctionAwait(
   Goto(&after_debug_hook);
   BIND(&after_debug_hook);
 
-  Await(context, generator, awaited, outer_promise, AwaitContext::kLength,
-        init_closure_context, Context::ASYNC_FUNCTION_AWAIT_RESOLVE_SHARED_FUN,
+  Await(context, generator, awaited, outer_promise,
+        Context::ASYNC_FUNCTION_AWAIT_RESOLVE_SHARED_FUN,
         Context::ASYNC_FUNCTION_AWAIT_REJECT_SHARED_FUN,
         is_predicted_as_caught);
 
@@ -144,43 +122,6 @@ void AsyncFunctionBuiltinsAssembler::AsyncFunctionAwait(
   Goto(&after_debug_hook);
 }
 
-void AsyncFunctionBuiltinsAssembler::AsyncFunctionAwaitOptimized(
-    Node* const context, Node* const generator, Node* const awaited,
-    Node* const outer_promise, const bool is_predicted_as_caught) {
-  CSA_SLOW_ASSERT(this, HasInstanceType(generator, JS_GENERATOR_OBJECT_TYPE));
-  CSA_SLOW_ASSERT(this, HasInstanceType(outer_promise, JS_PROMISE_TYPE));
-
-  ContextInitializer init_closure_context = [&](Node* context) {
-    StoreContextElementNoWriteBarrier(context, AwaitContext::kGeneratorSlot,
-                                      generator);
-  };
-
-  // TODO(jgruber): AsyncBuiltinsAssembler::Await currently does not reuse
-  // the awaited promise if it is already a promise. Reuse is non-spec compliant
-  // but part of our old behavior gives us a couple of percent
-  // performance boost.
-  // TODO(jgruber): Use a faster specialized version of
-  // InternalPerformPromiseThen.
-
-  Label after_debug_hook(this), call_debug_hook(this, Label::kDeferred);
-  GotoIf(HasAsyncEventDelegate(), &call_debug_hook);
-  Goto(&after_debug_hook);
-  BIND(&after_debug_hook);
-
-  AwaitOptimized(
-      context, generator, awaited, outer_promise, AwaitContext::kLength,
-      init_closure_context, Context::ASYNC_FUNCTION_AWAIT_RESOLVE_SHARED_FUN,
-      Context::ASYNC_FUNCTION_AWAIT_REJECT_SHARED_FUN, is_predicted_as_caught);
-
-  // Return outer promise to avoid adding an load of the outer promise before
-  // suspending in BytecodeGenerator.
-  Return(outer_promise);
-
-  BIND(&call_debug_hook);
-  CallRuntime(Runtime::kDebugAsyncFunctionSuspended, context, outer_promise);
-  Goto(&after_debug_hook);
-}
-
 // Called by the parser from the desugaring of 'await' when catch
 // prediction indicates that there is a locally surrounding catch block.
 TF_BUILTIN(AsyncFunctionAwaitCaught, AsyncFunctionBuiltinsAssembler) {
@@ -196,19 +137,6 @@ TF_BUILTIN(AsyncFunctionAwaitCaught, AsyncFunctionBuiltinsAssembler) {
                      kIsPredictedAsCaught);
 }
 
-TF_BUILTIN(AsyncFunctionAwaitCaughtOptimized, AsyncFunctionBuiltinsAssembler) {
-  CSA_ASSERT_JS_ARGC_EQ(this, 3);
-  Node* const generator = Parameter(Descriptor::kGenerator);
-  Node* const awaited = Parameter(Descriptor::kAwaited);
-  Node* const outer_promise = Parameter(Descriptor::kOuterPromise);
-  Node* const context = Parameter(Descriptor::kContext);
-
-  static const bool kIsPredictedAsCaught = true;
-
-  AsyncFunctionAwaitOptimized(context, generator, awaited, outer_promise,
-                              kIsPredictedAsCaught);
-}
-
 // Called by the parser from the desugaring of 'await' when catch
 // prediction indicates no locally surrounding catch block.
 TF_BUILTIN(AsyncFunctionAwaitUncaught, AsyncFunctionBuiltinsAssembler) {
@@ -224,20 +152,6 @@ TF_BUILTIN(AsyncFunctionAwaitUncaught, AsyncFunctionBuiltinsAssembler) {
                      kIsPredictedAsCaught);
 }
 
-TF_BUILTIN(AsyncFunctionAwaitUncaughtOptimized,
-           AsyncFunctionBuiltinsAssembler) {
-  CSA_ASSERT_JS_ARGC_EQ(this, 3);
-  Node* const generator = Parameter(Descriptor::kGenerator);
-  Node* const awaited = Parameter(Descriptor::kAwaited);
-  Node* const outer_promise = Parameter(Descriptor::kOuterPromise);
-  Node* const context = Parameter(Descriptor::kContext);
-
-  static const bool kIsPredictedAsCaught = false;
-
-  AsyncFunctionAwaitOptimized(context, generator, awaited, outer_promise,
-                              kIsPredictedAsCaught);
-}
-
 TF_BUILTIN(AsyncFunctionPromiseCreate, AsyncFunctionBuiltinsAssembler) {
   CSA_ASSERT_JS_ARGC_EQ(this, 0);
   Node* const context = Parameter(Descriptor::kContext);
diff --git a/deps/v8/src/builtins/builtins-async-gen.cc b/deps/v8/src/builtins/builtins-async-gen.cc
index 4568507a9f..dda781b1a8 100644
--- a/deps/v8/src/builtins/builtins-async-gen.cc
+++ b/deps/v8/src/builtins/builtins-async-gen.cc
@@ -23,16 +23,15 @@ class ValueUnwrapContext {
 
 }  // namespace
 
-Node* AsyncBuiltinsAssembler::Await(
-    Node* context, Node* generator, Node* value, Node* outer_promise,
-    int context_length, const ContextInitializer& init_closure_context,
-    Node* on_resolve_context_index, Node* on_reject_context_index,
-    Node* is_predicted_as_caught) {
-  DCHECK_GE(context_length, Context::MIN_CONTEXT_SLOTS);
-
+Node* AsyncBuiltinsAssembler::AwaitOld(Node* context, Node* generator,
+                                       Node* value, Node* outer_promise,
+                                       Node* on_resolve_context_index,
+                                       Node* on_reject_context_index,
+                                       Node* is_predicted_as_caught) {
   Node* const native_context = LoadNativeContext(context);
 
-  static const int kWrappedPromiseOffset = FixedArray::SizeFor(context_length);
+  static const int kWrappedPromiseOffset =
+      FixedArray::SizeFor(Context::MIN_CONTEXT_SLOTS);
   static const int kThrowawayPromiseOffset =
       kWrappedPromiseOffset + JSPromise::kSizeWithEmbedderFields;
   static const int kResolveClosureOffset =
@@ -45,9 +44,20 @@ Node* AsyncBuiltinsAssembler::Await(
   Node* const base = AllocateInNewSpace(kTotalSize);
   Node* const closure_context = base;
   {
-    // Initialize closure context
-    InitializeFunctionContext(native_context, closure_context, context_length);
-    init_closure_context(closure_context);
+    // Initialize the await context, storing the {generator} as extension.
+    StoreMapNoWriteBarrier(closure_context, RootIndex::kAwaitContextMap);
+    StoreObjectFieldNoWriteBarrier(closure_context, Context::kLengthOffset,
+                                   SmiConstant(Context::MIN_CONTEXT_SLOTS));
+    Node* const empty_scope_info =
+        LoadContextElement(native_context, Context::SCOPE_INFO_INDEX);
+    StoreContextElementNoWriteBarrier(
+        closure_context, Context::SCOPE_INFO_INDEX, empty_scope_info);
+    StoreContextElementNoWriteBarrier(closure_context, Context::PREVIOUS_INDEX,
+                                      native_context);
+    StoreContextElementNoWriteBarrier(closure_context, Context::EXTENSION_INDEX,
+                                      generator);
+    StoreContextElementNoWriteBarrier(
+        closure_context, Context::NATIVE_CONTEXT_INDEX, native_context);
   }
 
   // Let promiseCapability be ! NewPromiseCapability(%Promise%).
@@ -149,11 +159,8 @@ Node* AsyncBuiltinsAssembler::Await(
 
 Node* AsyncBuiltinsAssembler::AwaitOptimized(
     Node* context, Node* generator, Node* value, Node* outer_promise,
-    int context_length, const ContextInitializer& init_closure_context,
     Node* on_resolve_context_index, Node* on_reject_context_index,
     Node* is_predicted_as_caught) {
-  DCHECK_GE(context_length, Context::MIN_CONTEXT_SLOTS);
-
   Node* const native_context = LoadNativeContext(context);
   Node* const promise_fun =
       LoadContextElement(native_context, Context::PROMISE_FUNCTION_INDEX);
@@ -161,7 +168,7 @@ Node* AsyncBuiltinsAssembler::AwaitOptimized(
   CSA_ASSERT(this, IsConstructor(promise_fun));
 
   static const int kThrowawayPromiseOffset =
-      FixedArray::SizeFor(context_length);
+      FixedArray::SizeFor(Context::MIN_CONTEXT_SLOTS);
   static const int kResolveClosureOffset =
       kThrowawayPromiseOffset + JSPromise::kSizeWithEmbedderFields;
   static const int kRejectClosureOffset =
@@ -176,9 +183,20 @@ Node* AsyncBuiltinsAssembler::AwaitOptimized(
   Node* const base = AllocateInNewSpace(kTotalSize);
   Node* const closure_context = base;
   {
-    // Initialize closure context
-    InitializeFunctionContext(native_context, closure_context, context_length);
-    init_closure_context(closure_context);
+    // Initialize the await context, storing the {generator} as extension.
+    StoreMapNoWriteBarrier(closure_context, RootIndex::kAwaitContextMap);
+    StoreObjectFieldNoWriteBarrier(closure_context, Context::kLengthOffset,
+                                   SmiConstant(Context::MIN_CONTEXT_SLOTS));
+    Node* const empty_scope_info =
+        LoadContextElement(native_context, Context::SCOPE_INFO_INDEX);
+    StoreContextElementNoWriteBarrier(
+        closure_context, Context::SCOPE_INFO_INDEX, empty_scope_info);
+    StoreContextElementNoWriteBarrier(closure_context, Context::PREVIOUS_INDEX,
+                                      native_context);
+    StoreContextElementNoWriteBarrier(closure_context, Context::EXTENSION_INDEX,
+                                      generator);
+    StoreContextElementNoWriteBarrier(
+        closure_context, Context::NATIVE_CONTEXT_INDEX, native_context);
   }
 
   Node* const promise_map =
@@ -261,6 +279,39 @@ Node* AsyncBuiltinsAssembler::AwaitOptimized(
                      on_resolve, on_reject, throwaway);
 }
 
+Node* AsyncBuiltinsAssembler::Await(Node* context, Node* generator, Node* value,
+                                    Node* outer_promise,
+                                    Node* on_resolve_context_index,
+                                    Node* on_reject_context_index,
+                                    Node* is_predicted_as_caught) {
+  VARIABLE(result, MachineRepresentation::kTagged);
+  Label if_old(this), if_new(this), done(this);
+
+  STATIC_ASSERT(sizeof(FLAG_harmony_await_optimization) == 1);
+
+  TNode<Word32T> flag_value = UncheckedCast<Word32T>(Load(
+      MachineType::Uint8(),
+      ExternalConstant(
+          ExternalReference::address_of_harmony_await_optimization_flag())));
+
+  Branch(Word32Equal(flag_value, Int32Constant(0)), &if_old, &if_new);
+
+  BIND(&if_old);
+  result.Bind(AwaitOld(context, generator, value, outer_promise,
+                       on_resolve_context_index, on_reject_context_index,
+                       is_predicted_as_caught));
+  Goto(&done);
+
+  BIND(&if_new);
+  result.Bind(AwaitOptimized(context, generator, value, outer_promise,
+                             on_resolve_context_index, on_reject_context_index,
+                             is_predicted_as_caught));
+  Goto(&done);
+
+  BIND(&done);
+  return result.value();
+}
+
 void AsyncBuiltinsAssembler::InitializeNativeClosure(Node* context,
                                                      Node* native_context,
                                                      Node* function,
@@ -275,11 +326,11 @@ void AsyncBuiltinsAssembler::InitializeNativeClosure(Node* context,
   STATIC_ASSERT(JSFunction::kSizeWithoutPrototype == 7 * kPointerSize);
   StoreMapNoWriteBarrier(function, function_map);
   StoreObjectFieldRoot(function, JSObject::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(function, JSObject::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(function, JSFunction::kFeedbackCellOffset,
-                       Heap::kManyClosuresCellRootIndex);
+                       RootIndex::kManyClosuresCell);
 
   Node* shared_info = LoadContextElement(native_context, context_index);
   CSA_ASSERT(this, IsSharedFunctionInfo(shared_info));
diff --git a/deps/v8/src/builtins/builtins-async-gen.h b/deps/v8/src/builtins/builtins-async-gen.h
index e5f487d8cc..9dafddef21 100644
--- a/deps/v8/src/builtins/builtins-async-gen.h
+++ b/deps/v8/src/builtins/builtins-async-gen.h
@@ -16,66 +16,29 @@ class AsyncBuiltinsAssembler : public PromiseBuiltinsAssembler {
       : PromiseBuiltinsAssembler(state) {}
 
  protected:
-  typedef std::function<void(Node*)> ContextInitializer;
-
   // Perform steps to resume generator after `value` is resolved.
   // `on_reject_context_index` is an index into the Native Context, which should
   // point to a SharedFunctioninfo instance used to create the closure. The
   // value following the reject index should be a similar value for the resolve
   // closure. Returns the Promise-wrapped `value`.
   Node* Await(Node* context, Node* generator, Node* value, Node* outer_promise,
-              int context_length,
-              const ContextInitializer& init_closure_context,
               Node* on_resolve_context_index, Node* on_reject_context_index,
               Node* is_predicted_as_caught);
-  Node* AwaitOptimized(Node* context, Node* generator, Node* value,
-                       Node* outer_promise, int context_length,
-                       const ContextInitializer& init_closure_context,
-                       Node* on_resolve_context_index,
-                       Node* on_reject_context_index,
-                       Node* is_predicted_as_caught);
   Node* Await(Node* context, Node* generator, Node* value, Node* outer_promise,
-              int context_length,
-              const ContextInitializer& init_closure_context,
               int on_resolve_context_index, int on_reject_context_index,
               Node* is_predicted_as_caught) {
-    return Await(context, generator, value, outer_promise, context_length,
-                 init_closure_context, IntPtrConstant(on_resolve_context_index),
+    return Await(context, generator, value, outer_promise,
+                 IntPtrConstant(on_resolve_context_index),
                  IntPtrConstant(on_reject_context_index),
                  is_predicted_as_caught);
   }
-  Node* AwaitOptimized(Node* context, Node* generator, Node* value,
-                       Node* outer_promise, int context_length,
-                       const ContextInitializer& init_closure_context,
-                       int on_resolve_context_index,
-                       int on_reject_context_index,
-                       Node* is_predicted_as_caught) {
-    return AwaitOptimized(
-        context, generator, value, outer_promise, context_length,
-        init_closure_context, IntPtrConstant(on_resolve_context_index),
-        IntPtrConstant(on_reject_context_index), is_predicted_as_caught);
-  }
   Node* Await(Node* context, Node* generator, Node* value, Node* outer_promise,
-              int context_length,
-              const ContextInitializer& init_closure_context,
               int on_resolve_context_index, int on_reject_context_index,
               bool is_predicted_as_caught) {
-    return Await(context, generator, value, outer_promise, context_length,
-                 init_closure_context, on_resolve_context_index,
-                 on_reject_context_index,
+    return Await(context, generator, value, outer_promise,
+                 on_resolve_context_index, on_reject_context_index,
                  BooleanConstant(is_predicted_as_caught));
   }
-  Node* AwaitOptimized(Node* context, Node* generator, Node* value,
-                       Node* outer_promise, int context_length,
-                       const ContextInitializer& init_closure_context,
-                       int on_resolve_context_index,
-                       int on_reject_context_index,
-                       bool is_predicted_as_caught) {
-    return AwaitOptimized(context, generator, value, outer_promise,
-                          context_length, init_closure_context,
-                          on_resolve_context_index, on_reject_context_index,
-                          BooleanConstant(is_predicted_as_caught));
-  }
 
   // Return a new built-in function object as defined in
   // Async Iterator Value Unwrap Functions
@@ -86,6 +49,14 @@ class AsyncBuiltinsAssembler : public PromiseBuiltinsAssembler {
                                Node* function, Node* context_index);
   Node* AllocateAsyncIteratorValueUnwrapContext(Node* native_context,
                                                 Node* done);
+
+  Node* AwaitOld(Node* context, Node* generator, Node* value,
+                 Node* outer_promise, Node* on_resolve_context_index,
+                 Node* on_reject_context_index, Node* is_predicted_as_caught);
+  Node* AwaitOptimized(Node* context, Node* generator, Node* value,
+                       Node* outer_promise, Node* on_resolve_context_index,
+                       Node* on_reject_context_index,
+                       Node* is_predicted_as_caught);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/builtins/builtins-async-generator-gen.cc b/deps/v8/src/builtins/builtins-async-generator-gen.cc
index bbb2571691..bff2de486a 100644
--- a/deps/v8/src/builtins/builtins-async-generator-gen.cc
+++ b/deps/v8/src/builtins/builtins-async-generator-gen.cc
@@ -17,13 +17,6 @@ using compiler::Node;
 
 namespace {
 
-// Describe fields of Context associated with AsyncGeneratorAwait resume
-// closures.
-class AwaitContext {
- public:
-  enum Fields { kGeneratorSlot = Context::MIN_CONTEXT_SLOTS, kLength };
-};
-
 class AsyncGeneratorBuiltinsAssembler : public AsyncBuiltinsAssembler {
  public:
   explicit AsyncGeneratorBuiltinsAssembler(CodeAssemblerState* state)
@@ -207,7 +200,7 @@ Node* AsyncGeneratorBuiltinsAssembler::AllocateAsyncGeneratorRequest(
     Node* promise) {
   CSA_SLOW_ASSERT(this, HasInstanceType(promise, JS_PROMISE_TYPE));
   Node* request = Allocate(AsyncGeneratorRequest::kSize);
-  StoreMapNoWriteBarrier(request, Heap::kAsyncGeneratorRequestMapRootIndex);
+  StoreMapNoWriteBarrier(request, RootIndex::kAsyncGeneratorRequestMap);
   StoreObjectFieldNoWriteBarrier(request, AsyncGeneratorRequest::kNextOffset,
                                  UndefinedConstant());
   StoreObjectFieldNoWriteBarrier(request,
@@ -218,15 +211,14 @@ Node* AsyncGeneratorBuiltinsAssembler::AllocateAsyncGeneratorRequest(
   StoreObjectFieldNoWriteBarrier(request, AsyncGeneratorRequest::kPromiseOffset,
                                  promise);
   StoreObjectFieldRoot(request, AsyncGeneratorRequest::kNextOffset,
-                       Heap::kUndefinedValueRootIndex);
+                       RootIndex::kUndefinedValue);
   return request;
 }
 
 void AsyncGeneratorBuiltinsAssembler::AsyncGeneratorAwaitResumeClosure(
     Node* context, Node* value,
     JSAsyncGeneratorObject::ResumeMode resume_mode) {
-  Node* const generator =
-      LoadContextElement(context, AwaitContext::kGeneratorSlot);
+  Node* const generator = LoadContextElement(context, Context::EXTENSION_INDEX);
   CSA_SLOW_ASSERT(this, TaggedIsAsyncGenerator(generator));
 
   SetGeneratorNotAwaiting(generator);
@@ -254,11 +246,6 @@ void AsyncGeneratorBuiltinsAssembler::AsyncGeneratorAwait(bool is_catchable) {
   Node* const request = LoadFirstAsyncGeneratorRequestFromQueue(generator);
   CSA_ASSERT(this, IsNotUndefined(request));
 
-  ContextInitializer init_closure_context = [&](Node* context) {
-    StoreContextElementNoWriteBarrier(context, AwaitContext::kGeneratorSlot,
-                                      generator);
-  };
-
   Node* outer_promise =
       LoadObjectField(request, AsyncGeneratorRequest::kPromiseOffset);
 
@@ -266,8 +253,8 @@ void AsyncGeneratorBuiltinsAssembler::AsyncGeneratorAwait(bool is_catchable) {
   const int reject_index = Context::ASYNC_GENERATOR_AWAIT_REJECT_SHARED_FUN;
 
   SetGeneratorAwaiting(generator);
-  Await(context, generator, value, outer_promise, AwaitContext::kLength,
-        init_closure_context, resolve_index, reject_index, is_catchable);
+  Await(context, generator, value, outer_promise, resolve_index, reject_index,
+        is_catchable);
   Return(UndefinedConstant());
 }
 
@@ -519,9 +506,9 @@ TF_BUILTIN(AsyncGeneratorResolve, AsyncGeneratorBuiltinsAssembler) {
                                    Context::ITERATOR_RESULT_MAP_INDEX);
     StoreMapNoWriteBarrier(iter_result, map);
     StoreObjectFieldRoot(iter_result, JSIteratorResult::kPropertiesOrHashOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
     StoreObjectFieldRoot(iter_result, JSIteratorResult::kElementsOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
     StoreObjectFieldNoWriteBarrier(iter_result, JSIteratorResult::kValueOffset,
                                    value);
     StoreObjectFieldNoWriteBarrier(iter_result, JSIteratorResult::kDoneOffset,
@@ -585,25 +572,19 @@ TF_BUILTIN(AsyncGeneratorYield, AsyncGeneratorBuiltinsAssembler) {
   Node* const request = LoadFirstAsyncGeneratorRequestFromQueue(generator);
   Node* const outer_promise = LoadPromiseFromAsyncGeneratorRequest(request);
 
-  ContextInitializer init_closure_context = [&](Node* context) {
-    StoreContextElementNoWriteBarrier(context, AwaitContext::kGeneratorSlot,
-                                      generator);
-  };
-
   const int on_resolve = Context::ASYNC_GENERATOR_YIELD_RESOLVE_SHARED_FUN;
   const int on_reject = Context::ASYNC_GENERATOR_AWAIT_REJECT_SHARED_FUN;
 
   SetGeneratorAwaiting(generator);
-  Await(context, generator, value, outer_promise, AwaitContext::kLength,
-        init_closure_context, on_resolve, on_reject, is_caught);
+  Await(context, generator, value, outer_promise, on_resolve, on_reject,
+        is_caught);
   Return(UndefinedConstant());
 }
 
 TF_BUILTIN(AsyncGeneratorYieldResolveClosure, AsyncGeneratorBuiltinsAssembler) {
   Node* const context = Parameter(Descriptor::kContext);
   Node* const value = Parameter(Descriptor::kValue);
-  Node* const generator =
-      LoadContextElement(context, AwaitContext::kGeneratorSlot);
+  Node* const generator = LoadContextElement(context, Context::EXTENSION_INDEX);
 
   SetGeneratorNotAwaiting(generator);
 
@@ -656,17 +637,11 @@ TF_BUILTIN(AsyncGeneratorReturn, AsyncGeneratorBuiltinsAssembler) {
 
   BIND(&perform_await);
 
-  ContextInitializer init_closure_context = [&](Node* context) {
-    StoreContextElementNoWriteBarrier(context, AwaitContext::kGeneratorSlot,
-                                      generator);
-  };
-
   SetGeneratorAwaiting(generator);
   Node* const context = Parameter(Descriptor::kContext);
   Node* const outer_promise = LoadPromiseFromAsyncGeneratorRequest(req);
-  Await(context, generator, value, outer_promise, AwaitContext::kLength,
-        init_closure_context, var_on_resolve.value(), var_on_reject.value(),
-        is_caught);
+  Await(context, generator, value, outer_promise, var_on_resolve.value(),
+        var_on_reject.value(), is_caught);
 
   Return(UndefinedConstant());
 }
@@ -689,8 +664,7 @@ TF_BUILTIN(AsyncGeneratorReturnClosedResolveClosure,
            AsyncGeneratorBuiltinsAssembler) {
   Node* const context = Parameter(Descriptor::kContext);
   Node* const value = Parameter(Descriptor::kValue);
-  Node* const generator =
-      LoadContextElement(context, AwaitContext::kGeneratorSlot);
+  Node* const generator = LoadContextElement(context, Context::EXTENSION_INDEX);
 
   SetGeneratorNotAwaiting(generator);
 
@@ -707,8 +681,7 @@ TF_BUILTIN(AsyncGeneratorReturnClosedRejectClosure,
            AsyncGeneratorBuiltinsAssembler) {
   Node* const context = Parameter(Descriptor::kContext);
   Node* const value = Parameter(Descriptor::kValue);
-  Node* const generator =
-      LoadContextElement(context, AwaitContext::kGeneratorSlot);
+  Node* const generator = LoadContextElement(context, Context::EXTENSION_INDEX);
 
   SetGeneratorNotAwaiting(generator);
 
diff --git a/deps/v8/src/builtins/builtins-async-iterator-gen.cc b/deps/v8/src/builtins/builtins-async-iterator-gen.cc
index 82db5fbd5d..3672bda9d1 100644
--- a/deps/v8/src/builtins/builtins-async-iterator-gen.cc
+++ b/deps/v8/src/builtins/builtins-async-iterator-gen.cc
@@ -333,20 +333,6 @@ TF_BUILTIN(AsyncFromSyncIteratorPrototypeNext, AsyncFromSyncBuiltinsAssembler) {
       "[Async-from-Sync Iterator].prototype.next");
 }
 
-TF_BUILTIN(AsyncFromSyncIteratorPrototypeNextOptimized,
-           AsyncFromSyncBuiltinsAssembler) {
-  Node* const iterator = Parameter(Descriptor::kReceiver);
-  Node* const value = Parameter(Descriptor::kValue);
-  Node* const context = Parameter(Descriptor::kContext);
-
-  auto get_method = [=](Node* const unused) {
-    return LoadObjectField(iterator, JSAsyncFromSyncIterator::kNextOffset);
-  };
-  Generate_AsyncFromSyncIteratorMethodOptimized(
-      context, iterator, value, get_method, UndefinedMethodHandler(),
-      "[Async-from-Sync Iterator].prototype.next");
-}
-
 // https://tc39.github.io/proposal-async-iteration/
 // Section #sec-%asyncfromsynciteratorprototype%.return
 TF_BUILTIN(AsyncFromSyncIteratorPrototypeReturn,
@@ -374,31 +360,6 @@ TF_BUILTIN(AsyncFromSyncIteratorPrototypeReturn,
       "[Async-from-Sync Iterator].prototype.return");
 }
 
-TF_BUILTIN(AsyncFromSyncIteratorPrototypeReturnOptimized,
-           AsyncFromSyncBuiltinsAssembler) {
-  Node* const iterator = Parameter(Descriptor::kReceiver);
-  Node* const value = Parameter(Descriptor::kValue);
-  Node* const context = Parameter(Descriptor::kContext);
-
-  auto if_return_undefined = [=](Node* const native_context,
-                                 Node* const promise, Label* if_exception) {
-    // If return is undefined, then
-    // Let iterResult be ! CreateIterResultObject(value, true)
-    Node* const iter_result = CallBuiltin(Builtins::kCreateIterResultObject,
-                                          context, value, TrueConstant());
-
-    // Perform ! Call(promiseCapability.[[Resolve]], undefined, « iterResult »).
-    // IfAbruptRejectPromise(nextDone, promiseCapability).
-    // Return promiseCapability.[[Promise]].
-    CallBuiltin(Builtins::kResolvePromise, context, promise, iter_result);
-    Return(promise);
-  };
-
-  Generate_AsyncFromSyncIteratorMethodOptimized(
-      context, iterator, value, factory()->return_string(), if_return_undefined,
-      "[Async-from-Sync Iterator].prototype.return");
-}
-
 // https://tc39.github.io/proposal-async-iteration/
 // Section #sec-%asyncfromsynciteratorprototype%.throw
 TF_BUILTIN(AsyncFromSyncIteratorPrototypeThrow,
@@ -416,20 +377,5 @@ TF_BUILTIN(AsyncFromSyncIteratorPrototypeThrow,
       reason);
 }
 
-TF_BUILTIN(AsyncFromSyncIteratorPrototypeThrowOptimized,
-           AsyncFromSyncBuiltinsAssembler) {
-  Node* const iterator = Parameter(Descriptor::kReceiver);
-  Node* const reason = Parameter(Descriptor::kReason);
-  Node* const context = Parameter(Descriptor::kContext);
-
-  auto if_throw_undefined = [=](Node* const native_context, Node* const promise,
-                                Label* if_exception) { Goto(if_exception); };
-
-  Generate_AsyncFromSyncIteratorMethodOptimized(
-      context, iterator, reason, factory()->throw_string(), if_throw_undefined,
-      "[Async-from-Sync Iterator].prototype.throw", Label::kNonDeferred,
-      reason);
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/builtins/builtins-boolean.cc b/deps/v8/src/builtins/builtins-boolean.cc
index 52645cbaa0..52ed0563c6 100644
--- a/deps/v8/src/builtins/builtins-boolean.cc
+++ b/deps/v8/src/builtins/builtins-boolean.cc
@@ -26,8 +26,9 @@ BUILTIN(BooleanConstructor) {
   Handle<JSReceiver> new_target = Handle<JSReceiver>::cast(args.new_target());
   DCHECK(*target == target->native_context()->boolean_function());
   Handle<JSObject> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   Handle<JSValue>::cast(result)->set_value(
       isolate->heap()->ToBoolean(value->BooleanValue(isolate)));
   return *result;
diff --git a/deps/v8/src/builtins/builtins-call-gen.cc b/deps/v8/src/builtins/builtins-call-gen.cc
index 4defe28cb7..e23f13d2b3 100644
--- a/deps/v8/src/builtins/builtins-call-gen.cc
+++ b/deps/v8/src/builtins/builtins-call-gen.cc
@@ -17,45 +17,75 @@ namespace internal {
 
 void Builtins::Generate_CallFunction_ReceiverIsNullOrUndefined(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallFunction(masm, ConvertReceiverMode::kNullOrUndefined);
 }
 
 void Builtins::Generate_CallFunction_ReceiverIsNotNullOrUndefined(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallFunction(masm, ConvertReceiverMode::kNotNullOrUndefined);
 }
 
 void Builtins::Generate_CallFunction_ReceiverIsAny(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallFunction(masm, ConvertReceiverMode::kAny);
 }
 
 void Builtins::Generate_CallBoundFunction(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallBoundFunctionImpl(masm);
 }
 
 void Builtins::Generate_Call_ReceiverIsNullOrUndefined(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_Call(masm, ConvertReceiverMode::kNullOrUndefined);
 }
 
 void Builtins::Generate_Call_ReceiverIsNotNullOrUndefined(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_Call(masm, ConvertReceiverMode::kNotNullOrUndefined);
 }
 
 void Builtins::Generate_Call_ReceiverIsAny(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_Call(masm, ConvertReceiverMode::kAny);
 }
 
 void Builtins::Generate_CallVarargs(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallOrConstructVarargs(masm, masm->isolate()->builtins()->Call());
 }
 
 void Builtins::Generate_CallForwardVarargs(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallOrConstructForwardVarargs(masm, CallOrConstructMode::kCall,
                                          masm->isolate()->builtins()->Call());
 }
 
 void Builtins::Generate_CallFunctionForwardVarargs(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallOrConstructForwardVarargs(
       masm, CallOrConstructMode::kCall,
       masm->isolate()->builtins()->CallFunction());
@@ -163,9 +193,9 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithArrayLike(
   BIND(&if_arguments);
   {
     TNode<JSArgumentsObject> js_arguments = CAST(arguments_list);
-    // Try to extract the elements from an JSArgumentsObject.
-    TNode<Object> length =
-        LoadObjectField(js_arguments, JSArgumentsObject::kLengthOffset);
+    // Try to extract the elements from an JSArgumentsObjectWithLength.
+    TNode<Object> length = LoadObjectField(
+        js_arguments, JSArgumentsObjectWithLength::kLengthOffset);
     TNode<FixedArrayBase> elements = LoadElements(js_arguments);
     TNode<Smi> elements_length = LoadFixedArrayBaseLength(elements);
     GotoIfNot(WordEqual(length, elements_length), &if_runtime);
@@ -211,11 +241,11 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithArrayLike(
     {
       if (new_target == nullptr) {
         Callable callable = CodeFactory::CallVarargs(isolate());
-        TailCallStub(callable, context, target, args_count, elements, length);
+        TailCallStub(callable, context, target, args_count, length, elements);
       } else {
         Callable callable = CodeFactory::ConstructVarargs(isolate());
-        TailCallStub(callable, context, target, new_target, args_count,
-                     elements, length);
+        TailCallStub(callable, context, target, new_target, args_count, length,
+                     elements);
       }
     }
 
@@ -266,11 +296,11 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructDoubleVarargs(
   {
     if (new_target == nullptr) {
       Callable callable = CodeFactory::CallVarargs(isolate());
-      TailCallStub(callable, context, target, args_count, new_elements, length);
+      TailCallStub(callable, context, target, args_count, length, new_elements);
     } else {
       Callable callable = CodeFactory::ConstructVarargs(isolate());
-      TailCallStub(callable, context, target, new_target, args_count,
-                   new_elements, length);
+      TailCallStub(callable, context, target, new_target, args_count, length,
+                   new_elements);
     }
   }
 }
@@ -299,7 +329,7 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
   // Check that the Array.prototype hasn't been modified in a way that would
   // affect iteration.
   TNode<PropertyCell> protector_cell =
-      CAST(LoadRoot(Heap::kArrayIteratorProtectorRootIndex));
+      CAST(LoadRoot(RootIndex::kArrayIteratorProtector));
   GotoIf(WordEqual(LoadObjectField(protector_cell, PropertyCell::kValueOffset),
                    SmiConstant(Isolate::kProtectorInvalid)),
          &if_generic);
@@ -325,8 +355,9 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
     TNode<Object> iterator_fn =
         GetProperty(context, spread, IteratorSymbolConstant());
     GotoIfNot(TaggedIsCallable(iterator_fn), &if_iterator_fn_not_callable);
-    TNode<JSArray> list = CAST(
-        CallBuiltin(Builtins::kIterableToList, context, spread, iterator_fn));
+    TNode<JSArray> list =
+        CAST(CallBuiltin(Builtins::kIterableToListMayPreserveHoles, context,
+                         spread, iterator_fn));
     var_length = LoadAndUntagToWord32ObjectField(list, JSArray::kLengthOffset);
 
     var_elements = LoadElements(list);
@@ -346,11 +377,11 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
 
     if (new_target == nullptr) {
       Callable callable = CodeFactory::CallVarargs(isolate());
-      TailCallStub(callable, context, target, args_count, elements, length);
+      TailCallStub(callable, context, target, args_count, length, elements);
     } else {
       Callable callable = CodeFactory::ConstructVarargs(isolate());
-      TailCallStub(callable, context, target, new_target, args_count, elements,
-                   length);
+      TailCallStub(callable, context, target, new_target, args_count, length,
+                   elements);
     }
   }
 
diff --git a/deps/v8/src/builtins/builtins-callsite.cc b/deps/v8/src/builtins/builtins-callsite.cc
index c41626dfd4..b580bb181f 100644
--- a/deps/v8/src/builtins/builtins-callsite.cc
+++ b/deps/v8/src/builtins/builtins-callsite.cc
@@ -137,6 +137,14 @@ BUILTIN(CallSitePrototypeGetTypeName) {
   return *it.Frame()->GetTypeName();
 }
 
+BUILTIN(CallSitePrototypeIsAsync) {
+  HandleScope scope(isolate);
+  CHECK_CALLSITE(recv, "isAsync");
+  FrameArrayIterator it(isolate, GetFrameArray(isolate, recv),
+                        GetFrameIndex(isolate, recv));
+  return isolate->heap()->ToBoolean(it.Frame()->IsAsync());
+}
+
 BUILTIN(CallSitePrototypeIsConstructor) {
   HandleScope scope(isolate);
   CHECK_CALLSITE(recv, "isConstructor");
diff --git a/deps/v8/src/builtins/builtins-collections-gen.cc b/deps/v8/src/builtins/builtins-collections-gen.cc
index aab0475e21..1ff64b0877 100644
--- a/deps/v8/src/builtins/builtins-collections-gen.cc
+++ b/deps/v8/src/builtins/builtins-collections-gen.cc
@@ -24,7 +24,7 @@ class BaseCollectionsAssembler : public CodeStubAssembler {
   explicit BaseCollectionsAssembler(compiler::CodeAssemblerState* state)
       : CodeStubAssembler(state) {}
 
-  virtual ~BaseCollectionsAssembler() {}
+  virtual ~BaseCollectionsAssembler() = default;
 
  protected:
   enum Variant { kMap, kSet, kWeakMap, kWeakSet };
@@ -628,7 +628,7 @@ class CollectionsBuiltinsAssembler : public BaseCollectionsAssembler {
   Node* AllocateJSCollectionIterator(Node* context, int map_index,
                                      Node* collection);
   TNode<Object> AllocateTable(Variant variant, TNode<Context> context,
-                              TNode<IntPtrT> at_least_space_for);
+                              TNode<IntPtrT> at_least_space_for) override;
   Node* GetHash(Node* const key);
   Node* CallGetHashRaw(Node* const key);
   Node* CallGetOrCreateHashRaw(Node* const key);
@@ -731,9 +731,9 @@ Node* CollectionsBuiltinsAssembler::AllocateJSCollectionIterator(
   Node* const iterator = AllocateInNewSpace(IteratorType::kSize);
   StoreMapNoWriteBarrier(iterator, iterator_map);
   StoreObjectFieldRoot(iterator, IteratorType::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(iterator, IteratorType::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(iterator, IteratorType::kTableOffset, table);
   StoreObjectFieldNoWriteBarrier(iterator, IteratorType::kIndexOffset,
                                  SmiConstant(0));
@@ -770,7 +770,7 @@ TF_BUILTIN(SetConstructor, CollectionsBuiltinsAssembler) {
 
 Node* CollectionsBuiltinsAssembler::CallGetOrCreateHashRaw(Node* const key) {
   Node* const function_addr =
-      ExternalConstant(ExternalReference::get_or_create_hash_raw(isolate()));
+      ExternalConstant(ExternalReference::get_or_create_hash_raw());
   Node* const isolate_ptr =
       ExternalConstant(ExternalReference::isolate_address(isolate()));
 
@@ -1699,7 +1699,7 @@ TF_BUILTIN(MapIteratorPrototypeNext, CollectionsBuiltinsAssembler) {
   BIND(&return_end);
   {
     StoreObjectFieldRoot(receiver, JSMapIterator::kTableOffset,
-                         Heap::kEmptyOrderedHashMapRootIndex);
+                         RootIndex::kEmptyOrderedHashMap);
     Goto(&return_value);
   }
 }
@@ -1907,7 +1907,7 @@ TF_BUILTIN(SetIteratorPrototypeNext, CollectionsBuiltinsAssembler) {
   BIND(&return_end);
   {
     StoreObjectFieldRoot(receiver, JSSetIterator::kTableOffset,
-                         Heap::kEmptyOrderedHashSetRootIndex);
+                         RootIndex::kEmptyOrderedHashSet);
     Goto(&return_value);
   }
 }
@@ -1986,7 +1986,7 @@ class WeakCollectionsBuiltinsAssembler : public BaseCollectionsAssembler {
                 TNode<IntPtrT> number_of_elements);
 
   TNode<Object> AllocateTable(Variant variant, TNode<Context> context,
-                              TNode<IntPtrT> at_least_space_for);
+                              TNode<IntPtrT> at_least_space_for) override;
 
   // Generates and sets the identity for a JSRececiver.
   TNode<Smi> CreateIdentityHash(TNode<Object> receiver);
@@ -2062,8 +2062,7 @@ TNode<Object> WeakCollectionsBuiltinsAssembler::AllocateTable(
   TNode<FixedArray> table = CAST(
       AllocateFixedArray(HOLEY_ELEMENTS, length, kAllowLargeObjectAllocation));
 
-  Heap::RootListIndex map_root_index = static_cast<Heap::RootListIndex>(
-      EphemeronHashTableShape::GetMapRootIndex());
+  RootIndex map_root_index = EphemeronHashTableShape::GetMapRootIndex();
   StoreMapNoWriteBarrier(table, map_root_index);
   StoreFixedArrayElement(table, EphemeronHashTable::kNumberOfElementsIndex,
                          SmiConstant(0), SKIP_WRITE_BARRIER);
@@ -2075,14 +2074,14 @@ TNode<Object> WeakCollectionsBuiltinsAssembler::AllocateTable(
 
   TNode<IntPtrT> start = KeyIndexFromEntry(IntPtrConstant(0));
   FillFixedArrayWithValue(HOLEY_ELEMENTS, table, start, length,
-                          Heap::kUndefinedValueRootIndex);
+                          RootIndex::kUndefinedValue);
   return table;
 }
 
 TNode<Smi> WeakCollectionsBuiltinsAssembler::CreateIdentityHash(
     TNode<Object> key) {
-  TNode<ExternalReference> function_addr = ExternalConstant(
-      ExternalReference::jsreceiver_create_identity_hash(isolate()));
+  TNode<ExternalReference> function_addr =
+      ExternalConstant(ExternalReference::jsreceiver_create_identity_hash());
   TNode<ExternalReference> isolate_ptr =
       ExternalConstant(ExternalReference::isolate_address(isolate()));
 
diff --git a/deps/v8/src/builtins/builtins-console.cc b/deps/v8/src/builtins/builtins-console.cc
index e9f252cb6a..d6819d8f66 100644
--- a/deps/v8/src/builtins/builtins-console.cc
+++ b/deps/v8/src/builtins/builtins-console.cc
@@ -32,7 +32,8 @@ namespace internal {
   V(CountReset, countReset)         \
   V(Assert, assert)                 \
   V(Profile, profile)               \
-  V(ProfileEnd, profileEnd)
+  V(ProfileEnd, profileEnd)         \
+  V(TimeLog, timeLog)
 
 namespace {
 void ConsoleCall(
diff --git a/deps/v8/src/builtins/builtins-constructor-gen.cc b/deps/v8/src/builtins/builtins-constructor-gen.cc
index 8e54c4c369..26c97ba681 100644
--- a/deps/v8/src/builtins/builtins-constructor-gen.cc
+++ b/deps/v8/src/builtins/builtins-constructor-gen.cc
@@ -19,17 +19,26 @@ namespace v8 {
 namespace internal {
 
 void Builtins::Generate_ConstructVarargs(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallOrConstructVarargs(masm,
                                   BUILTIN_CODE(masm->isolate(), Construct));
 }
 
 void Builtins::Generate_ConstructForwardVarargs(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallOrConstructForwardVarargs(
       masm, CallOrConstructMode::kConstruct,
       BUILTIN_CODE(masm->isolate(), Construct));
 }
 
 void Builtins::Generate_ConstructFunctionForwardVarargs(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_CallOrConstructForwardVarargs(
       masm, CallOrConstructMode::kConstruct,
       BUILTIN_CODE(masm->isolate(), ConstructFunction));
@@ -77,11 +86,11 @@ TF_BUILTIN(FastNewClosure, ConstructorBuiltinsAssembler) {
     Goto(&cell_done);
 
     BIND(&no_closures);
-    StoreMapNoWriteBarrier(feedback_cell, Heap::kOneClosureCellMapRootIndex);
+    StoreMapNoWriteBarrier(feedback_cell, RootIndex::kOneClosureCellMap);
     Goto(&cell_done);
 
     BIND(&one_closure);
-    StoreMapNoWriteBarrier(feedback_cell, Heap::kManyClosuresCellMapRootIndex);
+    StoreMapNoWriteBarrier(feedback_cell, RootIndex::kManyClosuresCellMap);
     Goto(&cell_done);
 
     BIND(&cell_done);
@@ -116,9 +125,9 @@ TF_BUILTIN(FastNewClosure, ConstructorBuiltinsAssembler) {
 
   // Initialize the rest of the function.
   StoreObjectFieldRoot(result, JSObject::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(result, JSObject::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   {
     // Set function prototype if necessary.
     Label done(this), init_prototype(this);
@@ -127,7 +136,7 @@ TF_BUILTIN(FastNewClosure, ConstructorBuiltinsAssembler) {
 
     BIND(&init_prototype);
     StoreObjectFieldRoot(result, JSFunction::kPrototypeOrInitialMapOffset,
-                         Heap::kTheHoleValueRootIndex);
+                         RootIndex::kTheHoleValue);
     Goto(&done);
     BIND(&done);
   }
@@ -236,13 +245,13 @@ Node* ConstructorBuiltinsAssembler::EmitFastNewFunctionContext(
   TNode<Context> function_context =
       UncheckedCast<Context>(AllocateInNewSpace(size));
 
-  Heap::RootListIndex context_type;
+  RootIndex context_type;
   switch (scope_type) {
     case EVAL_SCOPE:
-      context_type = Heap::kEvalContextMapRootIndex;
+      context_type = RootIndex::kEvalContextMap;
       break;
     case FUNCTION_SCOPE:
-      context_type = Heap::kFunctionContextMapRootIndex;
+      context_type = RootIndex::kFunctionContextMap;
       break;
     default:
       UNREACHABLE();
diff --git a/deps/v8/src/builtins/builtins-conversion-gen.cc b/deps/v8/src/builtins/builtins-conversion-gen.cc
index 7bdc2759c4..b898056658 100644
--- a/deps/v8/src/builtins/builtins-conversion-gen.cc
+++ b/deps/v8/src/builtins/builtins-conversion-gen.cc
@@ -48,10 +48,8 @@ void ConversionBuiltinsAssembler::Generate_NonPrimitiveToPrimitive(
         if_resultisnotprimitive(this, Label::kDeferred);
     GotoIf(TaggedIsSmi(result), &if_resultisprimitive);
     Node* result_instance_type = LoadInstanceType(result);
-    STATIC_ASSERT(FIRST_PRIMITIVE_TYPE == FIRST_TYPE);
-    Branch(Int32LessThanOrEqual(result_instance_type,
-                                Int32Constant(LAST_PRIMITIVE_TYPE)),
-           &if_resultisprimitive, &if_resultisnotprimitive);
+    Branch(IsPrimitiveInstanceType(result_instance_type), &if_resultisprimitive,
+           &if_resultisnotprimitive);
 
     BIND(&if_resultisprimitive);
     {
@@ -108,7 +106,62 @@ TF_BUILTIN(ToName, CodeStubAssembler) {
   Node* context = Parameter(Descriptor::kContext);
   Node* input = Parameter(Descriptor::kArgument);
 
-  Return(ToName(context, input));
+  VARIABLE(var_input, MachineRepresentation::kTagged, input);
+  Label loop(this, &var_input);
+  Goto(&loop);
+  BIND(&loop);
+  {
+    // Load the current {input} value.
+    Node* input = var_input.value();
+
+    // Dispatch based on the type of the {input.}
+    Label if_inputisbigint(this), if_inputisname(this), if_inputisnumber(this),
+        if_inputisoddball(this), if_inputisreceiver(this, Label::kDeferred);
+    GotoIf(TaggedIsSmi(input), &if_inputisnumber);
+    Node* input_instance_type = LoadInstanceType(input);
+    STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);
+    GotoIf(IsNameInstanceType(input_instance_type), &if_inputisname);
+    GotoIf(IsJSReceiverInstanceType(input_instance_type), &if_inputisreceiver);
+    GotoIf(IsHeapNumberInstanceType(input_instance_type), &if_inputisnumber);
+    Branch(IsBigIntInstanceType(input_instance_type), &if_inputisbigint,
+           &if_inputisoddball);
+
+    BIND(&if_inputisbigint);
+    {
+      // We don't have a fast-path for BigInt currently, so just
+      // tail call to the %ToString runtime function here for now.
+      TailCallRuntime(Runtime::kToString, context, input);
+    }
+
+    BIND(&if_inputisname);
+    {
+      // The {input} is already a Name.
+      Return(input);
+    }
+
+    BIND(&if_inputisnumber);
+    {
+      // Convert the String {input} to a Number.
+      TailCallBuiltin(Builtins::kNumberToString, context, input);
+    }
+
+    BIND(&if_inputisoddball);
+    {
+      // Just return the {input}'s string representation.
+      CSA_ASSERT(this, IsOddballInstanceType(input_instance_type));
+      Return(LoadObjectField(input, Oddball::kToStringOffset));
+    }
+
+    BIND(&if_inputisreceiver);
+    {
+      // Convert the JSReceiver {input} to a primitive first,
+      // and then run the loop again with the new {input},
+      // which is then a primitive value.
+      var_input.Bind(CallBuiltin(Builtins::kNonPrimitiveToPrimitive_String,
+                                 context, input));
+      Goto(&loop);
+    }
+  }
 }
 
 TF_BUILTIN(NonNumberToNumber, CodeStubAssembler) {
@@ -205,10 +258,7 @@ void ConversionBuiltinsAssembler::Generate_OrdinaryToPrimitive(
       // Return the {result} if it is a primitive.
       GotoIf(TaggedIsSmi(result), &return_result);
       Node* result_instance_type = LoadInstanceType(result);
-      STATIC_ASSERT(FIRST_PRIMITIVE_TYPE == FIRST_TYPE);
-      GotoIf(Int32LessThanOrEqual(result_instance_type,
-                                  Int32Constant(LAST_PRIMITIVE_TYPE)),
-             &return_result);
+      GotoIf(IsPrimitiveInstanceType(result_instance_type), &return_result);
     }
 
     // Just continue with the next {name} if the {method} is not callable.
@@ -384,9 +434,9 @@ TF_BUILTIN(ToObject, CodeStubAssembler) {
   Node* js_value = Allocate(JSValue::kSize);
   StoreMapNoWriteBarrier(js_value, initial_map);
   StoreObjectFieldRoot(js_value, JSValue::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(js_value, JSObject::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectField(js_value, JSValue::kValueOffset, object);
   Return(js_value);
 
diff --git a/deps/v8/src/builtins/builtins-data-view-gen.h b/deps/v8/src/builtins/builtins-data-view-gen.h
index 6c755c4d08..4a55a90eef 100644
--- a/deps/v8/src/builtins/builtins-data-view-gen.h
+++ b/deps/v8/src/builtins/builtins-data-view-gen.h
@@ -17,25 +17,17 @@ class DataViewBuiltinsAssembler : public BaseBuiltinsFromDSLAssembler {
   explicit DataViewBuiltinsAssembler(compiler::CodeAssemblerState* state)
       : BaseBuiltinsFromDSLAssembler(state) {}
 
-  TNode<Number> LoadDataViewByteOffset(TNode<JSDataView> data_view) {
-    return CAST(LoadObjectField(data_view, JSDataView::kByteOffsetOffset));
-  }
-
-  TNode<Number> LoadDataViewByteLength(TNode<JSDataView> data_view) {
-    return CAST(LoadObjectField(data_view, JSDataView::kByteLengthOffset));
-  }
-
-  TNode<Int32T> LoadUint8(TNode<RawPtrT> data_pointer, TNode<IntPtrT> offset) {
+  TNode<Int32T> LoadUint8(TNode<RawPtrT> data_pointer, TNode<UintPtrT> offset) {
     return UncheckedCast<Int32T>(
         Load(MachineType::Uint8(), data_pointer, offset));
   }
 
-  TNode<Int32T> LoadInt8(TNode<RawPtrT> data_pointer, TNode<IntPtrT> offset) {
+  TNode<Int32T> LoadInt8(TNode<RawPtrT> data_pointer, TNode<UintPtrT> offset) {
     return UncheckedCast<Int32T>(
         Load(MachineType::Int8(), data_pointer, offset));
   }
 
-  void StoreWord8(TNode<RawPtrT> data_pointer, TNode<IntPtrT> offset,
+  void StoreWord8(TNode<RawPtrT> data_pointer, TNode<UintPtrT> offset,
                   TNode<Word32T> value) {
     StoreNoWriteBarrier(MachineRepresentation::kWord8, data_pointer, offset,
                         value);
diff --git a/deps/v8/src/builtins/builtins-dataview.cc b/deps/v8/src/builtins/builtins-dataview.cc
index 72ea685982..f40cd0f68e 100644
--- a/deps/v8/src/builtins/builtins-dataview.cc
+++ b/deps/v8/src/builtins/builtins-dataview.cc
@@ -43,51 +43,52 @@ BUILTIN(DataViewConstructor) {
   Handle<JSArrayBuffer> array_buffer = Handle<JSArrayBuffer>::cast(buffer);
 
   // 4. Let offset be ? ToIndex(byteOffset).
-  Handle<Object> offset;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, offset,
+      isolate, byte_offset,
       Object::ToIndex(isolate, byte_offset, MessageTemplate::kInvalidOffset));
+  size_t view_byte_offset = byte_offset->Number();
 
   // 5. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
   //    We currently violate the specification at this point. TODO: Fix that.
 
   // 6. Let bufferByteLength be the value of buffer's
   // [[ArrayBufferByteLength]] internal slot.
-  double const buffer_byte_length = array_buffer->byte_length()->Number();
+  size_t const buffer_byte_length = array_buffer->byte_length();
 
   // 7. If offset > bufferByteLength, throw a RangeError exception.
-  if (offset->Number() > buffer_byte_length) {
+  if (view_byte_offset > buffer_byte_length) {
     THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewRangeError(MessageTemplate::kInvalidOffset, offset));
+        isolate, NewRangeError(MessageTemplate::kInvalidOffset, byte_offset));
   }
 
-  Handle<Object> view_byte_length;
+  size_t view_byte_length;
   if (byte_length->IsUndefined(isolate)) {
     // 8. If byteLength is either not present or undefined, then
     //       a. Let viewByteLength be bufferByteLength - offset.
-    view_byte_length =
-        isolate->factory()->NewNumber(buffer_byte_length - offset->Number());
+    view_byte_length = buffer_byte_length - view_byte_offset;
   } else {
     // 9. Else,
     //       a. Let viewByteLength be ? ToIndex(byteLength).
     //       b. If offset+viewByteLength > bufferByteLength, throw a
     //          RangeError exception.
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, view_byte_length,
+        isolate, byte_length,
         Object::ToIndex(isolate, byte_length,
                         MessageTemplate::kInvalidDataViewLength));
-    if (offset->Number() + view_byte_length->Number() > buffer_byte_length) {
+    if (view_byte_offset + byte_length->Number() > buffer_byte_length) {
       THROW_NEW_ERROR_RETURN_FAILURE(
           isolate, NewRangeError(MessageTemplate::kInvalidDataViewLength));
     }
+    view_byte_length = byte_length->Number();
   }
 
   // 10. Let O be ? OrdinaryCreateFromConstructor(NewTarget,
   //     "%DataViewPrototype%", «[[DataView]], [[ViewedArrayBuffer]],
   //     [[ByteLength]], [[ByteOffset]]»).
   Handle<JSObject> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   for (int i = 0; i < ArrayBufferView::kEmbedderFieldCount; ++i) {
     Handle<JSDataView>::cast(result)->SetEmbedderField(i, Smi::kZero);
   }
@@ -96,10 +97,10 @@ BUILTIN(DataViewConstructor) {
   Handle<JSDataView>::cast(result)->set_buffer(*array_buffer);
 
   // 12. Set O's [[ByteLength]] internal slot to viewByteLength.
-  Handle<JSDataView>::cast(result)->set_byte_length(*view_byte_length);
+  Handle<JSDataView>::cast(result)->set_byte_length(view_byte_length);
 
   // 13. Set O's [[ByteOffset]] internal slot to offset.
-  Handle<JSDataView>::cast(result)->set_byte_offset(*offset);
+  Handle<JSDataView>::cast(result)->set_byte_offset(view_byte_offset);
 
   // 14. Return O.
   return *result;
diff --git a/deps/v8/src/builtins/builtins-date-gen.cc b/deps/v8/src/builtins/builtins-date-gen.cc
index 4d3c7faa53..e0cb199920 100644
--- a/deps/v8/src/builtins/builtins-date-gen.cc
+++ b/deps/v8/src/builtins/builtins-date-gen.cc
@@ -193,11 +193,11 @@ TF_BUILTIN(DatePrototypeToPrimitive, CodeStubAssembler) {
       hint_is_invalid(this, Label::kDeferred);
 
   // Fast cases for internalized strings.
-  Node* number_string = LoadRoot(Heap::knumber_stringRootIndex);
+  Node* number_string = LoadRoot(RootIndex::knumber_string);
   GotoIf(WordEqual(hint, number_string), &hint_is_number);
-  Node* default_string = LoadRoot(Heap::kdefault_stringRootIndex);
+  Node* default_string = LoadRoot(RootIndex::kdefault_string);
   GotoIf(WordEqual(hint, default_string), &hint_is_string);
-  Node* string_string = LoadRoot(Heap::kstring_stringRootIndex);
+  Node* string_string = LoadRoot(RootIndex::kstring_string);
   GotoIf(WordEqual(hint, string_string), &hint_is_string);
 
   // Slow-case with actual string comparisons.
diff --git a/deps/v8/src/builtins/builtins-date.cc b/deps/v8/src/builtins/builtins-date.cc
index 569a5807e2..91da4d6d7d 100644
--- a/deps/v8/src/builtins/builtins-date.cc
+++ b/deps/v8/src/builtins/builtins-date.cc
@@ -10,6 +10,10 @@
 #include "src/counters.h"
 #include "src/dateparser-inl.h"
 #include "src/objects-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/intl-objects.h"
+#include "src/objects/js-date-time-format.h"
+#endif
 
 namespace v8 {
 namespace internal {
@@ -835,6 +839,65 @@ BUILTIN(DatePrototypeToTimeString) {
       isolate, isolate->factory()->NewStringFromUtf8(CStrVector(buffer)));
 }
 
+#ifdef V8_INTL_SUPPORT
+// ecma402 #sup-date.prototype.tolocaledatestring
+BUILTIN(DatePrototypeToLocaleDateString) {
+  HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kDateToLocaleDateString);
+
+  CHECK_RECEIVER(JSDate, date, "Date.prototype.toLocaleDateString");
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSDateTimeFormat::ToLocaleDateTime(
+                   isolate,
+                   date,                                     // date
+                   args.atOrUndefined(isolate, 1),           // locales
+                   args.atOrUndefined(isolate, 2),           // options
+                   JSDateTimeFormat::RequiredOption::kDate,  // required
+                   JSDateTimeFormat::DefaultsOption::kDate,  // defaults
+                   "dateformatdate"));                       // service
+}
+
+// ecma402 #sup-date.prototype.tolocalestring
+BUILTIN(DatePrototypeToLocaleString) {
+  HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kDateToLocaleString);
+
+  CHECK_RECEIVER(JSDate, date, "Date.prototype.toLocaleString");
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSDateTimeFormat::ToLocaleDateTime(
+                   isolate,
+                   date,                                    // date
+                   args.atOrUndefined(isolate, 1),          // locales
+                   args.atOrUndefined(isolate, 2),          // options
+                   JSDateTimeFormat::RequiredOption::kAny,  // required
+                   JSDateTimeFormat::DefaultsOption::kAll,  // defaults
+                   "dateformatall"));                       // service
+}
+
+// ecma402 #sup-date.prototype.tolocaletimestring
+BUILTIN(DatePrototypeToLocaleTimeString) {
+  HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kDateToLocaleTimeString);
+
+  CHECK_RECEIVER(JSDate, date, "Date.prototype.toLocaleTimeString");
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSDateTimeFormat::ToLocaleDateTime(
+                   isolate,
+                   date,                                     // date
+                   args.atOrUndefined(isolate, 1),           // locales
+                   args.atOrUndefined(isolate, 2),           // options
+                   JSDateTimeFormat::RequiredOption::kTime,  // required
+                   JSDateTimeFormat::DefaultsOption::kTime,  // defaults
+                   "dateformattime"));                       // service
+}
+#endif  // V8_INTL_SUPPORT
+
 // ES6 section 20.3.4.43 Date.prototype.toUTCString ( )
 BUILTIN(DatePrototypeToUTCString) {
   HandleScope scope(isolate);
diff --git a/deps/v8/src/builtins/builtins-definitions.h b/deps/v8/src/builtins/builtins-definitions.h
index 62765b802f..c47fa7b19b 100644
--- a/deps/v8/src/builtins/builtins-definitions.h
+++ b/deps/v8/src/builtins/builtins-definitions.h
@@ -5,7 +5,7 @@
 #ifndef V8_BUILTINS_BUILTINS_DEFINITIONS_H_
 #define V8_BUILTINS_BUILTINS_DEFINITIONS_H_
 
-#include "src/interpreter/bytecodes.h"
+#include "builtins-generated/bytecodes-builtins-list.h"
 
 // include generated header
 #include "torque-generated/builtin-definitions-from-dsl.h"
@@ -26,11 +26,13 @@ namespace internal {
 // TFH: Handlers in Turbofan, with CodeStub linkage.
 //      Args: name, interface descriptor
 // BCH: Bytecode Handlers, with bytecode dispatch linkage.
-//      Args: name
+//      Args: name, OperandScale, Bytecode
+// DLH: Deserialize Lazy Handlers, with bytecode dispatch linkage.
+//      Args: name, OperandScale
 // ASM: Builtin in platform-dependent assembly.
 //      Args: name
 
-#define BUILTIN_LIST_BASE(CPP, API, TFJ, TFC, TFS, TFH, ASM)                   \
+#define BUILTIN_LIST_BASE(CPP, API, TFJ, TFC, TFS, TFH, DLH, ASM)              \
   /* GC write barrirer */                                                      \
   TFC(RecordWrite, RecordWrite, 1)                                             \
                                                                                \
@@ -127,6 +129,10 @@ namespace internal {
   TFC(CompileLazy, JSTrampoline, 1)                                            \
   TFC(CompileLazyDeoptimizedCode, JSTrampoline, 1)                             \
   TFC(DeserializeLazy, JSTrampoline, 1)                                        \
+  /* The three lazy bytecode handlers do not declare a bytecode. */            \
+  DLH(DeserializeLazyHandler, interpreter::OperandScale::kSingle)              \
+  DLH(DeserializeLazyWideHandler, interpreter::OperandScale::kDouble)          \
+  DLH(DeserializeLazyExtraWideHandler, interpreter::OperandScale::kQuadruple)  \
   ASM(InstantiateAsmJs)                                                        \
   ASM(NotifyDeoptimized)                                                       \
                                                                                \
@@ -155,8 +161,6 @@ namespace internal {
   ASM(ContinueToJavaScriptBuiltin)                                             \
   ASM(ContinueToJavaScriptBuiltinWithResult)                                   \
                                                                                \
-  ASM(OnStackReplacement)                                                      \
-                                                                               \
   /* API callback handling */                                                  \
   API(HandleApiCall)                                                           \
   API(HandleApiCallAsFunction)                                                 \
@@ -204,7 +208,6 @@ namespace internal {
   TFC(ToBooleanLazyDeoptContinuation, TypeConversionStackParameter, 1)         \
                                                                                \
   /* Handlers */                                                               \
-  TFH(KeyedLoadIC_Megamorphic, LoadWithVector)                                 \
   TFH(KeyedLoadIC_PolymorphicName, LoadWithVector)                             \
   TFH(KeyedLoadIC_Slow, LoadWithVector)                                        \
   TFH(KeyedStoreIC_Megamorphic, StoreWithVector)                               \
@@ -319,12 +322,11 @@ namespace internal {
   TFJ(ArrayPrototypeShift, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
   /* ES6 #sec-array.prototype.slice */                                         \
   TFJ(ArrayPrototypeSlice, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
-  /* ES6 #sec-array.prototype.splice */                                        \
-  CPP(ArraySplice)                                                             \
   /* ES6 #sec-array.prototype.unshift */                                       \
   CPP(ArrayUnshift)                                                            \
   /* Support for Array.from and other array-copying idioms */                  \
   TFS(CloneFastJSArray, kSource)                                               \
+  TFS(CloneFastJSArrayFillingHoles, kSource)                                   \
   TFS(ExtractFastJSArray, kSource, kBegin, kCount)                             \
   /* ES6 #sec-array.prototype.every */                                         \
   TFS(ArrayEveryLoopContinuation, kReceiver, kCallbackFn, kThisArg, kArray,    \
@@ -427,12 +429,8 @@ namespace internal {
   /* AsyncFunction */                                                          \
   TFJ(AsyncFunctionAwaitCaught, 3, kReceiver, kGenerator, kAwaited,            \
       kOuterPromise)                                                           \
-  TFJ(AsyncFunctionAwaitCaughtOptimized, 3, kReceiver, kGenerator, kAwaited,   \
-      kOuterPromise)                                                           \
   TFJ(AsyncFunctionAwaitUncaught, 3, kReceiver, kGenerator, kAwaited,          \
       kOuterPromise)                                                           \
-  TFJ(AsyncFunctionAwaitUncaughtOptimized, 3, kReceiver, kGenerator, kAwaited, \
-      kOuterPromise)                                                           \
   TFJ(AsyncFunctionAwaitRejectClosure, 1, kReceiver, kSentError)               \
   TFJ(AsyncFunctionAwaitResolveClosure, 1, kReceiver, kSentValue)              \
   TFJ(AsyncFunctionPromiseCreate, 0, kReceiver)                                \
@@ -466,6 +464,7 @@ namespace internal {
   CPP(CallSitePrototypeGetScriptNameOrSourceURL)                               \
   CPP(CallSitePrototypeGetThis)                                                \
   CPP(CallSitePrototypeGetTypeName)                                            \
+  CPP(CallSitePrototypeIsAsync)                                                \
   CPP(CallSitePrototypeIsConstructor)                                          \
   CPP(CallSitePrototypeIsEval)                                                 \
   CPP(CallSitePrototypeIsNative)                                               \
@@ -493,6 +492,7 @@ namespace internal {
   CPP(ConsoleProfile)                                                          \
   CPP(ConsoleProfileEnd)                                                       \
   CPP(ConsoleTime)                                                             \
+  CPP(ConsoleTimeLog)                                                          \
   CPP(ConsoleTimeEnd)                                                          \
   CPP(ConsoleTimeStamp)                                                        \
   CPP(ConsoleContext)                                                          \
@@ -629,10 +629,14 @@ namespace internal {
                                                                                \
   /* ICs */                                                                    \
   TFH(LoadIC, LoadWithVector)                                                  \
+  TFH(LoadIC_Megamorphic, LoadWithVector)                                      \
   TFH(LoadIC_Noninlined, LoadWithVector)                                       \
   TFH(LoadICTrampoline, Load)                                                  \
+  TFH(LoadICTrampoline_Megamorphic, Load)                                      \
   TFH(KeyedLoadIC, LoadWithVector)                                             \
+  TFH(KeyedLoadIC_Megamorphic, LoadWithVector)                                 \
   TFH(KeyedLoadICTrampoline, Load)                                             \
+  TFH(KeyedLoadICTrampoline_Megamorphic, Load)                                 \
   TFH(StoreGlobalIC, StoreGlobalWithVector)                                    \
   TFH(StoreGlobalICTrampoline, StoreGlobal)                                    \
   TFH(StoreIC, StoreWithVector)                                                \
@@ -645,6 +649,13 @@ namespace internal {
   TFH(LoadGlobalICTrampoline, LoadGlobal)                                      \
   TFH(LoadGlobalICInsideTypeofTrampoline, LoadGlobal)                          \
   TFH(CloneObjectIC, CloneObjectWithVector)                                    \
+  TFH(CloneObjectIC_Slow, CloneObjectWithVector)                               \
+                                                                               \
+  /* IterableToList */                                                         \
+  /* ES #sec-iterabletolist */                                                 \
+  TFS(IterableToList, kIterable, kIteratorFn)                                  \
+  TFS(IterableToListWithSymbolLookup, kIterable)                               \
+  TFS(IterableToListMayPreserveHoles, kIterable, kIteratorFn)                  \
                                                                                \
   /* Map */                                                                    \
   TFS(FindOrderedHashMapEntry, kTable, kKey)                                   \
@@ -1013,6 +1024,7 @@ namespace internal {
   TFJ(AtomicsAnd, 3, kReceiver, kArray, kIndex, kValue)                        \
   TFJ(AtomicsOr, 3, kReceiver, kArray, kIndex, kValue)                         \
   TFJ(AtomicsXor, 3, kReceiver, kArray, kIndex, kValue)                        \
+  CPP(AtomicsNotify)                                                           \
   CPP(AtomicsIsLockFree)                                                       \
   CPP(AtomicsWait)                                                             \
   CPP(AtomicsWake)                                                             \
@@ -1111,6 +1123,7 @@ namespace internal {
   /* StringIterator */                                                         \
   /* ES6 #sec-%stringiteratorprototype%.next */                                \
   TFJ(StringIteratorPrototypeNext, 0, kReceiver)                               \
+  TFS(StringToList, kSource)                                                   \
                                                                                \
   /* Symbol */                                                                 \
   /* ES #sec-symbol-constructor */                                             \
@@ -1129,7 +1142,6 @@ namespace internal {
   TFJ(SymbolPrototypeValueOf, 0, kReceiver)                                    \
                                                                                \
   /* TypedArray */                                                             \
-  TFS(IterableToList, kIterable, kIteratorFn)                                  \
   TFS(TypedArrayInitialize, kHolder, kLength, kElementSize, kInitialize,       \
       kBufferConstructor)                                                      \
   TFS(TypedArrayInitializeWithBuffer, kHolder, kLength, kBuffer, kElementSize, \
@@ -1208,11 +1220,11 @@ namespace internal {
   /* Wasm */                                                                   \
   ASM(WasmCompileLazy)                                                         \
   TFC(WasmAllocateHeapNumber, AllocateHeapNumber, 1)                           \
-  TFC(WasmArgumentsAdaptor, ArgumentAdaptor, 1)                                \
   TFC(WasmCallJavaScript, CallTrampoline, 1)                                   \
   TFC(WasmGrowMemory, WasmGrowMemory, 1)                                       \
   TFC(WasmStackGuard, NoContext, 1)                                            \
   TFC(WasmToNumber, TypeConversion, 1)                                         \
+  TFC(WasmThrow, WasmThrow, 1)                                                 \
   TFS(ThrowWasmTrapUnreachable)                                                \
   TFS(ThrowWasmTrapMemOutOfBounds)                                             \
   TFS(ThrowWasmTrapUnalignedAccess)                                            \
@@ -1282,13 +1294,10 @@ namespace internal {
   /* See tc39.github.io/proposal-async-iteration/ */                           \
   /* #sec-%asyncfromsynciteratorprototype%-object) */                          \
   TFJ(AsyncFromSyncIteratorPrototypeNext, 1, kReceiver, kValue)                \
-  TFJ(AsyncFromSyncIteratorPrototypeNextOptimized, 1, kReceiver, kValue)       \
   /* #sec-%asyncfromsynciteratorprototype%.throw */                            \
   TFJ(AsyncFromSyncIteratorPrototypeThrow, 1, kReceiver, kReason)              \
-  TFJ(AsyncFromSyncIteratorPrototypeThrowOptimized, 1, kReceiver, kReason)     \
   /* #sec-%asyncfromsynciteratorprototype%.return */                           \
   TFJ(AsyncFromSyncIteratorPrototypeReturn, 1, kReceiver, kValue)              \
-  TFJ(AsyncFromSyncIteratorPrototypeReturnOptimized, 1, kReceiver, kValue)     \
   /* #sec-async-iterator-value-unwrap-functions */                             \
   TFJ(AsyncIteratorValueUnwrap, 1, kReceiver, kValue)                          \
                                                                                \
@@ -1305,10 +1314,9 @@ namespace internal {
   ASM(CEntry_Return2_SaveFPRegs_ArgvOnStack_BuiltinExit)                       \
                                                                                \
   /* String helpers */                                                         \
-  TFS(StringAdd_CheckNone_NotTenured, kLeft, kRight)                           \
-  TFS(StringAdd_CheckNone_Tenured, kLeft, kRight)                              \
-  TFS(StringAdd_ConvertLeft_NotTenured, kLeft, kRight)                         \
-  TFS(StringAdd_ConvertRight_NotTenured, kLeft, kRight)                        \
+  TFS(StringAdd_CheckNone, kLeft, kRight)                                      \
+  TFS(StringAdd_ConvertLeft, kLeft, kRight)                                    \
+  TFS(StringAdd_ConvertRight, kLeft, kRight)                                   \
   TFS(SubString, kString, kFrom, kTo)                                          \
                                                                                \
   /* Miscellaneous */                                                          \
@@ -1328,73 +1336,119 @@ namespace internal {
 #define BUILTIN_LIST_INTL(CPP, TFJ, TFS)                               \
   /* ecma402 #sec-intl.collator */                                     \
   CPP(CollatorConstructor)                                             \
-  TFS(StringToLowerCaseIntl, kString)                                  \
-  /* ES #sec-string.prototype.tolowercase */                           \
-  TFJ(StringPrototypeToLowerCaseIntl, 0, kReceiver)                    \
-  /* ES #sec-string.prototype.touppercase */                           \
-  CPP(StringPrototypeToUpperCaseIntl)                                  \
-  /* ES #sec-string.prototype.normalize */                             \
-  CPP(StringPrototypeNormalizeIntl)                                    \
-  /* ecma402 #sec-intl.numberformat.prototype.formattoparts */         \
-  CPP(NumberFormatPrototypeFormatToParts)                              \
+  /* ecma 402 #sec-collator-compare-functions*/                        \
+  CPP(CollatorInternalCompare)                                         \
+  /* ecma402 #sec-intl.collator.prototype.compare */                   \
+  CPP(CollatorPrototypeCompare)                                        \
+  /* ecma402 #sec-intl.collator.supportedlocalesof */                  \
+  CPP(CollatorSupportedLocalesOf)                                      \
+  CPP(CollatorPrototypeResolvedOptions)                                \
+  /* ecma402 #sup-date.prototype.tolocaledatestring */                 \
+  CPP(DatePrototypeToLocaleDateString)                                 \
+  /* ecma402 #sup-date.prototype.tolocalestring */                     \
+  CPP(DatePrototypeToLocaleString)                                     \
+  /* ecma402 #sup-date.prototype.tolocaletimestring */                 \
+  CPP(DatePrototypeToLocaleTimeString)                                 \
+  /* ecma402 #sec-intl.datetimeformat */                               \
+  CPP(DateTimeFormatConstructor)                                       \
+  /* ecma402 #sec-datetime-format-functions */                         \
+  CPP(DateTimeFormatInternalFormat)                                    \
+  /* ecma402 #sec-intl.datetimeformat.prototype.format */              \
+  CPP(DateTimeFormatPrototypeFormat)                                   \
   /* ecma402 #sec-intl.datetimeformat.prototype.formattoparts */       \
   CPP(DateTimeFormatPrototypeFormatToParts)                            \
-  /* ecma402 #new proposal */                                          \
+  /* ecma402 #sec-intl.datetimeformat.prototype.resolvedoptions */     \
+  CPP(DateTimeFormatPrototypeResolvedOptions)                          \
+  /* ecma402 #sec-intl.datetimeformat.supportedlocalesof */            \
+  CPP(DateTimeFormatSupportedLocalesOf)                                \
   /* ecma402 #sec-intl-listformat-constructor */                       \
   CPP(ListFormatConstructor)                                           \
-  /* ecma402 #sec-intl.listformat.prototype.resolvedoptions */         \
-  CPP(ListFormatPrototypeResolvedOptions)                              \
   /* ecma402 #sec-intl-list-format.prototype.format */                 \
   TFJ(ListFormatPrototypeFormat,                                       \
       SharedFunctionInfo::kDontAdaptArgumentsSentinel)                 \
   /* ecma402 #sec-intl-list-format.prototype.formattoparts */          \
   TFJ(ListFormatPrototypeFormatToParts,                                \
       SharedFunctionInfo::kDontAdaptArgumentsSentinel)                 \
+  /* ecma402 #sec-intl.listformat.prototype.resolvedoptions */         \
+  CPP(ListFormatPrototypeResolvedOptions)                              \
+  /* ecma402 #sec-intl.ListFormat.supportedlocalesof */                \
+  CPP(ListFormatSupportedLocalesOf)                                    \
   /* ecma402 #sec-intl-locale-constructor */                           \
   CPP(LocaleConstructor)                                               \
-  CPP(LocalePrototypeLanguage)                                         \
-  CPP(LocalePrototypeScript)                                           \
-  CPP(LocalePrototypeRegion)                                           \
   CPP(LocalePrototypeBaseName)                                         \
   CPP(LocalePrototypeCalendar)                                         \
   CPP(LocalePrototypeCaseFirst)                                        \
   CPP(LocalePrototypeCollation)                                        \
   CPP(LocalePrototypeHourCycle)                                        \
-  CPP(LocalePrototypeNumeric)                                          \
-  CPP(LocalePrototypeNumberingSystem)                                  \
-  CPP(LocalePrototypeToString)                                         \
+  CPP(LocalePrototypeLanguage)                                         \
   /* ecma402 #sec-Intl.Locale.prototype.maximize */                    \
   CPP(LocalePrototypeMaximize)                                         \
   /* ecma402 #sec-Intl.Locale.prototype.minimize */                    \
   CPP(LocalePrototypeMinimize)                                         \
+  CPP(LocalePrototypeNumeric)                                          \
+  CPP(LocalePrototypeNumberingSystem)                                  \
+  CPP(LocalePrototypeRegion)                                           \
+  CPP(LocalePrototypeScript)                                           \
+  CPP(LocalePrototypeToString)                                         \
+  /* ecma402 #sec-intl.numberformat */                                 \
+  CPP(NumberFormatConstructor)                                         \
   /* ecma402 #sec-number-format-functions */                           \
   CPP(NumberFormatInternalFormatNumber)                                \
   /* ecma402 #sec-intl.numberformat.prototype.format */                \
   CPP(NumberFormatPrototypeFormatNumber)                               \
-  /* ecma402 #sec-datetime-format-functions */                         \
-  CPP(DateTimeFormatInternalFormat)                                    \
-  /* ecma402 #sec-intl.datetimeformat.prototype.format */              \
-  CPP(DateTimeFormatPrototypeFormat)                                   \
+  /* ecma402 #sec-intl.numberformat.prototype.formattoparts */         \
+  CPP(NumberFormatPrototypeFormatToParts)                              \
+  /* ecma402 #sec-intl.numberformat.prototype.resolvedoptions */       \
+  CPP(NumberFormatPrototypeResolvedOptions)                            \
+  /* ecma402 #sec-intl.numberformat.supportedlocalesof */              \
+  CPP(NumberFormatSupportedLocalesOf)                                  \
   /* ecma402 #sec-intl.pluralrules */                                  \
   CPP(PluralRulesConstructor)                                          \
+  CPP(PluralRulesPrototypeResolvedOptions)                             \
+  /* ecma402 #sec-intl.pluralrules.prototype.select */                 \
+  CPP(PluralRulesPrototypeSelect)                                      \
+  /* ecma402 #sec-intl.pluralrules.supportedlocalesof */               \
+  CPP(PluralRulesSupportedLocalesOf)                                   \
   /* ecma402 #sec-intl.RelativeTimeFormat.constructor */               \
   CPP(RelativeTimeFormatConstructor)                                   \
-  /* ecma402 #sec-intl.RelativeTimeFormat.prototype.resolvedOptions */ \
-  CPP(RelativeTimeFormatPrototypeResolvedOptions)                      \
   /* ecma402 #sec-intl.RelativeTimeFormat.prototype.format */          \
   CPP(RelativeTimeFormatPrototypeFormat)                               \
   /* ecma402 #sec-intl.RelativeTimeFormat.prototype.formatToParts */   \
   CPP(RelativeTimeFormatPrototypeFormatToParts)                        \
+  /* ecma402 #sec-intl.RelativeTimeFormat.prototype.resolvedOptions */ \
+  CPP(RelativeTimeFormatPrototypeResolvedOptions)                      \
+  /* ecma402 #sec-intl.RelativeTimeFormat.supportedlocalesof */        \
+  CPP(RelativeTimeFormatSupportedLocalesOf)                            \
+  /* ES #sec-string.prototype.normalize */                             \
+  CPP(StringPrototypeNormalizeIntl)                                    \
   /* ecma402 #sup-string.prototype.tolocalelowercase */                \
   CPP(StringPrototypeToLocaleLowerCase)                                \
   /* ecma402 #sup-string.prototype.tolocaleuppercase */                \
   CPP(StringPrototypeToLocaleUpperCase)                                \
-  /* ecma402 #sec-intl.collator.prototype.compare */                   \
-  CPP(CollatorPrototypeCompare)                                        \
-  /* ecma 402 #sec-collator-compare-functions*/                        \
-  CPP(CollatorInternalCompare)                                         \
-  CPP(BreakIteratorInternalAdoptText)                                  \
-  CPP(BreakIteratorPrototypeAdoptText)
+  /* ES #sec-string.prototype.tolowercase */                           \
+  TFJ(StringPrototypeToLowerCaseIntl, 0, kReceiver)                    \
+  /* ES #sec-string.prototype.touppercase */                           \
+  CPP(StringPrototypeToUpperCaseIntl)                                  \
+  TFS(StringToLowerCaseIntl, kString)                                  \
+  /* ecma402 #sec-Intl.Segmenter */                                    \
+  CPP(SegmenterConstructor)                                            \
+  /* ecma402 #sec-Intl.Segmenter.prototype.resolvedOptions */          \
+  CPP(SegmenterPrototypeResolvedOptions)                               \
+  /* ecma402  #sec-Intl.Segmenter.supportedLocalesOf */                \
+  CPP(SegmenterSupportedLocalesOf)                                     \
+  CPP(V8BreakIteratorConstructor)                                      \
+  CPP(V8BreakIteratorInternalAdoptText)                                \
+  CPP(V8BreakIteratorInternalBreakType)                                \
+  CPP(V8BreakIteratorInternalCurrent)                                  \
+  CPP(V8BreakIteratorInternalFirst)                                    \
+  CPP(V8BreakIteratorInternalNext)                                     \
+  CPP(V8BreakIteratorPrototypeAdoptText)                               \
+  CPP(V8BreakIteratorPrototypeBreakType)                               \
+  CPP(V8BreakIteratorPrototypeCurrent)                                 \
+  CPP(V8BreakIteratorPrototypeFirst)                                   \
+  CPP(V8BreakIteratorPrototypeNext)                                    \
+  CPP(V8BreakIteratorPrototypeResolvedOptions)                         \
+  CPP(V8BreakIteratorSupportedLocalesOf)
 #else
 #define BUILTIN_LIST_INTL(CPP, TFJ, TFS)      \
   /* no-op fallback version */                \
@@ -1409,16 +1463,10 @@ namespace internal {
   CPP(StringPrototypeToUpperCase)
 #endif  // V8_INTL_SUPPORT
 
-#ifdef V8_EMBEDDED_BYTECODE_HANDLERS
-#define BUILTIN_LIST_BYTECODE_HANDLERS(BCH) BYTECODE_LIST(BCH)
-#else
-#define BUILTIN_LIST_BYTECODE_HANDLERS(BCH)
-#endif  // V8_EMBEDDED_BYTECODE_HANDLERS
-
-#define BUILTIN_LIST(CPP, API, TFJ, TFC, TFS, TFH, BCH, ASM) \
-  BUILTIN_LIST_BASE(CPP, API, TFJ, TFC, TFS, TFH, ASM)       \
-  BUILTIN_LIST_FROM_DSL(CPP, API, TFJ, TFC, TFS, TFH, ASM)   \
-  BUILTIN_LIST_INTL(CPP, TFJ, TFS)                           \
+#define BUILTIN_LIST(CPP, API, TFJ, TFC, TFS, TFH, BCH, DLH, ASM) \
+  BUILTIN_LIST_BASE(CPP, API, TFJ, TFC, TFS, TFH, DLH, ASM)       \
+  BUILTIN_LIST_FROM_DSL(CPP, API, TFJ, TFC, TFS, TFH, ASM)        \
+  BUILTIN_LIST_INTL(CPP, TFJ, TFS)                                \
   BUILTIN_LIST_BYTECODE_HANDLERS(BCH)
 
 // The exception thrown in the following builtins are caught
@@ -1426,14 +1474,9 @@ namespace internal {
 #define BUILTIN_PROMISE_REJECTION_PREDICTION_LIST(V) \
   V(AsyncFromSyncIteratorPrototypeNext)              \
   V(AsyncFromSyncIteratorPrototypeReturn)            \
-  V(AsyncFromSyncIteratorPrototypeNextOptimized)     \
-  V(AsyncFromSyncIteratorPrototypeThrowOptimized)    \
-  V(AsyncFromSyncIteratorPrototypeReturnOptimized)   \
   V(AsyncFromSyncIteratorPrototypeThrow)             \
   V(AsyncFunctionAwaitCaught)                        \
-  V(AsyncFunctionAwaitCaughtOptimized)               \
   V(AsyncFunctionAwaitUncaught)                      \
-  V(AsyncFunctionAwaitUncaughtOptimized)             \
   V(AsyncGeneratorResolve)                           \
   V(AsyncGeneratorAwaitCaught)                       \
   V(AsyncGeneratorAwaitUncaught)                     \
@@ -1449,11 +1492,11 @@ namespace internal {
 #define WASM_RUNTIME_STUB_LIST(V, VTRAP) \
   FOREACH_WASM_TRAPREASON(VTRAP)         \
   V(WasmAllocateHeapNumber)              \
-  V(WasmArgumentsAdaptor)                \
   V(WasmCallJavaScript)                  \
   V(WasmGrowMemory)                      \
   V(WasmStackGuard)                      \
   V(WasmToNumber)                        \
+  V(WasmThrow)                           \
   V(DoubleToI)
 
 // The exception thrown in the following builtins are caught internally and will
@@ -1464,23 +1507,27 @@ namespace internal {
 
 #define BUILTIN_LIST_C(V)                                            \
   BUILTIN_LIST(V, V, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, \
-               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN)
+               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN)
 
 #define BUILTIN_LIST_A(V)                                                      \
   BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, \
-               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, V)
+               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, \
+               V)
 
 #define BUILTIN_LIST_TFS(V)                                                    \
   BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, \
-               V, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN)
+               V, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN,              \
+               IGNORE_BUILTIN)
 
-#define BUILTIN_LIST_TFJ(V)                                       \
-  BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, V, IGNORE_BUILTIN, \
-               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN)
+#define BUILTIN_LIST_TFJ(V)                                                    \
+  BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, V, IGNORE_BUILTIN,              \
+               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, \
+               IGNORE_BUILTIN)
 
-#define BUILTIN_LIST_TFC(V)                                       \
-  BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, V, \
-               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN)
+#define BUILTIN_LIST_TFC(V)                                                    \
+  BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, V,              \
+               IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, \
+               IGNORE_BUILTIN)
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/builtins/builtins-descriptors.h b/deps/v8/src/builtins/builtins-descriptors.h
index 97b85bc295..2961a61f63 100644
--- a/deps/v8/src/builtins/builtins-descriptors.h
+++ b/deps/v8/src/builtins/builtins-descriptors.h
@@ -43,7 +43,8 @@ namespace internal {
 
 BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, DEFINE_TFJ_INTERFACE_DESCRIPTOR,
              DEFINE_TFC_INTERFACE_DESCRIPTOR, DEFINE_TFS_INTERFACE_DESCRIPTOR,
-             DEFINE_TFH_INTERFACE_DESCRIPTOR, IGNORE_BUILTIN, IGNORE_BUILTIN)
+             DEFINE_TFH_INTERFACE_DESCRIPTOR, IGNORE_BUILTIN, IGNORE_BUILTIN,
+             IGNORE_BUILTIN)
 
 #undef DEFINE_TFJ_INTERFACE_DESCRIPTOR
 #undef DEFINE_TFC_INTERFACE_DESCRIPTOR
diff --git a/deps/v8/src/builtins/builtins-function-gen.cc b/deps/v8/src/builtins/builtins-function-gen.cc
index eb4ace31e4..2f3c876852 100644
--- a/deps/v8/src/builtins/builtins-function-gen.cc
+++ b/deps/v8/src/builtins/builtins-function-gen.cc
@@ -62,7 +62,7 @@ TF_BUILTIN(FastFunctionPrototypeBind, CodeStubAssembler) {
     const int length_index = JSFunction::kLengthDescriptorIndex;
     TNode<Name> maybe_length = CAST(LoadWeakFixedArrayElement(
         descriptors, DescriptorArray::ToKeyIndex(length_index)));
-    GotoIf(WordNotEqual(maybe_length, LoadRoot(Heap::klength_stringRootIndex)),
+    GotoIf(WordNotEqual(maybe_length, LoadRoot(RootIndex::klength_string)),
            &slow);
 
     TNode<Object> maybe_length_accessor = CAST(LoadWeakFixedArrayElement(
@@ -74,8 +74,7 @@ TF_BUILTIN(FastFunctionPrototypeBind, CodeStubAssembler) {
     const int name_index = JSFunction::kNameDescriptorIndex;
     TNode<Name> maybe_name = CAST(LoadWeakFixedArrayElement(
         descriptors, DescriptorArray::ToKeyIndex(name_index)));
-    GotoIf(WordNotEqual(maybe_name, LoadRoot(Heap::kname_stringRootIndex)),
-           &slow);
+    GotoIf(WordNotEqual(maybe_name, LoadRoot(RootIndex::kname_string)), &slow);
 
     TNode<Object> maybe_name_accessor = CAST(LoadWeakFixedArrayElement(
         descriptors, DescriptorArray::ToValueIndex(name_index)));
diff --git a/deps/v8/src/builtins/builtins-function.cc b/deps/v8/src/builtins/builtins-function.cc
index c97bd8a587..43a3853715 100644
--- a/deps/v8/src/builtins/builtins-function.cc
+++ b/deps/v8/src/builtins/builtins-function.cc
@@ -41,11 +41,7 @@ MaybeHandle<Object> CreateDynamicFunction(Isolate* isolate,
     IncrementalStringBuilder builder(isolate);
     builder.AppendCharacter('(');
     builder.AppendCString(token);
-    if (FLAG_harmony_function_tostring) {
-      builder.AppendCString(" anonymous(");
-    } else {
-      builder.AppendCharacter('(');
-    }
+    builder.AppendCString(" anonymous(");
     bool parenthesis_in_arg_string = false;
     if (argc > 1) {
       for (int i = 1; i < argc; ++i) {
@@ -55,31 +51,10 @@ MaybeHandle<Object> CreateDynamicFunction(Isolate* isolate,
             isolate, param, Object::ToString(isolate, args.at(i)), Object);
         param = String::Flatten(isolate, param);
         builder.AppendString(param);
-        if (!FLAG_harmony_function_tostring) {
-          // If the formal parameters string include ) - an illegal
-          // character - it may make the combined function expression
-          // compile. We avoid this problem by checking for this early on.
-          DisallowHeapAllocation no_gc;  // Ensure vectors stay valid.
-          String::FlatContent param_content = param->GetFlatContent();
-          for (int i = 0, length = param->length(); i < length; ++i) {
-            if (param_content.Get(i) == ')') {
-              parenthesis_in_arg_string = true;
-              break;
-            }
-          }
-        }
       }
-      if (!FLAG_harmony_function_tostring) {
-        // If the formal parameters include an unbalanced block comment, the
-        // function must be rejected. Since JavaScript does not allow nested
-        // comments we can include a trailing block comment to catch this.
-        builder.AppendCString("\n/*``*/");
-      }
-    }
-    if (FLAG_harmony_function_tostring) {
-      builder.AppendCharacter('\n');
-      parameters_end_pos = builder.Length();
     }
+    builder.AppendCharacter('\n');
+    parameters_end_pos = builder.Length();
     builder.AppendCString(") {\n");
     if (argc > 0) {
       Handle<String> body;
@@ -303,7 +278,7 @@ BUILTIN(FunctionPrototypeToString) {
   }
   // With the revised toString behavior, all callable objects are valid
   // receivers for this method.
-  if (FLAG_harmony_function_tostring && receiver->IsJSReceiver() &&
+  if (receiver->IsJSReceiver() &&
       JSReceiver::cast(*receiver)->map()->is_callable()) {
     return ReadOnlyRoots(isolate).function_native_code_string();
   }
diff --git a/deps/v8/src/builtins/builtins-handler-gen.cc b/deps/v8/src/builtins/builtins-handler-gen.cc
index 29422ab72c..8b5dc182cf 100644
--- a/deps/v8/src/builtins/builtins-handler-gen.cc
+++ b/deps/v8/src/builtins/builtins-handler-gen.cc
@@ -28,7 +28,7 @@ TF_BUILTIN(KeyedLoadIC_Slow, CodeStubAssembler) {
   Node* name = Parameter(Descriptor::kName);
   Node* context = Parameter(Descriptor::kContext);
 
-  TailCallRuntime(Runtime::kKeyedGetProperty, context, receiver, name);
+  TailCallRuntime(Runtime::kGetProperty, context, receiver, name);
 }
 
 void Builtins::Generate_KeyedStoreIC_Megamorphic(
diff --git a/deps/v8/src/builtins/builtins-ic-gen.cc b/deps/v8/src/builtins/builtins-ic-gen.cc
index bbfabc7a0d..94d75a8f32 100644
--- a/deps/v8/src/builtins/builtins-ic-gen.cc
+++ b/deps/v8/src/builtins/builtins-ic-gen.cc
@@ -21,13 +21,16 @@ namespace internal {
   }
 
 IC_BUILTIN(LoadIC)
+IC_BUILTIN(LoadIC_Megamorphic)
 IC_BUILTIN(LoadIC_Noninlined)
 IC_BUILTIN(LoadIC_Uninitialized)
-IC_BUILTIN(KeyedLoadIC)
 IC_BUILTIN(LoadICTrampoline)
-IC_BUILTIN(KeyedLoadICTrampoline)
+IC_BUILTIN(LoadICTrampoline_Megamorphic)
+IC_BUILTIN(KeyedLoadIC)
 IC_BUILTIN(KeyedLoadIC_Megamorphic)
 IC_BUILTIN(KeyedLoadIC_PolymorphicName)
+IC_BUILTIN(KeyedLoadICTrampoline)
+IC_BUILTIN(KeyedLoadICTrampoline_Megamorphic)
 IC_BUILTIN(StoreGlobalIC)
 IC_BUILTIN(StoreGlobalICTrampoline)
 IC_BUILTIN(StoreIC)
@@ -36,6 +39,7 @@ IC_BUILTIN(KeyedStoreIC)
 IC_BUILTIN(KeyedStoreICTrampoline)
 IC_BUILTIN(StoreInArrayLiteralIC)
 IC_BUILTIN(CloneObjectIC)
+IC_BUILTIN(CloneObjectIC_Slow)
 
 IC_BUILTIN_PARAM(LoadGlobalIC, LoadGlobalIC, NOT_INSIDE_TYPEOF)
 IC_BUILTIN_PARAM(LoadGlobalICInsideTypeof, LoadGlobalIC, INSIDE_TYPEOF)
diff --git a/deps/v8/src/builtins/builtins-internal-gen.cc b/deps/v8/src/builtins/builtins-internal-gen.cc
index 7ff88c5a53..44a18099bf 100644
--- a/deps/v8/src/builtins/builtins-internal-gen.cc
+++ b/deps/v8/src/builtins/builtins-internal-gen.cc
@@ -24,10 +24,16 @@ using TNode = compiler::TNode<T>;
 // Interrupt and stack checks.
 
 void Builtins::Generate_InterruptCheck(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   masm->TailCallRuntime(Runtime::kInterrupt);
 }
 
 void Builtins::Generate_StackCheck(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   masm->TailCallRuntime(Runtime::kStackGuard);
 }
 
@@ -350,18 +356,11 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
 };
 
 TF_BUILTIN(RecordWrite, RecordWriteCodeStubAssembler) {
-  Node* object = BitcastTaggedToWord(Parameter(Descriptor::kObject));
-  Node* slot = Parameter(Descriptor::kSlot);
-  Node* isolate = Parameter(Descriptor::kIsolate);
-  Node* remembered_set = Parameter(Descriptor::kRememberedSet);
-  Node* fp_mode = Parameter(Descriptor::kFPMode);
-
-  Node* value = Load(MachineType::Pointer(), slot);
-
   Label generational_wb(this);
   Label incremental_wb(this);
   Label exit(this);
 
+  Node* remembered_set = Parameter(Descriptor::kRememberedSet);
   Branch(ShouldEmitRememberSet(remembered_set), &generational_wb,
          &incremental_wb);
 
@@ -369,40 +368,58 @@ TF_BUILTIN(RecordWrite, RecordWriteCodeStubAssembler) {
   {
     Label test_old_to_new_flags(this);
     Label store_buffer_exit(this), store_buffer_incremental_wb(this);
+
     // When incremental marking is not on, we skip cross generation pointer
     // checking here, because there are checks for
     // `kPointersFromHereAreInterestingMask` and
     // `kPointersToHereAreInterestingMask` in
     // `src/compiler/<arch>/code-generator-<arch>.cc` before calling this stub,
     // which serves as the cross generation checking.
+    Node* slot = Parameter(Descriptor::kSlot);
     Branch(IsMarking(), &test_old_to_new_flags, &store_buffer_exit);
 
     BIND(&test_old_to_new_flags);
     {
+      Node* value = Load(MachineType::Pointer(), slot);
+
       // TODO(albertnetymk): Try to cache the page flag for value and object,
       // instead of calling IsPageFlagSet each time.
       Node* value_in_new_space =
           IsPageFlagSet(value, MemoryChunk::kIsInNewSpaceMask);
       GotoIfNot(value_in_new_space, &incremental_wb);
 
+      Node* object = BitcastTaggedToWord(Parameter(Descriptor::kObject));
       Node* object_in_new_space =
           IsPageFlagSet(object, MemoryChunk::kIsInNewSpaceMask);
-      GotoIf(object_in_new_space, &incremental_wb);
-
-      Goto(&store_buffer_incremental_wb);
+      Branch(object_in_new_space, &incremental_wb,
+             &store_buffer_incremental_wb);
     }
 
     BIND(&store_buffer_exit);
-    { InsertToStoreBufferAndGoto(isolate, slot, fp_mode, &exit); }
+    {
+      Node* isolate_constant =
+          ExternalConstant(ExternalReference::isolate_address(isolate()));
+      Node* fp_mode = Parameter(Descriptor::kFPMode);
+      InsertToStoreBufferAndGoto(isolate_constant, slot, fp_mode, &exit);
+    }
 
     BIND(&store_buffer_incremental_wb);
-    { InsertToStoreBufferAndGoto(isolate, slot, fp_mode, &incremental_wb); }
+    {
+      Node* isolate_constant =
+          ExternalConstant(ExternalReference::isolate_address(isolate()));
+      Node* fp_mode = Parameter(Descriptor::kFPMode);
+      InsertToStoreBufferAndGoto(isolate_constant, slot, fp_mode,
+                                 &incremental_wb);
+    }
   }
 
   BIND(&incremental_wb);
   {
     Label call_incremental_wb(this);
 
+    Node* slot = Parameter(Descriptor::kSlot);
+    Node* value = Load(MachineType::Pointer(), slot);
+
     // There are two cases we need to call incremental write barrier.
     // 1) value_is_white
     GotoIf(IsWhite(value), &call_incremental_wb);
@@ -411,20 +428,23 @@ TF_BUILTIN(RecordWrite, RecordWriteCodeStubAssembler) {
     // is_compacting = true when is_marking = true
     GotoIfNot(IsPageFlagSet(value, MemoryChunk::kEvacuationCandidateMask),
               &exit);
-    GotoIf(
-        IsPageFlagSet(object, MemoryChunk::kSkipEvacuationSlotsRecordingMask),
-        &exit);
 
-    Goto(&call_incremental_wb);
+    Node* object = BitcastTaggedToWord(Parameter(Descriptor::kObject));
+    Branch(
+        IsPageFlagSet(object, MemoryChunk::kSkipEvacuationSlotsRecordingMask),
+        &exit, &call_incremental_wb);
 
     BIND(&call_incremental_wb);
     {
       Node* function = ExternalConstant(
           ExternalReference::incremental_marking_record_write_function());
+      Node* isolate_constant =
+          ExternalConstant(ExternalReference::isolate_address(isolate()));
+      Node* fp_mode = Parameter(Descriptor::kFPMode);
       CallCFunction3WithCallerSavedRegistersMode(
           MachineType::Int32(), MachineType::Pointer(), MachineType::Pointer(),
-          MachineType::Pointer(), function, object, slot, isolate, fp_mode,
-          &exit);
+          MachineType::Pointer(), function, object, slot, isolate_constant,
+          fp_mode, &exit);
     }
   }
 
@@ -454,7 +474,7 @@ class DeletePropertyBaseAssembler : public AccessorAssembler {
            dont_delete);
     // Overwrite the entry itself (see NameDictionary::SetEntry).
     TNode<HeapObject> filler = TheHoleConstant();
-    DCHECK(Heap::RootIsImmortalImmovable(Heap::kTheHoleValueRootIndex));
+    DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kTheHoleValue));
     StoreFixedArrayElement(properties, key_index, filler, SKIP_WRITE_BARRIER);
     StoreValueByKeyIndex<NameDictionary>(properties, key_index, filler,
                                          SKIP_WRITE_BARRIER);
@@ -609,11 +629,14 @@ class InternalBuiltinsAssembler : public CodeStubAssembler {
   explicit InternalBuiltinsAssembler(compiler::CodeAssemblerState* state)
       : CodeStubAssembler(state) {}
 
-  TNode<IntPtrT> GetPendingMicrotaskCount();
-  void SetPendingMicrotaskCount(TNode<IntPtrT> count);
-
-  TNode<FixedArray> GetMicrotaskQueue();
-  void SetMicrotaskQueue(TNode<FixedArray> queue);
+  TNode<MicrotaskQueue> GetDefaultMicrotaskQueue();
+  TNode<IntPtrT> GetPendingMicrotaskCount(
+      TNode<MicrotaskQueue> microtask_queue);
+  void SetPendingMicrotaskCount(TNode<MicrotaskQueue> microtask_queue,
+                                TNode<IntPtrT> new_num_tasks);
+  TNode<FixedArray> GetQueuedMicrotasks(TNode<MicrotaskQueue> microtask_queue);
+  void SetQueuedMicrotasks(TNode<MicrotaskQueue> microtask_queue,
+                           TNode<FixedArray> new_queue);
 
   TNode<Context> GetCurrentContext();
   void SetCurrentContext(TNode<Context> context);
@@ -700,37 +723,34 @@ TF_BUILTIN(AdaptorWithBuiltinExitFrame, InternalBuiltinsAssembler) {
   GenerateAdaptorWithExitFrameType<Descriptor>(Builtins::BUILTIN_EXIT);
 }
 
-TNode<IntPtrT> InternalBuiltinsAssembler::GetPendingMicrotaskCount() {
-  auto ref = ExternalReference::pending_microtask_count_address(isolate());
-  if (kIntSize == 8) {
-    return TNode<IntPtrT>::UncheckedCast(
-        Load(MachineType::Int64(), ExternalConstant(ref)));
-  } else {
-    Node* const value = Load(MachineType::Int32(), ExternalConstant(ref));
-    return ChangeInt32ToIntPtr(value);
-  }
+TNode<MicrotaskQueue> InternalBuiltinsAssembler::GetDefaultMicrotaskQueue() {
+  return TNode<MicrotaskQueue>::UncheckedCast(
+      LoadRoot(RootIndex::kDefaultMicrotaskQueue));
 }
 
-void InternalBuiltinsAssembler::SetPendingMicrotaskCount(TNode<IntPtrT> count) {
-  auto ref = ExternalReference::pending_microtask_count_address(isolate());
-  auto rep = kIntSize == 8 ? MachineRepresentation::kWord64
-                           : MachineRepresentation::kWord32;
-  if (kIntSize == 4 && kPointerSize == 8) {
-    Node* const truncated_count =
-        TruncateInt64ToInt32(TNode<Int64T>::UncheckedCast(count));
-    StoreNoWriteBarrier(rep, ExternalConstant(ref), truncated_count);
-  } else {
-    StoreNoWriteBarrier(rep, ExternalConstant(ref), count);
-  }
+TNode<IntPtrT> InternalBuiltinsAssembler::GetPendingMicrotaskCount(
+    TNode<MicrotaskQueue> microtask_queue) {
+  TNode<IntPtrT> result = LoadAndUntagObjectField(
+      microtask_queue, MicrotaskQueue::kPendingMicrotaskCountOffset);
+  return result;
 }
 
-TNode<FixedArray> InternalBuiltinsAssembler::GetMicrotaskQueue() {
-  return TNode<FixedArray>::UncheckedCast(
-      LoadRoot(Heap::kMicrotaskQueueRootIndex));
+void InternalBuiltinsAssembler::SetPendingMicrotaskCount(
+    TNode<MicrotaskQueue> microtask_queue, TNode<IntPtrT> new_num_tasks) {
+  StoreObjectField(microtask_queue,
+                   MicrotaskQueue::kPendingMicrotaskCountOffset,
+                   SmiFromIntPtr(new_num_tasks));
 }
 
-void InternalBuiltinsAssembler::SetMicrotaskQueue(TNode<FixedArray> queue) {
-  StoreRoot(Heap::kMicrotaskQueueRootIndex, queue);
+TNode<FixedArray> InternalBuiltinsAssembler::GetQueuedMicrotasks(
+    TNode<MicrotaskQueue> microtask_queue) {
+  return LoadObjectField<FixedArray>(microtask_queue,
+                                     MicrotaskQueue::kQueueOffset);
+}
+
+void InternalBuiltinsAssembler::SetQueuedMicrotasks(
+    TNode<MicrotaskQueue> microtask_queue, TNode<FixedArray> new_queue) {
+  StoreObjectField(microtask_queue, MicrotaskQueue::kQueueOffset, new_queue);
 }
 
 TNode<Context> InternalBuiltinsAssembler::GetCurrentContext() {
@@ -819,9 +839,10 @@ void InternalBuiltinsAssembler::RunPromiseHook(
 TF_BUILTIN(EnqueueMicrotask, InternalBuiltinsAssembler) {
   Node* microtask = Parameter(Descriptor::kMicrotask);
 
-  TNode<IntPtrT> num_tasks = GetPendingMicrotaskCount();
+  TNode<MicrotaskQueue> microtask_queue = GetDefaultMicrotaskQueue();
+  TNode<IntPtrT> num_tasks = GetPendingMicrotaskCount(microtask_queue);
   TNode<IntPtrT> new_num_tasks = IntPtrAdd(num_tasks, IntPtrConstant(1));
-  TNode<FixedArray> queue = GetMicrotaskQueue();
+  TNode<FixedArray> queue = GetQueuedMicrotasks(microtask_queue);
   TNode<IntPtrT> queue_length = LoadAndUntagFixedArrayBaseLength(queue);
 
   Label if_append(this), if_grow(this), done(this);
@@ -851,8 +872,8 @@ TF_BUILTIN(EnqueueMicrotask, InternalBuiltinsAssembler) {
       StoreFixedArrayElement(new_queue, num_tasks, microtask,
                              SKIP_WRITE_BARRIER);
       FillFixedArrayWithValue(PACKED_ELEMENTS, new_queue, new_num_tasks,
-                              new_queue_length, Heap::kUndefinedValueRootIndex);
-      SetMicrotaskQueue(new_queue);
+                              new_queue_length, RootIndex::kUndefinedValue);
+      SetQueuedMicrotasks(microtask_queue, new_queue);
       Goto(&done);
     }
 
@@ -865,8 +886,8 @@ TF_BUILTIN(EnqueueMicrotask, InternalBuiltinsAssembler) {
       CopyFixedArrayElements(PACKED_ELEMENTS, queue, new_queue, num_tasks);
       StoreFixedArrayElement(new_queue, num_tasks, microtask);
       FillFixedArrayWithValue(PACKED_ELEMENTS, new_queue, new_num_tasks,
-                              new_queue_length, Heap::kUndefinedValueRootIndex);
-      SetMicrotaskQueue(new_queue);
+                              new_queue_length, RootIndex::kUndefinedValue);
+      SetQueuedMicrotasks(microtask_queue, new_queue);
       Goto(&done);
     }
   }
@@ -878,13 +899,14 @@ TF_BUILTIN(EnqueueMicrotask, InternalBuiltinsAssembler) {
   }
 
   BIND(&done);
-  SetPendingMicrotaskCount(new_num_tasks);
+  SetPendingMicrotaskCount(microtask_queue, new_num_tasks);
   Return(UndefinedConstant());
 }
 
 TF_BUILTIN(RunMicrotasks, InternalBuiltinsAssembler) {
   // Load the current context from the isolate.
   TNode<Context> current_context = GetCurrentContext();
+  TNode<MicrotaskQueue> microtask_queue = GetDefaultMicrotaskQueue();
 
   Label init_queue_loop(this);
   Goto(&init_queue_loop);
@@ -893,17 +915,17 @@ TF_BUILTIN(RunMicrotasks, InternalBuiltinsAssembler) {
     TVARIABLE(IntPtrT, index, IntPtrConstant(0));
     Label loop(this, &index), loop_next(this);
 
-    TNode<IntPtrT> num_tasks = GetPendingMicrotaskCount();
+    TNode<IntPtrT> num_tasks = GetPendingMicrotaskCount(microtask_queue);
     ReturnIf(IntPtrEqual(num_tasks, IntPtrConstant(0)), UndefinedConstant());
 
-    TNode<FixedArray> queue = GetMicrotaskQueue();
+    TNode<FixedArray> queue = GetQueuedMicrotasks(microtask_queue);
 
     CSA_ASSERT(this, IntPtrGreaterThanOrEqual(
                          LoadAndUntagFixedArrayBaseLength(queue), num_tasks));
     CSA_ASSERT(this, IntPtrGreaterThan(num_tasks, IntPtrConstant(0)));
 
-    SetPendingMicrotaskCount(IntPtrConstant(0));
-    SetMicrotaskQueue(EmptyFixedArrayConstant());
+    SetQueuedMicrotasks(microtask_queue, EmptyFixedArrayConstant());
+    SetPendingMicrotaskCount(microtask_queue, IntPtrConstant(0));
 
     Goto(&loop);
     BIND(&loop);
@@ -1099,20 +1121,20 @@ TF_BUILTIN(RunMicrotasks, InternalBuiltinsAssembler) {
 }
 
 TF_BUILTIN(AllocateInNewSpace, CodeStubAssembler) {
-  TNode<Int32T> requested_size =
-      UncheckedCast<Int32T>(Parameter(Descriptor::kRequestedSize));
+  TNode<IntPtrT> requested_size =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kRequestedSize));
 
   TailCallRuntime(Runtime::kAllocateInNewSpace, NoContextConstant(),
-                  SmiFromInt32(requested_size));
+                  SmiFromIntPtr(requested_size));
 }
 
 TF_BUILTIN(AllocateInOldSpace, CodeStubAssembler) {
-  TNode<Int32T> requested_size =
-      UncheckedCast<Int32T>(Parameter(Descriptor::kRequestedSize));
+  TNode<IntPtrT> requested_size =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kRequestedSize));
 
   int flags = AllocateTargetSpace::encode(OLD_SPACE);
   TailCallRuntime(Runtime::kAllocateInTargetSpace, NoContextConstant(),
-                  SmiFromInt32(requested_size), SmiConstant(flags));
+                  SmiFromIntPtr(requested_size), SmiConstant(flags));
 }
 
 TF_BUILTIN(Abort, CodeStubAssembler) {
@@ -1178,6 +1200,9 @@ void Builtins::Generate_CEntry_Return2_SaveFPRegs_ArgvOnStack_BuiltinExit(
 }
 
 void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   // CallApiGetterStub only exists as a stub to avoid duplicating code between
   // here and code-stubs-<arch>.cc. For example, see CallApiFunctionAndReturn.
   // Here we abuse the instantiated stub to generate code.
@@ -1186,6 +1211,9 @@ void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_CallApiCallback_Argc0(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   // The common variants of CallApiCallbackStub (i.e. all that are embedded into
   // the snapshot) are generated as builtins. The rest remain available as code
   // stubs. Here we abuse the instantiated stub to generate code and avoid
@@ -1196,6 +1224,9 @@ void Builtins::Generate_CallApiCallback_Argc0(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_CallApiCallback_Argc1(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   // The common variants of CallApiCallbackStub (i.e. all that are embedded into
   // the snapshot) are generated as builtins. The rest remain available as code
   // stubs. Here we abuse the instantiated stub to generate code and avoid
@@ -1207,27 +1238,23 @@ void Builtins::Generate_CallApiCallback_Argc1(MacroAssembler* masm) {
 
 // ES6 [[Get]] operation.
 TF_BUILTIN(GetProperty, CodeStubAssembler) {
-  Label call_runtime(this, Label::kDeferred), return_undefined(this), end(this);
-
   Node* object = Parameter(Descriptor::kObject);
   Node* key = Parameter(Descriptor::kKey);
   Node* context = Parameter(Descriptor::kContext);
-  VARIABLE(var_result, MachineRepresentation::kTagged);
+  Label if_notfound(this), if_proxy(this, Label::kDeferred),
+      if_slow(this, Label::kDeferred);
 
   CodeStubAssembler::LookupInHolder lookup_property_in_holder =
-      [=, &var_result, &end](Node* receiver, Node* holder, Node* holder_map,
-                             Node* holder_instance_type, Node* unique_name,
-                             Label* next_holder, Label* if_bailout) {
+      [=](Node* receiver, Node* holder, Node* holder_map,
+          Node* holder_instance_type, Node* unique_name, Label* next_holder,
+          Label* if_bailout) {
         VARIABLE(var_value, MachineRepresentation::kTagged);
         Label if_found(this);
         TryGetOwnProperty(context, receiver, holder, holder_map,
                           holder_instance_type, unique_name, &if_found,
                           &var_value, next_holder, if_bailout);
         BIND(&if_found);
-        {
-          var_result.Bind(var_value.value());
-          Goto(&end);
-        }
+        Return(var_value.value());
       };
 
   CodeStubAssembler::LookupInHolder lookup_element_in_holder =
@@ -1240,23 +1267,26 @@ TF_BUILTIN(GetProperty, CodeStubAssembler) {
       };
 
   TryPrototypeChainLookup(object, key, lookup_property_in_holder,
-                          lookup_element_in_holder, &return_undefined,
-                          &call_runtime);
+                          lookup_element_in_holder, &if_notfound, &if_slow,
+                          &if_proxy);
 
-  BIND(&return_undefined);
-  {
-    var_result.Bind(UndefinedConstant());
-    Goto(&end);
-  }
+  BIND(&if_notfound);
+  Return(UndefinedConstant());
+
+  BIND(&if_slow);
+  TailCallRuntime(Runtime::kGetProperty, context, object, key);
 
-  BIND(&call_runtime);
+  BIND(&if_proxy);
   {
-    var_result.Bind(CallRuntime(Runtime::kGetProperty, context, object, key));
-    Goto(&end);
+    // Convert the {key} to a Name first.
+    Node* name = CallBuiltin(Builtins::kToName, context, key);
+
+    // The {object} is a JSProxy instance, look up the {name} on it, passing
+    // {object} both as receiver and holder. If {name} is absent we can safely
+    // return undefined from here.
+    TailCallBuiltin(Builtins::kProxyGetProperty, context, object, name, object,
+                    SmiConstant(OnNonExistent::kReturnUndefined));
   }
-
-  BIND(&end);
-  Return(var_result.value());
 }
 
 // ES6 [[Set]] operation.
diff --git a/deps/v8/src/builtins/builtins-interpreter-gen.cc b/deps/v8/src/builtins/builtins-interpreter-gen.cc
index f0d5160330..fa1684c54b 100644
--- a/deps/v8/src/builtins/builtins-interpreter-gen.cc
+++ b/deps/v8/src/builtins/builtins-interpreter-gen.cc
@@ -10,12 +10,18 @@ namespace v8 {
 namespace internal {
 
 void Builtins::Generate_InterpreterPushArgsThenCall(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   return Generate_InterpreterPushArgsThenCallImpl(
       masm, ConvertReceiverMode::kAny, InterpreterPushArgsMode::kOther);
 }
 
 void Builtins::Generate_InterpreterPushUndefinedAndArgsThenCall(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   return Generate_InterpreterPushArgsThenCallImpl(
       masm, ConvertReceiverMode::kNullOrUndefined,
       InterpreterPushArgsMode::kOther);
@@ -23,24 +29,36 @@ void Builtins::Generate_InterpreterPushUndefinedAndArgsThenCall(
 
 void Builtins::Generate_InterpreterPushArgsThenCallWithFinalSpread(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   return Generate_InterpreterPushArgsThenCallImpl(
       masm, ConvertReceiverMode::kAny,
       InterpreterPushArgsMode::kWithFinalSpread);
 }
 
 void Builtins::Generate_InterpreterPushArgsThenConstruct(MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   return Generate_InterpreterPushArgsThenConstructImpl(
       masm, InterpreterPushArgsMode::kOther);
 }
 
 void Builtins::Generate_InterpreterPushArgsThenConstructWithFinalSpread(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   return Generate_InterpreterPushArgsThenConstructImpl(
       masm, InterpreterPushArgsMode::kWithFinalSpread);
 }
 
 void Builtins::Generate_InterpreterPushArgsThenConstructArrayFunction(
     MacroAssembler* masm) {
+#ifdef V8_TARGET_ARCH_IA32
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   return Generate_InterpreterPushArgsThenConstructImpl(
       masm, InterpreterPushArgsMode::kArrayFunction);
 }
diff --git a/deps/v8/src/builtins/builtins-intl-gen.cc b/deps/v8/src/builtins/builtins-intl-gen.cc
index 77e2e81a6c..49405141c1 100644
--- a/deps/v8/src/builtins/builtins-intl-gen.cc
+++ b/deps/v8/src/builtins/builtins-intl-gen.cc
@@ -41,8 +41,8 @@ TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
   Label call_c(this), return_string(this), runtime(this, Label::kDeferred);
 
   // Early exit on empty strings.
-  TNode<Smi> const length = LoadStringLengthAsSmi(string);
-  GotoIf(SmiEqual(length, SmiConstant(0)), &return_string);
+  TNode<Uint32T> const length = LoadStringLengthAsWord32(string);
+  GotoIf(Word32Equal(length, Uint32Constant(0)), &return_string);
 
   // Unpack strings if possible, and bail to runtime unless we get a one-byte
   // flat string.
@@ -60,7 +60,8 @@ TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
   Node* const dst = AllocateSeqOneByteString(context, length);
 
   const int kMaxShortStringLength = 24;  // Determined empirically.
-  GotoIf(SmiGreaterThan(length, SmiConstant(kMaxShortStringLength)), &call_c);
+  GotoIf(Uint32GreaterThan(length, Uint32Constant(kMaxShortStringLength)),
+         &call_c);
 
   {
     Node* const dst_ptr = PointerToSeqStringData(dst);
@@ -69,7 +70,7 @@ TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
 
     Node* const start_address = to_direct.PointerToData(&call_c);
     TNode<IntPtrT> const end_address =
-        Signed(IntPtrAdd(start_address, SmiUntag(length)));
+        Signed(IntPtrAdd(start_address, ChangeUint32ToWord(length)));
 
     Node* const to_lower_table_addr =
         ExternalConstant(ExternalReference::intl_to_latin1_lower_table());
@@ -177,10 +178,8 @@ void IntlBuiltinsAssembler::ListFormatCommon(TNode<Context> context,
   BIND(&has_list);
   {
     // 5. Let x be ? IterableToList(list).
-    IteratorBuiltinsAssembler iterator_assembler(state());
-    // TODO(adamk): Consider exposing IterableToList as a buitin and calling
-    // it from here instead of inlining the operation.
-    TNode<JSArray> x = iterator_assembler.IterableToList(context, list);
+    TNode<Object> x =
+        CallBuiltin(Builtins::kIterableToListWithSymbolLookup, context, list);
 
     // 6. Return ? FormatList(lf, x).
     args.PopAndReturn(CallRuntime(format_func_id, context, list_format, x));
diff --git a/deps/v8/src/builtins/builtins-intl.cc b/deps/v8/src/builtins/builtins-intl.cc
index 1d54d0da80..01c8a9ddcd 100644
--- a/deps/v8/src/builtins/builtins-intl.cc
+++ b/deps/v8/src/builtins/builtins-intl.cc
@@ -10,7 +10,6 @@
 #include <list>
 #include <memory>
 
-#include "src/builtins/builtins-intl.h"
 #include "src/builtins/builtins-utils-inl.h"
 #include "src/builtins/builtins.h"
 #include "src/date.h"
@@ -19,11 +18,16 @@
 #include "src/objects-inl.h"
 #include "src/objects/intl-objects.h"
 #include "src/objects/js-array-inl.h"
+#include "src/objects/js-break-iterator-inl.h"
 #include "src/objects/js-collator-inl.h"
+#include "src/objects/js-date-time-format-inl.h"
 #include "src/objects/js-list-format-inl.h"
 #include "src/objects/js-locale-inl.h"
+#include "src/objects/js-number-format-inl.h"
 #include "src/objects/js-plural-rules-inl.h"
 #include "src/objects/js-relative-time-format-inl.h"
+#include "src/objects/js-segmenter-inl.h"
+#include "src/property-descriptor.h"
 
 #include "unicode/datefmt.h"
 #include "unicode/decimfmt.h"
@@ -32,12 +36,10 @@
 #include "unicode/listformatter.h"
 #include "unicode/normalizer2.h"
 #include "unicode/numfmt.h"
-#include "unicode/reldatefmt.h"
 #include "unicode/smpdtfmt.h"
 #include "unicode/udat.h"
 #include "unicode/ufieldpositer.h"
 #include "unicode/unistr.h"
-#include "unicode/ureldatefmt.h"
 #include "unicode/ustring.h"
 
 namespace v8 {
@@ -128,329 +130,30 @@ BUILTIN(StringPrototypeNormalizeIntl) {
                    result.length())));
 }
 
-namespace {
-
-// The list comes from third_party/icu/source/i18n/unicode/unum.h.
-// They're mapped to NumberFormat part types mentioned throughout
-// https://tc39.github.io/ecma402/#sec-partitionnumberpattern .
-Handle<String> IcuNumberFieldIdToNumberType(int32_t field_id, double number,
-                                            Isolate* isolate) {
-  switch (static_cast<UNumberFormatFields>(field_id)) {
-    case UNUM_INTEGER_FIELD:
-      if (std::isfinite(number)) return isolate->factory()->integer_string();
-      if (std::isnan(number)) return isolate->factory()->nan_string();
-      return isolate->factory()->infinity_string();
-    case UNUM_FRACTION_FIELD:
-      return isolate->factory()->fraction_string();
-    case UNUM_DECIMAL_SEPARATOR_FIELD:
-      return isolate->factory()->decimal_string();
-    case UNUM_GROUPING_SEPARATOR_FIELD:
-      return isolate->factory()->group_string();
-    case UNUM_CURRENCY_FIELD:
-      return isolate->factory()->currency_string();
-    case UNUM_PERCENT_FIELD:
-      return isolate->factory()->percentSign_string();
-    case UNUM_SIGN_FIELD:
-      return number < 0 ? isolate->factory()->minusSign_string()
-                        : isolate->factory()->plusSign_string();
-
-    case UNUM_EXPONENT_SYMBOL_FIELD:
-    case UNUM_EXPONENT_SIGN_FIELD:
-    case UNUM_EXPONENT_FIELD:
-      // We should never get these because we're not using any scientific
-      // formatter.
-      UNREACHABLE();
-      return Handle<String>();
-
-    case UNUM_PERMILL_FIELD:
-      // We're not creating any permill formatter, and it's not even clear how
-      // that would be possible with the ICU API.
-      UNREACHABLE();
-      return Handle<String>();
-
-    default:
-      UNREACHABLE();
-      return Handle<String>();
-  }
-}
-
-// The list comes from third_party/icu/source/i18n/unicode/udat.h.
-// They're mapped to DateTimeFormat components listed at
-// https://tc39.github.io/ecma402/#sec-datetimeformat-abstracts .
-
-Handle<String> IcuDateFieldIdToDateType(int32_t field_id, Isolate* isolate) {
-  switch (field_id) {
-    case -1:
-      return isolate->factory()->literal_string();
-    case UDAT_YEAR_FIELD:
-    case UDAT_EXTENDED_YEAR_FIELD:
-    case UDAT_YEAR_NAME_FIELD:
-      return isolate->factory()->year_string();
-    case UDAT_MONTH_FIELD:
-    case UDAT_STANDALONE_MONTH_FIELD:
-      return isolate->factory()->month_string();
-    case UDAT_DATE_FIELD:
-      return isolate->factory()->day_string();
-    case UDAT_HOUR_OF_DAY1_FIELD:
-    case UDAT_HOUR_OF_DAY0_FIELD:
-    case UDAT_HOUR1_FIELD:
-    case UDAT_HOUR0_FIELD:
-      return isolate->factory()->hour_string();
-    case UDAT_MINUTE_FIELD:
-      return isolate->factory()->minute_string();
-    case UDAT_SECOND_FIELD:
-      return isolate->factory()->second_string();
-    case UDAT_DAY_OF_WEEK_FIELD:
-    case UDAT_DOW_LOCAL_FIELD:
-    case UDAT_STANDALONE_DAY_FIELD:
-      return isolate->factory()->weekday_string();
-    case UDAT_AM_PM_FIELD:
-      return isolate->factory()->dayperiod_string();
-    case UDAT_TIMEZONE_FIELD:
-    case UDAT_TIMEZONE_RFC_FIELD:
-    case UDAT_TIMEZONE_GENERIC_FIELD:
-    case UDAT_TIMEZONE_SPECIAL_FIELD:
-    case UDAT_TIMEZONE_LOCALIZED_GMT_OFFSET_FIELD:
-    case UDAT_TIMEZONE_ISO_FIELD:
-    case UDAT_TIMEZONE_ISO_LOCAL_FIELD:
-      return isolate->factory()->timeZoneName_string();
-    case UDAT_ERA_FIELD:
-      return isolate->factory()->era_string();
-    default:
-      // Other UDAT_*_FIELD's cannot show up because there is no way to specify
-      // them via options of Intl.DateTimeFormat.
-      UNREACHABLE();
-      // To prevent MSVC from issuing C4715 warning.
-      return Handle<String>();
-  }
-}
-
-bool cmp_NumberFormatSpan(const NumberFormatSpan& a,
-                          const NumberFormatSpan& b) {
-  // Regions that start earlier should be encountered earlier.
-  if (a.begin_pos < b.begin_pos) return true;
-  if (a.begin_pos > b.begin_pos) return false;
-  // For regions that start in the same place, regions that last longer should
-  // be encountered earlier.
-  if (a.end_pos < b.end_pos) return false;
-  if (a.end_pos > b.end_pos) return true;
-  // For regions that are exactly the same, one of them must be the "literal"
-  // backdrop we added, which has a field_id of -1, so consider higher field_ids
-  // to be later.
-  return a.field_id < b.field_id;
-}
-
-MaybeHandle<Object> FormatNumberToParts(Isolate* isolate,
-                                        icu::NumberFormat* fmt, double number) {
-  Factory* factory = isolate->factory();
-
-  icu::UnicodeString formatted;
-  icu::FieldPositionIterator fp_iter;
-  UErrorCode status = U_ZERO_ERROR;
-  fmt->format(number, formatted, &fp_iter, status);
-  if (U_FAILURE(status)) {
-    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), Object);
-  }
-
-  Handle<JSArray> result = factory->NewJSArray(0);
-  int32_t length = formatted.length();
-  if (length == 0) return result;
-
-  std::vector<NumberFormatSpan> regions;
-  // Add a "literal" backdrop for the entire string. This will be used if no
-  // other region covers some part of the formatted string. It's possible
-  // there's another field with exactly the same begin and end as this backdrop,
-  // in which case the backdrop's field_id of -1 will give it lower priority.
-  regions.push_back(NumberFormatSpan(-1, 0, formatted.length()));
-
-  {
-    icu::FieldPosition fp;
-    while (fp_iter.next(fp)) {
-      regions.push_back(NumberFormatSpan(fp.getField(), fp.getBeginIndex(),
-                                         fp.getEndIndex()));
-    }
-  }
-
-  std::vector<NumberFormatSpan> parts = FlattenRegionsToParts(&regions);
-
-  int index = 0;
-  for (auto it = parts.begin(); it < parts.end(); it++) {
-    NumberFormatSpan part = *it;
-    Handle<String> field_type_string =
-        part.field_id == -1
-            ? isolate->factory()->literal_string()
-            : IcuNumberFieldIdToNumberType(part.field_id, number, isolate);
-    Handle<String> substring;
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, substring,
-        Intl::ToString(isolate, formatted, part.begin_pos, part.end_pos),
-        Object);
-    Intl::AddElement(isolate, result, index, field_type_string, substring);
-    ++index;
-  }
-  JSObject::ValidateElements(*result);
-
-  return result;
-}
-
-MaybeHandle<Object> FormatDateToParts(Isolate* isolate, icu::DateFormat* format,
-                                      double date_value) {
-  Factory* factory = isolate->factory();
-
-  icu::UnicodeString formatted;
-  icu::FieldPositionIterator fp_iter;
-  icu::FieldPosition fp;
-  UErrorCode status = U_ZERO_ERROR;
-  format->format(date_value, formatted, &fp_iter, status);
-  if (U_FAILURE(status)) {
-    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), Object);
-  }
+BUILTIN(V8BreakIteratorSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
 
-  Handle<JSArray> result = factory->NewJSArray(0);
-  int32_t length = formatted.length();
-  if (length == 0) return result;
-
-  int index = 0;
-  int32_t previous_end_pos = 0;
-  Handle<String> substring;
-  while (fp_iter.next(fp)) {
-    int32_t begin_pos = fp.getBeginIndex();
-    int32_t end_pos = fp.getEndIndex();
-
-    if (previous_end_pos < begin_pos) {
-      ASSIGN_RETURN_ON_EXCEPTION(
-          isolate, substring,
-          Intl::ToString(isolate, formatted, previous_end_pos, begin_pos),
-          Object);
-      Intl::AddElement(isolate, result, index,
-                       IcuDateFieldIdToDateType(-1, isolate), substring);
-      ++index;
-    }
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, substring,
-        Intl::ToString(isolate, formatted, begin_pos, end_pos), Object);
-    Intl::AddElement(isolate, result, index,
-                     IcuDateFieldIdToDateType(fp.getField(), isolate),
-                     substring);
-    previous_end_pos = end_pos;
-    ++index;
-  }
-  if (previous_end_pos < length) {
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, substring,
-        Intl::ToString(isolate, formatted, previous_end_pos, length), Object);
-    Intl::AddElement(isolate, result, index,
-                     IcuDateFieldIdToDateType(-1, isolate), substring);
-  }
-  JSObject::ValidateElements(*result);
-  return result;
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kBreakIterator,
+                                        locales, options));
 }
 
-}  // namespace
-
-// Flattens a list of possibly-overlapping "regions" to a list of
-// non-overlapping "parts". At least one of the input regions must span the
-// entire space of possible indexes. The regions parameter will sorted in-place
-// according to some criteria; this is done for performance to avoid copying the
-// input.
-std::vector<NumberFormatSpan> FlattenRegionsToParts(
-    std::vector<NumberFormatSpan>* regions) {
-  // The intention of this algorithm is that it's used to translate ICU "fields"
-  // to JavaScript "parts" of a formatted string. Each ICU field and JavaScript
-  // part has an integer field_id, which corresponds to something like "grouping
-  // separator", "fraction", or "percent sign", and has a begin and end
-  // position. Here's a diagram of:
-
-  // var nf = new Intl.NumberFormat(['de'], {style:'currency',currency:'EUR'});
-  // nf.formatToParts(123456.78);
-
-  //               :       6
-  //  input regions:    0000000211 7
-  // ('-' means -1):    ------------
-  // formatted string: "123.456,78 €"
-  // output parts:      0006000211-7
-
-  // To illustrate the requirements of this algorithm, here's a contrived and
-  // convoluted example of inputs and expected outputs:
-
-  //              :          4
-  //              :      22 33    3
-  //              :      11111   22
-  // input regions:     0000000  111
-  //              :     ------------
-  // formatted string: "abcdefghijkl"
-  // output parts:      0221340--231
-  // (The characters in the formatted string are irrelevant to this function.)
-
-  // We arrange the overlapping input regions like a mountain range where
-  // smaller regions are "on top" of larger regions, and we output a birds-eye
-  // view of the mountains, so that smaller regions take priority over larger
-  // regions.
-  std::sort(regions->begin(), regions->end(), cmp_NumberFormatSpan);
-  std::vector<size_t> overlapping_region_index_stack;
-  // At least one item in regions must be a region spanning the entire string.
-  // Due to the sorting above, the first item in the vector will be one of them.
-  overlapping_region_index_stack.push_back(0);
-  NumberFormatSpan top_region = regions->at(0);
-  size_t region_iterator = 1;
-  int32_t entire_size = top_region.end_pos;
-
-  std::vector<NumberFormatSpan> out_parts;
-
-  // The "climber" is a cursor that advances from left to right climbing "up"
-  // and "down" the mountains. Whenever the climber moves to the right, that
-  // represents an item of output.
-  int32_t climber = 0;
-  while (climber < entire_size) {
-    int32_t next_region_begin_pos;
-    if (region_iterator < regions->size()) {
-      next_region_begin_pos = regions->at(region_iterator).begin_pos;
-    } else {
-      // finish off the rest of the input by proceeding to the end.
-      next_region_begin_pos = entire_size;
-    }
+BUILTIN(NumberFormatSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
 
-    if (climber < next_region_begin_pos) {
-      while (top_region.end_pos < next_region_begin_pos) {
-        if (climber < top_region.end_pos) {
-          // step down
-          out_parts.push_back(NumberFormatSpan(top_region.field_id, climber,
-                                               top_region.end_pos));
-          climber = top_region.end_pos;
-        } else {
-          // drop down
-        }
-        overlapping_region_index_stack.pop_back();
-        top_region = regions->at(overlapping_region_index_stack.back());
-      }
-      if (climber < next_region_begin_pos) {
-        // cross a plateau/mesa/valley
-        out_parts.push_back(NumberFormatSpan(top_region.field_id, climber,
-                                             next_region_begin_pos));
-        climber = next_region_begin_pos;
-      }
-    }
-    if (region_iterator < regions->size()) {
-      overlapping_region_index_stack.push_back(region_iterator++);
-      top_region = regions->at(overlapping_region_index_stack.back());
-    }
-  }
-  return out_parts;
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kNumberFormat,
+                                        locales, options));
 }
 
 BUILTIN(NumberFormatPrototypeFormatToParts) {
   const char* const method = "Intl.NumberFormat.prototype.formatToParts";
   HandleScope handle_scope(isolate);
-  CHECK_RECEIVER(JSObject, number_format_holder, method);
-
-  if (!Intl::IsObjectOfType(isolate, number_format_holder,
-                            Intl::Type::kNumberFormat)) {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate,
-        NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                     isolate->factory()->NewStringFromAsciiChecked(method),
-                     number_format_holder));
-  }
+  CHECK_RECEIVER(JSNumberFormat, number_format, method);
 
   Handle<Object> x;
   if (args.length() >= 2) {
@@ -460,12 +163,33 @@ BUILTIN(NumberFormatPrototypeFormatToParts) {
     x = isolate->factory()->nan_value();
   }
 
-  icu::DecimalFormat* number_format =
-      NumberFormat::UnpackNumberFormat(number_format_holder);
-  CHECK_NOT_NULL(number_format);
+  RETURN_RESULT_OR_FAILURE(isolate, JSNumberFormat::FormatToParts(
+                                        isolate, number_format, x->Number()));
+}
+
+BUILTIN(DateTimeFormatPrototypeResolvedOptions) {
+  const char* const method = "Intl.DateTimeFormat.prototype.resolvedOptions";
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSReceiver, format_holder, method);
+
+  // 3. Let dtf be ? UnwrapDateTimeFormat(dtf).
+  Handle<JSDateTimeFormat> date_time_format;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, date_time_format,
+      JSDateTimeFormat::UnwrapDateTimeFormat(isolate, format_holder));
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSDateTimeFormat::ResolvedOptions(isolate, date_time_format));
+}
+
+BUILTIN(DateTimeFormatSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
 
   RETURN_RESULT_OR_FAILURE(
-      isolate, FormatNumberToParts(isolate, number_format, x->Number()));
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kDateFormat,
+                                        locales, options));
 }
 
 BUILTIN(DateTimeFormatPrototypeFormatToParts) {
@@ -474,13 +198,14 @@ BUILTIN(DateTimeFormatPrototypeFormatToParts) {
   CHECK_RECEIVER(JSObject, date_format_holder, method);
   Factory* factory = isolate->factory();
 
-  if (!Intl::IsObjectOfType(isolate, date_format_holder,
-                            Intl::Type::kDateTimeFormat)) {
+  if (!date_format_holder->IsJSDateTimeFormat()) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
                               factory->NewStringFromAsciiChecked(method),
                               date_format_holder));
   }
+  Handle<JSDateTimeFormat> dtf =
+      Handle<JSDateTimeFormat>::cast(date_format_holder);
 
   Handle<Object> x = args.atOrUndefined(isolate, 1);
   if (x->IsUndefined(isolate)) {
@@ -496,12 +221,142 @@ BUILTIN(DateTimeFormatPrototypeFormatToParts) {
         isolate, NewRangeError(MessageTemplate::kInvalidTimeValue));
   }
 
-  icu::SimpleDateFormat* date_format =
-      DateFormat::UnpackDateFormat(date_format_holder);
-  CHECK_NOT_NULL(date_format);
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSDateTimeFormat::FormatToParts(isolate, dtf, date_value));
+}
+
+namespace {
+Handle<JSFunction> CreateBoundFunction(Isolate* isolate,
+                                       Handle<JSObject> object,
+                                       Builtins::Name builtin_id, int len) {
+  Handle<NativeContext> native_context(isolate->context()->native_context(),
+                                       isolate);
+  Handle<Context> context = isolate->factory()->NewBuiltinContext(
+      native_context,
+      static_cast<int>(Intl::BoundFunctionContextSlot::kLength));
+
+  context->set(static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction),
+               *object);
+
+  Handle<SharedFunctionInfo> info =
+      isolate->factory()->NewSharedFunctionInfoForBuiltin(
+          isolate->factory()->empty_string(), builtin_id, kNormalFunction);
+  info->set_internal_formal_parameter_count(len);
+  info->set_length(len);
+
+  Handle<Map> map = isolate->strict_function_without_prototype_map();
+
+  Handle<JSFunction> new_bound_function =
+      isolate->factory()->NewFunctionFromSharedFunctionInfo(map, info, context);
+  return new_bound_function;
+}
+
+/**
+ * Common code shared between DateTimeFormatConstructor and
+ * NumberFormatConstrutor
+ */
+template <class T>
+Object* FormatConstructor(BuiltinArguments args, Isolate* isolate,
+                          Handle<Object> constructor, const char* method) {
+  Handle<JSReceiver> new_target;
+  // 1. If NewTarget is undefined, let newTarget be the active
+  // function object, else let newTarget be NewTarget.
+  if (args.new_target()->IsUndefined(isolate)) {
+    new_target = args.target();
+  } else {
+    new_target = Handle<JSReceiver>::cast(args.new_target());
+  }
+
+  // [[Construct]]
+  Handle<JSFunction> target = args.target();
+
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
+
+  // 2. Let format be ? OrdinaryCreateFromConstructor(newTarget,
+  // "%<T>Prototype%", ...).
+
+  Handle<JSObject> format_obj;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, format_obj,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
+  Handle<T> format = Handle<T>::cast(format_obj);
+
+  // 3. Perform ? Initialize<T>(Format, locales, options).
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, format, T::Initialize(isolate, format, locales, options));
+  // 4. Let this be the this value.
+  Handle<Object> receiver = args.receiver();
+
+  // 5. If NewTarget is undefined and ? InstanceofOperator(this, %<T>%)
+  // is true, then
+  //
+  // Look up the intrinsic value that has been stored on the context.
+  // Call the instanceof function
+  Handle<Object> is_instance_of_obj;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, is_instance_of_obj,
+      Object::InstanceOf(isolate, receiver, constructor));
+
+  // Get the boolean value of the result
+  bool is_instance_of = is_instance_of_obj->BooleanValue(isolate);
+
+  if (args.new_target()->IsUndefined(isolate) && is_instance_of) {
+    if (!receiver->IsJSReceiver()) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
+                       isolate->factory()->NewStringFromAsciiChecked(method),
+                       receiver));
+    }
+    Handle<JSReceiver> rec = Handle<JSReceiver>::cast(receiver);
+    // a. Perform ? DefinePropertyOrThrow(this,
+    // %Intl%.[[FallbackSymbol]], PropertyDescriptor{ [[Value]]: format,
+    // [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: false }).
+    PropertyDescriptor desc;
+    desc.set_value(format);
+    desc.set_writable(false);
+    desc.set_enumerable(false);
+    desc.set_configurable(false);
+    Maybe<bool> success = JSReceiver::DefineOwnProperty(
+        isolate, rec, isolate->factory()->intl_fallback_symbol(), &desc,
+        kThrowOnError);
+    MAYBE_RETURN(success, ReadOnlyRoots(isolate).exception());
+    CHECK(success.FromJust());
+    // b. b. Return this.
+    return *receiver;
+  }
+  // 6. Return format.
+  return *format;
+}
+
+}  // namespace
+
+BUILTIN(NumberFormatConstructor) {
+  HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kNumberFormat);
+
+  return FormatConstructor<JSNumberFormat>(
+      args, isolate, isolate->intl_number_format_function(),
+      "Intl.NumberFormat");
+}
+
+BUILTIN(NumberFormatPrototypeResolvedOptions) {
+  HandleScope scope(isolate);
+  const char* const method = "Intl.NumberFormat.prototype.resolvedOptions";
+
+  // 1. Let nf be the this value.
+  // 2. If Type(nf) is not Object, throw a TypeError exception.
+  CHECK_RECEIVER(JSReceiver, number_format_holder, method);
+
+  // 3. Let nf be ? UnwrapNumberFormat(nf)
+  Handle<JSNumberFormat> number_format;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, number_format,
+      JSNumberFormat::UnwrapNumberFormat(isolate, number_format_holder));
 
-  RETURN_RESULT_OR_FAILURE(isolate,
-                           FormatDateToParts(isolate, date_format, date_value));
+  return *JSNumberFormat::ResolvedOptions(isolate, number_format);
 }
 
 BUILTIN(NumberFormatPrototypeFormatNumber) {
@@ -513,17 +368,12 @@ BUILTIN(NumberFormatPrototypeFormatNumber) {
   CHECK_RECEIVER(JSReceiver, receiver, method);
 
   // 3. Let nf be ? UnwrapNumberFormat(nf).
-  Handle<JSObject> number_format_holder;
+  Handle<JSNumberFormat> number_format;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, number_format_holder,
-      NumberFormat::Unwrap(isolate, receiver, method));
+      isolate, number_format,
+      JSNumberFormat::UnwrapNumberFormat(isolate, receiver));
 
-  DCHECK(Intl::IsObjectOfType(isolate, number_format_holder,
-                              Intl::Type::kNumberFormat));
-
-  Handle<Object> bound_format = Handle<Object>(
-      number_format_holder->GetEmbedderField(NumberFormat::kBoundFormatIndex),
-      isolate);
+  Handle<Object> bound_format(number_format->bound_format(), isolate);
 
   // 4. If nf.[[BoundFormat]] is undefined, then
   if (!bound_format->IsUndefined(isolate)) {
@@ -532,29 +382,11 @@ BUILTIN(NumberFormatPrototypeFormatNumber) {
     return *bound_format;
   }
 
-  Handle<NativeContext> native_context(isolate->context()->native_context(),
-                                       isolate);
-
-  Handle<Context> context = isolate->factory()->NewBuiltinContext(
-      native_context, NumberFormat::ContextSlot::kLength);
-
-  // 4. b. Set F.[[NumberFormat]] to nf.
-  context->set(NumberFormat::ContextSlot::kNumberFormat, *number_format_holder);
-
-  Handle<SharedFunctionInfo> info = Handle<SharedFunctionInfo>(
-      native_context->number_format_internal_format_number_shared_fun(),
-      isolate);
-
-  Handle<Map> map = isolate->strict_function_without_prototype_map();
-
-  // 4. a. Let F be a new built-in function object as defined in
-  // Number Format Functions (11.1.4).
-  Handle<JSFunction> new_bound_format_function =
-      isolate->factory()->NewFunctionFromSharedFunctionInfo(map, info, context);
+  Handle<JSFunction> new_bound_format_function = CreateBoundFunction(
+      isolate, number_format, Builtins::kNumberFormatInternalFormatNumber, 1);
 
   // 4. c. Set nf.[[BoundFormat]] to F.
-  number_format_holder->SetEmbedderField(NumberFormat::kBoundFormatIndex,
-                                         *new_bound_format_function);
+  number_format->set_bound_format(*new_bound_format_function);
 
   // 5. Return nf.[[BoundFormat]].
   return *new_bound_format_function;
@@ -566,14 +398,12 @@ BUILTIN(NumberFormatInternalFormatNumber) {
   Handle<Context> context = Handle<Context>(isolate->context(), isolate);
 
   // 1. Let nf be F.[[NumberFormat]].
-  Handle<JSObject> number_format_holder = Handle<JSObject>(
-      JSObject::cast(context->get(NumberFormat::ContextSlot::kNumberFormat)),
-      isolate);
-
   // 2. Assert: Type(nf) is Object and nf has an
   //    [[InitializedNumberFormat]] internal slot.
-  DCHECK(Intl::IsObjectOfType(isolate, number_format_holder,
-                              Intl::Type::kNumberFormat));
+  Handle<JSNumberFormat> number_format = Handle<JSNumberFormat>(
+      JSNumberFormat::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
+      isolate);
 
   // 3. If value is not provided, let value be undefined.
   Handle<Object> value = args.atOrUndefined(isolate, 1);
@@ -590,8 +420,18 @@ BUILTIN(NumberFormatInternalFormatNumber) {
 
   double number = number_obj->Number();
   // Return FormatNumber(nf, x).
-  RETURN_RESULT_OR_FAILURE(isolate, NumberFormat::FormatNumber(
-                                        isolate, number_format_holder, number));
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSNumberFormat::FormatNumber(isolate, number_format, number));
+}
+
+BUILTIN(DateTimeFormatConstructor) {
+  HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kDateTimeFormat);
+
+  return FormatConstructor<JSDateTimeFormat>(
+      args, isolate, isolate->intl_date_time_format_function(),
+      "Intl.DateTimeFormat");
 }
 
 BUILTIN(DateTimeFormatPrototypeFormat) {
@@ -603,16 +443,12 @@ BUILTIN(DateTimeFormatPrototypeFormat) {
   CHECK_RECEIVER(JSReceiver, receiver, method);
 
   // 3. Let dtf be ? UnwrapDateTimeFormat(dtf).
-  Handle<JSObject> date_format_holder;
+  Handle<JSDateTimeFormat> format;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, date_format_holder,
-      DateFormat::Unwrap(isolate, receiver, method));
-  DCHECK(Intl::IsObjectOfType(isolate, date_format_holder,
-                              Intl::Type::kDateTimeFormat));
+      isolate, format,
+      JSDateTimeFormat::UnwrapDateTimeFormat(isolate, receiver));
 
-  Handle<Object> bound_format = Handle<Object>(
-      date_format_holder->GetEmbedderField(DateFormat::kBoundFormatIndex),
-      isolate);
+  Handle<Object> bound_format = Handle<Object>(format->bound_format(), isolate);
 
   // 4. If dtf.[[BoundFormat]] is undefined, then
   if (!bound_format->IsUndefined(isolate)) {
@@ -621,26 +457,11 @@ BUILTIN(DateTimeFormatPrototypeFormat) {
     return *bound_format;
   }
 
-  Handle<NativeContext> native_context(isolate->context()->native_context(),
-                                       isolate);
-  Handle<Context> context = isolate->factory()->NewBuiltinContext(
-      native_context, DateFormat::ContextSlot::kLength);
-
-  // 4.b. Set F.[[DateTimeFormat]] to dtf.
-  context->set(DateFormat::ContextSlot::kDateFormat, *date_format_holder);
-
-  Handle<SharedFunctionInfo> info = Handle<SharedFunctionInfo>(
-      native_context->date_format_internal_format_shared_fun(), isolate);
-  Handle<Map> map = isolate->strict_function_without_prototype_map();
-
-  // 4.a. Let F be a new built-in function object as defined in DateTime Format
-  // Functions (12.1.5).
-  Handle<JSFunction> new_bound_format_function =
-      isolate->factory()->NewFunctionFromSharedFunctionInfo(map, info, context);
+  Handle<JSFunction> new_bound_format_function = CreateBoundFunction(
+      isolate, format, Builtins::kDateTimeFormatInternalFormat, 1);
 
   // 4.c. Set dtf.[[BoundFormat]] to F.
-  date_format_holder->SetEmbedderField(DateFormat::kBoundFormatIndex,
-                                       *new_bound_format_function);
+  format->set_bound_format(*new_bound_format_function);
 
   // 5. Return dtf.[[BoundFormat]].
   return *new_bound_format_function;
@@ -651,23 +472,24 @@ BUILTIN(DateTimeFormatInternalFormat) {
   Handle<Context> context = Handle<Context>(isolate->context(), isolate);
 
   // 1. Let dtf be F.[[DateTimeFormat]].
-  Handle<JSObject> date_format_holder = Handle<JSObject>(
-      JSObject::cast(context->get(DateFormat::ContextSlot::kDateFormat)),
-      isolate);
-
   // 2. Assert: Type(dtf) is Object and dtf has an [[InitializedDateTimeFormat]]
   // internal slot.
-  DCHECK(Intl::IsObjectOfType(isolate, date_format_holder,
-                              Intl::Type::kDateTimeFormat));
+  Handle<JSDateTimeFormat> date_format_holder = Handle<JSDateTimeFormat>(
+      JSDateTimeFormat::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
+      isolate);
 
   Handle<Object> date = args.atOrUndefined(isolate, 1);
 
-  RETURN_RESULT_OR_FAILURE(
-      isolate, DateFormat::DateTimeFormat(isolate, date_format_holder, date));
+  RETURN_RESULT_OR_FAILURE(isolate, JSDateTimeFormat::DateTimeFormat(
+                                        isolate, date_format_holder, date));
 }
 
 BUILTIN(ListFormatConstructor) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kListFormat);
+
   // 1. If NewTarget is undefined, throw a TypeError exception.
   if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
     THROW_NEW_ERROR_RETURN_FAILURE(
@@ -682,8 +504,9 @@ BUILTIN(ListFormatConstructor) {
   Handle<JSObject> result;
   // 2. Let listFormat be OrdinaryCreateFromConstructor(NewTarget,
   //    "%ListFormatPrototype%").
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   Handle<JSListFormat> format = Handle<JSListFormat>::cast(result);
   format->set_flags(0);
 
@@ -691,8 +514,8 @@ BUILTIN(ListFormatConstructor) {
   Handle<Object> options = args.atOrUndefined(isolate, 2);
 
   // 3. Return InitializeListFormat(listFormat, locales, options).
-  RETURN_RESULT_OR_FAILURE(isolate, JSListFormat::InitializeListFormat(
-                                        isolate, format, locales, options));
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSListFormat::Initialize(isolate, format, locales, options));
 }
 
 BUILTIN(ListFormatPrototypeResolvedOptions) {
@@ -702,42 +525,62 @@ BUILTIN(ListFormatPrototypeResolvedOptions) {
   return *JSListFormat::ResolvedOptions(isolate, format_holder);
 }
 
+BUILTIN(ListFormatSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kListFormatter,
+                                        locales, options));
+}
+
 namespace {
 
 MaybeHandle<JSLocale> CreateLocale(Isolate* isolate,
                                    Handle<JSFunction> constructor,
                                    Handle<JSReceiver> new_target,
                                    Handle<Object> tag, Handle<Object> options) {
-  Handle<JSObject> result;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, result,
-                             JSObject::New(constructor, new_target), JSLocale);
-
-  // First parameter is a locale, as a string/object. Can't be empty.
+  Handle<JSObject> locale;
+  // 6. Let locale be ? OrdinaryCreateFromConstructor(NewTarget,
+  // %LocalePrototype%, internalSlotsList).
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, locale,
+      JSObject::New(constructor, new_target, Handle<AllocationSite>::null()),
+      JSLocale);
+
+  // 7. If Type(tag) is not String or Object, throw a TypeError exception.
   if (!tag->IsString() && !tag->IsJSReceiver()) {
     THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kLocaleNotEmpty),
                     JSLocale);
   }
 
   Handle<String> locale_string;
+  // 8. If Type(tag) is Object and tag has an [[InitializedLocale]] internal
+  // slot, then
   if (tag->IsJSLocale() && Handle<JSLocale>::cast(tag)->locale()->IsString()) {
+    // a. Let tag be tag.[[Locale]].
     locale_string =
         Handle<String>(Handle<JSLocale>::cast(tag)->locale(), isolate);
-  } else {
+  } else {  // 9. Else,
+    // a. Let tag be ? ToString(tag).
     ASSIGN_RETURN_ON_EXCEPTION(isolate, locale_string,
                                Object::ToString(isolate, tag), JSLocale);
   }
 
   Handle<JSReceiver> options_object;
-  if (options->IsNullOrUndefined(isolate)) {
-    // Make empty options bag.
+  // 10. If options is undefined, then
+  if (options->IsUndefined(isolate)) {
+    // a. Let options be ! ObjectCreate(null).
     options_object = isolate->factory()->NewJSObjectWithNullProto();
-  } else {
+  } else {  // 11. Else
+    // a. Let options be ? ToObject(options).
     ASSIGN_RETURN_ON_EXCEPTION(isolate, options_object,
                                Object::ToObject(isolate, options), JSLocale);
   }
 
-  return JSLocale::InitializeLocale(isolate, Handle<JSLocale>::cast(result),
-                                    locale_string, options_object);
+  return JSLocale::Initialize(isolate, Handle<JSLocale>::cast(locale),
+                              locale_string, options_object);
 }
 
 }  // namespace
@@ -745,6 +588,9 @@ MaybeHandle<JSLocale> CreateLocale(Isolate* isolate,
 // Intl.Locale implementation
 BUILTIN(LocaleConstructor) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kLocale);
+
   if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewTypeError(MessageTemplate::kConstructorNotFunction,
@@ -786,186 +632,17 @@ BUILTIN(LocalePrototypeMinimize) {
                    isolate->factory()->NewJSObjectWithNullProto()));
 }
 
-namespace {
-
-MaybeHandle<JSArray> GenerateRelativeTimeFormatParts(
-    Isolate* isolate, icu::UnicodeString formatted,
-    icu::UnicodeString integer_part, Handle<String> unit) {
-  Factory* factory = isolate->factory();
-  Handle<JSArray> array = factory->NewJSArray(0);
-  int32_t found = formatted.indexOf(integer_part);
-
-  Handle<String> substring;
-  if (found < 0) {
-    // Cannot find the integer_part in the formatted.
-    // Return [{'type': 'literal', 'value': formatted}]
-    ASSIGN_RETURN_ON_EXCEPTION(isolate, substring,
-                               Intl::ToString(isolate, formatted), JSArray);
-    Intl::AddElement(isolate, array,
-                     0,                          // index
-                     factory->literal_string(),  // field_type_string
-                     substring);
-  } else {
-    // Found the formatted integer in the result.
-    int index = 0;
-
-    // array.push({
-    //     'type': 'literal',
-    //     'value': formatted.substring(0, found)})
-    if (found > 0) {
-      ASSIGN_RETURN_ON_EXCEPTION(isolate, substring,
-                                 Intl::ToString(isolate, formatted, 0, found),
-                                 JSArray);
-      Intl::AddElement(isolate, array, index++,
-                       factory->literal_string(),  // field_type_string
-                       substring);
-    }
-
-    // array.push({
-    //     'type': 'integer',
-    //     'value': formatted.substring(found, found + integer_part.length),
-    //     'unit': unit})
-    ASSIGN_RETURN_ON_EXCEPTION(isolate, substring,
-                               Intl::ToString(isolate, formatted, found,
-                                              found + integer_part.length()),
-                               JSArray);
-    Intl::AddElement(isolate, array, index++,
-                     factory->integer_string(),  // field_type_string
-                     substring, factory->unit_string(), unit);
-
-    // array.push({
-    //     'type': 'literal',
-    //     'value': formatted.substring(
-    //         found + integer_part.length, formatted.length)})
-    if (found + integer_part.length() < formatted.length()) {
-      ASSIGN_RETURN_ON_EXCEPTION(
-          isolate, substring,
-          Intl::ToString(isolate, formatted, found + integer_part.length(),
-                         formatted.length()),
-          JSArray);
-      Intl::AddElement(isolate, array, index,
-                       factory->literal_string(),  // field_type_string
-                       substring);
-    }
-  }
-  return array;
-}
-
-bool GetURelativeDateTimeUnit(Handle<String> unit,
-                              URelativeDateTimeUnit* unit_enum) {
-  std::unique_ptr<char[]> unit_str = unit->ToCString();
-  if ((strcmp("second", unit_str.get()) == 0) ||
-      (strcmp("seconds", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_SECOND;
-  } else if ((strcmp("minute", unit_str.get()) == 0) ||
-             (strcmp("minutes", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_MINUTE;
-  } else if ((strcmp("hour", unit_str.get()) == 0) ||
-             (strcmp("hours", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_HOUR;
-  } else if ((strcmp("day", unit_str.get()) == 0) ||
-             (strcmp("days", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_DAY;
-  } else if ((strcmp("week", unit_str.get()) == 0) ||
-             (strcmp("weeks", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_WEEK;
-  } else if ((strcmp("month", unit_str.get()) == 0) ||
-             (strcmp("months", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_MONTH;
-  } else if ((strcmp("quarter", unit_str.get()) == 0) ||
-             (strcmp("quarters", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_QUARTER;
-  } else if ((strcmp("year", unit_str.get()) == 0) ||
-             (strcmp("years", unit_str.get()) == 0)) {
-    *unit_enum = UDAT_REL_UNIT_YEAR;
-  } else {
-    return false;
-  }
-  return true;
-}
-
-MaybeHandle<Object> RelativeTimeFormatPrototypeFormatCommon(
-    BuiltinArguments args, Isolate* isolate,
-    Handle<JSRelativeTimeFormat> format_holder, const char* func_name,
-    bool to_parts) {
-  Factory* factory = isolate->factory();
-  Handle<Object> value_obj = args.atOrUndefined(isolate, 1);
-  Handle<Object> unit_obj = args.atOrUndefined(isolate, 2);
-
-  // 3. Let value be ? ToNumber(value).
-  Handle<Object> value;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, value,
-                             Object::ToNumber(isolate, value_obj), Object);
-  double number = value->Number();
-  // 4. Let unit be ? ToString(unit).
-  Handle<String> unit;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, unit, Object::ToString(isolate, unit_obj),
-                             Object);
-
-  // 4. If isFinite(value) is false, then throw a RangeError exception.
-  if (!std::isfinite(number)) {
-    THROW_NEW_ERROR(
-        isolate,
-        NewRangeError(MessageTemplate::kNotFiniteNumber,
-                      isolate->factory()->NewStringFromAsciiChecked(func_name)),
-        Object);
-  }
-
-  icu::RelativeDateTimeFormatter* formatter =
-      JSRelativeTimeFormat::UnpackFormatter(format_holder);
-  CHECK_NOT_NULL(formatter);
-
-  URelativeDateTimeUnit unit_enum;
-  if (!GetURelativeDateTimeUnit(unit, &unit_enum)) {
-    THROW_NEW_ERROR(
-        isolate,
-        NewRangeError(MessageTemplate::kInvalidUnit,
-                      isolate->factory()->NewStringFromAsciiChecked(func_name),
-                      unit),
-        Object);
-  }
-
-  UErrorCode status = U_ZERO_ERROR;
-  icu::UnicodeString formatted;
-  if (unit_enum == UDAT_REL_UNIT_QUARTER) {
-    // ICU have not yet implement UDAT_REL_UNIT_QUARTER.
-  } else {
-    if (format_holder->numeric() == JSRelativeTimeFormat::Numeric::ALWAYS) {
-      formatter->formatNumeric(number, unit_enum, formatted, status);
-    } else {
-      DCHECK_EQ(JSRelativeTimeFormat::Numeric::AUTO, format_holder->numeric());
-      formatter->format(number, unit_enum, formatted, status);
-    }
-  }
-
-  if (U_FAILURE(status)) {
-    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), Object);
-  }
-
-  if (to_parts) {
-    icu::UnicodeString integer;
-    icu::FieldPosition pos;
-    formatter->getNumberFormat().format(std::abs(number), integer, pos, status);
-    if (U_FAILURE(status)) {
-      THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError),
-                      Object);
-    }
-
-    Handle<JSArray> elements;
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, elements,
-        GenerateRelativeTimeFormatParts(isolate, formatted, integer, unit),
-        Object);
-    return elements;
-  }
+BUILTIN(RelativeTimeFormatSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
 
-  return factory->NewStringFromTwoByte(Vector<const uint16_t>(
-      reinterpret_cast<const uint16_t*>(formatted.getBuffer()),
-      formatted.length()));
+  RETURN_RESULT_OR_FAILURE(
+      isolate,
+      Intl::SupportedLocalesOf(isolate, ICUService::kRelativeDateTimeFormatter,
+                               locales, options));
 }
 
-}  // namespace
-
 BUILTIN(RelativeTimeFormatPrototypeFormat) {
   HandleScope scope(isolate);
   // 1. Let relativeTimeFormat be the this value.
@@ -974,9 +651,12 @@ BUILTIN(RelativeTimeFormatPrototypeFormat) {
   //    true, throw a TypeError exception.
   CHECK_RECEIVER(JSRelativeTimeFormat, format_holder,
                  "Intl.RelativeTimeFormat.prototype.format");
-  RETURN_RESULT_OR_FAILURE(isolate,
-                           RelativeTimeFormatPrototypeFormatCommon(
-                               args, isolate, format_holder, "format", false));
+  Handle<Object> value_obj = args.atOrUndefined(isolate, 1);
+  Handle<Object> unit_obj = args.atOrUndefined(isolate, 2);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSRelativeTimeFormat::Format(isolate, value_obj, unit_obj,
+                                            format_holder, "format", false));
 }
 
 BUILTIN(RelativeTimeFormatPrototypeFormatToParts) {
@@ -987,9 +667,11 @@ BUILTIN(RelativeTimeFormatPrototypeFormatToParts) {
   //    true, throw a TypeError exception.
   CHECK_RECEIVER(JSRelativeTimeFormat, format_holder,
                  "Intl.RelativeTimeFormat.prototype.formatToParts");
-  RETURN_RESULT_OR_FAILURE(
-      isolate, RelativeTimeFormatPrototypeFormatCommon(
-                   args, isolate, format_holder, "formatToParts", true));
+  Handle<Object> value_obj = args.atOrUndefined(isolate, 1);
+  Handle<Object> unit_obj = args.atOrUndefined(isolate, 2);
+  RETURN_RESULT_OR_FAILURE(isolate, JSRelativeTimeFormat::Format(
+                                        isolate, value_obj, unit_obj,
+                                        format_holder, "formatToParts", true));
 }
 
 // Locale getters.
@@ -1033,7 +715,7 @@ BUILTIN(LocalePrototypeCaseFirst) {
   HandleScope scope(isolate);
   CHECK_RECEIVER(JSLocale, locale_holder, "Intl.Locale.prototype.caseFirst");
 
-  return locale_holder->case_first();
+  return *(locale_holder->CaseFirstAsString());
 }
 
 BUILTIN(LocalePrototypeCollation) {
@@ -1047,14 +729,23 @@ BUILTIN(LocalePrototypeHourCycle) {
   HandleScope scope(isolate);
   CHECK_RECEIVER(JSLocale, locale_holder, "Intl.Locale.prototype.hourCycle");
 
-  return locale_holder->hour_cycle();
+  return *(locale_holder->HourCycleAsString());
 }
 
 BUILTIN(LocalePrototypeNumeric) {
   HandleScope scope(isolate);
   CHECK_RECEIVER(JSLocale, locale_holder, "Intl.Locale.prototype.numeric");
 
-  return locale_holder->numeric();
+  switch (locale_holder->numeric()) {
+    case JSLocale::Numeric::TRUE_VALUE:
+      return *(isolate->factory()->true_value());
+    case JSLocale::Numeric::FALSE_VALUE:
+      return *(isolate->factory()->false_value());
+    case JSLocale::Numeric::NOTSET:
+      return *(isolate->factory()->undefined_value());
+    case JSLocale::Numeric::COUNT:
+      UNREACHABLE();
+  }
 }
 
 BUILTIN(LocalePrototypeNumberingSystem) {
@@ -1074,6 +765,9 @@ BUILTIN(LocalePrototypeToString) {
 
 BUILTIN(RelativeTimeFormatConstructor) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kRelativeTimeFormat);
+
   // 1. If NewTarget is undefined, throw a TypeError exception.
   if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
     THROW_NEW_ERROR_RETURN_FAILURE(
@@ -1089,8 +783,9 @@ BUILTIN(RelativeTimeFormatConstructor) {
   // 2. Let relativeTimeFormat be
   //    ! OrdinaryCreateFromConstructor(NewTarget,
   //                                    "%RelativeTimeFormatPrototype%").
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   Handle<JSRelativeTimeFormat> format =
       Handle<JSRelativeTimeFormat>::cast(result);
   format->set_flags(0);
@@ -1100,9 +795,8 @@ BUILTIN(RelativeTimeFormatConstructor) {
 
   // 3. Return ? InitializeRelativeTimeFormat(relativeTimeFormat, locales,
   //                                          options).
-  RETURN_RESULT_OR_FAILURE(isolate,
-                           JSRelativeTimeFormat::InitializeRelativeTimeFormat(
-                               isolate, format, locales, options));
+  RETURN_RESULT_OR_FAILURE(isolate, JSRelativeTimeFormat::Initialize(
+                                        isolate, format, locales, options));
 }
 
 BUILTIN(RelativeTimeFormatPrototypeResolvedOptions) {
@@ -1114,7 +808,11 @@ BUILTIN(RelativeTimeFormatPrototypeResolvedOptions) {
 
 BUILTIN(StringPrototypeToLocaleLowerCase) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kStringToLocaleLowerCase);
+
   TO_THIS_STRING(string, "String.prototype.toLocaleLowerCase");
+
   RETURN_RESULT_OR_FAILURE(
       isolate, Intl::StringLocaleConvertCase(isolate, string, false,
                                              args.atOrUndefined(isolate, 1)));
@@ -1122,7 +820,11 @@ BUILTIN(StringPrototypeToLocaleLowerCase) {
 
 BUILTIN(StringPrototypeToLocaleUpperCase) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kStringToLocaleUpperCase);
+
   TO_THIS_STRING(string, "String.prototype.toLocaleUpperCase");
+
   RETURN_RESULT_OR_FAILURE(
       isolate, Intl::StringLocaleConvertCase(isolate, string, true,
                                              args.atOrUndefined(isolate, 1)));
@@ -1131,6 +833,8 @@ BUILTIN(StringPrototypeToLocaleUpperCase) {
 BUILTIN(PluralRulesConstructor) {
   HandleScope scope(isolate);
 
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kPluralRules);
+
   // 1. If NewTarget is undefined, throw a TypeError exception.
   if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
     THROW_NEW_ERROR_RETURN_FAILURE(
@@ -1152,19 +856,61 @@ BUILTIN(PluralRulesConstructor) {
   // [[MinimumFractionDigits]], [[MaximumFractionDigits]],
   // [[MinimumSignificantDigits]], [[MaximumSignificantDigits]] »).
   Handle<JSObject> plural_rules_obj;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, plural_rules_obj,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, plural_rules_obj,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   Handle<JSPluralRules> plural_rules =
       Handle<JSPluralRules>::cast(plural_rules_obj);
 
   // 3. Return ? InitializePluralRules(pluralRules, locales, options).
   RETURN_RESULT_OR_FAILURE(
-      isolate, JSPluralRules::InitializePluralRules(isolate, plural_rules,
-                                                    locales, options));
+      isolate,
+      JSPluralRules::Initialize(isolate, plural_rules, locales, options));
+}
+
+BUILTIN(PluralRulesPrototypeResolvedOptions) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSPluralRules, plural_rules_holder,
+                 "Intl.PluralRules.prototype.resolvedOptions");
+  return *JSPluralRules::ResolvedOptions(isolate, plural_rules_holder);
+}
+
+BUILTIN(PluralRulesPrototypeSelect) {
+  HandleScope scope(isolate);
+
+  // 1. Let pr be the this value.
+  // 2. If Type(pr) is not Object, throw a TypeError exception.
+  // 3. If pr does not have an [[InitializedPluralRules]] internal slot, throw a
+  // TypeError exception.
+  CHECK_RECEIVER(JSPluralRules, plural_rules,
+                 "Intl.PluralRules.prototype.select");
+
+  // 4. Let n be ? ToNumber(value).
+  Handle<Object> number = args.atOrUndefined(isolate, 1);
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, number,
+                                     Object::ToNumber(isolate, number));
+  double number_double = number->Number();
+
+  // 5. Return ? ResolvePlural(pr, n).
+  RETURN_RESULT_OR_FAILURE(isolate, JSPluralRules::ResolvePlural(
+                                        isolate, plural_rules, number_double));
+}
+
+BUILTIN(PluralRulesSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kPluralRules,
+                                        locales, options));
 }
 
 BUILTIN(CollatorConstructor) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kCollator);
+
   Handle<JSReceiver> new_target;
   // 1. If NewTarget is undefined, let newTarget be the active
   // function object, else let newTarget be NewTarget.
@@ -1183,14 +929,31 @@ BUILTIN(CollatorConstructor) {
   // 5. Let collator be ? OrdinaryCreateFromConstructor(newTarget,
   // "%CollatorPrototype%", internalSlotsList).
   Handle<JSObject> collator_obj;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, collator_obj,
-                                     JSObject::New(target, new_target));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, collator_obj,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
   Handle<JSCollator> collator = Handle<JSCollator>::cast(collator_obj);
-  collator->set_flags(0);
 
   // 6. Return ? InitializeCollator(collator, locales, options).
-  RETURN_RESULT_OR_FAILURE(isolate, JSCollator::InitializeCollator(
-                                        isolate, collator, locales, options));
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSCollator::Initialize(isolate, collator, locales, options));
+}
+
+BUILTIN(CollatorPrototypeResolvedOptions) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSCollator, collator_holder,
+                 "Intl.Collator.prototype.resolvedOptions");
+  return *JSCollator::ResolvedOptions(isolate, collator_holder);
+}
+
+BUILTIN(CollatorSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kCollator, locales,
+                                        options));
 }
 
 BUILTIN(CollatorPrototypeCompare) {
@@ -1211,21 +974,8 @@ BUILTIN(CollatorPrototypeCompare) {
     return *bound_compare;
   }
 
-  Handle<NativeContext> native_context(isolate->context()->native_context(),
-                                       isolate);
-  Handle<Context> context = isolate->factory()->NewBuiltinContext(
-      native_context, JSCollator::ContextSlot::kLength);
-
-  // 4.b. Set F.[[Collator]] to collator.
-  context->set(JSCollator::ContextSlot::kCollator, *collator);
-
-  Handle<SharedFunctionInfo> info = Handle<SharedFunctionInfo>(
-      native_context->collator_internal_compare_shared_fun(), isolate);
-  Handle<Map> map = isolate->strict_function_without_prototype_map();
-
-  // 4.a. Let F be a new built-in function object as defined in 10.3.3.1.
-  Handle<JSFunction> new_bound_compare_function =
-      isolate->factory()->NewFunctionFromSharedFunctionInfo(map, info, context);
+  Handle<JSFunction> new_bound_compare_function = CreateBoundFunction(
+      isolate, collator, Builtins::kCollatorInternalCompare, 2);
 
   // 4.c. Set collator.[[BoundCompare]] to F.
   collator->set_bound_compare(*new_bound_compare_function);
@@ -1242,7 +992,8 @@ BUILTIN(CollatorInternalCompare) {
   // 2. Assert: Type(collator) is Object and collator has an
   // [[InitializedCollator]] internal slot.
   Handle<JSCollator> collator_holder = Handle<JSCollator>(
-      JSCollator::cast(context->get(JSCollator::ContextSlot::kCollator)),
+      JSCollator::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
       isolate);
 
   // 3. If x is not provided, let x be undefined.
@@ -1263,71 +1014,280 @@ BUILTIN(CollatorInternalCompare) {
   return *Intl::CompareStrings(isolate, collator_holder, string_x, string_y);
 }
 
-BUILTIN(BreakIteratorPrototypeAdoptText) {
-  const char* const method = "get Intl.v8BreakIterator.prototype.adoptText";
+BUILTIN(SegmenterConstructor) {
   HandleScope scope(isolate);
 
-  CHECK_RECEIVER(JSObject, break_iterator_holder, method);
-  if (!Intl::IsObjectOfType(isolate, break_iterator_holder,
-                            Intl::Type::kBreakIterator)) {
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kSegmenter);
+
+  // 1. If NewTarget is undefined, throw a TypeError exception.
+  if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
     THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate,
-        NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                     isolate->factory()->NewStringFromAsciiChecked(method),
-                     break_iterator_holder));
+        isolate, NewTypeError(MessageTemplate::kConstructorNotFunction,
+                              isolate->factory()->NewStringFromStaticChars(
+                                  "Intl.Segmenter")));
   }
+  // [[Construct]]
+  Handle<JSFunction> target = args.target();
+  Handle<JSReceiver> new_target = Handle<JSReceiver>::cast(args.new_target());
 
-  Handle<Object> bound_adopt_text =
-      Handle<Object>(break_iterator_holder->GetEmbedderField(
-                         V8BreakIterator::kBoundAdoptTextIndex),
-                     isolate);
+  Handle<JSObject> result;
+  // 2. Let segmenter be OrdinaryCreateFromConstructor(NewTarget,
+  //    "%SegmenterPrototype%").
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
+  Handle<JSSegmenter> segmenter = Handle<JSSegmenter>::cast(result);
+  segmenter->set_flags(0);
 
-  if (!bound_adopt_text->IsUndefined(isolate)) {
-    DCHECK(bound_adopt_text->IsJSFunction());
-    return *bound_adopt_text;
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSSegmenter::Initialize(isolate, segmenter, locales, options));
+}
+
+BUILTIN(SegmenterSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Intl::SupportedLocalesOf(isolate, ICUService::kSegmenter,
+                                        locales, options));
+}
+
+BUILTIN(SegmenterPrototypeResolvedOptions) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSSegmenter, segmenter_holder,
+                 "Intl.Segmenter.prototype.resolvedOptions");
+  return *JSSegmenter::ResolvedOptions(isolate, segmenter_holder);
+}
+
+BUILTIN(V8BreakIteratorConstructor) {
+  HandleScope scope(isolate);
+  Handle<JSReceiver> new_target;
+
+  if (args.new_target()->IsUndefined(isolate)) {
+    new_target = args.target();
+  } else {
+    new_target = Handle<JSReceiver>::cast(args.new_target());
   }
 
-  Handle<NativeContext> native_context(isolate->context()->native_context(),
-                                       isolate);
-  Handle<Context> context = isolate->factory()->NewBuiltinContext(
-      native_context, static_cast<int>(V8BreakIterator::ContextSlot::kLength));
+  // [[Construct]]
+  Handle<JSFunction> target = args.target();
 
-  context->set(static_cast<int>(V8BreakIterator::ContextSlot::kV8BreakIterator),
-               *break_iterator_holder);
+  Handle<Object> locales = args.atOrUndefined(isolate, 1);
+  Handle<Object> options = args.atOrUndefined(isolate, 2);
 
-  Handle<SharedFunctionInfo> info = Handle<SharedFunctionInfo>(
-      native_context->break_iterator_internal_adopt_text_shared_fun(), isolate);
-  Handle<Map> map = isolate->strict_function_without_prototype_map();
+  Handle<JSObject> break_iterator_obj;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, break_iterator_obj,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
+  Handle<JSV8BreakIterator> break_iterator =
+      Handle<JSV8BreakIterator>::cast(break_iterator_obj);
 
-  Handle<JSFunction> new_bound_adopt_text_function =
-      isolate->factory()->NewFunctionFromSharedFunctionInfo(map, info, context);
+  RETURN_RESULT_OR_FAILURE(
+      isolate,
+      JSV8BreakIterator::Initialize(isolate, break_iterator, locales, options));
+}
 
-  break_iterator_holder->SetEmbedderField(V8BreakIterator::kBoundAdoptTextIndex,
-                                          *new_bound_adopt_text_function);
+BUILTIN(V8BreakIteratorPrototypeResolvedOptions) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSV8BreakIterator, break_iterator,
+                 "Intl.v8BreakIterator.prototype.resolvedOptions");
+  return *JSV8BreakIterator::ResolvedOptions(isolate, break_iterator);
+}
+
+BUILTIN(V8BreakIteratorPrototypeAdoptText) {
+  const char* const method = "get Intl.v8BreakIterator.prototype.adoptText";
+  HandleScope scope(isolate);
+
+  CHECK_RECEIVER(JSV8BreakIterator, break_iterator, method);
+
+  Handle<Object> bound_adopt_text(break_iterator->bound_adopt_text(), isolate);
+  if (!bound_adopt_text->IsUndefined(isolate)) {
+    DCHECK(bound_adopt_text->IsJSFunction());
+    return *bound_adopt_text;
+  }
 
+  Handle<JSFunction> new_bound_adopt_text_function = CreateBoundFunction(
+      isolate, break_iterator, Builtins::kV8BreakIteratorInternalAdoptText, 1);
+  break_iterator->set_bound_adopt_text(*new_bound_adopt_text_function);
   return *new_bound_adopt_text_function;
 }
 
-BUILTIN(BreakIteratorInternalAdoptText) {
+BUILTIN(V8BreakIteratorInternalAdoptText) {
   HandleScope scope(isolate);
   Handle<Context> context = Handle<Context>(isolate->context(), isolate);
 
-  Handle<JSObject> break_iterator_holder = Handle<JSObject>(
-      JSObject::cast(context->get(
-          static_cast<int>(V8BreakIterator::ContextSlot::kV8BreakIterator))),
+  Handle<JSV8BreakIterator> break_iterator_holder = Handle<JSV8BreakIterator>(
+      JSV8BreakIterator::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
       isolate);
 
-  DCHECK(Intl::IsObjectOfType(isolate, break_iterator_holder,
-                              Intl::Type::kBreakIterator));
-
   Handle<Object> input_text = args.atOrUndefined(isolate, 1);
   Handle<String> text;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, text,
                                      Object::ToString(isolate, input_text));
 
-  V8BreakIterator::AdoptText(isolate, break_iterator_holder, text);
+  JSV8BreakIterator::AdoptText(isolate, break_iterator_holder, text);
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
+BUILTIN(V8BreakIteratorPrototypeFirst) {
+  const char* const method = "get Intl.v8BreakIterator.prototype.first";
+  HandleScope scope(isolate);
+
+  CHECK_RECEIVER(JSV8BreakIterator, break_iterator_holder, method);
+
+  Handle<Object> bound_first(break_iterator_holder->bound_first(), isolate);
+  if (!bound_first->IsUndefined(isolate)) {
+    DCHECK(bound_first->IsJSFunction());
+    return *bound_first;
+  }
+
+  Handle<JSFunction> new_bound_first_function =
+      CreateBoundFunction(isolate, break_iterator_holder,
+                          Builtins::kV8BreakIteratorInternalFirst, 0);
+  break_iterator_holder->set_bound_first(*new_bound_first_function);
+  return *new_bound_first_function;
+}
+
+BUILTIN(V8BreakIteratorInternalFirst) {
+  HandleScope scope(isolate);
+  Handle<Context> context = Handle<Context>(isolate->context(), isolate);
+
+  Handle<JSV8BreakIterator> break_iterator_holder = Handle<JSV8BreakIterator>(
+      JSV8BreakIterator::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
+      isolate);
+
+  icu::BreakIterator* break_iterator =
+      break_iterator_holder->break_iterator()->raw();
+  CHECK_NOT_NULL(break_iterator);
+
+  return *isolate->factory()->NewNumberFromInt(break_iterator->first());
+}
+
+BUILTIN(V8BreakIteratorPrototypeNext) {
+  const char* const method = "get Intl.v8BreakIterator.prototype.next";
+  HandleScope scope(isolate);
+
+  CHECK_RECEIVER(JSV8BreakIterator, break_iterator_holder, method);
+
+  Handle<Object> bound_next(break_iterator_holder->bound_next(), isolate);
+  if (!bound_next->IsUndefined(isolate)) {
+    DCHECK(bound_next->IsJSFunction());
+    return *bound_next;
+  }
+
+  Handle<JSFunction> new_bound_next_function =
+      CreateBoundFunction(isolate, break_iterator_holder,
+                          Builtins::kV8BreakIteratorInternalNext, 0);
+  break_iterator_holder->set_bound_next(*new_bound_next_function);
+  return *new_bound_next_function;
+}
+
+BUILTIN(V8BreakIteratorInternalNext) {
+  HandleScope scope(isolate);
+  Handle<Context> context = Handle<Context>(isolate->context(), isolate);
+
+  Handle<JSV8BreakIterator> break_iterator_holder = Handle<JSV8BreakIterator>(
+      JSV8BreakIterator::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
+      isolate);
+
+  icu::BreakIterator* break_iterator =
+      break_iterator_holder->break_iterator()->raw();
+  CHECK_NOT_NULL(break_iterator);
+
+  return *isolate->factory()->NewNumberFromInt(break_iterator->next());
+}
+
+BUILTIN(V8BreakIteratorPrototypeCurrent) {
+  const char* const method = "get Intl.v8BreakIterator.prototype.current";
+  HandleScope scope(isolate);
+
+  CHECK_RECEIVER(JSV8BreakIterator, break_iterator_holder, method);
+
+  Handle<Object> bound_current(break_iterator_holder->bound_current(), isolate);
+  if (!bound_current->IsUndefined(isolate)) {
+    DCHECK(bound_current->IsJSFunction());
+    return *bound_current;
+  }
+
+  Handle<JSFunction> new_bound_current_function =
+      CreateBoundFunction(isolate, break_iterator_holder,
+                          Builtins::kV8BreakIteratorInternalCurrent, 0);
+  break_iterator_holder->set_bound_current(*new_bound_current_function);
+  return *new_bound_current_function;
+}
+
+BUILTIN(V8BreakIteratorInternalCurrent) {
+  HandleScope scope(isolate);
+  Handle<Context> context = Handle<Context>(isolate->context(), isolate);
+
+  Handle<JSV8BreakIterator> break_iterator_holder = Handle<JSV8BreakIterator>(
+      JSV8BreakIterator::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
+      isolate);
+
+  icu::BreakIterator* break_iterator =
+      break_iterator_holder->break_iterator()->raw();
+  CHECK_NOT_NULL(break_iterator);
+
+  return *isolate->factory()->NewNumberFromInt(break_iterator->current());
+}
+
+BUILTIN(V8BreakIteratorPrototypeBreakType) {
+  const char* const method = "get Intl.v8BreakIterator.prototype.breakType";
+  HandleScope scope(isolate);
+
+  CHECK_RECEIVER(JSV8BreakIterator, break_iterator_holder, method);
+
+  Handle<Object> bound_break_type(break_iterator_holder->bound_break_type(),
+                                  isolate);
+  if (!bound_break_type->IsUndefined(isolate)) {
+    DCHECK(bound_break_type->IsJSFunction());
+    return *bound_break_type;
+  }
+
+  Handle<JSFunction> new_bound_break_type_function =
+      CreateBoundFunction(isolate, break_iterator_holder,
+                          Builtins::kV8BreakIteratorInternalBreakType, 0);
+  break_iterator_holder->set_bound_break_type(*new_bound_break_type_function);
+  return *new_bound_break_type_function;
+}
+
+BUILTIN(V8BreakIteratorInternalBreakType) {
+  HandleScope scope(isolate);
+  Handle<Context> context = Handle<Context>(isolate->context(), isolate);
+
+  Handle<JSV8BreakIterator> break_iterator_holder = Handle<JSV8BreakIterator>(
+      JSV8BreakIterator::cast(context->get(
+          static_cast<int>(Intl::BoundFunctionContextSlot::kBoundFunction))),
+      isolate);
+
+  icu::BreakIterator* break_iterator =
+      break_iterator_holder->break_iterator()->raw();
+  CHECK_NOT_NULL(break_iterator);
+
+  int32_t status = break_iterator->getRuleStatus();
+  // Keep return values in sync with JavaScript BreakType enum.
+  if (status >= UBRK_WORD_NONE && status < UBRK_WORD_NONE_LIMIT) {
+    return *isolate->factory()->NewStringFromStaticChars("none");
+  } else if (status >= UBRK_WORD_NUMBER && status < UBRK_WORD_NUMBER_LIMIT) {
+    return ReadOnlyRoots(isolate).number_string();
+  } else if (status >= UBRK_WORD_LETTER && status < UBRK_WORD_LETTER_LIMIT) {
+    return *isolate->factory()->NewStringFromStaticChars("letter");
+  } else if (status >= UBRK_WORD_KANA && status < UBRK_WORD_KANA_LIMIT) {
+    return *isolate->factory()->NewStringFromStaticChars("kana");
+  } else if (status >= UBRK_WORD_IDEO && status < UBRK_WORD_IDEO_LIMIT) {
+    return *isolate->factory()->NewStringFromStaticChars("ideo");
+  } else {
+    return *isolate->factory()->NewStringFromStaticChars("unknown");
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/builtins/builtins-intl.h b/deps/v8/src/builtins/builtins-intl.h
deleted file mode 100644
index 419ff14db1..0000000000
--- a/deps/v8/src/builtins/builtins-intl.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_BUILTINS_BUILTINS_INTL_H_
-#define V8_BUILTINS_BUILTINS_INTL_H_
-
-#include <stdint.h>
-#include <vector>
-
-namespace v8 {
-namespace internal {
-
-struct NumberFormatSpan {
-  int32_t field_id;
-  int32_t begin_pos;
-  int32_t end_pos;
-
-  NumberFormatSpan() {}
-  NumberFormatSpan(int32_t field_id, int32_t begin_pos, int32_t end_pos)
-      : field_id(field_id), begin_pos(begin_pos), end_pos(end_pos) {}
-};
-
-std::vector<NumberFormatSpan> FlattenRegionsToParts(
-    std::vector<NumberFormatSpan>* regions);
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_BUILTINS_BUILTINS_INTL_H_
diff --git a/deps/v8/src/builtins/builtins-iterator-gen.cc b/deps/v8/src/builtins/builtins-iterator-gen.cc
index 1e16a6b1de..802ed2edb2 100644
--- a/deps/v8/src/builtins/builtins-iterator-gen.cc
+++ b/deps/v8/src/builtins/builtins-iterator-gen.cc
@@ -5,6 +5,10 @@
 #include "src/builtins/builtins-iterator-gen.h"
 #include "src/builtins/growable-fixed-array-gen.h"
 
+#include "src/builtins/builtins-string-gen.h"
+#include "src/builtins/builtins-utils-gen.h"
+#include "src/builtins/builtins.h"
+#include "src/code-stub-assembler.h"
 #include "src/heap/factory-inl.h"
 
 namespace v8 {
@@ -38,8 +42,7 @@ IteratorRecord IteratorBuiltinsAssembler::GetIterator(Node* context,
 
   BIND(&if_not_callable);
   {
-    Node* ret = CallRuntime(Runtime::kThrowTypeError, context,
-                            SmiConstant(MessageTemplate::kNotIterable), object);
+    Node* ret = CallRuntime(Runtime::kThrowIteratorError, context, object);
     GotoIfException(ret, if_exception, exception);
     Unreachable();
   }
@@ -197,62 +200,104 @@ void IteratorBuiltinsAssembler::IteratorCloseOnException(
 
 TNode<JSArray> IteratorBuiltinsAssembler::IterableToList(
     TNode<Context> context, TNode<Object> iterable, TNode<Object> iterator_fn) {
-  Label fast_path(this), slow_path(this), done(this);
+  // 1. Let iteratorRecord be ? GetIterator(items, method).
+  IteratorRecord iterator_record = GetIterator(context, iterable, iterator_fn);
+
+  // 2. Let values be a new empty List.
+  GrowableFixedArray values(state());
+
+  Variable* vars[] = {values.var_array(), values.var_length(),
+                      values.var_capacity()};
+  Label loop_start(this, 3, vars), done(this);
+  Goto(&loop_start);
+  // 3. Let next be true.
+  // 4. Repeat, while next is not false
+  BIND(&loop_start);
+  {
+    //  a. Set next to ? IteratorStep(iteratorRecord).
+    TNode<Object> next = CAST(IteratorStep(context, iterator_record, &done));
+    //  b. If next is not false, then
+    //   i. Let nextValue be ? IteratorValue(next).
+    TNode<Object> next_value = CAST(IteratorValue(context, next));
+    //   ii. Append nextValue to the end of the List values.
+    values.Push(next_value);
+    Goto(&loop_start);
+  }
 
-  TVARIABLE(JSArray, created_list);
+  BIND(&done);
+  return values.ToJSArray(context);
+}
 
-  Branch(IsFastJSArrayWithNoCustomIteration(iterable, context), &fast_path,
-         &slow_path);
+TF_BUILTIN(IterableToList, IteratorBuiltinsAssembler) {
+  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
+  TNode<Object> iterable = CAST(Parameter(Descriptor::kIterable));
+  TNode<Object> iterator_fn = CAST(Parameter(Descriptor::kIteratorFn));
 
-  // This is a fast-path for ignoring the iterator.
-  BIND(&fast_path);
-  {
-    TNode<JSArray> input_array = CAST(iterable);
-    created_list = CAST(CloneFastJSArray(context, input_array));
-    Goto(&done);
-  }
+  Return(IterableToList(context, iterable, iterator_fn));
+}
 
-  BIND(&slow_path);
-  {
-    // 1. Let iteratorRecord be ? GetIterator(items, method).
-    IteratorRecord iterator_record =
-        GetIterator(context, iterable, iterator_fn);
+// This builtin always returns a new JSArray and is thus safe to use even in the
+// presence of code that may call back into user-JS. This builtin will take the
+// fast path if the iterable is a fast array and the Array prototype and the
+// Symbol.iterator is untouched. The fast path skips the iterator and copies the
+// backing store to the new array. Note that if the array has holes, the holes
+// will be copied to the new array, which is inconsistent with the behavior of
+// an actual iteration, where holes should be replaced with undefined (if the
+// prototype has no elements). To maintain the correct behavior for holey
+// arrays, use the builtins IterableToList or IterableToListWithSymbolLookup.
+TF_BUILTIN(IterableToListMayPreserveHoles, IteratorBuiltinsAssembler) {
+  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
+  TNode<Object> iterable = CAST(Parameter(Descriptor::kIterable));
+  TNode<Object> iterator_fn = CAST(Parameter(Descriptor::kIteratorFn));
 
-    // 2. Let values be a new empty List.
-    GrowableFixedArray values(state());
+  Label slow_path(this);
 
-    Variable* vars[] = {values.var_array(), values.var_length(),
-                        values.var_capacity()};
-    Label loop_start(this, 3, vars), loop_end(this);
-    Goto(&loop_start);
-    // 3. Let next be true.
-    // 4. Repeat, while next is not false
-    BIND(&loop_start);
-    {
-      //  a. Set next to ? IteratorStep(iteratorRecord).
-      TNode<Object> next =
-          CAST(IteratorStep(context, iterator_record, &loop_end));
-      //  b. If next is not false, then
-      //   i. Let nextValue be ? IteratorValue(next).
-      TNode<Object> next_value = CAST(IteratorValue(context, next));
-      //   ii. Append nextValue to the end of the List values.
-      values.Push(next_value);
-      Goto(&loop_start);
-    }
-    BIND(&loop_end);
+  GotoIfNot(IsFastJSArrayWithNoCustomIteration(iterable, context), &slow_path);
 
-    created_list = values.ToJSArray(context);
-    Goto(&done);
-  }
+  // The fast path will copy holes to the new array.
+  TailCallBuiltin(Builtins::kCloneFastJSArray, context, iterable);
 
-  BIND(&done);
-  return created_list.value();
+  BIND(&slow_path);
+  TailCallBuiltin(Builtins::kIterableToList, context, iterable, iterator_fn);
 }
 
-TNode<JSArray> IteratorBuiltinsAssembler::IterableToList(
-    TNode<Context> context, TNode<Object> iterable) {
-  TNode<Object> method = GetIteratorMethod(context, iterable);
-  return IterableToList(context, iterable, method);
+// This builtin loads the property Symbol.iterator as the iterator, and has a
+// fast path for fast arrays and another one for strings. These fast paths will
+// only be taken if Symbol.iterator and the Iterator prototype are not modified
+// in a way that changes the original iteration behavior.
+// * In case of fast holey arrays, holes will be converted to undefined to
+// reflect iteration semantics. Note that replacement by undefined is only
+// correct when the NoElements protector is valid.
+TF_BUILTIN(IterableToListWithSymbolLookup, IteratorBuiltinsAssembler) {
+  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
+  TNode<Object> iterable = CAST(Parameter(Descriptor::kIterable));
+
+  Label slow_path(this), check_string(this);
+
+  GotoIfForceSlowPath(&slow_path);
+
+  GotoIfNot(IsFastJSArrayWithNoCustomIteration(iterable, context),
+            &check_string);
+
+  // Fast path for fast JSArray.
+  TailCallBuiltin(Builtins::kCloneFastJSArrayFillingHoles, context, iterable);
+
+  BIND(&check_string);
+  {
+    StringBuiltinsAssembler string_assembler(state());
+    GotoIfNot(string_assembler.IsStringPrimitiveWithNoCustomIteration(iterable,
+                                                                      context),
+              &slow_path);
+
+    // Fast path for strings.
+    TailCallBuiltin(Builtins::kStringToList, context, iterable);
+  }
+
+  BIND(&slow_path);
+  {
+    TNode<Object> iterator_fn = GetIteratorMethod(context, iterable);
+    TailCallBuiltin(Builtins::kIterableToList, context, iterable, iterator_fn);
+  }
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/builtins/builtins-iterator-gen.h b/deps/v8/src/builtins/builtins-iterator-gen.h
index 71d4b9753c..f61f7f52c0 100644
--- a/deps/v8/src/builtins/builtins-iterator-gen.h
+++ b/deps/v8/src/builtins/builtins-iterator-gen.h
@@ -54,10 +54,11 @@ class IteratorBuiltinsAssembler : public CodeStubAssembler {
   void IteratorCloseOnException(Node* context, const IteratorRecord& iterator,
                                 Variable* exception);
 
-  // /#sec-iterabletolist
+  // #sec-iterabletolist
+  // Build a JSArray by iterating over {iterable} using {iterator_fn},
+  // following the ECMAscript operation with the same name.
   TNode<JSArray> IterableToList(TNode<Context> context, TNode<Object> iterable,
                                 TNode<Object> iterator_fn);
-  TNode<JSArray> IterableToList(TNode<Context> context, TNode<Object> iterable);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/builtins/builtins-lazy-gen.cc b/deps/v8/src/builtins/builtins-lazy-gen.cc
index d1314733c7..c11722ec6b 100644
--- a/deps/v8/src/builtins/builtins-lazy-gen.cc
+++ b/deps/v8/src/builtins/builtins-lazy-gen.cc
@@ -86,7 +86,7 @@ void LazyBuiltinsAssembler::MaybeTailCallOptimizedCodeSlot(
   {
     // Optimized code slot is a weak reference.
     TNode<Code> optimized_code =
-        CAST(ToWeakHeapObject(maybe_optimized_code_entry, &fallthrough));
+        CAST(GetHeapObjectAssumeWeak(maybe_optimized_code_entry, &fallthrough));
 
     // Check if the optimized code is marked for deopt. If it is, call the
     // runtime to clear it.
diff --git a/deps/v8/src/builtins/builtins-math-gen.cc b/deps/v8/src/builtins/builtins-math-gen.cc
index 952bdda5de..36b0d30939 100644
--- a/deps/v8/src/builtins/builtins-math-gen.cc
+++ b/deps/v8/src/builtins/builtins-math-gen.cc
@@ -413,7 +413,16 @@ TF_BUILTIN(MathRandom, CodeStubAssembler) {
   GotoIf(SmiAbove(smi_index.value(), SmiConstant(0)), &if_cached);
 
   // Cache exhausted, populate the cache. Return value is the new index.
-  smi_index = CAST(CallRuntime(Runtime::kGenerateRandomNumbers, context));
+  Node* const refill_math_random =
+      ExternalConstant(ExternalReference::refill_math_random());
+  Node* const isolate_ptr =
+      ExternalConstant(ExternalReference::isolate_address(isolate()));
+  MachineType type_tagged = MachineType::AnyTagged();
+  MachineType type_ptr = MachineType::Pointer();
+
+  smi_index =
+      CAST(CallCFunction2(type_tagged, type_ptr, type_tagged,
+                          refill_math_random, isolate_ptr, native_context));
   Goto(&if_cached);
 
   // Compute next index by decrement.
diff --git a/deps/v8/src/builtins/builtins-number-gen.cc b/deps/v8/src/builtins/builtins-number-gen.cc
index cfc81612f2..582f6242ad 100644
--- a/deps/v8/src/builtins/builtins-number-gen.cc
+++ b/deps/v8/src/builtins/builtins-number-gen.cc
@@ -525,17 +525,15 @@ TF_BUILTIN(Add, AddStubAssembler) {
   BIND(&string_add_convert_left);
   {
     // Convert {left} to a String and concatenate it with the String {right}.
-    Callable callable =
-        CodeFactory::StringAdd(isolate(), STRING_ADD_CONVERT_LEFT, NOT_TENURED);
-    Return(CallStub(callable, context, var_left.value(), var_right.value()));
+    TailCallBuiltin(Builtins::kStringAdd_ConvertLeft, context, var_left.value(),
+                    var_right.value());
   }
 
   BIND(&string_add_convert_right);
   {
     // Convert {right} to a String and concatenate it with the String {left}.
-    Callable callable = CodeFactory::StringAdd(
-        isolate(), STRING_ADD_CONVERT_RIGHT, NOT_TENURED);
-    Return(CallStub(callable, context, var_left.value(), var_right.value()));
+    TailCallBuiltin(Builtins::kStringAdd_ConvertRight, context,
+                    var_left.value(), var_right.value());
   }
 
   BIND(&do_bigint_add);
diff --git a/deps/v8/src/builtins/builtins-number.cc b/deps/v8/src/builtins/builtins-number.cc
index 2f21c2d4b1..d15c41105d 100644
--- a/deps/v8/src/builtins/builtins-number.cc
+++ b/deps/v8/src/builtins/builtins-number.cc
@@ -111,6 +111,9 @@ BUILTIN(NumberPrototypeToFixed) {
 // ES6 section 20.1.3.4 Number.prototype.toLocaleString ( [ r1 [ , r2 ] ] )
 BUILTIN(NumberPrototypeToLocaleString) {
   HandleScope scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kNumberToLocaleString);
+
   Handle<Object> value = args.at(0);
 
   // Unwrap the receiver {value}.
diff --git a/deps/v8/src/builtins/builtins-object-gen.cc b/deps/v8/src/builtins/builtins-object-gen.cc
index a8d83e641f..fbac2e1abc 100644
--- a/deps/v8/src/builtins/builtins-object-gen.cc
+++ b/deps/v8/src/builtins/builtins-object-gen.cc
@@ -46,11 +46,6 @@ class ObjectBuiltinsAssembler : public CodeStubAssembler {
 
   TNode<Word32T> IsStringWrapperElementsKind(TNode<Map> map);
 
-  // Checks that |map| has only simple properties, returns bitfield3.
-  TNode<Uint32T> EnsureOnlyHasSimpleProperties(TNode<Map> map,
-                                               TNode<Int32T> instance_type,
-                                               Label* bailout);
-
   void ObjectAssignFast(TNode<Context> context, TNode<JSReceiver> to,
                         TNode<Object> from, Label* slow);
 };
@@ -96,8 +91,7 @@ void ObjectBuiltinsAssembler::ReturnToStringFormat(Node* context,
   Node* lhs = StringConstant("[object ");
   Node* rhs = StringConstant("]");
 
-  Callable callable =
-      CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
+  Callable callable = CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE);
 
   Return(CallStub(callable, context, CallStub(callable, context, lhs, string),
                   rhs));
@@ -304,7 +298,7 @@ TNode<JSArray> ObjectEntriesValuesBuiltinsAssembler::FastGetOwnValuesOrEntries(
     // So the array filled by the-hole even if enum_cache exists.
     FillFixedArrayWithValue(PACKED_ELEMENTS, values_or_entries,
                             IntPtrConstant(0), object_enum_length,
-                            Heap::kTheHoleValueRootIndex);
+                            RootIndex::kTheHoleValue);
 
     TVARIABLE(IntPtrT, var_result_index, IntPtrConstant(0));
     TVARIABLE(IntPtrT, var_descriptor_number, IntPtrConstant(0));
@@ -524,18 +518,6 @@ TF_BUILTIN(ObjectAssign, ObjectBuiltinsAssembler) {
   args.PopAndReturn(to);
 }
 
-TNode<Uint32T> ObjectBuiltinsAssembler::EnsureOnlyHasSimpleProperties(
-    TNode<Map> map, TNode<Int32T> instance_type, Label* bailout) {
-  GotoIf(IsCustomElementsReceiverInstanceType(instance_type), bailout);
-
-  TNode<Uint32T> bit_field3 = LoadMapBitField3(map);
-  GotoIf(IsSetWord32(bit_field3, Map::IsDictionaryMapBit::kMask |
-                                     Map::HasHiddenPrototypeBit::kMask),
-         bailout);
-
-  return bit_field3;
-}
-
 // This function mimics what FastAssign() function does for C++ implementation.
 void ObjectBuiltinsAssembler::ObjectAssignFast(TNode<Context> context,
                                                TNode<JSReceiver> to,
@@ -553,8 +535,9 @@ void ObjectBuiltinsAssembler::ObjectAssignFast(TNode<Context> context,
     GotoIf(IsJSReceiverInstanceType(from_instance_type), &cont);
     GotoIfNot(IsStringInstanceType(from_instance_type), &done);
     {
-      Branch(SmiEqual(LoadStringLengthAsSmi(CAST(from)), SmiConstant(0)), &done,
-             slow);
+      Branch(
+          Word32Equal(LoadStringLengthAsWord32(CAST(from)), Int32Constant(0)),
+          &done, slow);
     }
     BIND(&cont);
   }
@@ -567,132 +550,18 @@ void ObjectBuiltinsAssembler::ObjectAssignFast(TNode<Context> context,
   TNode<BoolT> to_is_simple_receiver = IsSimpleObjectMap(to_map);
 
   GotoIfNot(IsJSObjectInstanceType(from_instance_type), slow);
-  TNode<Uint32T> from_bit_field3 =
-      EnsureOnlyHasSimpleProperties(from_map, from_instance_type, slow);
-
   GotoIfNot(IsEmptyFixedArray(LoadElements(CAST(from))), slow);
 
-  TNode<DescriptorArray> from_descriptors = LoadMapDescriptors(from_map);
-  TNode<Uint32T> nof_descriptors =
-      DecodeWord32<Map::NumberOfOwnDescriptorsBits>(from_bit_field3);
-
-  TVARIABLE(BoolT, var_stable, Int32TrueConstant());
-  VariableList list({&var_stable}, zone());
-
-  DescriptorArrayForEach(
-      list, Unsigned(Int32Constant(0)), nof_descriptors,
-      [=, &var_stable](TNode<UintPtrT> descriptor_key_index) {
-        TNode<Name> next_key = CAST(
-            LoadWeakFixedArrayElement(from_descriptors, descriptor_key_index));
-
-        TVARIABLE(Object, var_value, SmiConstant(0));
-        Label do_store(this), next_iteration(this);
-
-        {
-          TVARIABLE(Map, var_from_map);
-          TVARIABLE(HeapObject, var_meta_storage);
-          TVARIABLE(IntPtrT, var_entry);
-          TVARIABLE(Uint32T, var_details);
-          Label if_found(this);
-
-          Label if_found_fast(this), if_found_dict(this);
-
-          Label if_stable(this), if_not_stable(this);
-          Branch(var_stable.value(), &if_stable, &if_not_stable);
-          BIND(&if_stable);
-          {
-            // Directly decode from the descriptor array if |from| did not
-            // change shape.
-            var_from_map = from_map;
-            var_meta_storage = from_descriptors;
-            var_entry = Signed(descriptor_key_index);
-            Goto(&if_found_fast);
-          }
-          BIND(&if_not_stable);
-          {
-            // If the map did change, do a slower lookup. We are still
-            // guaranteed that the object has a simple shape, and that the key
-            // is a name.
-            var_from_map = LoadMap(CAST(from));
-            TryLookupPropertyInSimpleObject(
-                CAST(from), var_from_map.value(), next_key, &if_found_fast,
-                &if_found_dict, &var_meta_storage, &var_entry, &next_iteration);
-          }
-
-          BIND(&if_found_fast);
-          {
-            TNode<DescriptorArray> descriptors = CAST(var_meta_storage.value());
-            TNode<IntPtrT> name_index = var_entry.value();
-
-            // Skip non-enumerable properties.
-            var_details = LoadDetailsByKeyIndex(descriptors, name_index);
-            GotoIf(IsSetWord32(var_details.value(),
-                               PropertyDetails::kAttributesDontEnumMask),
-                   &next_iteration);
-
-            LoadPropertyFromFastObject(from, var_from_map.value(), descriptors,
-                                       name_index, var_details.value(),
-                                       &var_value);
-            Goto(&if_found);
-          }
-          BIND(&if_found_dict);
-          {
-            Node* dictionary = var_meta_storage.value();
-            Node* entry = var_entry.value();
-
-            TNode<Uint32T> details =
-                LoadDetailsByKeyIndex<NameDictionary>(dictionary, entry);
-            // Skip non-enumerable properties.
-            GotoIf(
-                IsSetWord32(details, PropertyDetails::kAttributesDontEnumMask),
-                &next_iteration);
-
-            var_details = details;
-            var_value = LoadValueByKeyIndex<NameDictionary>(dictionary, entry);
-            Goto(&if_found);
-          }
-
-          // Here we have details and value which could be an accessor.
-          BIND(&if_found);
-          {
-            Label slow_load(this, Label::kDeferred);
-
-            var_value =
-                CallGetterIfAccessor(var_value.value(), var_details.value(),
-                                     context, from, &slow_load, kCallJSGetter);
-            Goto(&do_store);
-
-            BIND(&slow_load);
-            {
-              var_value =
-                  CallRuntime(Runtime::kGetProperty, context, from, next_key);
-              Goto(&do_store);
-            }
-          }
-        }
-
-        // Store property to target object.
-        BIND(&do_store);
-        {
-          KeyedStoreGenericGenerator::SetProperty(
-              state(), context, to, to_is_simple_receiver, next_key,
-              var_value.value(), LanguageMode::kStrict);
-
-          // Check if the |from| object is still stable, i.e. we can proceed
-          // using property details from preloaded |from_descriptors|.
-          var_stable = Select<BoolT>(
-              var_stable.value(),
-              [=] { return WordEqual(LoadMap(CAST(from)), from_map); },
-              [=] { return Int32FalseConstant(); });
-
-          Goto(&next_iteration);
-        }
-
-        BIND(&next_iteration);
-      });
+  ForEachEnumerableOwnProperty(context, from_map, CAST(from),
+                               [=](TNode<Name> key, TNode<Object> value) {
+                                 KeyedStoreGenericGenerator::SetProperty(
+                                     state(), context, to,
+                                     to_is_simple_receiver, key, value,
+                                     LanguageMode::kStrict);
+                               },
+                               slow);
 
   Goto(&done);
-
   BIND(&done);
 }
 
@@ -1008,13 +877,13 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
 
   BIND(&if_arguments);
   {
-    var_default.Bind(LoadRoot(Heap::karguments_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::karguments_to_string));
     Goto(&checkstringtag);
   }
 
   BIND(&if_array);
   {
-    var_default.Bind(LoadRoot(Heap::karray_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::karray_to_string));
     Goto(&checkstringtag);
   }
 
@@ -1027,26 +896,26 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
         boolean_constructor, JSFunction::kPrototypeOrInitialMapOffset);
     Node* boolean_prototype =
         LoadObjectField(boolean_initial_map, Map::kPrototypeOffset);
-    var_default.Bind(LoadRoot(Heap::kboolean_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kboolean_to_string));
     var_holder.Bind(boolean_prototype);
     Goto(&checkstringtag);
   }
 
   BIND(&if_date);
   {
-    var_default.Bind(LoadRoot(Heap::kdate_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kdate_to_string));
     Goto(&checkstringtag);
   }
 
   BIND(&if_error);
   {
-    var_default.Bind(LoadRoot(Heap::kerror_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kerror_to_string));
     Goto(&checkstringtag);
   }
 
   BIND(&if_function);
   {
-    var_default.Bind(LoadRoot(Heap::kfunction_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kfunction_to_string));
     Goto(&checkstringtag);
   }
 
@@ -1059,7 +928,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
         number_constructor, JSFunction::kPrototypeOrInitialMapOffset);
     Node* number_prototype =
         LoadObjectField(number_initial_map, Map::kPrototypeOffset);
-    var_default.Bind(LoadRoot(Heap::knumber_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::knumber_to_string));
     var_holder.Bind(number_prototype);
     Goto(&checkstringtag);
   }
@@ -1067,7 +936,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
   BIND(&if_object);
   {
     CSA_ASSERT(this, IsJSReceiver(receiver));
-    var_default.Bind(LoadRoot(Heap::kobject_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kobject_to_string));
     Goto(&checkstringtag);
   }
 
@@ -1082,10 +951,10 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
     GotoIf(IsSymbolMap(receiver_map), &if_symbol);
     GotoIf(IsUndefined(receiver), &return_undefined);
     CSA_ASSERT(this, IsNull(receiver));
-    Return(LoadRoot(Heap::knull_to_stringRootIndex));
+    Return(LoadRoot(RootIndex::knull_to_string));
 
     BIND(&return_undefined);
-    Return(LoadRoot(Heap::kundefined_to_stringRootIndex));
+    Return(LoadRoot(RootIndex::kundefined_to_string));
   }
 
   BIND(&if_proxy);
@@ -1099,12 +968,12 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
         CallRuntime(Runtime::kArrayIsArray, context, receiver);
     TNode<String> builtin_tag = Select<String>(
         IsTrue(receiver_is_array),
-        [=] { return CAST(LoadRoot(Heap::kArray_stringRootIndex)); },
+        [=] { return CAST(LoadRoot(RootIndex::kArray_string)); },
         [=] {
           return Select<String>(
               IsCallableMap(receiver_map),
-              [=] { return CAST(LoadRoot(Heap::kFunction_stringRootIndex)); },
-              [=] { return CAST(LoadRoot(Heap::kObject_stringRootIndex)); });
+              [=] { return CAST(LoadRoot(RootIndex::kFunction_string)); },
+              [=] { return CAST(LoadRoot(RootIndex::kObject_string)); });
         });
 
     // Lookup the @@toStringTag property on the {receiver}.
@@ -1125,7 +994,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
 
   BIND(&if_regexp);
   {
-    var_default.Bind(LoadRoot(Heap::kregexp_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kregexp_to_string));
     Goto(&checkstringtag);
   }
 
@@ -1138,7 +1007,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
         string_constructor, JSFunction::kPrototypeOrInitialMapOffset);
     Node* string_prototype =
         LoadObjectField(string_initial_map, Map::kPrototypeOffset);
-    var_default.Bind(LoadRoot(Heap::kstring_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kstring_to_string));
     var_holder.Bind(string_prototype);
     Goto(&checkstringtag);
   }
@@ -1152,7 +1021,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
         symbol_constructor, JSFunction::kPrototypeOrInitialMapOffset);
     Node* symbol_prototype =
         LoadObjectField(symbol_initial_map, Map::kPrototypeOffset);
-    var_default.Bind(LoadRoot(Heap::kobject_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kobject_to_string));
     var_holder.Bind(symbol_prototype);
     Goto(&checkstringtag);
   }
@@ -1166,7 +1035,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
         bigint_constructor, JSFunction::kPrototypeOrInitialMapOffset);
     Node* bigint_prototype =
         LoadObjectField(bigint_initial_map, Map::kPrototypeOffset);
-    var_default.Bind(LoadRoot(Heap::kobject_to_stringRootIndex));
+    var_default.Bind(LoadRoot(RootIndex::kobject_to_string));
     var_holder.Bind(bigint_prototype);
     Goto(&checkstringtag);
   }
@@ -1209,7 +1078,7 @@ TF_BUILTIN(ObjectPrototypeToString, ObjectBuiltinsAssembler) {
     BIND(&return_generic);
     {
       Node* tag = GetProperty(context, ToObject(context, receiver),
-                              LoadRoot(Heap::kto_string_tag_symbolRootIndex));
+                              LoadRoot(RootIndex::kto_string_tag_symbol));
       GotoIf(TaggedIsSmi(tag), &return_default);
       GotoIfNot(IsString(tag), &return_default);
       ReturnToStringFormat(context, tag);
@@ -1271,7 +1140,7 @@ TF_BUILTIN(CreateObjectWithoutProperties, ObjectBuiltinsAssembler) {
     TNode<MaybeObject> maybe_map = LoadMaybeWeakObjectField(
         prototype_info, PrototypeInfo::kObjectCreateMapOffset);
     GotoIf(IsStrongReferenceTo(maybe_map, UndefinedConstant()), &call_runtime);
-    map.Bind(ToWeakHeapObject(maybe_map, &call_runtime));
+    map.Bind(GetHeapObjectAssumeWeak(maybe_map, &call_runtime));
     Goto(&instantiate_map);
   }
 
@@ -1323,7 +1192,7 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
     GotoIf(IsSpecialReceiverMap(properties_map), &call_runtime);
     // Stay on the fast path only if there are no elements.
     GotoIfNot(WordEqual(LoadElements(properties),
-                        LoadRoot(Heap::kEmptyFixedArrayRootIndex)),
+                        LoadRoot(RootIndex::kEmptyFixedArray)),
               &call_runtime);
     // Handle dictionary objects or fast objects with properties in runtime.
     Node* bit_field3 = LoadMapBitField3(properties_map);
@@ -1367,7 +1236,7 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
           prototype_info, PrototypeInfo::kObjectCreateMapOffset);
       GotoIf(IsStrongReferenceTo(maybe_map, UndefinedConstant()),
              &call_runtime);
-      map.Bind(ToWeakHeapObject(maybe_map, &call_runtime));
+      map.Bind(GetHeapObjectAssumeWeak(maybe_map, &call_runtime));
       Goto(&instantiate_map);
     }
 
@@ -1476,8 +1345,7 @@ TF_BUILTIN(CreateGeneratorObject, ObjectBuiltinsAssembler) {
                          formal_parameter_count);
   Node* parameters_and_registers = AllocateFixedArray(HOLEY_ELEMENTS, size);
   FillFixedArrayWithValue(HOLEY_ELEMENTS, parameters_and_registers,
-                          IntPtrConstant(0), size,
-                          Heap::kUndefinedValueRootIndex);
+                          IntPtrConstant(0), size, RootIndex::kUndefinedValue);
   // TODO(cbruni): support start_offset to avoid double initialization.
   Node* result = AllocateJSObjectFromMap(maybe_map, nullptr, nullptr, kNone,
                                          kWithSlackTracking);
@@ -1522,7 +1390,7 @@ TF_BUILTIN(ObjectGetOwnPropertyDescriptor, ObjectBuiltinsAssembler) {
   object = ToObject_Inline(CAST(context), CAST(object));
 
   // 2. Let key be ? ToPropertyKey(P).
-  key = ToName(context, key);
+  key = CallBuiltin(Builtins::kToName, context, key);
 
   // 3. Let desc be ? obj.[[GetOwnProperty]](key).
   Label if_keyisindex(this), if_iskeyunique(this),
diff --git a/deps/v8/src/builtins/builtins-promise-gen.cc b/deps/v8/src/builtins/builtins-promise-gen.cc
index 241a2041bd..1d43217999 100644
--- a/deps/v8/src/builtins/builtins-promise-gen.cc
+++ b/deps/v8/src/builtins/builtins-promise-gen.cc
@@ -28,9 +28,9 @@ Node* PromiseBuiltinsAssembler::AllocateJSPromise(Node* context) {
   Node* const promise = Allocate(JSPromise::kSizeWithEmbedderFields);
   StoreMapNoWriteBarrier(promise, promise_map);
   StoreObjectFieldRoot(promise, JSPromise::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(promise, JSPromise::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   return promise;
 }
 
@@ -137,7 +137,7 @@ TF_BUILTIN(NewPromiseCapability, PromiseBuiltinsAssembler) {
         CreatePromiseResolvingFunctions(promise, debug_event, native_context);
 
     Node* capability = Allocate(PromiseCapability::kSize);
-    StoreMapNoWriteBarrier(capability, Heap::kPromiseCapabilityMapRootIndex);
+    StoreMapNoWriteBarrier(capability, RootIndex::kPromiseCapabilityMap);
     StoreObjectFieldNoWriteBarrier(capability,
                                    PromiseCapability::kPromiseOffset, promise);
     StoreObjectFieldNoWriteBarrier(capability,
@@ -150,13 +150,13 @@ TF_BUILTIN(NewPromiseCapability, PromiseBuiltinsAssembler) {
   BIND(&if_slow_promise_capability);
   {
     Node* capability = Allocate(PromiseCapability::kSize);
-    StoreMapNoWriteBarrier(capability, Heap::kPromiseCapabilityMapRootIndex);
+    StoreMapNoWriteBarrier(capability, RootIndex::kPromiseCapabilityMap);
     StoreObjectFieldRoot(capability, PromiseCapability::kPromiseOffset,
-                         Heap::kUndefinedValueRootIndex);
+                         RootIndex::kUndefinedValue);
     StoreObjectFieldRoot(capability, PromiseCapability::kResolveOffset,
-                         Heap::kUndefinedValueRootIndex);
+                         RootIndex::kUndefinedValue);
     StoreObjectFieldRoot(capability, PromiseCapability::kRejectOffset,
-                         Heap::kUndefinedValueRootIndex);
+                         RootIndex::kUndefinedValue);
 
     Node* executor_context =
         CreatePromiseGetCapabilitiesExecutorContext(capability, native_context);
@@ -352,7 +352,7 @@ void PromiseBuiltinsAssembler::PerformPromiseThen(
 
     BIND(&if_fulfilled);
     {
-      var_map.Bind(LoadRoot(Heap::kPromiseFulfillReactionJobTaskMapRootIndex));
+      var_map.Bind(LoadRoot(RootIndex::kPromiseFulfillReactionJobTaskMap));
       var_handler.Bind(on_fulfilled);
       Goto(&enqueue);
     }
@@ -360,7 +360,7 @@ void PromiseBuiltinsAssembler::PerformPromiseThen(
     BIND(&if_rejected);
     {
       CSA_ASSERT(this, IsPromiseStatus(status, v8::Promise::kRejected));
-      var_map.Bind(LoadRoot(Heap::kPromiseRejectReactionJobTaskMapRootIndex));
+      var_map.Bind(LoadRoot(RootIndex::kPromiseRejectReactionJobTaskMap));
       var_handler.Bind(on_rejected);
       GotoIf(PromiseHasHandler(promise), &enqueue);
       CallRuntime(Runtime::kPromiseRevokeReject, context, promise);
@@ -401,7 +401,7 @@ Node* PromiseBuiltinsAssembler::AllocatePromiseReaction(
     Node* next, Node* promise_or_capability, Node* fulfill_handler,
     Node* reject_handler) {
   Node* const reaction = Allocate(PromiseReaction::kSize);
-  StoreMapNoWriteBarrier(reaction, Heap::kPromiseReactionMapRootIndex);
+  StoreMapNoWriteBarrier(reaction, RootIndex::kPromiseReactionMap);
   StoreObjectFieldNoWriteBarrier(reaction, PromiseReaction::kNextOffset, next);
   StoreObjectFieldNoWriteBarrier(reaction,
                                  PromiseReaction::kPromiseOrCapabilityOffset,
@@ -431,10 +431,10 @@ Node* PromiseBuiltinsAssembler::AllocatePromiseReactionJobTask(
 }
 
 Node* PromiseBuiltinsAssembler::AllocatePromiseReactionJobTask(
-    Heap::RootListIndex map_root_index, Node* context, Node* argument,
-    Node* handler, Node* promise_or_capability) {
-  DCHECK(map_root_index == Heap::kPromiseFulfillReactionJobTaskMapRootIndex ||
-         map_root_index == Heap::kPromiseRejectReactionJobTaskMapRootIndex);
+    RootIndex map_root_index, Node* context, Node* argument, Node* handler,
+    Node* promise_or_capability) {
+  DCHECK(map_root_index == RootIndex::kPromiseFulfillReactionJobTaskMap ||
+         map_root_index == RootIndex::kPromiseRejectReactionJobTaskMap);
   Node* const map = LoadRoot(map_root_index);
   return AllocatePromiseReactionJobTask(map, context, argument, handler,
                                         promise_or_capability);
@@ -444,7 +444,7 @@ Node* PromiseBuiltinsAssembler::AllocatePromiseResolveThenableJobTask(
     Node* promise_to_resolve, Node* then, Node* thenable, Node* context) {
   Node* const microtask = Allocate(PromiseResolveThenableJobTask::kSize);
   StoreMapNoWriteBarrier(microtask,
-                         Heap::kPromiseResolveThenableJobTaskMapRootIndex);
+                         RootIndex::kPromiseResolveThenableJobTaskMap);
   StoreObjectFieldNoWriteBarrier(
       microtask, PromiseResolveThenableJobTask::kContextOffset, context);
   StoreObjectFieldNoWriteBarrier(
@@ -502,8 +502,8 @@ Node* PromiseBuiltinsAssembler::TriggerPromiseReactions(
       // of stores here to avoid screwing up the store buffer.
       STATIC_ASSERT(PromiseReaction::kSize == PromiseReactionJobTask::kSize);
       if (type == PromiseReaction::kFulfill) {
-        StoreMapNoWriteBarrier(
-            current, Heap::kPromiseFulfillReactionJobTaskMapRootIndex);
+        StoreMapNoWriteBarrier(current,
+                               RootIndex::kPromiseFulfillReactionJobTaskMap);
         StoreObjectField(current, PromiseReactionJobTask::kArgumentOffset,
                          argument);
         StoreObjectField(current, PromiseReactionJobTask::kContextOffset,
@@ -516,7 +516,7 @@ Node* PromiseBuiltinsAssembler::TriggerPromiseReactions(
         Node* handler =
             LoadObjectField(current, PromiseReaction::kRejectHandlerOffset);
         StoreMapNoWriteBarrier(current,
-                               Heap::kPromiseRejectReactionJobTaskMapRootIndex);
+                               RootIndex::kPromiseRejectReactionJobTaskMap);
         StoreObjectField(current, PromiseReactionJobTask::kArgumentOffset,
                          argument);
         StoreObjectField(current, PromiseReactionJobTask::kContextOffset,
diff --git a/deps/v8/src/builtins/builtins-promise-gen.h b/deps/v8/src/builtins/builtins-promise-gen.h
index 4954b383fe..39b2a24683 100644
--- a/deps/v8/src/builtins/builtins-promise-gen.h
+++ b/deps/v8/src/builtins/builtins-promise-gen.h
@@ -89,9 +89,8 @@ class PromiseBuiltinsAssembler : public CodeStubAssembler {
   Node* AllocatePromiseReaction(Node* next, Node* promise_or_capability,
                                 Node* fulfill_handler, Node* reject_handler);
 
-  Node* AllocatePromiseReactionJobTask(Heap::RootListIndex map_root_index,
-                                       Node* context, Node* argument,
-                                       Node* handler,
+  Node* AllocatePromiseReactionJobTask(RootIndex map_root_index, Node* context,
+                                       Node* argument, Node* handler,
                                        Node* promise_or_capability);
   Node* AllocatePromiseReactionJobTask(Node* map, Node* context, Node* argument,
                                        Node* handler,
diff --git a/deps/v8/src/builtins/builtins-proxy-gen.cc b/deps/v8/src/builtins/builtins-proxy-gen.cc
index 34caf58688..f0d891910a 100644
--- a/deps/v8/src/builtins/builtins-proxy-gen.cc
+++ b/deps/v8/src/builtins/builtins-proxy-gen.cc
@@ -58,7 +58,7 @@ Node* ProxiesCodeStubAssembler::AllocateProxy(Node* target, Node* handler,
   Node* proxy = Allocate(JSProxy::kSize);
   StoreMapNoWriteBarrier(proxy, map.value());
   StoreObjectFieldRoot(proxy, JSProxy::kPropertiesOrHashOffset,
-                       Heap::kEmptyPropertyDictionaryRootIndex);
+                       RootIndex::kEmptyPropertyDictionary);
   StoreObjectFieldNoWriteBarrier(proxy, JSProxy::kTargetOffset, target);
   StoreObjectFieldNoWriteBarrier(proxy, JSProxy::kHandlerOffset, handler);
 
@@ -124,7 +124,7 @@ Node* ProxiesCodeStubAssembler::AllocateJSArrayForCodeStubArguments(
 Node* ProxiesCodeStubAssembler::CreateProxyRevokeFunctionContext(
     Node* proxy, Node* native_context) {
   Node* const context = Allocate(FixedArray::SizeFor(kProxyContextLength));
-  StoreMapNoWriteBarrier(context, Heap::kFunctionContextMapRootIndex);
+  StoreMapNoWriteBarrier(context, RootIndex::kFunctionContextMap);
   InitializeFunctionContext(native_context, context, kProxyContextLength);
   StoreContextElementNoWriteBarrier(context, kProxySlot, proxy);
   return context;
@@ -230,9 +230,9 @@ TF_BUILTIN(ProxyRevocable, ProxiesCodeStubAssembler) {
       native_context, Context::PROXY_REVOCABLE_RESULT_MAP_INDEX);
   StoreMapNoWriteBarrier(result, result_map);
   StoreObjectFieldRoot(result, JSProxyRevocableResult::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(result, JSProxyRevocableResult::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(result, JSProxyRevocableResult::kProxyOffset,
                                  proxy);
   StoreObjectFieldNoWriteBarrier(result, JSProxyRevocableResult::kRevokeOffset,
diff --git a/deps/v8/src/builtins/builtins-reflect.cc b/deps/v8/src/builtins/builtins-reflect.cc
index 3dd07a796a..cd3f2b4bed 100644
--- a/deps/v8/src/builtins/builtins-reflect.cc
+++ b/deps/v8/src/builtins/builtins-reflect.cc
@@ -218,7 +218,7 @@ BUILTIN(ReflectSet) {
   LookupIterator it = LookupIterator::PropertyOrElement(
       isolate, receiver, name, Handle<JSReceiver>::cast(target));
   Maybe<bool> result = Object::SetSuperProperty(
-      &it, value, LanguageMode::kSloppy, Object::MAY_BE_STORE_FROM_KEYED);
+      &it, value, LanguageMode::kSloppy, StoreOrigin::kMaybeKeyed);
   MAYBE_RETURN(result, ReadOnlyRoots(isolate).exception());
   return *isolate->factory()->ToBoolean(result.FromJust());
 }
diff --git a/deps/v8/src/builtins/builtins-regexp-gen.cc b/deps/v8/src/builtins/builtins-regexp-gen.cc
index 206602aaa7..30717f41de 100644
--- a/deps/v8/src/builtins/builtins-regexp-gen.cc
+++ b/deps/v8/src/builtins/builtins-regexp-gen.cc
@@ -81,13 +81,13 @@ TNode<JSRegExpResult> RegExpBuiltinsAssembler::AllocateRegExpResult(
   // Initialize the elements.
 
   DCHECK(!IsDoubleElementsKind(elements_kind));
-  const Heap::RootListIndex map_index = Heap::kFixedArrayMapRootIndex;
+  const RootIndex map_index = RootIndex::kFixedArrayMap;
   DCHECK(Heap::RootIsImmortalImmovable(map_index));
   StoreMapNoWriteBarrier(elements, map_index);
   StoreObjectFieldNoWriteBarrier(elements, FixedArray::kLengthOffset, length);
 
   FillFixedArrayWithValue(elements_kind, elements, IntPtrZero(), length_intptr,
-                          Heap::kUndefinedValueRootIndex);
+                          RootIndex::kUndefinedValue);
 
   return CAST(result);
 }
@@ -862,7 +862,7 @@ TNode<BoolT> RegExpBuiltinsAssembler::IsFastRegExpWithOriginalExec(
   TVARIABLE(BoolT, var_result);
 
 #ifdef V8_ENABLE_FORCE_SLOW_PATH
-  var_result = BoolConstant(0);
+  var_result = BoolConstant(false);
   GotoIfForceSlowPath(&out);
 #endif
 
@@ -1103,7 +1103,7 @@ Node* RegExpBuiltinsAssembler::FlagsGetter(Node* const context,
   Isolate* isolate = this->isolate();
 
   TNode<IntPtrT> const int_one = IntPtrConstant(1);
-  TVARIABLE(Smi, var_length, SmiZero());
+  TVARIABLE(Uint32T, var_length, Uint32Constant(0));
   TVARIABLE(IntPtrT, var_flags);
 
   // First, count the number of characters we will need and check which flags
@@ -1115,13 +1115,13 @@ Node* RegExpBuiltinsAssembler::FlagsGetter(Node* const context,
     Node* const flags_smi = LoadObjectField(regexp, JSRegExp::kFlagsOffset);
     var_flags = SmiUntag(flags_smi);
 
-#define CASE_FOR_FLAG(FLAG)                                  \
-  do {                                                       \
-    Label next(this);                                        \
-    GotoIfNot(IsSetWord(var_flags.value(), FLAG), &next);    \
-    var_length = SmiAdd(var_length.value(), SmiConstant(1)); \
-    Goto(&next);                                             \
-    BIND(&next);                                             \
+#define CASE_FOR_FLAG(FLAG)                                        \
+  do {                                                             \
+    Label next(this);                                              \
+    GotoIfNot(IsSetWord(var_flags.value(), FLAG), &next);          \
+    var_length = Uint32Add(var_length.value(), Uint32Constant(1)); \
+    Goto(&next);                                                   \
+    BIND(&next);                                                   \
   } while (false)
 
     CASE_FOR_FLAG(JSRegExp::kGlobal);
@@ -1145,7 +1145,7 @@ Node* RegExpBuiltinsAssembler::FlagsGetter(Node* const context,
     Label if_isflagset(this);                                              \
     BranchIfToBooleanIsTrue(flag, &if_isflagset, &next);                   \
     BIND(&if_isflagset);                                                   \
-    var_length = SmiAdd(var_length.value(), SmiConstant(1));               \
+    var_length = Uint32Add(var_length.value(), Uint32Constant(1));         \
     var_flags = Signed(WordOr(var_flags.value(), IntPtrConstant(FLAG)));   \
     Goto(&next);                                                           \
     BIND(&next);                                                           \
@@ -2109,9 +2109,9 @@ TNode<Object> RegExpBuiltinsAssembler::MatchAllIterator(
     StoreMapNoWriteBarrier(iterator, map);
     StoreObjectFieldRoot(iterator,
                          JSRegExpStringIterator::kPropertiesOrHashOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
     StoreObjectFieldRoot(iterator, JSRegExpStringIterator::kElementsOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
 
     // 5. Set iterator.[[IteratingRegExp]] to R.
     StoreObjectFieldNoWriteBarrier(
@@ -2903,14 +2903,13 @@ Node* RegExpBuiltinsAssembler::ReplaceSimpleStringFastPath(
       TNode<String> first_part =
           CAST(CallBuiltin(Builtins::kSubString, context, string,
                            var_last_match_end.value(), match_start));
-      var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone_NotTenured,
-                                    context, var_result.value(), first_part));
+      var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                    var_result.value(), first_part));
 
       GotoIf(SmiEqual(replace_length, SmiZero()), &loop_end);
 
-      var_result =
-          CAST(CallBuiltin(Builtins::kStringAdd_CheckNone_NotTenured, context,
-                           var_result.value(), replace_string));
+      var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                    var_result.value(), replace_string));
       Goto(&loop_end);
 
       BIND(&loop_end);
@@ -2936,8 +2935,8 @@ Node* RegExpBuiltinsAssembler::ReplaceSimpleStringFastPath(
     TNode<String> last_part =
         CAST(CallBuiltin(Builtins::kSubString, context, string,
                          var_last_match_end.value(), string_length));
-    var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone_NotTenured,
-                                  context, var_result.value(), last_part));
+    var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                  var_result.value(), last_part));
     Goto(&out);
   }
 
diff --git a/deps/v8/src/builtins/builtins-sharedarraybuffer-gen.cc b/deps/v8/src/builtins/builtins-sharedarraybuffer-gen.cc
index 52673bfd36..4befb13d7c 100644
--- a/deps/v8/src/builtins/builtins-sharedarraybuffer-gen.cc
+++ b/deps/v8/src/builtins/builtins-sharedarraybuffer-gen.cc
@@ -11,6 +11,8 @@ namespace v8 {
 namespace internal {
 
 using compiler::Node;
+template <typename T>
+using TNode = compiler::TNode<T>;
 
 class SharedArrayBufferBuiltinsAssembler : public CodeStubAssembler {
  public:
@@ -21,7 +23,8 @@ class SharedArrayBufferBuiltinsAssembler : public CodeStubAssembler {
  protected:
   typedef Node* (CodeAssembler::*AssemblerFunction)(MachineType type,
                                                     Node* base, Node* offset,
-                                                    Node* value);
+                                                    Node* value,
+                                                    Node* value_high);
   void ValidateSharedTypedArray(Node* tagged, Node* context,
                                 Node** out_instance_type,
                                 Node** out_backing_store);
@@ -35,6 +38,11 @@ class SharedArrayBufferBuiltinsAssembler : public CodeStubAssembler {
   void AtomicBinopBuiltinCommon(Node* array, Node* index, Node* value,
                                 Node* context, AssemblerFunction function,
                                 Runtime::FunctionId runtime_function);
+
+  // Create a BigInt from the result of a 64-bit atomic operation, using
+  // projections on 32-bit platforms.
+  TNode<BigInt> BigIntFromSigned64(Node* signed64);
+  TNode<BigInt> BigIntFromUnsigned64(Node* unsigned64);
 };
 
 void SharedArrayBufferBuiltinsAssembler::ValidateSharedTypedArray(
@@ -50,10 +58,9 @@ void SharedArrayBufferBuiltinsAssembler::ValidateSharedTypedArray(
             &invalid);
 
   // Fail if the array's JSArrayBuffer is not shared.
-  Node* array_buffer = LoadObjectField(tagged, JSTypedArray::kBufferOffset);
-  Node* bitfield = LoadObjectField(array_buffer, JSArrayBuffer::kBitFieldOffset,
-                                   MachineType::Uint32());
-  GotoIfNot(IsSetWord32<JSArrayBuffer::IsShared>(bitfield), &invalid);
+  TNode<JSArrayBuffer> array_buffer = LoadJSArrayBufferViewBuffer(CAST(tagged));
+  TNode<Uint32T> bitfield = LoadJSArrayBufferBitField(array_buffer);
+  GotoIfNot(IsSetWord32<JSArrayBuffer::IsSharedBit>(bitfield), &invalid);
 
   // Fail if the array's element type is float32, float64 or clamped.
   Node* elements_instance_type = LoadInstanceType(LoadElements(tagged));
@@ -63,8 +70,13 @@ void SharedArrayBufferBuiltinsAssembler::ValidateSharedTypedArray(
   STATIC_ASSERT(FIXED_UINT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_UINT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_UINT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
-  Branch(Int32LessThan(elements_instance_type,
+  GotoIf(Int32LessThan(elements_instance_type,
                        Int32Constant(FIXED_FLOAT32_ARRAY_TYPE)),
+         &not_float_or_clamped);
+  STATIC_ASSERT(FIXED_BIGINT64_ARRAY_TYPE > FIXED_UINT8_CLAMPED_ARRAY_TYPE);
+  STATIC_ASSERT(FIXED_BIGUINT64_ARRAY_TYPE > FIXED_UINT8_CLAMPED_ARRAY_TYPE);
+  Branch(Int32GreaterThan(elements_instance_type,
+                          Int32Constant(FIXED_UINT8_CLAMPED_ARRAY_TYPE)),
          &not_float_or_clamped, &invalid);
 
   BIND(&invalid);
@@ -76,15 +88,12 @@ void SharedArrayBufferBuiltinsAssembler::ValidateSharedTypedArray(
   BIND(&not_float_or_clamped);
   *out_instance_type = elements_instance_type;
 
-  Node* backing_store =
-      LoadObjectField(array_buffer, JSArrayBuffer::kBackingStoreOffset);
-  Node* byte_offset = ChangeUint32ToWord(TruncateTaggedToWord32(
-      context, LoadObjectField(tagged, JSArrayBufferView::kByteOffsetOffset)));
-  *out_backing_store =
-      IntPtrAdd(BitcastTaggedToWord(backing_store), byte_offset);
+  TNode<RawPtrT> backing_store = LoadJSArrayBufferBackingStore(array_buffer);
+  TNode<UintPtrT> byte_offset = LoadJSArrayBufferViewByteOffset(CAST(tagged));
+  *out_backing_store = IntPtrAdd(backing_store, byte_offset);
 }
 
-// https://tc39.github.io/ecmascript_sharedmem/shmem.html#Atomics.ValidateAtomicAccess
+// https://tc39.github.io/ecma262/#sec-validateatomicaccess
 Node* SharedArrayBufferBuiltinsAssembler::ConvertTaggedAtomicIndexToWord32(
     Node* tagged, Node* context, Node** number_index) {
   VARIABLE(var_result, MachineRepresentation::kWord32);
@@ -112,7 +121,7 @@ void SharedArrayBufferBuiltinsAssembler::ValidateAtomicIndex(Node* array,
   // Check if the index is in bounds. If not, throw RangeError.
   Label check_passed(this);
   Node* array_length_word32 =
-      TruncateTaggedToWord32(context, LoadTypedArrayLength(CAST(array)));
+      TruncateTaggedToWord32(context, LoadJSTypedArrayLength(CAST(array)));
   GotoIf(Uint32LessThan(index_word, array_length_word32), &check_passed);
 
   ThrowRangeError(context, MessageTemplate::kInvalidAtomicAccessIndex);
@@ -130,10 +139,32 @@ void SharedArrayBufferBuiltinsAssembler::DebugSanityCheckAtomicIndex(
   CSA_ASSERT(this,
              Uint32LessThan(index_word,
                             TruncateTaggedToWord32(
-                                context, LoadTypedArrayLength(CAST(array)))));
+                                context, LoadJSTypedArrayLength(CAST(array)))));
 }
 #endif
 
+TNode<BigInt> SharedArrayBufferBuiltinsAssembler::BigIntFromSigned64(
+    Node* signed64) {
+  if (Is64()) {
+    return BigIntFromInt64(UncheckedCast<IntPtrT>(signed64));
+  } else {
+    TNode<IntPtrT> low = UncheckedCast<IntPtrT>(Projection(0, signed64));
+    TNode<IntPtrT> high = UncheckedCast<IntPtrT>(Projection(1, signed64));
+    return BigIntFromInt32Pair(low, high);
+  }
+}
+
+TNode<BigInt> SharedArrayBufferBuiltinsAssembler::BigIntFromUnsigned64(
+    Node* unsigned64) {
+  if (Is64()) {
+    return BigIntFromUint64(UncheckedCast<UintPtrT>(unsigned64));
+  } else {
+    TNode<UintPtrT> low = UncheckedCast<UintPtrT>(Projection(0, unsigned64));
+    TNode<UintPtrT> high = UncheckedCast<UintPtrT>(Projection(1, unsigned64));
+    return BigIntFromUint32Pair(low, high);
+  }
+}
+
 TF_BUILTIN(AtomicsLoad, SharedArrayBufferBuiltinsAssembler) {
   Node* array = Parameter(Descriptor::kArray);
   Node* index = Parameter(Descriptor::kIndex);
@@ -150,14 +181,14 @@ TF_BUILTIN(AtomicsLoad, SharedArrayBufferBuiltinsAssembler) {
   Node* index_word = ChangeUint32ToWord(index_word32);
 
   Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
-      other(this);
+      i64(this), u64(this), other(this);
   int32_t case_values[] = {
-      FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
-      FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
-  };
-  Label* case_labels[] = {
-      &i8, &u8, &i16, &u16, &i32, &u32,
+      FIXED_INT8_ARRAY_TYPE,     FIXED_UINT8_ARRAY_TYPE,
+      FIXED_INT16_ARRAY_TYPE,    FIXED_UINT16_ARRAY_TYPE,
+      FIXED_INT32_ARRAY_TYPE,    FIXED_UINT32_ARRAY_TYPE,
+      FIXED_BIGINT64_ARRAY_TYPE, FIXED_BIGUINT64_ARRAY_TYPE,
   };
+  Label* case_labels[] = {&i8, &u8, &i16, &u16, &i32, &u32, &i64, &u64};
   Switch(instance_type, &other, case_values, case_labels,
          arraysize(case_labels));
 
@@ -184,7 +215,24 @@ TF_BUILTIN(AtomicsLoad, SharedArrayBufferBuiltinsAssembler) {
   BIND(&u32);
   Return(ChangeUint32ToTagged(AtomicLoad(MachineType::Uint32(), backing_store,
                                          WordShl(index_word, 2))));
+#if V8_TARGET_ARCH_MIPS && !_MIPS_ARCH_MIPS32R6
+  BIND(&i64);
+  Return(CallRuntime(Runtime::kAtomicsLoad64, context, array, index_integer));
 
+  BIND(&u64);
+  Return(CallRuntime(Runtime::kAtomicsLoad64, context, array, index_integer));
+#else
+  BIND(&i64);
+  // This uses Uint64() intentionally: AtomicLoad is not implemented for
+  // Int64(), which is fine because the machine instruction only cares
+  // about words.
+  Return(BigIntFromSigned64(AtomicLoad(MachineType::Uint64(), backing_store,
+                                       WordShl(index_word, 3))));
+
+  BIND(&u64);
+  Return(BigIntFromUnsigned64(AtomicLoad(MachineType::Uint64(), backing_store,
+                                         WordShl(index_word, 3))));
+#endif
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
   Unreachable();
@@ -206,6 +254,13 @@ TF_BUILTIN(AtomicsStore, SharedArrayBufferBuiltinsAssembler) {
   ValidateAtomicIndex(array, index_word32, context);
   Node* index_word = ChangeUint32ToWord(index_word32);
 
+  Label u8(this), u16(this), u32(this), u64(this), other(this);
+  STATIC_ASSERT(FIXED_BIGINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  STATIC_ASSERT(FIXED_BIGUINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  GotoIf(
+      Int32GreaterThan(instance_type, Int32Constant(FIXED_UINT32_ARRAY_TYPE)),
+      &u64);
+
   Node* value_integer = ToInteger_Inline(CAST(context), CAST(value));
   Node* value_word32 = TruncateTaggedToWord32(context, value_integer);
 
@@ -213,14 +268,11 @@ TF_BUILTIN(AtomicsStore, SharedArrayBufferBuiltinsAssembler) {
   DebugSanityCheckAtomicIndex(array, index_word32, context);
 #endif
 
-  Label u8(this), u16(this), u32(this), other(this);
   int32_t case_values[] = {
       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
   };
-  Label* case_labels[] = {
-      &u8, &u8, &u16, &u16, &u32, &u32,
-  };
+  Label* case_labels[] = {&u8, &u8, &u16, &u16, &u32, &u32};
   Switch(instance_type, &other, case_values, case_labels,
          arraysize(case_labels));
 
@@ -239,6 +291,24 @@ TF_BUILTIN(AtomicsStore, SharedArrayBufferBuiltinsAssembler) {
               WordShl(index_word, 2), value_word32);
   Return(value_integer);
 
+  BIND(&u64);
+#if V8_TARGET_ARCH_MIPS && !_MIPS_ARCH_MIPS32R6
+  Return(CallRuntime(Runtime::kAtomicsStore64, context, array, index_integer,
+                     value));
+#else
+  TNode<BigInt> value_bigint = ToBigInt(CAST(context), CAST(value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
+  TVARIABLE(UintPtrT, var_low);
+  TVARIABLE(UintPtrT, var_high);
+  BigIntToRawBytes(value_bigint, &var_low, &var_high);
+  Node* high = Is64() ? nullptr : static_cast<Node*>(var_high.value());
+  AtomicStore(MachineRepresentation::kWord64, backing_store,
+              WordShl(index_word, 3), var_low.value(), high);
+  Return(value_bigint);
+#endif
+
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
   Unreachable();
@@ -259,22 +329,26 @@ TF_BUILTIN(AtomicsExchange, SharedArrayBufferBuiltinsAssembler) {
       ConvertTaggedAtomicIndexToWord32(index, context, &index_integer);
   ValidateAtomicIndex(array, index_word32, context);
 
-  Node* value_integer = ToInteger_Inline(CAST(context), CAST(value));
-
-#if DEBUG
-  DebugSanityCheckAtomicIndex(array, index_word32, context);
-#endif
-
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
   Return(CallRuntime(Runtime::kAtomicsExchange, context, array, index_integer,
-                     value_integer));
+                     value));
 #else
   Node* index_word = ChangeUint32ToWord(index_word32);
 
+  Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
+      i64(this), u64(this), big(this), other(this);
+  STATIC_ASSERT(FIXED_BIGINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  STATIC_ASSERT(FIXED_BIGUINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  GotoIf(
+      Int32GreaterThan(instance_type, Int32Constant(FIXED_UINT32_ARRAY_TYPE)),
+      &big);
+
+  Node* value_integer = ToInteger_Inline(CAST(context), CAST(value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
   Node* value_word32 = TruncateTaggedToWord32(context, value_integer);
 
-  Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
-      other(this);
   int32_t case_values[] = {
       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
@@ -311,6 +385,34 @@ TF_BUILTIN(AtomicsExchange, SharedArrayBufferBuiltinsAssembler) {
       AtomicExchange(MachineType::Uint32(), backing_store,
                      WordShl(index_word, 2), value_word32)));
 
+  BIND(&big);
+  TNode<BigInt> value_bigint = ToBigInt(CAST(context), CAST(value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
+  TVARIABLE(UintPtrT, var_low);
+  TVARIABLE(UintPtrT, var_high);
+  BigIntToRawBytes(value_bigint, &var_low, &var_high);
+  Node* high = Is64() ? nullptr : static_cast<Node*>(var_high.value());
+  GotoIf(Word32Equal(instance_type, Int32Constant(FIXED_BIGINT64_ARRAY_TYPE)),
+         &i64);
+  GotoIf(Word32Equal(instance_type, Int32Constant(FIXED_BIGUINT64_ARRAY_TYPE)),
+         &u64);
+  Unreachable();
+
+  BIND(&i64);
+  // This uses Uint64() intentionally: AtomicExchange is not implemented for
+  // Int64(), which is fine because the machine instruction only cares
+  // about words.
+  Return(BigIntFromSigned64(AtomicExchange(MachineType::Uint64(), backing_store,
+                                           WordShl(index_word, 3),
+                                           var_low.value(), high)));
+
+  BIND(&u64);
+  Return(BigIntFromUnsigned64(
+      AtomicExchange(MachineType::Uint64(), backing_store,
+                     WordShl(index_word, 3), var_low.value(), high)));
+
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
   Unreachable();
@@ -333,26 +435,29 @@ TF_BUILTIN(AtomicsCompareExchange, SharedArrayBufferBuiltinsAssembler) {
       ConvertTaggedAtomicIndexToWord32(index, context, &index_integer);
   ValidateAtomicIndex(array, index_word32, context);
 
-  Node* old_value_integer = ToInteger_Inline(CAST(context), CAST(old_value));
-  Node* new_value_integer = ToInteger_Inline(CAST(context), CAST(new_value));
-
-#if DEBUG
-  DebugSanityCheckAtomicIndex(array, index_word32, context);
-#endif
-
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64 || \
     V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
   Return(CallRuntime(Runtime::kAtomicsCompareExchange, context, array,
-                     index_integer, old_value_integer, new_value_integer));
+                     index_integer, old_value, new_value));
 #else
   Node* index_word = ChangeUint32ToWord(index_word32);
 
-  Node* old_value_word32 = TruncateTaggedToWord32(context, old_value_integer);
+  Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
+      i64(this), u64(this), big(this), other(this);
+  STATIC_ASSERT(FIXED_BIGINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  STATIC_ASSERT(FIXED_BIGUINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  GotoIf(
+      Int32GreaterThan(instance_type, Int32Constant(FIXED_UINT32_ARRAY_TYPE)),
+      &big);
 
+  Node* old_value_integer = ToInteger_Inline(CAST(context), CAST(old_value));
+  Node* new_value_integer = ToInteger_Inline(CAST(context), CAST(new_value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
+  Node* old_value_word32 = TruncateTaggedToWord32(context, old_value_integer);
   Node* new_value_word32 = TruncateTaggedToWord32(context, new_value_integer);
 
-  Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
-      other(this);
   int32_t case_values[] = {
       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
@@ -393,6 +498,39 @@ TF_BUILTIN(AtomicsCompareExchange, SharedArrayBufferBuiltinsAssembler) {
       MachineType::Uint32(), backing_store, WordShl(index_word, 2),
       old_value_word32, new_value_word32)));
 
+  BIND(&big);
+  TNode<BigInt> old_value_bigint = ToBigInt(CAST(context), CAST(old_value));
+  TNode<BigInt> new_value_bigint = ToBigInt(CAST(context), CAST(new_value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
+  TVARIABLE(UintPtrT, var_old_low);
+  TVARIABLE(UintPtrT, var_old_high);
+  TVARIABLE(UintPtrT, var_new_low);
+  TVARIABLE(UintPtrT, var_new_high);
+  BigIntToRawBytes(old_value_bigint, &var_old_low, &var_old_high);
+  BigIntToRawBytes(new_value_bigint, &var_new_low, &var_new_high);
+  Node* old_high = Is64() ? nullptr : static_cast<Node*>(var_old_high.value());
+  Node* new_high = Is64() ? nullptr : static_cast<Node*>(var_new_high.value());
+  GotoIf(Word32Equal(instance_type, Int32Constant(FIXED_BIGINT64_ARRAY_TYPE)),
+         &i64);
+  GotoIf(Word32Equal(instance_type, Int32Constant(FIXED_BIGUINT64_ARRAY_TYPE)),
+         &u64);
+  Unreachable();
+
+  BIND(&i64);
+  // This uses Uint64() intentionally: AtomicCompareExchange is not implemented
+  // for Int64(), which is fine because the machine instruction only cares
+  // about words.
+  Return(BigIntFromSigned64(AtomicCompareExchange(
+      MachineType::Uint64(), backing_store, WordShl(index_word, 3),
+      var_old_low.value(), var_new_low.value(), old_high, new_high)));
+
+  BIND(&u64);
+  Return(BigIntFromUnsigned64(AtomicCompareExchange(
+      MachineType::Uint64(), backing_store, WordShl(index_word, 3),
+      var_old_low.value(), var_new_low.value(), old_high, new_high)));
+
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
   Unreachable();
@@ -429,27 +567,27 @@ void SharedArrayBufferBuiltinsAssembler::AtomicBinopBuiltinCommon(
       ConvertTaggedAtomicIndexToWord32(index, context, &index_integer);
   ValidateAtomicIndex(array, index_word32, context);
 
-  Node* value_integer = ToInteger_Inline(CAST(context), CAST(value));
-
-#if DEBUG
-  // In Debug mode, we re-validate the index as a sanity check because
-  // ToInteger above calls out to JavaScript. A SharedArrayBuffer can't be
-  // neutered and the TypedArray length can't change either, so skipping this
-  // check in Release mode is safe.
-  ValidateAtomicIndex(array, index_word32, context);
-#endif
-
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64 || \
     V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
-  Return(CallRuntime(runtime_function, context, array, index_integer,
-                     value_integer));
+  Return(CallRuntime(runtime_function, context, array, index_integer, value));
 #else
   Node* index_word = ChangeUint32ToWord(index_word32);
 
+  Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
+      i64(this), u64(this), big(this), other(this);
+
+  STATIC_ASSERT(FIXED_BIGINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  STATIC_ASSERT(FIXED_BIGUINT64_ARRAY_TYPE > FIXED_UINT32_ARRAY_TYPE);
+  GotoIf(
+      Int32GreaterThan(instance_type, Int32Constant(FIXED_UINT32_ARRAY_TYPE)),
+      &big);
+
+  Node* value_integer = ToInteger_Inline(CAST(context), CAST(value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
   Node* value_word32 = TruncateTaggedToWord32(context, value_integer);
 
-  Label i8(this), u8(this), i16(this), u16(this), i32(this), u32(this),
-      other(this);
   int32_t case_values[] = {
       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
@@ -462,29 +600,59 @@ void SharedArrayBufferBuiltinsAssembler::AtomicBinopBuiltinCommon(
 
   BIND(&i8);
   Return(SmiFromInt32((this->*function)(MachineType::Int8(), backing_store,
-                                        index_word, value_word32)));
+                                        index_word, value_word32, nullptr)));
 
   BIND(&u8);
   Return(SmiFromInt32((this->*function)(MachineType::Uint8(), backing_store,
-                                        index_word, value_word32)));
+                                        index_word, value_word32, nullptr)));
 
   BIND(&i16);
   Return(SmiFromInt32((this->*function)(MachineType::Int16(), backing_store,
-                                        WordShl(index_word, 1), value_word32)));
+                                        WordShl(index_word, 1), value_word32,
+                                        nullptr)));
 
   BIND(&u16);
   Return(SmiFromInt32((this->*function)(MachineType::Uint16(), backing_store,
-                                        WordShl(index_word, 1), value_word32)));
+                                        WordShl(index_word, 1), value_word32,
+                                        nullptr)));
 
   BIND(&i32);
   Return(ChangeInt32ToTagged(
       (this->*function)(MachineType::Int32(), backing_store,
-                        WordShl(index_word, 2), value_word32)));
+                        WordShl(index_word, 2), value_word32, nullptr)));
 
   BIND(&u32);
   Return(ChangeUint32ToTagged(
       (this->*function)(MachineType::Uint32(), backing_store,
-                        WordShl(index_word, 2), value_word32)));
+                        WordShl(index_word, 2), value_word32, nullptr)));
+
+  BIND(&big);
+  TNode<BigInt> value_bigint = ToBigInt(CAST(context), CAST(value));
+#if DEBUG
+  DebugSanityCheckAtomicIndex(array, index_word32, context);
+#endif
+  TVARIABLE(UintPtrT, var_low);
+  TVARIABLE(UintPtrT, var_high);
+  BigIntToRawBytes(value_bigint, &var_low, &var_high);
+  Node* high = Is64() ? nullptr : static_cast<Node*>(var_high.value());
+  GotoIf(Word32Equal(instance_type, Int32Constant(FIXED_BIGINT64_ARRAY_TYPE)),
+         &i64);
+  GotoIf(Word32Equal(instance_type, Int32Constant(FIXED_BIGUINT64_ARRAY_TYPE)),
+         &u64);
+  Unreachable();
+
+  BIND(&i64);
+  // This uses Uint64() intentionally: Atomic* ops are not implemented for
+  // Int64(), which is fine because the machine instructions only care
+  // about words.
+  Return(BigIntFromSigned64(
+      (this->*function)(MachineType::Uint64(), backing_store,
+                        WordShl(index_word, 3), var_low.value(), high)));
+
+  BIND(&u64);
+  Return(BigIntFromUnsigned64(
+      (this->*function)(MachineType::Uint64(), backing_store,
+                        WordShl(index_word, 3), var_low.value(), high)));
 
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
diff --git a/deps/v8/src/builtins/builtins-sharedarraybuffer.cc b/deps/v8/src/builtins/builtins-sharedarraybuffer.cc
index 92c1c65d1f..859d634cc9 100644
--- a/deps/v8/src/builtins/builtins-sharedarraybuffer.cc
+++ b/deps/v8/src/builtins/builtins-sharedarraybuffer.cc
@@ -74,6 +74,7 @@ V8_WARN_UNUSED_RESULT Maybe<size_t> ValidateAtomicAccess(
 
   size_t access_index;
   if (!TryNumberToSize(*access_index_obj, &access_index) ||
+      typed_array->WasNeutered() ||
       access_index >= typed_array->length_value()) {
     isolate->Throw(*isolate->factory()->NewRangeError(
         MessageTemplate::kInvalidAtomicAccessIndex));
@@ -82,28 +83,24 @@ V8_WARN_UNUSED_RESULT Maybe<size_t> ValidateAtomicAccess(
   return Just<size_t>(access_index);
 }
 
-// ES #sec-atomics.wake
-// Atomics.wake( typedArray, index, count )
-BUILTIN(AtomicsWake) {
-  HandleScope scope(isolate);
-  Handle<Object> array = args.atOrUndefined(isolate, 1);
-  Handle<Object> index = args.atOrUndefined(isolate, 2);
-  Handle<Object> count = args.atOrUndefined(isolate, 3);
-
+namespace {
+MaybeHandle<Object> AtomicsWake(Isolate* isolate, Handle<Object> array,
+                                Handle<Object> index, Handle<Object> count) {
   Handle<JSTypedArray> sta;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, sta, ValidateSharedIntegerTypedArray(isolate, array, true));
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, sta, ValidateSharedIntegerTypedArray(isolate, array, true),
+      Object);
 
   Maybe<size_t> maybe_index = ValidateAtomicAccess(isolate, sta, index);
-  if (maybe_index.IsNothing()) return ReadOnlyRoots(isolate).exception();
+  MAYBE_RETURN_NULL(maybe_index);
   size_t i = maybe_index.FromJust();
 
   uint32_t c;
   if (count->IsUndefined(isolate)) {
     c = kMaxUInt32;
   } else {
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, count,
-                                       Object::ToInteger(isolate, count));
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, count,
+                               Object::ToInteger(isolate, count), Object);
     double count_double = count->Number();
     if (count_double < 0)
       count_double = 0;
@@ -113,9 +110,35 @@ BUILTIN(AtomicsWake) {
   }
 
   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
-  size_t addr = (i << 2) + NumberToSize(sta->byte_offset());
+  size_t addr = (i << 2) + sta->byte_offset();
+
+  return Handle<Object>(FutexEmulation::Wake(array_buffer, addr, c), isolate);
+}
+
+}  // namespace
+
+// ES #sec-atomics.wake
+// Atomics.wake( typedArray, index, count )
+BUILTIN(AtomicsWake) {
+  HandleScope scope(isolate);
+  Handle<Object> array = args.atOrUndefined(isolate, 1);
+  Handle<Object> index = args.atOrUndefined(isolate, 2);
+  Handle<Object> count = args.atOrUndefined(isolate, 3);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kAtomicsWake);
+  RETURN_RESULT_OR_FAILURE(isolate, AtomicsWake(isolate, array, index, count));
+}
+
+// ES #sec-atomics.notify
+// Atomics.notify( typedArray, index, count )
+BUILTIN(AtomicsNotify) {
+  HandleScope scope(isolate);
+  Handle<Object> array = args.atOrUndefined(isolate, 1);
+  Handle<Object> index = args.atOrUndefined(isolate, 2);
+  Handle<Object> count = args.atOrUndefined(isolate, 3);
 
-  return FutexEmulation::Wake(array_buffer, addr, c);
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kAtomicsNotify);
+  RETURN_RESULT_OR_FAILURE(isolate, AtomicsWake(isolate, array, index, count));
 }
 
 // ES #sec-atomics.wait
@@ -158,7 +181,7 @@ BUILTIN(AtomicsWait) {
   }
 
   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
-  size_t addr = (i << 2) + NumberToSize(sta->byte_offset());
+  size_t addr = (i << 2) + sta->byte_offset();
 
   return FutexEmulation::Wait(isolate, array_buffer, addr, value_int32,
                               timeout_number);
diff --git a/deps/v8/src/builtins/builtins-string-gen.cc b/deps/v8/src/builtins/builtins-string-gen.cc
index c46a3fd35d..574f425a0a 100644
--- a/deps/v8/src/builtins/builtins-string-gen.cc
+++ b/deps/v8/src/builtins/builtins-string-gen.cc
@@ -39,11 +39,11 @@ Node* StringBuiltinsAssembler::DirectStringData(Node* string,
   BIND(&if_external);
   {
     // This is only valid for ExternalStrings where the resource data
-    // pointer is cached (i.e. no short external strings).
-    CSA_ASSERT(
-        this, Word32NotEqual(Word32And(string_instance_type,
-                                       Int32Constant(kShortExternalStringMask)),
-                             Int32Constant(kShortExternalStringTag)));
+    // pointer is cached (i.e. no uncached external strings).
+    CSA_ASSERT(this, Word32NotEqual(
+                         Word32And(string_instance_type,
+                                   Int32Constant(kUncachedExternalStringMask)),
+                         Int32Constant(kUncachedExternalStringTag)));
     var_data.Bind(LoadObjectField(string, ExternalString::kResourceDataOffset,
                                   MachineType::Pointer()));
     Goto(&if_join);
@@ -191,11 +191,11 @@ void StringBuiltinsAssembler::StringEqual_Core(
 
   // Check if both {lhs} and {rhs} are direct strings, and that in case of
   // ExternalStrings the data pointer is cached.
-  STATIC_ASSERT(kShortExternalStringTag != 0);
+  STATIC_ASSERT(kUncachedExternalStringTag != 0);
   STATIC_ASSERT(kIsIndirectStringTag != 0);
   int const kBothDirectStringMask =
-      kIsIndirectStringMask | kShortExternalStringMask |
-      ((kIsIndirectStringMask | kShortExternalStringMask) << 8);
+      kIsIndirectStringMask | kUncachedExternalStringMask |
+      ((kIsIndirectStringMask | kUncachedExternalStringMask) << 8);
   GotoIfNot(Word32Equal(Word32And(both_instance_types,
                                   Int32Constant(kBothDirectStringMask)),
                         Int32Constant(0)),
@@ -284,67 +284,31 @@ void StringBuiltinsAssembler::StringEqual_Loop(
   }
 }
 
-void StringBuiltinsAssembler::Generate_StringAdd(StringAddFlags flags,
-                                                 PretenureFlag pretenure_flag,
-                                                 Node* context, Node* left,
-                                                 Node* right) {
-  switch (flags) {
-    case STRING_ADD_CONVERT_LEFT: {
-      // TODO(danno): The ToString and JSReceiverToPrimitive below could be
-      // combined to avoid duplicate smi and instance type checks.
-      left = ToString(context, JSReceiverToPrimitive(context, left));
-      Callable callable = CodeFactory::StringAdd(
-          isolate(), STRING_ADD_CHECK_NONE, pretenure_flag);
-      TailCallStub(callable, context, left, right);
-      break;
-    }
-    case STRING_ADD_CONVERT_RIGHT: {
-      // TODO(danno): The ToString and JSReceiverToPrimitive below could be
-      // combined to avoid duplicate smi and instance type checks.
-      right = ToString(context, JSReceiverToPrimitive(context, right));
-      Callable callable = CodeFactory::StringAdd(
-          isolate(), STRING_ADD_CHECK_NONE, pretenure_flag);
-      TailCallStub(callable, context, left, right);
-      break;
-    }
-    case STRING_ADD_CHECK_NONE: {
-      CodeStubAssembler::AllocationFlag allocation_flags =
-          (pretenure_flag == TENURED) ? CodeStubAssembler::kPretenured
-                                      : CodeStubAssembler::kNone;
-      Return(StringAdd(context, CAST(left), CAST(right), allocation_flags));
-      break;
-    }
-  }
-}
-
-TF_BUILTIN(StringAdd_CheckNone_NotTenured, StringBuiltinsAssembler) {
-  Node* left = Parameter(Descriptor::kLeft);
-  Node* right = Parameter(Descriptor::kRight);
+TF_BUILTIN(StringAdd_CheckNone, StringBuiltinsAssembler) {
+  TNode<String> left = CAST(Parameter(Descriptor::kLeft));
+  TNode<String> right = CAST(Parameter(Descriptor::kRight));
   Node* context = Parameter(Descriptor::kContext);
-  Generate_StringAdd(STRING_ADD_CHECK_NONE, NOT_TENURED, context, left, right);
+  Return(StringAdd(context, left, right));
 }
 
-TF_BUILTIN(StringAdd_CheckNone_Tenured, StringBuiltinsAssembler) {
-  Node* left = Parameter(Descriptor::kLeft);
-  Node* right = Parameter(Descriptor::kRight);
+TF_BUILTIN(StringAdd_ConvertLeft, StringBuiltinsAssembler) {
+  TNode<Object> left = CAST(Parameter(Descriptor::kLeft));
+  TNode<String> right = CAST(Parameter(Descriptor::kRight));
   Node* context = Parameter(Descriptor::kContext);
-  Generate_StringAdd(STRING_ADD_CHECK_NONE, TENURED, context, left, right);
+  // TODO(danno): The ToString and JSReceiverToPrimitive below could be
+  // combined to avoid duplicate smi and instance type checks.
+  left = ToString(context, JSReceiverToPrimitive(context, left));
+  TailCallBuiltin(Builtins::kStringAdd_CheckNone, context, left, right);
 }
 
-TF_BUILTIN(StringAdd_ConvertLeft_NotTenured, StringBuiltinsAssembler) {
-  Node* left = Parameter(Descriptor::kLeft);
-  Node* right = Parameter(Descriptor::kRight);
+TF_BUILTIN(StringAdd_ConvertRight, StringBuiltinsAssembler) {
+  TNode<String> left = CAST(Parameter(Descriptor::kLeft));
+  TNode<Object> right = CAST(Parameter(Descriptor::kRight));
   Node* context = Parameter(Descriptor::kContext);
-  Generate_StringAdd(STRING_ADD_CONVERT_LEFT, NOT_TENURED, context, left,
-                     right);
-}
-
-TF_BUILTIN(StringAdd_ConvertRight_NotTenured, StringBuiltinsAssembler) {
-  Node* left = Parameter(Descriptor::kLeft);
-  Node* right = Parameter(Descriptor::kRight);
-  Node* context = Parameter(Descriptor::kContext);
-  Generate_StringAdd(STRING_ADD_CONVERT_RIGHT, NOT_TENURED, context, left,
-                     right);
+  // TODO(danno): The ToString and JSReceiverToPrimitive below could be
+  // combined to avoid duplicate smi and instance type checks.
+  right = ToString(context, JSReceiverToPrimitive(context, right));
+  TailCallBuiltin(Builtins::kStringAdd_CheckNone, context, left, right);
 }
 
 TF_BUILTIN(SubString, StringBuiltinsAssembler) {
@@ -354,12 +318,10 @@ TF_BUILTIN(SubString, StringBuiltinsAssembler) {
   Return(SubString(string, SmiUntag(from), SmiUntag(to)));
 }
 
-void StringBuiltinsAssembler::GenerateStringAt(char const* method_name,
-                                               TNode<Context> context,
-                                               Node* receiver,
-                                               TNode<Object> maybe_position,
-                                               TNode<Object> default_return,
-                                               StringAtAccessor accessor) {
+void StringBuiltinsAssembler::GenerateStringAt(
+    char const* method_name, TNode<Context> context, Node* receiver,
+    TNode<Object> maybe_position, TNode<Object> default_return,
+    const StringAtAccessor& accessor) {
   // Check that {receiver} is coercible to Object and convert it to a String.
   TNode<String> string = ToThisString(context, receiver, method_name);
 
@@ -587,8 +549,9 @@ TF_BUILTIN(StringGreaterThanOrEqual, StringBuiltinsAssembler) {
 }
 
 TF_BUILTIN(StringCharAt, StringBuiltinsAssembler) {
-  Node* receiver = Parameter(Descriptor::kReceiver);
-  Node* position = Parameter(Descriptor::kPosition);
+  TNode<String> receiver = CAST(Parameter(Descriptor::kReceiver));
+  TNode<IntPtrT> position =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kPosition));
 
   // Load the character code at the {position} from the {receiver}.
   TNode<Int32T> code = StringCharCodeAt(receiver, position);
@@ -639,7 +602,6 @@ TF_BUILTIN(StringFromCharCode, CodeStubAssembler) {
   Node* context = Parameter(Descriptor::kContext);
 
   CodeStubArguments arguments(this, ChangeInt32ToIntPtr(argc));
-  TNode<Smi> smi_argc = SmiTag(arguments.GetLength(INTPTR_PARAMETERS));
   // Check if we have exactly one argument (plus the implicit receiver), i.e.
   // if the parent frame is not an arguments adaptor frame.
   Label if_oneargument(this), if_notoneargument(this);
@@ -664,7 +626,7 @@ TF_BUILTIN(StringFromCharCode, CodeStubAssembler) {
   {
     Label two_byte(this);
     // Assume that the resulting string contains only one-byte characters.
-    Node* one_byte_result = AllocateSeqOneByteString(context, smi_argc);
+    Node* one_byte_result = AllocateSeqOneByteString(context, Unsigned(argc));
 
     TVARIABLE(IntPtrT, var_max_index);
     var_max_index = IntPtrConstant(0);
@@ -698,7 +660,7 @@ TF_BUILTIN(StringFromCharCode, CodeStubAssembler) {
     // At least one of the characters in the string requires a 16-bit
     // representation.  Allocate a SeqTwoByteString to hold the resulting
     // string.
-    Node* two_byte_result = AllocateSeqTwoByteString(context, smi_argc);
+    Node* two_byte_result = AllocateSeqTwoByteString(context, Unsigned(argc));
 
     // Copy the characters that have already been put in the 8-bit string into
     // their corresponding positions in the new 16-bit string.
@@ -817,7 +779,7 @@ TF_BUILTIN(StringPrototypeConcat, CodeStubAssembler) {
 
 void StringBuiltinsAssembler::StringIndexOf(
     Node* const subject_string, Node* const search_string, Node* const position,
-    std::function<void(Node*)> f_return) {
+    const std::function<void(Node*)>& f_return) {
   CSA_ASSERT(this, IsString(subject_string));
   CSA_ASSERT(this, IsString(search_string));
   CSA_ASSERT(this, TaggedIsSmi(position));
@@ -1229,8 +1191,6 @@ TF_BUILTIN(StringPrototypeRepeat, StringBuiltinsAssembler) {
   TNode<Object> count = CAST(Parameter(Descriptor::kCount));
   Node* const string =
       ToThisString(context, receiver, "String.prototype.repeat");
-  Node* const is_stringempty =
-      SmiEqual(LoadStringLengthAsSmi(string), SmiConstant(0));
 
   VARIABLE(
       var_count, MachineRepresentation::kTagged,
@@ -1248,7 +1208,8 @@ TF_BUILTIN(StringPrototypeRepeat, StringBuiltinsAssembler) {
       TNode<Smi> smi_count = CAST(var_count.value());
       GotoIf(SmiLessThan(smi_count, SmiConstant(0)), &invalid_count);
       GotoIf(SmiEqual(smi_count, SmiConstant(0)), &return_emptystring);
-      GotoIf(is_stringempty, &return_emptystring);
+      GotoIf(Word32Equal(LoadStringLengthAsWord32(string), Int32Constant(0)),
+             &return_emptystring);
       GotoIf(SmiGreaterThan(smi_count, SmiConstant(String::kMaxLength)),
              &invalid_string_length);
       Return(CallBuiltin(Builtins::kStringRepeat, context, string, smi_count));
@@ -1266,7 +1227,8 @@ TF_BUILTIN(StringPrototypeRepeat, StringBuiltinsAssembler) {
              &invalid_count);
       GotoIf(Float64LessThan(number_value, Float64Constant(0.0)),
              &invalid_count);
-      Branch(is_stringempty, &return_emptystring, &invalid_string_length);
+      Branch(Word32Equal(LoadStringLengthAsWord32(string), Int32Constant(0)),
+             &return_emptystring, &invalid_string_length);
     }
   }
 
@@ -1311,9 +1273,6 @@ TF_BUILTIN(StringRepeat, StringBuiltinsAssembler) {
   VARIABLE(var_temp, MachineRepresentation::kTagged, string);
   TVARIABLE(Smi, var_count, count);
 
-  Callable stringadd_callable =
-      CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
-
   Label loop(this, {&var_count, &var_result, &var_temp}), return_result(this);
   Goto(&loop);
   BIND(&loop);
@@ -1321,16 +1280,16 @@ TF_BUILTIN(StringRepeat, StringBuiltinsAssembler) {
     {
       Label next(this);
       GotoIfNot(SmiToInt32(SmiAnd(var_count.value(), SmiConstant(1))), &next);
-      var_result.Bind(CallStub(stringadd_callable, context, var_result.value(),
-                               var_temp.value()));
+      var_result.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                  var_result.value(), var_temp.value()));
       Goto(&next);
       BIND(&next);
     }
 
     var_count = SmiShr(var_count.value(), 1);
     GotoIf(SmiEqual(var_count.value(), SmiConstant(0)), &return_result);
-    var_temp.Bind(CallStub(stringadd_callable, context, var_temp.value(),
-                           var_temp.value()));
+    var_temp.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                              var_temp.value(), var_temp.value()));
     Goto(&loop);
   }
 
@@ -1369,16 +1328,16 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
   TNode<String> const subject_string = ToString_Inline(context, receiver);
   TNode<String> const search_string = ToString_Inline(context, search);
 
-  TNode<Smi> const subject_length = LoadStringLengthAsSmi(subject_string);
-  TNode<Smi> const search_length = LoadStringLengthAsSmi(search_string);
+  TNode<IntPtrT> const subject_length = LoadStringLengthAsWord(subject_string);
+  TNode<IntPtrT> const search_length = LoadStringLengthAsWord(search_string);
 
   // Fast-path single-char {search}, long cons {receiver}, and simple string
   // {replace}.
   {
     Label next(this);
 
-    GotoIfNot(SmiEqual(search_length, SmiConstant(1)), &next);
-    GotoIfNot(SmiGreaterThan(subject_length, SmiConstant(0xFF)), &next);
+    GotoIfNot(WordEqual(search_length, IntPtrConstant(1)), &next);
+    GotoIfNot(IntPtrGreaterThan(subject_length, IntPtrConstant(0xFF)), &next);
     GotoIf(TaggedIsSmi(replace), &next);
     GotoIfNot(IsString(replace), &next);
 
@@ -1430,10 +1389,8 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
     BIND(&next);
   }
 
-  TNode<Smi> const match_end_index = SmiAdd(match_start_index, search_length);
-
-  Callable stringadd_callable =
-      CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
+  TNode<Smi> const match_end_index =
+      SmiAdd(match_start_index, SmiFromIntPtr(search_length));
 
   VARIABLE(var_result, MachineRepresentation::kTagged, EmptyStringConstant());
 
@@ -1465,8 +1422,8 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
         CallJS(call_callable, context, replace, UndefinedConstant(),
                search_string, match_start_index, subject_string);
     Node* const replacement_string = ToString_Inline(context, replacement);
-    var_result.Bind(CallStub(stringadd_callable, context, var_result.value(),
-                             replacement_string));
+    var_result.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                var_result.value(), replacement_string));
     Goto(&out);
   }
 
@@ -1476,8 +1433,8 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
     Node* const replacement =
         GetSubstitution(context, subject_string, match_start_index,
                         match_end_index, replace_string);
-    var_result.Bind(
-        CallStub(stringadd_callable, context, var_result.value(), replacement));
+    var_result.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                var_result.value(), replacement));
     Goto(&out);
   }
 
@@ -1485,9 +1442,9 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
   {
     Node* const suffix =
         CallBuiltin(Builtins::kStringSubstring, context, subject_string,
-                    SmiUntag(match_end_index), SmiUntag(subject_length));
-    Node* const result =
-        CallStub(stringadd_callable, context, var_result.value(), suffix);
+                    SmiUntag(match_end_index), subject_length);
+    Node* const result = CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                     var_result.value(), suffix);
     Return(result);
   }
 }
@@ -1679,8 +1636,6 @@ class StringPadAssembler : public StringBuiltinsAssembler {
           SmiLessThanOrEqual(smi_max_length, SmiConstant(String::kMaxLength)),
           &invalid_string_length);
 
-      Callable stringadd_callable =
-          CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
       CSA_ASSERT(this, SmiGreaterThan(smi_max_length, string_length));
       TNode<Smi> const pad_length = SmiSub(smi_max_length, string_length);
 
@@ -1717,19 +1672,20 @@ class StringPadAssembler : public StringBuiltinsAssembler {
           Node* const remainder_string = CallBuiltin(
               Builtins::kStringSubstring, context, var_fill_string.value(),
               IntPtrConstant(0), ChangeInt32ToIntPtr(remaining_word32));
-          var_pad.Bind(CallStub(stringadd_callable, context, var_pad.value(),
-                                remainder_string));
+          var_pad.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                                   var_pad.value(), remainder_string));
           Goto(&return_result);
         }
       }
       BIND(&return_result);
       CSA_ASSERT(this,
                  SmiEqual(pad_length, LoadStringLengthAsSmi(var_pad.value())));
-      arguments.PopAndReturn(variant == kStart
-                                 ? CallStub(stringadd_callable, context,
-                                            var_pad.value(), receiver_string)
-                                 : CallStub(stringadd_callable, context,
-                                            receiver_string, var_pad.value()));
+      arguments.PopAndReturn(
+          variant == kStart
+              ? CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                            var_pad.value(), receiver_string)
+              : CallBuiltin(Builtins::kStringAdd_CheckNone, context,
+                            receiver_string, var_pad.value()));
     }
     BIND(&dont_pad);
     arguments.PopAndReturn(receiver_string);
@@ -1844,7 +1800,7 @@ TNode<JSArray> StringBuiltinsAssembler::StringToArray(
     TNode<RawPtrT> string_data = UncheckedCast<RawPtrT>(
         to_direct.PointerToData(&fill_thehole_and_call_runtime));
     TNode<IntPtrT> string_data_offset = to_direct.offset();
-    TNode<Object> cache = LoadRoot(Heap::kSingleCharacterStringCacheRootIndex);
+    TNode<Object> cache = LoadRoot(RootIndex::kSingleCharacterStringCache);
 
     BuildFastLoop(
         IntPtrConstant(0), length,
@@ -1876,7 +1832,7 @@ TNode<JSArray> StringBuiltinsAssembler::StringToArray(
     BIND(&fill_thehole_and_call_runtime);
     {
       FillFixedArrayWithValue(PACKED_ELEMENTS, elements, IntPtrConstant(0),
-                              length, Heap::kTheHoleValueRootIndex);
+                              length, RootIndex::kTheHoleValue);
       Goto(&call_runtime);
     }
   }
@@ -2303,10 +2259,10 @@ void StringTrimAssembler::ScanForNonWhiteSpaceOrLineTerminator(
   BIND(&out);
 }
 
-void StringTrimAssembler::BuildLoop(Variable* const var_index, Node* const end,
-                                    int increment, Label* const if_none_found,
-                                    Label* const out,
-                                    std::function<Node*(Node*)> get_character) {
+void StringTrimAssembler::BuildLoop(
+    Variable* const var_index, Node* const end, int increment,
+    Label* const if_none_found, Label* const out,
+    const std::function<Node*(Node*)>& get_character) {
   Label loop(this, var_index);
   Goto(&loop);
   BIND(&loop);
@@ -2403,14 +2359,14 @@ TF_BUILTIN(StringPrototypeIterator, CodeStubAssembler) {
       ToThisString(context, receiver, "String.prototype[Symbol.iterator]");
 
   Node* native_context = LoadNativeContext(context);
-  Node* map =
-      LoadContextElement(native_context, Context::STRING_ITERATOR_MAP_INDEX);
+  Node* map = LoadContextElement(native_context,
+                                 Context::INITIAL_STRING_ITERATOR_MAP_INDEX);
   Node* iterator = Allocate(JSStringIterator::kSize);
   StoreMapNoWriteBarrier(iterator, map);
   StoreObjectFieldRoot(iterator, JSValue::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(iterator, JSObject::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(iterator, JSStringIterator::kStringOffset,
                                  string);
   Node* index = SmiConstant(0);
@@ -2537,6 +2493,85 @@ TF_BUILTIN(StringIteratorPrototypeNext, StringBuiltinsAssembler) {
   }
 }
 
+TNode<BoolT> StringBuiltinsAssembler::IsStringPrimitiveWithNoCustomIteration(
+    TNode<Object> object, TNode<Context> context) {
+  Label if_false(this, Label::kDeferred), exit(this);
+  TVARIABLE(BoolT, var_result);
+
+  GotoIf(TaggedIsSmi(object), &if_false);
+  GotoIfNot(IsString(CAST(object)), &if_false);
+
+  // Check that the String iterator hasn't been modified in a way that would
+  // affect iteration.
+  Node* protector_cell = LoadRoot(RootIndex::kStringIteratorProtector);
+  DCHECK(isolate()->heap()->string_iterator_protector()->IsPropertyCell());
+  var_result =
+      WordEqual(LoadObjectField(protector_cell, PropertyCell::kValueOffset),
+                SmiConstant(Isolate::kProtectorValid));
+  Goto(&exit);
+
+  BIND(&if_false);
+  {
+    var_result = Int32FalseConstant();
+    Goto(&exit);
+  }
+
+  BIND(&exit);
+  return var_result.value();
+}
+
+TNode<JSArray> StringBuiltinsAssembler::StringToList(TNode<Context> context,
+                                                     TNode<String> string) {
+  CSA_ASSERT(this, IsStringPrimitiveWithNoCustomIteration(string, context));
+  const ElementsKind kind = PACKED_ELEMENTS;
+  const TNode<IntPtrT> length = LoadStringLengthAsWord(string);
+
+  Node* const array_map =
+      LoadJSArrayElementsMap(kind, LoadNativeContext(context));
+  Node* const array = AllocateJSArray(kind, array_map, length, SmiTag(length));
+  Node* const elements = LoadElements(array);
+
+  const int first_element_offset = FixedArray::kHeaderSize - kHeapObjectTag;
+  TNode<IntPtrT> first_to_element_offset =
+      ElementOffsetFromIndex(IntPtrConstant(0), kind, INTPTR_PARAMETERS, 0);
+  VARIABLE(
+      var_offset, MachineType::PointerRepresentation(),
+      IntPtrAdd(first_to_element_offset, IntPtrConstant(first_element_offset)));
+  TVARIABLE(IntPtrT, var_position, IntPtrConstant(0));
+  Label done(this), next_codepoint(this, {&var_position, &var_offset});
+
+  Goto(&next_codepoint);
+
+  BIND(&next_codepoint);
+  {
+    // Loop condition.
+    GotoIfNot(IntPtrLessThan(var_position.value(), length), &done);
+    const UnicodeEncoding encoding = UnicodeEncoding::UTF16;
+    TNode<Int32T> ch =
+        LoadSurrogatePairAt(string, length, var_position.value(), encoding);
+    TNode<String> value = StringFromSingleCodePoint(ch, encoding);
+
+    Store(elements, var_offset.value(), value);
+
+    // Increment the position.
+    TNode<IntPtrT> ch_length = LoadStringLengthAsWord(value);
+    var_position = IntPtrAdd(var_position.value(), ch_length);
+    // Increment the array offset and continue the loop.
+    var_offset.Bind(
+        IntPtrAdd(var_offset.value(), IntPtrConstant(kPointerSize)));
+    Goto(&next_codepoint);
+  }
+
+  BIND(&done);
+  return UncheckedCast<JSArray>(array);
+}
+
+TF_BUILTIN(StringToList, StringBuiltinsAssembler) {
+  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
+  TNode<String> string = CAST(Parameter(Descriptor::kSource));
+  Return(StringToList(context, string));
+}
+
 // -----------------------------------------------------------------------------
 // ES6 section B.2.3 Additional Properties of the String.prototype object
 
diff --git a/deps/v8/src/builtins/builtins-string-gen.h b/deps/v8/src/builtins/builtins-string-gen.h
index 06ac127f13..2420ad3014 100644
--- a/deps/v8/src/builtins/builtins-string-gen.h
+++ b/deps/v8/src/builtins/builtins-string-gen.h
@@ -23,8 +23,12 @@ class StringBuiltinsAssembler : public CodeStubAssembler {
                         Node* rhs, Node* rhs_instance_type,
                         TNode<IntPtrT> length, Label* if_equal,
                         Label* if_not_equal, Label* if_indirect);
+  TNode<BoolT> IsStringPrimitiveWithNoCustomIteration(TNode<Object> object,
+                                                      TNode<Context> context);
 
  protected:
+  TNode<JSArray> StringToList(TNode<Context> context, TNode<String> string);
+
   void StringEqual_Loop(Node* lhs, Node* lhs_instance_type,
                         MachineType lhs_type, Node* rhs,
                         Node* rhs_instance_type, MachineType rhs_type,
@@ -64,7 +68,7 @@ class StringBuiltinsAssembler : public CodeStubAssembler {
   void GenerateStringAt(const char* method_name, TNode<Context> context,
                         Node* receiver, TNode<Object> maybe_position,
                         TNode<Object> default_return,
-                        StringAtAccessor accessor);
+                        const StringAtAccessor& accessor);
 
   TNode<Int32T> LoadSurrogatePairAt(SloppyTNode<String> string,
                                     SloppyTNode<IntPtrT> length,
@@ -72,7 +76,8 @@ class StringBuiltinsAssembler : public CodeStubAssembler {
                                     UnicodeEncoding encoding);
 
   void StringIndexOf(Node* const subject_string, Node* const search_string,
-                     Node* const position, std::function<void(Node*)> f_return);
+                     Node* const position,
+                     const std::function<void(Node*)>& f_return);
 
   TNode<Smi> IndexOfDollarChar(Node* const context, Node* const string);
 
@@ -107,9 +112,6 @@ class StringBuiltinsAssembler : public CodeStubAssembler {
                                  Handle<Symbol> symbol,
                                  const NodeFunction0& regexp_call,
                                  const NodeFunction1& generic_call);
-
-  void Generate_StringAdd(StringAddFlags flags, PretenureFlag pretenure_flag,
-                          Node* context, Node* left, Node* right);
 };
 
 class StringIncludesIndexOfAssembler : public StringBuiltinsAssembler {
@@ -145,7 +147,7 @@ class StringTrimAssembler : public StringBuiltinsAssembler {
 
   void BuildLoop(Variable* const var_index, Node* const end, int increment,
                  Label* const if_none_found, Label* const out,
-                 std::function<Node*(Node*)> get_character);
+                 const std::function<Node*(Node*)>& get_character);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/builtins/builtins-string.cc b/deps/v8/src/builtins/builtins-string.cc
index 0dafa230b5..7aba998aa4 100644
--- a/deps/v8/src/builtins/builtins-string.cc
+++ b/deps/v8/src/builtins/builtins-string.cc
@@ -195,6 +195,9 @@ BUILTIN(StringPrototypeLastIndexOf) {
 // do anything locale specific.
 BUILTIN(StringPrototypeLocaleCompare) {
   HandleScope handle_scope(isolate);
+
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kStringLocaleCompare);
+
 #ifdef V8_INTL_SUPPORT
   TO_THIS_STRING(str1, "String.prototype.localeCompare");
   Handle<String> str2;
diff --git a/deps/v8/src/builtins/builtins-symbol.cc b/deps/v8/src/builtins/builtins-symbol.cc
index 55c0307484..97e0def67c 100644
--- a/deps/v8/src/builtins/builtins-symbol.cc
+++ b/deps/v8/src/builtins/builtins-symbol.cc
@@ -39,7 +39,7 @@ BUILTIN(SymbolFor) {
   Handle<String> key;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, key,
                                      Object::ToString(isolate, key_obj));
-  return *isolate->SymbolFor(Heap::kPublicSymbolTableRootIndex, key, false);
+  return *isolate->SymbolFor(RootIndex::kPublicSymbolTable, key, false);
 }
 
 // ES6 section 19.4.2.5 Symbol.keyFor.
diff --git a/deps/v8/src/builtins/builtins-typed-array-gen.cc b/deps/v8/src/builtins/builtins-typed-array-gen.cc
index c7c416d924..99979b0283 100644
--- a/deps/v8/src/builtins/builtins-typed-array-gen.cc
+++ b/deps/v8/src/builtins/builtins-typed-array-gen.cc
@@ -5,7 +5,6 @@
 #include "src/builtins/builtins-typed-array-gen.h"
 
 #include "src/builtins/builtins-constructor-gen.h"
-#include "src/builtins/builtins-iterator-gen.h"
 #include "src/builtins/builtins-utils-gen.h"
 #include "src/builtins/builtins.h"
 #include "src/builtins/growable-fixed-array-gen.h"
@@ -33,12 +32,12 @@ TNode<Map> TypedArrayBuiltinsAssembler::LoadMapForType(
   TVARIABLE(Map, var_typed_map);
   TNode<Map> array_map = LoadMap(array);
   TNode<Int32T> elements_kind = LoadMapElementsKind(array_map);
+  ReadOnlyRoots roots(isolate());
 
   DispatchTypedArrayByElementsKind(
       elements_kind,
       [&](ElementsKind kind, int size, int typed_array_fun_index) {
-        Handle<Map> map(isolate()->heap()->MapForFixedTypedArray(kind),
-                        isolate());
+        Handle<Map> map(roots.MapForFixedTypedArray(kind), isolate());
         var_typed_map = HeapConstant(map);
       });
 
@@ -65,11 +64,15 @@ TNode<UintPtrT> TypedArrayBuiltinsAssembler::CalculateExternalPointer(
 //  - Set EmbedderFields to 0.
 void TypedArrayBuiltinsAssembler::SetupTypedArray(TNode<JSTypedArray> holder,
                                                   TNode<Smi> length,
-                                                  TNode<Number> byte_offset,
-                                                  TNode<Number> byte_length) {
+                                                  TNode<UintPtrT> byte_offset,
+                                                  TNode<UintPtrT> byte_length) {
   StoreObjectField(holder, JSTypedArray::kLengthOffset, length);
-  StoreObjectField(holder, JSArrayBufferView::kByteOffsetOffset, byte_offset);
-  StoreObjectField(holder, JSArrayBufferView::kByteLengthOffset, byte_length);
+  StoreObjectFieldNoWriteBarrier(holder, JSArrayBufferView::kByteOffsetOffset,
+                                 byte_offset,
+                                 MachineType::PointerRepresentation());
+  StoreObjectFieldNoWriteBarrier(holder, JSArrayBufferView::kByteLengthOffset,
+                                 byte_length,
+                                 MachineType::PointerRepresentation());
   for (int offset = JSTypedArray::kSize;
        offset < JSTypedArray::kSizeWithEmbedderFields; offset += kPointerSize) {
     StoreObjectField(holder, offset, SmiConstant(0));
@@ -114,7 +117,8 @@ TF_BUILTIN(TypedArrayInitializeWithBuffer, TypedArrayBuiltinsAssembler) {
   // SmiMul returns a heap number in case of Smi overflow.
   TNode<Number> byte_length = SmiMul(length, element_size);
 
-  SetupTypedArray(holder, length, byte_offset, byte_length);
+  SetupTypedArray(holder, length, ChangeNonnegativeNumberToUintPtr(byte_offset),
+                  ChangeNonnegativeNumberToUintPtr(byte_length));
   AttachBuffer(holder, buffer, fixed_typed_map, length, byte_offset);
   Return(UndefinedConstant());
 }
@@ -146,8 +150,6 @@ TF_BUILTIN(TypedArrayInitialize, TypedArrayBuiltinsAssembler) {
   // SmiMul returns a heap number in case of Smi overflow.
   TNode<Number> byte_length = SmiMul(length, element_size);
 
-  SetupTypedArray(holder, length, byte_offset, byte_length);
-
   TNode<Map> fixed_typed_map = LoadMapForType(holder);
 
   // If target and new_target for the buffer differ, allocate off-heap.
@@ -173,7 +175,7 @@ TF_BUILTIN(TypedArrayInitialize, TypedArrayBuiltinsAssembler) {
     Node* native_context = LoadNativeContext(context);
     Node* map =
         LoadContextElement(native_context, Context::ARRAY_BUFFER_MAP_INDEX);
-    Node* empty_fixed_array = LoadRoot(Heap::kEmptyFixedArrayRootIndex);
+    Node* empty_fixed_array = LoadRoot(RootIndex::kEmptyFixedArray);
 
     Node* buffer = Allocate(JSArrayBuffer::kSizeWithEmbedderFields);
     StoreMapNoWriteBarrier(buffer, map);
@@ -189,14 +191,15 @@ TF_BUILTIN(TypedArrayInitialize, TypedArrayBuiltinsAssembler) {
     //  - Set all embedder fields to Smi(0).
     StoreObjectFieldNoWriteBarrier(buffer, JSArrayBuffer::kBitFieldSlot,
                                    SmiConstant(0));
-    int32_t bitfield_value = (1 << JSArrayBuffer::IsExternal::kShift) |
-                             (1 << JSArrayBuffer::IsNeuterable::kShift);
+    int32_t bitfield_value = (1 << JSArrayBuffer::IsExternalBit::kShift) |
+                             (1 << JSArrayBuffer::IsNeuterableBit::kShift);
     StoreObjectFieldNoWriteBarrier(buffer, JSArrayBuffer::kBitFieldOffset,
                                    Int32Constant(bitfield_value),
                                    MachineRepresentation::kWord32);
 
     StoreObjectFieldNoWriteBarrier(buffer, JSArrayBuffer::kByteLengthOffset,
-                                   byte_length);
+                                   SmiToIntPtr(CAST(byte_length)),
+                                   MachineType::PointerRepresentation());
     StoreObjectFieldNoWriteBarrier(buffer, JSArrayBuffer::kBackingStoreOffset,
                                    SmiConstant(0));
     for (int i = 0; i < v8::ArrayBuffer::kEmbedderFieldCount; i++) {
@@ -305,6 +308,8 @@ TF_BUILTIN(TypedArrayInitialize, TypedArrayBuiltinsAssembler) {
   }
 
   BIND(&done);
+  SetupTypedArray(holder, length, ChangeNonnegativeNumberToUintPtr(byte_offset),
+                  ChangeNonnegativeNumberToUintPtr(byte_length));
   Return(UndefinedConstant());
 }
 
@@ -399,8 +404,8 @@ void TypedArrayBuiltinsAssembler::ConstructByArrayBuffer(
   BIND(&length_undefined);
   {
     ThrowIfArrayBufferIsDetached(context, buffer, "Construct");
-    Node* buffer_byte_length =
-        LoadObjectField(buffer, JSArrayBuffer::kByteLengthOffset);
+    TNode<Number> buffer_byte_length = ChangeUintPtrToTagged(
+        LoadObjectField<UintPtrT>(buffer, JSArrayBuffer::kByteLengthOffset));
 
     Node* remainder = CallBuiltin(Builtins::kModulus, context,
                                   buffer_byte_length, element_size);
@@ -424,8 +429,8 @@ void TypedArrayBuiltinsAssembler::ConstructByArrayBuffer(
     new_byte_length.Bind(SmiMul(new_length, element_size));
     // Reading the byte length must come after the ToIndex operation, which
     // could cause the buffer to become detached.
-    Node* buffer_byte_length =
-        LoadObjectField(buffer, JSArrayBuffer::kByteLengthOffset);
+    TNode<Number> buffer_byte_length = ChangeUintPtrToTagged(
+        LoadObjectField<UintPtrT>(buffer, JSArrayBuffer::kByteLengthOffset));
 
     Node* end = CallBuiltin(Builtins::kAdd, context, offset.value(),
                             new_byte_length.value());
@@ -502,7 +507,7 @@ void TypedArrayBuiltinsAssembler::ConstructByTypedArray(
   Goto(&check_for_sab);
 
   BIND(&if_notdetached);
-  source_length = LoadTypedArrayLength(typed_array);
+  source_length = LoadJSTypedArrayLength(typed_array);
   Goto(&check_for_sab);
 
   // The spec requires that constructing a typed array using a SAB-backed typed
@@ -511,7 +516,7 @@ void TypedArrayBuiltinsAssembler::ConstructByTypedArray(
   BIND(&check_for_sab);
   TNode<Uint32T> bitfield =
       LoadObjectField<Uint32T>(source_buffer, JSArrayBuffer::kBitFieldOffset);
-  Branch(IsSetWord32<JSArrayBuffer::IsShared>(bitfield), &construct,
+  Branch(IsSetWord32<JSArrayBuffer::IsSharedBit>(bitfield), &construct,
          &if_buffernotshared);
 
   BIND(&if_buffernotshared);
@@ -640,8 +645,9 @@ void TypedArrayBuiltinsAssembler::ConstructByIterable(
   Label fast_path(this), slow_path(this), done(this);
   CSA_ASSERT(this, IsCallable(iterator_fn));
 
-  TNode<JSArray> array_like = CAST(
-      CallBuiltin(Builtins::kIterableToList, context, iterable, iterator_fn));
+  TNode<JSArray> array_like =
+      CAST(CallBuiltin(Builtins::kIterableToListMayPreserveHoles, context,
+                       iterable, iterator_fn));
   TNode<Object> initial_length = LoadJSArrayLength(array_like);
 
   TNode<JSFunction> default_constructor = CAST(LoadContextElement(
@@ -674,6 +680,17 @@ TF_BUILTIN(CreateTypedArray, TypedArrayBuiltinsAssembler) {
   ConstructorBuiltinsAssembler constructor_assembler(this->state());
   TNode<JSTypedArray> result = CAST(
       constructor_assembler.EmitFastNewObject(context, target, new_target));
+  // We need to set the byte_offset / byte_length to some sane values
+  // to keep the heap verifier happy.
+  // TODO(bmeurer): Fix this initialization to not use EmitFastNewObject,
+  // which causes the problem, since it puts Undefined into all slots of
+  // the object even though that doesn't make any sense for these fields.
+  StoreObjectFieldNoWriteBarrier(result, JSTypedArray::kByteOffsetOffset,
+                                 UintPtrConstant(0),
+                                 MachineType::PointerRepresentation());
+  StoreObjectFieldNoWriteBarrier(result, JSTypedArray::kByteLengthOffset,
+                                 UintPtrConstant(0),
+                                 MachineType::PointerRepresentation());
 
   TNode<Smi> element_size =
       SmiTag(GetTypedArrayElementSize(LoadElementsKind(result)));
@@ -775,50 +792,58 @@ TF_BUILTIN(TypedArrayConstructor, TypedArrayBuiltinsAssembler) {
   }
 }
 
-void TypedArrayBuiltinsAssembler::GenerateTypedArrayPrototypeGetter(
-    Node* context, Node* receiver, const char* method_name, int object_offset) {
-  // Check if the {receiver} is actually a JSTypedArray.
-  ThrowIfNotInstanceType(context, receiver, JS_TYPED_ARRAY_TYPE, method_name);
-
-  // Check if the {receiver}'s JSArrayBuffer was neutered.
-  Node* receiver_buffer =
-      LoadObjectField(receiver, JSTypedArray::kBufferOffset);
-  Label if_receiverisneutered(this, Label::kDeferred);
-  GotoIf(IsDetachedBuffer(receiver_buffer), &if_receiverisneutered);
-  Return(LoadObjectField(receiver, object_offset));
-
-  BIND(&if_receiverisneutered);
-  {
-    // The {receiver}s buffer was neutered, default to zero.
-    Return(SmiConstant(0));
-  }
-}
-
 // ES6 #sec-get-%typedarray%.prototype.bytelength
 TF_BUILTIN(TypedArrayPrototypeByteLength, TypedArrayBuiltinsAssembler) {
+  const char* const kMethodName = "get TypedArray.prototype.byteLength";
   Node* context = Parameter(Descriptor::kContext);
   Node* receiver = Parameter(Descriptor::kReceiver);
-  GenerateTypedArrayPrototypeGetter(context, receiver,
-                                    "get TypedArray.prototype.byteLength",
-                                    JSTypedArray::kByteLengthOffset);
+
+  // Check if the {receiver} is actually a JSTypedArray.
+  ThrowIfNotInstanceType(context, receiver, JS_TYPED_ARRAY_TYPE, kMethodName);
+
+  // Default to zero if the {receiver}s buffer was neutered.
+  TNode<JSArrayBuffer> receiver_buffer =
+      LoadJSArrayBufferViewBuffer(CAST(receiver));
+  TNode<UintPtrT> byte_length = Select<UintPtrT>(
+      IsDetachedBuffer(receiver_buffer), [=] { return UintPtrConstant(0); },
+      [=] { return LoadJSArrayBufferViewByteLength(CAST(receiver)); });
+  Return(ChangeUintPtrToTagged(byte_length));
 }
 
 // ES6 #sec-get-%typedarray%.prototype.byteoffset
 TF_BUILTIN(TypedArrayPrototypeByteOffset, TypedArrayBuiltinsAssembler) {
+  const char* const kMethodName = "get TypedArray.prototype.byteOffset";
   Node* context = Parameter(Descriptor::kContext);
   Node* receiver = Parameter(Descriptor::kReceiver);
-  GenerateTypedArrayPrototypeGetter(context, receiver,
-                                    "get TypedArray.prototype.byteOffset",
-                                    JSTypedArray::kByteOffsetOffset);
+
+  // Check if the {receiver} is actually a JSTypedArray.
+  ThrowIfNotInstanceType(context, receiver, JS_TYPED_ARRAY_TYPE, kMethodName);
+
+  // Default to zero if the {receiver}s buffer was neutered.
+  TNode<JSArrayBuffer> receiver_buffer =
+      LoadJSArrayBufferViewBuffer(CAST(receiver));
+  TNode<UintPtrT> byte_offset = Select<UintPtrT>(
+      IsDetachedBuffer(receiver_buffer), [=] { return UintPtrConstant(0); },
+      [=] { return LoadJSArrayBufferViewByteOffset(CAST(receiver)); });
+  Return(ChangeUintPtrToTagged(byte_offset));
 }
 
 // ES6 #sec-get-%typedarray%.prototype.length
 TF_BUILTIN(TypedArrayPrototypeLength, TypedArrayBuiltinsAssembler) {
+  const char* const kMethodName = "get TypedArray.prototype.length";
   Node* context = Parameter(Descriptor::kContext);
   Node* receiver = Parameter(Descriptor::kReceiver);
-  GenerateTypedArrayPrototypeGetter(context, receiver,
-                                    "get TypedArray.prototype.length",
-                                    JSTypedArray::kLengthOffset);
+
+  // Check if the {receiver} is actually a JSTypedArray.
+  ThrowIfNotInstanceType(context, receiver, JS_TYPED_ARRAY_TYPE, kMethodName);
+
+  // Default to zero if the {receiver}s buffer was neutered.
+  TNode<JSArrayBuffer> receiver_buffer =
+      LoadJSArrayBufferViewBuffer(CAST(receiver));
+  TNode<Smi> length = Select<Smi>(
+      IsDetachedBuffer(receiver_buffer), [=] { return SmiConstant(0); },
+      [=] { return LoadJSTypedArrayLength(CAST(receiver)); });
+  Return(length);
 }
 
 TNode<Word32T> TypedArrayBuiltinsAssembler::IsUint8ElementsKind(
@@ -923,7 +948,7 @@ TNode<JSTypedArray> TypedArrayBuiltinsAssembler::CreateByLength(
   // If newTypedArray.[[ArrayLength]] < argumentList[0], throw a TypeError
   // exception.
   Label if_length_is_not_short(this);
-  TNode<Smi> new_length = LoadTypedArrayLength(new_typed_array);
+  TNode<Smi> new_length = LoadJSTypedArrayLength(new_typed_array);
   GotoIfNot(SmiLessThan(new_length, len), &if_length_is_not_short);
   ThrowTypeError(context, MessageTemplate::kTypedArrayTooShort);
 
@@ -979,8 +1004,8 @@ void TypedArrayBuiltinsAssembler::SetTypedArraySource(
 
   // Check for possible range errors.
 
-  TNode<IntPtrT> source_length = SmiUntag(LoadTypedArrayLength(source));
-  TNode<IntPtrT> target_length = SmiUntag(LoadTypedArrayLength(target));
+  TNode<IntPtrT> source_length = SmiUntag(LoadJSTypedArrayLength(source));
+  TNode<IntPtrT> target_length = SmiUntag(LoadJSTypedArrayLength(target));
   TNode<IntPtrT> required_target_length = IntPtrAdd(source_length, offset);
 
   GotoIf(IntPtrGreaterThan(required_target_length, target_length),
@@ -1030,7 +1055,7 @@ void TypedArrayBuiltinsAssembler::SetTypedArraySource(
                           IsBigInt64ElementsKind(target_el_kind)),
            &exception);
 
-    TNode<IntPtrT> source_length = SmiUntag(LoadTypedArrayLength(source));
+    TNode<IntPtrT> source_length = SmiUntag(LoadJSTypedArrayLength(source));
     CallCCopyTypedArrayElementsToTypedArray(source, target, source_length,
                                             offset);
     Goto(&out);
@@ -1051,7 +1076,7 @@ void TypedArrayBuiltinsAssembler::SetJSArraySource(
              IntPtrLessThanOrEqual(offset, IntPtrConstant(Smi::kMaxValue)));
 
   TNode<IntPtrT> source_length = SmiUntag(LoadFastJSArrayLength(source));
-  TNode<IntPtrT> target_length = SmiUntag(LoadTypedArrayLength(target));
+  TNode<IntPtrT> target_length = SmiUntag(LoadJSTypedArrayLength(target));
 
   // Maybe out of bounds?
   GotoIf(IntPtrGreaterThan(IntPtrAdd(source_length, offset), target_length),
@@ -1266,7 +1291,7 @@ TF_BUILTIN(TypedArrayPrototypeSlice, TypedArrayBuiltinsAssembler) {
   TNode<JSTypedArray> source =
       ValidateTypedArray(context, receiver, method_name);
 
-  TNode<Smi> source_length = LoadTypedArrayLength(source);
+  TNode<Smi> source_length = LoadJSTypedArrayLength(source);
 
   // Convert start offset argument to integer, and calculate relative offset.
   TNode<Object> start = args.GetOptionalArgumentValue(0, SmiConstant(0));
@@ -1299,7 +1324,7 @@ TF_BUILTIN(TypedArrayPrototypeSlice, TypedArrayBuiltinsAssembler) {
   CSA_ASSERT(this, Word32BinaryNot(IsDetachedBuffer(LoadObjectField(
                        result_array, JSTypedArray::kBufferOffset))));
   TNode<JSArrayBuffer> receiver_buffer =
-      LoadArrayBufferViewBuffer(CAST(receiver));
+      LoadJSArrayBufferViewBuffer(CAST(receiver));
   ThrowIfArrayBufferIsDetached(context, receiver_buffer, method_name);
 
   // result_array could be a different type from source or share the same
@@ -1332,24 +1357,16 @@ TF_BUILTIN(TypedArrayPrototypeSlice, TypedArrayBuiltinsAssembler) {
     TNode<IntPtrT> count_bytes = IntPtrMul(SmiToIntPtr(count), source_el_size);
 
 #ifdef DEBUG
-    Label done(this), to_intptr_failed(this, Label::kDeferred);
-    TNode<IntPtrT> target_byte_length = TryToIntptr(
-        LoadObjectField<Number>(result_array, JSTypedArray::kByteLengthOffset),
-        &to_intptr_failed);
-    CSA_ASSERT(this, IntPtrLessThanOrEqual(count_bytes, target_byte_length));
-
-    TNode<IntPtrT> source_byte_length = TryToIntptr(
-        LoadObjectField<Number>(source, JSTypedArray::kByteLengthOffset),
-        &to_intptr_failed);
-    TNode<IntPtrT> source_size_in_bytes =
-        IntPtrSub(source_byte_length, source_start_bytes);
-    CSA_ASSERT(this, IntPtrLessThanOrEqual(count_bytes, source_size_in_bytes));
-    Goto(&done);
-
-    BIND(&to_intptr_failed);
-    Unreachable();
-
-    BIND(&done);
+    TNode<UintPtrT> target_byte_length =
+        LoadJSArrayBufferViewByteLength(result_array);
+    CSA_ASSERT(this, UintPtrLessThanOrEqual(Unsigned(count_bytes),
+                                            target_byte_length));
+    TNode<UintPtrT> source_byte_length =
+        LoadJSArrayBufferViewByteLength(source);
+    TNode<UintPtrT> source_size_in_bytes =
+        UintPtrSub(source_byte_length, Unsigned(source_start_bytes));
+    CSA_ASSERT(this, UintPtrLessThanOrEqual(Unsigned(count_bytes),
+                                            source_size_in_bytes));
 #endif  // DEBUG
 
     CallCMemmove(target_data_ptr, source_start, count_bytes);
@@ -1395,7 +1412,7 @@ TF_BUILTIN(TypedArrayPrototypeSubArray, TypedArrayBuiltinsAssembler) {
   // 5. Let buffer be O.[[ViewedArrayBuffer]].
   TNode<JSArrayBuffer> buffer = GetBuffer(context, source);
   // 6. Let srcLength be O.[[ArrayLength]].
-  TNode<Smi> source_length = LoadTypedArrayLength(source);
+  TNode<Smi> source_length = LoadJSTypedArrayLength(source);
 
   // 7. Let relativeBegin be ? ToInteger(begin).
   // 8. If relativeBegin < 0, let beginIndex be max((srcLength + relativeBegin),
@@ -1430,7 +1447,7 @@ TF_BUILTIN(TypedArrayPrototypeSubArray, TypedArrayBuiltinsAssembler) {
 
   // 14. Let srcByteOffset be O.[[ByteOffset]].
   TNode<Number> source_byte_offset =
-      LoadObjectField<Number>(source, JSTypedArray::kByteOffsetOffset);
+      ChangeUintPtrToTagged(LoadJSArrayBufferViewByteOffset(source));
 
   // 15. Let beginByteOffset be srcByteOffset + beginIndex × elementSize.
   TNode<Number> offset = SmiMul(var_begin.value(), SmiFromIntPtr(element_size));
@@ -1606,17 +1623,6 @@ TF_BUILTIN(TypedArrayOf, TypedArrayBuiltinsAssembler) {
                  "%TypedArray%.of");
 }
 
-// This builtin always returns a new JSArray and is thus safe to use even in the
-// presence of code that may call back into user-JS.
-TF_BUILTIN(IterableToList, TypedArrayBuiltinsAssembler) {
-  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-  TNode<Object> iterable = CAST(Parameter(Descriptor::kIterable));
-  TNode<Object> iterator_fn = CAST(Parameter(Descriptor::kIteratorFn));
-
-  IteratorBuiltinsAssembler iterator_assembler(state());
-  Return(iterator_assembler.IterableToList(context, iterable, iterator_fn));
-}
-
 // ES6 #sec-%typedarray%.from
 TF_BUILTIN(TypedArrayFrom, TypedArrayBuiltinsAssembler) {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
@@ -1818,7 +1824,7 @@ TF_BUILTIN(TypedArrayPrototypeFilter, TypedArrayBuiltinsAssembler) {
       ValidateTypedArray(context, receiver, method_name);
 
   // 3. Let len be O.[[ArrayLength]].
-  TNode<Smi> length = LoadTypedArrayLength(source);
+  TNode<Smi> length = LoadJSTypedArrayLength(source);
 
   // 4. If IsCallable(callbackfn) is false, throw a TypeError exception.
   TNode<Object> callbackfn = args.GetOptionalArgumentValue(0);
diff --git a/deps/v8/src/builtins/builtins-typed-array-gen.h b/deps/v8/src/builtins/builtins-typed-array-gen.h
index 11768d660a..1e35ae69a9 100644
--- a/deps/v8/src/builtins/builtins-typed-array-gen.h
+++ b/deps/v8/src/builtins/builtins-typed-array-gen.h
@@ -21,9 +21,6 @@ class TypedArrayBuiltinsAssembler : public BaseBuiltinsFromDSLAssembler {
                                             const char* method_name);
 
  protected:
-  void GenerateTypedArrayPrototypeGetter(Node* context, Node* receiver,
-                                         const char* method_name,
-                                         int object_offset);
   void GenerateTypedArrayPrototypeIterationMethod(TNode<Context> context,
                                                   TNode<Object> receiver,
                                                   const char* method_name,
@@ -50,7 +47,8 @@ class TypedArrayBuiltinsAssembler : public BaseBuiltinsFromDSLAssembler {
                            TNode<Smi> element_size);
 
   void SetupTypedArray(TNode<JSTypedArray> holder, TNode<Smi> length,
-                       TNode<Number> byte_offset, TNode<Number> byte_length);
+                       TNode<UintPtrT> byte_offset,
+                       TNode<UintPtrT> byte_length);
   void AttachBuffer(TNode<JSTypedArray> holder, TNode<JSArrayBuffer> buffer,
                     TNode<Map> map, TNode<Smi> length,
                     TNode<Number> byte_offset);
diff --git a/deps/v8/src/builtins/builtins-wasm-gen.cc b/deps/v8/src/builtins/builtins-wasm-gen.cc
index facfaf93f8..60be33de20 100644
--- a/deps/v8/src/builtins/builtins-wasm-gen.cc
+++ b/deps/v8/src/builtins/builtins-wasm-gen.cc
@@ -38,16 +38,19 @@ class WasmBuiltinsAssembler : public CodeStubAssembler {
         LoadFromParentFrame(WasmCompiledFrameConstants::kWasmInstanceOffset));
   }
 
+  TNode<Object> LoadContextFromInstance(TNode<Object> instance) {
+    return UncheckedCast<Object>(
+        Load(MachineType::AnyTagged(), instance,
+             IntPtrConstant(WasmInstanceObject::kNativeContextOffset -
+                            kHeapObjectTag)));
+  }
+
   TNode<Code> LoadCEntryFromInstance(TNode<Object> instance) {
     return UncheckedCast<Code>(
         Load(MachineType::AnyTagged(), instance,
              IntPtrConstant(WasmInstanceObject::kCEntryStubOffset -
                             kHeapObjectTag)));
   }
-
-  TNode<Code> LoadCEntryFromFrame() {
-    return LoadCEntryFromInstance(LoadInstanceFromFrame());
-  }
 };
 
 TF_BUILTIN(WasmAllocateHeapNumber, WasmBuiltinsAssembler) {
@@ -55,18 +58,6 @@ TF_BUILTIN(WasmAllocateHeapNumber, WasmBuiltinsAssembler) {
   TailCallStub(AllocateHeapNumberDescriptor(), target, NoContextConstant());
 }
 
-TF_BUILTIN(WasmArgumentsAdaptor, WasmBuiltinsAssembler) {
-  TNode<Object> context = UncheckedParameter(Descriptor::kContext);
-  TNode<Object> function = UncheckedParameter(Descriptor::kTarget);
-  TNode<Object> new_target = UncheckedParameter(Descriptor::kNewTarget);
-  TNode<Object> argc1 = UncheckedParameter(Descriptor::kActualArgumentsCount);
-  TNode<Object> argc2 = UncheckedParameter(Descriptor::kExpectedArgumentsCount);
-  TNode<Code> target =
-      LoadBuiltinFromFrame(Builtins::kArgumentsAdaptorTrampoline);
-  TailCallStub(ArgumentAdaptorDescriptor{}, target, context, function,
-               new_target, argc1, argc2);
-}
-
 TF_BUILTIN(WasmCallJavaScript, WasmBuiltinsAssembler) {
   TNode<Object> context = UncheckedParameter(Descriptor::kContext);
   TNode<Object> function = UncheckedParameter(Descriptor::kFunction);
@@ -83,9 +74,18 @@ TF_BUILTIN(WasmToNumber, WasmBuiltinsAssembler) {
 }
 
 TF_BUILTIN(WasmStackGuard, WasmBuiltinsAssembler) {
-  TNode<Code> centry = LoadCEntryFromFrame();
-  TailCallRuntimeWithCEntry(Runtime::kWasmStackGuard, centry,
-                            NoContextConstant());
+  TNode<Object> instance = LoadInstanceFromFrame();
+  TNode<Code> centry = LoadCEntryFromInstance(instance);
+  TNode<Object> context = LoadContextFromInstance(instance);
+  TailCallRuntimeWithCEntry(Runtime::kWasmStackGuard, centry, context);
+}
+
+TF_BUILTIN(WasmThrow, WasmBuiltinsAssembler) {
+  TNode<Object> exception = UncheckedParameter(Descriptor::kException);
+  TNode<Object> instance = LoadInstanceFromFrame();
+  TNode<Code> centry = LoadCEntryFromInstance(instance);
+  TNode<Object> context = LoadContextFromInstance(instance);
+  TailCallRuntimeWithCEntry(Runtime::kThrow, centry, context, exception);
 }
 
 TF_BUILTIN(WasmGrowMemory, WasmBuiltinsAssembler) {
@@ -100,9 +100,9 @@ TF_BUILTIN(WasmGrowMemory, WasmBuiltinsAssembler) {
   TNode<Smi> num_pages_smi = SmiFromInt32(num_pages);
   TNode<Object> instance = LoadInstanceFromFrame();
   TNode<Code> centry = LoadCEntryFromInstance(instance);
-  TNode<Smi> ret_smi = UncheckedCast<Smi>(
-      CallRuntimeWithCEntry(Runtime::kWasmGrowMemory, centry,
-                            NoContextConstant(), instance, num_pages_smi));
+  TNode<Object> context = LoadContextFromInstance(instance);
+  TNode<Smi> ret_smi = UncheckedCast<Smi>(CallRuntimeWithCEntry(
+      Runtime::kWasmGrowMemory, centry, context, instance, num_pages_smi));
   TNode<Int32T> ret = SmiToInt32(ret_smi);
   ReturnRaw(ret);
 
@@ -112,10 +112,12 @@ TF_BUILTIN(WasmGrowMemory, WasmBuiltinsAssembler) {
 
 #define DECLARE_ENUM(name)                                                    \
   TF_BUILTIN(ThrowWasm##name, WasmBuiltinsAssembler) {                        \
-    TNode<Code> centry = LoadCEntryFromFrame();                               \
+    TNode<Object> instance = LoadInstanceFromFrame();                         \
+    TNode<Code> centry = LoadCEntryFromInstance(instance);                    \
+    TNode<Object> context = LoadContextFromInstance(instance);                \
     int message_id = wasm::WasmOpcodes::TrapReasonToMessageId(wasm::k##name); \
-    TailCallRuntimeWithCEntry(Runtime::kThrowWasmError, centry,               \
-                              NoContextConstant(), SmiConstant(message_id));  \
+    TailCallRuntimeWithCEntry(Runtime::kThrowWasmError, centry, context,      \
+                              SmiConstant(message_id));                       \
   }
 FOREACH_WASM_TRAPREASON(DECLARE_ENUM)
 #undef DECLARE_ENUM
diff --git a/deps/v8/src/builtins/builtins.cc b/deps/v8/src/builtins/builtins.cc
index b2c7433e8d..103f00c56e 100644
--- a/deps/v8/src/builtins/builtins.cc
+++ b/deps/v8/src/builtins/builtins.cc
@@ -51,13 +51,12 @@ struct BuiltinMetadata {
 #define DECL_TFC(Name, ...) { #Name, Builtins::TFC, {} },
 #define DECL_TFS(Name, ...) { #Name, Builtins::TFS, {} },
 #define DECL_TFH(Name, ...) { #Name, Builtins::TFH, {} },
-#define DECL_BCH(Name, ...) { #Name "Handler", Builtins::BCH, {} }, \
-                            { #Name "WideHandler", Builtins::BCH, {} }, \
-                            { #Name "ExtraWideHandler", Builtins::BCH, {} },
+#define DECL_BCH(Name, ...) { #Name, Builtins::BCH, {} },
+#define DECL_DLH(Name, ...) { #Name, Builtins::DLH, {} },
 #define DECL_ASM(Name, ...) { #Name, Builtins::ASM, {} },
 const BuiltinMetadata builtin_metadata[] = {
   BUILTIN_LIST(DECL_CPP, DECL_API, DECL_TFJ, DECL_TFC, DECL_TFS, DECL_TFH,
-               DECL_BCH, DECL_ASM)
+               DECL_BCH, DECL_DLH, DECL_ASM)
 };
 #undef DECL_CPP
 #undef DECL_API
@@ -66,6 +65,7 @@ const BuiltinMetadata builtin_metadata[] = {
 #undef DECL_TFS
 #undef DECL_TFH
 #undef DECL_BCH
+#undef DECL_DLH
 #undef DECL_ASM
 // clang-format on
 
@@ -166,11 +166,12 @@ Callable Builtins::CallableFor(Isolate* isolate, Name name) {
     break;                                             \
   }
     BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, IGNORE_BUILTIN, CASE_OTHER,
-                 CASE_OTHER, CASE_OTHER, IGNORE_BUILTIN, IGNORE_BUILTIN)
+                 CASE_OTHER, CASE_OTHER, IGNORE_BUILTIN, IGNORE_BUILTIN,
+                 IGNORE_BUILTIN)
 #undef CASE_OTHER
     default:
       Builtins::Kind kind = Builtins::KindOf(name);
-      DCHECK_NE(kind, BCH);
+      DCHECK(kind != BCH && kind != DLH);
       if (kind == TFJ || kind == CPP) {
         return Callable(code, JSTrampolineDescriptor{});
       }
@@ -264,8 +265,11 @@ bool Builtins::IsLazy(int index) {
     case kArrayReduceRightPreLoopEagerDeoptContinuation:
     case kArraySomeLoopEagerDeoptContinuation:
     case kArraySomeLoopLazyDeoptContinuation:
-    case kAsyncGeneratorAwaitCaught:            // https://crbug.com/v8/6786.
-    case kAsyncGeneratorAwaitUncaught:          // https://crbug.com/v8/6786.
+    case kAsyncFunctionAwaitResolveClosure:   // https://crbug.com/v8/7522
+    case kAsyncGeneratorAwaitResolveClosure:  // https://crbug.com/v8/7522
+    case kAsyncGeneratorYieldResolveClosure:  // https://crbug.com/v8/7522
+    case kAsyncGeneratorAwaitCaught:          // https://crbug.com/v8/6786.
+    case kAsyncGeneratorAwaitUncaught:        // https://crbug.com/v8/6786.
     // CEntry variants must be immovable, whereas lazy deserialization allocates
     // movable code.
     case kCEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit:
@@ -281,9 +285,13 @@ bool Builtins::IsLazy(int index) {
     case kCompileLazy:
     case kDebugBreakTrampoline:
     case kDeserializeLazy:
+    case kDeserializeLazyHandler:
+    case kDeserializeLazyWideHandler:
+    case kDeserializeLazyExtraWideHandler:
     case kFunctionPrototypeHasInstance:  // https://crbug.com/v8/6786.
     case kHandleApiCall:
     case kIllegal:
+    case kIllegalHandler:
     case kInstantiateAsmJs:
     case kInterpreterEnterBytecodeAdvance:
     case kInterpreterEnterBytecodeDispatch:
@@ -306,27 +314,21 @@ bool Builtins::IsLazy(int index) {
       return false;
     default:
       // TODO(6624): Extend to other kinds.
-      return KindOf(index) == TFJ;
+      return KindOf(index) == TFJ || KindOf(index) == BCH;
   }
   UNREACHABLE();
 }
 
 // static
+bool Builtins::IsLazyDeserializer(Code* code) {
+  return IsLazyDeserializer(code->builtin_index());
+}
+
+// static
 bool Builtins::IsIsolateIndependent(int index) {
   DCHECK(IsBuiltinId(index));
 #ifndef V8_TARGET_ARCH_IA32
   switch (index) {
-// Bytecode handlers do not yet support being embedded.
-#ifdef V8_EMBEDDED_BYTECODE_HANDLERS
-#define BYTECODE_BUILTIN(Name, ...) \
-  case k##Name##Handler:            \
-  case k##Name##WideHandler:        \
-  case k##Name##ExtraWideHandler:   \
-    return false;
-    BUILTIN_LIST_BYTECODE_HANDLERS(BYTECODE_BUILTIN)
-#undef BYTECODE_BUILTIN
-#endif  // V8_EMBEDDED_BYTECODE_HANDLERS
-
     // TODO(jgruber): There's currently two blockers for moving
     // InterpreterEntryTrampoline into the binary:
     // 1. InterpreterEnterBytecode calculates a pointer into the middle of
@@ -423,6 +425,7 @@ const char* Builtins::KindNameOf(int index) {
     case TFS: return "TFS";
     case TFH: return "TFH";
     case BCH: return "BCH";
+    case DLH: return "DLH";
     case ASM: return "ASM";
   }
   // clang-format on
diff --git a/deps/v8/src/builtins/builtins.h b/deps/v8/src/builtins/builtins.h
index 0bd3c317bf..9f404a0ac0 100644
--- a/deps/v8/src/builtins/builtins.h
+++ b/deps/v8/src/builtins/builtins.h
@@ -25,6 +25,11 @@ namespace compiler {
 class CodeAssemblerState;
 }
 
+template <typename T>
+static constexpr T FirstFromVarArgs(T x, ...) noexcept {
+  return x;
+}
+
 // Convenience macro to avoid generating named accessors for all builtins.
 #define BUILTIN_CODE(isolate, name) \
   (isolate)->builtins()->builtin_handle(Builtins::k##name)
@@ -40,13 +45,16 @@ class Builtins {
 
   enum Name : int32_t {
 #define DEF_ENUM(Name, ...) k##Name,
-#define DEF_ENUM_BYTECODE_HANDLER(Name, ...) \
-  k##Name##Handler, k##Name##WideHandler, k##Name##ExtraWideHandler,
     BUILTIN_LIST(DEF_ENUM, DEF_ENUM, DEF_ENUM, DEF_ENUM, DEF_ENUM, DEF_ENUM,
-                 DEF_ENUM_BYTECODE_HANDLER, DEF_ENUM)
+                 DEF_ENUM, DEF_ENUM, DEF_ENUM)
 #undef DEF_ENUM
-#undef DEF_ENUM_BYTECODE_HANDLER
-        builtin_count
+        builtin_count,
+
+#define EXTRACT_NAME(Name, ...) k##Name,
+    // Define kFirstBytecodeHandler,
+    kFirstBytecodeHandler =
+        FirstFromVarArgs(BUILTIN_LIST_BYTECODE_HANDLERS(EXTRACT_NAME) 0)
+#undef EXTRACT_NAME
   };
 
   static const int32_t kNoBuiltinId = -1;
@@ -56,7 +64,7 @@ class Builtins {
   }
 
   // The different builtin kinds are documented in builtins-definitions.h.
-  enum Kind { CPP, API, TFJ, TFC, TFS, TFH, BCH, ASM };
+  enum Kind { CPP, API, TFJ, TFC, TFS, TFH, BCH, DLH, ASM };
 
   static BailoutId GetContinuationBailoutId(Name name);
   static Name GetBuiltinFromBailoutId(BailoutId);
@@ -111,6 +119,35 @@ class Builtins {
   // special cases such as CompileLazy and DeserializeLazy.
   static bool IsLazy(int index);
 
+  static constexpr int kFirstWideBytecodeHandler =
+      kFirstBytecodeHandler + kNumberOfBytecodeHandlers;
+  static constexpr int kFirstExtraWideBytecodeHandler =
+      kFirstWideBytecodeHandler + kNumberOfWideBytecodeHandlers;
+  STATIC_ASSERT(kFirstExtraWideBytecodeHandler +
+                    kNumberOfWideBytecodeHandlers ==
+                builtin_count);
+
+  // Returns the index of the appropriate lazy deserializer in the builtins
+  // table.
+  static constexpr int LazyDeserializerForBuiltin(const int index) {
+    return index < kFirstWideBytecodeHandler
+               ? (index < kFirstBytecodeHandler
+                      ? Builtins::kDeserializeLazy
+                      : Builtins::kDeserializeLazyHandler)
+               : (index < kFirstExtraWideBytecodeHandler
+                      ? Builtins::kDeserializeLazyWideHandler
+                      : Builtins::kDeserializeLazyExtraWideHandler);
+  }
+
+  static constexpr bool IsLazyDeserializer(int builtin_index) {
+    return builtin_index == kDeserializeLazy ||
+           builtin_index == kDeserializeLazyHandler ||
+           builtin_index == kDeserializeLazyWideHandler ||
+           builtin_index == kDeserializeLazyExtraWideHandler;
+  }
+
+  static bool IsLazyDeserializer(Code* code);
+
   // Helper methods used for testing isolate-independent builtins.
   // TODO(jgruber,v8:6666): Remove once all builtins have been migrated.
   static bool IsIsolateIndependent(int index);
@@ -179,7 +216,8 @@ class Builtins {
   static void Generate_##Name(compiler::CodeAssemblerState* state);
 
   BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN, DECLARE_TF, DECLARE_TF,
-               DECLARE_TF, DECLARE_TF, IGNORE_BUILTIN, DECLARE_ASM)
+               DECLARE_TF, DECLARE_TF, IGNORE_BUILTIN, IGNORE_BUILTIN,
+               DECLARE_ASM)
 
 #undef DECLARE_ASM
 #undef DECLARE_TF
diff --git a/deps/v8/src/builtins/constants-table-builder.cc b/deps/v8/src/builtins/constants-table-builder.cc
index 04c0655bf7..26995453dd 100644
--- a/deps/v8/src/builtins/constants-table-builder.cc
+++ b/deps/v8/src/builtins/constants-table-builder.cc
@@ -19,14 +19,14 @@ BuiltinsConstantsTableBuilder::BuiltinsConstantsTableBuilder(Isolate* isolate)
   // as a constant, which means that codegen will load it using the root
   // register.
   DCHECK(isolate_->heap()->RootCanBeTreatedAsConstant(
-      Heap::kEmptyFixedArrayRootIndex));
+      RootIndex::kEmptyFixedArray));
 }
 
 uint32_t BuiltinsConstantsTableBuilder::AddObject(Handle<Object> object) {
 #ifdef DEBUG
   // Roots must not be inserted into the constants table as they are already
   // accessibly from the root list.
-  Heap::RootListIndex root_list_index;
+  RootIndex root_list_index;
   DCHECK(!isolate_->heap()->IsRootHandle(object, &root_list_index));
 
   // Not yet finalized.
@@ -56,7 +56,7 @@ void BuiltinsConstantsTableBuilder::PatchSelfReference(
 #ifdef DEBUG
   // Roots must not be inserted into the constants table as they are already
   // accessibly from the root list.
-  Heap::RootListIndex root_list_index;
+  RootIndex root_list_index;
   DCHECK(!isolate_->heap()->IsRootHandle(code_object, &root_list_index));
 
   // Not yet finalized.
diff --git a/deps/v8/src/builtins/data-view.tq b/deps/v8/src/builtins/data-view.tq
index 874c122995..1e86f88d83 100644
--- a/deps/v8/src/builtins/data-view.tq
+++ b/deps/v8/src/builtins/data-view.tq
@@ -3,15 +3,14 @@
 // found in the LICENSE file.
 
 module data_view {
-
   extern operator '.buffer'
-      macro LoadArrayBufferViewBuffer(JSArrayBufferView): JSArrayBuffer;
+      macro LoadJSArrayBufferViewBuffer(JSArrayBufferView): JSArrayBuffer;
   extern operator '.byte_length'
-      macro LoadDataViewByteLength(JSDataView): Number;
+      macro LoadJSArrayBufferViewByteLength(JSArrayBufferView): uintptr;
   extern operator '.byte_offset'
-      macro LoadDataViewByteOffset(JSDataView): Number;
+      macro LoadJSArrayBufferViewByteOffset(JSArrayBufferView): uintptr;
   extern operator '.backing_store'
-      macro LoadArrayBufferBackingStore(JSArrayBuffer): RawPtr;
+      macro LoadJSArrayBufferBackingStore(JSArrayBuffer): RawPtr;
 
   macro MakeDataViewGetterNameString(kind: constexpr ElementsKind): String {
     if constexpr (kind == UINT8_ELEMENTS) {
@@ -69,10 +68,10 @@ module data_view {
     return IsDetachedBuffer(view.buffer);
   }
 
-  macro ValidateDataView(context: Context,
-      o: Object, method: String): JSDataView {
+  macro ValidateDataView(
+      context: Context, o: Object, method: String): JSDataView {
     try {
-      return cast<JSDataView>(o) otherwise CastError;
+      return Cast<JSDataView>(o) otherwise CastError;
     }
     label CastError {
       ThrowTypeError(context, kIncompatibleMethodReceiver, method);
@@ -82,35 +81,35 @@ module data_view {
   // ES6 section 24.2.4.1 get DataView.prototype.buffer
   javascript builtin DataViewPrototypeGetBuffer(
       context: Context, receiver: Object, ...arguments): JSArrayBuffer {
-    let data_view: JSDataView = ValidateDataView(
-      context, receiver, 'get DataView.prototype.buffer');
-    return data_view.buffer;
+    let dataView: JSDataView =
+        ValidateDataView(context, receiver, 'get DataView.prototype.buffer');
+    return dataView.buffer;
   }
 
   // ES6 section 24.2.4.2 get DataView.prototype.byteLength
   javascript builtin DataViewPrototypeGetByteLength(
       context: Context, receiver: Object, ...arguments): Number {
-    let data_view: JSDataView = ValidateDataView(
+    let dataView: JSDataView = ValidateDataView(
         context, receiver, 'get DataView.prototype.byte_length');
-    if (WasNeutered(data_view)) {
+    if (WasNeutered(dataView)) {
       // TODO(bmeurer): According to the ES6 spec, we should throw a TypeError
-      // here if the JSArrayBuffer of the {data_view} was neutered.
+      // here if the JSArrayBuffer of the {dataView} was neutered.
       return 0;
     }
-    return data_view.byte_length;
+    return Convert<Number>(dataView.byte_length);
   }
 
   // ES6 section 24.2.4.3 get DataView.prototype.byteOffset
   javascript builtin DataViewPrototypeGetByteOffset(
       context: Context, receiver: Object, ...arguments): Number {
-    let data_view: JSDataView = ValidateDataView(
+    let dataView: JSDataView = ValidateDataView(
         context, receiver, 'get DataView.prototype.byte_offset');
-    if (WasNeutered(data_view)) {
+    if (WasNeutered(dataView)) {
       // TODO(bmeurer): According to the ES6 spec, we should throw a TypeError
-      // here if the JSArrayBuffer of the {data_view} was neutered.
+      // here if the JSArrayBuffer of the {dataView} was neutered.
       return 0;
     }
-    return data_view.byte_offset;
+    return Convert<Number>(dataView.byte_offset);
   }
 
   extern macro BitcastInt32ToFloat32(uint32): float32;
@@ -120,109 +119,110 @@ module data_view {
   extern macro Float64InsertLowWord32(float64, uint32): float64;
   extern macro Float64InsertHighWord32(float64, uint32): float64;
 
-  extern macro LoadUint8(RawPtr, intptr): uint32;
-  extern macro LoadInt8(RawPtr, intptr): int32;
+  extern macro LoadUint8(RawPtr, uintptr): uint32;
+  extern macro LoadInt8(RawPtr, uintptr): int32;
 
-  macro LoadDataView8(buffer: JSArrayBuffer, offset: intptr,
-                          signed: constexpr bool): Smi {
+  macro LoadDataView8(
+      buffer: JSArrayBuffer, offset: uintptr, signed: constexpr bool): Smi {
     if constexpr (signed) {
-      return convert<Smi>(LoadInt8(buffer.backing_store, offset));
+      return Convert<Smi>(LoadInt8(buffer.backing_store, offset));
     } else {
-      return convert<Smi>(LoadUint8(buffer.backing_store, offset));
+      return Convert<Smi>(LoadUint8(buffer.backing_store, offset));
     }
   }
 
-  macro LoadDataView16(buffer: JSArrayBuffer, offset: intptr,
-                       requested_little_endian: bool,
-                       signed: constexpr bool): Number {
-    let data_pointer: RawPtr = buffer.backing_store;
+  macro LoadDataView16(
+      buffer: JSArrayBuffer, offset: uintptr, requestedLittleEndian: bool,
+      signed: constexpr bool): Number {
+    let dataPointer: RawPtr = buffer.backing_store;
 
     let b0: int32;
     let b1: int32;
     let result: int32;
 
     // Sign-extend the most significant byte by loading it as an Int8.
-    if (requested_little_endian) {
-      b0 = Signed(LoadUint8(data_pointer, offset));
-      b1 = LoadInt8(data_pointer, offset + 1);
+    if (requestedLittleEndian) {
+      b0 = Signed(LoadUint8(dataPointer, offset));
+      b1 = LoadInt8(dataPointer, offset + 1);
       result = (b1 << 8) + b0;
     } else {
-      b0 = LoadInt8(data_pointer, offset);
-      b1 = Signed(LoadUint8(data_pointer, offset + 1));
+      b0 = LoadInt8(dataPointer, offset);
+      b1 = Signed(LoadUint8(dataPointer, offset + 1));
       result = (b0 << 8) + b1;
     }
     if constexpr (signed) {
-      return convert<Smi>(result);
+      return Convert<Smi>(result);
     } else {
       // Bit-mask the higher bits to prevent sign extension if we're unsigned.
-      return convert<Smi>(result & 0xFFFF);
+      return Convert<Smi>(result & 0xFFFF);
     }
   }
 
-  macro LoadDataView32(buffer: JSArrayBuffer, offset: intptr,
-                       requested_little_endian: bool,
-                       kind: constexpr ElementsKind): Number {
-    let data_pointer: RawPtr = buffer.backing_store;
+  macro LoadDataView32(
+      buffer: JSArrayBuffer, offset: uintptr, requestedLittleEndian: bool,
+      kind: constexpr ElementsKind): Number {
+    let dataPointer: RawPtr = buffer.backing_store;
 
-    let b0: uint32 = LoadUint8(data_pointer, offset);
-    let b1: uint32 = LoadUint8(data_pointer, offset + 1);
-    let b2: uint32 = LoadUint8(data_pointer, offset + 2);
-    let b3: uint32 = LoadUint8(data_pointer, offset + 3);
+    let b0: uint32 = LoadUint8(dataPointer, offset);
+    let b1: uint32 = LoadUint8(dataPointer, offset + 1);
+    let b2: uint32 = LoadUint8(dataPointer, offset + 2);
+    let b3: uint32 = LoadUint8(dataPointer, offset + 3);
     let result: uint32;
 
-    if (requested_little_endian) {
+    if (requestedLittleEndian) {
       result = (b3 << 24) | (b2 << 16) | (b1 << 8) | b0;
     } else {
       result = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
     }
 
     if constexpr (kind == INT32_ELEMENTS) {
-      return convert<Number>(Signed(result));
+      return Convert<Number>(Signed(result));
     } else if constexpr (kind == UINT32_ELEMENTS) {
-      return convert<Number>(result);
+      return Convert<Number>(result);
     } else if constexpr (kind == FLOAT32_ELEMENTS) {
-      let float_res: float64 = convert<float64>(BitcastInt32ToFloat32(result));
-      return convert<Number>(float_res);
+      let floatRes: float64 = Convert<float64>(BitcastInt32ToFloat32(result));
+      return Convert<Number>(floatRes);
     } else {
       unreachable;
     }
   }
 
-  macro LoadDataViewFloat64(buffer: JSArrayBuffer, offset: intptr,
-                            requested_little_endian: bool): Number {
-    let data_pointer: RawPtr = buffer.backing_store;
-
-    let b0: uint32 = LoadUint8(data_pointer, offset);
-    let b1: uint32 = LoadUint8(data_pointer, offset + 1);
-    let b2: uint32 = LoadUint8(data_pointer, offset + 2);
-    let b3: uint32 = LoadUint8(data_pointer, offset + 3);
-    let b4: uint32 = LoadUint8(data_pointer, offset + 4);
-    let b5: uint32 = LoadUint8(data_pointer, offset + 5);
-    let b6: uint32 = LoadUint8(data_pointer, offset + 6);
-    let b7: uint32 = LoadUint8(data_pointer, offset + 7);
-    let low_word: uint32;
-    let high_word: uint32;
-
-    if (requested_little_endian) {
-      low_word = (b3 << 24) | (b2 << 16) | (b1 << 8) | b0;
-      high_word = (b7 << 24) | (b6 << 16) | (b5 << 8) | b4;
+  macro LoadDataViewFloat64(
+      buffer: JSArrayBuffer, offset: uintptr,
+      requestedLittleEndian: bool): Number {
+    let dataPointer: RawPtr = buffer.backing_store;
+
+    let b0: uint32 = LoadUint8(dataPointer, offset);
+    let b1: uint32 = LoadUint8(dataPointer, offset + 1);
+    let b2: uint32 = LoadUint8(dataPointer, offset + 2);
+    let b3: uint32 = LoadUint8(dataPointer, offset + 3);
+    let b4: uint32 = LoadUint8(dataPointer, offset + 4);
+    let b5: uint32 = LoadUint8(dataPointer, offset + 5);
+    let b6: uint32 = LoadUint8(dataPointer, offset + 6);
+    let b7: uint32 = LoadUint8(dataPointer, offset + 7);
+    let lowWord: uint32;
+    let highWord: uint32;
+
+    if (requestedLittleEndian) {
+      lowWord = (b3 << 24) | (b2 << 16) | (b1 << 8) | b0;
+      highWord = (b7 << 24) | (b6 << 16) | (b5 << 8) | b4;
     } else {
-      high_word = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
-      low_word = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7;
+      highWord = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
+      lowWord = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7;
     }
 
     let result: float64 = 0;
-    result = Float64InsertLowWord32(result, low_word);
-    result = Float64InsertHighWord32(result, high_word);
+    result = Float64InsertLowWord32(result, lowWord);
+    result = Float64InsertHighWord32(result, highWord);
 
-    return convert<Number>(result);
+    return Convert<Number>(result);
   }
 
   extern macro AllocateBigInt(intptr): BigInt;
   extern macro StoreBigIntBitfield(BigInt, intptr): void;
   extern macro StoreBigIntDigit(BigInt, constexpr int31, uintptr): void;
-  extern macro DataViewEncodeBigIntBits(constexpr bool,
-      constexpr int31): intptr;
+  extern macro DataViewEncodeBigIntBits(
+      constexpr bool, constexpr int31): intptr;
 
   const kPositiveBigInt: constexpr bool = false;
   const kNegativeBigInt: constexpr bool = true;
@@ -230,173 +230,168 @@ module data_view {
   const kOneDigitBigInt: constexpr int31 = 1;
   const kTwoDigitBigInt: constexpr int31 = 2;
 
-  macro CreateEmptyBigInt(is_positive: bool, length: constexpr int31): BigInt {
+  macro CreateEmptyBigInt(isPositive: bool, length: constexpr int31): BigInt {
     // Allocate a BigInt with the desired length (number of digits).
     let result: BigInt = AllocateBigInt(length);
 
     // Write the desired sign and length to the BigInt bitfield.
-    if (is_positive) {
-      StoreBigIntBitfield(result,
-          DataViewEncodeBigIntBits(kPositiveBigInt, length));
+    if (isPositive) {
+      StoreBigIntBitfield(
+          result, DataViewEncodeBigIntBits(kPositiveBigInt, length));
     } else {
-      StoreBigIntBitfield(result,
-          DataViewEncodeBigIntBits(kNegativeBigInt, length));
+      StoreBigIntBitfield(
+          result, DataViewEncodeBigIntBits(kNegativeBigInt, length));
     }
 
     return result;
   }
 
   // Create a BigInt on a 64-bit architecture from two 32-bit values.
-  macro MakeBigIntOn64Bit(low_word: uint32, high_word: uint32,
-                          signed: constexpr bool): BigInt {
-
+  macro MakeBigIntOn64Bit(
+      lowWord: uint32, highWord: uint32, signed: constexpr bool): BigInt {
     // 0n is represented by a zero-length BigInt.
-    if (low_word == 0 && high_word == 0) {
+    if (lowWord == 0 && highWord == 0) {
       return AllocateBigInt(kZeroDigitBigInt);
     }
 
-    let is_positive: bool = true;
-    let high_part: intptr = Signed(convert<uintptr>(high_word));
-    let low_part: intptr = Signed(convert<uintptr>(low_word));
-    let raw_value: intptr = (high_part << 32) + low_part;
+    let isPositive: bool = true;
+    let highPart: intptr = Signed(Convert<uintptr>(highWord));
+    let lowPart: intptr = Signed(Convert<uintptr>(lowWord));
+    let rawValue: intptr = (highPart << 32) + lowPart;
 
     if constexpr (signed) {
-      if (raw_value < 0) {
-        is_positive = false;
-        // We have to store the absolute value of raw_value in the digit.
-        raw_value = 0 - raw_value;
+      if (rawValue < 0) {
+        isPositive = false;
+        // We have to store the absolute value of rawValue in the digit.
+        rawValue = 0 - rawValue;
       }
     }
 
     // Allocate the BigInt and store the absolute value.
-    let result: BigInt = CreateEmptyBigInt(is_positive, kOneDigitBigInt);
+    let result: BigInt = CreateEmptyBigInt(isPositive, kOneDigitBigInt);
 
-    StoreBigIntDigit(result, 0, Unsigned(raw_value));
+    StoreBigIntDigit(result, 0, Unsigned(rawValue));
 
     return result;
   }
 
   // Create a BigInt on a 32-bit architecture from two 32-bit values.
-  macro MakeBigIntOn32Bit(low_word: uint32, high_word: uint32,
-                          signed: constexpr bool): BigInt {
-
+  macro MakeBigIntOn32Bit(
+      lowWord: uint32, highWord: uint32, signed: constexpr bool): BigInt {
     // 0n is represented by a zero-length BigInt.
-    if (low_word == 0 && high_word == 0) {
+    if (lowWord == 0 && highWord == 0) {
       return AllocateBigInt(kZeroDigitBigInt);
     }
 
     // On a 32-bit platform, we might need 1 or 2 digits to store the number.
-    let need_two_digits: bool = false;
-    let is_positive: bool = true;
+    let needTwoDigits: bool = false;
+    let isPositive: bool = true;
 
-    // We need to do some math on low_word and high_word,
-    // so convert them to int32.
-    let low_part: int32 = Signed(low_word);
-    let high_part: int32 = Signed(high_word);
+    // We need to do some math on lowWord and highWord,
+    // so Convert them to int32.
+    let lowPart: int32 = Signed(lowWord);
+    let highPart: int32 = Signed(highWord);
 
-    // If high_word == 0, the number is positive, and we only need 1 digit,
+    // If highWord == 0, the number is positive, and we only need 1 digit,
     // so we don't have anything to do.
     // Otherwise, all cases are possible.
-    if (high_word != 0) {
+    if (highWord != 0) {
       if constexpr (signed) {
-
-        // If high_part < 0, the number is always negative.
-        if (high_part < 0) {
-          is_positive = false;
+        // If highPart < 0, the number is always negative.
+        if (highPart < 0) {
+          isPositive = false;
 
           // We have to compute the absolute value by hand.
           // There will be a negative carry from the low word
           // to the high word iff low != 0.
-          high_part = 0 - high_part;
-          if (low_part != 0) {
-            high_part = high_part - 1;
+          highPart = 0 - highPart;
+          if (lowPart != 0) {
+            highPart = highPart - 1;
           }
-          low_part = 0 - low_part;
+          lowPart = 0 - lowPart;
 
-          // Here, high_part could be 0 again so we might have 1 or 2 digits.
-          if (high_part != 0) {
-            need_two_digits = true;
+          // Here, highPart could be 0 again so we might have 1 or 2 digits.
+          if (highPart != 0) {
+            needTwoDigits = true;
           }
 
         } else {
           // In this case, the number is positive, and we need 2 digits.
-          need_two_digits = true;
+          needTwoDigits = true;
         }
 
       } else {
         // In this case, the number is positive (unsigned),
         // and we need 2 digits.
-        need_two_digits = true;
+        needTwoDigits = true;
       }
     }
 
     // Allocate the BigInt with the right sign and length.
     let result: BigInt;
-    if (need_two_digits) {
-      result = CreateEmptyBigInt(is_positive, kTwoDigitBigInt);
+    if (needTwoDigits) {
+      result = CreateEmptyBigInt(isPositive, kTwoDigitBigInt);
     } else {
-      result = CreateEmptyBigInt(is_positive, kOneDigitBigInt);
+      result = CreateEmptyBigInt(isPositive, kOneDigitBigInt);
     }
 
     // Finally, write the digit(s) to the BigInt.
-    StoreBigIntDigit(result, 0, Unsigned(convert<intptr>(low_part)));
+    StoreBigIntDigit(result, 0, Unsigned(Convert<intptr>(lowPart)));
 
-    if (need_two_digits) {
-      StoreBigIntDigit(result, 1, Unsigned(convert<intptr>(high_part)));
+    if (needTwoDigits) {
+      StoreBigIntDigit(result, 1, Unsigned(Convert<intptr>(highPart)));
     }
 
     return result;
   }
 
-  macro MakeBigInt(low_word: uint32, high_word: uint32,
-                   signed: constexpr bool): BigInt {
+  macro MakeBigInt(
+      lowWord: uint32, highWord: uint32, signed: constexpr bool): BigInt {
     // A BigInt digit has the platform word size, so we only need one digit
     // on 64-bit platforms but may need two on 32-bit.
     if constexpr (Is64()) {
-      return MakeBigIntOn64Bit(low_word, high_word, signed);
+      return MakeBigIntOn64Bit(lowWord, highWord, signed);
     } else {
-      return MakeBigIntOn32Bit(low_word, high_word, signed);
+      return MakeBigIntOn32Bit(lowWord, highWord, signed);
     }
   }
 
-  macro LoadDataViewBigInt(buffer: JSArrayBuffer, offset: intptr,
-                           requested_little_endian: bool,
-                           signed: constexpr bool): BigInt {
-    let data_pointer: RawPtr = buffer.backing_store;
-
-    let b0: uint32 = LoadUint8(data_pointer, offset);
-    let b1: uint32 = LoadUint8(data_pointer, offset + 1);
-    let b2: uint32 = LoadUint8(data_pointer, offset + 2);
-    let b3: uint32 = LoadUint8(data_pointer, offset + 3);
-    let b4: uint32 = LoadUint8(data_pointer, offset + 4);
-    let b5: uint32 = LoadUint8(data_pointer, offset + 5);
-    let b6: uint32 = LoadUint8(data_pointer, offset + 6);
-    let b7: uint32 = LoadUint8(data_pointer, offset + 7);
-    let low_word: uint32;
-    let high_word: uint32;
-
-    if (requested_little_endian) {
-      low_word = (b3 << 24) | (b2 << 16) | (b1 << 8) | b0;
-      high_word = (b7 << 24) | (b6 << 16) | (b5 << 8) | b4;
+  macro LoadDataViewBigInt(
+      buffer: JSArrayBuffer, offset: uintptr, requestedLittleEndian: bool,
+      signed: constexpr bool): BigInt {
+    let dataPointer: RawPtr = buffer.backing_store;
+
+    let b0: uint32 = LoadUint8(dataPointer, offset);
+    let b1: uint32 = LoadUint8(dataPointer, offset + 1);
+    let b2: uint32 = LoadUint8(dataPointer, offset + 2);
+    let b3: uint32 = LoadUint8(dataPointer, offset + 3);
+    let b4: uint32 = LoadUint8(dataPointer, offset + 4);
+    let b5: uint32 = LoadUint8(dataPointer, offset + 5);
+    let b6: uint32 = LoadUint8(dataPointer, offset + 6);
+    let b7: uint32 = LoadUint8(dataPointer, offset + 7);
+    let lowWord: uint32;
+    let highWord: uint32;
+
+    if (requestedLittleEndian) {
+      lowWord = (b3 << 24) | (b2 << 16) | (b1 << 8) | b0;
+      highWord = (b7 << 24) | (b6 << 16) | (b5 << 8) | b4;
     } else {
-      high_word = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
-      low_word = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7;
+      highWord = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3;
+      lowWord = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7;
     }
 
-    return MakeBigInt(low_word, high_word, signed);
+    return MakeBigInt(lowWord, highWord, signed);
   }
 
-  extern macro ToSmiIndex(Object, Context): Smi labels RangeError;
+  extern macro ToSmiIndex(Object, Context): Smi
+      labels RangeError;
   extern macro DataViewElementSize(constexpr ElementsKind): constexpr int31;
 
-  macro DataViewGet(context: Context,
-                    receiver: Object,
-                    offset: Object,
-                    requested_little_endian: Object,
-                    kind: constexpr ElementsKind): Numeric {
-
-    let data_view: JSDataView = ValidateDataView(
-        context, receiver, MakeDataViewGetterNameString(kind));
+  macro DataViewGet(
+      context: Context, receiver: Object, offset: Object,
+      requestedLittleEndian: Object, kind: constexpr ElementsKind): Numeric {
+    let dataView: JSDataView =
+        ValidateDataView(context, receiver, MakeDataViewGetterNameString(kind));
 
     let getIndex: Number;
     try {
@@ -406,28 +401,26 @@ module data_view {
       ThrowRangeError(context, kInvalidDataViewAccessorOffset);
     }
 
-    let littleEndian: bool = ToBoolean(requested_little_endian);
-    let buffer: JSArrayBuffer = data_view.buffer;
+    let littleEndian: bool = ToBoolean(requestedLittleEndian);
+    let buffer: JSArrayBuffer = dataView.buffer;
 
     if (IsDetachedBuffer(buffer)) {
-      ThrowTypeError(context, kDetachedOperation,
-                     MakeDataViewGetterNameString(kind));
+      ThrowTypeError(
+          context, kDetachedOperation, MakeDataViewGetterNameString(kind));
     }
 
-    let viewOffset: Number = data_view.byte_offset;
-    let viewSize: Number = data_view.byte_length;
-    let elementSize: Number = DataViewElementSize(kind);
+    let getIndexFloat: float64 = Convert<float64>(getIndex);
+    let getIndexWord: uintptr = Convert<uintptr>(getIndexFloat);
 
-    if (getIndex + elementSize > viewSize) {
+    let viewOffsetWord: uintptr = dataView.byte_offset;
+    let viewSizeFloat: float64 = Convert<float64>(dataView.byte_length);
+    let elementSizeFloat: float64 = Convert<float64>(DataViewElementSize(kind));
+
+    if (getIndexFloat + elementSizeFloat > viewSizeFloat) {
       ThrowRangeError(context, kInvalidDataViewAccessorOffset);
     }
 
-    let getIndexFloat: float64 = convert<float64>(getIndex);
-    let getIndexIntptr: intptr = Signed(convert<uintptr>(getIndexFloat));
-    let viewOffsetFloat: float64 = convert<float64>(viewOffset);
-    let viewOffsetIntptr: intptr = Signed(convert<uintptr>(viewOffsetFloat));
-
-    let bufferIndex: intptr = getIndexIntptr + viewOffsetIntptr;
+    let bufferIndex: uintptr = getIndexWord + viewOffsetWord;
 
     if constexpr (kind == UINT8_ELEMENTS) {
       return LoadDataView8(buffer, bufferIndex, false);
@@ -455,201 +448,173 @@ module data_view {
   }
 
   javascript builtin DataViewPrototypeGetUint8(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, Undefined, UINT8_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    return DataViewGet(context, receiver, offset, Undefined, UINT8_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetInt8(
       context: Context, receiver: Object, ...arguments): Object {
-    let offset: Object = arguments.length > 0 ?
-        arguments[0] :
-        Undefined;
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
     return DataViewGet(context, receiver, offset, Undefined, INT8_ELEMENTS);
   }
 
   javascript builtin DataViewPrototypeGetUint16(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         UINT16_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, UINT16_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetInt16(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         INT16_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, INT16_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetUint32(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         UINT32_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, UINT32_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetInt32(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         INT32_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, INT32_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetFloat32(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         FLOAT32_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, FLOAT32_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetFloat64(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         FLOAT64_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, FLOAT64_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetBigUint64(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         BIGUINT64_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, BIGUINT64_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeGetBigInt64(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewGet(context, receiver, offset, is_little_endian,
-                         BIGINT64_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewGet(
+        context, receiver, offset, isLittleEndian, BIGINT64_ELEMENTS);
+  }
 
   extern macro ToNumber(Context, Object): Number;
   extern macro ToBigInt(Context, Object): BigInt;
   extern macro TruncateFloat64ToFloat32(float64): float32;
   extern macro TruncateFloat64ToWord32(float64): uint32;
 
-  extern macro StoreWord8(RawPtr, intptr, uint32): void;
+  extern macro StoreWord8(RawPtr, uintptr, uint32): void;
 
-  macro StoreDataView8(buffer: JSArrayBuffer, offset: intptr,
-                       value: uint32) {
+  macro StoreDataView8(buffer: JSArrayBuffer, offset: uintptr, value: uint32) {
     StoreWord8(buffer.backing_store, offset, value & 0xFF);
   }
 
-  macro StoreDataView16(buffer: JSArrayBuffer, offset: intptr, value: uint32,
-                        requested_little_endian: bool) {
-    let data_pointer: RawPtr = buffer.backing_store;
+  macro StoreDataView16(
+      buffer: JSArrayBuffer, offset: uintptr, value: uint32,
+      requestedLittleEndian: bool) {
+    let dataPointer: RawPtr = buffer.backing_store;
 
     let b0: uint32 = value & 0xFF;
     let b1: uint32 = (value >>> 8) & 0xFF;
 
-    if (requested_little_endian) {
-      StoreWord8(data_pointer, offset, b0);
-      StoreWord8(data_pointer, offset + 1, b1);
+    if (requestedLittleEndian) {
+      StoreWord8(dataPointer, offset, b0);
+      StoreWord8(dataPointer, offset + 1, b1);
     } else {
-      StoreWord8(data_pointer, offset, b1);
-      StoreWord8(data_pointer, offset + 1, b0);
+      StoreWord8(dataPointer, offset, b1);
+      StoreWord8(dataPointer, offset + 1, b0);
     }
   }
 
-  macro StoreDataView32(buffer: JSArrayBuffer, offset: intptr, value: uint32,
-                        requested_little_endian: bool) {
-    let data_pointer: RawPtr = buffer.backing_store;
+  macro StoreDataView32(
+      buffer: JSArrayBuffer, offset: uintptr, value: uint32,
+      requestedLittleEndian: bool) {
+    let dataPointer: RawPtr = buffer.backing_store;
 
     let b0: uint32 = value & 0xFF;
     let b1: uint32 = (value >>> 8) & 0xFF;
     let b2: uint32 = (value >>> 16) & 0xFF;
-    let b3: uint32 = value >>> 24; // We don't need to mask here.
+    let b3: uint32 = value >>> 24;  // We don't need to mask here.
 
-    if (requested_little_endian) {
-      StoreWord8(data_pointer, offset, b0);
-      StoreWord8(data_pointer, offset + 1, b1);
-      StoreWord8(data_pointer, offset + 2, b2);
-      StoreWord8(data_pointer, offset + 3, b3);
+    if (requestedLittleEndian) {
+      StoreWord8(dataPointer, offset, b0);
+      StoreWord8(dataPointer, offset + 1, b1);
+      StoreWord8(dataPointer, offset + 2, b2);
+      StoreWord8(dataPointer, offset + 3, b3);
     } else {
-      StoreWord8(data_pointer, offset, b3);
-      StoreWord8(data_pointer, offset + 1, b2);
-      StoreWord8(data_pointer, offset + 2, b1);
-      StoreWord8(data_pointer, offset + 3, b0);
-    }
-  }
-
-  macro StoreDataView64(buffer: JSArrayBuffer, offset: intptr,
-                        low_word: uint32, high_word: uint32,
-                        requested_little_endian: bool) {
-    let data_pointer: RawPtr = buffer.backing_store;
-
-    let b0: uint32 = low_word & 0xFF;
-    let b1: uint32 = (low_word >>> 8) & 0xFF;
-    let b2: uint32 = (low_word >>> 16) & 0xFF;
-    let b3: uint32 = low_word >>> 24;
-
-    let b4: uint32 = high_word & 0xFF;
-    let b5: uint32 = (high_word >>> 8) & 0xFF;
-    let b6: uint32 = (high_word >>> 16) & 0xFF;
-    let b7: uint32 = high_word >>> 24;
-
-
-    if (requested_little_endian) {
-      StoreWord8(data_pointer, offset, b0);
-      StoreWord8(data_pointer, offset + 1, b1);
-      StoreWord8(data_pointer, offset + 2, b2);
-      StoreWord8(data_pointer, offset + 3, b3);
-      StoreWord8(data_pointer, offset + 4, b4);
-      StoreWord8(data_pointer, offset + 5, b5);
-      StoreWord8(data_pointer, offset + 6, b6);
-      StoreWord8(data_pointer, offset + 7, b7);
+      StoreWord8(dataPointer, offset, b3);
+      StoreWord8(dataPointer, offset + 1, b2);
+      StoreWord8(dataPointer, offset + 2, b1);
+      StoreWord8(dataPointer, offset + 3, b0);
+    }
+  }
+
+  macro StoreDataView64(
+      buffer: JSArrayBuffer, offset: uintptr, lowWord: uint32, highWord: uint32,
+      requestedLittleEndian: bool) {
+    let dataPointer: RawPtr = buffer.backing_store;
+
+    let b0: uint32 = lowWord & 0xFF;
+    let b1: uint32 = (lowWord >>> 8) & 0xFF;
+    let b2: uint32 = (lowWord >>> 16) & 0xFF;
+    let b3: uint32 = lowWord >>> 24;
+
+    let b4: uint32 = highWord & 0xFF;
+    let b5: uint32 = (highWord >>> 8) & 0xFF;
+    let b6: uint32 = (highWord >>> 16) & 0xFF;
+    let b7: uint32 = highWord >>> 24;
+
+    if (requestedLittleEndian) {
+      StoreWord8(dataPointer, offset, b0);
+      StoreWord8(dataPointer, offset + 1, b1);
+      StoreWord8(dataPointer, offset + 2, b2);
+      StoreWord8(dataPointer, offset + 3, b3);
+      StoreWord8(dataPointer, offset + 4, b4);
+      StoreWord8(dataPointer, offset + 5, b5);
+      StoreWord8(dataPointer, offset + 6, b6);
+      StoreWord8(dataPointer, offset + 7, b7);
     } else {
-      StoreWord8(data_pointer, offset, b7);
-      StoreWord8(data_pointer, offset + 1, b6);
-      StoreWord8(data_pointer, offset + 2, b5);
-      StoreWord8(data_pointer, offset + 3, b4);
-      StoreWord8(data_pointer, offset + 4, b3);
-      StoreWord8(data_pointer, offset + 5, b2);
-      StoreWord8(data_pointer, offset + 6, b1);
-      StoreWord8(data_pointer, offset + 7, b0);
+      StoreWord8(dataPointer, offset, b7);
+      StoreWord8(dataPointer, offset + 1, b6);
+      StoreWord8(dataPointer, offset + 2, b5);
+      StoreWord8(dataPointer, offset + 3, b4);
+      StoreWord8(dataPointer, offset + 4, b3);
+      StoreWord8(dataPointer, offset + 5, b2);
+      StoreWord8(dataPointer, offset + 6, b1);
+      StoreWord8(dataPointer, offset + 7, b0);
     }
   }
 
@@ -660,55 +625,48 @@ module data_view {
   // We might get here a BigInt that is bigger than 64 bits, but we're only
   // interested in the 64 lowest ones. This means the lowest BigInt digit
   // on 64-bit platforms, and the 2 lowest BigInt digits on 32-bit ones.
-  macro StoreDataViewBigInt(buffer: JSArrayBuffer, offset: intptr,
-                            bigint_value: BigInt,
-                            requested_little_endian: bool) {
-
-    let length: uintptr = DataViewDecodeBigIntLength(bigint_value);
-    let sign: uintptr = DataViewDecodeBigIntSign(bigint_value);
+  macro StoreDataViewBigInt(
+      buffer: JSArrayBuffer, offset: uintptr, bigIntValue: BigInt,
+      requestedLittleEndian: bool) {
+    let length: uintptr = DataViewDecodeBigIntLength(bigIntValue);
+    let sign: uintptr = DataViewDecodeBigIntSign(bigIntValue);
 
     // The 32-bit words that will hold the BigInt's value in
     // two's complement representation.
-    let low_word: uint32 = 0;
-    let high_word: uint32 = 0;
+    let lowWord: uint32 = 0;
+    let highWord: uint32 = 0;
 
     // The length is nonzero if and only if the BigInt's value is nonzero.
     if (length != 0) {
       if constexpr (Is64()) {
         // There is always exactly 1 BigInt digit to load in this case.
-        let value: uintptr = LoadBigIntDigit(bigint_value, 0);
-        low_word = convert<uint32>(value); // Truncates value to 32 bits.
-        high_word = convert<uint32>(value >>> 32);
-      }
-      else { // There might be either 1 or 2 BigInt digits we need to load.
-        low_word = convert<uint32>(LoadBigIntDigit(bigint_value, 0));
-        if (length >= 2) { // Only load the second digit if there is one.
-          high_word = convert<uint32>(LoadBigIntDigit(bigint_value, 1));
+        let value: uintptr = LoadBigIntDigit(bigIntValue, 0);
+        lowWord = Convert<uint32>(value);  // Truncates value to 32 bits.
+        highWord = Convert<uint32>(value >>> 32);
+      } else {  // There might be either 1 or 2 BigInt digits we need to load.
+        lowWord = Convert<uint32>(LoadBigIntDigit(bigIntValue, 0));
+        if (length >= 2) {  // Only load the second digit if there is one.
+          highWord = Convert<uint32>(LoadBigIntDigit(bigIntValue, 1));
         }
       }
     }
 
-    if (sign != 0) { // The number is negative, convert it.
-      high_word = Unsigned(0 - Signed(high_word));
-      if (low_word != 0) {
-        high_word = Unsigned(Signed(high_word) - 1);
+    if (sign != 0) {  // The number is negative, Convert it.
+      highWord = Unsigned(0 - Signed(highWord));
+      if (lowWord != 0) {
+        highWord = Unsigned(Signed(highWord) - 1);
       }
-      low_word = Unsigned(0 - Signed(low_word));
+      lowWord = Unsigned(0 - Signed(lowWord));
     }
 
-    StoreDataView64(buffer, offset, low_word, high_word,
-                    requested_little_endian);
+    StoreDataView64(buffer, offset, lowWord, highWord, requestedLittleEndian);
   }
 
-  macro DataViewSet(context: Context,
-                    receiver: Object,
-                    offset: Object,
-                    value: Object,
-                    requested_little_endian: Object,
-                    kind: constexpr ElementsKind): Object {
-
-    let data_view: JSDataView = ValidateDataView(
-        context, receiver, MakeDataViewSetterNameString(kind));
+  macro DataViewSet(
+      context: Context, receiver: Object, offset: Object, value: Object,
+      requestedLittleEndian: Object, kind: constexpr ElementsKind): Object {
+    let dataView: JSDataView =
+        ValidateDataView(context, receiver, MakeDataViewSetterNameString(kind));
 
     let getIndex: Number;
     try {
@@ -718,215 +676,160 @@ module data_view {
       ThrowRangeError(context, kInvalidDataViewAccessorOffset);
     }
 
-    let littleEndian: bool = ToBoolean(requested_little_endian);
-    let buffer: JSArrayBuffer = data_view.buffer;
+    let littleEndian: bool = ToBoolean(requestedLittleEndian);
+    let buffer: JSArrayBuffer = dataView.buffer;
 
-    let bigint_value: BigInt;
-    let num_value: Number;
+    let bigIntValue: BigInt;
+    let numValue: Number;
     // According to ES6 section 24.2.1.2 SetViewValue, we must perform
     // the conversion before doing the bounds check.
     if constexpr (kind == BIGUINT64_ELEMENTS || kind == BIGINT64_ELEMENTS) {
-      bigint_value = ToBigInt(context, value);
+      bigIntValue = ToBigInt(context, value);
     } else {
-      num_value = ToNumber(context, value);
+      numValue = ToNumber(context, value);
     }
 
     if (IsDetachedBuffer(buffer)) {
-      ThrowTypeError(context, kDetachedOperation,
-                     MakeDataViewSetterNameString(kind));
+      ThrowTypeError(
+          context, kDetachedOperation, MakeDataViewSetterNameString(kind));
     }
 
-    let viewOffset: Number = data_view.byte_offset;
-    let viewSize: Number = data_view.byte_length;
-    let elementSize: Number = DataViewElementSize(kind);
+    let getIndexFloat: float64 = Convert<float64>(getIndex);
+    let getIndexWord: uintptr = Convert<uintptr>(getIndexFloat);
+
+    let viewOffsetWord: uintptr = dataView.byte_offset;
+    let viewSizeFloat: float64 = Convert<float64>(dataView.byte_length);
+    let elementSizeFloat: float64 = Convert<float64>(DataViewElementSize(kind));
 
-    if (getIndex + elementSize > viewSize) {
+    if (getIndexFloat + elementSizeFloat > viewSizeFloat) {
       ThrowRangeError(context, kInvalidDataViewAccessorOffset);
     }
 
-    let getIndexFloat: float64 = convert<float64>(getIndex);
-    let getIndexIntptr: intptr = Signed(convert<uintptr>(getIndexFloat));
-    let viewOffsetFloat: float64 = convert<float64>(viewOffset);
-    let viewOffsetIntptr: intptr = Signed(convert<uintptr>(viewOffsetFloat));
-
-    let bufferIndex: intptr = getIndexIntptr + viewOffsetIntptr;
+    let bufferIndex: uintptr = getIndexWord + viewOffsetWord;
 
     if constexpr (kind == BIGUINT64_ELEMENTS || kind == BIGINT64_ELEMENTS) {
-      StoreDataViewBigInt(buffer, bufferIndex, bigint_value,
-                          littleEndian);
-    }
-    else {
-      let double_value: float64 = ChangeNumberToFloat64(num_value);
+      StoreDataViewBigInt(buffer, bufferIndex, bigIntValue, littleEndian);
+    } else {
+      let doubleValue: float64 = ChangeNumberToFloat64(numValue);
 
       if constexpr (kind == UINT8_ELEMENTS || kind == INT8_ELEMENTS) {
-        StoreDataView8(buffer, bufferIndex,
-                      TruncateFloat64ToWord32(double_value));
-      }
-      else if constexpr (kind == UINT16_ELEMENTS || kind == INT16_ELEMENTS) {
-        StoreDataView16(buffer, bufferIndex,
-                        TruncateFloat64ToWord32(double_value), littleEndian);
-      }
-      else if constexpr (kind == UINT32_ELEMENTS || kind == INT32_ELEMENTS) {
-        StoreDataView32(buffer, bufferIndex,
-                        TruncateFloat64ToWord32(double_value), littleEndian);
-      }
-      else if constexpr (kind == FLOAT32_ELEMENTS) {
-        let float_value: float32 = TruncateFloat64ToFloat32(double_value);
-        StoreDataView32(buffer, bufferIndex,
-                        BitcastFloat32ToInt32(float_value), littleEndian);
-      }
-      else if constexpr (kind == FLOAT64_ELEMENTS) {
-        let low_word: uint32 = Float64ExtractLowWord32(double_value);
-        let high_word: uint32 = Float64ExtractHighWord32(double_value);
-        StoreDataView64(buffer, bufferIndex, low_word, high_word,
-                        littleEndian);
+        StoreDataView8(
+            buffer, bufferIndex, TruncateFloat64ToWord32(doubleValue));
+      } else if constexpr (kind == UINT16_ELEMENTS || kind == INT16_ELEMENTS) {
+        StoreDataView16(
+            buffer, bufferIndex, TruncateFloat64ToWord32(doubleValue),
+            littleEndian);
+      } else if constexpr (kind == UINT32_ELEMENTS || kind == INT32_ELEMENTS) {
+        StoreDataView32(
+            buffer, bufferIndex, TruncateFloat64ToWord32(doubleValue),
+            littleEndian);
+      } else if constexpr (kind == FLOAT32_ELEMENTS) {
+        let floatValue: float32 = TruncateFloat64ToFloat32(doubleValue);
+        StoreDataView32(
+            buffer, bufferIndex, BitcastFloat32ToInt32(floatValue),
+            littleEndian);
+      } else if constexpr (kind == FLOAT64_ELEMENTS) {
+        let lowWord: uint32 = Float64ExtractLowWord32(doubleValue);
+        let highWord: uint32 = Float64ExtractHighWord32(doubleValue);
+        StoreDataView64(buffer, bufferIndex, lowWord, highWord, littleEndian);
       }
     }
     return Undefined;
   }
 
   javascript builtin DataViewPrototypeSetUint8(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value, Undefined,
-                         UINT8_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, Undefined, UINT8_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetInt8(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value, Undefined,
-                         INT8_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, Undefined, INT8_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetUint16(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, UINT16_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, UINT16_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetInt16(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, INT16_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, INT16_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetUint32(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, UINT32_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, UINT32_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetInt32(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, INT32_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, INT32_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetFloat32(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, FLOAT32_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, FLOAT32_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetFloat64(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, FLOAT64_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, FLOAT64_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetBigUint64(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, BIGUINT64_ELEMENTS);
-    }
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, BIGUINT64_ELEMENTS);
+  }
 
   javascript builtin DataViewPrototypeSetBigInt64(
-    context: Context, receiver: Object, ...arguments): Object {
-      let offset: Object = arguments.length > 0 ?
-          arguments[0] :
-          Undefined;
-      let value : Object = arguments.length > 1 ?
-          arguments[1] :
-          Undefined;
-      let is_little_endian : Object = arguments.length > 2 ?
-          arguments[2] :
-          Undefined;
-      return DataViewSet(context, receiver, offset, value,
-                         is_little_endian, BIGINT64_ELEMENTS);
-    }
-
+      context: Context, receiver: Object, ...arguments): Object {
+    let offset: Object = arguments.length > 0 ? arguments[0] : Undefined;
+    let value: Object = arguments.length > 1 ? arguments[1] : Undefined;
+    let isLittleEndian: Object =
+        arguments.length > 2 ? arguments[2] : Undefined;
+    return DataViewSet(
+        context, receiver, offset, value, isLittleEndian, BIGINT64_ELEMENTS);
+  }
 }
diff --git a/deps/v8/src/builtins/generate-bytecodes-builtins-list.cc b/deps/v8/src/builtins/generate-bytecodes-builtins-list.cc
new file mode 100644
index 0000000000..8266807b43
--- /dev/null
+++ b/deps/v8/src/builtins/generate-bytecodes-builtins-list.cc
@@ -0,0 +1,97 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <fstream>
+#include <iostream>
+
+#include "src/interpreter/bytecodes.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+void WriteBytecode(std::ofstream& out, Bytecode bytecode,
+                   OperandScale operand_scale, int* count, int offset_table[],
+                   int table_index) {
+  DCHECK_NOT_NULL(count);
+  if (Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) {
+    out << " \\\n  V(" << Bytecodes::ToString(bytecode, operand_scale, "")
+        << "Handler, interpreter::OperandScale::k" << operand_scale
+        << ", interpreter::Bytecode::k" << Bytecodes::ToString(bytecode) << ")";
+    offset_table[table_index] = *count;
+    (*count)++;
+  } else {
+    offset_table[table_index] = -1;
+  }
+}
+
+void WriteHeader(const char* header_filename) {
+  std::ofstream out(header_filename);
+
+  out << "// Automatically generated from interpreter/bytecodes.h\n"
+      << "// The following list macro is used to populate the builtins list\n"
+      << "// with the bytecode handlers\n\n"
+      << "#ifndef V8_BUILTINS_GENERATED_BYTECODES_BUILTINS_LIST\n"
+      << "#define V8_BUILTINS_GENERATED_BYTECODES_BUILTINS_LIST\n\n"
+      << "namespace v8 {\n"
+      << "namespace internal {\n\n"
+      << "#define BUILTIN_LIST_BYTECODE_HANDLERS(V)";
+
+  constexpr int kTableSize =
+      BytecodeOperands::kOperandScaleCount * Bytecodes::kBytecodeCount;
+  int offset_table[kTableSize];
+  int count = 0;
+  int index = 0;
+
+#define ADD_BYTECODES(Name, ...)                                             \
+  WriteBytecode(out, Bytecode::k##Name, operand_scale, &count, offset_table, \
+                index++);
+  OperandScale operand_scale = OperandScale::kSingle;
+  BYTECODE_LIST(ADD_BYTECODES)
+  int single_count = count;
+  operand_scale = OperandScale::kDouble;
+  BYTECODE_LIST(ADD_BYTECODES)
+  int wide_count = count - single_count;
+  operand_scale = OperandScale::kQuadruple;
+  BYTECODE_LIST(ADD_BYTECODES)
+#undef ADD_BYTECODES
+  int extra_wide_count = count - wide_count - single_count;
+  CHECK_GT(single_count, wide_count);
+  CHECK_EQ(single_count, Bytecodes::kBytecodeCount);
+  CHECK_EQ(wide_count, extra_wide_count);
+  out << "\n\nconst int kNumberOfBytecodeHandlers = " << single_count << ";\n"
+      << "const int kNumberOfWideBytecodeHandlers = " << wide_count << ";\n\n"
+      << "// Mapping from (Bytecode + OperandScaleAsIndex * |Bytecodes|) to\n"
+      << "// a dense form with all the illegal Bytecode/OperandScale\n"
+      << "// combinations removed. Used to index into the builtins table.\n"
+      << "constexpr int kBytecodeToBuiltinsMapping[" << kTableSize << "] = {\n"
+      << "    ";
+
+  for (int i = 0; i < kTableSize; ++i) {
+    if (i == single_count || i == 2 * single_count) {
+      out << "\n    ";
+    }
+    out << offset_table[i] << ", ";
+  }
+
+  out << "};\n\n"
+      << "}  // namespace internal\n"
+      << "}  // namespace v8\n"
+      << "#endif  // V8_BUILTINS_GENERATED_BYTECODES_BUILTINS_LIST\n";
+}
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+int main(int argc, const char* argv[]) {
+  if (argc != 2) {
+    std::cerr << "Usage: " << argv[0] << " <output filename>\n";
+    std::exit(1);
+  }
+
+  v8::internal::interpreter::WriteHeader(argv[1]);
+
+  return 0;
+}
diff --git a/deps/v8/src/builtins/ia32/builtins-ia32.cc b/deps/v8/src/builtins/ia32/builtins-ia32.cc
index 4707667bbf..063daed5e3 100644
--- a/deps/v8/src/builtins/ia32/builtins-ia32.cc
+++ b/deps/v8/src/builtins/ia32/builtins-ia32.cc
@@ -22,6 +22,7 @@ namespace internal {
 
 void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address,
                                 ExitFrameType exit_frame_type) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   __ mov(kJavaScriptCallExtraArg1Register,
          Immediate(ExternalReference::Create(address)));
   if (exit_frame_type == BUILTIN_EXIT) {
@@ -70,6 +71,7 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 namespace {
 
 void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax: number of arguments
   //  -- edi: constructor function
@@ -88,10 +90,10 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ SmiUntag(eax);
 
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
 
-    // Set up pointer to last argument.
-    __ lea(ebx, Operand(ebp, StandardFrameConstants::kCallerSPOffset));
+    // Set up pointer to last argument. We are using esi as scratch register.
+    __ lea(esi, Operand(ebp, StandardFrameConstants::kCallerSPOffset));
 
     // Copy arguments and receiver to the expression stack.
     Label loop, entry;
@@ -100,7 +102,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     //  --                eax: number of arguments (untagged)
     //  --                edi: constructor function
     //  --                edx: new target
-    //  --                ebx: pointer to last argument
+    //  --                esi: pointer to last argument
     //  --                ecx: counter
     //  -- sp[0*kPointerSize]: the hole (receiver)
     //  -- sp[1*kPointerSize]: number of arguments (tagged)
@@ -108,7 +110,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // -----------------------------------
     __ jmp(&entry);
     __ bind(&loop);
-    __ push(Operand(ebx, ecx, times_4, 0));
+    __ push(Operand(esi, ecx, times_4, 0));
     __ bind(&entry);
     __ dec(ecx);
     __ j(greater_equal, &loop);
@@ -118,27 +120,54 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // edi: constructor function
     // edx: new target
     ParameterCount actual(eax);
+    // Reload context from the frame.
+    __ mov(esi, Operand(ebp, ConstructFrameConstants::kContextOffset));
     __ InvokeFunction(edi, edx, actual, CALL_FUNCTION);
 
     // Restore context from the frame.
     __ mov(esi, Operand(ebp, ConstructFrameConstants::kContextOffset));
     // Restore smi-tagged arguments count from the frame.
-    __ mov(ebx, Operand(ebp, ConstructFrameConstants::kLengthOffset));
+    __ mov(edx, Operand(ebp, ConstructFrameConstants::kLengthOffset));
     // Leave construct frame.
   }
 
   // Remove caller arguments from the stack and return.
   STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
-  __ pop(ecx);
-  __ lea(esp, Operand(esp, ebx, times_2, 1 * kPointerSize));  // 1 ~ receiver
-  __ push(ecx);
+  __ PopReturnAddressTo(ecx);
+  __ lea(esp, Operand(esp, edx, times_2, 1 * kPointerSize));  // 1 ~ receiver
+  __ PushReturnAddressFrom(ecx);
   __ ret(0);
 }
 
+static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
+                                        Register scratch, Label* stack_overflow,
+                                        bool include_receiver = false) {
+  // Check the stack for overflow. We are not trying to catch
+  // interruptions (e.g. debug break and preemption) here, so the "real stack
+  // limit" is checked.
+  ExternalReference real_stack_limit =
+      ExternalReference::address_of_real_stack_limit(masm->isolate());
+  // Compute the space that is left as a negative number in scratch. If
+  // we already overflowed, this will be a positive number.
+  __ mov(scratch, __ StaticVariable(real_stack_limit));
+  __ sub(scratch, esp);
+  // Add the size of the arguments.
+  static_assert(kPointerSize == 4,
+                "The next instruction assumes kPointerSize == 4");
+  __ lea(scratch, Operand(scratch, num_args, times_4, 0));
+  if (include_receiver) {
+    __ add(scratch, Immediate(kPointerSize));
+  }
+  // See if we overflowed, i.e. scratch is positive.
+  __ cmp(scratch, Immediate(0));
+  __ j(greater, stack_overflow);  // Signed comparison.
+}
+
 }  // namespace
 
 // The construct stub for ES5 constructor functions and ES6 class constructors.
 void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax: number of arguments (untagged)
   //  -- edi: constructor function
@@ -158,7 +187,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     __ Push(esi);
     __ Push(ecx);
     __ Push(edi);
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ Push(edx);
 
     // ----------- S t a t e -------------
@@ -169,8 +198,8 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     //  --         sp[4*kPointerSize]: context
     // -----------------------------------
 
-    __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
-    __ test(FieldOperand(ebx, SharedFunctionInfo::kFlagsOffset),
+    __ mov(eax, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+    __ test(FieldOperand(eax, SharedFunctionInfo::kFlagsOffset),
             Immediate(SharedFunctionInfo::IsDerivedConstructorBit::kMask));
     __ j(not_zero, &not_create_implicit_receiver);
 
@@ -182,7 +211,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(eax, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(eax, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                         eax: implicit receiver
@@ -216,13 +245,27 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     //  -- sp[5*kPointerSize]: context
     // -----------------------------------
 
-    // Restore constructor function and argument count.
-    __ mov(edi, Operand(ebp, ConstructFrameConstants::kConstructorOffset));
+    // Restore argument count.
     __ mov(eax, Operand(ebp, ConstructFrameConstants::kLengthOffset));
     __ SmiUntag(eax);
 
     // Set up pointer to last argument.
-    __ lea(ebx, Operand(ebp, StandardFrameConstants::kCallerSPOffset));
+    __ lea(edi, Operand(ebp, StandardFrameConstants::kCallerSPOffset));
+
+    // Check if we have enough stack space to push all arguments.
+    // Argument count in eax. Clobbers ecx.
+    Label enough_stack_space, stack_overflow;
+    Generate_StackOverflowCheck(masm, eax, ecx, &stack_overflow);
+    __ jmp(&enough_stack_space);
+
+    __ bind(&stack_overflow);
+    // Restore context from the frame.
+    __ mov(esi, Operand(ebp, ConstructFrameConstants::kContextOffset));
+    __ CallRuntime(Runtime::kThrowStackOverflow);
+    // This should be unreachable.
+    __ int3();
+
+    __ bind(&enough_stack_space);
 
     // Copy arguments and receiver to the expression stack.
     Label loop, entry;
@@ -230,23 +273,24 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // ----------- S t a t e -------------
     //  --                        eax: number of arguments (untagged)
     //  --                        edx: new target
-    //  --                        ebx: pointer to last argument
+    //  --                        edi: pointer to last argument
     //  --                        ecx: counter (tagged)
     //  --         sp[0*kPointerSize]: implicit receiver
     //  --         sp[1*kPointerSize]: implicit receiver
     //  --         sp[2*kPointerSize]: padding
-    //  -- edi and sp[3*kPointerSize]: constructor function
+    //  --         sp[3*kPointerSize]: constructor function
     //  --         sp[4*kPointerSize]: number of arguments (tagged)
     //  --         sp[5*kPointerSize]: context
     // -----------------------------------
     __ jmp(&entry, Label::kNear);
     __ bind(&loop);
-    __ Push(Operand(ebx, ecx, times_pointer_size, 0));
+    __ Push(Operand(edi, ecx, times_pointer_size, 0));
     __ bind(&entry);
     __ dec(ecx);
     __ j(greater_equal, &loop);
 
-    // Call the function.
+    // Restore and and call the constructor function.
+    __ mov(edi, Operand(ebp, ConstructFrameConstants::kConstructorOffset));
     ParameterCount actual(eax);
     __ InvokeFunction(edi, edx, actual, CALL_FUNCTION);
 
@@ -272,8 +316,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(eax, Heap::kUndefinedValueRootIndex, &use_receiver,
-                  Label::kNear);
+    __ JumpIfRoot(eax, RootIndex::kUndefinedValue, &use_receiver, Label::kNear);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -295,57 +338,33 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ mov(eax, Operand(esp, 0 * kPointerSize));
-    __ JumpIfRoot(eax, Heap::kTheHoleValueRootIndex, &do_throw);
+    __ JumpIfRoot(eax, RootIndex::kTheHoleValue, &do_throw);
 
     __ bind(&leave_frame);
     // Restore smi-tagged arguments count from the frame.
-    __ mov(ebx, Operand(ebp, ConstructFrameConstants::kLengthOffset));
+    __ mov(edx, Operand(ebp, ConstructFrameConstants::kLengthOffset));
     // Leave construct frame.
   }
   // Remove caller arguments from the stack and return.
   STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
   __ pop(ecx);
-  __ lea(esp, Operand(esp, ebx, times_2, 1 * kPointerSize));  // 1 ~ receiver
+  __ lea(esp, Operand(esp, edx, times_2, 1 * kPointerSize));  // 1 ~ receiver
   __ push(ecx);
   __ ret(0);
 }
 
 void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   Generate_JSBuiltinsConstructStubHelper(masm);
 }
 
 void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   FrameScope scope(masm, StackFrame::INTERNAL);
   __ push(edi);
   __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
 }
 
-static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
-                                        Register scratch1, Register scratch2,
-                                        Label* stack_overflow,
-                                        bool include_receiver = false) {
-  // Check the stack for overflow. We are not trying to catch
-  // interruptions (e.g. debug break and preemption) here, so the "real stack
-  // limit" is checked.
-  ExternalReference real_stack_limit =
-      ExternalReference::address_of_real_stack_limit(masm->isolate());
-  __ mov(scratch1, __ StaticVariable(real_stack_limit));
-  // Make scratch2 the space we have left. The stack might already be overflowed
-  // here which will cause scratch2 to become negative.
-  __ mov(scratch2, esp);
-  __ sub(scratch2, scratch1);
-  // Make scratch1 the space we need for the array when it is unrolled onto the
-  // stack.
-  __ mov(scratch1, num_args);
-  if (include_receiver) {
-    __ add(scratch1, Immediate(1));
-  }
-  __ shl(scratch1, kPointerSizeLog2);
-  // Check if the arguments will overflow the stack.
-  __ cmp(scratch2, scratch1);
-  __ j(less_equal, stack_overflow);  // Signed comparison.
-}
-
 static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                              bool is_construct) {
   ProfileEntryHookStub::MaybeCallEntryHook(masm);
@@ -353,26 +372,29 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
+    const Register scratch1 = edx;
+    const Register scratch2 = edi;
+
     // Setup the context (we need to use the caller context from the isolate).
     ExternalReference context_address = ExternalReference::Create(
         IsolateAddressId::kContextAddress, masm->isolate());
     __ mov(esi, __ StaticVariable(context_address));
 
-    // Load the previous frame pointer (ebx) to access C arguments
-    __ mov(ebx, Operand(ebp, 0));
+    // Load the previous frame pointer (edx) to access C arguments
+    __ mov(scratch1, Operand(ebp, 0));
 
     // Push the function and the receiver onto the stack.
-    __ push(Operand(ebx, EntryFrameConstants::kFunctionArgOffset));
-    __ push(Operand(ebx, EntryFrameConstants::kReceiverArgOffset));
+    __ push(Operand(scratch1, EntryFrameConstants::kFunctionArgOffset));
+    __ push(Operand(scratch1, EntryFrameConstants::kReceiverArgOffset));
 
     // Load the number of arguments and setup pointer to the arguments.
-    __ mov(eax, Operand(ebx, EntryFrameConstants::kArgcOffset));
-    __ mov(ebx, Operand(ebx, EntryFrameConstants::kArgvOffset));
+    __ mov(eax, Operand(scratch1, EntryFrameConstants::kArgcOffset));
+    __ mov(scratch1, Operand(scratch1, EntryFrameConstants::kArgvOffset));
 
     // Check if we have enough stack space to push all arguments.
-    // Argument count in eax. Clobbers ecx and edx.
+    // Argument count in eax. Clobbers ecx.
     Label enough_stack_space, stack_overflow;
-    Generate_StackOverflowCheck(masm, eax, ecx, edx, &stack_overflow);
+    Generate_StackOverflowCheck(masm, eax, ecx, &stack_overflow);
     __ jmp(&enough_stack_space);
 
     __ bind(&stack_overflow);
@@ -387,19 +409,20 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     __ Move(ecx, Immediate(0));
     __ jmp(&entry, Label::kNear);
     __ bind(&loop);
-    __ mov(edx, Operand(ebx, ecx, times_4, 0));  // push parameter from argv
-    __ push(Operand(edx, 0));                    // dereference handle
+    // Push the parameter from argv.
+    __ mov(scratch2, Operand(scratch1, ecx, times_4, 0));
+    __ push(Operand(scratch2, 0));  // dereference handle
     __ inc(ecx);
     __ bind(&entry);
     __ cmp(ecx, eax);
     __ j(not_equal, &loop);
 
     // Load the previous frame pointer (ebx) to access C arguments
-    __ mov(ebx, Operand(ebp, 0));
+    __ mov(scratch2, Operand(ebp, 0));
 
     // Get the new.target and function from the frame.
-    __ mov(edx, Operand(ebx, EntryFrameConstants::kNewTargetArgOffset));
-    __ mov(edi, Operand(ebx, EntryFrameConstants::kFunctionArgOffset));
+    __ mov(edx, Operand(scratch2, EntryFrameConstants::kNewTargetArgOffset));
+    __ mov(edi, Operand(scratch2, EntryFrameConstants::kFunctionArgOffset));
 
     // Invoke the code.
     Handle<Code> builtin = is_construct
@@ -415,10 +438,12 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
 }
 
 void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   Generate_JSEntryTrampolineHelper(masm, false);
 }
 
 void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   Generate_JSEntryTrampolineHelper(masm, true);
 }
 
@@ -437,6 +462,8 @@ static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
 
 // static
 void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax    : the value to pass to the generator
   //  -- edx    : the JSGeneratorObject to resume
@@ -471,7 +498,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRoot(esp, ecx, Heap::kRealStackLimitRootIndex);
+  __ CompareRoot(esp, ecx, RootIndex::kRealStackLimit);
   __ j(below, &stack_overflow);
 
   // Pop return address.
@@ -488,26 +515,34 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   //  -- esp[0] : generator receiver
   // -----------------------------------
 
-  // Copy the function arguments from the generator object's register file.
-  __ mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
-  __ movzx_w(
-      ecx, FieldOperand(ecx, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ mov(ebx,
-         FieldOperand(edx, JSGeneratorObject::kParametersAndRegistersOffset));
   {
-    Label done_loop, loop;
-    __ Set(edi, 0);
+    Assembler::AllowExplicitEbxAccessScope root_is_spilled(masm);
+    __ movd(xmm0, ebx);
 
-    __ bind(&loop);
-    __ cmp(edi, ecx);
-    __ j(greater_equal, &done_loop);
-    __ Push(
-        FieldOperand(ebx, edi, times_pointer_size, FixedArray::kHeaderSize));
-    __ add(edi, Immediate(1));
-    __ jmp(&loop);
+    // Copy the function arguments from the generator object's register file.
+    __ mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+    __ movzx_w(ecx, FieldOperand(
+                        ecx, SharedFunctionInfo::kFormalParameterCountOffset));
+    __ mov(ebx,
+           FieldOperand(edx, JSGeneratorObject::kParametersAndRegistersOffset));
+    {
+      Label done_loop, loop;
+      __ Set(edi, 0);
 
-    __ bind(&done_loop);
+      __ bind(&loop);
+      __ cmp(edi, ecx);
+      __ j(greater_equal, &done_loop);
+      __ Push(
+          FieldOperand(ebx, edi, times_pointer_size, FixedArray::kHeaderSize));
+      __ add(edi, Immediate(1));
+      __ jmp(&loop);
+
+      __ bind(&done_loop);
+    }
+
+    // Restore registers.
     __ mov(edi, FieldOperand(edx, JSGeneratorObject::kFunctionOffset));
+    __ movd(ebx, xmm0);
   }
 
   // Underlying function needs to have bytecode available.
@@ -542,7 +577,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     __ Push(edx);
     __ Push(edi);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(edx);
     __ mov(edi, FieldOperand(edx, JSGeneratorObject::kFunctionOffset));
@@ -567,10 +602,11 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   }
 }
 
-static void ReplaceClosureCodeWithOptimizedCode(
-    MacroAssembler* masm, Register optimized_code, Register closure,
-    Register scratch1, Register scratch2, Register scratch3) {
-
+static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
+                                                Register optimized_code,
+                                                Register closure,
+                                                Register scratch1,
+                                                Register scratch2) {
   // Store the optimized code in the closure.
   __ mov(FieldOperand(closure, JSFunction::kCodeOffset), optimized_code);
   __ mov(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
@@ -611,21 +647,25 @@ static void TailCallRuntimeIfMarkerEquals(MacroAssembler* masm,
 }
 
 static void MaybeTailCallOptimizedCodeSlot(MacroAssembler* masm,
-                                           Register feedback_vector,
                                            Register scratch) {
   // ----------- S t a t e -------------
   //  -- eax : argument count (preserved for callee if needed, and caller)
   //  -- edx : new target (preserved for callee if needed, and caller)
   //  -- edi : target function (preserved for callee if needed, and caller)
-  //  -- feedback vector (preserved for caller if needed)
   // -----------------------------------
-  DCHECK(!AreAliased(feedback_vector, eax, edx, edi, scratch));
+  DCHECK(!AreAliased(eax, edx, edi, scratch));
 
   Label optimized_code_slot_is_weak_ref, fallthrough;
 
   Register closure = edi;
-  Register optimized_code_entry = scratch;
+  // Load the feedback vector from the closure.
+  Register feedback_vector = scratch;
+  __ mov(feedback_vector,
+         FieldOperand(closure, JSFunction::kFeedbackCellOffset));
+  __ mov(feedback_vector, FieldOperand(feedback_vector, Cell::kValueOffset));
 
+  // Load the optimized code from the feedback vector and re-use the register.
+  Register optimized_code_entry = scratch;
   __ mov(optimized_code_entry,
          FieldOperand(feedback_vector, FeedbackVector::kOptimizedCodeOffset));
 
@@ -686,10 +726,8 @@ static void MaybeTailCallOptimizedCodeSlot(MacroAssembler* masm,
 
     // Optimized code is good, get it into the closure and link the closure into
     // the optimized functions list, then tail call the optimized code.
-    // The feedback vector is no longer used, so re-use it as a scratch
-    // register.
     ReplaceClosureCodeWithOptimizedCode(masm, optimized_code_entry, closure,
-                                        edx, eax, feedback_vector);
+                                        edx, eax);
     static_assert(kJavaScriptCallCodeStartRegister == ecx, "ABI mismatch");
     __ Move(ecx, optimized_code_entry);
     __ add(ecx, Immediate(Code::kHeaderSize - kHeapObjectTag));
@@ -716,15 +754,19 @@ static void MaybeTailCallOptimizedCodeSlot(MacroAssembler* masm,
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
-                                          Register bytecode, Register scratch1,
+                                          Register scratch1, Register scratch2,
                                           Label* if_return) {
   Register bytecode_size_table = scratch1;
+  Register bytecode = scratch2;
   DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
                      bytecode));
-
   __ Move(bytecode_size_table,
           Immediate(ExternalReference::bytecode_size_table_address()));
 
+  // Load the current bytecode.
+  __ movzx_b(bytecode, Operand(kInterpreterBytecodeArrayRegister,
+                               kInterpreterBytecodeOffsetRegister, times_1, 0));
+
   // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
   Label process_bytecode, extra_wide;
   STATIC_ASSERT(0 == static_cast<int>(interpreter::Bytecode::kWide));
@@ -732,7 +774,7 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   STATIC_ASSERT(2 == static_cast<int>(interpreter::Bytecode::kDebugBreakWide));
   STATIC_ASSERT(3 ==
                 static_cast<int>(interpreter::Bytecode::kDebugBreakExtraWide));
-  __ cmpb(bytecode, Immediate(0x3));
+  __ cmp(bytecode, Immediate(0x3));
   __ j(above, &process_bytecode, Label::kNear);
   __ test(bytecode, Immediate(0x1));
   __ j(not_equal, &extra_wide, Label::kNear);
@@ -754,9 +796,9 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   __ bind(&process_bytecode);
 
 // Bailout to the return label if this is a return bytecode.
-#define JUMP_IF_EQUAL(NAME)                                             \
-  __ cmpb(bytecode,                                                     \
-          Immediate(static_cast<int>(interpreter::Bytecode::k##NAME))); \
+#define JUMP_IF_EQUAL(NAME)                                            \
+  __ cmp(bytecode,                                                     \
+         Immediate(static_cast<int>(interpreter::Bytecode::k##NAME))); \
   __ j(equal, if_return);
   RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
 #undef JUMP_IF_EQUAL
@@ -780,18 +822,23 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
 // The function builds an interpreter frame.  See InterpreterFrameConstants in
 // frames.h for its layout.
 void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   ProfileEntryHookStub::MaybeCallEntryHook(masm);
 
+  __ VerifyRootRegister();
+
   Register closure = edi;
-  Register feedback_vector = ebx;
 
-  // Load the feedback vector from the closure.
+  // Read off the optimized code slot in the closure's feedback vector, and if
+  // there is optimized code or an optimization marker, call that instead.
+  MaybeTailCallOptimizedCodeSlot(masm, ecx);
+
+  // Load the feedback vector and increment the invocation count.
+  Register feedback_vector = ecx;
   __ mov(feedback_vector,
          FieldOperand(closure, JSFunction::kFeedbackCellOffset));
   __ mov(feedback_vector, FieldOperand(feedback_vector, Cell::kValueOffset));
-  // Read off the optimized code slot in the feedback vector, and if there
-  // is optimized code or an optimization marker, call that instead.
-  MaybeTailCallOptimizedCodeSlot(masm, feedback_vector, ecx);
+  __ inc(FieldOperand(feedback_vector, FeedbackVector::kInvocationCountOffset));
 
   // Open a frame scope to indicate that there is a frame on the stack.  The
   // MANUAL indicates that the scope shouldn't actually generate code to set
@@ -811,8 +858,6 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister, eax);
   __ Pop(eax);
 
-  __ inc(FieldOperand(feedback_vector, FeedbackVector::kInvocationCountOffset));
-
   // Check function data field is actually a BytecodeArray object.
   if (FLAG_debug_code) {
     __ AssertNotSmi(kInterpreterBytecodeArrayRegister);
@@ -836,16 +881,17 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // Allocate the local and temporary register file on the stack.
   {
     // Load frame size from the BytecodeArray object.
-    __ mov(ebx, FieldOperand(kInterpreterBytecodeArrayRegister,
-                             BytecodeArray::kFrameSizeOffset));
+    Register frame_size = ecx;
+    __ mov(frame_size, FieldOperand(kInterpreterBytecodeArrayRegister,
+                                    BytecodeArray::kFrameSizeOffset));
 
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
-    __ mov(ecx, esp);
-    __ sub(ecx, ebx);
+    __ mov(eax, esp);
+    __ sub(eax, frame_size);
     ExternalReference stack_limit =
         ExternalReference::address_of_real_stack_limit(masm->isolate());
-    __ cmp(ecx, __ StaticVariable(stack_limit));
+    __ cmp(eax, __ StaticVariable(stack_limit));
     __ j(above_equal, &ok);
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ bind(&ok);
@@ -860,7 +906,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     __ push(eax);
     // Continue loop if not done.
     __ bind(&loop_check);
-    __ sub(ebx, Immediate(kPointerSize));
+    __ sub(frame_size, Immediate(kPointerSize));
     __ j(greater_equal, &loop_header);
   }
 
@@ -876,7 +922,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator and bytecode offset into registers.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
   __ mov(kInterpreterBytecodeOffsetRegister,
          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
 
@@ -887,11 +933,12 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ mov(kInterpreterDispatchTableRegister,
          Immediate(ExternalReference::interpreter_dispatch_table_address(
              masm->isolate())));
-  __ movzx_b(ebx, Operand(kInterpreterBytecodeArrayRegister,
+  __ movzx_b(ecx, Operand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
   __ mov(
       kJavaScriptCallCodeStartRegister,
-      Operand(kInterpreterDispatchTableRegister, ebx, times_pointer_size, 0));
+      Operand(kInterpreterDispatchTableRegister, ecx, times_pointer_size, 0));
+  __ VerifyRootRegister();
   __ call(kJavaScriptCallCodeStartRegister);
   masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());
 
@@ -907,16 +954,15 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
   // Either return, or advance to the next bytecode and dispatch.
   Label do_return;
-  __ movzx_b(ebx, Operand(kInterpreterBytecodeArrayRegister,
-                          kInterpreterBytecodeOffsetRegister, times_1, 0));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, ebx, ecx,
-                                &do_return);
+                                kInterpreterBytecodeOffsetRegister, ecx,
+                                kInterpreterDispatchTableRegister, &do_return);
   __ jmp(&do_dispatch);
 
   __ bind(&do_return);
   // The return value is in eax.
-  LeaveInterpreterFrame(masm, ebx, ecx);
+  LeaveInterpreterFrame(masm, edx, ecx);
+  __ VerifyRootRegister();
   __ ret(0);
 }
 
@@ -924,6 +970,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 static void Generate_InterpreterPushArgs(MacroAssembler* masm,
                                          Register array_limit,
                                          Register start_address) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- start_address : Pointer to the last argument in the args array.
   //  -- array_limit : Pointer to one before the first argument in the
@@ -943,62 +990,62 @@ static void Generate_InterpreterPushArgs(MacroAssembler* masm,
 void Builtins::Generate_InterpreterPushArgsThenCallImpl(
     MacroAssembler* masm, ConvertReceiverMode receiver_mode,
     InterpreterPushArgsMode mode) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   DCHECK(mode != InterpreterPushArgsMode::kArrayFunction);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
-  //  -- ebx : the address of the first argument to be pushed. Subsequent
+  //  -- ecx : the address of the first argument to be pushed. Subsequent
   //           arguments should be consecutive above this, in the same order as
   //           they are to be pushed onto the stack.
   //  -- edi : the target to call (can be any Object).
   // -----------------------------------
+
+  const Register scratch = edx;
+  const Register argv = ecx;
+
   Label stack_overflow;
-  // Compute the expected number of arguments.
-  __ mov(ecx, eax);
-  __ add(ecx, Immediate(1));  // Add one for receiver.
+  // Add a stack check before pushing the arguments.
+  Generate_StackOverflowCheck(masm, eax, scratch, &stack_overflow, true);
+
+  __ movd(xmm0, eax);  // Spill number of arguments.
 
-  // Add a stack check before pushing the arguments. We need an extra register
-  // to perform a stack check. So push it onto the stack temporarily. This
-  // might cause stack overflow, but it will be detected by the check.
-  __ Push(edi);
-  Generate_StackOverflowCheck(masm, ecx, edx, edi, &stack_overflow);
-  __ Pop(edi);
+  // Compute the expected number of arguments.
+  __ mov(scratch, eax);
+  __ add(scratch, Immediate(1));  // Add one for receiver.
 
   // Pop return address to allow tail-call after pushing arguments.
-  __ Pop(edx);
+  __ PopReturnAddressTo(eax);
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
-    __ sub(ecx, Immediate(1));  // Subtract one for receiver.
+    __ PushRoot(RootIndex::kUndefinedValue);
+    __ sub(scratch, Immediate(1));  // Subtract one for receiver.
   }
 
   // Find the address of the last argument.
-  __ shl(ecx, kPointerSizeLog2);
-  __ neg(ecx);
-  __ add(ecx, ebx);
-  Generate_InterpreterPushArgs(masm, ecx, ebx);
-
-  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
-    __ Pop(ebx);                // Pass the spread in a register
-    __ sub(eax, Immediate(1));  // Subtract one for spread
-  }
+  __ shl(scratch, kPointerSizeLog2);
+  __ neg(scratch);
+  __ add(scratch, argv);
+  Generate_InterpreterPushArgs(masm, scratch, argv);
 
   // Call the target.
-  __ Push(edx);  // Re-push return address.
 
   if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
+    __ Pop(ecx);                // Pass the spread in a register
+    __ PushReturnAddressFrom(eax);
+    __ movd(eax, xmm0);         // Restore number of arguments.
+    __ sub(eax, Immediate(1));  // Subtract one for spread
     __ Jump(BUILTIN_CODE(masm->isolate(), CallWithSpread),
             RelocInfo::CODE_TARGET);
   } else {
+    __ PushReturnAddressFrom(eax);
+    __ movd(eax, xmm0);  // Restore number of arguments.
     __ Jump(masm->isolate()->builtins()->Call(ConvertReceiverMode::kAny),
             RelocInfo::CODE_TARGET);
   }
 
   __ bind(&stack_overflow);
   {
-    // Pop the temporary registers, so that return address is on top of stack.
-    __ Pop(edi);
-
     __ TailCallRuntime(Runtime::kThrowStackOverflow);
 
     // This should be unreachable.
@@ -1008,44 +1055,40 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
 namespace {
 
-// This function modified start_addr, and only reads the contents of num_args
-// register. scratch1 and scratch2 are used as temporary registers. Their
-// original values are restored after the use.
+// This function modifies start_addr, and only reads the contents of num_args
+// register. scratch1 and scratch2 are used as temporary registers.
 void Generate_InterpreterPushZeroAndArgsAndReturnAddress(
     MacroAssembler* masm, Register num_args, Register start_addr,
-    Register scratch1, Register scratch2, int num_slots_above_ret_addr,
+    Register scratch1, Register scratch2, int num_slots_to_move,
     Label* stack_overflow) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // We have to move return address and the temporary registers above it
   // before we can copy arguments onto the stack. To achieve this:
   // Step 1: Increment the stack pointer by num_args + 1 (for receiver).
-  // Step 2: Move the return address and values above it to the top of stack.
+  // Step 2: Move the return address and values around it to the top of stack.
   // Step 3: Copy the arguments into the correct locations.
   //  current stack    =====>    required stack layout
-  // |             |            | scratch1      | (2) <-- esp(1)
-  // |             |            | ....          | (2)
-  // |             |            | scratch-n     | (2)
-  // |             |            | return addr   | (2)
+  // |             |            | return addr   | (2) <-- esp (1)
+  // |             |            | addtl. slot   |
   // |             |            | arg N         | (3)
-  // | scratch1    | <-- esp    | ....          |
-  // | ....        |            | arg 1         |
-  // | scratch-n   |            | arg 0         |
-  // | return addr |            | receiver slot |
+  // |             |            | ....          |
+  // |             |            | arg 1         |
+  // | return addr | <-- esp    | arg 0         |
+  // | addtl. slot |            | receiver slot |
 
   // Check for stack overflow before we increment the stack pointer.
-  Generate_StackOverflowCheck(masm, num_args, scratch1, scratch2,
-                              stack_overflow, true);
+  Generate_StackOverflowCheck(masm, num_args, scratch1, stack_overflow, true);
 
-  // Step 1 - Update the stack pointer. scratch1 already contains the required
-  // increment to the stack. i.e. num_args + 1 stack slots. This is computed in
-  // Generate_StackOverflowCheck.
+  // Step 1 - Update the stack pointer.
 
+  __ lea(scratch1, Operand(num_args, times_4, kPointerSize));
   __ AllocateStackFrame(scratch1);
 
-  // Step 2 move return_address and slots above it to the correct locations.
+  // Step 2 move return_address and slots around it to the correct locations.
   // Move from top to bottom, otherwise we may overwrite when num_args = 0 or 1,
   // basically when the source and destination overlap. We at least need one
   // extra slot for receiver, so no extra checks are required to avoid copy.
-  for (int i = 0; i < num_slots_above_ret_addr + 1; i++) {
+  for (int i = 0; i < num_slots_to_move + 1; i++) {
     __ mov(scratch1,
            Operand(esp, num_args, times_pointer_size, (i + 1) * kPointerSize));
     __ mov(Operand(esp, i * kPointerSize), scratch1);
@@ -1055,7 +1098,7 @@ void Generate_InterpreterPushZeroAndArgsAndReturnAddress(
   // Slot meant for receiver contains return address. Reset it so that
   // we will not incorrectly interpret return address as an object.
   __ mov(Operand(esp, num_args, times_pointer_size,
-                 (num_slots_above_ret_addr + 1) * kPointerSize),
+                 (num_slots_to_move + 1) * kPointerSize),
          Immediate(0));
   __ mov(scratch1, num_args);
 
@@ -1064,7 +1107,7 @@ void Generate_InterpreterPushZeroAndArgsAndReturnAddress(
   __ bind(&loop_header);
   __ mov(scratch2, Operand(start_addr, 0));
   __ mov(Operand(esp, scratch1, times_pointer_size,
-                 num_slots_above_ret_addr * kPointerSize),
+                 num_slots_to_move * kPointerSize),
          scratch2);
   __ sub(start_addr, Immediate(kPointerSize));
   __ sub(scratch1, Immediate(1));
@@ -1078,69 +1121,74 @@ void Generate_InterpreterPushZeroAndArgsAndReturnAddress(
 // static
 void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
     MacroAssembler* masm, InterpreterPushArgsMode mode) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
-  //  -- eax : the number of arguments (not including the receiver)
-  //  -- edx : the new target
-  //  -- edi : the constructor
-  //  -- ebx : allocation site feedback (if available or undefined)
-  //  -- ecx : the address of the first argument to be pushed. Subsequent
-  //           arguments should be consecutive above this, in the same order as
-  //           they are to be pushed onto the stack.
+  //  -- eax     : the number of arguments (not including the receiver)
+  //  -- ecx     : the address of the first argument to be pushed. Subsequent
+  //               arguments should be consecutive above this, in the same order
+  //               as they are to be pushed onto the stack.
+  //  -- esp[0]  : return address
+  //  -- esp[4]  : allocation site feedback (if available or undefined)
+  //  -- esp[8]  : the new target
+  //  -- esp[12] : the constructor
   // -----------------------------------
+
   Label stack_overflow;
-  // We need two scratch registers. Push edi and edx onto stack.
-  __ Push(edi);
-  __ Push(edx);
 
-  // Push arguments and move return address to the top of stack.
-  // The eax register is readonly. The ecx register will be modified. The edx
-  // and edi registers will be modified but restored to their original values.
-  Generate_InterpreterPushZeroAndArgsAndReturnAddress(masm, eax, ecx, edx, edi,
-                                                      2, &stack_overflow);
+  // Push arguments and move return address and stack spill slots to the top of
+  // stack. The eax register is readonly. The ecx register will be modified. edx
+  // and edi are used as scratch registers.
+  Generate_InterpreterPushZeroAndArgsAndReturnAddress(
+      masm, eax, ecx, edx, edi,
+      InterpreterPushArgsThenConstructDescriptor::kStackArgumentsCount,
+      &stack_overflow);
 
-  // Restore edi and edx
-  __ Pop(edx);
-  __ Pop(edi);
-
-  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
-    __ PopReturnAddressTo(ecx);
-    __ Pop(ebx);  // Pass the spread in a register
-    __ PushReturnAddressFrom(ecx);
-    __ sub(eax, Immediate(1));  // Subtract one for spread
-  } else {
-    __ AssertUndefinedOrAllocationSite(ebx);
-  }
+  // Call the appropriate constructor. eax and ecx already contain intended
+  // values, remaining registers still need to be initialized from the stack.
 
   if (mode == InterpreterPushArgsMode::kArrayFunction) {
-    // Tail call to the array construct stub (still in the caller
-    // context at this point).
-    __ AssertFunction(edi);
-    // TODO(v8:6666): When rewriting ia32 ASM builtins to not clobber the
-    // kRootRegister ebx, this useless move can be removed.
-    __ Move(kJavaScriptCallExtraArg1Register, ebx);
-    Handle<Code> code = BUILTIN_CODE(masm->isolate(), ArrayConstructorImpl);
-    __ Jump(code, RelocInfo::CODE_TARGET);
+    // Tail call to the array construct stub (still in the caller context at
+    // this point).
+
+    __ movd(xmm0, eax);  // Spill number of arguments.
+    __ PopReturnAddressTo(eax);
+    __ Pop(kJavaScriptCallExtraArg1Register);
+    __ Pop(kJavaScriptCallNewTargetRegister);
+    __ Pop(kJavaScriptCallTargetRegister);
+    __ PushReturnAddressFrom(eax);
+    __ movd(eax, xmm0);  // Reload number of arguments.
+
+    __ AssertFunction(kJavaScriptCallTargetRegister);
+    __ AssertUndefinedOrAllocationSite(kJavaScriptCallExtraArg1Register);
+    __ Jump(BUILTIN_CODE(masm->isolate(), ArrayConstructorImpl),
+            RelocInfo::CODE_TARGET);
   } else if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
-    // Call the constructor with unmodified eax, edi, edx values.
+    __ movd(xmm0, eax);  // Spill number of arguments.
+    __ PopReturnAddressTo(eax);
+    __ Drop(1);  // The allocation site is unused.
+    __ Pop(kJavaScriptCallNewTargetRegister);
+    __ Pop(kJavaScriptCallTargetRegister);
+    __ Pop(ecx);  // Pop the spread (i.e. the first argument), overwriting ecx.
+    __ PushReturnAddressFrom(eax);
+    __ movd(eax, xmm0);         // Reload number of arguments.
+    __ sub(eax, Immediate(1));  // The actual argc thus decrements by one.
+
     __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithSpread),
             RelocInfo::CODE_TARGET);
   } else {
     DCHECK_EQ(InterpreterPushArgsMode::kOther, mode);
-    // Call the constructor with unmodified eax, edi, edx values.
+    __ PopReturnAddressTo(ecx);
+    __ Drop(1);  // The allocation site is unused.
+    __ Pop(kJavaScriptCallNewTargetRegister);
+    __ Pop(kJavaScriptCallTargetRegister);
+    __ PushReturnAddressFrom(ecx);
+
     __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
   }
 
   __ bind(&stack_overflow);
-  {
-    // Pop the temporary registers, so that return address is on top of stack.
-    __ Pop(edx);
-    __ Pop(edi);
-
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-
-    // This should be unreachable.
-    __ int3();
-  }
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
+  __ int3();
 }
 
 static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
@@ -1151,26 +1199,30 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
       masm->isolate()->heap()->interpreter_entry_return_pc_offset());
   DCHECK_NE(interpreter_entry_return_pc_offset, Smi::kZero);
 
+  static constexpr Register scratch = ecx;
+
   // If the SFI function_data is an InterpreterData, get the trampoline stored
   // in it, otherwise get the trampoline from the builtins list.
-  __ mov(ebx, Operand(ebp, StandardFrameConstants::kFunctionOffset));
-  __ mov(ebx, FieldOperand(ebx, JSFunction::kSharedFunctionInfoOffset));
-  __ mov(ebx, FieldOperand(ebx, SharedFunctionInfo::kFunctionDataOffset));
+  __ mov(scratch, Operand(ebp, StandardFrameConstants::kFunctionOffset));
+  __ mov(scratch, FieldOperand(scratch, JSFunction::kSharedFunctionInfoOffset));
+  __ mov(scratch,
+         FieldOperand(scratch, SharedFunctionInfo::kFunctionDataOffset));
   __ Push(eax);
-  __ CmpObjectType(ebx, INTERPRETER_DATA_TYPE, eax);
+  __ CmpObjectType(scratch, INTERPRETER_DATA_TYPE, eax);
   __ j(not_equal, &builtin_trampoline, Label::kNear);
 
-  __ mov(ebx, FieldOperand(ebx, InterpreterData::kInterpreterTrampolineOffset));
+  __ mov(scratch,
+         FieldOperand(scratch, InterpreterData::kInterpreterTrampolineOffset));
   __ jmp(&trampoline_loaded, Label::kNear);
 
   __ bind(&builtin_trampoline);
-  __ Move(ebx, BUILTIN_CODE(masm->isolate(), InterpreterEntryTrampoline));
+  __ Move(scratch, BUILTIN_CODE(masm->isolate(), InterpreterEntryTrampoline));
 
   __ bind(&trampoline_loaded);
   __ Pop(eax);
-  __ add(ebx, Immediate(interpreter_entry_return_pc_offset->value() +
-                        Code::kHeaderSize - kHeapObjectTag));
-  __ push(ebx);
+  __ add(scratch, Immediate(interpreter_entry_return_pc_offset->value() +
+                            Code::kHeaderSize - kHeapObjectTag));
+  __ push(scratch);
 
   // Initialize the dispatch table register.
   __ mov(kInterpreterDispatchTableRegister,
@@ -1185,7 +1237,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
     // Check function data field is actually a BytecodeArray object.
     __ AssertNotSmi(kInterpreterBytecodeArrayRegister);
     __ CmpObjectType(kInterpreterBytecodeArrayRegister, BYTECODE_ARRAY_TYPE,
-                     ebx);
+                     scratch);
     __ Assert(
         equal,
         AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
@@ -1197,15 +1249,17 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   // Dispatch to the target bytecode.
-  __ movzx_b(ebx, Operand(kInterpreterBytecodeArrayRegister,
-                          kInterpreterBytecodeOffsetRegister, times_1, 0));
-  __ mov(
-      kJavaScriptCallCodeStartRegister,
-      Operand(kInterpreterDispatchTableRegister, ebx, times_pointer_size, 0));
+  __ movzx_b(scratch, Operand(kInterpreterBytecodeArrayRegister,
+                              kInterpreterBytecodeOffsetRegister, times_1, 0));
+  __ mov(kJavaScriptCallCodeStartRegister,
+         Operand(kInterpreterDispatchTableRegister, scratch, times_pointer_size,
+                 0));
   __ jmp(kJavaScriptCallCodeStartRegister);
 }
 
 void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // Get bytecode array and bytecode offset from the stack frame.
   __ mov(kInterpreterBytecodeArrayRegister,
          Operand(ebp, InterpreterFrameConstants::kBytecodeArrayFromFp));
@@ -1213,20 +1267,16 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
          Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
-  // Load the current bytecode
-  __ movzx_b(ebx, Operand(kInterpreterBytecodeArrayRegister,
-                          kInterpreterBytecodeOffsetRegister, times_1, 0));
-
   // Advance to the next bytecode.
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, ebx, ecx,
+                                kInterpreterBytecodeOffsetRegister, ecx, esi,
                                 &if_return);
 
   // Convert new bytecode offset to a Smi and save in the stackframe.
-  __ mov(ebx, kInterpreterBytecodeOffsetRegister);
-  __ SmiTag(ebx);
-  __ mov(Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp), ebx);
+  __ mov(ecx, kInterpreterBytecodeOffsetRegister);
+  __ SmiTag(ecx);
+  __ mov(Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp), ecx);
 
   Generate_InterpreterEnterBytecode(masm);
 
@@ -1236,10 +1286,13 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   Generate_InterpreterEnterBytecode(masm);
 }
 
 void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax : argument count (preserved for callee)
   //  -- edx : new target (preserved for callee)
@@ -1272,7 +1325,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
             ebp, StandardFrameConstants::kCallerSPOffset + i * kPointerSize));
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done, Label::kNear);
@@ -1291,10 +1344,10 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
     __ SmiUntag(ecx);
     scope.GenerateLeaveFrame();
 
-    __ PopReturnAddressTo(ebx);
+    __ PopReturnAddressTo(edx);
     __ inc(ecx);
     __ lea(esp, Operand(esp, ecx, times_pointer_size, 0));
-    __ PushReturnAddressFrom(ebx);
+    __ PushReturnAddressFrom(edx);
     __ ret(0);
 
     __ bind(&failed);
@@ -1316,7 +1369,13 @@ namespace {
 void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
                                       bool java_script_builtin,
                                       bool with_result) {
+#ifdef V8_EMBEDDED_BUILTINS
+  // TODO(v8:6666): Fold into Default config once root is fully supported.
+  const RegisterConfiguration* config(
+      RegisterConfiguration::PreserveRootIA32());
+#else
   const RegisterConfiguration* config(RegisterConfiguration::Default());
+#endif
   int allocatable_register_count = config->num_allocatable_general_registers();
   if (with_result) {
     // Overwrite the hole inserted by the deoptimizer with the return value from
@@ -1346,24 +1405,42 @@ void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
 }  // namespace
 
 void Builtins::Generate_ContinueToCodeStubBuiltin(MacroAssembler* masm) {
+#ifdef V8_EMBEDDED_BUILTINS
+  // TODO(v8:6666): Remove the ifdef once root is preserved by default.
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_ContinueToBuiltinHelper(masm, false, false);
 }
 
 void Builtins::Generate_ContinueToCodeStubBuiltinWithResult(
     MacroAssembler* masm) {
+#ifdef V8_EMBEDDED_BUILTINS
+  // TODO(v8:6666): Remove the ifdef once root is preserved by default.
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_ContinueToBuiltinHelper(masm, false, true);
 }
 
 void Builtins::Generate_ContinueToJavaScriptBuiltin(MacroAssembler* masm) {
+#ifdef V8_EMBEDDED_BUILTINS
+  // TODO(v8:6666): Remove the ifdef once root is preserved by default.
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_ContinueToBuiltinHelper(masm, true, false);
 }
 
 void Builtins::Generate_ContinueToJavaScriptBuiltinWithResult(
     MacroAssembler* masm) {
+#ifdef V8_EMBEDDED_BUILTINS
+  // TODO(v8:6666): Remove the ifdef once root is preserved by default.
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
   Generate_ContinueToBuiltinHelper(masm, true, true);
 }
 
 void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     __ CallRuntime(Runtime::kNotifyDeoptimized);
@@ -1377,6 +1454,8 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
 
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax     : argc
   //  -- esp[0]  : return address
@@ -1385,32 +1464,37 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   //  -- esp[12] : receiver
   // -----------------------------------
 
-  // 1. Load receiver into edi, argArray into ebx (if present), remove all
+  // 1. Load receiver into xmm0, argArray into edx (if present), remove all
   // arguments from the stack (including the receiver), and push thisArg (if
   // present) instead.
   {
     Label no_arg_array, no_this_arg;
-    __ LoadRoot(edx, Heap::kUndefinedValueRootIndex);
-    __ mov(ebx, edx);
-    __ mov(edi, Operand(esp, eax, times_pointer_size, kPointerSize));
+    // Spill receiver to allow the usage of edi as a scratch register.
+    __ movd(xmm0, Operand(esp, eax, times_pointer_size, kPointerSize));
+
+    __ LoadRoot(edx, RootIndex::kUndefinedValue);
+    __ mov(edi, edx);
     __ test(eax, eax);
     __ j(zero, &no_this_arg, Label::kNear);
     {
-      __ mov(edx, Operand(esp, eax, times_pointer_size, 0));
+      __ mov(edi, Operand(esp, eax, times_pointer_size, 0));
       __ cmp(eax, Immediate(1));
       __ j(equal, &no_arg_array, Label::kNear);
-      __ mov(ebx, Operand(esp, eax, times_pointer_size, -kPointerSize));
+      __ mov(edx, Operand(esp, eax, times_pointer_size, -kPointerSize));
       __ bind(&no_arg_array);
     }
     __ bind(&no_this_arg);
     __ PopReturnAddressTo(ecx);
     __ lea(esp, Operand(esp, eax, times_pointer_size, kPointerSize));
-    __ Push(edx);
+    __ Push(edi);
     __ PushReturnAddressFrom(ecx);
+
+    // Restore receiver to edi.
+    __ movd(edi, xmm0);
   }
 
   // ----------- S t a t e -------------
-  //  -- ebx    : argArray
+  //  -- edx    : argArray
   //  -- edi    : receiver
   //  -- esp[0] : return address
   //  -- esp[4] : thisArg
@@ -1422,9 +1506,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(ebx, Heap::kNullValueRootIndex, &no_arguments, Label::kNear);
-  __ JumpIfRoot(ebx, Heap::kUndefinedValueRootIndex, &no_arguments,
-                Label::kNear);
+  __ JumpIfRoot(edx, RootIndex::kNullValue, &no_arguments, Label::kNear);
+  __ JumpIfRoot(edx, RootIndex::kUndefinedValue, &no_arguments, Label::kNear);
 
   // 4a. Apply the receiver to the given argArray.
   __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
@@ -1441,6 +1524,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
 // static
 void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // Stack Layout:
   // esp[0]           : Return address
   // esp[8]           : Argument n
@@ -1456,9 +1541,9 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     Label done;
     __ test(eax, eax);
     __ j(not_zero, &done, Label::kNear);
-    __ PopReturnAddressTo(ebx);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
-    __ PushReturnAddressFrom(ebx);
+    __ PopReturnAddressTo(edx);
+    __ PushRoot(RootIndex::kUndefinedValue);
+    __ PushReturnAddressFrom(edx);
     __ inc(eax);
     __ bind(&done);
   }
@@ -1473,11 +1558,11 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     Label loop;
     __ mov(ecx, eax);
     __ bind(&loop);
-    __ mov(ebx, Operand(esp, ecx, times_pointer_size, 0));
-    __ mov(Operand(esp, ecx, times_pointer_size, kPointerSize), ebx);
+    __ mov(edx, Operand(esp, ecx, times_pointer_size, 0));
+    __ mov(Operand(esp, ecx, times_pointer_size, kPointerSize), edx);
     __ dec(ecx);
     __ j(not_sign, &loop);  // While non-negative (to copy return address).
-    __ pop(ebx);            // Discard copy of return address.
+    __ pop(edx);            // Discard copy of return address.
     __ dec(eax);  // One fewer argument (first argument is new receiver).
   }
 
@@ -1486,6 +1571,8 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax     : argc
   //  -- esp[0]  : return address
@@ -1495,31 +1582,38 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   //  -- esp[16] : receiver
   // -----------------------------------
 
-  // 1. Load target into edi (if present), argumentsList into ebx (if present),
+  // 1. Load target into edi (if present), argumentsList into edx (if present),
   // remove all arguments from the stack (including the receiver), and push
   // thisArgument (if present) instead.
   {
     Label done;
-    __ LoadRoot(edi, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(edi, RootIndex::kUndefinedValue);
     __ mov(edx, edi);
-    __ mov(ebx, edi);
+    __ mov(ecx, edi);
     __ cmp(eax, Immediate(1));
     __ j(below, &done, Label::kNear);
     __ mov(edi, Operand(esp, eax, times_pointer_size, -0 * kPointerSize));
     __ j(equal, &done, Label::kNear);
-    __ mov(edx, Operand(esp, eax, times_pointer_size, -1 * kPointerSize));
+    __ mov(ecx, Operand(esp, eax, times_pointer_size, -1 * kPointerSize));
     __ cmp(eax, Immediate(3));
     __ j(below, &done, Label::kNear);
-    __ mov(ebx, Operand(esp, eax, times_pointer_size, -2 * kPointerSize));
+    __ mov(edx, Operand(esp, eax, times_pointer_size, -2 * kPointerSize));
     __ bind(&done);
-    __ PopReturnAddressTo(ecx);
+
+    // Spill argumentsList to use edx as a scratch register.
+    __ movd(xmm0, edx);
+
+    __ PopReturnAddressTo(edx);
     __ lea(esp, Operand(esp, eax, times_pointer_size, kPointerSize));
-    __ Push(edx);
-    __ PushReturnAddressFrom(ecx);
+    __ Push(ecx);
+    __ PushReturnAddressFrom(edx);
+
+    // Restore argumentsList.
+    __ movd(edx, xmm0);
   }
 
   // ----------- S t a t e -------------
-  //  -- ebx    : argumentsList
+  //  -- edx    : argumentsList
   //  -- edi    : target
   //  -- esp[0] : return address
   //  -- esp[4] : thisArgument
@@ -1535,6 +1629,8 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax     : argc
   //  -- esp[0]  : return address
@@ -1544,33 +1640,40 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   //  -- esp[16] : receiver
   // -----------------------------------
 
-  // 1. Load target into edi (if present), argumentsList into ebx (if present),
+  // 1. Load target into edi (if present), argumentsList into ecx (if present),
   // new.target into edx (if present, otherwise use target), remove all
   // arguments from the stack (including the receiver), and push thisArgument
   // (if present) instead.
   {
     Label done;
-    __ LoadRoot(edi, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(edi, RootIndex::kUndefinedValue);
     __ mov(edx, edi);
-    __ mov(ebx, edi);
+    __ mov(ecx, edi);
     __ cmp(eax, Immediate(1));
     __ j(below, &done, Label::kNear);
     __ mov(edi, Operand(esp, eax, times_pointer_size, -0 * kPointerSize));
     __ mov(edx, edi);
     __ j(equal, &done, Label::kNear);
-    __ mov(ebx, Operand(esp, eax, times_pointer_size, -1 * kPointerSize));
+    __ mov(ecx, Operand(esp, eax, times_pointer_size, -1 * kPointerSize));
     __ cmp(eax, Immediate(3));
     __ j(below, &done, Label::kNear);
     __ mov(edx, Operand(esp, eax, times_pointer_size, -2 * kPointerSize));
     __ bind(&done);
+
+    // Spill argumentsList to use ecx as a scratch register.
+    __ movd(xmm0, ecx);
+
     __ PopReturnAddressTo(ecx);
     __ lea(esp, Operand(esp, eax, times_pointer_size, kPointerSize));
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ PushReturnAddressFrom(ecx);
+
+    // Restore argumentsList.
+    __ movd(ecx, xmm0);
   }
 
   // ----------- S t a t e -------------
-  //  -- ebx    : argumentsList
+  //  -- ecx    : argumentsList
   //  -- edx    : new.target
   //  -- edi    : target
   //  -- esp[0] : return address
@@ -1591,6 +1694,8 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax : argc
   //  -- esp[0] : return address
@@ -1600,19 +1705,18 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   if (FLAG_debug_code) {
     // Initial map for the builtin InternalArray function should be a map.
-    __ mov(ebx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
+    __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a nullptr and a Smi.
-    __ test(ebx, Immediate(kSmiTagMask));
+    __ test(ecx, Immediate(kSmiTagMask));
     __ Assert(not_zero,
               AbortReason::kUnexpectedInitialMapForInternalArrayFunction);
-    __ CmpObjectType(ebx, MAP_TYPE, ecx);
+    __ CmpObjectType(ecx, MAP_TYPE, ecx);
     __ Assert(equal,
               AbortReason::kUnexpectedInitialMapForInternalArrayFunction);
   }
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  __ mov(ebx, masm->isolate()->factory()->undefined_value());
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -1639,45 +1743,57 @@ static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
 
 static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
   // Retrieve the number of arguments from the stack.
-  __ mov(ebx, Operand(ebp, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ mov(edi, Operand(ebp, ArgumentsAdaptorFrameConstants::kLengthOffset));
 
   // Leave the frame.
   __ leave();
 
   // Remove caller arguments from the stack.
   STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
-  __ pop(ecx);
-  __ lea(esp, Operand(esp, ebx, times_2, 1 * kPointerSize));  // 1 ~ receiver
-  __ push(ecx);
+  __ PopReturnAddressTo(ecx);
+  __ lea(esp, Operand(esp, edi, times_2, 1 * kPointerSize));  // 1 ~ receiver
+  __ PushReturnAddressFrom(ecx);
 }
 
 // static
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- edi    : target
+  //  -- esi    : context for the Call / Construct builtin
   //  -- eax    : number of parameters on the stack (not including the receiver)
-  //  -- ebx    : arguments list (a FixedArray)
   //  -- ecx    : len (number of elements to from args)
-  //  -- edx    : new.target (checked to be constructor or undefined)
+  //  -- ecx    : new.target (checked to be constructor or undefined)
+  //  -- esp[4] : arguments list (a FixedArray)
   //  -- esp[0] : return address.
   // -----------------------------------
 
-  // We need to preserve eax, edi and ebx.
+  // We need to preserve eax, edi, esi and ebx.
   __ movd(xmm0, edx);
   __ movd(xmm1, edi);
   __ movd(xmm2, eax);
+  __ movd(xmm3, esi);  // Spill the context.
+
+  // TODO(v8:6666): Remove this usage of ebx to enable kRootRegister support.
+  const Register kArgumentsList = esi;
+  const Register kArgumentsLength = ecx;
+
+  __ PopReturnAddressTo(edx);
+  __ pop(kArgumentsList);
+  __ PushReturnAddressFrom(edx);
 
   if (masm->emit_debug_code()) {
-    // Allow ebx to be a FixedArray, or a FixedDoubleArray if ecx == 0.
+    // Allow kArgumentsList to be a FixedArray, or a FixedDoubleArray if
+    // kArgumentsLength == 0.
     Label ok, fail;
-    __ AssertNotSmi(ebx);
-    __ mov(edx, FieldOperand(ebx, HeapObject::kMapOffset));
+    __ AssertNotSmi(kArgumentsList);
+    __ mov(edx, FieldOperand(kArgumentsList, HeapObject::kMapOffset));
     __ CmpInstanceType(edx, FIXED_ARRAY_TYPE);
     __ j(equal, &ok);
     __ CmpInstanceType(edx, FIXED_DOUBLE_ARRAY_TYPE);
     __ j(not_equal, &fail);
-    __ cmp(ecx, 0);
+    __ cmp(kArgumentsLength, 0);
     __ j(equal, &ok);
     // Fall through.
     __ bind(&fail);
@@ -1686,25 +1802,10 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ bind(&ok);
   }
 
-  // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    ExternalReference real_stack_limit =
-        ExternalReference::address_of_real_stack_limit(masm->isolate());
-    __ mov(edx, __ StaticVariable(real_stack_limit));
-    // Make edx the space we have left. The stack might already be overflowed
-    // here which will cause edx to become negative.
-    __ neg(edx);
-    __ add(edx, esp);
-    __ sar(edx, kPointerSizeLog2);
-    // Check if the arguments will overflow the stack.
-    __ cmp(edx, ecx);
-    __ j(greater, &done, Label::kNear);  // Signed comparison.
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  // Check the stack for overflow. We are not trying to catch interruptions
+  // (i.e. debug break and preemption) here, so check the "real stack limit".
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, kArgumentsLength, edx, &stack_overflow);
 
   // Push additional arguments onto the stack.
   {
@@ -1712,14 +1813,14 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ Move(eax, Immediate(0));
     Label done, push, loop;
     __ bind(&loop);
-    __ cmp(eax, ecx);
+    __ cmp(eax, kArgumentsLength);
     __ j(equal, &done, Label::kNear);
     // Turn the hole into undefined as we go.
-    __ mov(edi,
-           FieldOperand(ebx, eax, times_pointer_size, FixedArray::kHeaderSize));
-    __ CompareRoot(edi, Heap::kTheHoleValueRootIndex);
+    __ mov(edi, FieldOperand(kArgumentsList, eax, times_pointer_size,
+                             FixedArray::kHeaderSize));
+    __ CompareRoot(edi, RootIndex::kTheHoleValue);
     __ j(not_equal, &push, Label::kNear);
-    __ LoadRoot(edi, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(edi, RootIndex::kUndefinedValue);
     __ bind(&push);
     __ Push(edi);
     __ inc(eax);
@@ -1729,34 +1830,45 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   }
 
   // Restore eax, edi and edx.
+  __ movd(esi, xmm3);  // Restore the context.
   __ movd(eax, xmm2);
   __ movd(edi, xmm1);
   __ movd(edx, xmm0);
 
   // Compute the actual parameter count.
-  __ add(eax, ecx);
+  __ add(eax, kArgumentsLength);
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ movd(esi, xmm3);  // Restore the context.
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
 void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
                                                       CallOrConstructMode mode,
                                                       Handle<Code> code) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edi : the target to call (can be any Object)
+  //  -- esi : context for the Call / Construct builtin
   //  -- edx : the new target (for [[Construct]] calls)
   //  -- ecx : start index (to support rest parameters)
   // -----------------------------------
 
+  __ movd(xmm0, esi);  // Spill the context.
+
+  Register scratch = esi;
+
   // Check if new.target has a [[Construct]] internal method.
   if (mode == CallOrConstructMode::kConstruct) {
     Label new_target_constructor, new_target_not_constructor;
     __ JumpIfSmi(edx, &new_target_not_constructor, Label::kNear);
-    __ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
-    __ test_b(FieldOperand(ebx, Map::kBitFieldOffset),
+    __ mov(scratch, FieldOperand(edx, HeapObject::kMapOffset));
+    __ test_b(FieldOperand(scratch, Map::kBitFieldOffset),
               Immediate(Map::IsConstructorBit::kMask));
     __ j(not_zero, &new_target_constructor, Label::kNear);
     __ bind(&new_target_not_constructor);
@@ -1764,18 +1876,18 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
       FrameScope scope(masm, StackFrame::MANUAL);
       __ EnterFrame(StackFrame::INTERNAL);
       __ Push(edx);
+      __ movd(esi, xmm0);  // Restore the context.
       __ CallRuntime(Runtime::kThrowNotConstructor);
     }
     __ bind(&new_target_constructor);
   }
 
-  // Preserve new.target (in case of [[Construct]]).
-  __ movd(xmm0, edx);
+  __ movd(xmm1, edx);  // Preserve new.target (in case of [[Construct]]).
 
   // Check if we have an arguments adaptor frame below the function frame.
   Label arguments_adaptor, arguments_done;
-  __ mov(ebx, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
-  __ cmp(Operand(ebx, CommonFrameConstants::kContextOrFrameTypeOffset),
+  __ mov(scratch, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
+  __ cmp(Operand(scratch, CommonFrameConstants::kContextOrFrameTypeOffset),
          Immediate(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
   __ j(equal, &arguments_adaptor, Label::kNear);
   {
@@ -1783,39 +1895,23 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
     __ mov(edx, FieldOperand(edx, JSFunction::kSharedFunctionInfoOffset));
     __ movzx_w(edx, FieldOperand(
                         edx, SharedFunctionInfo::kFormalParameterCountOffset));
-    __ mov(ebx, ebp);
+    __ mov(scratch, ebp);
   }
   __ jmp(&arguments_done, Label::kNear);
   __ bind(&arguments_adaptor);
   {
     // Just load the length from the ArgumentsAdaptorFrame.
-    __ mov(edx, Operand(ebx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+    __ mov(edx,
+           Operand(scratch, ArgumentsAdaptorFrameConstants::kLengthOffset));
     __ SmiUntag(edx);
   }
   __ bind(&arguments_done);
 
-  Label stack_done;
+  Label stack_done, stack_overflow;
   __ sub(edx, ecx);
   __ j(less_equal, &stack_done);
   {
-    // Check for stack overflow.
-    {
-      // Check the stack for overflow. We are not trying to catch interruptions
-      // (i.e. debug break and preemption) here, so check the "real stack
-      // limit".
-      Label done;
-      __ LoadRoot(ecx, Heap::kRealStackLimitRootIndex);
-      // Make ecx the space we have left. The stack might already be
-      // overflowed here which will cause ecx to become negative.
-      __ neg(ecx);
-      __ add(ecx, esp);
-      __ sar(ecx, kPointerSizeLog2);
-      // Check if the arguments will overflow the stack.
-      __ cmp(ecx, edx);
-      __ j(greater, &done, Label::kNear);  // Signed comparison.
-      __ TailCallRuntime(Runtime::kThrowStackOverflow);
-      __ bind(&done);
-    }
+    Generate_StackOverflowCheck(masm, edx, ecx, &stack_overflow);
 
     // Forward the arguments from the caller frame.
     {
@@ -1824,7 +1920,7 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
       __ PopReturnAddressTo(ecx);
       __ bind(&loop);
       {
-        __ Push(Operand(ebx, edx, times_pointer_size, 1 * kPointerSize));
+        __ Push(Operand(scratch, edx, times_pointer_size, 1 * kPointerSize));
         __ dec(edx);
         __ j(not_zero, &loop);
       }
@@ -1833,16 +1929,22 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
   }
   __ bind(&stack_done);
 
-  // Restore new.target (in case of [[Construct]]).
-  __ movd(edx, xmm0);
+  __ movd(edx, xmm1);  // Restore new.target (in case of [[Construct]]).
+  __ movd(esi, xmm0);  // Restore the context.
 
   // Tail-call to the {code} handler.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ movd(esi, xmm0);  // Restore the context.
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
 void Builtins::Generate_CallFunction(MacroAssembler* masm,
                                      ConvertReceiverMode mode) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edi : the function to call (checked to be a JSFunction)
@@ -1883,13 +1985,15 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ mov(ecx, Operand(esp, eax, times_pointer_size, kPointerSize));
       __ JumpIfSmi(ecx, &convert_to_object, Label::kNear);
       STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
-      __ CmpObjectType(ecx, FIRST_JS_RECEIVER_TYPE, ebx);
+      __ CmpObjectType(ecx, FIRST_JS_RECEIVER_TYPE, ecx);  // Clobbers ecx.
       __ j(above_equal, &done_convert);
+      // Reload the receiver (it was clobbered by CmpObjectType).
+      __ mov(ecx, Operand(esp, eax, times_pointer_size, kPointerSize));
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(ecx, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy, Label::kNear);
-        __ JumpIfNotRoot(ecx, Heap::kNullValueRootIndex, &convert_to_object,
+        __ JumpIfRoot(ecx, RootIndex::kUndefinedValue, &convert_global_proxy,
+                      Label::kNear);
+        __ JumpIfNotRoot(ecx, RootIndex::kNullValue, &convert_to_object,
                          Label::kNear);
         __ bind(&convert_global_proxy);
         {
@@ -1932,9 +2036,9 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
   // -----------------------------------
 
   __ movzx_w(
-      ebx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
+      ecx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
   ParameterCount actual(eax);
-  ParameterCount expected(ebx);
+  ParameterCount expected(ecx);
   __ InvokeFunctionCode(edi, no_reg, expected, actual, JUMP_FUNCTION);
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -1948,40 +2052,43 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 namespace {
 
 void Generate_PushBoundArguments(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edx : new.target (only in case of [[Construct]])
   //  -- edi : target (checked to be a JSBoundFunction)
   // -----------------------------------
 
-  // Load [[BoundArguments]] into ecx and length of that into ebx.
+  __ movd(xmm0, edx);  // Spill edx.
+
+  // Load [[BoundArguments]] into ecx and length of that into edx.
   Label no_bound_arguments;
   __ mov(ecx, FieldOperand(edi, JSBoundFunction::kBoundArgumentsOffset));
-  __ mov(ebx, FieldOperand(ecx, FixedArray::kLengthOffset));
-  __ SmiUntag(ebx);
-  __ test(ebx, ebx);
+  __ mov(edx, FieldOperand(ecx, FixedArray::kLengthOffset));
+  __ SmiUntag(edx);
+  __ test(edx, edx);
   __ j(zero, &no_bound_arguments);
   {
     // ----------- S t a t e -------------
-    //  -- eax : the number of arguments (not including the receiver)
-    //  -- edx : new.target (only in case of [[Construct]])
-    //  -- edi : target (checked to be a JSBoundFunction)
-    //  -- ecx : the [[BoundArguments]] (implemented as FixedArray)
-    //  -- ebx : the number of [[BoundArguments]]
+    //  -- eax  : the number of arguments (not including the receiver)
+    //  -- xmm0 : new.target (only in case of [[Construct]])
+    //  -- edi  : target (checked to be a JSBoundFunction)
+    //  -- ecx  : the [[BoundArguments]] (implemented as FixedArray)
+    //  -- edx  : the number of [[BoundArguments]]
     // -----------------------------------
 
     // Reserve stack space for the [[BoundArguments]].
     {
       Label done;
-      __ lea(ecx, Operand(ebx, times_pointer_size, 0));
+      __ lea(ecx, Operand(edx, times_pointer_size, 0));
       __ sub(esp, ecx);
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CompareRoot(esp, ecx, Heap::kRealStackLimitRootIndex);
-      __ j(greater, &done, Label::kNear);  // Signed comparison.
+      __ CompareRoot(esp, ecx, RootIndex::kRealStackLimit);
+      __ j(above_equal, &done, Label::kNear);
       // Restore the stack pointer.
-      __ lea(esp, Operand(esp, ebx, times_pointer_size, 0));
+      __ lea(esp, Operand(esp, edx, times_pointer_size, 0));
       {
         FrameScope scope(masm, StackFrame::MANUAL);
         __ EnterFrame(StackFrame::INTERNAL);
@@ -1997,10 +2104,10 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     {
       Label loop;
       __ Set(ecx, 0);
-      __ lea(ebx, Operand(esp, ebx, times_pointer_size, 0));
+      __ lea(edx, Operand(esp, edx, times_pointer_size, 0));
       __ bind(&loop);
-      __ movd(xmm0, Operand(ebx, ecx, times_pointer_size, 0));
-      __ movd(Operand(esp, ecx, times_pointer_size, 0), xmm0);
+      __ movd(xmm1, Operand(edx, ecx, times_pointer_size, 0));
+      __ movd(Operand(esp, ecx, times_pointer_size, 0), xmm1);
       __ inc(ecx);
       __ cmp(ecx, eax);
       __ j(less, &loop);
@@ -2010,13 +2117,13 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     {
       Label loop;
       __ mov(ecx, FieldOperand(edi, JSBoundFunction::kBoundArgumentsOffset));
-      __ mov(ebx, FieldOperand(ecx, FixedArray::kLengthOffset));
-      __ SmiUntag(ebx);
+      __ mov(edx, FieldOperand(ecx, FixedArray::kLengthOffset));
+      __ SmiUntag(edx);
       __ bind(&loop);
-      __ dec(ebx);
-      __ movd(xmm0, FieldOperand(ecx, ebx, times_pointer_size,
+      __ dec(edx);
+      __ movd(xmm1, FieldOperand(ecx, edx, times_pointer_size,
                                  FixedArray::kHeaderSize));
-      __ movd(Operand(esp, eax, times_pointer_size, 0), xmm0);
+      __ movd(Operand(esp, eax, times_pointer_size, 0), xmm1);
       __ lea(eax, Operand(eax, 1));
       __ j(greater, &loop);
     }
@@ -2026,13 +2133,16 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     // [[BoundArguments]]), so we need to subtract one for the return address.
     __ dec(eax);
   }
+
   __ bind(&no_bound_arguments);
+  __ movd(edx, xmm0);  // Reload edx.
 }
 
 }  // namespace
 
 // static
 void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edi : the function to call (checked to be a JSBoundFunction)
@@ -2040,8 +2150,8 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
   __ AssertBoundFunction(edi);
 
   // Patch the receiver to [[BoundThis]].
-  __ mov(ebx, FieldOperand(edi, JSBoundFunction::kBoundThisOffset));
-  __ mov(Operand(esp, eax, times_pointer_size, kPointerSize), ebx);
+  __ mov(ecx, FieldOperand(edi, JSBoundFunction::kBoundThisOffset));
+  __ mov(Operand(esp, eax, times_pointer_size, kPointerSize), ecx);
 
   // Push the [[BoundArguments]] onto the stack.
   Generate_PushBoundArguments(masm);
@@ -2054,6 +2164,7 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
 
 // static
 void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edi : the target to call (can be any Object).
@@ -2101,6 +2212,7 @@ void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
 
 // static
 void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edx : the new target (checked to be a constructor)
@@ -2109,10 +2221,6 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
   __ AssertConstructor(edi);
   __ AssertFunction(edi);
 
-  // Calling convention for function specific ConstructStubs require
-  // ebx to contain either an AllocationSite or undefined.
-  __ LoadRoot(ebx, Heap::kUndefinedValueRootIndex);
-
   Label call_generic_stub;
 
   // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
@@ -2121,16 +2229,23 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
           Immediate(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
   __ j(zero, &call_generic_stub, Label::kNear);
 
+  // Calling convention for function specific ConstructStubs require
+  // ecx to contain either an AllocationSite or undefined.
+  __ LoadRoot(ecx, RootIndex::kUndefinedValue);
   __ Jump(BUILTIN_CODE(masm->isolate(), JSBuiltinsConstructStub),
           RelocInfo::CODE_TARGET);
 
   __ bind(&call_generic_stub);
+  // Calling convention for function specific ConstructStubs require
+  // ecx to contain either an AllocationSite or undefined.
+  __ LoadRoot(ecx, RootIndex::kUndefinedValue);
   __ Jump(BUILTIN_CODE(masm->isolate(), JSConstructStubGeneric),
           RelocInfo::CODE_TARGET);
 }
 
 // static
 void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edx : the new target (checked to be a constructor)
@@ -2213,18 +2328,23 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax : actual number of arguments
-  //  -- ebx : expected number of arguments
+  //  -- ecx : expected number of arguments
   //  -- edx : new target (passed through to callee)
   //  -- edi : function (passed through to callee)
   // -----------------------------------
 
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
+  const Register kExpectedNumberOfArgumentsRegister = ecx;
+
   Label invoke, dont_adapt_arguments, stack_overflow;
   __ IncrementCounter(masm->isolate()->counters()->arguments_adaptors(), 1);
 
   Label enough, too_few;
-  __ cmp(ebx, SharedFunctionInfo::kDontAdaptArgumentsSentinel);
+  __ cmp(kExpectedNumberOfArgumentsRegister,
+         SharedFunctionInfo::kDontAdaptArgumentsSentinel);
   __ j(equal, &dont_adapt_arguments);
-  __ cmp(eax, ebx);
+  __ cmp(eax, kExpectedNumberOfArgumentsRegister);
   __ j(less, &too_few);
 
   {  // Enough parameters: Actual >= expected.
@@ -2232,7 +2352,8 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     EnterArgumentsAdaptorFrame(masm);
     // edi is used as a scratch register. It should be restored from the frame
     // when needed.
-    Generate_StackOverflowCheck(masm, ebx, ecx, edi, &stack_overflow);
+    Generate_StackOverflowCheck(masm, kExpectedNumberOfArgumentsRegister, edi,
+                                &stack_overflow);
 
     // Copy receiver and all expected arguments.
     const int offset = StandardFrameConstants::kCallerSPOffset;
@@ -2244,7 +2365,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     __ inc(eax);
     __ push(Operand(edi, 0));
     __ sub(edi, Immediate(kPointerSize));
-    __ cmp(eax, ebx);
+    __ cmp(eax, kExpectedNumberOfArgumentsRegister);
     __ j(less, &copy);
     // eax now contains the expected number of arguments.
     __ jmp(&invoke);
@@ -2255,16 +2376,17 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     EnterArgumentsAdaptorFrame(masm);
     // edi is used as a scratch register. It should be restored from the frame
     // when needed.
-    Generate_StackOverflowCheck(masm, ebx, ecx, edi, &stack_overflow);
+    Generate_StackOverflowCheck(masm, kExpectedNumberOfArgumentsRegister, edi,
+                                &stack_overflow);
 
-    // Remember expected arguments in ecx.
-    __ mov(ecx, ebx);
+    // Remember expected arguments in xmm0.
+    __ movd(xmm0, kExpectedNumberOfArgumentsRegister);
 
     // Copy receiver and all actual arguments.
     const int offset = StandardFrameConstants::kCallerSPOffset;
     __ lea(edi, Operand(ebp, eax, times_4, offset));
-    // ebx = expected - actual.
-    __ sub(ebx, eax);
+    // ecx = expected - actual.
+    __ sub(kExpectedNumberOfArgumentsRegister, eax);
     // eax = -actual - 1
     __ neg(eax);
     __ sub(eax, Immediate(1));
@@ -2282,11 +2404,11 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     __ bind(&fill);
     __ inc(eax);
     __ push(Immediate(masm->isolate()->factory()->undefined_value()));
-    __ cmp(eax, ebx);
+    __ cmp(eax, kExpectedNumberOfArgumentsRegister);
     __ j(less, &fill);
 
     // Restore expected arguments.
-    __ mov(eax, ecx);
+    __ movd(eax, xmm0);
   }
 
   // Call the entry point.
@@ -2325,15 +2447,12 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   }
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ mov(eax, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
-    __ mov(eax, Operand(eax, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ mov(eax, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ mov(eax, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
+  __ mov(eax, Operand(eax, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -2350,23 +2469,21 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
 
   __ bind(&skip);
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ leave();
-  }
+  __ leave();
 
   // Load deoptimization data from the code object.
-  __ mov(ebx, Operand(eax, Code::kDeoptimizationDataOffset - kHeapObjectTag));
+  __ mov(ecx, Operand(eax, Code::kDeoptimizationDataOffset - kHeapObjectTag));
 
   // Load the OSR entrypoint offset from the deoptimization data.
-  __ mov(ebx, Operand(ebx, FixedArray::OffsetOfElementAt(
+  __ mov(ecx, Operand(ecx, FixedArray::OffsetOfElementAt(
                                DeoptimizationData::kOsrPcOffsetIndex) -
                                kHeapObjectTag));
-  __ SmiUntag(ebx);
+  __ SmiUntag(ecx);
 
   // Compute the target address = code_obj + header_size + osr_offset
-  __ lea(eax, Operand(eax, ebx, times_1, Code::kHeaderSize - kHeapObjectTag));
+  __ lea(eax, Operand(eax, ecx, times_1, Code::kHeaderSize - kHeapObjectTag));
 
   // Overwrite the return address on the stack.
   __ mov(Operand(esp, 0), eax);
@@ -2375,15 +2492,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   __ ret(0);
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // The function index was put in edi by the jump table trampoline.
   // Convert to Smi for the runtime call.
   __ SmiTag(edi);
@@ -2394,6 +2505,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     // Save all parameter registers (see wasm-linkage.cc). They might be
     // overwritten in the runtime call below. We don't have any callee-saved
     // registers in wasm, so no need to store anything else.
+    Assembler::AllowExplicitEbxAccessScope root_is_spilled(masm);
     static_assert(WasmCompileLazyFrameConstants::kNumberOfSavedGpParamRegs ==
                       arraysize(wasm::kGpParamRegisters),
                   "frame size mismatch");
@@ -2420,7 +2532,12 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     // Initialize the JavaScript context with 0. CEntry will use it to
     // set the current context on the isolate.
     __ Move(kContextRegister, Smi::kZero);
-    __ CallRuntimeWithCEntry(Runtime::kWasmCompileLazy, ecx);
+    {
+      // At this point, ebx has been spilled to the stack but is not yet
+      // overwritten with another value. We can still use it as kRootRegister.
+      Assembler::SupportsRootRegisterScope root_is_unclobbered(masm);
+      __ CallRuntimeWithCEntry(Runtime::kWasmCompileLazy, ecx);
+    }
     // The entrypoint address is the return value.
     __ mov(edi, kReturnRegister0);
 
@@ -2452,6 +2569,11 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // If argv_mode == kArgvInRegister:
   // ecx: pointer to the first argument
 
+#ifdef V8_EMBEDDED_BUILTINS
+  // TODO(v8:6666): Remove the ifdef once branch load poisoning is removed.
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+#endif
+
   STATIC_ASSERT(eax == kRuntimeCallArgCountRegister);
   STATIC_ASSERT(ecx == kRuntimeCallArgvRegister);
   STATIC_ASSERT(edx == kRuntimeCallFunctionRegister);
@@ -2571,11 +2693,16 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
   __ bind(&skip);
 
+#ifdef V8_EMBEDDED_BUILTINS
+  STATIC_ASSERT(kRootRegister == kSpeculationPoisonRegister);
+  CHECK(!FLAG_untrusted_code_mitigations);
+#else
   // Reset the masking register. This is done independent of the underlying
-  // feature flag {FLAG_branch_load_poisoning} to make the snapshot work with
-  // both configurations. It is safe to always do this, because the underlying
-  // register is caller-saved and can be arbitrarily clobbered.
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
   __ ResetSpeculationPoisonRegister();
+#endif
 
   // Compute the handler entry address and jump to it.
   __ mov(edi, __ StaticVariable(pending_handler_entrypoint_address));
@@ -2583,6 +2710,8 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 }
 
 void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   Label check_negative, process_64_bits, done;
 
   // Account for return address and saved regs.
@@ -2596,6 +2725,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
   MemOperand return_operand = mantissa_operand;
 
   Register scratch1 = ebx;
+  Assembler::AllowExplicitEbxAccessScope root_is_spilled(masm);
 
   // Since we must use ecx for shifts below, use some other register (eax)
   // to calculate the result.
@@ -2676,6 +2806,8 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   const Register exponent = eax;
   const Register scratch = ecx;
   const XMMRegister double_result = xmm3;
@@ -2843,9 +2975,10 @@ void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
       RelocInfo::CODE_TARGET);
 
   __ bind(&not_one_case);
-  // TODO(v8:6666): When rewriting ia32 ASM builtins to not clobber the
-  // kRootRegister ebx, this useless move can be removed.
-  __ Move(kJavaScriptCallExtraArg1Register, ebx);
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ mov(kJavaScriptCallExtraArg1Register,
+         masm->isolate()->factory()->undefined_value());
   Handle<Code> code = BUILTIN_CODE(masm->isolate(), ArrayNArgumentsConstructor);
   __ Jump(code, RelocInfo::CODE_TARGET);
 }
@@ -2853,6 +2986,8 @@ void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
 }  // namespace
 
 void Builtins::Generate_InternalArrayConstructorImpl(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
   //  -- eax : argc
   //  -- edi : constructor
diff --git a/deps/v8/src/builtins/mips/builtins-mips.cc b/deps/v8/src/builtins/mips/builtins-mips.cc
index 0c892c960f..a2a335c70f 100644
--- a/deps/v8/src/builtins/mips/builtins-mips.cc
+++ b/deps/v8/src/builtins/mips/builtins-mips.cc
@@ -56,7 +56,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -109,7 +108,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ SmiUntag(a0);
 
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
 
     // Set up pointer to last argument.
     __ Addu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
@@ -176,7 +175,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Preserve the incoming parameters on the stack.
     __ SmiTag(a0);
     __ Push(cp, a0, a1);
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ Push(a3);
 
     // ----------- S t a t e -------------
@@ -201,7 +200,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(v0, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(v0, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                          v0: receiver
@@ -291,7 +290,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(v0, Heap::kUndefinedValueRootIndex, &use_receiver);
+    __ JumpIfRoot(v0, RootIndex::kUndefinedValue, &use_receiver);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -313,7 +312,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ lw(v0, MemOperand(sp, 0 * kPointerSize));
-    __ JumpIfRoot(v0, Heap::kTheHoleValueRootIndex, &do_throw);
+    __ JumpIfRoot(v0, RootIndex::kTheHoleValue, &do_throw);
 
     __ bind(&leave_frame);
     // Restore smi-tagged arguments count from the frame.
@@ -342,7 +341,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc) {
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  __ LoadRoot(a2, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(a2, RootIndex::kRealStackLimit);
   // Make a2 the space we have left. The stack might already be overflowed
   // here which will cause a2 to become negative.
   __ Subu(a2, sp, a2);
@@ -410,7 +409,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
 
     // Initialize all JavaScript callee-saved registers, since they will be seen
     // by the garbage collector as part of handlers.
-    __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(t0, RootIndex::kUndefinedValue);
     __ mov(s1, t0);
     __ mov(s2, t0);
     __ mov(s3, t0);
@@ -491,7 +490,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ LoadRoot(kScratchReg, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
   __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));
 
   // Push receiver.
@@ -558,7 +557,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     FrameScope scope(masm, StackFrame::INTERNAL);
     __ Push(a1, t0);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(a1);
   }
@@ -854,7 +853,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ Subu(t1, sp, Operand(t0));
-    __ LoadRoot(a2, Heap::kRealStackLimitRootIndex);
+    __ LoadRoot(a2, RootIndex::kRealStackLimit);
     __ Branch(&ok, hs, t1, Operand(a2));
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ bind(&ok);
@@ -862,7 +861,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // If ok, push undefined as the initial value for all register file entries.
     Label loop_header;
     Label loop_check;
-    __ LoadRoot(t1, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(t1, RootIndex::kUndefinedValue);
     __ Branch(&loop_check);
     __ bind(&loop_header);
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
@@ -886,7 +885,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator with undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
@@ -934,7 +933,7 @@ static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  __ LoadRoot(scratch1, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(scratch1, RootIndex::kRealStackLimit);
   // Make scratch1 the space we have left. The stack might already be overflowed
   // here which will cause scratch1 to become negative.
   __ subu(scratch1, sp, scratch1);
@@ -983,7 +982,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ mov(t0, a0);  // No receiver.
   }
 
@@ -1191,7 +1190,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
         __ push(t4);
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done);
@@ -1290,15 +1289,10 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Addu(sp, sp, Operand(1 * kPointerSize));  // Remove accumulator.
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ lw(a0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-    __ lw(a0, MemOperand(a0, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ lw(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ lw(a0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a0, MemOperand(a0, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -1310,11 +1304,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   // If the code object is null, just return to the caller.
   __ Ret(eq, v0, Operand(Smi::kZero));
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ LeaveFrame(StackFrame::STUB);
-  }
+  __ LeaveFrame(StackFrame::STUB);
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
@@ -1336,14 +1328,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   __ Ret();
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -1359,7 +1343,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   {
     Label no_arg;
     Register scratch = t0;
-    __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a2, RootIndex::kUndefinedValue);
     __ mov(a3, a2);
     // Lsa() cannot be used hare as scratch value used later.
     __ sll(scratch, a0, kPointerSizeLog2);
@@ -1389,8 +1373,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(a2, Heap::kNullValueRootIndex, &no_arguments);
-  __ JumpIfRoot(a2, Heap::kUndefinedValueRootIndex, &no_arguments);
+  __ JumpIfRoot(a2, RootIndex::kNullValue, &no_arguments);
+  __ JumpIfRoot(a2, RootIndex::kUndefinedValue, &no_arguments);
 
   // 4a. Apply the receiver to the given argArray.
   __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
@@ -1412,7 +1396,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
   {
     Label done;
     __ Branch(&done, ne, a0, Operand(zero_reg));
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ Addu(a0, a0, Operand(1));
     __ bind(&done);
   }
@@ -1462,7 +1446,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   {
     Label no_arg;
     Register scratch = t0;
-    __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a1, RootIndex::kUndefinedValue);
     __ mov(a2, a1);
     __ mov(a3, a1);
     __ sll(scratch, a0, kPointerSizeLog2);
@@ -1514,7 +1498,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   {
     Label no_arg;
     Register scratch = t0;
-    __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a1, RootIndex::kUndefinedValue);
     __ mov(a2, a1);
     // Lsa() cannot be used hare as scratch value used later.
     __ sll(scratch, a0, kPointerSizeLog2);
@@ -1603,32 +1587,20 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   }
 
   // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(t1, Heap::kRealStackLimitRootIndex);
-    // Make ip the space we have left. The stack might already be overflowed
-    // here which will cause ip to become negative.
-    __ Subu(t1, sp, t1);
-    // Check if the arguments will overflow the stack.
-    __ sll(kScratchReg, t0, kPointerSizeLog2);
-    __ Branch(&done, gt, t1, Operand(kScratchReg));  // Signed comparison.
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, t0, kScratchReg, t1, &stack_overflow);
 
   // Push arguments onto the stack (thisArgument is already on the stack).
   {
     __ mov(t2, zero_reg);
     Label done, push, loop;
-    __ LoadRoot(t1, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(t1, RootIndex::kTheHoleValue);
     __ bind(&loop);
     __ Branch(&done, eq, t2, Operand(t0));
     __ Lsa(kScratchReg, a2, t2, kPointerSizeLog2);
     __ lw(kScratchReg, FieldMemOperand(kScratchReg, FixedArray::kHeaderSize));
     __ Branch(&push, ne, t1, Operand(kScratchReg));
-    __ LoadRoot(kScratchReg, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(kScratchReg, RootIndex::kUndefinedValue);
     __ bind(&push);
     __ Push(kScratchReg);
     __ Addu(t2, t2, Operand(1));
@@ -1639,6 +1611,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -1772,9 +1747,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ Branch(&done_convert, hs, t0, Operand(FIRST_JS_RECEIVER_TYPE));
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(a3, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy);
-        __ JumpIfNotRoot(a3, Heap::kNullValueRootIndex, &convert_to_object);
+        __ JumpIfRoot(a3, RootIndex::kUndefinedValue, &convert_global_proxy);
+        __ JumpIfNotRoot(a3, RootIndex::kNullValue, &convert_to_object);
         __ bind(&convert_global_proxy);
         {
           // Patch receiver to global proxy.
@@ -1863,8 +1837,8 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
     __ Subu(sp, sp, Operand(t1));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    __ LoadRoot(kScratchReg, Heap::kRealStackLimitRootIndex);
-    __ Branch(&done, gt, sp, Operand(kScratchReg));  // Signed comparison.
+    __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
+    __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Addu(sp, sp, Operand(t1));
     {
@@ -1973,7 +1947,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // a2 to contain either an AllocationSite or undefined.
-  __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(a2, RootIndex::kUndefinedValue);
 
   Label call_generic_stub;
 
@@ -2021,8 +1995,8 @@ void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
     __ Subu(sp, sp, Operand(t1));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    __ LoadRoot(kScratchReg, Heap::kRealStackLimitRootIndex);
-    __ Branch(&done, gt, sp, Operand(kScratchReg));  // Signed comparison.
+    __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
+    __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Addu(sp, sp, Operand(t1));
     {
@@ -2218,7 +2192,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // a1: function
     // a2: expected number of arguments
     // a3: new target (passed through to callee)
-    __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(t0, RootIndex::kUndefinedValue);
     __ sll(t2, a2, kPointerSizeLog2);
     __ Subu(t1, fp, Operand(t2));
     // Adjust for frame.
@@ -2391,7 +2365,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ LoadRoot(t0, Heap::kExceptionRootIndex);
+  __ LoadRoot(t0, RootIndex::kException);
   __ Branch(&exception_returned, eq, t0, Operand(v0));
 
   // Check that there is no pending exception, otherwise we
@@ -2402,7 +2376,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
         IsolateAddressId::kPendingExceptionAddress, masm->isolate());
     __ li(a2, pending_exception_address);
     __ lw(a2, MemOperand(a2));
-    __ LoadRoot(t0, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(t0, RootIndex::kTheHoleValue);
     // Cannot use check here as it attempts to generate call into runtime.
     __ Branch(&okay, eq, t0, Operand(a2));
     __ stop("Unexpected pending exception");
@@ -2462,9 +2436,9 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ bind(&zero);
 
   // Reset the masking register. This is done independent of the underlying
-  // feature flag {FLAG_branch_load_poisoning} to make the snapshot work with
-  // both configurations. It is safe to always do this, because the underlying
-  // register is caller-saved and can be arbitrarily clobbered.
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
   __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
@@ -2705,6 +2679,10 @@ namespace {
 
 void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
                                           ElementsKind kind) {
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
+
   __ Jump(CodeFactory::InternalArrayNoArgumentConstructor(masm->isolate(), kind)
               .code(),
           RelocInfo::CODE_TARGET, lo, a0, Operand(1));
diff --git a/deps/v8/src/builtins/mips64/builtins-mips64.cc b/deps/v8/src/builtins/mips64/builtins-mips64.cc
index d59f7c0ce5..4f1ba93a99 100644
--- a/deps/v8/src/builtins/mips64/builtins-mips64.cc
+++ b/deps/v8/src/builtins/mips64/builtins-mips64.cc
@@ -56,7 +56,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -108,7 +107,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ SmiUntag(a0);
 
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
 
     // Set up pointer to last argument.
     __ Daddu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
@@ -176,7 +175,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Preserve the incoming parameters on the stack.
     __ SmiTag(a0);
     __ Push(cp, a0, a1);
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ Push(a3);
 
     // ----------- S t a t e -------------
@@ -201,7 +200,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(v0, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(v0, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                          v0: receiver
@@ -291,7 +290,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(v0, Heap::kUndefinedValueRootIndex, &use_receiver);
+    __ JumpIfRoot(v0, RootIndex::kUndefinedValue, &use_receiver);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -313,7 +312,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ Ld(v0, MemOperand(sp, 0 * kPointerSize));
-    __ JumpIfRoot(v0, Heap::kTheHoleValueRootIndex, &do_throw);
+    __ JumpIfRoot(v0, RootIndex::kTheHoleValue, &do_throw);
 
     __ bind(&leave_frame);
     // Restore smi-tagged arguments count from the frame.
@@ -382,7 +381,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ LoadRoot(kScratchReg, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
   __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));
 
   // Push receiver.
@@ -451,7 +450,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     FrameScope scope(masm, StackFrame::INTERNAL);
     __ Push(a1, a4);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(a1);
   }
@@ -488,7 +487,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc) {
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  __ LoadRoot(a2, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(a2, RootIndex::kRealStackLimit);
   // Make a2 the space we have left. The stack might already be overflowed
   // here which will cause r2 to become negative.
   __ dsubu(a2, sp, a2);
@@ -555,7 +554,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
 
     // Initialize all JavaScript callee-saved registers, since they will be seen
     // by the garbage collector as part of handlers.
-    __ LoadRoot(a4, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a4, RootIndex::kUndefinedValue);
     __ mov(s1, a4);
     __ mov(s2, a4);
     __ mov(s3, a4);
@@ -853,7 +852,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ Dsubu(a5, sp, Operand(a4));
-    __ LoadRoot(a2, Heap::kRealStackLimitRootIndex);
+    __ LoadRoot(a2, RootIndex::kRealStackLimit);
     __ Branch(&ok, hs, a5, Operand(a2));
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ bind(&ok);
@@ -861,7 +860,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // If ok, push undefined as the initial value for all register file entries.
     Label loop_header;
     Label loop_check;
-    __ LoadRoot(a5, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a5, RootIndex::kUndefinedValue);
     __ Branch(&loop_check);
     __ bind(&loop_header);
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
@@ -885,7 +884,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator as undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
@@ -933,7 +932,7 @@ static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  __ LoadRoot(scratch1, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(scratch1, RootIndex::kRealStackLimit);
   // Make scratch1 the space we have left. The stack might already be overflowed
   // here which will cause scratch1 to become negative.
   __ dsubu(scratch1, sp, scratch1);
@@ -980,7 +979,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ Dsubu(a3, a3, Operand(1));  // Subtract one for receiver.
   }
 
@@ -1188,7 +1187,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
         __ push(t2);
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done);
@@ -1287,15 +1286,10 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Daddu(sp, sp, Operand(1 * kPointerSize));  // Remove state.
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ Ld(a0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-    __ Ld(a0, MemOperand(a0, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ Ld(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ Ld(a0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ Ld(a0, MemOperand(a0, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -1307,11 +1301,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   // If the code object is null, just return to the caller.
   __ Ret(eq, v0, Operand(Smi::kZero));
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ LeaveFrame(StackFrame::STUB);
-  }
+  __ LeaveFrame(StackFrame::STUB);
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
@@ -1332,14 +1324,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   __ Ret();
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -1356,7 +1340,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   Register undefined_value = a3;
   Register scratch = a4;
 
-  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
 
   // 1. Load receiver into a1, argArray into a2 (if present), remove all
   // arguments from the stack (including the receiver), and push thisArg (if
@@ -1390,7 +1374,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(arg_array, Heap::kNullValueRootIndex, &no_arguments);
+  __ JumpIfRoot(arg_array, RootIndex::kNullValue, &no_arguments);
   __ Branch(&no_arguments, eq, arg_array, Operand(undefined_value));
 
   // 4a. Apply the receiver to the given argArray.
@@ -1414,7 +1398,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
   {
     Label done;
     __ Branch(&done, ne, a0, Operand(zero_reg));
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ Daddu(a0, a0, Operand(1));
     __ bind(&done);
   }
@@ -1465,7 +1449,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   Register undefined_value = a3;
   Register scratch = a4;
 
-  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
 
   // 1. Load target into a1 (if present), argumentsList into a2 (if present),
   // remove all arguments from the stack (including the receiver), and push
@@ -1521,7 +1505,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   Register undefined_value = a4;
   Register scratch = a5;
 
-  __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
 
   // 1. Load target into a1 (if present), argumentsList into a2 (if present),
   // new.target into a3 (if present, otherwise use target), remove all
@@ -1620,20 +1604,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   Register len = a4;
 
   // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(a5, Heap::kRealStackLimitRootIndex);
-    // Make ip the space we have left. The stack might already be overflowed
-    // here which will cause ip to become negative.
-    __ Dsubu(a5, sp, a5);
-    // Check if the arguments will overflow the stack.
-    __ dsll(kScratchReg, len, kPointerSizeLog2);
-    __ Branch(&done, gt, a5, Operand(kScratchReg));  // Signed comparison.
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, len, kScratchReg, a5, &stack_overflow);
 
   // Push arguments onto the stack (thisArgument is already on the stack).
   {
@@ -1646,11 +1618,11 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ Daddu(a0, a0, len);  // The 'len' argument for Call() or Construct().
     __ dsll(scratch, len, kPointerSizeLog2);
     __ Dsubu(scratch, sp, Operand(scratch));
-    __ LoadRoot(t1, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(t1, RootIndex::kTheHoleValue);
     __ bind(&loop);
     __ Ld(a5, MemOperand(src));
     __ Branch(&push, ne, a5, Operand(t1));
-    __ LoadRoot(a5, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a5, RootIndex::kUndefinedValue);
     __ bind(&push);
     __ daddiu(src, src, kPointerSize);
     __ Push(a5);
@@ -1660,6 +1632,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -1793,9 +1768,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ Branch(&done_convert, hs, a4, Operand(FIRST_JS_RECEIVER_TYPE));
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(a3, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy);
-        __ JumpIfNotRoot(a3, Heap::kNullValueRootIndex, &convert_to_object);
+        __ JumpIfRoot(a3, RootIndex::kUndefinedValue, &convert_global_proxy);
+        __ JumpIfNotRoot(a3, RootIndex::kNullValue, &convert_to_object);
         __ bind(&convert_global_proxy);
         {
           // Patch receiver to global proxy.
@@ -1883,8 +1857,8 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
     __ Dsubu(sp, sp, Operand(a5));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    __ LoadRoot(kScratchReg, Heap::kRealStackLimitRootIndex);
-    __ Branch(&done, gt, sp, Operand(kScratchReg));  // Signed comparison.
+    __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
+    __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Daddu(sp, sp, Operand(a5));
     {
@@ -1990,7 +1964,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // a2 to contain either an AllocationSite or undefined.
-  __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(a2, RootIndex::kUndefinedValue);
 
   Label call_generic_stub;
 
@@ -2037,8 +2011,8 @@ void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
     __ Dsubu(sp, sp, Operand(a5));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    __ LoadRoot(kScratchReg, Heap::kRealStackLimitRootIndex);
-    __ Branch(&done, gt, sp, Operand(kScratchReg));  // Signed comparison.
+    __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
+    __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Daddu(sp, sp, Operand(a5));
     {
@@ -2235,7 +2209,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // a1: function
     // a2: expected number of arguments
     // a3: new target (passed through to callee)
-    __ LoadRoot(a5, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(a5, RootIndex::kUndefinedValue);
     __ dsll(a6, a2, kPointerSizeLog2);
     __ Dsubu(a4, fp, Operand(a6));
     // Adjust for frame.
@@ -2409,7 +2383,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ LoadRoot(a4, Heap::kExceptionRootIndex);
+  __ LoadRoot(a4, RootIndex::kException);
   __ Branch(&exception_returned, eq, a4, Operand(v0));
 
   // Check that there is no pending exception, otherwise we
@@ -2420,7 +2394,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
         IsolateAddressId::kPendingExceptionAddress, masm->isolate());
     __ li(a2, pending_exception_address);
     __ Ld(a2, MemOperand(a2));
-    __ LoadRoot(a4, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(a4, RootIndex::kTheHoleValue);
     // Cannot use check here as it attempts to generate call into runtime.
     __ Branch(&okay, eq, a4, Operand(a2));
     __ stop("Unexpected pending exception");
@@ -2480,9 +2454,9 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ bind(&zero);
 
   // Reset the masking register. This is done independent of the underlying
-  // feature flag {FLAG_branch_load_poisoning} to make the snapshot work with
-  // both configurations. It is safe to always do this, because the underlying
-  // register is caller-saved and can be arbitrarily clobbered.
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
   __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
@@ -2724,6 +2698,10 @@ namespace {
 
 void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
                                           ElementsKind kind) {
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
+
   __ Jump(CodeFactory::InternalArrayNoArgumentConstructor(masm->isolate(), kind)
               .code(),
           RelocInfo::CODE_TARGET, lo, a0, Operand(1));
diff --git a/deps/v8/src/builtins/ppc/builtins-ppc.cc b/deps/v8/src/builtins/ppc/builtins-ppc.cc
index 01a0e4e371..4446f81e58 100644
--- a/deps/v8/src/builtins/ppc/builtins-ppc.cc
+++ b/deps/v8/src/builtins/ppc/builtins-ppc.cc
@@ -53,8 +53,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  // tail call a stub
-  __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -109,7 +107,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ Push(cp, r3);
     __ SmiUntag(r3, SetRC);
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     // Set up pointer to last argument.
     __ addi(r7, fp, Operand(StandardFrameConstants::kCallerSPOffset));
 
@@ -184,7 +182,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Preserve the incoming parameters on the stack.
     __ SmiTag(r3);
     __ Push(cp, r3, r4);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ Push(r6);
 
     // ----------- S t a t e -------------
@@ -209,7 +207,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(r3, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(r3, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                          r3: receiver
@@ -303,7 +301,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(r3, Heap::kUndefinedValueRootIndex, &use_receiver);
+    __ JumpIfRoot(r3, RootIndex::kUndefinedValue, &use_receiver);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -325,7 +323,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ LoadP(r3, MemOperand(sp));
-    __ JumpIfRoot(r3, Heap::kTheHoleValueRootIndex, &do_throw);
+    __ JumpIfRoot(r3, RootIndex::kTheHoleValue, &do_throw);
 
     __ bind(&leave_frame);
     // Restore smi-tagged arguments count from the frame.
@@ -402,7 +400,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+  __ CompareRoot(sp, RootIndex::kRealStackLimit);
   __ blt(&stack_overflow);
 
   // Push receiver.
@@ -468,7 +466,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
     __ Push(r4, r7);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(r4);
     __ LoadP(r7, FieldMemOperand(r4, JSGeneratorObject::kFunctionOffset));
@@ -505,7 +503,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc) {
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  __ LoadRoot(r5, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(r5, RootIndex::kRealStackLimit);
   // Make r5 the space we have left. The stack might already be overflowed
   // here which will cause r5 to become negative.
   __ sub(r5, sp, r5);
@@ -573,7 +571,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
 
     // Initialize all JavaScript callee-saved registers, since they will be seen
     // by the garbage collector as part of handlers.
-    __ LoadRoot(r7, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r7, RootIndex::kUndefinedValue);
     __ mr(r14, r7);
     __ mr(r15, r7);
     __ mr(r16, r7);
@@ -887,7 +885,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ sub(r8, sp, r5);
-    __ LoadRoot(r0, Heap::kRealStackLimitRootIndex);
+    __ LoadRoot(r0, RootIndex::kRealStackLimit);
     __ cmpl(r8, r0);
     __ bge(&ok);
     __ CallRuntime(Runtime::kThrowStackOverflow);
@@ -896,7 +894,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // If ok, push undefined as the initial value for all register file entries.
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
     Label loop, no_args;
-    __ LoadRoot(r8, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r8, RootIndex::kUndefinedValue);
     __ ShiftRightImm(r5, r5, Operand(kPointerSizeLog2), SetRC);
     __ beq(&no_args, cr0);
     __ mtctr(r5);
@@ -920,7 +918,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator with undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
   Label do_dispatch;
@@ -968,7 +966,7 @@ static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  __ LoadRoot(scratch, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(scratch, RootIndex::kRealStackLimit);
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
   __ sub(scratch, sp, scratch);
@@ -1014,7 +1012,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ mr(r6, r3);  // Argument count is correct.
   }
 
@@ -1227,7 +1225,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
         __ push(r7);
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done);
@@ -1327,15 +1325,10 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Ret();
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ LoadP(r3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-    __ LoadP(r3, MemOperand(r3, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ LoadP(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ LoadP(r3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ LoadP(r3, MemOperand(r3, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
@@ -1352,11 +1345,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
 
   __ bind(&skip);
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ LeaveFrame(StackFrame::STUB);
-  }
+  __ LeaveFrame(StackFrame::STUB);
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
@@ -1386,14 +1377,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   }
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -1413,7 +1396,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
     Register scratch = r7;
     __ ShiftLeftImm(arg_size, r3, Operand(kPointerSizeLog2));
     __ add(new_sp, sp, arg_size);
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
     __ mr(r5, scratch);
     __ LoadP(r4, MemOperand(new_sp, 0));  // receiver
     __ cmpi(arg_size, Operand(kPointerSize));
@@ -1438,8 +1421,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(r5, Heap::kNullValueRootIndex, &no_arguments);
-  __ JumpIfRoot(r5, Heap::kUndefinedValueRootIndex, &no_arguments);
+  __ JumpIfRoot(r5, RootIndex::kNullValue, &no_arguments);
+  __ JumpIfRoot(r5, RootIndex::kUndefinedValue, &no_arguments);
 
   // 4a. Apply the receiver to the given argArray.
   __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
@@ -1462,7 +1445,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     Label done;
     __ cmpi(r3, Operand::Zero());
     __ bne(&done);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ addi(r3, r3, Operand(1));
     __ bind(&done);
   }
@@ -1517,7 +1500,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
     Register scratch = r7;
     __ ShiftLeftImm(arg_size, r3, Operand(kPointerSizeLog2));
     __ add(new_sp, sp, arg_size);
-    __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r4, RootIndex::kUndefinedValue);
     __ mr(scratch, r4);
     __ mr(r5, r4);
     __ cmpi(arg_size, Operand(kPointerSize));
@@ -1567,7 +1550,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
     Register new_sp = r7;
     __ ShiftLeftImm(arg_size, r3, Operand(kPointerSizeLog2));
     __ add(new_sp, sp, arg_size);
-    __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r4, RootIndex::kUndefinedValue);
     __ mr(r5, r4);
     __ mr(r6, r4);
     __ StoreP(r4, MemOperand(new_sp, 0));  // receiver (undefined)
@@ -1666,21 +1649,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   }
 
   // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(ip, Heap::kRealStackLimitRootIndex);
-    // Make ip the space we have left. The stack might already be overflowed
-    // here which will cause ip to become negative.
-    __ sub(ip, sp, ip);
-    // Check if the arguments will overflow the stack.
-    __ ShiftLeftImm(r0, r7, Operand(kPointerSizeLog2));
-    __ cmp(ip, r0);  // Signed comparison.
-    __ bgt(&done);
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, r7, ip, &stack_overflow);
 
   // Push arguments onto the stack (thisArgument is already on the stack).
   {
@@ -1692,9 +1662,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ mtctr(r7);
     __ bind(&loop);
     __ LoadPU(ip, MemOperand(r5, kPointerSize));
-    __ CompareRoot(ip, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(ip, RootIndex::kTheHoleValue);
     __ bne(&skip);
-    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(ip, RootIndex::kUndefinedValue);
     __ bind(&skip);
     __ push(ip);
     __ bdnz(&loop);
@@ -1704,6 +1674,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -1840,9 +1813,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ bge(&done_convert);
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(r6, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy);
-        __ JumpIfNotRoot(r6, Heap::kNullValueRootIndex, &convert_to_object);
+        __ JumpIfRoot(r6, RootIndex::kUndefinedValue, &convert_global_proxy);
+        __ JumpIfNotRoot(r6, RootIndex::kNullValue, &convert_to_object);
         __ bind(&convert_global_proxy);
         {
           // Patch receiver to global proxy.
@@ -1930,7 +1902,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+      __ CompareRoot(sp, RootIndex::kRealStackLimit);
       __ bgt(&done);  // Signed comparison.
       // Restore the stack pointer.
       __ mr(sp, r9);
@@ -2062,7 +2034,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // r5 to contain either an AllocationSite or undefined.
-  __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(r5, RootIndex::kUndefinedValue);
 
   Label call_generic_stub;
 
@@ -2246,7 +2218,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // r4: function
     // r5: expected number of arguments
     // r6: new target (passed through to callee)
-    __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r0, RootIndex::kUndefinedValue);
     __ ShiftLeftImm(r7, r5, Operand(kPointerSizeLog2));
     __ sub(r7, fp, r7);
     // Adjust for frame.
@@ -2435,7 +2407,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ CompareRoot(r3, Heap::kExceptionRootIndex);
+  __ CompareRoot(r3, RootIndex::kException);
   __ beq(&exception_returned);
 
   // Check that there is no pending exception, otherwise we
@@ -2447,7 +2419,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
     __ Move(r6, pending_exception_address);
     __ LoadP(r6, MemOperand(r6));
-    __ CompareRoot(r6, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(r6, RootIndex::kTheHoleValue);
     // Cannot use check here as it attempts to generate call into runtime.
     __ beq(&okay);
     __ stop("Unexpected pending exception");
@@ -2512,10 +2484,11 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ StoreP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   __ bind(&skip);
 
-  // Reset the masking register.
-  if (FLAG_branch_load_poisoning) {
-    __ ResetSpeculationPoisonRegister();
-  }
+  // Reset the masking register. This is done independent of the underlying
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
+  __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
   ConstantPoolUnavailableScope constant_pool_unavailable(masm);
@@ -2743,6 +2716,10 @@ namespace {
 
 void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
                                           ElementsKind kind) {
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
+
   __ cmpli(r3, Operand(1));
 
   __ Jump(CodeFactory::InternalArrayNoArgumentConstructor(masm->isolate(), kind)
diff --git a/deps/v8/src/builtins/s390/builtins-s390.cc b/deps/v8/src/builtins/s390/builtins-s390.cc
index b92011c38b..198ba0971d 100644
--- a/deps/v8/src/builtins/s390/builtins-s390.cc
+++ b/deps/v8/src/builtins/s390/builtins-s390.cc
@@ -53,8 +53,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  // tail call a stub
-  __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -108,7 +106,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ Push(cp, r2);
     __ SmiUntag(r2);
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     // Set up pointer to last argument.
     __ la(r6, MemOperand(fp, StandardFrameConstants::kCallerSPOffset));
 
@@ -178,7 +176,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Preserve the incoming parameters on the stack.
     __ SmiTag(r2);
     __ Push(cp, r2, r3);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ Push(r5);
 
     // ----------- S t a t e -------------
@@ -203,7 +201,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(r2, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(r2, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  --                          r2: receiver
@@ -295,7 +293,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(r2, Heap::kUndefinedValueRootIndex, &use_receiver);
+    __ JumpIfRoot(r2, RootIndex::kUndefinedValue, &use_receiver);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -317,7 +315,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ LoadP(r2, MemOperand(sp));
-    __ JumpIfRoot(r2, Heap::kTheHoleValueRootIndex, &do_throw);
+    __ JumpIfRoot(r2, RootIndex::kTheHoleValue, &do_throw);
 
     __ bind(&leave_frame);
     // Restore smi-tagged arguments count from the frame.
@@ -393,7 +391,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+  __ CompareRoot(sp, RootIndex::kRealStackLimit);
   __ blt(&stack_overflow);
 
   // Push receiver.
@@ -468,7 +466,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
     __ Push(r3, r6);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(r3);
     __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
@@ -505,7 +503,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc) {
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  __ LoadRoot(r4, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(r4, RootIndex::kRealStackLimit);
   // Make r4 the space we have left. The stack might already be overflowed
   // here which will cause r4 to become negative.
   __ SubP(r4, sp, r4);
@@ -581,7 +579,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
 
     // Initialize all JavaScript callee-saved registers, since they will be seen
     // by the garbage collector as part of handlers.
-    __ LoadRoot(r6, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r6, RootIndex::kUndefinedValue);
     __ LoadRR(r7, r6);
     __ LoadRR(r8, r6);
     __ LoadRR(r9, r6);
@@ -890,7 +888,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     Label ok;
     __ SubP(r8, sp, r4);
-    __ LoadRoot(r0, Heap::kRealStackLimitRootIndex);
+    __ LoadRoot(r0, RootIndex::kRealStackLimit);
     __ CmpLogicalP(r8, r0);
     __ bge(&ok);
     __ CallRuntime(Runtime::kThrowStackOverflow);
@@ -899,7 +897,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // If ok, push undefined as the initial value for all register file entries.
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
     Label loop, no_args;
-    __ LoadRoot(r8, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r8, RootIndex::kUndefinedValue);
     __ ShiftRightP(r4, r4, Operand(kPointerSizeLog2));
     __ LoadAndTestP(r4, r4);
     __ beq(&no_args);
@@ -924,7 +922,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator with undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
   Label do_dispatch;
@@ -973,7 +971,7 @@ static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  __ LoadRoot(scratch, Heap::kRealStackLimitRootIndex);
+  __ LoadRoot(scratch, RootIndex::kRealStackLimit);
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
   __ SubP(scratch, sp, scratch);
@@ -1020,7 +1018,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ LoadRR(r5, r2);  // Argument count is correct.
   }
 
@@ -1230,7 +1228,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
         __ push(r6);
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done);
@@ -1329,15 +1327,10 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Ret();
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ LoadP(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-    __ LoadP(r2, MemOperand(r2, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ LoadP(r2, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ LoadP(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ LoadP(r2, MemOperand(r2, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -1354,11 +1347,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
 
   __ bind(&skip);
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ LeaveFrame(StackFrame::STUB);
-  }
+  __ LeaveFrame(StackFrame::STUB);
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
@@ -1380,14 +1371,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   __ Ret();
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 // static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
@@ -1407,7 +1390,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
     Register scratch = r6;
     __ ShiftLeftP(arg_size, r2, Operand(kPointerSizeLog2));
     __ AddP(new_sp, sp, arg_size);
-    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
     __ LoadRR(r4, scratch);
     __ LoadP(r3, MemOperand(new_sp, 0));  // receiver
     __ CmpP(arg_size, Operand(kPointerSize));
@@ -1432,8 +1415,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(r4, Heap::kNullValueRootIndex, &no_arguments);
-  __ JumpIfRoot(r4, Heap::kUndefinedValueRootIndex, &no_arguments);
+  __ JumpIfRoot(r4, RootIndex::kNullValue, &no_arguments);
+  __ JumpIfRoot(r4, RootIndex::kUndefinedValue, &no_arguments);
 
   // 4a. Apply the receiver to the given argArray.
   __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
@@ -1456,7 +1439,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     Label done;
     __ CmpP(r2, Operand::Zero());
     __ bne(&done, Label::kNear);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ AddP(r2, Operand(1));
     __ bind(&done);
   }
@@ -1511,7 +1494,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
     Register scratch = r6;
     __ ShiftLeftP(arg_size, r2, Operand(kPointerSizeLog2));
     __ AddP(new_sp, sp, arg_size);
-    __ LoadRoot(r3, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r3, RootIndex::kUndefinedValue);
     __ LoadRR(scratch, r3);
     __ LoadRR(r4, r3);
     __ CmpP(arg_size, Operand(kPointerSize));
@@ -1561,7 +1544,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
     Register new_sp = r6;
     __ ShiftLeftP(arg_size, r2, Operand(kPointerSizeLog2));
     __ AddP(new_sp, sp, arg_size);
-    __ LoadRoot(r3, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r3, RootIndex::kUndefinedValue);
     __ LoadRR(r4, r3);
     __ LoadRR(r5, r3);
     __ StoreP(r3, MemOperand(new_sp, 0));  // receiver (undefined)
@@ -1670,21 +1653,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   }
 
   // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(ip, Heap::kRealStackLimitRootIndex);
-    // Make ip the space we have left. The stack might already be overflowed
-    // here which will cause ip to become negative.
-    __ SubP(ip, sp, ip);
-    // Check if the arguments will overflow the stack.
-    __ ShiftLeftP(r0, r6, Operand(kPointerSizeLog2));
-    __ CmpP(ip, r0);  // Signed comparison.
-    __ bgt(&done);
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, r6, ip, &stack_overflow);
 
   // Push arguments onto the stack (thisArgument is already on the stack).
   {
@@ -1697,9 +1667,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ bind(&loop);
     __ LoadP(ip, MemOperand(r4, kPointerSize));
     __ la(r4, MemOperand(r4, kPointerSize));
-    __ CompareRoot(ip, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(ip, RootIndex::kTheHoleValue);
     __ bne(&skip, Label::kNear);
-    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(ip, RootIndex::kUndefinedValue);
     __ bind(&skip);
     __ push(ip);
     __ BranchOnCount(r1, &loop);
@@ -1709,6 +1679,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -1845,9 +1818,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ bge(&done_convert);
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(r5, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy);
-        __ JumpIfNotRoot(r5, Heap::kNullValueRootIndex, &convert_to_object);
+        __ JumpIfRoot(r5, RootIndex::kUndefinedValue, &convert_global_proxy);
+        __ JumpIfNotRoot(r5, RootIndex::kNullValue, &convert_to_object);
         __ bind(&convert_global_proxy);
         {
           // Patch receiver to global proxy.
@@ -1936,7 +1908,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CompareRoot(sp, Heap::kRealStackLimitRootIndex);
+      __ CompareRoot(sp, RootIndex::kRealStackLimit);
       __ bgt(&done);  // Signed comparison.
       // Restore the stack pointer.
       __ LoadRR(sp, r8);
@@ -2069,7 +2041,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // r4 to contain either an AllocationSite or undefined.
-  __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(r4, RootIndex::kUndefinedValue);
 
   Label call_generic_stub;
 
@@ -2251,7 +2223,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // Fill the remaining expected arguments with undefined.
     // r3: function
     // r4: expected number of argumentus
-    __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r0, RootIndex::kUndefinedValue);
     __ ShiftLeftP(r6, r4, Operand(kPointerSizeLog2));
     __ SubP(r6, fp, r6);
     // Adjust for frame.
@@ -2408,6 +2380,9 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
     __ LoadRR(r3, r2);
     __ la(r2, MemOperand(sp, (kStackFrameExtraParamSlot + 1) * kPointerSize));
     isolate_reg = r5;
+    // Clang doesn't preserve r2 (result buffer)
+    // write to r8 (preserved) before entry
+    __ LoadRR(r8, r2);
   }
   // Call C built-in.
   __ Move(isolate_reg, ExternalReference::isolate_address(masm->isolate()));
@@ -2433,13 +2408,14 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // If return value is on the stack, pop it to registers.
   if (needs_return_buffer) {
+    __ LoadRR(r2, r8);
     __ LoadP(r3, MemOperand(r2, kPointerSize));
     __ LoadP(r2, MemOperand(r2));
   }
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ CompareRoot(r2, Heap::kExceptionRootIndex);
+  __ CompareRoot(r2, RootIndex::kException);
   __ beq(&exception_returned, Label::kNear);
 
   // Check that there is no pending exception, otherwise we
@@ -2450,7 +2426,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
         IsolateAddressId::kPendingExceptionAddress, masm->isolate());
     __ Move(r1, pending_exception_address);
     __ LoadP(r1, MemOperand(r1));
-    __ CompareRoot(r1, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(r1, RootIndex::kTheHoleValue);
     // Cannot use check here as it attempts to generate call into runtime.
     __ beq(&okay, Label::kNear);
     __ stop("Unexpected pending exception");
@@ -2511,10 +2487,11 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ StoreP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   __ bind(&skip);
 
-  // Reset the masking register.
-  if (FLAG_branch_load_poisoning) {
-    __ ResetSpeculationPoisonRegister();
-  }
+  // Reset the masking register. This is done independent of the underlying
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
+  __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
   __ Move(r3, pending_handler_entrypoint_address);
@@ -2729,6 +2706,10 @@ namespace {
 
 void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
                                           ElementsKind kind) {
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
+
   __ CmpLogicalP(r2, Operand(1));
 
   __ Jump(CodeFactory::InternalArrayNoArgumentConstructor(masm->isolate(), kind)
diff --git a/deps/v8/src/builtins/setup-builtins-internal.cc b/deps/v8/src/builtins/setup-builtins-internal.cc
index 93a2b8b5f3..630473f407 100644
--- a/deps/v8/src/builtins/setup-builtins-internal.cc
+++ b/deps/v8/src/builtins/setup-builtins-internal.cc
@@ -12,6 +12,7 @@
 #include "src/interface-descriptors.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/interpreter/interpreter-generator.h"
+#include "src/interpreter/interpreter.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 #include "src/objects/shared-function-info.h"
@@ -26,6 +27,7 @@ BUILTIN_LIST_C(FORWARD_DECLARE)
 #undef FORWARD_DECLARE
 
 namespace {
+
 void PostBuildProfileAndTracing(Isolate* isolate, Code* code,
                                 const char* name) {
   PROFILE(isolate, CodeCreateEvent(CodeEventListener::BUILTIN_TAG,
@@ -48,10 +50,11 @@ AssemblerOptions BuiltinAssemblerOptions(Isolate* isolate,
     return options;
   }
 
-  CodeRange* code_range = isolate->heap()->memory_allocator()->code_range();
+  const base::AddressRegion& code_range =
+      isolate->heap()->memory_allocator()->code_range();
   bool pc_relative_calls_fit_in_code_range =
-      code_range->valid() &&
-      code_range->size() <= kMaxPCRelativeCodeRangeInMB * MB;
+      !code_range.is_empty() &&
+      code_range.size() <= kMaxPCRelativeCodeRangeInMB * MB;
 
   options.isolate_independent_code = true;
   options.use_pc_relative_calls_and_jumps = pc_relative_calls_fit_in_code_range;
@@ -180,6 +183,7 @@ Code* BuildWithCodeStubAssemblerCS(Isolate* isolate, int32_t builtin_index,
   PostBuildProfileAndTracing(isolate, *code, name);
   return *code;
 }
+
 }  // anonymous namespace
 
 // static
@@ -246,26 +250,36 @@ void SetupIsolateDelegate::ReplacePlaceholders(Isolate* isolate) {
   }
 }
 
-#ifdef V8_EMBEDDED_BYTECODE_HANDLERS
 namespace {
+
 Code* GenerateBytecodeHandler(Isolate* isolate, int builtin_index,
-                              const char* name, interpreter::Bytecode bytecode,
-                              interpreter::OperandScale operand_scale) {
-  if (!interpreter::Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) {
-    // TODO(v8:8068): Consider returning something else to avoid placeholders
-    // being serialized with the snapshot.
-    return nullptr;
-  }
+                              const char* name,
+                              interpreter::OperandScale operand_scale,
+                              interpreter::Bytecode bytecode) {
+  DCHECK(interpreter::Bytecodes::BytecodeHasHandler(bytecode, operand_scale));
 
   Handle<Code> code = interpreter::GenerateBytecodeHandler(
-      isolate, bytecode, operand_scale, builtin_index);
+      isolate, bytecode, operand_scale, builtin_index,
+      BuiltinAssemblerOptions(isolate, builtin_index));
 
   PostBuildProfileAndTracing(isolate, *code, name);
 
   return *code;
 }
+
+Code* GenerateLazyBytecodeHandler(Isolate* isolate, int builtin_index,
+                                  const char* name,
+                                  interpreter::OperandScale operand_scale) {
+  Handle<Code> code = interpreter::GenerateDeserializeLazyHandler(
+      isolate, operand_scale, builtin_index,
+      BuiltinAssemblerOptions(isolate, builtin_index));
+
+  PostBuildProfileAndTracing(isolate, *code, name);
+
+  return *code;
+}
+
 }  // namespace
-#endif
 
 // static
 void SetupIsolateDelegate::SetupBuiltinsInternal(Isolate* isolate) {
@@ -309,19 +323,15 @@ void SetupIsolateDelegate::SetupBuiltinsInternal(Isolate* isolate) {
       CallDescriptors::InterfaceDescriptor, #Name, 1);     \
   AddBuiltin(builtins, index++, code);
 
-#define BUILD_BCH_WITH_SCALE(Code, Scale)                               \
+#define BUILD_BCH(Name, OperandScale, Bytecode)                         \
   code = GenerateBytecodeHandler(isolate, index, Builtins::name(index), \
-                                 interpreter::Bytecode::k##Code,        \
-                                 interpreter::OperandScale::k##Scale);  \
-  if (code) {                                                           \
-    AddBuiltin(builtins, index, code);                                  \
-  }                                                                     \
-  ++index;
-
-#define BUILD_BCH(Code, ...)         \
-  BUILD_BCH_WITH_SCALE(Code, Single) \
-  BUILD_BCH_WITH_SCALE(Code, Double) \
-  BUILD_BCH_WITH_SCALE(Code, Quadruple)
+                                 OperandScale, Bytecode);               \
+  AddBuiltin(builtins, index++, code);
+
+#define BUILD_DLH(Name, OperandScale)                                       \
+  code = GenerateLazyBytecodeHandler(isolate, index, Builtins::name(index), \
+                                     OperandScale);                         \
+  AddBuiltin(builtins, index++, code);
 
 #define BUILD_ASM(Name)                                                     \
   code = BuildWithMacroAssembler(isolate, index, Builtins::Generate_##Name, \
@@ -329,7 +339,7 @@ void SetupIsolateDelegate::SetupBuiltinsInternal(Isolate* isolate) {
   AddBuiltin(builtins, index++, code);
 
   BUILTIN_LIST(BUILD_CPP, BUILD_API, BUILD_TFJ, BUILD_TFC, BUILD_TFS, BUILD_TFH,
-               BUILD_BCH, BUILD_ASM);
+               BUILD_BCH, BUILD_DLH, BUILD_ASM);
 
 #undef BUILD_CPP
 #undef BUILD_API
@@ -338,7 +348,7 @@ void SetupIsolateDelegate::SetupBuiltinsInternal(Isolate* isolate) {
 #undef BUILD_TFS
 #undef BUILD_TFH
 #undef BUILD_BCH
-#undef BUILD_BCH_WITH_SCALE
+#undef BUILD_DLH
 #undef BUILD_ASM
   CHECK_EQ(Builtins::builtin_count, index);
 
diff --git a/deps/v8/src/builtins/typed-array.tq b/deps/v8/src/builtins/typed-array.tq
index 7552b094e7..b3ff7dbca1 100644
--- a/deps/v8/src/builtins/typed-array.tq
+++ b/deps/v8/src/builtins/typed-array.tq
@@ -16,7 +16,7 @@ module typed_array {
   type LoadFn = builtin(Context, JSTypedArray, Smi) => Object;
   type StoreFn = builtin(Context, JSTypedArray, Smi, Object) => Object;
 
-  macro KindForArrayType<T : type>(): constexpr ElementsKind;
+  macro KindForArrayType<T: type>(): constexpr ElementsKind;
   KindForArrayType<FixedUint8Array>(): constexpr ElementsKind {
     return UINT8_ELEMENTS;
   }
@@ -51,17 +51,17 @@ module typed_array {
     return BIGINT64_ELEMENTS;
   }
 
-  builtin LoadFixedElement<T : type>(
+  builtin LoadFixedElement<T: type>(
       context: Context, array: JSTypedArray, index: Smi): Object {
     return LoadFixedTypedArrayElementAsTagged(
         array.data_ptr, index, KindForArrayType<T>(), SMI_PARAMETERS);
   }
 
-  builtin StoreFixedElement<T : type>(
+  builtin StoreFixedElement<T: type>(
       context: Context, array: JSTypedArray, index: Smi,
       value: Object): Object {
     const elements: FixedTypedArrayBase =
-        unsafe_cast<FixedTypedArrayBase>(array.elements);
+        UnsafeCast<FixedTypedArrayBase>(array.elements);
     StoreFixedTypedArrayElementFromTagged(
         context, elements, index, value, KindForArrayType<T>(), SMI_PARAMETERS);
     return Undefined;
@@ -69,7 +69,8 @@ module typed_array {
 
   macro CallCompareWithDetachedCheck(
       context: Context, array: JSTypedArray, comparefn: Callable, a: Object,
-      b: Object): Number labels Detached {
+      b: Object): Number
+      labels Detached {
     // a. Let v be ? ToNumber(? Call(comparefn, undefined, x, y)).
     const v: Number =
         ToNumber_Inline(context, Call(context, comparefn, Undefined, a, b));
@@ -86,37 +87,37 @@ module typed_array {
 
   // InsertionSort is used for smaller arrays.
   macro TypedArrayInsertionSort(
-      context: Context, array: JSTypedArray, from_arg: Smi, to_arg: Smi,
-      comparefn: Callable, Load: LoadFn, Store: StoreFn)
+      context: Context, array: JSTypedArray, fromArg: Smi, toArg: Smi,
+      comparefn: Callable, load: LoadFn, store: StoreFn)
   labels Detached {
-    let from: Smi = from_arg;
-    let to: Smi = to_arg;
+    let from: Smi = fromArg;
+    let to: Smi = toArg;
 
     if (IsDetachedBuffer(array.buffer)) goto Detached;
 
     for (let i: Smi = from + 1; i < to; ++i) {
-      const element: Object = Load(context, array, i);
+      const element: Object = load(context, array, i);
       let j: Smi = i - 1;
       for (; j >= from; --j) {
-        const tmp: Object = Load(context, array, j);
+        const tmp: Object = load(context, array, j);
         const order: Number = CallCompareWithDetachedCheck(
             context, array, comparefn, tmp, element) otherwise Detached;
         if (order > 0) {
-          Store(context, array, j + 1, tmp);
+          store(context, array, j + 1, tmp);
         } else {
           break;
         }
       }
-      Store(context, array, j + 1, element);
+      store(context, array, j + 1, element);
     }
   }
 
   macro TypedArrayQuickSortImpl(
-      context: Context, array: JSTypedArray, from_arg: Smi, to_arg: Smi,
-      comparefn: Callable, Load: LoadFn, Store: StoreFn)
+      context: Context, array: JSTypedArray, fromArg: Smi, toArg: Smi,
+      comparefn: Callable, load: LoadFn, store: StoreFn)
   labels Detached {
-    let from: Smi = from_arg;
-    let to: Smi = to_arg;
+    let from: Smi = fromArg;
+    let to: Smi = toArg;
 
     while (to - from > 1) {
       if (to - from <= 10) {
@@ -124,21 +125,21 @@ module typed_array {
         //               Currently it does not make any difference when the
         //               benchmarks are run locally.
         TypedArrayInsertionSort(
-            context, array, from, to, comparefn, Load, Store)
-        otherwise Detached;
+            context, array, from, to, comparefn, load, store)
+            otherwise Detached;
         break;
       }
 
-      // TODO(szuend): Check if a more involved third_index calculation is
+      // TODO(szuend): Check if a more involved thirdIndex calculation is
       //               worth it for very large arrays.
-      const third_index: Smi = from + ((to - from) >>> 1);
+      const thirdIndex: Smi = from + ((to - from) >>> 1);
 
       if (IsDetachedBuffer(array.buffer)) goto Detached;
 
       // Find a pivot as the median of first, last and middle element.
-      let v0: Object = Load(context, array, from);
-      let v1: Object = Load(context, array, to - 1);
-      let v2: Object = Load(context, array, third_index);
+      let v0: Object = load(context, array, from);
+      let v1: Object = load(context, array, to - 1);
+      let v2: Object = load(context, array, thirdIndex);
 
       const c01: Number = CallCompareWithDetachedCheck(
           context, array, comparefn, v0, v1) otherwise Detached;
@@ -170,81 +171,82 @@ module typed_array {
       }
 
       // v0 <= v1 <= v2.
-      Store(context, array, from, v0);
-      Store(context, array, to - 1, v2);
+      store(context, array, from, v0);
+      store(context, array, to - 1, v2);
 
       const pivot: Object = v1;
-      let low_end: Smi = from + 1;   // Upper bound of elems lower than pivot.
-      let high_start: Smi = to - 1;  // Lower bound of elems greater than pivot.
+      let lowEnd: Smi = from + 1;   // Upper bound of elems lower than pivot.
+      let highStart: Smi = to - 1;  // Lower bound of elems greater than pivot.
 
-      let low_end_value: Object = Load(context, array, low_end);
-      Store(context, array, third_index, low_end_value);
-      Store(context, array, low_end, pivot);
+      let lowEndValue: Object = load(context, array, lowEnd);
+      store(context, array, thirdIndex, lowEndValue);
+      store(context, array, lowEnd, pivot);
 
-      // From low_end to idx are elements equal to pivot.
-      // From idx to high_start are elements that haven"t been compared yet.
-      for (let idx: Smi = low_end + 1; idx < high_start; idx++) {
-        let element: Object = Load(context, array, idx);
+      // From lowEnd to idx are elements equal to pivot.
+      // From idx to highStart are elements that haven"t been compared yet.
+      for (let idx: Smi = lowEnd + 1; idx < highStart; idx++) {
+        let element: Object = load(context, array, idx);
         let order: Number = CallCompareWithDetachedCheck(
             context, array, comparefn, element, pivot) otherwise Detached;
 
         if (order < 0) {
-          low_end_value = Load(context, array, low_end);
-          Store(context, array, idx, low_end_value);
-          Store(context, array, low_end, element);
-          low_end++;
+          lowEndValue = load(context, array, lowEnd);
+          store(context, array, idx, lowEndValue);
+          store(context, array, lowEnd, element);
+          lowEnd++;
         } else if (order > 0) {
-          let break_for: bool = false;
+          let breakFor: bool = false;
 
           while (order > 0) {
-            high_start--;
-            if (high_start == idx) {
-              break_for = true;
+            highStart--;
+            if (highStart == idx) {
+              breakFor = true;
               break;
             }
 
-            const top_elem: Object = Load(context, array, high_start);
+            const topElement: Object = load(context, array, highStart);
             order = CallCompareWithDetachedCheck(
-                context, array, comparefn, top_elem, pivot) otherwise Detached;
+                context, array, comparefn, topElement, pivot)
+                otherwise Detached;
           }
 
-          if (break_for) {
+          if (breakFor) {
             break;
           }
 
-          const high_start_value: Object = Load(context, array, high_start);
-          Store(context, array, idx, high_start_value);
-          Store(context, array, high_start, element);
+          const highStartValue: Object = load(context, array, highStart);
+          store(context, array, idx, highStartValue);
+          store(context, array, highStart, element);
 
           if (order < 0) {
-            element = Load(context, array, idx);
+            element = load(context, array, idx);
 
-            low_end_value = Load(context, array, low_end);
-            Store(context, array, idx, low_end_value);
-            Store(context, array, low_end, element);
-            low_end++;
+            lowEndValue = load(context, array, lowEnd);
+            store(context, array, idx, lowEndValue);
+            store(context, array, lowEnd, element);
+            lowEnd++;
           }
         }
       }
 
-      if ((to - high_start) < (low_end - from)) {
+      if ((to - highStart) < (lowEnd - from)) {
         TypedArrayQuickSort(
-            context, array, high_start, to, comparefn, Load, Store);
-        to = low_end;
+            context, array, highStart, to, comparefn, load, store);
+        to = lowEnd;
       } else {
         TypedArrayQuickSort(
-            context, array, from, low_end, comparefn, Load, Store);
-        from = high_start;
+            context, array, from, lowEnd, comparefn, load, store);
+        from = highStart;
       }
     }
   }
 
   builtin TypedArrayQuickSort(
       context: Context, array: JSTypedArray, from: Smi, to: Smi,
-      comparefn: Callable, Load: LoadFn, Store: StoreFn): JSTypedArray {
+      comparefn: Callable, load: LoadFn, store: StoreFn): JSTypedArray {
     try {
-      TypedArrayQuickSortImpl(context, array, from, to, comparefn, Load, Store)
-      otherwise Detached;
+      TypedArrayQuickSortImpl(context, array, from, to, comparefn, load, store)
+          otherwise Detached;
     }
     label Detached {
       ThrowTypeError(
@@ -258,10 +260,10 @@ module typed_array {
       context: Context, receiver: Object, ...arguments): JSTypedArray {
     // 1. If comparefn is not undefined and IsCallable(comparefn) is false,
     //    throw a TypeError exception.
-    const comparefn_obj: Object =
+    const comparefnObj: Object =
         arguments.length > 0 ? arguments[0] : Undefined;
-    if (comparefn_obj != Undefined && !TaggedIsCallable(comparefn_obj)) {
-      ThrowTypeError(context, kBadSortComparisonFunction, comparefn_obj);
+    if (comparefnObj != Undefined && !TaggedIsCallable(comparefnObj)) {
+      ThrowTypeError(context, kBadSortComparisonFunction, comparefnObj);
     }
 
     // 2. Let obj be the this value.
@@ -273,7 +275,7 @@ module typed_array {
         ValidateTypedArray(context, obj, '%TypedArray%.prototype.sort');
 
     // Default sorting is done in C++ using std::sort
-    if (comparefn_obj == Undefined) {
+    if (comparefnObj == Undefined) {
       return TypedArraySortFast(context, obj);
     }
 
@@ -282,48 +284,48 @@ module typed_array {
 
     try {
       const comparefn: Callable =
-          cast<Callable>(comparefn_obj) otherwise CastError;
+          Cast<Callable>(comparefnObj) otherwise CastError;
       let loadfn: LoadFn;
       let storefn: StoreFn;
 
-      let elements_kind: ElementsKind = array.elements_kind;
+      let elementsKind: ElementsKind = array.elements_kind;
 
-      if (IsElementsKindGreaterThan(elements_kind, UINT32_ELEMENTS)) {
-        if (elements_kind == INT32_ELEMENTS) {
+      if (IsElementsKindGreaterThan(elementsKind, UINT32_ELEMENTS)) {
+        if (elementsKind == INT32_ELEMENTS) {
           loadfn = LoadFixedElement<FixedInt32Array>;
           storefn = StoreFixedElement<FixedInt32Array>;
-        } else if (elements_kind == FLOAT32_ELEMENTS) {
+        } else if (elementsKind == FLOAT32_ELEMENTS) {
           loadfn = LoadFixedElement<FixedFloat32Array>;
           storefn = StoreFixedElement<FixedFloat32Array>;
-        } else if (elements_kind == FLOAT64_ELEMENTS) {
+        } else if (elementsKind == FLOAT64_ELEMENTS) {
           loadfn = LoadFixedElement<FixedFloat64Array>;
           storefn = StoreFixedElement<FixedFloat64Array>;
-        } else if (elements_kind == UINT8_CLAMPED_ELEMENTS) {
+        } else if (elementsKind == UINT8_CLAMPED_ELEMENTS) {
           loadfn = LoadFixedElement<FixedUint8ClampedArray>;
           storefn = StoreFixedElement<FixedUint8ClampedArray>;
-        } else if (elements_kind == BIGUINT64_ELEMENTS) {
+        } else if (elementsKind == BIGUINT64_ELEMENTS) {
           loadfn = LoadFixedElement<FixedBigUint64Array>;
           storefn = StoreFixedElement<FixedBigUint64Array>;
-        } else if (elements_kind == BIGINT64_ELEMENTS) {
+        } else if (elementsKind == BIGINT64_ELEMENTS) {
           loadfn = LoadFixedElement<FixedBigInt64Array>;
           storefn = StoreFixedElement<FixedBigInt64Array>;
         } else {
           unreachable;
         }
       } else {
-        if (elements_kind == UINT8_ELEMENTS) {
+        if (elementsKind == UINT8_ELEMENTS) {
           loadfn = LoadFixedElement<FixedUint8Array>;
           storefn = StoreFixedElement<FixedUint8Array>;
-        } else if (elements_kind == INT8_ELEMENTS) {
+        } else if (elementsKind == INT8_ELEMENTS) {
           loadfn = LoadFixedElement<FixedInt8Array>;
           storefn = StoreFixedElement<FixedInt8Array>;
-        } else if (elements_kind == UINT16_ELEMENTS) {
+        } else if (elementsKind == UINT16_ELEMENTS) {
           loadfn = LoadFixedElement<FixedUint16Array>;
           storefn = StoreFixedElement<FixedUint16Array>;
-        } else if (elements_kind == INT16_ELEMENTS) {
+        } else if (elementsKind == INT16_ELEMENTS) {
           loadfn = LoadFixedElement<FixedInt16Array>;
           storefn = StoreFixedElement<FixedInt16Array>;
-        } else if (elements_kind == UINT32_ELEMENTS) {
+        } else if (elementsKind == UINT32_ELEMENTS) {
           loadfn = LoadFixedElement<FixedUint32Array>;
           storefn = StoreFixedElement<FixedUint32Array>;
         } else {
diff --git a/deps/v8/src/builtins/x64/builtins-x64.cc b/deps/v8/src/builtins/x64/builtins-x64.cc
index 5c2094105c..2bc7768417 100644
--- a/deps/v8/src/builtins/x64/builtins-x64.cc
+++ b/deps/v8/src/builtins/x64/builtins-x64.cc
@@ -87,7 +87,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ Push(rcx);
 
     // The receiver for the builtin/api call.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
 
     // Set up pointer to last argument.
     __ leap(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
@@ -135,6 +135,26 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
 
   __ ret(0);
 }
+
+void Generate_StackOverflowCheck(
+    MacroAssembler* masm, Register num_args, Register scratch,
+    Label* stack_overflow,
+    Label::Distance stack_overflow_distance = Label::kFar) {
+  // Check the stack for overflow. We are not trying to catch
+  // interruptions (e.g. debug break and preemption) here, so the "real stack
+  // limit" is checked.
+  __ LoadRoot(kScratchRegister, RootIndex::kRealStackLimit);
+  __ movp(scratch, rsp);
+  // Make scratch the space we have left. The stack might already be overflowed
+  // here which will cause scratch to become negative.
+  __ subp(scratch, kScratchRegister);
+  __ sarp(scratch, Immediate(kPointerSizeLog2));
+  // Check if the arguments will overflow the stack.
+  __ cmpp(scratch, num_args);
+  // Signed comparison.
+  __ j(less_equal, stack_overflow, stack_overflow_distance);
+}
+
 }  // namespace
 
 // The construct stub for ES5 constructor functions and ES6 class constructors.
@@ -157,7 +177,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     __ Push(rsi);
     __ Push(rcx);
     __ Push(rdi);
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ Push(rdx);
 
     // ----------- S t a t e -------------
@@ -181,7 +201,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     // Else: use TheHoleValue as receiver for constructor call
     __ bind(&not_create_implicit_receiver);
-    __ LoadRoot(rax, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(rax, RootIndex::kTheHoleValue);
 
     // ----------- S t a t e -------------
     //  -- rax                          implicit receiver
@@ -221,6 +241,21 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Set up pointer to last argument.
     __ leap(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
 
+    // Check if we have enough stack space to push all arguments.
+    // Argument count in rax. Clobbers rcx.
+    Label enough_stack_space, stack_overflow;
+    Generate_StackOverflowCheck(masm, rax, rcx, &stack_overflow, Label::kNear);
+    __ jmp(&enough_stack_space, Label::kNear);
+
+    __ bind(&stack_overflow);
+    // Restore context from the frame.
+    __ movp(rsi, Operand(rbp, ConstructFrameConstants::kContextOffset));
+    __ CallRuntime(Runtime::kThrowStackOverflow);
+    // This should be unreachable.
+    __ int3();
+
+    __ bind(&enough_stack_space);
+
     // Copy arguments and receiver to the expression stack.
     Label loop, entry;
     __ movp(rcx, rax);
@@ -269,8 +304,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     Label use_receiver, do_throw, leave_frame;
 
     // If the result is undefined, we jump out to using the implicit receiver.
-    __ JumpIfRoot(rax, Heap::kUndefinedValueRootIndex, &use_receiver,
-                  Label::kNear);
+    __ JumpIfRoot(rax, RootIndex::kUndefinedValue, &use_receiver, Label::kNear);
 
     // Otherwise we do a smi check and fall through to check if the return value
     // is a valid receiver.
@@ -292,7 +326,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // on-stack receiver as the result.
     __ bind(&use_receiver);
     __ movp(rax, Operand(rsp, 0 * kPointerSize));
-    __ JumpIfRoot(rax, Heap::kTheHoleValueRootIndex, &do_throw, Label::kNear);
+    __ JumpIfRoot(rax, RootIndex::kTheHoleValue, &do_throw, Label::kNear);
 
     __ bind(&leave_frame);
     // Restore the arguments count.
@@ -317,25 +351,6 @@ void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
   __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
 }
 
-static void Generate_StackOverflowCheck(
-    MacroAssembler* masm, Register num_args, Register scratch,
-    Label* stack_overflow,
-    Label::Distance stack_overflow_distance = Label::kFar) {
-  // Check the stack for overflow. We are not trying to catch
-  // interruptions (e.g. debug break and preemption) here, so the "real stack
-  // limit" is checked.
-  __ LoadRoot(kScratchRegister, Heap::kRealStackLimitRootIndex);
-  __ movp(scratch, rsp);
-  // Make scratch the space we have left. The stack might already be overflowed
-  // here which will cause scratch to become negative.
-  __ subp(scratch, kScratchRegister);
-  __ sarp(scratch, Immediate(kPointerSizeLog2));
-  // Check if the arguments will overflow the stack.
-  __ cmpp(scratch, num_args);
-  // Signed comparison.
-  __ j(less_equal, stack_overflow, stack_overflow_distance);
-}
-
 static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                              bool is_construct) {
   ProfileEntryHookStub::MaybeCallEntryHook(masm);
@@ -533,7 +548,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRoot(rsp, Heap::kRealStackLimitRootIndex);
+  __ CompareRoot(rsp, RootIndex::kRealStackLimit);
   __ j(below, &stack_overflow);
 
   // Pop return address.
@@ -602,7 +617,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     __ Push(rdx);
     __ Push(rdi);
     // Push hole as receiver since we do not use it for stepping.
-    __ PushRoot(Heap::kTheHoleValueRootIndex);
+    __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(rdx);
     __ movp(rdi, FieldOperand(rdx, JSGeneratorObject::kFunctionOffset));
@@ -905,7 +920,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     Label ok;
     __ movp(rax, rsp);
     __ subp(rax, rcx);
-    __ CompareRoot(rax, Heap::kRealStackLimitRootIndex);
+    __ CompareRoot(rax, RootIndex::kRealStackLimit);
     __ j(above_equal, &ok, Label::kNear);
     __ CallRuntime(Runtime::kThrowStackOverflow);
     __ bind(&ok);
@@ -913,7 +928,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // If ok, push undefined as the initial value for all register file entries.
     Label loop_header;
     Label loop_check;
-    __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(rax, RootIndex::kUndefinedValue);
     __ j(always, &loop_check, Label::kNear);
     __ bind(&loop_header);
     // TODO(rmcilroy): Consider doing more than one push per loop iteration.
@@ -937,7 +952,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&no_incoming_new_target_or_generator_register);
 
   // Load accumulator with undefined.
-  __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
   // Load the dispatch table into a register and dispatch to the bytecode
   // handler at the current bytecode offset.
@@ -1026,7 +1041,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
 
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ decl(rcx);  // Subtract one for receiver.
   }
 
@@ -1251,7 +1266,7 @@ void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
             rbp, StandardFrameConstants::kCallerSPOffset + i * kPointerSize));
       }
       for (int i = 0; i < 3 - j; ++i) {
-        __ PushRoot(Heap::kUndefinedValueRootIndex);
+        __ PushRoot(RootIndex::kUndefinedValue);
       }
       if (j < 3) {
         __ jmp(&args_done, Label::kNear);
@@ -1370,7 +1385,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   {
     Label no_arg_array, no_this_arg;
     StackArgumentsAccessor args(rsp, rax);
-    __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(rdx, RootIndex::kUndefinedValue);
     __ movp(rbx, rdx);
     __ movp(rdi, args.GetReceiverOperand());
     __ testp(rax, rax);
@@ -1402,9 +1417,8 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 
   // 3. Tail call with no arguments if argArray is null or undefined.
   Label no_arguments;
-  __ JumpIfRoot(rbx, Heap::kNullValueRootIndex, &no_arguments, Label::kNear);
-  __ JumpIfRoot(rbx, Heap::kUndefinedValueRootIndex, &no_arguments,
-                Label::kNear);
+  __ JumpIfRoot(rbx, RootIndex::kNullValue, &no_arguments, Label::kNear);
+  __ JumpIfRoot(rbx, RootIndex::kUndefinedValue, &no_arguments, Label::kNear);
 
   // 4a. Apply the receiver to the given argArray.
   __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
@@ -1438,7 +1452,7 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
     __ testp(rax, rax);
     __ j(not_zero, &done, Label::kNear);
     __ PopReturnAddressTo(rbx);
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ PushReturnAddressFrom(rbx);
     __ incp(rax);
     __ bind(&done);
@@ -1488,7 +1502,7 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   {
     Label done;
     StackArgumentsAccessor args(rsp, rax);
-    __ LoadRoot(rdi, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(rdi, RootIndex::kUndefinedValue);
     __ movp(rdx, rdi);
     __ movp(rbx, rdi);
     __ cmpp(rax, Immediate(1));
@@ -1539,7 +1553,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   {
     Label done;
     StackArgumentsAccessor args(rsp, rax);
-    __ LoadRoot(rdi, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(rdi, RootIndex::kUndefinedValue);
     __ movp(rdx, rdi);
     __ movp(rbx, rdi);
     __ cmpp(rax, Immediate(1));
@@ -1554,7 +1568,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
     __ bind(&done);
     __ PopReturnAddressTo(rcx);
     __ leap(rsp, Operand(rsp, rax, times_pointer_size, kPointerSize));
-    __ PushRoot(Heap::kUndefinedValueRootIndex);
+    __ PushRoot(RootIndex::kUndefinedValue);
     __ PushReturnAddressFrom(rcx);
   }
 
@@ -1601,7 +1615,6 @@ void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
 
   // Run the native code for the InternalArray function called as a normal
   // function.
-  __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
           RelocInfo::CODE_TARGET);
 }
@@ -1701,7 +1714,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 
     // Fill remaining expected arguments with undefined values.
     Label fill;
-    __ LoadRoot(kScratchRegister, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
     __ bind(&fill);
     __ incp(r8);
     __ Push(kScratchRegister);
@@ -1777,23 +1790,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ bind(&ok);
   }
 
-  // Check for stack overflow.
-  {
-    // Check the stack for overflow. We are not trying to catch interruptions
-    // (i.e. debug break and preemption) here, so check the "real stack limit".
-    Label done;
-    __ LoadRoot(kScratchRegister, Heap::kRealStackLimitRootIndex);
-    __ movp(r8, rsp);
-    // Make r8 the space we have left. The stack might already be overflowed
-    // here which will cause r8 to become negative.
-    __ subp(r8, kScratchRegister);
-    __ sarp(r8, Immediate(kPointerSizeLog2));
-    // Check if the arguments will overflow the stack.
-    __ cmpp(r8, rcx);
-    __ j(greater, &done, Label::kNear);  // Signed comparison.
-    __ TailCallRuntime(Runtime::kThrowStackOverflow);
-    __ bind(&done);
-  }
+  Label stack_overflow;
+  Generate_StackOverflowCheck(masm, rcx, r8, &stack_overflow, Label::kNear);
 
   // Push additional arguments onto the stack.
   {
@@ -1806,9 +1804,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     // Turn the hole into undefined as we go.
     __ movp(r11,
             FieldOperand(rbx, r9, times_pointer_size, FixedArray::kHeaderSize));
-    __ CompareRoot(r11, Heap::kTheHoleValueRootIndex);
+    __ CompareRoot(r11, RootIndex::kTheHoleValue);
     __ j(not_equal, &push, Label::kNear);
-    __ LoadRoot(r11, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r11, RootIndex::kUndefinedValue);
     __ bind(&push);
     __ Push(r11);
     __ incl(r9);
@@ -1820,6 +1818,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
+
+  __ bind(&stack_overflow);
+  __ TailCallRuntime(Runtime::kThrowStackOverflow);
 }
 
 // static
@@ -1957,9 +1958,9 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ j(above_equal, &done_convert);
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
-        __ JumpIfRoot(rcx, Heap::kUndefinedValueRootIndex,
-                      &convert_global_proxy, Label::kNear);
-        __ JumpIfNotRoot(rcx, Heap::kNullValueRootIndex, &convert_to_object,
+        __ JumpIfRoot(rcx, RootIndex::kUndefinedValue, &convert_global_proxy,
+                      Label::kNear);
+        __ JumpIfNotRoot(rcx, RootIndex::kNullValue, &convert_to_object,
                          Label::kNear);
         __ bind(&convert_global_proxy);
         {
@@ -2049,8 +2050,8 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CompareRoot(rsp, Heap::kRealStackLimitRootIndex);
-      __ j(greater, &done, Label::kNear);  // Signed comparison.
+      __ CompareRoot(rsp, RootIndex::kRealStackLimit);
+      __ j(above_equal, &done, Label::kNear);
       // Restore the stack pointer.
       __ leap(rsp, Operand(rsp, rbx, times_pointer_size, 0));
       {
@@ -2183,7 +2184,7 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
 
   // Calling convention for function specific ConstructStubs require
   // rbx to contain either an AllocationSite or undefined.
-  __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(rbx, RootIndex::kUndefinedValue);
 
   // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
   __ movp(rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
@@ -2277,15 +2278,10 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
           RelocInfo::CODE_TARGET);
 }
 
-static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
-                                              bool has_handler_frame) {
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame.
-  if (has_handler_frame) {
-    __ movp(rax, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
-    __ movp(rax, Operand(rax, JavaScriptFrameConstants::kFunctionOffset));
-  } else {
-    __ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
-  }
+  __ movp(rax, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
+  __ movp(rax, Operand(rax, JavaScriptFrameConstants::kFunctionOffset));
 
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -2302,11 +2298,9 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
 
   __ bind(&skip);
 
-  // Drop any potential handler frame that is be sitting on top of the actual
+  // Drop the handler frame that is be sitting on top of the actual
   // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  if (has_handler_frame) {
-    __ leave();
-  }
+  __ leave();
 
   // Load deoptimization data from the code object.
   __ movp(rbx, Operand(rax, Code::kDeoptimizationDataOffset - kHeapObjectTag));
@@ -2326,14 +2320,6 @@ static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
   __ ret(0);
 }
 
-void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, false);
-}
-
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
-  Generate_OnStackReplacementHelper(masm, true);
-}
-
 void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   // The function index was pushed to the stack by the caller as int32.
   __ Pop(r11);
@@ -2486,14 +2472,14 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Check result for exception sentinel.
   Label exception_returned;
-  __ CompareRoot(rax, Heap::kExceptionRootIndex);
+  __ CompareRoot(rax, RootIndex::kException);
   __ j(equal, &exception_returned);
 
   // Check that there is no pending exception, otherwise we
   // should have returned the exception sentinel.
   if (FLAG_debug_code) {
     Label okay;
-    __ LoadRoot(r14, Heap::kTheHoleValueRootIndex);
+    __ LoadRoot(r14, RootIndex::kTheHoleValue);
     ExternalReference pending_exception_address = ExternalReference::Create(
         IsolateAddressId::kPendingExceptionAddress, masm->isolate());
     Operand pending_exception_operand =
@@ -2547,9 +2533,9 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ bind(&skip);
 
   // Reset the masking register. This is done independent of the underlying
-  // feature flag {FLAG_branch_load_poisoning} to make the snapshot work with
-  // both configurations. It is safe to always do this, because the underlying
-  // register is caller-saved and can be arbitrarily clobbered.
+  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
+  // with both configurations. It is safe to always do this, because the
+  // underlying register is caller-saved and can be arbitrarily clobbered.
   __ ResetSpeculationPoisonRegister();
 
   // Compute the handler entry address and jump to it.
@@ -2789,6 +2775,9 @@ void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
       RelocInfo::CODE_TARGET);
 
   __ bind(&not_one_case);
+  // Load undefined into the allocation site parameter as required by
+  // ArrayNArgumentsConstructor.
+  __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
   Handle<Code> code = BUILTIN_CODE(masm->isolate(), ArrayNArgumentsConstructor);
   __ Jump(code, RelocInfo::CODE_TARGET);
 }
diff --git a/deps/v8/src/callable.h b/deps/v8/src/callable.h
index 3d9eb274b0..c24c9ae554 100644
--- a/deps/v8/src/callable.h
+++ b/deps/v8/src/callable.h
@@ -14,7 +14,7 @@ namespace internal {
 class Code;
 
 // Associates a body of code with an interface descriptor.
-class Callable final BASE_EMBEDDED {
+class Callable final {
  public:
   Callable(Handle<Code> code, CallInterfaceDescriptor descriptor)
       : code_(code), descriptor_(descriptor) {}
diff --git a/deps/v8/src/cancelable-task.h b/deps/v8/src/cancelable-task.h
index 64ca681416..0ef3ca5a15 100644
--- a/deps/v8/src/cancelable-task.h
+++ b/deps/v8/src/cancelable-task.h
@@ -134,7 +134,6 @@ class V8_EXPORT_PRIVATE Cancelable {
   DISALLOW_COPY_AND_ASSIGN(Cancelable);
 };
 
-
 // Multiple inheritance can be used because Task is a pure interface.
 class V8_EXPORT_PRIVATE CancelableTask : public Cancelable,
                                          NON_EXPORTED_BASE(public Task) {
@@ -155,6 +154,32 @@ class V8_EXPORT_PRIVATE CancelableTask : public Cancelable,
   DISALLOW_COPY_AND_ASSIGN(CancelableTask);
 };
 
+// TODO(clemensh): Use std::function and move implementation to cc file.
+template <typename Func>
+class CancelableLambdaTask final : public CancelableTask {
+ public:
+  CancelableLambdaTask(Isolate* isolate, Func func)
+      : CancelableTask(isolate), func_(std::move(func)) {}
+  CancelableLambdaTask(CancelableTaskManager* manager, Func func)
+      : CancelableTask(manager), func_(std::move(func)) {}
+  void RunInternal() final { func_(); }
+
+ private:
+  Func func_;
+};
+
+template <typename Func>
+std::unique_ptr<CancelableTask> MakeCancelableLambdaTask(Isolate* isolate,
+                                                         Func func) {
+  return std::unique_ptr<CancelableTask>(
+      new CancelableLambdaTask<Func>(isolate, std::move(func)));
+}
+template <typename Func>
+std::unique_ptr<CancelableTask> MakeCancelableLambdaTask(
+    CancelableTaskManager* manager, Func func) {
+  return std::unique_ptr<CancelableTask>(
+      new CancelableLambdaTask<Func>(manager, std::move(func)));
+}
 
 // Multiple inheritance can be used because IdleTask is a pure interface.
 class CancelableIdleTask : public Cancelable, public IdleTask {
@@ -175,6 +200,33 @@ class CancelableIdleTask : public Cancelable, public IdleTask {
   DISALLOW_COPY_AND_ASSIGN(CancelableIdleTask);
 };
 
+template <typename Func>
+class CancelableIdleLambdaTask final : public CancelableIdleTask {
+ public:
+  CancelableIdleLambdaTask(Isolate* isolate, Func func)
+      : CancelableIdleTask(isolate), func_(std::move(func)) {}
+  CancelableIdleLambdaTask(CancelableTaskManager* manager, Func func)
+      : CancelableIdleTask(manager), func_(std::move(func)) {}
+  void RunInternal(double deadline_in_seconds) final {
+    func_(deadline_in_seconds);
+  }
+
+ private:
+  Func func_;
+};
+
+template <typename Func>
+std::unique_ptr<CancelableIdleTask> MakeCancelableIdleLambdaTask(
+    Isolate* isolate, Func func) {
+  return std::unique_ptr<CancelableIdleTask>(
+      new CancelableIdleLambdaTask<Func>(isolate, std::move(func)));
+}
+template <typename Func>
+std::unique_ptr<CancelableIdleTask> MakeCancelableIdleLambdaTask(
+    CancelableTaskManager* manager, Func func) {
+  return std::unique_ptr<CancelableIdleTask>(
+      new CancelableIdleLambdaTask<Func>(manager, std::move(func)));
+}
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/char-predicates-inl.h b/deps/v8/src/char-predicates-inl.h
index 7e198d5808..3662514bca 100644
--- a/deps/v8/src/char-predicates-inl.h
+++ b/deps/v8/src/char-predicates-inl.h
@@ -18,23 +18,14 @@ inline int AsciiAlphaToLower(uc32 c) {
   return c | 0x20;
 }
 
-
 inline bool IsCarriageReturn(uc32 c) {
   return c == 0x000D;
 }
 
-
 inline bool IsLineFeed(uc32 c) {
   return c == 0x000A;
 }
 
-
-inline bool IsInRange(int value, int lower_limit, int higher_limit) {
-  DCHECK(lower_limit <= higher_limit);
-  return static_cast<unsigned int>(value - lower_limit) <=
-      static_cast<unsigned int>(higher_limit - lower_limit);
-}
-
 inline bool IsAsciiIdentifier(uc32 c) {
   return IsAlphaNumeric(c) || c == '$' || c == '_';
 }
@@ -58,6 +49,8 @@ inline bool IsOctalDigit(uc32 c) {
   return IsInRange(c, '0', '7');
 }
 
+inline bool IsNonOctalDecimalDigit(uc32 c) { return IsInRange(c, '8', '9'); }
+
 inline bool IsBinaryDigit(uc32 c) {
   // ECMA-262, 6th, 7.8.3
   return c == '0' || c == '1';
diff --git a/deps/v8/src/checks.h b/deps/v8/src/checks.h
index 8eb10f43dd..4a0afa4f57 100644
--- a/deps/v8/src/checks.h
+++ b/deps/v8/src/checks.h
@@ -5,7 +5,7 @@
 #ifndef V8_CHECKS_H_
 #define V8_CHECKS_H_
 
-#include "include/v8.h"
+#include "include/v8-internal.h"
 #include "src/base/logging.h"
 #include "src/globals.h"
 
diff --git a/deps/v8/src/code-events.h b/deps/v8/src/code-events.h
index ec07a2e107..07a883be0d 100644
--- a/deps/v8/src/code-events.h
+++ b/deps/v8/src/code-events.h
@@ -66,7 +66,7 @@ class CodeEventListener {
   };
 #undef DECLARE_ENUM
 
-  virtual ~CodeEventListener() {}
+  virtual ~CodeEventListener() = default;
 
   virtual void CodeCreateEvent(LogEventsAndTags tag, AbstractCode* code,
                                const char* comment) = 0;
@@ -98,7 +98,7 @@ class CodeEventDispatcher {
  public:
   using LogEventsAndTags = CodeEventListener::LogEventsAndTags;
 
-  CodeEventDispatcher() {}
+  CodeEventDispatcher() = default;
 
   bool AddListener(CodeEventListener* listener) {
     base::LockGuard<base::Mutex> guard(&mutex_);
diff --git a/deps/v8/src/code-factory.cc b/deps/v8/src/code-factory.cc
index b6eb03f81b..cffb16b7d4 100644
--- a/deps/v8/src/code-factory.cc
+++ b/deps/v8/src/code-factory.cc
@@ -166,27 +166,15 @@ Callable CodeFactory::OrdinaryToPrimitive(Isolate* isolate,
 }
 
 // static
-Callable CodeFactory::StringAdd(Isolate* isolate, StringAddFlags flags,
-                                PretenureFlag pretenure_flag) {
-  if (pretenure_flag == NOT_TENURED) {
-    switch (flags) {
-      case STRING_ADD_CHECK_NONE:
-        return Builtins::CallableFor(isolate,
-                                     Builtins::kStringAdd_CheckNone_NotTenured);
-      case STRING_ADD_CONVERT_LEFT:
-        return Builtins::CallableFor(
-            isolate, Builtins::kStringAdd_ConvertLeft_NotTenured);
-      case STRING_ADD_CONVERT_RIGHT:
-        return Builtins::CallableFor(
-            isolate, Builtins::kStringAdd_ConvertRight_NotTenured);
-    }
-  } else {
-    CHECK_EQ(TENURED, pretenure_flag);
-    CHECK_EQ(STRING_ADD_CHECK_NONE, flags);
-    return Builtins::CallableFor(isolate,
-                                 Builtins::kStringAdd_CheckNone_Tenured);
+Callable CodeFactory::StringAdd(Isolate* isolate, StringAddFlags flags) {
+  switch (flags) {
+    case STRING_ADD_CHECK_NONE:
+      return Builtins::CallableFor(isolate, Builtins::kStringAdd_CheckNone);
+    case STRING_ADD_CONVERT_LEFT:
+      return Builtins::CallableFor(isolate, Builtins::kStringAdd_ConvertLeft);
+    case STRING_ADD_CONVERT_RIGHT:
+      return Builtins::CallableFor(isolate, Builtins::kStringAdd_ConvertRight);
   }
-
   UNREACHABLE();
 }
 
@@ -218,7 +206,7 @@ Callable CodeFactory::FastNewFunctionContext(Isolate* isolate,
 // static
 Callable CodeFactory::ArgumentAdaptor(Isolate* isolate) {
   return Callable(BUILTIN_CODE(isolate, ArgumentsAdaptorTrampoline),
-                  ArgumentAdaptorDescriptor{});
+                  ArgumentsAdaptorDescriptor{});
 }
 
 // static
diff --git a/deps/v8/src/code-factory.h b/deps/v8/src/code-factory.h
index cba6136a38..3e8bc3790c 100644
--- a/deps/v8/src/code-factory.h
+++ b/deps/v8/src/code-factory.h
@@ -59,8 +59,7 @@ class V8_EXPORT_PRIVATE CodeFactory final {
                                       OrdinaryToPrimitiveHint hint);
 
   static Callable StringAdd(Isolate* isolate,
-                            StringAddFlags flags = STRING_ADD_CHECK_NONE,
-                            PretenureFlag pretenure_flag = NOT_TENURED);
+                            StringAddFlags flags = STRING_ADD_CHECK_NONE);
 
   static Callable FastNewFunctionContext(Isolate* isolate,
                                          ScopeType scope_type);
diff --git a/deps/v8/src/code-stub-assembler.cc b/deps/v8/src/code-stub-assembler.cc
index 5bd780b520..e307ca5cc3 100644
--- a/deps/v8/src/code-stub-assembler.cc
+++ b/deps/v8/src/code-stub-assembler.cc
@@ -225,7 +225,7 @@ TNode<Object> CodeStubAssembler::NoContextConstant() {
       CodeStubAssembler::name##Constant() {                           \
     return UncheckedCast<std::remove_reference<decltype(              \
         *std::declval<Heap>().rootAccessorName())>::type>(            \
-        LoadRoot(Heap::k##rootIndexName##RootIndex));                 \
+        LoadRoot(RootIndex::k##rootIndexName));                       \
   }
 HEAP_MUTABLE_IMMOVABLE_OBJECT_LIST(HEAP_CONSTANT_ACCESSOR);
 #undef HEAP_CONSTANT_ACCESSOR
@@ -236,7 +236,7 @@ HEAP_MUTABLE_IMMOVABLE_OBJECT_LIST(HEAP_CONSTANT_ACCESSOR);
       CodeStubAssembler::name##Constant() {                           \
     return UncheckedCast<std::remove_reference<decltype(              \
         *std::declval<ReadOnlyRoots>().rootAccessorName())>::type>(   \
-        LoadRoot(Heap::k##rootIndexName##RootIndex));                 \
+        LoadRoot(RootIndex::k##rootIndexName));                       \
   }
 HEAP_IMMUTABLE_IMMOVABLE_OBJECT_LIST(HEAP_CONSTANT_ACCESSOR);
 #undef HEAP_CONSTANT_ACCESSOR
@@ -906,6 +906,17 @@ TNode<Smi> CodeStubAssembler::TrySmiDiv(TNode<Smi> dividend, TNode<Smi> divisor,
   return SmiFromInt32(untagged_result);
 }
 
+TNode<Smi> CodeStubAssembler::SmiLexicographicCompare(TNode<Smi> x,
+                                                      TNode<Smi> y) {
+  TNode<ExternalReference> smi_lexicographic_compare =
+      ExternalConstant(ExternalReference::smi_lexicographic_compare_function());
+  TNode<ExternalReference> isolate_ptr =
+      ExternalConstant(ExternalReference::isolate_address(isolate()));
+  return CAST(CallCFunction3(MachineType::AnyTagged(), MachineType::Pointer(),
+                             MachineType::AnyTagged(), MachineType::AnyTagged(),
+                             smi_lexicographic_compare, isolate_ptr, x, y));
+}
+
 TNode<Int32T> CodeStubAssembler::TruncateIntPtrToInt32(
     SloppyTNode<IntPtrT> value) {
   if (Is64()) {
@@ -962,9 +973,9 @@ void CodeStubAssembler::BranchIfPrototypesHaveNoElements(
   CSA_SLOW_ASSERT(this, IsMap(receiver_map));
   VARIABLE(var_map, MachineRepresentation::kTagged, receiver_map);
   Label loop_body(this, &var_map);
-  Node* empty_fixed_array = LoadRoot(Heap::kEmptyFixedArrayRootIndex);
+  Node* empty_fixed_array = LoadRoot(RootIndex::kEmptyFixedArray);
   Node* empty_slow_element_dictionary =
-      LoadRoot(Heap::kEmptySlowElementDictionaryRootIndex);
+      LoadRoot(RootIndex::kEmptySlowElementDictionary);
   Goto(&loop_body);
 
   BIND(&loop_body);
@@ -1039,7 +1050,7 @@ TNode<BoolT> CodeStubAssembler::IsFastJSArrayWithNoCustomIteration(
   {
     // Check that the Array.prototype hasn't been modified in a way that would
     // affect iteration.
-    Node* protector_cell = LoadRoot(Heap::kArrayIteratorProtectorRootIndex);
+    Node* protector_cell = LoadRoot(RootIndex::kArrayIteratorProtector);
     DCHECK(isolate()->heap()->array_iterator_protector()->IsPropertyCell());
     var_result =
         WordEqual(LoadObjectField(protector_cell, PropertyCell::kValueOffset),
@@ -1098,6 +1109,19 @@ void CodeStubAssembler::GotoIfForceSlowPath(Label* if_true) {
 #endif
 }
 
+void CodeStubAssembler::GotoIfDebugExecutionModeChecksSideEffects(
+    Label* if_true) {
+  STATIC_ASSERT(sizeof(DebugInfo::ExecutionMode) >= sizeof(int32_t));
+
+  TNode<ExternalReference> execution_mode_address = ExternalConstant(
+      ExternalReference::debug_execution_mode_address(isolate()));
+  TNode<Int32T> execution_mode =
+      UncheckedCast<Int32T>(Load(MachineType::Int32(), execution_mode_address));
+
+  GotoIf(Word32Equal(execution_mode, Int32Constant(DebugInfo::kSideEffects)),
+         if_true);
+}
+
 Node* CodeStubAssembler::AllocateRaw(Node* size_in_bytes, AllocationFlags flags,
                                      Node* top_address, Node* limit_address) {
   // TODO(jgruber, chromium:848672): TNodeify AllocateRaw.
@@ -1192,7 +1216,7 @@ Node* CodeStubAssembler::AllocateRaw(Node* size_in_bytes, AllocationFlags flags,
     BIND(&needs_filler);
     // Store a filler and increase the address by kPointerSize.
     StoreNoWriteBarrier(MachineRepresentation::kTagged, top,
-                        LoadRoot(Heap::kOnePointerFillerMapRootIndex));
+                        LoadRoot(RootIndex::kOnePointerFillerMap));
     address.Bind(IntPtrAdd(no_runtime_result, IntPtrConstant(4)));
 
     Goto(&done_filling);
@@ -1370,14 +1394,14 @@ Node* CodeStubAssembler::LoadBufferObject(Node* buffer, int offset,
 
 Node* CodeStubAssembler::LoadObjectField(SloppyTNode<HeapObject> object,
                                          int offset, MachineType rep) {
-  CSA_ASSERT(this, IsStrongHeapObject(object));
+  CSA_ASSERT(this, IsStrong(object));
   return Load(rep, object, IntPtrConstant(offset - kHeapObjectTag));
 }
 
 Node* CodeStubAssembler::LoadObjectField(SloppyTNode<HeapObject> object,
                                          SloppyTNode<IntPtrT> offset,
                                          MachineType rep) {
-  CSA_ASSERT(this, IsStrongHeapObject(object));
+  CSA_ASSERT(this, IsStrong(object));
   return Load(rep, object, IntPtrSub(offset, IntPtrConstant(kHeapObjectTag)));
 }
 
@@ -1423,19 +1447,19 @@ TNode<IntPtrT> CodeStubAssembler::LoadAndUntagSmi(Node* base, int index) {
 }
 
 TNode<Int32T> CodeStubAssembler::LoadAndUntagToWord32Root(
-    Heap::RootListIndex root_index) {
+    RootIndex root_index) {
   Node* roots_array_start =
       ExternalConstant(ExternalReference::roots_array_start(isolate()));
-  int index = root_index * kPointerSize;
+  int offset = static_cast<int>(root_index) * kPointerSize;
   if (SmiValuesAre32Bits()) {
 #if V8_TARGET_LITTLE_ENDIAN
-    index += kPointerSize / 2;
+    offset += kPointerSize / 2;
 #endif
     return UncheckedCast<Int32T>(
-        Load(MachineType::Int32(), roots_array_start, IntPtrConstant(index)));
+        Load(MachineType::Int32(), roots_array_start, IntPtrConstant(offset)));
   } else {
     return SmiToInt32(Load(MachineType::AnyTagged(), roots_array_start,
-                           IntPtrConstant(index)));
+                           IntPtrConstant(offset)));
   }
 }
 
@@ -1521,6 +1545,11 @@ TNode<Number> CodeStubAssembler::LoadJSArrayLength(SloppyTNode<JSArray> array) {
   return CAST(LoadObjectField(array, JSArray::kLengthOffset));
 }
 
+TNode<Object> CodeStubAssembler::LoadJSArgumentsObjectWithLength(
+    SloppyTNode<JSArgumentsObjectWithLength> array) {
+  return LoadObjectField(array, JSArgumentsObjectWithLength::kLengthOffset);
+}
+
 TNode<Smi> CodeStubAssembler::LoadFastJSArrayLength(
     SloppyTNode<JSArray> array) {
   TNode<Object> length = LoadJSArrayLength(array);
@@ -1557,11 +1586,6 @@ TNode<IntPtrT> CodeStubAssembler::LoadAndUntagWeakFixedArrayLength(
   return LoadAndUntagObjectField(array, WeakFixedArray::kLengthOffset);
 }
 
-TNode<Smi> CodeStubAssembler::LoadTypedArrayLength(
-    TNode<JSTypedArray> typed_array) {
-  return CAST(LoadObjectField(typed_array, JSTypedArray::kLengthOffset));
-}
-
 TNode<Int32T> CodeStubAssembler::LoadMapBitField(SloppyTNode<Map> map) {
   CSA_SLOW_ASSERT(this, IsMap(map));
   return UncheckedCast<Int32T>(
@@ -1620,7 +1644,7 @@ TNode<PrototypeInfo> CodeStubAssembler::LoadMapPrototypeInfo(
 
   BIND(&if_strong_heap_object);
   GotoIfNot(WordEqual(LoadMap(CAST(prototype_info.value())),
-                      LoadRoot(Heap::kPrototypeInfoMapRootIndex)),
+                      LoadRoot(RootIndex::kPrototypeInfoMap)),
             if_no_proto_info);
   return CAST(prototype_info.value());
 }
@@ -1686,6 +1710,19 @@ TNode<Object> CodeStubAssembler::LoadMapBackPointer(SloppyTNode<Map> map) {
                         [=] { return UndefinedConstant(); });
 }
 
+TNode<Uint32T> CodeStubAssembler::EnsureOnlyHasSimpleProperties(
+    TNode<Map> map, TNode<Int32T> instance_type, Label* bailout) {
+  // This check can have false positives, since it applies to any JSValueType.
+  GotoIf(IsCustomElementsReceiverInstanceType(instance_type), bailout);
+
+  TNode<Uint32T> bit_field3 = LoadMapBitField3(map);
+  GotoIf(IsSetWord32(bit_field3, Map::IsDictionaryMapBit::kMask |
+                                     Map::HasHiddenPrototypeBit::kMask),
+         bailout);
+
+  return bit_field3;
+}
+
 TNode<IntPtrT> CodeStubAssembler::LoadJSReceiverIdentityHash(
     SloppyTNode<Object> receiver, Label* if_no_hash) {
   TVARIABLE(IntPtrT, var_hash);
@@ -1758,16 +1795,20 @@ TNode<Uint32T> CodeStubAssembler::LoadNameHash(SloppyTNode<Name> name,
   return Unsigned(Word32Shr(hash_field, Int32Constant(Name::kHashShift)));
 }
 
+TNode<Smi> CodeStubAssembler::LoadStringLengthAsSmi(
+    SloppyTNode<String> string) {
+  return SmiFromIntPtr(LoadStringLengthAsWord(string));
+}
+
 TNode<IntPtrT> CodeStubAssembler::LoadStringLengthAsWord(
-    SloppyTNode<String> object) {
-  return SmiUntag(LoadStringLengthAsSmi(object));
+    SloppyTNode<String> string) {
+  return Signed(ChangeUint32ToWord(LoadStringLengthAsWord32(string)));
 }
 
-TNode<Smi> CodeStubAssembler::LoadStringLengthAsSmi(
-    SloppyTNode<String> object) {
-  CSA_ASSERT(this, IsString(object));
-  return CAST(LoadObjectField(object, String::kLengthOffset,
-                              MachineType::TaggedPointer()));
+TNode<Uint32T> CodeStubAssembler::LoadStringLengthAsWord32(
+    SloppyTNode<String> string) {
+  CSA_ASSERT(this, IsString(string));
+  return LoadObjectField<Uint32T>(string, String::kLengthOffset);
 }
 
 Node* CodeStubAssembler::PointerToSeqStringData(Node* seq_string) {
@@ -1817,49 +1858,46 @@ void CodeStubAssembler::DispatchMaybeObject(TNode<MaybeObject> maybe_object,
   Goto(if_strong);
 }
 
-TNode<BoolT> CodeStubAssembler::IsStrongHeapObject(TNode<MaybeObject> value) {
+TNode<BoolT> CodeStubAssembler::IsStrong(TNode<MaybeObject> value) {
   return WordEqual(WordAnd(BitcastMaybeObjectToWord(value),
                            IntPtrConstant(kHeapObjectTagMask)),
                    IntPtrConstant(kHeapObjectTag));
 }
 
-TNode<HeapObject> CodeStubAssembler::ToStrongHeapObject(
+TNode<HeapObject> CodeStubAssembler::GetHeapObjectIfStrong(
     TNode<MaybeObject> value, Label* if_not_strong) {
-  GotoIfNot(IsStrongHeapObject(value), if_not_strong);
+  GotoIfNot(IsStrong(value), if_not_strong);
   return CAST(value);
 }
 
-TNode<BoolT> CodeStubAssembler::IsWeakOrClearedHeapObject(
-    TNode<MaybeObject> value) {
+TNode<BoolT> CodeStubAssembler::IsWeakOrCleared(TNode<MaybeObject> value) {
   return WordEqual(WordAnd(BitcastMaybeObjectToWord(value),
                            IntPtrConstant(kHeapObjectTagMask)),
                    IntPtrConstant(kWeakHeapObjectTag));
 }
 
-TNode<BoolT> CodeStubAssembler::IsClearedWeakHeapObject(
-    TNode<MaybeObject> value) {
+TNode<BoolT> CodeStubAssembler::IsCleared(TNode<MaybeObject> value) {
   return WordEqual(BitcastMaybeObjectToWord(value),
                    IntPtrConstant(kClearedWeakHeapObject));
 }
 
-TNode<BoolT> CodeStubAssembler::IsNotClearedWeakHeapObject(
-    TNode<MaybeObject> value) {
+TNode<BoolT> CodeStubAssembler::IsNotCleared(TNode<MaybeObject> value) {
   return WordNotEqual(BitcastMaybeObjectToWord(value),
                       IntPtrConstant(kClearedWeakHeapObject));
 }
 
-TNode<HeapObject> CodeStubAssembler::ToWeakHeapObject(
+TNode<HeapObject> CodeStubAssembler::GetHeapObjectAssumeWeak(
     TNode<MaybeObject> value) {
-  CSA_ASSERT(this, IsWeakOrClearedHeapObject(value));
-  CSA_ASSERT(this, IsNotClearedWeakHeapObject(value));
+  CSA_ASSERT(this, IsWeakOrCleared(value));
+  CSA_ASSERT(this, IsNotCleared(value));
   return UncheckedCast<HeapObject>(BitcastWordToTagged(WordAnd(
       BitcastMaybeObjectToWord(value), IntPtrConstant(~kWeakHeapObjectMask))));
 }
 
-TNode<HeapObject> CodeStubAssembler::ToWeakHeapObject(TNode<MaybeObject> value,
-                                                      Label* if_cleared) {
-  GotoIf(IsClearedWeakHeapObject(value), if_cleared);
-  return ToWeakHeapObject(value);
+TNode<HeapObject> CodeStubAssembler::GetHeapObjectAssumeWeak(
+    TNode<MaybeObject> value, Label* if_cleared) {
+  GotoIf(IsCleared(value), if_cleared);
+  return GetHeapObjectAssumeWeak(value);
 }
 
 TNode<BoolT> CodeStubAssembler::IsWeakReferenceTo(TNode<MaybeObject> object,
@@ -1999,108 +2037,88 @@ TNode<RawPtrT> CodeStubAssembler::LoadFixedTypedArrayBackingStore(
 
 Node* CodeStubAssembler::LoadFixedBigInt64ArrayElementAsTagged(
     Node* data_pointer, Node* offset) {
-  TVARIABLE(BigInt, var_result);
-  Label done(this), if_zero(this);
   if (Is64()) {
     TNode<IntPtrT> value = UncheckedCast<IntPtrT>(
         Load(MachineType::IntPtr(), data_pointer, offset));
-    Label if_positive(this), if_negative(this);
-    GotoIf(IntPtrEqual(value, IntPtrConstant(0)), &if_zero);
-    var_result = AllocateRawBigInt(IntPtrConstant(1));
-    Branch(IntPtrGreaterThan(value, IntPtrConstant(0)), &if_positive,
-           &if_negative);
-
-    BIND(&if_positive);
-    {
-      StoreBigIntBitfield(var_result.value(),
-                          IntPtrConstant(BigInt::SignBits::encode(false) |
-                                         BigInt::LengthBits::encode(1)));
-      StoreBigIntDigit(var_result.value(), 0, Unsigned(value));
-      Goto(&done);
-    }
-
-    BIND(&if_negative);
-    {
-      StoreBigIntBitfield(var_result.value(),
-                          IntPtrConstant(BigInt::SignBits::encode(true) |
-                                         BigInt::LengthBits::encode(1)));
-      StoreBigIntDigit(var_result.value(), 0,
-                       Unsigned(IntPtrSub(IntPtrConstant(0), value)));
-      Goto(&done);
-    }
+    return BigIntFromInt64(value);
   } else {
     DCHECK(!Is64());
-    TVARIABLE(WordT, var_sign, IntPtrConstant(BigInt::SignBits::encode(false)));
-    TVARIABLE(IntPtrT, var_low);
-    TVARIABLE(IntPtrT, var_high);
 #if defined(V8_TARGET_BIG_ENDIAN)
-    var_high = UncheckedCast<IntPtrT>(
+    TNode<IntPtrT> high = UncheckedCast<IntPtrT>(
         Load(MachineType::UintPtr(), data_pointer, offset));
-    var_low = UncheckedCast<IntPtrT>(
+    TNode<IntPtrT> low = UncheckedCast<IntPtrT>(
         Load(MachineType::UintPtr(), data_pointer,
              Int32Add(offset, Int32Constant(kPointerSize))));
 #else
-    var_low = UncheckedCast<IntPtrT>(
+    TNode<IntPtrT> low = UncheckedCast<IntPtrT>(
         Load(MachineType::UintPtr(), data_pointer, offset));
-    var_high = UncheckedCast<IntPtrT>(
+    TNode<IntPtrT> high = UncheckedCast<IntPtrT>(
         Load(MachineType::UintPtr(), data_pointer,
              Int32Add(offset, Int32Constant(kPointerSize))));
 #endif
+    return BigIntFromInt32Pair(low, high);
+  }
+}
 
-    Label high_zero(this), negative(this), allocate_one_digit(this),
-        allocate_two_digits(this);
-
-    GotoIf(WordEqual(var_high.value(), IntPtrConstant(0)), &high_zero);
-    Branch(IntPtrLessThan(var_high.value(), IntPtrConstant(0)), &negative,
+TNode<BigInt> CodeStubAssembler::BigIntFromInt32Pair(TNode<IntPtrT> low,
+                                                     TNode<IntPtrT> high) {
+  DCHECK(!Is64());
+  TVARIABLE(BigInt, var_result);
+  TVARIABLE(WordT, var_sign, IntPtrConstant(BigInt::SignBits::encode(false)));
+  TVARIABLE(IntPtrT, var_high, high);
+  TVARIABLE(IntPtrT, var_low, low);
+  Label high_zero(this), negative(this), allocate_one_digit(this),
+      allocate_two_digits(this), if_zero(this), done(this);
+
+  GotoIf(WordEqual(var_high.value(), IntPtrConstant(0)), &high_zero);
+  Branch(IntPtrLessThan(var_high.value(), IntPtrConstant(0)), &negative,
+         &allocate_two_digits);
+
+  BIND(&high_zero);
+  Branch(WordEqual(var_low.value(), IntPtrConstant(0)), &if_zero,
+         &allocate_one_digit);
+
+  BIND(&negative);
+  {
+    var_sign = IntPtrConstant(BigInt::SignBits::encode(true));
+    // We must negate the value by computing "0 - (high|low)", performing
+    // both parts of the subtraction separately and manually taking care
+    // of the carry bit (which is 1 iff low != 0).
+    var_high = IntPtrSub(IntPtrConstant(0), var_high.value());
+    Label carry(this), no_carry(this);
+    Branch(WordEqual(var_low.value(), IntPtrConstant(0)), &no_carry, &carry);
+    BIND(&carry);
+    var_high = IntPtrSub(var_high.value(), IntPtrConstant(1));
+    Goto(&no_carry);
+    BIND(&no_carry);
+    var_low = IntPtrSub(IntPtrConstant(0), var_low.value());
+    // var_high was non-zero going into this block, but subtracting the
+    // carry bit from it could bring us back onto the "one digit" path.
+    Branch(WordEqual(var_high.value(), IntPtrConstant(0)), &allocate_one_digit,
            &allocate_two_digits);
+  }
 
-    BIND(&high_zero);
-    Branch(WordEqual(var_low.value(), IntPtrConstant(0)), &if_zero,
-           &allocate_one_digit);
-
-    BIND(&negative);
-    {
-      var_sign = IntPtrConstant(BigInt::SignBits::encode(true));
-      // We must negate the value by computing "0 - (high|low)", performing
-      // both parts of the subtraction separately and manually taking care
-      // of the carry bit (which is 1 iff low != 0).
-      var_high = IntPtrSub(IntPtrConstant(0), var_high.value());
-      Label carry(this), no_carry(this);
-      Branch(WordEqual(var_low.value(), IntPtrConstant(0)), &no_carry, &carry);
-      BIND(&carry);
-      var_high = IntPtrSub(var_high.value(), IntPtrConstant(1));
-      Goto(&no_carry);
-      BIND(&no_carry);
-      var_low = IntPtrSub(IntPtrConstant(0), var_low.value());
-      // var_high was non-zero going into this block, but subtracting the
-      // carry bit from it could bring us back onto the "one digit" path.
-      Branch(WordEqual(var_high.value(), IntPtrConstant(0)),
-             &allocate_one_digit, &allocate_two_digits);
-    }
-
-    BIND(&allocate_one_digit);
-    {
-      var_result = AllocateRawBigInt(IntPtrConstant(1));
-      StoreBigIntBitfield(
-          var_result.value(),
-          WordOr(var_sign.value(),
-                 IntPtrConstant(BigInt::LengthBits::encode(1))));
-      StoreBigIntDigit(var_result.value(), 0, Unsigned(var_low.value()));
-      Goto(&done);
-    }
+  BIND(&allocate_one_digit);
+  {
+    var_result = AllocateRawBigInt(IntPtrConstant(1));
+    StoreBigIntBitfield(var_result.value(),
+                        WordOr(var_sign.value(),
+                               IntPtrConstant(BigInt::LengthBits::encode(1))));
+    StoreBigIntDigit(var_result.value(), 0, Unsigned(var_low.value()));
+    Goto(&done);
+  }
 
-    BIND(&allocate_two_digits);
-    {
-      var_result = AllocateRawBigInt(IntPtrConstant(2));
-      StoreBigIntBitfield(
-          var_result.value(),
-          WordOr(var_sign.value(),
-                 IntPtrConstant(BigInt::LengthBits::encode(2))));
-      StoreBigIntDigit(var_result.value(), 0, Unsigned(var_low.value()));
-      StoreBigIntDigit(var_result.value(), 1, Unsigned(var_high.value()));
-      Goto(&done);
-    }
+  BIND(&allocate_two_digits);
+  {
+    var_result = AllocateRawBigInt(IntPtrConstant(2));
+    StoreBigIntBitfield(var_result.value(),
+                        WordOr(var_sign.value(),
+                               IntPtrConstant(BigInt::LengthBits::encode(2))));
+    StoreBigIntDigit(var_result.value(), 0, Unsigned(var_low.value()));
+    StoreBigIntDigit(var_result.value(), 1, Unsigned(var_high.value()));
+    Goto(&done);
   }
+
   BIND(&if_zero);
   var_result = AllocateBigInt(IntPtrConstant(0));
   Goto(&done);
@@ -2109,21 +2127,53 @@ Node* CodeStubAssembler::LoadFixedBigInt64ArrayElementAsTagged(
   return var_result.value();
 }
 
+TNode<BigInt> CodeStubAssembler::BigIntFromInt64(TNode<IntPtrT> value) {
+  DCHECK(Is64());
+  TVARIABLE(BigInt, var_result);
+  Label done(this), if_positive(this), if_negative(this), if_zero(this);
+  GotoIf(WordEqual(value, IntPtrConstant(0)), &if_zero);
+  var_result = AllocateRawBigInt(IntPtrConstant(1));
+  Branch(IntPtrGreaterThan(value, IntPtrConstant(0)), &if_positive,
+         &if_negative);
+
+  BIND(&if_positive);
+  {
+    StoreBigIntBitfield(var_result.value(),
+                        IntPtrConstant(BigInt::SignBits::encode(false) |
+                                       BigInt::LengthBits::encode(1)));
+    StoreBigIntDigit(var_result.value(), 0, Unsigned(value));
+    Goto(&done);
+  }
+
+  BIND(&if_negative);
+  {
+    StoreBigIntBitfield(var_result.value(),
+                        IntPtrConstant(BigInt::SignBits::encode(true) |
+                                       BigInt::LengthBits::encode(1)));
+    StoreBigIntDigit(var_result.value(), 0,
+                     Unsigned(IntPtrSub(IntPtrConstant(0), value)));
+    Goto(&done);
+  }
+
+  BIND(&if_zero);
+  {
+    var_result = AllocateBigInt(IntPtrConstant(0));
+    Goto(&done);
+  }
+
+  BIND(&done);
+  return var_result.value();
+}
+
 Node* CodeStubAssembler::LoadFixedBigUint64ArrayElementAsTagged(
     Node* data_pointer, Node* offset) {
-  TVARIABLE(BigInt, var_result);
   Label if_zero(this), done(this);
   if (Is64()) {
     TNode<UintPtrT> value = UncheckedCast<UintPtrT>(
         Load(MachineType::UintPtr(), data_pointer, offset));
-    GotoIf(IntPtrEqual(value, IntPtrConstant(0)), &if_zero);
-    var_result = AllocateBigInt(IntPtrConstant(1));
-    StoreBigIntDigit(var_result.value(), 0, value);
-    Goto(&done);
+    return BigIntFromUint64(value);
   } else {
     DCHECK(!Is64());
-    Label high_zero(this);
-
 #if defined(V8_TARGET_BIG_ENDIAN)
     TNode<UintPtrT> high = UncheckedCast<UintPtrT>(
         Load(MachineType::UintPtr(), data_pointer, offset));
@@ -2137,19 +2187,28 @@ Node* CodeStubAssembler::LoadFixedBigUint64ArrayElementAsTagged(
         Load(MachineType::UintPtr(), data_pointer,
              Int32Add(offset, Int32Constant(kPointerSize))));
 #endif
+    return BigIntFromUint32Pair(low, high);
+  }
+}
 
-    GotoIf(WordEqual(high, IntPtrConstant(0)), &high_zero);
-    var_result = AllocateBigInt(IntPtrConstant(2));
-    StoreBigIntDigit(var_result.value(), 0, low);
-    StoreBigIntDigit(var_result.value(), 1, high);
-    Goto(&done);
+TNode<BigInt> CodeStubAssembler::BigIntFromUint32Pair(TNode<UintPtrT> low,
+                                                      TNode<UintPtrT> high) {
+  DCHECK(!Is64());
+  TVARIABLE(BigInt, var_result);
+  Label high_zero(this), if_zero(this), done(this);
+
+  GotoIf(WordEqual(high, IntPtrConstant(0)), &high_zero);
+  var_result = AllocateBigInt(IntPtrConstant(2));
+  StoreBigIntDigit(var_result.value(), 0, low);
+  StoreBigIntDigit(var_result.value(), 1, high);
+  Goto(&done);
+
+  BIND(&high_zero);
+  GotoIf(WordEqual(low, IntPtrConstant(0)), &if_zero);
+  var_result = AllocateBigInt(IntPtrConstant(1));
+  StoreBigIntDigit(var_result.value(), 0, low);
+  Goto(&done);
 
-    BIND(&high_zero);
-    GotoIf(WordEqual(low, IntPtrConstant(0)), &if_zero);
-    var_result = AllocateBigInt(IntPtrConstant(1));
-    StoreBigIntDigit(var_result.value(), 0, low);
-    Goto(&done);
-  }
   BIND(&if_zero);
   var_result = AllocateBigInt(IntPtrConstant(0));
   Goto(&done);
@@ -2158,6 +2217,22 @@ Node* CodeStubAssembler::LoadFixedBigUint64ArrayElementAsTagged(
   return var_result.value();
 }
 
+TNode<BigInt> CodeStubAssembler::BigIntFromUint64(TNode<UintPtrT> value) {
+  DCHECK(Is64());
+  TVARIABLE(BigInt, var_result);
+  Label done(this), if_zero(this);
+  GotoIf(WordEqual(value, IntPtrConstant(0)), &if_zero);
+  var_result = AllocateBigInt(IntPtrConstant(1));
+  StoreBigIntDigit(var_result.value(), 0, value);
+  Goto(&done);
+
+  BIND(&if_zero);
+  var_result = AllocateBigInt(IntPtrConstant(0));
+  Goto(&done);
+  BIND(&done);
+  return var_result.value();
+}
+
 Node* CodeStubAssembler::LoadFixedTypedArrayElementAsTagged(
     Node* data_pointer, Node* index_node, ElementsKind elements_kind,
     ParameterMode parameter_mode) {
@@ -2452,8 +2527,16 @@ TNode<Object> CodeStubAssembler::LoadContextElement(
 TNode<Object> CodeStubAssembler::LoadContextElement(
     SloppyTNode<Context> context, SloppyTNode<IntPtrT> slot_index) {
   Node* offset =
-      IntPtrAdd(TimesPointerSize(slot_index),
-                IntPtrConstant(Context::kHeaderSize - kHeapObjectTag));
+      ElementOffsetFromIndex(slot_index, PACKED_ELEMENTS, INTPTR_PARAMETERS,
+                             Context::kHeaderSize - kHeapObjectTag);
+  return UncheckedCast<Object>(Load(MachineType::AnyTagged(), context, offset));
+}
+
+TNode<Object> CodeStubAssembler::LoadContextElement(TNode<Context> context,
+                                                    TNode<Smi> slot_index) {
+  Node* offset =
+      ElementOffsetFromIndex(slot_index, PACKED_ELEMENTS, SMI_PARAMETERS,
+                             Context::kHeaderSize - kHeapObjectTag);
   return UncheckedCast<Object>(Load(MachineType::AnyTagged(), context, offset));
 }
 
@@ -2488,7 +2571,7 @@ TNode<Context> CodeStubAssembler::LoadNativeContext(
 
 TNode<Context> CodeStubAssembler::LoadModuleContext(
     SloppyTNode<Context> context) {
-  Node* module_map = LoadRoot(Heap::kModuleContextMapRootIndex);
+  Node* module_map = LoadRoot(RootIndex::kModuleContextMap);
   Variable cur_context(this, MachineRepresentation::kTaggedPointer);
   cur_context.Bind(context);
 
@@ -2671,8 +2754,8 @@ Node* CodeStubAssembler::StoreMap(Node* object, Node* map) {
       object, IntPtrConstant(HeapObject::kMapOffset - kHeapObjectTag), map);
 }
 
-Node* CodeStubAssembler::StoreMapNoWriteBarrier(
-    Node* object, Heap::RootListIndex map_root_index) {
+Node* CodeStubAssembler::StoreMapNoWriteBarrier(Node* object,
+                                                RootIndex map_root_index) {
   return StoreMapNoWriteBarrier(object, LoadRoot(map_root_index));
 }
 
@@ -2684,7 +2767,7 @@ Node* CodeStubAssembler::StoreMapNoWriteBarrier(Node* object, Node* map) {
 }
 
 Node* CodeStubAssembler::StoreObjectFieldRoot(Node* object, int offset,
-                                              Heap::RootListIndex root_index) {
+                                              RootIndex root_index) {
   if (Heap::RootIsImmortalImmovable(root_index)) {
     return StoreObjectFieldNoWriteBarrier(object, offset, LoadRoot(root_index));
   } else {
@@ -2800,7 +2883,7 @@ void CodeStubAssembler::EnsureArrayLengthWritable(TNode<Map> map,
   TNode<Name> maybe_length = CAST(LoadWeakFixedArrayElement(
       descriptors, DescriptorArray::ToKeyIndex(length_index)));
   CSA_ASSERT(this,
-             WordEqual(maybe_length, LoadRoot(Heap::klength_stringRootIndex)));
+             WordEqual(maybe_length, LoadRoot(RootIndex::klength_string)));
 #endif
 
   TNode<Uint32T> details = LoadDetailsByKeyIndex(
@@ -2941,7 +3024,7 @@ void CodeStubAssembler::BuildAppendJSArray(ElementsKind kind, Node* array,
 Node* CodeStubAssembler::AllocateCellWithValue(Node* value,
                                                WriteBarrierMode mode) {
   Node* result = Allocate(Cell::kSize, kNone);
-  StoreMapNoWriteBarrier(result, Heap::kCellMapRootIndex);
+  StoreMapNoWriteBarrier(result, RootIndex::kCellMap);
   StoreCellValue(result, value, mode);
   return result;
 }
@@ -2965,7 +3048,7 @@ Node* CodeStubAssembler::StoreCellValue(Node* cell, Node* value,
 
 TNode<HeapNumber> CodeStubAssembler::AllocateHeapNumber() {
   Node* result = Allocate(HeapNumber::kSize, kNone);
-  Heap::RootListIndex heap_map_index = Heap::kHeapNumberMapRootIndex;
+  RootIndex heap_map_index = RootIndex::kHeapNumberMap;
   StoreMapNoWriteBarrier(result, heap_map_index);
   return UncheckedCast<HeapNumber>(result);
 }
@@ -2979,7 +3062,7 @@ TNode<HeapNumber> CodeStubAssembler::AllocateHeapNumberWithValue(
 
 TNode<MutableHeapNumber> CodeStubAssembler::AllocateMutableHeapNumber() {
   Node* result = Allocate(MutableHeapNumber::kSize, kNone);
-  Heap::RootListIndex heap_map_index = Heap::kMutableHeapNumberMapRootIndex;
+  RootIndex heap_map_index = RootIndex::kMutableHeapNumberMap;
   StoreMapNoWriteBarrier(result, heap_map_index);
   return UncheckedCast<MutableHeapNumber>(result);
 }
@@ -3005,7 +3088,7 @@ TNode<BigInt> CodeStubAssembler::AllocateRawBigInt(TNode<IntPtrT> length) {
   TNode<IntPtrT> size = IntPtrAdd(IntPtrConstant(BigInt::kHeaderSize),
                                   Signed(WordShl(length, kPointerSizeLog2)));
   Node* raw_result = Allocate(size, kNone);
-  StoreMapNoWriteBarrier(raw_result, Heap::kBigIntMapRootIndex);
+  StoreMapNoWriteBarrier(raw_result, RootIndex::kBigIntMap);
   return UncheckedCast<BigInt>(raw_result);
 }
 
@@ -3035,20 +3118,20 @@ TNode<UintPtrT> CodeStubAssembler::LoadBigIntDigit(TNode<BigInt> bigint,
 }
 
 TNode<String> CodeStubAssembler::AllocateSeqOneByteString(
-    int length, AllocationFlags flags) {
+    uint32_t length, AllocationFlags flags) {
   Comment("AllocateSeqOneByteString");
   if (length == 0) {
-    return CAST(LoadRoot(Heap::kempty_stringRootIndex));
+    return CAST(LoadRoot(RootIndex::kempty_string));
   }
   Node* result = Allocate(SeqOneByteString::SizeFor(length), flags);
-  DCHECK(Heap::RootIsImmortalImmovable(Heap::kOneByteStringMapRootIndex));
-  StoreMapNoWriteBarrier(result, Heap::kOneByteStringMapRootIndex);
+  DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kOneByteStringMap));
+  StoreMapNoWriteBarrier(result, RootIndex::kOneByteStringMap);
   StoreObjectFieldNoWriteBarrier(result, SeqOneByteString::kLengthOffset,
-                                 SmiConstant(length),
-                                 MachineRepresentation::kTagged);
-  StoreObjectFieldNoWriteBarrier(result, SeqOneByteString::kHashFieldSlot,
-                                 IntPtrConstant(String::kEmptyHashField),
-                                 MachineType::PointerRepresentation());
+                                 Uint32Constant(length),
+                                 MachineRepresentation::kWord32);
+  StoreObjectFieldNoWriteBarrier(result, SeqOneByteString::kHashFieldOffset,
+                                 Int32Constant(String::kEmptyHashField),
+                                 MachineRepresentation::kWord32);
   return CAST(result);
 }
 
@@ -3059,7 +3142,7 @@ TNode<BoolT> CodeStubAssembler::IsZeroOrContext(SloppyTNode<Object> object) {
 }
 
 TNode<String> CodeStubAssembler::AllocateSeqOneByteString(
-    Node* context, TNode<Smi> length, AllocationFlags flags) {
+    Node* context, TNode<Uint32T> length, AllocationFlags flags) {
   Comment("AllocateSeqOneByteString");
   CSA_SLOW_ASSERT(this, IsZeroOrContext(context));
   VARIABLE(var_result, MachineRepresentation::kTagged);
@@ -3067,10 +3150,10 @@ TNode<String> CodeStubAssembler::AllocateSeqOneByteString(
   // Compute the SeqOneByteString size and check if it fits into new space.
   Label if_lengthiszero(this), if_sizeissmall(this),
       if_notsizeissmall(this, Label::kDeferred), if_join(this);
-  GotoIf(SmiEqual(length, SmiConstant(0)), &if_lengthiszero);
+  GotoIf(Word32Equal(length, Uint32Constant(0)), &if_lengthiszero);
 
   Node* raw_size = GetArrayAllocationSize(
-      SmiUntag(length), UINT8_ELEMENTS, INTPTR_PARAMETERS,
+      Signed(ChangeUint32ToWord(length)), UINT8_ELEMENTS, INTPTR_PARAMETERS,
       SeqOneByteString::kHeaderSize + kObjectAlignmentMask);
   Node* size = WordAnd(raw_size, IntPtrConstant(~kObjectAlignmentMask));
   Branch(IntPtrLessThanOrEqual(size, IntPtrConstant(kMaxRegularHeapObjectSize)),
@@ -3080,13 +3163,13 @@ TNode<String> CodeStubAssembler::AllocateSeqOneByteString(
   {
     // Just allocate the SeqOneByteString in new space.
     Node* result = AllocateInNewSpace(size, flags);
-    DCHECK(Heap::RootIsImmortalImmovable(Heap::kOneByteStringMapRootIndex));
-    StoreMapNoWriteBarrier(result, Heap::kOneByteStringMapRootIndex);
+    DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kOneByteStringMap));
+    StoreMapNoWriteBarrier(result, RootIndex::kOneByteStringMap);
     StoreObjectFieldNoWriteBarrier(result, SeqOneByteString::kLengthOffset,
-                                   length, MachineRepresentation::kTagged);
-    StoreObjectFieldNoWriteBarrier(result, SeqOneByteString::kHashFieldSlot,
-                                   IntPtrConstant(String::kEmptyHashField),
-                                   MachineType::PointerRepresentation());
+                                   length, MachineRepresentation::kWord32);
+    StoreObjectFieldNoWriteBarrier(result, SeqOneByteString::kHashFieldOffset,
+                                   Int32Constant(String::kEmptyHashField),
+                                   MachineRepresentation::kWord32);
     var_result.Bind(result);
     Goto(&if_join);
   }
@@ -3094,15 +3177,15 @@ TNode<String> CodeStubAssembler::AllocateSeqOneByteString(
   BIND(&if_notsizeissmall);
   {
     // We might need to allocate in large object space, go to the runtime.
-    Node* result =
-        CallRuntime(Runtime::kAllocateSeqOneByteString, context, length);
+    Node* result = CallRuntime(Runtime::kAllocateSeqOneByteString, context,
+                               ChangeUint32ToTagged(length));
     var_result.Bind(result);
     Goto(&if_join);
   }
 
   BIND(&if_lengthiszero);
   {
-    var_result.Bind(LoadRoot(Heap::kempty_stringRootIndex));
+    var_result.Bind(LoadRoot(RootIndex::kempty_string));
     Goto(&if_join);
   }
 
@@ -3111,25 +3194,25 @@ TNode<String> CodeStubAssembler::AllocateSeqOneByteString(
 }
 
 TNode<String> CodeStubAssembler::AllocateSeqTwoByteString(
-    int length, AllocationFlags flags) {
+    uint32_t length, AllocationFlags flags) {
   Comment("AllocateSeqTwoByteString");
   if (length == 0) {
-    return CAST(LoadRoot(Heap::kempty_stringRootIndex));
+    return CAST(LoadRoot(RootIndex::kempty_string));
   }
   Node* result = Allocate(SeqTwoByteString::SizeFor(length), flags);
-  DCHECK(Heap::RootIsImmortalImmovable(Heap::kStringMapRootIndex));
-  StoreMapNoWriteBarrier(result, Heap::kStringMapRootIndex);
+  DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kStringMap));
+  StoreMapNoWriteBarrier(result, RootIndex::kStringMap);
   StoreObjectFieldNoWriteBarrier(result, SeqTwoByteString::kLengthOffset,
-                                 SmiConstant(Smi::FromInt(length)),
-                                 MachineRepresentation::kTagged);
-  StoreObjectFieldNoWriteBarrier(result, SeqTwoByteString::kHashFieldSlot,
-                                 IntPtrConstant(String::kEmptyHashField),
-                                 MachineType::PointerRepresentation());
+                                 Uint32Constant(length),
+                                 MachineRepresentation::kWord32);
+  StoreObjectFieldNoWriteBarrier(result, SeqTwoByteString::kHashFieldOffset,
+                                 Int32Constant(String::kEmptyHashField),
+                                 MachineRepresentation::kWord32);
   return CAST(result);
 }
 
 TNode<String> CodeStubAssembler::AllocateSeqTwoByteString(
-    Node* context, TNode<Smi> length, AllocationFlags flags) {
+    Node* context, TNode<Uint32T> length, AllocationFlags flags) {
   CSA_SLOW_ASSERT(this, IsZeroOrContext(context));
   Comment("AllocateSeqTwoByteString");
   VARIABLE(var_result, MachineRepresentation::kTagged);
@@ -3137,10 +3220,10 @@ TNode<String> CodeStubAssembler::AllocateSeqTwoByteString(
   // Compute the SeqTwoByteString size and check if it fits into new space.
   Label if_lengthiszero(this), if_sizeissmall(this),
       if_notsizeissmall(this, Label::kDeferred), if_join(this);
-  GotoIf(SmiEqual(length, SmiConstant(0)), &if_lengthiszero);
+  GotoIf(Word32Equal(length, Uint32Constant(0)), &if_lengthiszero);
 
   Node* raw_size = GetArrayAllocationSize(
-      SmiUntag(length), UINT16_ELEMENTS, INTPTR_PARAMETERS,
+      Signed(ChangeUint32ToWord(length)), UINT16_ELEMENTS, INTPTR_PARAMETERS,
       SeqOneByteString::kHeaderSize + kObjectAlignmentMask);
   Node* size = WordAnd(raw_size, IntPtrConstant(~kObjectAlignmentMask));
   Branch(IntPtrLessThanOrEqual(size, IntPtrConstant(kMaxRegularHeapObjectSize)),
@@ -3150,13 +3233,13 @@ TNode<String> CodeStubAssembler::AllocateSeqTwoByteString(
   {
     // Just allocate the SeqTwoByteString in new space.
     Node* result = AllocateInNewSpace(size, flags);
-    DCHECK(Heap::RootIsImmortalImmovable(Heap::kStringMapRootIndex));
-    StoreMapNoWriteBarrier(result, Heap::kStringMapRootIndex);
+    DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kStringMap));
+    StoreMapNoWriteBarrier(result, RootIndex::kStringMap);
     StoreObjectFieldNoWriteBarrier(result, SeqTwoByteString::kLengthOffset,
-                                   length, MachineRepresentation::kTagged);
-    StoreObjectFieldNoWriteBarrier(result, SeqTwoByteString::kHashFieldSlot,
-                                   IntPtrConstant(String::kEmptyHashField),
-                                   MachineType::PointerRepresentation());
+                                   length, MachineRepresentation::kWord32);
+    StoreObjectFieldNoWriteBarrier(result, SeqTwoByteString::kHashFieldOffset,
+                                   Int32Constant(String::kEmptyHashField),
+                                   MachineRepresentation::kWord32);
     var_result.Bind(result);
     Goto(&if_join);
   }
@@ -3164,15 +3247,15 @@ TNode<String> CodeStubAssembler::AllocateSeqTwoByteString(
   BIND(&if_notsizeissmall);
   {
     // We might need to allocate in large object space, go to the runtime.
-    Node* result =
-        CallRuntime(Runtime::kAllocateSeqTwoByteString, context, length);
+    Node* result = CallRuntime(Runtime::kAllocateSeqTwoByteString, context,
+                               ChangeUint32ToTagged(length));
     var_result.Bind(result);
     Goto(&if_join);
   }
 
   BIND(&if_lengthiszero);
   {
-    var_result.Bind(LoadRoot(Heap::kempty_stringRootIndex));
+    var_result.Bind(LoadRoot(RootIndex::kempty_string));
     Goto(&if_join);
   }
 
@@ -3180,19 +3263,20 @@ TNode<String> CodeStubAssembler::AllocateSeqTwoByteString(
   return CAST(var_result.value());
 }
 
-TNode<String> CodeStubAssembler::AllocateSlicedString(
-    Heap::RootListIndex map_root_index, TNode<Smi> length, TNode<String> parent,
-    TNode<Smi> offset) {
-  DCHECK(map_root_index == Heap::kSlicedOneByteStringMapRootIndex ||
-         map_root_index == Heap::kSlicedStringMapRootIndex);
+TNode<String> CodeStubAssembler::AllocateSlicedString(RootIndex map_root_index,
+                                                      TNode<Uint32T> length,
+                                                      TNode<String> parent,
+                                                      TNode<Smi> offset) {
+  DCHECK(map_root_index == RootIndex::kSlicedOneByteStringMap ||
+         map_root_index == RootIndex::kSlicedStringMap);
   Node* result = Allocate(SlicedString::kSize);
   DCHECK(Heap::RootIsImmortalImmovable(map_root_index));
   StoreMapNoWriteBarrier(result, map_root_index);
+  StoreObjectFieldNoWriteBarrier(result, SlicedString::kHashFieldOffset,
+                                 Int32Constant(String::kEmptyHashField),
+                                 MachineRepresentation::kWord32);
   StoreObjectFieldNoWriteBarrier(result, SlicedString::kLengthOffset, length,
-                                 MachineRepresentation::kTagged);
-  StoreObjectFieldNoWriteBarrier(result, SlicedString::kHashFieldSlot,
-                                 IntPtrConstant(String::kEmptyHashField),
-                                 MachineType::PointerRepresentation());
+                                 MachineRepresentation::kWord32);
   StoreObjectFieldNoWriteBarrier(result, SlicedString::kParentOffset, parent,
                                  MachineRepresentation::kTagged);
   StoreObjectFieldNoWriteBarrier(result, SlicedString::kOffsetOffset, offset,
@@ -3201,30 +3285,32 @@ TNode<String> CodeStubAssembler::AllocateSlicedString(
 }
 
 TNode<String> CodeStubAssembler::AllocateSlicedOneByteString(
-    TNode<Smi> length, TNode<String> parent, TNode<Smi> offset) {
-  return AllocateSlicedString(Heap::kSlicedOneByteStringMapRootIndex, length,
+    TNode<Uint32T> length, TNode<String> parent, TNode<Smi> offset) {
+  return AllocateSlicedString(RootIndex::kSlicedOneByteStringMap, length,
                               parent, offset);
 }
 
 TNode<String> CodeStubAssembler::AllocateSlicedTwoByteString(
-    TNode<Smi> length, TNode<String> parent, TNode<Smi> offset) {
-  return AllocateSlicedString(Heap::kSlicedStringMapRootIndex, length, parent,
+    TNode<Uint32T> length, TNode<String> parent, TNode<Smi> offset) {
+  return AllocateSlicedString(RootIndex::kSlicedStringMap, length, parent,
                               offset);
 }
 
-TNode<String> CodeStubAssembler::AllocateConsString(
-    Heap::RootListIndex map_root_index, TNode<Smi> length, TNode<String> first,
-    TNode<String> second, AllocationFlags flags) {
-  DCHECK(map_root_index == Heap::kConsOneByteStringMapRootIndex ||
-         map_root_index == Heap::kConsStringMapRootIndex);
+TNode<String> CodeStubAssembler::AllocateConsString(RootIndex map_root_index,
+                                                    TNode<Uint32T> length,
+                                                    TNode<String> first,
+                                                    TNode<String> second,
+                                                    AllocationFlags flags) {
+  DCHECK(map_root_index == RootIndex::kConsOneByteStringMap ||
+         map_root_index == RootIndex::kConsStringMap);
   Node* result = Allocate(ConsString::kSize, flags);
   DCHECK(Heap::RootIsImmortalImmovable(map_root_index));
   StoreMapNoWriteBarrier(result, map_root_index);
   StoreObjectFieldNoWriteBarrier(result, ConsString::kLengthOffset, length,
-                                 MachineRepresentation::kTagged);
-  StoreObjectFieldNoWriteBarrier(result, ConsString::kHashFieldSlot,
-                                 IntPtrConstant(String::kEmptyHashField),
-                                 MachineType::PointerRepresentation());
+                                 MachineRepresentation::kWord32);
+  StoreObjectFieldNoWriteBarrier(result, ConsString::kHashFieldOffset,
+                                 Int32Constant(String::kEmptyHashField),
+                                 MachineRepresentation::kWord32);
   bool const new_space = !(flags & kPretenured);
   if (new_space) {
     StoreObjectFieldNoWriteBarrier(result, ConsString::kFirstOffset, first,
@@ -3239,24 +3325,23 @@ TNode<String> CodeStubAssembler::AllocateConsString(
 }
 
 TNode<String> CodeStubAssembler::AllocateOneByteConsString(
-    TNode<Smi> length, TNode<String> first, TNode<String> second,
+    TNode<Uint32T> length, TNode<String> first, TNode<String> second,
     AllocationFlags flags) {
-  return AllocateConsString(Heap::kConsOneByteStringMapRootIndex, length, first,
+  return AllocateConsString(RootIndex::kConsOneByteStringMap, length, first,
                             second, flags);
 }
 
 TNode<String> CodeStubAssembler::AllocateTwoByteConsString(
-    TNode<Smi> length, TNode<String> first, TNode<String> second,
+    TNode<Uint32T> length, TNode<String> first, TNode<String> second,
     AllocationFlags flags) {
-  return AllocateConsString(Heap::kConsStringMapRootIndex, length, first,
-                            second, flags);
+  return AllocateConsString(RootIndex::kConsStringMap, length, first, second,
+                            flags);
 }
 
-TNode<String> CodeStubAssembler::NewConsString(Node* context, TNode<Smi> length,
+TNode<String> CodeStubAssembler::NewConsString(TNode<Uint32T> length,
                                                TNode<String> left,
                                                TNode<String> right,
                                                AllocationFlags flags) {
-  CSA_ASSERT(this, IsContext(context));
   // Added string can be a cons string.
   Comment("Allocating ConsString");
   Node* left_instance_type = LoadInstanceType(left);
@@ -3333,8 +3418,8 @@ TNode<NameDictionary> CodeStubAssembler::AllocateNameDictionaryWithCapacity(
       UncheckedCast<NameDictionary>(AllocateInNewSpace(store_size));
   Comment("Initialize NameDictionary");
   // Initialize FixedArray fields.
-  DCHECK(Heap::RootIsImmortalImmovable(Heap::kNameDictionaryMapRootIndex));
-  StoreMapNoWriteBarrier(result, Heap::kNameDictionaryMapRootIndex);
+  DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kNameDictionaryMap));
+  StoreMapNoWriteBarrier(result, RootIndex::kNameDictionaryMap);
   StoreObjectFieldNoWriteBarrier(result, FixedArray::kLengthOffset,
                                  SmiFromIntPtr(length));
   // Initialized HashTable fields.
@@ -3398,8 +3483,8 @@ Node* CodeStubAssembler::AllocateOrderedHashTable() {
   // Allocate the table and add the proper map.
   const ElementsKind elements_kind = HOLEY_ELEMENTS;
   TNode<IntPtrT> length_intptr = IntPtrConstant(kFixedArrayLength);
-  TNode<Map> fixed_array_map = CAST(LoadRoot(
-      static_cast<Heap::RootListIndex>(CollectionType::GetMapRootIndex())));
+  TNode<Map> fixed_array_map =
+      CAST(LoadRoot(CollectionType::GetMapRootIndex()));
   TNode<FixedArray> table =
       CAST(AllocateFixedArray(elements_kind, length_intptr,
                               kAllowLargeObjectAllocation, fixed_array_map));
@@ -3472,8 +3557,8 @@ TNode<CollectionType> CodeStubAssembler::AllocateSmallOrderedHashTable(
       UncheckedCast<IntPtrT>(TimesPointerSize(total_size_word_aligned));
 
   // Allocate the table and add the proper map.
-  TNode<Map> small_ordered_hash_map = CAST(LoadRoot(
-      static_cast<Heap::RootListIndex>(CollectionType::GetMapRootIndex())));
+  TNode<Map> small_ordered_hash_map =
+      CAST(LoadRoot(CollectionType::GetMapRootIndex()));
   TNode<Object> table_obj = CAST(AllocateInNewSpace(total_size_word_aligned));
   StoreMapNoWriteBarrier(table_obj, small_ordered_hash_map);
   TNode<CollectionType> table = UncheckedCast<CollectionType>(table_obj);
@@ -3521,7 +3606,7 @@ CodeStubAssembler::AllocateSmallOrderedHashTable<SmallOrderedHashSet>(
 template <typename CollectionType>
 void CodeStubAssembler::FindOrderedHashTableEntry(
     Node* table, Node* hash,
-    std::function<void(Node*, Label*, Label*)> key_compare,
+    const std::function<void(Node*, Label*, Label*)>& key_compare,
     Variable* entry_start_position, Label* entry_found, Label* not_found) {
   // Get the index of the bucket.
   Node* const number_of_buckets = SmiUntag(CAST(LoadFixedArrayElement(
@@ -3588,11 +3673,11 @@ void CodeStubAssembler::FindOrderedHashTableEntry(
 
 template void CodeStubAssembler::FindOrderedHashTableEntry<OrderedHashMap>(
     Node* table, Node* hash,
-    std::function<void(Node*, Label*, Label*)> key_compare,
+    const std::function<void(Node*, Label*, Label*)>& key_compare,
     Variable* entry_start_position, Label* entry_found, Label* not_found);
 template void CodeStubAssembler::FindOrderedHashTableEntry<OrderedHashSet>(
     Node* table, Node* hash,
-    std::function<void(Node*, Label*, Label*)> key_compare,
+    const std::function<void(Node*, Label*, Label*)>& key_compare,
     Variable* entry_start_position, Label* entry_found, Label* not_found);
 
 Node* CodeStubAssembler::AllocateStruct(Node* map, AllocationFlags flags) {
@@ -3643,7 +3728,7 @@ void CodeStubAssembler::InitializeJSObjectFromMap(
   if (properties == nullptr) {
     CSA_ASSERT(this, Word32BinaryNot(IsDictionaryMap((map))));
     StoreObjectFieldRoot(object, JSObject::kPropertiesOrHashOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
   } else {
     CSA_ASSERT(this, Word32Or(Word32Or(IsPropertyArray(properties),
                                        IsNameDictionary(properties)),
@@ -3653,7 +3738,7 @@ void CodeStubAssembler::InitializeJSObjectFromMap(
   }
   if (elements == nullptr) {
     StoreObjectFieldRoot(object, JSObject::kElementsOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
   } else {
     CSA_ASSERT(this, IsFixedArray(elements));
     StoreObjectFieldNoWriteBarrier(object, JSObject::kElementsOffset, elements);
@@ -3672,7 +3757,7 @@ void CodeStubAssembler::InitializeJSObjectBodyNoSlackTracking(
   CSA_ASSERT(
       this, IsClearWord32<Map::ConstructionCounterBits>(LoadMapBitField3(map)));
   InitializeFieldsWithRoot(object, IntPtrConstant(start_offset), instance_size,
-                           Heap::kUndefinedValueRootIndex);
+                           RootIndex::kUndefinedValue);
 }
 
 void CodeStubAssembler::InitializeJSObjectBodyWithSlackTracking(
@@ -3711,11 +3796,11 @@ void CodeStubAssembler::InitializeJSObjectBodyWithSlackTracking(
 
     Comment("iInitialize filler fields");
     InitializeFieldsWithRoot(object, used_size, instance_size,
-                             Heap::kOnePointerFillerMapRootIndex);
+                             RootIndex::kOnePointerFillerMap);
 
     Comment("Initialize undefined fields");
     InitializeFieldsWithRoot(object, IntPtrConstant(start_offset), used_size,
-                             Heap::kUndefinedValueRootIndex);
+                             RootIndex::kUndefinedValue);
 
     STATIC_ASSERT(Map::kNoSlackTracking == 0);
     GotoIf(IsClearWord32<Map::ConstructionCounterBits>(new_bit_field3),
@@ -3792,9 +3877,9 @@ CodeStubAssembler::AllocateUninitializedJSArrayWithElements(
   StoreObjectFieldNoWriteBarrier(array, JSObject::kElementsOffset, elements);
   // Setup elements object.
   STATIC_ASSERT(FixedArrayBase::kHeaderSize == 2 * kPointerSize);
-  Heap::RootListIndex elements_map_index =
-      IsDoubleElementsKind(kind) ? Heap::kFixedDoubleArrayMapRootIndex
-                                 : Heap::kFixedArrayMapRootIndex;
+  RootIndex elements_map_index = IsDoubleElementsKind(kind)
+                                     ? RootIndex::kFixedDoubleArrayMap
+                                     : RootIndex::kFixedArrayMap;
   DCHECK(Heap::RootIsImmortalImmovable(elements_map_index));
   StoreMapNoWriteBarrier(elements, elements_map_index);
   TNode<Smi> capacity_smi = ParameterToTagged(capacity, capacity_mode);
@@ -3820,7 +3905,7 @@ Node* CodeStubAssembler::AllocateUninitializedJSArray(Node* array_map,
   StoreObjectFieldNoWriteBarrier(array, JSArray::kLengthOffset, length);
 
   StoreObjectFieldRoot(array, JSArray::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
 
   if (allocation_site != nullptr) {
     InitializeAllocationMemento(array, IntPtrConstant(JSArray::kSize),
@@ -3845,7 +3930,7 @@ Node* CodeStubAssembler::AllocateJSArray(ElementsKind kind, Node* array_map,
     array = AllocateUninitializedJSArrayWithoutElements(array_map, length,
                                                         allocation_site);
     StoreObjectFieldRoot(array, JSArray::kElementsOffset,
-                         Heap::kEmptyFixedArrayRootIndex);
+                         RootIndex::kEmptyFixedArray);
   } else if (TryGetIntPtrOrSmiConstantValue(capacity, &capacity_as_constant,
                                             capacity_mode) &&
              capacity_as_constant > 0) {
@@ -3855,7 +3940,7 @@ Node* CodeStubAssembler::AllocateJSArray(ElementsKind kind, Node* array_map,
     // Fill in the elements with holes.
     FillFixedArrayWithValue(kind, elements,
                             IntPtrOrSmiConstant(0, capacity_mode), capacity,
-                            Heap::kTheHoleValueRootIndex, capacity_mode);
+                            RootIndex::kTheHoleValue, capacity_mode);
   } else {
     Label out(this), empty(this), nonempty(this);
     VARIABLE(var_array, MachineRepresentation::kTagged);
@@ -3870,7 +3955,7 @@ Node* CodeStubAssembler::AllocateJSArray(ElementsKind kind, Node* array_map,
       var_array.Bind(AllocateUninitializedJSArrayWithoutElements(
           array_map, length, allocation_site));
       StoreObjectFieldRoot(var_array.value(), JSArray::kElementsOffset,
-                           Heap::kEmptyFixedArrayRootIndex);
+                           RootIndex::kEmptyFixedArray);
       Goto(&out);
     }
 
@@ -3884,7 +3969,7 @@ Node* CodeStubAssembler::AllocateJSArray(ElementsKind kind, Node* array_map,
       // Fill in the elements with holes.
       FillFixedArrayWithValue(kind, elements,
                               IntPtrOrSmiConstant(0, capacity_mode), capacity,
-                              Heap::kTheHoleValueRootIndex, capacity_mode);
+                              RootIndex::kTheHoleValue, capacity_mode);
       Goto(&out);
     }
 
@@ -3918,23 +4003,66 @@ Node* CodeStubAssembler::ExtractFastJSArray(Node* context, Node* array,
 
 Node* CodeStubAssembler::CloneFastJSArray(Node* context, Node* array,
                                           ParameterMode mode,
-                                          Node* allocation_site) {
-  Node* original_array_map = LoadMap(array);
-  Node* elements_kind = LoadMapElementsKind(original_array_map);
+                                          Node* allocation_site,
+                                          HoleConversionMode convert_holes) {
+  // TODO(dhai): we should be able to assert IsFastJSArray(array) here, but this
+  // function is also used to copy boilerplates even when the no-elements
+  // protector is invalid. This function should be renamed to reflect its uses.
+  CSA_ASSERT(this, IsJSArray(array));
 
   Node* length = LoadJSArrayLength(array);
-  Node* new_elements = ExtractFixedArray(
+  Node* new_elements = nullptr;
+  VARIABLE(var_new_elements, MachineRepresentation::kTagged);
+  TVARIABLE(Int32T, var_elements_kind, LoadMapElementsKind(LoadMap(array)));
+
+  Label allocate_jsarray(this), holey_extract(this);
+
+  bool need_conversion =
+      convert_holes == HoleConversionMode::kConvertToUndefined;
+  if (need_conversion) {
+    // We need to take care of holes, if the array is of holey elements kind.
+    GotoIf(IsHoleyFastElementsKind(var_elements_kind.value()), &holey_extract);
+  }
+
+  // Simple extraction that preserves holes.
+  new_elements = ExtractFixedArray(
       LoadElements(array), IntPtrOrSmiConstant(0, mode),
       TaggedToParameter(length, mode), nullptr,
       ExtractFixedArrayFlag::kAllFixedArraysDontCopyCOW, mode);
-
-  // Use the cannonical map for the Array's ElementsKind
+  var_new_elements.Bind(new_elements);
+  Goto(&allocate_jsarray);
+
+  if (need_conversion) {
+    BIND(&holey_extract);
+    // Convert holes to undefined.
+    TVARIABLE(BoolT, var_holes_converted, Int32FalseConstant());
+    // Copy |array|'s elements store. The copy will be compatible with the
+    // original elements kind unless there are holes in the source. Any holes
+    // get converted to undefined, hence in that case the copy is compatible
+    // only with PACKED_ELEMENTS and HOLEY_ELEMENTS, and we will choose
+    // PACKED_ELEMENTS. Also, if we want to replace holes, we must not use
+    // ExtractFixedArrayFlag::kDontCopyCOW.
+    new_elements = ExtractFixedArray(
+        LoadElements(array), IntPtrOrSmiConstant(0, mode),
+        TaggedToParameter(length, mode), nullptr,
+        ExtractFixedArrayFlag::kAllFixedArrays, mode, &var_holes_converted);
+    var_new_elements.Bind(new_elements);
+    // If the array type didn't change, use the original elements kind.
+    GotoIfNot(var_holes_converted.value(), &allocate_jsarray);
+    // Otherwise use PACKED_ELEMENTS for the target's elements kind.
+    var_elements_kind = Int32Constant(PACKED_ELEMENTS);
+    Goto(&allocate_jsarray);
+  }
+
+  BIND(&allocate_jsarray);
+  // Use the cannonical map for the chosen elements kind.
   Node* native_context = LoadNativeContext(context);
-  Node* array_map = LoadJSArrayElementsMap(elements_kind, native_context);
+  Node* array_map =
+      LoadJSArrayElementsMap(var_elements_kind.value(), native_context);
 
   Node* result = AllocateUninitializedJSArrayWithoutElements(array_map, length,
                                                              allocation_site);
-  StoreObjectField(result, JSObject::kElementsOffset, new_elements);
+  StoreObjectField(result, JSObject::kElementsOffset, var_new_elements.value());
   return result;
 }
 
@@ -3963,9 +4091,9 @@ TNode<FixedArrayBase> CodeStubAssembler::AllocateFixedArray(
       StoreMap(array, fixed_array_map);
     }
   } else {
-    Heap::RootListIndex map_index = IsDoubleElementsKind(kind)
-                                        ? Heap::kFixedDoubleArrayMapRootIndex
-                                        : Heap::kFixedArrayMapRootIndex;
+    RootIndex map_index = IsDoubleElementsKind(kind)
+                              ? RootIndex::kFixedDoubleArrayMap
+                              : RootIndex::kFixedArrayMap;
     DCHECK(Heap::RootIsImmortalImmovable(map_index));
     StoreMapNoWriteBarrier(array, map_index);
   }
@@ -3974,62 +4102,59 @@ TNode<FixedArrayBase> CodeStubAssembler::AllocateFixedArray(
   return UncheckedCast<FixedArray>(array);
 }
 
-TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedArray(
-    Node* fixed_array, Node* first, Node* count, Node* capacity,
-    ExtractFixedArrayFlags extract_flags, ParameterMode parameter_mode) {
+TNode<FixedArray> CodeStubAssembler::ExtractToFixedArray(
+    Node* source, Node* first, Node* count, Node* capacity, Node* source_map,
+    ElementsKind from_kind, AllocationFlags allocation_flags,
+    ExtractFixedArrayFlags extract_flags, ParameterMode parameter_mode,
+    HoleConversionMode convert_holes, TVariable<BoolT>* var_holes_converted) {
+  DCHECK_NE(first, nullptr);
+  DCHECK_NE(count, nullptr);
+  DCHECK_NE(capacity, nullptr);
+  DCHECK(extract_flags & ExtractFixedArrayFlag::kFixedArrays);
+  CSA_ASSERT(this,
+             WordNotEqual(IntPtrOrSmiConstant(0, parameter_mode), capacity));
+  CSA_ASSERT(this, WordEqual(source_map, LoadMap(source)));
+
   VARIABLE(var_result, MachineRepresentation::kTagged);
-  VARIABLE(var_fixed_array_map, MachineRepresentation::kTagged);
-  const AllocationFlags flags =
-      (extract_flags & ExtractFixedArrayFlag::kNewSpaceAllocationOnly)
-          ? CodeStubAssembler::kNone
-          : CodeStubAssembler::kAllowLargeObjectAllocation;
-  if (first == nullptr) {
-    first = IntPtrOrSmiConstant(0, parameter_mode);
-  }
-  if (count == nullptr) {
-    count =
-        IntPtrOrSmiSub(TaggedToParameter(LoadFixedArrayBaseLength(fixed_array),
-                                         parameter_mode),
-                       first, parameter_mode);
+  VARIABLE(var_target_map, MachineRepresentation::kTagged, source_map);
 
-    CSA_ASSERT(
-        this, IntPtrOrSmiLessThanOrEqual(IntPtrOrSmiConstant(0, parameter_mode),
-                                         count, parameter_mode));
-  }
-  if (capacity == nullptr) {
-    capacity = count;
-  } else {
-    CSA_ASSERT(this, Word32BinaryNot(IntPtrOrSmiGreaterThan(
-                         IntPtrOrSmiAdd(first, count, parameter_mode), capacity,
-                         parameter_mode)));
-  }
+  Label done(this, {&var_result}), is_cow(this),
+      new_space_check(this, {&var_target_map});
 
-  Label if_fixed_double_array(this), empty(this), cow(this),
-      done(this, {&var_result, &var_fixed_array_map});
-  var_fixed_array_map.Bind(LoadMap(fixed_array));
-  GotoIf(WordEqual(IntPtrOrSmiConstant(0, parameter_mode), capacity), &empty);
+  // If source_map is either FixedDoubleArrayMap, or FixedCOWArrayMap but
+  // we can't just use COW, use FixedArrayMap as the target map. Otherwise, use
+  // source_map as the target map.
+  if (IsDoubleElementsKind(from_kind)) {
+    CSA_ASSERT(this, IsFixedDoubleArrayMap(source_map));
+    var_target_map.Bind(LoadRoot(RootIndex::kFixedArrayMap));
+    Goto(&new_space_check);
+  } else {
+    CSA_ASSERT(this, Word32BinaryNot(IsFixedDoubleArrayMap(source_map)));
+    Branch(WordEqual(var_target_map.value(),
+                     LoadRoot(RootIndex::kFixedCOWArrayMap)),
+           &is_cow, &new_space_check);
 
-  if (extract_flags & ExtractFixedArrayFlag::kFixedDoubleArrays) {
-    if (extract_flags & ExtractFixedArrayFlag::kFixedArrays) {
-      GotoIf(IsFixedDoubleArrayMap(var_fixed_array_map.value()),
-             &if_fixed_double_array);
-    } else {
-      CSA_ASSERT(this, IsFixedDoubleArrayMap(var_fixed_array_map.value()));
+    BIND(&is_cow);
+    {
+      // |source| is a COW array, so we don't actually need to allocate a new
+      // array unless:
+      // 1) |extract_flags| forces us to, or
+      // 2) we're asked to extract only part of the |source| (|first| != 0).
+      if (extract_flags & ExtractFixedArrayFlag::kDontCopyCOW) {
+        Branch(WordNotEqual(IntPtrOrSmiConstant(0, parameter_mode), first),
+               &new_space_check, [&] {
+                 var_result.Bind(source);
+                 Goto(&done);
+               });
+      } else {
+        var_target_map.Bind(LoadRoot(RootIndex::kFixedArrayMap));
+        Goto(&new_space_check);
+      }
     }
-  } else {
-    DCHECK(extract_flags & ExtractFixedArrayFlag::kFixedArrays);
-    CSA_ASSERT(this, Word32BinaryNot(
-                         IsFixedDoubleArrayMap(var_fixed_array_map.value())));
   }
 
-  if (extract_flags & ExtractFixedArrayFlag::kFixedArrays) {
-    Label new_space_check(this, {&var_fixed_array_map});
-    Branch(WordEqual(var_fixed_array_map.value(),
-                     LoadRoot(Heap::kFixedCOWArrayMapRootIndex)),
-           &cow, &new_space_check);
-
-    BIND(&new_space_check);
-
+  BIND(&new_space_check);
+  {
     bool handle_old_space = true;
     if (extract_flags & ExtractFixedArrayFlag::kNewSpaceAllocationOnly) {
       handle_old_space = false;
@@ -4050,60 +4175,208 @@ TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedArray(
           capacity, &old_space, FixedArray::kHeaderSize, parameter_mode);
     }
 
-    Comment("Copy PACKED_ELEMENTS new space");
-
-    ElementsKind kind = PACKED_ELEMENTS;
+    Comment("Copy FixedArray new space");
+    // We use PACKED_ELEMENTS to tell AllocateFixedArray and
+    // CopyFixedArrayElements that we want a FixedArray.
+    ElementsKind to_kind = PACKED_ELEMENTS;
     Node* to_elements =
-        AllocateFixedArray(kind, capacity, parameter_mode,
-                           AllocationFlag::kNone, var_fixed_array_map.value());
+        AllocateFixedArray(to_kind, capacity, parameter_mode,
+                           AllocationFlag::kNone, var_target_map.value());
     var_result.Bind(to_elements);
-    CopyFixedArrayElements(kind, fixed_array, kind, to_elements, first, count,
-                           capacity, SKIP_WRITE_BARRIER, parameter_mode);
+    CopyFixedArrayElements(from_kind, source, to_kind, to_elements, first,
+                           count, capacity, SKIP_WRITE_BARRIER, parameter_mode,
+                           convert_holes, var_holes_converted);
     Goto(&done);
 
     if (handle_old_space) {
       BIND(&old_space);
       {
-        Comment("Copy PACKED_ELEMENTS old space");
+        Comment("Copy FixedArray old space");
 
-        to_elements = AllocateFixedArray(kind, capacity, parameter_mode, flags,
-                                         var_fixed_array_map.value());
+        to_elements =
+            AllocateFixedArray(to_kind, capacity, parameter_mode,
+                               allocation_flags, var_target_map.value());
         var_result.Bind(to_elements);
-        CopyFixedArrayElements(kind, fixed_array, kind, to_elements, first,
+        CopyFixedArrayElements(from_kind, source, to_kind, to_elements, first,
                                count, capacity, UPDATE_WRITE_BARRIER,
-                               parameter_mode);
+                               parameter_mode, convert_holes,
+                               var_holes_converted);
         Goto(&done);
       }
     }
+  }
 
-    BIND(&cow);
-    {
-      if (extract_flags & ExtractFixedArrayFlag::kDontCopyCOW) {
-        Branch(WordNotEqual(IntPtrOrSmiConstant(0, parameter_mode), first),
-               &new_space_check, [&] {
-                 var_result.Bind(fixed_array);
-                 Goto(&done);
-               });
-      } else {
-        var_fixed_array_map.Bind(LoadRoot(Heap::kFixedArrayMapRootIndex));
-        Goto(&new_space_check);
-      }
-    }
+  BIND(&done);
+  return UncheckedCast<FixedArray>(var_result.value());
+}
+
+TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedDoubleArrayFillingHoles(
+    Node* from_array, Node* first, Node* count, Node* capacity,
+    Node* fixed_array_map, TVariable<BoolT>* var_holes_converted,
+    AllocationFlags allocation_flags, ExtractFixedArrayFlags extract_flags,
+    ParameterMode mode) {
+  DCHECK_NE(first, nullptr);
+  DCHECK_NE(count, nullptr);
+  DCHECK_NE(capacity, nullptr);
+  DCHECK_NE(var_holes_converted, nullptr);
+  CSA_ASSERT(this, IsFixedDoubleArrayMap(fixed_array_map));
+
+  VARIABLE(var_result, MachineRepresentation::kTagged);
+  ElementsKind kind = PACKED_DOUBLE_ELEMENTS;
+  Node* to_elements = AllocateFixedArray(kind, capacity, mode, allocation_flags,
+                                         fixed_array_map);
+  var_result.Bind(to_elements);
+  // We first try to copy the FixedDoubleArray to a new FixedDoubleArray.
+  // |var_holes_converted| is set to False preliminarily.
+  *var_holes_converted = Int32FalseConstant();
+
+  // The construction of the loop and the offsets for double elements is
+  // extracted from CopyFixedArrayElements.
+  CSA_SLOW_ASSERT(this, MatchesParameterMode(count, mode));
+  CSA_SLOW_ASSERT(this, MatchesParameterMode(capacity, mode));
+  CSA_SLOW_ASSERT(this, IsFixedArrayWithKindOrEmpty(from_array, kind));
+  STATIC_ASSERT(FixedArray::kHeaderSize == FixedDoubleArray::kHeaderSize);
+
+  Comment("[ ExtractFixedDoubleArrayFillingHoles");
+
+  // This copy can trigger GC, so we pre-initialize the array with holes.
+  FillFixedArrayWithValue(kind, to_elements, IntPtrOrSmiConstant(0, mode),
+                          capacity, RootIndex::kTheHoleValue, mode);
+
+  const int first_element_offset = FixedArray::kHeaderSize - kHeapObjectTag;
+  Node* first_from_element_offset =
+      ElementOffsetFromIndex(first, kind, mode, 0);
+  Node* limit_offset = IntPtrAdd(first_from_element_offset,
+                                 IntPtrConstant(first_element_offset));
+  VARIABLE(var_from_offset, MachineType::PointerRepresentation(),
+           ElementOffsetFromIndex(IntPtrOrSmiAdd(first, count, mode), kind,
+                                  mode, first_element_offset));
+
+  Label decrement(this, {&var_from_offset}), done(this);
+  Node* to_array_adjusted =
+      IntPtrSub(BitcastTaggedToWord(to_elements), first_from_element_offset);
+
+  Branch(WordEqual(var_from_offset.value(), limit_offset), &done, &decrement);
+
+  BIND(&decrement);
+  {
+    Node* from_offset =
+        IntPtrSub(var_from_offset.value(), IntPtrConstant(kDoubleSize));
+    var_from_offset.Bind(from_offset);
+
+    Node* to_offset = from_offset;
+
+    Label if_hole(this);
+
+    Node* value = LoadElementAndPrepareForStore(
+        from_array, var_from_offset.value(), kind, kind, &if_hole);
+
+    StoreNoWriteBarrier(MachineRepresentation::kFloat64, to_array_adjusted,
+                        to_offset, value);
+
+    Node* compare = WordNotEqual(from_offset, limit_offset);
+    Branch(compare, &decrement, &done);
+
+    BIND(&if_hole);
+    // We are unlucky: there are holes! We need to restart the copy, this time
+    // we will copy the FixedDoubleArray to a new FixedArray with undefined
+    // replacing holes. We signal this to the caller through
+    // |var_holes_converted|.
+    *var_holes_converted = Int32TrueConstant();
+    to_elements =
+        ExtractToFixedArray(from_array, first, count, capacity, fixed_array_map,
+                            kind, allocation_flags, extract_flags, mode,
+                            HoleConversionMode::kConvertToUndefined);
+    var_result.Bind(to_elements);
+    Goto(&done);
+  }
+
+  BIND(&done);
+  Comment("] ExtractFixedDoubleArrayFillingHoles");
+  return UncheckedCast<FixedArrayBase>(var_result.value());
+}
+
+TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedArray(
+    Node* source, Node* first, Node* count, Node* capacity,
+    ExtractFixedArrayFlags extract_flags, ParameterMode parameter_mode,
+    TVariable<BoolT>* var_holes_converted) {
+  DCHECK(extract_flags & ExtractFixedArrayFlag::kFixedArrays ||
+         extract_flags & ExtractFixedArrayFlag::kFixedDoubleArrays);
+  // If we want to replace holes, ExtractFixedArrayFlag::kDontCopyCOW should not
+  // be used, because that disables the iteration which detects holes.
+  DCHECK_IMPLIES(var_holes_converted != nullptr,
+                 !(extract_flags & ExtractFixedArrayFlag::kDontCopyCOW));
+  HoleConversionMode convert_holes =
+      var_holes_converted != nullptr ? HoleConversionMode::kConvertToUndefined
+                                     : HoleConversionMode::kDontConvert;
+  VARIABLE(var_result, MachineRepresentation::kTagged);
+  const AllocationFlags allocation_flags =
+      (extract_flags & ExtractFixedArrayFlag::kNewSpaceAllocationOnly)
+          ? CodeStubAssembler::kNone
+          : CodeStubAssembler::kAllowLargeObjectAllocation;
+  if (first == nullptr) {
+    first = IntPtrOrSmiConstant(0, parameter_mode);
+  }
+  if (count == nullptr) {
+    count = IntPtrOrSmiSub(
+        TaggedToParameter(LoadFixedArrayBaseLength(source), parameter_mode),
+        first, parameter_mode);
+
+    CSA_ASSERT(
+        this, IntPtrOrSmiLessThanOrEqual(IntPtrOrSmiConstant(0, parameter_mode),
+                                         count, parameter_mode));
+  }
+  if (capacity == nullptr) {
+    capacity = count;
   } else {
-    Goto(&if_fixed_double_array);
+    CSA_ASSERT(this, Word32BinaryNot(IntPtrOrSmiGreaterThan(
+                         IntPtrOrSmiAdd(first, count, parameter_mode), capacity,
+                         parameter_mode)));
   }
 
-  if (extract_flags & ExtractFixedArrayFlag::kFixedDoubleArrays) {
-    BIND(&if_fixed_double_array);
+  Label if_fixed_double_array(this), empty(this), done(this, {&var_result});
+  Node* source_map = LoadMap(source);
+  GotoIf(WordEqual(IntPtrOrSmiConstant(0, parameter_mode), capacity), &empty);
 
-    Comment("Copy PACKED_DOUBLE_ELEMENTS");
+  if (extract_flags & ExtractFixedArrayFlag::kFixedDoubleArrays) {
+    if (extract_flags & ExtractFixedArrayFlag::kFixedArrays) {
+      GotoIf(IsFixedDoubleArrayMap(source_map), &if_fixed_double_array);
+    } else {
+      CSA_ASSERT(this, IsFixedDoubleArrayMap(source_map));
+    }
+  }
 
-    ElementsKind kind = PACKED_DOUBLE_ELEMENTS;
-    Node* to_elements = AllocateFixedArray(kind, capacity, parameter_mode,
-                                           flags, var_fixed_array_map.value());
+  if (extract_flags & ExtractFixedArrayFlag::kFixedArrays) {
+    // Here we can only get |source| as FixedArray, never FixedDoubleArray.
+    // PACKED_ELEMENTS is used to signify that the source is a FixedArray.
+    Node* to_elements =
+        ExtractToFixedArray(source, first, count, capacity, source_map,
+                            PACKED_ELEMENTS, allocation_flags, extract_flags,
+                            parameter_mode, convert_holes, var_holes_converted);
     var_result.Bind(to_elements);
-    CopyFixedArrayElements(kind, fixed_array, kind, to_elements, first, count,
-                           capacity, SKIP_WRITE_BARRIER, parameter_mode);
+    Goto(&done);
+  }
+
+  if (extract_flags & ExtractFixedArrayFlag::kFixedDoubleArrays) {
+    BIND(&if_fixed_double_array);
+    Comment("Copy FixedDoubleArray");
+
+    if (convert_holes == HoleConversionMode::kConvertToUndefined) {
+      Node* to_elements = ExtractFixedDoubleArrayFillingHoles(
+          source, first, count, capacity, source_map, var_holes_converted,
+          allocation_flags, extract_flags, parameter_mode);
+      var_result.Bind(to_elements);
+    } else {
+      // We use PACKED_DOUBLE_ELEMENTS to signify that both the source and
+      // the target are FixedDoubleArray. That it is PACKED or HOLEY does not
+      // matter.
+      ElementsKind kind = PACKED_DOUBLE_ELEMENTS;
+      Node* to_elements = AllocateFixedArray(kind, capacity, parameter_mode,
+                                             allocation_flags, source_map);
+      var_result.Bind(to_elements);
+      CopyFixedArrayElements(kind, source, kind, to_elements, first, count,
+                             capacity, SKIP_WRITE_BARRIER, parameter_mode);
+    }
 
     Goto(&done);
   }
@@ -4145,7 +4418,7 @@ Node* CodeStubAssembler::AllocatePropertyArray(Node* capacity_node,
   Node* total_size = GetPropertyArrayAllocationSize(capacity_node, mode);
 
   Node* array = Allocate(total_size, flags);
-  Heap::RootListIndex map_index = Heap::kPropertyArrayMapRootIndex;
+  RootIndex map_index = RootIndex::kPropertyArrayMap;
   DCHECK(Heap::RootIsImmortalImmovable(map_index));
   StoreMapNoWriteBarrier(array, map_index);
   InitializePropertyArrayLength(array, capacity_node, mode);
@@ -4170,14 +4443,15 @@ void CodeStubAssembler::FillPropertyArrayWithUndefined(Node* array,
                              mode);
 }
 
-void CodeStubAssembler::FillFixedArrayWithValue(
-    ElementsKind kind, Node* array, Node* from_node, Node* to_node,
-    Heap::RootListIndex value_root_index, ParameterMode mode) {
+void CodeStubAssembler::FillFixedArrayWithValue(ElementsKind kind, Node* array,
+                                                Node* from_node, Node* to_node,
+                                                RootIndex value_root_index,
+                                                ParameterMode mode) {
   CSA_SLOW_ASSERT(this, MatchesParameterMode(from_node, mode));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(to_node, mode));
   CSA_SLOW_ASSERT(this, IsFixedArrayWithKind(array, kind));
-  DCHECK(value_root_index == Heap::kTheHoleValueRootIndex ||
-         value_root_index == Heap::kUndefinedValueRootIndex);
+  DCHECK(value_root_index == RootIndex::kTheHoleValue ||
+         value_root_index == RootIndex::kUndefinedValue);
 
   // Determine the value to initialize the {array} based
   // on the {value_root_index} and the elements {kind}.
@@ -4200,6 +4474,33 @@ void CodeStubAssembler::FillFixedArrayWithValue(
       mode);
 }
 
+void CodeStubAssembler::StoreFixedDoubleArrayHole(
+    TNode<FixedDoubleArray> array, Node* index, ParameterMode parameter_mode) {
+  CSA_SLOW_ASSERT(this, MatchesParameterMode(index, parameter_mode));
+  Node* offset =
+      ElementOffsetFromIndex(index, PACKED_DOUBLE_ELEMENTS, parameter_mode,
+                             FixedArray::kHeaderSize - kHeapObjectTag);
+  CSA_ASSERT(this, IsOffsetInBounds(
+                       offset, LoadAndUntagFixedArrayBaseLength(array),
+                       FixedDoubleArray::kHeaderSize, PACKED_DOUBLE_ELEMENTS));
+  Node* double_hole =
+      Is64() ? ReinterpretCast<UintPtrT>(Int64Constant(kHoleNanInt64))
+             : ReinterpretCast<UintPtrT>(Int32Constant(kHoleNanLower32));
+  // TODO(danno): When we have a Float32/Float64 wrapper class that
+  // preserves double bits during manipulation, remove this code/change
+  // this to an indexed Float64 store.
+  if (Is64()) {
+    StoreNoWriteBarrier(MachineRepresentation::kWord64, array, offset,
+                        double_hole);
+  } else {
+    StoreNoWriteBarrier(MachineRepresentation::kWord32, array, offset,
+                        double_hole);
+    StoreNoWriteBarrier(MachineRepresentation::kWord32, array,
+                        IntPtrAdd(offset, IntPtrConstant(kPointerSize)),
+                        double_hole);
+  }
+}
+
 void CodeStubAssembler::FillFixedArrayWithSmiZero(TNode<FixedArray> array,
                                                   TNode<IntPtrT> length) {
   CSA_ASSERT(this, WordEqual(length, LoadAndUntagFixedArrayBaseLength(array)));
@@ -4245,7 +4546,10 @@ void CodeStubAssembler::FillFixedDoubleArrayWithZero(
 void CodeStubAssembler::CopyFixedArrayElements(
     ElementsKind from_kind, Node* from_array, ElementsKind to_kind,
     Node* to_array, Node* first_element, Node* element_count, Node* capacity,
-    WriteBarrierMode barrier_mode, ParameterMode mode) {
+    WriteBarrierMode barrier_mode, ParameterMode mode,
+    HoleConversionMode convert_holes, TVariable<BoolT>* var_holes_converted) {
+  DCHECK_IMPLIES(var_holes_converted != nullptr,
+                 convert_holes == HoleConversionMode::kConvertToUndefined);
   CSA_SLOW_ASSERT(this, MatchesParameterMode(element_count, mode));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(capacity, mode));
   CSA_SLOW_ASSERT(this, IsFixedArrayWithKindOrEmpty(from_array, from_kind));
@@ -4273,15 +4577,25 @@ void CodeStubAssembler::CopyFixedArrayElements(
       Is64() ? ReinterpretCast<UintPtrT>(Int64Constant(kHoleNanInt64))
              : ReinterpretCast<UintPtrT>(Int32Constant(kHoleNanLower32));
 
-  if (doubles_to_objects_conversion) {
-    // If the copy might trigger a GC, make sure that the FixedArray is
-    // pre-initialized with holes to make sure that it's always in a
-    // consistent state.
+  // If copying might trigger a GC, we pre-initialize the FixedArray such that
+  // it's always in a consistent state.
+  if (convert_holes == HoleConversionMode::kConvertToUndefined) {
+    DCHECK(IsObjectElementsKind(to_kind));
+    // Use undefined for the part that we copy and holes for the rest.
+    // Later if we run into a hole in the source we can just skip the writing
+    // to the target and are still guaranteed that we get an undefined.
     FillFixedArrayWithValue(to_kind, to_array, IntPtrOrSmiConstant(0, mode),
-                            capacity, Heap::kTheHoleValueRootIndex, mode);
+                            element_count, RootIndex::kUndefinedValue, mode);
+    FillFixedArrayWithValue(to_kind, to_array, element_count, capacity,
+                            RootIndex::kTheHoleValue, mode);
+  } else if (doubles_to_objects_conversion) {
+    // Pre-initialized the target with holes so later if we run into a hole in
+    // the source we can just skip the writing to the target.
+    FillFixedArrayWithValue(to_kind, to_array, IntPtrOrSmiConstant(0, mode),
+                            capacity, RootIndex::kTheHoleValue, mode);
   } else if (element_count != capacity) {
     FillFixedArrayWithValue(to_kind, to_array, element_count, capacity,
-                            Heap::kTheHoleValueRootIndex, mode);
+                            RootIndex::kTheHoleValue, mode);
   }
 
   Node* first_from_element_offset =
@@ -4302,8 +4616,10 @@ void CodeStubAssembler::CopyFixedArrayElements(
                                               first_element_offset));
   }
 
-  Variable* vars[] = {&var_from_offset, &var_to_offset};
-  Label decrement(this, 2, vars);
+  Variable* vars[] = {&var_from_offset, &var_to_offset, var_holes_converted};
+  int num_vars =
+      var_holes_converted != nullptr ? arraysize(vars) : arraysize(vars) - 1;
+  Label decrement(this, num_vars, vars);
 
   Node* to_array_adjusted =
       element_offset_matches
@@ -4329,9 +4645,13 @@ void CodeStubAssembler::CopyFixedArrayElements(
       var_to_offset.Bind(to_offset);
     }
 
-    Label next_iter(this), store_double_hole(this);
+    Label next_iter(this), store_double_hole(this), signal_hole(this);
     Label* if_hole;
-    if (doubles_to_objects_conversion) {
+    if (convert_holes == HoleConversionMode::kConvertToUndefined) {
+      // The target elements array is already preinitialized with undefined
+      // so we only need to signal that a hole was found and continue the loop.
+      if_hole = &signal_hole;
+    } else if (doubles_to_objects_conversion) {
       // The target elements array is already preinitialized with holes, so we
       // can just proceed with the next iteration.
       if_hole = &next_iter;
@@ -4378,6 +4698,13 @@ void CodeStubAssembler::CopyFixedArrayElements(
                             double_hole);
       }
       Goto(&next_iter);
+    } else if (if_hole == &signal_hole) {
+      // This case happens only when IsObjectElementsKind(to_kind).
+      BIND(&signal_hole);
+      if (var_holes_converted != nullptr) {
+        *var_holes_converted = Int32TrueConstant();
+      }
+      Goto(&next_iter);
     }
 
     BIND(&next_iter);
@@ -4393,9 +4720,8 @@ TNode<FixedArray> CodeStubAssembler::HeapObjectToFixedArray(
     TNode<HeapObject> base, Label* cast_fail) {
   Label fixed_array(this);
   TNode<Map> map = LoadMap(base);
-  GotoIf(WordEqual(map, LoadRoot(Heap::kFixedArrayMapRootIndex)), &fixed_array);
-  GotoIf(WordNotEqual(map, LoadRoot(Heap::kFixedCOWArrayMapRootIndex)),
-         cast_fail);
+  GotoIf(WordEqual(map, LoadRoot(RootIndex::kFixedArrayMap)), &fixed_array);
+  GotoIf(WordNotEqual(map, LoadRoot(RootIndex::kFixedCOWArrayMap)), cast_fail);
   Goto(&fixed_array);
   BIND(&fixed_array);
   return UncheckedCast<FixedArray>(base);
@@ -4603,7 +4929,7 @@ void CodeStubAssembler::InitializeAllocationMemento(Node* base,
                                                     Node* allocation_site) {
   Comment("[Initialize AllocationMemento");
   Node* memento = InnerAllocate(base, base_allocation_size);
-  StoreMapNoWriteBarrier(memento, Heap::kAllocationMementoMapRootIndex);
+  StoreMapNoWriteBarrier(memento, RootIndex::kAllocationMementoMap);
   StoreObjectFieldNoWriteBarrier(
       memento, AllocationMemento::kAllocationSiteOffset, allocation_site);
   if (FLAG_allocation_site_pretenuring) {
@@ -4891,28 +5217,13 @@ TNode<Number> CodeStubAssembler::ChangeUint32ToTagged(
       if_join(this);
   TVARIABLE(Number, var_result);
   // If {value} > 2^31 - 1, we need to store it in a HeapNumber.
-  Branch(Uint32LessThan(Int32Constant(Smi::kMaxValue), value), &if_overflow,
+  Branch(Uint32LessThan(Uint32Constant(Smi::kMaxValue), value), &if_overflow,
          &if_not_overflow);
 
   BIND(&if_not_overflow);
   {
-    if (SmiValuesAre32Bits()) {
-      var_result =
-          SmiTag(ReinterpretCast<IntPtrT>(ChangeUint32ToUint64(value)));
-    } else {
-      DCHECK(SmiValuesAre31Bits());
-      // If tagging {value} results in an overflow, we need to use a HeapNumber
-      // to represent it.
-      // TODO(tebbi): This overflow can never happen.
-      TNode<PairT<Int32T, BoolT>> pair = Int32AddWithOverflow(
-          UncheckedCast<Int32T>(value), UncheckedCast<Int32T>(value));
-      TNode<BoolT> overflow = Projection<1>(pair);
-      GotoIf(overflow, &if_overflow);
-
-      TNode<IntPtrT> almost_tagged_value =
-          ChangeInt32ToIntPtr(Projection<0>(pair));
-      var_result = BitcastWordToTaggedSigned(almost_tagged_value);
-    }
+    // The {value} is definitely in valid Smi range.
+    var_result = SmiTag(Signed(ChangeUint32ToWord(value)));
   }
   Goto(&if_join);
 
@@ -4927,6 +5238,32 @@ TNode<Number> CodeStubAssembler::ChangeUint32ToTagged(
   return var_result.value();
 }
 
+TNode<Number> CodeStubAssembler::ChangeUintPtrToTagged(TNode<UintPtrT> value) {
+  Label if_overflow(this, Label::kDeferred), if_not_overflow(this),
+      if_join(this);
+  TVARIABLE(Number, var_result);
+  // If {value} > 2^31 - 1, we need to store it in a HeapNumber.
+  Branch(UintPtrLessThan(UintPtrConstant(Smi::kMaxValue), value), &if_overflow,
+         &if_not_overflow);
+
+  BIND(&if_not_overflow);
+  {
+    // The {value} is definitely in valid Smi range.
+    var_result = SmiTag(Signed(value));
+  }
+  Goto(&if_join);
+
+  BIND(&if_overflow);
+  {
+    TNode<Float64T> float64_value = ChangeUintPtrToFloat64(value);
+    var_result = AllocateHeapNumberWithValue(float64_value);
+  }
+  Goto(&if_join);
+
+  BIND(&if_join);
+  return var_result.value();
+}
+
 TNode<String> CodeStubAssembler::ToThisString(Node* context, Node* value,
                                               char const* method_name) {
   VARIABLE(var_value, MachineRepresentation::kTagged, value);
@@ -5229,6 +5566,13 @@ TNode<BoolT> CodeStubAssembler::IsExtensibleMap(SloppyTNode<Map> map) {
   return IsSetWord32<Map::IsExtensibleBit>(LoadMapBitField2(map));
 }
 
+TNode<BoolT> CodeStubAssembler::IsExtensibleNonPrototypeMap(TNode<Map> map) {
+  int kMask = Map::IsExtensibleBit::kMask | Map::IsPrototypeMapBit::kMask;
+  int kExpected = Map::IsExtensibleBit::kMask;
+  return Word32Equal(Word32And(LoadMapBitField2(map), Int32Constant(kMask)),
+                     Int32Constant(kExpected));
+}
+
 TNode<BoolT> CodeStubAssembler::IsCallableMap(SloppyTNode<Map> map) {
   CSA_ASSERT(this, IsMap(map));
   return IsSetWord32<Map::IsCallableBit>(LoadMapBitField(map));
@@ -5246,42 +5590,42 @@ TNode<BoolT> CodeStubAssembler::IsUndetectableMap(SloppyTNode<Map> map) {
 
 TNode<BoolT> CodeStubAssembler::IsNoElementsProtectorCellInvalid() {
   Node* invalid = SmiConstant(Isolate::kProtectorInvalid);
-  Node* cell = LoadRoot(Heap::kNoElementsProtectorRootIndex);
+  Node* cell = LoadRoot(RootIndex::kNoElementsProtector);
   Node* cell_value = LoadObjectField(cell, PropertyCell::kValueOffset);
   return WordEqual(cell_value, invalid);
 }
 
 TNode<BoolT> CodeStubAssembler::IsPromiseResolveProtectorCellInvalid() {
   Node* invalid = SmiConstant(Isolate::kProtectorInvalid);
-  Node* cell = LoadRoot(Heap::kPromiseResolveProtectorRootIndex);
+  Node* cell = LoadRoot(RootIndex::kPromiseResolveProtector);
   Node* cell_value = LoadObjectField(cell, Cell::kValueOffset);
   return WordEqual(cell_value, invalid);
 }
 
 TNode<BoolT> CodeStubAssembler::IsPromiseThenProtectorCellInvalid() {
   Node* invalid = SmiConstant(Isolate::kProtectorInvalid);
-  Node* cell = LoadRoot(Heap::kPromiseThenProtectorRootIndex);
+  Node* cell = LoadRoot(RootIndex::kPromiseThenProtector);
   Node* cell_value = LoadObjectField(cell, PropertyCell::kValueOffset);
   return WordEqual(cell_value, invalid);
 }
 
 TNode<BoolT> CodeStubAssembler::IsArraySpeciesProtectorCellInvalid() {
   Node* invalid = SmiConstant(Isolate::kProtectorInvalid);
-  Node* cell = LoadRoot(Heap::kArraySpeciesProtectorRootIndex);
+  Node* cell = LoadRoot(RootIndex::kArraySpeciesProtector);
   Node* cell_value = LoadObjectField(cell, PropertyCell::kValueOffset);
   return WordEqual(cell_value, invalid);
 }
 
 TNode<BoolT> CodeStubAssembler::IsTypedArraySpeciesProtectorCellInvalid() {
   Node* invalid = SmiConstant(Isolate::kProtectorInvalid);
-  Node* cell = LoadRoot(Heap::kTypedArraySpeciesProtectorRootIndex);
+  Node* cell = LoadRoot(RootIndex::kTypedArraySpeciesProtector);
   Node* cell_value = LoadObjectField(cell, PropertyCell::kValueOffset);
   return WordEqual(cell_value, invalid);
 }
 
 TNode<BoolT> CodeStubAssembler::IsPromiseSpeciesProtectorCellInvalid() {
   Node* invalid = SmiConstant(Isolate::kProtectorInvalid);
-  Node* cell = LoadRoot(Heap::kPromiseSpeciesProtectorRootIndex);
+  Node* cell = LoadRoot(RootIndex::kPromiseSpeciesProtector);
   Node* cell_value = LoadObjectField(cell, PropertyCell::kValueOffset);
   return WordEqual(cell_value, invalid);
 }
@@ -5320,7 +5664,7 @@ TNode<BoolT> CodeStubAssembler::IsCallable(SloppyTNode<HeapObject> object) {
 }
 
 TNode<BoolT> CodeStubAssembler::IsCell(SloppyTNode<HeapObject> object) {
-  return WordEqual(LoadMap(object), LoadRoot(Heap::kCellMapRootIndex));
+  return WordEqual(LoadMap(object), LoadRoot(RootIndex::kCellMap));
 }
 
 TNode<BoolT> CodeStubAssembler::IsCode(SloppyTNode<HeapObject> object) {
@@ -5402,11 +5746,11 @@ TNode<BoolT> CodeStubAssembler::IsExternalStringInstanceType(
       Int32Constant(kExternalStringTag));
 }
 
-TNode<BoolT> CodeStubAssembler::IsShortExternalStringInstanceType(
+TNode<BoolT> CodeStubAssembler::IsUncachedExternalStringInstanceType(
     SloppyTNode<Int32T> instance_type) {
   CSA_ASSERT(this, IsStringInstanceType(instance_type));
-  STATIC_ASSERT(kShortExternalStringTag != 0);
-  return IsSetWord32(instance_type, kShortExternalStringMask);
+  STATIC_ASSERT(kUncachedExternalStringTag != 0);
+  return IsSetWord32(instance_type, kUncachedExternalStringMask);
 }
 
 TNode<BoolT> CodeStubAssembler::IsJSReceiverInstanceType(
@@ -5619,6 +5963,16 @@ TNode<BoolT> CodeStubAssembler::IsHeapNumber(SloppyTNode<HeapObject> object) {
   return IsHeapNumberMap(LoadMap(object));
 }
 
+TNode<BoolT> CodeStubAssembler::IsHeapNumberInstanceType(
+    SloppyTNode<Int32T> instance_type) {
+  return InstanceTypeEqual(instance_type, HEAP_NUMBER_TYPE);
+}
+
+TNode<BoolT> CodeStubAssembler::IsOddballInstanceType(
+    SloppyTNode<Int32T> instance_type) {
+  return InstanceTypeEqual(instance_type, ODDBALL_TYPE);
+}
+
 TNode<BoolT> CodeStubAssembler::IsMutableHeapNumber(
     SloppyTNode<HeapObject> object) {
   return IsMutableHeapNumberMap(LoadMap(object));
@@ -5634,8 +5988,12 @@ TNode<BoolT> CodeStubAssembler::IsFeedbackVector(
 }
 
 TNode<BoolT> CodeStubAssembler::IsName(SloppyTNode<HeapObject> object) {
-  return Int32LessThanOrEqual(LoadInstanceType(object),
-                              Int32Constant(LAST_NAME_TYPE));
+  return IsNameInstanceType(LoadInstanceType(object));
+}
+
+TNode<BoolT> CodeStubAssembler::IsNameInstanceType(
+    SloppyTNode<Int32T> instance_type) {
+  return Int32LessThanOrEqual(instance_type, Int32Constant(LAST_NAME_TYPE));
 }
 
 TNode<BoolT> CodeStubAssembler::IsString(SloppyTNode<HeapObject> object) {
@@ -5668,20 +6026,19 @@ TNode<BoolT> CodeStubAssembler::IsPrimitiveInstanceType(
 
 TNode<BoolT> CodeStubAssembler::IsPrivateSymbol(
     SloppyTNode<HeapObject> object) {
-  return Select<BoolT>(
-      IsSymbol(object),
-      [=] {
-        TNode<Symbol> symbol = CAST(object);
-        TNode<Int32T> flags =
-            SmiToInt32(LoadObjectField<Smi>(symbol, Symbol::kFlagsOffset));
-        return IsSetWord32(flags, 1 << Symbol::kPrivateBit);
-      },
-      [=] { return Int32FalseConstant(); });
+  return Select<BoolT>(IsSymbol(object),
+                       [=] {
+                         TNode<Symbol> symbol = CAST(object);
+                         TNode<Uint32T> flags = LoadObjectField<Uint32T>(
+                             symbol, Symbol::kFlagsOffset);
+                         return IsSetWord32<Symbol::IsPrivateBit>(flags);
+                       },
+                       [=] { return Int32FalseConstant(); });
 }
 
 TNode<BoolT> CodeStubAssembler::IsNativeContext(
     SloppyTNode<HeapObject> object) {
-  return WordEqual(LoadMap(object), LoadRoot(Heap::kNativeContextMapRootIndex));
+  return WordEqual(LoadMap(object), LoadRoot(RootIndex::kNativeContextMap));
 }
 
 TNode<BoolT> CodeStubAssembler::IsFixedDoubleArray(
@@ -5968,7 +6325,7 @@ TNode<String> CodeStubAssembler::StringFromSingleCharCode(TNode<Int32T> code) {
   {
     // Load the isolate wide single character string cache.
     TNode<FixedArray> cache =
-        CAST(LoadRoot(Heap::kSingleCharacterStringCacheRootIndex));
+        CAST(LoadRoot(RootIndex::kSingleCharacterStringCache));
     TNode<IntPtrT> code_index = Signed(ChangeUint32ToWord(code));
 
     // Check if we have an entry for the {code} in the single character string
@@ -6021,7 +6378,7 @@ TNode<String> CodeStubAssembler::StringFromSingleCharCode(TNode<Int32T> code) {
 // 0 <= |from_index| <= |from_index| + |character_count| < from_string.length.
 TNode<String> CodeStubAssembler::AllocAndCopyStringCharacters(
     Node* from, Node* from_instance_type, TNode<IntPtrT> from_index,
-    TNode<Smi> character_count) {
+    TNode<IntPtrT> character_count) {
   Label end(this), one_byte_sequential(this), two_byte_sequential(this);
   TVARIABLE(String, var_result);
 
@@ -6031,10 +6388,10 @@ TNode<String> CodeStubAssembler::AllocAndCopyStringCharacters(
   // The subject string is a sequential one-byte string.
   BIND(&one_byte_sequential);
   {
-    TNode<String> result =
-        AllocateSeqOneByteString(NoContextConstant(), character_count);
+    TNode<String> result = AllocateSeqOneByteString(
+        NoContextConstant(), Unsigned(TruncateIntPtrToInt32(character_count)));
     CopyStringCharacters(from, result, from_index, IntPtrConstant(0),
-                         SmiUntag(character_count), String::ONE_BYTE_ENCODING,
+                         character_count, String::ONE_BYTE_ENCODING,
                          String::ONE_BYTE_ENCODING);
     var_result = result;
     Goto(&end);
@@ -6043,10 +6400,10 @@ TNode<String> CodeStubAssembler::AllocAndCopyStringCharacters(
   // The subject string is a sequential two-byte string.
   BIND(&two_byte_sequential);
   {
-    TNode<String> result =
-        AllocateSeqTwoByteString(NoContextConstant(), character_count);
+    TNode<String> result = AllocateSeqTwoByteString(
+        NoContextConstant(), Unsigned(TruncateIntPtrToInt32(character_count)));
     CopyStringCharacters(from, result, from_index, IntPtrConstant(0),
-                         SmiUntag(character_count), String::TWO_BYTE_ENCODING,
+                         character_count, String::TWO_BYTE_ENCODING,
                          String::TWO_BYTE_ENCODING);
     var_result = result;
     Goto(&end);
@@ -6109,15 +6466,17 @@ TNode<String> CodeStubAssembler::SubString(TNode<String> string,
 
       BIND(&one_byte_slice);
       {
-        var_result = AllocateSlicedOneByteString(SmiTag(substr_length),
-                                                 direct_string, SmiTag(offset));
+        var_result = AllocateSlicedOneByteString(
+            Unsigned(TruncateIntPtrToInt32(substr_length)), direct_string,
+            SmiTag(offset));
         Goto(&end);
       }
 
       BIND(&two_byte_slice);
       {
-        var_result = AllocateSlicedTwoByteString(SmiTag(substr_length),
-                                                 direct_string, SmiTag(offset));
+        var_result = AllocateSlicedTwoByteString(
+            Unsigned(TruncateIntPtrToInt32(substr_length)), direct_string,
+            SmiTag(offset));
         Goto(&end);
       }
 
@@ -6129,7 +6488,7 @@ TNode<String> CodeStubAssembler::SubString(TNode<String> string,
     GotoIf(to_direct.is_external(), &external_string);
 
     var_result = AllocAndCopyStringCharacters(direct_string, instance_type,
-                                              offset, SmiTag(substr_length));
+                                              offset, substr_length);
 
     Counters* counters = isolate()->counters();
     IncrementCounter(counters->sub_string_native(), 1);
@@ -6143,7 +6502,7 @@ TNode<String> CodeStubAssembler::SubString(TNode<String> string,
     Node* const fake_sequential_string = to_direct.PointerToString(&runtime);
 
     var_result = AllocAndCopyStringCharacters(
-        fake_sequential_string, instance_type, offset, SmiTag(substr_length));
+        fake_sequential_string, instance_type, offset, substr_length);
 
     Counters* counters = isolate()->counters();
     IncrementCounter(counters->sub_string_native(), 1);
@@ -6314,7 +6673,7 @@ TNode<RawPtrT> ToDirectStringAssembler::TryToSequential(
 
   BIND(&if_isexternal);
   {
-    GotoIf(IsShortExternalStringInstanceType(var_instance_type_.value()),
+    GotoIf(IsUncachedExternalStringInstanceType(var_instance_type_.value()),
            if_bailout);
 
     TNode<String> string = CAST(var_string_.value());
@@ -6424,36 +6783,37 @@ TNode<String> CodeStubAssembler::StringAdd(Node* context, TNode<String> left,
       done(this, &result), done_native(this, &result);
   Counters* counters = isolate()->counters();
 
-  TNode<Smi> left_length = LoadStringLengthAsSmi(left);
-  GotoIf(SmiNotEqual(SmiConstant(0), left_length), &check_right);
+  TNode<Uint32T> left_length = LoadStringLengthAsWord32(left);
+  GotoIfNot(Word32Equal(left_length, Uint32Constant(0)), &check_right);
   result = right;
   Goto(&done_native);
 
   BIND(&check_right);
-  TNode<Smi> right_length = LoadStringLengthAsSmi(right);
-  GotoIf(SmiNotEqual(SmiConstant(0), right_length), &cons);
+  TNode<Uint32T> right_length = LoadStringLengthAsWord32(right);
+  GotoIfNot(Word32Equal(right_length, Uint32Constant(0)), &cons);
   result = left;
   Goto(&done_native);
 
   BIND(&cons);
   {
-    TNode<Smi> new_length = SmiAdd(left_length, right_length);
+    TNode<Uint32T> new_length = Uint32Add(left_length, right_length);
 
     // If new length is greater than String::kMaxLength, goto runtime to
     // throw. Note: we also need to invalidate the string length protector, so
     // can't just throw here directly.
-    GotoIf(SmiAbove(new_length, SmiConstant(String::kMaxLength)), &runtime);
+    GotoIf(Uint32GreaterThan(new_length, Uint32Constant(String::kMaxLength)),
+           &runtime);
 
     TVARIABLE(String, var_left, left);
     TVARIABLE(String, var_right, right);
     Variable* input_vars[2] = {&var_left, &var_right};
     Label non_cons(this, 2, input_vars);
     Label slow(this, Label::kDeferred);
-    GotoIf(SmiLessThan(new_length, SmiConstant(ConsString::kMinLength)),
+    GotoIf(Uint32LessThan(new_length, Uint32Constant(ConsString::kMinLength)),
            &non_cons);
 
-    result = NewConsString(context, new_length, var_left.value(),
-                           var_right.value(), flags);
+    result =
+        NewConsString(new_length, var_left.value(), var_right.value(), flags);
     Goto(&done_native);
 
     BIND(&non_cons);
@@ -6472,8 +6832,8 @@ TNode<String> CodeStubAssembler::StringAdd(Node* context, TNode<String> left,
     GotoIf(IsSetWord32(xored_instance_types, kStringEncodingMask), &runtime);
     GotoIf(IsSetWord32(ored_instance_types, kStringRepresentationMask), &slow);
 
-    TNode<IntPtrT> word_left_length = SmiUntag(left_length);
-    TNode<IntPtrT> word_right_length = SmiUntag(right_length);
+    TNode<IntPtrT> word_left_length = Signed(ChangeUint32ToWord(left_length));
+    TNode<IntPtrT> word_right_length = Signed(ChangeUint32ToWord(right_length));
 
     Label two_byte(this);
     GotoIf(Word32Equal(Word32And(ored_instance_types,
@@ -6613,7 +6973,7 @@ TNode<String> CodeStubAssembler::NumberToString(TNode<Number> input) {
       done(this, &result);
 
   // Load the number string cache.
-  Node* number_string_cache = LoadRoot(Heap::kNumberStringCacheRootIndex);
+  Node* number_string_cache = LoadRoot(RootIndex::kNumberStringCache);
 
   // Make the hash mask from the length of the number string cache. It
   // contains two elements (number and string) for each cache entry.
@@ -6688,52 +7048,6 @@ TNode<String> CodeStubAssembler::NumberToString(TNode<Number> input) {
   return result.value();
 }
 
-TNode<Name> CodeStubAssembler::ToName(SloppyTNode<Context> context,
-                                      SloppyTNode<Object> value) {
-  Label end(this);
-  TVARIABLE(Name, var_result);
-
-  Label is_number(this);
-  GotoIf(TaggedIsSmi(value), &is_number);
-
-  Label not_name(this);
-  TNode<Int32T> value_instance_type = LoadInstanceType(CAST(value));
-  STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);
-  GotoIf(Int32GreaterThan(value_instance_type, Int32Constant(LAST_NAME_TYPE)),
-         &not_name);
-
-  var_result = CAST(value);
-  Goto(&end);
-
-  BIND(&is_number);
-  {
-    var_result = CAST(CallBuiltin(Builtins::kNumberToString, context, value));
-    Goto(&end);
-  }
-
-  BIND(&not_name);
-  {
-    GotoIf(InstanceTypeEqual(value_instance_type, HEAP_NUMBER_TYPE),
-           &is_number);
-
-    Label not_oddball(this);
-    GotoIfNot(InstanceTypeEqual(value_instance_type, ODDBALL_TYPE),
-              &not_oddball);
-
-    var_result = LoadObjectField<String>(CAST(value), Oddball::kToStringOffset);
-    Goto(&end);
-
-    BIND(&not_oddball);
-    {
-      var_result = CAST(CallRuntime(Runtime::kToName, context, value));
-      Goto(&end);
-    }
-  }
-
-  BIND(&end);
-  return var_result.value();
-}
-
 Node* CodeStubAssembler::NonNumberToNumberOrNumeric(
     Node* context, Node* input, Object::Conversion mode,
     BigIntHandling bigint_handling) {
@@ -8114,6 +8428,125 @@ void CodeStubAssembler::DescriptorArrayForEach(
                 IndexAdvanceMode::kPost);
 }
 
+void CodeStubAssembler::ForEachEnumerableOwnProperty(
+    TNode<Context> context, TNode<Map> map, TNode<JSObject> object,
+    const ForEachKeyValueFunction& body, Label* bailout) {
+  TNode<Int32T> type = LoadMapInstanceType(map);
+  TNode<Uint32T> bit_field3 = EnsureOnlyHasSimpleProperties(map, type, bailout);
+
+  TNode<DescriptorArray> descriptors = LoadMapDescriptors(map);
+  TNode<Uint32T> nof_descriptors =
+      DecodeWord32<Map::NumberOfOwnDescriptorsBits>(bit_field3);
+
+  TVARIABLE(BoolT, var_stable, Int32TrueConstant());
+  VariableList list({&var_stable}, zone());
+
+  DescriptorArrayForEach(
+      list, Unsigned(Int32Constant(0)), nof_descriptors,
+      [=, &var_stable](TNode<UintPtrT> descriptor_key_index) {
+        TNode<Name> next_key =
+            CAST(LoadWeakFixedArrayElement(descriptors, descriptor_key_index));
+
+        TVARIABLE(Object, var_value, SmiConstant(0));
+        Label callback(this), next_iteration(this);
+
+        {
+          TVARIABLE(Map, var_map);
+          TVARIABLE(HeapObject, var_meta_storage);
+          TVARIABLE(IntPtrT, var_entry);
+          TVARIABLE(Uint32T, var_details);
+          Label if_found(this);
+
+          Label if_found_fast(this), if_found_dict(this);
+
+          Label if_stable(this), if_not_stable(this);
+          Branch(var_stable.value(), &if_stable, &if_not_stable);
+          BIND(&if_stable);
+          {
+            // Directly decode from the descriptor array if |object| did not
+            // change shape.
+            var_map = map;
+            var_meta_storage = descriptors;
+            var_entry = Signed(descriptor_key_index);
+            Goto(&if_found_fast);
+          }
+          BIND(&if_not_stable);
+          {
+            // If the map did change, do a slower lookup. We are still
+            // guaranteed that the object has a simple shape, and that the key
+            // is a name.
+            var_map = LoadMap(object);
+            TryLookupPropertyInSimpleObject(
+                object, var_map.value(), next_key, &if_found_fast,
+                &if_found_dict, &var_meta_storage, &var_entry, &next_iteration);
+          }
+
+          BIND(&if_found_fast);
+          {
+            TNode<DescriptorArray> descriptors = CAST(var_meta_storage.value());
+            TNode<IntPtrT> name_index = var_entry.value();
+
+            // Skip non-enumerable properties.
+            var_details = LoadDetailsByKeyIndex(descriptors, name_index);
+            GotoIf(IsSetWord32(var_details.value(),
+                               PropertyDetails::kAttributesDontEnumMask),
+                   &next_iteration);
+
+            LoadPropertyFromFastObject(object, var_map.value(), descriptors,
+                                       name_index, var_details.value(),
+                                       &var_value);
+            Goto(&if_found);
+          }
+          BIND(&if_found_dict);
+          {
+            TNode<NameDictionary> dictionary = CAST(var_meta_storage.value());
+            TNode<IntPtrT> entry = var_entry.value();
+
+            TNode<Uint32T> details =
+                LoadDetailsByKeyIndex<NameDictionary>(dictionary, entry);
+            // Skip non-enumerable properties.
+            GotoIf(
+                IsSetWord32(details, PropertyDetails::kAttributesDontEnumMask),
+                &next_iteration);
+
+            var_details = details;
+            var_value = LoadValueByKeyIndex<NameDictionary>(dictionary, entry);
+            Goto(&if_found);
+          }
+
+          // Here we have details and value which could be an accessor.
+          BIND(&if_found);
+          {
+            Label slow_load(this, Label::kDeferred);
+
+            var_value = CallGetterIfAccessor(var_value.value(),
+                                             var_details.value(), context,
+                                             object, &slow_load, kCallJSGetter);
+            Goto(&callback);
+
+            BIND(&slow_load);
+            var_value =
+                CallRuntime(Runtime::kGetProperty, context, object, next_key);
+            Goto(&callback);
+
+            BIND(&callback);
+            body(next_key, var_value.value());
+
+            // Check if |object| is still stable, i.e. we can proceed using
+            // property details from preloaded |descriptors|.
+            var_stable =
+                Select<BoolT>(var_stable.value(),
+                              [=] { return WordEqual(LoadMap(object), map); },
+                              [=] { return Int32FalseConstant(); });
+
+            Goto(&next_iteration);
+          }
+        }
+
+        BIND(&next_iteration);
+      });
+}
+
 void CodeStubAssembler::DescriptorLookup(
     SloppyTNode<Name> unique_name, SloppyTNode<DescriptorArray> descriptors,
     SloppyTNode<Uint32T> bitfield3, Label* if_found,
@@ -8708,7 +9141,7 @@ void CodeStubAssembler::TryLookupElement(Node* object, Node* map,
     Node* buffer = LoadObjectField(object, JSArrayBufferView::kBufferOffset);
     GotoIf(IsDetachedBuffer(buffer), if_absent);
 
-    Node* length = SmiUntag(LoadTypedArrayLength(CAST(object)));
+    Node* length = SmiUntag(LoadJSTypedArrayLength(CAST(object)));
     Branch(UintPtrLessThan(intptr_index, length), if_found, if_absent);
   }
   BIND(&if_oob);
@@ -9111,25 +9544,22 @@ void CodeStubAssembler::CheckForAssociatedProtector(Node* name,
                                                     Label* if_protector) {
   // This list must be kept in sync with LookupIterator::UpdateProtector!
   // TODO(jkummerow): Would it be faster to have a bit in Symbol::flags()?
-  GotoIf(WordEqual(name, LoadRoot(Heap::kconstructor_stringRootIndex)),
-         if_protector);
-  GotoIf(WordEqual(name, LoadRoot(Heap::kiterator_symbolRootIndex)),
-         if_protector);
-  GotoIf(WordEqual(name, LoadRoot(Heap::knext_stringRootIndex)), if_protector);
-  GotoIf(WordEqual(name, LoadRoot(Heap::kspecies_symbolRootIndex)),
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::kconstructor_string)),
          if_protector);
-  GotoIf(WordEqual(name, LoadRoot(Heap::kis_concat_spreadable_symbolRootIndex)),
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::kiterator_symbol)), if_protector);
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::knext_string)), if_protector);
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::kspecies_symbol)), if_protector);
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::kis_concat_spreadable_symbol)),
          if_protector);
-  GotoIf(WordEqual(name, LoadRoot(Heap::kresolve_stringRootIndex)),
-         if_protector);
-  GotoIf(WordEqual(name, LoadRoot(Heap::kthen_stringRootIndex)), if_protector);
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::kresolve_string)), if_protector);
+  GotoIf(WordEqual(name, LoadRoot(RootIndex::kthen_string)), if_protector);
   // Fall through if no case matched.
 }
 
 TNode<Map> CodeStubAssembler::LoadReceiverMap(SloppyTNode<Object> receiver) {
   return Select<Map>(
       TaggedIsSmi(receiver),
-      [=] { return CAST(LoadRoot(Heap::kHeapNumberMapRootIndex)); },
+      [=] { return CAST(LoadRoot(RootIndex::kHeapNumberMap)); },
       [=] { return LoadMap(UncheckedCast<HeapObject>(receiver)); });
 }
 
@@ -9452,38 +9882,46 @@ void CodeStubAssembler::EmitBigTypedArrayElementStore(
   EmitBigTypedArrayElementStore(elements, backing_store, offset, bigint_value);
 }
 
-void CodeStubAssembler::EmitBigTypedArrayElementStore(
-    TNode<FixedTypedArrayBase> elements, TNode<RawPtrT> backing_store,
-    TNode<IntPtrT> offset, TNode<BigInt> bigint_value) {
-  TNode<WordT> bitfield = LoadBigIntBitfield(bigint_value);
+void CodeStubAssembler::BigIntToRawBytes(TNode<BigInt> bigint,
+                                         TVariable<UintPtrT>* var_low,
+                                         TVariable<UintPtrT>* var_high) {
+  Label done(this);
+  *var_low = Unsigned(IntPtrConstant(0));
+  *var_high = Unsigned(IntPtrConstant(0));
+  TNode<WordT> bitfield = LoadBigIntBitfield(bigint);
   TNode<UintPtrT> length = DecodeWord<BigIntBase::LengthBits>(bitfield);
   TNode<UintPtrT> sign = DecodeWord<BigIntBase::SignBits>(bitfield);
-  TVARIABLE(UintPtrT, var_low, Unsigned(IntPtrConstant(0)));
-  // Only used on 32-bit platforms.
-  TVARIABLE(UintPtrT, var_high, Unsigned(IntPtrConstant(0)));
-  Label do_store(this);
-  GotoIf(WordEqual(length, IntPtrConstant(0)), &do_store);
-  var_low = LoadBigIntDigit(bigint_value, 0);
+  GotoIf(WordEqual(length, IntPtrConstant(0)), &done);
+  *var_low = LoadBigIntDigit(bigint, 0);
   if (!Is64()) {
     Label load_done(this);
     GotoIf(WordEqual(length, IntPtrConstant(1)), &load_done);
-    var_high = LoadBigIntDigit(bigint_value, 1);
+    *var_high = LoadBigIntDigit(bigint, 1);
     Goto(&load_done);
     BIND(&load_done);
   }
-  GotoIf(WordEqual(sign, IntPtrConstant(0)), &do_store);
+  GotoIf(WordEqual(sign, IntPtrConstant(0)), &done);
   // Negative value. Simulate two's complement.
   if (!Is64()) {
-    var_high = Unsigned(IntPtrSub(IntPtrConstant(0), var_high.value()));
+    *var_high = Unsigned(IntPtrSub(IntPtrConstant(0), var_high->value()));
     Label no_carry(this);
-    GotoIf(WordEqual(var_low.value(), IntPtrConstant(0)), &no_carry);
-    var_high = Unsigned(IntPtrSub(var_high.value(), IntPtrConstant(1)));
+    GotoIf(WordEqual(var_low->value(), IntPtrConstant(0)), &no_carry);
+    *var_high = Unsigned(IntPtrSub(var_high->value(), IntPtrConstant(1)));
     Goto(&no_carry);
     BIND(&no_carry);
   }
-  var_low = Unsigned(IntPtrSub(IntPtrConstant(0), var_low.value()));
-  Goto(&do_store);
-  BIND(&do_store);
+  *var_low = Unsigned(IntPtrSub(IntPtrConstant(0), var_low->value()));
+  Goto(&done);
+  BIND(&done);
+}
+
+void CodeStubAssembler::EmitBigTypedArrayElementStore(
+    TNode<FixedTypedArrayBase> elements, TNode<RawPtrT> backing_store,
+    TNode<IntPtrT> offset, TNode<BigInt> bigint_value) {
+  TVARIABLE(UintPtrT, var_low);
+  // Only used on 32-bit platforms.
+  TVARIABLE(UintPtrT, var_high);
+  BigIntToRawBytes(bigint_value, &var_low, &var_high);
 
   // Assert that offset < elements.length. Given that it's an offset for a raw
   // pointer we correct it by the usual kHeapObjectTag offset.
@@ -9548,7 +9986,7 @@ void CodeStubAssembler::EmitElementStore(Node* object, Node* key, Node* value,
 
     // Bounds check.
     Node* length =
-        TaggedToParameter(LoadTypedArrayLength(CAST(object)), parameter_mode);
+        TaggedToParameter(LoadJSTypedArrayLength(CAST(object)), parameter_mode);
 
     if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
       // Skip the store if we write beyond the length or
@@ -9793,9 +10231,8 @@ void CodeStubAssembler::TrapAllocationMemento(Node* object,
   BIND(&map_check);
   {
     TNode<Object> memento_map = LoadObjectField(object, kMementoMapOffset);
-    Branch(
-        WordEqual(memento_map, LoadRoot(Heap::kAllocationMementoMapRootIndex)),
-        memento_found, &no_memento_found);
+    Branch(WordEqual(memento_map, LoadRoot(RootIndex::kAllocationMementoMap)),
+           memento_found, &no_memento_found);
   }
   BIND(&no_memento_found);
   Comment("] TrapAllocationMemento");
@@ -9809,7 +10246,7 @@ TNode<AllocationSite> CodeStubAssembler::CreateAllocationSiteInFeedbackVector(
     SloppyTNode<FeedbackVector> feedback_vector, TNode<Smi> slot) {
   TNode<IntPtrT> size = IntPtrConstant(AllocationSite::kSizeWithWeakNext);
   Node* site = Allocate(size, CodeStubAssembler::kPretenured);
-  StoreMapNoWriteBarrier(site, Heap::kAllocationSiteWithWeakNextMapRootIndex);
+  StoreMapNoWriteBarrier(site, RootIndex::kAllocationSiteWithWeakNextMap);
   // Should match AllocationSite::Initialize.
   TNode<WordT> field = UpdateWord<AllocationSite::ElementsKindBits>(
       IntPtrConstant(0), IntPtrConstant(GetInitialFastElementsKind()));
@@ -9833,7 +10270,7 @@ TNode<AllocationSite> CodeStubAssembler::CreateAllocationSiteInFeedbackVector(
 
   // Store an empty fixed array for the code dependency.
   StoreObjectFieldRoot(site, AllocationSite::kDependentCodeOffset,
-                       Heap::kEmptyWeakFixedArrayRootIndex);
+                       RootIndex::kEmptyWeakFixedArray);
 
   // Link the object to the allocation site list
   TNode<ExternalReference> site_list = ExternalConstant(
@@ -10001,9 +10438,10 @@ void CodeStubAssembler::GotoIfFixedArraySizeDoesntFitInNewSpace(
          doesnt_fit);
 }
 
-void CodeStubAssembler::InitializeFieldsWithRoot(
-    Node* object, Node* start_offset, Node* end_offset,
-    Heap::RootListIndex root_index) {
+void CodeStubAssembler::InitializeFieldsWithRoot(Node* object,
+                                                 Node* start_offset,
+                                                 Node* end_offset,
+                                                 RootIndex root_index) {
   CSA_SLOW_ASSERT(this, TaggedIsNotSmi(object));
   start_offset = IntPtrAdd(start_offset, IntPtrConstant(-kHeapObjectTag));
   end_offset = IntPtrAdd(end_offset, IntPtrConstant(-kHeapObjectTag));
@@ -10037,6 +10475,10 @@ void CodeStubAssembler::BranchIfNumberRelationalComparison(
                     // Both {left} and {right} are Smi, so just perform a fast
                     // Smi comparison.
                     switch (op) {
+                      case Operation::kEqual:
+                        BranchIfSmiEqual(smi_left, smi_right, if_true,
+                                         if_false);
+                        break;
                       case Operation::kLessThan:
                         BranchIfSmiLessThan(smi_left, smi_right, if_true,
                                             if_false);
@@ -10083,6 +10525,10 @@ void CodeStubAssembler::BranchIfNumberRelationalComparison(
   BIND(&do_float_comparison);
   {
     switch (op) {
+      case Operation::kEqual:
+        Branch(Float64Equal(var_left_float.value(), var_right_float.value()),
+               if_true, if_false);
+        break;
       case Operation::kLessThan:
         Branch(Float64LessThan(var_left_float.value(), var_right_float.value()),
                if_true, if_false);
@@ -10493,15 +10939,16 @@ Node* CodeStubAssembler::RelationalComparison(Operation op, Node* left,
           }
 
           // If {left} is a receiver, call ToPrimitive(left, hint Number).
-          // Otherwise call ToNumeric(left) and then ToNumeric(right).
+          // Otherwise call ToNumeric(right) and then ToNumeric(left), the
+          // order here is important as it's observable by user code.
           STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
           Label if_left_receiver(this, Label::kDeferred);
           GotoIf(IsJSReceiverInstanceType(left_instance_type),
                  &if_left_receiver);
 
+          var_right.Bind(CallBuiltin(Builtins::kToNumeric, context, right));
           var_left.Bind(
               CallBuiltin(Builtins::kNonNumberToNumeric, context, left));
-          var_right.Bind(CallBuiltin(Builtins::kToNumeric, context, right));
           Goto(&loop);
 
           BIND(&if_left_receiver);
@@ -11448,7 +11895,7 @@ TNode<Oddball> CodeStubAssembler::HasProperty(SloppyTNode<Context> context,
 
   BIND(&if_proxy);
   {
-    TNode<Name> name = ToName(context, key);
+    TNode<Name> name = CAST(CallBuiltin(Builtins::kToName, context, key));
     switch (mode) {
       case kHasProperty:
         GotoIf(IsPrivateSymbol(name), &return_false);
@@ -11914,9 +12361,9 @@ TNode<JSArrayIterator> CodeStubAssembler::CreateArrayIterator(
   Node* iterator = Allocate(JSArrayIterator::kSize);
   StoreMapNoWriteBarrier(iterator, iterator_map);
   StoreObjectFieldRoot(iterator, JSArrayIterator::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(iterator, JSArrayIterator::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(
       iterator, JSArrayIterator::kIteratedObjectOffset, object);
   StoreObjectFieldNoWriteBarrier(iterator, JSArrayIterator::kNextIndexOffset,
@@ -11936,9 +12383,9 @@ Node* CodeStubAssembler::AllocateJSIteratorResult(Node* context, Node* value,
   Node* result = Allocate(JSIteratorResult::kSize);
   StoreMapNoWriteBarrier(result, map);
   StoreObjectFieldRoot(result, JSIteratorResult::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(result, JSIteratorResult::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(result, JSIteratorResult::kValueOffset, value);
   StoreObjectFieldNoWriteBarrier(result, JSIteratorResult::kDoneOffset, done);
   return result;
@@ -11953,7 +12400,7 @@ Node* CodeStubAssembler::AllocateJSIteratorResultForEntry(Node* context,
   TNode<FixedArray> elements = UncheckedCast<FixedArray>(
       Allocate(elements_size + JSArray::kSize + JSIteratorResult::kSize));
   StoreObjectFieldRoot(elements, FixedArray::kMapOffset,
-                       Heap::kFixedArrayMapRootIndex);
+                       RootIndex::kFixedArrayMap);
   StoreObjectFieldNoWriteBarrier(elements, FixedArray::kLengthOffset, length);
   StoreFixedArrayElement(elements, 0, key);
   StoreFixedArrayElement(elements, 1, value);
@@ -11962,7 +12409,7 @@ Node* CodeStubAssembler::AllocateJSIteratorResultForEntry(Node* context,
   Node* array = InnerAllocate(elements, elements_size);
   StoreMapNoWriteBarrier(array, array_map);
   StoreObjectFieldRoot(array, JSArray::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(array, JSArray::kElementsOffset, elements);
   StoreObjectFieldNoWriteBarrier(array, JSArray::kLengthOffset, length);
   Node* iterator_map =
@@ -11970,12 +12417,12 @@ Node* CodeStubAssembler::AllocateJSIteratorResultForEntry(Node* context,
   Node* result = InnerAllocate(array, JSArray::kSize);
   StoreMapNoWriteBarrier(result, iterator_map);
   StoreObjectFieldRoot(result, JSIteratorResult::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(result, JSIteratorResult::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldNoWriteBarrier(result, JSIteratorResult::kValueOffset, array);
   StoreObjectFieldRoot(result, JSIteratorResult::kDoneOffset,
-                       Heap::kFalseValueRootIndex);
+                       RootIndex::kFalseValue);
   return result;
 }
 
@@ -11988,12 +12435,19 @@ Node* CodeStubAssembler::ArraySpeciesCreate(TNode<Context> context,
                      len);
 }
 
+Node* CodeStubAssembler::InternalArrayCreate(TNode<Context> context,
+                                             TNode<Number> len) {
+  Node* native_context = LoadNativeContext(context);
+  Node* const constructor = LoadContextElement(
+      native_context, Context::INTERNAL_ARRAY_FUNCTION_INDEX);
+  return ConstructJS(CodeFactory::Construct(isolate()), context, constructor,
+                     len);
+}
+
 Node* CodeStubAssembler::IsDetachedBuffer(Node* buffer) {
   CSA_ASSERT(this, HasInstanceType(buffer, JS_ARRAY_BUFFER_TYPE));
-
-  Node* buffer_bit_field = LoadObjectField(
-      buffer, JSArrayBuffer::kBitFieldOffset, MachineType::Uint32());
-  return IsSetWord32<JSArrayBuffer::WasNeutered>(buffer_bit_field);
+  TNode<Uint32T> buffer_bit_field = LoadJSArrayBufferBitField(CAST(buffer));
+  return IsSetWord32<JSArrayBuffer::WasNeuteredBit>(buffer_bit_field);
 }
 
 void CodeStubAssembler::ThrowIfArrayBufferIsDetached(
@@ -12009,22 +12463,44 @@ void CodeStubAssembler::ThrowIfArrayBufferIsDetached(
 void CodeStubAssembler::ThrowIfArrayBufferViewBufferIsDetached(
     SloppyTNode<Context> context, TNode<JSArrayBufferView> array_buffer_view,
     const char* method_name) {
-  TNode<JSArrayBuffer> buffer = LoadArrayBufferViewBuffer(array_buffer_view);
+  TNode<JSArrayBuffer> buffer = LoadJSArrayBufferViewBuffer(array_buffer_view);
   ThrowIfArrayBufferIsDetached(context, buffer, method_name);
 }
 
-TNode<JSArrayBuffer> CodeStubAssembler::LoadArrayBufferViewBuffer(
-    TNode<JSArrayBufferView> array_buffer_view) {
-  return LoadObjectField<JSArrayBuffer>(array_buffer_view,
-                                        JSArrayBufferView::kBufferOffset);
+TNode<Uint32T> CodeStubAssembler::LoadJSArrayBufferBitField(
+    TNode<JSArrayBuffer> array_buffer) {
+  return LoadObjectField<Uint32T>(array_buffer, JSArrayBuffer::kBitFieldOffset);
 }
 
-TNode<RawPtrT> CodeStubAssembler::LoadArrayBufferBackingStore(
+TNode<RawPtrT> CodeStubAssembler::LoadJSArrayBufferBackingStore(
     TNode<JSArrayBuffer> array_buffer) {
   return LoadObjectField<RawPtrT>(array_buffer,
                                   JSArrayBuffer::kBackingStoreOffset);
 }
 
+TNode<JSArrayBuffer> CodeStubAssembler::LoadJSArrayBufferViewBuffer(
+    TNode<JSArrayBufferView> array_buffer_view) {
+  return LoadObjectField<JSArrayBuffer>(array_buffer_view,
+                                        JSArrayBufferView::kBufferOffset);
+}
+
+TNode<UintPtrT> CodeStubAssembler::LoadJSArrayBufferViewByteLength(
+    TNode<JSArrayBufferView> array_buffer_view) {
+  return LoadObjectField<UintPtrT>(array_buffer_view,
+                                   JSArrayBufferView::kByteLengthOffset);
+}
+
+TNode<UintPtrT> CodeStubAssembler::LoadJSArrayBufferViewByteOffset(
+    TNode<JSArrayBufferView> array_buffer_view) {
+  return LoadObjectField<UintPtrT>(array_buffer_view,
+                                   JSArrayBufferView::kByteOffsetOffset);
+}
+
+TNode<Smi> CodeStubAssembler::LoadJSTypedArrayLength(
+    TNode<JSTypedArray> typed_array) {
+  return LoadObjectField<Smi>(typed_array, JSTypedArray::kLengthOffset);
+}
+
 CodeStubArguments::CodeStubArguments(
     CodeStubAssembler* assembler, Node* argc, Node* fp,
     CodeStubAssembler::ParameterMode param_mode, ReceiverMode receiver_mode)
@@ -12367,11 +12843,11 @@ Node* CodeStubAssembler::AllocateFunctionWithMapAndContext(Node* map,
   STATIC_ASSERT(JSFunction::kSizeWithoutPrototype == 7 * kPointerSize);
   StoreMapNoWriteBarrier(fun, map);
   StoreObjectFieldRoot(fun, JSObject::kPropertiesOrHashOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(fun, JSObject::kElementsOffset,
-                       Heap::kEmptyFixedArrayRootIndex);
+                       RootIndex::kEmptyFixedArray);
   StoreObjectFieldRoot(fun, JSFunction::kFeedbackCellOffset,
-                       Heap::kManyClosuresCellRootIndex);
+                       RootIndex::kManyClosuresCell);
   StoreObjectFieldNoWriteBarrier(fun, JSFunction::kSharedFunctionInfoOffset,
                                  shared_info);
   StoreObjectFieldNoWriteBarrier(fun, JSFunction::kContextOffset, context);
@@ -12522,7 +12998,7 @@ void CodeStubAssembler::PerformStackCheck(TNode<Context> context) {
 void CodeStubAssembler::InitializeFunctionContext(Node* native_context,
                                                   Node* context, int slots) {
   DCHECK_GE(slots, Context::MIN_CONTEXT_SLOTS);
-  StoreMapNoWriteBarrier(context, Heap::kFunctionContextMapRootIndex);
+  StoreMapNoWriteBarrier(context, RootIndex::kFunctionContextMap);
   StoreObjectFieldNoWriteBarrier(context, FixedArray::kLengthOffset,
                                  SmiConstant(slots));
 
diff --git a/deps/v8/src/code-stub-assembler.h b/deps/v8/src/code-stub-assembler.h
index 38fc9717de..69ac5e27bb 100644
--- a/deps/v8/src/code-stub-assembler.h
+++ b/deps/v8/src/code-stub-assembler.h
@@ -11,6 +11,7 @@
 #include "src/compiler/code-assembler.h"
 #include "src/globals.h"
 #include "src/objects.h"
+#include "src/objects/arguments.h"
 #include "src/objects/bigint.h"
 #include "src/roots.h"
 
@@ -32,8 +33,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(PromiseSpeciesProtector, promise_species_protector,                    \
     PromiseSpeciesProtector)                                               \
   V(TypedArraySpeciesProtector, typed_array_species_protector,             \
-    TypedArraySpeciesProtector)                                            \
-  V(StoreHandler0Map, store_handler0_map, StoreHandler0Map)
+    TypedArraySpeciesProtector)
 
 #define HEAP_IMMUTABLE_IMMOVABLE_OBJECT_LIST(V)                              \
   V(AccessorInfoMap, accessor_info_map, AccessorInfoMap)                     \
@@ -70,6 +70,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(PreParsedScopeDataMap, pre_parsed_scope_data_map, PreParsedScopeDataMap) \
   V(prototype_string, prototype_string, PrototypeString)                     \
   V(SharedFunctionInfoMap, shared_function_info_map, SharedFunctionInfoMap)  \
+  V(StoreHandler0Map, store_handler0_map, StoreHandler0Map)                  \
   V(SymbolMap, symbol_map, SymbolMap)                                        \
   V(TheHoleValue, the_hole_value, TheHole)                                   \
   V(TransitionArrayMap, transition_array_map, TransitionArrayMap)            \
@@ -346,6 +347,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
     return CAST(p_o);
   }
 
+  TNode<Context> UnsafeCastObjectToContext(TNode<Object> p_o) {
+    return CAST(p_o);
+  }
+
   TNode<FixedDoubleArray> UnsafeCastObjectToFixedDoubleArray(
       TNode<Object> p_o) {
     return CAST(p_o);
@@ -403,6 +408,11 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 
   TNode<Map> UnsafeCastObjectToMap(TNode<Object> p_o) { return CAST(p_o); }
 
+  TNode<JSArgumentsObjectWithLength> RawCastObjectToJSArgumentsObjectWithLength(
+      TNode<Object> p_o) {
+    return TNode<JSArgumentsObjectWithLength>::UncheckedCast(p_o);
+  }
+
   Node* MatchesParameterMode(Node* value, ParameterMode mode);
 
 #define PARAMETER_BINOP(OpName, IntPtrOpName, SmiOpName) \
@@ -592,6 +602,13 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // if the division needs to be performed as a floating point operation.
   TNode<Smi> TrySmiDiv(TNode<Smi> dividend, TNode<Smi> divisor, Label* bailout);
 
+  // Compares two Smis a and b as if they were converted to strings and then
+  // compared lexicographically. Returns:
+  // -1 iff x < y.
+  //  0 iff x == y.
+  //  1 iff x > y.
+  TNode<Smi> SmiLexicographicCompare(TNode<Smi> x, TNode<Smi> y);
+
   // Smi | HeapNumber operations.
   TNode<Number> NumberInc(SloppyTNode<Number> value);
   TNode<Number> NumberDec(SloppyTNode<Number> value);
@@ -765,6 +782,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // Works only with V8_ENABLE_FORCE_SLOW_PATH compile time flag. Nop otherwise.
   void GotoIfForceSlowPath(Label* if_true);
 
+  // Branches to {if_true} when Debug::ExecutionMode is DebugInfo::kSideEffect.
+  void GotoIfDebugExecutionModeChecksSideEffects(Label* if_true);
+
   // Load value from current frame by given offset in bytes.
   Node* LoadFromFrame(int offset, MachineType rep = MachineType::AnyTagged());
   // Load value from current parent frame by given offset in bytes.
@@ -817,7 +837,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // Load a SMI and untag it.
   TNode<IntPtrT> LoadAndUntagSmi(Node* base, int index);
   // Load a SMI root, untag it, and convert to Word32.
-  TNode<Int32T> LoadAndUntagToWord32Root(Heap::RootListIndex root_index);
+  TNode<Int32T> LoadAndUntagToWord32Root(RootIndex root_index);
 
   TNode<MaybeObject> LoadMaybeWeakObjectField(SloppyTNode<HeapObject> object,
                                               int offset) {
@@ -847,6 +867,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // Load the elements backing store of a JSObject.
   TNode<FixedArrayBase> LoadElements(SloppyTNode<JSObject> object);
   // Load the length of a JSArray instance.
+  TNode<Object> LoadJSArgumentsObjectWithLength(
+      SloppyTNode<JSArgumentsObjectWithLength> array);
+  // Load the length of a JSArray instance.
   TNode<Number> LoadJSArrayLength(SloppyTNode<JSArray> array);
   // Load the length of a fast JSArray instance. Returns a positive Smi.
   TNode<Smi> LoadFastJSArrayLength(SloppyTNode<JSArray> array);
@@ -859,8 +882,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<Smi> LoadWeakFixedArrayLength(TNode<WeakFixedArray> array);
   TNode<IntPtrT> LoadAndUntagWeakFixedArrayLength(
       SloppyTNode<WeakFixedArray> array);
-  // Load the length of a JSTypedArray instance.
-  TNode<Smi> LoadTypedArrayLength(TNode<JSTypedArray> typed_array);
   // Load the bit field of a Map.
   TNode<Int32T> LoadMapBitField(SloppyTNode<Map> map);
   // Load bit field 2 of a map.
@@ -892,6 +913,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* LoadMapEnumLength(SloppyTNode<Map> map);
   // Load the back-pointer of a Map.
   TNode<Object> LoadMapBackPointer(SloppyTNode<Map> map);
+  // Checks that |map| has only simple properties, returns bitfield3.
+  TNode<Uint32T> EnsureOnlyHasSimpleProperties(TNode<Map> map,
+                                               TNode<Int32T> instance_type,
+                                               Label* bailout);
   // Load the identity hash of a JSRececiver.
   TNode<IntPtrT> LoadJSReceiverIdentityHash(SloppyTNode<Object> receiver,
                                             Label* if_no_hash = nullptr);
@@ -912,10 +937,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<Uint32T> LoadNameHash(SloppyTNode<Name> name,
                               Label* if_hash_not_computed = nullptr);
 
-  // Load length field of a String object as intptr_t value.
-  TNode<IntPtrT> LoadStringLengthAsWord(SloppyTNode<String> object);
   // Load length field of a String object as Smi value.
-  TNode<Smi> LoadStringLengthAsSmi(SloppyTNode<String> object);
+  TNode<Smi> LoadStringLengthAsSmi(SloppyTNode<String> string);
+  // Load length field of a String object as intptr_t value.
+  TNode<IntPtrT> LoadStringLengthAsWord(SloppyTNode<String> string);
+  // Load length field of a String object as uint32_t value.
+  TNode<Uint32T> LoadStringLengthAsWord32(SloppyTNode<String> string);
   // Loads a pointer to the sequential String char array.
   Node* PointerToSeqStringData(Node* seq_string);
   // Load value field of a JSValue object.
@@ -933,23 +960,23 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                            Label* if_cleared, Label* if_weak, Label* if_strong,
                            TVariable<Object>* extracted);
   // See MaybeObject for semantics of these functions.
-  TNode<BoolT> IsStrongHeapObject(TNode<MaybeObject> value);
+  TNode<BoolT> IsStrong(TNode<MaybeObject> value);
   // This variant is for overzealous checking.
-  TNode<BoolT> IsStrongHeapObject(TNode<Object> value) {
-    return IsStrongHeapObject(ReinterpretCast<MaybeObject>(value));
+  TNode<BoolT> IsStrong(TNode<Object> value) {
+    return IsStrong(ReinterpretCast<MaybeObject>(value));
   }
-  TNode<HeapObject> ToStrongHeapObject(TNode<MaybeObject> value,
-                                       Label* if_not_strong);
+  TNode<HeapObject> GetHeapObjectIfStrong(TNode<MaybeObject> value,
+                                          Label* if_not_strong);
 
-  TNode<BoolT> IsWeakOrClearedHeapObject(TNode<MaybeObject> value);
-  TNode<BoolT> IsClearedWeakHeapObject(TNode<MaybeObject> value);
-  TNode<BoolT> IsNotClearedWeakHeapObject(TNode<MaybeObject> value);
+  TNode<BoolT> IsWeakOrCleared(TNode<MaybeObject> value);
+  TNode<BoolT> IsCleared(TNode<MaybeObject> value);
+  TNode<BoolT> IsNotCleared(TNode<MaybeObject> value);
 
   // Removes the weak bit + asserts it was set.
-  TNode<HeapObject> ToWeakHeapObject(TNode<MaybeObject> value);
+  TNode<HeapObject> GetHeapObjectAssumeWeak(TNode<MaybeObject> value);
 
-  TNode<HeapObject> ToWeakHeapObject(TNode<MaybeObject> value,
-                                     Label* if_cleared);
+  TNode<HeapObject> GetHeapObjectAssumeWeak(TNode<MaybeObject> value,
+                                            Label* if_cleared);
 
   TNode<BoolT> IsWeakReferenceTo(TNode<MaybeObject> object,
                                  TNode<Object> value);
@@ -1089,6 +1116,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* LoadFixedBigInt64ArrayElementAsTagged(Node* data_pointer, Node* offset);
   Node* LoadFixedBigUint64ArrayElementAsTagged(Node* data_pointer,
                                                Node* offset);
+  // 64-bit platforms only:
+  TNode<BigInt> BigIntFromInt64(TNode<IntPtrT> value);
+  TNode<BigInt> BigIntFromUint64(TNode<UintPtrT> value);
+  // 32-bit platforms only:
+  TNode<BigInt> BigIntFromInt32Pair(TNode<IntPtrT> low, TNode<IntPtrT> high);
+  TNode<BigInt> BigIntFromUint32Pair(TNode<UintPtrT> low, TNode<UintPtrT> high);
 
   void StoreFixedTypedArrayElementFromTagged(
       TNode<Context> context, TNode<FixedTypedArrayBase> elements,
@@ -1100,6 +1133,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                    int slot_index);
   TNode<Object> LoadContextElement(SloppyTNode<Context> context,
                                    SloppyTNode<IntPtrT> slot_index);
+  TNode<Object> LoadContextElement(TNode<Context> context,
+                                   TNode<Smi> slot_index);
   void StoreContextElement(SloppyTNode<Context> context, int slot_index,
                            SloppyTNode<Object> value);
   void StoreContextElement(SloppyTNode<Context> context,
@@ -1151,11 +1186,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
       MachineRepresentation rep = MachineRepresentation::kTagged);
   // Store the Map of an HeapObject.
   Node* StoreMap(Node* object, Node* map);
-  Node* StoreMapNoWriteBarrier(Node* object,
-                               Heap::RootListIndex map_root_index);
+  Node* StoreMapNoWriteBarrier(Node* object, RootIndex map_root_index);
   Node* StoreMapNoWriteBarrier(Node* object, Node* map);
-  Node* StoreObjectFieldRoot(Node* object, int offset,
-                             Heap::RootListIndex root);
+  Node* StoreObjectFieldRoot(Node* object, int offset, RootIndex root);
   // Store an array element to a FixedArray.
   void StoreFixedArrayElement(
       TNode<FixedArray> object, int index, SloppyTNode<Object> value,
@@ -1203,6 +1236,19 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
       TNode<FixedDoubleArray> object, Node* index, TNode<Float64T> value,
       ParameterMode parameter_mode = INTPTR_PARAMETERS);
 
+  void StoreFixedDoubleArrayElementSmi(TNode<FixedDoubleArray> object,
+                                       TNode<Smi> index,
+                                       TNode<Float64T> value) {
+    StoreFixedDoubleArrayElement(object, index, value, SMI_PARAMETERS);
+  }
+
+  void StoreFixedDoubleArrayHole(TNode<FixedDoubleArray> array, Node* index,
+                                 ParameterMode mode = INTPTR_PARAMETERS);
+  void StoreFixedDoubleArrayHoleSmi(TNode<FixedDoubleArray> array,
+                                    TNode<Smi> index) {
+    StoreFixedDoubleArrayHole(array, index, SMI_PARAMETERS);
+  }
+
   Node* StoreFeedbackVectorSlot(
       Node* object, Node* index, Node* value,
       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
@@ -1267,47 +1313,47 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<UintPtrT> LoadBigIntDigit(TNode<BigInt> bigint, int digit_index);
 
   // Allocate a SeqOneByteString with the given length.
-  TNode<String> AllocateSeqOneByteString(int length,
+  TNode<String> AllocateSeqOneByteString(uint32_t length,
                                          AllocationFlags flags = kNone);
-  TNode<String> AllocateSeqOneByteString(Node* context, TNode<Smi> length,
+  TNode<String> AllocateSeqOneByteString(Node* context, TNode<Uint32T> length,
                                          AllocationFlags flags = kNone);
   // Allocate a SeqTwoByteString with the given length.
-  TNode<String> AllocateSeqTwoByteString(int length,
+  TNode<String> AllocateSeqTwoByteString(uint32_t length,
                                          AllocationFlags flags = kNone);
-  TNode<String> AllocateSeqTwoByteString(Node* context, TNode<Smi> length,
+  TNode<String> AllocateSeqTwoByteString(Node* context, TNode<Uint32T> length,
                                          AllocationFlags flags = kNone);
 
   // Allocate a SlicedOneByteString with the given length, parent and offset.
   // |length| and |offset| are expected to be tagged.
 
-  TNode<String> AllocateSlicedOneByteString(TNode<Smi> length,
+  TNode<String> AllocateSlicedOneByteString(TNode<Uint32T> length,
                                             TNode<String> parent,
                                             TNode<Smi> offset);
   // Allocate a SlicedTwoByteString with the given length, parent and offset.
   // |length| and |offset| are expected to be tagged.
-  TNode<String> AllocateSlicedTwoByteString(TNode<Smi> length,
+  TNode<String> AllocateSlicedTwoByteString(TNode<Uint32T> length,
                                             TNode<String> parent,
                                             TNode<Smi> offset);
 
   // Allocate a one-byte ConsString with the given length, first and second
   // parts. |length| is expected to be tagged, and |first| and |second| are
   // expected to be one-byte strings.
-  TNode<String> AllocateOneByteConsString(TNode<Smi> length,
+  TNode<String> AllocateOneByteConsString(TNode<Uint32T> length,
                                           TNode<String> first,
                                           TNode<String> second,
                                           AllocationFlags flags = kNone);
   // Allocate a two-byte ConsString with the given length, first and second
   // parts. |length| is expected to be tagged, and |first| and |second| are
   // expected to be two-byte strings.
-  TNode<String> AllocateTwoByteConsString(TNode<Smi> length,
+  TNode<String> AllocateTwoByteConsString(TNode<Uint32T> length,
                                           TNode<String> first,
                                           TNode<String> second,
                                           AllocationFlags flags = kNone);
 
   // Allocate an appropriate one- or two-byte ConsString with the first and
   // second parts specified by |left| and |right|.
-  TNode<String> NewConsString(Node* context, TNode<Smi> length,
-                              TNode<String> left, TNode<String> right,
+  TNode<String> NewConsString(TNode<Uint32T> length, TNode<String> left,
+                              TNode<String> right,
                               AllocationFlags flags = kNone);
 
   TNode<NameDictionary> AllocateNameDictionary(int at_least_space_for);
@@ -1333,7 +1379,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   template <typename CollectionType>
   void FindOrderedHashTableEntry(
       Node* table, Node* hash,
-      std::function<void(Node*, Label*, Label*)> key_compare,
+      const std::function<void(Node*, Label*, Label*)>& key_compare,
       Variable* entry_start_position, Label* entry_found, Label* not_found);
 
   template <typename CollectionType>
@@ -1386,9 +1432,21 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                            INTPTR_PARAMETERS);
   }
 
-  Node* CloneFastJSArray(Node* context, Node* array,
-                         ParameterMode mode = INTPTR_PARAMETERS,
-                         Node* allocation_site = nullptr);
+  enum class HoleConversionMode { kDontConvert, kConvertToUndefined };
+  // Clone a fast JSArray |array| into a new fast JSArray.
+  // |convert_holes| tells the function to convert holes into undefined or not.
+  // If |convert_holes| is set to kConvertToUndefined, but the function did not
+  // find any hole in |array|, the resulting array will have the same elements
+  // kind as |array|. If the function did find a hole, it will convert holes in
+  // |array| to undefined in the resulting array, who will now have
+  // PACKED_ELEMENTS kind.
+  // If |convert_holes| is set kDontConvert, holes are also copied to the
+  // resulting array, who will have the same elements kind as |array|. The
+  // function generates significantly less code in this case.
+  Node* CloneFastJSArray(
+      Node* context, Node* array, ParameterMode mode = INTPTR_PARAMETERS,
+      Node* allocation_site = nullptr,
+      HoleConversionMode convert_holes = HoleConversionMode::kDontConvert);
 
   Node* ExtractFastJSArray(Node* context, Node* array, Node* begin, Node* count,
                            ParameterMode mode = INTPTR_PARAMETERS,
@@ -1418,7 +1476,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<FixedDoubleArray> AllocateZeroedFixedDoubleArray(
       TNode<IntPtrT> capacity) {
     TNode<FixedDoubleArray> result = UncheckedCast<FixedDoubleArray>(
-        AllocateFixedArray(FLOAT64_ELEMENTS, capacity,
+        AllocateFixedArray(PACKED_DOUBLE_ELEMENTS, capacity,
                            AllocationFlag::kAllowLargeObjectAllocation));
     FillFixedDoubleArrayWithZero(result, capacity);
     return result;
@@ -1438,10 +1496,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 
   Node* ArraySpeciesCreate(TNode<Context> context, TNode<Object> originalArray,
                            TNode<Number> len);
+  Node* InternalArrayCreate(TNode<Context> context, TNode<Number> len);
 
   void FillFixedArrayWithValue(ElementsKind kind, Node* array, Node* from_index,
-                               Node* to_index,
-                               Heap::RootListIndex value_root_index,
+                               Node* to_index, RootIndex value_root_index,
                                ParameterMode mode = INTPTR_PARAMETERS);
 
   // Uses memset to effectively initialize the given FixedArray with zeroes.
@@ -1486,11 +1544,18 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // Copies |element_count| elements from |from_array| starting from element
   // |first_element| to |to_array| of |capacity| size respecting both array's
   // elements kinds.
+  // |convert_holes| tells the function whether to convert holes to undefined.
+  // |var_holes_converted| can be used to signify that the conversion happened
+  // (i.e. that there were holes). If |convert_holes_to_undefined| is
+  // HoleConversionMode::kConvertToUndefined, then it must not be the case that
+  // IsDoubleElementsKind(to_kind).
   void CopyFixedArrayElements(
       ElementsKind from_kind, Node* from_array, ElementsKind to_kind,
       Node* to_array, Node* first_element, Node* element_count, Node* capacity,
       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
-      ParameterMode mode = INTPTR_PARAMETERS);
+      ParameterMode mode = INTPTR_PARAMETERS,
+      HoleConversionMode convert_holes = HoleConversionMode::kDontConvert,
+      TVariable<BoolT>* var_holes_converted = nullptr);
 
   void CopyFixedArrayElements(
       ElementsKind from_kind, TNode<FixedArrayBase> from_array,
@@ -1507,12 +1572,16 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 
   TNode<FixedDoubleArray> HeapObjectToFixedDoubleArray(TNode<HeapObject> base,
                                                        Label* cast_fail) {
-    GotoIf(WordNotEqual(LoadMap(base),
-                        LoadRoot(Heap::kFixedDoubleArrayMapRootIndex)),
-           cast_fail);
+    GotoIf(
+        WordNotEqual(LoadMap(base), LoadRoot(RootIndex::kFixedDoubleArrayMap)),
+        cast_fail);
     return UncheckedCast<FixedDoubleArray>(base);
   }
 
+  TNode<Int32T> ConvertElementsKindToInt(TNode<Int32T> elements_kind) {
+    return UncheckedCast<Int32T>(elements_kind);
+  }
+
   enum class ExtractFixedArrayFlag {
     kFixedArrays = 1,
     kFixedDoubleArrays = 2,
@@ -1525,8 +1594,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   typedef base::Flags<ExtractFixedArrayFlag> ExtractFixedArrayFlags;
 
   // Copy a portion of an existing FixedArray or FixedDoubleArray into a new
-  // FixedArray, including special appropriate handling for empty arrays and COW
-  // arrays.
+  // array, including special appropriate handling for empty arrays and COW
+  // arrays. The result array will be of the same type as the original array.
   //
   // * |source| is either a FixedArray or FixedDoubleArray from which to copy
   // elements.
@@ -1546,12 +1615,16 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // passed as the |source| parameter.
   // * |parameter_mode| determines the parameter mode of |first|, |count| and
   // |capacity|.
+  // * If |var_holes_converted| is given, any holes will be converted to
+  // undefined and the variable will be set according to whether or not there
+  // were any hole.
   TNode<FixedArrayBase> ExtractFixedArray(
       Node* source, Node* first, Node* count = nullptr,
       Node* capacity = nullptr,
       ExtractFixedArrayFlags extract_flags =
           ExtractFixedArrayFlag::kAllFixedArrays,
-      ParameterMode parameter_mode = INTPTR_PARAMETERS);
+      ParameterMode parameter_mode = INTPTR_PARAMETERS,
+      TVariable<BoolT>* var_holes_converted = nullptr);
 
   TNode<FixedArrayBase> ExtractFixedArray(
       TNode<FixedArrayBase> source, TNode<Smi> first, TNode<Smi> count,
@@ -1562,6 +1635,68 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                              SMI_PARAMETERS);
   }
 
+  // Copy a portion of an existing FixedArray or FixedDoubleArray into a new
+  // FixedArray, including special appropriate handling for COW arrays.
+  // * |source| is either a FixedArray or FixedDoubleArray from which to copy
+  // elements. |source| is assumed to be non-empty.
+  // * |first| is the starting element index to copy from.
+  // * |count| is the number of elements to copy out of the source array
+  // starting from and including the element indexed by |start|.
+  // * |capacity| determines the size of the allocated result array, with
+  // |capacity| >= |count|.
+  // * |source_map| is the map of the |source|.
+  // * |from_kind| is the elements kind that is consistent with |source| being
+  // a FixedArray or FixedDoubleArray. This function only cares about double vs.
+  // non-double, so as to distinguish FixedDoubleArray vs. FixedArray. It does
+  // not care about holeyness. For example, when |source| is a FixedArray,
+  // PACKED/HOLEY_ELEMENTS can be used, but not PACKED_DOUBLE_ELEMENTS.
+  // * |allocation_flags| and |extract_flags| influence how the target
+  // FixedArray is allocated.
+  // * |parameter_mode| determines the parameter mode of |first|, |count| and
+  // |capacity|.
+  // * |convert_holes| is used to signify that the target array should use
+  // undefined in places of holes.
+  // * If |convert_holes| is true and |var_holes_converted| not nullptr, then
+  // |var_holes_converted| is used to signal whether any holes were found and
+  // converted. The caller should use this information to decide which map is
+  // compatible with the result array. For example, if the input was of
+  // HOLEY_SMI_ELEMENTS kind, and a conversion took place, the result will be
+  // compatible only with HOLEY_ELEMENTS and PACKED_ELEMENTS.
+  TNode<FixedArray> ExtractToFixedArray(
+      Node* source, Node* first, Node* count, Node* capacity, Node* source_map,
+      ElementsKind from_kind = PACKED_ELEMENTS,
+      AllocationFlags allocation_flags = AllocationFlag::kNone,
+      ExtractFixedArrayFlags extract_flags =
+          ExtractFixedArrayFlag::kAllFixedArrays,
+      ParameterMode parameter_mode = INTPTR_PARAMETERS,
+      HoleConversionMode convert_holes = HoleConversionMode::kDontConvert,
+      TVariable<BoolT>* var_holes_converted = nullptr);
+
+  // Attempt to copy a FixedDoubleArray to another FixedDoubleArray. In the case
+  // where the source array has a hole, produce a FixedArray instead where holes
+  // are replaced with undefined.
+  // * |source| is a FixedDoubleArray from which to copy elements.
+  // * |first| is the starting element index to copy from.
+  // * |count| is the number of elements to copy out of the source array
+  // starting from and including the element indexed by |start|.
+  // * |capacity| determines the size of the allocated result array, with
+  // |capacity| >= |count|.
+  // * |source_map| is the map of |source|. It will be used as the map of the
+  // target array if the target can stay a FixedDoubleArray. Otherwise if the
+  // target array needs to be a FixedArray, the FixedArrayMap will be used.
+  // * |var_holes_converted| is used to signal whether a FixedAray
+  // is produced or not.
+  // * |allocation_flags| and |extract_flags| influence how the target array is
+  // allocated.
+  // * |parameter_mode| determines the parameter mode of |first|, |count| and
+  // |capacity|.
+  TNode<FixedArrayBase> ExtractFixedDoubleArrayFillingHoles(
+      Node* source, Node* first, Node* count, Node* capacity, Node* source_map,
+      TVariable<BoolT>* var_holes_converted, AllocationFlags allocation_flags,
+      ExtractFixedArrayFlags extract_flags =
+          ExtractFixedArrayFlag::kAllFixedArrays,
+      ParameterMode parameter_mode = INTPTR_PARAMETERS);
+
   // Copy the entire contents of a FixedArray or FixedDoubleArray to a new
   // array, including special appropriate handling for empty arrays and COW
   // arrays.
@@ -1657,6 +1792,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<Number> ChangeFloat64ToTagged(SloppyTNode<Float64T> value);
   TNode<Number> ChangeInt32ToTagged(SloppyTNode<Int32T> value);
   TNode<Number> ChangeUint32ToTagged(SloppyTNode<Uint32T> value);
+  TNode<Number> ChangeUintPtrToTagged(TNode<UintPtrT> value);
   TNode<Uint32T> ChangeNumberToUint32(TNode<Number> value);
   TNode<Float64T> ChangeNumberToFloat64(SloppyTNode<Number> value);
   TNode<UintPtrT> ChangeNonnegativeNumberToUintPtr(TNode<Number> value);
@@ -1736,6 +1872,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<BoolT> IsNameDictionary(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsGlobalDictionary(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsExtensibleMap(SloppyTNode<Map> map);
+  TNode<BoolT> IsExtensibleNonPrototypeMap(TNode<Map> map);
   TNode<BoolT> IsExternalStringInstanceType(SloppyTNode<Int32T> instance_type);
   TNode<BoolT> IsFastJSArray(SloppyTNode<Object> object,
                              SloppyTNode<Context> context);
@@ -1756,6 +1893,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<BoolT> IsHashTable(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsEphemeronHashTable(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsHeapNumber(SloppyTNode<HeapObject> object);
+  TNode<BoolT> IsHeapNumberInstanceType(SloppyTNode<Int32T> instance_type);
+  TNode<BoolT> IsOddballInstanceType(SloppyTNode<Int32T> instance_type);
   TNode<BoolT> IsIndirectStringInstanceType(SloppyTNode<Int32T> instance_type);
   TNode<BoolT> IsJSArrayBuffer(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsJSDataView(TNode<HeapObject> object);
@@ -1788,6 +1927,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<BoolT> IsMap(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsMutableHeapNumber(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsName(SloppyTNode<HeapObject> object);
+  TNode<BoolT> IsNameInstanceType(SloppyTNode<Int32T> instance_type);
   TNode<BoolT> IsNativeContext(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsNullOrJSReceiver(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsNullOrUndefined(SloppyTNode<Object> object);
@@ -1804,7 +1944,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                               SloppyTNode<Map> map);
   TNode<BoolT> IsSequentialStringInstanceType(
       SloppyTNode<Int32T> instance_type);
-  TNode<BoolT> IsShortExternalStringInstanceType(
+  TNode<BoolT> IsUncachedExternalStringInstanceType(
       SloppyTNode<Int32T> instance_type);
   TNode<BoolT> IsSpecialReceiverInstanceType(TNode<Int32T> instance_type);
   TNode<BoolT> IsCustomElementsReceiverInstanceType(
@@ -1929,8 +2069,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<Number> StringToNumber(TNode<String> input);
   // Convert a Number to a String.
   TNode<String> NumberToString(TNode<Number> input);
-  // Convert an object to a name.
-  TNode<Name> ToName(SloppyTNode<Context> context, SloppyTNode<Object> value);
   // Convert a Non-Number object to a Number.
   TNode<Number> NonNumberToNumber(
       SloppyTNode<Context> context, SloppyTNode<HeapObject> input,
@@ -2530,11 +2668,17 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                      TNode<Object> value,
                                      TNode<Context> context,
                                      Label* opt_if_neutered);
-  // Part of the above, refactored out to reuse in another place
+  // Part of the above, refactored out to reuse in another place.
   void EmitBigTypedArrayElementStore(TNode<FixedTypedArrayBase> elements,
                                      TNode<RawPtrT> backing_store,
                                      TNode<IntPtrT> offset,
                                      TNode<BigInt> bigint_value);
+  // Implements the BigInt part of
+  // https://tc39.github.io/proposal-bigint/#sec-numbertorawbytes,
+  // including truncation to 64 bits (i.e. modulo 2^64).
+  // {var_high} is only used on 32-bit platforms.
+  void BigIntToRawBytes(TNode<BigInt> bigint, TVariable<UintPtrT>* var_low,
+                        TVariable<UintPtrT>* var_high);
 
   void EmitElementStore(Node* object, Node* key, Node* value, bool is_jsarray,
                         ElementsKind elements_kind,
@@ -2553,6 +2697,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                               ElementsKind to_kind, bool is_jsarray,
                               Label* bailout);
 
+  void TransitionElementsKind(TNode<JSReceiver> object, TNode<Map> map,
+                              ElementsKind from_kind, ElementsKind to_kind,
+                              Label* bailout) {
+    TransitionElementsKind(object, map, from_kind, to_kind, true, bailout);
+  }
+
   void TrapAllocationMemento(Node* object, Label* memento_found);
 
   TNode<IntPtrT> PageFromAddress(TNode<IntPtrT> address);
@@ -2635,7 +2785,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                                                ParameterMode mode);
 
   void InitializeFieldsWithRoot(Node* object, Node* start_offset,
-                                Node* end_offset, Heap::RootListIndex root);
+                                Node* end_offset, RootIndex root);
 
   Node* RelationalComparison(Operation op, Node* left, Node* right,
                              Node* context,
@@ -2644,26 +2794,32 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   void BranchIfNumberRelationalComparison(Operation op, Node* left, Node* right,
                                           Label* if_true, Label* if_false);
 
-  void BranchIfNumberLessThan(Node* left, Node* right, Label* if_true,
-                              Label* if_false) {
+  void BranchIfNumberEqual(TNode<Number> left, TNode<Number> right,
+                           Label* if_true, Label* if_false) {
+    BranchIfNumberRelationalComparison(Operation::kEqual, left, right, if_true,
+                                       if_false);
+  }
+
+  void BranchIfNumberLessThan(TNode<Number> left, TNode<Number> right,
+                              Label* if_true, Label* if_false) {
     BranchIfNumberRelationalComparison(Operation::kLessThan, left, right,
                                        if_true, if_false);
   }
 
-  void BranchIfNumberLessThanOrEqual(Node* left, Node* right, Label* if_true,
-                                     Label* if_false) {
+  void BranchIfNumberLessThanOrEqual(TNode<Number> left, TNode<Number> right,
+                                     Label* if_true, Label* if_false) {
     BranchIfNumberRelationalComparison(Operation::kLessThanOrEqual, left, right,
                                        if_true, if_false);
   }
 
-  void BranchIfNumberGreaterThan(Node* left, Node* right, Label* if_true,
-                                 Label* if_false) {
+  void BranchIfNumberGreaterThan(TNode<Number> left, TNode<Number> right,
+                                 Label* if_true, Label* if_false) {
     BranchIfNumberRelationalComparison(Operation::kGreaterThan, left, right,
                                        if_true, if_false);
   }
 
-  void BranchIfNumberGreaterThanOrEqual(Node* left, Node* right, Label* if_true,
-                                        Label* if_false) {
+  void BranchIfNumberGreaterThanOrEqual(TNode<Number> left, TNode<Number> right,
+                                        Label* if_true, Label* if_false) {
     BranchIfNumberRelationalComparison(Operation::kGreaterThanOrEqual, left,
                                        right, if_true, if_false);
   }
@@ -2694,6 +2850,14 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                              SloppyTNode<Object> key,
                              HasPropertyLookupMode mode);
 
+  // Due to naming conflict with the builtin function namespace.
+  TNode<Oddball> HasProperty_Inline(TNode<Context> context,
+                                    TNode<JSReceiver> object,
+                                    TNode<Object> key) {
+    return HasProperty(context, object, key,
+                       HasPropertyLookupMode::kHasProperty);
+  }
+
   Node* Typeof(Node* value);
 
   TNode<Object> GetSuperConstructor(SloppyTNode<Context> context,
@@ -2710,17 +2874,28 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 
   TNode<BoolT> IsRuntimeCallStatsEnabled();
 
-  // TypedArray/ArrayBuffer helpers
+  // JSArrayBuffer helpers
+  TNode<Uint32T> LoadJSArrayBufferBitField(TNode<JSArrayBuffer> array_buffer);
+  TNode<RawPtrT> LoadJSArrayBufferBackingStore(
+      TNode<JSArrayBuffer> array_buffer);
   Node* IsDetachedBuffer(Node* buffer);
   void ThrowIfArrayBufferIsDetached(SloppyTNode<Context> context,
                                     TNode<JSArrayBuffer> array_buffer,
                                     const char* method_name);
+
+  // JSArrayBufferView helpers
+  TNode<JSArrayBuffer> LoadJSArrayBufferViewBuffer(
+      TNode<JSArrayBufferView> array_buffer_view);
+  TNode<UintPtrT> LoadJSArrayBufferViewByteLength(
+      TNode<JSArrayBufferView> array_buffer_view);
+  TNode<UintPtrT> LoadJSArrayBufferViewByteOffset(
+      TNode<JSArrayBufferView> array_buffer_view);
   void ThrowIfArrayBufferViewBufferIsDetached(
       SloppyTNode<Context> context, TNode<JSArrayBufferView> array_buffer_view,
       const char* method_name);
-  TNode<JSArrayBuffer> LoadArrayBufferViewBuffer(
-      TNode<JSArrayBufferView> array_buffer_view);
-  TNode<RawPtrT> LoadArrayBufferBackingStore(TNode<JSArrayBuffer> array_buffer);
+
+  // JSTypedArray helpers
+  TNode<Smi> LoadJSTypedArrayLength(TNode<JSTypedArray> typed_array);
 
   TNode<IntPtrT> ElementOffsetFromIndex(Node* index, ElementsKind kind,
                                         ParameterMode mode, int base_size = 0);
@@ -2851,6 +3026,17 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
                               TNode<Uint32T> end_descriptor,
                               const ForEachDescriptorBodyFunction& body);
 
+  typedef std::function<void(TNode<Name> key, TNode<Object> value)>
+      ForEachKeyValueFunction;
+
+  // For each JSObject property (in DescriptorArray order), check if the key is
+  // enumerable, and if so, load the value from the receiver and evaluate the
+  // closure.
+  void ForEachEnumerableOwnProperty(TNode<Context> context, TNode<Map> map,
+                                    TNode<JSObject> object,
+                                    const ForEachKeyValueFunction& body,
+                                    Label* bailout);
+
   TNode<Object> CallGetterIfAccessor(Node* value, Node* details, Node* context,
                                      Node* receiver, Label* if_bailout,
                                      GetOwnPropertyMode mode = kCallJSGetter);
@@ -2889,12 +3075,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* EmitKeyedSloppyArguments(Node* receiver, Node* key, Node* value,
                                  Label* bailout);
 
-  TNode<String> AllocateSlicedString(Heap::RootListIndex map_root_index,
-                                     TNode<Smi> length, TNode<String> parent,
-                                     TNode<Smi> offset);
+  TNode<String> AllocateSlicedString(RootIndex map_root_index,
+                                     TNode<Uint32T> length,
+                                     TNode<String> parent, TNode<Smi> offset);
 
-  TNode<String> AllocateConsString(Heap::RootListIndex map_root_index,
-                                   TNode<Smi> length, TNode<String> first,
+  TNode<String> AllocateConsString(RootIndex map_root_index,
+                                   TNode<Uint32T> length, TNode<String> first,
                                    TNode<String> second, AllocationFlags flags);
 
   // Allocate a MutableHeapNumber without initializing its value.
@@ -2918,7 +3104,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   TNode<String> AllocAndCopyStringCharacters(Node* from,
                                              Node* from_instance_type,
                                              TNode<IntPtrT> from_index,
-                                             TNode<Smi> character_count);
+                                             TNode<IntPtrT> character_count);
 
   static const int kElementLoopUnrollThreshold = 8;
 
diff --git a/deps/v8/src/code-stubs.h b/deps/v8/src/code-stubs.h
index 745aa1aa24..4630fe7639 100644
--- a/deps/v8/src/code-stubs.h
+++ b/deps/v8/src/code-stubs.h
@@ -12,6 +12,7 @@ namespace v8 {
 namespace internal {
 
 // Forward declarations.
+class CodeStubDescriptor;
 class Isolate;
 namespace compiler {
 class CodeAssemblerState;
@@ -114,7 +115,7 @@ class CodeStub : public ZoneObject {
   static const char* MajorName(Major major_key);
 
   explicit CodeStub(Isolate* isolate) : minor_key_(0), isolate_(isolate) {}
-  virtual ~CodeStub() {}
+  virtual ~CodeStub() = default;
 
   static void GenerateStubsAheadOfTime(Isolate* isolate);
 
@@ -299,7 +300,9 @@ class CodeStubDescriptor {
     DCHECK(!stack_parameter_count_.is_valid());
   }
 
-  void set_call_descriptor(CallInterfaceDescriptor d) { call_descriptor_ = d; }
+  void set_call_descriptor(CallInterfaceDescriptor d) {
+    call_descriptor_ = std::move(d);
+  }
   CallInterfaceDescriptor call_descriptor() const { return call_descriptor_; }
 
   int GetRegisterParameterCount() const {
diff --git a/deps/v8/src/codegen.cc b/deps/v8/src/codegen.cc
index 10dfdbbd4a..198ee8f572 100644
--- a/deps/v8/src/codegen.cc
+++ b/deps/v8/src/codegen.cc
@@ -12,19 +12,17 @@
 namespace v8 {
 namespace internal {
 
-#define UNARY_MATH_FUNCTION(name, generator)                             \
-  static UnaryMathFunctionWithIsolate fast_##name##_function = nullptr;  \
-  double std_##name(double x, Isolate* isolate) { return std::name(x); } \
-  void init_fast_##name##_function(Isolate* isolate) {                   \
-    if (FLAG_fast_math) fast_##name##_function = generator(isolate);     \
-    if (!fast_##name##_function) fast_##name##_function = std_##name;    \
-  }                                                                      \
-  void lazily_initialize_fast_##name(Isolate* isolate) {                 \
-    if (!fast_##name##_function) init_fast_##name##_function(isolate);   \
-  }                                                                      \
-  double fast_##name(double x, Isolate* isolate) {                       \
-    return (*fast_##name##_function)(x, isolate);                        \
-  }
+#define UNARY_MATH_FUNCTION(name, generator)                          \
+  static UnaryMathFunction fast_##name##_function = nullptr;          \
+  double std_##name(double x) { return std::name(x); }                \
+  void init_fast_##name##_function() {                                \
+    if (FLAG_fast_math) fast_##name##_function = generator();         \
+    if (!fast_##name##_function) fast_##name##_function = std_##name; \
+  }                                                                   \
+  void lazily_initialize_fast_##name() {                              \
+    if (!fast_##name##_function) init_fast_##name##_function();       \
+  }                                                                   \
+  double fast_##name(double x) { return (*fast_##name##_function)(x); }
 
 UNARY_MATH_FUNCTION(sqrt, CreateSqrtFunction)
 
diff --git a/deps/v8/src/codegen.h b/deps/v8/src/codegen.h
index 1b57c74447..3e07c86fc2 100644
--- a/deps/v8/src/codegen.h
+++ b/deps/v8/src/codegen.h
@@ -5,21 +5,19 @@
 #ifndef V8_CODEGEN_H_
 #define V8_CODEGEN_H_
 
-#include "src/globals.h"
-
 namespace v8 {
 namespace internal {
 
 // Results of the library implementation of transcendental functions may differ
 // from the one we use in our generated code.  Therefore we use the same
 // generated code both in runtime and compiled code.
-typedef double (*UnaryMathFunctionWithIsolate)(double x, Isolate* isolate);
+typedef double (*UnaryMathFunction)(double x);
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate);
+UnaryMathFunction CreateSqrtFunction();
 
 // Custom implementation of math functions.
-double fast_sqrt(double input, Isolate* isolate);
-void lazily_initialize_fast_sqrt(Isolate* isolate);
+double fast_sqrt(double input);
+void lazily_initialize_fast_sqrt();
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/collector.h b/deps/v8/src/collector.h
index a3e940663f..bfaa9d42ce 100644
--- a/deps/v8/src/collector.h
+++ b/deps/v8/src/collector.h
@@ -184,7 +184,7 @@ class SequenceCollector : public Collector<T, growth_factor, max_growth> {
       : Collector<T, growth_factor, max_growth>(initial_capacity),
         sequence_start_(kNoSequence) {}
 
-  virtual ~SequenceCollector() {}
+  ~SequenceCollector() override = default;
 
   void StartSequence() {
     DCHECK_EQ(sequence_start_, kNoSequence);
@@ -208,7 +208,7 @@ class SequenceCollector : public Collector<T, growth_factor, max_growth> {
     sequence_start_ = kNoSequence;
   }
 
-  virtual void Reset() {
+  void Reset() override {
     sequence_start_ = kNoSequence;
     this->Collector<T, growth_factor, max_growth>::Reset();
   }
@@ -218,7 +218,7 @@ class SequenceCollector : public Collector<T, growth_factor, max_growth> {
   int sequence_start_;
 
   // Move the currently active sequence to the new chunk.
-  virtual void NewChunk(int new_capacity) {
+  void NewChunk(int new_capacity) override {
     if (sequence_start_ == kNoSequence) {
       // Fall back on default behavior if no sequence has been started.
       this->Collector<T, growth_factor, max_growth>::NewChunk(new_capacity);
diff --git a/deps/v8/src/compilation-cache.cc b/deps/v8/src/compilation-cache.cc
index 61b83b1a18..0068c83362 100644
--- a/deps/v8/src/compilation-cache.cc
+++ b/deps/v8/src/compilation-cache.cc
@@ -34,8 +34,6 @@ CompilationCache::CompilationCache(Isolate* isolate)
   }
 }
 
-CompilationCache::~CompilationCache() {}
-
 Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) {
   DCHECK(generation < generations_);
   Handle<CompilationCacheTable> result;
diff --git a/deps/v8/src/compilation-cache.h b/deps/v8/src/compilation-cache.h
index 3a4fe2e7b5..ed3f1986b6 100644
--- a/deps/v8/src/compilation-cache.h
+++ b/deps/v8/src/compilation-cache.h
@@ -213,7 +213,7 @@ class CompilationCache {
 
  private:
   explicit CompilationCache(Isolate* isolate);
-  ~CompilationCache();
+  ~CompilationCache() = default;
 
   base::HashMap* EagerOptimizingSet();
 
diff --git a/deps/v8/src/compilation-statistics.h b/deps/v8/src/compilation-statistics.h
index cb66f86532..bfd9a5c66a 100644
--- a/deps/v8/src/compilation-statistics.h
+++ b/deps/v8/src/compilation-statistics.h
@@ -24,7 +24,7 @@ struct AsPrintableStatistics {
 
 class CompilationStatistics final : public Malloced {
  public:
-  CompilationStatistics() {}
+  CompilationStatistics() = default;
 
   class BasicStats {
    public:
diff --git a/deps/v8/src/compiler-dispatcher/compiler-dispatcher-job.h b/deps/v8/src/compiler-dispatcher/compiler-dispatcher-job.h
index aed4960119..827a2aa18d 100644
--- a/deps/v8/src/compiler-dispatcher/compiler-dispatcher-job.h
+++ b/deps/v8/src/compiler-dispatcher/compiler-dispatcher-job.h
@@ -21,16 +21,14 @@ class V8_EXPORT_PRIVATE CompilerDispatcherJob {
 
   enum class Status {
     kInitial,
-    kPrepared,
-    kCompiled,
-    kHasErrorsToReport,
+    kReadyToFinalize,
     kDone,
     kFailed,
   };
 
   CompilerDispatcherJob(Type type) : type_(type), status_(Status::kInitial) {}
 
-  virtual ~CompilerDispatcherJob() {}
+  virtual ~CompilerDispatcherJob() = default;
 
   Type type() const { return type_; }
 
@@ -48,26 +46,19 @@ class V8_EXPORT_PRIVATE CompilerDispatcherJob {
 
   // Return true if the next step can be run on any thread.
   bool NextStepCanRunOnAnyThread() const {
-    return status() == Status::kPrepared;
+    return status() == Status::kInitial;
   }
 
   // Casts to implementations.
   const UnoptimizedCompileJob* AsUnoptimizedCompileJob() const;
 
-  // Transition from kInitial to kPrepared. Must only be invoked on the
-  // main thread.
-  virtual void PrepareOnMainThread(Isolate* isolate) = 0;
-
-  // Transition from kPrepared to kCompiled (or kReportErrors).
+  // Transition from kInitial to kReadyToFinalize.
   virtual void Compile(bool on_background_thread) = 0;
 
-  // Transition from kCompiled to kDone (or kFailed). Must only be invoked on
-  // the main thread.
-  virtual void FinalizeOnMainThread(Isolate* isolate) = 0;
-
-  // Transition from kReportErrors to kFailed. Must only be invoked on the main
-  // thread.
-  virtual void ReportErrorsOnMainThread(Isolate* isolate) = 0;
+  // Transition from kReadyToFinalize to kDone (or kFailed). Must only be
+  // invoked on the main thread.
+  virtual void FinalizeOnMainThread(Isolate* isolate,
+                                    Handle<SharedFunctionInfo> shared) = 0;
 
   // Free all resources. Must only be invoked on the main thread.
   virtual void ResetOnMainThread(Isolate* isolate) = 0;
@@ -75,9 +66,6 @@ class V8_EXPORT_PRIVATE CompilerDispatcherJob {
   // Estimate how long the next step will take using the tracer.
   virtual double EstimateRuntimeOfNextStepInMs() const = 0;
 
-  // Print short description of job. Must only be invoked on the main thread.
-  virtual void ShortPrintOnMainThread() = 0;
-
  protected:
   void set_status(Status status) { status_ = status; }
 
diff --git a/deps/v8/src/compiler-dispatcher/compiler-dispatcher-tracer.cc b/deps/v8/src/compiler-dispatcher/compiler-dispatcher-tracer.cc
index 862efda83e..ab8bc5adec 100644
--- a/deps/v8/src/compiler-dispatcher/compiler-dispatcher-tracer.cc
+++ b/deps/v8/src/compiler-dispatcher/compiler-dispatcher-tracer.cc
@@ -63,7 +63,7 @@ CompilerDispatcherTracer::CompilerDispatcherTracer(Isolate* isolate)
   }
 }
 
-CompilerDispatcherTracer::~CompilerDispatcherTracer() {}
+CompilerDispatcherTracer::~CompilerDispatcherTracer() = default;
 
 void CompilerDispatcherTracer::RecordPrepare(double duration_ms) {
   base::LockGuard<base::Mutex> lock(&mutex_);
diff --git a/deps/v8/src/compiler-dispatcher/compiler-dispatcher.cc b/deps/v8/src/compiler-dispatcher/compiler-dispatcher.cc
index 6bbcefa781..6148770385 100644
--- a/deps/v8/src/compiler-dispatcher/compiler-dispatcher.cc
+++ b/deps/v8/src/compiler-dispatcher/compiler-dispatcher.cc
@@ -4,8 +4,7 @@
 
 #include "src/compiler-dispatcher/compiler-dispatcher.h"
 
-#include "include/v8-platform.h"
-#include "include/v8.h"
+#include "src/ast/ast.h"
 #include "src/base/platform/time.h"
 #include "src/base/template-utils.h"
 #include "src/cancelable-task.h"
@@ -13,6 +12,7 @@
 #include "src/compiler-dispatcher/compiler-dispatcher-tracer.h"
 #include "src/compiler-dispatcher/unoptimized-compile-job.h"
 #include "src/flags.h"
+#include "src/global-handles.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
@@ -22,157 +22,35 @@ namespace {
 
 enum class ExceptionHandling { kSwallow, kThrow };
 
-bool DoNextStepOnMainThread(Isolate* isolate, CompilerDispatcherJob* job,
-                            ExceptionHandling exception_handling) {
+void FinalizeJobOnMainThread(Isolate* isolate, CompilerDispatcherJob* job,
+                             Handle<SharedFunctionInfo> shared,
+                             ExceptionHandling exception_handling) {
   DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.CompilerDispatcherForgroundStep");
-  switch (job->status()) {
-    case CompilerDispatcherJob::Status::kInitial:
-      job->PrepareOnMainThread(isolate);
-      break;
-    case CompilerDispatcherJob::Status::kPrepared:
-      job->Compile(false);
-      break;
-    case CompilerDispatcherJob::Status::kCompiled:
-      job->FinalizeOnMainThread(isolate);
-      break;
-    case CompilerDispatcherJob::Status::kHasErrorsToReport:
-      job->ReportErrorsOnMainThread(isolate);
-      break;
-    case CompilerDispatcherJob::Status::kFailed:
-    case CompilerDispatcherJob::Status::kDone:
-      UNREACHABLE();
-  }
+  DCHECK_EQ(job->status(), CompilerDispatcherJob::Status::kReadyToFinalize);
 
+  job->FinalizeOnMainThread(isolate, shared);
   DCHECK_EQ(job->IsFailed(), isolate->has_pending_exception());
   if (job->IsFailed() && exception_handling == ExceptionHandling::kSwallow) {
     isolate->clear_pending_exception();
   }
-  return job->IsFailed();
-}
-
-void DoNextStepOnBackgroundThread(CompilerDispatcherJob* job) {
-  DCHECK(job->NextStepCanRunOnAnyThread());
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.CompilerDispatcherBackgroundStep");
-  switch (job->status()) {
-    case CompilerDispatcherJob::Status::kPrepared:
-      job->Compile(true);
-      break;
-    default:
-      UNREACHABLE();
-  }
 }
 
 // Theoretically we get 50ms of idle time max, however it's unlikely that
 // we'll get all of it so try to be a conservative.
 const double kMaxIdleTimeToExpectInMs = 40;
 
-class MemoryPressureTask : public CancelableTask {
- public:
-  MemoryPressureTask(CancelableTaskManager* task_manager,
-                     CompilerDispatcher* dispatcher);
-  ~MemoryPressureTask() override;
-
-  // CancelableTask implementation.
-  void RunInternal() override;
-
- private:
-  CompilerDispatcher* dispatcher_;
-
-  DISALLOW_COPY_AND_ASSIGN(MemoryPressureTask);
-};
-
-MemoryPressureTask::MemoryPressureTask(CancelableTaskManager* task_manager,
-                                       CompilerDispatcher* dispatcher)
-    : CancelableTask(task_manager), dispatcher_(dispatcher) {}
-
-MemoryPressureTask::~MemoryPressureTask() {}
-
-void MemoryPressureTask::RunInternal() {
-  dispatcher_->AbortAll(BlockingBehavior::kDontBlock);
-}
-
 }  // namespace
 
-class CompilerDispatcher::AbortTask : public CancelableTask {
- public:
-  AbortTask(CancelableTaskManager* task_manager,
-            CompilerDispatcher* dispatcher);
-  ~AbortTask() override;
-
-  // CancelableTask implementation.
-  void RunInternal() override;
-
- private:
-  CompilerDispatcher* dispatcher_;
-
-  DISALLOW_COPY_AND_ASSIGN(AbortTask);
-};
-
-CompilerDispatcher::AbortTask::AbortTask(CancelableTaskManager* task_manager,
-                                         CompilerDispatcher* dispatcher)
-    : CancelableTask(task_manager), dispatcher_(dispatcher) {}
-
-CompilerDispatcher::AbortTask::~AbortTask() {}
-
-void CompilerDispatcher::AbortTask::RunInternal() {
-  dispatcher_->AbortInactiveJobs();
-}
-
-class CompilerDispatcher::WorkerTask : public CancelableTask {
- public:
-  WorkerTask(CancelableTaskManager* task_manager,
-             CompilerDispatcher* dispatcher);
-  ~WorkerTask() override;
-
-  // CancelableTask implementation.
-  void RunInternal() override;
-
- private:
-  CompilerDispatcher* dispatcher_;
-
-  DISALLOW_COPY_AND_ASSIGN(WorkerTask);
-};
-
-CompilerDispatcher::WorkerTask::WorkerTask(CancelableTaskManager* task_manager,
-                                           CompilerDispatcher* dispatcher)
-    : CancelableTask(task_manager), dispatcher_(dispatcher) {}
-
-CompilerDispatcher::WorkerTask::~WorkerTask() {}
-
-void CompilerDispatcher::WorkerTask::RunInternal() {
-  dispatcher_->DoBackgroundWork();
-}
-
-class CompilerDispatcher::IdleTask : public CancelableIdleTask {
- public:
-  IdleTask(CancelableTaskManager* task_manager, CompilerDispatcher* dispatcher);
-  ~IdleTask() override;
-
-  // CancelableIdleTask implementation.
-  void RunInternal(double deadline_in_seconds) override;
-
- private:
-  CompilerDispatcher* dispatcher_;
-
-  DISALLOW_COPY_AND_ASSIGN(IdleTask);
-};
-
-CompilerDispatcher::IdleTask::IdleTask(CancelableTaskManager* task_manager,
-                                       CompilerDispatcher* dispatcher)
-    : CancelableIdleTask(task_manager), dispatcher_(dispatcher) {}
-
-CompilerDispatcher::IdleTask::~IdleTask() {}
-
-void CompilerDispatcher::IdleTask::RunInternal(double deadline_in_seconds) {
-  dispatcher_->DoIdleWork(deadline_in_seconds);
-}
-
 CompilerDispatcher::CompilerDispatcher(Isolate* isolate, Platform* platform,
                                        size_t max_stack_size)
     : isolate_(isolate),
+      allocator_(isolate->allocator()),
+      worker_thread_runtime_call_stats_(
+          isolate->counters()->worker_thread_runtime_call_stats()),
+      background_compile_timer_(
+          isolate->counters()->compile_function_on_background()),
+      taskrunner_(platform->GetForegroundTaskRunner(
+          reinterpret_cast<v8::Isolate*>(isolate))),
       platform_(platform),
       max_stack_size_(max_stack_size),
       trace_compiler_dispatcher_(FLAG_trace_compiler_dispatcher),
@@ -201,6 +79,8 @@ CompilerDispatcher::~CompilerDispatcher() {
 bool CompilerDispatcher::CanEnqueue() {
   if (!IsEnabled()) return false;
 
+  // TODO(rmcilroy): Investigate if MemoryPressureLevel::kNone is ever sent on
+  // Android, if not, remove this check.
   if (memory_pressure_level_.Value() != MemoryPressureLevel::kNone) {
     return false;
   }
@@ -213,86 +93,65 @@ bool CompilerDispatcher::CanEnqueue() {
   return true;
 }
 
-bool CompilerDispatcher::CanEnqueue(Handle<SharedFunctionInfo> function) {
-  if (!CanEnqueue()) return false;
-
-  // We only handle functions (no eval / top-level code / native) that are
-  // attached to a script.
-  if (!function->script()->IsScript() || function->is_toplevel() ||
-      function->native()) {
-    return false;
-  }
+base::Optional<CompilerDispatcher::JobId> CompilerDispatcher::Enqueue(
+    const ParseInfo* outer_parse_info, const AstRawString* function_name,
+    const FunctionLiteral* function_literal) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.CompilerDispatcherEnqueue");
+  RuntimeCallTimerScope runtimeTimer(
+      isolate_, RuntimeCallCounterId::kCompileEnqueueOnDispatcher);
 
-  return true;
-}
+  if (!CanEnqueue()) return base::nullopt;
 
-CompilerDispatcher::JobId CompilerDispatcher::Enqueue(
-    std::unique_ptr<CompilerDispatcherJob> job) {
-  DCHECK(!job->IsFinished());
-  JobMap::const_iterator it = InsertJob(std::move(job));
-  ConsiderJobForBackgroundProcessing(it->second.get());
-  ScheduleIdleTaskIfNeeded();
-  return it->first;
-}
-
-CompilerDispatcher::JobId CompilerDispatcher::EnqueueAndStep(
-    std::unique_ptr<CompilerDispatcherJob> job) {
-  DCHECK(!job->IsFinished());
+  std::unique_ptr<CompilerDispatcherJob> job(new UnoptimizedCompileJob(
+      tracer_.get(), allocator_, outer_parse_info, function_name,
+      function_literal, worker_thread_runtime_call_stats_,
+      background_compile_timer_, max_stack_size_));
   JobMap::const_iterator it = InsertJob(std::move(job));
+  JobId id = it->first;
   if (trace_compiler_dispatcher_) {
-    PrintF("CompilerDispatcher: stepping ");
-    it->second->ShortPrintOnMainThread();
-    PrintF("\n");
+    PrintF("CompilerDispatcher: enqueued job %zu for function literal id %d\n",
+           id, function_literal->function_literal_id());
   }
-  DoNextStepOnMainThread(isolate_, it->second.get(),
-                         ExceptionHandling::kSwallow);
+
+  // Post a idle task and a background worker task to perform the compilation
+  // either on the worker thread or during idle time (whichever is first).
   ConsiderJobForBackgroundProcessing(it->second.get());
-  RemoveIfFinished(it);
   ScheduleIdleTaskIfNeeded();
-  return it->first;
+  return base::make_optional(id);
 }
 
-bool CompilerDispatcher::Enqueue(Handle<SharedFunctionInfo> function) {
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.CompilerDispatcherEnqueue");
-  if (!CanEnqueue(function)) return false;
-  if (IsEnqueued(function)) return true;
-
-  if (trace_compiler_dispatcher_) {
-    PrintF("CompilerDispatcher: enqueuing ");
-    function->ShortPrint();
-    PrintF(" for parse and compile\n");
-  }
+bool CompilerDispatcher::IsEnabled() const { return FLAG_compiler_dispatcher; }
 
-  std::unique_ptr<CompilerDispatcherJob> job(new UnoptimizedCompileJob(
-      isolate_, tracer_.get(), function, max_stack_size_));
-  Enqueue(std::move(job));
-  return true;
+bool CompilerDispatcher::IsEnqueued(Handle<SharedFunctionInfo> function) const {
+  if (jobs_.empty()) return false;
+  return GetJobFor(function) != jobs_.end();
 }
 
-bool CompilerDispatcher::EnqueueAndStep(Handle<SharedFunctionInfo> function) {
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.CompilerDispatcherEnqueueAndStep");
-  if (!CanEnqueue(function)) return false;
-  if (IsEnqueued(function)) return true;
+bool CompilerDispatcher::IsEnqueued(JobId job_id) const {
+  return jobs_.find(job_id) != jobs_.end();
+}
+void CompilerDispatcher::RegisterSharedFunctionInfo(
+    JobId job_id, SharedFunctionInfo* function) {
+  DCHECK_NE(jobs_.find(job_id), jobs_.end());
+  DCHECK_EQ(job_id_to_shared_.find(job_id), job_id_to_shared_.end());
 
   if (trace_compiler_dispatcher_) {
-    PrintF("CompilerDispatcher: enqueuing ");
+    PrintF("CompilerDispatcher: registering ");
     function->ShortPrint();
-    PrintF(" for parse and compile\n");
+    PrintF(" with job id %zu\n", job_id);
   }
 
-  std::unique_ptr<CompilerDispatcherJob> job(new UnoptimizedCompileJob(
-      isolate_, tracer_.get(), function, max_stack_size_));
-  EnqueueAndStep(std::move(job));
-  return true;
-}
+  // Make a global handle to the function.
+  Handle<SharedFunctionInfo> function_handle =
+      isolate_->global_handles()->Create(function);
 
-bool CompilerDispatcher::IsEnabled() const { return FLAG_compiler_dispatcher; }
+  // Register mapping.
+  job_id_to_shared_.insert(std::make_pair(job_id, function_handle));
+  shared_to_unoptimized_job_id_.Set(function_handle, job_id);
 
-bool CompilerDispatcher::IsEnqueued(Handle<SharedFunctionInfo> function) const {
-  if (jobs_.empty()) return false;
-  return GetJobFor(function) != jobs_.end();
+  // Schedule an idle task to finalize job if it is ready.
+  ScheduleIdleTaskIfNeeded();
 }
 
 void CompilerDispatcher::WaitForJobIfRunningOnBackground(
@@ -316,54 +175,41 @@ void CompilerDispatcher::WaitForJobIfRunningOnBackground(
   DCHECK(running_background_jobs_.find(job) == running_background_jobs_.end());
 }
 
-bool CompilerDispatcher::FinishNow(CompilerDispatcherJob* job) {
+bool CompilerDispatcher::FinishNow(Handle<SharedFunctionInfo> function) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.CompilerDispatcherFinishNow");
+  RuntimeCallTimerScope runtimeTimer(
+      isolate_, RuntimeCallCounterId::kCompileFinishNowOnDispatcher);
   if (trace_compiler_dispatcher_) {
     PrintF("CompilerDispatcher: finishing ");
-    job->ShortPrintOnMainThread();
+    function->ShortPrint();
     PrintF(" now\n");
   }
+
+  JobMap::const_iterator it = GetJobFor(function);
+  CHECK(it != jobs_.end());
+  CompilerDispatcherJob* job = it->second.get();
   WaitForJobIfRunningOnBackground(job);
   while (!job->IsFinished()) {
-    DoNextStepOnMainThread(isolate_, job, ExceptionHandling::kThrow);
-  }
-  return !job->IsFailed();
-}
-
-bool CompilerDispatcher::FinishNow(Handle<SharedFunctionInfo> function) {
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.CompilerDispatcherFinishNow");
-  JobMap::const_iterator job = GetJobFor(function);
-  CHECK(job != jobs_.end());
-  bool result = FinishNow(job->second.get());
-  RemoveIfFinished(job);
-  return result;
-}
-
-void CompilerDispatcher::FinishAllNow() {
-  // First finish all jobs not running in background
-  for (auto it = jobs_.cbegin(); it != jobs_.cend();) {
-    CompilerDispatcherJob* job = it->second.get();
-    bool is_running_in_background;
-    {
-      base::LockGuard<base::Mutex> lock(&mutex_);
-      is_running_in_background =
-          running_background_jobs_.find(job) != running_background_jobs_.end();
-      pending_background_jobs_.erase(job);
-    }
-    if (!is_running_in_background) {
-      while (!job->IsFinished()) {
-        DoNextStepOnMainThread(isolate_, job, ExceptionHandling::kThrow);
+    switch (job->status()) {
+      case CompilerDispatcherJob::Status::kInitial:
+        job->Compile(false);
+        break;
+      case CompilerDispatcherJob::Status::kReadyToFinalize: {
+        FinalizeJobOnMainThread(isolate_, job, function,
+                                ExceptionHandling::kThrow);
+        break;
       }
-      it = RemoveIfFinished(it);
-    } else {
-      ++it;
+      case CompilerDispatcherJob::Status::kFailed:
+      case CompilerDispatcherJob::Status::kDone:
+        UNREACHABLE();
     }
   }
-  // Potentially wait for jobs that were running in background
-  for (auto it = jobs_.cbegin(); it != jobs_.cend();
-       it = RemoveIfFinished(it)) {
-    FinishNow(it->second.get());
-  }
+  DCHECK_EQ(job->IsFailed(), isolate_->has_pending_exception());
+  DCHECK(job->IsFinished());
+  bool result = !job->IsFailed();
+  RemoveJob(it);
+  return result;
 }
 
 void CompilerDispatcher::AbortAll(BlockingBehavior blocking) {
@@ -373,9 +219,7 @@ void CompilerDispatcher::AbortAll(BlockingBehavior blocking) {
     for (auto& it : jobs_) {
       WaitForJobIfRunningOnBackground(it.second.get());
       if (trace_compiler_dispatcher_) {
-        PrintF("CompilerDispatcher: aborted ");
-        it.second->ShortPrintOnMainThread();
-        PrintF("\n");
+        PrintF("CompilerDispatcher: aborted job %zu\n", it.first);
       }
       it.second->ResetOnMainThread(isolate_);
     }
@@ -394,6 +238,7 @@ void CompilerDispatcher::AbortAll(BlockingBehavior blocking) {
     base::LockGuard<base::Mutex> lock(&mutex_);
     abort_ = true;
     pending_background_jobs_.clear();
+    idle_task_scheduled_ = false;  // Idle task cancelled by TryAbortAll.
   }
   AbortInactiveJobs();
 
@@ -421,9 +266,7 @@ void CompilerDispatcher::AbortInactiveJobs() {
       }
     }
     if (trace_compiler_dispatcher_) {
-      PrintF("CompilerDispatcher: aborted ");
-      job->second->ShortPrintOnMainThread();
-      PrintF("\n");
+      PrintF("CompilerDispatcher: aborted job %zu\n", job->first);
     }
     it = RemoveJob(job);
   }
@@ -458,9 +301,9 @@ void CompilerDispatcher::MemoryPressureNotification(
       abort_ = true;
       pending_background_jobs_.clear();
     }
-    platform_->CallOnForegroundThread(
-        reinterpret_cast<v8::Isolate*>(isolate_),
-        new MemoryPressureTask(task_manager_.get(), this));
+    taskrunner_->PostTask(MakeCancelableLambdaTask(task_manager_.get(), [this] {
+      AbortAll(BlockingBehavior::kDontBlock);
+    }));
   }
 }
 
@@ -470,22 +313,20 @@ CompilerDispatcher::JobMap::const_iterator CompilerDispatcher::GetJobFor(
   JobMap::const_iterator job = jobs_.end();
   if (job_id_ptr) {
     job = jobs_.find(*job_id_ptr);
-    DCHECK(job == jobs_.end() ||
-           job->second->AsUnoptimizedCompileJob()->IsAssociatedWith(shared));
   }
   return job;
 }
 
 void CompilerDispatcher::ScheduleIdleTaskFromAnyThread() {
-  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate_);
-  if (!platform_->IdleTasksEnabled(v8_isolate)) return;
+  if (!taskrunner_->IdleTasksEnabled()) return;
   {
     base::LockGuard<base::Mutex> lock(&mutex_);
-    if (idle_task_scheduled_) return;
+    if (idle_task_scheduled_ || abort_) return;
     idle_task_scheduled_ = true;
   }
-  platform_->CallIdleOnForegroundThread(
-      v8_isolate, new IdleTask(task_manager_.get(), this));
+  taskrunner_->PostIdleTask(MakeCancelableIdleLambdaTask(
+      task_manager_.get(),
+      [this](double deadline_in_seconds) { DoIdleWork(deadline_in_seconds); }));
 }
 
 void CompilerDispatcher::ScheduleIdleTaskIfNeeded() {
@@ -494,9 +335,8 @@ void CompilerDispatcher::ScheduleIdleTaskIfNeeded() {
 }
 
 void CompilerDispatcher::ScheduleAbortTask() {
-  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate_);
-  platform_->CallOnForegroundThread(v8_isolate,
-                                    new AbortTask(task_manager_.get(), this));
+  taskrunner_->PostTask(MakeCancelableLambdaTask(
+      task_manager_.get(), [this] { AbortInactiveJobs(); }));
 }
 
 void CompilerDispatcher::ConsiderJobForBackgroundProcessing(
@@ -520,11 +360,13 @@ void CompilerDispatcher::ScheduleMoreWorkerTasksIfNeeded() {
     }
     ++num_worker_tasks_;
   }
-  platform_->CallOnWorkerThread(
-      base::make_unique<WorkerTask>(task_manager_.get(), this));
+  platform_->CallOnWorkerThread(MakeCancelableLambdaTask(
+      task_manager_.get(), [this] { DoBackgroundWork(); }));
 }
 
 void CompilerDispatcher::DoBackgroundWork() {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.CompilerDispatcherDoBackgroundWork");
   for (;;) {
     CompilerDispatcherJob* job = nullptr;
     {
@@ -547,7 +389,10 @@ void CompilerDispatcher::DoBackgroundWork() {
       PrintF("CompilerDispatcher: doing background work\n");
     }
 
-    DoNextStepOnBackgroundThread(job);
+    DCHECK(job->NextStepCanRunOnAnyThread());
+    DCHECK_EQ(job->status(), CompilerDispatcherJob::Status::kInitial);
+    job->Compile(true);
+
     // Unconditionally schedule an idle task, as all background steps have to be
     // followed by a main thread step.
     ScheduleIdleTaskFromAnyThread();
@@ -579,6 +424,8 @@ void CompilerDispatcher::DoBackgroundWork() {
 }
 
 void CompilerDispatcher::DoIdleWork(double deadline_in_seconds) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.CompilerDispatcherDoIdleWork");
   bool aborted = false;
   {
     base::LockGuard<base::Mutex> lock(&mutex_);
@@ -593,11 +440,11 @@ void CompilerDispatcher::DoIdleWork(double deadline_in_seconds) {
 
   // Number of jobs that are unlikely to make progress during any idle callback
   // due to their estimated duration.
-  size_t too_long_jobs = 0;
+  size_t jobs_unlikely_to_progress = 0;
 
   // Iterate over all available jobs & remaining time. For each job, decide
   // whether to 1) skip it (if it would take too long), 2) erase it (if it's
-  // finished), or 3) make progress on it.
+  // finished), or 3) make progress on it if possible.
   double idle_time_in_seconds =
       deadline_in_seconds - platform_->MonotonicallyIncreasingTime();
 
@@ -620,6 +467,7 @@ void CompilerDispatcher::DoIdleWork(double deadline_in_seconds) {
       ++job;
       continue;
     }
+    DCHECK(!job->second->IsFinished());
     auto it = pending_background_jobs_.find(job->second.get());
     double estimate_in_ms = job->second->EstimateRuntimeOfNextStepInMs();
     if (idle_time_in_seconds <
@@ -628,29 +476,44 @@ void CompilerDispatcher::DoIdleWork(double deadline_in_seconds) {
       // If there's not enough time left, try to estimate whether we would
       // have managed to finish the job in a large idle task to assess
       // whether we should ask for another idle callback.
-      if (estimate_in_ms > kMaxIdleTimeToExpectInMs) ++too_long_jobs;
+      // TODO(rmcilroy): Consider running the job anyway when we have a long
+      // idle time since this would probably be the best time to run.
+      if (estimate_in_ms > kMaxIdleTimeToExpectInMs)
+        ++jobs_unlikely_to_progress;
       if (it == pending_background_jobs_.end()) {
         lock.reset();
         ConsiderJobForBackgroundProcessing(job->second.get());
       }
       ++job;
-    } else if (job->second->IsFinished()) {
-      DCHECK(it == pending_background_jobs_.end());
-      lock.reset();
-      job = RemoveJob(job);
-      continue;
-    } else {
-      // Do one step, and keep processing the job (as we don't advance the
-      // iterator).
+    } else if (job->second->status() ==
+               CompilerDispatcherJob::Status::kInitial) {
       if (it != pending_background_jobs_.end()) {
         pending_background_jobs_.erase(it);
       }
       lock.reset();
-      DoNextStepOnMainThread(isolate_, job->second.get(),
-                             ExceptionHandling::kSwallow);
+      job->second->Compile(false);
+      // Don't update job so we can immediately finalize it on the next loop.
+    } else {
+      DCHECK_EQ(job->second->status(),
+                CompilerDispatcherJob::Status::kReadyToFinalize);
+      DCHECK(it == pending_background_jobs_.end());
+      lock.reset();
+
+      auto shared_it = job_id_to_shared_.find(job->first);
+      if (shared_it != job_id_to_shared_.end()) {
+        Handle<SharedFunctionInfo> shared = shared_it->second;
+        FinalizeJobOnMainThread(isolate_, job->second.get(), shared,
+                                ExceptionHandling::kSwallow);
+        DCHECK(job->second->IsFinished());
+        job = RemoveJob(job);
+      } else {
+        // If we can't step the job yet, go to the next job.
+        ++jobs_unlikely_to_progress;
+        ++job;
+      }
     }
   }
-  if (jobs_.size() > too_long_jobs) ScheduleIdleTaskIfNeeded();
+  if (jobs_.size() > jobs_unlikely_to_progress) ScheduleIdleTaskIfNeeded();
 }
 
 CompilerDispatcher::JobMap::const_iterator CompilerDispatcher::RemoveIfFinished(
@@ -661,9 +524,8 @@ CompilerDispatcher::JobMap::const_iterator CompilerDispatcher::RemoveIfFinished(
 
   if (trace_compiler_dispatcher_) {
     bool result = !job->second->IsFailed();
-    PrintF("CompilerDispatcher: finished working on ");
-    job->second->ShortPrintOnMainThread();
-    PrintF(": %s\n", result ? "success" : "failure");
+    PrintF("CompilerDispatcher: finished working on job %zu: %s\n", job->first,
+           result ? "success" : "failure");
     tracer_->DumpStatistics();
   }
 
@@ -677,44 +539,34 @@ CompilerDispatcher::JobMap::const_iterator CompilerDispatcher::InsertJob(
   std::tie(it, added) =
       jobs_.insert(std::make_pair(next_job_id_++, std::move(job)));
   DCHECK(added);
-
-  JobId id = it->first;
-  CompilerDispatcherJob* inserted_job = it->second.get();
-
-  // Maps unoptimized jobs' SFIs to their job id.
-  if (inserted_job->type() ==
-      CompilerDispatcherJob::Type::kUnoptimizedCompile) {
-    Handle<SharedFunctionInfo> shared =
-        inserted_job->AsUnoptimizedCompileJob()->shared();
-    if (!shared.is_null()) {
-      shared_to_unoptimized_job_id_.Set(shared, id);
-    }
-  }
-
   return it;
 }
 
 CompilerDispatcher::JobMap::const_iterator CompilerDispatcher::RemoveJob(
     CompilerDispatcher::JobMap::const_iterator it) {
   CompilerDispatcherJob* job = it->second.get();
-  job->ResetOnMainThread(isolate_);
 
-  // Unmaps unoptimized jobs' SFIs to their job id.
-  if (job->type() == CompilerDispatcherJob::Type::kUnoptimizedCompile) {
-    Handle<SharedFunctionInfo> shared =
-        job->AsUnoptimizedCompileJob()->shared();
-    if (!shared.is_null()) {
-      JobId deleted_id;
-      shared_to_unoptimized_job_id_.Delete(shared, &deleted_id);
-      DCHECK_EQ(it->first, deleted_id);
-    }
+  // Delete SFI associated with job if its been registered.
+  auto shared_it = job_id_to_shared_.find(it->first);
+  if (shared_it != job_id_to_shared_.end()) {
+    Handle<SharedFunctionInfo> shared = shared_it->second;
+
+    JobId deleted_id;
+    shared_to_unoptimized_job_id_.Delete(shared, &deleted_id);
+    DCHECK_EQ(it->first, deleted_id);
+
+    job_id_to_shared_.erase(shared_it);
+    GlobalHandles::Destroy(Handle<Object>::cast(shared).location());
   }
 
+  job->ResetOnMainThread(isolate_);
+
   it = jobs_.erase(it);
   if (jobs_.empty()) {
     base::LockGuard<base::Mutex> lock(&mutex_);
     if (num_worker_tasks_ == 0) abort_ = false;
   }
+
   return it;
 }
 
diff --git a/deps/v8/src/compiler-dispatcher/compiler-dispatcher.h b/deps/v8/src/compiler-dispatcher/compiler-dispatcher.h
index d7b2dc802f..dd024e297a 100644
--- a/deps/v8/src/compiler-dispatcher/compiler-dispatcher.h
+++ b/deps/v8/src/compiler-dispatcher/compiler-dispatcher.h
@@ -13,6 +13,7 @@
 
 #include "src/base/atomic-utils.h"
 #include "src/base/macros.h"
+#include "src/base/optional.h"
 #include "src/base/platform/condition-variable.h"
 #include "src/base/platform/mutex.h"
 #include "src/base/platform/semaphore.h"
@@ -27,6 +28,7 @@ enum class MemoryPressureLevel;
 
 namespace internal {
 
+class AstRawString;
 class AstValueFactory;
 class CancelableTaskManager;
 class CompilerDispatcherJob;
@@ -37,6 +39,8 @@ class FunctionLiteral;
 class Isolate;
 class ParseInfo;
 class SharedFunctionInfo;
+class TimedHistogram;
+class WorkerThreadRuntimeCallStats;
 class Zone;
 
 template <typename T>
@@ -79,24 +83,23 @@ class V8_EXPORT_PRIVATE CompilerDispatcher {
   // Returns true if the compiler dispatcher is enabled.
   bool IsEnabled() const;
 
-  // Enqueue a job for parse and compile. Returns true if a job was enqueued.
-  bool Enqueue(Handle<SharedFunctionInfo> function);
+  base::Optional<JobId> Enqueue(const ParseInfo* outer_parse_info,
+                                const AstRawString* function_name,
+                                const FunctionLiteral* function_literal);
 
-  // Like Enqueue, but also advances the job so that it can potentially
-  // continue running on a background thread (if at all possible). Returns
-  // true if the job was enqueued.
-  bool EnqueueAndStep(Handle<SharedFunctionInfo> function);
+  // Registers the given |function| with the compilation job |job_id|.
+  void RegisterSharedFunctionInfo(JobId job_id, SharedFunctionInfo* function);
 
-  // Returns true if there is a pending job for the given function.
+  // Returns true if there is a pending job with the given id.
+  bool IsEnqueued(JobId job_id) const;
+
+  // Returns true if there is a pending job registered for the given function.
   bool IsEnqueued(Handle<SharedFunctionInfo> function) const;
 
   // Blocks until the given function is compiled (and does so as fast as
   // possible). Returns true if the compile job was successful.
   bool FinishNow(Handle<SharedFunctionInfo> function);
 
-  // Blocks until all jobs are finished.
-  void FinishAllNow();
-
   // Aborts a given job. Blocks if requested.
   void Abort(Handle<SharedFunctionInfo> function, BlockingBehavior blocking);
 
@@ -124,15 +127,15 @@ class V8_EXPORT_PRIVATE CompilerDispatcher {
   FRIEND_TEST(CompilerDispatcherTest, CompileMultipleOnBackgroundThread);
 
   typedef std::map<JobId, std::unique_ptr<CompilerDispatcherJob>> JobMap;
+  typedef std::map<JobId, Handle<SharedFunctionInfo>> JobIdToSharedMap;
   typedef IdentityMap<JobId, FreeStoreAllocationPolicy> SharedToJobIdMap;
   class AbortTask;
   class WorkerTask;
   class IdleTask;
 
+  bool CanEnqueue();
   void WaitForJobIfRunningOnBackground(CompilerDispatcherJob* job);
   void AbortInactiveJobs();
-  bool CanEnqueue();
-  bool CanEnqueue(Handle<SharedFunctionInfo> function);
   JobMap::const_iterator GetJobFor(Handle<SharedFunctionInfo> shared) const;
   void ConsiderJobForBackgroundProcessing(CompilerDispatcherJob* job);
   void ScheduleMoreWorkerTasksIfNeeded();
@@ -141,17 +144,18 @@ class V8_EXPORT_PRIVATE CompilerDispatcher {
   void ScheduleAbortTask();
   void DoBackgroundWork();
   void DoIdleWork(double deadline_in_seconds);
-  JobId Enqueue(std::unique_ptr<CompilerDispatcherJob> job);
-  JobId EnqueueAndStep(std::unique_ptr<CompilerDispatcherJob> job);
   // Returns job if not removed otherwise iterator following the removed job.
   JobMap::const_iterator RemoveIfFinished(JobMap::const_iterator job);
   // Returns iterator to the inserted job.
   JobMap::const_iterator InsertJob(std::unique_ptr<CompilerDispatcherJob> job);
   // Returns iterator following the removed job.
   JobMap::const_iterator RemoveJob(JobMap::const_iterator job);
-  bool FinishNow(CompilerDispatcherJob* job);
 
   Isolate* isolate_;
+  AccountingAllocator* allocator_;
+  WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats_;
+  TimedHistogram* background_compile_timer_;
+  std::shared_ptr<v8::TaskRunner> taskrunner_;
   Platform* platform_;
   size_t max_stack_size_;
 
@@ -168,6 +172,9 @@ class V8_EXPORT_PRIVATE CompilerDispatcher {
   // Mapping from job_id to job.
   JobMap jobs_;
 
+  // Mapping from job_id to SharedFunctionInfo.
+  JobIdToSharedMap job_id_to_shared_;
+
   // Mapping from SharedFunctionInfo to the corresponding unoptimized
   // compilation's JobId;
   SharedToJobIdMap shared_to_unoptimized_job_id_;
diff --git a/deps/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc b/deps/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc
index 47b2181a88..492e80abe0 100644
--- a/deps/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc
+++ b/deps/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc
@@ -41,12 +41,16 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
  public:
   explicit CompileTask(Isolate* isolate,
                        OptimizingCompileDispatcher* dispatcher)
-      : CancelableTask(isolate), isolate_(isolate), dispatcher_(dispatcher) {
+      : CancelableTask(isolate),
+        isolate_(isolate),
+        worker_thread_runtime_call_stats_(
+            isolate->counters()->worker_thread_runtime_call_stats()),
+        dispatcher_(dispatcher) {
     base::LockGuard<base::Mutex> lock_guard(&dispatcher_->ref_count_mutex_);
     ++dispatcher_->ref_count_;
   }
 
-  virtual ~CompileTask() {}
+  ~CompileTask() override = default;
 
  private:
   // v8::Task overrides.
@@ -56,8 +60,13 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
     DisallowHandleDereference no_deref;
 
     {
-      TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
+      WorkerThreadRuntimeCallStatsScope runtime_call_stats_scope(
+          worker_thread_runtime_call_stats_);
+      RuntimeCallTimerScope runtimeTimer(
+          runtime_call_stats_scope.Get(),
+          RuntimeCallCounterId::kRecompileConcurrent);
 
+      TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
       TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                    "V8.RecompileConcurrent");
 
@@ -77,6 +86,7 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
   }
 
   Isolate* isolate_;
+  WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats_;
   OptimizingCompileDispatcher* dispatcher_;
 
   DISALLOW_COPY_AND_ASSIGN(CompileTask);
@@ -210,7 +220,7 @@ void OptimizingCompileDispatcher::InstallOptimizedFunctions() {
       }
       DisposeCompilationJob(job, false);
     } else {
-      Compiler::FinalizeCompilationJob(job, isolate_);
+      Compiler::FinalizeOptimizedCompilationJob(job, isolate_);
     }
   }
 }
diff --git a/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.cc b/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.cc
index 2e8065ed11..59f4c3e8ff 100644
--- a/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.cc
+++ b/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.cc
@@ -5,11 +5,9 @@
 #include "src/compiler-dispatcher/unoptimized-compile-job.h"
 
 #include "src/assert-scope.h"
-#include "src/base/optional.h"
 #include "src/compiler-dispatcher/compiler-dispatcher-tracer.h"
 #include "src/compiler.h"
 #include "src/flags.h"
-#include "src/global-handles.h"
 #include "src/interpreter/interpreter.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
@@ -23,329 +21,51 @@
 namespace v8 {
 namespace internal {
 
-namespace {
-
-class OneByteWrapper : public v8::String::ExternalOneByteStringResource {
- public:
-  OneByteWrapper(const void* data, int length) : data_(data), length_(length) {}
-  ~OneByteWrapper() override = default;
-
-  const char* data() const override {
-    return reinterpret_cast<const char*>(data_);
-  }
-
-  size_t length() const override { return static_cast<size_t>(length_); }
-
- private:
-  const void* data_;
-  int length_;
-
-  DISALLOW_COPY_AND_ASSIGN(OneByteWrapper);
-};
-
-class TwoByteWrapper : public v8::String::ExternalStringResource {
- public:
-  TwoByteWrapper(const void* data, int length) : data_(data), length_(length) {}
-  ~TwoByteWrapper() override = default;
-
-  const uint16_t* data() const override {
-    return reinterpret_cast<const uint16_t*>(data_);
-  }
-
-  size_t length() const override { return static_cast<size_t>(length_); }
-
- private:
-  const void* data_;
-  int length_;
-
-  DISALLOW_COPY_AND_ASSIGN(TwoByteWrapper);
-};
-
-}  // namespace
-
-UnoptimizedCompileJob::UnoptimizedCompileJob(Isolate* isolate,
-                                             CompilerDispatcherTracer* tracer,
-                                             Handle<SharedFunctionInfo> shared,
-                                             size_t max_stack_size)
+UnoptimizedCompileJob::UnoptimizedCompileJob(
+    CompilerDispatcherTracer* tracer, AccountingAllocator* allocator,
+    const ParseInfo* outer_parse_info, const AstRawString* function_name,
+    const FunctionLiteral* function_literal,
+    WorkerThreadRuntimeCallStats* worker_thread_runtime_stats,
+    TimedHistogram* timer, size_t max_stack_size)
     : CompilerDispatcherJob(Type::kUnoptimizedCompile),
-      main_thread_id_(isolate->thread_id().ToInteger()),
       tracer_(tracer),
-      allocator_(isolate->allocator()),
-      context_(isolate->global_handles()->Create(isolate->context())),
-      shared_(isolate->global_handles()->Create(*shared)),
-      max_stack_size_(max_stack_size),
-      trace_compiler_dispatcher_jobs_(FLAG_trace_compiler_dispatcher_jobs) {
-  DCHECK(!shared_->is_toplevel());
-  // TODO(rmcilroy): Handle functions with non-empty outer scope info.
-  DCHECK(!shared_->HasOuterScopeInfo());
-  HandleScope scope(isolate);
-  Handle<Script> script(Script::cast(shared_->script()), isolate);
-  Handle<String> source(String::cast(script->source()), isolate);
-  if (trace_compiler_dispatcher_jobs_) {
-    PrintF("UnoptimizedCompileJob[%p] created for ", static_cast<void*>(this));
-    ShortPrintOnMainThread();
-    PrintF(" in initial state.\n");
-  }
-}
+      task_(new BackgroundCompileTask(allocator, outer_parse_info,
+                                      function_name, function_literal,
+                                      worker_thread_runtime_stats, timer,
+                                      static_cast<int>(max_stack_size))) {}
 
 UnoptimizedCompileJob::~UnoptimizedCompileJob() {
   DCHECK(status() == Status::kInitial || status() == Status::kDone);
-  if (!shared_.is_null()) {
-    DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-    i::GlobalHandles::Destroy(Handle<Object>::cast(shared_).location());
-  }
-  if (!context_.is_null()) {
-    DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-    i::GlobalHandles::Destroy(Handle<Object>::cast(context_).location());
-  }
-}
-
-bool UnoptimizedCompileJob::IsAssociatedWith(
-    Handle<SharedFunctionInfo> shared) const {
-  return *shared_ == *shared;
-}
-
-void UnoptimizedCompileJob::PrepareOnMainThread(Isolate* isolate) {
-  DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-  DCHECK_EQ(isolate->thread_id().ToInteger(), main_thread_id_);
-  DCHECK_EQ(status(), Status::kInitial);
-  COMPILER_DISPATCHER_TRACE_SCOPE(tracer_, kPrepare);
-
-  if (trace_compiler_dispatcher_jobs_) {
-    PrintF("UnoptimizedCompileJob[%p]: Preparing to parse\n",
-           static_cast<void*>(this));
-  }
-
-  ParseInfo* parse_info = new ParseInfo(isolate, shared_);
-  parse_info_.reset(parse_info);
-
-  unicode_cache_.reset(new UnicodeCache());
-  parse_info_->set_unicode_cache(unicode_cache_.get());
-  parse_info_->set_function_literal_id(shared_->FunctionLiteralId(isolate));
-  if (V8_UNLIKELY(FLAG_runtime_stats)) {
-    parse_info_->set_runtime_call_stats(new (parse_info_->zone())
-                                            RuntimeCallStats());
-  }
-
-  Handle<Script> script = parse_info->script();
-  HandleScope scope(isolate);
-
-  DCHECK(script->type() != Script::TYPE_NATIVE);
-  Handle<String> source(String::cast(script->source()), isolate);
-  if (source->IsExternalTwoByteString() || source->IsExternalOneByteString()) {
-    std::unique_ptr<Utf16CharacterStream> stream(ScannerStream::For(
-        isolate, source, shared_->StartPosition(), shared_->EndPosition()));
-    parse_info_->set_character_stream(std::move(stream));
-  } else {
-    source = String::Flatten(isolate, source);
-    const void* data;
-    int offset = 0;
-    int length = source->length();
-
-    // Objects in lo_space don't move, so we can just read the contents from
-    // any thread.
-    if (isolate->heap()->lo_space()->Contains(*source)) {
-      // We need to globalize the handle to the flattened string here, in
-      // case it's not referenced from anywhere else.
-      source_ = isolate->global_handles()->Create(*source);
-      DisallowHeapAllocation no_allocation;
-      String::FlatContent content = source->GetFlatContent();
-      DCHECK(content.IsFlat());
-      data =
-          content.IsOneByte()
-              ? reinterpret_cast<const void*>(content.ToOneByteVector().start())
-              : reinterpret_cast<const void*>(content.ToUC16Vector().start());
-    } else {
-      // Otherwise, create a copy of the part of the string we'll parse in the
-      // zone.
-      length = (shared_->EndPosition() - shared_->StartPosition());
-      offset = shared_->StartPosition();
-
-      int byte_len = length * (source->IsOneByteRepresentation() ? 1 : 2);
-      data = parse_info_->zone()->New(byte_len);
-
-      DisallowHeapAllocation no_allocation;
-      String::FlatContent content = source->GetFlatContent();
-      DCHECK(content.IsFlat());
-      if (content.IsOneByte()) {
-        MemCopy(const_cast<void*>(data),
-                &content.ToOneByteVector().at(shared_->StartPosition()),
-                byte_len);
-      } else {
-        MemCopy(const_cast<void*>(data),
-                &content.ToUC16Vector().at(shared_->StartPosition()), byte_len);
-      }
-    }
-    Handle<String> wrapper;
-    if (source->IsOneByteRepresentation()) {
-      ExternalOneByteString::Resource* resource =
-          new OneByteWrapper(data, length);
-      wrapper = isolate->factory()
-                    ->NewExternalStringFromOneByte(resource)
-                    .ToHandleChecked();
-    } else {
-      ExternalTwoByteString::Resource* resource =
-          new TwoByteWrapper(data, length);
-      wrapper = isolate->factory()
-                    ->NewExternalStringFromTwoByte(resource)
-                    .ToHandleChecked();
-    }
-    wrapper_ = isolate->global_handles()->Create(*wrapper);
-    std::unique_ptr<Utf16CharacterStream> stream(
-        ScannerStream::For(isolate, wrapper_, shared_->StartPosition() - offset,
-                           shared_->EndPosition() - offset));
-    parse_info_->set_character_stream(std::move(stream));
-  }
-
-  parser_.reset(new Parser(parse_info_.get()));
-  parser_->DeserializeScopeChain(isolate, parse_info_.get(),
-                                 parse_info_->maybe_outer_scope_info());
-
-  // Initailize the name after setting up the ast_value_factory.
-  Handle<String> name(shared_->Name(), isolate);
-  parse_info_->set_function_name(
-      parse_info_->ast_value_factory()->GetString(name));
-
-  set_status(Status::kPrepared);
 }
 
 void UnoptimizedCompileJob::Compile(bool on_background_thread) {
-  DCHECK_EQ(status(), Status::kPrepared);
+  DCHECK_EQ(status(), Status::kInitial);
   COMPILER_DISPATCHER_TRACE_SCOPE_WITH_NUM(
       tracer_, kCompile,
-      parse_info_->end_position() - parse_info_->start_position());
-  if (trace_compiler_dispatcher_jobs_) {
-    PrintF("UnoptimizedCompileJob[%p]: Compiling\n", static_cast<void*>(this));
-  }
-
-  DisallowHeapAllocation no_allocation;
-  DisallowHandleAllocation no_handles;
-  DisallowHandleDereference no_deref;
-
-  parse_info_->set_on_background_thread(on_background_thread);
-  uintptr_t stack_limit = GetCurrentStackPosition() - max_stack_size_ * KB;
-  parser_->set_stack_limit(stack_limit);
-  parse_info_->set_stack_limit(stack_limit);
-  parser_->ParseOnBackground(parse_info_.get());
-
-  if (parse_info_->literal() == nullptr) {
-    // Parser sets error in pending error handler.
-    set_status(Status::kHasErrorsToReport);
-    return;
-  }
-
-  if (!Compiler::Analyze(parse_info_.get())) {
-    parse_info_->pending_error_handler()->set_stack_overflow();
-    set_status(Status::kHasErrorsToReport);
-    return;
-  }
-
-  compilation_job_.reset(interpreter::Interpreter::NewCompilationJob(
-      parse_info_.get(), parse_info_->literal(), allocator_, nullptr));
-
-  if (!compilation_job_.get()) {
-    parse_info_->pending_error_handler()->set_stack_overflow();
-    set_status(Status::kHasErrorsToReport);
-    return;
-  }
-
-  if (compilation_job_->ExecuteJob() != CompilationJob::SUCCEEDED) {
-    parse_info_->pending_error_handler()->set_stack_overflow();
-    set_status(Status::kHasErrorsToReport);
-    return;
-  }
-
-  set_status(Status::kCompiled);
+      task_->info()->end_position() - task_->info()->start_position());
+  task_->Run();
+  set_status(Status::kReadyToFinalize);
 }
 
-void UnoptimizedCompileJob::FinalizeOnMainThread(Isolate* isolate) {
-  DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-  DCHECK_EQ(isolate->thread_id().ToInteger(), main_thread_id_);
-  DCHECK_EQ(status(), Status::kCompiled);
-  DCHECK_NOT_NULL(parse_info_->literal());
-  DCHECK_NOT_NULL(compilation_job_.get());
+void UnoptimizedCompileJob::FinalizeOnMainThread(
+    Isolate* isolate, Handle<SharedFunctionInfo> shared) {
+  DCHECK_EQ(ThreadId::Current().ToInteger(), isolate->thread_id().ToInteger());
+  DCHECK_EQ(status(), Status::kReadyToFinalize);
   COMPILER_DISPATCHER_TRACE_SCOPE(tracer_, kFinalize);
-  if (trace_compiler_dispatcher_jobs_) {
-    PrintF("UnoptimizedCompileJob[%p]: Finalizing compiling\n",
-           static_cast<void*>(this));
-  }
 
-  Handle<Script> script(Script::cast(shared_->script()), isolate);
-  DCHECK_EQ(*parse_info_->script(), shared_->script());
-
-  parser_->UpdateStatistics(isolate, script);
-  parse_info_->UpdateBackgroundParseStatisticsOnMainThread(isolate);
-  parser_->HandleSourceURLComments(isolate, script);
-
-  {
-    HandleScope scope(isolate);
-    // Internalize ast values onto the heap.
-    parse_info_->ast_value_factory()->Internalize(isolate);
-    // Allocate scope infos for the literal.
-    DeclarationScope::AllocateScopeInfos(parse_info_.get(), isolate);
-    if (compilation_job_->state() == CompilationJob::State::kFailed ||
-        !Compiler::FinalizeCompilationJob(compilation_job_.release(), shared_,
-                                          isolate)) {
-      if (!isolate->has_pending_exception()) isolate->StackOverflow();
-      set_status(Status::kFailed);
-      return;
-    }
-  }
-
-  ResetDataOnMainThread(isolate);
-  set_status(Status::kDone);
-}
-
-void UnoptimizedCompileJob::ReportErrorsOnMainThread(Isolate* isolate) {
-  DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-  DCHECK_EQ(isolate->thread_id().ToInteger(), main_thread_id_);
-  DCHECK_EQ(status(), Status::kHasErrorsToReport);
-
-  if (trace_compiler_dispatcher_jobs_) {
-    PrintF("UnoptimizedCompileJob[%p]: Reporting Errors\n",
-           static_cast<void*>(this));
-  }
-
-  // Ensure we report errors in the correct context for the job.
-  SaveContext save(isolate);
-  isolate->set_context(context());
-
-  Handle<Script> script(Script::cast(shared_->script()), isolate);
-  parse_info_->pending_error_handler()->ReportErrors(
-      isolate, script, parse_info_->ast_value_factory());
+  bool succeeded = Compiler::FinalizeBackgroundCompileTask(
+      task_.get(), shared, isolate, Compiler::KEEP_EXCEPTION);
 
   ResetDataOnMainThread(isolate);
-  set_status(Status::kFailed);
+  set_status(succeeded ? Status::kDone : Status::kFailed);
 }
 
 void UnoptimizedCompileJob::ResetDataOnMainThread(Isolate* isolate) {
-  DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-  DCHECK_EQ(isolate->thread_id().ToInteger(), main_thread_id_);
-
-  compilation_job_.reset();
-  parser_.reset();
-  unicode_cache_.reset();
-  parse_info_.reset();
-
-  if (!source_.is_null()) {
-    DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-    DCHECK_EQ(isolate->thread_id().ToInteger(), main_thread_id_);
-    i::GlobalHandles::Destroy(Handle<Object>::cast(source_).location());
-    source_ = Handle<String>::null();
-  }
-  if (!wrapper_.is_null()) {
-    DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-    DCHECK_EQ(isolate->thread_id().ToInteger(), main_thread_id_);
-    i::GlobalHandles::Destroy(Handle<Object>::cast(wrapper_).location());
-    wrapper_ = Handle<String>::null();
-  }
+  DCHECK_EQ(ThreadId::Current().ToInteger(), isolate->thread_id().ToInteger());
+  task_.reset();
 }
 
 void UnoptimizedCompileJob::ResetOnMainThread(Isolate* isolate) {
-  if (trace_compiler_dispatcher_jobs_) {
-    PrintF("UnoptimizedCompileJob[%p]: Resetting\n", static_cast<void*>(this));
-  }
-
   ResetDataOnMainThread(isolate);
   set_status(Status::kInitial);
 }
@@ -353,14 +73,12 @@ void UnoptimizedCompileJob::ResetOnMainThread(Isolate* isolate) {
 double UnoptimizedCompileJob::EstimateRuntimeOfNextStepInMs() const {
   switch (status()) {
     case Status::kInitial:
-      return tracer_->EstimatePrepareInMs();
-    case Status::kPrepared:
-      return tracer_->EstimateCompileInMs(parse_info_->end_position() -
-                                          parse_info_->start_position());
-    case Status::kCompiled:
+      return tracer_->EstimateCompileInMs(task_->info()->end_position() -
+                                          task_->info()->start_position());
+    case Status::kReadyToFinalize:
+      // TODO(rmcilroy): Pass size of bytecode to tracer to get better estimate.
       return tracer_->EstimateFinalizeInMs();
 
-    case Status::kHasErrorsToReport:
     case Status::kFailed:
     case Status::kDone:
       return 0.0;
@@ -369,11 +87,5 @@ double UnoptimizedCompileJob::EstimateRuntimeOfNextStepInMs() const {
   UNREACHABLE();
 }
 
-void UnoptimizedCompileJob::ShortPrintOnMainThread() {
-  DCHECK_EQ(ThreadId::Current().ToInteger(), main_thread_id_);
-  DCHECK(!shared_.is_null());
-  shared_->ShortPrint();
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.h b/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.h
index 3e08388ca0..31a66e4eb4 100644
--- a/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.h
+++ b/deps/v8/src/compiler-dispatcher/unoptimized-compile-job.h
@@ -15,8 +15,11 @@
 namespace v8 {
 namespace internal {
 
+class AccountingAllocator;
+class AstRawString;
 class AstValueFactory;
 class AstStringConstants;
+class BackgroundCompileTask;
 class CompilerDispatcherTracer;
 class DeferredHandles;
 class FunctionLiteral;
@@ -25,32 +28,30 @@ class ParseInfo;
 class Parser;
 class SharedFunctionInfo;
 class String;
+class TimedHistogram;
 class UnicodeCache;
 class UnoptimizedCompilationJob;
-class Utf16CharacterStream;
+class WorkerThreadRuntimeCallStats;
 
+// TODO(rmcilroy): Remove this class entirely and just have CompilerDispatcher
+// manage BackgroundCompileTasks.
 class V8_EXPORT_PRIVATE UnoptimizedCompileJob : public CompilerDispatcherJob {
  public:
   // Creates a UnoptimizedCompileJob in the initial state.
-  UnoptimizedCompileJob(Isolate* isolate, CompilerDispatcherTracer* tracer,
-                        Handle<SharedFunctionInfo> shared,
-                        size_t max_stack_size);
+  UnoptimizedCompileJob(
+      CompilerDispatcherTracer* tracer, AccountingAllocator* allocator,
+      const ParseInfo* outer_parse_info, const AstRawString* function_name,
+      const FunctionLiteral* function_literal,
+      WorkerThreadRuntimeCallStats* worker_thread_runtime_stats,
+      TimedHistogram* timer, size_t max_stack_size);
   ~UnoptimizedCompileJob() override;
 
-  Handle<SharedFunctionInfo> shared() const { return shared_; }
-
-  // Returns true if this UnoptimizedCompileJob was created for the given
-  // function.
-  bool IsAssociatedWith(Handle<SharedFunctionInfo> shared) const;
-
   // CompilerDispatcherJob implementation.
-  void PrepareOnMainThread(Isolate* isolate) override;
   void Compile(bool on_background_thread) override;
-  void FinalizeOnMainThread(Isolate* isolate) override;
-  void ReportErrorsOnMainThread(Isolate* isolate) override;
+  void FinalizeOnMainThread(Isolate* isolate,
+                            Handle<SharedFunctionInfo> shared) override;
   void ResetOnMainThread(Isolate* isolate) override;
   double EstimateRuntimeOfNextStepInMs() const override;
-  void ShortPrintOnMainThread() override;
 
  private:
   friend class CompilerDispatcherTest;
@@ -58,26 +59,8 @@ class V8_EXPORT_PRIVATE UnoptimizedCompileJob : public CompilerDispatcherJob {
 
   void ResetDataOnMainThread(Isolate* isolate);
 
-  Context* context() { return *context_; }
-
-  int main_thread_id_;
   CompilerDispatcherTracer* tracer_;
-  AccountingAllocator* allocator_;
-  Handle<Context> context_;            // Global handle.
-  Handle<SharedFunctionInfo> shared_;  // Global handle.
-  Handle<String> source_;              // Global handle.
-  Handle<String> wrapper_;             // Global handle.
-  size_t max_stack_size_;
-
-  // Members required for parsing.
-  std::unique_ptr<UnicodeCache> unicode_cache_;
-  std::unique_ptr<ParseInfo> parse_info_;
-  std::unique_ptr<Parser> parser_;
-
-  // Members required for compiling.
-  std::unique_ptr<UnoptimizedCompilationJob> compilation_job_;
-
-  bool trace_compiler_dispatcher_jobs_;
+  std::unique_ptr<BackgroundCompileTask> task_;
 
   DISALLOW_COPY_AND_ASSIGN(UnoptimizedCompileJob);
 };
diff --git a/deps/v8/src/compiler.cc b/deps/v8/src/compiler.cc
index 58c1099135..7cb8a45696 100644
--- a/deps/v8/src/compiler.cc
+++ b/deps/v8/src/compiler.cc
@@ -124,6 +124,14 @@ void LogFunctionCompilation(CodeEventListener::LogEventsAndTags tag,
                              shared->DebugName()));
 }
 
+ScriptOriginOptions OriginOptionsForEval(Object* script) {
+  if (!script->IsScript()) return ScriptOriginOptions();
+
+  const auto outer_origin_options = Script::cast(script)->origin_options();
+  return ScriptOriginOptions(outer_origin_options.IsSharedCrossOrigin(),
+                             outer_origin_options.IsOpaque());
+}
+
 }  // namespace
 
 // ----------------------------------------------------------------------------
@@ -765,61 +773,6 @@ MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
   return MaybeHandle<Code>();
 }
 
-CompilationJob::Status FinalizeOptimizedCompilationJob(
-    OptimizedCompilationJob* job, Isolate* isolate) {
-  OptimizedCompilationInfo* compilation_info = job->compilation_info();
-
-  TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kRecompileSynchronous);
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.RecompileSynchronous");
-
-  Handle<SharedFunctionInfo> shared = compilation_info->shared_info();
-
-  // Reset profiler ticks, function is no longer considered hot.
-  compilation_info->closure()->feedback_vector()->set_profiler_ticks(0);
-
-  DCHECK(!shared->HasBreakInfo());
-
-  // 1) Optimization on the concurrent thread may have failed.
-  // 2) The function may have already been optimized by OSR.  Simply continue.
-  //    Except when OSR already disabled optimization for some reason.
-  // 3) The code may have already been invalidated due to dependency change.
-  // 4) Code generation may have failed.
-  if (job->state() == CompilationJob::State::kReadyToFinalize) {
-    if (shared->optimization_disabled()) {
-      job->RetryOptimization(BailoutReason::kOptimizationDisabled);
-    } else if (job->FinalizeJob(isolate) == CompilationJob::SUCCEEDED) {
-      job->RecordCompilationStats();
-      job->RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG,
-                                     isolate);
-      InsertCodeIntoOptimizedCodeCache(compilation_info);
-      if (FLAG_trace_opt) {
-        PrintF("[completed optimizing ");
-        compilation_info->closure()->ShortPrint();
-        PrintF("]\n");
-      }
-      compilation_info->closure()->set_code(*compilation_info->code());
-      return CompilationJob::SUCCEEDED;
-    }
-  }
-
-  DCHECK_EQ(job->state(), CompilationJob::State::kFailed);
-  if (FLAG_trace_opt) {
-    PrintF("[aborted optimizing ");
-    compilation_info->closure()->ShortPrint();
-    PrintF(" because: %s]\n",
-           GetBailoutReason(compilation_info->bailout_reason()));
-  }
-  compilation_info->closure()->set_code(shared->GetCode());
-  // Clear the InOptimizationQueue marker, if it exists.
-  if (compilation_info->closure()->IsInOptimizationQueue()) {
-    compilation_info->closure()->ClearOptimizationMarker();
-  }
-  return CompilationJob::FAILED;
-}
-
 bool FailWithPendingException(Isolate* isolate, ParseInfo* parse_info,
                               Compiler::ClearExceptionFlag flag) {
   if (flag == Compiler::CLEAR_EXCEPTION) {
@@ -909,7 +862,7 @@ MaybeHandle<SharedFunctionInfo> CompileToplevel(ParseInfo* parse_info,
                           &inner_function_jobs);
 }
 
-std::unique_ptr<UnoptimizedCompilationJob> CompileTopLevelOnBackgroundThread(
+std::unique_ptr<UnoptimizedCompilationJob> CompileOnBackgroundThread(
     ParseInfo* parse_info, AccountingAllocator* allocator,
     UnoptimizedCompilationJobList* inner_function_jobs) {
   DisallowHeapAccess no_heap_access;
@@ -917,15 +870,11 @@ std::unique_ptr<UnoptimizedCompilationJob> CompileTopLevelOnBackgroundThread(
                "V8.CompileCodeBackground");
   RuntimeCallTimerScope runtimeTimer(
       parse_info->runtime_call_stats(),
-      parse_info->is_eval() ? RuntimeCallCounterId::kCompileBackgroundEval
-                            : RuntimeCallCounterId::kCompileBackgroundScript);
-
-  LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
-  parse_info->set_language_mode(
-      stricter_language_mode(parse_info->language_mode(), language_mode));
-
-  // Can't access scope info data off-main-thread.
-  DCHECK(!parse_info->consumed_preparsed_scope_data()->HasData());
+      parse_info->is_toplevel()
+          ? parse_info->is_eval()
+                ? RuntimeCallCounterId::kCompileBackgroundEval
+                : RuntimeCallCounterId::kCompileBackgroundScript
+          : RuntimeCallCounterId::kCompileBackgroundFunction);
 
   // Generate the unoptimized bytecode or asm-js data.
   std::unique_ptr<UnoptimizedCompilationJob> outer_function_job(
@@ -933,89 +882,137 @@ std::unique_ptr<UnoptimizedCompilationJob> CompileTopLevelOnBackgroundThread(
   return outer_function_job;
 }
 
-class BackgroundCompileTask : public ScriptCompiler::ScriptStreamingTask {
- public:
-  BackgroundCompileTask(ScriptStreamingData* source, Isolate* isolate);
-
-  virtual void Run();
-
- private:
-  ScriptStreamingData* source_;  // Not owned.
-  int stack_size_;
-  AccountingAllocator* allocator_;
-  TimedHistogram* timer_;
-
-  DISALLOW_COPY_AND_ASSIGN(BackgroundCompileTask);
-};
+}  // namespace
 
-BackgroundCompileTask::BackgroundCompileTask(ScriptStreamingData* source,
+BackgroundCompileTask::BackgroundCompileTask(ScriptStreamingData* streamed_data,
                                              Isolate* isolate)
-    : source_(source),
+    : info_(new ParseInfo(isolate)),
       stack_size_(i::FLAG_stack_size),
+      worker_thread_runtime_call_stats_(
+          isolate->counters()->worker_thread_runtime_call_stats()),
+      allocator_(isolate->allocator()),
       timer_(isolate->counters()->compile_script_on_background()) {
   VMState<PARSER> state(isolate);
 
   // Prepare the data for the internalization phase and compilation phase, which
   // will happen in the main thread after parsing.
-  ParseInfo* info = new ParseInfo(isolate);
   LOG(isolate, ScriptEvent(Logger::ScriptEventType::kStreamingCompile,
-                           info->script_id()));
-  if (V8_UNLIKELY(FLAG_runtime_stats)) {
-    info->set_runtime_call_stats(new (info->zone()) RuntimeCallStats());
-  } else {
-    info->set_runtime_call_stats(nullptr);
-  }
-  info->set_toplevel();
-  std::unique_ptr<Utf16CharacterStream> stream(
-      ScannerStream::For(source->source_stream.get(), source->encoding,
-                         info->runtime_call_stats()));
-  info->set_character_stream(std::move(stream));
-  info->set_unicode_cache(&source_->unicode_cache);
-  info->set_allow_lazy_parsing();
-  if (V8_UNLIKELY(info->block_coverage_enabled())) {
-    info->AllocateSourceRangeMap();
+                           info_->script_id()));
+  info_->set_toplevel();
+  info_->set_unicode_cache(&unicode_cache_);
+  info_->set_allow_lazy_parsing();
+  if (V8_UNLIKELY(info_->block_coverage_enabled())) {
+    info_->AllocateSourceRangeMap();
   }
   LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
-  info->set_language_mode(
-      stricter_language_mode(info->language_mode(), language_mode));
+  info_->set_language_mode(
+      stricter_language_mode(info_->language_mode(), language_mode));
 
-  source->info.reset(info);
-  allocator_ = isolate->allocator();
+  std::unique_ptr<Utf16CharacterStream> stream(ScannerStream::For(
+      streamed_data->source_stream.get(), streamed_data->encoding));
+  info_->set_character_stream(std::move(stream));
+}
 
-  // Parser needs to stay alive for finalizing the parsing on the main
-  // thread.
-  source_->parser.reset(new Parser(source_->info.get()));
-  source_->parser->DeserializeScopeChain(isolate, source_->info.get(),
-                                         MaybeHandle<ScopeInfo>());
+BackgroundCompileTask::BackgroundCompileTask(
+    AccountingAllocator* allocator, const ParseInfo* outer_parse_info,
+    const AstRawString* function_name, const FunctionLiteral* function_literal,
+    WorkerThreadRuntimeCallStats* worker_thread_runtime_stats,
+    TimedHistogram* timer, int max_stack_size)
+    : info_(ParseInfo::FromParent(outer_parse_info, allocator, function_literal,
+                                  function_name)),
+      stack_size_(max_stack_size),
+      worker_thread_runtime_call_stats_(worker_thread_runtime_stats),
+      allocator_(allocator),
+      timer_(timer) {
+  DCHECK(outer_parse_info->is_toplevel());
+  DCHECK(!function_literal->is_toplevel());
+
+  info_->set_unicode_cache(&unicode_cache_);
+
+  // Clone the character stream so both can be accessed independently.
+  std::unique_ptr<Utf16CharacterStream> character_stream =
+      outer_parse_info->character_stream()->Clone();
+  character_stream->Seek(function_literal->start_position());
+  info_->set_character_stream(std::move(character_stream));
+
+  // Get preparsed scope data from the function literal.
+  if (function_literal->produced_preparsed_scope_data()) {
+    DCHECK(FLAG_preparser_scope_analysis);
+    ZonePreParsedScopeData* serialized_data =
+        function_literal->produced_preparsed_scope_data()->Serialize(
+            info_->zone());
+    info_->set_consumed_preparsed_scope_data(
+        ConsumedPreParsedScopeData::For(info_->zone(), serialized_data));
+  }
 }
 
+namespace {
+
+// A scope object that ensures a parse info's runtime call stats, stack limit
+// and on_background_thread fields is set correctly during worker-thread
+// compile, and restores it after going out of scope.
+class OffThreadParseInfoScope {
+ public:
+  OffThreadParseInfoScope(
+      ParseInfo* parse_info,
+      WorkerThreadRuntimeCallStats* worker_thread_runtime_stats, int stack_size)
+      : parse_info_(parse_info),
+        original_runtime_call_stats_(parse_info_->runtime_call_stats()),
+        original_stack_limit_(parse_info_->stack_limit()),
+        worker_thread_scope_(worker_thread_runtime_stats) {
+    parse_info_->set_on_background_thread(true);
+    parse_info_->set_runtime_call_stats(worker_thread_scope_.Get());
+    parse_info_->set_stack_limit(GetCurrentStackPosition() - stack_size * KB);
+  }
+
+  ~OffThreadParseInfoScope() {
+    parse_info_->set_stack_limit(original_stack_limit_);
+    parse_info_->set_runtime_call_stats(original_runtime_call_stats_);
+    parse_info_->set_on_background_thread(false);
+  }
+
+ private:
+  ParseInfo* parse_info_;
+  RuntimeCallStats* original_runtime_call_stats_;
+  uintptr_t original_stack_limit_;
+  WorkerThreadRuntimeCallStatsScope worker_thread_scope_;
+
+  DISALLOW_COPY_AND_ASSIGN(OffThreadParseInfoScope);
+};
+
+}  // namespace
+
 void BackgroundCompileTask::Run() {
-  TimedHistogramScope timer(timer_);
+  DisallowHeapAllocation no_allocation;
+  DisallowHandleAllocation no_handles;
   DisallowHeapAccess no_heap_access;
 
-  source_->info->set_on_background_thread(true);
+  TimedHistogramScope timer(timer_);
+  OffThreadParseInfoScope off_thread_scope(
+      info_.get(), worker_thread_runtime_call_stats_, stack_size_);
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "BackgroundCompileTask::Run");
+  RuntimeCallTimerScope runtimeTimer(
+      info_->runtime_call_stats(),
+      RuntimeCallCounterId::kCompileBackgroundCompileTask);
+
+  // Update the character stream's runtime call stats.
+  info_->character_stream()->set_runtime_call_stats(
+      info_->runtime_call_stats());
 
-  // Reset the stack limit of the parser to reflect correctly that we're on a
-  // background thread.
-  uintptr_t old_stack_limit = source_->info->stack_limit();
-  uintptr_t stack_limit = GetCurrentStackPosition() - stack_size_ * KB;
-  source_->info->set_stack_limit(stack_limit);
-  source_->parser->set_stack_limit(stack_limit);
+  // Parser needs to stay alive for finalizing the parsing on the main
+  // thread.
+  parser_.reset(new Parser(info_.get()));
+  parser_->InitializeEmptyScopeChain(info_.get());
 
-  source_->parser->ParseOnBackground(source_->info.get());
-  if (source_->info->literal() != nullptr) {
+  parser_->ParseOnBackground(info_.get());
+  if (info_->literal() != nullptr) {
     // Parsing has succeeded, compile.
-    source_->outer_function_job = CompileTopLevelOnBackgroundThread(
-        source_->info.get(), allocator_, &source_->inner_function_jobs);
+    outer_function_job_ = CompileOnBackgroundThread(info_.get(), allocator_,
+                                                    &inner_function_jobs_);
   }
-
-  source_->info->EmitBackgroundParseStatisticsOnBackgroundThread();
-
-  source_->info->set_on_background_thread(false);
-  source_->info->set_stack_limit(old_stack_limit);
 }
 
-}  // namespace
 
 // ----------------------------------------------------------------------------
 // Implementation of Compiler
@@ -1074,10 +1071,12 @@ bool Compiler::Compile(Handle<SharedFunctionInfo> shared_info,
 
   if (FLAG_preparser_scope_analysis) {
     if (shared_info->HasUncompiledDataWithPreParsedScope()) {
-      parse_info.consumed_preparsed_scope_data()->SetData(
-          isolate, handle(shared_info->uncompiled_data_with_pre_parsed_scope()
-                              ->pre_parsed_scope_data(),
-                          isolate));
+      parse_info.set_consumed_preparsed_scope_data(
+          ConsumedPreParsedScopeData::For(
+              isolate,
+              handle(shared_info->uncompiled_data_with_pre_parsed_scope()
+                         ->pre_parsed_scope_data(),
+                     isolate)));
     }
   }
 
@@ -1150,6 +1149,43 @@ bool Compiler::Compile(Handle<JSFunction> function, ClearExceptionFlag flag) {
   return true;
 }
 
+bool Compiler::FinalizeBackgroundCompileTask(
+    BackgroundCompileTask* task, Handle<SharedFunctionInfo> shared_info,
+    Isolate* isolate, ClearExceptionFlag flag) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.FinalizeBackgroundCompileTask");
+  RuntimeCallTimerScope runtimeTimer(
+      isolate, RuntimeCallCounterId::kCompileFinalizeBackgroundCompileTask);
+  HandleScope scope(isolate);
+  ParseInfo* parse_info = task->info();
+  DCHECK(!parse_info->is_toplevel());
+  DCHECK(!shared_info->is_compiled());
+
+  Handle<Script> script(Script::cast(shared_info->script()), isolate);
+  parse_info->set_script(script);
+
+  task->parser()->UpdateStatistics(isolate, script);
+  task->parser()->HandleSourceURLComments(isolate, script);
+
+  if (parse_info->literal() == nullptr || !task->outer_function_job()) {
+    // Parsing or compile failed on background thread - report error messages.
+    return FailWithPendingException(isolate, parse_info, flag);
+  }
+
+  // Parsing has succeeded - finalize compilation.
+  parse_info->ast_value_factory()->Internalize(isolate);
+  if (!FinalizeUnoptimizedCode(parse_info, isolate, shared_info,
+                               task->outer_function_job(),
+                               task->inner_function_jobs())) {
+    // Finalization failed - throw an exception.
+    return FailWithPendingException(isolate, parse_info, flag);
+  }
+
+  DCHECK(!isolate->has_pending_exception());
+  DCHECK(shared_info->is_compiled());
+  return true;
+}
+
 bool Compiler::CompileOptimized(Handle<JSFunction> function,
                                 ConcurrencyMode mode) {
   if (function->IsOptimized()) return true;
@@ -1192,9 +1228,7 @@ MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
     Handle<String> source, Handle<SharedFunctionInfo> outer_info,
     Handle<Context> context, LanguageMode language_mode,
     ParseRestriction restriction, int parameters_end_pos,
-    int eval_scope_position, int eval_position, int line_offset,
-    int column_offset, Handle<Object> script_name,
-    ScriptOriginOptions options) {
+    int eval_scope_position, int eval_position) {
   Isolate* isolate = context->GetIsolate();
   int source_length = source->length();
   isolate->counters()->total_eval_size()->Increment(source_length);
@@ -1209,8 +1243,7 @@ MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
   // is unused (just 0), which means it's an available field to use to indicate
   // this separation. But to make sure we're not causing other false hits, we
   // negate the scope position.
-  if (FLAG_harmony_function_tostring &&
-      restriction == ONLY_SINGLE_FUNCTION_LITERAL &&
+  if (restriction == ONLY_SINGLE_FUNCTION_LITERAL &&
       parameters_end_pos != kNoSourcePosition) {
     // use the parameters_end_pos as the eval_scope_position in the eval cache.
     DCHECK_EQ(eval_scope_position, 0);
@@ -1233,14 +1266,8 @@ MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
     allow_eval_cache = true;
   } else {
     ParseInfo parse_info(isolate);
-    script = parse_info.CreateScript(isolate, source, options);
-    if (!script_name.is_null()) {
-      // TODO(cbruni): check whether we can store this data in options
-      script->set_name(*script_name);
-      script->set_line_offset(line_offset);
-      script->set_column_offset(column_offset);
-      LOG(isolate, ScriptDetails(*script));
-    }
+    script = parse_info.CreateScript(
+        isolate, source, OriginOptionsForEval(outer_info->script()));
     script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
     script->set_eval_from_shared(*outer_info);
     if (eval_position == kNoSourcePosition) {
@@ -1252,6 +1279,7 @@ MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
         FrameSummary summary = FrameSummary::GetTop(it.javascript_frame());
         script->set_eval_from_shared(
             summary.AsJavaScript().function()->shared());
+        script->set_origin_options(OriginOptionsForEval(*summary.script()));
         eval_position = -summary.code_offset();
       } else {
         eval_position = 0;
@@ -1754,11 +1782,6 @@ MaybeHandle<JSFunction> Compiler::GetWrappedFunction(
                                                             NOT_TENURED);
 }
 
-ScriptCompiler::ScriptStreamingTask* Compiler::NewBackgroundCompileTask(
-    ScriptStreamingData* source, Isolate* isolate) {
-  return new BackgroundCompileTask(source, isolate);
-}
-
 MaybeHandle<SharedFunctionInfo>
 Compiler::GetSharedFunctionInfoForStreamedScript(
     Isolate* isolate, Handle<String> source,
@@ -1772,9 +1795,9 @@ Compiler::GetSharedFunctionInfoForStreamedScript(
   isolate->counters()->total_load_size()->Increment(source_length);
   isolate->counters()->total_compile_size()->Increment(source_length);
 
-  ParseInfo* parse_info = streaming_data->info.get();
-  parse_info->UpdateBackgroundParseStatisticsOnMainThread(isolate);
-
+  BackgroundCompileTask* task = streaming_data->task.get();
+  ParseInfo* parse_info = task->info();
+  DCHECK(parse_info->is_toplevel());
   // Check if compile cache already holds the SFI, if so no need to finalize
   // the code compiled on the background thread.
   CompilationCache* compilation_cache = isolate->compilation_cache();
@@ -1793,21 +1816,20 @@ Compiler::GetSharedFunctionInfoForStreamedScript(
     Handle<Script> script =
         NewScript(isolate, parse_info, source, script_details, origin_options,
                   NOT_NATIVES_CODE);
-    streaming_data->parser->UpdateStatistics(isolate, script);
-    streaming_data->parser->HandleSourceURLComments(isolate, script);
+    task->parser()->UpdateStatistics(isolate, script);
+    task->parser()->HandleSourceURLComments(isolate, script);
 
-    if (parse_info->literal() == nullptr) {
+    if (parse_info->literal() == nullptr || !task->outer_function_job()) {
       // Parsing has failed - report error messages.
-      parse_info->pending_error_handler()->ReportErrors(
-          isolate, script, parse_info->ast_value_factory());
+      FailWithPendingException(isolate, parse_info,
+                               Compiler::ClearExceptionFlag::KEEP_EXCEPTION);
     } else {
       // Parsing has succeeded - finalize compilation.
-      if (streaming_data->outer_function_job) {
-        maybe_result = FinalizeTopLevel(
-            parse_info, isolate, streaming_data->outer_function_job.get(),
-            &streaming_data->inner_function_jobs);
-      } else {
-        // Compilation failed on background thread - throw an exception.
+      maybe_result =
+          FinalizeTopLevel(parse_info, isolate, task->outer_function_job(),
+                           task->inner_function_jobs());
+      if (maybe_result.is_null()) {
+        // Finalization failed - throw an exception.
         FailWithPendingException(isolate, parse_info,
                                  Compiler::ClearExceptionFlag::KEEP_EXCEPTION);
       }
@@ -1856,23 +1878,62 @@ MaybeHandle<Code> Compiler::GetOptimizedCodeForOSR(Handle<JSFunction> function,
                           osr_frame);
 }
 
-bool Compiler::FinalizeCompilationJob(OptimizedCompilationJob* raw_job,
-                                      Isolate* isolate) {
+bool Compiler::FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
+                                               Isolate* isolate) {
   VMState<COMPILER> state(isolate);
   // Take ownership of compilation job.  Deleting job also tears down the zone.
-  std::unique_ptr<OptimizedCompilationJob> job(raw_job);
-  return FinalizeOptimizedCompilationJob(job.get(), isolate) ==
-         CompilationJob::SUCCEEDED;
-}
+  std::unique_ptr<OptimizedCompilationJob> job_scope(job);
+  OptimizedCompilationInfo* compilation_info = job->compilation_info();
 
-bool Compiler::FinalizeCompilationJob(UnoptimizedCompilationJob* raw_job,
-                                      Handle<SharedFunctionInfo> shared_info,
-                                      Isolate* isolate) {
-  VMState<BYTECODE_COMPILER> state(isolate);
-  // Take ownership of compilation job.  Deleting job also tears down the zone.
-  std::unique_ptr<UnoptimizedCompilationJob> job(raw_job);
-  return FinalizeUnoptimizedCompilationJob(job.get(), shared_info, isolate) ==
-         CompilationJob::SUCCEEDED;
+  TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
+  RuntimeCallTimerScope runtimeTimer(
+      isolate, RuntimeCallCounterId::kRecompileSynchronous);
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.RecompileSynchronous");
+
+  Handle<SharedFunctionInfo> shared = compilation_info->shared_info();
+
+  // Reset profiler ticks, function is no longer considered hot.
+  compilation_info->closure()->feedback_vector()->set_profiler_ticks(0);
+
+  DCHECK(!shared->HasBreakInfo());
+
+  // 1) Optimization on the concurrent thread may have failed.
+  // 2) The function may have already been optimized by OSR.  Simply continue.
+  //    Except when OSR already disabled optimization for some reason.
+  // 3) The code may have already been invalidated due to dependency change.
+  // 4) Code generation may have failed.
+  if (job->state() == CompilationJob::State::kReadyToFinalize) {
+    if (shared->optimization_disabled()) {
+      job->RetryOptimization(BailoutReason::kOptimizationDisabled);
+    } else if (job->FinalizeJob(isolate) == CompilationJob::SUCCEEDED) {
+      job->RecordCompilationStats();
+      job->RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG,
+                                     isolate);
+      InsertCodeIntoOptimizedCodeCache(compilation_info);
+      if (FLAG_trace_opt) {
+        PrintF("[completed optimizing ");
+        compilation_info->closure()->ShortPrint();
+        PrintF("]\n");
+      }
+      compilation_info->closure()->set_code(*compilation_info->code());
+      return CompilationJob::SUCCEEDED;
+    }
+  }
+
+  DCHECK_EQ(job->state(), CompilationJob::State::kFailed);
+  if (FLAG_trace_opt) {
+    PrintF("[aborted optimizing ");
+    compilation_info->closure()->ShortPrint();
+    PrintF(" because: %s]\n",
+           GetBailoutReason(compilation_info->bailout_reason()));
+  }
+  compilation_info->closure()->set_code(shared->GetCode());
+  // Clear the InOptimizationQueue marker, if it exists.
+  if (compilation_info->closure()->IsInOptimizationQueue()) {
+    compilation_info->closure()->ClearOptimizationMarker();
+  }
+  return CompilationJob::FAILED;
 }
 
 void Compiler::PostInstantiation(Handle<JSFunction> function,
@@ -1920,14 +1981,9 @@ ScriptStreamingData::ScriptStreamingData(
     ScriptCompiler::StreamedSource::Encoding encoding)
     : source_stream(source_stream), encoding(encoding) {}
 
-ScriptStreamingData::~ScriptStreamingData() {}
+ScriptStreamingData::~ScriptStreamingData() = default;
 
-void ScriptStreamingData::Release() {
-  parser.reset();
-  info.reset();
-  outer_function_job.reset();
-  inner_function_jobs.clear();
-}
+void ScriptStreamingData::Release() { task.reset(); }
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler.h b/deps/v8/src/compiler.h
index b3a5b73997..f32d771266 100644
--- a/deps/v8/src/compiler.h
+++ b/deps/v8/src/compiler.h
@@ -20,6 +20,8 @@ namespace v8 {
 namespace internal {
 
 // Forward declarations.
+class AstRawString;
+class BackgroundCompileTask;
 class JavaScriptFrame;
 class OptimizedCompilationInfo;
 class OptimizedCompilationJob;
@@ -27,8 +29,10 @@ class ParseInfo;
 class Parser;
 class ScriptData;
 struct ScriptStreamingData;
+class TimedHistogram;
 class UnoptimizedCompilationInfo;
 class UnoptimizedCompilationJob;
+class WorkerThreadRuntimeCallStats;
 
 typedef std::forward_list<std::unique_ptr<UnoptimizedCompilationJob>>
     UnoptimizedCompilationJobList;
@@ -61,19 +65,14 @@ class V8_EXPORT_PRIVATE Compiler : public AllStatic {
   V8_WARN_UNUSED_RESULT static MaybeHandle<SharedFunctionInfo>
   CompileForLiveEdit(ParseInfo* parse_info, Isolate* isolate);
 
-  // Creates a new task that when run will parse and compile the streamed
-  // script associated with |streaming_data| and can be finalized with
-  // Compiler::GetSharedFunctionInfoForStreamedScript.
-  // Note: does not take ownership of streaming_data.
-  static ScriptCompiler::ScriptStreamingTask* NewBackgroundCompileTask(
-      ScriptStreamingData* streaming_data, Isolate* isolate);
+  // Finalize and install code from previously run background compile task.
+  static bool FinalizeBackgroundCompileTask(
+      BackgroundCompileTask* task, Handle<SharedFunctionInfo> shared_info,
+      Isolate* isolate, ClearExceptionFlag flag);
 
-  // Generate and install code from previously queued compilation job.
-  static bool FinalizeCompilationJob(UnoptimizedCompilationJob* job,
-                                     Handle<SharedFunctionInfo> shared_info,
-                                     Isolate* isolate);
-  static bool FinalizeCompilationJob(OptimizedCompilationJob* job,
-                                     Isolate* isolate);
+  // Finalize and install optimized code from previously run job.
+  static bool FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
+                                              Isolate* isolate);
 
   // Give the compiler a chance to perform low-latency initialization tasks of
   // the given {function} on its instantiation. Note that only the runtime will
@@ -101,9 +100,7 @@ class V8_EXPORT_PRIVATE Compiler : public AllStatic {
       Handle<String> source, Handle<SharedFunctionInfo> outer_info,
       Handle<Context> context, LanguageMode language_mode,
       ParseRestriction restriction, int parameters_end_pos,
-      int eval_scope_position, int eval_position, int line_offset = 0,
-      int column_offset = 0, Handle<Object> script_name = Handle<Object>(),
-      ScriptOriginOptions options = ScriptOriginOptions());
+      int eval_scope_position, int eval_position);
 
   struct ScriptDetails {
     ScriptDetails() : line_offset(0), column_offset(0) {}
@@ -192,7 +189,7 @@ class V8_EXPORT_PRIVATE CompilationJob {
 
   CompilationJob(uintptr_t stack_limit, State initial_state)
       : state_(initial_state), stack_limit_(stack_limit) {}
-  virtual ~CompilationJob() {}
+  virtual ~CompilationJob() = default;
 
   void set_stack_limit(uintptr_t stack_limit) { stack_limit_ = stack_limit; }
   uintptr_t stack_limit() const { return stack_limit_; }
@@ -319,6 +316,57 @@ class OptimizedCompilationJob : public CompilationJob {
   const char* compiler_name_;
 };
 
+class BackgroundCompileTask {
+ public:
+  // Creates a new task that when run will parse and compile the streamed
+  // script associated with |data| and can be finalized with
+  // Compiler::GetSharedFunctionInfoForStreamedScript.
+  // Note: does not take ownership of |data|.
+  BackgroundCompileTask(ScriptStreamingData* data, Isolate* isolate);
+
+  // Creates a new task that when run will parse and compile the
+  // |function_literal| and can be finalized with
+  // Compiler::FinalizeBackgroundCompileTask.
+  BackgroundCompileTask(
+      AccountingAllocator* allocator, const ParseInfo* outer_parse_info,
+      const AstRawString* function_name,
+      const FunctionLiteral* function_literal,
+      WorkerThreadRuntimeCallStats* worker_thread_runtime_stats,
+      TimedHistogram* timer, int max_stack_size);
+
+  void Run();
+
+  ParseInfo* info() { return info_.get(); }
+  Parser* parser() { return parser_.get(); }
+  UnoptimizedCompilationJob* outer_function_job() {
+    return outer_function_job_.get();
+  }
+  UnoptimizedCompilationJobList* inner_function_jobs() {
+    return &inner_function_jobs_;
+  }
+
+ private:
+  // Data needed for parsing, and data needed to to be passed between thread
+  // between parsing and compilation. These need to be initialized before the
+  // compilation starts.
+  std::unique_ptr<ParseInfo> info_;
+  std::unique_ptr<Parser> parser_;
+  // TODO(rmcilroy): Consider having thread-local unicode-caches rather than
+  // creating a new one each time.
+  UnicodeCache unicode_cache_;
+
+  // Data needed for finalizing compilation after background compilation.
+  std::unique_ptr<UnoptimizedCompilationJob> outer_function_job_;
+  UnoptimizedCompilationJobList inner_function_jobs_;
+
+  int stack_size_;
+  WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats_;
+  AccountingAllocator* allocator_;
+  TimedHistogram* timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(BackgroundCompileTask);
+};
+
 // Contains all data which needs to be transmitted between threads for
 // background parsing and compiling and finalizing it on the main thread.
 struct ScriptStreamingData {
@@ -331,18 +379,9 @@ struct ScriptStreamingData {
   // Internal implementation of v8::ScriptCompiler::StreamedSource.
   std::unique_ptr<ScriptCompiler::ExternalSourceStream> source_stream;
   ScriptCompiler::StreamedSource::Encoding encoding;
-  std::unique_ptr<ScriptCompiler::CachedData> cached_data;
 
-  // Data needed for parsing, and data needed to to be passed between thread
-  // between parsing and compilation. These need to be initialized before the
-  // compilation starts.
-  UnicodeCache unicode_cache;
-  std::unique_ptr<ParseInfo> info;
-  std::unique_ptr<Parser> parser;
-
-  // Data needed for finalizing compilation after background compilation.
-  std::unique_ptr<UnoptimizedCompilationJob> outer_function_job;
-  UnoptimizedCompilationJobList inner_function_jobs;
+  // Task that performs background parsing and compilation.
+  std::unique_ptr<BackgroundCompileTask> task;
 
   DISALLOW_COPY_AND_ASSIGN(ScriptStreamingData);
 };
diff --git a/deps/v8/src/compiler/access-builder.cc b/deps/v8/src/compiler/access-builder.cc
index 0342a9c950..a0648d0257 100644
--- a/deps/v8/src/compiler/access-builder.cc
+++ b/deps/v8/src/compiler/access-builder.cc
@@ -67,20 +67,20 @@ FieldAccess AccessBuilder::ForBigIntBitfield() {
 
 // static
 FieldAccess AccessBuilder::ForJSObjectPropertiesOrHash() {
-  FieldAccess access = {kTaggedBase,         JSObject::kPropertiesOrHashOffset,
-                        MaybeHandle<Name>(), MaybeHandle<Map>(),
-                        Type::Any(),         MachineType::AnyTagged(),
-                        kPointerWriteBarrier};
+  FieldAccess access = {kTaggedBase,          JSObject::kPropertiesOrHashOffset,
+                        MaybeHandle<Name>(),  MaybeHandle<Map>(),
+                        Type::Any(),          MachineType::AnyTagged(),
+                        kPointerWriteBarrier, LoadSensitivity::kCritical};
   return access;
 }
 
 
 // static
 FieldAccess AccessBuilder::ForJSObjectElements() {
-  FieldAccess access = {kTaggedBase,         JSObject::kElementsOffset,
-                        MaybeHandle<Name>(), MaybeHandle<Map>(),
-                        Type::Internal(),    MachineType::TaggedPointer(),
-                        kPointerWriteBarrier};
+  FieldAccess access = {kTaggedBase,          JSObject::kElementsOffset,
+                        MaybeHandle<Name>(),  MaybeHandle<Map>(),
+                        Type::Internal(),     MachineType::TaggedPointer(),
+                        kPointerWriteBarrier, LoadSensitivity::kCritical};
   return access;
 }
 
@@ -357,9 +357,9 @@ FieldAccess AccessBuilder::ForJSArrayBufferViewByteLength() {
                         JSArrayBufferView::kByteLengthOffset,
                         MaybeHandle<Name>(),
                         MaybeHandle<Map>(),
-                        TypeCache::Get().kPositiveInteger,
-                        MachineType::AnyTagged(),
-                        kFullWriteBarrier};
+                        TypeCache::Get().kJSArrayBufferViewByteLengthType,
+                        MachineType::UintPtr(),
+                        kNoWriteBarrier};
   return access;
 }
 
@@ -369,9 +369,9 @@ FieldAccess AccessBuilder::ForJSArrayBufferViewByteOffset() {
                         JSArrayBufferView::kByteOffsetOffset,
                         MaybeHandle<Name>(),
                         MaybeHandle<Map>(),
-                        TypeCache::Get().kPositiveInteger,
-                        MachineType::AnyTagged(),
-                        kFullWriteBarrier};
+                        TypeCache::Get().kJSArrayBufferViewByteOffsetType,
+                        MachineType::UintPtr(),
+                        kNoWriteBarrier};
   return access;
 }
 
@@ -494,7 +494,7 @@ FieldAccess AccessBuilder::ForFixedTypedArrayBaseBasePointer() {
       kTaggedBase,           FixedTypedArrayBase::kBasePointerOffset,
       MaybeHandle<Name>(),   MaybeHandle<Map>(),
       Type::OtherInternal(), MachineType::AnyTagged(),
-      kPointerWriteBarrier};
+      kPointerWriteBarrier,  LoadSensitivity::kCritical};
   return access;
 }
 
@@ -506,7 +506,8 @@ FieldAccess AccessBuilder::ForFixedTypedArrayBaseExternalPointer() {
                         MaybeHandle<Map>(),
                         Type::ExternalPointer(),
                         MachineType::Pointer(),
-                        kNoWriteBarrier};
+                        kNoWriteBarrier,
+                        LoadSensitivity::kCritical};
   return access;
 }
 
@@ -611,7 +612,7 @@ FieldAccess AccessBuilder::ForStringLength() {
                         Handle<Name>(),
                         MaybeHandle<Map>(),
                         TypeCache::Get().kStringLengthType,
-                        MachineType::TaggedSigned(),
+                        MachineType::Uint32(),
                         kNoWriteBarrier};
   return access;
 }
@@ -801,10 +802,11 @@ FieldAccess AccessBuilder::ForValue() {
 
 // static
 FieldAccess AccessBuilder::ForArgumentsLength() {
-  FieldAccess access = {kTaggedBase,         JSArgumentsObject::kLengthOffset,
-                        Handle<Name>(),      MaybeHandle<Map>(),
-                        Type::NonInternal(), MachineType::AnyTagged(),
-                        kFullWriteBarrier};
+  FieldAccess access = {
+      kTaggedBase,         JSArgumentsObjectWithLength::kLengthOffset,
+      Handle<Name>(),      MaybeHandle<Map>(),
+      Type::NonInternal(), MachineType::AnyTagged(),
+      kFullWriteBarrier};
   return access;
 }
 
@@ -834,10 +836,10 @@ FieldAccess AccessBuilder::ForFixedArraySlot(
 
 // static
 FieldAccess AccessBuilder::ForCellValue() {
-  FieldAccess access = {kTaggedBase,      Cell::kValueOffset,
-                        Handle<Name>(),   MaybeHandle<Map>(),
-                        Type::Any(),      MachineType::AnyTagged(),
-                        kFullWriteBarrier};
+  FieldAccess access = {kTaggedBase,       Cell::kValueOffset,
+                        Handle<Name>(),    MaybeHandle<Map>(),
+                        Type::Any(),       MachineType::AnyTagged(),
+                        kFullWriteBarrier, LoadSensitivity::kCritical};
   return access;
 }
 
diff --git a/deps/v8/src/compiler/access-builder.h b/deps/v8/src/compiler/access-builder.h
index 945edf3014..889a139a38 100644
--- a/deps/v8/src/compiler/access-builder.h
+++ b/deps/v8/src/compiler/access-builder.h
@@ -9,6 +9,7 @@
 #include "src/compiler/simplified-operator.h"
 #include "src/elements-kind.h"
 #include "src/globals.h"
+#include "src/objects/js-objects.h"
 
 namespace v8 {
 namespace internal {
diff --git a/deps/v8/src/compiler/access-info.cc b/deps/v8/src/compiler/access-info.cc
index 0b7d1a18a1..5bf515f654 100644
--- a/deps/v8/src/compiler/access-info.cc
+++ b/deps/v8/src/compiler/access-info.cc
@@ -65,7 +65,7 @@ std::ostream& operator<<(std::ostream& os, AccessMode access_mode) {
   UNREACHABLE();
 }
 
-ElementAccessInfo::ElementAccessInfo() {}
+ElementAccessInfo::ElementAccessInfo() = default;
 
 ElementAccessInfo::ElementAccessInfo(MapHandles const& receiver_maps,
                                      ElementsKind elements_kind)
@@ -74,7 +74,7 @@ ElementAccessInfo::ElementAccessInfo(MapHandles const& receiver_maps,
 // static
 PropertyAccessInfo PropertyAccessInfo::NotFound(MapHandles const& receiver_maps,
                                                 MaybeHandle<JSObject> holder) {
-  return PropertyAccessInfo(holder, receiver_maps);
+  return PropertyAccessInfo(kNotFound, holder, receiver_maps);
 }
 
 // static
@@ -111,14 +111,21 @@ PropertyAccessInfo PropertyAccessInfo::ModuleExport(
                             receiver_maps);
 }
 
+// static
+PropertyAccessInfo PropertyAccessInfo::StringLength(
+    MapHandles const& receiver_maps) {
+  return PropertyAccessInfo(kStringLength, MaybeHandle<JSObject>(),
+                            receiver_maps);
+}
+
 PropertyAccessInfo::PropertyAccessInfo()
     : kind_(kInvalid),
       field_representation_(MachineRepresentation::kNone),
       field_type_(Type::None()) {}
 
-PropertyAccessInfo::PropertyAccessInfo(MaybeHandle<JSObject> holder,
+PropertyAccessInfo::PropertyAccessInfo(Kind kind, MaybeHandle<JSObject> holder,
                                        MapHandles const& receiver_maps)
-    : kind_(kNotFound),
+    : kind_(kind),
       receiver_maps_(receiver_maps),
       holder_(holder),
       field_representation_(MachineRepresentation::kNone),
@@ -218,7 +225,8 @@ bool PropertyAccessInfo::Merge(PropertyAccessInfo const* that,
       return false;
     }
 
-    case kNotFound: {
+    case kNotFound:
+    case kStringLength: {
       this->receiver_maps_.insert(this->receiver_maps_.end(),
                                   that->receiver_maps_.begin(),
                                   that->receiver_maps_.end());
@@ -396,11 +404,12 @@ bool AccessInfoFactory::ComputePropertyAccessInfo(
               // The field type was cleared by the GC, so we don't know anything
               // about the contents now.
             } else if (descriptors_field_type->IsClass()) {
-              dependencies()->DependOnFieldType(MapRef(js_heap_broker(), map),
-                                                number);
+              MapRef map_ref(js_heap_broker(), map);
+              map_ref.SerializeOwnDescriptors();  // TODO(neis): Remove later.
+              dependencies()->DependOnFieldType(map_ref, number);
               // Remember the field map, and try to infer a useful type.
               Handle<Map> map(descriptors_field_type->AsClass(), isolate());
-              field_type = Type::For(js_heap_broker(), map);
+              field_type = Type::For(MapRef(js_heap_broker(), map));
               field_map = MaybeHandle<Map>(map);
             }
           }
@@ -620,18 +629,20 @@ bool AccessInfoFactory::ConsolidateElementLoad(MapHandles const& maps,
 
 bool AccessInfoFactory::LookupSpecialFieldAccessor(
     Handle<Map> map, Handle<Name> name, PropertyAccessInfo* access_info) {
+  // Check for String::length field accessor.
+  if (map->IsStringMap()) {
+    if (Name::Equals(isolate(), name, factory()->length_string())) {
+      *access_info = PropertyAccessInfo::StringLength(MapHandles{map});
+      return true;
+    }
+    return false;
+  }
   // Check for special JSObject field accessors.
   FieldIndex field_index;
   if (Accessors::IsJSObjectFieldAccessor(isolate(), map, name, &field_index)) {
     Type field_type = Type::NonInternal();
     MachineRepresentation field_representation = MachineRepresentation::kTagged;
-    if (map->IsStringMap()) {
-      DCHECK(Name::Equals(isolate(), factory()->length_string(), name));
-      // The String::length property is always a smi in the range
-      // [0, String::kMaxLength].
-      field_type = type_cache_.kStringLengthType;
-      field_representation = MachineRepresentation::kTaggedSigned;
-    } else if (map->IsJSArrayMap()) {
+    if (map->IsJSArrayMap()) {
       DCHECK(Name::Equals(isolate(), factory()->length_string(), name));
       // The JSArray::length property is a smi in the range
       // [0, FixedDoubleArray::kMaxLength] in case of fast double
@@ -698,11 +709,13 @@ bool AccessInfoFactory::LookupTransition(Handle<Map> map, Handle<Name> name,
       // Store is not safe if the field type was cleared.
       return false;
     } else if (descriptors_field_type->IsClass()) {
-      dependencies()->DependOnFieldType(
-          MapRef(js_heap_broker(), transition_map), number);
+      MapRef transition_map_ref(js_heap_broker(), transition_map);
+      transition_map_ref
+          .SerializeOwnDescriptors();  // TODO(neis): Remove later.
+      dependencies()->DependOnFieldType(transition_map_ref, number);
       // Remember the field map, and try to infer a useful type.
       Handle<Map> map(descriptors_field_type->AsClass(), isolate());
-      field_type = Type::For(js_heap_broker(), map);
+      field_type = Type::For(MapRef(js_heap_broker(), map));
       field_map = MaybeHandle<Map>(map);
     }
   }
diff --git a/deps/v8/src/compiler/access-info.h b/deps/v8/src/compiler/access-info.h
index e9890bbb7a..9d6828ee69 100644
--- a/deps/v8/src/compiler/access-info.h
+++ b/deps/v8/src/compiler/access-info.h
@@ -65,7 +65,8 @@ class PropertyAccessInfo final {
     kDataField,
     kDataConstantField,
     kAccessorConstant,
-    kModuleExport
+    kModuleExport,
+    kStringLength
   };
 
   static PropertyAccessInfo NotFound(MapHandles const& receiver_maps,
@@ -84,6 +85,7 @@ class PropertyAccessInfo final {
                                              MaybeHandle<JSObject> holder);
   static PropertyAccessInfo ModuleExport(MapHandles const& receiver_maps,
                                          Handle<Cell> cell);
+  static PropertyAccessInfo StringLength(MapHandles const& receiver_maps);
 
   PropertyAccessInfo();
 
@@ -98,6 +100,7 @@ class PropertyAccessInfo final {
   bool IsDataConstantField() const { return kind() == kDataConstantField; }
   bool IsAccessorConstant() const { return kind() == kAccessorConstant; }
   bool IsModuleExport() const { return kind() == kModuleExport; }
+  bool IsStringLength() const { return kind() == kStringLength; }
 
   bool HasTransitionMap() const { return !transition_map().is_null(); }
 
@@ -115,7 +118,7 @@ class PropertyAccessInfo final {
   Handle<Cell> export_cell() const;
 
  private:
-  PropertyAccessInfo(MaybeHandle<JSObject> holder,
+  PropertyAccessInfo(Kind kind, MaybeHandle<JSObject> holder,
                      MapHandles const& receiver_maps);
   PropertyAccessInfo(Kind kind, MaybeHandle<JSObject> holder,
                      Handle<Object> constant, MapHandles const& receiver_maps);
diff --git a/deps/v8/src/compiler/allocation-builder.h b/deps/v8/src/compiler/allocation-builder.h
index 4aabac1c11..6943e3ae78 100644
--- a/deps/v8/src/compiler/allocation-builder.h
+++ b/deps/v8/src/compiler/allocation-builder.h
@@ -50,7 +50,7 @@ class AllocationBuilder final {
 
   // Compound allocation of a context.
   void AllocateContext(int length, Handle<Map> map) {
-    DCHECK(map->instance_type() >= BLOCK_CONTEXT_TYPE &&
+    DCHECK(map->instance_type() >= AWAIT_CONTEXT_TYPE &&
            map->instance_type() <= WITH_CONTEXT_TYPE);
     int size = FixedArray::SizeFor(length);
     Allocate(size, NOT_TENURED, Type::OtherInternal());
diff --git a/deps/v8/src/compiler/arm/code-generator-arm.cc b/deps/v8/src/compiler/arm/code-generator-arm.cc
index 8e1c1ab8f4..718272b2cc 100644
--- a/deps/v8/src/compiler/arm/code-generator-arm.cc
+++ b/deps/v8/src/compiler/arm/code-generator-arm.cc
@@ -125,6 +125,9 @@ class ArmOperandConverter final : public InstructionOperandConverter {
         return Operand::EmbeddedNumber(constant.ToFloat64().value());
       case Constant::kExternalReference:
         return Operand(constant.ToExternalReference());
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kInt64:
       case Constant::kHeapObject:
       // TODO(dcarney): loading RPO constants on arm.
@@ -416,48 +419,39 @@ void ComputePoisonedAddressForLoad(CodeGenerator* codegen,
     __ dmb(ISH);                                                             \
   } while (0)
 
-#define ASSEMBLE_ATOMIC64_ARITH_BINOP(instr1, instr2)                       \
-  do {                                                                      \
-    Label binop;                                                            \
-    __ add(i.TempRegister(0), i.InputRegister(2), i.InputRegister(3));      \
-    __ dmb(ISH);                                                            \
-    __ bind(&binop);                                                        \
-    __ ldrexd(i.OutputRegister(0), i.OutputRegister(1), i.TempRegister(0)); \
-    __ instr1(i.TempRegister(1), i.OutputRegister(0), i.InputRegister(0),   \
-              SBit::SetCC);                                                 \
-    __ instr2(i.TempRegister(2), i.OutputRegister(1),                       \
-              Operand(i.InputRegister(1)));                                 \
-    DCHECK_EQ(LeaveCC, i.OutputSBit());                                     \
-    __ strexd(i.TempRegister(3), i.TempRegister(1), i.TempRegister(2),      \
-              i.TempRegister(0));                                           \
-    __ teq(i.TempRegister(3), Operand(0));                                  \
-    __ b(ne, &binop);                                                       \
-    __ dmb(ISH);                                                            \
+#define ASSEMBLE_ATOMIC64_ARITH_BINOP(instr1, instr2)                  \
+  do {                                                                 \
+    Label binop;                                                       \
+    __ add(i.TempRegister(0), i.InputRegister(2), i.InputRegister(3)); \
+    __ dmb(ISH);                                                       \
+    __ bind(&binop);                                                   \
+    __ ldrexd(r2, r3, i.TempRegister(0));                              \
+    __ instr1(i.TempRegister(1), r2, i.InputRegister(0), SBit::SetCC); \
+    __ instr2(i.TempRegister(2), r3, Operand(i.InputRegister(1)));     \
+    DCHECK_EQ(LeaveCC, i.OutputSBit());                                \
+    __ strexd(i.TempRegister(3), i.TempRegister(1), i.TempRegister(2), \
+              i.TempRegister(0));                                      \
+    __ teq(i.TempRegister(3), Operand(0));                             \
+    __ b(ne, &binop);                                                  \
+    __ dmb(ISH);                                                       \
   } while (0)
 
-#define ASSEMBLE_ATOMIC64_LOGIC_BINOP(instr)                                \
-  do {                                                                      \
-    Label binop;                                                            \
-    __ add(i.TempRegister(0), i.InputRegister(2), i.InputRegister(3));      \
-    __ dmb(ISH);                                                            \
-    __ bind(&binop);                                                        \
-    __ ldrexd(i.OutputRegister(0), i.OutputRegister(1), i.TempRegister(0)); \
-    __ instr(i.TempRegister(1), i.OutputRegister(0),                        \
-             Operand(i.InputRegister(0)));                                  \
-    __ instr(i.TempRegister(2), i.OutputRegister(1),                        \
-             Operand(i.InputRegister(1)));                                  \
-    __ strexd(i.TempRegister(3), i.TempRegister(1), i.TempRegister(2),      \
-              i.TempRegister(0));                                           \
-    __ teq(i.TempRegister(3), Operand(0));                                  \
-    __ b(ne, &binop);                                                       \
-    __ dmb(ISH);                                                            \
+#define ASSEMBLE_ATOMIC64_LOGIC_BINOP(instr)                           \
+  do {                                                                 \
+    Label binop;                                                       \
+    __ add(i.TempRegister(0), i.InputRegister(2), i.InputRegister(3)); \
+    __ dmb(ISH);                                                       \
+    __ bind(&binop);                                                   \
+    __ ldrexd(r2, r3, i.TempRegister(0));                              \
+    __ instr(i.TempRegister(1), r2, Operand(i.InputRegister(0)));      \
+    __ instr(i.TempRegister(2), r3, Operand(i.InputRegister(1)));      \
+    __ strexd(i.TempRegister(3), i.TempRegister(1), i.TempRegister(2), \
+              i.TempRegister(0));                                      \
+    __ teq(i.TempRegister(3), Operand(0));                             \
+    __ b(ne, &binop);                                                  \
+    __ dmb(ISH);                                                       \
   } while (0)
 
-#define ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(op)       \
-  if (arch_opcode == kArmWord64AtomicNarrow##op) { \
-    __ mov(i.OutputRegister(1), Operand(0));       \
-  }
-
 #define ASSEMBLE_IEEE754_BINOP(name)                                           \
   do {                                                                         \
     /* TODO(bmeurer): We should really get rid of this special instruction, */ \
@@ -607,6 +601,19 @@ void AdjustStackPointerForTailCall(
   }
 }
 
+#if DEBUG
+bool VerifyOutputOfAtomicPairInstr(ArmOperandConverter* converter,
+                                   const Instruction* instr, Register low,
+                                   Register high) {
+  if (instr->OutputCount() > 0) {
+    if (converter->OutputRegister(0) != low) return false;
+    if (instr->OutputCount() == 2 && converter->OutputRegister(1) != high)
+      return false;
+  }
+  return true;
+}
+#endif
+
 }  // namespace
 
 void CodeGenerator::AssembleTailCallBeforeGap(Instruction* instr,
@@ -2684,23 +2691,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ sxtb(i.OutputRegister(0), i.OutputRegister(0));
       break;
     case kWord32AtomicExchangeUint8:
-    case kArmWord64AtomicNarrowExchangeUint8:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(ldrexb, strexb);
-      ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(ExchangeUint8);
       break;
     case kWord32AtomicExchangeInt16:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(ldrexh, strexh);
       __ sxth(i.OutputRegister(0), i.OutputRegister(0));
       break;
     case kWord32AtomicExchangeUint16:
-    case kArmWord64AtomicNarrowExchangeUint16:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(ldrexh, strexh);
-      ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(ExchangeUint16);
       break;
     case kWord32AtomicExchangeWord32:
-    case kArmWord64AtomicNarrowExchangeUint32:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(ldrex, strex);
-      ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(ExchangeUint32);
       break;
     case kWord32AtomicCompareExchangeInt8:
       __ add(i.TempRegister(1), i.InputRegister(0), i.InputRegister(1));
@@ -2710,12 +2711,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ sxtb(i.OutputRegister(0), i.OutputRegister(0));
       break;
     case kWord32AtomicCompareExchangeUint8:
-    case kArmWord64AtomicNarrowCompareExchangeUint8:
       __ add(i.TempRegister(1), i.InputRegister(0), i.InputRegister(1));
       __ uxtb(i.TempRegister(2), i.InputRegister(2));
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER(ldrexb, strexb,
                                                i.TempRegister(2));
-      ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(CompareExchangeUint8);
       break;
     case kWord32AtomicCompareExchangeInt16:
       __ add(i.TempRegister(1), i.InputRegister(0), i.InputRegister(1));
@@ -2725,19 +2724,15 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ sxth(i.OutputRegister(0), i.OutputRegister(0));
       break;
     case kWord32AtomicCompareExchangeUint16:
-    case kArmWord64AtomicNarrowCompareExchangeUint16:
       __ add(i.TempRegister(1), i.InputRegister(0), i.InputRegister(1));
       __ uxth(i.TempRegister(2), i.InputRegister(2));
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER(ldrexh, strexh,
                                                i.TempRegister(2));
-      ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(CompareExchangeUint16);
       break;
     case kWord32AtomicCompareExchangeWord32:
-    case kArmWord64AtomicNarrowCompareExchangeUint32:
       __ add(i.TempRegister(1), i.InputRegister(0), i.InputRegister(1));
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER(ldrex, strex,
                                                i.InputRegister(2));
-      ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(CompareExchangeUint32);
       break;
 #define ATOMIC_BINOP_CASE(op, inst)                    \
   case kWord32Atomic##op##Int8:                        \
@@ -2745,23 +2740,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     __ sxtb(i.OutputRegister(0), i.OutputRegister(0)); \
     break;                                             \
   case kWord32Atomic##op##Uint8:                       \
-  case kArmWord64AtomicNarrow##op##Uint8:              \
     ASSEMBLE_ATOMIC_BINOP(ldrexb, strexb, inst);       \
-    ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(op##Uint8);       \
     break;                                             \
   case kWord32Atomic##op##Int16:                       \
     ASSEMBLE_ATOMIC_BINOP(ldrexh, strexh, inst);       \
     __ sxth(i.OutputRegister(0), i.OutputRegister(0)); \
     break;                                             \
   case kWord32Atomic##op##Uint16:                      \
-  case kArmWord64AtomicNarrow##op##Uint16:             \
     ASSEMBLE_ATOMIC_BINOP(ldrexh, strexh, inst);       \
-    ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(op##Uint16);      \
     break;                                             \
   case kWord32Atomic##op##Word32:                      \
-  case kArmWord64AtomicNarrow##op##Uint32:             \
     ASSEMBLE_ATOMIC_BINOP(ldrex, strex, inst);         \
-    ATOMIC_NARROW_OP_CLEAR_HIGH_WORD(op##Uint32);      \
     break;
       ATOMIC_BINOP_CASE(Add, add)
       ATOMIC_BINOP_CASE(Sub, sub)
@@ -2769,11 +2758,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ATOMIC_BINOP_CASE(Or, orr)
       ATOMIC_BINOP_CASE(Xor, eor)
 #undef ATOMIC_BINOP_CASE
-    case kArmWord32AtomicPairLoad:
+    case kArmWord32AtomicPairLoad: {
+      DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr, r0, r1));
       __ add(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));
-      __ ldrexd(i.OutputRegister(0), i.OutputRegister(1), i.TempRegister(0));
+      __ ldrexd(r0, r1, i.TempRegister(0));
       __ dmb(ISH);
       break;
+    }
     case kArmWord32AtomicPairStore: {
       Label store;
       __ add(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));
@@ -2787,28 +2778,32 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ dmb(ISH);
       break;
     }
-#define ATOMIC_ARITH_BINOP_CASE(op, instr1, instr2) \
-  case kArmWord32AtomicPair##op: {                  \
-    ASSEMBLE_ATOMIC64_ARITH_BINOP(instr1, instr2);  \
-    break;                                          \
+#define ATOMIC_ARITH_BINOP_CASE(op, instr1, instr2)           \
+  case kArmWord32AtomicPair##op: {                            \
+    DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr, r2, r3)); \
+    ASSEMBLE_ATOMIC64_ARITH_BINOP(instr1, instr2);            \
+    break;                                                    \
   }
       ATOMIC_ARITH_BINOP_CASE(Add, add, adc)
       ATOMIC_ARITH_BINOP_CASE(Sub, sub, sbc)
 #undef ATOMIC_ARITH_BINOP_CASE
-#define ATOMIC_LOGIC_BINOP_CASE(op, instr) \
-  case kArmWord32AtomicPair##op: {         \
-    ASSEMBLE_ATOMIC64_LOGIC_BINOP(instr);  \
-    break;                                 \
+#define ATOMIC_LOGIC_BINOP_CASE(op, instr1)                   \
+  case kArmWord32AtomicPair##op: {                            \
+    DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr, r2, r3)); \
+    ASSEMBLE_ATOMIC64_LOGIC_BINOP(instr1);                    \
+    break;                                                    \
   }
       ATOMIC_LOGIC_BINOP_CASE(And, and_)
       ATOMIC_LOGIC_BINOP_CASE(Or, orr)
       ATOMIC_LOGIC_BINOP_CASE(Xor, eor)
+#undef ATOMIC_LOGIC_BINOP_CASE
     case kArmWord32AtomicPairExchange: {
+      DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr, r6, r7));
       Label exchange;
       __ add(i.TempRegister(0), i.InputRegister(2), i.InputRegister(3));
       __ dmb(ISH);
       __ bind(&exchange);
-      __ ldrexd(i.OutputRegister(0), i.OutputRegister(1), i.TempRegister(0));
+      __ ldrexd(r6, r7, i.TempRegister(0));
       __ strexd(i.TempRegister(1), i.InputRegister(0), i.InputRegister(1),
                 i.TempRegister(0));
       __ teq(i.TempRegister(1), Operand(0));
@@ -2817,15 +2812,16 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmWord32AtomicPairCompareExchange: {
+      DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr, r2, r3));
       __ add(i.TempRegister(0), i.InputRegister(4), i.InputRegister(5));
       Label compareExchange;
       Label exit;
       __ dmb(ISH);
       __ bind(&compareExchange);
-      __ ldrexd(i.OutputRegister(0), i.OutputRegister(1), i.TempRegister(0));
-      __ teq(i.InputRegister(0), Operand(i.OutputRegister(0)));
+      __ ldrexd(r2, r3, i.TempRegister(0));
+      __ teq(i.InputRegister(0), Operand(r2));
       __ b(ne, &exit);
-      __ teq(i.InputRegister(1), Operand(i.OutputRegister(1)));
+      __ teq(i.InputRegister(1), Operand(r3));
       __ b(ne, &exit);
       __ strexd(i.TempRegister(1), i.InputRegister(2), i.InputRegister(3),
                 i.TempRegister(0));
@@ -2835,8 +2831,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ dmb(ISH);
       break;
     }
-#undef ATOMIC_LOGIC_BINOP_CASE
-#undef ATOMIC_NARROW_OP_CLEAR_HIGH_WORD
 #undef ASSEMBLE_ATOMIC_LOAD_INTEGER
 #undef ASSEMBLE_ATOMIC_STORE_INTEGER
 #undef ASSEMBLE_ATOMIC_EXCHANGE_INTEGER
@@ -3192,7 +3186,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
   auto MoveConstantToRegister = [&](Register dst, Constant src) {
     if (src.type() == Constant::kHeapObject) {
       Handle<HeapObject> src_object = src.ToHeapObject();
-      Heap::RootListIndex index;
+      RootIndex index;
       if (IsMaterializableFromRoot(src_object, &index)) {
         __ LoadRoot(dst, index);
       } else {
diff --git a/deps/v8/src/compiler/arm/instruction-codes-arm.h b/deps/v8/src/compiler/arm/instruction-codes-arm.h
index ca8684a375..751530e206 100644
--- a/deps/v8/src/compiler/arm/instruction-codes-arm.h
+++ b/deps/v8/src/compiler/arm/instruction-codes-arm.h
@@ -11,295 +11,274 @@ namespace compiler {
 
 // ARM-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
-#define TARGET_ARCH_OPCODE_LIST(V)              \
-  V(ArmAdd)                                     \
-  V(ArmAnd)                                     \
-  V(ArmBic)                                     \
-  V(ArmClz)                                     \
-  V(ArmCmp)                                     \
-  V(ArmCmn)                                     \
-  V(ArmTst)                                     \
-  V(ArmTeq)                                     \
-  V(ArmOrr)                                     \
-  V(ArmEor)                                     \
-  V(ArmSub)                                     \
-  V(ArmRsb)                                     \
-  V(ArmMul)                                     \
-  V(ArmMla)                                     \
-  V(ArmMls)                                     \
-  V(ArmSmull)                                   \
-  V(ArmSmmul)                                   \
-  V(ArmSmmla)                                   \
-  V(ArmUmull)                                   \
-  V(ArmSdiv)                                    \
-  V(ArmUdiv)                                    \
-  V(ArmMov)                                     \
-  V(ArmMvn)                                     \
-  V(ArmBfc)                                     \
-  V(ArmUbfx)                                    \
-  V(ArmSbfx)                                    \
-  V(ArmSxtb)                                    \
-  V(ArmSxth)                                    \
-  V(ArmSxtab)                                   \
-  V(ArmSxtah)                                   \
-  V(ArmUxtb)                                    \
-  V(ArmUxth)                                    \
-  V(ArmUxtab)                                   \
-  V(ArmRbit)                                    \
-  V(ArmRev)                                     \
-  V(ArmUxtah)                                   \
-  V(ArmAddPair)                                 \
-  V(ArmSubPair)                                 \
-  V(ArmMulPair)                                 \
-  V(ArmLslPair)                                 \
-  V(ArmLsrPair)                                 \
-  V(ArmAsrPair)                                 \
-  V(ArmVcmpF32)                                 \
-  V(ArmVaddF32)                                 \
-  V(ArmVsubF32)                                 \
-  V(ArmVmulF32)                                 \
-  V(ArmVmlaF32)                                 \
-  V(ArmVmlsF32)                                 \
-  V(ArmVdivF32)                                 \
-  V(ArmVabsF32)                                 \
-  V(ArmVnegF32)                                 \
-  V(ArmVsqrtF32)                                \
-  V(ArmVcmpF64)                                 \
-  V(ArmVaddF64)                                 \
-  V(ArmVsubF64)                                 \
-  V(ArmVmulF64)                                 \
-  V(ArmVmlaF64)                                 \
-  V(ArmVmlsF64)                                 \
-  V(ArmVdivF64)                                 \
-  V(ArmVmodF64)                                 \
-  V(ArmVabsF64)                                 \
-  V(ArmVnegF64)                                 \
-  V(ArmVsqrtF64)                                \
-  V(ArmVrintmF32)                               \
-  V(ArmVrintmF64)                               \
-  V(ArmVrintpF32)                               \
-  V(ArmVrintpF64)                               \
-  V(ArmVrintzF32)                               \
-  V(ArmVrintzF64)                               \
-  V(ArmVrintaF64)                               \
-  V(ArmVrintnF32)                               \
-  V(ArmVrintnF64)                               \
-  V(ArmVcvtF32F64)                              \
-  V(ArmVcvtF64F32)                              \
-  V(ArmVcvtF32S32)                              \
-  V(ArmVcvtF32U32)                              \
-  V(ArmVcvtF64S32)                              \
-  V(ArmVcvtF64U32)                              \
-  V(ArmVcvtS32F32)                              \
-  V(ArmVcvtU32F32)                              \
-  V(ArmVcvtS32F64)                              \
-  V(ArmVcvtU32F64)                              \
-  V(ArmVmovU32F32)                              \
-  V(ArmVmovF32U32)                              \
-  V(ArmVmovLowU32F64)                           \
-  V(ArmVmovLowF64U32)                           \
-  V(ArmVmovHighU32F64)                          \
-  V(ArmVmovHighF64U32)                          \
-  V(ArmVmovF64U32U32)                           \
-  V(ArmVmovU32U32F64)                           \
-  V(ArmVldrF32)                                 \
-  V(ArmVstrF32)                                 \
-  V(ArmVldrF64)                                 \
-  V(ArmVld1F64)                                 \
-  V(ArmVstrF64)                                 \
-  V(ArmVst1F64)                                 \
-  V(ArmVld1S128)                                \
-  V(ArmVst1S128)                                \
-  V(ArmFloat32Max)                              \
-  V(ArmFloat64Max)                              \
-  V(ArmFloat32Min)                              \
-  V(ArmFloat64Min)                              \
-  V(ArmFloat64SilenceNaN)                       \
-  V(ArmLdrb)                                    \
-  V(ArmLdrsb)                                   \
-  V(ArmStrb)                                    \
-  V(ArmLdrh)                                    \
-  V(ArmLdrsh)                                   \
-  V(ArmStrh)                                    \
-  V(ArmLdr)                                     \
-  V(ArmStr)                                     \
-  V(ArmPush)                                    \
-  V(ArmPoke)                                    \
-  V(ArmPeek)                                    \
-  V(ArmDsbIsb)                                  \
-  V(ArmF32x4Splat)                              \
-  V(ArmF32x4ExtractLane)                        \
-  V(ArmF32x4ReplaceLane)                        \
-  V(ArmF32x4SConvertI32x4)                      \
-  V(ArmF32x4UConvertI32x4)                      \
-  V(ArmF32x4Abs)                                \
-  V(ArmF32x4Neg)                                \
-  V(ArmF32x4RecipApprox)                        \
-  V(ArmF32x4RecipSqrtApprox)                    \
-  V(ArmF32x4Add)                                \
-  V(ArmF32x4AddHoriz)                           \
-  V(ArmF32x4Sub)                                \
-  V(ArmF32x4Mul)                                \
-  V(ArmF32x4Min)                                \
-  V(ArmF32x4Max)                                \
-  V(ArmF32x4Eq)                                 \
-  V(ArmF32x4Ne)                                 \
-  V(ArmF32x4Lt)                                 \
-  V(ArmF32x4Le)                                 \
-  V(ArmI32x4Splat)                              \
-  V(ArmI32x4ExtractLane)                        \
-  V(ArmI32x4ReplaceLane)                        \
-  V(ArmI32x4SConvertF32x4)                      \
-  V(ArmI32x4SConvertI16x8Low)                   \
-  V(ArmI32x4SConvertI16x8High)                  \
-  V(ArmI32x4Neg)                                \
-  V(ArmI32x4Shl)                                \
-  V(ArmI32x4ShrS)                               \
-  V(ArmI32x4Add)                                \
-  V(ArmI32x4AddHoriz)                           \
-  V(ArmI32x4Sub)                                \
-  V(ArmI32x4Mul)                                \
-  V(ArmI32x4MinS)                               \
-  V(ArmI32x4MaxS)                               \
-  V(ArmI32x4Eq)                                 \
-  V(ArmI32x4Ne)                                 \
-  V(ArmI32x4GtS)                                \
-  V(ArmI32x4GeS)                                \
-  V(ArmI32x4UConvertF32x4)                      \
-  V(ArmI32x4UConvertI16x8Low)                   \
-  V(ArmI32x4UConvertI16x8High)                  \
-  V(ArmI32x4ShrU)                               \
-  V(ArmI32x4MinU)                               \
-  V(ArmI32x4MaxU)                               \
-  V(ArmI32x4GtU)                                \
-  V(ArmI32x4GeU)                                \
-  V(ArmI16x8Splat)                              \
-  V(ArmI16x8ExtractLane)                        \
-  V(ArmI16x8ReplaceLane)                        \
-  V(ArmI16x8SConvertI8x16Low)                   \
-  V(ArmI16x8SConvertI8x16High)                  \
-  V(ArmI16x8Neg)                                \
-  V(ArmI16x8Shl)                                \
-  V(ArmI16x8ShrS)                               \
-  V(ArmI16x8SConvertI32x4)                      \
-  V(ArmI16x8Add)                                \
-  V(ArmI16x8AddSaturateS)                       \
-  V(ArmI16x8AddHoriz)                           \
-  V(ArmI16x8Sub)                                \
-  V(ArmI16x8SubSaturateS)                       \
-  V(ArmI16x8Mul)                                \
-  V(ArmI16x8MinS)                               \
-  V(ArmI16x8MaxS)                               \
-  V(ArmI16x8Eq)                                 \
-  V(ArmI16x8Ne)                                 \
-  V(ArmI16x8GtS)                                \
-  V(ArmI16x8GeS)                                \
-  V(ArmI16x8UConvertI8x16Low)                   \
-  V(ArmI16x8UConvertI8x16High)                  \
-  V(ArmI16x8ShrU)                               \
-  V(ArmI16x8UConvertI32x4)                      \
-  V(ArmI16x8AddSaturateU)                       \
-  V(ArmI16x8SubSaturateU)                       \
-  V(ArmI16x8MinU)                               \
-  V(ArmI16x8MaxU)                               \
-  V(ArmI16x8GtU)                                \
-  V(ArmI16x8GeU)                                \
-  V(ArmI8x16Splat)                              \
-  V(ArmI8x16ExtractLane)                        \
-  V(ArmI8x16ReplaceLane)                        \
-  V(ArmI8x16Neg)                                \
-  V(ArmI8x16Shl)                                \
-  V(ArmI8x16ShrS)                               \
-  V(ArmI8x16SConvertI16x8)                      \
-  V(ArmI8x16Add)                                \
-  V(ArmI8x16AddSaturateS)                       \
-  V(ArmI8x16Sub)                                \
-  V(ArmI8x16SubSaturateS)                       \
-  V(ArmI8x16Mul)                                \
-  V(ArmI8x16MinS)                               \
-  V(ArmI8x16MaxS)                               \
-  V(ArmI8x16Eq)                                 \
-  V(ArmI8x16Ne)                                 \
-  V(ArmI8x16GtS)                                \
-  V(ArmI8x16GeS)                                \
-  V(ArmI8x16ShrU)                               \
-  V(ArmI8x16UConvertI16x8)                      \
-  V(ArmI8x16AddSaturateU)                       \
-  V(ArmI8x16SubSaturateU)                       \
-  V(ArmI8x16MinU)                               \
-  V(ArmI8x16MaxU)                               \
-  V(ArmI8x16GtU)                                \
-  V(ArmI8x16GeU)                                \
-  V(ArmS128Zero)                                \
-  V(ArmS128Dup)                                 \
-  V(ArmS128And)                                 \
-  V(ArmS128Or)                                  \
-  V(ArmS128Xor)                                 \
-  V(ArmS128Not)                                 \
-  V(ArmS128Select)                              \
-  V(ArmS32x4ZipLeft)                            \
-  V(ArmS32x4ZipRight)                           \
-  V(ArmS32x4UnzipLeft)                          \
-  V(ArmS32x4UnzipRight)                         \
-  V(ArmS32x4TransposeLeft)                      \
-  V(ArmS32x4TransposeRight)                     \
-  V(ArmS32x4Shuffle)                            \
-  V(ArmS16x8ZipLeft)                            \
-  V(ArmS16x8ZipRight)                           \
-  V(ArmS16x8UnzipLeft)                          \
-  V(ArmS16x8UnzipRight)                         \
-  V(ArmS16x8TransposeLeft)                      \
-  V(ArmS16x8TransposeRight)                     \
-  V(ArmS8x16ZipLeft)                            \
-  V(ArmS8x16ZipRight)                           \
-  V(ArmS8x16UnzipLeft)                          \
-  V(ArmS8x16UnzipRight)                         \
-  V(ArmS8x16TransposeLeft)                      \
-  V(ArmS8x16TransposeRight)                     \
-  V(ArmS8x16Concat)                             \
-  V(ArmS8x16Shuffle)                            \
-  V(ArmS32x2Reverse)                            \
-  V(ArmS16x4Reverse)                            \
-  V(ArmS16x2Reverse)                            \
-  V(ArmS8x8Reverse)                             \
-  V(ArmS8x4Reverse)                             \
-  V(ArmS8x2Reverse)                             \
-  V(ArmS1x4AnyTrue)                             \
-  V(ArmS1x4AllTrue)                             \
-  V(ArmS1x8AnyTrue)                             \
-  V(ArmS1x8AllTrue)                             \
-  V(ArmS1x16AnyTrue)                            \
-  V(ArmS1x16AllTrue)                            \
-  V(ArmWord32AtomicPairLoad)                    \
-  V(ArmWord32AtomicPairStore)                   \
-  V(ArmWord32AtomicPairAdd)                     \
-  V(ArmWord32AtomicPairSub)                     \
-  V(ArmWord32AtomicPairAnd)                     \
-  V(ArmWord32AtomicPairOr)                      \
-  V(ArmWord32AtomicPairXor)                     \
-  V(ArmWord32AtomicPairExchange)                \
-  V(ArmWord32AtomicPairCompareExchange)         \
-  V(ArmWord64AtomicNarrowAddUint8)              \
-  V(ArmWord64AtomicNarrowAddUint16)             \
-  V(ArmWord64AtomicNarrowAddUint32)             \
-  V(ArmWord64AtomicNarrowSubUint8)              \
-  V(ArmWord64AtomicNarrowSubUint16)             \
-  V(ArmWord64AtomicNarrowSubUint32)             \
-  V(ArmWord64AtomicNarrowAndUint8)              \
-  V(ArmWord64AtomicNarrowAndUint16)             \
-  V(ArmWord64AtomicNarrowAndUint32)             \
-  V(ArmWord64AtomicNarrowOrUint8)               \
-  V(ArmWord64AtomicNarrowOrUint16)              \
-  V(ArmWord64AtomicNarrowOrUint32)              \
-  V(ArmWord64AtomicNarrowXorUint8)              \
-  V(ArmWord64AtomicNarrowXorUint16)             \
-  V(ArmWord64AtomicNarrowXorUint32)             \
-  V(ArmWord64AtomicNarrowExchangeUint8)         \
-  V(ArmWord64AtomicNarrowExchangeUint16)        \
-  V(ArmWord64AtomicNarrowExchangeUint32)        \
-  V(ArmWord64AtomicNarrowCompareExchangeUint8)  \
-  V(ArmWord64AtomicNarrowCompareExchangeUint16) \
-  V(ArmWord64AtomicNarrowCompareExchangeUint32)
+#define TARGET_ARCH_OPCODE_LIST(V) \
+  V(ArmAdd)                        \
+  V(ArmAnd)                        \
+  V(ArmBic)                        \
+  V(ArmClz)                        \
+  V(ArmCmp)                        \
+  V(ArmCmn)                        \
+  V(ArmTst)                        \
+  V(ArmTeq)                        \
+  V(ArmOrr)                        \
+  V(ArmEor)                        \
+  V(ArmSub)                        \
+  V(ArmRsb)                        \
+  V(ArmMul)                        \
+  V(ArmMla)                        \
+  V(ArmMls)                        \
+  V(ArmSmull)                      \
+  V(ArmSmmul)                      \
+  V(ArmSmmla)                      \
+  V(ArmUmull)                      \
+  V(ArmSdiv)                       \
+  V(ArmUdiv)                       \
+  V(ArmMov)                        \
+  V(ArmMvn)                        \
+  V(ArmBfc)                        \
+  V(ArmUbfx)                       \
+  V(ArmSbfx)                       \
+  V(ArmSxtb)                       \
+  V(ArmSxth)                       \
+  V(ArmSxtab)                      \
+  V(ArmSxtah)                      \
+  V(ArmUxtb)                       \
+  V(ArmUxth)                       \
+  V(ArmUxtab)                      \
+  V(ArmRbit)                       \
+  V(ArmRev)                        \
+  V(ArmUxtah)                      \
+  V(ArmAddPair)                    \
+  V(ArmSubPair)                    \
+  V(ArmMulPair)                    \
+  V(ArmLslPair)                    \
+  V(ArmLsrPair)                    \
+  V(ArmAsrPair)                    \
+  V(ArmVcmpF32)                    \
+  V(ArmVaddF32)                    \
+  V(ArmVsubF32)                    \
+  V(ArmVmulF32)                    \
+  V(ArmVmlaF32)                    \
+  V(ArmVmlsF32)                    \
+  V(ArmVdivF32)                    \
+  V(ArmVabsF32)                    \
+  V(ArmVnegF32)                    \
+  V(ArmVsqrtF32)                   \
+  V(ArmVcmpF64)                    \
+  V(ArmVaddF64)                    \
+  V(ArmVsubF64)                    \
+  V(ArmVmulF64)                    \
+  V(ArmVmlaF64)                    \
+  V(ArmVmlsF64)                    \
+  V(ArmVdivF64)                    \
+  V(ArmVmodF64)                    \
+  V(ArmVabsF64)                    \
+  V(ArmVnegF64)                    \
+  V(ArmVsqrtF64)                   \
+  V(ArmVrintmF32)                  \
+  V(ArmVrintmF64)                  \
+  V(ArmVrintpF32)                  \
+  V(ArmVrintpF64)                  \
+  V(ArmVrintzF32)                  \
+  V(ArmVrintzF64)                  \
+  V(ArmVrintaF64)                  \
+  V(ArmVrintnF32)                  \
+  V(ArmVrintnF64)                  \
+  V(ArmVcvtF32F64)                 \
+  V(ArmVcvtF64F32)                 \
+  V(ArmVcvtF32S32)                 \
+  V(ArmVcvtF32U32)                 \
+  V(ArmVcvtF64S32)                 \
+  V(ArmVcvtF64U32)                 \
+  V(ArmVcvtS32F32)                 \
+  V(ArmVcvtU32F32)                 \
+  V(ArmVcvtS32F64)                 \
+  V(ArmVcvtU32F64)                 \
+  V(ArmVmovU32F32)                 \
+  V(ArmVmovF32U32)                 \
+  V(ArmVmovLowU32F64)              \
+  V(ArmVmovLowF64U32)              \
+  V(ArmVmovHighU32F64)             \
+  V(ArmVmovHighF64U32)             \
+  V(ArmVmovF64U32U32)              \
+  V(ArmVmovU32U32F64)              \
+  V(ArmVldrF32)                    \
+  V(ArmVstrF32)                    \
+  V(ArmVldrF64)                    \
+  V(ArmVld1F64)                    \
+  V(ArmVstrF64)                    \
+  V(ArmVst1F64)                    \
+  V(ArmVld1S128)                   \
+  V(ArmVst1S128)                   \
+  V(ArmFloat32Max)                 \
+  V(ArmFloat64Max)                 \
+  V(ArmFloat32Min)                 \
+  V(ArmFloat64Min)                 \
+  V(ArmFloat64SilenceNaN)          \
+  V(ArmLdrb)                       \
+  V(ArmLdrsb)                      \
+  V(ArmStrb)                       \
+  V(ArmLdrh)                       \
+  V(ArmLdrsh)                      \
+  V(ArmStrh)                       \
+  V(ArmLdr)                        \
+  V(ArmStr)                        \
+  V(ArmPush)                       \
+  V(ArmPoke)                       \
+  V(ArmPeek)                       \
+  V(ArmDsbIsb)                     \
+  V(ArmF32x4Splat)                 \
+  V(ArmF32x4ExtractLane)           \
+  V(ArmF32x4ReplaceLane)           \
+  V(ArmF32x4SConvertI32x4)         \
+  V(ArmF32x4UConvertI32x4)         \
+  V(ArmF32x4Abs)                   \
+  V(ArmF32x4Neg)                   \
+  V(ArmF32x4RecipApprox)           \
+  V(ArmF32x4RecipSqrtApprox)       \
+  V(ArmF32x4Add)                   \
+  V(ArmF32x4AddHoriz)              \
+  V(ArmF32x4Sub)                   \
+  V(ArmF32x4Mul)                   \
+  V(ArmF32x4Min)                   \
+  V(ArmF32x4Max)                   \
+  V(ArmF32x4Eq)                    \
+  V(ArmF32x4Ne)                    \
+  V(ArmF32x4Lt)                    \
+  V(ArmF32x4Le)                    \
+  V(ArmI32x4Splat)                 \
+  V(ArmI32x4ExtractLane)           \
+  V(ArmI32x4ReplaceLane)           \
+  V(ArmI32x4SConvertF32x4)         \
+  V(ArmI32x4SConvertI16x8Low)      \
+  V(ArmI32x4SConvertI16x8High)     \
+  V(ArmI32x4Neg)                   \
+  V(ArmI32x4Shl)                   \
+  V(ArmI32x4ShrS)                  \
+  V(ArmI32x4Add)                   \
+  V(ArmI32x4AddHoriz)              \
+  V(ArmI32x4Sub)                   \
+  V(ArmI32x4Mul)                   \
+  V(ArmI32x4MinS)                  \
+  V(ArmI32x4MaxS)                  \
+  V(ArmI32x4Eq)                    \
+  V(ArmI32x4Ne)                    \
+  V(ArmI32x4GtS)                   \
+  V(ArmI32x4GeS)                   \
+  V(ArmI32x4UConvertF32x4)         \
+  V(ArmI32x4UConvertI16x8Low)      \
+  V(ArmI32x4UConvertI16x8High)     \
+  V(ArmI32x4ShrU)                  \
+  V(ArmI32x4MinU)                  \
+  V(ArmI32x4MaxU)                  \
+  V(ArmI32x4GtU)                   \
+  V(ArmI32x4GeU)                   \
+  V(ArmI16x8Splat)                 \
+  V(ArmI16x8ExtractLane)           \
+  V(ArmI16x8ReplaceLane)           \
+  V(ArmI16x8SConvertI8x16Low)      \
+  V(ArmI16x8SConvertI8x16High)     \
+  V(ArmI16x8Neg)                   \
+  V(ArmI16x8Shl)                   \
+  V(ArmI16x8ShrS)                  \
+  V(ArmI16x8SConvertI32x4)         \
+  V(ArmI16x8Add)                   \
+  V(ArmI16x8AddSaturateS)          \
+  V(ArmI16x8AddHoriz)              \
+  V(ArmI16x8Sub)                   \
+  V(ArmI16x8SubSaturateS)          \
+  V(ArmI16x8Mul)                   \
+  V(ArmI16x8MinS)                  \
+  V(ArmI16x8MaxS)                  \
+  V(ArmI16x8Eq)                    \
+  V(ArmI16x8Ne)                    \
+  V(ArmI16x8GtS)                   \
+  V(ArmI16x8GeS)                   \
+  V(ArmI16x8UConvertI8x16Low)      \
+  V(ArmI16x8UConvertI8x16High)     \
+  V(ArmI16x8ShrU)                  \
+  V(ArmI16x8UConvertI32x4)         \
+  V(ArmI16x8AddSaturateU)          \
+  V(ArmI16x8SubSaturateU)          \
+  V(ArmI16x8MinU)                  \
+  V(ArmI16x8MaxU)                  \
+  V(ArmI16x8GtU)                   \
+  V(ArmI16x8GeU)                   \
+  V(ArmI8x16Splat)                 \
+  V(ArmI8x16ExtractLane)           \
+  V(ArmI8x16ReplaceLane)           \
+  V(ArmI8x16Neg)                   \
+  V(ArmI8x16Shl)                   \
+  V(ArmI8x16ShrS)                  \
+  V(ArmI8x16SConvertI16x8)         \
+  V(ArmI8x16Add)                   \
+  V(ArmI8x16AddSaturateS)          \
+  V(ArmI8x16Sub)                   \
+  V(ArmI8x16SubSaturateS)          \
+  V(ArmI8x16Mul)                   \
+  V(ArmI8x16MinS)                  \
+  V(ArmI8x16MaxS)                  \
+  V(ArmI8x16Eq)                    \
+  V(ArmI8x16Ne)                    \
+  V(ArmI8x16GtS)                   \
+  V(ArmI8x16GeS)                   \
+  V(ArmI8x16ShrU)                  \
+  V(ArmI8x16UConvertI16x8)         \
+  V(ArmI8x16AddSaturateU)          \
+  V(ArmI8x16SubSaturateU)          \
+  V(ArmI8x16MinU)                  \
+  V(ArmI8x16MaxU)                  \
+  V(ArmI8x16GtU)                   \
+  V(ArmI8x16GeU)                   \
+  V(ArmS128Zero)                   \
+  V(ArmS128Dup)                    \
+  V(ArmS128And)                    \
+  V(ArmS128Or)                     \
+  V(ArmS128Xor)                    \
+  V(ArmS128Not)                    \
+  V(ArmS128Select)                 \
+  V(ArmS32x4ZipLeft)               \
+  V(ArmS32x4ZipRight)              \
+  V(ArmS32x4UnzipLeft)             \
+  V(ArmS32x4UnzipRight)            \
+  V(ArmS32x4TransposeLeft)         \
+  V(ArmS32x4TransposeRight)        \
+  V(ArmS32x4Shuffle)               \
+  V(ArmS16x8ZipLeft)               \
+  V(ArmS16x8ZipRight)              \
+  V(ArmS16x8UnzipLeft)             \
+  V(ArmS16x8UnzipRight)            \
+  V(ArmS16x8TransposeLeft)         \
+  V(ArmS16x8TransposeRight)        \
+  V(ArmS8x16ZipLeft)               \
+  V(ArmS8x16ZipRight)              \
+  V(ArmS8x16UnzipLeft)             \
+  V(ArmS8x16UnzipRight)            \
+  V(ArmS8x16TransposeLeft)         \
+  V(ArmS8x16TransposeRight)        \
+  V(ArmS8x16Concat)                \
+  V(ArmS8x16Shuffle)               \
+  V(ArmS32x2Reverse)               \
+  V(ArmS16x4Reverse)               \
+  V(ArmS16x2Reverse)               \
+  V(ArmS8x8Reverse)                \
+  V(ArmS8x4Reverse)                \
+  V(ArmS8x2Reverse)                \
+  V(ArmS1x4AnyTrue)                \
+  V(ArmS1x4AllTrue)                \
+  V(ArmS1x8AnyTrue)                \
+  V(ArmS1x8AllTrue)                \
+  V(ArmS1x16AnyTrue)               \
+  V(ArmS1x16AllTrue)               \
+  V(ArmWord32AtomicPairLoad)       \
+  V(ArmWord32AtomicPairStore)      \
+  V(ArmWord32AtomicPairAdd)        \
+  V(ArmWord32AtomicPairSub)        \
+  V(ArmWord32AtomicPairAnd)        \
+  V(ArmWord32AtomicPairOr)         \
+  V(ArmWord32AtomicPairXor)        \
+  V(ArmWord32AtomicPairExchange)   \
+  V(ArmWord32AtomicPairCompareExchange)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/arm/instruction-scheduler-arm.cc b/deps/v8/src/compiler/arm/instruction-scheduler-arm.cc
index 56ff02689a..3de063b3fe 100644
--- a/deps/v8/src/compiler/arm/instruction-scheduler-arm.cc
+++ b/deps/v8/src/compiler/arm/instruction-scheduler-arm.cc
@@ -285,27 +285,6 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArmWord32AtomicPairXor:
     case kArmWord32AtomicPairExchange:
     case kArmWord32AtomicPairCompareExchange:
-    case kArmWord64AtomicNarrowAddUint8:
-    case kArmWord64AtomicNarrowAddUint16:
-    case kArmWord64AtomicNarrowAddUint32:
-    case kArmWord64AtomicNarrowSubUint8:
-    case kArmWord64AtomicNarrowSubUint16:
-    case kArmWord64AtomicNarrowSubUint32:
-    case kArmWord64AtomicNarrowAndUint8:
-    case kArmWord64AtomicNarrowAndUint16:
-    case kArmWord64AtomicNarrowAndUint32:
-    case kArmWord64AtomicNarrowOrUint8:
-    case kArmWord64AtomicNarrowOrUint16:
-    case kArmWord64AtomicNarrowOrUint32:
-    case kArmWord64AtomicNarrowXorUint8:
-    case kArmWord64AtomicNarrowXorUint16:
-    case kArmWord64AtomicNarrowXorUint32:
-    case kArmWord64AtomicNarrowExchangeUint8:
-    case kArmWord64AtomicNarrowExchangeUint16:
-    case kArmWord64AtomicNarrowExchangeUint32:
-    case kArmWord64AtomicNarrowCompareExchangeUint8:
-    case kArmWord64AtomicNarrowCompareExchangeUint16:
-    case kArmWord64AtomicNarrowCompareExchangeUint32:
       return kHasSideEffect;
 
 #define CASE(Name) case k##Name:
diff --git a/deps/v8/src/compiler/arm/instruction-selector-arm.cc b/deps/v8/src/compiler/arm/instruction-selector-arm.cc
index 277d9779c0..28d7a7fcd0 100644
--- a/deps/v8/src/compiler/arm/instruction-selector-arm.cc
+++ b/deps/v8/src/compiler/arm/instruction-selector-arm.cc
@@ -411,36 +411,33 @@ void VisitPairAtomicBinOp(InstructionSelector* selector, Node* node,
   Node* value = node->InputAt(2);
   Node* value_high = node->InputAt(3);
   AddressingMode addressing_mode = kMode_Offset_RR;
-  InstructionOperand inputs[] = {g.UseUniqueRegister(value),
-                                 g.UseUniqueRegister(value_high),
-                                 g.UseRegister(base), g.UseRegister(index)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r2),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), r3)};
-  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(r6),
-                                g.TempRegister(r7), g.TempRegister()};
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-                 arraysize(temps), temps);
-}
-
-void VisitNarrowAtomicBinOp(InstructionSelector* selector, Node* node,
-                            ArchOpcode opcode) {
-  ArmOperandGenerator g(selector);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
-  AddressingMode addressing_mode = kMode_Offset_RR;
-  InstructionOperand inputs[3] = {g.UseRegister(base), g.UseRegister(index),
-                                  g.UseUniqueRegister(value)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r4),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), r5)};
-  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
-                                g.TempRegister()};
+  InstructionOperand inputs[] = {
+      g.UseUniqueRegister(value), g.UseUniqueRegister(value_high),
+      g.UseUniqueRegister(base), g.UseUniqueRegister(index)};
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-                 arraysize(temps), temps);
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r2),
+                                    g.DefineAsFixed(projection1, r3)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(r6),
+                                  g.TempRegister(r7), g.TempRegister()};
+    selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+                   arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r2)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(r6),
+                                  g.TempRegister(r7), g.TempRegister(),
+                                  g.TempRegister(r3)};
+    selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+                   arraysize(temps), temps);
+  } else {
+    InstructionOperand temps[] = {g.TempRegister(),   g.TempRegister(r6),
+                                  g.TempRegister(r7), g.TempRegister(),
+                                  g.TempRegister(r2), g.TempRegister(r3)};
+    selector->Emit(code, 0, nullptr, arraysize(inputs), inputs,
+                   arraysize(temps), temps);
+  }
 }
 
 }  // namespace
@@ -2265,16 +2262,29 @@ void InstructionSelector::VisitWord32AtomicPairLoad(Node* node) {
   ArmOperandGenerator g(this);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
-  InstructionOperand inputs[] = {g.UseRegister(base), g.UseRegister(index)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r0),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), r1)};
-  InstructionOperand temps[] = {g.TempRegister()};
   AddressingMode addressing_mode = kMode_Offset_RR;
   InstructionCode code =
       kArmWord32AtomicPairLoad | AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-       arraysize(temps), temps);
+  InstructionOperand inputs[] = {g.UseUniqueRegister(base),
+                                 g.UseUniqueRegister(index)};
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r0),
+                                    g.DefineAsFixed(projection1, r1)};
+    InstructionOperand temps[] = {g.TempRegister()};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r0)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(r1)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else {
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(r0),
+                                  g.TempRegister(r1)};
+    Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
+  }
 }
 
 void InstructionSelector::VisitWord32AtomicPairStore(Node* node) {
@@ -2314,39 +2324,6 @@ void InstructionSelector::VisitWord32AtomicPairXor(Node* node) {
   VisitPairAtomicBinOp(this, node, kArmWord32AtomicPairXor);
 }
 
-void InstructionSelector::VisitWord64AtomicNarrowBinop(Node* node,
-                                                       ArchOpcode uint8_op,
-                                                       ArchOpcode uint16_op,
-                                                       ArchOpcode uint32_op) {
-  MachineType type = AtomicOpType(node->op());
-  DCHECK(type != MachineType::Uint64());
-  ArchOpcode opcode = kArchNop;
-  if (type == MachineType::Uint32()) {
-    opcode = uint32_op;
-  } else if (type == MachineType::Uint16()) {
-    opcode = uint16_op;
-  } else if (type == MachineType::Uint8()) {
-    opcode = uint8_op;
-  } else {
-    UNREACHABLE();
-    return;
-  }
-  VisitNarrowAtomicBinOp(this, node, opcode);
-}
-
-#define VISIT_ATOMIC_BINOP(op)                                            \
-  void InstructionSelector::VisitWord64AtomicNarrow##op(Node* node) {     \
-    VisitWord64AtomicNarrowBinop(node, kArmWord64AtomicNarrow##op##Uint8, \
-                                 kArmWord64AtomicNarrow##op##Uint16,      \
-                                 kArmWord64AtomicNarrow##op##Uint32);     \
-  }
-VISIT_ATOMIC_BINOP(Add)
-VISIT_ATOMIC_BINOP(Sub)
-VISIT_ATOMIC_BINOP(And)
-VISIT_ATOMIC_BINOP(Or)
-VISIT_ATOMIC_BINOP(Xor)
-#undef VISIT_ATOMIC_BINOP
-
 void InstructionSelector::VisitWord32AtomicPairExchange(Node* node) {
   ArmOperandGenerator g(this);
   Node* base = node->InputAt(0);
@@ -2354,95 +2331,63 @@ void InstructionSelector::VisitWord32AtomicPairExchange(Node* node) {
   Node* value = node->InputAt(2);
   Node* value_high = node->InputAt(3);
   AddressingMode addressing_mode = kMode_Offset_RR;
-  InstructionOperand inputs[] = {g.UseFixed(value, r0),
-                                 g.UseFixed(value_high, r1),
-                                 g.UseRegister(base), g.UseRegister(index)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r6),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), r7)};
-  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+  InstructionOperand inputs[] = {
+      g.UseFixed(value, r0), g.UseFixed(value_high, r1),
+      g.UseUniqueRegister(base), g.UseUniqueRegister(index)};
   InstructionCode code = kArmWord32AtomicPairExchange |
                          AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-       arraysize(temps), temps);
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowExchange(Node* node) {
-  ArmOperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
-  ArchOpcode opcode = kArchNop;
-  MachineType type = AtomicOpType(node->op());
-  if (type == MachineType::Uint8()) {
-    opcode = kArmWord64AtomicNarrowExchangeUint8;
-  } else if (type == MachineType::Uint16()) {
-    opcode = kArmWord64AtomicNarrowExchangeUint16;
-  } else if (type == MachineType::Uint32()) {
-    opcode = kArmWord64AtomicNarrowExchangeUint32;
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r6),
+                                    g.DefineAsFixed(projection1, r7)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r6)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
+                                  g.TempRegister(r7)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
   } else {
-    UNREACHABLE();
-    return;
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
+                                  g.TempRegister(r6), g.TempRegister(r7)};
+    Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
   }
-  AddressingMode addressing_mode = kMode_Offset_RR;
-  InstructionOperand inputs[] = {g.UseRegister(base), g.UseRegister(index),
-                                 g.UseUniqueRegister(value)};
-  InstructionOperand outputs[] = {
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 0)),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
-  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-       arraysize(temps), temps);
 }
 
 void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   ArmOperandGenerator g(this);
   AddressingMode addressing_mode = kMode_Offset_RR;
-  InstructionOperand inputs[] = {
-      g.UseFixed(node->InputAt(2), r4), g.UseFixed(node->InputAt(3), r5),
-      g.UseFixed(node->InputAt(4), r8), g.UseFixed(node->InputAt(5), r9),
-      g.UseRegister(node->InputAt(0)),  g.UseRegister(node->InputAt(1))};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r2),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), r3)};
-  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+  InstructionOperand inputs[] = {g.UseFixed(node->InputAt(2), r4),
+                                 g.UseFixed(node->InputAt(3), r5),
+                                 g.UseFixed(node->InputAt(4), r8),
+                                 g.UseFixed(node->InputAt(5), r9),
+                                 g.UseUniqueRegister(node->InputAt(0)),
+                                 g.UseUniqueRegister(node->InputAt(1))};
   InstructionCode code = kArmWord32AtomicPairCompareExchange |
                          AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-       arraysize(temps), temps);
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowCompareExchange(Node* node) {
-  ArmOperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* old_value = node->InputAt(2);
-  Node* new_value = node->InputAt(3);
-  ArchOpcode opcode = kArchNop;
-  MachineType type = AtomicOpType(node->op());
-  if (type == MachineType::Uint8()) {
-    opcode = kArmWord64AtomicNarrowCompareExchangeUint8;
-  } else if (type == MachineType::Uint16()) {
-    opcode = kArmWord64AtomicNarrowCompareExchangeUint16;
-  } else if (type == MachineType::Uint32()) {
-    opcode = kArmWord64AtomicNarrowCompareExchangeUint32;
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r2),
+                                    g.DefineAsFixed(projection1, r3)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {
+        g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r2)};
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
+                                  g.TempRegister(r3)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
   } else {
-    UNREACHABLE();
-    return;
+    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
+                                  g.TempRegister(r2), g.TempRegister(r3)};
+    Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
   }
-  AddressingMode addressing_mode = kMode_Offset_RR;
-  InstructionOperand inputs[] = {g.UseRegister(base), g.UseRegister(index),
-                                 g.UseUniqueRegister(old_value),
-                                 g.UseUniqueRegister(new_value)};
-  InstructionOperand outputs[] = {
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 0)),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
-  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
-                                g.TempRegister()};
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-       arraysize(temps), temps);
 }
 
 #define SIMD_TYPE_LIST(V) \
diff --git a/deps/v8/src/compiler/arm64/code-generator-arm64.cc b/deps/v8/src/compiler/arm64/code-generator-arm64.cc
index 867c3687a1..128ed9ffee 100644
--- a/deps/v8/src/compiler/arm64/code-generator-arm64.cc
+++ b/deps/v8/src/compiler/arm64/code-generator-arm64.cc
@@ -225,6 +225,9 @@ class Arm64OperandConverter final : public InstructionOperandConverter {
         return Operand(constant.ToExternalReference());
       case Constant::kHeapObject:
         return Operand(constant.ToHeapObject());
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kRpoNumber:
         UNREACHABLE();  // TODO(dcarney): RPO immediates on arm64.
         break;
@@ -2578,7 +2581,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
   auto MoveConstantToRegister = [&](Register dst, Constant src) {
     if (src.type() == Constant::kHeapObject) {
       Handle<HeapObject> src_object = src.ToHeapObject();
-      Heap::RootListIndex index;
+      RootIndex index;
       if (IsMaterializableFromRoot(src_object, &index)) {
         __ LoadRoot(dst, index);
       } else {
diff --git a/deps/v8/src/compiler/arm64/instruction-selector-arm64.cc b/deps/v8/src/compiler/arm64/instruction-selector-arm64.cc
index b2e8b4b205..dd9914b8bc 100644
--- a/deps/v8/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/deps/v8/src/compiler/arm64/instruction-selector-arm64.cc
@@ -1195,9 +1195,11 @@ void InstructionSelector::VisitWord64Ror(Node* node) {
   V(RoundInt32ToFloat32, kArm64Int32ToFloat32)                \
   V(RoundUint32ToFloat32, kArm64Uint32ToFloat32)              \
   V(ChangeInt32ToFloat64, kArm64Int32ToFloat64)               \
+  V(ChangeInt64ToFloat64, kArm64Int64ToFloat64)               \
   V(ChangeUint32ToFloat64, kArm64Uint32ToFloat64)             \
   V(TruncateFloat32ToInt32, kArm64Float32ToInt32)             \
   V(ChangeFloat64ToInt32, kArm64Float64ToInt32)               \
+  V(ChangeFloat64ToInt64, kArm64Float64ToInt64)               \
   V(TruncateFloat32ToUint32, kArm64Float32ToUint32)           \
   V(ChangeFloat64ToUint32, kArm64Float64ToUint32)             \
   V(ChangeFloat64ToUint64, kArm64Float64ToUint64)             \
diff --git a/deps/v8/src/compiler/branch-elimination.cc b/deps/v8/src/compiler/branch-elimination.cc
index 741de6f264..90ad85fb50 100644
--- a/deps/v8/src/compiler/branch-elimination.cc
+++ b/deps/v8/src/compiler/branch-elimination.cc
@@ -21,7 +21,7 @@ BranchElimination::BranchElimination(Editor* editor, JSGraph* js_graph,
       zone_(zone),
       dead_(js_graph->Dead()) {}
 
-BranchElimination::~BranchElimination() {}
+BranchElimination::~BranchElimination() = default;
 
 
 Reduction BranchElimination::Reduce(Node* node) {
diff --git a/deps/v8/src/compiler/bytecode-analysis.cc b/deps/v8/src/compiler/bytecode-analysis.cc
index 980869ccd3..255a4f3926 100644
--- a/deps/v8/src/compiler/bytecode-analysis.cc
+++ b/deps/v8/src/compiler/bytecode-analysis.cc
@@ -666,7 +666,7 @@ bool BytecodeAnalysis::ResumeJumpTargetsAreValid() {
       valid = false;
     }
     // Check loops.
-    for (const std::pair<int, LoopInfo>& loop_info : header_to_info_) {
+    for (const std::pair<const int, LoopInfo>& loop_info : header_to_info_) {
       if (!loop_info.second.resume_jump_targets().empty()) {
         PrintF(stderr,
                "Found %zu resume targets at loop at offset %d, but no resume "
@@ -700,7 +700,7 @@ bool BytecodeAnalysis::ResumeJumpTargetsAreValid() {
     valid = false;
   }
   // Check loops.
-  for (const std::pair<int, LoopInfo>& loop_info : header_to_info_) {
+  for (const std::pair<const int, LoopInfo>& loop_info : header_to_info_) {
     if (!ResumeJumpTargetLeavesResolveSuspendIds(
             loop_info.first, loop_info.second.resume_jump_targets(),
             &unresolved_suspend_ids)) {
@@ -714,7 +714,7 @@ bool BytecodeAnalysis::ResumeJumpTargetsAreValid() {
            "Found suspend ids that are not resolved by a final leaf resume "
            "jump:\n");
 
-    for (const std::pair<int, int>& target : unresolved_suspend_ids) {
+    for (const std::pair<const int, int>& target : unresolved_suspend_ids) {
       PrintF(stderr, "  %d -> %d\n", target.first, target.second);
     }
     valid = false;
diff --git a/deps/v8/src/compiler/bytecode-analysis.h b/deps/v8/src/compiler/bytecode-analysis.h
index 6ff9ed021a..bc788943d7 100644
--- a/deps/v8/src/compiler/bytecode-analysis.h
+++ b/deps/v8/src/compiler/bytecode-analysis.h
@@ -92,7 +92,7 @@ struct V8_EXPORT_PRIVATE LoopInfo {
   ZoneVector<ResumeJumpTarget> resume_jump_targets_;
 };
 
-class V8_EXPORT_PRIVATE BytecodeAnalysis BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE BytecodeAnalysis {
  public:
   BytecodeAnalysis(Handle<BytecodeArray> bytecode_array, Zone* zone,
                    bool do_liveness_analysis);
diff --git a/deps/v8/src/compiler/bytecode-graph-builder.cc b/deps/v8/src/compiler/bytecode-graph-builder.cc
index 5fad7bc920..4405aff207 100644
--- a/deps/v8/src/compiler/bytecode-graph-builder.cc
+++ b/deps/v8/src/compiler/bytecode-graph-builder.cc
@@ -571,7 +571,9 @@ Node* BytecodeGraphBuilder::BuildLoadNativeContextField(int index) {
 }
 
 VectorSlotPair BytecodeGraphBuilder::CreateVectorSlotPair(int slot_id) {
-  return VectorSlotPair(feedback_vector(), FeedbackVector::ToSlot(slot_id));
+  FeedbackSlot slot = FeedbackVector::ToSlot(slot_id);
+  FeedbackNexus nexus(feedback_vector(), slot);
+  return VectorSlotPair(feedback_vector(), slot, nexus.ic_state());
 }
 
 void BytecodeGraphBuilder::CreateGraph() {
@@ -801,7 +803,7 @@ void BytecodeGraphBuilder::AdvanceToOsrEntryAndPeelLoops(
   int current_parent_offset =
       analysis.GetLoopInfoFor(osr_offset).parent_offset();
   while (current_parent_offset != -1) {
-    LoopInfo current_parent_loop =
+    const LoopInfo& current_parent_loop =
         analysis.GetLoopInfoFor(current_parent_offset);
     // We iterate until the back edge of the parent loop, which we detect by
     // the offset that the JumpLoop targets.
@@ -1337,6 +1339,17 @@ void BytecodeGraphBuilder::VisitLdaNamedProperty() {
   environment()->BindAccumulator(node, Environment::kAttachFrameState);
 }
 
+void BytecodeGraphBuilder::VisitLdaNamedPropertyNoFeedback() {
+  PrepareEagerCheckpoint();
+  Node* object =
+      environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
+  Handle<Name> name(
+      Name::cast(bytecode_iterator().GetConstantForIndexOperand(1)), isolate());
+  const Operator* op = javascript()->LoadNamed(name, VectorSlotPair());
+  Node* node = NewNode(op, object);
+  environment()->BindAccumulator(node, Environment::kAttachFrameState);
+}
+
 void BytecodeGraphBuilder::VisitLdaKeyedProperty() {
   PrepareEagerCheckpoint();
   Node* key = environment()->LookupAccumulator();
@@ -1400,6 +1413,21 @@ void BytecodeGraphBuilder::VisitStaNamedProperty() {
   BuildNamedStore(StoreMode::kNormal);
 }
 
+void BytecodeGraphBuilder::VisitStaNamedPropertyNoFeedback() {
+  PrepareEagerCheckpoint();
+  Node* value = environment()->LookupAccumulator();
+  Node* object =
+      environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
+  Handle<Name> name(
+      Name::cast(bytecode_iterator().GetConstantForIndexOperand(1)), isolate());
+  LanguageMode language_mode =
+      static_cast<LanguageMode>(bytecode_iterator().GetFlagOperand(2));
+  const Operator* op =
+      javascript()->StoreNamed(language_mode, name, VectorSlotPair());
+  Node* node = NewNode(op, object, value);
+  environment()->RecordAfterState(node, Environment::kAttachFrameState);
+}
+
 void BytecodeGraphBuilder::VisitStaNamedOwnProperty() {
   BuildNamedStore(StoreMode::kOwn);
 }
@@ -1601,6 +1629,12 @@ void BytecodeGraphBuilder::VisitCreateEmptyArrayLiteral() {
   environment()->BindAccumulator(literal);
 }
 
+void BytecodeGraphBuilder::VisitCreateArrayFromIterable() {
+  Node* iterable = NewNode(javascript()->CreateArrayFromIterable(),
+                           environment()->LookupAccumulator());
+  environment()->BindAccumulator(iterable, Environment::kAttachFrameState);
+}
+
 void BytecodeGraphBuilder::VisitCreateObjectLiteral() {
   Handle<ObjectBoilerplateDescription> constant_properties(
       ObjectBoilerplateDescription::cast(
@@ -1655,8 +1689,9 @@ void BytecodeGraphBuilder::VisitGetTemplateObject() {
         TemplateObjectDescription::CreateTemplateObject(isolate(), description);
     nexus.vector()->Set(slot, *cached_value);
   } else {
-    cached_value = handle(
-        JSArray::cast(nexus.GetFeedback()->ToStrongHeapObject()), isolate());
+    cached_value =
+        handle(JSArray::cast(nexus.GetFeedback()->GetHeapObjectAssumeStrong()),
+               isolate());
   }
 
   Node* template_object = jsgraph()->HeapConstant(cached_value);
@@ -1781,6 +1816,36 @@ void BytecodeGraphBuilder::VisitCallAnyReceiver() {
   BuildCallVarArgs(ConvertReceiverMode::kAny);
 }
 
+void BytecodeGraphBuilder::VisitCallNoFeedback() {
+  DCHECK_EQ(interpreter::Bytecodes::GetReceiverMode(
+                bytecode_iterator().current_bytecode()),
+            ConvertReceiverMode::kAny);
+
+  PrepareEagerCheckpoint();
+  Node* callee =
+      environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
+
+  interpreter::Register first_reg = bytecode_iterator().GetRegisterOperand(1);
+  size_t reg_count = bytecode_iterator().GetRegisterCountOperand(2);
+
+  // The receiver is the first register, followed by the arguments in the
+  // consecutive registers.
+  int arg_count = static_cast<int>(reg_count) - 1;
+  // The arity of the Call node -- includes the callee, receiver and function
+  // arguments.
+  int arity = 2 + arg_count;
+
+  // Setting call frequency to a value less than min_inlining frequency to
+  // prevent inlining of one-shot call node.
+  DCHECK(CallFrequency::kNoFeedbackCallFrequency < FLAG_min_inlining_frequency);
+  const Operator* call = javascript()->Call(
+      arity, CallFrequency(CallFrequency::kNoFeedbackCallFrequency));
+  Node* const* call_args = ProcessCallVarArgs(ConvertReceiverMode::kAny, callee,
+                                              first_reg, arg_count);
+  Node* value = ProcessCallArguments(call, call_args, arity);
+  environment()->BindAccumulator(value, Environment::kAttachFrameState);
+}
+
 void BytecodeGraphBuilder::VisitCallProperty() {
   BuildCallVarArgs(ConvertReceiverMode::kNotNullOrUndefined);
 }
@@ -3403,7 +3468,9 @@ Node* BytecodeGraphBuilder::MakeNode(const Operator* op, int value_input_count,
     memcpy(buffer, value_inputs, kPointerSize * value_input_count);
     Node** current_input = buffer + value_input_count;
     if (has_context) {
-      *current_input++ = environment()->Context();
+      *current_input++ = OperatorProperties::NeedsExactContext(op)
+                             ? environment()->Context()
+                             : jsgraph()->HeapConstant(native_context());
     }
     if (has_frame_state) {
       // The frame state will be inserted later. Here we misuse the {Dead} node
diff --git a/deps/v8/src/compiler/c-linkage.cc b/deps/v8/src/compiler/c-linkage.cc
index 02b6f5fb3d..1300cd258d 100644
--- a/deps/v8/src/compiler/c-linkage.cc
+++ b/deps/v8/src/compiler/c-linkage.cc
@@ -99,10 +99,15 @@ namespace {
 #define CALLEE_SAVE_FP_REGISTERS \
   f20.bit() | f22.bit() | f24.bit() | f26.bit() | f28.bit() | f30.bit()
 
-#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
+#elif V8_TARGET_ARCH_PPC64
 // ===========================================================================
 // == ppc & ppc64 ============================================================
 // ===========================================================================
+#ifdef V8_TARGET_LITTLE_ENDIAN  // ppc64le linux
+#define STACK_SHADOW_WORDS 12
+#else  // AIX
+#define STACK_SHADOW_WORDS 14
+#endif
 #define PARAM_REGISTERS r3, r4, r5, r6, r7, r8, r9, r10
 #define CALLEE_SAVE_REGISTERS                                                 \
   r14.bit() | r15.bit() | r16.bit() | r17.bit() | r18.bit() | r19.bit() |     \
@@ -117,6 +122,7 @@ namespace {
 // ===========================================================================
 // == s390x ==================================================================
 // ===========================================================================
+#define STACK_SHADOW_WORDS 20
 #define PARAM_REGISTERS r2, r3, r4, r5, r6
 #define CALLEE_SAVE_REGISTERS \
   r6.bit() | r7.bit() | r8.bit() | r9.bit() | r10.bit() | ip.bit() | r13.bit()
@@ -124,15 +130,6 @@ namespace {
   d8.bit() | d9.bit() | d10.bit() | d11.bit() | d12.bit() | d13.bit() | \
       d14.bit() | d15.bit()
 
-#elif V8_TARGET_ARCH_S390
-// ===========================================================================
-// == s390 ===================================================================
-// ===========================================================================
-#define PARAM_REGISTERS r2, r3, r4, r5, r6
-#define CALLEE_SAVE_REGISTERS \
-  r6.bit() | r7.bit() | r8.bit() | r9.bit() | r10.bit() | ip.bit() | r13.bit()
-#define CALLEE_SAVE_FP_REGISTERS (d4.bit() | d6.bit())
-
 #else
 // ===========================================================================
 // == unknown ================================================================
diff --git a/deps/v8/src/compiler/checkpoint-elimination.h b/deps/v8/src/compiler/checkpoint-elimination.h
index 87f14c27a6..97e05c130d 100644
--- a/deps/v8/src/compiler/checkpoint-elimination.h
+++ b/deps/v8/src/compiler/checkpoint-elimination.h
@@ -18,7 +18,7 @@ class V8_EXPORT_PRIVATE CheckpointElimination final
     : public NON_EXPORTED_BASE(AdvancedReducer) {
  public:
   explicit CheckpointElimination(Editor* editor);
-  ~CheckpointElimination() final {}
+  ~CheckpointElimination() final = default;
 
   const char* reducer_name() const override { return "CheckpointElimination"; }
 
diff --git a/deps/v8/src/compiler/code-assembler.cc b/deps/v8/src/compiler/code-assembler.cc
index 4f400846d4..93e384444e 100644
--- a/deps/v8/src/compiler/code-assembler.cc
+++ b/deps/v8/src/compiler/code-assembler.cc
@@ -61,10 +61,11 @@ CodeAssemblerState::CodeAssemblerState(Isolate* isolate, Zone* zone,
                                        int32_t builtin_index)
     : CodeAssemblerState(
           isolate, zone,
-          Linkage::GetJSCallDescriptor(zone, false, parameter_count,
-                                       kind == Code::BUILTIN
-                                           ? CallDescriptor::kPushArgumentCount
-                                           : CallDescriptor::kNoFlags),
+          Linkage::GetJSCallDescriptor(
+              zone, false, parameter_count,
+              (kind == Code::BUILTIN ? CallDescriptor::kPushArgumentCount
+                                     : CallDescriptor::kNoFlags) |
+                  CallDescriptor::kCanUseRoots),
           kind, name, poisoning_level, 0, builtin_index) {}
 
 CodeAssemblerState::CodeAssemblerState(Isolate* isolate, Zone* zone,
@@ -84,13 +85,13 @@ CodeAssemblerState::CodeAssemblerState(Isolate* isolate, Zone* zone,
       code_generated_(false),
       variables_(zone) {}
 
-CodeAssemblerState::~CodeAssemblerState() {}
+CodeAssemblerState::~CodeAssemblerState() = default;
 
 int CodeAssemblerState::parameter_count() const {
   return static_cast<int>(raw_assembler_->call_descriptor()->ParameterCount());
 }
 
-CodeAssembler::~CodeAssembler() {}
+CodeAssembler::~CodeAssembler() = default;
 
 #if DEBUG
 void CodeAssemblerState::PrintCurrentBlock(std::ostream& os) {
@@ -309,7 +310,7 @@ TNode<Float64T> CodeAssembler::Float64Constant(double value) {
 }
 
 TNode<HeapNumber> CodeAssembler::NaNConstant() {
-  return UncheckedCast<HeapNumber>(LoadRoot(Heap::kNanValueRootIndex));
+  return UncheckedCast<HeapNumber>(LoadRoot(RootIndex::kNanValue));
 }
 
 bool CodeAssembler::ToInt32Constant(Node* node, int32_t& out_value) {
@@ -924,6 +925,17 @@ TNode<UintPtrT> CodeAssembler::ChangeFloat64ToUintPtr(
       raw_assembler()->ChangeFloat64ToUint32(value));
 }
 
+TNode<Float64T> CodeAssembler::ChangeUintPtrToFloat64(TNode<UintPtrT> value) {
+  if (raw_assembler()->machine()->Is64()) {
+    // TODO(turbofan): Maybe we should introduce a ChangeUint64ToFloat64
+    // machine operator to TurboFan here?
+    return ReinterpretCast<Float64T>(
+        raw_assembler()->RoundUint64ToFloat64(value));
+  }
+  return ReinterpretCast<Float64T>(
+      raw_assembler()->ChangeUint32ToFloat64(value));
+}
+
 Node* CodeAssembler::RoundIntPtrToFloat64(Node* value) {
   if (raw_assembler()->machine()->Is64()) {
     return raw_assembler()->RoundInt64ToFloat64(value);
@@ -952,7 +964,7 @@ Node* CodeAssembler::AtomicLoad(MachineType rep, Node* base, Node* offset) {
   return raw_assembler()->AtomicLoad(rep, base, offset);
 }
 
-TNode<Object> CodeAssembler::LoadRoot(Heap::RootListIndex root_index) {
+TNode<Object> CodeAssembler::LoadRoot(RootIndex root_index) {
   if (isolate()->heap()->RootCanBeTreatedAsConstant(root_index)) {
     Handle<Object> root = isolate()->heap()->root_handle(root_index);
     if (root->IsSmi()) {
@@ -967,8 +979,9 @@ TNode<Object> CodeAssembler::LoadRoot(Heap::RootListIndex root_index) {
   // cases, it would boil down to loading from a fixed kRootRegister offset.
   Node* roots_array_start =
       ExternalConstant(ExternalReference::roots_array_start(isolate()));
+  size_t offset = static_cast<size_t>(root_index) * kPointerSize;
   return UncheckedCast<Object>(Load(MachineType::AnyTagged(), roots_array_start,
-                                    IntPtrConstant(root_index * kPointerSize)));
+                                    IntPtrConstant(offset)));
 }
 
 Node* CodeAssembler::Store(Node* base, Node* value) {
@@ -998,14 +1011,16 @@ Node* CodeAssembler::StoreNoWriteBarrier(MachineRepresentation rep, Node* base,
 }
 
 Node* CodeAssembler::AtomicStore(MachineRepresentation rep, Node* base,
-                                 Node* offset, Node* value) {
-  return raw_assembler()->AtomicStore(rep, base, offset, value);
+                                 Node* offset, Node* value, Node* value_high) {
+  return raw_assembler()->AtomicStore(rep, base, offset, value, value_high);
 }
 
-#define ATOMIC_FUNCTION(name)                                        \
-  Node* CodeAssembler::Atomic##name(MachineType type, Node* base,    \
-                                    Node* offset, Node* value) {     \
-    return raw_assembler()->Atomic##name(type, base, offset, value); \
+#define ATOMIC_FUNCTION(name)                                       \
+  Node* CodeAssembler::Atomic##name(MachineType type, Node* base,   \
+                                    Node* offset, Node* value,      \
+                                    Node* value_high) {             \
+    return raw_assembler()->Atomic##name(type, base, offset, value, \
+                                         value_high);               \
   }
 ATOMIC_FUNCTION(Exchange);
 ATOMIC_FUNCTION(Add);
@@ -1017,17 +1032,20 @@ ATOMIC_FUNCTION(Xor);
 
 Node* CodeAssembler::AtomicCompareExchange(MachineType type, Node* base,
                                            Node* offset, Node* old_value,
-                                           Node* new_value) {
-  return raw_assembler()->AtomicCompareExchange(type, base, offset, old_value,
-                                                new_value);
+                                           Node* new_value,
+                                           Node* old_value_high,
+                                           Node* new_value_high) {
+  return raw_assembler()->AtomicCompareExchange(
+      type, base, offset, old_value, old_value_high, new_value, new_value_high);
 }
 
-Node* CodeAssembler::StoreRoot(Heap::RootListIndex root_index, Node* value) {
+Node* CodeAssembler::StoreRoot(RootIndex root_index, Node* value) {
   DCHECK(Heap::RootCanBeWrittenAfterInitialization(root_index));
   Node* roots_array_start =
       ExternalConstant(ExternalReference::roots_array_start(isolate()));
+  size_t offset = static_cast<size_t>(root_index) * kPointerSize;
   return StoreNoWriteBarrier(MachineRepresentation::kTagged, roots_array_start,
-                             IntPtrConstant(root_index * kPointerSize), value);
+                             IntPtrConstant(offset), value);
 }
 
 Node* CodeAssembler::Retain(Node* value) {
@@ -1035,6 +1053,7 @@ Node* CodeAssembler::Retain(Node* value) {
 }
 
 Node* CodeAssembler::Projection(int index, Node* value) {
+  DCHECK(index < value->op()->ValueOutputCount());
   return raw_assembler()->Projection(index, value);
 }
 
@@ -1392,8 +1411,8 @@ void CodeAssembler::Branch(SloppyTNode<IntegralT> condition, Label* true_label,
 }
 
 void CodeAssembler::Branch(TNode<BoolT> condition,
-                           std::function<void()> true_body,
-                           std::function<void()> false_body) {
+                           const std::function<void()>& true_body,
+                           const std::function<void()>& false_body) {
   int32_t constant;
   if (ToInt32Constant(condition, constant)) {
     return constant ? true_body() : false_body();
@@ -1410,7 +1429,7 @@ void CodeAssembler::Branch(TNode<BoolT> condition,
 }
 
 void CodeAssembler::Branch(TNode<BoolT> condition, Label* true_label,
-                           std::function<void()> false_body) {
+                           const std::function<void()>& false_body) {
   int32_t constant;
   if (ToInt32Constant(condition, constant)) {
     return constant ? Goto(true_label) : false_body();
@@ -1423,7 +1442,7 @@ void CodeAssembler::Branch(TNode<BoolT> condition, Label* true_label,
 }
 
 void CodeAssembler::Branch(TNode<BoolT> condition,
-                           std::function<void()> true_body,
+                           const std::function<void()>& true_body,
                            Label* false_label) {
   int32_t constant;
   if (ToInt32Constant(condition, constant)) {
@@ -1735,6 +1754,43 @@ void CodeAssemblerLabel::UpdateVariablesAfterBind() {
   bound_ = true;
 }
 
+void CodeAssemblerParameterizedLabelBase::AddInputs(std::vector<Node*> inputs) {
+  if (!phi_nodes_.empty()) {
+    DCHECK_EQ(inputs.size(), phi_nodes_.size());
+    for (size_t i = 0; i < inputs.size(); ++i) {
+      state_->raw_assembler_->AppendPhiInput(phi_nodes_[i], inputs[i]);
+    }
+  } else {
+    DCHECK_EQ(inputs.size(), phi_inputs_.size());
+    for (size_t i = 0; i < inputs.size(); ++i) {
+      phi_inputs_[i].push_back(inputs[i]);
+    }
+  }
+}
+
+Node* CodeAssemblerParameterizedLabelBase::CreatePhi(
+    MachineRepresentation rep, const std::vector<Node*>& inputs) {
+  for (Node* input : inputs) {
+    // We use {nullptr} as a sentinel for an uninitialized value. We must not
+    // create phi nodes for these.
+    if (input == nullptr) return nullptr;
+  }
+  return state_->raw_assembler_->Phi(rep, static_cast<int>(inputs.size()),
+                                     &inputs.front());
+}
+
+const std::vector<Node*>& CodeAssemblerParameterizedLabelBase::CreatePhis(
+    std::vector<MachineRepresentation> representations) {
+  DCHECK(is_used());
+  DCHECK(phi_nodes_.empty());
+  phi_nodes_.reserve(phi_inputs_.size());
+  DCHECK_EQ(representations.size(), phi_inputs_.size());
+  for (size_t i = 0; i < phi_inputs_.size(); ++i) {
+    phi_nodes_.push_back(CreatePhi(representations[i], phi_inputs_[i]));
+  }
+  return phi_nodes_;
+}
+
 }  // namespace compiler
 
 Smi* CheckObjectType(Object* value, Smi* type, String* location) {
diff --git a/deps/v8/src/compiler/code-assembler.h b/deps/v8/src/compiler/code-assembler.h
index 6b9089da6b..3a5f06bb95 100644
--- a/deps/v8/src/compiler/code-assembler.h
+++ b/deps/v8/src/compiler/code-assembler.h
@@ -27,11 +27,23 @@
 namespace v8 {
 namespace internal {
 
-class Callable;
 class CallInterfaceDescriptor;
+class Callable;
+class Factory;
+class InterpreterData;
 class Isolate;
+class JSAsyncGeneratorObject;
+class JSCollator;
 class JSCollection;
+class JSDateTimeFormat;
+class JSListFormat;
+class JSLocale;
+class JSNumberFormat;
+class JSPluralRules;
 class JSRegExpStringIterator;
+class JSRelativeTimeFormat;
+class JSSegmenter;
+class JSV8BreakIterator;
 class JSWeakCollection;
 class JSWeakMap;
 class JSWeakSet;
@@ -41,8 +53,7 @@ class PromiseFulfillReactionJobTask;
 class PromiseReaction;
 class PromiseReactionJobTask;
 class PromiseRejectReactionJobTask;
-class InterpreterData;
-class Factory;
+class TorqueAssembler;
 class Zone;
 
 template <typename T>
@@ -245,6 +256,7 @@ class StringWrapper;
 class SymbolWrapper;
 class Undetectable;
 class UniqueName;
+class WasmExceptionObject;
 class WasmExportedFunctionData;
 class WasmGlobalObject;
 class WasmMemoryObject;
@@ -697,6 +709,12 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   TNode<Int32T> Int32Constant(int32_t value);
   TNode<Int64T> Int64Constant(int64_t value);
   TNode<IntPtrT> IntPtrConstant(intptr_t value);
+  TNode<Uint32T> Uint32Constant(uint32_t value) {
+    return Unsigned(Int32Constant(bit_cast<int32_t>(value)));
+  }
+  TNode<UintPtrT> UintPtrConstant(uintptr_t value) {
+    return Unsigned(IntPtrConstant(bit_cast<intptr_t>(value)));
+  }
   TNode<Number> NumberConstant(double value);
   TNode<Smi> SmiConstant(Smi* value);
   TNode<Smi> SmiConstant(int value);
@@ -773,11 +791,11 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   void Branch(SloppyTNode<IntegralT> condition, Label* true_label,
               Label* false_label);
 
-  void Branch(TNode<BoolT> condition, std::function<void()> true_body,
-              std::function<void()> false_body);
+  void Branch(TNode<BoolT> condition, const std::function<void()>& true_body,
+              const std::function<void()>& false_body);
   void Branch(TNode<BoolT> condition, Label* true_label,
-              std::function<void()> false_body);
-  void Branch(TNode<BoolT> condition, std::function<void()> true_body,
+              const std::function<void()>& false_body);
+  void Branch(TNode<BoolT> condition, const std::function<void()>& true_body,
               Label* false_label);
 
   void Switch(Node* index, Label* default_label, const int32_t* case_values,
@@ -808,7 +826,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   Node* AtomicLoad(MachineType rep, Node* base, Node* offset);
 
   // Load a value from the root array.
-  TNode<Object> LoadRoot(Heap::RootListIndex root_index);
+  TNode<Object> LoadRoot(RootIndex root_index);
 
   // Store value to raw memory location.
   Node* Store(Node* base, Node* value);
@@ -817,28 +835,38 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   Node* StoreNoWriteBarrier(MachineRepresentation rep, Node* base, Node* value);
   Node* StoreNoWriteBarrier(MachineRepresentation rep, Node* base, Node* offset,
                             Node* value);
+  // {value_high} is used for 64-bit stores on 32-bit platforms, must be
+  // nullptr in other cases.
   Node* AtomicStore(MachineRepresentation rep, Node* base, Node* offset,
-                    Node* value);
+                    Node* value, Node* value_high = nullptr);
 
   // Exchange value at raw memory location
-  Node* AtomicExchange(MachineType type, Node* base, Node* offset, Node* value);
+  Node* AtomicExchange(MachineType type, Node* base, Node* offset, Node* value,
+                       Node* value_high = nullptr);
 
   // Compare and Exchange value at raw memory location
   Node* AtomicCompareExchange(MachineType type, Node* base, Node* offset,
-                              Node* old_value, Node* new_value);
+                              Node* old_value, Node* new_value,
+                              Node* old_value_high = nullptr,
+                              Node* new_value_high = nullptr);
 
-  Node* AtomicAdd(MachineType type, Node* base, Node* offset, Node* value);
+  Node* AtomicAdd(MachineType type, Node* base, Node* offset, Node* value,
+                  Node* value_high = nullptr);
 
-  Node* AtomicSub(MachineType type, Node* base, Node* offset, Node* value);
+  Node* AtomicSub(MachineType type, Node* base, Node* offset, Node* value,
+                  Node* value_high = nullptr);
 
-  Node* AtomicAnd(MachineType type, Node* base, Node* offset, Node* value);
+  Node* AtomicAnd(MachineType type, Node* base, Node* offset, Node* value,
+                  Node* value_high = nullptr);
 
-  Node* AtomicOr(MachineType type, Node* base, Node* offset, Node* value);
+  Node* AtomicOr(MachineType type, Node* base, Node* offset, Node* value,
+                 Node* value_high = nullptr);
 
-  Node* AtomicXor(MachineType type, Node* base, Node* offset, Node* value);
+  Node* AtomicXor(MachineType type, Node* base, Node* offset, Node* value,
+                  Node* value_high = nullptr);
 
   // Store a value to the root array.
-  Node* StoreRoot(Heap::RootListIndex root_index, Node* value);
+  Node* StoreRoot(RootIndex root_index, Node* value);
 
 // Basic arithmetic operations.
 #define DECLARE_CODE_ASSEMBLER_BINARY_OP(name, ResType, Arg1Type, Arg2Type) \
@@ -906,6 +934,11 @@ class V8_EXPORT_PRIVATE CodeAssembler {
         Int32Add(static_cast<Node*>(left), static_cast<Node*>(right)));
   }
 
+  TNode<Uint32T> Uint32Add(TNode<Uint32T> left, TNode<Uint32T> right) {
+    return Unsigned(
+        Int32Add(static_cast<Node*>(left), static_cast<Node*>(right)));
+  }
+
   TNode<WordT> IntPtrAdd(SloppyTNode<WordT> left, SloppyTNode<WordT> right);
   TNode<WordT> IntPtrSub(SloppyTNode<WordT> left, SloppyTNode<WordT> right);
   TNode<WordT> IntPtrMul(SloppyTNode<WordT> left, SloppyTNode<WordT> right);
@@ -921,6 +954,14 @@ class V8_EXPORT_PRIVATE CodeAssembler {
     return Signed(
         IntPtrMul(static_cast<Node*>(left), static_cast<Node*>(right)));
   }
+  TNode<UintPtrT> UintPtrAdd(TNode<UintPtrT> left, TNode<UintPtrT> right) {
+    return Unsigned(
+        IntPtrAdd(static_cast<Node*>(left), static_cast<Node*>(right)));
+  }
+  TNode<UintPtrT> UintPtrSub(TNode<UintPtrT> left, TNode<UintPtrT> right) {
+    return Unsigned(
+        IntPtrSub(static_cast<Node*>(left), static_cast<Node*>(right)));
+  }
 
   TNode<WordT> WordShl(SloppyTNode<WordT> value, int shift);
   TNode<WordT> WordShr(SloppyTNode<WordT> value, int shift);
@@ -970,6 +1011,8 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   // Changes a double to an inptr_t for pointer arithmetic outside of Smi range.
   // Assumes that the double can be exactly represented as an int.
   TNode<UintPtrT> ChangeFloat64ToUintPtr(SloppyTNode<Float64T> value);
+  // Same in the opposite direction.
+  TNode<Float64T> ChangeUintPtrToFloat64(TNode<UintPtrT> value);
 
   // Changes an intptr_t to a double, e.g. for storing an element index
   // outside Smi range in a HeapNumber. Lossless on 32-bit,
@@ -1117,7 +1160,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
                     TArgs... args) {
     int argc = static_cast<int>(sizeof...(args));
     Node* arity = Int32Constant(argc);
-    Node* receiver = LoadRoot(Heap::kUndefinedValueRootIndex);
+    Node* receiver = LoadRoot(RootIndex::kUndefinedValue);
 
     // Construct(target, new_target, arity, receiver, arguments...)
     return CallStub(callable, context, new_target, new_target, arity, receiver,
@@ -1380,6 +1423,60 @@ class CodeAssemblerLabel {
   std::map<CodeAssemblerVariable::Impl*, std::vector<Node*>> variable_merges_;
 };
 
+class CodeAssemblerParameterizedLabelBase {
+ public:
+  bool is_used() const { return plain_label_.is_used(); }
+  explicit CodeAssemblerParameterizedLabelBase(CodeAssembler* assembler,
+                                               size_t arity,
+                                               CodeAssemblerLabel::Type type)
+      : state_(assembler->state()),
+        phi_inputs_(arity),
+        plain_label_(assembler, type) {}
+
+ protected:
+  CodeAssemblerLabel* plain_label() { return &plain_label_; }
+  void AddInputs(std::vector<Node*> inputs);
+  Node* CreatePhi(MachineRepresentation rep, const std::vector<Node*>& inputs);
+  const std::vector<Node*>& CreatePhis(
+      std::vector<MachineRepresentation> representations);
+
+ private:
+  CodeAssemblerState* state_;
+  std::vector<std::vector<Node*>> phi_inputs_;
+  std::vector<Node*> phi_nodes_;
+  CodeAssemblerLabel plain_label_;
+};
+
+template <class... Types>
+class CodeAssemblerParameterizedLabel
+    : public CodeAssemblerParameterizedLabelBase {
+ public:
+  static constexpr size_t kArity = sizeof...(Types);
+  explicit CodeAssemblerParameterizedLabel(CodeAssembler* assembler,
+                                           CodeAssemblerLabel::Type type)
+      : CodeAssemblerParameterizedLabelBase(assembler, kArity, type) {}
+
+ private:
+  friend class internal::TorqueAssembler;
+
+  void AddInputs(TNode<Types>... inputs) {
+    CodeAssemblerParameterizedLabelBase::AddInputs(
+        std::vector<Node*>{inputs...});
+  }
+  void CreatePhis(TNode<Types>*... results) {
+    const std::vector<Node*>& phi_nodes =
+        CodeAssemblerParameterizedLabelBase::CreatePhis(
+            {MachineRepresentationOf<Types>::value...});
+    auto it = phi_nodes.begin();
+    USE(it);
+    ITERATE_PACK(AssignPhi(results, *(it++)));
+  }
+  template <class T>
+  static void AssignPhi(TNode<T>* result, Node* phi) {
+    if (phi != nullptr) *result = TNode<T>::UncheckedCast(phi);
+  }
+};
+
 class V8_EXPORT_PRIVATE CodeAssemblerState {
  public:
   // Create with CallStub linkage.
@@ -1413,6 +1510,7 @@ class V8_EXPORT_PRIVATE CodeAssemblerState {
   friend class CodeAssemblerLabel;
   friend class CodeAssemblerVariable;
   friend class CodeAssemblerTester;
+  friend class CodeAssemblerParameterizedLabelBase;
 
   CodeAssemblerState(Isolate* isolate, Zone* zone,
                      CallDescriptor* call_descriptor, Code::Kind kind,
diff --git a/deps/v8/src/compiler/code-generator.cc b/deps/v8/src/compiler/code-generator.cc
index 83060f9e38..b6d782d96a 100644
--- a/deps/v8/src/compiler/code-generator.cc
+++ b/deps/v8/src/compiler/code-generator.cc
@@ -16,6 +16,7 @@
 #include "src/lsan.h"
 #include "src/macro-assembler-inl.h"
 #include "src/optimized-compilation-info.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -69,7 +70,7 @@ CodeGenerator::CodeGenerator(
       caller_registers_saved_(false),
       jump_tables_(nullptr),
       ools_(nullptr),
-      osr_helper_(osr_helper),
+      osr_helper_(std::move(osr_helper)),
       osr_pc_offset_(-1),
       optimized_out_literal_id_(-1),
       source_position_table_builder_(
@@ -453,8 +454,8 @@ void CodeGenerator::RecordSafepoint(ReferenceMap* references,
   }
 }
 
-bool CodeGenerator::IsMaterializableFromRoot(
-    Handle<HeapObject> object, Heap::RootListIndex* index_return) {
+bool CodeGenerator::IsMaterializableFromRoot(Handle<HeapObject> object,
+                                             RootIndex* index_return) {
   const CallDescriptor* incoming_descriptor =
       linkage()->GetIncomingDescriptor();
   if (incoming_descriptor->flags() & CallDescriptor::kCanUseRoots) {
@@ -1033,7 +1034,7 @@ void CodeGenerator::BuildTranslationForFrameStateDescriptor(
       DCHECK(descriptor->bailout_id().IsValidForConstructStub());
       translation->BeginConstructStubFrame(
           descriptor->bailout_id(), shared_info_id,
-          static_cast<unsigned int>(descriptor->parameters_count()));
+          static_cast<unsigned int>(descriptor->parameters_count() + 1));
       break;
     case FrameStateType::kBuiltinContinuation: {
       BailoutId bailout_id = descriptor->bailout_id();
@@ -1111,6 +1112,8 @@ void CodeGenerator::AddTranslationForOperand(Translation* translation,
     } else if (type == MachineType::Uint8() || type == MachineType::Uint16() ||
                type == MachineType::Uint32()) {
       translation->StoreUint32StackSlot(LocationOperand::cast(op)->index());
+    } else if (type == MachineType::Int64()) {
+      translation->StoreInt64StackSlot(LocationOperand::cast(op)->index());
     } else {
       CHECK_EQ(MachineRepresentation::kTagged, type.representation());
       translation->StoreStackSlot(LocationOperand::cast(op)->index());
@@ -1132,6 +1135,8 @@ void CodeGenerator::AddTranslationForOperand(Translation* translation,
     } else if (type == MachineType::Uint8() || type == MachineType::Uint16() ||
                type == MachineType::Uint32()) {
       translation->StoreUint32Register(converter.ToRegister(op));
+    } else if (type == MachineType::Int64()) {
+      translation->StoreInt64Register(converter.ToRegister(op));
     } else {
       CHECK_EQ(MachineRepresentation::kTagged, type.representation());
       translation->StoreRegister(converter.ToRegister(op));
@@ -1182,12 +1187,14 @@ void CodeGenerator::AddTranslationForOperand(Translation* translation,
         }
         break;
       case Constant::kInt64:
-        // When pointers are 8 bytes, we can use int64 constants to represent
-        // Smis.
-        DCHECK(type.representation() == MachineRepresentation::kWord64 ||
-               type.representation() == MachineRepresentation::kTagged);
         DCHECK_EQ(8, kPointerSize);
-        {
+        if (type.representation() == MachineRepresentation::kWord64) {
+          literal =
+              DeoptimizationLiteral(static_cast<double>(constant.ToInt64()));
+        } else {
+          // When pointers are 8 bytes, we can use int64 constants to represent
+          // Smis.
+          DCHECK_EQ(MachineRepresentation::kTagged, type.representation());
           Smi* smi = reinterpret_cast<Smi*>(constant.ToInt64());
           DCHECK(smi->IsSmi());
           literal = DeoptimizationLiteral(smi->value());
@@ -1207,6 +1214,10 @@ void CodeGenerator::AddTranslationForOperand(Translation* translation,
         DCHECK_EQ(MachineRepresentation::kTagged, type.representation());
         literal = DeoptimizationLiteral(constant.ToHeapObject());
         break;
+      case Constant::kDelayedStringConstant:
+        DCHECK_EQ(MachineRepresentation::kTagged, type.representation());
+        literal = DeoptimizationLiteral(constant.ToDelayedStringConstant());
+        break;
       default:
         UNREACHABLE();
     }
@@ -1262,10 +1273,21 @@ OutOfLineCode::OutOfLineCode(CodeGenerator* gen)
   gen->ools_ = this;
 }
 
-OutOfLineCode::~OutOfLineCode() {}
+OutOfLineCode::~OutOfLineCode() = default;
 
 Handle<Object> DeoptimizationLiteral::Reify(Isolate* isolate) const {
-  return object_.is_null() ? isolate->factory()->NewNumber(number_) : object_;
+  switch (kind_) {
+    case DeoptimizationLiteralKind::kObject: {
+      return object_;
+    }
+    case DeoptimizationLiteralKind::kNumber: {
+      return isolate->factory()->NewNumber(number_);
+    }
+    case DeoptimizationLiteralKind::kString: {
+      return string_->AllocateStringConstant(isolate);
+    }
+  }
+  UNREACHABLE();
 }
 
 }  // namespace compiler
diff --git a/deps/v8/src/compiler/code-generator.h b/deps/v8/src/compiler/code-generator.h
index 5d4941f825..1ba0e32ce6 100644
--- a/deps/v8/src/compiler/code-generator.h
+++ b/deps/v8/src/compiler/code-generator.h
@@ -50,28 +50,40 @@ class InstructionOperandIterator {
   size_t pos_;
 };
 
-// Either a non-null Handle<Object> or a double.
+enum class DeoptimizationLiteralKind { kObject, kNumber, kString };
+
+// Either a non-null Handle<Object>, a double or a StringConstantBase.
 class DeoptimizationLiteral {
  public:
-  DeoptimizationLiteral() : object_(), number_(0) {}
+  DeoptimizationLiteral() : object_(), number_(0), string_(nullptr) {}
   explicit DeoptimizationLiteral(Handle<Object> object)
-      : object_(object), number_(0) {
+      : kind_(DeoptimizationLiteralKind::kObject), object_(object) {
     DCHECK(!object_.is_null());
   }
-  explicit DeoptimizationLiteral(double number) : object_(), number_(number) {}
+  explicit DeoptimizationLiteral(double number)
+      : kind_(DeoptimizationLiteralKind::kNumber), number_(number) {}
+  explicit DeoptimizationLiteral(const StringConstantBase* string)
+      : kind_(DeoptimizationLiteralKind::kString), string_(string) {}
 
   Handle<Object> object() const { return object_; }
+  const StringConstantBase* string() const { return string_; }
 
   bool operator==(const DeoptimizationLiteral& other) const {
-    return object_.equals(other.object_) &&
-           bit_cast<uint64_t>(number_) == bit_cast<uint64_t>(other.number_);
+    return kind_ == other.kind_ && object_.equals(other.object_) &&
+           bit_cast<uint64_t>(number_) == bit_cast<uint64_t>(other.number_) &&
+           bit_cast<intptr_t>(string_) == bit_cast<intptr_t>(other.string_);
   }
 
   Handle<Object> Reify(Isolate* isolate) const;
 
+  DeoptimizationLiteralKind kind() const { return kind_; }
+
  private:
+  DeoptimizationLiteralKind kind_;
+
   Handle<Object> object_;
-  double number_;
+  double number_ = 0;
+  const StringConstantBase* string_ = nullptr;
 };
 
 // Generates native code for a sequence of instructions.
@@ -151,7 +163,7 @@ class CodeGenerator final : public GapResolver::Assembler {
   // which is cheaper on some platforms than materializing the actual heap
   // object constant.
   bool IsMaterializableFromRoot(Handle<HeapObject> object,
-                                Heap::RootListIndex* index_return);
+                                RootIndex* index_return);
 
   enum CodeGenResult { kSuccess, kTooManyDeoptimizationBailouts };
 
diff --git a/deps/v8/src/compiler/common-node-cache.h b/deps/v8/src/compiler/common-node-cache.h
index bce8d0f62e..6a36c979a1 100644
--- a/deps/v8/src/compiler/common-node-cache.h
+++ b/deps/v8/src/compiler/common-node-cache.h
@@ -23,7 +23,7 @@ namespace compiler {
 class CommonNodeCache final {
  public:
   explicit CommonNodeCache(Zone* zone) : zone_(zone) {}
-  ~CommonNodeCache() {}
+  ~CommonNodeCache() = default;
 
   Node** FindInt32Constant(int32_t value) {
     return int32_constants_.Find(zone(), value);
diff --git a/deps/v8/src/compiler/common-operator-reducer.h b/deps/v8/src/compiler/common-operator-reducer.h
index f1b29eaf76..32b3181b7a 100644
--- a/deps/v8/src/compiler/common-operator-reducer.h
+++ b/deps/v8/src/compiler/common-operator-reducer.h
@@ -28,7 +28,7 @@ class V8_EXPORT_PRIVATE CommonOperatorReducer final
                         JSHeapBroker* js_heap_broker,
                         CommonOperatorBuilder* common,
                         MachineOperatorBuilder* machine, Zone* temp_zone);
-  ~CommonOperatorReducer() final {}
+  ~CommonOperatorReducer() final = default;
 
   const char* reducer_name() const override { return "CommonOperatorReducer"; }
 
diff --git a/deps/v8/src/compiler/common-operator.cc b/deps/v8/src/compiler/common-operator.cc
index 253a92eb84..9ed6943367 100644
--- a/deps/v8/src/compiler/common-operator.cc
+++ b/deps/v8/src/compiler/common-operator.cc
@@ -136,6 +136,13 @@ const Operator* CommonOperatorBuilder::MarkAsSafetyCheck(
   }
 }
 
+const Operator* CommonOperatorBuilder::DelayedStringConstant(
+    const StringConstantBase* str) {
+  return new (zone()) Operator1<const StringConstantBase*>(
+      IrOpcode::kDelayedStringConstant, Operator::kPure,
+      "DelayedStringConstant", 0, 0, 0, 1, 0, 0, str);
+}
+
 bool operator==(SelectParameters const& lhs, SelectParameters const& rhs) {
   return lhs.representation() == rhs.representation() &&
          lhs.hint() == rhs.hint();
@@ -1194,6 +1201,11 @@ Handle<HeapObject> HeapConstantOf(const Operator* op) {
   return OpParameter<Handle<HeapObject>>(op);
 }
 
+const StringConstantBase* StringConstantBaseOf(const Operator* op) {
+  DCHECK_EQ(IrOpcode::kDelayedStringConstant, op->opcode());
+  return OpParameter<const StringConstantBase*>(op);
+}
+
 const Operator* CommonOperatorBuilder::RelocatableInt32Constant(
     int32_t value, RelocInfo::Mode rmode) {
   return new (zone()) Operator1<RelocatablePtrConstantInfo>(  // --
@@ -1431,7 +1443,8 @@ const Operator* CommonOperatorBuilder::Call(
               Operator::ZeroIfNoThrow(call_descriptor->properties()),
               call_descriptor) {}
 
-    void PrintParameter(std::ostream& os, PrintVerbosity verbose) const {
+    void PrintParameter(std::ostream& os,
+                        PrintVerbosity verbose) const override {
       os << "[" << *parameter() << "]";
     }
   };
@@ -1455,7 +1468,8 @@ const Operator* CommonOperatorBuilder::CallWithCallerSavedRegisters(
               Operator::ZeroIfNoThrow(call_descriptor->properties()),
               call_descriptor) {}
 
-    void PrintParameter(std::ostream& os, PrintVerbosity verbose) const {
+    void PrintParameter(std::ostream& os,
+                        PrintVerbosity verbose) const override {
       os << "[" << *parameter() << "]";
     }
   };
@@ -1474,7 +1488,8 @@ const Operator* CommonOperatorBuilder::TailCall(
                   call_descriptor->FrameStateCount(),
               1, 1, 0, 0, 1, call_descriptor) {}
 
-    void PrintParameter(std::ostream& os, PrintVerbosity verbose) const {
+    void PrintParameter(std::ostream& os,
+                        PrintVerbosity verbose) const override {
       os << "[" << *parameter() << "]";
     }
   };
diff --git a/deps/v8/src/compiler/common-operator.h b/deps/v8/src/compiler/common-operator.h
index 9bdaedea20..609dfc8c1b 100644
--- a/deps/v8/src/compiler/common-operator.h
+++ b/deps/v8/src/compiler/common-operator.h
@@ -11,12 +11,16 @@
 #include "src/globals.h"
 #include "src/machine-type.h"
 #include "src/reloc-info.h"
+#include "src/string-constants.h"
 #include "src/vector-slot-pair.h"
 #include "src/zone/zone-containers.h"
 #include "src/zone/zone-handle-set.h"
 
 namespace v8 {
 namespace internal {
+
+class StringConstantBase;
+
 namespace compiler {
 
 // Forward declarations.
@@ -255,7 +259,7 @@ class SparseInputMask final {
   // An iterator over a node's sparse inputs.
   class InputIterator final {
    public:
-    InputIterator() {}
+    InputIterator() = default;
     InputIterator(BitMaskType bit_mask, Node* parent);
 
     Node* parent() const { return parent_; }
@@ -433,6 +437,9 @@ const FrameStateInfo& FrameStateInfoOf(const Operator* op)
 
 Handle<HeapObject> HeapConstantOf(const Operator* op) V8_WARN_UNUSED_RESULT;
 
+const StringConstantBase* StringConstantBaseOf(const Operator* op)
+    V8_WARN_UNUSED_RESULT;
+
 // Interface for building common operators that can be used at any level of IR,
 // including JavaScript, mid-level, and low-level.
 class V8_EXPORT_PRIVATE CommonOperatorBuilder final
@@ -535,6 +542,8 @@ class V8_EXPORT_PRIVATE CommonOperatorBuilder final
   const Operator* MarkAsSafetyCheck(const Operator* op,
                                     IsSafetyCheck safety_check);
 
+  const Operator* DelayedStringConstant(const StringConstantBase* str);
+
  private:
   Zone* zone() const { return zone_; }
 
diff --git a/deps/v8/src/compiler/compilation-dependencies.cc b/deps/v8/src/compiler/compilation-dependencies.cc
index b67adbd7ca..d5eb8b54be 100644
--- a/deps/v8/src/compiler/compilation-dependencies.cc
+++ b/deps/v8/src/compiler/compilation-dependencies.cc
@@ -17,7 +17,7 @@ CompilationDependencies::CompilationDependencies(Isolate* isolate, Zone* zone)
 class CompilationDependencies::Dependency : public ZoneObject {
  public:
   virtual bool IsValid() const = 0;
-  virtual void Install(MaybeObjectHandle code) = 0;
+  virtual void Install(const MaybeObjectHandle& code) = 0;
 };
 
 class InitialMapDependency final : public CompilationDependencies::Dependency {
@@ -36,7 +36,7 @@ class InitialMapDependency final : public CompilationDependencies::Dependency {
            function->initial_map() == *initial_map_.object<Map>();
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(function_.isolate(), code,
                                      initial_map_.object<Map>(),
@@ -68,7 +68,7 @@ class PrototypePropertyDependency final
            function->prototype() == *prototype_.object();
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     Handle<JSFunction> function = function_.object<JSFunction>();
     if (!function->has_initial_map()) JSFunction::EnsureHasInitialMap(function);
@@ -90,7 +90,7 @@ class StableMapDependency final : public CompilationDependencies::Dependency {
 
   bool IsValid() const override { return map_.object<Map>()->is_stable(); }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(map_.isolate(), code, map_.object<Map>(),
                                      DependentCode::kPrototypeCheckGroup);
@@ -108,7 +108,7 @@ class TransitionDependency final : public CompilationDependencies::Dependency {
 
   bool IsValid() const override { return !map_.object<Map>()->is_deprecated(); }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(map_.isolate(), code, map_.object<Map>(),
                                      DependentCode::kTransitionGroup);
@@ -132,7 +132,7 @@ class PretenureModeDependency final
     return mode_ == site_.object<AllocationSite>()->GetPretenureMode();
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(
         site_.isolate(), code, site_.object<AllocationSite>(),
@@ -162,7 +162,7 @@ class FieldTypeDependency final : public CompilationDependencies::Dependency {
     return *type == owner->instance_descriptors()->GetFieldType(descriptor_);
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(owner_.isolate(), code,
                                      owner_.object<Map>(),
@@ -193,7 +193,7 @@ class GlobalPropertyDependency final
            read_only_ == cell->property_details().IsReadOnly();
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(cell_.isolate(), code,
                                      cell_.object<PropertyCell>(),
@@ -217,7 +217,7 @@ class ProtectorDependency final : public CompilationDependencies::Dependency {
     return cell->value() == Smi::FromInt(Isolate::kProtectorValid);
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(cell_.isolate(), code,
                                      cell_.object<PropertyCell>(),
@@ -249,7 +249,7 @@ class ElementsKindDependency final
     return kind_ == kind;
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     SLOW_DCHECK(IsValid());
     DependentCode::InstallDependency(
         site_.isolate(), code, site_.object<AllocationSite>(),
@@ -271,13 +271,14 @@ class InitialMapInstanceSizePredictionDependency final
   bool IsValid() const override {
     // The dependency is valid if the prediction is the same as the current
     // slack tracking result.
+    if (!function_.object<JSFunction>()->has_initial_map()) return false;
     int instance_size =
         function_.object<JSFunction>()->ComputeInstanceSizeWithMinSlack(
             function_.isolate());
     return instance_size == instance_size_;
   }
 
-  void Install(MaybeObjectHandle code) override {
+  void Install(const MaybeObjectHandle& code) override {
     DCHECK(IsValid());
     // Finish the slack tracking.
     function_.object<JSFunction>()->CompleteInobjectSlackTrackingIfActive();
diff --git a/deps/v8/src/compiler/constant-folding-reducer.cc b/deps/v8/src/compiler/constant-folding-reducer.cc
index a447b2a07c..4508d90b71 100644
--- a/deps/v8/src/compiler/constant-folding-reducer.cc
+++ b/deps/v8/src/compiler/constant-folding-reducer.cc
@@ -17,7 +17,7 @@ ConstantFoldingReducer::ConstantFoldingReducer(Editor* editor, JSGraph* jsgraph,
       jsgraph_(jsgraph),
       js_heap_broker_(js_heap_broker) {}
 
-ConstantFoldingReducer::~ConstantFoldingReducer() {}
+ConstantFoldingReducer::~ConstantFoldingReducer() = default;
 
 Reduction ConstantFoldingReducer::Reduce(Node* node) {
   DisallowHeapAccess no_heap_access;
diff --git a/deps/v8/src/compiler/dead-code-elimination.h b/deps/v8/src/compiler/dead-code-elimination.h
index 217d58ef31..a1cab2f0f0 100644
--- a/deps/v8/src/compiler/dead-code-elimination.h
+++ b/deps/v8/src/compiler/dead-code-elimination.h
@@ -41,7 +41,7 @@ class V8_EXPORT_PRIVATE DeadCodeElimination final
  public:
   DeadCodeElimination(Editor* editor, Graph* graph,
                       CommonOperatorBuilder* common, Zone* temp_zone);
-  ~DeadCodeElimination() final {}
+  ~DeadCodeElimination() final = default;
 
   const char* reducer_name() const override { return "DeadCodeElimination"; }
 
diff --git a/deps/v8/src/compiler/effect-control-linearizer.cc b/deps/v8/src/compiler/effect-control-linearizer.cc
index 4bb4f8df77..97f78418d0 100644
--- a/deps/v8/src/compiler/effect-control-linearizer.cc
+++ b/deps/v8/src/compiler/effect-control-linearizer.cc
@@ -628,9 +628,15 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kChangeInt32ToTagged:
       result = LowerChangeInt32ToTagged(node);
       break;
+    case IrOpcode::kChangeInt64ToTagged:
+      result = LowerChangeInt64ToTagged(node);
+      break;
     case IrOpcode::kChangeUint32ToTagged:
       result = LowerChangeUint32ToTagged(node);
       break;
+    case IrOpcode::kChangeUint64ToTagged:
+      result = LowerChangeUint64ToTagged(node);
+      break;
     case IrOpcode::kChangeFloat64ToTagged:
       result = LowerChangeFloat64ToTagged(node);
       break;
@@ -640,6 +646,9 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kChangeTaggedSignedToInt32:
       result = LowerChangeTaggedSignedToInt32(node);
       break;
+    case IrOpcode::kChangeTaggedSignedToInt64:
+      result = LowerChangeTaggedSignedToInt64(node);
+      break;
     case IrOpcode::kChangeTaggedToBit:
       result = LowerChangeTaggedToBit(node);
       break;
@@ -649,6 +658,9 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kChangeTaggedToUint32:
       result = LowerChangeTaggedToUint32(node);
       break;
+    case IrOpcode::kChangeTaggedToInt64:
+      result = LowerChangeTaggedToInt64(node);
+      break;
     case IrOpcode::kChangeTaggedToFloat64:
       result = LowerChangeTaggedToFloat64(node);
       break;
@@ -718,12 +730,24 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kCheckedInt32ToTaggedSigned:
       result = LowerCheckedInt32ToTaggedSigned(node, frame_state);
       break;
+    case IrOpcode::kCheckedInt64ToInt32:
+      result = LowerCheckedInt64ToInt32(node, frame_state);
+      break;
+    case IrOpcode::kCheckedInt64ToTaggedSigned:
+      result = LowerCheckedInt64ToTaggedSigned(node, frame_state);
+      break;
     case IrOpcode::kCheckedUint32ToInt32:
       result = LowerCheckedUint32ToInt32(node, frame_state);
       break;
     case IrOpcode::kCheckedUint32ToTaggedSigned:
       result = LowerCheckedUint32ToTaggedSigned(node, frame_state);
       break;
+    case IrOpcode::kCheckedUint64ToInt32:
+      result = LowerCheckedUint64ToInt32(node, frame_state);
+      break;
+    case IrOpcode::kCheckedUint64ToTaggedSigned:
+      result = LowerCheckedUint64ToTaggedSigned(node, frame_state);
+      break;
     case IrOpcode::kCheckedFloat64ToInt32:
       result = LowerCheckedFloat64ToInt32(node, frame_state);
       break;
@@ -824,15 +848,15 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kNewConsString:
       result = LowerNewConsString(node);
       break;
-    case IrOpcode::kArrayBufferWasNeutered:
-      result = LowerArrayBufferWasNeutered(node);
-      break;
     case IrOpcode::kSameValue:
       result = LowerSameValue(node);
       break;
     case IrOpcode::kDeadValue:
       result = LowerDeadValue(node);
       break;
+    case IrOpcode::kStringConcat:
+      result = LowerStringConcat(node);
+      break;
     case IrOpcode::kStringFromSingleCharCode:
       result = LowerStringFromSingleCharCode(node);
       break;
@@ -1120,6 +1144,35 @@ Node* EffectControlLinearizer::LowerChangeInt32ToTagged(Node* node) {
   return done.PhiAt(0);
 }
 
+Node* EffectControlLinearizer::LowerChangeInt64ToTagged(Node* node) {
+  Node* value = node->InputAt(0);
+
+  auto if_not_in_smi_range = __ MakeDeferredLabel();
+  auto done = __ MakeLabel(MachineRepresentation::kTagged);
+
+  Node* value32 = __ TruncateInt64ToInt32(value);
+  __ GotoIfNot(__ Word64Equal(__ ChangeInt32ToInt64(value32), value),
+               &if_not_in_smi_range);
+
+  if (SmiValuesAre32Bits()) {
+    Node* value_smi = ChangeInt64ToSmi(value);
+    __ Goto(&done, value_smi);
+  } else {
+    Node* add = __ Int32AddWithOverflow(value32, value32);
+    Node* ovf = __ Projection(1, add);
+    __ GotoIf(ovf, &if_not_in_smi_range);
+    Node* value_smi = ChangeInt32ToIntPtr(__ Projection(0, add));
+    __ Goto(&done, value_smi);
+  }
+
+  __ Bind(&if_not_in_smi_range);
+  Node* number = AllocateHeapNumberWithValue(__ ChangeInt64ToFloat64(value));
+  __ Goto(&done, number);
+
+  __ Bind(&done);
+  return done.PhiAt(0);
+}
+
 Node* EffectControlLinearizer::LowerChangeUint32ToTagged(Node* node) {
   Node* value = node->InputAt(0);
 
@@ -1139,11 +1192,36 @@ Node* EffectControlLinearizer::LowerChangeUint32ToTagged(Node* node) {
   return done.PhiAt(0);
 }
 
+Node* EffectControlLinearizer::LowerChangeUint64ToTagged(Node* node) {
+  Node* value = node->InputAt(0);
+
+  auto if_not_in_smi_range = __ MakeDeferredLabel();
+  auto done = __ MakeLabel(MachineRepresentation::kTagged);
+
+  Node* check =
+      __ Uint64LessThanOrEqual(value, __ Int64Constant(Smi::kMaxValue));
+  __ GotoIfNot(check, &if_not_in_smi_range);
+  __ Goto(&done, ChangeInt64ToSmi(value));
+
+  __ Bind(&if_not_in_smi_range);
+  Node* number = AllocateHeapNumberWithValue(__ ChangeInt64ToFloat64(value));
+
+  __ Goto(&done, number);
+  __ Bind(&done);
+
+  return done.PhiAt(0);
+}
+
 Node* EffectControlLinearizer::LowerChangeTaggedSignedToInt32(Node* node) {
   Node* value = node->InputAt(0);
   return ChangeSmiToInt32(value);
 }
 
+Node* EffectControlLinearizer::LowerChangeTaggedSignedToInt64(Node* node) {
+  Node* value = node->InputAt(0);
+  return ChangeSmiToInt64(value);
+}
+
 Node* EffectControlLinearizer::LowerChangeTaggedToBit(Node* node) {
   Node* value = node->InputAt(0);
   return __ WordEqual(value, __ TrueConstant());
@@ -1280,6 +1358,26 @@ Node* EffectControlLinearizer::LowerChangeTaggedToUint32(Node* node) {
   return done.PhiAt(0);
 }
 
+Node* EffectControlLinearizer::LowerChangeTaggedToInt64(Node* node) {
+  Node* value = node->InputAt(0);
+
+  auto if_not_smi = __ MakeDeferredLabel();
+  auto done = __ MakeLabel(MachineRepresentation::kWord64);
+
+  Node* check = ObjectIsSmi(value);
+  __ GotoIfNot(check, &if_not_smi);
+  __ Goto(&done, ChangeSmiToInt64(value));
+
+  __ Bind(&if_not_smi);
+  STATIC_ASSERT(HeapNumber::kValueOffset == Oddball::kToNumberRawOffset);
+  Node* vfalse = __ LoadField(AccessBuilder::ForHeapNumberValue(), value);
+  vfalse = __ ChangeFloat64ToInt64(vfalse);
+  __ Goto(&done, vfalse);
+
+  __ Bind(&done);
+  return done.PhiAt(0);
+}
+
 Node* EffectControlLinearizer::LowerChangeTaggedToFloat64(Node* node) {
   return LowerTruncateTaggedToFloat64(node);
 }
@@ -1353,7 +1451,7 @@ void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
   size_t const map_count = maps.size();
 
   if (p.flags() & CheckMapsFlag::kTryMigrateInstance) {
-    auto done = __ MakeDeferredLabel();
+    auto done = __ MakeLabel();
     auto migrate = __ MakeDeferredLabel();
 
     // Load the current map of the {value}.
@@ -1364,10 +1462,11 @@ void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
       Node* map = __ HeapConstant(maps[i]);
       Node* check = __ WordEqual(value_map, map);
       if (i == map_count - 1) {
-        __ GotoIfNot(check, &migrate);
-        __ Goto(&done);
+        __ Branch(check, &done, &migrate, IsSafetyCheck::kCriticalSafetyCheck);
       } else {
-        __ GotoIf(check, &done);
+        auto next_map = __ MakeLabel();
+        __ Branch(check, &done, &next_map, IsSafetyCheck::kCriticalSafetyCheck);
+        __ Bind(&next_map);
       }
     }
 
@@ -1382,7 +1481,8 @@ void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
                        __ Int32Constant(Map::IsDeprecatedBit::kMask)),
           __ Int32Constant(0));
       __ DeoptimizeIf(DeoptimizeReason::kWrongMap, p.feedback(),
-                      if_not_deprecated, frame_state);
+                      if_not_deprecated, frame_state,
+                      IsSafetyCheck::kCriticalSafetyCheck);
 
       Operator::Properties properties = Operator::kNoDeopt | Operator::kNoThrow;
       Runtime::FunctionId id = Runtime::kTryMigrateInstance;
@@ -1393,7 +1493,7 @@ void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
                              __ Int32Constant(1), __ NoContextConstant());
       Node* check = ObjectIsSmi(result);
       __ DeoptimizeIf(DeoptimizeReason::kInstanceMigrationFailed, p.feedback(),
-                      check, frame_state);
+                      check, frame_state, IsSafetyCheck::kCriticalSafetyCheck);
     }
 
     // Reload the current map of the {value}.
@@ -1405,9 +1505,11 @@ void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
       Node* check = __ WordEqual(value_map, map);
       if (i == map_count - 1) {
         __ DeoptimizeIfNot(DeoptimizeReason::kWrongMap, p.feedback(), check,
-                           frame_state);
+                           frame_state, IsSafetyCheck::kCriticalSafetyCheck);
       } else {
-        __ GotoIf(check, &done);
+        auto next_map = __ MakeLabel();
+        __ Branch(check, &done, &next_map, IsSafetyCheck::kCriticalSafetyCheck);
+        __ Bind(&next_map);
       }
     }
 
@@ -1424,9 +1526,11 @@ void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
       Node* check = __ WordEqual(value_map, map);
       if (i == map_count - 1) {
         __ DeoptimizeIfNot(DeoptimizeReason::kWrongMap, p.feedback(), check,
-                           frame_state);
+                           frame_state, IsSafetyCheck::kCriticalSafetyCheck);
       } else {
-        __ GotoIf(check, &done);
+        auto next_map = __ MakeLabel();
+        __ Branch(check, &done, &next_map, IsSafetyCheck::kCriticalSafetyCheck);
+        __ Bind(&next_map);
       }
     }
     __ Goto(&done);
@@ -1447,7 +1551,14 @@ Node* EffectControlLinearizer::LowerCompareMaps(Node* node) {
   for (size_t i = 0; i < map_count; ++i) {
     Node* map = __ HeapConstant(maps[i]);
     Node* check = __ WordEqual(value_map, map);
-    __ GotoIf(check, &done, __ Int32Constant(1));
+    auto next_map = __ MakeLabel();
+    auto passed = __ MakeLabel();
+    __ Branch(check, &passed, &next_map, IsSafetyCheck::kCriticalSafetyCheck);
+
+    __ Bind(&passed);
+    __ Goto(&done, __ Int32Constant(1));
+
+    __ Bind(&next_map);
   }
   __ Goto(&done, __ Int32Constant(0));
 
@@ -1544,6 +1655,24 @@ void EffectControlLinearizer::LowerCheckIf(Node* node, Node* frame_state) {
   __ DeoptimizeIfNot(p.reason(), p.feedback(), value, frame_state);
 }
 
+Node* EffectControlLinearizer::LowerStringConcat(Node* node) {
+  Node* lhs = node->InputAt(1);
+  Node* rhs = node->InputAt(2);
+
+  Callable const callable =
+      CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE);
+  auto call_descriptor = Linkage::GetStubCallDescriptor(
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), CallDescriptor::kNoFlags,
+      Operator::kNoDeopt | Operator::kNoWrite | Operator::kNoThrow);
+
+  Node* value =
+      __ Call(call_descriptor, jsgraph()->HeapConstant(callable.code()), lhs,
+              rhs, __ NoContextConstant());
+
+  return value;
+}
+
 Node* EffectControlLinearizer::LowerCheckedInt32Add(Node* node,
                                                     Node* frame_state) {
   Node* lhs = node->InputAt(0);
@@ -1572,63 +1701,87 @@ Node* EffectControlLinearizer::LowerCheckedInt32Div(Node* node,
                                                     Node* frame_state) {
   Node* lhs = node->InputAt(0);
   Node* rhs = node->InputAt(1);
-
-  auto if_not_positive = __ MakeDeferredLabel();
-  auto if_is_minint = __ MakeDeferredLabel();
-  auto done = __ MakeLabel(MachineRepresentation::kWord32);
-  auto minint_check_done = __ MakeLabel();
-
   Node* zero = __ Int32Constant(0);
 
-  // Check if {rhs} is positive (and not zero).
-  Node* check0 = __ Int32LessThan(zero, rhs);
-  __ GotoIfNot(check0, &if_not_positive);
+  // Check if the {rhs} is a known power of two.
+  Int32Matcher m(rhs);
+  if (m.IsPowerOf2()) {
+    // Since we know that {rhs} is a power of two, we can perform a fast
+    // check to see if the relevant least significant bits of the {lhs}
+    // are all zero, and if so we know that we can perform a division
+    // safely (and fast by doing an arithmetic - aka sign preserving -
+    // right shift on {lhs}).
+    int32_t divisor = m.Value();
+    Node* mask = __ Int32Constant(divisor - 1);
+    Node* shift = __ Int32Constant(WhichPowerOf2(divisor));
+    Node* check = __ Word32Equal(__ Word32And(lhs, mask), zero);
+    __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, VectorSlotPair(),
+                       check, frame_state);
+    return __ Word32Sar(lhs, shift);
+  } else {
+    auto if_rhs_positive = __ MakeLabel();
+    auto if_rhs_negative = __ MakeDeferredLabel();
+    auto done = __ MakeLabel(MachineRepresentation::kWord32);
 
-  // Fast case, no additional checking required.
-  __ Goto(&done, __ Int32Div(lhs, rhs));
+    // Check if {rhs} is positive (and not zero).
+    Node* check_rhs_positive = __ Int32LessThan(zero, rhs);
+    __ Branch(check_rhs_positive, &if_rhs_positive, &if_rhs_negative);
 
-  {
-    __ Bind(&if_not_positive);
+    __ Bind(&if_rhs_positive);
+    {
+      // Fast case, no additional checking required.
+      __ Goto(&done, __ Int32Div(lhs, rhs));
+    }
 
-    // Check if {rhs} is zero.
-    Node* check = __ Word32Equal(rhs, zero);
-    __ DeoptimizeIf(DeoptimizeReason::kDivisionByZero, VectorSlotPair(), check,
-                    frame_state);
+    __ Bind(&if_rhs_negative);
+    {
+      auto if_lhs_minint = __ MakeDeferredLabel();
+      auto if_lhs_notminint = __ MakeLabel();
+
+      // Check if {rhs} is zero.
+      Node* check_rhs_zero = __ Word32Equal(rhs, zero);
+      __ DeoptimizeIf(DeoptimizeReason::kDivisionByZero, VectorSlotPair(),
+                      check_rhs_zero, frame_state);
+
+      // Check if {lhs} is zero, as that would produce minus zero.
+      Node* check_lhs_zero = __ Word32Equal(lhs, zero);
+      __ DeoptimizeIf(DeoptimizeReason::kMinusZero, VectorSlotPair(),
+                      check_lhs_zero, frame_state);
+
+      // Check if {lhs} is kMinInt and {rhs} is -1, in which case we'd have
+      // to return -kMinInt, which is not representable as Word32.
+      Node* check_lhs_minint = graph()->NewNode(machine()->Word32Equal(), lhs,
+                                                __ Int32Constant(kMinInt));
+      __ Branch(check_lhs_minint, &if_lhs_minint, &if_lhs_notminint);
+
+      __ Bind(&if_lhs_minint);
+      {
+        // Check that {rhs} is not -1, otherwise result would be -kMinInt.
+        Node* check_rhs_minusone = __ Word32Equal(rhs, __ Int32Constant(-1));
+        __ DeoptimizeIf(DeoptimizeReason::kOverflow, VectorSlotPair(),
+                        check_rhs_minusone, frame_state);
 
-    // Check if {lhs} is zero, as that would produce minus zero.
-    check = __ Word32Equal(lhs, zero);
-    __ DeoptimizeIf(DeoptimizeReason::kMinusZero, VectorSlotPair(), check,
-                    frame_state);
+        // Perform the actual integer division.
+        __ Goto(&done, __ Int32Div(lhs, rhs));
+      }
 
-    // Check if {lhs} is kMinInt and {rhs} is -1, in which case we'd have
-    // to return -kMinInt, which is not representable.
-    Node* minint = __ Int32Constant(std::numeric_limits<int32_t>::min());
-    Node* check1 = graph()->NewNode(machine()->Word32Equal(), lhs, minint);
-    __ GotoIf(check1, &if_is_minint);
-    __ Goto(&minint_check_done);
-
-    __ Bind(&if_is_minint);
-    // Check if {rhs} is -1.
-    Node* minusone = __ Int32Constant(-1);
-    Node* is_minus_one = __ Word32Equal(rhs, minusone);
-    __ DeoptimizeIf(DeoptimizeReason::kOverflow, VectorSlotPair(), is_minus_one,
-                    frame_state);
-    __ Goto(&minint_check_done);
+      __ Bind(&if_lhs_notminint);
+      {
+        // Perform the actual integer division.
+        __ Goto(&done, __ Int32Div(lhs, rhs));
+      }
+    }
 
-    __ Bind(&minint_check_done);
-    // Perform the actual integer division.
-    __ Goto(&done, __ Int32Div(lhs, rhs));
-  }
+    __ Bind(&done);
+    Node* value = done.PhiAt(0);
 
-  __ Bind(&done);
-  Node* value = done.PhiAt(0);
+    // Check if the remainder is non-zero.
+    Node* check = __ Word32Equal(lhs, __ Int32Mul(value, rhs));
+    __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, VectorSlotPair(),
+                       check, frame_state);
 
-  // Check if the remainder is non-zero.
-  Node* check = __ Word32Equal(lhs, __ Int32Mul(rhs, value));
-  __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, VectorSlotPair(), check,
-                     frame_state);
-
-  return value;
+    return value;
+  }
 }
 
 Node* EffectControlLinearizer::BuildUint32Mod(Node* lhs, Node* rhs) {
@@ -1722,8 +1875,11 @@ Node* EffectControlLinearizer::LowerCheckedInt32Mod(Node* node,
 
   __ Bind(&if_lhs_negative);
   {
-    // The {lhs} is a negative integer.
-    Node* res = BuildUint32Mod(__ Int32Sub(zero, lhs), rhs);
+    // The {lhs} is a negative integer. This is very unlikely and
+    // we intentionally don't use the BuildUint32Mod() here, which
+    // would try to figure out whether {rhs} is a power of two,
+    // since this is intended to be a slow-path.
+    Node* res = __ Uint32Mod(__ Int32Sub(zero, lhs), rhs);
 
     // Check if we would have to return -0.
     __ DeoptimizeIf(DeoptimizeReason::kMinusZero, VectorSlotPair(),
@@ -1739,22 +1895,38 @@ Node* EffectControlLinearizer::LowerCheckedUint32Div(Node* node,
                                                      Node* frame_state) {
   Node* lhs = node->InputAt(0);
   Node* rhs = node->InputAt(1);
-
   Node* zero = __ Int32Constant(0);
 
-  // Ensure that {rhs} is not zero, otherwise we'd have to return NaN.
-  Node* check = __ Word32Equal(rhs, zero);
-  __ DeoptimizeIf(DeoptimizeReason::kDivisionByZero, VectorSlotPair(), check,
-                  frame_state);
+  // Check if the {rhs} is a known power of two.
+  Uint32Matcher m(rhs);
+  if (m.IsPowerOf2()) {
+    // Since we know that {rhs} is a power of two, we can perform a fast
+    // check to see if the relevant least significant bits of the {lhs}
+    // are all zero, and if so we know that we can perform a division
+    // safely (and fast by doing a logical - aka zero extending - right
+    // shift on {lhs}).
+    uint32_t divisor = m.Value();
+    Node* mask = __ Uint32Constant(divisor - 1);
+    Node* shift = __ Uint32Constant(WhichPowerOf2(divisor));
+    Node* check = __ Word32Equal(__ Word32And(lhs, mask), zero);
+    __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, VectorSlotPair(),
+                       check, frame_state);
+    return __ Word32Shr(lhs, shift);
+  } else {
+    // Ensure that {rhs} is not zero, otherwise we'd have to return NaN.
+    Node* check = __ Word32Equal(rhs, zero);
+    __ DeoptimizeIf(DeoptimizeReason::kDivisionByZero, VectorSlotPair(), check,
+                    frame_state);
 
-  // Perform the actual unsigned integer division.
-  Node* value = __ Uint32Div(lhs, rhs);
+    // Perform the actual unsigned integer division.
+    Node* value = __ Uint32Div(lhs, rhs);
 
-  // Check if the remainder is non-zero.
-  check = __ Word32Equal(lhs, __ Int32Mul(rhs, value));
-  __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, VectorSlotPair(), check,
-                     frame_state);
-  return value;
+    // Check if the remainder is non-zero.
+    check = __ Word32Equal(lhs, __ Int32Mul(rhs, value));
+    __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, VectorSlotPair(),
+                       check, frame_state);
+    return value;
+  }
 }
 
 Node* EffectControlLinearizer::LowerCheckedUint32Mod(Node* node,
@@ -1815,13 +1987,48 @@ Node* EffectControlLinearizer::LowerCheckedInt32ToTaggedSigned(
 
   Node* add = __ Int32AddWithOverflow(value, value);
   Node* check = __ Projection(1, add);
-  __ DeoptimizeIf(DeoptimizeReason::kOverflow, params.feedback(), check,
+  __ DeoptimizeIf(DeoptimizeReason::kLostPrecision, params.feedback(), check,
                   frame_state);
   Node* result = __ Projection(0, add);
   result = ChangeInt32ToIntPtr(result);
   return result;
 }
 
+Node* EffectControlLinearizer::LowerCheckedInt64ToInt32(Node* node,
+                                                        Node* frame_state) {
+  Node* value = node->InputAt(0);
+  const CheckParameters& params = CheckParametersOf(node->op());
+
+  Node* value32 = __ TruncateInt64ToInt32(value);
+  Node* check = __ Word64Equal(__ ChangeInt32ToInt64(value32), value);
+  __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, params.feedback(), check,
+                     frame_state);
+  return value32;
+}
+
+Node* EffectControlLinearizer::LowerCheckedInt64ToTaggedSigned(
+    Node* node, Node* frame_state) {
+  Node* value = node->InputAt(0);
+  const CheckParameters& params = CheckParametersOf(node->op());
+
+  Node* value32 = __ TruncateInt64ToInt32(value);
+  Node* check = __ Word64Equal(__ ChangeInt32ToInt64(value32), value);
+  __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, params.feedback(), check,
+                     frame_state);
+
+  if (SmiValuesAre32Bits()) {
+    return ChangeInt64ToSmi(value);
+  } else {
+    Node* add = __ Int32AddWithOverflow(value32, value32);
+    Node* check = __ Projection(1, add);
+    __ DeoptimizeIf(DeoptimizeReason::kLostPrecision, params.feedback(), check,
+                    frame_state);
+    Node* result = __ Projection(0, add);
+    result = ChangeInt32ToIntPtr(result);
+    return result;
+  }
+}
+
 Node* EffectControlLinearizer::LowerCheckedUint32ToInt32(Node* node,
                                                          Node* frame_state) {
   Node* value = node->InputAt(0);
@@ -1842,6 +2049,29 @@ Node* EffectControlLinearizer::LowerCheckedUint32ToTaggedSigned(
   return ChangeUint32ToSmi(value);
 }
 
+Node* EffectControlLinearizer::LowerCheckedUint64ToInt32(Node* node,
+                                                         Node* frame_state) {
+  Node* value = node->InputAt(0);
+  const CheckParameters& params = CheckParametersOf(node->op());
+
+  Node* check = __ Uint64LessThanOrEqual(value, __ Int64Constant(kMaxInt));
+  __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, params.feedback(), check,
+                     frame_state);
+  return __ TruncateInt64ToInt32(value);
+}
+
+Node* EffectControlLinearizer::LowerCheckedUint64ToTaggedSigned(
+    Node* node, Node* frame_state) {
+  Node* value = node->InputAt(0);
+  const CheckParameters& params = CheckParametersOf(node->op());
+
+  Node* check =
+      __ Uint64LessThanOrEqual(value, __ Int64Constant(Smi::kMaxValue));
+  __ DeoptimizeIfNot(DeoptimizeReason::kLostPrecision, params.feedback(), check,
+                     frame_state);
+  return ChangeInt64ToSmi(value);
+}
+
 Node* EffectControlLinearizer::BuildCheckedFloat64ToInt32(
     CheckForMinusZeroMode mode, const VectorSlotPair& feedback, Node* value,
     Node* frame_state) {
@@ -2065,7 +2295,8 @@ Node* EffectControlLinearizer::LowerNumberToString(Node* node) {
   Operator::Properties properties = Operator::kEliminatable;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), argument,
                  __ NoContextConstant());
 }
@@ -2521,7 +2752,8 @@ Node* EffectControlLinearizer::LowerTypeOf(Node* node) {
   Operator::Properties const properties = Operator::kEliminatable;
   CallDescriptor::Flags const flags = CallDescriptor::kNoAllocate;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), obj,
                  __ NoContextConstant());
 }
@@ -2533,7 +2765,8 @@ Node* EffectControlLinearizer::LowerToBoolean(Node* node) {
   Operator::Properties const properties = Operator::kEliminatable;
   CallDescriptor::Flags const flags = CallDescriptor::kNoAllocate;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), obj,
                  __ NoContextConstant());
 }
@@ -2721,7 +2954,8 @@ Node* EffectControlLinearizer::LowerNewArgumentsElements(Node* node) {
   Operator::Properties const properties = node->op()->properties();
   CallDescriptor::Flags const flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), frame,
                  length, __ SmiConstant(mapped_count), __ NoContextConstant());
 }
@@ -2765,26 +2999,13 @@ Node* EffectControlLinearizer::LowerNewConsString(Node* node) {
   Node* result = __ Allocate(NOT_TENURED, __ Int32Constant(ConsString::kSize));
   __ StoreField(AccessBuilder::ForMap(), result, result_map);
   __ StoreField(AccessBuilder::ForNameHashField(), result,
-                jsgraph()->Int32Constant(Name::kEmptyHashField));
+                __ Int32Constant(Name::kEmptyHashField));
   __ StoreField(AccessBuilder::ForStringLength(), result, length);
   __ StoreField(AccessBuilder::ForConsStringFirst(), result, first);
   __ StoreField(AccessBuilder::ForConsStringSecond(), result, second);
   return result;
 }
 
-Node* EffectControlLinearizer::LowerArrayBufferWasNeutered(Node* node) {
-  Node* value = node->InputAt(0);
-
-  Node* value_bit_field =
-      __ LoadField(AccessBuilder::ForJSArrayBufferBitField(), value);
-  return __ Word32Equal(
-      __ Word32Equal(
-          __ Word32And(value_bit_field,
-                       __ Int32Constant(JSArrayBuffer::WasNeutered::kMask)),
-          __ Int32Constant(0)),
-      __ Int32Constant(0));
-}
-
 Node* EffectControlLinearizer::LowerSameValue(Node* node) {
   Node* lhs = node->InputAt(0);
   Node* rhs = node->InputAt(1);
@@ -2794,7 +3015,8 @@ Node* EffectControlLinearizer::LowerSameValue(Node* node) {
   Operator::Properties properties = Operator::kEliminatable;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), lhs, rhs,
                  __ NoContextConstant());
 }
@@ -2816,7 +3038,8 @@ Node* EffectControlLinearizer::LowerStringToNumber(Node* node) {
   Operator::Properties properties = Operator::kEliminatable;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), string,
                  __ NoContextConstant());
 }
@@ -2828,9 +3051,9 @@ Node* EffectControlLinearizer::LowerStringCharCodeAt(Node* node) {
   // We need a loop here to properly deal with indirect strings
   // (SlicedString, ConsString and ThinString).
   auto loop = __ MakeLoopLabel(MachineRepresentation::kTagged,
-                               MachineRepresentation::kWord32);
+                               MachineType::PointerRepresentation());
   auto loop_next = __ MakeLabel(MachineRepresentation::kTagged,
-                                MachineRepresentation::kWord32);
+                                MachineType::PointerRepresentation());
   auto loop_done = __ MakeLabel(MachineRepresentation::kWord32);
   __ Goto(&loop, receiver, position);
   __ Bind(&loop);
@@ -2897,11 +3120,11 @@ Node* EffectControlLinearizer::LowerStringCharCodeAt(Node* node) {
 
     __ Bind(&if_externalstring);
     {
-      // We need to bailout to the runtime for short external strings.
+      // We need to bailout to the runtime for uncached external strings.
       __ GotoIf(__ Word32Equal(
                     __ Word32And(receiver_instance_type,
-                                 __ Int32Constant(kShortExternalStringMask)),
-                    __ Int32Constant(kShortExternalStringTag)),
+                                 __ Int32Constant(kUncachedExternalStringMask)),
+                    __ Int32Constant(kUncachedExternalStringTag)),
                 &if_runtime);
 
       Node* receiver_data = __ LoadField(
@@ -2917,16 +3140,14 @@ Node* EffectControlLinearizer::LowerStringCharCodeAt(Node* node) {
 
       __ Bind(&if_onebyte);
       {
-        Node* result = __ Load(MachineType::Uint8(), receiver_data,
-                               ChangeInt32ToIntPtr(position));
+        Node* result = __ Load(MachineType::Uint8(), receiver_data, position);
         __ Goto(&loop_done, result);
       }
 
       __ Bind(&if_twobyte);
       {
-        Node* result = __ Load(
-            MachineType::Uint16(), receiver_data,
-            __ Word32Shl(ChangeInt32ToIntPtr(position), __ Int32Constant(1)));
+        Node* result = __ Load(MachineType::Uint16(), receiver_data,
+                               __ WordShl(position, __ IntPtrConstant(1)));
         __ Goto(&loop_done, result);
       }
     }
@@ -2938,7 +3159,7 @@ Node* EffectControlLinearizer::LowerStringCharCodeAt(Node* node) {
       Node* receiver_parent =
           __ LoadField(AccessBuilder::ForSlicedStringParent(), receiver);
       __ Goto(&loop_next, receiver_parent,
-              __ Int32Add(position, ChangeSmiToInt32(receiver_offset)));
+              __ IntAdd(position, ChangeSmiToIntPtr(receiver_offset)));
     }
 
     __ Bind(&if_runtime);
@@ -2948,7 +3169,7 @@ Node* EffectControlLinearizer::LowerStringCharCodeAt(Node* node) {
       auto call_descriptor = Linkage::GetRuntimeCallDescriptor(
           graph()->zone(), id, 2, properties, CallDescriptor::kNoFlags);
       Node* result = __ Call(call_descriptor, __ CEntryStubConstant(1),
-                             receiver, ChangeInt32ToSmi(position),
+                             receiver, ChangeIntPtrToSmi(position),
                              __ ExternalConstant(ExternalReference::Create(id)),
                              __ Int32Constant(2), __ NoContextConstant());
       __ Goto(&loop_done, ChangeSmiToInt32(result));
@@ -2974,7 +3195,8 @@ Node* EffectControlLinearizer::LowerStringCodePointAt(
   Operator::Properties properties = Operator::kNoThrow | Operator::kNoWrite;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), receiver,
                  position, __ NoContextConstant());
 }
@@ -3035,9 +3257,9 @@ Node* EffectControlLinearizer::LowerStringFromSingleCharCode(Node* node) {
       __ StoreField(AccessBuilder::ForMap(), vtrue2,
                     __ HeapConstant(factory()->one_byte_string_map()));
       __ StoreField(AccessBuilder::ForNameHashField(), vtrue2,
-                    __ IntPtrConstant(Name::kEmptyHashField));
+                    __ Int32Constant(Name::kEmptyHashField));
       __ StoreField(AccessBuilder::ForStringLength(), vtrue2,
-                    __ SmiConstant(1));
+                    __ Int32Constant(1));
       __ Store(
           StoreRepresentation(MachineRepresentation::kWord8, kNoWriteBarrier),
           vtrue2,
@@ -3059,8 +3281,9 @@ Node* EffectControlLinearizer::LowerStringFromSingleCharCode(Node* node) {
     __ StoreField(AccessBuilder::ForMap(), vfalse1,
                   __ HeapConstant(factory()->string_map()));
     __ StoreField(AccessBuilder::ForNameHashField(), vfalse1,
-                  __ IntPtrConstant(Name::kEmptyHashField));
-    __ StoreField(AccessBuilder::ForStringLength(), vfalse1, __ SmiConstant(1));
+                  __ Int32Constant(Name::kEmptyHashField));
+    __ StoreField(AccessBuilder::ForStringLength(), vfalse1,
+                  __ Int32Constant(1));
     __ Store(
         StoreRepresentation(MachineRepresentation::kWord16, kNoWriteBarrier),
         vfalse1,
@@ -3083,7 +3306,8 @@ Node* EffectControlLinearizer::LowerStringToLowerCaseIntl(Node* node) {
   Operator::Properties properties = Operator::kNoDeopt | Operator::kNoThrow;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), receiver,
                  __ NoContextConstant());
 }
@@ -3157,9 +3381,9 @@ Node* EffectControlLinearizer::LowerStringFromSingleCodePoint(Node* node) {
         __ StoreField(AccessBuilder::ForMap(), vtrue2,
                       __ HeapConstant(factory()->one_byte_string_map()));
         __ StoreField(AccessBuilder::ForNameHashField(), vtrue2,
-                      __ IntPtrConstant(Name::kEmptyHashField));
+                      __ Int32Constant(Name::kEmptyHashField));
         __ StoreField(AccessBuilder::ForStringLength(), vtrue2,
-                      __ SmiConstant(1));
+                      __ Int32Constant(1));
         __ Store(
             StoreRepresentation(MachineRepresentation::kWord8, kNoWriteBarrier),
             vtrue2,
@@ -3183,7 +3407,7 @@ Node* EffectControlLinearizer::LowerStringFromSingleCodePoint(Node* node) {
       __ StoreField(AccessBuilder::ForNameHashField(), vfalse1,
                     __ IntPtrConstant(Name::kEmptyHashField));
       __ StoreField(AccessBuilder::ForStringLength(), vfalse1,
-                    __ SmiConstant(1));
+                    __ Int32Constant(1));
       __ Store(
           StoreRepresentation(MachineRepresentation::kWord16, kNoWriteBarrier),
           vfalse1,
@@ -3228,8 +3452,9 @@ Node* EffectControlLinearizer::LowerStringFromSingleCodePoint(Node* node) {
     __ StoreField(AccessBuilder::ForMap(), vfalse0,
                   __ HeapConstant(factory()->string_map()));
     __ StoreField(AccessBuilder::ForNameHashField(), vfalse0,
-                  __ IntPtrConstant(Name::kEmptyHashField));
-    __ StoreField(AccessBuilder::ForStringLength(), vfalse0, __ SmiConstant(2));
+                  __ Int32Constant(Name::kEmptyHashField));
+    __ StoreField(AccessBuilder::ForStringLength(), vfalse0,
+                  __ Int32Constant(2));
     __ Store(
         StoreRepresentation(MachineRepresentation::kWord32, kNoWriteBarrier),
         vfalse0,
@@ -3252,7 +3477,8 @@ Node* EffectControlLinearizer::LowerStringIndexOf(Node* node) {
   Operator::Properties properties = Operator::kEliminatable;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), subject,
                  search_string, position, __ NoContextConstant());
 }
@@ -3271,7 +3497,8 @@ Node* EffectControlLinearizer::LowerStringComparison(Callable const& callable,
   Operator::Properties properties = Operator::kEliminatable;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), lhs, rhs,
                  __ NoContextConstant());
 }
@@ -3286,7 +3513,8 @@ Node* EffectControlLinearizer::LowerStringSubstring(Node* node) {
   Operator::Properties properties = Operator::kEliminatable;
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   return __ Call(call_descriptor, __ HeapConstant(callable.code()), receiver,
                  start, end, __ NoContextConstant());
 }
@@ -3314,10 +3542,25 @@ Node* EffectControlLinearizer::LowerCheckFloat64Hole(Node* node,
   CheckFloat64HoleParameters const& params =
       CheckFloat64HoleParametersOf(node->op());
   Node* value = node->InputAt(0);
-  Node* check = __ Word32Equal(__ Float64ExtractHighWord32(value),
-                               __ Int32Constant(kHoleNanUpper32));
-  __ DeoptimizeIf(DeoptimizeReason::kHole, params.feedback(), check,
-                  frame_state);
+
+  auto if_nan = __ MakeDeferredLabel();
+  auto done = __ MakeLabel();
+
+  // First check whether {value} is a NaN at all...
+  __ Branch(__ Float64Equal(value, value), &done, &if_nan);
+
+  __ Bind(&if_nan);
+  {
+    // ...and only if {value} is a NaN, perform the expensive bit
+    // check. See http://crbug.com/v8/8264 for details.
+    Node* check = __ Word32Equal(__ Float64ExtractHighWord32(value),
+                                 __ Int32Constant(kHoleNanUpper32));
+    __ DeoptimizeIf(DeoptimizeReason::kHole, params.feedback(), check,
+                    frame_state);
+    __ Goto(&done);
+  }
+
+  __ Bind(&done);
   return value;
 }
 
@@ -3440,8 +3683,8 @@ Node* EffectControlLinearizer::AllocateHeapNumberWithValue(Node* value) {
   return result;
 }
 
-Node* EffectControlLinearizer::ChangeInt32ToSmi(Node* value) {
-  return __ WordShl(ChangeInt32ToIntPtr(value), SmiShiftBitsConstant());
+Node* EffectControlLinearizer::ChangeIntPtrToSmi(Node* value) {
+  return __ WordShl(value, SmiShiftBitsConstant());
 }
 
 Node* EffectControlLinearizer::ChangeInt32ToIntPtr(Node* value) {
@@ -3458,6 +3701,15 @@ Node* EffectControlLinearizer::ChangeIntPtrToInt32(Node* value) {
   return value;
 }
 
+Node* EffectControlLinearizer::ChangeInt32ToSmi(Node* value) {
+  return ChangeIntPtrToSmi(ChangeInt32ToIntPtr(value));
+}
+
+Node* EffectControlLinearizer::ChangeInt64ToSmi(Node* value) {
+  DCHECK(machine()->Is64());
+  return ChangeIntPtrToSmi(value);
+}
+
 Node* EffectControlLinearizer::ChangeUint32ToUintPtr(Node* value) {
   if (machine()->Is64()) {
     value = __ ChangeUint32ToUint64(value);
@@ -3482,6 +3734,11 @@ Node* EffectControlLinearizer::ChangeSmiToInt32(Node* value) {
   return value;
 }
 
+Node* EffectControlLinearizer::ChangeSmiToInt64(Node* value) {
+  CHECK(machine()->Is64());
+  return ChangeSmiToIntPtr(value);
+}
+
 Node* EffectControlLinearizer::ObjectIsSmi(Node* value) {
   return __ WordEqual(__ WordAnd(value, __ IntPtrConstant(kSmiTagMask)),
                       __ IntPtrConstant(kSmiTag));
@@ -3578,7 +3835,8 @@ Node* EffectControlLinearizer::LowerEnsureWritableFastElements(Node* node) {
       Builtins::CallableFor(isolate(), Builtins::kCopyFastSmiOrObjectElements);
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), flags, properties);
   Node* result = __ Call(call_descriptor, __ HeapConstant(callable.code()),
                          object, __ NoContextConstant());
   __ Goto(&done, result);
@@ -3614,7 +3872,8 @@ Node* EffectControlLinearizer::LowerMaybeGrowFastElements(Node* node,
                                   Builtins::kGrowFastSmiOrObjectElements);
   CallDescriptor::Flags call_flags = CallDescriptor::kNoFlags;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, call_flags, properties);
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), call_flags, properties);
   Node* new_elements =
       __ Call(call_descriptor, __ HeapConstant(callable.code()), object,
               ChangeInt32ToSmi(index), __ NoContextConstant());
@@ -3830,12 +4089,6 @@ Node* EffectControlLinearizer::LowerLoadDataViewElement(Node* node) {
   Node* index = node->InputAt(2);
   Node* is_little_endian = node->InputAt(3);
 
-  // On 64-bit platforms, we need to feed a Word64 index to the Load and
-  // Store operators.
-  if (machine()->Is64()) {
-    index = __ ChangeUint32ToUint64(index);
-  }
-
   // We need to keep the {buffer} alive so that the GC will not release the
   // ArrayBuffer (if there's any) as long as we are still operating on it.
   __ Retain(buffer);
@@ -3878,12 +4131,6 @@ void EffectControlLinearizer::LowerStoreDataViewElement(Node* node) {
   Node* value = node->InputAt(3);
   Node* is_little_endian = node->InputAt(4);
 
-  // On 64-bit platforms, we need to feed a Word64 index to the Load and
-  // Store operators.
-  if (machine()->Is64()) {
-    index = __ ChangeUint32ToUint64(index);
-  }
-
   // We need to keep the {buffer} alive so that the GC will not release the
   // ArrayBuffer (if there's any) as long as we are still operating on it.
   __ Retain(buffer);
@@ -4366,7 +4613,8 @@ Node* EffectControlLinearizer::LowerConvertReceiver(Node* node) {
       Callable callable = Builtins::CallableFor(isolate(), Builtins::kToObject);
       CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
       auto call_descriptor = Linkage::GetStubCallDescriptor(
-          graph()->zone(), callable.descriptor(), 0, flags, properties);
+          graph()->zone(), callable.descriptor(),
+          callable.descriptor().GetStackParameterCount(), flags, properties);
       Node* native_context = __ LoadField(
           AccessBuilder::ForJSGlobalProxyNativeContext(), global_proxy);
       Node* result = __ Call(call_descriptor, __ HeapConstant(callable.code()),
@@ -4401,7 +4649,8 @@ Node* EffectControlLinearizer::LowerConvertReceiver(Node* node) {
       Callable callable = Builtins::CallableFor(isolate(), Builtins::kToObject);
       CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
       auto call_descriptor = Linkage::GetStubCallDescriptor(
-          graph()->zone(), callable.descriptor(), 0, flags, properties);
+          graph()->zone(), callable.descriptor(),
+          callable.descriptor().GetStackParameterCount(), flags, properties);
       Node* native_context = __ LoadField(
           AccessBuilder::ForJSGlobalProxyNativeContext(), global_proxy);
       Node* result = __ Call(call_descriptor, __ HeapConstant(callable.code()),
@@ -4762,7 +5011,8 @@ Node* EffectControlLinearizer::LowerFindOrderedHashMapEntry(Node* node) {
     Operator::Properties const properties = node->op()->properties();
     CallDescriptor::Flags const flags = CallDescriptor::kNoFlags;
     auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), 0, flags, properties);
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(), flags, properties);
     return __ Call(call_descriptor, __ HeapConstant(callable.code()), table,
                    key, __ NoContextConstant());
   }
@@ -4799,14 +5049,14 @@ Node* EffectControlLinearizer::LowerFindOrderedHashMapEntryForInt32Key(
                                   kHeapObjectTag))));
 
   auto loop = __ MakeLoopLabel(MachineType::PointerRepresentation());
-  auto done = __ MakeLabel(MachineRepresentation::kWord32);
+  auto done = __ MakeLabel(MachineType::PointerRepresentation());
   __ Goto(&loop, first_entry);
   __ Bind(&loop);
   {
     Node* entry = loop.PhiAt(0);
     Node* check =
         __ WordEqual(entry, __ IntPtrConstant(OrderedHashMap::kNotFound));
-    __ GotoIf(check, &done, __ Int32Constant(-1));
+    __ GotoIf(check, &done, entry);
     entry = __ IntAdd(
         __ IntMul(entry, __ IntPtrConstant(OrderedHashMap::kEntrySize)),
         number_of_buckets);
@@ -4835,10 +5085,7 @@ Node* EffectControlLinearizer::LowerFindOrderedHashMapEntryForInt32Key(
               &if_match, &if_notmatch);
 
     __ Bind(&if_match);
-    {
-      Node* index = ChangeIntPtrToInt32(entry);
-      __ Goto(&done, index);
-    }
+    __ Goto(&done, entry);
 
     __ Bind(&if_notmatch);
     {
diff --git a/deps/v8/src/compiler/effect-control-linearizer.h b/deps/v8/src/compiler/effect-control-linearizer.h
index 272bc44599..fcc4cad728 100644
--- a/deps/v8/src/compiler/effect-control-linearizer.h
+++ b/deps/v8/src/compiler/effect-control-linearizer.h
@@ -49,13 +49,17 @@ class V8_EXPORT_PRIVATE EffectControlLinearizer {
   Node* LowerChangeBitToTagged(Node* node);
   Node* LowerChangeInt31ToTaggedSigned(Node* node);
   Node* LowerChangeInt32ToTagged(Node* node);
+  Node* LowerChangeInt64ToTagged(Node* node);
   Node* LowerChangeUint32ToTagged(Node* node);
+  Node* LowerChangeUint64ToTagged(Node* node);
   Node* LowerChangeFloat64ToTagged(Node* node);
   Node* LowerChangeFloat64ToTaggedPointer(Node* node);
   Node* LowerChangeTaggedSignedToInt32(Node* node);
+  Node* LowerChangeTaggedSignedToInt64(Node* node);
   Node* LowerChangeTaggedToBit(Node* node);
   Node* LowerChangeTaggedToInt32(Node* node);
   Node* LowerChangeTaggedToUint32(Node* node);
+  Node* LowerChangeTaggedToInt64(Node* node);
   Node* LowerChangeTaggedToTaggedSigned(Node* node);
   Node* LowerCheckBounds(Node* node, Node* frame_state);
   Node* LowerPoisonIndex(Node* node);
@@ -75,8 +79,12 @@ class V8_EXPORT_PRIVATE EffectControlLinearizer {
   Node* LowerCheckedUint32Mod(Node* node, Node* frame_state);
   Node* LowerCheckedInt32Mul(Node* node, Node* frame_state);
   Node* LowerCheckedInt32ToTaggedSigned(Node* node, Node* frame_state);
+  Node* LowerCheckedInt64ToInt32(Node* node, Node* frame_state);
+  Node* LowerCheckedInt64ToTaggedSigned(Node* node, Node* frame_state);
   Node* LowerCheckedUint32ToInt32(Node* node, Node* frame_state);
   Node* LowerCheckedUint32ToTaggedSigned(Node* node, Node* frame_state);
+  Node* LowerCheckedUint64ToInt32(Node* node, Node* frame_state);
+  Node* LowerCheckedUint64ToTaggedSigned(Node* node, Node* frame_state);
   Node* LowerCheckedFloat64ToInt32(Node* node, Node* frame_state);
   Node* LowerCheckedTaggedSignedToInt32(Node* node, Node* frame_state);
   Node* LowerCheckedTaggedToInt32(Node* node, Node* frame_state);
@@ -120,9 +128,9 @@ class V8_EXPORT_PRIVATE EffectControlLinearizer {
   Node* LowerNewSmiOrObjectElements(Node* node);
   Node* LowerNewArgumentsElements(Node* node);
   Node* LowerNewConsString(Node* node);
-  Node* LowerArrayBufferWasNeutered(Node* node);
   Node* LowerSameValue(Node* node);
   Node* LowerDeadValue(Node* node);
+  Node* LowerStringConcat(Node* node);
   Node* LowerStringToNumber(Node* node);
   Node* LowerStringCharCodeAt(Node* node);
   Node* LowerStringCodePointAt(Node* node, UnicodeEncoding encoding);
@@ -188,11 +196,14 @@ class V8_EXPORT_PRIVATE EffectControlLinearizer {
 
   Node* ChangeInt32ToSmi(Node* value);
   Node* ChangeInt32ToIntPtr(Node* value);
+  Node* ChangeInt64ToSmi(Node* value);
   Node* ChangeIntPtrToInt32(Node* value);
+  Node* ChangeIntPtrToSmi(Node* value);
   Node* ChangeUint32ToUintPtr(Node* value);
   Node* ChangeUint32ToSmi(Node* value);
   Node* ChangeSmiToIntPtr(Node* value);
   Node* ChangeSmiToInt32(Node* value);
+  Node* ChangeSmiToInt64(Node* value);
   Node* ObjectIsSmi(Node* value);
   Node* LoadFromSeqString(Node* receiver, Node* position, Node* is_one_byte);
 
diff --git a/deps/v8/src/compiler/escape-analysis.cc b/deps/v8/src/compiler/escape-analysis.cc
index 0e6822a9ca..9b1ef8d907 100644
--- a/deps/v8/src/compiler/escape-analysis.cc
+++ b/deps/v8/src/compiler/escape-analysis.cc
@@ -9,6 +9,8 @@
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/operator-properties.h"
 #include "src/compiler/simplified-operator.h"
+#include "src/handles-inl.h"
+#include "src/objects/map-inl.h"
 
 #ifdef DEBUG
 #define TRACE(...)                                    \
@@ -282,7 +284,7 @@ EffectGraphReducer::EffectGraphReducer(
       state_(graph, kNumStates),
       revisit_(zone),
       stack_(zone),
-      reduce_(reduce) {}
+      reduce_(std::move(reduce)) {}
 
 void EffectGraphReducer::ReduceFrom(Node* node) {
   // Perform DFS and eagerly trigger revisitation as soon as possible.
@@ -498,6 +500,14 @@ int OffsetOfFieldAccess(const Operator* op) {
   return access.offset;
 }
 
+int OffsetOfElementAt(ElementAccess const& access, int index) {
+  DCHECK_GE(index, 0);
+  DCHECK_GE(ElementSizeLog2Of(access.machine_type.representation()),
+            kPointerSizeLog2);
+  return access.header_size +
+         (index << ElementSizeLog2Of(access.machine_type.representation()));
+}
+
 Maybe<int> OffsetOfElementsAccess(const Operator* op, Node* index_node) {
   DCHECK(op->opcode() == IrOpcode::kLoadElement ||
          op->opcode() == IrOpcode::kStoreElement);
@@ -507,11 +517,7 @@ Maybe<int> OffsetOfElementsAccess(const Operator* op, Node* index_node) {
   double min = index_type.Min();
   int index = static_cast<int>(min);
   if (!(index == min && index == max)) return Nothing<int>();
-  ElementAccess access = ElementAccessOf(op);
-  DCHECK_GE(ElementSizeLog2Of(access.machine_type.representation()),
-            kPointerSizeLog2);
-  return Just(access.header_size + (index << ElementSizeLog2Of(
-                                        access.machine_type.representation())));
+  return Just(OffsetOfElementAt(ElementAccessOf(op), index));
 }
 
 Node* LowerCompareMapsWithoutLoad(Node* checked_map,
@@ -616,9 +622,62 @@ void ReduceNode(const Operator* op, EscapeAnalysisTracker::Scope* current,
           OffsetOfElementsAccess(op, index).To(&offset) &&
           vobject->FieldAt(offset).To(&var) && current->Get(var).To(&value)) {
         current->SetReplacement(value);
-      } else {
-        current->SetEscaped(object);
+      } else if (vobject && !vobject->HasEscaped()) {
+        // Compute the known length (aka the number of elements) of {object}
+        // based on the virtual object information.
+        ElementAccess const& access = ElementAccessOf(op);
+        int const length =
+            (vobject->size() - access.header_size) >>
+            ElementSizeLog2Of(access.machine_type.representation());
+        Variable var0, var1;
+        Node* value0;
+        Node* value1;
+        if (length == 1 &&
+            vobject->FieldAt(OffsetOfElementAt(access, 0)).To(&var) &&
+            current->Get(var).To(&value) &&
+            (value == nullptr ||
+             NodeProperties::GetType(value).Is(access.type))) {
+          // The {object} has no elements, and we know that the LoadElement
+          // {index} must be within bounds, thus it must always yield this
+          // one element of {object}.
+          current->SetReplacement(value);
+          break;
+        } else if (length == 2 &&
+                   vobject->FieldAt(OffsetOfElementAt(access, 0)).To(&var0) &&
+                   current->Get(var0).To(&value0) &&
+                   (value0 == nullptr ||
+                    NodeProperties::GetType(value0).Is(access.type)) &&
+                   vobject->FieldAt(OffsetOfElementAt(access, 1)).To(&var1) &&
+                   current->Get(var1).To(&value1) &&
+                   (value1 == nullptr ||
+                    NodeProperties::GetType(value1).Is(access.type))) {
+          if (value0 && value1) {
+            // The {object} has exactly two elements, so the LoadElement
+            // must return one of them (i.e. either the element at index
+            // 0 or the one at index 1). So we can turn the LoadElement
+            // into a Select operation instead (still allowing the {object}
+            // to be scalar replaced). We must however mark the elements
+            // of the {object} itself as escaping.
+            Node* check =
+                jsgraph->graph()->NewNode(jsgraph->simplified()->NumberEqual(),
+                                          index, jsgraph->ZeroConstant());
+            NodeProperties::SetType(check, Type::Boolean());
+            Node* select = jsgraph->graph()->NewNode(
+                jsgraph->common()->Select(access.machine_type.representation()),
+                check, value0, value1);
+            NodeProperties::SetType(select, access.type);
+            current->SetReplacement(select);
+            current->SetEscaped(value0);
+            current->SetEscaped(value1);
+            break;
+          } else {
+            // If the variables have no values, we have
+            // not reached the fixed-point yet.
+            break;
+          }
+        }
       }
+      current->SetEscaped(object);
       break;
     }
     case IrOpcode::kTypeGuard: {
@@ -669,9 +728,10 @@ void ReduceNode(const Operator* op, EscapeAnalysisTracker::Scope* current,
           current->Get(map_field).To(&map)) {
         if (map) {
           Type const map_type = NodeProperties::GetType(map);
+          AllowHandleDereference handle_dereference;
           if (map_type.IsHeapConstant() &&
               params.maps().contains(
-                  bit_cast<Handle<Map>>(map_type.AsHeapConstant()->Value()))) {
+                  Handle<Map>::cast(map_type.AsHeapConstant()->Value()))) {
             current->MarkForDeletion();
             break;
           }
diff --git a/deps/v8/src/compiler/escape-analysis.h b/deps/v8/src/compiler/escape-analysis.h
index 71aae6b2a4..c3d4e5978d 100644
--- a/deps/v8/src/compiler/escape-analysis.h
+++ b/deps/v8/src/compiler/escape-analysis.h
@@ -121,13 +121,7 @@ class VirtualObject : public Dependable {
   typedef ZoneVector<Variable>::const_iterator const_iterator;
   VirtualObject(VariableTracker* var_states, Id id, int size);
   Maybe<Variable> FieldAt(int offset) const {
-    if (offset % kPointerSize != 0) {
-      // We do not support fields that are not word-aligned. Bail out by
-      // treating the object as escaping. This can only happen for
-      // {Name::kHashFieldOffset} on 64bit big endian architectures.
-      DCHECK_EQ(Name::kHashFieldOffset, offset);
-      return Nothing<Variable>();
-    }
+    CHECK_EQ(0, offset % kPointerSize);
     CHECK(!HasEscaped());
     if (offset >= size()) {
       // TODO(tebbi): Reading out-of-bounds can only happen in unreachable
diff --git a/deps/v8/src/compiler/frame-states.cc b/deps/v8/src/compiler/frame-states.cc
index 15ca8367b0..bd210d714d 100644
--- a/deps/v8/src/compiler/frame-states.cc
+++ b/deps/v8/src/compiler/frame-states.cc
@@ -145,6 +145,12 @@ Node* CreateStubBuiltinContinuationFrameState(
   // by the deoptimizer and aren't explicitly passed in the frame state.
   int stack_parameter_count = descriptor.GetRegisterParameterCount() -
                               DeoptimizerParameterCountFor(mode);
+  // Reserving space in the vector, except for the case where
+  // stack_parameter_count is -1.
+  actual_parameters.reserve(stack_parameter_count >= 0
+                                ? stack_parameter_count +
+                                      descriptor.GetRegisterParameterCount()
+                                : 0);
   for (int i = 0; i < stack_parameter_count; ++i) {
     actual_parameters.push_back(
         parameters[descriptor.GetRegisterParameterCount() + i]);
diff --git a/deps/v8/src/compiler/gap-resolver.cc b/deps/v8/src/compiler/gap-resolver.cc
index 4542a73685..c102c62ad4 100644
--- a/deps/v8/src/compiler/gap-resolver.cc
+++ b/deps/v8/src/compiler/gap-resolver.cc
@@ -13,11 +13,6 @@ namespace compiler {
 
 namespace {
 
-#define REP_BIT(rep) (1 << static_cast<int>(rep))
-
-const int kFloat32Bit = REP_BIT(MachineRepresentation::kFloat32);
-const int kFloat64Bit = REP_BIT(MachineRepresentation::kFloat64);
-
 // Splits a FP move between two location operands into the equivalent series of
 // moves between smaller sub-operands, e.g. a double move to two single moves.
 // This helps reduce the number of cycles that would normally occur under FP
@@ -91,8 +86,8 @@ void GapResolver::Resolve(ParallelMove* moves) {
     }
     i++;
     if (!kSimpleFPAliasing && move->destination().IsFPRegister()) {
-      reps |=
-          REP_BIT(LocationOperand::cast(move->destination()).representation());
+      reps |= RepresentationBit(
+          LocationOperand::cast(move->destination()).representation());
     }
   }
 
@@ -100,7 +95,7 @@ void GapResolver::Resolve(ParallelMove* moves) {
     if (reps && !base::bits::IsPowerOfTwo(reps)) {
       // Start with the smallest FP moves, so we never encounter smaller moves
       // in the middle of a cycle of larger moves.
-      if ((reps & kFloat32Bit) != 0) {
+      if ((reps & RepresentationBit(MachineRepresentation::kFloat32)) != 0) {
         split_rep_ = MachineRepresentation::kFloat32;
         for (size_t i = 0; i < moves->size(); ++i) {
           auto move = (*moves)[i];
@@ -108,7 +103,7 @@ void GapResolver::Resolve(ParallelMove* moves) {
             PerformMove(moves, move);
         }
       }
-      if ((reps & kFloat64Bit) != 0) {
+      if ((reps & RepresentationBit(MachineRepresentation::kFloat64)) != 0) {
         split_rep_ = MachineRepresentation::kFloat64;
         for (size_t i = 0; i < moves->size(); ++i) {
           auto move = (*moves)[i];
diff --git a/deps/v8/src/compiler/gap-resolver.h b/deps/v8/src/compiler/gap-resolver.h
index d4c402587f..9a4fe4e6d6 100644
--- a/deps/v8/src/compiler/gap-resolver.h
+++ b/deps/v8/src/compiler/gap-resolver.h
@@ -16,7 +16,7 @@ class GapResolver final {
   // Interface used by the gap resolver to emit moves and swaps.
   class Assembler {
    public:
-    virtual ~Assembler() {}
+    virtual ~Assembler() = default;
 
     // Assemble move.
     virtual void AssembleMove(InstructionOperand* source,
diff --git a/deps/v8/src/compiler/graph-assembler.cc b/deps/v8/src/compiler/graph-assembler.cc
index 496f322106..de02f941be 100644
--- a/deps/v8/src/compiler/graph-assembler.cc
+++ b/deps/v8/src/compiler/graph-assembler.cc
@@ -26,8 +26,14 @@ Node* GraphAssembler::Int32Constant(int32_t value) {
   return jsgraph()->Int32Constant(value);
 }
 
-Node* GraphAssembler::UniqueInt32Constant(int32_t value) {
-  return graph()->NewNode(common()->Int32Constant(value));
+Node* GraphAssembler::Int64Constant(int64_t value) {
+  return jsgraph()->Int64Constant(value);
+}
+
+Node* GraphAssembler::UniqueIntPtrConstant(intptr_t value) {
+  return graph()->NewNode(
+      machine()->Is64() ? common()->Int64Constant(value)
+                        : common()->Int32Constant(static_cast<int32_t>(value)));
 }
 
 Node* GraphAssembler::SmiConstant(int32_t value) {
@@ -208,9 +214,11 @@ Node* GraphAssembler::Word32PoisonOnSpeculation(Node* value) {
 
 Node* GraphAssembler::DeoptimizeIf(DeoptimizeReason reason,
                                    VectorSlotPair const& feedback,
-                                   Node* condition, Node* frame_state) {
+                                   Node* condition, Node* frame_state,
+                                   IsSafetyCheck is_safety_check) {
   return current_control_ = current_effect_ = graph()->NewNode(
-             common()->DeoptimizeIf(DeoptimizeKind::kEager, reason, feedback),
+             common()->DeoptimizeIf(DeoptimizeKind::kEager, reason, feedback,
+                                    is_safety_check),
              condition, frame_state, current_effect_, current_control_);
 }
 
@@ -225,7 +233,8 @@ Node* GraphAssembler::DeoptimizeIfNot(DeoptimizeReason reason,
 }
 
 void GraphAssembler::Branch(Node* condition, GraphAssemblerLabel<0u>* if_true,
-                            GraphAssemblerLabel<0u>* if_false) {
+                            GraphAssemblerLabel<0u>* if_false,
+                            IsSafetyCheck is_safety_check) {
   DCHECK_NOT_NULL(current_control_);
 
   BranchHint hint = BranchHint::kNone;
@@ -233,8 +242,8 @@ void GraphAssembler::Branch(Node* condition, GraphAssemblerLabel<0u>* if_true,
     hint = if_false->IsDeferred() ? BranchHint::kTrue : BranchHint::kFalse;
   }
 
-  Node* branch =
-      graph()->NewNode(common()->Branch(hint), condition, current_control_);
+  Node* branch = graph()->NewNode(common()->Branch(hint, is_safety_check),
+                                  condition, current_control_);
 
   current_control_ = graph()->NewNode(common()->IfTrue(), branch);
   MergeState(if_true);
@@ -269,9 +278,10 @@ Operator const* GraphAssembler::ToNumberOperator() {
     Callable callable =
         Builtins::CallableFor(jsgraph()->isolate(), Builtins::kToNumber);
     CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
-    auto call_descriptor =
-        Linkage::GetStubCallDescriptor(graph()->zone(), callable.descriptor(),
-                                       0, flags, Operator::kEliminatable);
+    auto call_descriptor = Linkage::GetStubCallDescriptor(
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(), flags,
+        Operator::kEliminatable);
     to_number_operator_.set(common()->Call(call_descriptor));
   }
   return to_number_operator_.get();
diff --git a/deps/v8/src/compiler/graph-assembler.h b/deps/v8/src/compiler/graph-assembler.h
index 79eb493608..fa527a8bb0 100644
--- a/deps/v8/src/compiler/graph-assembler.h
+++ b/deps/v8/src/compiler/graph-assembler.h
@@ -21,9 +21,11 @@ namespace compiler {
 #define PURE_ASSEMBLER_MACH_UNOP_LIST(V) \
   V(ChangeInt32ToInt64)                  \
   V(ChangeInt32ToFloat64)                \
+  V(ChangeInt64ToFloat64)                \
   V(ChangeUint32ToFloat64)               \
   V(ChangeUint32ToUint64)                \
   V(ChangeFloat64ToInt32)                \
+  V(ChangeFloat64ToInt64)                \
   V(ChangeFloat64ToUint32)               \
   V(TruncateInt64ToInt32)                \
   V(RoundFloat64ToInt32)                 \
@@ -57,8 +59,10 @@ namespace compiler {
   V(Int32Sub)                             \
   V(Int32Mul)                             \
   V(Int32LessThanOrEqual)                 \
-  V(Uint32LessThanOrEqual)                \
   V(Uint32LessThan)                       \
+  V(Uint32LessThanOrEqual)                \
+  V(Uint64LessThan)                       \
+  V(Uint64LessThanOrEqual)                \
   V(Int32LessThan)                        \
   V(Float64Add)                           \
   V(Float64Sub)                           \
@@ -70,6 +74,7 @@ namespace compiler {
   V(Float64InsertLowWord32)               \
   V(Float64InsertHighWord32)              \
   V(Word32Equal)                          \
+  V(Word64Equal)                          \
   V(WordEqual)
 
 #define CHECKED_ASSEMBLER_MACH_BINOP_LIST(V) \
@@ -176,7 +181,8 @@ class GraphAssembler {
   Node* IntPtrConstant(intptr_t value);
   Node* Uint32Constant(int32_t value);
   Node* Int32Constant(int32_t value);
-  Node* UniqueInt32Constant(int32_t value);
+  Node* Int64Constant(int64_t value);
+  Node* UniqueIntPtrConstant(intptr_t value);
   Node* SmiConstant(int32_t value);
   Node* Float64Constant(double value);
   Node* Projection(int index, Node* value);
@@ -228,8 +234,10 @@ class GraphAssembler {
 
   Node* Word32PoisonOnSpeculation(Node* value);
 
-  Node* DeoptimizeIf(DeoptimizeReason reason, VectorSlotPair const& feedback,
-                     Node* condition, Node* frame_state);
+  Node* DeoptimizeIf(
+      DeoptimizeReason reason, VectorSlotPair const& feedback, Node* condition,
+      Node* frame_state,
+      IsSafetyCheck is_safety_check = IsSafetyCheck::kSafetyCheck);
   Node* DeoptimizeIfNot(
       DeoptimizeReason reason, VectorSlotPair const& feedback, Node* condition,
       Node* frame_state,
@@ -247,7 +255,8 @@ class GraphAssembler {
   void Goto(GraphAssemblerLabel<sizeof...(Vars)>* label, Vars...);
 
   void Branch(Node* condition, GraphAssemblerLabel<0u>* if_true,
-              GraphAssemblerLabel<0u>* if_false);
+              GraphAssemblerLabel<0u>* if_false,
+              IsSafetyCheck is_safety_check = IsSafetyCheck::kNoSafetyCheck);
 
   // Control helpers.
   // {GotoIf(c, l)} is equivalent to {Branch(c, l, templ);Bind(templ)}.
diff --git a/deps/v8/src/compiler/graph-reducer.cc b/deps/v8/src/compiler/graph-reducer.cc
index dc7b23521f..fafa322d87 100644
--- a/deps/v8/src/compiler/graph-reducer.cc
+++ b/deps/v8/src/compiler/graph-reducer.cc
@@ -37,7 +37,7 @@ GraphReducer::GraphReducer(Zone* zone, Graph* graph, Node* dead)
   }
 }
 
-GraphReducer::~GraphReducer() {}
+GraphReducer::~GraphReducer() = default;
 
 
 void GraphReducer::AddReducer(Reducer* reducer) {
diff --git a/deps/v8/src/compiler/graph-reducer.h b/deps/v8/src/compiler/graph-reducer.h
index adb97ddf4d..b9fd455b9b 100644
--- a/deps/v8/src/compiler/graph-reducer.h
+++ b/deps/v8/src/compiler/graph-reducer.h
@@ -46,7 +46,7 @@ class Reduction final {
 // phase.
 class V8_EXPORT_PRIVATE Reducer {
  public:
-  virtual ~Reducer() {}
+  virtual ~Reducer() = default;
 
   // Only used for tracing, when using the --trace_turbo_reduction flag.
   virtual const char* reducer_name() const = 0;
@@ -73,7 +73,7 @@ class AdvancedReducer : public Reducer {
   // Observe the actions of this reducer.
   class Editor {
    public:
-    virtual ~Editor() {}
+    virtual ~Editor() = default;
 
     // Replace {node} with {replacement}.
     virtual void Replace(Node* node, Node* replacement) = 0;
@@ -130,7 +130,7 @@ class V8_EXPORT_PRIVATE GraphReducer
     : public NON_EXPORTED_BASE(AdvancedReducer::Editor) {
  public:
   GraphReducer(Zone* zone, Graph* graph, Node* dead = nullptr);
-  ~GraphReducer();
+  ~GraphReducer() override;
 
   Graph* graph() const { return graph_; }
 
diff --git a/deps/v8/src/compiler/graph-trimmer.cc b/deps/v8/src/compiler/graph-trimmer.cc
index c3de2cd809..e1dbfffff5 100644
--- a/deps/v8/src/compiler/graph-trimmer.cc
+++ b/deps/v8/src/compiler/graph-trimmer.cc
@@ -16,7 +16,7 @@ GraphTrimmer::GraphTrimmer(Zone* zone, Graph* graph)
 }
 
 
-GraphTrimmer::~GraphTrimmer() {}
+GraphTrimmer::~GraphTrimmer() = default;
 
 
 void GraphTrimmer::TrimGraph() {
diff --git a/deps/v8/src/compiler/graph-visualizer.cc b/deps/v8/src/compiler/graph-visualizer.cc
index feb0a8e9d3..cbb7188993 100644
--- a/deps/v8/src/compiler/graph-visualizer.cc
+++ b/deps/v8/src/compiler/graph-visualizer.cc
@@ -46,6 +46,12 @@ TurboJsonFile::TurboJsonFile(OptimizedCompilationInfo* info,
 
 TurboJsonFile::~TurboJsonFile() { flush(); }
 
+TurboCfgFile::TurboCfgFile(Isolate* isolate)
+    : std::ofstream(Isolate::GetTurboCfgFileName(isolate).c_str(),
+                    std::ios_base::app) {}
+
+TurboCfgFile::~TurboCfgFile() { flush(); }
+
 std::ostream& operator<<(std::ostream& out,
                          const SourcePositionAsJSON& asJSON) {
   asJSON.sp.PrintJson(out);
@@ -302,9 +308,11 @@ class JSONGraphNodeWriter {
     if (opcode == IrOpcode::kBranch) {
       os_ << ",\"rankInputs\":[0]";
     }
-    SourcePosition position = positions_->GetSourcePosition(node);
-    if (position.IsKnown()) {
-      os_ << ", \"sourcePosition\" : " << AsJSON(position);
+    if (positions_ != nullptr) {
+      SourcePosition position = positions_->GetSourcePosition(node);
+      if (position.IsKnown()) {
+        os_ << ", \"sourcePosition\" : " << AsJSON(position);
+      }
     }
     if (origins_) {
       NodeOrigin origin = origins_->GetNodeOrigin(node);
@@ -432,7 +440,7 @@ class GraphC1Visualizer {
   void PrintLiveRange(const LiveRange* range, const char* type, int vreg);
   void PrintLiveRangeChain(const TopLevelLiveRange* range, const char* type);
 
-  class Tag final BASE_EMBEDDED {
+  class Tag final {
    public:
     Tag(GraphC1Visualizer* visualizer, const char* name) {
       name_ = name;
@@ -766,7 +774,12 @@ void GraphC1Visualizer::PrintLiveRange(const LiveRange* range, const char* type,
       }
     }
 
-    os_ << " " << vreg;
+    // The toplevel range is always suffixed with :0. Use that as parent.
+    os_ << " " << vreg << ":0";
+
+    // TODO(herhut) Find something useful to print for the hint field
+    os_ << " unknown";
+
     for (const UseInterval* interval = range->first_interval();
          interval != nullptr; interval = interval->next()) {
       os_ << " [" << interval->start().value() << ", "
@@ -950,6 +963,290 @@ std::ostream& operator<<(std::ostream& os, const AsScheduledGraph& scheduled) {
   return os;
 }
 
+std::ostream& operator<<(std::ostream& os, const InstructionOperandAsJSON& o) {
+  const RegisterConfiguration* conf = o.register_configuration_;
+  const InstructionOperand* op = o.op_;
+  const InstructionSequence* code = o.code_;
+  os << "{";
+  switch (op->kind()) {
+    case InstructionOperand::UNALLOCATED: {
+      const UnallocatedOperand* unalloc = UnallocatedOperand::cast(op);
+      os << "\"type\": \"unallocated\", ";
+      os << "\"text\": \"v" << unalloc->virtual_register() << "\"";
+      if (unalloc->basic_policy() == UnallocatedOperand::FIXED_SLOT) {
+        os << ",\"tooltip\": \"FIXED_SLOT: " << unalloc->fixed_slot_index()
+           << "\"";
+        break;
+      }
+      switch (unalloc->extended_policy()) {
+        case UnallocatedOperand::NONE:
+          break;
+        case UnallocatedOperand::FIXED_REGISTER: {
+          os << ",\"tooltip\": \"FIXED_REGISTER: "
+             << conf->GetGeneralRegisterName(unalloc->fixed_register_index())
+             << "\"";
+          break;
+        }
+        case UnallocatedOperand::FIXED_FP_REGISTER: {
+          os << ",\"tooltip\": \"FIXED_FP_REGISTER: "
+             << conf->GetDoubleRegisterName(unalloc->fixed_register_index())
+             << "\"";
+          break;
+        }
+        case UnallocatedOperand::MUST_HAVE_REGISTER: {
+          os << ",\"tooltip\": \"MUST_HAVE_REGISTER\"";
+          break;
+        }
+        case UnallocatedOperand::MUST_HAVE_SLOT: {
+          os << ",\"tooltip\": \"MUST_HAVE_SLOT\"";
+          break;
+        }
+        case UnallocatedOperand::SAME_AS_FIRST_INPUT: {
+          os << ",\"tooltip\": \"SAME_AS_FIRST_INPUT\"";
+          break;
+        }
+        case UnallocatedOperand::REGISTER_OR_SLOT: {
+          os << ",\"tooltip\": \"REGISTER_OR_SLOT\"";
+          break;
+        }
+        case UnallocatedOperand::REGISTER_OR_SLOT_OR_CONSTANT: {
+          os << ",\"tooltip\": \"REGISTER_OR_SLOT_OR_CONSTANT\"";
+          break;
+        }
+      }
+      break;
+    }
+    case InstructionOperand::CONSTANT: {
+      int vreg = ConstantOperand::cast(op)->virtual_register();
+      os << "\"type\": \"constant\", ";
+      os << "\"text\": \"v" << vreg << "\",";
+      os << "\"tooltip\": \"";
+      std::stringstream tooltip;
+      tooltip << code->GetConstant(vreg);
+      for (const auto& c : tooltip.str()) {
+        os << AsEscapedUC16ForJSON(c);
+      }
+      os << "\"";
+      break;
+    }
+    case InstructionOperand::IMMEDIATE: {
+      os << "\"type\": \"immediate\", ";
+      const ImmediateOperand* imm = ImmediateOperand::cast(op);
+      switch (imm->type()) {
+        case ImmediateOperand::INLINE: {
+          os << "\"text\": \"#" << imm->inline_value() << "\"";
+          break;
+        }
+        case ImmediateOperand::INDEXED: {
+          int index = imm->indexed_value();
+          os << "\"text\": \"imm:" << index << "\",";
+          os << "\"tooltip\": \"";
+          std::stringstream tooltip;
+          tooltip << code->GetImmediate(imm);
+          for (const auto& c : tooltip.str()) {
+            os << AsEscapedUC16ForJSON(c);
+          }
+          os << "\"";
+          break;
+        }
+      }
+      break;
+    }
+    case InstructionOperand::EXPLICIT:
+    case InstructionOperand::ALLOCATED: {
+      const LocationOperand* allocated = LocationOperand::cast(op);
+      os << "\"type\": ";
+      if (allocated->IsExplicit()) {
+        os << "\"explicit\", ";
+      } else {
+        os << "\"allocated\", ";
+      }
+      os << "\"text\": \"";
+      if (op->IsStackSlot()) {
+        os << "stack:" << allocated->index();
+      } else if (op->IsFPStackSlot()) {
+        os << "fp_stack:" << allocated->index();
+      } else if (op->IsRegister()) {
+        os << conf->GetGeneralOrSpecialRegisterName(allocated->register_code());
+      } else if (op->IsDoubleRegister()) {
+        os << conf->GetDoubleRegisterName(allocated->register_code());
+      } else if (op->IsFloatRegister()) {
+        os << conf->GetFloatRegisterName(allocated->register_code());
+      } else {
+        DCHECK(op->IsSimd128Register());
+        os << conf->GetSimd128RegisterName(allocated->register_code());
+      }
+      os << "\",";
+      os << "\"tooltip\": \""
+         << MachineReprToString(allocated->representation()) << "\"";
+      break;
+    }
+    case InstructionOperand::INVALID:
+      UNREACHABLE();
+  }
+  os << "}";
+  return os;
+}
+
+std::ostream& operator<<(std::ostream& os, const InstructionAsJSON& i) {
+  const Instruction* instr = i.instr_;
+  InstructionOperandAsJSON json_op = {i.register_configuration_, nullptr,
+                                      i.code_};
+
+  os << "{";
+  os << "\"id\": " << i.index_ << ",";
+  os << "\"opcode\": \"" << ArchOpcodeField::decode(instr->opcode()) << "\",";
+  os << "\"flags\": \"";
+  FlagsMode fm = FlagsModeField::decode(instr->opcode());
+  AddressingMode am = AddressingModeField::decode(instr->opcode());
+  if (am != kMode_None) {
+    os << " : " << AddressingModeField::decode(instr->opcode());
+  }
+  if (fm != kFlags_none) {
+    os << " && " << fm << " if "
+       << FlagsConditionField::decode(instr->opcode());
+  }
+  os << "\",";
+
+  os << "\"gaps\": [";
+  for (int i = Instruction::FIRST_GAP_POSITION;
+       i <= Instruction::LAST_GAP_POSITION; i++) {
+    if (i != Instruction::FIRST_GAP_POSITION) os << ",";
+    os << "[";
+    const ParallelMove* pm = instr->parallel_moves()[i];
+    if (pm == nullptr) {
+      os << "]";
+      continue;
+    }
+    bool first = true;
+    for (MoveOperands* move : *pm) {
+      if (move->IsEliminated()) continue;
+      if (!first) os << ",";
+      first = false;
+      json_op.op_ = &move->destination();
+      os << "[" << json_op << ",";
+      json_op.op_ = &move->source();
+      os << json_op << "]";
+    }
+    os << "]";
+  }
+  os << "],";
+
+  os << "\"outputs\": [";
+  bool need_comma = false;
+  for (size_t i = 0; i < instr->OutputCount(); i++) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    json_op.op_ = instr->OutputAt(i);
+    os << json_op;
+  }
+  os << "],";
+
+  os << "\"inputs\": [";
+  need_comma = false;
+  for (size_t i = 0; i < instr->InputCount(); i++) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    json_op.op_ = instr->InputAt(i);
+    os << json_op;
+  }
+  os << "],";
+
+  os << "\"temps\": [";
+  need_comma = false;
+  for (size_t i = 0; i < instr->TempCount(); i++) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    json_op.op_ = instr->TempAt(i);
+    os << json_op;
+  }
+  os << "]";
+  os << "}";
+
+  return os;
+}
+
+std::ostream& operator<<(std::ostream& os, const InstructionBlockAsJSON& b) {
+  const InstructionBlock* block = b.block_;
+  const InstructionSequence* code = b.code_;
+  os << "{";
+  os << "\"id\": " << block->rpo_number() << ",";
+  os << "\"deferred\": " << block->IsDeferred() << ",";
+  os << "\"loop_header\": " << block->IsLoopHeader() << ",";
+  if (block->IsLoopHeader()) {
+    os << "\"loop_end\": " << block->loop_end() << ",";
+  }
+  os << "\"predecessors\": [";
+  bool need_comma = false;
+  for (RpoNumber pred : block->predecessors()) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    os << pred.ToInt();
+  }
+  os << "],";
+  os << "\"successors\": [";
+  need_comma = false;
+  for (RpoNumber succ : block->successors()) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    os << succ.ToInt();
+  }
+  os << "],";
+  os << "\"phis\": [";
+  bool needs_comma = false;
+  InstructionOperandAsJSON json_op = {b.register_configuration_, nullptr, code};
+  for (const PhiInstruction* phi : block->phis()) {
+    if (needs_comma) os << ",";
+    needs_comma = true;
+    json_op.op_ = &phi->output();
+    os << "{\"output\" : " << json_op << ",";
+    os << "\"operands\": [";
+    bool op_needs_comma = false;
+    for (int input : phi->operands()) {
+      if (op_needs_comma) os << ",";
+      op_needs_comma = true;
+      os << "\"v" << input << "\"";
+    }
+    os << "]}";
+  }
+  os << "],";
+
+  os << "\"instructions\": [";
+  InstructionAsJSON json_instr = {b.register_configuration_, -1, nullptr, code};
+  need_comma = false;
+  for (int j = block->first_instruction_index();
+       j <= block->last_instruction_index(); j++) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    json_instr.index_ = j;
+    json_instr.instr_ = code->InstructionAt(j);
+    os << json_instr;
+  }
+  os << "]";
+  os << "}";
+
+  return os;
+}
+
+std::ostream& operator<<(std::ostream& os, const InstructionSequenceAsJSON& s) {
+  const InstructionSequence* code = s.sequence_;
+
+  os << "\"blocks\": [";
+  InstructionBlockAsJSON json_block = {s.register_configuration_, nullptr,
+                                       code};
+
+  bool need_comma = false;
+  for (int i = 0; i < code->InstructionBlockCount(); i++) {
+    if (need_comma) os << ",";
+    need_comma = true;
+    json_block.block_ = code->InstructionBlockAt(RpoNumber::FromInt(i));
+    os << json_block;
+  }
+  os << "]";
+
+  return os;
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler/graph-visualizer.h b/deps/v8/src/compiler/graph-visualizer.h
index 5573c346ee..93524d74cd 100644
--- a/deps/v8/src/compiler/graph-visualizer.h
+++ b/deps/v8/src/compiler/graph-visualizer.h
@@ -17,11 +17,15 @@ namespace v8 {
 namespace internal {
 
 class OptimizedCompilationInfo;
+class RegisterConfiguration;
 class SharedFunctionInfo;
 class SourcePosition;
 namespace compiler {
 
 class Graph;
+class Instruction;
+class InstructionBlock;
+class InstructionOperand;
 class InstructionSequence;
 class NodeOrigin;
 class NodeOriginTable;
@@ -31,7 +35,12 @@ class SourcePositionTable;
 
 struct TurboJsonFile : public std::ofstream {
   TurboJsonFile(OptimizedCompilationInfo* info, std::ios_base::openmode mode);
-  ~TurboJsonFile();
+  ~TurboJsonFile() override;
+};
+
+struct TurboCfgFile : public std::ofstream {
+  explicit TurboCfgFile(Isolate* isolate = nullptr);
+  ~TurboCfgFile() override;
 };
 
 struct SourcePositionAsJSON {
@@ -147,6 +156,36 @@ std::ostream& operator<<(std::ostream& os, const AsC1V& ac);
 std::ostream& operator<<(std::ostream& os,
                          const AsC1VRegisterAllocationData& ac);
 
+struct InstructionOperandAsJSON {
+  const RegisterConfiguration* register_configuration_;
+  const InstructionOperand* op_;
+  const InstructionSequence* code_;
+};
+
+std::ostream& operator<<(std::ostream& os, const InstructionOperandAsJSON& o);
+
+struct InstructionAsJSON {
+  const RegisterConfiguration* register_configuration_;
+  int index_;
+  const Instruction* instr_;
+  const InstructionSequence* code_;
+};
+std::ostream& operator<<(std::ostream& os, const InstructionAsJSON& i);
+
+struct InstructionBlockAsJSON {
+  const RegisterConfiguration* register_configuration_;
+  const InstructionBlock* block_;
+  const InstructionSequence* code_;
+};
+
+std::ostream& operator<<(std::ostream& os, const InstructionBlockAsJSON& b);
+
+struct InstructionSequenceAsJSON {
+  const RegisterConfiguration* register_configuration_;
+  const InstructionSequence* sequence_;
+};
+std::ostream& operator<<(std::ostream& os, const InstructionSequenceAsJSON& s);
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler/graph.h b/deps/v8/src/compiler/graph.h
index 3c5c9c4de8..eafb043992 100644
--- a/deps/v8/src/compiler/graph.h
+++ b/deps/v8/src/compiler/graph.h
@@ -110,7 +110,7 @@ class V8_EXPORT_PRIVATE Graph final : public NON_EXPORTED_BASE(ZoneObject) {
 // in a graph.
 class GraphDecorator : public ZoneObject {
  public:
-  virtual ~GraphDecorator() {}
+  virtual ~GraphDecorator() = default;
   virtual void Decorate(Node* node) = 0;
 };
 
diff --git a/deps/v8/src/compiler/ia32/code-generator-ia32.cc b/deps/v8/src/compiler/ia32/code-generator-ia32.cc
index 9d54eaeb90..c73ad99ad1 100644
--- a/deps/v8/src/compiler/ia32/code-generator-ia32.cc
+++ b/deps/v8/src/compiler/ia32/code-generator-ia32.cc
@@ -80,6 +80,9 @@ class IA32OperandConverter : public InstructionOperandConverter {
         return Immediate(constant.ToExternalReference());
       case Constant::kHeapObject:
         return Immediate(constant.ToHeapObject());
+      case Constant::kDelayedStringConstant:
+        return Immediate::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kInt64:
         break;
       case Constant::kRpoNumber:
@@ -427,21 +430,30 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ j(not_equal, &binop);                                    \
   } while (false)
 
-#define ASSEMBLE_I64ATOMIC_BINOP(instr1, instr2)         \
-  do {                                                   \
-    Label binop;                                         \
-    __ bind(&binop);                                     \
-    __ mov(i.OutputRegister(0), i.MemoryOperand(2));     \
-    __ mov(i.OutputRegister(1), i.NextMemoryOperand(2)); \
-    __ push(i.InputRegister(0));                         \
-    __ push(i.InputRegister(1));                         \
-    __ instr1(i.InputRegister(0), i.OutputRegister(0));  \
-    __ instr2(i.InputRegister(1), i.OutputRegister(1));  \
-    __ lock();                                           \
-    __ cmpxchg8b(i.MemoryOperand(2));                    \
-    __ pop(i.InputRegister(1));                          \
-    __ pop(i.InputRegister(0));                          \
-    __ j(not_equal, &binop);                             \
+#define ASSEMBLE_I64ATOMIC_BINOP(instr1, instr2)                        \
+  do {                                                                  \
+    Label binop;                                                        \
+    __ bind(&binop);                                                    \
+    TurboAssembler::AllowExplicitEbxAccessScope spill_register(tasm()); \
+    __ mov(eax, i.MemoryOperand(2));                                    \
+    __ mov(edx, i.NextMemoryOperand(2));                                \
+    __ push(ebx);                                                       \
+    frame_access_state()->IncreaseSPDelta(1);                           \
+    InstructionOperand* op = instr->InputAt(0);                         \
+    if (op->IsImmediate() || op->IsConstant()) {                        \
+      __ mov(ebx, i.ToImmediate(op));                                   \
+    } else {                                                            \
+      __ mov(ebx, i.ToOperand(op));                                     \
+    }                                                                   \
+    __ push(i.InputRegister(1));                                        \
+    __ instr1(ebx, eax);                                                \
+    __ instr2(i.InputRegister(1), edx);                                 \
+    __ lock();                                                          \
+    __ cmpxchg8b(i.MemoryOperand(2));                                   \
+    __ pop(i.InputRegister(1));                                         \
+    __ pop(ebx);                                                        \
+    frame_access_state()->IncreaseSPDelta(-1);                          \
+    __ j(not_equal, &binop);                                            \
   } while (false);
 
 #define ASSEMBLE_MOVX(mov_instr)                            \
@@ -497,7 +509,7 @@ void CodeGenerator::AssemblePopArgumentsAdaptorFrame(Register args_reg,
   // There are not enough temp registers left on ia32 for a call instruction
   // so we pick some scratch registers and save/restore them manually here.
   int scratch_count = 3;
-  Register scratch1 = ebx;
+  Register scratch1 = esi;
   Register scratch2 = ecx;
   Register scratch3 = edx;
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
@@ -547,6 +559,18 @@ void AdjustStackPointerForTailCall(TurboAssembler* tasm,
   }
 }
 
+#ifdef DEBUG
+bool VerifyOutputOfAtomicPairInstr(IA32OperandConverter* converter,
+                                   const Instruction* instr) {
+  if (instr->OutputCount() > 0) {
+    if (converter->OutputRegister(0) != eax) return false;
+    if (instr->OutputCount() == 2 && converter->OutputRegister(1) != edx)
+      return false;
+  }
+  return true;
+}
+#endif
+
 }  // namespace
 
 void CodeGenerator::AssembleTailCallBeforeGap(Instruction* instr,
@@ -609,9 +633,11 @@ void CodeGenerator::AssembleCodeStartRegisterCheck() {
 //    3. if it is not zero then it jumps to the builtin.
 void CodeGenerator::BailoutIfDeoptimized() {
   int offset = Code::kCodeDataContainerOffset - Code::kHeaderSize;
-  __ mov(ebx, Operand(kJavaScriptCallCodeStartRegister, offset));
-  __ test(FieldOperand(ebx, CodeDataContainer::kKindSpecificFlagsOffset),
+  __ push(eax);  // Push eax so we can use it as a scratch register.
+  __ mov(eax, Operand(kJavaScriptCallCodeStartRegister, offset));
+  __ test(FieldOperand(eax, CodeDataContainer::kKindSpecificFlagsOffset),
           Immediate(1 << Code::kMarkedForDeoptimizationBit));
+  __ pop(eax);  // Restore eax.
   // Ensure we're not serializing (otherwise we'd need to use an indirection to
   // access the builtin below).
   DCHECK(!isolate()->ShouldLoadConstantsFromRootList());
@@ -1369,8 +1395,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kSSEFloat64Mod: {
-      // TODO(dcarney): alignment is wrong.
+      Register tmp = i.TempRegister(1);
+      __ mov(tmp, esp);
       __ sub(esp, Immediate(kDoubleSize));
+      __ and_(esp, -8);  // align to 8 byte boundary.
       // Move values to st(0) and st(1).
       __ movsd(Operand(esp, 0), i.InputDoubleRegister(1));
       __ fld_d(Operand(esp, 0));
@@ -1379,10 +1407,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // Loop while fprem isn't done.
       Label mod_loop;
       __ bind(&mod_loop);
-      // This instructions traps on all kinds inputs, but we are assuming the
+      // This instruction traps on all kinds of inputs, but we are assuming the
       // floating point control word is set to ignore them all.
       __ fprem();
-      // The following 2 instruction implicitly use eax.
+      // fnstsw_ax clobbers eax.
+      DCHECK_EQ(eax, i.TempRegister(0));
       __ fnstsw_ax();
       __ sahf();
       __ j(parity_even, &mod_loop);
@@ -1390,7 +1419,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ fstp(1);
       __ fstp_d(Operand(esp, 0));
       __ movsd(i.OutputDoubleRegister(), Operand(esp, 0));
-      __ add(esp, Immediate(kDoubleSize));
+      __ mov(esp, tmp);
       break;
     }
     case kSSEFloat64Abs: {
@@ -1463,10 +1492,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     case kSSEFloat64InsertLowWord32:
-      __ Pinsrd(i.OutputDoubleRegister(), i.InputOperand(1), 0, true);
+      __ Pinsrd(i.OutputDoubleRegister(), i.InputOperand(1), 0);
       break;
     case kSSEFloat64InsertHighWord32:
-      __ Pinsrd(i.OutputDoubleRegister(), i.InputOperand(1), 1, true);
+      __ Pinsrd(i.OutputDoubleRegister(), i.InputOperand(1), 1);
       break;
     case kSSEFloat64LoadLowWord32:
       __ movd(i.OutputDoubleRegister(), i.InputOperand(0));
@@ -3639,15 +3668,31 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kIA32Word32AtomicPairLoad: {
       XMMRegister tmp = i.ToDoubleRegister(instr->TempAt(0));
       __ movq(tmp, i.MemoryOperand());
-      __ Pextrd(i.OutputRegister(0), tmp, 0);
-      __ Pextrd(i.OutputRegister(1), tmp, 1);
+      if (instr->OutputCount() == 2) {
+        __ Pextrd(i.OutputRegister(0), tmp, 0);
+        __ Pextrd(i.OutputRegister(1), tmp, 1);
+      } else if (instr->OutputCount() == 1) {
+        __ Pextrd(i.OutputRegister(0), tmp, 0);
+        __ Pextrd(i.TempRegister(1), tmp, 1);
+      }
       break;
     }
     case kIA32Word32AtomicPairStore: {
+      TurboAssembler::AllowExplicitEbxAccessScope spill_register(tasm());
       __ mov(i.TempRegister(0), i.MemoryOperand(2));
       __ mov(i.TempRegister(1), i.NextMemoryOperand(2));
+      __ push(ebx);
+      frame_access_state()->IncreaseSPDelta(1);
+      InstructionOperand* op = instr->InputAt(0);
+      if (op->IsImmediate() || op->IsConstant()) {
+        __ mov(ebx, i.ToImmediate(op));
+      } else {
+        __ mov(ebx, i.ToOperand(op));
+      }
       __ lock();
       __ cmpxchg8b(i.MemoryOperand(2));
+      __ pop(ebx);
+      frame_access_state()->IncreaseSPDelta(-1);
       break;
     }
     case kWord32AtomicExchangeInt8: {
@@ -3674,32 +3719,23 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ xchg(i.InputRegister(0), i.MemoryOperand(1));
       break;
     }
-    // For the narrow Word64 operations below, i.OutputRegister(1) contains
-    // the high-order 32 bits for the 64bit operation. As the data exchange
-    // fits in one register, the i.OutputRegister(1) needs to be cleared for
-    // the correct return value to be propagated back.
-    case kIA32Word64AtomicNarrowExchangeUint8: {
-      __ xchg_b(i.OutputRegister(0), i.MemoryOperand(1));
-      __ movzx_b(i.OutputRegister(0), i.OutputRegister(0));
-      __ xor_(i.OutputRegister(1), i.OutputRegister(1));
-      break;
-    }
-    case kIA32Word64AtomicNarrowExchangeUint16: {
-      __ xchg_w(i.OutputRegister(0), i.MemoryOperand(1));
-      __ movzx_w(i.OutputRegister(0), i.OutputRegister(0));
-      __ xor_(i.OutputRegister(1), i.OutputRegister(1));
-      break;
-    }
-    case kIA32Word64AtomicNarrowExchangeUint32: {
-      __ xchg(i.OutputRegister(0), i.MemoryOperand(1));
-      __ xor_(i.OutputRegister(1), i.OutputRegister(1));
-      break;
-    }
     case kIA32Word32AtomicPairExchange: {
-      __ mov(i.OutputRegister(0), i.MemoryOperand(2));
-      __ mov(i.OutputRegister(1), i.NextMemoryOperand(2));
+      DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr));
+      TurboAssembler::AllowExplicitEbxAccessScope spill_ebx(tasm());
+      __ mov(eax, i.MemoryOperand(2));
+      __ mov(edx, i.NextMemoryOperand(2));
+      __ push(ebx);
+      frame_access_state()->IncreaseSPDelta(1);
+      InstructionOperand* op = instr->InputAt(0);
+      if (op->IsImmediate() || op->IsConstant()) {
+        __ mov(ebx, i.ToImmediate(op));
+      } else {
+        __ mov(ebx, i.ToOperand(op));
+      }
       __ lock();
       __ cmpxchg8b(i.MemoryOperand(2));
+      __ pop(ebx);
+      frame_access_state()->IncreaseSPDelta(-1);
       break;
     }
     case kWord32AtomicCompareExchangeInt8: {
@@ -3731,29 +3767,20 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ cmpxchg(i.MemoryOperand(2), i.InputRegister(1));
       break;
     }
-    case kIA32Word64AtomicNarrowCompareExchangeUint8: {
-      __ lock();
-      __ cmpxchg_b(i.MemoryOperand(2), i.InputRegister(1));
-      __ movzx_b(i.OutputRegister(0), i.OutputRegister(0));
-      __ xor_(i.OutputRegister(1), i.OutputRegister(1));
-      break;
-    }
-    case kIA32Word64AtomicNarrowCompareExchangeUint16: {
-      __ lock();
-      __ cmpxchg_w(i.MemoryOperand(2), i.InputRegister(1));
-      __ movzx_w(i.OutputRegister(0), i.OutputRegister(0));
-      __ xor_(i.OutputRegister(1), i.OutputRegister(1));
-      break;
-    }
-    case kIA32Word64AtomicNarrowCompareExchangeUint32: {
-      __ lock();
-      __ cmpxchg(i.MemoryOperand(2), i.InputRegister(1));
-      __ xor_(i.OutputRegister(1), i.OutputRegister(1));
-      break;
-    }
     case kIA32Word32AtomicPairCompareExchange: {
+      TurboAssembler::AllowExplicitEbxAccessScope spill_ebx(tasm());
+      __ push(ebx);
+      frame_access_state()->IncreaseSPDelta(1);
+      InstructionOperand* op = instr->InputAt(2);
+      if (op->IsImmediate() || op->IsConstant()) {
+        __ mov(ebx, i.ToImmediate(op));
+      } else {
+        __ mov(ebx, i.ToOperand(op));
+      }
       __ lock();
       __ cmpxchg8b(i.MemoryOperand(4));
+      __ pop(ebx);
+      frame_access_state()->IncreaseSPDelta(-1);
       break;
     }
 #define ATOMIC_BINOP_CASE(op, inst)                       \
@@ -3762,12 +3789,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     __ movsx_b(eax, eax);                                 \
     break;                                                \
   }                                                       \
-  case kIA32Word64AtomicNarrow##op##Uint8: {              \
-    ASSEMBLE_ATOMIC_BINOP(inst, mov_b, cmpxchg_b);        \
-    __ movzx_b(i.OutputRegister(0), i.OutputRegister(0)); \
-    __ xor_(i.OutputRegister(1), i.OutputRegister(1));    \
-    break;                                                \
-  }                                                       \
   case kWord32Atomic##op##Uint8: {                        \
     ASSEMBLE_ATOMIC_BINOP(inst, mov_b, cmpxchg_b);        \
     __ movzx_b(eax, eax);                                 \
@@ -3778,22 +3799,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     __ movsx_w(eax, eax);                                 \
     break;                                                \
   }                                                       \
-  case kIA32Word64AtomicNarrow##op##Uint16: {             \
-    ASSEMBLE_ATOMIC_BINOP(inst, mov_w, cmpxchg_w);        \
-    __ movzx_w(i.OutputRegister(0), i.OutputRegister(0)); \
-    __ xor_(i.OutputRegister(1), i.OutputRegister(1));    \
-    break;                                                \
-  }                                                       \
   case kWord32Atomic##op##Uint16: {                       \
     ASSEMBLE_ATOMIC_BINOP(inst, mov_w, cmpxchg_w);        \
     __ movzx_w(eax, eax);                                 \
     break;                                                \
   }                                                       \
-  case kIA32Word64AtomicNarrow##op##Uint32: {             \
-    ASSEMBLE_ATOMIC_BINOP(inst, mov, cmpxchg);            \
-    __ xor_(i.OutputRegister(1), i.OutputRegister(1));    \
-    break;                                                \
-  }                                                       \
   case kWord32Atomic##op##Word32: {                       \
     ASSEMBLE_ATOMIC_BINOP(inst, mov, cmpxchg);            \
     break;                                                \
@@ -3804,10 +3814,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ATOMIC_BINOP_CASE(Or, or_)
       ATOMIC_BINOP_CASE(Xor, xor_)
 #undef ATOMIC_BINOP_CASE
-#define ATOMIC_BINOP_CASE(op, instr1, instr2) \
-  case kIA32Word32AtomicPair##op: {           \
-    ASSEMBLE_I64ATOMIC_BINOP(instr1, instr2)  \
-    break;                                    \
+#define ATOMIC_BINOP_CASE(op, instr1, instr2)         \
+  case kIA32Word32AtomicPair##op: {                   \
+    DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr)); \
+    ASSEMBLE_I64ATOMIC_BINOP(instr1, instr2)          \
+    break;                                            \
   }
       ATOMIC_BINOP_CASE(Add, add, adc)
       ATOMIC_BINOP_CASE(And, and_, and_)
@@ -3815,26 +3826,36 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ATOMIC_BINOP_CASE(Xor, xor_, xor_)
 #undef ATOMIC_BINOP_CASE
     case kIA32Word32AtomicPairSub: {
+      DCHECK(VerifyOutputOfAtomicPairInstr(&i, instr));
       Label binop;
       __ bind(&binop);
+      TurboAssembler::AllowExplicitEbxAccessScope spill_register(tasm());
       // Move memory operand into edx:eax
-      __ mov(i.OutputRegister(0), i.MemoryOperand(2));
-      __ mov(i.OutputRegister(1), i.NextMemoryOperand(2));
+      __ mov(eax, i.MemoryOperand(2));
+      __ mov(edx, i.NextMemoryOperand(2));
       // Save input registers temporarily on the stack.
-      __ push(i.InputRegister(0));
+      __ push(ebx);
+      frame_access_state()->IncreaseSPDelta(1);
+      InstructionOperand* op = instr->InputAt(0);
+      if (op->IsImmediate() || op->IsConstant()) {
+        __ mov(ebx, i.ToImmediate(op));
+      } else {
+        __ mov(ebx, i.ToOperand(op));
+      }
       __ push(i.InputRegister(1));
       // Negate input in place
-      __ neg(i.InputRegister(0));
+      __ neg(ebx);
       __ adc(i.InputRegister(1), 0);
       __ neg(i.InputRegister(1));
       // Add memory operand, negated input.
-      __ add(i.InputRegister(0), i.OutputRegister(0));
-      __ adc(i.InputRegister(1), i.OutputRegister(1));
+      __ add(ebx, eax);
+      __ adc(i.InputRegister(1), edx);
       __ lock();
       __ cmpxchg8b(i.MemoryOperand(2));
       // Restore input registers
       __ pop(i.InputRegister(1));
-      __ pop(i.InputRegister(0));
+      __ pop(ebx);
+      frame_access_state()->IncreaseSPDelta(-1);
       __ j(not_equal, &binop);
       break;
     }
diff --git a/deps/v8/src/compiler/ia32/instruction-codes-ia32.h b/deps/v8/src/compiler/ia32/instruction-codes-ia32.h
index 97f3763cf5..e157a29e13 100644
--- a/deps/v8/src/compiler/ia32/instruction-codes-ia32.h
+++ b/deps/v8/src/compiler/ia32/instruction-codes-ia32.h
@@ -11,377 +11,356 @@ namespace compiler {
 
 // IA32-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
-#define TARGET_ARCH_OPCODE_LIST(V)               \
-  V(IA32Add)                                     \
-  V(IA32And)                                     \
-  V(IA32Cmp)                                     \
-  V(IA32Cmp16)                                   \
-  V(IA32Cmp8)                                    \
-  V(IA32Test)                                    \
-  V(IA32Test16)                                  \
-  V(IA32Test8)                                   \
-  V(IA32Or)                                      \
-  V(IA32Xor)                                     \
-  V(IA32Sub)                                     \
-  V(IA32Imul)                                    \
-  V(IA32ImulHigh)                                \
-  V(IA32UmulHigh)                                \
-  V(IA32Idiv)                                    \
-  V(IA32Udiv)                                    \
-  V(IA32Not)                                     \
-  V(IA32Neg)                                     \
-  V(IA32Shl)                                     \
-  V(IA32Shr)                                     \
-  V(IA32Sar)                                     \
-  V(IA32AddPair)                                 \
-  V(IA32SubPair)                                 \
-  V(IA32MulPair)                                 \
-  V(IA32ShlPair)                                 \
-  V(IA32ShrPair)                                 \
-  V(IA32SarPair)                                 \
-  V(IA32Ror)                                     \
-  V(IA32Lzcnt)                                   \
-  V(IA32Tzcnt)                                   \
-  V(IA32Popcnt)                                  \
-  V(IA32Bswap)                                   \
-  V(LFence)                                      \
-  V(SSEFloat32Cmp)                               \
-  V(SSEFloat32Add)                               \
-  V(SSEFloat32Sub)                               \
-  V(SSEFloat32Mul)                               \
-  V(SSEFloat32Div)                               \
-  V(SSEFloat32Abs)                               \
-  V(SSEFloat32Neg)                               \
-  V(SSEFloat32Sqrt)                              \
-  V(SSEFloat32Round)                             \
-  V(SSEFloat64Cmp)                               \
-  V(SSEFloat64Add)                               \
-  V(SSEFloat64Sub)                               \
-  V(SSEFloat64Mul)                               \
-  V(SSEFloat64Div)                               \
-  V(SSEFloat64Mod)                               \
-  V(SSEFloat32Max)                               \
-  V(SSEFloat64Max)                               \
-  V(SSEFloat32Min)                               \
-  V(SSEFloat64Min)                               \
-  V(SSEFloat64Abs)                               \
-  V(SSEFloat64Neg)                               \
-  V(SSEFloat64Sqrt)                              \
-  V(SSEFloat64Round)                             \
-  V(SSEFloat32ToFloat64)                         \
-  V(SSEFloat64ToFloat32)                         \
-  V(SSEFloat32ToInt32)                           \
-  V(SSEFloat32ToUint32)                          \
-  V(SSEFloat64ToInt32)                           \
-  V(SSEFloat64ToUint32)                          \
-  V(SSEInt32ToFloat32)                           \
-  V(SSEUint32ToFloat32)                          \
-  V(SSEInt32ToFloat64)                           \
-  V(SSEUint32ToFloat64)                          \
-  V(SSEFloat64ExtractLowWord32)                  \
-  V(SSEFloat64ExtractHighWord32)                 \
-  V(SSEFloat64InsertLowWord32)                   \
-  V(SSEFloat64InsertHighWord32)                  \
-  V(SSEFloat64LoadLowWord32)                     \
-  V(SSEFloat64SilenceNaN)                        \
-  V(AVXFloat32Add)                               \
-  V(AVXFloat32Sub)                               \
-  V(AVXFloat32Mul)                               \
-  V(AVXFloat32Div)                               \
-  V(AVXFloat64Add)                               \
-  V(AVXFloat64Sub)                               \
-  V(AVXFloat64Mul)                               \
-  V(AVXFloat64Div)                               \
-  V(AVXFloat64Abs)                               \
-  V(AVXFloat64Neg)                               \
-  V(AVXFloat32Abs)                               \
-  V(AVXFloat32Neg)                               \
-  V(IA32Movsxbl)                                 \
-  V(IA32Movzxbl)                                 \
-  V(IA32Movb)                                    \
-  V(IA32Movsxwl)                                 \
-  V(IA32Movzxwl)                                 \
-  V(IA32Movw)                                    \
-  V(IA32Movl)                                    \
-  V(IA32Movss)                                   \
-  V(IA32Movsd)                                   \
-  V(IA32Movdqu)                                  \
-  V(IA32BitcastFI)                               \
-  V(IA32BitcastIF)                               \
-  V(IA32Lea)                                     \
-  V(IA32Push)                                    \
-  V(IA32PushFloat32)                             \
-  V(IA32PushFloat64)                             \
-  V(IA32PushSimd128)                             \
-  V(IA32Poke)                                    \
-  V(IA32Peek)                                    \
-  V(IA32StackCheck)                              \
-  V(SSEF32x4Splat)                               \
-  V(AVXF32x4Splat)                               \
-  V(SSEF32x4ExtractLane)                         \
-  V(AVXF32x4ExtractLane)                         \
-  V(SSEF32x4ReplaceLane)                         \
-  V(AVXF32x4ReplaceLane)                         \
-  V(IA32F32x4SConvertI32x4)                      \
-  V(SSEF32x4UConvertI32x4)                       \
-  V(AVXF32x4UConvertI32x4)                       \
-  V(SSEF32x4Abs)                                 \
-  V(AVXF32x4Abs)                                 \
-  V(SSEF32x4Neg)                                 \
-  V(AVXF32x4Neg)                                 \
-  V(IA32F32x4RecipApprox)                        \
-  V(IA32F32x4RecipSqrtApprox)                    \
-  V(SSEF32x4Add)                                 \
-  V(AVXF32x4Add)                                 \
-  V(SSEF32x4AddHoriz)                            \
-  V(AVXF32x4AddHoriz)                            \
-  V(SSEF32x4Sub)                                 \
-  V(AVXF32x4Sub)                                 \
-  V(SSEF32x4Mul)                                 \
-  V(AVXF32x4Mul)                                 \
-  V(SSEF32x4Min)                                 \
-  V(AVXF32x4Min)                                 \
-  V(SSEF32x4Max)                                 \
-  V(AVXF32x4Max)                                 \
-  V(SSEF32x4Eq)                                  \
-  V(AVXF32x4Eq)                                  \
-  V(SSEF32x4Ne)                                  \
-  V(AVXF32x4Ne)                                  \
-  V(SSEF32x4Lt)                                  \
-  V(AVXF32x4Lt)                                  \
-  V(SSEF32x4Le)                                  \
-  V(AVXF32x4Le)                                  \
-  V(IA32I32x4Splat)                              \
-  V(IA32I32x4ExtractLane)                        \
-  V(SSEI32x4ReplaceLane)                         \
-  V(AVXI32x4ReplaceLane)                         \
-  V(SSEI32x4SConvertF32x4)                       \
-  V(AVXI32x4SConvertF32x4)                       \
-  V(IA32I32x4SConvertI16x8Low)                   \
-  V(IA32I32x4SConvertI16x8High)                  \
-  V(IA32I32x4Neg)                                \
-  V(SSEI32x4Shl)                                 \
-  V(AVXI32x4Shl)                                 \
-  V(SSEI32x4ShrS)                                \
-  V(AVXI32x4ShrS)                                \
-  V(SSEI32x4Add)                                 \
-  V(AVXI32x4Add)                                 \
-  V(SSEI32x4AddHoriz)                            \
-  V(AVXI32x4AddHoriz)                            \
-  V(SSEI32x4Sub)                                 \
-  V(AVXI32x4Sub)                                 \
-  V(SSEI32x4Mul)                                 \
-  V(AVXI32x4Mul)                                 \
-  V(SSEI32x4MinS)                                \
-  V(AVXI32x4MinS)                                \
-  V(SSEI32x4MaxS)                                \
-  V(AVXI32x4MaxS)                                \
-  V(SSEI32x4Eq)                                  \
-  V(AVXI32x4Eq)                                  \
-  V(SSEI32x4Ne)                                  \
-  V(AVXI32x4Ne)                                  \
-  V(SSEI32x4GtS)                                 \
-  V(AVXI32x4GtS)                                 \
-  V(SSEI32x4GeS)                                 \
-  V(AVXI32x4GeS)                                 \
-  V(SSEI32x4UConvertF32x4)                       \
-  V(AVXI32x4UConvertF32x4)                       \
-  V(IA32I32x4UConvertI16x8Low)                   \
-  V(IA32I32x4UConvertI16x8High)                  \
-  V(SSEI32x4ShrU)                                \
-  V(AVXI32x4ShrU)                                \
-  V(SSEI32x4MinU)                                \
-  V(AVXI32x4MinU)                                \
-  V(SSEI32x4MaxU)                                \
-  V(AVXI32x4MaxU)                                \
-  V(SSEI32x4GtU)                                 \
-  V(AVXI32x4GtU)                                 \
-  V(SSEI32x4GeU)                                 \
-  V(AVXI32x4GeU)                                 \
-  V(IA32I16x8Splat)                              \
-  V(IA32I16x8ExtractLane)                        \
-  V(SSEI16x8ReplaceLane)                         \
-  V(AVXI16x8ReplaceLane)                         \
-  V(IA32I16x8SConvertI8x16Low)                   \
-  V(IA32I16x8SConvertI8x16High)                  \
-  V(IA32I16x8Neg)                                \
-  V(SSEI16x8Shl)                                 \
-  V(AVXI16x8Shl)                                 \
-  V(SSEI16x8ShrS)                                \
-  V(AVXI16x8ShrS)                                \
-  V(SSEI16x8SConvertI32x4)                       \
-  V(AVXI16x8SConvertI32x4)                       \
-  V(SSEI16x8Add)                                 \
-  V(AVXI16x8Add)                                 \
-  V(SSEI16x8AddSaturateS)                        \
-  V(AVXI16x8AddSaturateS)                        \
-  V(SSEI16x8AddHoriz)                            \
-  V(AVXI16x8AddHoriz)                            \
-  V(SSEI16x8Sub)                                 \
-  V(AVXI16x8Sub)                                 \
-  V(SSEI16x8SubSaturateS)                        \
-  V(AVXI16x8SubSaturateS)                        \
-  V(SSEI16x8Mul)                                 \
-  V(AVXI16x8Mul)                                 \
-  V(SSEI16x8MinS)                                \
-  V(AVXI16x8MinS)                                \
-  V(SSEI16x8MaxS)                                \
-  V(AVXI16x8MaxS)                                \
-  V(SSEI16x8Eq)                                  \
-  V(AVXI16x8Eq)                                  \
-  V(SSEI16x8Ne)                                  \
-  V(AVXI16x8Ne)                                  \
-  V(SSEI16x8GtS)                                 \
-  V(AVXI16x8GtS)                                 \
-  V(SSEI16x8GeS)                                 \
-  V(AVXI16x8GeS)                                 \
-  V(IA32I16x8UConvertI8x16Low)                   \
-  V(IA32I16x8UConvertI8x16High)                  \
-  V(SSEI16x8ShrU)                                \
-  V(AVXI16x8ShrU)                                \
-  V(SSEI16x8UConvertI32x4)                       \
-  V(AVXI16x8UConvertI32x4)                       \
-  V(SSEI16x8AddSaturateU)                        \
-  V(AVXI16x8AddSaturateU)                        \
-  V(SSEI16x8SubSaturateU)                        \
-  V(AVXI16x8SubSaturateU)                        \
-  V(SSEI16x8MinU)                                \
-  V(AVXI16x8MinU)                                \
-  V(SSEI16x8MaxU)                                \
-  V(AVXI16x8MaxU)                                \
-  V(SSEI16x8GtU)                                 \
-  V(AVXI16x8GtU)                                 \
-  V(SSEI16x8GeU)                                 \
-  V(AVXI16x8GeU)                                 \
-  V(IA32I8x16Splat)                              \
-  V(IA32I8x16ExtractLane)                        \
-  V(SSEI8x16ReplaceLane)                         \
-  V(AVXI8x16ReplaceLane)                         \
-  V(SSEI8x16SConvertI16x8)                       \
-  V(AVXI8x16SConvertI16x8)                       \
-  V(IA32I8x16Neg)                                \
-  V(SSEI8x16Shl)                                 \
-  V(AVXI8x16Shl)                                 \
-  V(IA32I8x16ShrS)                               \
-  V(SSEI8x16Add)                                 \
-  V(AVXI8x16Add)                                 \
-  V(SSEI8x16AddSaturateS)                        \
-  V(AVXI8x16AddSaturateS)                        \
-  V(SSEI8x16Sub)                                 \
-  V(AVXI8x16Sub)                                 \
-  V(SSEI8x16SubSaturateS)                        \
-  V(AVXI8x16SubSaturateS)                        \
-  V(SSEI8x16Mul)                                 \
-  V(AVXI8x16Mul)                                 \
-  V(SSEI8x16MinS)                                \
-  V(AVXI8x16MinS)                                \
-  V(SSEI8x16MaxS)                                \
-  V(AVXI8x16MaxS)                                \
-  V(SSEI8x16Eq)                                  \
-  V(AVXI8x16Eq)                                  \
-  V(SSEI8x16Ne)                                  \
-  V(AVXI8x16Ne)                                  \
-  V(SSEI8x16GtS)                                 \
-  V(AVXI8x16GtS)                                 \
-  V(SSEI8x16GeS)                                 \
-  V(AVXI8x16GeS)                                 \
-  V(SSEI8x16UConvertI16x8)                       \
-  V(AVXI8x16UConvertI16x8)                       \
-  V(SSEI8x16AddSaturateU)                        \
-  V(AVXI8x16AddSaturateU)                        \
-  V(SSEI8x16SubSaturateU)                        \
-  V(AVXI8x16SubSaturateU)                        \
-  V(IA32I8x16ShrU)                               \
-  V(SSEI8x16MinU)                                \
-  V(AVXI8x16MinU)                                \
-  V(SSEI8x16MaxU)                                \
-  V(AVXI8x16MaxU)                                \
-  V(SSEI8x16GtU)                                 \
-  V(AVXI8x16GtU)                                 \
-  V(SSEI8x16GeU)                                 \
-  V(AVXI8x16GeU)                                 \
-  V(IA32S128Zero)                                \
-  V(SSES128Not)                                  \
-  V(AVXS128Not)                                  \
-  V(SSES128And)                                  \
-  V(AVXS128And)                                  \
-  V(SSES128Or)                                   \
-  V(AVXS128Or)                                   \
-  V(SSES128Xor)                                  \
-  V(AVXS128Xor)                                  \
-  V(SSES128Select)                               \
-  V(AVXS128Select)                               \
-  V(IA32S8x16Shuffle)                            \
-  V(IA32S32x4Swizzle)                            \
-  V(IA32S32x4Shuffle)                            \
-  V(IA32S16x8Blend)                              \
-  V(IA32S16x8HalfShuffle1)                       \
-  V(IA32S16x8HalfShuffle2)                       \
-  V(IA32S8x16Alignr)                             \
-  V(IA32S16x8Dup)                                \
-  V(IA32S8x16Dup)                                \
-  V(SSES16x8UnzipHigh)                           \
-  V(AVXS16x8UnzipHigh)                           \
-  V(SSES16x8UnzipLow)                            \
-  V(AVXS16x8UnzipLow)                            \
-  V(SSES8x16UnzipHigh)                           \
-  V(AVXS8x16UnzipHigh)                           \
-  V(SSES8x16UnzipLow)                            \
-  V(AVXS8x16UnzipLow)                            \
-  V(IA32S64x2UnpackHigh)                         \
-  V(IA32S32x4UnpackHigh)                         \
-  V(IA32S16x8UnpackHigh)                         \
-  V(IA32S8x16UnpackHigh)                         \
-  V(IA32S64x2UnpackLow)                          \
-  V(IA32S32x4UnpackLow)                          \
-  V(IA32S16x8UnpackLow)                          \
-  V(IA32S8x16UnpackLow)                          \
-  V(SSES8x16TransposeLow)                        \
-  V(AVXS8x16TransposeLow)                        \
-  V(SSES8x16TransposeHigh)                       \
-  V(AVXS8x16TransposeHigh)                       \
-  V(SSES8x8Reverse)                              \
-  V(AVXS8x8Reverse)                              \
-  V(SSES8x4Reverse)                              \
-  V(AVXS8x4Reverse)                              \
-  V(SSES8x2Reverse)                              \
-  V(AVXS8x2Reverse)                              \
-  V(IA32S1x4AnyTrue)                             \
-  V(IA32S1x4AllTrue)                             \
-  V(IA32S1x8AnyTrue)                             \
-  V(IA32S1x8AllTrue)                             \
-  V(IA32S1x16AnyTrue)                            \
-  V(IA32S1x16AllTrue)                            \
-  V(IA32Word32AtomicPairLoad)                    \
-  V(IA32Word32AtomicPairStore)                   \
-  V(IA32Word32AtomicPairAdd)                     \
-  V(IA32Word32AtomicPairSub)                     \
-  V(IA32Word32AtomicPairAnd)                     \
-  V(IA32Word32AtomicPairOr)                      \
-  V(IA32Word32AtomicPairXor)                     \
-  V(IA32Word32AtomicPairExchange)                \
-  V(IA32Word32AtomicPairCompareExchange)         \
-  V(IA32Word64AtomicNarrowAddUint8)              \
-  V(IA32Word64AtomicNarrowAddUint16)             \
-  V(IA32Word64AtomicNarrowAddUint32)             \
-  V(IA32Word64AtomicNarrowSubUint8)              \
-  V(IA32Word64AtomicNarrowSubUint16)             \
-  V(IA32Word64AtomicNarrowSubUint32)             \
-  V(IA32Word64AtomicNarrowAndUint8)              \
-  V(IA32Word64AtomicNarrowAndUint16)             \
-  V(IA32Word64AtomicNarrowAndUint32)             \
-  V(IA32Word64AtomicNarrowOrUint8)               \
-  V(IA32Word64AtomicNarrowOrUint16)              \
-  V(IA32Word64AtomicNarrowOrUint32)              \
-  V(IA32Word64AtomicNarrowXorUint8)              \
-  V(IA32Word64AtomicNarrowXorUint16)             \
-  V(IA32Word64AtomicNarrowXorUint32)             \
-  V(IA32Word64AtomicNarrowExchangeUint8)         \
-  V(IA32Word64AtomicNarrowExchangeUint16)        \
-  V(IA32Word64AtomicNarrowExchangeUint32)        \
-  V(IA32Word64AtomicNarrowCompareExchangeUint8)  \
-  V(IA32Word64AtomicNarrowCompareExchangeUint16) \
-  V(IA32Word64AtomicNarrowCompareExchangeUint32)
+#define TARGET_ARCH_OPCODE_LIST(V) \
+  V(IA32Add)                       \
+  V(IA32And)                       \
+  V(IA32Cmp)                       \
+  V(IA32Cmp16)                     \
+  V(IA32Cmp8)                      \
+  V(IA32Test)                      \
+  V(IA32Test16)                    \
+  V(IA32Test8)                     \
+  V(IA32Or)                        \
+  V(IA32Xor)                       \
+  V(IA32Sub)                       \
+  V(IA32Imul)                      \
+  V(IA32ImulHigh)                  \
+  V(IA32UmulHigh)                  \
+  V(IA32Idiv)                      \
+  V(IA32Udiv)                      \
+  V(IA32Not)                       \
+  V(IA32Neg)                       \
+  V(IA32Shl)                       \
+  V(IA32Shr)                       \
+  V(IA32Sar)                       \
+  V(IA32AddPair)                   \
+  V(IA32SubPair)                   \
+  V(IA32MulPair)                   \
+  V(IA32ShlPair)                   \
+  V(IA32ShrPair)                   \
+  V(IA32SarPair)                   \
+  V(IA32Ror)                       \
+  V(IA32Lzcnt)                     \
+  V(IA32Tzcnt)                     \
+  V(IA32Popcnt)                    \
+  V(IA32Bswap)                     \
+  V(LFence)                        \
+  V(SSEFloat32Cmp)                 \
+  V(SSEFloat32Add)                 \
+  V(SSEFloat32Sub)                 \
+  V(SSEFloat32Mul)                 \
+  V(SSEFloat32Div)                 \
+  V(SSEFloat32Abs)                 \
+  V(SSEFloat32Neg)                 \
+  V(SSEFloat32Sqrt)                \
+  V(SSEFloat32Round)               \
+  V(SSEFloat64Cmp)                 \
+  V(SSEFloat64Add)                 \
+  V(SSEFloat64Sub)                 \
+  V(SSEFloat64Mul)                 \
+  V(SSEFloat64Div)                 \
+  V(SSEFloat64Mod)                 \
+  V(SSEFloat32Max)                 \
+  V(SSEFloat64Max)                 \
+  V(SSEFloat32Min)                 \
+  V(SSEFloat64Min)                 \
+  V(SSEFloat64Abs)                 \
+  V(SSEFloat64Neg)                 \
+  V(SSEFloat64Sqrt)                \
+  V(SSEFloat64Round)               \
+  V(SSEFloat32ToFloat64)           \
+  V(SSEFloat64ToFloat32)           \
+  V(SSEFloat32ToInt32)             \
+  V(SSEFloat32ToUint32)            \
+  V(SSEFloat64ToInt32)             \
+  V(SSEFloat64ToUint32)            \
+  V(SSEInt32ToFloat32)             \
+  V(SSEUint32ToFloat32)            \
+  V(SSEInt32ToFloat64)             \
+  V(SSEUint32ToFloat64)            \
+  V(SSEFloat64ExtractLowWord32)    \
+  V(SSEFloat64ExtractHighWord32)   \
+  V(SSEFloat64InsertLowWord32)     \
+  V(SSEFloat64InsertHighWord32)    \
+  V(SSEFloat64LoadLowWord32)       \
+  V(SSEFloat64SilenceNaN)          \
+  V(AVXFloat32Add)                 \
+  V(AVXFloat32Sub)                 \
+  V(AVXFloat32Mul)                 \
+  V(AVXFloat32Div)                 \
+  V(AVXFloat64Add)                 \
+  V(AVXFloat64Sub)                 \
+  V(AVXFloat64Mul)                 \
+  V(AVXFloat64Div)                 \
+  V(AVXFloat64Abs)                 \
+  V(AVXFloat64Neg)                 \
+  V(AVXFloat32Abs)                 \
+  V(AVXFloat32Neg)                 \
+  V(IA32Movsxbl)                   \
+  V(IA32Movzxbl)                   \
+  V(IA32Movb)                      \
+  V(IA32Movsxwl)                   \
+  V(IA32Movzxwl)                   \
+  V(IA32Movw)                      \
+  V(IA32Movl)                      \
+  V(IA32Movss)                     \
+  V(IA32Movsd)                     \
+  V(IA32Movdqu)                    \
+  V(IA32BitcastFI)                 \
+  V(IA32BitcastIF)                 \
+  V(IA32Lea)                       \
+  V(IA32Push)                      \
+  V(IA32PushFloat32)               \
+  V(IA32PushFloat64)               \
+  V(IA32PushSimd128)               \
+  V(IA32Poke)                      \
+  V(IA32Peek)                      \
+  V(IA32StackCheck)                \
+  V(SSEF32x4Splat)                 \
+  V(AVXF32x4Splat)                 \
+  V(SSEF32x4ExtractLane)           \
+  V(AVXF32x4ExtractLane)           \
+  V(SSEF32x4ReplaceLane)           \
+  V(AVXF32x4ReplaceLane)           \
+  V(IA32F32x4SConvertI32x4)        \
+  V(SSEF32x4UConvertI32x4)         \
+  V(AVXF32x4UConvertI32x4)         \
+  V(SSEF32x4Abs)                   \
+  V(AVXF32x4Abs)                   \
+  V(SSEF32x4Neg)                   \
+  V(AVXF32x4Neg)                   \
+  V(IA32F32x4RecipApprox)          \
+  V(IA32F32x4RecipSqrtApprox)      \
+  V(SSEF32x4Add)                   \
+  V(AVXF32x4Add)                   \
+  V(SSEF32x4AddHoriz)              \
+  V(AVXF32x4AddHoriz)              \
+  V(SSEF32x4Sub)                   \
+  V(AVXF32x4Sub)                   \
+  V(SSEF32x4Mul)                   \
+  V(AVXF32x4Mul)                   \
+  V(SSEF32x4Min)                   \
+  V(AVXF32x4Min)                   \
+  V(SSEF32x4Max)                   \
+  V(AVXF32x4Max)                   \
+  V(SSEF32x4Eq)                    \
+  V(AVXF32x4Eq)                    \
+  V(SSEF32x4Ne)                    \
+  V(AVXF32x4Ne)                    \
+  V(SSEF32x4Lt)                    \
+  V(AVXF32x4Lt)                    \
+  V(SSEF32x4Le)                    \
+  V(AVXF32x4Le)                    \
+  V(IA32I32x4Splat)                \
+  V(IA32I32x4ExtractLane)          \
+  V(SSEI32x4ReplaceLane)           \
+  V(AVXI32x4ReplaceLane)           \
+  V(SSEI32x4SConvertF32x4)         \
+  V(AVXI32x4SConvertF32x4)         \
+  V(IA32I32x4SConvertI16x8Low)     \
+  V(IA32I32x4SConvertI16x8High)    \
+  V(IA32I32x4Neg)                  \
+  V(SSEI32x4Shl)                   \
+  V(AVXI32x4Shl)                   \
+  V(SSEI32x4ShrS)                  \
+  V(AVXI32x4ShrS)                  \
+  V(SSEI32x4Add)                   \
+  V(AVXI32x4Add)                   \
+  V(SSEI32x4AddHoriz)              \
+  V(AVXI32x4AddHoriz)              \
+  V(SSEI32x4Sub)                   \
+  V(AVXI32x4Sub)                   \
+  V(SSEI32x4Mul)                   \
+  V(AVXI32x4Mul)                   \
+  V(SSEI32x4MinS)                  \
+  V(AVXI32x4MinS)                  \
+  V(SSEI32x4MaxS)                  \
+  V(AVXI32x4MaxS)                  \
+  V(SSEI32x4Eq)                    \
+  V(AVXI32x4Eq)                    \
+  V(SSEI32x4Ne)                    \
+  V(AVXI32x4Ne)                    \
+  V(SSEI32x4GtS)                   \
+  V(AVXI32x4GtS)                   \
+  V(SSEI32x4GeS)                   \
+  V(AVXI32x4GeS)                   \
+  V(SSEI32x4UConvertF32x4)         \
+  V(AVXI32x4UConvertF32x4)         \
+  V(IA32I32x4UConvertI16x8Low)     \
+  V(IA32I32x4UConvertI16x8High)    \
+  V(SSEI32x4ShrU)                  \
+  V(AVXI32x4ShrU)                  \
+  V(SSEI32x4MinU)                  \
+  V(AVXI32x4MinU)                  \
+  V(SSEI32x4MaxU)                  \
+  V(AVXI32x4MaxU)                  \
+  V(SSEI32x4GtU)                   \
+  V(AVXI32x4GtU)                   \
+  V(SSEI32x4GeU)                   \
+  V(AVXI32x4GeU)                   \
+  V(IA32I16x8Splat)                \
+  V(IA32I16x8ExtractLane)          \
+  V(SSEI16x8ReplaceLane)           \
+  V(AVXI16x8ReplaceLane)           \
+  V(IA32I16x8SConvertI8x16Low)     \
+  V(IA32I16x8SConvertI8x16High)    \
+  V(IA32I16x8Neg)                  \
+  V(SSEI16x8Shl)                   \
+  V(AVXI16x8Shl)                   \
+  V(SSEI16x8ShrS)                  \
+  V(AVXI16x8ShrS)                  \
+  V(SSEI16x8SConvertI32x4)         \
+  V(AVXI16x8SConvertI32x4)         \
+  V(SSEI16x8Add)                   \
+  V(AVXI16x8Add)                   \
+  V(SSEI16x8AddSaturateS)          \
+  V(AVXI16x8AddSaturateS)          \
+  V(SSEI16x8AddHoriz)              \
+  V(AVXI16x8AddHoriz)              \
+  V(SSEI16x8Sub)                   \
+  V(AVXI16x8Sub)                   \
+  V(SSEI16x8SubSaturateS)          \
+  V(AVXI16x8SubSaturateS)          \
+  V(SSEI16x8Mul)                   \
+  V(AVXI16x8Mul)                   \
+  V(SSEI16x8MinS)                  \
+  V(AVXI16x8MinS)                  \
+  V(SSEI16x8MaxS)                  \
+  V(AVXI16x8MaxS)                  \
+  V(SSEI16x8Eq)                    \
+  V(AVXI16x8Eq)                    \
+  V(SSEI16x8Ne)                    \
+  V(AVXI16x8Ne)                    \
+  V(SSEI16x8GtS)                   \
+  V(AVXI16x8GtS)                   \
+  V(SSEI16x8GeS)                   \
+  V(AVXI16x8GeS)                   \
+  V(IA32I16x8UConvertI8x16Low)     \
+  V(IA32I16x8UConvertI8x16High)    \
+  V(SSEI16x8ShrU)                  \
+  V(AVXI16x8ShrU)                  \
+  V(SSEI16x8UConvertI32x4)         \
+  V(AVXI16x8UConvertI32x4)         \
+  V(SSEI16x8AddSaturateU)          \
+  V(AVXI16x8AddSaturateU)          \
+  V(SSEI16x8SubSaturateU)          \
+  V(AVXI16x8SubSaturateU)          \
+  V(SSEI16x8MinU)                  \
+  V(AVXI16x8MinU)                  \
+  V(SSEI16x8MaxU)                  \
+  V(AVXI16x8MaxU)                  \
+  V(SSEI16x8GtU)                   \
+  V(AVXI16x8GtU)                   \
+  V(SSEI16x8GeU)                   \
+  V(AVXI16x8GeU)                   \
+  V(IA32I8x16Splat)                \
+  V(IA32I8x16ExtractLane)          \
+  V(SSEI8x16ReplaceLane)           \
+  V(AVXI8x16ReplaceLane)           \
+  V(SSEI8x16SConvertI16x8)         \
+  V(AVXI8x16SConvertI16x8)         \
+  V(IA32I8x16Neg)                  \
+  V(SSEI8x16Shl)                   \
+  V(AVXI8x16Shl)                   \
+  V(IA32I8x16ShrS)                 \
+  V(SSEI8x16Add)                   \
+  V(AVXI8x16Add)                   \
+  V(SSEI8x16AddSaturateS)          \
+  V(AVXI8x16AddSaturateS)          \
+  V(SSEI8x16Sub)                   \
+  V(AVXI8x16Sub)                   \
+  V(SSEI8x16SubSaturateS)          \
+  V(AVXI8x16SubSaturateS)          \
+  V(SSEI8x16Mul)                   \
+  V(AVXI8x16Mul)                   \
+  V(SSEI8x16MinS)                  \
+  V(AVXI8x16MinS)                  \
+  V(SSEI8x16MaxS)                  \
+  V(AVXI8x16MaxS)                  \
+  V(SSEI8x16Eq)                    \
+  V(AVXI8x16Eq)                    \
+  V(SSEI8x16Ne)                    \
+  V(AVXI8x16Ne)                    \
+  V(SSEI8x16GtS)                   \
+  V(AVXI8x16GtS)                   \
+  V(SSEI8x16GeS)                   \
+  V(AVXI8x16GeS)                   \
+  V(SSEI8x16UConvertI16x8)         \
+  V(AVXI8x16UConvertI16x8)         \
+  V(SSEI8x16AddSaturateU)          \
+  V(AVXI8x16AddSaturateU)          \
+  V(SSEI8x16SubSaturateU)          \
+  V(AVXI8x16SubSaturateU)          \
+  V(IA32I8x16ShrU)                 \
+  V(SSEI8x16MinU)                  \
+  V(AVXI8x16MinU)                  \
+  V(SSEI8x16MaxU)                  \
+  V(AVXI8x16MaxU)                  \
+  V(SSEI8x16GtU)                   \
+  V(AVXI8x16GtU)                   \
+  V(SSEI8x16GeU)                   \
+  V(AVXI8x16GeU)                   \
+  V(IA32S128Zero)                  \
+  V(SSES128Not)                    \
+  V(AVXS128Not)                    \
+  V(SSES128And)                    \
+  V(AVXS128And)                    \
+  V(SSES128Or)                     \
+  V(AVXS128Or)                     \
+  V(SSES128Xor)                    \
+  V(AVXS128Xor)                    \
+  V(SSES128Select)                 \
+  V(AVXS128Select)                 \
+  V(IA32S8x16Shuffle)              \
+  V(IA32S32x4Swizzle)              \
+  V(IA32S32x4Shuffle)              \
+  V(IA32S16x8Blend)                \
+  V(IA32S16x8HalfShuffle1)         \
+  V(IA32S16x8HalfShuffle2)         \
+  V(IA32S8x16Alignr)               \
+  V(IA32S16x8Dup)                  \
+  V(IA32S8x16Dup)                  \
+  V(SSES16x8UnzipHigh)             \
+  V(AVXS16x8UnzipHigh)             \
+  V(SSES16x8UnzipLow)              \
+  V(AVXS16x8UnzipLow)              \
+  V(SSES8x16UnzipHigh)             \
+  V(AVXS8x16UnzipHigh)             \
+  V(SSES8x16UnzipLow)              \
+  V(AVXS8x16UnzipLow)              \
+  V(IA32S64x2UnpackHigh)           \
+  V(IA32S32x4UnpackHigh)           \
+  V(IA32S16x8UnpackHigh)           \
+  V(IA32S8x16UnpackHigh)           \
+  V(IA32S64x2UnpackLow)            \
+  V(IA32S32x4UnpackLow)            \
+  V(IA32S16x8UnpackLow)            \
+  V(IA32S8x16UnpackLow)            \
+  V(SSES8x16TransposeLow)          \
+  V(AVXS8x16TransposeLow)          \
+  V(SSES8x16TransposeHigh)         \
+  V(AVXS8x16TransposeHigh)         \
+  V(SSES8x8Reverse)                \
+  V(AVXS8x8Reverse)                \
+  V(SSES8x4Reverse)                \
+  V(AVXS8x4Reverse)                \
+  V(SSES8x2Reverse)                \
+  V(AVXS8x2Reverse)                \
+  V(IA32S1x4AnyTrue)               \
+  V(IA32S1x4AllTrue)               \
+  V(IA32S1x8AnyTrue)               \
+  V(IA32S1x8AllTrue)               \
+  V(IA32S1x16AnyTrue)              \
+  V(IA32S1x16AllTrue)              \
+  V(IA32Word32AtomicPairLoad)      \
+  V(IA32Word32AtomicPairStore)     \
+  V(IA32Word32AtomicPairAdd)       \
+  V(IA32Word32AtomicPairSub)       \
+  V(IA32Word32AtomicPairAnd)       \
+  V(IA32Word32AtomicPairOr)        \
+  V(IA32Word32AtomicPairXor)       \
+  V(IA32Word32AtomicPairExchange)  \
+  V(IA32Word32AtomicPairCompareExchange)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/ia32/instruction-scheduler-ia32.cc b/deps/v8/src/compiler/ia32/instruction-scheduler-ia32.cc
index 07d42bc614..54454e41cb 100644
--- a/deps/v8/src/compiler/ia32/instruction-scheduler-ia32.cc
+++ b/deps/v8/src/compiler/ia32/instruction-scheduler-ia32.cc
@@ -380,27 +380,6 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kIA32Word32AtomicPairXor:
     case kIA32Word32AtomicPairExchange:
     case kIA32Word32AtomicPairCompareExchange:
-    case kIA32Word64AtomicNarrowAddUint8:
-    case kIA32Word64AtomicNarrowAddUint16:
-    case kIA32Word64AtomicNarrowAddUint32:
-    case kIA32Word64AtomicNarrowSubUint8:
-    case kIA32Word64AtomicNarrowSubUint16:
-    case kIA32Word64AtomicNarrowSubUint32:
-    case kIA32Word64AtomicNarrowAndUint8:
-    case kIA32Word64AtomicNarrowAndUint16:
-    case kIA32Word64AtomicNarrowAndUint32:
-    case kIA32Word64AtomicNarrowOrUint8:
-    case kIA32Word64AtomicNarrowOrUint16:
-    case kIA32Word64AtomicNarrowOrUint32:
-    case kIA32Word64AtomicNarrowXorUint8:
-    case kIA32Word64AtomicNarrowXorUint16:
-    case kIA32Word64AtomicNarrowXorUint32:
-    case kIA32Word64AtomicNarrowExchangeUint8:
-    case kIA32Word64AtomicNarrowExchangeUint16:
-    case kIA32Word64AtomicNarrowExchangeUint32:
-    case kIA32Word64AtomicNarrowCompareExchangeUint8:
-    case kIA32Word64AtomicNarrowCompareExchangeUint16:
-    case kIA32Word64AtomicNarrowCompareExchangeUint32:
       return kHasSideEffect;
 
 #define CASE(Name) case k##Name:
diff --git a/deps/v8/src/compiler/ia32/instruction-selector-ia32.cc b/deps/v8/src/compiler/ia32/instruction-selector-ia32.cc
index ce2f14e97f..43b572170f 100644
--- a/deps/v8/src/compiler/ia32/instruction-selector-ia32.cc
+++ b/deps/v8/src/compiler/ia32/instruction-selector-ia32.cc
@@ -935,10 +935,10 @@ void InstructionSelector::VisitRoundUint32ToFloat32(Node* node) {
 
 void InstructionSelector::VisitFloat64Mod(Node* node) {
   IA32OperandGenerator g(this);
-  InstructionOperand temps[] = {g.TempRegister(eax)};
+  InstructionOperand temps[] = {g.TempRegister(eax), g.TempRegister()};
   Emit(kSSEFloat64Mod, g.DefineSameAsFirst(node),
-       g.UseRegister(node->InputAt(0)), g.UseRegister(node->InputAt(1)), 1,
-       temps);
+       g.UseRegister(node->InputAt(0)), g.UseRegister(node->InputAt(1)),
+       arraysize(temps), temps);
 }
 
 void InstructionSelector::VisitFloat32Max(Node* node) {
@@ -1343,43 +1343,42 @@ void VisitPairAtomicBinOp(InstructionSelector* selector, Node* node,
   // For Word64 operations, the value input is split into the a high node,
   // and a low node in the int64-lowering phase.
   Node* value_high = node->InputAt(3);
+#if defined(V8_EMBEDDED_BUILTINS)
+  bool block_root_register = !selector->CanUseRootsRegister();
+#else
+  bool block_root_register = true;
+#endif
 
   // Wasm lives in 32-bit address space, so we do not need to worry about
   // base/index lowering. This will need to be fixed for Wasm64.
   AddressingMode addressing_mode;
   InstructionOperand inputs[] = {
-      g.UseFixed(value, ebx), g.UseFixed(value_high, ecx),
+      g.UseUniqueRegisterOrSlotOrConstant(value), g.UseFixed(value_high, ecx),
       g.UseUniqueRegister(base),
       g.GetEffectiveIndexOperand(index, &addressing_mode)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), eax),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), edx)};
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs);
-}
-
-void VisitNarrowAtomicBinOp(InstructionSelector* selector, Node* node,
-                            ArchOpcode opcode, MachineType type) {
-  IA32OperandGenerator g(selector);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
-
-  // Wasm lives in 32-bit address space, so we do not need to worry about
-  // base/index lowering. This will need to be fixed for Wasm64.
-  AddressingMode addressing_mode;
-  InstructionOperand inputs[] = {
-      g.UseUniqueRegister(value), g.UseUniqueRegister(base),
-      g.GetEffectiveIndexOperand(index, &addressing_mode)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), eax),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), edx)};
-  InstructionOperand temp[] = {(type == MachineType::Uint8())
-                                   ? g.UseByteRegister(node)
-                                   : g.TempRegister()};
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-                 arraysize(temp), temp);
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand temps[] = {g.TempRegister(ebx)};
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, eax),
+                                    g.DefineAsFixed(projection1, edx)};
+    const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
+    selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+                   num_temps, temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, eax)};
+    InstructionOperand temps[] = {g.TempRegister(edx), g.TempRegister(ebx)};
+    const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
+    selector->Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+                   num_temps, temps);
+  } else {
+    InstructionOperand temps[] = {g.TempRegister(eax), g.TempRegister(edx),
+                                  g.TempRegister(ebx)};
+    const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
+    selector->Emit(code, 0, nullptr, arraysize(inputs), inputs, num_temps,
+                   temps);
+  }
 }
 
 }  // namespace
@@ -1769,14 +1768,27 @@ void InstructionSelector::VisitWord32AtomicPairLoad(Node* node) {
   Node* index = node->InputAt(1);
   InstructionOperand inputs[] = {g.UseUniqueRegister(base),
                                  g.GetEffectiveIndexOperand(index, &mode)};
-  InstructionOperand temps[] = {g.TempDoubleRegister()};
-  InstructionOperand outputs[] = {
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 0)),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
   InstructionCode code =
       kIA32Word32AtomicPairLoad | AddressingModeField::encode(mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-       arraysize(temps), temps);
+
+  if (projection1) {
+    InstructionOperand temps[] = {g.TempDoubleRegister()};
+    InstructionOperand outputs[] = {g.DefineAsRegister(projection0),
+                                    g.DefineAsRegister(projection1)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand temps[] = {g.TempDoubleRegister(), g.TempRegister()};
+    InstructionOperand outputs[] = {g.DefineAsRegister(projection0)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else {
+    InstructionOperand temps[] = {g.TempDoubleRegister(), g.TempRegister(),
+                                  g.TempRegister()};
+    Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
+  }
 }
 
 void InstructionSelector::VisitWord32AtomicPairStore(Node* node) {
@@ -1785,19 +1797,26 @@ void InstructionSelector::VisitWord32AtomicPairStore(Node* node) {
   Node* index = node->InputAt(1);
   Node* value = node->InputAt(2);
   Node* value_high = node->InputAt(3);
+#if defined(V8_EMBEDDED_BUILTINS)
+  bool block_root_register = !CanUseRootsRegister();
+#else
+  bool block_root_register = true;
+#endif
 
   AddressingMode addressing_mode;
   InstructionOperand inputs[] = {
-      g.UseFixed(value, ebx), g.UseFixed(value_high, ecx),
+      g.UseUniqueRegisterOrSlotOrConstant(value), g.UseFixed(value_high, ecx),
       g.UseUniqueRegister(base),
       g.GetEffectiveIndexOperand(index, &addressing_mode)};
   // Allocating temp registers here as stores are performed using an atomic
   // exchange, the output of which is stored in edx:eax, which should be saved
   // and restored at the end of the instruction.
-  InstructionOperand temps[] = {g.TempRegister(eax), g.TempRegister(edx)};
+  InstructionOperand temps[] = {g.TempRegister(eax), g.TempRegister(edx),
+                                g.TempRegister(ebx)};
+  const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
   InstructionCode code =
       kIA32Word32AtomicPairStore | AddressingModeField::encode(addressing_mode);
-  Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
+  Emit(code, 0, nullptr, arraysize(inputs), inputs, num_temps, temps);
 }
 
 void InstructionSelector::VisitWord32AtomicPairAdd(Node* node) {
@@ -1828,125 +1847,45 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   IA32OperandGenerator g(this);
   Node* index = node->InputAt(1);
   AddressingMode addressing_mode;
+#if defined(V8_EMBEDDED_BUILTINS)
+  bool block_root_register = !CanUseRootsRegister();
+#else
+  bool block_root_register = true;
+#endif
+
   InstructionOperand inputs[] = {
       // High, Low values of old value
       g.UseFixed(node->InputAt(2), eax), g.UseFixed(node->InputAt(3), edx),
       // High, Low values of new value
-      g.UseFixed(node->InputAt(4), ebx), g.UseFixed(node->InputAt(5), ecx),
+      g.UseUniqueRegisterOrSlotOrConstant(node->InputAt(4)),
+      g.UseFixed(node->InputAt(5), ecx),
       // InputAt(0) => base
       g.UseUniqueRegister(node->InputAt(0)),
       g.GetEffectiveIndexOperand(index, &addressing_mode)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), eax),
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 1), edx)};
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
   InstructionCode code = kIA32Word32AtomicPairCompareExchange |
                          AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs);
-}
 
-void InstructionSelector::VisitWord64AtomicNarrowBinop(Node* node,
-                                                       ArchOpcode uint8_op,
-                                                       ArchOpcode uint16_op,
-                                                       ArchOpcode uint32_op) {
-  MachineType type = AtomicOpType(node->op());
-  DCHECK(type != MachineType::Uint64());
-  ArchOpcode opcode = kArchNop;
-  if (type == MachineType::Uint32()) {
-    opcode = uint32_op;
-  } else if (type == MachineType::Uint16()) {
-    opcode = uint16_op;
-  } else if (type == MachineType::Uint8()) {
-    opcode = uint8_op;
-  } else {
-    UNREACHABLE();
-    return;
-  }
-  VisitNarrowAtomicBinOp(this, node, opcode, type);
-}
-
-#define VISIT_ATOMIC_BINOP(op)                                             \
-  void InstructionSelector::VisitWord64AtomicNarrow##op(Node* node) {      \
-    VisitWord64AtomicNarrowBinop(node, kIA32Word64AtomicNarrow##op##Uint8, \
-                                 kIA32Word64AtomicNarrow##op##Uint16,      \
-                                 kIA32Word64AtomicNarrow##op##Uint32);     \
-  }
-VISIT_ATOMIC_BINOP(Add)
-VISIT_ATOMIC_BINOP(Sub)
-VISIT_ATOMIC_BINOP(And)
-VISIT_ATOMIC_BINOP(Or)
-VISIT_ATOMIC_BINOP(Xor)
-#undef VISIT_ATOMIC_BINOP
-
-void InstructionSelector::VisitWord64AtomicNarrowExchange(Node* node) {
-  MachineType type = AtomicOpType(node->op());
-  DCHECK(type != MachineType::Uint64());
-  ArchOpcode opcode = kArchNop;
-  if (type == MachineType::Uint32()) {
-    opcode = kIA32Word64AtomicNarrowExchangeUint32;
-  } else if (type == MachineType::Uint16()) {
-    opcode = kIA32Word64AtomicNarrowExchangeUint16;
-  } else if (type == MachineType::Uint8()) {
-    opcode = kIA32Word64AtomicNarrowExchangeUint8;
-  } else {
-    UNREACHABLE();
-    return;
-  }
-  IA32OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
-  AddressingMode addressing_mode;
-  InstructionOperand value_operand =
-      (type.representation() == MachineRepresentation::kWord8)
-          ? g.UseFixed(value, edx)
-          : g.UseUniqueRegister(value);
-  InstructionOperand inputs[] = {
-      value_operand, g.UseUniqueRegister(base),
-      g.GetEffectiveIndexOperand(index, &addressing_mode)};
-  InstructionOperand outputs[2];
-  if (type.representation() == MachineRepresentation::kWord8) {
-    // Using DefineSameAsFirst requires the register to be unallocated.
-    outputs[0] = g.DefineAsFixed(NodeProperties::FindProjection(node, 0), edx);
-  } else {
-    outputs[0] = g.DefineSameAsFirst(NodeProperties::FindProjection(node, 0));
-  }
-  outputs[1] = g.DefineAsRegister(NodeProperties::FindProjection(node, 1));
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs);
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowCompareExchange(Node* node) {
-  MachineType type = AtomicOpType(node->op());
-  DCHECK(type != MachineType::Uint64());
-  ArchOpcode opcode = kArchNop;
-  if (type == MachineType::Uint32()) {
-    opcode = kIA32Word64AtomicNarrowCompareExchangeUint32;
-  } else if (type == MachineType::Uint16()) {
-    opcode = kIA32Word64AtomicNarrowCompareExchangeUint16;
-  } else if (type == MachineType::Uint8()) {
-    opcode = kIA32Word64AtomicNarrowCompareExchangeUint8;
+  if (projection1) {
+    InstructionOperand temps[] = {g.TempRegister(ebx)};
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, eax),
+                                    g.DefineAsFixed(projection1, edx)};
+    const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         num_temps, temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, eax)};
+    InstructionOperand temps[] = {g.TempRegister(edx), g.TempRegister(ebx)};
+    const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         num_temps, temps);
   } else {
-    UNREACHABLE();
-    return;
+    InstructionOperand temps[] = {g.TempRegister(eax), g.TempRegister(edx),
+                                  g.TempRegister(ebx)};
+    const int num_temps = arraysize(temps) - (block_root_register ? 0 : 1);
+    Emit(code, 0, nullptr, arraysize(inputs), inputs, num_temps, temps);
   }
-  IA32OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* old_value = node->InputAt(2);
-  Node* new_value = node->InputAt(3);
-  AddressingMode addressing_mode;
-  InstructionOperand new_value_operand =
-      (type.representation() == MachineRepresentation::kWord8)
-          ? g.UseByteRegister(new_value)
-          : g.UseUniqueRegister(new_value);
-  InstructionOperand inputs[] = {
-      g.UseFixed(old_value, eax), new_value_operand, g.UseUniqueRegister(base),
-      g.GetEffectiveIndexOperand(index, &addressing_mode)};
-  InstructionOperand outputs[] = {
-      g.DefineAsFixed(NodeProperties::FindProjection(node, 0), eax),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs);
 }
 
 #define SIMD_INT_TYPES(V) \
diff --git a/deps/v8/src/compiler/instruction-selector-impl.h b/deps/v8/src/compiler/instruction-selector-impl.h
index 27f37215df..bff70d5edf 100644
--- a/deps/v8/src/compiler/instruction-selector-impl.h
+++ b/deps/v8/src/compiler/instruction-selector-impl.h
@@ -5,6 +5,7 @@
 #ifndef V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 
+#include "src/compiler/common-operator.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/linkage.h"
@@ -154,6 +155,12 @@ class OperandGenerator {
                          UnallocatedOperand::USED_AT_START, GetVReg(node)));
   }
 
+  InstructionOperand UseUniqueRegisterOrSlotOrConstant(Node* node) {
+    return Use(node, UnallocatedOperand(
+                         UnallocatedOperand::REGISTER_OR_SLOT_OR_CONSTANT,
+                         GetVReg(node)));
+  }
+
   InstructionOperand UseRegister(Node* node) {
     return Use(node, UnallocatedOperand(UnallocatedOperand::MUST_HAVE_REGISTER,
                                         UnallocatedOperand::USED_AT_START,
@@ -319,6 +326,8 @@ class OperandGenerator {
       }
       case IrOpcode::kHeapConstant:
         return Constant(HeapConstantOf(node->op()));
+      case IrOpcode::kDelayedStringConstant:
+        return Constant(StringConstantBaseOf(node->op()));
       case IrOpcode::kDeadValue: {
         switch (DeadValueRepresentationOf(node->op())) {
           case MachineRepresentation::kBit:
diff --git a/deps/v8/src/compiler/instruction-selector.cc b/deps/v8/src/compiler/instruction-selector.cc
index d15a633257..4bd4dc18fe 100644
--- a/deps/v8/src/compiler/instruction-selector.cc
+++ b/deps/v8/src/compiler/instruction-selector.cc
@@ -456,6 +456,7 @@ InstructionOperand OperandForDeopt(Isolate* isolate, OperandGenerator* g,
     case IrOpcode::kNumberConstant:
     case IrOpcode::kFloat32Constant:
     case IrOpcode::kFloat64Constant:
+    case IrOpcode::kDelayedStringConstant:
       return g->UseImmediate(input);
     case IrOpcode::kHeapConstant: {
       if (!CanBeTaggedPointer(rep)) {
@@ -470,9 +471,9 @@ InstructionOperand OperandForDeopt(Isolate* isolate, OperandGenerator* g,
       }
 
       Handle<HeapObject> constant = HeapConstantOf(input->op());
-      Heap::RootListIndex root_index;
+      RootIndex root_index;
       if (isolate->heap()->IsRootHandle(constant, &root_index) &&
-          root_index == Heap::kOptimizedOutRootIndex) {
+          root_index == RootIndex::kOptimizedOut) {
         // For an optimized-out object we return an invalid instruction
         // operand, so that we take the fast path for optimized-out values.
         return InstructionOperand();
@@ -1081,6 +1082,7 @@ void InstructionSelector::VisitBlock(BasicBlock* block) {
     std::reverse(instructions_.begin() + instruction_start,
                  instructions_.end());
     if (!node) return true;
+    if (!source_positions_) return true;
     SourcePosition source_position = source_positions_->GetSourcePosition(node);
     if (source_position.IsKnown() && IsSourcePositionUsed(node)) {
       sequence()->SetSourcePosition(instructions_[instruction_start],
@@ -1293,6 +1295,8 @@ void InstructionSelector::VisitNode(Node* node) {
       if (!IsSmiDouble(value)) MarkAsReference(node);
       return VisitConstant(node);
     }
+    case IrOpcode::kDelayedStringConstant:
+      return MarkAsReference(node), VisitConstant(node);
     case IrOpcode::kCall:
       return VisitCall(node);
     case IrOpcode::kCallWithCallerSavedRegisters:
@@ -1467,10 +1471,14 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsFloat64(node), VisitChangeFloat32ToFloat64(node);
     case IrOpcode::kChangeInt32ToFloat64:
       return MarkAsFloat64(node), VisitChangeInt32ToFloat64(node);
+    case IrOpcode::kChangeInt64ToFloat64:
+      return MarkAsFloat64(node), VisitChangeInt64ToFloat64(node);
     case IrOpcode::kChangeUint32ToFloat64:
       return MarkAsFloat64(node), VisitChangeUint32ToFloat64(node);
     case IrOpcode::kChangeFloat64ToInt32:
       return MarkAsWord32(node), VisitChangeFloat64ToInt32(node);
+    case IrOpcode::kChangeFloat64ToInt64:
+      return MarkAsWord64(node), VisitChangeFloat64ToInt64(node);
     case IrOpcode::kChangeFloat64ToUint32:
       return MarkAsWord32(node), VisitChangeFloat64ToUint32(node);
     case IrOpcode::kChangeFloat64ToUint64:
@@ -1747,21 +1755,6 @@ void InstructionSelector::VisitNode(Node* node) {
       ATOMIC_CASE(Exchange)
       ATOMIC_CASE(CompareExchange)
 #undef ATOMIC_CASE
-#define ATOMIC_CASE(name)                              \
-  case IrOpcode::kWord64AtomicNarrow##name: {          \
-    MachineType type = AtomicOpType(node->op());       \
-    MarkAsRepresentation(type.representation(), node); \
-    MarkPairProjectionsAsWord32(node);                 \
-    return VisitWord64AtomicNarrow##name(node);        \
-  }
-      ATOMIC_CASE(Add)
-      ATOMIC_CASE(Sub)
-      ATOMIC_CASE(And)
-      ATOMIC_CASE(Or)
-      ATOMIC_CASE(Xor)
-      ATOMIC_CASE(Exchange)
-      ATOMIC_CASE(CompareExchange)
-#undef ATOMIC_CASE
     case IrOpcode::kSpeculationFence:
       return VisitSpeculationFence(node);
     case IrOpcode::kProtectedLoad: {
@@ -2299,11 +2292,18 @@ void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
   UNIMPLEMENTED();
 }
 
+void InstructionSelector::VisitChangeInt64ToFloat64(Node* node) {
+  UNIMPLEMENTED();
+}
 
 void InstructionSelector::VisitChangeUint32ToUint64(Node* node) {
   UNIMPLEMENTED();
 }
 
+void InstructionSelector::VisitChangeFloat64ToInt64(Node* node) {
+  UNIMPLEMENTED();
+}
+
 void InstructionSelector::VisitChangeFloat64ToUint64(Node* node) {
   UNIMPLEMENTED();
 }
@@ -2389,7 +2389,7 @@ void InstructionSelector::VisitWord32PairShr(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitWord32PairSar(Node* node) { UNIMPLEMENTED(); }
 #endif  // V8_TARGET_ARCH_64_BIT
 
-#if !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM
+#if !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_MIPS
 void InstructionSelector::VisitWord32AtomicPairLoad(Node* node) {
   UNIMPLEMENTED();
 }
@@ -2425,49 +2425,10 @@ void InstructionSelector::VisitWord32AtomicPairExchange(Node* node) {
 void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   UNIMPLEMENTED();
 }
+#endif  // !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_MIPS
 
-void InstructionSelector::VisitWord64AtomicNarrowAdd(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowSub(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowAnd(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowOr(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowXor(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowExchange(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitWord64AtomicNarrowCompareExchange(Node* node) {
-  UNIMPLEMENTED();
-}
-#endif  // !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM
-
-#if !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS && \
-    !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_IA32
-void InstructionSelector::VisitF32x4SConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitF32x4UConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS
-        // && !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_IA32
-
-#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64
+#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 && \
+    !V8_TARGET_ARCH_S390 && !V8_TARGET_ARCH_PPC
 void InstructionSelector::VisitWord64AtomicLoad(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitWord64AtomicStore(Node* node) {
@@ -2491,65 +2452,11 @@ void InstructionSelector::VisitWord64AtomicExchange(Node* node) {
 void InstructionSelector::VisitWord64AtomicCompareExchange(Node* node) {
   UNIMPLEMENTED();
 }
-#endif  // !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64
+#endif  // !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_PPC
+        // !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_S390
 
 #if !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS && \
     !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_IA32
-void InstructionSelector::VisitI32x4SConvertF32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4UConvertF32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4SConvertI16x8Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4SConvertI16x8High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4UConvertI16x8Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4UConvertI16x8High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SConvertI8x16Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SConvertI8x16High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8UConvertI8x16Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8UConvertI8x16High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-void InstructionSelector::VisitI16x8UConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16SConvertI16x8(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16UConvertI16x8(Node* node) {
-  UNIMPLEMENTED();
-}
-
 void InstructionSelector::VisitI8x16Shl(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitI8x16ShrS(Node* node) { UNIMPLEMENTED(); }
@@ -2559,18 +2466,6 @@ void InstructionSelector::VisitI8x16ShrU(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI8x16Mul(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitS8x16Shuffle(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS1x4AnyTrue(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS1x4AllTrue(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS1x8AnyTrue(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS1x8AllTrue(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS1x16AnyTrue(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS1x16AllTrue(Node* node) { UNIMPLEMENTED(); }
 #endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS
         // && !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_IA32
 
@@ -2807,7 +2702,7 @@ void InstructionSelector::VisitTailCall(Node* node) {
   buffer.instruction_args.push_back(g.TempImmediate(optional_padding_slot));
 
   int first_unused_stack_slot =
-      (V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK ? 1 : 0) +
+      (V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK ? true : false) +
       stack_param_delta;
   buffer.instruction_args.push_back(g.TempImmediate(first_unused_stack_slot));
 
diff --git a/deps/v8/src/compiler/instruction.cc b/deps/v8/src/compiler/instruction.cc
index 83ed28fb53..04a2bd9581 100644
--- a/deps/v8/src/compiler/instruction.cc
+++ b/deps/v8/src/compiler/instruction.cc
@@ -593,6 +593,13 @@ Handle<Code> Constant::ToCode() const {
   return value;
 }
 
+const StringConstantBase* Constant::ToDelayedStringConstant() const {
+  DCHECK_EQ(kDelayedStringConstant, type());
+  const StringConstantBase* value =
+      bit_cast<StringConstantBase*>(static_cast<intptr_t>(value_));
+  return value;
+}
+
 std::ostream& operator<<(std::ostream& os, const Constant& constant) {
   switch (constant.type()) {
     case Constant::kInt32:
@@ -609,6 +616,9 @@ std::ostream& operator<<(std::ostream& os, const Constant& constant) {
       return os << Brief(*constant.ToHeapObject());
     case Constant::kRpoNumber:
       return os << "RPO" << constant.ToRpoNumber().ToInt();
+    case Constant::kDelayedStringConstant:
+      return os << "DelayedStringConstant: "
+                << constant.ToDelayedStringConstant();
   }
   UNREACHABLE();
 }
@@ -942,7 +952,7 @@ void InstructionSequence::MarkAsRepresentation(MachineRepresentation rep,
   DCHECK_IMPLIES(representations_[virtual_register] != rep,
                  representations_[virtual_register] == DefaultRepresentation());
   representations_[virtual_register] = rep;
-  representation_mask_ |= 1 << static_cast<int>(rep);
+  representation_mask_ |= RepresentationBit(rep);
 }
 
 int InstructionSequence::AddDeoptimizationEntry(
diff --git a/deps/v8/src/compiler/instruction.h b/deps/v8/src/compiler/instruction.h
index 1991e309d3..39d083c2de 100644
--- a/deps/v8/src/compiler/instruction.h
+++ b/deps/v8/src/compiler/instruction.h
@@ -1039,7 +1039,8 @@ class V8_EXPORT_PRIVATE Constant final {
     kFloat64,
     kExternalReference,
     kHeapObject,
-    kRpoNumber
+    kRpoNumber,
+    kDelayedStringConstant
   };
 
   explicit Constant(int32_t v);
@@ -1047,10 +1048,12 @@ class V8_EXPORT_PRIVATE Constant final {
   explicit Constant(float v) : type_(kFloat32), value_(bit_cast<int32_t>(v)) {}
   explicit Constant(double v) : type_(kFloat64), value_(bit_cast<int64_t>(v)) {}
   explicit Constant(ExternalReference ref)
-      : type_(kExternalReference), value_(bit_cast<intptr_t>(ref)) {}
+      : type_(kExternalReference), value_(bit_cast<intptr_t>(ref.address())) {}
   explicit Constant(Handle<HeapObject> obj)
       : type_(kHeapObject), value_(bit_cast<intptr_t>(obj)) {}
   explicit Constant(RpoNumber rpo) : type_(kRpoNumber), value_(rpo.ToInt()) {}
+  explicit Constant(const StringConstantBase* str)
+      : type_(kDelayedStringConstant), value_(bit_cast<intptr_t>(str)) {}
   explicit Constant(RelocatablePtrConstantInfo info);
 
   Type type() const { return type_; }
@@ -1090,7 +1093,7 @@ class V8_EXPORT_PRIVATE Constant final {
 
   ExternalReference ToExternalReference() const {
     DCHECK_EQ(kExternalReference, type());
-    return bit_cast<ExternalReference>(static_cast<intptr_t>(value_));
+    return ExternalReference::FromRawAddress(static_cast<Address>(value_));
   }
 
   RpoNumber ToRpoNumber() const {
@@ -1100,6 +1103,7 @@ class V8_EXPORT_PRIVATE Constant final {
 
   Handle<HeapObject> ToHeapObject() const;
   Handle<Code> ToCode() const;
+  const StringConstantBase* ToDelayedStringConstant() const;
 
  private:
   Type type_;
@@ -1293,7 +1297,8 @@ class FrameStateDescriptor : public ZoneObject {
   FrameStateDescriptor* outer_state() const { return outer_state_; }
   bool HasContext() const {
     return FrameStateFunctionInfo::IsJSFunctionType(type_) ||
-           type_ == FrameStateType::kBuiltinContinuation;
+           type_ == FrameStateType::kBuiltinContinuation ||
+           type_ == FrameStateType::kConstructStub;
   }
 
   size_t GetSize() const;
@@ -1321,7 +1326,7 @@ class FrameStateDescriptor : public ZoneObject {
 // frame state descriptor that we have to go back to.
 class DeoptimizationEntry final {
  public:
-  DeoptimizationEntry() {}
+  DeoptimizationEntry() = default;
   DeoptimizationEntry(FrameStateDescriptor* descriptor, DeoptimizeKind kind,
                       DeoptimizeReason reason, VectorSlotPair const& feedback)
       : descriptor_(descriptor),
@@ -1520,7 +1525,6 @@ class V8_EXPORT_PRIVATE InstructionSequence final
   }
   MachineRepresentation GetRepresentation(int virtual_register) const;
   void MarkAsRepresentation(MachineRepresentation rep, int virtual_register);
-  int representation_mask() const { return representation_mask_; }
 
   bool IsReference(int virtual_register) const {
     return CanBeTaggedPointer(GetRepresentation(virtual_register));
@@ -1528,6 +1532,14 @@ class V8_EXPORT_PRIVATE InstructionSequence final
   bool IsFP(int virtual_register) const {
     return IsFloatingPoint(GetRepresentation(virtual_register));
   }
+  int representation_mask() const { return representation_mask_; }
+  bool HasFPVirtualRegisters() const {
+    constexpr int kFPRepMask =
+        RepresentationBit(MachineRepresentation::kFloat32) |
+        RepresentationBit(MachineRepresentation::kFloat64) |
+        RepresentationBit(MachineRepresentation::kSimd128);
+    return (representation_mask() & kFPRepMask) != 0;
+  }
 
   Instruction* GetBlockStart(RpoNumber rpo) const;
 
diff --git a/deps/v8/src/compiler/int64-lowering.cc b/deps/v8/src/compiler/int64-lowering.cc
index 8066ce5dca..41a5098081 100644
--- a/deps/v8/src/compiler/int64-lowering.cc
+++ b/deps/v8/src/compiler/int64-lowering.cc
@@ -127,9 +127,10 @@ void Int64Lowering::LowerWord64AtomicBinop(Node* node, const Operator* op) {
 }
 
 void Int64Lowering::LowerWord64AtomicNarrowOp(Node* node, const Operator* op) {
-  DefaultLowering(node, true);
+  Node* value = node->InputAt(2);
+  node->ReplaceInput(2, GetReplacementLow(value));
   NodeProperties::ChangeOp(node, op);
-  ReplaceNodeWithProjections(node);
+  ReplaceNode(node, node, graph()->NewNode(common()->Int32Constant(0)));
 }
 
 // static
@@ -915,8 +916,7 @@ void Int64Lowering::LowerNode(Node* node) {
     if (type == MachineType::Uint64()) {                                    \
       LowerWord64AtomicBinop(node, machine()->Word32AtomicPair##name());    \
     } else {                                                                \
-      LowerWord64AtomicNarrowOp(node,                                       \
-                                machine()->Word64AtomicNarrow##name(type)); \
+      LowerWord64AtomicNarrowOp(node, machine()->Word32Atomic##name(type)); \
     }                                                                       \
     break;                                                                  \
   }
@@ -940,8 +940,15 @@ void Int64Lowering::LowerNode(Node* node) {
                                  machine()->Word32AtomicPairCompareExchange());
         ReplaceNodeWithProjections(node);
       } else {
-        LowerWord64AtomicNarrowOp(
-            node, machine()->Word64AtomicNarrowCompareExchange(type));
+        DCHECK(type == MachineType::Uint32() || type == MachineType::Uint16() ||
+               type == MachineType::Uint8());
+        Node* old_value = node->InputAt(2);
+        node->ReplaceInput(2, GetReplacementLow(old_value));
+        Node* new_value = node->InputAt(3);
+        node->ReplaceInput(3, GetReplacementLow(new_value));
+        NodeProperties::ChangeOp(node,
+                                 machine()->Word32AtomicCompareExchange(type));
+        ReplaceNode(node, node, graph()->NewNode(common()->Int32Constant(0)));
       }
       break;
     }
diff --git a/deps/v8/src/compiler/js-call-reducer.cc b/deps/v8/src/compiler/js-call-reducer.cc
index a06f4490a6..5b04731a64 100644
--- a/deps/v8/src/compiler/js-call-reducer.cc
+++ b/deps/v8/src/compiler/js-call-reducer.cc
@@ -25,6 +25,7 @@
 #include "src/objects/arguments-inl.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/js-array-inl.h"
+#include "src/objects/js-objects.h"
 #include "src/vector-slot-pair.h"
 
 namespace v8 {
@@ -865,7 +866,8 @@ Reduction JSCallReducer::ReduceReflectGet(Node* node) {
     Callable callable =
         Builtins::CallableFor(isolate(), Builtins::kGetProperty);
     auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), 0,
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(),
         CallDescriptor::kNeedsFrameState, Operator::kNoProperties);
     Node* stub_code = jsgraph()->HeapConstant(callable.code());
     vtrue = etrue = if_true =
@@ -2160,12 +2162,8 @@ Node* JSCallReducer::DoFilterPostCallbackWork(ElementsKind kind, Node** control,
                                               Node* callback_value) {
   Node* boolean_result =
       graph()->NewNode(simplified()->ToBoolean(), callback_value);
-
-  Node* check_boolean_result =
-      graph()->NewNode(simplified()->ReferenceEqual(), boolean_result,
-                       jsgraph()->TrueConstant());
   Node* boolean_branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                          check_boolean_result, *control);
+                                          boolean_result, *control);
 
   Node* if_true = graph()->NewNode(common()->IfTrue(), boolean_branch);
   Node* etrue = *effect;
@@ -2465,11 +2463,8 @@ Reduction JSCallReducer::ReduceArrayEvery(Node* node,
   {
     Node* boolean_result =
         graph()->NewNode(simplified()->ToBoolean(), callback_value);
-    Node* check_boolean_result =
-        graph()->NewNode(simplified()->ReferenceEqual(), boolean_result,
-                         jsgraph()->TrueConstant());
     Node* boolean_branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                            check_boolean_result, control);
+                                            boolean_result, control);
     if_false_callback = graph()->NewNode(common()->IfFalse(), boolean_branch);
     efalse_callback = effect;
 
@@ -2585,7 +2580,8 @@ Reduction JSCallReducer::ReduceArrayIndexOfIncludes(
           : GetCallableForArrayIncludes(receiver_map->elements_kind(),
                                         isolate());
   CallDescriptor const* const desc = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, CallDescriptor::kNoFlags,
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), CallDescriptor::kNoFlags,
       Operator::kEliminatable);
   // The stub expects the following arguments: the receiver array, its elements,
   // the search_element, the array length, and the index to start searching
@@ -2821,11 +2817,8 @@ Reduction JSCallReducer::ReduceArraySome(Node* node,
   {
     Node* boolean_result =
         graph()->NewNode(simplified()->ToBoolean(), callback_value);
-    Node* check_boolean_result =
-        graph()->NewNode(simplified()->ReferenceEqual(), boolean_result,
-                         jsgraph()->TrueConstant());
     Node* boolean_branch = graph()->NewNode(
-        common()->Branch(BranchHint::kFalse), check_boolean_result, control);
+        common()->Branch(BranchHint::kFalse), boolean_result, control);
     if_true_callback = graph()->NewNode(common()->IfTrue(), boolean_branch);
     etrue_callback = effect;
 
@@ -3026,7 +3019,7 @@ Reduction JSCallReducer::ReduceCallOrConstructWithArrayLikeOrSpread(
         if (access.offset == JSArray::kLengthOffset) {
           // Ignore uses for arguments#length.
           STATIC_ASSERT(JSArray::kLengthOffset ==
-                        JSArgumentsObject::kLengthOffset);
+                        JSArgumentsObjectWithLength::kLengthOffset);
           continue;
         } else if (access.offset == JSObject::kElementsOffset) {
           // Ignore safe uses for arguments#elements.
@@ -3332,7 +3325,7 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
   }
 
   HeapObject* heap_object;
-  if (nexus.GetFeedback()->ToWeakHeapObject(&heap_object)) {
+  if (nexus.GetFeedback()->GetHeapObjectIfWeak(&heap_object)) {
     Handle<HeapObject> feedback(heap_object, isolate());
     // Check if we want to use CallIC feedback here.
     if (!ShouldUseCallICFeedback(target)) return NoChange();
@@ -3468,53 +3461,53 @@ Reduction JSCallReducer::ReduceJSCall(Node* node,
           node, JS_DATA_VIEW_TYPE,
           AccessBuilder::ForJSArrayBufferViewByteOffset());
     case Builtins::kDataViewPrototypeGetUint8:
-      return ReduceDataViewPrototypeGet(node,
-                                        ExternalArrayType::kExternalUint8Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalUint8Array);
     case Builtins::kDataViewPrototypeGetInt8:
-      return ReduceDataViewPrototypeGet(node,
-                                        ExternalArrayType::kExternalInt8Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalInt8Array);
     case Builtins::kDataViewPrototypeGetUint16:
-      return ReduceDataViewPrototypeGet(
-          node, ExternalArrayType::kExternalUint16Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalUint16Array);
     case Builtins::kDataViewPrototypeGetInt16:
-      return ReduceDataViewPrototypeGet(node,
-                                        ExternalArrayType::kExternalInt16Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalInt16Array);
     case Builtins::kDataViewPrototypeGetUint32:
-      return ReduceDataViewPrototypeGet(
-          node, ExternalArrayType::kExternalUint32Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalUint32Array);
     case Builtins::kDataViewPrototypeGetInt32:
-      return ReduceDataViewPrototypeGet(node,
-                                        ExternalArrayType::kExternalInt32Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalInt32Array);
     case Builtins::kDataViewPrototypeGetFloat32:
-      return ReduceDataViewPrototypeGet(
-          node, ExternalArrayType::kExternalFloat32Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalFloat32Array);
     case Builtins::kDataViewPrototypeGetFloat64:
-      return ReduceDataViewPrototypeGet(
-          node, ExternalArrayType::kExternalFloat64Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kGet,
+                                  ExternalArrayType::kExternalFloat64Array);
     case Builtins::kDataViewPrototypeSetUint8:
-      return ReduceDataViewPrototypeSet(node,
-                                        ExternalArrayType::kExternalUint8Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalUint8Array);
     case Builtins::kDataViewPrototypeSetInt8:
-      return ReduceDataViewPrototypeSet(node,
-                                        ExternalArrayType::kExternalInt8Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalInt8Array);
     case Builtins::kDataViewPrototypeSetUint16:
-      return ReduceDataViewPrototypeSet(
-          node, ExternalArrayType::kExternalUint16Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalUint16Array);
     case Builtins::kDataViewPrototypeSetInt16:
-      return ReduceDataViewPrototypeSet(node,
-                                        ExternalArrayType::kExternalInt16Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalInt16Array);
     case Builtins::kDataViewPrototypeSetUint32:
-      return ReduceDataViewPrototypeSet(
-          node, ExternalArrayType::kExternalUint32Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalUint32Array);
     case Builtins::kDataViewPrototypeSetInt32:
-      return ReduceDataViewPrototypeSet(node,
-                                        ExternalArrayType::kExternalInt32Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalInt32Array);
     case Builtins::kDataViewPrototypeSetFloat32:
-      return ReduceDataViewPrototypeSet(
-          node, ExternalArrayType::kExternalFloat32Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalFloat32Array);
     case Builtins::kDataViewPrototypeSetFloat64:
-      return ReduceDataViewPrototypeSet(
-          node, ExternalArrayType::kExternalFloat64Array);
+      return ReduceDataViewAccess(node, DataViewAccess::kSet,
+                                  ExternalArrayType::kExternalFloat64Array);
     case Builtins::kTypedArrayPrototypeByteLength:
       return ReduceArrayBufferViewAccessor(
           node, JS_TYPED_ARRAY_TYPE,
@@ -3758,7 +3751,7 @@ Reduction JSCallReducer::ReduceJSConstruct(Node* node) {
     }
 
     HeapObject* feedback_object;
-    if (nexus.GetFeedback()->ToStrongHeapObject(&feedback_object) &&
+    if (nexus.GetFeedback()->GetHeapObjectIfStrong(&feedback_object) &&
         feedback_object->IsAllocationSite()) {
       // The feedback is an AllocationSite, which means we have called the
       // Array function and collected transition (and pretenuring) feedback
@@ -3787,7 +3780,7 @@ Reduction JSCallReducer::ReduceJSConstruct(Node* node) {
       NodeProperties::ReplaceValueInput(node, array_function, 1);
       NodeProperties::ChangeOp(node, javascript()->CreateArray(arity, site));
       return Changed(node);
-    } else if (nexus.GetFeedback()->ToWeakHeapObject(&feedback_object) &&
+    } else if (nexus.GetFeedback()->GetHeapObjectIfWeak(&feedback_object) &&
                !HeapObjectMatcher(new_target).HasValue()) {
       Handle<HeapObject> object(feedback_object, isolate());
       if (object->IsConstructor()) {
@@ -4835,7 +4828,8 @@ Reduction JSCallReducer::ReduceArrayPrototypeSlice(Node* node) {
   Callable callable =
       Builtins::CallableFor(isolate(), Builtins::kCloneFastJSArray);
   auto call_descriptor = Linkage::GetStubCallDescriptor(
-      graph()->zone(), callable.descriptor(), 0, CallDescriptor::kNoFlags,
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), CallDescriptor::kNoFlags,
       Operator::kNoThrow | Operator::kNoDeopt);
 
   // Calls to Builtins::kCloneFastJSArray produce COW arrays
@@ -4993,18 +4987,22 @@ Reduction JSCallReducer::ReduceArrayIteratorPrototypeNext(Node* node) {
       dependencies()->DependOnProtector(PropertyCellRef(
           js_heap_broker(), factory()->array_buffer_neutering_protector()));
     } else {
-      // Deoptimize if the array buffer was neutered.
+      // Bail out if the {iterated_object}s JSArrayBuffer was neutered.
       Node* buffer = effect = graph()->NewNode(
           simplified()->LoadField(AccessBuilder::ForJSArrayBufferViewBuffer()),
           iterated_object, effect, control);
-
-      Node* check = effect = graph()->NewNode(
-          simplified()->ArrayBufferWasNeutered(), buffer, effect, control);
-      check = graph()->NewNode(simplified()->BooleanNot(), check);
-      // TODO(bmeurer): Pass p.feedback(), or better introduce
-      // CheckArrayBufferNotNeutered?
+      Node* buffer_bit_field = effect = graph()->NewNode(
+          simplified()->LoadField(AccessBuilder::ForJSArrayBufferBitField()),
+          buffer, effect, control);
+      Node* check = graph()->NewNode(
+          simplified()->NumberEqual(),
+          graph()->NewNode(
+              simplified()->NumberBitwiseAnd(), buffer_bit_field,
+              jsgraph()->Constant(JSArrayBuffer::WasNeuteredBit::kMask)),
+          jsgraph()->ZeroConstant());
       effect = graph()->NewNode(
-          simplified()->CheckIf(DeoptimizeReason::kArrayBufferWasNeutered),
+          simplified()->CheckIf(DeoptimizeReason::kArrayBufferWasNeutered,
+                                p.feedback()),
           check, effect, control);
     }
   }
@@ -5341,9 +5339,6 @@ Reduction JSCallReducer::ReduceStringFromCodePoint(Node* node) {
     Node* control = NodeProperties::GetControlInput(node);
     Node* input = NodeProperties::GetValueInput(node, 2);
 
-    input = effect = graph()->NewNode(simplified()->CheckSmi(p.feedback()),
-                                      input, effect, control);
-
     input = effect =
         graph()->NewNode(simplified()->CheckBounds(p.feedback()), input,
                          jsgraph()->Constant(0x10FFFF + 1), effect, control);
@@ -5452,9 +5447,9 @@ Reduction JSCallReducer::ReduceStringPrototypeConcat(
   if (p.speculation_mode() == SpeculationMode::kDisallowSpeculation) {
     return NoChange();
   }
+
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
-  Node* context = NodeProperties::GetContextInput(node);
   Node* receiver = effect =
       graph()->NewNode(simplified()->CheckString(p.feedback()),
                        NodeProperties::GetValueInput(node, 1), effect, control);
@@ -5463,26 +5458,22 @@ Reduction JSCallReducer::ReduceStringPrototypeConcat(
     ReplaceWithValue(node, receiver, effect, control);
     return Replace(receiver);
   }
+
   Node* argument = effect =
       graph()->NewNode(simplified()->CheckString(p.feedback()),
                        NodeProperties::GetValueInput(node, 2), effect, control);
+  Node* receiver_length =
+      graph()->NewNode(simplified()->StringLength(), receiver);
+  Node* argument_length =
+      graph()->NewNode(simplified()->StringLength(), argument);
+  Node* length = graph()->NewNode(simplified()->NumberAdd(), receiver_length,
+                                  argument_length);
+  length = effect = graph()->NewNode(
+      simplified()->CheckBounds(p.feedback()), length,
+      jsgraph()->Constant(String::kMaxLength + 1), effect, control);
 
-  Callable const callable =
-      CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
-  auto call_descriptor =
-      Linkage::GetStubCallDescriptor(graph()->zone(), callable.descriptor(), 0,
-                                     CallDescriptor::kNeedsFrameState,
-                                     Operator::kNoDeopt | Operator::kNoWrite);
-
-  // TODO(turbofan): Massage the FrameState of the {node} here once we
-  // have an artificial builtin frame type, so that it looks like the
-  // exception from StringAdd overflow came from String.prototype.concat
-  // builtin instead of the calling function.
-  Node* outer_frame_state = NodeProperties::GetFrameStateInput(node);
-
-  Node* value = effect = control = graph()->NewNode(
-      common()->Call(call_descriptor), jsgraph()->HeapConstant(callable.code()),
-      receiver, argument, context, outer_frame_state, effect, control);
+  Node* value = graph()->NewNode(simplified()->StringConcat(), length, receiver,
+                                 argument);
 
   ReplaceWithValue(node, value, effect, control);
   return Replace(value);
@@ -5524,7 +5515,7 @@ Reduction JSCallReducer::ReduceAsyncFunctionPromiseRelease(Node* node) {
 Node* JSCallReducer::CreateArtificialFrameState(
     Node* node, Node* outer_frame_state, int parameter_count,
     BailoutId bailout_id, FrameStateType frame_state_type,
-    Handle<SharedFunctionInfo> shared) {
+    Handle<SharedFunctionInfo> shared, Node* context) {
   const FrameStateFunctionInfo* state_info =
       common()->CreateFrameStateFunctionInfo(frame_state_type,
                                              parameter_count + 1, 0, shared);
@@ -5534,6 +5525,7 @@ Node* JSCallReducer::CreateArtificialFrameState(
   const Operator* op0 = common()->StateValues(0, SparseInputMask::Dense());
   Node* node0 = graph()->NewNode(op0);
   std::vector<Node*> params;
+  params.reserve(parameter_count + 1);
   for (int parameter = 0; parameter < parameter_count + 1; ++parameter) {
     params.push_back(node->InputAt(1 + parameter));
   }
@@ -5541,9 +5533,11 @@ Node* JSCallReducer::CreateArtificialFrameState(
       static_cast<int>(params.size()), SparseInputMask::Dense());
   Node* params_node = graph()->NewNode(
       op_param, static_cast<int>(params.size()), &params.front());
-  return graph()->NewNode(op, params_node, node0, node0,
-                          jsgraph()->UndefinedConstant(), node->InputAt(0),
-                          outer_frame_state);
+  if (!context) {
+    context = jsgraph()->UndefinedConstant();
+  }
+  return graph()->NewNode(op, params_node, node0, node0, context,
+                          node->InputAt(0), outer_frame_state);
 }
 
 Reduction JSCallReducer::ReducePromiseConstructor(Node* node) {
@@ -5580,7 +5574,7 @@ Reduction JSCallReducer::ReducePromiseConstructor(Node* node) {
   DCHECK_EQ(1, promise_shared->internal_formal_parameter_count());
   Node* constructor_frame_state = CreateArtificialFrameState(
       node, outer_frame_state, 1, BailoutId::ConstructStubInvoke(),
-      FrameStateType::kConstructStub, promise_shared);
+      FrameStateType::kConstructStub, promise_shared, context);
 
   // The deopt continuation of this frame state is never called; the frame state
   // is only necessary to obtain the right stack trace.
@@ -6150,7 +6144,7 @@ Reduction JSCallReducer::ReduceTypedArrayConstructor(
   // reconstruct the proper frame when deoptimizing within the constructor.
   frame_state = CreateArtificialFrameState(
       node, frame_state, arity, BailoutId::ConstructStubInvoke(),
-      FrameStateType::kConstructStub, shared);
+      FrameStateType::kConstructStub, shared, context);
 
   // This continuation just returns the newly created JSTypedArray. We
   // pass the_hole as the receiver, just like the builtin construct stub
@@ -6497,8 +6491,9 @@ Reduction JSCallReducer::ReduceCollectionIteratorPrototypeNext(
     Callable const callable =
         Builtins::CallableFor(isolate(), Builtins::kOrderedHashTableHealIndex);
     auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), 0, CallDescriptor::kNoFlags,
-        Operator::kEliminatable);
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(),
+        CallDescriptor::kNoFlags, Operator::kEliminatable);
     index = effect =
         graph()->NewNode(common()->Call(call_descriptor),
                          jsgraph()->HeapConstant(callable.code()), table, index,
@@ -6720,6 +6715,7 @@ Reduction JSCallReducer::ReduceArrayBufferViewAccessor(
   Node* receiver = NodeProperties::GetValueInput(node, 1);
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
+
   if (NodeProperties::HasInstanceTypeWitness(isolate(), receiver, effect,
                                              instance_type)) {
     // Load the {receiver}s field.
@@ -6733,17 +6729,28 @@ Reduction JSCallReducer::ReduceArrayBufferViewAccessor(
       dependencies()->DependOnProtector(PropertyCellRef(
           js_heap_broker(), factory()->array_buffer_neutering_protector()));
     } else {
-      // Check if the {receiver}s buffer was neutered.
+      // Check whether {receiver}s JSArrayBuffer was neutered.
       Node* buffer = effect = graph()->NewNode(
           simplified()->LoadField(AccessBuilder::ForJSArrayBufferViewBuffer()),
           receiver, effect, control);
-      Node* check = effect = graph()->NewNode(
-          simplified()->ArrayBufferWasNeutered(), buffer, effect, control);
-
-      // Default to zero if the {receiver}s buffer was neutered.
+      Node* buffer_bit_field = effect = graph()->NewNode(
+          simplified()->LoadField(AccessBuilder::ForJSArrayBufferBitField()),
+          buffer, effect, control);
+      Node* check = graph()->NewNode(
+          simplified()->NumberEqual(),
+          graph()->NewNode(
+              simplified()->NumberBitwiseAnd(), buffer_bit_field,
+              jsgraph()->Constant(JSArrayBuffer::WasNeuteredBit::kMask)),
+          jsgraph()->ZeroConstant());
+
+      // TODO(turbofan): Ideally we would bail out here if the {receiver}s
+      // JSArrayBuffer was neutered, but there's no way to guard against
+      // deoptimization loops right now, since the JSCall {node} is usually
+      // created from a LOAD_IC inlining, and so there's no CALL_IC slot
+      // from which we could use the speculation bit.
       value = graph()->NewNode(
-          common()->Select(MachineRepresentation::kTagged, BranchHint::kFalse),
-          check, jsgraph()->ZeroConstant(), value);
+          common()->Select(MachineRepresentation::kTagged, BranchHint::kTrue),
+          check, value, jsgraph()->ZeroConstant());
     }
 
     ReplaceWithValue(node, value, effect, control);
@@ -6767,160 +6774,33 @@ uint32_t ExternalArrayElementSize(const ExternalArrayType element_type) {
 }
 }  // namespace
 
-Reduction JSCallReducer::ReduceDataViewPrototypeGet(
-    Node* node, ExternalArrayType element_type) {
-  uint32_t const element_size = ExternalArrayElementSize(element_type);
+Reduction JSCallReducer::ReduceDataViewAccess(Node* node, DataViewAccess access,
+                                              ExternalArrayType element_type) {
+  size_t const element_size = ExternalArrayElementSize(element_type);
   CallParameters const& p = CallParametersOf(node->op());
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
   Node* receiver = NodeProperties::GetValueInput(node, 1);
-
-  if (p.speculation_mode() == SpeculationMode::kDisallowSpeculation) {
-    return NoChange();
-  }
-
   Node* offset = node->op()->ValueInputCount() > 2
                      ? NodeProperties::GetValueInput(node, 2)
                      : jsgraph()->ZeroConstant();
-
-  Node* is_little_endian = node->op()->ValueInputCount() > 3
-                               ? NodeProperties::GetValueInput(node, 3)
-                               : jsgraph()->FalseConstant();
-
-  // Only do stuff if the {receiver} is really a DataView.
-  if (NodeProperties::HasInstanceTypeWitness(isolate(), receiver, effect,
-                                             JS_DATA_VIEW_TYPE)) {
-    // Check that the {offset} is within range for the {receiver}.
-    HeapObjectMatcher m(receiver);
-    if (m.HasValue()) {
-      // We only deal with DataViews here whose [[ByteLength]] is at least
-      // {element_size} and less than 2^31-{element_size}.
-      Handle<JSDataView> dataview = Handle<JSDataView>::cast(m.Value());
-      if (dataview->byte_length()->Number() < element_size ||
-          dataview->byte_length()->Number() - element_size > kMaxInt) {
-        return NoChange();
-      }
-
-      // The {receiver}s [[ByteOffset]] must be within Unsigned31 range.
-      if (dataview->byte_offset()->Number() > kMaxInt) {
-        return NoChange();
-      }
-
-      // Check that the {offset} is within range of the {byte_length}.
-      Node* byte_length = jsgraph()->Constant(
-          dataview->byte_length()->Number() - (element_size - 1));
-      offset = effect =
-          graph()->NewNode(simplified()->CheckBounds(p.feedback()), offset,
-                           byte_length, effect, control);
-
-      // Add the [[ByteOffset]] to compute the effective offset.
-      Node* byte_offset =
-          jsgraph()->Constant(dataview->byte_offset()->Number());
-      offset = graph()->NewNode(simplified()->NumberAdd(), offset, byte_offset);
-    } else {
-      // We only deal with DataViews here that have Smi [[ByteLength]]s.
-      Node* byte_length = effect =
-          graph()->NewNode(simplified()->LoadField(
-                               AccessBuilder::ForJSArrayBufferViewByteLength()),
-                           receiver, effect, control);
-      byte_length = effect = graph()->NewNode(
-          simplified()->CheckSmi(p.feedback()), byte_length, effect, control);
-
-      // Check that the {offset} is within range of the {byte_length}.
-      offset = effect =
-          graph()->NewNode(simplified()->CheckBounds(p.feedback()), offset,
-                           byte_length, effect, control);
-
-      if (element_size > 0) {
-        // For non-byte accesses we also need to check that the {offset}
-        // plus the {element_size}-1 fits within the given {byte_length}.
-        Node* end_offset =
-            graph()->NewNode(simplified()->NumberAdd(), offset,
-                             jsgraph()->Constant(element_size - 1));
-        effect = graph()->NewNode(simplified()->CheckBounds(p.feedback()),
-                                  end_offset, byte_length, effect, control);
-      }
-
-      // The {receiver}s [[ByteOffset]] also needs to be a (positive) Smi.
-      Node* byte_offset = effect =
-          graph()->NewNode(simplified()->LoadField(
-                               AccessBuilder::ForJSArrayBufferViewByteOffset()),
-                           receiver, effect, control);
-      byte_offset = effect = graph()->NewNode(
-          simplified()->CheckSmi(p.feedback()), byte_offset, effect, control);
-
-      // Compute the buffer index at which we'll read.
-      offset = graph()->NewNode(simplified()->NumberAdd(), offset, byte_offset);
-    }
-
-    // Coerce {is_little_endian} to boolean.
-    is_little_endian =
-        graph()->NewNode(simplified()->ToBoolean(), is_little_endian);
-
-    // Get the underlying buffer and check that it has not been neutered.
-    Node* buffer = effect = graph()->NewNode(
-        simplified()->LoadField(AccessBuilder::ForJSArrayBufferViewBuffer()),
-        receiver, effect, control);
-
-    if (isolate()->IsArrayBufferNeuteringIntact()) {
-      // Add a code dependency so we are deoptimized in case an ArrayBuffer
-      // gets neutered.
-      dependencies()->DependOnProtector(PropertyCellRef(
-          js_heap_broker(), factory()->array_buffer_neutering_protector()));
-    } else {
-      // If the buffer was neutered, deopt and let the unoptimized code throw.
-      Node* check_neutered = effect = graph()->NewNode(
-          simplified()->ArrayBufferWasNeutered(), buffer, effect, control);
-      check_neutered =
-          graph()->NewNode(simplified()->BooleanNot(), check_neutered);
-      effect = graph()->NewNode(
-          simplified()->CheckIf(DeoptimizeReason::kArrayBufferWasNeutered,
-                                p.feedback()),
-          check_neutered, effect, control);
-    }
-
-    // Get the buffer's backing store.
-    Node* backing_store = effect = graph()->NewNode(
-        simplified()->LoadField(AccessBuilder::ForJSArrayBufferBackingStore()),
-        buffer, effect, control);
-
-    // Perform the load.
-    Node* value = effect = graph()->NewNode(
-        simplified()->LoadDataViewElement(element_type), buffer, backing_store,
-        offset, is_little_endian, effect, control);
-
-    // Continue on the regular path.
-    ReplaceWithValue(node, value, effect, control);
-    return Changed(value);
-  }
-
-  return NoChange();
-}
-
-Reduction JSCallReducer::ReduceDataViewPrototypeSet(
-    Node* node, ExternalArrayType element_type) {
-  uint32_t const element_size = ExternalArrayElementSize(element_type);
-  CallParameters const& p = CallParametersOf(node->op());
-  Node* effect = NodeProperties::GetEffectInput(node);
-  Node* control = NodeProperties::GetControlInput(node);
-  Node* receiver = NodeProperties::GetValueInput(node, 1);
+  Node* value = (access == DataViewAccess::kGet)
+                    ? nullptr
+                    : (node->op()->ValueInputCount() > 3
+                           ? NodeProperties::GetValueInput(node, 3)
+                           : jsgraph()->ZeroConstant());
+  Node* is_little_endian = (access == DataViewAccess::kGet)
+                               ? (node->op()->ValueInputCount() > 3
+                                      ? NodeProperties::GetValueInput(node, 3)
+                                      : jsgraph()->FalseConstant())
+                               : (node->op()->ValueInputCount() > 4
+                                      ? NodeProperties::GetValueInput(node, 4)
+                                      : jsgraph()->FalseConstant());
 
   if (p.speculation_mode() == SpeculationMode::kDisallowSpeculation) {
     return NoChange();
   }
 
-  Node* offset = node->op()->ValueInputCount() > 2
-                     ? NodeProperties::GetValueInput(node, 2)
-                     : jsgraph()->ZeroConstant();
-
-  Node* value = node->op()->ValueInputCount() > 3
-                    ? NodeProperties::GetValueInput(node, 3)
-                    : jsgraph()->ZeroConstant();
-
-  Node* is_little_endian = node->op()->ValueInputCount() > 4
-                               ? NodeProperties::GetValueInput(node, 4)
-                               : jsgraph()->FalseConstant();
-
   // Only do stuff if the {receiver} is really a DataView.
   if (NodeProperties::HasInstanceTypeWitness(isolate(), receiver, effect,
                                              JS_DATA_VIEW_TYPE)) {
@@ -6930,26 +6810,25 @@ Reduction JSCallReducer::ReduceDataViewPrototypeSet(
       // We only deal with DataViews here whose [[ByteLength]] is at least
       // {element_size} and less than 2^31-{element_size}.
       Handle<JSDataView> dataview = Handle<JSDataView>::cast(m.Value());
-      if (dataview->byte_length()->Number() < element_size ||
-          dataview->byte_length()->Number() - element_size > kMaxInt) {
+      if (dataview->byte_length() < element_size ||
+          dataview->byte_length() - element_size > kMaxInt) {
         return NoChange();
       }
 
       // The {receiver}s [[ByteOffset]] must be within Unsigned31 range.
-      if (dataview->byte_offset()->Number() > kMaxInt) {
+      if (dataview->byte_offset() > kMaxInt) {
         return NoChange();
       }
 
       // Check that the {offset} is within range of the {byte_length}.
-      Node* byte_length = jsgraph()->Constant(
-          dataview->byte_length()->Number() - (element_size - 1));
+      Node* byte_length =
+          jsgraph()->Constant(dataview->byte_length() - (element_size - 1));
       offset = effect =
           graph()->NewNode(simplified()->CheckBounds(p.feedback()), offset,
                            byte_length, effect, control);
 
       // Add the [[ByteOffset]] to compute the effective offset.
-      Node* byte_offset =
-          jsgraph()->Constant(dataview->byte_offset()->Number());
+      Node* byte_offset = jsgraph()->Constant(dataview->byte_offset());
       offset = graph()->NewNode(simplified()->NumberAdd(), offset, byte_offset);
     } else {
       // We only deal with DataViews here that have Smi [[ByteLength]]s.
@@ -6992,10 +6871,12 @@ Reduction JSCallReducer::ReduceDataViewPrototypeSet(
         graph()->NewNode(simplified()->ToBoolean(), is_little_endian);
 
     // Coerce {value} to Number.
-    value = effect = graph()->NewNode(
-        simplified()->SpeculativeToNumber(NumberOperationHint::kNumberOrOddball,
-                                          p.feedback()),
-        value, effect, control);
+    if (access == DataViewAccess::kSet) {
+      value = effect = graph()->NewNode(
+          simplified()->SpeculativeToNumber(
+              NumberOperationHint::kNumberOrOddball, p.feedback()),
+          value, effect, control);
+    }
 
     // Get the underlying buffer and check that it has not been neutered.
     Node* buffer = effect = graph()->NewNode(
@@ -7008,15 +6889,20 @@ Reduction JSCallReducer::ReduceDataViewPrototypeSet(
       dependencies()->DependOnProtector(PropertyCellRef(
           js_heap_broker(), factory()->array_buffer_neutering_protector()));
     } else {
-      // If the buffer was neutered, deopt and let the unoptimized code throw.
-      Node* check_neutered = effect = graph()->NewNode(
-          simplified()->ArrayBufferWasNeutered(), buffer, effect, control);
-      check_neutered =
-          graph()->NewNode(simplified()->BooleanNot(), check_neutered);
+      // Bail out if the {buffer} was neutered.
+      Node* buffer_bit_field = effect = graph()->NewNode(
+          simplified()->LoadField(AccessBuilder::ForJSArrayBufferBitField()),
+          buffer, effect, control);
+      Node* check = graph()->NewNode(
+          simplified()->NumberEqual(),
+          graph()->NewNode(
+              simplified()->NumberBitwiseAnd(), buffer_bit_field,
+              jsgraph()->Constant(JSArrayBuffer::WasNeuteredBit::kMask)),
+          jsgraph()->ZeroConstant());
       effect = graph()->NewNode(
           simplified()->CheckIf(DeoptimizeReason::kArrayBufferWasNeutered,
                                 p.feedback()),
-          check_neutered, effect, control);
+          check, effect, control);
     }
 
     // Get the buffer's backing store.
@@ -7024,12 +6910,21 @@ Reduction JSCallReducer::ReduceDataViewPrototypeSet(
         simplified()->LoadField(AccessBuilder::ForJSArrayBufferBackingStore()),
         buffer, effect, control);
 
-    // Perform the store.
-    effect = graph()->NewNode(simplified()->StoreDataViewElement(element_type),
-                              buffer, backing_store, offset, value,
-                              is_little_endian, effect, control);
-
-    Node* value = jsgraph()->UndefinedConstant();
+    switch (access) {
+      case DataViewAccess::kGet:
+        // Perform the load.
+        value = effect = graph()->NewNode(
+            simplified()->LoadDataViewElement(element_type), buffer,
+            backing_store, offset, is_little_endian, effect, control);
+        break;
+      case DataViewAccess::kSet:
+        // Perform the store.
+        effect = graph()->NewNode(
+            simplified()->StoreDataViewElement(element_type), buffer,
+            backing_store, offset, value, is_little_endian, effect, control);
+        value = jsgraph()->UndefinedConstant();
+        break;
+    }
 
     // Continue on the regular path.
     ReplaceWithValue(node, value, effect, control);
@@ -7242,39 +7137,30 @@ Reduction JSCallReducer::ReduceRegExpPrototypeTest(Node* node) {
 Reduction JSCallReducer::ReduceNumberConstructor(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCall, node->opcode());
   CallParameters const& p = CallParametersOf(node->op());
+  Node* target = NodeProperties::GetValueInput(node, 0);
+  Node* receiver = NodeProperties::GetValueInput(node, 1);
+  Node* value = p.arity() < 3 ? jsgraph()->ZeroConstant()
+                              : NodeProperties::GetValueInput(node, 2);
+  Node* context = NodeProperties::GetContextInput(node);
+  Node* frame_state = NodeProperties::GetFrameStateInput(node);
 
-  if (p.arity() <= 2) {
-    ReplaceWithValue(node, jsgraph()->ZeroConstant());
-  }
-
-  // We don't have a new.target argument, so we can convert to number,
-  // but must also convert BigInts.
-  if (p.arity() == 3) {
-    Node* target = NodeProperties::GetValueInput(node, 0);
-    Node* context = NodeProperties::GetContextInput(node);
-    Node* value = NodeProperties::GetValueInput(node, 2);
-    Node* outer_frame_state = NodeProperties::GetFrameStateInput(node);
-    Handle<SharedFunctionInfo> number_constructor(
-        handle(native_context()->number_function()->shared(), isolate()));
-
-    const std::vector<Node*> checkpoint_parameters({
-        jsgraph()->UndefinedConstant(), /* receiver */
-    });
-    int checkpoint_parameters_size =
-        static_cast<int>(checkpoint_parameters.size());
-
-    Node* frame_state = CreateJavaScriptBuiltinContinuationFrameState(
-        jsgraph(), number_constructor,
-        Builtins::kGenericConstructorLazyDeoptContinuation, target, context,
-        checkpoint_parameters.data(), checkpoint_parameters_size,
-        outer_frame_state, ContinuationFrameStateMode::LAZY);
-
-    NodeProperties::ReplaceValueInputs(node, value);
-    NodeProperties::ChangeOp(node, javascript()->ToNumberConvertBigInt());
-    NodeProperties::ReplaceFrameStateInput(node, frame_state);
-    return Changed(node);
-  }
-  return NoChange();
+  // Create the artificial frame state in the middle of the Number constructor.
+  Handle<SharedFunctionInfo> shared_info(
+      handle(native_context()->number_function()->shared(), isolate()));
+  Node* stack_parameters[] = {receiver};
+  int stack_parameter_count = arraysize(stack_parameters);
+  Node* continuation_frame_state =
+      CreateJavaScriptBuiltinContinuationFrameState(
+          jsgraph(), shared_info,
+          Builtins::kGenericConstructorLazyDeoptContinuation, target, context,
+          stack_parameters, stack_parameter_count, frame_state,
+          ContinuationFrameStateMode::LAZY);
+
+  // Convert the {value} to a Number.
+  NodeProperties::ReplaceValueInputs(node, value);
+  NodeProperties::ChangeOp(node, javascript()->ToNumberConvertBigInt());
+  NodeProperties::ReplaceFrameStateInput(node, continuation_frame_state);
+  return Changed(node);
 }
 
 Graph* JSCallReducer::graph() const { return jsgraph()->graph(); }
diff --git a/deps/v8/src/compiler/js-call-reducer.h b/deps/v8/src/compiler/js-call-reducer.h
index e04870ed2f..6683a0b18e 100644
--- a/deps/v8/src/compiler/js-call-reducer.h
+++ b/deps/v8/src/compiler/js-call-reducer.h
@@ -15,6 +15,7 @@ namespace internal {
 
 // Forward declarations.
 class Factory;
+class JSGlobalProxy;
 class VectorSlotPair;
 
 namespace compiler {
@@ -182,10 +183,9 @@ class V8_EXPORT_PRIVATE JSCallReducer final : public AdvancedReducer {
                                           InstanceType instance_type,
                                           FieldAccess const& access);
 
-  Reduction ReduceDataViewPrototypeGet(Node* node,
-                                       ExternalArrayType element_type);
-  Reduction ReduceDataViewPrototypeSet(Node* node,
-                                       ExternalArrayType element_type);
+  enum class DataViewAccess { kGet, kSet };
+  Reduction ReduceDataViewAccess(Node* node, DataViewAccess access,
+                                 ExternalArrayType element_type);
 
   Reduction ReduceDatePrototypeGetTime(Node* node);
   Reduction ReduceDateNow(Node* node);
@@ -230,7 +230,8 @@ class V8_EXPORT_PRIVATE JSCallReducer final : public AdvancedReducer {
   Node* CreateArtificialFrameState(Node* node, Node* outer_frame_state,
                                    int parameter_count, BailoutId bailout_id,
                                    FrameStateType frame_state_type,
-                                   Handle<SharedFunctionInfo> shared);
+                                   Handle<SharedFunctionInfo> shared,
+                                   Node* context = nullptr);
 
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }
diff --git a/deps/v8/src/compiler/js-context-specialization.cc b/deps/v8/src/compiler/js-context-specialization.cc
index ef2297c9d6..1b2f3c3a7c 100644
--- a/deps/v8/src/compiler/js-context-specialization.cc
+++ b/deps/v8/src/compiler/js-context-specialization.cc
@@ -144,8 +144,9 @@ Reduction JSContextSpecialization::ReduceJSLoadContext(Node* node) {
 
   // Now walk up the concrete context chain for the remaining depth.
   ContextRef concrete = maybe_concrete.value();
+  concrete.Serialize();  // TODO(neis): Remove later.
   for (; depth > 0; --depth) {
-    concrete = concrete.previous().value();
+    concrete = concrete.previous();
   }
 
   if (!access.immutable()) {
@@ -164,7 +165,7 @@ Reduction JSContextSpecialization::ReduceJSLoadContext(Node* node) {
     // We must be conservative and check if the value in the slot is currently
     // the hole or undefined. Only if it is neither of these, can we be sure
     // that it won't change anymore.
-    OddballType oddball_type = maybe_value->oddball_type();
+    OddballType oddball_type = maybe_value->AsHeapObject().map().oddball_type();
     if (oddball_type == OddballType::kUndefined ||
         oddball_type == OddballType::kHole) {
       maybe_value.reset();
@@ -205,8 +206,9 @@ Reduction JSContextSpecialization::ReduceJSStoreContext(Node* node) {
 
   // Now walk up the concrete context chain for the remaining depth.
   ContextRef concrete = maybe_concrete.value();
+  concrete.Serialize();  // TODO(neis): Remove later.
   for (; depth > 0; --depth) {
-    concrete = concrete.previous().value();
+    concrete = concrete.previous();
   }
 
   return SimplifyJSStoreContext(node, jsgraph()->Constant(concrete), depth);
diff --git a/deps/v8/src/compiler/js-create-lowering.cc b/deps/v8/src/compiler/js-create-lowering.cc
index 6484e05061..3848e1f814 100644
--- a/deps/v8/src/compiler/js-create-lowering.cc
+++ b/deps/v8/src/compiler/js-create-lowering.cc
@@ -129,10 +129,10 @@ Reduction JSCreateLowering::ReduceJSCreate(Node* node) {
 
   JSFunctionRef constructor =
       target_type.AsHeapConstant()->Ref().AsJSFunction();
-  if (!constructor.IsConstructor()) return NoChange();
+  if (!constructor.map().is_constructor()) return NoChange();
   JSFunctionRef original_constructor =
       new_target_type.AsHeapConstant()->Ref().AsJSFunction();
-  if (!original_constructor.IsConstructor()) return NoChange();
+  if (!original_constructor.map().is_constructor()) return NoChange();
 
   // Check if we can inline the allocation.
   if (!IsAllocationInlineable(constructor, original_constructor)) {
@@ -198,8 +198,8 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
         // Load the arguments object map.
         Node* const arguments_map = jsgraph()->Constant(
             has_aliased_arguments
-                ? native_context_ref().fast_aliased_arguments_map()
-                : native_context_ref().sloppy_arguments_map());
+                ? native_context().fast_aliased_arguments_map()
+                : native_context().sloppy_arguments_map());
         // Actually allocate and initialize the arguments object.
         AllocationBuilder a(jsgraph(), effect, control);
         Node* properties = jsgraph()->EmptyFixedArrayConstant();
@@ -228,7 +228,7 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
                              arguments_frame, arguments_length, effect);
         // Load the arguments object map.
         Node* const arguments_map =
-            jsgraph()->Constant(native_context_ref().strict_arguments_map());
+            jsgraph()->Constant(native_context().strict_arguments_map());
         // Actually allocate and initialize the arguments object.
         AllocationBuilder a(jsgraph(), effect, control);
         Node* properties = jsgraph()->EmptyFixedArrayConstant();
@@ -258,7 +258,7 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
                              arguments_frame, rest_length, effect);
         // Load the JSArray object map.
         Node* const jsarray_map = jsgraph()->Constant(
-            native_context_ref().js_array_packed_elements_map());
+            native_context().js_array_packed_elements_map());
         // Actually allocate and initialize the jsarray.
         AllocationBuilder a(jsgraph(), effect, control);
         Node* properties = jsgraph()->EmptyFixedArrayConstant();
@@ -302,9 +302,8 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
       effect = elements->op()->EffectOutputCount() > 0 ? elements : effect;
       // Load the arguments object map.
       Node* const arguments_map = jsgraph()->Constant(
-          has_aliased_arguments
-              ? native_context_ref().fast_aliased_arguments_map()
-              : native_context_ref().sloppy_arguments_map());
+          has_aliased_arguments ? native_context().fast_aliased_arguments_map()
+                                : native_context().sloppy_arguments_map());
       // Actually allocate and initialize the arguments object.
       AllocationBuilder a(jsgraph(), effect, control);
       Node* properties = jsgraph()->EmptyFixedArrayConstant();
@@ -340,7 +339,7 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
       effect = elements->op()->EffectOutputCount() > 0 ? elements : effect;
       // Load the arguments object map.
       Node* const arguments_map =
-          jsgraph()->Constant(native_context_ref().strict_arguments_map());
+          jsgraph()->Constant(native_context().strict_arguments_map());
       // Actually allocate and initialize the arguments object.
       AllocationBuilder a(jsgraph(), effect, control);
       Node* properties = jsgraph()->EmptyFixedArrayConstant();
@@ -376,8 +375,8 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
           AllocateRestArguments(effect, control, args_state, start_index);
       effect = elements->op()->EffectOutputCount() > 0 ? elements : effect;
       // Load the JSArray object map.
-      Node* const jsarray_map = jsgraph()->Constant(
-          native_context_ref().js_array_packed_elements_map());
+      Node* const jsarray_map =
+          jsgraph()->Constant(native_context().js_array_packed_elements_map());
       // Actually allocate and initialize the jsarray.
       AllocationBuilder a(jsgraph(), effect, control);
       Node* properties = jsgraph()->EmptyFixedArrayConstant();
@@ -476,7 +475,8 @@ Reduction JSCreateLowering::ReduceJSCreateGeneratorObject(Node* node) {
 // Constructs an array with a variable {length} when no upper bound
 // is known for the capacity.
 Reduction JSCreateLowering::ReduceNewArray(
-    Node* node, Node* length, MapRef initial_map, PretenureFlag pretenure,
+    Node* node, Node* length, MapRef initial_map, ElementsKind elements_kind,
+    PretenureFlag pretenure,
     const SlackTrackingPrediction& slack_tracking_prediction) {
   DCHECK_EQ(IrOpcode::kJSCreateArray, node->opcode());
   Node* effect = NodeProperties::GetEffectInput(node);
@@ -485,8 +485,8 @@ Reduction JSCreateLowering::ReduceNewArray(
   // Constructing an Array via new Array(N) where N is an unsigned
   // integer, always creates a holey backing store.
   ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
-      initial_map, initial_map.AsElementsKind(
-                       GetHoleyElementsKind(initial_map.elements_kind())));
+      initial_map,
+      initial_map.AsElementsKind(GetHoleyElementsKind(elements_kind)));
 
   // Check that the {limit} is an unsigned integer in the valid range.
   // This has to be kept in sync with src/runtime/runtime-array.cc,
@@ -525,7 +525,7 @@ Reduction JSCreateLowering::ReduceNewArray(
 // upper bound is known for the {capacity}.
 Reduction JSCreateLowering::ReduceNewArray(
     Node* node, Node* length, int capacity, MapRef initial_map,
-    PretenureFlag pretenure,
+    ElementsKind elements_kind, PretenureFlag pretenure,
     const SlackTrackingPrediction& slack_tracking_prediction) {
   DCHECK(node->opcode() == IrOpcode::kJSCreateArray ||
          node->opcode() == IrOpcode::kJSCreateEmptyLiteralArray);
@@ -533,12 +533,11 @@ Reduction JSCreateLowering::ReduceNewArray(
   Node* control = NodeProperties::GetControlInput(node);
 
   // Determine the appropriate elements kind.
-  ElementsKind elements_kind = initial_map.elements_kind();
   if (NodeProperties::GetType(length).Max() > 0.0) {
     elements_kind = GetHoleyElementsKind(elements_kind);
-    ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
-        initial_map, initial_map.AsElementsKind(elements_kind));
   }
+  ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
+      initial_map, initial_map.AsElementsKind(elements_kind));
   DCHECK(IsFastElementsKind(elements_kind));
 
   // Setup elements and properties.
@@ -570,15 +569,16 @@ Reduction JSCreateLowering::ReduceNewArray(
 
 Reduction JSCreateLowering::ReduceNewArray(
     Node* node, std::vector<Node*> values, MapRef initial_map,
-    PretenureFlag pretenure,
+    ElementsKind elements_kind, PretenureFlag pretenure,
     const SlackTrackingPrediction& slack_tracking_prediction) {
   DCHECK_EQ(IrOpcode::kJSCreateArray, node->opcode());
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
 
   // Determine the appropriate elements kind.
-  ElementsKind elements_kind = initial_map.elements_kind();
   DCHECK(IsFastElementsKind(elements_kind));
+  ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
+      initial_map, initial_map.AsElementsKind(elements_kind));
 
   // Check {values} based on the {elements_kind}. These checks are guarded
   // by the {elements_kind} feedback on the {site}, so it's safe to just
@@ -625,68 +625,6 @@ Reduction JSCreateLowering::ReduceNewArray(
   return Changed(node);
 }
 
-Reduction JSCreateLowering::ReduceNewArrayToStubCall(
-    Node* node, base::Optional<AllocationSiteRef> site) {
-  CreateArrayParameters const& p = CreateArrayParametersOf(node->op());
-  int const arity = static_cast<int>(p.arity());
-  Node* target = NodeProperties::GetValueInput(node, 0);
-  Node* new_target = NodeProperties::GetValueInput(node, 1);
-  Type new_target_type = NodeProperties::GetType(new_target);
-  Node* type_info =
-      site ? jsgraph()->Constant(*site) : jsgraph()->UndefinedConstant();
-
-  ElementsKind elements_kind =
-      site ? site->GetElementsKind() : GetInitialFastElementsKind();
-  AllocationSiteOverrideMode override_mode =
-      (!site || AllocationSite::ShouldTrack(elements_kind))
-          ? DISABLE_ALLOCATION_SITES
-          : DONT_OVERRIDE;
-
-  // The Array constructor can only trigger an observable side-effect
-  // if the new.target may be a proxy.
-  Operator::Properties const properties =
-      (new_target != target || new_target_type.Maybe(Type::Proxy()))
-          ? Operator::kNoDeopt
-          : Operator::kNoDeopt | Operator::kNoWrite;
-
-  if (arity == 0) {
-    Callable callable = CodeFactory::ArrayNoArgumentConstructor(
-        isolate(), elements_kind, override_mode);
-    auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), arity + 1,
-        CallDescriptor::kNeedsFrameState, properties);
-    node->ReplaceInput(0, jsgraph()->HeapConstant(callable.code()));
-    node->InsertInput(graph()->zone(), 2, type_info);
-    node->InsertInput(graph()->zone(), 3, jsgraph()->Constant(arity));
-    node->InsertInput(graph()->zone(), 4, jsgraph()->UndefinedConstant());
-    NodeProperties::ChangeOp(node, common()->Call(call_descriptor));
-  } else if (arity == 1) {
-    // Require elements kind to "go holey".
-    Callable callable = CodeFactory::ArraySingleArgumentConstructor(
-        isolate(), GetHoleyElementsKind(elements_kind), override_mode);
-    auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), arity + 1,
-        CallDescriptor::kNeedsFrameState, properties);
-    node->ReplaceInput(0, jsgraph()->HeapConstant(callable.code()));
-    node->InsertInput(graph()->zone(), 2, type_info);
-    node->InsertInput(graph()->zone(), 3, jsgraph()->Constant(arity));
-    node->InsertInput(graph()->zone(), 4, jsgraph()->UndefinedConstant());
-    NodeProperties::ChangeOp(node, common()->Call(call_descriptor));
-  } else {
-    DCHECK_GT(arity, 1);
-    Handle<Code> code = BUILTIN_CODE(isolate(), ArrayNArgumentsConstructor);
-    auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), ArrayNArgumentsConstructorDescriptor{}, arity + 1,
-        CallDescriptor::kNeedsFrameState);
-    node->ReplaceInput(0, jsgraph()->HeapConstant(code));
-    node->InsertInput(graph()->zone(), 2, type_info);
-    node->InsertInput(graph()->zone(), 3, jsgraph()->Constant(arity));
-    node->InsertInput(graph()->zone(), 4, jsgraph()->UndefinedConstant());
-    NodeProperties::ChangeOp(node, common()->Call(call_descriptor));
-  }
-  return Changed(node);
-}
-
 Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateArray, node->opcode());
   CreateArrayParameters const& p = CreateArrayParametersOf(node->op());
@@ -699,7 +637,7 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
     }
   }
   PretenureFlag pretenure = NOT_TENURED;
-  JSFunctionRef constructor = native_context_ref().array_function();
+  JSFunctionRef constructor = native_context().array_function();
   Node* target = NodeProperties::GetValueInput(node, 0);
   Node* new_target = NodeProperties::GetValueInput(node, 1);
   Type new_target_type = (target == new_target)
@@ -711,8 +649,8 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
       new_target_type.AsHeapConstant()->Ref().IsJSFunction()) {
     JSFunctionRef original_constructor =
         new_target_type.AsHeapConstant()->Ref().AsJSFunction();
-    DCHECK(constructor.IsConstructor());
-    DCHECK(original_constructor.IsConstructor());
+    DCHECK(constructor.map().is_constructor());
+    DCHECK(original_constructor.map().is_constructor());
 
     // Check if we can inline the allocation.
     if (IsAllocationInlineable(constructor, original_constructor)) {
@@ -726,10 +664,9 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
       bool can_inline_call = false;
 
       // Check if we have a feedback {site} on the {node}.
+      ElementsKind elements_kind = initial_map.elements_kind();
       if (site_ref) {
-        ElementsKind elements_kind = site_ref->GetElementsKind();
-        ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
-            initial_map, initial_map.AsElementsKind(elements_kind));
+        elements_kind = site_ref->GetElementsKind();
         can_inline_call = site_ref->CanInlineCall();
         pretenure = dependencies()->DependOnPretenureMode(*site_ref);
         dependencies()->DependOnElementsKind(*site_ref);
@@ -740,7 +677,8 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
       if (arity == 0) {
         Node* length = jsgraph()->ZeroConstant();
         int capacity = JSArray::kPreallocatedArrayElements;
-        return ReduceNewArray(node, length, capacity, initial_map, pretenure,
+        return ReduceNewArray(node, length, capacity, initial_map,
+                              elements_kind, pretenure,
                               slack_tracking_prediction);
       } else if (arity == 1) {
         Node* length = NodeProperties::GetValueInput(node, 2);
@@ -748,26 +686,25 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
         if (!length_type.Maybe(Type::Number())) {
           // Handle the single argument case, where we know that the value
           // cannot be a valid Array length.
-          ElementsKind elements_kind = initial_map.elements_kind();
           elements_kind = GetMoreGeneralElementsKind(
               elements_kind, IsHoleyElementsKind(elements_kind)
                                  ? HOLEY_ELEMENTS
                                  : PACKED_ELEMENTS);
-          ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
-              initial_map, initial_map.AsElementsKind(elements_kind));
           return ReduceNewArray(node, std::vector<Node*>{length}, initial_map,
-                                pretenure, slack_tracking_prediction);
+                                elements_kind, pretenure,
+                                slack_tracking_prediction);
         }
         if (length_type.Is(Type::SignedSmall()) && length_type.Min() >= 0 &&
             length_type.Max() <= kElementLoopUnrollLimit &&
             length_type.Min() == length_type.Max()) {
           int capacity = static_cast<int>(length_type.Max());
-          return ReduceNewArray(node, length, capacity, initial_map, pretenure,
+          return ReduceNewArray(node, length, capacity, initial_map,
+                                elements_kind, pretenure,
                                 slack_tracking_prediction);
         }
         if (length_type.Maybe(Type::UnsignedSmall()) && can_inline_call) {
-          return ReduceNewArray(node, length, initial_map, pretenure,
-                                slack_tracking_prediction);
+          return ReduceNewArray(node, length, initial_map, elements_kind,
+                                pretenure, slack_tracking_prediction);
         }
       } else if (arity <= JSArray::kInitialMaxFastElementArray) {
         // Gather the values to store into the newly created array.
@@ -791,7 +728,6 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
         }
 
         // Try to figure out the ideal elements kind statically.
-        ElementsKind elements_kind = initial_map.elements_kind();
         if (values_all_smis) {
           // Smis can be stored with any elements kind.
         } else if (values_all_numbers) {
@@ -812,18 +748,12 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
           // we cannot inline this invocation of the Array constructor here.
           return NoChange();
         }
-        ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(
-            initial_map, initial_map.AsElementsKind(elements_kind));
-        return ReduceNewArray(node, values, initial_map, pretenure,
-                              slack_tracking_prediction);
+        return ReduceNewArray(node, values, initial_map, elements_kind,
+                              pretenure, slack_tracking_prediction);
       }
     }
   }
-
-  // TODO(bmeurer): Optimize the subclassing case.
-  if (target != new_target) return NoChange();
-
-  return ReduceNewArrayToStubCall(node, site_ref);
+  return NoChange();
 }
 
 Reduction JSCreateLowering::ReduceJSCreateArrayIterator(Node* node) {
@@ -838,7 +768,7 @@ Reduction JSCreateLowering::ReduceJSCreateArrayIterator(Node* node) {
   AllocationBuilder a(jsgraph(), effect, control);
   a.Allocate(JSArrayIterator::kSize, NOT_TENURED, Type::OtherObject());
   a.Store(AccessBuilder::ForMap(),
-          native_context_ref().initial_array_iterator_map());
+          native_context().initial_array_iterator_map());
   a.Store(AccessBuilder::ForJSObjectPropertiesOrHash(),
           jsgraph()->EmptyFixedArrayConstant());
   a.Store(AccessBuilder::ForJSObjectElements(),
@@ -902,8 +832,8 @@ Reduction JSCreateLowering::ReduceJSCreateCollectionIterator(Node* node) {
   AllocationBuilder a(jsgraph(), effect, control);
   a.Allocate(JSCollectionIterator::kSize, NOT_TENURED, Type::OtherObject());
   a.Store(AccessBuilder::ForMap(),
-          MapForCollectionIterationKind(
-              native_context_ref(), p.collection_kind(), p.iteration_kind()));
+          MapForCollectionIterationKind(native_context(), p.collection_kind(),
+                                        p.iteration_kind()));
   a.Store(AccessBuilder::ForJSObjectPropertiesOrHash(),
           jsgraph()->EmptyFixedArrayConstant());
   a.Store(AccessBuilder::ForJSObjectElements(),
@@ -975,7 +905,7 @@ Reduction JSCreateLowering::ReduceJSCreateClosure(Node* node) {
   }
 
   MapRef function_map =
-      native_context_ref().GetFunctionMapFromIndex(shared.function_map_index());
+      native_context().GetFunctionMapFromIndex(shared.function_map_index());
   DCHECK(!function_map.IsInobjectSlackTrackingInProgress());
   DCHECK(!function_map.is_dictionary_map());
 
@@ -1025,7 +955,7 @@ Reduction JSCreateLowering::ReduceJSCreateIterResultObject(Node* node) {
   Node* effect = NodeProperties::GetEffectInput(node);
 
   Node* iterator_result_map =
-      jsgraph()->Constant(native_context_ref().iterator_result_map());
+      jsgraph()->Constant(native_context().iterator_result_map());
 
   // Emit code to allocate the JSIteratorResult instance.
   AllocationBuilder a(jsgraph(), effect, graph()->start());
@@ -1047,7 +977,8 @@ Reduction JSCreateLowering::ReduceJSCreateStringIterator(Node* node) {
   Node* string = NodeProperties::GetValueInput(node, 0);
   Node* effect = NodeProperties::GetEffectInput(node);
 
-  Node* map = jsgraph()->Constant(native_context_ref().string_iterator_map());
+  Node* map =
+      jsgraph()->Constant(native_context().initial_string_iterator_map());
   // Allocate new iterator and attach the iterator to this string.
   AllocationBuilder a(jsgraph(), effect, graph()->start());
   a.Allocate(JSStringIterator::kSize, NOT_TENURED, Type::OtherObject());
@@ -1070,7 +1001,7 @@ Reduction JSCreateLowering::ReduceJSCreateKeyValueArray(Node* node) {
   Node* effect = NodeProperties::GetEffectInput(node);
 
   Node* array_map =
-      jsgraph()->Constant(native_context_ref().js_array_packed_elements_map());
+      jsgraph()->Constant(native_context().js_array_packed_elements_map());
   Node* properties = jsgraph()->EmptyFixedArrayConstant();
   Node* length = jsgraph()->Constant(2);
 
@@ -1097,7 +1028,7 @@ Reduction JSCreateLowering::ReduceJSCreatePromise(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreatePromise, node->opcode());
   Node* effect = NodeProperties::GetEffectInput(node);
 
-  MapRef promise_map = native_context_ref().promise_function().initial_map();
+  MapRef promise_map = native_context().promise_function().initial_map();
 
   AllocationBuilder a(jsgraph(), effect, graph()->start());
   a.Allocate(promise_map.instance_size());
@@ -1157,14 +1088,15 @@ Reduction JSCreateLowering::ReduceJSCreateEmptyLiteralArray(Node* node) {
     AllocationSiteRef site = feedback.AsAllocationSite();
     DCHECK(!site.PointsToLiteral());
     MapRef initial_map =
-        native_context_ref().GetInitialJSArrayMap(site.GetElementsKind());
+        native_context().GetInitialJSArrayMap(site.GetElementsKind());
     PretenureFlag const pretenure = dependencies()->DependOnPretenureMode(site);
     dependencies()->DependOnElementsKind(site);
     Node* length = jsgraph()->ZeroConstant();
     DCHECK(!initial_map.IsInobjectSlackTrackingInProgress());
     SlackTrackingPrediction slack_tracking_prediction(
         initial_map, initial_map.instance_size());
-    return ReduceNewArray(node, length, 0, initial_map, pretenure,
+    return ReduceNewArray(node, length, 0, initial_map,
+                          initial_map.elements_kind(), pretenure,
                           slack_tracking_prediction);
   }
   return NoChange();
@@ -1176,7 +1108,7 @@ Reduction JSCreateLowering::ReduceJSCreateEmptyLiteralObject(Node* node) {
   Node* control = NodeProperties::GetControlInput(node);
 
   // Retrieve the initial map for the object.
-  MapRef map = native_context_ref().object_function().initial_map();
+  MapRef map = native_context().object_function().initial_map();
   DCHECK(!map.is_dictionary_map());
   DCHECK(!map.IsInobjectSlackTrackingInProgress());
   Node* js_object_map = jsgraph()->Constant(map);
@@ -1253,7 +1185,7 @@ Reduction JSCreateLowering::ReduceJSCreateFunctionContext(Node* node) {
     a.Store(AccessBuilder::ForContextSlot(Context::PREVIOUS_INDEX), context);
     a.Store(AccessBuilder::ForContextSlot(Context::EXTENSION_INDEX), extension);
     a.Store(AccessBuilder::ForContextSlot(Context::NATIVE_CONTEXT_INDEX),
-            jsgraph()->HeapConstant(native_context()));
+            jsgraph()->Constant(native_context()));
     for (int i = Context::MIN_CONTEXT_SLOTS; i < context_length; ++i) {
       a.Store(AccessBuilder::ForContextSlot(i), jsgraph()->UndefinedConstant());
     }
@@ -1280,7 +1212,7 @@ Reduction JSCreateLowering::ReduceJSCreateWithContext(Node* node) {
   a.Store(AccessBuilder::ForContextSlot(Context::PREVIOUS_INDEX), context);
   a.Store(AccessBuilder::ForContextSlot(Context::EXTENSION_INDEX), extension);
   a.Store(AccessBuilder::ForContextSlot(Context::NATIVE_CONTEXT_INDEX),
-          jsgraph()->HeapConstant(native_context()));
+          jsgraph()->Constant(native_context()));
   RelaxControls(node);
   a.FinishAndChange(node);
   return Changed(node);
@@ -1303,7 +1235,7 @@ Reduction JSCreateLowering::ReduceJSCreateCatchContext(Node* node) {
   a.Store(AccessBuilder::ForContextSlot(Context::PREVIOUS_INDEX), context);
   a.Store(AccessBuilder::ForContextSlot(Context::EXTENSION_INDEX), extension);
   a.Store(AccessBuilder::ForContextSlot(Context::NATIVE_CONTEXT_INDEX),
-          jsgraph()->HeapConstant(native_context()));
+          jsgraph()->Constant(native_context()));
   a.Store(AccessBuilder::ForContextSlot(Context::THROWN_OBJECT_INDEX),
           exception);
   RelaxControls(node);
@@ -1332,7 +1264,7 @@ Reduction JSCreateLowering::ReduceJSCreateBlockContext(Node* node) {
     a.Store(AccessBuilder::ForContextSlot(Context::PREVIOUS_INDEX), context);
     a.Store(AccessBuilder::ForContextSlot(Context::EXTENSION_INDEX), extension);
     a.Store(AccessBuilder::ForContextSlot(Context::NATIVE_CONTEXT_INDEX),
-            jsgraph()->HeapConstant(native_context()));
+            jsgraph()->Constant(native_context()));
     for (int i = Context::MIN_CONTEXT_SLOTS; i < context_length; ++i) {
       a.Store(AccessBuilder::ForContextSlot(i), jsgraph()->UndefinedConstant());
     }
@@ -1344,6 +1276,24 @@ Reduction JSCreateLowering::ReduceJSCreateBlockContext(Node* node) {
   return NoChange();
 }
 
+namespace {
+base::Optional<MapRef> GetObjectCreateMap(JSHeapBroker* broker,
+                                          HeapObjectRef prototype) {
+  MapRef standard_map =
+      broker->native_context().object_function().initial_map();
+  if (prototype.equals(standard_map.prototype())) {
+    return standard_map;
+  }
+  if (prototype.map().oddball_type() == OddballType::kNull) {
+    return broker->native_context().slow_object_with_null_prototype_map();
+  }
+  if (prototype.IsJSObject()) {
+    return prototype.AsJSObject().GetObjectCreateMap();
+  }
+  return base::Optional<MapRef>();
+}
+}  // namespace
+
 Reduction JSCreateLowering::ReduceJSCreateObject(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateObject, node->opcode());
   Node* effect = NodeProperties::GetEffectInput(node);
@@ -1353,13 +1303,14 @@ Reduction JSCreateLowering::ReduceJSCreateObject(Node* node) {
   if (!prototype_type.IsHeapConstant()) return NoChange();
 
   HeapObjectRef prototype_const = prototype_type.AsHeapConstant()->Ref();
-  auto maybe_instance_map = prototype_const.TryGetObjectCreateMap();
+  auto maybe_instance_map =
+      GetObjectCreateMap(js_heap_broker(), prototype_const);
   if (!maybe_instance_map) return NoChange();
   MapRef instance_map = maybe_instance_map.value();
 
   Node* properties = jsgraph()->EmptyFixedArrayConstant();
   if (instance_map.is_dictionary_map()) {
-    DCHECK_EQ(prototype_const.type().oddball_type(), OddballType::kNull);
+    DCHECK_EQ(prototype_const.map().oddball_type(), OddballType::kNull);
     // Allocate an empty NameDictionary as backing store for the properties.
     Handle<Map> map = isolate()->factory()->name_dictionary_map();
     int capacity =
@@ -1441,7 +1392,8 @@ Node* JSCreateLowering::AllocateArguments(Node* effect, Node* control,
   a.AllocateArray(argument_count, factory()->fixed_array_map());
   for (int i = 0; i < argument_count; ++i, ++parameters_it) {
     DCHECK_NOT_NULL((*parameters_it).node);
-    a.Store(AccessBuilder::ForFixedArraySlot(i), (*parameters_it).node);
+    a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
+            (*parameters_it).node);
   }
   return a.Finish();
 }
@@ -1471,7 +1423,8 @@ Node* JSCreateLowering::AllocateRestArguments(Node* effect, Node* control,
   a.AllocateArray(num_elements, factory()->fixed_array_map());
   for (int i = 0; i < num_elements; ++i, ++parameters_it) {
     DCHECK_NOT_NULL((*parameters_it).node);
-    a.Store(AccessBuilder::ForFixedArraySlot(i), (*parameters_it).node);
+    a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
+            (*parameters_it).node);
   }
   return a.Finish();
 }
@@ -1508,22 +1461,27 @@ Node* JSCreateLowering::AllocateAliasedArguments(
   AllocationBuilder aa(jsgraph(), effect, control);
   aa.AllocateArray(argument_count, factory()->fixed_array_map());
   for (int i = 0; i < mapped_count; ++i, ++parameters_it) {
-    aa.Store(AccessBuilder::ForFixedArraySlot(i), jsgraph()->TheHoleConstant());
+    aa.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
+             jsgraph()->TheHoleConstant());
   }
   for (int i = mapped_count; i < argument_count; ++i, ++parameters_it) {
     DCHECK_NOT_NULL((*parameters_it).node);
-    aa.Store(AccessBuilder::ForFixedArraySlot(i), (*parameters_it).node);
+    aa.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
+             (*parameters_it).node);
   }
   Node* arguments = aa.Finish();
 
   // Actually allocate the backing store.
   AllocationBuilder a(jsgraph(), arguments, control);
   a.AllocateArray(mapped_count + 2, factory()->sloppy_arguments_elements_map());
-  a.Store(AccessBuilder::ForFixedArraySlot(0), context);
-  a.Store(AccessBuilder::ForFixedArraySlot(1), arguments);
+  a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(0),
+          context);
+  a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(1),
+          arguments);
   for (int i = 0; i < mapped_count; ++i) {
     int idx = Context::MIN_CONTEXT_SLOTS + parameter_count - 1 - i;
-    a.Store(AccessBuilder::ForFixedArraySlot(i + 2), jsgraph()->Constant(idx));
+    a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i + 2),
+            jsgraph()->Constant(idx));
   }
   return a.Finish();
 }
@@ -1561,8 +1519,10 @@ Node* JSCreateLowering::AllocateAliasedArguments(
   // Actually allocate the backing store.
   AllocationBuilder a(jsgraph(), arguments, control);
   a.AllocateArray(mapped_count + 2, factory()->sloppy_arguments_elements_map());
-  a.Store(AccessBuilder::ForFixedArraySlot(0), context);
-  a.Store(AccessBuilder::ForFixedArraySlot(1), arguments);
+  a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(0),
+          context);
+  a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(1),
+          arguments);
   for (int i = 0; i < mapped_count; ++i) {
     int idx = Context::MIN_CONTEXT_SLOTS + parameter_count - 1 - i;
     Node* value = graph()->NewNode(
@@ -1570,7 +1530,8 @@ Node* JSCreateLowering::AllocateAliasedArguments(
         graph()->NewNode(simplified()->NumberLessThan(), jsgraph()->Constant(i),
                          arguments_length),
         jsgraph()->Constant(idx), jsgraph()->TheHoleConstant());
-    a.Store(AccessBuilder::ForFixedArraySlot(i + 2), value);
+    a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i + 2),
+            value);
   }
   return a.Finish();
 }
@@ -1648,7 +1609,7 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
         MaybeHandle<Map>(), Type::Any(),    MachineType::AnyTagged(),
         kFullWriteBarrier};
     Node* value;
-    if (boilerplate.IsUnboxedDoubleField(index)) {
+    if (boilerplate_map.IsUnboxedDoubleField(i)) {
       access.machine_type = MachineType::Float64();
       access.type = Type::Number();
       value = jsgraph()->Constant(boilerplate.RawFastDoublePropertyAt(index));
@@ -1670,7 +1631,11 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
         value = effect = builder.Finish();
       } else if (property_details.representation().IsSmi()) {
         // Ensure that value is stored as smi.
-        value = boilerplate_value.oddball_type() == OddballType::kUninitialized
+        bool is_uninitialized =
+            boilerplate_value.IsHeapObject() &&
+            boilerplate_value.AsHeapObject().map().oddball_type() ==
+                OddballType::kUninitialized;
+        value = is_uninitialized
                     ? jsgraph()->ZeroConstant()
                     : jsgraph()->Constant(boilerplate_value.AsSmi());
       } else {
@@ -1698,11 +1663,11 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
   // Actually allocate and initialize the object.
   AllocationBuilder builder(jsgraph(), effect, control);
   builder.Allocate(boilerplate_map.instance_size(), pretenure,
-                   Type::For(js_heap_broker(), boilerplate_map.object<Map>()));
+                   Type::For(boilerplate_map));
   builder.Store(AccessBuilder::ForMap(), boilerplate_map);
   builder.Store(AccessBuilder::ForJSObjectPropertiesOrHash(), properties);
   builder.Store(AccessBuilder::ForJSObjectElements(), elements);
-  if (boilerplate_map.IsJSArrayMap()) {
+  if (boilerplate.IsJSArray()) {
     JSArrayRef boilerplate_array = boilerplate.AsJSArray();
     builder.Store(
         AccessBuilder::ForJSArrayLength(boilerplate_array.GetElementsKind()),
@@ -1744,16 +1709,12 @@ Node* JSCreateLowering::AllocateFastLiteralElements(Node* effect, Node* control,
   } else {
     FixedArrayRef elements = boilerplate_elements.AsFixedArray();
     for (int i = 0; i < elements_length; ++i) {
-      if (elements.is_the_hole(i)) {
-        elements_values[i] = jsgraph()->TheHoleConstant();
+      ObjectRef element_value = elements.get(i);
+      if (element_value.IsJSObject()) {
+        elements_values[i] = effect = AllocateFastLiteral(
+            effect, control, element_value.AsJSObject(), pretenure);
       } else {
-        ObjectRef element_value = elements.get(i);
-        if (element_value.IsJSObject()) {
-          elements_values[i] = effect = AllocateFastLiteral(
-              effect, control, element_value.AsJSObject(), pretenure);
-        } else {
-          elements_values[i] = jsgraph()->Constant(element_value);
-        }
+        elements_values[i] = jsgraph()->Constant(element_value);
       }
     }
   }
@@ -1790,8 +1751,7 @@ Node* JSCreateLowering::AllocateLiteralRegExp(Node* effect, Node* control,
       JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
 
   AllocationBuilder builder(jsgraph(), effect, control);
-  builder.Allocate(size, pretenure,
-                   Type::For(js_heap_broker(), boilerplate_map.object<Map>()));
+  builder.Allocate(size, pretenure, Type::For(boilerplate_map));
   builder.Store(AccessBuilder::ForMap(), boilerplate_map);
   builder.Store(AccessBuilder::ForJSObjectPropertiesOrHash(),
                 boilerplate.raw_properties_or_hash());
@@ -1820,8 +1780,8 @@ SimplifiedOperatorBuilder* JSCreateLowering::simplified() const {
   return jsgraph()->simplified();
 }
 
-NativeContextRef JSCreateLowering::native_context_ref() const {
-  return NativeContextRef(js_heap_broker(), native_context());
+NativeContextRef JSCreateLowering::native_context() const {
+  return js_heap_broker()->native_context();
 }
 
 }  // namespace compiler
diff --git a/deps/v8/src/compiler/js-create-lowering.h b/deps/v8/src/compiler/js-create-lowering.h
index 151be1b35c..4099edb7b6 100644
--- a/deps/v8/src/compiler/js-create-lowering.h
+++ b/deps/v8/src/compiler/js-create-lowering.h
@@ -33,15 +33,13 @@ class V8_EXPORT_PRIVATE JSCreateLowering final
     : public NON_EXPORTED_BASE(AdvancedReducer) {
  public:
   JSCreateLowering(Editor* editor, CompilationDependencies* dependencies,
-                   JSGraph* jsgraph, JSHeapBroker* js_heap_broker,
-                   Handle<Context> native_context, Zone* zone)
+                   JSGraph* jsgraph, JSHeapBroker* js_heap_broker, Zone* zone)
       : AdvancedReducer(editor),
         dependencies_(dependencies),
         jsgraph_(jsgraph),
         js_heap_broker_(js_heap_broker),
-        native_context_(native_context),
         zone_(zone) {}
-  ~JSCreateLowering() final {}
+  ~JSCreateLowering() final = default;
 
   const char* reducer_name() const override { return "JSCreateLowering"; }
 
@@ -69,15 +67,16 @@ class V8_EXPORT_PRIVATE JSCreateLowering final
   Reduction ReduceJSCreateBlockContext(Node* node);
   Reduction ReduceJSCreateGeneratorObject(Node* node);
   Reduction ReduceNewArray(
-      Node* node, Node* length, MapRef initial_map, PretenureFlag pretenure,
+      Node* node, Node* length, MapRef initial_map, ElementsKind elements_kind,
+      PretenureFlag pretenure,
       const SlackTrackingPrediction& slack_tracking_prediction);
   Reduction ReduceNewArray(
       Node* node, Node* length, int capacity, MapRef initial_map,
-      PretenureFlag pretenure,
+      ElementsKind elements_kind, PretenureFlag pretenure,
       const SlackTrackingPrediction& slack_tracking_prediction);
   Reduction ReduceNewArray(
       Node* node, std::vector<Node*> values, MapRef initial_map,
-      PretenureFlag pretenure,
+      ElementsKind elements_kind, PretenureFlag pretenure,
       const SlackTrackingPrediction& slack_tracking_prediction);
   Reduction ReduceJSCreateObject(Node* node);
 
@@ -109,15 +108,11 @@ class V8_EXPORT_PRIVATE JSCreateLowering final
   Node* AllocateLiteralRegExp(Node* effect, Node* control,
                               JSRegExpRef boilerplate);
 
-  Reduction ReduceNewArrayToStubCall(Node* node,
-                                     base::Optional<AllocationSiteRef> site);
-
   Factory* factory() const;
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }
   Isolate* isolate() const;
-  Handle<Context> native_context() const { return native_context_; }
-  NativeContextRef native_context_ref() const;
+  NativeContextRef native_context() const;
   CommonOperatorBuilder* common() const;
   SimplifiedOperatorBuilder* simplified() const;
   CompilationDependencies* dependencies() const { return dependencies_; }
@@ -127,7 +122,6 @@ class V8_EXPORT_PRIVATE JSCreateLowering final
   CompilationDependencies* const dependencies_;
   JSGraph* const jsgraph_;
   JSHeapBroker* const js_heap_broker_;
-  Handle<Context> const native_context_;
   Zone* const zone_;
 };
 
diff --git a/deps/v8/src/compiler/js-generic-lowering.cc b/deps/v8/src/compiler/js-generic-lowering.cc
index 0903f181b9..731159f3d1 100644
--- a/deps/v8/src/compiler/js-generic-lowering.cc
+++ b/deps/v8/src/compiler/js-generic-lowering.cc
@@ -33,7 +33,7 @@ CallDescriptor::Flags FrameStateFlagForCall(Node* node) {
 
 JSGenericLowering::JSGenericLowering(JSGraph* jsgraph) : jsgraph_(jsgraph) {}
 
-JSGenericLowering::~JSGenericLowering() {}
+JSGenericLowering::~JSGenericLowering() = default;
 
 
 Reduction JSGenericLowering::Reduce(Node* node) {
@@ -79,7 +79,6 @@ REPLACE_STUB_CALL(Increment)
 REPLACE_STUB_CALL(Negate)
 REPLACE_STUB_CALL(HasProperty)
 REPLACE_STUB_CALL(Equal)
-REPLACE_STUB_CALL(ToInteger)
 REPLACE_STUB_CALL(ToLength)
 REPLACE_STUB_CALL(ToNumber)
 REPLACE_STUB_CALL(ToNumberConvertBigInt)
@@ -95,12 +94,14 @@ REPLACE_STUB_CALL(RejectPromise)
 REPLACE_STUB_CALL(ResolvePromise)
 #undef REPLACE_STUB_CALL
 
-void JSGenericLowering::ReplaceWithStubCall(Node* node, Callable callable,
+void JSGenericLowering::ReplaceWithStubCall(Node* node,
+                                            Callable callable,
                                             CallDescriptor::Flags flags) {
   ReplaceWithStubCall(node, callable, flags, node->op()->properties());
 }
 
-void JSGenericLowering::ReplaceWithStubCall(Node* node, Callable callable,
+void JSGenericLowering::ReplaceWithStubCall(Node* node,
+                                            Callable callable,
                                             CallDescriptor::Flags flags,
                                             Operator::Properties properties) {
   const CallInterfaceDescriptor& descriptor = callable.descriptor();
@@ -146,12 +147,16 @@ void JSGenericLowering::LowerJSLoadProperty(Node* node) {
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
   node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
-    Callable callable =
-        Builtins::CallableFor(isolate(), Builtins::kKeyedLoadICTrampoline);
+    Callable callable = Builtins::CallableFor(
+        isolate(), p.feedback().ic_state() == MEGAMORPHIC
+                       ? Builtins::kKeyedLoadICTrampoline_Megamorphic
+                       : Builtins::kKeyedLoadICTrampoline);
     ReplaceWithStubCall(node, callable, flags);
   } else {
-    Callable callable =
-        Builtins::CallableFor(isolate(), Builtins::kKeyedLoadIC);
+    Callable callable = Builtins::CallableFor(
+        isolate(), p.feedback().ic_state() == MEGAMORPHIC
+                       ? Builtins::kKeyedLoadIC_Megamorphic
+                       : Builtins::kKeyedLoadIC);
     Node* vector = jsgraph()->HeapConstant(p.feedback().vector());
     node->InsertInput(zone(), 3, vector);
     ReplaceWithStubCall(node, callable, flags);
@@ -164,20 +169,30 @@ void JSGenericLowering::LowerJSLoadNamed(Node* node) {
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
+  if (!p.feedback().IsValid()) {
+    Callable callable =
+        Builtins::CallableFor(isolate(), Builtins::kGetProperty);
+    ReplaceWithStubCall(node, callable, flags);
+    return;
+  }
   node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
-    Callable callable =
-        Builtins::CallableFor(isolate(), Builtins::kLoadICTrampoline);
+    Callable callable = Builtins::CallableFor(
+        isolate(), p.feedback().ic_state() == MEGAMORPHIC
+                       ? Builtins::kLoadICTrampoline_Megamorphic
+                       : Builtins::kLoadICTrampoline);
     ReplaceWithStubCall(node, callable, flags);
   } else {
-    Callable callable = Builtins::CallableFor(isolate(), Builtins::kLoadIC);
+    Callable callable =
+        Builtins::CallableFor(isolate(), p.feedback().ic_state() == MEGAMORPHIC
+                                             ? Builtins::kLoadIC_Megamorphic
+                                             : Builtins::kLoadIC);
     Node* vector = jsgraph()->HeapConstant(p.feedback().vector());
     node->InsertInput(zone(), 3, vector);
     ReplaceWithStubCall(node, callable, flags);
   }
 }
 
-
 void JSGenericLowering::LowerJSLoadGlobal(Node* node) {
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   const LoadGlobalParameters& p = LoadGlobalParametersOf(node->op());
@@ -222,6 +237,12 @@ void JSGenericLowering::LowerJSStoreNamed(Node* node) {
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
+  if (!p.feedback().IsValid()) {
+    node->InsertInput(
+        zone(), 3, jsgraph()->SmiConstant(static_cast<int>(p.language_mode())));
+    ReplaceWithRuntimeCall(node, Runtime::kSetNamedProperty);
+    return;
+  }
   node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable =
@@ -513,6 +534,13 @@ void JSGenericLowering::LowerJSCreateEmptyLiteralArray(Node* node) {
   ReplaceWithStubCall(node, callable, flags);
 }
 
+void JSGenericLowering::LowerJSCreateArrayFromIterable(Node* node) {
+  CallDescriptor::Flags flags = FrameStateFlagForCall(node);
+  Callable callable = Builtins::CallableFor(
+      isolate(), Builtins::kIterableToListWithSymbolLookup);
+  ReplaceWithStubCall(node, callable, flags);
+}
+
 void JSGenericLowering::LowerJSCreateLiteralObject(Node* node) {
   CreateLiteralParameters const& p = CreateLiteralParametersOf(node->op());
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
diff --git a/deps/v8/src/compiler/js-graph.cc b/deps/v8/src/compiler/js-graph.cc
index b3ef85fb07..7b74c2a32c 100644
--- a/deps/v8/src/compiler/js-graph.cc
+++ b/deps/v8/src/compiler/js-graph.cc
@@ -68,7 +68,8 @@ Node* JSGraph::Constant(Handle<Object> value) {
 
 Node* JSGraph::Constant(const ObjectRef& ref) {
   if (ref.IsSmi()) return Constant(ref.AsSmi());
-  OddballType oddball_type = ref.oddball_type();
+  OddballType oddball_type =
+      ref.AsHeapObject().GetHeapObjectType().oddball_type();
   if (ref.IsHeapNumber()) {
     return Constant(ref.AsHeapNumber().value());
   } else if (oddball_type == OddballType::kUndefined) {
@@ -99,19 +100,6 @@ Node* JSGraph::Constant(double value) {
   return NumberConstant(value);
 }
 
-
-Node* JSGraph::Constant(int32_t value) {
-  if (value == 0) return ZeroConstant();
-  if (value == 1) return OneConstant();
-  return NumberConstant(value);
-}
-
-Node* JSGraph::Constant(uint32_t value) {
-  if (value == 0) return ZeroConstant();
-  if (value == 1) return OneConstant();
-  return NumberConstant(value);
-}
-
 Node* JSGraph::NumberConstant(double value) {
   Node** loc = cache_.FindNumberConstant(value);
   if (*loc == nullptr) {
diff --git a/deps/v8/src/compiler/js-graph.h b/deps/v8/src/compiler/js-graph.h
index 517b799a24..774b8e7433 100644
--- a/deps/v8/src/compiler/js-graph.h
+++ b/deps/v8/src/compiler/js-graph.h
@@ -61,12 +61,6 @@ class V8_EXPORT_PRIVATE JSGraph : public MachineGraph {
   // Creates a NumberConstant node, usually canonicalized.
   Node* Constant(double value);
 
-  // Creates a NumberConstant node, usually canonicalized.
-  Node* Constant(int32_t value);
-
-  // Creates a NumberConstant node, usually canonicalized.
-  Node* Constant(uint32_t value);
-
   // Creates a HeapConstant node for either true or false.
   Node* BooleanConstant(bool is_true) {
     return is_true ? TrueConstant() : FalseConstant();
diff --git a/deps/v8/src/compiler/js-heap-broker.cc b/deps/v8/src/compiler/js-heap-broker.cc
index 949dca377d..a95bfaad21 100644
--- a/deps/v8/src/compiler/js-heap-broker.cc
+++ b/deps/v8/src/compiler/js-heap-broker.cc
@@ -4,7 +4,12 @@
 
 #include "src/compiler/js-heap-broker.h"
 
+#include "src/ast/modules.h"
+#include "src/bootstrapper.h"
+#include "src/boxed-float.h"
+#include "src/code-factory.h"
 #include "src/compiler/graph-reducer.h"
+#include "src/compiler/per-isolate-compiler-cache.h"
 #include "src/objects-inl.h"
 #include "src/objects/js-array-inl.h"
 #include "src/objects/js-regexp-inl.h"
@@ -19,16 +24,39 @@ namespace compiler {
 HEAP_BROKER_OBJECT_LIST(FORWARD_DECL)
 #undef FORWARD_DECL
 
-// TODO(neis): It would be nice to share the serialized data for read-only
-// objects.
+// There are three kinds of ObjectData values.
+//
+// kSmi: The underlying V8 object is a Smi and the data is an instance of the
+//   base class (ObjectData), i.e. it's basically just the handle.  Because the
+//   object is a Smi, it's safe to access the handle in order to extract the
+//   number value, and AsSmi() does exactly that.
+//
+// kSerializedHeapObject: The underlying V8 object is a HeapObject and the
+//   data is an instance of the corresponding (most-specific) subclass, e.g.
+//   JSFunctionData, which provides serialized information about the object.
+//
+// kUnserializedHeapObject: The underlying V8 object is a HeapObject and the
+//   data is an instance of the base class (ObjectData), i.e. it basically
+//   carries no information other than the handle.
+//
+enum ObjectDataKind { kSmi, kSerializedHeapObject, kUnserializedHeapObject };
 
 class ObjectData : public ZoneObject {
  public:
-  static ObjectData* Serialize(JSHeapBroker* broker, Handle<Object> object);
-
-  ObjectData(JSHeapBroker* broker_, Handle<Object> object_, bool is_smi_)
-      : broker(broker_), object(object_), is_smi(is_smi_) {
-    broker->AddData(object, this);
+  ObjectData(JSHeapBroker* broker, ObjectData** storage, Handle<Object> object,
+             ObjectDataKind kind)
+      : object_(object), kind_(kind) {
+    // This assignment ensures we don't end up inserting the same object
+    // in an endless recursion.
+    *storage = this;
+
+    broker->Trace("Creating data %p for handle %" V8PRIuPTR " (", this,
+                  object.address());
+    if (FLAG_trace_heap_broker) {
+      object->ShortPrint();
+      PrintF(")\n");
+    }
+    CHECK_NOT_NULL(broker->isolate()->handle_scope_data()->canonical_scope);
   }
 
 #define DECLARE_IS_AND_AS(Name) \
@@ -37,137 +65,356 @@ class ObjectData : public ZoneObject {
   HEAP_BROKER_OBJECT_LIST(DECLARE_IS_AND_AS)
 #undef DECLARE_IS_AND_AS
 
-  JSHeapBroker* const broker;
-  Handle<Object> const object;
-  bool const is_smi;
-};
+  Handle<Object> object() const { return object_; }
+  ObjectDataKind kind() const { return kind_; }
+  bool is_smi() const { return kind_ == kSmi; }
 
-// TODO(neis): Perhaps add a boolean that indicates whether serialization of an
-// object has completed. That could be used to add safety checks.
-
-#define GET_OR_CREATE(name) \
-  broker->GetOrCreateData(handle(object_->name(), broker->isolate()))
+ private:
+  Handle<Object> const object_;
+  ObjectDataKind const kind_;
+};
 
 class HeapObjectData : public ObjectData {
  public:
+  HeapObjectData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<HeapObject> object);
+
+  bool boolean_value() const { return boolean_value_; }
+  MapData* map() const { return map_; }
+
   static HeapObjectData* Serialize(JSHeapBroker* broker,
                                    Handle<HeapObject> object);
 
-  HeapObjectType const type;
-  MapData* const map;
+ private:
+  bool const boolean_value_;
+  MapData* const map_;
+};
+
+class PropertyCellData : public HeapObjectData {
+ public:
+  PropertyCellData(JSHeapBroker* broker, ObjectData** storage,
+                   Handle<PropertyCell> object);
+
+  PropertyDetails property_details() const { return property_details_; }
 
-  HeapObjectData(JSHeapBroker* broker_, Handle<HeapObject> object_,
-                 HeapObjectType type_)
-      : ObjectData(broker_, object_, false),
-        type(type_),
-        map(GET_OR_CREATE(map)->AsMap()) {
-    CHECK(broker_->SerializingAllowed());
+  void Serialize(JSHeapBroker* broker);
+  ObjectData* value() { return value_; }
+
+ private:
+  PropertyDetails const property_details_;
+
+  bool serialized_ = false;
+  ObjectData* value_ = nullptr;
+};
+
+void JSHeapBroker::IncrementTracingIndentation() { ++tracing_indentation_; }
+
+void JSHeapBroker::DecrementTracingIndentation() { --tracing_indentation_; }
+
+class TraceScope {
+ public:
+  TraceScope(JSHeapBroker* broker, const char* label)
+      : TraceScope(broker, static_cast<void*>(broker), label) {}
+
+  TraceScope(JSHeapBroker* broker, ObjectData* data, const char* label)
+      : TraceScope(broker, static_cast<void*>(data), label) {}
+
+  ~TraceScope() { broker_->DecrementTracingIndentation(); }
+
+ private:
+  JSHeapBroker* const broker_;
+
+  TraceScope(JSHeapBroker* broker, void* self, const char* label)
+      : broker_(broker) {
+    broker_->Trace("Running %s on %p.\n", label, self);
+    broker_->IncrementTracingIndentation();
   }
 };
 
-class PropertyCellData : public HeapObjectData {
+PropertyCellData::PropertyCellData(JSHeapBroker* broker, ObjectData** storage,
+                                   Handle<PropertyCell> object)
+    : HeapObjectData(broker, storage, object),
+      property_details_(object->property_details()) {}
+
+void PropertyCellData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "PropertyCellData::Serialize");
+  auto cell = Handle<PropertyCell>::cast(object());
+  DCHECK_NULL(value_);
+  value_ = broker->GetOrCreateData(cell->value());
+}
+
+class JSObjectField {
  public:
-  PropertyCellData(JSHeapBroker* broker_, Handle<PropertyCell> object_,
-                   HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  bool IsDouble() const { return object_ == nullptr; }
+  double AsDouble() const {
+    CHECK(IsDouble());
+    return number_;
+  }
+
+  bool IsObject() const { return object_ != nullptr; }
+  ObjectData* AsObject() const {
+    CHECK(IsObject());
+    return object_;
+  }
+
+  explicit JSObjectField(double value) : number_(value) {}
+  explicit JSObjectField(ObjectData* value) : object_(value) {}
+
+ private:
+  ObjectData* object_ = nullptr;
+  double number_ = 0;
 };
 
 class JSObjectData : public HeapObjectData {
  public:
-  JSObjectData(JSHeapBroker* broker_, Handle<JSObject> object_,
-               HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  JSObjectData(JSHeapBroker* broker, ObjectData** storage,
+               Handle<JSObject> object);
+
+  // Recursively serializes all reachable JSObjects.
+  void SerializeAsBoilerplate(JSHeapBroker* broker);
+  // Shallow serialization of {elements}.
+  void SerializeElements(JSHeapBroker* broker);
+
+  const JSObjectField& GetInobjectField(int property_index) const;
+  FixedArrayBaseData* elements() const;
+
+  // This method is only used to assert our invariants.
+  bool cow_or_empty_elements_tenured() const;
+
+  void SerializeObjectCreateMap(JSHeapBroker* broker);
+  MapData* object_create_map() const {  // Can be nullptr.
+    CHECK(serialized_object_create_map_);
+    return object_create_map_;
+  }
+
+ private:
+  void SerializeRecursive(JSHeapBroker* broker, int max_depths);
+
+  FixedArrayBaseData* elements_ = nullptr;
+  bool cow_or_empty_elements_tenured_ = false;
+  // The {serialized_as_boilerplate} flag is set when all recursively
+  // reachable JSObjects are serialized.
+  bool serialized_as_boilerplate_ = false;
+  bool serialized_elements_ = false;
+
+  ZoneVector<JSObjectField> inobject_fields_;
+
+  bool serialized_object_create_map_ = false;
+  MapData* object_create_map_ = nullptr;
 };
 
+void JSObjectData::SerializeObjectCreateMap(JSHeapBroker* broker) {
+  if (serialized_object_create_map_) return;
+  serialized_object_create_map_ = true;
+
+  TraceScope tracer(broker, this, "JSObjectData::SerializeObjectCreateMap");
+  Handle<JSObject> jsobject = Handle<JSObject>::cast(object());
+
+  if (jsobject->map()->is_prototype_map()) {
+    Handle<Object> maybe_proto_info(jsobject->map()->prototype_info(),
+                                    broker->isolate());
+    if (maybe_proto_info->IsPrototypeInfo()) {
+      auto proto_info = Handle<PrototypeInfo>::cast(maybe_proto_info);
+      if (proto_info->HasObjectCreateMap()) {
+        DCHECK_NULL(object_create_map_);
+        object_create_map_ =
+            broker->GetOrCreateData(proto_info->ObjectCreateMap())->AsMap();
+      }
+    }
+  }
+}
+
 class JSFunctionData : public JSObjectData {
  public:
-  JSGlobalProxyData* const global_proxy;
-  MapData* const initial_map;  // Can be nullptr.
-  bool const has_prototype;
-  ObjectData* const prototype;  // Can be nullptr.
-  bool const PrototypeRequiresRuntimeLookup;
-  SharedFunctionInfoData* const shared;
-
-  JSFunctionData(JSHeapBroker* broker_, Handle<JSFunction> object_,
-                 HeapObjectType type_);
+  JSFunctionData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<JSFunction> object);
+
+  bool has_initial_map() const { return has_initial_map_; }
+  bool has_prototype() const { return has_prototype_; }
+  bool PrototypeRequiresRuntimeLookup() const {
+    return PrototypeRequiresRuntimeLookup_;
+  }
+
+  void Serialize(JSHeapBroker* broker);
+
+  JSGlobalProxyData* global_proxy() const { return global_proxy_; }
+  MapData* initial_map() const { return initial_map_; }
+  ObjectData* prototype() const { return prototype_; }
+  SharedFunctionInfoData* shared() const { return shared_; }
+  int initial_map_instance_size_with_min_slack() const {
+    CHECK(serialized_);
+    return initial_map_instance_size_with_min_slack_;
+  }
+
+ private:
+  bool has_initial_map_;
+  bool has_prototype_;
+  bool PrototypeRequiresRuntimeLookup_;
+
+  bool serialized_ = false;
+
+  JSGlobalProxyData* global_proxy_ = nullptr;
+  MapData* initial_map_ = nullptr;
+  ObjectData* prototype_ = nullptr;
+  SharedFunctionInfoData* shared_ = nullptr;
+  int initial_map_instance_size_with_min_slack_;
 };
 
 class JSRegExpData : public JSObjectData {
  public:
-  JSRegExpData(JSHeapBroker* broker_, Handle<JSRegExp> object_,
-               HeapObjectType type_)
-      : JSObjectData(broker_, object_, type_) {}
+  JSRegExpData(JSHeapBroker* broker, ObjectData** storage,
+               Handle<JSRegExp> object)
+      : JSObjectData(broker, storage, object) {}
+
+  void SerializeAsRegExpBoilerplate(JSHeapBroker* broker);
+
+  ObjectData* raw_properties_or_hash() const { return raw_properties_or_hash_; }
+  ObjectData* data() const { return data_; }
+  ObjectData* source() const { return source_; }
+  ObjectData* flags() const { return flags_; }
+  ObjectData* last_index() const { return last_index_; }
+
+ private:
+  bool serialized_as_reg_exp_boilerplate_ = false;
+
+  ObjectData* raw_properties_or_hash_ = nullptr;
+  ObjectData* data_ = nullptr;
+  ObjectData* source_ = nullptr;
+  ObjectData* flags_ = nullptr;
+  ObjectData* last_index_ = nullptr;
 };
 
 class HeapNumberData : public HeapObjectData {
  public:
-  HeapNumberData(JSHeapBroker* broker_, Handle<HeapNumber> object_,
-                 HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  HeapNumberData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<HeapNumber> object)
+      : HeapObjectData(broker, storage, object), value_(object->value()) {}
+
+  double value() const { return value_; }
+
+ private:
+  double const value_;
 };
 
 class MutableHeapNumberData : public HeapObjectData {
  public:
-  MutableHeapNumberData(JSHeapBroker* broker_,
-                        Handle<MutableHeapNumber> object_, HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  MutableHeapNumberData(JSHeapBroker* broker, ObjectData** storage,
+                        Handle<MutableHeapNumber> object)
+      : HeapObjectData(broker, storage, object), value_(object->value()) {}
+
+  double value() const { return value_; }
+
+ private:
+  double const value_;
 };
 
 class ContextData : public HeapObjectData {
  public:
-  ContextData(JSHeapBroker* broker_, Handle<Context> object_,
-              HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  ContextData(JSHeapBroker* broker, ObjectData** storage,
+              Handle<Context> object);
+  void Serialize(JSHeapBroker* broker);
+
+  ContextData* previous() const {
+    CHECK(serialized_);
+    return previous_;
+  }
+
+ private:
+  bool serialized_ = false;
+  ContextData* previous_ = nullptr;
 };
 
+ContextData::ContextData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<Context> object)
+    : HeapObjectData(broker, storage, object) {}
+
+void ContextData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "ContextData::Serialize");
+  Handle<Context> context = Handle<Context>::cast(object());
+
+  DCHECK_NULL(previous_);
+  // Context::previous DCHECK-fails when called on the native context.
+  if (!context->IsNativeContext()) {
+    previous_ = broker->GetOrCreateData(context->previous())->AsContext();
+    previous_->Serialize(broker);
+  }
+}
+
 class NativeContextData : public ContextData {
  public:
-#define DECL_MEMBER(type, name) type##Data* const name;
+#define DECL_ACCESSOR(type, name) \
+  type##Data* name() const { return name##_; }
+  BROKER_NATIVE_CONTEXT_FIELDS(DECL_ACCESSOR)
+#undef DECL_ACCESSOR
+
+  const ZoneVector<MapData*>& function_maps() const {
+    CHECK(serialized_);
+    return function_maps_;
+  }
+
+  NativeContextData(JSHeapBroker* broker, ObjectData** storage,
+                    Handle<NativeContext> object);
+  void Serialize(JSHeapBroker* broker);
+
+ private:
+  bool serialized_ = false;
+#define DECL_MEMBER(type, name) type##Data* name##_ = nullptr;
   BROKER_NATIVE_CONTEXT_FIELDS(DECL_MEMBER)
 #undef DECL_MEMBER
-
-  NativeContextData(JSHeapBroker* broker_, Handle<NativeContext> object_,
-                    HeapObjectType type_)
-      : ContextData(broker_, object_, type_)
-#define INIT_MEMBER(type, name) , name(GET_OR_CREATE(name)->As##type())
-            BROKER_NATIVE_CONTEXT_FIELDS(INIT_MEMBER)
-#undef INIT_MEMBER
-  {
-  }
+  ZoneVector<MapData*> function_maps_;
 };
 
 class NameData : public HeapObjectData {
  public:
-  NameData(JSHeapBroker* broker, Handle<Name> object, HeapObjectType type)
-      : HeapObjectData(broker, object, type) {}
+  NameData(JSHeapBroker* broker, ObjectData** storage, Handle<Name> object)
+      : HeapObjectData(broker, storage, object) {}
 };
 
 class StringData : public NameData {
  public:
-  StringData(JSHeapBroker* broker, Handle<String> object, HeapObjectType type)
-      : NameData(broker, object, type),
-        length(object->length()),
-        first_char(length > 0 ? object->Get(0) : 0) {
-    int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_BINARY;
-    if (length <= kMaxLengthForDoubleConversion) {
-      to_number = StringToDouble(
-          broker->isolate(), broker->isolate()->unicode_cache(), object, flags);
-    }
-  }
+  StringData(JSHeapBroker* broker, ObjectData** storage, Handle<String> object);
 
-  int const length;
-  uint16_t const first_char;
-  base::Optional<double> to_number;
+  int length() const { return length_; }
+  uint16_t first_char() const { return first_char_; }
+  base::Optional<double> to_number() const { return to_number_; }
+  bool is_external_string() const { return is_external_string_; }
+  bool is_seq_string() const { return is_seq_string_; }
 
  private:
+  int const length_;
+  uint16_t const first_char_;
+  base::Optional<double> to_number_;
+  bool const is_external_string_;
+  bool const is_seq_string_;
+
   static constexpr int kMaxLengthForDoubleConversion = 23;
 };
 
+StringData::StringData(JSHeapBroker* broker, ObjectData** storage,
+                       Handle<String> object)
+    : NameData(broker, storage, object),
+      length_(object->length()),
+      first_char_(length_ > 0 ? object->Get(0) : 0),
+      is_external_string_(object->IsExternalString()),
+      is_seq_string_(object->IsSeqString()) {
+  int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_BINARY;
+  if (length_ <= kMaxLengthForDoubleConversion) {
+    to_number_ = StringToDouble(
+        broker->isolate(), broker->isolate()->unicode_cache(), object, flags);
+  }
+}
+
 class InternalizedStringData : public StringData {
  public:
-  InternalizedStringData(JSHeapBroker* broker,
-                         Handle<InternalizedString> object, HeapObjectType type)
-      : StringData(broker, object, type) {}
+  InternalizedStringData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<InternalizedString> object)
+      : StringData(broker, storage, object) {}
 };
 
 namespace {
@@ -258,93 +505,239 @@ bool IsInlinableFastLiteral(Handle<JSObject> boilerplate) {
 
 class AllocationSiteData : public HeapObjectData {
  public:
-  AllocationSiteData(JSHeapBroker* broker, Handle<AllocationSite> object_,
-                     HeapObjectType type_)
-      : HeapObjectData(broker, object_, type_),
-        PointsToLiteral(object_->PointsToLiteral()),
-        GetPretenureMode(object_->GetPretenureMode()),
-        nested_site(GET_OR_CREATE(nested_site)) {
-    if (PointsToLiteral) {
-      if (IsInlinableFastLiteral(
-              handle(object_->boilerplate(), broker->isolate()))) {
-        boilerplate = GET_OR_CREATE(boilerplate)->AsJSObject();
-      }
-    } else {
-      GetElementsKind = object_->GetElementsKind();
-      CanInlineCall = object_->CanInlineCall();
-    }
-  }
+  AllocationSiteData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<AllocationSite> object);
+  void SerializeBoilerplate(JSHeapBroker* broker);
 
-  bool const PointsToLiteral;
-  PretenureFlag const GetPretenureMode;
-  ObjectData* const nested_site;
-  JSObjectData* boilerplate = nullptr;
+  bool PointsToLiteral() const { return PointsToLiteral_; }
+  PretenureFlag GetPretenureMode() const { return GetPretenureMode_; }
+  ObjectData* nested_site() const { return nested_site_; }
+  bool IsFastLiteral() const { return IsFastLiteral_; }
+  JSObjectData* boilerplate() const { return boilerplate_; }
 
   // These are only valid if PointsToLiteral is false.
-  ElementsKind GetElementsKind = NO_ELEMENTS;
-  bool CanInlineCall = false;
+  ElementsKind GetElementsKind() const { return GetElementsKind_; }
+  bool CanInlineCall() const { return CanInlineCall_; }
+
+ private:
+  bool const PointsToLiteral_;
+  PretenureFlag const GetPretenureMode_;
+  ObjectData* nested_site_ = nullptr;
+  bool IsFastLiteral_ = false;
+  JSObjectData* boilerplate_ = nullptr;
+  ElementsKind GetElementsKind_ = NO_ELEMENTS;
+  bool CanInlineCall_ = false;
+  bool serialized_boilerplate_ = false;
 };
 
 // Only used in JSNativeContextSpecialization.
 class ScriptContextTableData : public HeapObjectData {
  public:
-  ScriptContextTableData(JSHeapBroker* broker_,
-                         Handle<ScriptContextTable> object_,
-                         HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  ScriptContextTableData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<ScriptContextTable> object)
+      : HeapObjectData(broker, storage, object) {}
+};
+
+struct PropertyDescriptor {
+  NameData* key = nullptr;
+  PropertyDetails details = PropertyDetails::Empty();
+  FieldIndex field_index;
+  MapData* field_owner = nullptr;
+  ObjectData* field_type = nullptr;
+  bool is_unboxed_double_field = false;
 };
 
 class MapData : public HeapObjectData {
  public:
-  InstanceType const instance_type;
-  int const instance_size;
-  byte const bit_field;
-  byte const bit_field2;
-  uint32_t const bit_field3;
-
-  MapData(JSHeapBroker* broker_, Handle<Map> object_, HeapObjectType type_);
+  MapData(JSHeapBroker* broker, ObjectData** storage, Handle<Map> object);
+
+  InstanceType instance_type() const { return instance_type_; }
+  int instance_size() const { return instance_size_; }
+  byte bit_field() const { return bit_field_; }
+  byte bit_field2() const { return bit_field2_; }
+  uint32_t bit_field3() const { return bit_field3_; }
+  bool can_be_deprecated() const { return can_be_deprecated_; }
+  bool can_transition() const { return can_transition_; }
+  int in_object_properties_start_in_words() const {
+    CHECK(InstanceTypeChecker::IsJSObject(instance_type()));
+    return in_object_properties_start_in_words_;
+  }
+  int in_object_properties() const {
+    CHECK(InstanceTypeChecker::IsJSObject(instance_type()));
+    return in_object_properties_;
+  }
 
   // Extra information.
-  void SerializeElementsKindGeneralizations();
-  const ZoneVector<MapData*>& elements_kind_generalizations() {
+
+  void SerializeElementsKindGeneralizations(JSHeapBroker* broker);
+  const ZoneVector<MapData*>& elements_kind_generalizations() const {
+    CHECK(serialized_elements_kind_generalizations_);
     return elements_kind_generalizations_;
   }
 
+  // Serialize the own part of the descriptor array and, recursively, that of
+  // any field owner.
+  void SerializeOwnDescriptors(JSHeapBroker* broker);
+  DescriptorArrayData* instance_descriptors() const {
+    CHECK(serialized_own_descriptors_);
+    return instance_descriptors_;
+  }
+
+  void SerializeConstructorOrBackpointer(JSHeapBroker* broker);
+  ObjectData* constructor_or_backpointer() const {
+    CHECK(serialized_constructor_or_backpointer_);
+    return constructor_or_backpointer_;
+  }
+
+  void SerializePrototype(JSHeapBroker* broker);
+  ObjectData* prototype() const {
+    CHECK(serialized_prototype_);
+    return prototype_;
+  }
+
  private:
+  InstanceType const instance_type_;
+  int const instance_size_;
+  byte const bit_field_;
+  byte const bit_field2_;
+  uint32_t const bit_field3_;
+  bool const can_be_deprecated_;
+  bool const can_transition_;
+  int const in_object_properties_start_in_words_;
+  int const in_object_properties_;
+
+  bool serialized_elements_kind_generalizations_ = false;
   ZoneVector<MapData*> elements_kind_generalizations_;
+
+  bool serialized_own_descriptors_ = false;
+  DescriptorArrayData* instance_descriptors_ = nullptr;
+
+  bool serialized_constructor_or_backpointer_ = false;
+  ObjectData* constructor_or_backpointer_ = nullptr;
+
+  bool serialized_prototype_ = false;
+  ObjectData* prototype_ = nullptr;
 };
 
-MapData::MapData(JSHeapBroker* broker_, Handle<Map> object_,
-                 HeapObjectType type_)
-    : HeapObjectData(broker_, object_, type_),
-      instance_type(object_->instance_type()),
-      instance_size(object_->instance_size()),
-      bit_field(object_->bit_field()),
-      bit_field2(object_->bit_field2()),
-      bit_field3(object_->bit_field3()),
+AllocationSiteData::AllocationSiteData(JSHeapBroker* broker,
+                                       ObjectData** storage,
+                                       Handle<AllocationSite> object)
+    : HeapObjectData(broker, storage, object),
+      PointsToLiteral_(object->PointsToLiteral()),
+      GetPretenureMode_(object->GetPretenureMode()) {
+  if (PointsToLiteral_) {
+    IsFastLiteral_ = IsInlinableFastLiteral(
+        handle(object->boilerplate(), broker->isolate()));
+  } else {
+    GetElementsKind_ = object->GetElementsKind();
+    CanInlineCall_ = object->CanInlineCall();
+  }
+}
+
+void AllocationSiteData::SerializeBoilerplate(JSHeapBroker* broker) {
+  if (serialized_boilerplate_) return;
+  serialized_boilerplate_ = true;
+
+  TraceScope tracer(broker, this, "AllocationSiteData::SerializeBoilerplate");
+  Handle<AllocationSite> site = Handle<AllocationSite>::cast(object());
+
+  CHECK(IsFastLiteral_);
+  DCHECK_NULL(boilerplate_);
+  boilerplate_ = broker->GetOrCreateData(site->boilerplate())->AsJSObject();
+  boilerplate_->SerializeAsBoilerplate(broker);
+
+  DCHECK_NULL(nested_site_);
+  nested_site_ = broker->GetOrCreateData(site->nested_site());
+  if (nested_site_->IsAllocationSite()) {
+    nested_site_->AsAllocationSite()->SerializeBoilerplate(broker);
+  }
+}
+
+HeapObjectData::HeapObjectData(JSHeapBroker* broker, ObjectData** storage,
+                               Handle<HeapObject> object)
+    : ObjectData(broker, storage, object, kSerializedHeapObject),
+      boolean_value_(object->BooleanValue(broker->isolate())),
+      // We have to use a raw cast below instead of AsMap() because of
+      // recursion. AsMap() would call IsMap(), which accesses the
+      // instance_type_ member. In the case of constructing the MapData for the
+      // meta map (whose map is itself), this member has not yet been
+      // initialized.
+      map_(static_cast<MapData*>(broker->GetOrCreateData(object->map()))) {
+  CHECK(broker->SerializingAllowed());
+}
+
+MapData::MapData(JSHeapBroker* broker, ObjectData** storage, Handle<Map> object)
+    : HeapObjectData(broker, storage, object),
+      instance_type_(object->instance_type()),
+      instance_size_(object->instance_size()),
+      bit_field_(object->bit_field()),
+      bit_field2_(object->bit_field2()),
+      bit_field3_(object->bit_field3()),
+      can_be_deprecated_(object->NumberOfOwnDescriptors() > 0
+                             ? object->CanBeDeprecated()
+                             : false),
+      can_transition_(object->CanTransition()),
+      in_object_properties_start_in_words_(
+          object->IsJSObjectMap() ? object->GetInObjectPropertiesStartInWords()
+                                  : 0),
+      in_object_properties_(
+          object->IsJSObjectMap() ? object->GetInObjectProperties() : 0),
       elements_kind_generalizations_(broker->zone()) {}
 
-JSFunctionData::JSFunctionData(JSHeapBroker* broker_,
-                               Handle<JSFunction> object_, HeapObjectType type_)
-    : JSObjectData(broker_, object_, type_),
-      global_proxy(GET_OR_CREATE(global_proxy)->AsJSGlobalProxy()),
-      initial_map(object_->has_prototype_slot() && object_->has_initial_map()
-                      ? GET_OR_CREATE(initial_map)->AsMap()
-                      : nullptr),
-      has_prototype(object_->has_prototype_slot() && object_->has_prototype()),
-      prototype(has_prototype ? GET_OR_CREATE(prototype) : nullptr),
-      PrototypeRequiresRuntimeLookup(object_->PrototypeRequiresRuntimeLookup()),
-      shared(GET_OR_CREATE(shared)->AsSharedFunctionInfo()) {
-  if (initial_map != nullptr && initial_map->instance_type == JS_ARRAY_TYPE) {
-    initial_map->SerializeElementsKindGeneralizations();
-  }
-}
-
-void MapData::SerializeElementsKindGeneralizations() {
-  broker->Trace("Computing ElementsKind generalizations of %p.\n", *object);
-  DCHECK_EQ(instance_type, JS_ARRAY_TYPE);
-  MapRef self(this);
+JSFunctionData::JSFunctionData(JSHeapBroker* broker, ObjectData** storage,
+                               Handle<JSFunction> object)
+    : JSObjectData(broker, storage, object),
+      has_initial_map_(object->has_prototype_slot() &&
+                       object->has_initial_map()),
+      has_prototype_(object->has_prototype_slot() && object->has_prototype()),
+      PrototypeRequiresRuntimeLookup_(
+          object->PrototypeRequiresRuntimeLookup()) {}
+
+void JSFunctionData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "JSFunctionData::Serialize");
+  Handle<JSFunction> function = Handle<JSFunction>::cast(object());
+
+  DCHECK_NULL(global_proxy_);
+  DCHECK_NULL(initial_map_);
+  DCHECK_NULL(prototype_);
+  DCHECK_NULL(shared_);
+
+  global_proxy_ =
+      broker->GetOrCreateData(function->global_proxy())->AsJSGlobalProxy();
+  shared_ = broker->GetOrCreateData(function->shared())->AsSharedFunctionInfo();
+  initial_map_ = has_initial_map()
+                     ? broker->GetOrCreateData(function->initial_map())->AsMap()
+                     : nullptr;
+  prototype_ = has_prototype() ? broker->GetOrCreateData(function->prototype())
+                               : nullptr;
+
+  if (initial_map_ != nullptr) {
+    initial_map_instance_size_with_min_slack_ =
+        function->ComputeInstanceSizeWithMinSlack(broker->isolate());
+    if (initial_map_->instance_type() == JS_ARRAY_TYPE) {
+      initial_map_->SerializeElementsKindGeneralizations(broker);
+    }
+    initial_map_->SerializeConstructorOrBackpointer(broker);
+    // TODO(neis): This is currently only needed for native_context's
+    // object_function, as used by GetObjectCreateMap. If no further use sites
+    // show up, we should move this into NativeContextData::Serialize.
+    initial_map_->SerializePrototype(broker);
+  }
+}
+
+void MapData::SerializeElementsKindGeneralizations(JSHeapBroker* broker) {
+  if (serialized_elements_kind_generalizations_) return;
+  serialized_elements_kind_generalizations_ = true;
+
+  TraceScope tracer(broker, this,
+                    "MapData::SerializeElementsKindGeneralizations");
+  DCHECK_EQ(instance_type(), JS_ARRAY_TYPE);
+  MapRef self(broker, this);
   ElementsKind from_kind = self.elements_kind();
+  DCHECK(elements_kind_generalizations_.empty());
   for (int i = FIRST_FAST_ELEMENTS_KIND; i <= LAST_FAST_ELEMENTS_KIND; i++) {
     ElementsKind to_kind = static_cast<ElementsKind>(i);
     if (IsMoreGeneralElementsKindTransition(from_kind, to_kind)) {
@@ -356,195 +749,583 @@ void MapData::SerializeElementsKindGeneralizations() {
   }
 }
 
+class DescriptorArrayData : public HeapObjectData {
+ public:
+  DescriptorArrayData(JSHeapBroker* broker, ObjectData** storage,
+                      Handle<DescriptorArray> object)
+      : HeapObjectData(broker, storage, object), contents_(broker->zone()) {}
+
+  ZoneVector<PropertyDescriptor>& contents() { return contents_; }
+
+ private:
+  ZoneVector<PropertyDescriptor> contents_;
+};
+
 class FeedbackVectorData : public HeapObjectData {
  public:
   const ZoneVector<ObjectData*>& feedback() { return feedback_; }
 
-  FeedbackVectorData(JSHeapBroker* broker_, Handle<FeedbackVector> object_,
-                     HeapObjectType type_);
+  FeedbackVectorData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<FeedbackVector> object);
+
+  void SerializeSlots(JSHeapBroker* broker);
 
  private:
+  bool serialized_ = false;
   ZoneVector<ObjectData*> feedback_;
 };
 
-FeedbackVectorData::FeedbackVectorData(JSHeapBroker* broker_,
-                                       Handle<FeedbackVector> object_,
-                                       HeapObjectType type_)
-    : HeapObjectData(broker_, object_, type_), feedback_(broker_->zone()) {
-  feedback_.reserve(object_->length());
-  for (int i = 0; i < object_->length(); ++i) {
-    MaybeObject* value = object_->get(i);
-    feedback_.push_back(value->IsObject()
-                            ? broker->GetOrCreateData(
-                                  handle(value->ToObject(), broker->isolate()))
-                            : nullptr);
+FeedbackVectorData::FeedbackVectorData(JSHeapBroker* broker,
+                                       ObjectData** storage,
+                                       Handle<FeedbackVector> object)
+    : HeapObjectData(broker, storage, object), feedback_(broker->zone()) {}
+
+void FeedbackVectorData::SerializeSlots(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "FeedbackVectorData::SerializeSlots");
+  Handle<FeedbackVector> vector = Handle<FeedbackVector>::cast(object());
+  DCHECK(feedback_.empty());
+  feedback_.reserve(vector->length());
+  for (int i = 0; i < vector->length(); ++i) {
+    MaybeObject* value = vector->get(i);
+    ObjectData* slot_value =
+        value->IsObject() ? broker->GetOrCreateData(value->cast<Object>())
+                          : nullptr;
+    feedback_.push_back(slot_value);
+    if (slot_value == nullptr) continue;
+
+    if (slot_value->IsAllocationSite() &&
+        slot_value->AsAllocationSite()->IsFastLiteral()) {
+      slot_value->AsAllocationSite()->SerializeBoilerplate(broker);
+    } else if (slot_value->IsJSRegExp()) {
+      slot_value->AsJSRegExp()->SerializeAsRegExpBoilerplate(broker);
+    }
   }
-  DCHECK_EQ(object_->length(), feedback_.size());
+  DCHECK_EQ(vector->length(), feedback_.size());
+  broker->Trace("Copied %zu slots.\n", feedback_.size());
 }
 
 class FixedArrayBaseData : public HeapObjectData {
  public:
-  int const length;
+  FixedArrayBaseData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<FixedArrayBase> object)
+      : HeapObjectData(broker, storage, object), length_(object->length()) {}
+
+  int length() const { return length_; }
 
-  FixedArrayBaseData(JSHeapBroker* broker_, Handle<FixedArrayBase> object_,
-                     HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_), length(object_->length()) {}
+ private:
+  int const length_;
 };
 
+JSObjectData::JSObjectData(JSHeapBroker* broker, ObjectData** storage,
+                           Handle<JSObject> object)
+    : HeapObjectData(broker, storage, object),
+      inobject_fields_(broker->zone()) {}
+
 class FixedArrayData : public FixedArrayBaseData {
  public:
-  FixedArrayData(JSHeapBroker* broker_, Handle<FixedArray> object_,
-                 HeapObjectType type_)
-      : FixedArrayBaseData(broker_, object_, type_) {}
+  FixedArrayData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<FixedArray> object);
+
+  // Creates all elements of the fixed array.
+  void SerializeContents(JSHeapBroker* broker);
+
+  ObjectData* Get(int i) const;
+
+ private:
+  bool serialized_contents_ = false;
+  ZoneVector<ObjectData*> contents_;
 };
 
+void FixedArrayData::SerializeContents(JSHeapBroker* broker) {
+  if (serialized_contents_) return;
+  serialized_contents_ = true;
+
+  TraceScope tracer(broker, this, "FixedArrayData::SerializeContents");
+  Handle<FixedArray> array = Handle<FixedArray>::cast(object());
+  CHECK_EQ(array->length(), length());
+  CHECK(contents_.empty());
+  contents_.reserve(static_cast<size_t>(length()));
+
+  for (int i = 0; i < length(); i++) {
+    Handle<Object> value(array->get(i), broker->isolate());
+    contents_.push_back(broker->GetOrCreateData(value));
+  }
+  broker->Trace("Copied %zu elements.\n", contents_.size());
+}
+
+FixedArrayData::FixedArrayData(JSHeapBroker* broker, ObjectData** storage,
+                               Handle<FixedArray> object)
+    : FixedArrayBaseData(broker, storage, object), contents_(broker->zone()) {}
+
 class FixedDoubleArrayData : public FixedArrayBaseData {
  public:
-  FixedDoubleArrayData(JSHeapBroker* broker_, Handle<FixedDoubleArray> object_,
-                       HeapObjectType type_)
-      : FixedArrayBaseData(broker_, object_, type_) {}
+  FixedDoubleArrayData(JSHeapBroker* broker, ObjectData** storage,
+                       Handle<FixedDoubleArray> object);
+
+  // Serializes all elements of the fixed array.
+  void SerializeContents(JSHeapBroker* broker);
+
+  Float64 Get(int i) const;
+
+ private:
+  bool serialized_contents_ = false;
+  ZoneVector<Float64> contents_;
 };
 
+FixedDoubleArrayData::FixedDoubleArrayData(JSHeapBroker* broker,
+                                           ObjectData** storage,
+                                           Handle<FixedDoubleArray> object)
+    : FixedArrayBaseData(broker, storage, object), contents_(broker->zone()) {}
+
+void FixedDoubleArrayData::SerializeContents(JSHeapBroker* broker) {
+  if (serialized_contents_) return;
+  serialized_contents_ = true;
+
+  TraceScope tracer(broker, this, "FixedDoubleArrayData::SerializeContents");
+  Handle<FixedDoubleArray> self = Handle<FixedDoubleArray>::cast(object());
+  CHECK_EQ(self->length(), length());
+  CHECK(contents_.empty());
+  contents_.reserve(static_cast<size_t>(length()));
+
+  for (int i = 0; i < length(); i++) {
+    contents_.push_back(Float64::FromBits(self->get_representation(i)));
+  }
+  broker->Trace("Copied %zu elements.\n", contents_.size());
+}
+
 class BytecodeArrayData : public FixedArrayBaseData {
  public:
-  int const register_count;
+  int register_count() const { return register_count_; }
 
-  BytecodeArrayData(JSHeapBroker* broker_, Handle<BytecodeArray> object_,
-                    HeapObjectType type_)
-      : FixedArrayBaseData(broker_, object_, type_),
-        register_count(object_->register_count()) {}
+  BytecodeArrayData(JSHeapBroker* broker, ObjectData** storage,
+                    Handle<BytecodeArray> object)
+      : FixedArrayBaseData(broker, storage, object),
+        register_count_(object->register_count()) {}
+
+ private:
+  int const register_count_;
 };
 
 class JSArrayData : public JSObjectData {
  public:
-  JSArrayData(JSHeapBroker* broker_, Handle<JSArray> object_,
-              HeapObjectType type_)
-      : JSObjectData(broker_, object_, type_) {}
+  JSArrayData(JSHeapBroker* broker, ObjectData** storage,
+              Handle<JSArray> object);
+  void Serialize(JSHeapBroker* broker);
+
+  ObjectData* length() const { return length_; }
+
+ private:
+  bool serialized_ = false;
+  ObjectData* length_ = nullptr;
 };
 
+JSArrayData::JSArrayData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<JSArray> object)
+    : JSObjectData(broker, storage, object) {}
+
+void JSArrayData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "JSArrayData::Serialize");
+  Handle<JSArray> jsarray = Handle<JSArray>::cast(object());
+  DCHECK_NULL(length_);
+  length_ = broker->GetOrCreateData(jsarray->length());
+}
+
 class ScopeInfoData : public HeapObjectData {
  public:
-  ScopeInfoData(JSHeapBroker* broker_, Handle<ScopeInfo> object_,
-                HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  ScopeInfoData(JSHeapBroker* broker, ObjectData** storage,
+                Handle<ScopeInfo> object);
+
+  int context_length() const { return context_length_; }
+
+ private:
+  int const context_length_;
 };
 
+ScopeInfoData::ScopeInfoData(JSHeapBroker* broker, ObjectData** storage,
+                             Handle<ScopeInfo> object)
+    : HeapObjectData(broker, storage, object),
+      context_length_(object->ContextLength()) {}
+
 class SharedFunctionInfoData : public HeapObjectData {
  public:
-  int const builtin_id;
-  BytecodeArrayData* const GetBytecodeArray;  // Can be nullptr.
-#define DECL_MEMBER(type, name) type const name;
-  BROKER_SFI_FIELDS(DECL_MEMBER)
-#undef DECL_MEMBER
-
-  SharedFunctionInfoData(JSHeapBroker* broker_,
-                         Handle<SharedFunctionInfo> object_,
-                         HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_),
-        builtin_id(object_->HasBuiltinId() ? object_->builtin_id()
+  int builtin_id() const { return builtin_id_; }
+  BytecodeArrayData* GetBytecodeArray() const { return GetBytecodeArray_; }
+#define DECL_ACCESSOR(type, name) \
+  type name() const { return name##_; }
+  BROKER_SFI_FIELDS(DECL_ACCESSOR)
+#undef DECL_ACCESSOR
+
+  SharedFunctionInfoData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<SharedFunctionInfo> object)
+      : HeapObjectData(broker, storage, object),
+        builtin_id_(object->HasBuiltinId() ? object->builtin_id()
                                            : Builtins::kNoBuiltinId),
-        GetBytecodeArray(
-            object_->HasBytecodeArray()
-                ? GET_OR_CREATE(GetBytecodeArray)->AsBytecodeArray()
+        GetBytecodeArray_(
+            object->HasBytecodeArray()
+                ? broker->GetOrCreateData(object->GetBytecodeArray())
+                      ->AsBytecodeArray()
                 : nullptr)
-#define INIT_MEMBER(type, name) , name(object_->name())
+#define INIT_MEMBER(type, name) , name##_(object->name())
             BROKER_SFI_FIELDS(INIT_MEMBER)
 #undef INIT_MEMBER
   {
-    DCHECK_EQ(HasBuiltinId, builtin_id != Builtins::kNoBuiltinId);
-    DCHECK_EQ(HasBytecodeArray, GetBytecodeArray != nullptr);
+    DCHECK_EQ(HasBuiltinId_, builtin_id_ != Builtins::kNoBuiltinId);
+    DCHECK_EQ(HasBytecodeArray_, GetBytecodeArray_ != nullptr);
   }
+
+ private:
+  int const builtin_id_;
+  BytecodeArrayData* const GetBytecodeArray_;
+#define DECL_MEMBER(type, name) type const name##_;
+  BROKER_SFI_FIELDS(DECL_MEMBER)
+#undef DECL_MEMBER
 };
 
 class ModuleData : public HeapObjectData {
  public:
-  ModuleData(JSHeapBroker* broker_, Handle<Module> object_,
-             HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  ModuleData(JSHeapBroker* broker, ObjectData** storage, Handle<Module> object);
+  void Serialize(JSHeapBroker* broker);
+
+  CellData* GetCell(int cell_index) const;
+
+ private:
+  bool serialized_ = false;
+  ZoneVector<CellData*> imports_;
+  ZoneVector<CellData*> exports_;
 };
 
+ModuleData::ModuleData(JSHeapBroker* broker, ObjectData** storage,
+                       Handle<Module> object)
+    : HeapObjectData(broker, storage, object),
+      imports_(broker->zone()),
+      exports_(broker->zone()) {}
+
+CellData* ModuleData::GetCell(int cell_index) const {
+  CHECK(serialized_);
+  CellData* cell;
+  switch (ModuleDescriptor::GetCellIndexKind(cell_index)) {
+    case ModuleDescriptor::kImport:
+      cell = imports_.at(Module::ImportIndex(cell_index));
+      break;
+    case ModuleDescriptor::kExport:
+      cell = exports_.at(Module::ExportIndex(cell_index));
+      break;
+    case ModuleDescriptor::kInvalid:
+      UNREACHABLE();
+      break;
+  }
+  CHECK_NOT_NULL(cell);
+  return cell;
+}
+
+void ModuleData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "ModuleData::Serialize");
+  Handle<Module> module = Handle<Module>::cast(object());
+
+  // TODO(neis): We could be smarter and only serialize the cells we care about.
+  // TODO(neis): Define a helper for serializing a FixedArray into a ZoneVector.
+
+  DCHECK(imports_.empty());
+  Handle<FixedArray> imports(module->regular_imports(), broker->isolate());
+  int const imports_length = imports->length();
+  imports_.reserve(imports_length);
+  for (int i = 0; i < imports_length; ++i) {
+    imports_.push_back(broker->GetOrCreateData(imports->get(i))->AsCell());
+  }
+  broker->Trace("Copied %zu imports.\n", imports_.size());
+
+  DCHECK(exports_.empty());
+  Handle<FixedArray> exports(module->regular_exports(), broker->isolate());
+  int const exports_length = exports->length();
+  exports_.reserve(exports_length);
+  for (int i = 0; i < exports_length; ++i) {
+    exports_.push_back(broker->GetOrCreateData(exports->get(i))->AsCell());
+  }
+  broker->Trace("Copied %zu exports.\n", exports_.size());
+}
+
 class CellData : public HeapObjectData {
  public:
-  CellData(JSHeapBroker* broker_, Handle<Cell> object_, HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  CellData(JSHeapBroker* broker, ObjectData** storage, Handle<Cell> object)
+      : HeapObjectData(broker, storage, object) {}
 };
 
 class JSGlobalProxyData : public JSObjectData {
  public:
-  JSGlobalProxyData(JSHeapBroker* broker_, Handle<JSGlobalProxy> object_,
-                    HeapObjectType type_)
-      : JSObjectData(broker_, object_, type_) {}
+  JSGlobalProxyData(JSHeapBroker* broker, ObjectData** storage,
+                    Handle<JSGlobalProxy> object)
+      : JSObjectData(broker, storage, object) {}
 };
 
 class CodeData : public HeapObjectData {
  public:
-  CodeData(JSHeapBroker* broker_, Handle<Code> object_, HeapObjectType type_)
-      : HeapObjectData(broker_, object_, type_) {}
+  CodeData(JSHeapBroker* broker, ObjectData** storage, Handle<Code> object)
+      : HeapObjectData(broker, storage, object) {}
 };
 
-#define DEFINE_IS_AND_AS(Name)                                          \
-  bool ObjectData::Is##Name() const {                                   \
-    if (broker->mode() == JSHeapBroker::kDisabled) {                    \
-      AllowHandleDereference allow_handle_dereference;                  \
-      return object->Is##Name();                                        \
-    }                                                                   \
-    if (is_smi) return false;                                           \
-    InstanceType instance_type =                                        \
-        static_cast<const HeapObjectData*>(this)->type.instance_type(); \
-    return InstanceTypeChecker::Is##Name(instance_type);                \
-  }                                                                     \
-  Name##Data* ObjectData::As##Name() {                                  \
-    CHECK_NE(broker->mode(), JSHeapBroker::kDisabled);                  \
-    CHECK(Is##Name());                                                  \
-    return static_cast<Name##Data*>(this);                              \
+#define DEFINE_IS_AND_AS(Name)                                            \
+  bool ObjectData::Is##Name() const {                                     \
+    if (kind() == kUnserializedHeapObject) {                              \
+      AllowHandleDereference allow_handle_dereference;                    \
+      return object()->Is##Name();                                        \
+    }                                                                     \
+    if (is_smi()) return false;                                           \
+    InstanceType instance_type =                                          \
+        static_cast<const HeapObjectData*>(this)->map()->instance_type(); \
+    return InstanceTypeChecker::Is##Name(instance_type);                  \
+  }                                                                       \
+  Name##Data* ObjectData::As##Name() {                                    \
+    CHECK_EQ(kind(), kSerializedHeapObject);                              \
+    CHECK(Is##Name());                                                    \
+    return static_cast<Name##Data*>(this);                                \
   }
 HEAP_BROKER_OBJECT_LIST(DEFINE_IS_AND_AS)
 #undef DEFINE_IS_AND_AS
 
-ObjectData* ObjectData::Serialize(JSHeapBroker* broker, Handle<Object> object) {
-  CHECK(broker->SerializingAllowed());
-  return object->IsSmi() ? new (broker->zone()) ObjectData(broker, object, true)
-                         : HeapObjectData::Serialize(
-                               broker, Handle<HeapObject>::cast(object));
+const JSObjectField& JSObjectData::GetInobjectField(int property_index) const {
+  CHECK_LT(static_cast<size_t>(property_index), inobject_fields_.size());
+  return inobject_fields_[property_index];
 }
 
-HeapObjectData* HeapObjectData::Serialize(JSHeapBroker* broker,
-                                          Handle<HeapObject> object) {
-  CHECK(broker->SerializingAllowed());
-  Handle<Map> map(object->map(), broker->isolate());
-  HeapObjectType type = broker->HeapObjectTypeFromMap(map);
+bool JSObjectData::cow_or_empty_elements_tenured() const {
+  return cow_or_empty_elements_tenured_;
+}
+
+FixedArrayBaseData* JSObjectData::elements() const { return elements_; }
 
-#define RETURN_CREATE_DATA_IF_MATCH(name)                     \
-  if (object->Is##name()) {                                   \
-    return new (broker->zone())                               \
-        name##Data(broker, Handle<name>::cast(object), type); \
+void JSObjectData::SerializeAsBoilerplate(JSHeapBroker* broker) {
+  SerializeRecursive(broker, kMaxFastLiteralDepth);
+}
+
+void JSObjectData::SerializeElements(JSHeapBroker* broker) {
+  if (serialized_elements_) return;
+  serialized_elements_ = true;
+
+  TraceScope tracer(broker, this, "JSObjectData::SerializeElements");
+  Handle<JSObject> boilerplate = Handle<JSObject>::cast(object());
+  Handle<FixedArrayBase> elements_object(boilerplate->elements(),
+                                         broker->isolate());
+  DCHECK_NULL(elements_);
+  elements_ = broker->GetOrCreateData(elements_object)->AsFixedArrayBase();
+}
+
+void MapData::SerializeConstructorOrBackpointer(JSHeapBroker* broker) {
+  if (serialized_constructor_or_backpointer_) return;
+  serialized_constructor_or_backpointer_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeConstructorOrBackpointer");
+  Handle<Map> map = Handle<Map>::cast(object());
+  DCHECK_NULL(constructor_or_backpointer_);
+  constructor_or_backpointer_ =
+      broker->GetOrCreateData(map->constructor_or_backpointer());
+}
+
+void MapData::SerializePrototype(JSHeapBroker* broker) {
+  if (serialized_prototype_) return;
+  serialized_prototype_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializePrototype");
+  Handle<Map> map = Handle<Map>::cast(object());
+  DCHECK_NULL(prototype_);
+  prototype_ = broker->GetOrCreateData(map->prototype());
+}
+
+void MapData::SerializeOwnDescriptors(JSHeapBroker* broker) {
+  if (serialized_own_descriptors_) return;
+  serialized_own_descriptors_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeOwnDescriptors");
+  Handle<Map> map = Handle<Map>::cast(object());
+
+  DCHECK_NULL(instance_descriptors_);
+  instance_descriptors_ =
+      broker->GetOrCreateData(map->instance_descriptors())->AsDescriptorArray();
+
+  int const number_of_own = map->NumberOfOwnDescriptors();
+  ZoneVector<PropertyDescriptor>& contents = instance_descriptors_->contents();
+  int const current_size = static_cast<int>(contents.size());
+  if (number_of_own <= current_size) return;
+
+  Isolate* const isolate = broker->isolate();
+  auto descriptors =
+      Handle<DescriptorArray>::cast(instance_descriptors_->object());
+  CHECK_EQ(*descriptors, map->instance_descriptors());
+  contents.reserve(number_of_own);
+
+  // Copy the new descriptors.
+  for (int i = current_size; i < number_of_own; ++i) {
+    PropertyDescriptor d;
+    d.key = broker->GetOrCreateData(descriptors->GetKey(i))->AsName();
+    d.details = descriptors->GetDetails(i);
+    if (d.details.location() == kField) {
+      d.field_index = FieldIndex::ForDescriptor(*map, i);
+      d.field_owner =
+          broker->GetOrCreateData(map->FindFieldOwner(isolate, i))->AsMap();
+      d.field_type = broker->GetOrCreateData(descriptors->GetFieldType(i));
+      d.is_unboxed_double_field = map->IsUnboxedDoubleField(d.field_index);
+      // Recurse.
+    }
+    contents.push_back(d);
+  }
+  CHECK_EQ(number_of_own, contents.size());
+
+  // Recurse on the new owner maps.
+  for (int i = current_size; i < number_of_own; ++i) {
+    const PropertyDescriptor& d = contents[i];
+    if (d.details.location() == kField) {
+      CHECK_LE(
+          Handle<Map>::cast(d.field_owner->object())->NumberOfOwnDescriptors(),
+          number_of_own);
+      d.field_owner->SerializeOwnDescriptors(broker);
+    }
   }
-  HEAP_BROKER_OBJECT_LIST(RETURN_CREATE_DATA_IF_MATCH)
-#undef RETURN_CREATE_DATA_IF_MATCH
-  UNREACHABLE();
+
+  broker->Trace("Copied %zu descriptors into %p (%zu total).\n",
+                number_of_own - current_size, instance_descriptors_,
+                number_of_own);
 }
 
-bool ObjectRef::equals(const ObjectRef& other) const {
-  return data_ == other.data_;
+void JSObjectData::SerializeRecursive(JSHeapBroker* broker, int depth) {
+  if (serialized_as_boilerplate_) return;
+  serialized_as_boilerplate_ = true;
+
+  TraceScope tracer(broker, this, "JSObjectData::SerializeRecursive");
+  Handle<JSObject> boilerplate = Handle<JSObject>::cast(object());
+
+  // We only serialize boilerplates that pass the IsInlinableFastLiteral
+  // check, so we only do a sanity check on the depth here.
+  CHECK_GT(depth, 0);
+  CHECK(!boilerplate->map()->is_deprecated());
+
+  // Serialize the elements.
+  Isolate* const isolate = broker->isolate();
+  Handle<FixedArrayBase> elements_object(boilerplate->elements(), isolate);
+
+  // Boilerplates need special serialization - we need to make sure COW arrays
+  // are tenured. Boilerplate objects should only be reachable from their
+  // allocation site, so it is safe to assume that the elements have not been
+  // serialized yet.
+
+  bool const empty_or_cow =
+      elements_object->length() == 0 ||
+      elements_object->map() == ReadOnlyRoots(isolate).fixed_cow_array_map();
+  if (empty_or_cow) {
+    // We need to make sure copy-on-write elements are tenured.
+    if (Heap::InNewSpace(*elements_object)) {
+      elements_object = isolate->factory()->CopyAndTenureFixedCOWArray(
+          Handle<FixedArray>::cast(elements_object));
+      boilerplate->set_elements(*elements_object);
+    }
+    cow_or_empty_elements_tenured_ = true;
+  }
+
+  DCHECK_NULL(elements_);
+  elements_ = broker->GetOrCreateData(elements_object)->AsFixedArrayBase();
+
+  if (empty_or_cow) {
+    // No need to do anything here. Empty or copy-on-write elements
+    // do not need to be serialized because we only need to store the elements
+    // reference to the allocated object.
+  } else if (boilerplate->HasSmiOrObjectElements()) {
+    elements_->AsFixedArray()->SerializeContents(broker);
+    Handle<FixedArray> fast_elements =
+        Handle<FixedArray>::cast(elements_object);
+    int length = elements_object->length();
+    for (int i = 0; i < length; i++) {
+      Handle<Object> value(fast_elements->get(i), isolate);
+      if (value->IsJSObject()) {
+        ObjectData* value_data = broker->GetOrCreateData(value);
+        value_data->AsJSObject()->SerializeRecursive(broker, depth - 1);
+      }
+    }
+  } else {
+    CHECK(boilerplate->HasDoubleElements());
+    CHECK_LE(elements_object->Size(), kMaxRegularHeapObjectSize);
+    elements_->AsFixedDoubleArray()->SerializeContents(broker);
+  }
+
+  // TODO(turbofan): Do we want to support out-of-object properties?
+  CHECK(boilerplate->HasFastProperties() &&
+        boilerplate->property_array()->length() == 0);
+  CHECK_EQ(inobject_fields_.size(), 0u);
+
+  // Check the in-object properties.
+  Handle<DescriptorArray> descriptors(
+      boilerplate->map()->instance_descriptors(), isolate);
+  int const limit = boilerplate->map()->NumberOfOwnDescriptors();
+  for (int i = 0; i < limit; i++) {
+    PropertyDetails details = descriptors->GetDetails(i);
+    if (details.location() != kField) continue;
+    DCHECK_EQ(kData, details.kind());
+
+    FieldIndex field_index = FieldIndex::ForDescriptor(boilerplate->map(), i);
+    // Make sure {field_index} agrees with {inobject_properties} on the index of
+    // this field.
+    DCHECK_EQ(field_index.property_index(),
+              static_cast<int>(inobject_fields_.size()));
+    if (boilerplate->IsUnboxedDoubleField(field_index)) {
+      double value = boilerplate->RawFastDoublePropertyAt(field_index);
+      inobject_fields_.push_back(JSObjectField{value});
+    } else {
+      Handle<Object> value(boilerplate->RawFastPropertyAt(field_index),
+                           isolate);
+      ObjectData* value_data = broker->GetOrCreateData(value);
+      if (value->IsJSObject()) {
+        value_data->AsJSObject()->SerializeRecursive(broker, depth - 1);
+      }
+      inobject_fields_.push_back(JSObjectField{value_data});
+    }
+  }
+  broker->Trace("Copied %zu in-object fields.\n", inobject_fields_.size());
+
+  map()->SerializeOwnDescriptors(broker);
+
+  if (IsJSArray()) AsJSArray()->Serialize(broker);
 }
 
-StringRef ObjectRef::TypeOf() const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference handle_dereference;
-  return StringRef(broker(),
-                   Object::TypeOf(broker()->isolate(), object<Object>()));
+void JSRegExpData::SerializeAsRegExpBoilerplate(JSHeapBroker* broker) {
+  if (serialized_as_reg_exp_boilerplate_) return;
+  serialized_as_reg_exp_boilerplate_ = true;
+
+  TraceScope tracer(broker, this, "JSRegExpData::SerializeAsRegExpBoilerplate");
+  Handle<JSRegExp> boilerplate = Handle<JSRegExp>::cast(object());
+
+  SerializeElements(broker);
+
+  raw_properties_or_hash_ =
+      broker->GetOrCreateData(boilerplate->raw_properties_or_hash());
+  data_ = broker->GetOrCreateData(boilerplate->data());
+  source_ = broker->GetOrCreateData(boilerplate->source());
+  flags_ = broker->GetOrCreateData(boilerplate->flags());
+  last_index_ = broker->GetOrCreateData(boilerplate->last_index());
+}
+
+bool ObjectRef::equals(const ObjectRef& other) const {
+  return data_ == other.data_;
 }
 
 Isolate* ObjectRef::isolate() const { return broker()->isolate(); }
 
-base::Optional<ContextRef> ContextRef::previous() const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference handle_dereference;
-  Context* previous = object<Context>()->previous();
-  if (previous == nullptr) return base::Optional<ContextRef>();
-  return ContextRef(broker(), handle(previous, broker()->isolate()));
+ContextRef ContextRef::previous() const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference handle_dereference;
+    return ContextRef(
+        broker(), handle(object<Context>()->previous(), broker()->isolate()));
+  }
+  return ContextRef(broker(), data()->AsContext()->previous());
 }
 
+// Not needed for TypedLowering.
 ObjectRef ContextRef::get(int index) const {
   AllowHandleAllocation handle_allocation;
   AllowHandleDereference handle_dereference;
@@ -552,17 +1333,24 @@ ObjectRef ContextRef::get(int index) const {
   return ObjectRef(broker(), value);
 }
 
-JSHeapBroker::JSHeapBroker(Isolate* isolate, Zone* zone)
+JSHeapBroker::JSHeapBroker(Isolate* isolate, Zone* broker_zone)
     : isolate_(isolate),
-      zone_(zone),
-      refs_(zone),
-      mode_(FLAG_concurrent_compiler_frontend ? kSerializing : kDisabled) {
-  Trace("%s", "Constructing heap broker.\n");
+      broker_zone_(broker_zone),
+      current_zone_(broker_zone),
+      refs_(new (zone())
+                RefsMap(kMinimalRefsBucketCount, AddressMatcher(), zone())) {
+  // Note that this initialization of the refs_ pointer with the minimal
+  // initial capacity is redundant in the normal use case (concurrent
+  // compilation enabled, standard objects to be serialized), as the map
+  // is going to be replaced immediatelly with a larger capacity one.
+  // It doesn't seem to affect the performance in a noticeable way though.
+  Trace("Constructing heap broker.\n");
 }
 
 void JSHeapBroker::Trace(const char* format, ...) const {
   if (FLAG_trace_heap_broker) {
     PrintF("[%p] ", this);
+    for (unsigned i = 0; i < tracing_indentation_; ++i) PrintF("  ");
     va_list arguments;
     va_start(arguments, format);
     base::OS::VPrint(format, arguments);
@@ -570,135 +1358,241 @@ void JSHeapBroker::Trace(const char* format, ...) const {
   }
 }
 
+void JSHeapBroker::StartSerializing() {
+  CHECK_EQ(mode_, kDisabled);
+  Trace("Starting serialization.\n");
+  mode_ = kSerializing;
+  refs_->Clear();
+}
+
+void JSHeapBroker::StopSerializing() {
+  CHECK_EQ(mode_, kSerializing);
+  Trace("Stopping serialization.\n");
+  mode_ = kSerialized;
+}
+
+void JSHeapBroker::Retire() {
+  CHECK_EQ(mode_, kSerialized);
+  Trace("Retiring.\n");
+  mode_ = kRetired;
+}
+
 bool JSHeapBroker::SerializingAllowed() const {
   return mode() == kSerializing ||
          (!FLAG_strict_heap_broker && mode() == kSerialized);
 }
 
-void JSHeapBroker::SerializeStandardObjects() {
-  Trace("Serializing standard objects.\n");
+void JSHeapBroker::SetNativeContextRef() {
+  native_context_ = NativeContextRef(this, isolate()->native_context());
+}
+
+bool IsShareable(Handle<Object> object, Isolate* isolate) {
+  Builtins* const b = isolate->builtins();
+
+  int index;
+  RootIndex root_index;
+  return (object->IsHeapObject() &&
+          b->IsBuiltinHandle(Handle<HeapObject>::cast(object), &index)) ||
+         isolate->heap()->IsRootHandle(object, &root_index);
+}
+
+void JSHeapBroker::SerializeShareableObjects() {
+  PerIsolateCompilerCache::Setup(isolate());
+  compiler_cache_ = isolate()->compiler_cache();
+
+  if (compiler_cache_->HasSnapshot()) {
+    RefsMap* snapshot = compiler_cache_->GetSnapshot();
+
+    refs_ = new (zone()) RefsMap(snapshot, zone());
+    return;
+  }
+
+  TraceScope tracer(
+      this, "JSHeapBroker::SerializeShareableObjects (building snapshot)");
+
+  refs_ =
+      new (zone()) RefsMap(kInitialRefsBucketCount, AddressMatcher(), zone());
+
+  current_zone_ = compiler_cache_->zone();
 
   Builtins* const b = isolate()->builtins();
-  Factory* const f = isolate()->factory();
+  {
+    Builtins::Name builtins[] = {
+        Builtins::kAllocateInNewSpace,
+        Builtins::kAllocateInOldSpace,
+        Builtins::kArgumentsAdaptorTrampoline,
+        Builtins::kArrayConstructorImpl,
+        Builtins::kCallFunctionForwardVarargs,
+        Builtins::kCallFunction_ReceiverIsAny,
+        Builtins::kCallFunction_ReceiverIsNotNullOrUndefined,
+        Builtins::kCallFunction_ReceiverIsNullOrUndefined,
+        Builtins::kConstructFunctionForwardVarargs,
+        Builtins::kForInFilter,
+        Builtins::kJSBuiltinsConstructStub,
+        Builtins::kJSConstructStubGeneric,
+        Builtins::kStringAdd_CheckNone,
+        Builtins::kStringAdd_ConvertLeft,
+        Builtins::kStringAdd_ConvertRight,
+        Builtins::kToNumber,
+        Builtins::kToObject,
+    };
+    for (auto id : builtins) {
+      GetOrCreateData(b->builtin_handle(id));
+    }
+  }
+  for (int32_t id = 0; id < Builtins::builtin_count; ++id) {
+    if (Builtins::KindOf(id) == Builtins::TFJ) {
+      GetOrCreateData(b->builtin_handle(id));
+    }
+  }
 
-  // Stuff used by JSGraph:
-  GetOrCreateData(f->empty_fixed_array());
+  for (RefsMap::Entry* p = refs_->Start(); p != nullptr; p = refs_->Next(p)) {
+    CHECK(IsShareable(p->value->object(), isolate()));
+  }
 
-  // Stuff used by JSCreateLowering:
+  // TODO(mslekova):
+  // Serialize root objects (from factory).
+  compiler_cache()->SetSnapshot(refs_);
+  current_zone_ = broker_zone_;
+}
+
+void JSHeapBroker::SerializeStandardObjects() {
+  if (mode() == kDisabled) return;
+  CHECK_EQ(mode(), kSerializing);
+
+  SerializeShareableObjects();
+
+  TraceScope tracer(this, "JSHeapBroker::SerializeStandardObjects");
+
+  SetNativeContextRef();
+  native_context().Serialize();
+
+  Factory* const f = isolate()->factory();
+
+  // Maps, strings, oddballs
+  GetOrCreateData(f->arguments_marker_map());
+  GetOrCreateData(f->bigint_string());
   GetOrCreateData(f->block_context_map());
+  GetOrCreateData(f->boolean_map());
+  GetOrCreateData(f->boolean_string());
   GetOrCreateData(f->catch_context_map());
+  GetOrCreateData(f->empty_fixed_array());
+  GetOrCreateData(f->empty_string());
   GetOrCreateData(f->eval_context_map());
+  GetOrCreateData(f->false_string());
+  GetOrCreateData(f->false_value());
   GetOrCreateData(f->fixed_array_map());
+  GetOrCreateData(f->fixed_cow_array_map());
   GetOrCreateData(f->fixed_double_array_map());
   GetOrCreateData(f->function_context_map());
+  GetOrCreateData(f->function_string());
+  GetOrCreateData(f->heap_number_map());
+  GetOrCreateData(f->length_string());
   GetOrCreateData(f->many_closures_cell_map());
+  GetOrCreateData(f->minus_zero_value());
   GetOrCreateData(f->mutable_heap_number_map());
   GetOrCreateData(f->name_dictionary_map());
+  GetOrCreateData(f->NaN_string());
+  GetOrCreateData(f->null_map());
+  GetOrCreateData(f->null_string());
+  GetOrCreateData(f->null_value());
+  GetOrCreateData(f->number_string());
+  GetOrCreateData(f->object_string());
   GetOrCreateData(f->one_pointer_filler_map());
+  GetOrCreateData(f->optimized_out());
+  GetOrCreateData(f->optimized_out_map());
+  GetOrCreateData(f->property_array_map());
   GetOrCreateData(f->sloppy_arguments_elements_map());
-  GetOrCreateData(f->with_context_map());
-
-  // Stuff used by TypedOptimization:
-  // Strings produced by typeof:
-  GetOrCreateData(f->boolean_string());
-  GetOrCreateData(f->number_string());
+  GetOrCreateData(f->stale_register());
+  GetOrCreateData(f->stale_register_map());
   GetOrCreateData(f->string_string());
-  GetOrCreateData(f->bigint_string());
   GetOrCreateData(f->symbol_string());
+  GetOrCreateData(f->termination_exception_map());
+  GetOrCreateData(f->the_hole_map());
+  GetOrCreateData(f->the_hole_value());
+  GetOrCreateData(f->true_string());
+  GetOrCreateData(f->true_value());
+  GetOrCreateData(f->undefined_map());
   GetOrCreateData(f->undefined_string());
-  GetOrCreateData(f->object_string());
-  GetOrCreateData(f->function_string());
-
-  // Stuff used by JSTypedLowering:
-  GetOrCreateData(f->length_string());
-  Builtins::Name builtins[] = {
-      Builtins::kArgumentsAdaptorTrampoline,
-      Builtins::kCallFunctionForwardVarargs,
-      Builtins::kStringAdd_CheckNone_NotTenured,
-      Builtins::kStringAdd_CheckNone_Tenured,
-      Builtins::kStringAdd_ConvertLeft_NotTenured,
-      Builtins::kStringAdd_ConvertRight_NotTenured,
-  };
-  for (auto id : builtins) {
-    GetOrCreateData(b->builtin_handle(id));
-  }
-  for (int32_t id = 0; id < Builtins::builtin_count; ++id) {
-    if (Builtins::KindOf(id) == Builtins::TFJ) {
-      GetOrCreateData(b->builtin_handle(id));
-    }
-  }
+  GetOrCreateData(f->undefined_value());
+  GetOrCreateData(f->uninitialized_map());
+  GetOrCreateData(f->with_context_map());
+  GetOrCreateData(f->zero_string());
+
+  // Property cells
+  GetOrCreateData(f->array_buffer_neutering_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+  GetOrCreateData(f->array_iterator_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+  GetOrCreateData(f->array_species_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+  GetOrCreateData(f->no_elements_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+  GetOrCreateData(f->promise_hook_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+  GetOrCreateData(f->promise_species_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+  GetOrCreateData(f->promise_then_protector())
+      ->AsPropertyCell()
+      ->Serialize(this);
+
+  // CEntry stub
+  GetOrCreateData(
+      CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs, kArgvOnStack, true));
 
   Trace("Finished serializing standard objects.\n");
 }
 
-HeapObjectType JSHeapBroker::HeapObjectTypeFromMap(Map* map) const {
-  AllowHandleDereference allow_handle_dereference;
-  OddballType oddball_type = OddballType::kNone;
-  if (map->instance_type() == ODDBALL_TYPE) {
-    ReadOnlyRoots roots(isolate_);
-    if (map == roots.undefined_map()) {
-      oddball_type = OddballType::kUndefined;
-    } else if (map == roots.null_map()) {
-      oddball_type = OddballType::kNull;
-    } else if (map == roots.boolean_map()) {
-      oddball_type = OddballType::kBoolean;
-    } else if (map == roots.the_hole_map()) {
-      oddball_type = OddballType::kHole;
-    } else if (map == roots.uninitialized_map()) {
-      oddball_type = OddballType::kUninitialized;
-    } else {
-      oddball_type = OddballType::kOther;
-      DCHECK(map == roots.termination_exception_map() ||
-             map == roots.arguments_marker_map() ||
-             map == roots.optimized_out_map() ||
-             map == roots.stale_register_map());
-    }
-  }
-  HeapObjectType::Flags flags(0);
-  if (map->is_undetectable()) flags |= HeapObjectType::kUndetectable;
-  if (map->is_callable()) flags |= HeapObjectType::kCallable;
-
-  return HeapObjectType(map->instance_type(), flags, oddball_type);
-}
-
 ObjectData* JSHeapBroker::GetData(Handle<Object> object) const {
-  auto it = refs_.find(object.address());
-  return it != refs_.end() ? it->second : nullptr;
+  RefsMap::Entry* entry = refs_->Lookup(object.address());
+  return entry ? entry->value : nullptr;
 }
 
+// clang-format off
 ObjectData* JSHeapBroker::GetOrCreateData(Handle<Object> object) {
   CHECK(SerializingAllowed());
-  ObjectData* data = GetData(object);
-  if (data == nullptr) {
+  RefsMap::Entry* entry = refs_->LookupOrInsert(object.address(), zone());
+  ObjectData** data_storage = &(entry->value);
+  if (*data_storage == nullptr) {
     // TODO(neis): Remove these Allow* once we serialize everything upfront.
     AllowHandleAllocation handle_allocation;
     AllowHandleDereference handle_dereference;
-    data = ObjectData::Serialize(this, object);
+    if (object->IsSmi()) {
+      new (zone()) ObjectData(this, data_storage, object, kSmi);
+#define CREATE_DATA_IF_MATCH(name)                                             \
+    } else if (object->Is##name()) {                                           \
+      new (zone()) name##Data(this, data_storage, Handle<name>::cast(object));
+    HEAP_BROKER_OBJECT_LIST(CREATE_DATA_IF_MATCH)
+#undef CREATE_DATA_IF_MATCH
+    } else {
+      UNREACHABLE();
+    }
   }
-  CHECK_NOT_NULL(data);
-  return data;
+  CHECK_NOT_NULL(*data_storage);
+  return (*data_storage);
 }
+// clang-format on
 
-void JSHeapBroker::AddData(Handle<Object> object, ObjectData* data) {
-  Trace("Creating data %p for handle %" V8PRIuPTR " (", data, object.address());
-  if (FLAG_trace_heap_broker) {
-    object->ShortPrint();
-    PrintF(")\n");
-  }
-  CHECK_NOT_NULL(isolate()->handle_scope_data()->canonical_scope);
-  CHECK(refs_.insert({object.address(), data}).second);
+ObjectData* JSHeapBroker::GetOrCreateData(Object* object) {
+  return GetOrCreateData(handle(object, isolate()));
 }
 
 #define DEFINE_IS_AND_AS(Name)                                    \
   bool ObjectRef::Is##Name() const { return data()->Is##Name(); } \
   Name##Ref ObjectRef::As##Name() const {                         \
     DCHECK(Is##Name());                                           \
-    return Name##Ref(data());                                     \
+    return Name##Ref(broker(), data());                           \
   }
 HEAP_BROKER_OBJECT_LIST(DEFINE_IS_AND_AS)
 #undef DEFINE_IS_AND_AS
 
-bool ObjectRef::IsSmi() const { return data()->is_smi; }
+bool ObjectRef::IsSmi() const { return data()->is_smi(); }
 
 int ObjectRef::AsSmi() const {
   DCHECK(IsSmi());
@@ -706,25 +1600,22 @@ int ObjectRef::AsSmi() const {
   return object<Smi>()->value();
 }
 
-HeapObjectType HeapObjectRef::type() const {
+base::Optional<MapRef> JSObjectRef::GetObjectCreateMap() const {
   if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
     AllowHandleDereference allow_handle_dereference;
-    return broker()->HeapObjectTypeFromMap(object<HeapObject>()->map());
-  } else {
-    return data()->AsHeapObject()->type;
-  }
-}
-
-base::Optional<MapRef> HeapObjectRef::TryGetObjectCreateMap() const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  Handle<Map> instance_map;
-  if (Map::TryGetObjectCreateMap(broker()->isolate(), object<HeapObject>())
-          .ToHandle(&instance_map)) {
-    return MapRef(broker(), instance_map);
-  } else {
-    return base::Optional<MapRef>();
+    AllowHeapAllocation heap_allocation;
+    Handle<Map> instance_map;
+    if (Map::TryGetObjectCreateMap(broker()->isolate(), object<HeapObject>())
+            .ToHandle(&instance_map)) {
+      return MapRef(broker(), instance_map);
+    } else {
+      return base::Optional<MapRef>();
+    }
   }
+  MapData* map_data = data()->AsJSObject()->object_create_map();
+  return map_data != nullptr ? MapRef(broker(), map_data)
+                             : base::Optional<MapRef>();
 }
 
 base::Optional<MapRef> MapRef::AsElementsKind(ElementsKind kind) const {
@@ -734,26 +1625,28 @@ base::Optional<MapRef> MapRef::AsElementsKind(ElementsKind kind) const {
     AllowHandleDereference allow_handle_dereference;
     return MapRef(broker(), Map::AsElementsKind(broker()->isolate(),
                                                 object<Map>(), kind));
-  } else {
-    if (kind == elements_kind()) return *this;
-    const ZoneVector<MapData*>& elements_kind_generalizations =
-        data()->AsMap()->elements_kind_generalizations();
-    for (auto data : elements_kind_generalizations) {
-      MapRef map(data);
-      if (map.elements_kind() == kind) return map;
-    }
-    return base::Optional<MapRef>();
   }
+  if (kind == elements_kind()) return *this;
+  const ZoneVector<MapData*>& elements_kind_generalizations =
+      data()->AsMap()->elements_kind_generalizations();
+  for (auto data : elements_kind_generalizations) {
+    MapRef map(broker(), data);
+    if (map.elements_kind() == kind) return map;
+  }
+  return base::Optional<MapRef>();
 }
 
 int JSFunctionRef::InitialMapInstanceSizeWithMinSlack() const {
-  AllowHandleDereference allow_handle_dereference;
-  AllowHandleAllocation handle_allocation;
-
-  return object<JSFunction>()->ComputeInstanceSizeWithMinSlack(
-      broker()->isolate());
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    AllowHandleAllocation handle_allocation;
+    return object<JSFunction>()->ComputeInstanceSizeWithMinSlack(
+        broker()->isolate());
+  }
+  return data()->AsJSFunction()->initial_map_instance_size_with_min_slack();
 }
 
+// Not needed for TypedLowering.
 base::Optional<ScriptContextTableRef::LookupResult>
 ScriptContextTableRef::lookup(const NameRef& name) const {
   AllowHandleAllocation handle_allocation;
@@ -773,127 +1666,192 @@ ScriptContextTableRef::lookup(const NameRef& name) const {
   return result;
 }
 
-OddballType ObjectRef::oddball_type() const {
-  return IsSmi() ? OddballType::kNone : AsHeapObject().type().oddball_type();
+OddballType MapRef::oddball_type() const {
+  if (instance_type() != ODDBALL_TYPE) {
+    return OddballType::kNone;
+  }
+  Factory* f = broker()->isolate()->factory();
+  if (equals(MapRef(broker(), f->undefined_map()))) {
+    return OddballType::kUndefined;
+  }
+  if (equals(MapRef(broker(), f->null_map()))) {
+    return OddballType::kNull;
+  }
+  if (equals(MapRef(broker(), f->boolean_map()))) {
+    return OddballType::kBoolean;
+  }
+  if (equals(MapRef(broker(), f->the_hole_map()))) {
+    return OddballType::kHole;
+  }
+  if (equals(MapRef(broker(), f->uninitialized_map()))) {
+    return OddballType::kUninitialized;
+  }
+  DCHECK(equals(MapRef(broker(), f->termination_exception_map())) ||
+         equals(MapRef(broker(), f->arguments_marker_map())) ||
+         equals(MapRef(broker(), f->optimized_out_map())) ||
+         equals(MapRef(broker(), f->stale_register_map())));
+  return OddballType::kOther;
 }
 
 ObjectRef FeedbackVectorRef::get(FeedbackSlot slot) const {
   if (broker()->mode() == JSHeapBroker::kDisabled) {
     AllowHandleAllocation handle_allocation;
     AllowHandleDereference handle_dereference;
-    Handle<Object> value(object<FeedbackVector>()->Get(slot)->ToObject(),
+    Handle<Object> value(object<FeedbackVector>()->Get(slot)->cast<Object>(),
                          broker()->isolate());
     return ObjectRef(broker(), value);
   }
   int i = FeedbackVector::GetIndex(slot);
-  return ObjectRef(data()->AsFeedbackVector()->feedback().at(i));
-}
-
-bool JSObjectRef::IsUnboxedDoubleField(FieldIndex index) const {
-  AllowHandleDereference handle_dereference;
-  return object<JSObject>()->IsUnboxedDoubleField(index);
+  return ObjectRef(broker(), data()->AsFeedbackVector()->feedback().at(i));
 }
 
 double JSObjectRef::RawFastDoublePropertyAt(FieldIndex index) const {
-  AllowHandleDereference handle_dereference;
-  return object<JSObject>()->RawFastDoublePropertyAt(index);
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference handle_dereference;
+    return object<JSObject>()->RawFastDoublePropertyAt(index);
+  }
+  JSObjectData* object_data = data()->AsJSObject();
+  CHECK(index.is_inobject());
+  return object_data->GetInobjectField(index.property_index()).AsDouble();
 }
 
 ObjectRef JSObjectRef::RawFastPropertyAt(FieldIndex index) const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference handle_dereference;
-  return ObjectRef(broker(),
-                   handle(object<JSObject>()->RawFastPropertyAt(index),
-                          broker()->isolate()));
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference handle_dereference;
+    return ObjectRef(broker(),
+                     handle(object<JSObject>()->RawFastPropertyAt(index),
+                            broker()->isolate()));
+  }
+  JSObjectData* object_data = data()->AsJSObject();
+  CHECK(index.is_inobject());
+  return ObjectRef(
+      broker(),
+      object_data->GetInobjectField(index.property_index()).AsObject());
 }
 
-
 bool AllocationSiteRef::IsFastLiteral() const {
   if (broker()->mode() == JSHeapBroker::kDisabled) {
-    AllowHeapAllocation
-        allow_heap_allocation;  // This is needed for TryMigrateInstance.
+    AllowHeapAllocation allow_heap_allocation;  // For TryMigrateInstance.
     AllowHandleAllocation allow_handle_allocation;
     AllowHandleDereference allow_handle_dereference;
     return IsInlinableFastLiteral(
         handle(object<AllocationSite>()->boilerplate(), broker()->isolate()));
-  } else {
-    return data()->AsAllocationSite()->boilerplate != nullptr;
   }
+  return data()->AsAllocationSite()->IsFastLiteral();
 }
 
 void JSObjectRef::EnsureElementsTenured() {
-  // TODO(jarin) Eventually, we will pretenure the boilerplates before
-  // the compilation job starts.
-  AllowHandleAllocation allow_handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  AllowHeapAllocation allow_heap_allocation;
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation allow_handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    AllowHeapAllocation allow_heap_allocation;
 
-  Handle<FixedArrayBase> object_elements = elements().object<FixedArrayBase>();
-  if (Heap::InNewSpace(*object_elements)) {
-    // If we would like to pretenure a fixed cow array, we must ensure that
-    // the array is already in old space, otherwise we'll create too many
-    // old-to-new-space pointers (overflowing the store buffer).
-    object_elements =
-        broker()->isolate()->factory()->CopyAndTenureFixedCOWArray(
-            Handle<FixedArray>::cast(object_elements));
-    object<JSObject>()->set_elements(*object_elements);
+    Handle<FixedArrayBase> object_elements =
+        elements().object<FixedArrayBase>();
+    if (Heap::InNewSpace(*object_elements)) {
+      // If we would like to pretenure a fixed cow array, we must ensure that
+      // the array is already in old space, otherwise we'll create too many
+      // old-to-new-space pointers (overflowing the store buffer).
+      object_elements =
+          broker()->isolate()->factory()->CopyAndTenureFixedCOWArray(
+              Handle<FixedArray>::cast(object_elements));
+      object<JSObject>()->set_elements(*object_elements);
+    }
+    return;
   }
+  CHECK(data()->AsJSObject()->cow_or_empty_elements_tenured());
 }
 
-FieldIndex MapRef::GetFieldIndexFor(int i) const {
-  AllowHandleDereference allow_handle_dereference;
-  return FieldIndex::ForDescriptor(*object<Map>(), i);
+FieldIndex MapRef::GetFieldIndexFor(int descriptor_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return FieldIndex::ForDescriptor(*object<Map>(), descriptor_index);
+  }
+  DescriptorArrayData* descriptors = data()->AsMap()->instance_descriptors();
+  return descriptors->contents().at(descriptor_index).field_index;
 }
 
 int MapRef::GetInObjectPropertyOffset(int i) const {
-  AllowHandleDereference allow_handle_dereference;
-  return object<Map>()->GetInObjectPropertyOffset(i);
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return object<Map>()->GetInObjectPropertyOffset(i);
+  }
+  return (GetInObjectPropertiesStartInWords() + i) * kPointerSize;
 }
 
-PropertyDetails MapRef::GetPropertyDetails(int i) const {
-  AllowHandleDereference allow_handle_dereference;
-  return object<Map>()->instance_descriptors()->GetDetails(i);
+PropertyDetails MapRef::GetPropertyDetails(int descriptor_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return object<Map>()->instance_descriptors()->GetDetails(descriptor_index);
+  }
+  DescriptorArrayData* descriptors = data()->AsMap()->instance_descriptors();
+  return descriptors->contents().at(descriptor_index).details;
 }
 
-NameRef MapRef::GetPropertyKey(int i) const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  return NameRef(broker(),
-                 handle(object<Map>()->instance_descriptors()->GetKey(i),
-                        broker()->isolate()));
+NameRef MapRef::GetPropertyKey(int descriptor_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    return NameRef(
+        broker(),
+        handle(object<Map>()->instance_descriptors()->GetKey(descriptor_index),
+               broker()->isolate()));
+  }
+  DescriptorArrayData* descriptors = data()->AsMap()->instance_descriptors();
+  return NameRef(broker(), descriptors->contents().at(descriptor_index).key);
 }
 
 bool MapRef::IsFixedCowArrayMap() const {
-  AllowHandleDereference allow_handle_dereference;
-  return *object<Map>() ==
-         ReadOnlyRoots(broker()->isolate()).fixed_cow_array_map();
+  Handle<Map> fixed_cow_array_map =
+      ReadOnlyRoots(broker()->isolate()).fixed_cow_array_map_handle();
+  return equals(MapRef(broker(), fixed_cow_array_map));
 }
 
-MapRef MapRef::FindFieldOwner(int descriptor) const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  Handle<Map> owner(
-      object<Map>()->FindFieldOwner(broker()->isolate(), descriptor),
-      broker()->isolate());
-  return MapRef(broker(), owner);
+MapRef MapRef::FindFieldOwner(int descriptor_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    Handle<Map> owner(
+        object<Map>()->FindFieldOwner(broker()->isolate(), descriptor_index),
+        broker()->isolate());
+    return MapRef(broker(), owner);
+  }
+  DescriptorArrayData* descriptors = data()->AsMap()->instance_descriptors();
+  return MapRef(broker(),
+                descriptors->contents().at(descriptor_index).field_owner);
 }
 
-ObjectRef MapRef::GetFieldType(int descriptor) const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  Handle<FieldType> field_type(
-      object<Map>()->instance_descriptors()->GetFieldType(descriptor),
-      broker()->isolate());
-  return ObjectRef(broker(), field_type);
+ObjectRef MapRef::GetFieldType(int descriptor_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    Handle<FieldType> field_type(
+        object<Map>()->instance_descriptors()->GetFieldType(descriptor_index),
+        broker()->isolate());
+    return ObjectRef(broker(), field_type);
+  }
+  DescriptorArrayData* descriptors = data()->AsMap()->instance_descriptors();
+  return ObjectRef(broker(),
+                   descriptors->contents().at(descriptor_index).field_type);
+}
+
+bool MapRef::IsUnboxedDoubleField(int descriptor_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return object<Map>()->IsUnboxedDoubleField(
+        FieldIndex::ForDescriptor(*object<Map>(), descriptor_index));
+  }
+  DescriptorArrayData* descriptors = data()->AsMap()->instance_descriptors();
+  return descriptors->contents().at(descriptor_index).is_unboxed_double_field;
 }
 
 uint16_t StringRef::GetFirstChar() {
   if (broker()->mode() == JSHeapBroker::kDisabled) {
     AllowHandleDereference allow_handle_dereference;
     return object<String>()->Get(0);
-  } else {
-    return data()->AsString()->first_char;
   }
+  return data()->AsString()->first_char();
 }
 
 base::Optional<double> StringRef::ToNumber() {
@@ -905,31 +1863,35 @@ base::Optional<double> StringRef::ToNumber() {
     return StringToDouble(broker()->isolate(),
                           broker()->isolate()->unicode_cache(),
                           object<String>(), flags);
-  } else {
-    return data()->AsString()->to_number;
   }
-}
-
-bool FixedArrayRef::is_the_hole(int i) const {
-  AllowHandleDereference allow_handle_dereference;
-  return object<FixedArray>()->is_the_hole(broker()->isolate(), i);
+  return data()->AsString()->to_number();
 }
 
 ObjectRef FixedArrayRef::get(int i) const {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  return ObjectRef(broker(),
-                   handle(object<FixedArray>()->get(i), broker()->isolate()));
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    return ObjectRef(broker(),
+                     handle(object<FixedArray>()->get(i), broker()->isolate()));
+  }
+  return ObjectRef(broker(), data()->AsFixedArray()->Get(i));
 }
 
 bool FixedDoubleArrayRef::is_the_hole(int i) const {
-  AllowHandleDereference allow_handle_dereference;
-  return object<FixedDoubleArray>()->is_the_hole(i);
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return object<FixedDoubleArray>()->is_the_hole(i);
+  }
+  return data()->AsFixedDoubleArray()->Get(i).is_hole_nan();
 }
 
 double FixedDoubleArrayRef::get_scalar(int i) const {
-  AllowHandleDereference allow_handle_dereference;
-  return object<FixedDoubleArray>()->get_scalar(i);
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return object<FixedDoubleArray>()->get_scalar(i);
+  }
+  CHECK(!data()->AsFixedDoubleArray()->Get(i).is_hole_nan());
+  return data()->AsFixedDoubleArray()->Get(i).get_scalar();
 }
 
 #define IF_BROKER_DISABLED_ACCESS_HANDLE_C(holder, name) \
@@ -939,54 +1901,34 @@ double FixedDoubleArrayRef::get_scalar(int i) const {
     return object<holder>()->name();                     \
   }
 
-// Macros for definining a const getter that, depending on the broker mode,
-// either looks into the handle or into the serialized data. The first one is
-// used for the rare case of a XYZRef class that does not have a corresponding
-// XYZ class in objects.h. The second one is used otherwise.
-#define BIMODAL_ACCESSOR(holder, result, name)                              \
-  result##Ref holder##Ref::name() const {                                   \
-    if (broker()->mode() == JSHeapBroker::kDisabled) {                      \
-      AllowHandleAllocation handle_allocation;                              \
-      AllowHandleDereference allow_handle_dereference;                      \
-      return result##Ref(                                                   \
-          broker(), handle(object<holder>()->name(), broker()->isolate())); \
-    } else {                                                                \
-      return result##Ref(data()->As##holder()->name);                       \
-    }                                                                       \
-  }
-
-// Like HANDLE_ACCESSOR except that the result type is not an XYZRef.
-#define BIMODAL_ACCESSOR_C(holder, result, name)      \
-  result holder##Ref::name() const {                  \
-    IF_BROKER_DISABLED_ACCESS_HANDLE_C(holder, name); \
-    return data()->As##holder()->name;                \
-  }
-
-// Like HANDLE_ACCESSOR_C but for BitFields.
-#define BIMODAL_ACCESSOR_B(holder, field, name, BitField)  \
-  typename BitField::FieldType holder##Ref::name() const { \
-    IF_BROKER_DISABLED_ACCESS_HANDLE_C(holder, name);      \
-    return BitField::decode(data()->As##holder()->field);  \
-  }
-
-// Macros for definining a const getter that always looks into the handle.
-// (These will go away once we serialize everything.) The first one is used for
-// the rare case of a XYZRef class that does not have a corresponding XYZ class
-// in objects.h. The second one is used otherwise.
-#define HANDLE_ACCESSOR(holder, result, name)                                  \
-  result##Ref holder##Ref::name() const {                                      \
+#define IF_BROKER_DISABLED_ACCESS_HANDLE(holder, result, name)                 \
+  if (broker()->mode() == JSHeapBroker::kDisabled) {                           \
     AllowHandleAllocation handle_allocation;                                   \
     AllowHandleDereference allow_handle_dereference;                           \
     return result##Ref(broker(),                                               \
                        handle(object<holder>()->name(), broker()->isolate())); \
   }
 
-// Like HANDLE_ACCESSOR except that the result type is not an XYZRef.
-#define HANDLE_ACCESSOR_C(holder, result, name)      \
-  result holder##Ref::name() const {                 \
-    AllowHandleAllocation handle_allocation;         \
-    AllowHandleDereference allow_handle_dereference; \
-    return object<holder>()->name();                 \
+// Macros for definining a const getter that, depending on the broker mode,
+// either looks into the handle or into the serialized data.
+#define BIMODAL_ACCESSOR(holder, result, name)                             \
+  result##Ref holder##Ref::name() const {                                  \
+    IF_BROKER_DISABLED_ACCESS_HANDLE(holder, result, name);                \
+    return result##Ref(broker(), ObjectRef::data()->As##holder()->name()); \
+  }
+
+// Like above except that the result type is not an XYZRef.
+#define BIMODAL_ACCESSOR_C(holder, result, name)      \
+  result holder##Ref::name() const {                  \
+    IF_BROKER_DISABLED_ACCESS_HANDLE_C(holder, name); \
+    return ObjectRef::data()->As##holder()->name();   \
+  }
+
+// Like above but for BitFields.
+#define BIMODAL_ACCESSOR_B(holder, field, name, BitField)              \
+  typename BitField::FieldType holder##Ref::name() const {             \
+    IF_BROKER_DISABLED_ACCESS_HANDLE_C(holder, name);                  \
+    return BitField::decode(ObjectRef::data()->As##holder()->field()); \
   }
 
 BIMODAL_ACCESSOR(AllocationSite, Object, nested_site)
@@ -997,59 +1939,39 @@ BIMODAL_ACCESSOR_C(AllocationSite, PretenureFlag, GetPretenureMode)
 
 BIMODAL_ACCESSOR_C(BytecodeArray, int, register_count)
 
-BIMODAL_ACCESSOR_C(FixedArrayBase, int, length)
-
 BIMODAL_ACCESSOR(HeapObject, Map, map)
-HANDLE_ACCESSOR_C(HeapObject, bool, IsExternalString)
-HANDLE_ACCESSOR_C(HeapObject, bool, IsSeqString)
-
-HANDLE_ACCESSOR_C(HeapNumber, double, value)
 
-HANDLE_ACCESSOR(JSArray, Object, length)
+BIMODAL_ACCESSOR(JSArray, Object, length)
 
 BIMODAL_ACCESSOR_C(JSFunction, bool, has_prototype)
+BIMODAL_ACCESSOR_C(JSFunction, bool, has_initial_map)
 BIMODAL_ACCESSOR_C(JSFunction, bool, PrototypeRequiresRuntimeLookup)
+BIMODAL_ACCESSOR(JSFunction, JSGlobalProxy, global_proxy)
 BIMODAL_ACCESSOR(JSFunction, Map, initial_map)
 BIMODAL_ACCESSOR(JSFunction, Object, prototype)
-HANDLE_ACCESSOR_C(JSFunction, bool, IsConstructor)
-HANDLE_ACCESSOR(JSFunction, JSGlobalProxy, global_proxy)
-HANDLE_ACCESSOR(JSFunction, SharedFunctionInfo, shared)
-
-HANDLE_ACCESSOR(JSObject, FixedArrayBase, elements)
-
-HANDLE_ACCESSOR(JSRegExp, Object, data)
-HANDLE_ACCESSOR(JSRegExp, Object, flags)
-HANDLE_ACCESSOR(JSRegExp, Object, last_index)
-HANDLE_ACCESSOR(JSRegExp, Object, raw_properties_or_hash)
-HANDLE_ACCESSOR(JSRegExp, Object, source)
+BIMODAL_ACCESSOR(JSFunction, SharedFunctionInfo, shared)
 
 BIMODAL_ACCESSOR_B(Map, bit_field2, elements_kind, Map::ElementsKindBits)
 BIMODAL_ACCESSOR_B(Map, bit_field3, is_deprecated, Map::IsDeprecatedBit)
 BIMODAL_ACCESSOR_B(Map, bit_field3, is_dictionary_map, Map::IsDictionaryMapBit)
+BIMODAL_ACCESSOR_B(Map, bit_field3, NumberOfOwnDescriptors,
+                   Map::NumberOfOwnDescriptorsBits)
 BIMODAL_ACCESSOR_B(Map, bit_field, has_prototype_slot, Map::HasPrototypeSlotBit)
+BIMODAL_ACCESSOR_B(Map, bit_field, is_callable, Map::IsCallableBit)
+BIMODAL_ACCESSOR_B(Map, bit_field, is_constructor, Map::IsConstructorBit)
+BIMODAL_ACCESSOR_B(Map, bit_field, is_undetectable, Map::IsUndetectableBit)
 BIMODAL_ACCESSOR_C(Map, int, instance_size)
-HANDLE_ACCESSOR_C(Map, bool, CanBeDeprecated)
-HANDLE_ACCESSOR_C(Map, bool, CanTransition)
-HANDLE_ACCESSOR_C(Map, bool, IsInobjectSlackTrackingInProgress)
-HANDLE_ACCESSOR_C(Map, bool, IsJSArrayMap)
-HANDLE_ACCESSOR_C(Map, bool, is_stable)
-HANDLE_ACCESSOR_C(Map, InstanceType, instance_type)
-HANDLE_ACCESSOR_C(Map, int, GetInObjectProperties)
-HANDLE_ACCESSOR_C(Map, int, GetInObjectPropertiesStartInWords)
-HANDLE_ACCESSOR_C(Map, int, NumberOfOwnDescriptors)
-HANDLE_ACCESSOR(Map, Object, constructor_or_backpointer)
-
-HANDLE_ACCESSOR_C(MutableHeapNumber, double, value)
+BIMODAL_ACCESSOR(Map, Object, prototype)
+BIMODAL_ACCESSOR_C(Map, InstanceType, instance_type)
+BIMODAL_ACCESSOR(Map, Object, constructor_or_backpointer)
 
 #define DEF_NATIVE_CONTEXT_ACCESSOR(type, name) \
   BIMODAL_ACCESSOR(NativeContext, type, name)
 BROKER_NATIVE_CONTEXT_FIELDS(DEF_NATIVE_CONTEXT_ACCESSOR)
 #undef DEF_NATIVE_CONTEXT_ACCESSOR
 
-HANDLE_ACCESSOR(PropertyCell, Object, value)
-HANDLE_ACCESSOR_C(PropertyCell, PropertyDetails, property_details)
-
-HANDLE_ACCESSOR_C(ScopeInfo, int, ContextLength)
+BIMODAL_ACCESSOR(PropertyCell, Object, value)
+BIMODAL_ACCESSOR_C(PropertyCell, PropertyDetails, property_details)
 
 BIMODAL_ACCESSOR_C(SharedFunctionInfo, int, builtin_id)
 BIMODAL_ACCESSOR(SharedFunctionInfo, BytecodeArray, GetBytecodeArray)
@@ -1060,17 +1982,61 @@ BROKER_SFI_FIELDS(DEF_SFI_ACCESSOR)
 
 BIMODAL_ACCESSOR_C(String, int, length)
 
-// TODO(neis): Provide StringShape() on StringRef.
+bool MapRef::IsInobjectSlackTrackingInProgress() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(Map, IsInobjectSlackTrackingInProgress);
+  return Map::ConstructionCounterBits::decode(data()->AsMap()->bit_field3()) !=
+         Map::kNoSlackTracking;
+}
 
-bool JSFunctionRef::has_initial_map() const {
-  IF_BROKER_DISABLED_ACCESS_HANDLE_C(JSFunction, has_initial_map);
-  return data()->AsJSFunction()->initial_map != nullptr;
+bool MapRef::is_stable() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(Map, is_stable);
+  return !Map::IsUnstableBit::decode(data()->AsMap()->bit_field3());
+}
+
+bool MapRef::CanBeDeprecated() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(Map, CanBeDeprecated);
+  CHECK_GT(NumberOfOwnDescriptors(), 0);
+  return data()->AsMap()->can_be_deprecated();
+}
+
+bool MapRef::CanTransition() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(Map, CanTransition);
+  return data()->AsMap()->can_transition();
+}
+
+int MapRef::GetInObjectPropertiesStartInWords() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(Map, GetInObjectPropertiesStartInWords);
+  return data()->AsMap()->in_object_properties_start_in_words();
+}
+
+int MapRef::GetInObjectProperties() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(Map, GetInObjectProperties);
+  return data()->AsMap()->in_object_properties();
+}
+
+int ScopeInfoRef::ContextLength() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(ScopeInfo, ContextLength);
+  return data()->AsScopeInfo()->context_length();
+}
+
+bool StringRef::IsExternalString() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(String, IsExternalString);
+  return data()->AsString()->is_external_string();
+}
+
+bool StringRef::IsSeqString() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(String, IsSeqString);
+  return data()->AsString()->is_seq_string();
 }
 
 MapRef NativeContextRef::GetFunctionMapFromIndex(int index) const {
-  DCHECK_LE(index, Context::LAST_FUNCTION_MAP_INDEX);
   DCHECK_GE(index, Context::FIRST_FUNCTION_MAP_INDEX);
-  return get(index).AsMap();
+  DCHECK_LE(index, Context::LAST_FUNCTION_MAP_INDEX);
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    return get(index).AsMap();
+  }
+  return MapRef(broker(), data()->AsNativeContext()->function_maps().at(
+                              index - Context::FIRST_FUNCTION_MAP_INDEX));
 }
 
 MapRef NativeContextRef::GetInitialJSArrayMap(ElementsKind kind) const {
@@ -1092,13 +2058,16 @@ MapRef NativeContextRef::GetInitialJSArrayMap(ElementsKind kind) const {
   }
 }
 
-bool ObjectRef::BooleanValue() {
-  AllowHandleDereference allow_handle_dereference;
-  return object<Object>()->BooleanValue(broker()->isolate());
+bool ObjectRef::BooleanValue() const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference allow_handle_dereference;
+    return object<Object>()->BooleanValue(broker()->isolate());
+  }
+  return IsSmi() ? (AsSmi() != 0) : data()->AsHeapObject()->boolean_value();
 }
 
 double ObjectRef::OddballToNumber() const {
-  OddballType type = oddball_type();
+  OddballType type = AsHeapObject().map().oddball_type();
 
   switch (type) {
     case OddballType::kBoolean: {
@@ -1122,14 +2091,28 @@ double ObjectRef::OddballToNumber() const {
   }
 }
 
-CellRef ModuleRef::GetCell(int cell_index) {
-  AllowHandleAllocation handle_allocation;
-  AllowHandleDereference allow_handle_dereference;
-  return CellRef(broker(), handle(object<Module>()->GetCell(cell_index),
-                                  broker()->isolate()));
+double HeapNumberRef::value() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(HeapNumber, value);
+  return data()->AsHeapNumber()->value();
+}
+
+double MutableHeapNumberRef::value() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(MutableHeapNumber, value);
+  return data()->AsMutableHeapNumber()->value();
 }
 
-ObjectRef::ObjectRef(JSHeapBroker* broker, Handle<Object> object) {
+CellRef ModuleRef::GetCell(int cell_index) const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    return CellRef(broker(), handle(object<Module>()->GetCell(cell_index),
+                                    broker()->isolate()));
+  }
+  return CellRef(broker(), data()->AsModule()->GetCell(cell_index));
+}
+
+ObjectRef::ObjectRef(JSHeapBroker* broker, Handle<Object> object)
+    : broker_(broker) {
   switch (broker->mode()) {
     case JSHeapBroker::kSerialized:
       data_ = FLAG_strict_heap_broker ? broker->GetData(object)
@@ -1138,31 +2121,80 @@ ObjectRef::ObjectRef(JSHeapBroker* broker, Handle<Object> object) {
     case JSHeapBroker::kSerializing:
       data_ = broker->GetOrCreateData(object);
       break;
-    case JSHeapBroker::kDisabled:
-      data_ = broker->GetData(object);
-      if (data_ == nullptr) {
+    case JSHeapBroker::kDisabled: {
+      RefsMap::Entry* entry =
+          broker->refs_->LookupOrInsert(object.address(), broker->zone());
+      ObjectData** storage = &(entry->value);
+      if (*storage == nullptr) {
         AllowHandleDereference handle_dereference;
-        data_ =
-            new (broker->zone()) ObjectData(broker, object, object->IsSmi());
+        entry->value = new (broker->zone())
+            ObjectData(broker, storage, object,
+                       object->IsSmi() ? kSmi : kUnserializedHeapObject);
       }
+      data_ = *storage;
       break;
+    }
+    case JSHeapBroker::kRetired:
+      UNREACHABLE();
   }
   CHECK_NOT_NULL(data_);
 }
 
+namespace {
+OddballType GetOddballType(Isolate* isolate, Map* map) {
+  if (map->instance_type() != ODDBALL_TYPE) {
+    return OddballType::kNone;
+  }
+  ReadOnlyRoots roots(isolate);
+  if (map == roots.undefined_map()) {
+    return OddballType::kUndefined;
+  }
+  if (map == roots.null_map()) {
+    return OddballType::kNull;
+  }
+  if (map == roots.boolean_map()) {
+    return OddballType::kBoolean;
+  }
+  if (map == roots.the_hole_map()) {
+    return OddballType::kHole;
+  }
+  if (map == roots.uninitialized_map()) {
+    return OddballType::kUninitialized;
+  }
+  DCHECK(map == roots.termination_exception_map() ||
+         map == roots.arguments_marker_map() ||
+         map == roots.optimized_out_map() || map == roots.stale_register_map());
+  return OddballType::kOther;
+}
+}  // namespace
+
+HeapObjectType HeapObjectRef::GetHeapObjectType() const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleDereference handle_dereference;
+    Map* map = Handle<HeapObject>::cast(object())->map();
+    HeapObjectType::Flags flags(0);
+    if (map->is_undetectable()) flags |= HeapObjectType::kUndetectable;
+    if (map->is_callable()) flags |= HeapObjectType::kCallable;
+    return HeapObjectType(map->instance_type(), flags,
+                          GetOddballType(broker()->isolate(), map));
+  }
+  HeapObjectType::Flags flags(0);
+  if (map().is_undetectable()) flags |= HeapObjectType::kUndetectable;
+  if (map().is_callable()) flags |= HeapObjectType::kCallable;
+  return HeapObjectType(map().instance_type(), flags, map().oddball_type());
+}
 base::Optional<JSObjectRef> AllocationSiteRef::boilerplate() const {
   if (broker()->mode() == JSHeapBroker::kDisabled) {
     AllowHandleAllocation handle_allocation;
     AllowHandleDereference allow_handle_dereference;
     return JSObjectRef(broker(), handle(object<AllocationSite>()->boilerplate(),
                                         broker()->isolate()));
+  }
+  JSObjectData* boilerplate = data()->AsAllocationSite()->boilerplate();
+  if (boilerplate) {
+    return JSObjectRef(broker(), boilerplate);
   } else {
-    JSObjectData* boilerplate = data()->AsAllocationSite()->boilerplate;
-    if (boilerplate) {
-      return JSObjectRef(boilerplate);
-    } else {
-      return base::nullopt;
-    }
+    return base::nullopt;
   }
 }
 
@@ -1170,11 +2202,79 @@ ElementsKind JSObjectRef::GetElementsKind() const {
   return map().elements_kind();
 }
 
-Handle<Object> ObjectRef::object() const { return data_->object; }
+FixedArrayBaseRef JSObjectRef::elements() const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    AllowHandleAllocation handle_allocation;
+    AllowHandleDereference allow_handle_dereference;
+    return FixedArrayBaseRef(
+        broker(), handle(object<JSObject>()->elements(), broker()->isolate()));
+  }
+  return FixedArrayBaseRef(broker(), data()->AsJSObject()->elements());
+}
 
-JSHeapBroker* ObjectRef::broker() const { return data_->broker; }
+int FixedArrayBaseRef::length() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE_C(FixedArrayBase, length);
+  return data()->AsFixedArrayBase()->length();
+}
 
-ObjectData* ObjectRef::data() const { return data_; }
+ObjectData* FixedArrayData::Get(int i) const {
+  CHECK_LT(i, static_cast<int>(contents_.size()));
+  CHECK_NOT_NULL(contents_[i]);
+  return contents_[i];
+}
+
+Float64 FixedDoubleArrayData::Get(int i) const {
+  CHECK_LT(i, static_cast<int>(contents_.size()));
+  return contents_[i];
+}
+
+void FeedbackVectorRef::SerializeSlots() {
+  data()->AsFeedbackVector()->SerializeSlots(broker());
+}
+
+ObjectRef JSRegExpRef::data() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE(JSRegExp, Object, data);
+  return ObjectRef(broker(), ObjectRef::data()->AsJSRegExp()->data());
+}
+
+ObjectRef JSRegExpRef::flags() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE(JSRegExp, Object, flags);
+  return ObjectRef(broker(), ObjectRef::data()->AsJSRegExp()->flags());
+}
+
+ObjectRef JSRegExpRef::last_index() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE(JSRegExp, Object, last_index);
+  return ObjectRef(broker(), ObjectRef::data()->AsJSRegExp()->last_index());
+}
+
+ObjectRef JSRegExpRef::raw_properties_or_hash() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE(JSRegExp, Object, raw_properties_or_hash);
+  return ObjectRef(broker(),
+                   ObjectRef::data()->AsJSRegExp()->raw_properties_or_hash());
+}
+
+ObjectRef JSRegExpRef::source() const {
+  IF_BROKER_DISABLED_ACCESS_HANDLE(JSRegExp, Object, source);
+  return ObjectRef(broker(), ObjectRef::data()->AsJSRegExp()->source());
+}
+
+Handle<Object> ObjectRef::object() const { return data_->object(); }
+
+JSHeapBroker* ObjectRef::broker() const { return broker_; }
+
+ObjectData* ObjectRef::data() const {
+  switch (broker()->mode()) {
+    case JSHeapBroker::kDisabled:
+      CHECK_NE(data_->kind(), kSerializedHeapObject);
+      return data_;
+    case JSHeapBroker::kSerializing:
+    case JSHeapBroker::kSerialized:
+      CHECK_NE(data_->kind(), kUnserializedHeapObject);
+      return data_;
+    case JSHeapBroker::kRetired:
+      UNREACHABLE();
+  }
+}
 
 Reduction NoChangeBecauseOfMissingData(JSHeapBroker* broker,
                                        const char* function, int line) {
@@ -1185,12 +2285,76 @@ Reduction NoChangeBecauseOfMissingData(JSHeapBroker* broker,
   return AdvancedReducer::NoChange();
 }
 
+NativeContextData::NativeContextData(JSHeapBroker* broker, ObjectData** storage,
+                                     Handle<NativeContext> object)
+    : ContextData(broker, storage, object), function_maps_(broker->zone()) {}
+
+void NativeContextData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "NativeContextData::Serialize");
+  Handle<NativeContext> context = Handle<NativeContext>::cast(object());
+
+#define SERIALIZE_MEMBER(type, name)                              \
+  DCHECK_NULL(name##_);                                           \
+  name##_ = broker->GetOrCreateData(context->name())->As##type(); \
+  if (name##_->IsJSFunction()) name##_->AsJSFunction()->Serialize(broker);
+  BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
+  if (!broker->isolate()->bootstrapper()->IsActive()) {
+    BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
+  }
+#undef SERIALIZE_MEMBER
+
+  DCHECK(function_maps_.empty());
+  int const first = Context::FIRST_FUNCTION_MAP_INDEX;
+  int const last = Context::LAST_FUNCTION_MAP_INDEX;
+  function_maps_.reserve(last + 1 - first);
+  for (int i = first; i <= last; ++i) {
+    function_maps_.push_back(broker->GetOrCreateData(context->get(i))->AsMap());
+  }
+}
+
+void JSFunctionRef::Serialize() {
+  if (broker()->mode() == JSHeapBroker::kDisabled) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsJSFunction()->Serialize(broker());
+}
+
+void JSObjectRef::SerializeObjectCreateMap() {
+  if (broker()->mode() == JSHeapBroker::kDisabled) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsJSObject()->SerializeObjectCreateMap(broker());
+}
+
+void MapRef::SerializeOwnDescriptors() {
+  if (broker()->mode() == JSHeapBroker::kDisabled) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsMap()->SerializeOwnDescriptors(broker());
+}
+
+void ModuleRef::Serialize() {
+  if (broker()->mode() == JSHeapBroker::kDisabled) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsModule()->Serialize(broker());
+}
+
+void ContextRef::Serialize() {
+  if (broker()->mode() == JSHeapBroker::kDisabled) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsContext()->Serialize(broker());
+}
+
+void NativeContextRef::Serialize() {
+  if (broker()->mode() == JSHeapBroker::kDisabled) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsNativeContext()->Serialize(broker());
+}
+
 #undef BIMODAL_ACCESSOR
 #undef BIMODAL_ACCESSOR_B
 #undef BIMODAL_ACCESSOR_C
-#undef GET_OR_CREATE
-#undef HANDLE_ACCESSOR
-#undef HANDLE_ACCESSOR_C
+#undef IF_BROKER_DISABLED_ACCESS_HANDLE
 #undef IF_BROKER_DISABLED_ACCESS_HANDLE_C
 
 }  // namespace compiler
diff --git a/deps/v8/src/compiler/js-heap-broker.h b/deps/v8/src/compiler/js-heap-broker.h
index 7ea12ee733..89f3ee871e 100644
--- a/deps/v8/src/compiler/js-heap-broker.h
+++ b/deps/v8/src/compiler/js-heap-broker.h
@@ -7,8 +7,10 @@
 
 #include "src/base/compiler-specific.h"
 #include "src/base/optional.h"
+#include "src/compiler/refs-map.h"
 #include "src/globals.h"
 #include "src/objects.h"
+#include "src/objects/builtin-function-id.h"
 #include "src/zone/zone-containers.h"
 
 namespace v8 {
@@ -25,35 +27,6 @@ enum class OddballType : uint8_t {
   kOther  // Oddball, but none of the above.
 };
 
-// TODO(neis): Get rid of the HeapObjectType class.
-class HeapObjectType {
- public:
-  enum Flag : uint8_t { kUndetectable = 1 << 0, kCallable = 1 << 1 };
-
-  typedef base::Flags<Flag> Flags;
-
-  HeapObjectType(InstanceType instance_type, Flags flags,
-                 OddballType oddball_type)
-      : instance_type_(instance_type),
-        oddball_type_(oddball_type),
-        flags_(flags) {
-    DCHECK_EQ(instance_type == ODDBALL_TYPE,
-              oddball_type != OddballType::kNone);
-  }
-
-  OddballType oddball_type() const { return oddball_type_; }
-  InstanceType instance_type() const { return instance_type_; }
-  Flags flags() const { return flags_; }
-
-  bool is_callable() const { return flags_ & kCallable; }
-  bool is_undetectable() const { return flags_ & kUndetectable; }
-
- private:
-  InstanceType const instance_type_;
-  OddballType const oddball_type_;
-  Flags const flags_;
-};
-
 // This list is sorted such that subtypes appear before their supertypes.
 // DO NOT VIOLATE THIS PROPERTY!
 #define HEAP_BROKER_OBJECT_LIST(V) \
@@ -64,6 +37,10 @@ class HeapObjectType {
   V(JSRegExp)                      \
   /* Subtypes of Context */        \
   V(NativeContext)                 \
+  /* Subtypes of FixedArray */     \
+  V(Context)                       \
+  V(ScopeInfo)                     \
+  V(ScriptContextTable)            \
   /* Subtypes of FixedArrayBase */ \
   V(BytecodeArray)                 \
   V(FixedArray)                    \
@@ -75,19 +52,17 @@ class HeapObjectType {
   V(AllocationSite)                \
   V(Cell)                          \
   V(Code)                          \
+  V(DescriptorArray)               \
   V(FeedbackVector)                \
-  V(Map)                           \
-  V(Module)                        \
-  V(ScopeInfo)                     \
-  V(ScriptContextTable)            \
-  V(SharedFunctionInfo)            \
-  V(Context)                       \
   V(FixedArrayBase)                \
   V(HeapNumber)                    \
   V(JSObject)                      \
+  V(Map)                           \
+  V(Module)                        \
   V(MutableHeapNumber)             \
   V(Name)                          \
   V(PropertyCell)                  \
+  V(SharedFunctionInfo)            \
   /* Subtypes of Object */         \
   V(HeapObject)
 
@@ -101,7 +76,10 @@ HEAP_BROKER_OBJECT_LIST(FORWARD_DECL)
 class ObjectRef {
  public:
   ObjectRef(JSHeapBroker* broker, Handle<Object> object);
-  explicit ObjectRef(ObjectData* data) : data_(data) { CHECK_NOT_NULL(data_); }
+  ObjectRef(JSHeapBroker* broker, ObjectData* data)
+      : broker_(broker), data_(data) {
+    CHECK_NOT_NULL(data_);
+  }
 
   bool equals(const ObjectRef& other) const;
 
@@ -113,8 +91,6 @@ class ObjectRef {
     return Handle<T>::cast(object());
   }
 
-  OddballType oddball_type() const;
-
   bool IsSmi() const;
   int AsSmi() const;
 
@@ -126,8 +102,7 @@ class ObjectRef {
   HEAP_BROKER_OBJECT_LIST(HEAP_AS_METHOD_DECL)
 #undef HEAP_AS_METHOD_DECL
 
-  StringRef TypeOf() const;
-  bool BooleanValue();
+  bool BooleanValue() const;
   double OddballToNumber() const;
 
   Isolate* isolate() const;
@@ -137,54 +112,94 @@ class ObjectRef {
   ObjectData* data() const;
 
  private:
+  JSHeapBroker* broker_;
   ObjectData* data_;
 };
 
+// Temporary class that carries information from a Map. We'd like to remove
+// this class and use MapRef instead, but we can't as long as we support the
+// kDisabled broker mode. That's because obtaining the MapRef via
+// HeapObjectRef::map() requires a HandleScope when the broker is disabled.
+// During OptimizeGraph we generally don't have a HandleScope, however. There
+// are two places where we therefore use GetHeapObjectType() instead. Both that
+// function and this class should eventually be removed.
+class HeapObjectType {
+ public:
+  enum Flag : uint8_t { kUndetectable = 1 << 0, kCallable = 1 << 1 };
+
+  typedef base::Flags<Flag> Flags;
+
+  HeapObjectType(InstanceType instance_type, Flags flags,
+                 OddballType oddball_type)
+      : instance_type_(instance_type),
+        oddball_type_(oddball_type),
+        flags_(flags) {
+    DCHECK_EQ(instance_type == ODDBALL_TYPE,
+              oddball_type != OddballType::kNone);
+  }
+
+  OddballType oddball_type() const { return oddball_type_; }
+  InstanceType instance_type() const { return instance_type_; }
+  Flags flags() const { return flags_; }
+
+  bool is_callable() const { return flags_ & kCallable; }
+  bool is_undetectable() const { return flags_ & kUndetectable; }
+
+ private:
+  InstanceType const instance_type_;
+  OddballType const oddball_type_;
+  Flags const flags_;
+};
+
 class HeapObjectRef : public ObjectRef {
  public:
   using ObjectRef::ObjectRef;
 
-  HeapObjectType type() const;
   MapRef map() const;
-  base::Optional<MapRef> TryGetObjectCreateMap() const;
-  bool IsSeqString() const;
-  bool IsExternalString() const;
+
+  // See the comment on the HeapObjectType class.
+  HeapObjectType GetHeapObjectType() const;
 };
 
 class PropertyCellRef : public HeapObjectRef {
  public:
   using HeapObjectRef::HeapObjectRef;
 
-  ObjectRef value() const;
   PropertyDetails property_details() const;
+  ObjectRef value() const;
 };
 
 class JSObjectRef : public HeapObjectRef {
  public:
   using HeapObjectRef::HeapObjectRef;
 
-  bool IsUnboxedDoubleField(FieldIndex index) const;
   double RawFastDoublePropertyAt(FieldIndex index) const;
   ObjectRef RawFastPropertyAt(FieldIndex index) const;
 
   FixedArrayBaseRef elements() const;
   void EnsureElementsTenured();
   ElementsKind GetElementsKind() const;
+
+  void SerializeObjectCreateMap();
+  base::Optional<MapRef> GetObjectCreateMap() const;
 };
 
 class JSFunctionRef : public JSObjectRef {
  public:
   using JSObjectRef::JSObjectRef;
 
-  bool IsConstructor() const;
   bool has_initial_map() const;
-  MapRef initial_map() const;
   bool has_prototype() const;
-  ObjectRef prototype() const;
   bool PrototypeRequiresRuntimeLookup() const;
+
+  void Serialize();
+
+  // The following are available only after calling Serialize().
+  ObjectRef prototype() const;
+  MapRef initial_map() const;
   JSGlobalProxyRef global_proxy() const;
-  int InitialMapInstanceSizeWithMinSlack() const;
   SharedFunctionInfoRef shared() const;
+  int InitialMapInstanceSizeWithMinSlack() const;
 };
 
 class JSRegExpRef : public JSObjectRef {
@@ -215,37 +230,48 @@ class MutableHeapNumberRef : public HeapObjectRef {
 class ContextRef : public HeapObjectRef {
  public:
   using HeapObjectRef::HeapObjectRef;
+  void Serialize();
 
-  base::Optional<ContextRef> previous() const;
+  ContextRef previous() const;
   ObjectRef get(int index) const;
 };
 
-#define BROKER_NATIVE_CONTEXT_FIELDS(V)       \
-  V(JSFunction, array_function)               \
-  V(JSFunction, object_function)              \
-  V(JSFunction, promise_function)             \
-  V(Map, fast_aliased_arguments_map)          \
-  V(Map, initial_array_iterator_map)          \
-  V(Map, iterator_result_map)                 \
-  V(Map, js_array_holey_double_elements_map)  \
-  V(Map, js_array_holey_elements_map)         \
-  V(Map, js_array_holey_smi_elements_map)     \
-  V(Map, js_array_packed_double_elements_map) \
-  V(Map, js_array_packed_elements_map)        \
-  V(Map, js_array_packed_smi_elements_map)    \
-  V(Map, map_key_iterator_map)                \
-  V(Map, map_key_value_iterator_map)          \
-  V(Map, map_value_iterator_map)              \
-  V(Map, set_key_value_iterator_map)          \
-  V(Map, set_value_iterator_map)              \
-  V(Map, sloppy_arguments_map)                \
-  V(Map, strict_arguments_map)                \
-  V(Map, string_iterator_map)                 \
+#define BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(V) \
+  V(JSFunction, array_function)                    \
+  V(JSFunction, object_function)                   \
+  V(JSFunction, promise_function)                  \
+  V(Map, fast_aliased_arguments_map)               \
+  V(Map, initial_array_iterator_map)               \
+  V(Map, initial_string_iterator_map)              \
+  V(Map, iterator_result_map)                      \
+  V(Map, js_array_holey_double_elements_map)       \
+  V(Map, js_array_holey_elements_map)              \
+  V(Map, js_array_holey_smi_elements_map)          \
+  V(Map, js_array_packed_double_elements_map)      \
+  V(Map, js_array_packed_elements_map)             \
+  V(Map, js_array_packed_smi_elements_map)         \
+  V(Map, sloppy_arguments_map)                     \
+  V(Map, slow_object_with_null_prototype_map)      \
+  V(Map, strict_arguments_map)                     \
   V(ScriptContextTable, script_context_table)
 
+// Those are set by Bootstrapper::ExportFromRuntime, which may not yet have
+// happened when Turbofan is invoked via --always-opt.
+#define BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(V) \
+  V(Map, map_key_iterator_map)                   \
+  V(Map, map_key_value_iterator_map)             \
+  V(Map, map_value_iterator_map)                 \
+  V(Map, set_key_value_iterator_map)             \
+  V(Map, set_value_iterator_map)
+
+#define BROKER_NATIVE_CONTEXT_FIELDS(V)      \
+  BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(V) \
+  BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(V)
+
 class NativeContextRef : public ContextRef {
  public:
   using ContextRef::ContextRef;
+  void Serialize();
 
 #define DECL_ACCESSOR(type, name) type##Ref name() const;
   BROKER_NATIVE_CONTEXT_FIELDS(DECL_ACCESSOR)
@@ -273,11 +299,18 @@ class ScriptContextTableRef : public HeapObjectRef {
   base::Optional<LookupResult> lookup(const NameRef& name) const;
 };
 
+class DescriptorArrayRef : public HeapObjectRef {
+ public:
+  using HeapObjectRef::HeapObjectRef;
+};
+
 class FeedbackVectorRef : public HeapObjectRef {
  public:
   using HeapObjectRef::HeapObjectRef;
 
   ObjectRef get(FeedbackSlot slot) const;
+
+  void SerializeSlots();
 };
 
 class AllocationSiteRef : public HeapObjectRef {
@@ -313,25 +346,32 @@ class MapRef : public HeapObjectRef {
   int GetInObjectPropertyOffset(int index) const;
   ElementsKind elements_kind() const;
   bool is_stable() const;
+  bool is_constructor() const;
   bool has_prototype_slot() const;
   bool is_deprecated() const;
   bool CanBeDeprecated() const;
   bool CanTransition() const;
   bool IsInobjectSlackTrackingInProgress() const;
   bool is_dictionary_map() const;
-  bool IsJSArrayMap() const;
   bool IsFixedCowArrayMap() const;
+  bool is_undetectable() const;
+  bool is_callable() const;
 
   ObjectRef constructor_or_backpointer() const;
+  ObjectRef prototype() const;
+
+  OddballType oddball_type() const;
 
   base::Optional<MapRef> AsElementsKind(ElementsKind kind) const;
 
   // Concerning the underlying instance_descriptors:
-  MapRef FindFieldOwner(int descriptor) const;
-  PropertyDetails GetPropertyDetails(int i) const;
-  NameRef GetPropertyKey(int i) const;
-  FieldIndex GetFieldIndexFor(int i) const;
-  ObjectRef GetFieldType(int descriptor) const;
+  void SerializeOwnDescriptors();
+  MapRef FindFieldOwner(int descriptor_index) const;
+  PropertyDetails GetPropertyDetails(int descriptor_index) const;
+  NameRef GetPropertyKey(int descriptor_index) const;
+  FieldIndex GetFieldIndexFor(int descriptor_index) const;
+  ObjectRef GetFieldType(int descriptor_index) const;
+  bool IsUnboxedDoubleField(int descriptor_index) const;
 };
 
 class FixedArrayBaseRef : public HeapObjectRef {
@@ -346,7 +386,6 @@ class FixedArrayRef : public FixedArrayBaseRef {
   using FixedArrayBaseRef::FixedArrayBaseRef;
 
   ObjectRef get(int i) const;
-  bool is_the_hole(int i) const;
 };
 
 class FixedDoubleArrayRef : public FixedArrayBaseRef {
@@ -400,7 +439,7 @@ class SharedFunctionInfoRef : public HeapObjectRef {
   BytecodeArrayRef GetBytecodeArray() const;
 #define DECL_ACCESSOR(type, name) type name() const;
   BROKER_SFI_FIELDS(DECL_ACCESSOR)
-#undef DECL_ACCSESOR
+#undef DECL_ACCESSOR
 };
 
 class StringRef : public NameRef {
@@ -410,13 +449,17 @@ class StringRef : public NameRef {
   int length() const;
   uint16_t GetFirstChar();
   base::Optional<double> ToNumber();
+  bool IsSeqString() const;
+  bool IsExternalString() const;
 };
 
 class ModuleRef : public HeapObjectRef {
  public:
   using HeapObjectRef::HeapObjectRef;
 
-  CellRef GetCell(int cell_index);
+  void Serialize();
+
+  CellRef GetCell(int cell_index) const;
 };
 
 class CellRef : public HeapObjectRef {
@@ -439,48 +482,56 @@ class InternalizedStringRef : public StringRef {
   using StringRef::StringRef;
 };
 
+class PerIsolateCompilerCache;
+
 class V8_EXPORT_PRIVATE JSHeapBroker : public NON_EXPORTED_BASE(ZoneObject) {
  public:
-  JSHeapBroker(Isolate* isolate, Zone* zone);
+  JSHeapBroker(Isolate* isolate, Zone* broker_zone);
+  void SetNativeContextRef();
   void SerializeStandardObjects();
 
-  HeapObjectType HeapObjectTypeFromMap(Handle<Map> map) const {
-    AllowHandleDereference handle_dereference;
-    return HeapObjectTypeFromMap(*map);
-  }
-
   Isolate* isolate() const { return isolate_; }
-  Zone* zone() const { return zone_; }
+  Zone* zone() const { return current_zone_; }
+  NativeContextRef native_context() const { return native_context_.value(); }
+  PerIsolateCompilerCache* compiler_cache() const { return compiler_cache_; }
 
-  enum BrokerMode { kDisabled, kSerializing, kSerialized };
+  enum BrokerMode { kDisabled, kSerializing, kSerialized, kRetired };
   BrokerMode mode() const { return mode_; }
-  void StopSerializing() {
-    CHECK_EQ(mode_, kSerializing);
-    mode_ = kSerialized;
-  }
+  void StartSerializing();
+  void StopSerializing();
+  void Retire();
   bool SerializingAllowed() const;
 
   // Returns nullptr iff handle unknown.
   ObjectData* GetData(Handle<Object>) const;
   // Never returns nullptr.
   ObjectData* GetOrCreateData(Handle<Object>);
+  // Like the previous but wraps argument in handle first (for convenience).
+  ObjectData* GetOrCreateData(Object*);
 
   void Trace(const char* format, ...) const;
+  void IncrementTracingIndentation();
+  void DecrementTracingIndentation();
 
  private:
   friend class HeapObjectRef;
   friend class ObjectRef;
   friend class ObjectData;
 
-  // TODO(neis): Remove eventually.
-  HeapObjectType HeapObjectTypeFromMap(Map* map) const;
-
-  void AddData(Handle<Object> object, ObjectData* data);
+  void SerializeShareableObjects();
 
   Isolate* const isolate_;
-  Zone* const zone_;
-  ZoneUnorderedMap<Address, ObjectData*> refs_;
-  BrokerMode mode_;
+  Zone* const broker_zone_;
+  Zone* current_zone_;
+  base::Optional<NativeContextRef> native_context_;
+  RefsMap* refs_;
+
+  BrokerMode mode_ = kDisabled;
+  unsigned tracing_indentation_ = 0;
+  PerIsolateCompilerCache* compiler_cache_;
+
+  static const size_t kMinimalRefsBucketCount = 8;     // must be power of 2
+  static const size_t kInitialRefsBucketCount = 1024;  // must be power of 2
 };
 
 #define ASSIGN_RETURN_NO_CHANGE_IF_DATA_MISSING(something_var,          \
diff --git a/deps/v8/src/compiler/js-heap-copy-reducer.cc b/deps/v8/src/compiler/js-heap-copy-reducer.cc
index 0bcc662771..ca510d5054 100644
--- a/deps/v8/src/compiler/js-heap-copy-reducer.cc
+++ b/deps/v8/src/compiler/js-heap-copy-reducer.cc
@@ -7,6 +7,7 @@
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-heap-broker.h"
 #include "src/compiler/js-operator.h"
+#include "src/compiler/node-properties.h"
 #include "src/heap/factory-inl.h"
 #include "src/objects/map.h"
 #include "src/objects/scope-info.h"
@@ -25,7 +26,11 @@ JSHeapBroker* JSHeapCopyReducer::broker() { return broker_; }
 Reduction JSHeapCopyReducer::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kHeapConstant: {
-      ObjectRef(broker(), HeapConstantOf(node->op()));
+      ObjectRef object(broker(), HeapConstantOf(node->op()));
+      if (object.IsJSFunction()) object.AsJSFunction().Serialize();
+      if (object.IsJSObject()) object.AsJSObject().SerializeObjectCreateMap();
+      if (object.IsModule()) object.AsModule().Serialize();
+      if (object.IsContext()) object.AsContext().Serialize();
       break;
     }
     case IrOpcode::kJSCreateArray: {
@@ -34,6 +39,23 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
       if (p.site().ToHandle(&site)) AllocationSiteRef(broker(), site);
       break;
     }
+    case IrOpcode::kJSCreateArguments: {
+      Node* const frame_state = NodeProperties::GetFrameStateInput(node);
+      FrameStateInfo state_info = FrameStateInfoOf(frame_state->op());
+      SharedFunctionInfoRef shared(broker(),
+                                   state_info.shared_info().ToHandleChecked());
+      break;
+    }
+    case IrOpcode::kJSCreateBlockContext: {
+      ScopeInfoRef(broker(), ScopeInfoOf(node->op()));
+      break;
+    }
+    case IrOpcode::kJSCreateBoundFunction: {
+      CreateBoundFunctionParameters const& p =
+          CreateBoundFunctionParametersOf(node->op());
+      MapRef(broker(), p.map());
+      break;
+    }
     case IrOpcode::kJSCreateCatchContext: {
       ScopeInfoRef(broker(), ScopeInfoOf(node->op()));
       break;
@@ -46,14 +68,8 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
       break;
     }
     case IrOpcode::kJSCreateEmptyLiteralArray: {
-      // TODO(neis, jarin) Force serialization of the entire feedback vector
-      // rather than just the one element.
       FeedbackParameter const& p = FeedbackParameterOf(node->op());
-      FeedbackVectorRef(broker(), p.feedback().vector());
-      Handle<Object> feedback(
-          p.feedback().vector()->Get(p.feedback().slot())->ToObject(),
-          broker()->isolate());
-      ObjectRef(broker(), feedback);
+      FeedbackVectorRef(broker(), p.feedback().vector()).SerializeSlots();
       break;
     }
     case IrOpcode::kJSCreateFunctionContext: {
@@ -65,7 +81,16 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
     case IrOpcode::kJSCreateLiteralArray:
     case IrOpcode::kJSCreateLiteralObject: {
       CreateLiteralParameters const& p = CreateLiteralParametersOf(node->op());
-      ObjectRef(broker(), p.feedback().vector());
+      FeedbackVectorRef(broker(), p.feedback().vector()).SerializeSlots();
+      break;
+    }
+    case IrOpcode::kJSCreateLiteralRegExp: {
+      CreateLiteralParameters const& p = CreateLiteralParametersOf(node->op());
+      FeedbackVectorRef(broker(), p.feedback().vector()).SerializeSlots();
+      break;
+    }
+    case IrOpcode::kJSCreateWithContext: {
+      ScopeInfoRef(broker(), ScopeInfoOf(node->op()));
       break;
     }
     case IrOpcode::kJSLoadNamed:
diff --git a/deps/v8/src/compiler/js-heap-copy-reducer.h b/deps/v8/src/compiler/js-heap-copy-reducer.h
index b94b930d78..1041a00fab 100644
--- a/deps/v8/src/compiler/js-heap-copy-reducer.h
+++ b/deps/v8/src/compiler/js-heap-copy-reducer.h
@@ -17,7 +17,7 @@ class JSHeapBroker;
 // by handles embedded in the graph is copied to the heap broker.
 // TODO(jarin) This is just a temporary solution until the graph uses only
 // ObjetRef-derived reference to refer to the heap data.
-class JSHeapCopyReducer : public Reducer {
+class V8_EXPORT_PRIVATE JSHeapCopyReducer : public Reducer {
  public:
   explicit JSHeapCopyReducer(JSHeapBroker* broker);
 
diff --git a/deps/v8/src/compiler/js-inlining.cc b/deps/v8/src/compiler/js-inlining.cc
index 2f31772883..3c5b1b8046 100644
--- a/deps/v8/src/compiler/js-inlining.cc
+++ b/deps/v8/src/compiler/js-inlining.cc
@@ -234,7 +234,8 @@ Node* JSInliner::CreateArtificialFrameState(Node* node, Node* outer_frame_state,
                                             int parameter_count,
                                             BailoutId bailout_id,
                                             FrameStateType frame_state_type,
-                                            Handle<SharedFunctionInfo> shared) {
+                                            Handle<SharedFunctionInfo> shared,
+                                            Node* context) {
   const FrameStateFunctionInfo* state_info =
       common()->CreateFrameStateFunctionInfo(frame_state_type,
                                              parameter_count + 1, 0, shared);
@@ -251,9 +252,11 @@ Node* JSInliner::CreateArtificialFrameState(Node* node, Node* outer_frame_state,
       static_cast<int>(params.size()), SparseInputMask::Dense());
   Node* params_node = graph()->NewNode(
       op_param, static_cast<int>(params.size()), &params.front());
-  return graph()->NewNode(op, params_node, node0, node0,
-                          jsgraph()->UndefinedConstant(), node->InputAt(0),
-                          outer_frame_state);
+  if (!context) {
+    context = jsgraph()->UndefinedConstant();
+  }
+  return graph()->NewNode(op, params_node, node0, node0, context,
+                          node->InputAt(0), outer_frame_state);
 }
 
 namespace {
@@ -536,14 +539,14 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
     // instantiation but before the invocation (i.e. inside {JSConstructStub}
     // where execution continues at {construct_stub_create_deopt_pc_offset}).
     Node* receiver = jsgraph()->TheHoleConstant();  // Implicit receiver.
+    Node* context = NodeProperties::GetContextInput(node);
     if (NeedsImplicitReceiver(shared_info)) {
       Node* effect = NodeProperties::GetEffectInput(node);
       Node* control = NodeProperties::GetControlInput(node);
-      Node* context = NodeProperties::GetContextInput(node);
       Node* frame_state_inside = CreateArtificialFrameState(
           node, frame_state, call.formal_arguments(),
           BailoutId::ConstructStubCreate(), FrameStateType::kConstructStub,
-          shared_info);
+          shared_info, context);
       Node* create =
           graph()->NewNode(javascript()->Create(), call.target(), new_target,
                            context, frame_state_inside, effect, control);
@@ -595,10 +598,10 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
     node->ReplaceInput(1, receiver);
     // Insert a construct stub frame into the chain of frame states. This will
     // reconstruct the proper frame when deoptimizing within the constructor.
-    frame_state =
-        CreateArtificialFrameState(node, frame_state, call.formal_arguments(),
-                                   BailoutId::ConstructStubInvoke(),
-                                   FrameStateType::kConstructStub, shared_info);
+    frame_state = CreateArtificialFrameState(
+        node, frame_state, call.formal_arguments(),
+        BailoutId::ConstructStubInvoke(), FrameStateType::kConstructStub,
+        shared_info, context);
   }
 
   // Insert a JSConvertReceiver node for sloppy callees. Note that the context
diff --git a/deps/v8/src/compiler/js-inlining.h b/deps/v8/src/compiler/js-inlining.h
index 1c7ee6c0b8..baca345f27 100644
--- a/deps/v8/src/compiler/js-inlining.h
+++ b/deps/v8/src/compiler/js-inlining.h
@@ -63,7 +63,8 @@ class JSInliner final : public AdvancedReducer {
   Node* CreateArtificialFrameState(Node* node, Node* outer_frame_state,
                                    int parameter_count, BailoutId bailout_id,
                                    FrameStateType frame_state_type,
-                                   Handle<SharedFunctionInfo> shared);
+                                   Handle<SharedFunctionInfo> shared,
+                                   Node* context = nullptr);
 
   Reduction InlineCall(Node* call, Node* new_target, Node* context,
                        Node* frame_state, Node* start, Node* end,
diff --git a/deps/v8/src/compiler/js-intrinsic-lowering.cc b/deps/v8/src/compiler/js-intrinsic-lowering.cc
index 194e876849..b132cfa6e9 100644
--- a/deps/v8/src/compiler/js-intrinsic-lowering.cc
+++ b/deps/v8/src/compiler/js-intrinsic-lowering.cc
@@ -32,16 +32,12 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
   switch (f->function_id) {
     case Runtime::kInlineCreateIterResultObject:
       return ReduceCreateIterResultObject(node);
-    case Runtime::kInlineDebugIsActive:
-      return ReduceDebugIsActive(node);
     case Runtime::kInlineDeoptimizeNow:
       return ReduceDeoptimizeNow(node);
     case Runtime::kInlineGeneratorClose:
       return ReduceGeneratorClose(node);
     case Runtime::kInlineCreateJSGeneratorObject:
       return ReduceCreateJSGeneratorObject(node);
-    case Runtime::kInlineGeneratorGetInputOrDebugPos:
-      return ReduceGeneratorGetInputOrDebugPos(node);
     case Runtime::kInlineAsyncGeneratorReject:
       return ReduceAsyncGeneratorReject(node);
     case Runtime::kInlineAsyncGeneratorResolve:
@@ -54,8 +50,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceIsInstanceType(node, JS_ARRAY_TYPE);
     case Runtime::kInlineIsTypedArray:
       return ReduceIsInstanceType(node, JS_TYPED_ARRAY_TYPE);
-    case Runtime::kInlineIsJSProxy:
-      return ReduceIsInstanceType(node, JS_PROXY_TYPE);
     case Runtime::kInlineIsJSReceiver:
       return ReduceIsJSReceiver(node);
     case Runtime::kInlineIsSmi:
@@ -64,12 +58,8 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceRejectPromise(node);
     case Runtime::kInlineResolvePromise:
       return ReduceResolvePromise(node);
-    case Runtime::kInlineToInteger:
-      return ReduceToInteger(node);
     case Runtime::kInlineToLength:
       return ReduceToLength(node);
-    case Runtime::kInlineToNumber:
-      return ReduceToNumber(node);
     case Runtime::kInlineToObject:
       return ReduceToObject(node);
     case Runtime::kInlineToString:
@@ -92,16 +82,6 @@ Reduction JSIntrinsicLowering::ReduceCreateIterResultObject(Node* node) {
                 context, effect);
 }
 
-Reduction JSIntrinsicLowering::ReduceDebugIsActive(Node* node) {
-  Node* const value = jsgraph()->ExternalConstant(
-      ExternalReference::debug_is_active_address(isolate()));
-  Node* const effect = NodeProperties::GetEffectInput(node);
-  Node* const control = NodeProperties::GetControlInput(node);
-  Operator const* const op =
-      simplified()->LoadField(AccessBuilder::ForExternalUint8Value());
-  return Change(node, op, value, effect, control);
-}
-
 Reduction JSIntrinsicLowering::ReduceDeoptimizeNow(Node* node) {
   Node* const frame_state = NodeProperties::GetFrameStateInput(node);
   Node* const effect = NodeProperties::GetEffectInput(node);
@@ -147,16 +127,6 @@ Reduction JSIntrinsicLowering::ReduceGeneratorClose(Node* node) {
   return Change(node, op, generator, closed, effect, control);
 }
 
-Reduction JSIntrinsicLowering::ReduceGeneratorGetInputOrDebugPos(Node* node) {
-  Node* const generator = NodeProperties::GetValueInput(node, 0);
-  Node* const effect = NodeProperties::GetEffectInput(node);
-  Node* const control = NodeProperties::GetControlInput(node);
-  Operator const* const op = simplified()->LoadField(
-      AccessBuilder::ForJSGeneratorObjectInputOrDebugPos());
-
-  return Change(node, op, generator, effect, control);
-}
-
 Reduction JSIntrinsicLowering::ReduceAsyncGeneratorReject(Node* node) {
   return Change(
       node, Builtins::CallableFor(isolate(), Builtins::kAsyncGeneratorReject),
@@ -258,17 +228,6 @@ Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op) {
   return Changed(node);
 }
 
-Reduction JSIntrinsicLowering::ReduceToInteger(Node* node) {
-  NodeProperties::ChangeOp(node, javascript()->ToInteger());
-  return Changed(node);
-}
-
-
-Reduction JSIntrinsicLowering::ReduceToNumber(Node* node) {
-  NodeProperties::ChangeOp(node, javascript()->ToNumber());
-  return Changed(node);
-}
-
 
 Reduction JSIntrinsicLowering::ReduceToLength(Node* node) {
   NodeProperties::ChangeOp(node, javascript()->ToLength());
@@ -300,11 +259,6 @@ Reduction JSIntrinsicLowering::ReduceCall(Node* node) {
   return Changed(node);
 }
 
-Reduction JSIntrinsicLowering::ReduceGetSuperConstructor(Node* node) {
-  NodeProperties::ChangeOp(node, javascript()->GetSuperConstructor());
-  return Changed(node);
-}
-
 Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op, Node* a,
                                       Node* b) {
   RelaxControls(node);
diff --git a/deps/v8/src/compiler/js-intrinsic-lowering.h b/deps/v8/src/compiler/js-intrinsic-lowering.h
index e0a55d7b06..f71af1156c 100644
--- a/deps/v8/src/compiler/js-intrinsic-lowering.h
+++ b/deps/v8/src/compiler/js-intrinsic-lowering.h
@@ -32,7 +32,7 @@ class V8_EXPORT_PRIVATE JSIntrinsicLowering final
     : public NON_EXPORTED_BASE(AdvancedReducer) {
  public:
   JSIntrinsicLowering(Editor* editor, JSGraph* jsgraph);
-  ~JSIntrinsicLowering() final {}
+  ~JSIntrinsicLowering() final = default;
 
   const char* reducer_name() const override { return "JSIntrinsicLowering"; }
 
@@ -40,11 +40,9 @@ class V8_EXPORT_PRIVATE JSIntrinsicLowering final
 
  private:
   Reduction ReduceCreateIterResultObject(Node* node);
-  Reduction ReduceDebugIsActive(Node* node);
   Reduction ReduceDeoptimizeNow(Node* node);
   Reduction ReduceCreateJSGeneratorObject(Node* node);
   Reduction ReduceGeneratorClose(Node* node);
-  Reduction ReduceGeneratorGetInputOrDebugPos(Node* node);
   Reduction ReduceAsyncGeneratorReject(Node* node);
   Reduction ReduceAsyncGeneratorResolve(Node* node);
   Reduction ReduceAsyncGeneratorYield(Node* node);
@@ -55,13 +53,10 @@ class V8_EXPORT_PRIVATE JSIntrinsicLowering final
   Reduction ReduceIsSmi(Node* node);
   Reduction ReduceRejectPromise(Node* node);
   Reduction ReduceResolvePromise(Node* node);
-  Reduction ReduceToInteger(Node* node);
   Reduction ReduceToLength(Node* node);
-  Reduction ReduceToNumber(Node* node);
   Reduction ReduceToObject(Node* node);
   Reduction ReduceToString(Node* node);
   Reduction ReduceCall(Node* node);
-  Reduction ReduceGetSuperConstructor(Node* node);
 
   Reduction Change(Node* node, const Operator* op);
   Reduction Change(Node* node, const Operator* op, Node* a, Node* b);
diff --git a/deps/v8/src/compiler/js-native-context-specialization.cc b/deps/v8/src/compiler/js-native-context-specialization.cc
index e35a860be0..d449e72367 100644
--- a/deps/v8/src/compiler/js-native-context-specialization.cc
+++ b/deps/v8/src/compiler/js-native-context-specialization.cc
@@ -17,12 +17,14 @@
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/property-access-builder.h"
 #include "src/compiler/type-cache.h"
+#include "src/dtoa.h"
 #include "src/feedback-vector.h"
 #include "src/field-index-inl.h"
 #include "src/isolate-inl.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/js-array-inl.h"
 #include "src/objects/templates.h"
+#include "src/string-constants.h"
 #include "src/vector-slot-pair.h"
 
 namespace v8 {
@@ -62,7 +64,7 @@ struct JSNativeContextSpecialization::ScriptContextTableLookupResult {
 JSNativeContextSpecialization::JSNativeContextSpecialization(
     Editor* editor, JSGraph* jsgraph, JSHeapBroker* js_heap_broker, Flags flags,
     Handle<Context> native_context, CompilationDependencies* dependencies,
-    Zone* zone)
+    Zone* zone, Zone* shared_zone)
     : AdvancedReducer(editor),
       jsgraph_(jsgraph),
       js_heap_broker_(js_heap_broker),
@@ -73,6 +75,7 @@ JSNativeContextSpecialization::JSNativeContextSpecialization(
       native_context_(js_heap_broker, native_context),
       dependencies_(dependencies),
       zone_(zone),
+      shared_zone_(shared_zone),
       type_cache_(TypeCache::Get()) {}
 
 Reduction JSNativeContextSpecialization::Reduce(Node* node) {
@@ -113,12 +116,98 @@ Reduction JSNativeContextSpecialization::Reduce(Node* node) {
       return ReduceJSStoreInArrayLiteral(node);
     case IrOpcode::kJSToObject:
       return ReduceJSToObject(node);
+    case IrOpcode::kJSToString:
+      return ReduceJSToString(node);
     default:
       break;
   }
   return NoChange();
 }
 
+// static
+base::Optional<size_t> JSNativeContextSpecialization::GetMaxStringLength(
+    JSHeapBroker* broker, Node* node) {
+  if (node->opcode() == IrOpcode::kDelayedStringConstant) {
+    return StringConstantBaseOf(node->op())->GetMaxStringConstantLength();
+  }
+
+  HeapObjectMatcher matcher(node);
+  if (matcher.HasValue() && matcher.Ref(broker).IsString()) {
+    StringRef input = matcher.Ref(broker).AsString();
+    return input.length();
+  }
+
+  NumberMatcher number_matcher(node);
+  if (number_matcher.HasValue()) {
+    return kBase10MaximalLength + 1;
+  }
+
+  // We don't support objects with possibly monkey-patched prototype.toString
+  // as it might have side-effects, so we shouldn't attempt lowering them.
+  return base::nullopt;
+}
+
+Reduction JSNativeContextSpecialization::ReduceJSToString(Node* node) {
+  DCHECK_EQ(IrOpcode::kJSToString, node->opcode());
+  Node* const input = node->InputAt(0);
+  Reduction reduction;
+
+  HeapObjectMatcher matcher(input);
+  if (matcher.HasValue() && matcher.Ref(js_heap_broker()).IsString()) {
+    reduction = Changed(input);  // JSToString(x:string) => x
+    ReplaceWithValue(node, reduction.replacement());
+    return reduction;
+  }
+
+  // TODO(turbofan): This optimization is weaker than what we used to have
+  // in js-typed-lowering for OrderedNumbers. We don't have types here though,
+  // so alternative approach should be designed if this causes performance
+  // regressions and the stronger optimization should be re-implemented.
+  NumberMatcher number_matcher(input);
+  if (number_matcher.HasValue()) {
+    const StringConstantBase* base =
+        new (shared_zone()) NumberToStringConstant(number_matcher.Value());
+    reduction =
+        Replace(graph()->NewNode(common()->DelayedStringConstant(base)));
+    ReplaceWithValue(node, reduction.replacement());
+    return reduction;
+  }
+
+  return NoChange();
+}
+
+const StringConstantBase*
+JSNativeContextSpecialization::CreateDelayedStringConstant(Node* node) {
+  if (node->opcode() == IrOpcode::kDelayedStringConstant) {
+    return StringConstantBaseOf(node->op());
+  } else {
+    NumberMatcher number_matcher(node);
+    if (number_matcher.HasValue()) {
+      return new (shared_zone()) NumberToStringConstant(number_matcher.Value());
+    } else {
+      HeapObjectMatcher matcher(node);
+      if (matcher.HasValue() && matcher.Ref(js_heap_broker()).IsString()) {
+        StringRef s = matcher.Ref(js_heap_broker()).AsString();
+        return new (shared_zone())
+            StringLiteral(s.object<String>(), static_cast<size_t>(s.length()));
+      } else {
+        UNREACHABLE();
+      }
+    }
+  }
+}
+
+namespace {
+bool IsStringConstant(JSHeapBroker* broker, Node* node) {
+  if (node->opcode() == IrOpcode::kDelayedStringConstant) {
+    return true;
+  }
+
+  HeapObjectMatcher matcher(node);
+  return matcher.HasValue() && matcher.Ref(broker).IsString();
+}
+}
+
 Reduction JSNativeContextSpecialization::ReduceJSAdd(Node* node) {
   // TODO(turbofan): This has to run together with the inlining and
   // native context specialization to be able to leverage the string
@@ -126,20 +215,30 @@ Reduction JSNativeContextSpecialization::ReduceJSAdd(Node* node) {
   // nevertheless find a better home for this at some point.
   DCHECK_EQ(IrOpcode::kJSAdd, node->opcode());
 
-  // Constant-fold string concatenation.
-  HeapObjectBinopMatcher m(node);
-  if (m.left().HasValue() && m.left().Value()->IsString() &&
-      m.right().HasValue() && m.right().Value()->IsString()) {
-    Handle<String> left = Handle<String>::cast(m.left().Value());
-    Handle<String> right = Handle<String>::cast(m.right().Value());
-    if (left->length() + right->length() <= String::kMaxLength) {
-      Handle<String> result =
-          factory()->NewConsString(left, right).ToHandleChecked();
-      Node* value = jsgraph()->HeapConstant(result);
-      ReplaceWithValue(node, value);
-      return Replace(value);
-    }
+  Node* const lhs = node->InputAt(0);
+  Node* const rhs = node->InputAt(1);
+
+  base::Optional<size_t> lhs_len = GetMaxStringLength(js_heap_broker(), lhs);
+  base::Optional<size_t> rhs_len = GetMaxStringLength(js_heap_broker(), rhs);
+  if (!lhs_len || !rhs_len) {
+    return NoChange();
   }
+
+  // Fold into DelayedStringConstant if at least one of the parameters is a
+  // string constant and the addition won't throw due to too long result.
+  if (*lhs_len + *rhs_len <= String::kMaxLength &&
+      (IsStringConstant(js_heap_broker(), lhs) ||
+       IsStringConstant(js_heap_broker(), rhs))) {
+    const StringConstantBase* left = CreateDelayedStringConstant(lhs);
+    const StringConstantBase* right = CreateDelayedStringConstant(rhs);
+    const StringConstantBase* cons =
+        new (shared_zone()) StringCons(left, right);
+
+    Node* reduced = graph()->NewNode(common()->DelayedStringConstant(cons));
+    ReplaceWithValue(node, reduced);
+    return Replace(reduced);
+  }
+
   return NoChange();
 }
 
@@ -151,15 +250,16 @@ Reduction JSNativeContextSpecialization::ReduceJSGetSuperConstructor(
   // Check if the input is a known JSFunction.
   HeapObjectMatcher m(constructor);
   if (!m.HasValue()) return NoChange();
-  Handle<JSFunction> function = Handle<JSFunction>::cast(m.Value());
-  Handle<Map> function_map(function->map(), isolate());
-  Handle<Object> function_prototype(function_map->prototype(), isolate());
+  JSFunctionRef function = m.Ref(js_heap_broker()).AsJSFunction();
+  MapRef function_map = function.map();
+  ObjectRef function_prototype = function_map.prototype();
 
   // We can constant-fold the super constructor access if the
   // {function}s map is stable, i.e. we can use a code dependency
   // to guard against [[Prototype]] changes of {function}.
-  if (function_map->is_stable() && function_prototype->IsConstructor()) {
-    dependencies()->DependOnStableMap(MapRef(js_heap_broker(), function_map));
+  if (function_map.is_stable() && function_prototype.IsHeapObject() &&
+      function_prototype.AsHeapObject().map().is_constructor()) {
+    dependencies()->DependOnStableMap(function_map);
     Node* value = jsgraph()->Constant(function_prototype);
     ReplaceWithValue(node, value);
     return Replace(value);
@@ -405,28 +505,27 @@ Reduction JSNativeContextSpecialization::ReduceJSOrdinaryHasInstance(
     return reduction.Changed() ? reduction : Changed(node);
   }
 
-  // Check if the {constructor} is a JSFunction.
+  // Optimize if we currently know the "prototype" property.
   if (m.Value()->IsJSFunction()) {
-    // Check if the {function} is a constructor and has an instance "prototype".
-    Handle<JSFunction> function = Handle<JSFunction>::cast(m.Value());
-    if (function->IsConstructor() && function->has_prototype_slot() &&
-        function->has_instance_prototype() &&
-        function->prototype()->IsJSReceiver()) {
-      // We need {function}'s initial map so that we can depend on it for the
-      // prototype constant-folding below.
-      if (!function->has_initial_map()) return NoChange();
-      MapRef initial_map = dependencies()->DependOnInitialMap(
-          JSFunctionRef(js_heap_broker(), function));
-      Node* prototype = jsgraph()->Constant(
-          handle(initial_map.object<Map>()->prototype(), isolate()));
-
-      // Lower the {node} to JSHasInPrototypeChain.
-      NodeProperties::ReplaceValueInput(node, object, 0);
-      NodeProperties::ReplaceValueInput(node, prototype, 1);
-      NodeProperties::ChangeOp(node, javascript()->HasInPrototypeChain());
-      Reduction const reduction = ReduceJSHasInPrototypeChain(node);
-      return reduction.Changed() ? reduction : Changed(node);
+    JSFunctionRef function = m.Ref(js_heap_broker()).AsJSFunction();
+    // TODO(neis): This is a temporary hack needed because the copy reducer
+    // runs only after this pass.
+    function.Serialize();
+    // TODO(neis): Remove the has_prototype_slot condition once the broker is
+    // always enabled.
+    if (!function.map().has_prototype_slot() || !function.has_prototype() ||
+        function.PrototypeRequiresRuntimeLookup()) {
+      return NoChange();
     }
+    ObjectRef prototype = dependencies()->DependOnPrototypeProperty(function);
+    Node* prototype_constant = jsgraph()->Constant(prototype);
+
+    // Lower the {node} to JSHasInPrototypeChain.
+    NodeProperties::ReplaceValueInput(node, object, 0);
+    NodeProperties::ReplaceValueInput(node, prototype_constant, 1);
+    NodeProperties::ChangeOp(node, javascript()->HasInPrototypeChain());
+    Reduction const reduction = ReduceJSHasInPrototypeChain(node);
+    return reduction.Changed() ? reduction : Changed(node);
   }
 
   return NoChange();
@@ -444,9 +543,11 @@ Reduction JSNativeContextSpecialization::ReduceJSPromiseResolve(Node* node) {
 
   // Check if the {constructor} is the %Promise% function.
   HeapObjectMatcher m(constructor);
-  if (!m.Is(handle(native_context().object<Context>()->promise_function(),
-                   isolate())))
+  if (!m.HasValue() ||
+      !m.Ref(js_heap_broker())
+           .equals(js_heap_broker()->native_context().promise_function())) {
     return NoChange();
+  }
 
   // Check if we know something about the {value}.
   ZoneHandleSet<Map> value_maps;
@@ -636,20 +737,19 @@ Reduction JSNativeContextSpecialization::ReduceGlobalAccess(
             property_cell_value_type = Type::Number();
             representation = MachineRepresentation::kTaggedPointer;
           } else {
-            Handle<Map> property_cell_value_map(
-                Handle<HeapObject>::cast(property_cell_value)->map(),
-                isolate());
-            property_cell_value_type =
-                Type::For(js_heap_broker(), property_cell_value_map);
+            MapRef property_cell_value_map(
+                js_heap_broker(),
+                handle(HeapObject::cast(*property_cell_value)->map(),
+                       isolate()));
+            property_cell_value_type = Type::For(property_cell_value_map);
             representation = MachineRepresentation::kTaggedPointer;
 
             // We can only use the property cell value map for map check
             // elimination if it's stable, i.e. the HeapObject wasn't
             // mutated without the cell state being updated.
-            if (property_cell_value_map->is_stable()) {
-              dependencies()->DependOnStableMap(
-                  MapRef(js_heap_broker(), property_cell_value_map));
-              map = property_cell_value_map;
+            if (property_cell_value_map.is_stable()) {
+              dependencies()->DependOnStableMap(property_cell_value_map);
+              map = property_cell_value_map.object<Map>();
             }
           }
         }
@@ -752,8 +852,8 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadGlobal(Node* node) {
       native_context().script_context_table().lookup(name);
   if (result) {
     ObjectRef contents = result->context.get(result->index);
-    OddballType oddball_type = contents.oddball_type();
-    if (oddball_type == OddballType::kHole) {
+    if (contents.IsHeapObject() &&
+        contents.AsHeapObject().map().oddball_type() == OddballType::kHole) {
       return NoChange();
     }
     Node* context = jsgraph()->Constant(result->context);
@@ -781,8 +881,9 @@ Reduction JSNativeContextSpecialization::ReduceJSStoreGlobal(Node* node) {
       native_context().script_context_table().lookup(name);
   if (result) {
     ObjectRef contents = result->context.get(result->index);
-    OddballType oddball_type = contents.oddball_type();
-    if (oddball_type == OddballType::kHole || result->immutable) {
+    if ((contents.IsHeapObject() &&
+         contents.AsHeapObject().map().oddball_type() == OddballType::kHole) ||
+        result->immutable) {
       return NoChange();
     }
     Node* context = jsgraph()->Constant(result->context);
@@ -1002,6 +1103,16 @@ Reduction JSNativeContextSpecialization::ReduceNamedAccess(
           this_effect = graph()->NewNode(simplified()->MapGuard(maps), receiver,
                                          this_effect, this_control);
         }
+
+        // If all {receiver_maps} are Strings we also need to rename the
+        // {receiver} here to make sure that TurboFan knows that along this
+        // path the {this_receiver} is a String. This is because we want
+        // strict checking of types, for example for StringLength operators.
+        if (HasOnlyStringMaps(receiver_maps)) {
+          this_receiver = this_effect =
+              graph()->NewNode(common()->TypeGuard(Type::String()), receiver,
+                               this_effect, this_control);
+        }
       }
 
       // Generate the actual property access.
@@ -1104,6 +1215,9 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadNamed(Node* node) {
         p.name().is_identical_to(factory()->prototype_string())) {
       // Optimize "prototype" property of functions.
       JSFunctionRef function = m.Ref(js_heap_broker()).AsJSFunction();
+      // TODO(neis): This is a temporary hack needed because the copy reducer
+      // runs only after this pass.
+      function.Serialize();
       // TODO(neis): Remove the has_prototype_slot condition once the broker is
       // always enabled.
       if (!function.map().has_prototype_slot() || !function.has_prototype() ||
@@ -1835,6 +1949,8 @@ JSNativeContextSpecialization::BuildPropertyLoad(
     value = effect =
         graph()->NewNode(simplified()->LoadField(AccessBuilder::ForCellValue()),
                          cell, effect, control);
+  } else if (access_info.IsStringLength()) {
+    value = graph()->NewNode(simplified()->StringLength(), receiver);
   } else {
     DCHECK(access_info.IsDataField() || access_info.IsDataConstantField());
     value = access_builder.BuildLoadDataField(name, access_info, receiver,
@@ -2095,8 +2211,9 @@ Reduction JSNativeContextSpecialization::ReduceJSStoreDataPropertyInLiteral(
   if (!Map::TryUpdate(isolate(), receiver_map).ToHandle(&receiver_map))
     return NoChange();
 
-  Handle<Name> cached_name = handle(
-      Name::cast(nexus.GetFeedbackExtra()->ToStrongHeapObject()), isolate());
+  Handle<Name> cached_name =
+      handle(Name::cast(nexus.GetFeedbackExtra()->GetHeapObjectAssumeStrong()),
+             isolate());
 
   PropertyAccessInfo access_info;
   AccessInfoFactory access_info_factory(js_heap_broker(), dependencies(),
@@ -2215,6 +2332,15 @@ ExternalArrayType GetArrayTypeFromElementsKind(ElementsKind kind) {
   UNREACHABLE();
 }
 
+MaybeHandle<JSTypedArray> GetTypedArrayConstant(Node* receiver) {
+  HeapObjectMatcher m(receiver);
+  if (!m.HasValue()) return MaybeHandle<JSTypedArray>();
+  if (!m.Value()->IsJSTypedArray()) return MaybeHandle<JSTypedArray>();
+  Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(m.Value());
+  if (typed_array->is_on_heap()) return MaybeHandle<JSTypedArray>();
+  return typed_array;
+}
+
 }  // namespace
 
 JSNativeContextSpecialization::ValueEffectControl
@@ -2236,17 +2362,12 @@ JSNativeContextSpecialization::BuildElementAccess(
 
     // Check if we can constant-fold information about the {receiver} (i.e.
     // for asm.js-like code patterns).
-    HeapObjectMatcher m(receiver);
-    if (m.HasValue() && m.Value()->IsJSTypedArray()) {
-      Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(m.Value());
-
-      // Determine the {receiver}s (known) length.
+    Handle<JSTypedArray> typed_array;
+    if (GetTypedArrayConstant(receiver).ToHandle(&typed_array)) {
+      buffer = jsgraph()->HeapConstant(typed_array->GetBuffer());
       length =
           jsgraph()->Constant(static_cast<double>(typed_array->length_value()));
 
-      // Check if the {receiver}s buffer was neutered.
-      buffer = jsgraph()->HeapConstant(typed_array->GetBuffer());
-
       // Load the (known) base and external pointer for the {receiver}. The
       // {external_pointer} might be invalid if the {buffer} was neutered, so
       // we need to make sure that any access is properly guarded.
@@ -2298,12 +2419,20 @@ JSNativeContextSpecialization::BuildElementAccess(
       dependencies()->DependOnProtector(PropertyCellRef(
           js_heap_broker(), factory()->array_buffer_neutering_protector()));
     } else {
-      // Default to zero if the {receiver}s buffer was neutered.
-      Node* check = effect = graph()->NewNode(
-          simplified()->ArrayBufferWasNeutered(), buffer, effect, control);
-      length = graph()->NewNode(
-          common()->Select(MachineRepresentation::kTagged, BranchHint::kFalse),
-          check, jsgraph()->ZeroConstant(), length);
+      // Deopt if the {buffer} was neutered.
+      // Note: A neutered buffer leads to megamorphic feedback.
+      Node* buffer_bit_field = effect = graph()->NewNode(
+          simplified()->LoadField(AccessBuilder::ForJSArrayBufferBitField()),
+          buffer, effect, control);
+      Node* check = graph()->NewNode(
+          simplified()->NumberEqual(),
+          graph()->NewNode(
+              simplified()->NumberBitwiseAnd(), buffer_bit_field,
+              jsgraph()->Constant(JSArrayBuffer::WasNeuteredBit::kMask)),
+          jsgraph()->ZeroConstant());
+      effect = graph()->NewNode(
+          simplified()->CheckIf(DeoptimizeReason::kArrayBufferWasNeutered),
+          check, effect, control);
     }
 
     if (load_mode == LOAD_IGNORE_OUT_OF_BOUNDS ||
diff --git a/deps/v8/src/compiler/js-native-context-specialization.h b/deps/v8/src/compiler/js-native-context-specialization.h
index 413e3c191f..0bd62e07c9 100644
--- a/deps/v8/src/compiler/js-native-context-specialization.h
+++ b/deps/v8/src/compiler/js-native-context-specialization.h
@@ -16,6 +16,9 @@ namespace internal {
 // Forward declarations.
 class Factory;
 class FeedbackNexus;
+class JSGlobalObject;
+class JSGlobalProxy;
+class StringConstantBase;
 
 namespace compiler {
 
@@ -36,7 +39,8 @@ class TypeCache;
 // folding some {LoadGlobal} nodes or strength reducing some {StoreGlobal}
 // nodes.  And also specializes {LoadNamed} and {StoreNamed} nodes according
 // to type feedback (if available).
-class JSNativeContextSpecialization final : public AdvancedReducer {
+class V8_EXPORT_PRIVATE JSNativeContextSpecialization final
+    : public AdvancedReducer {
  public:
   // Flags that control the mode of operation.
   enum Flag {
@@ -50,7 +54,7 @@ class JSNativeContextSpecialization final : public AdvancedReducer {
                                 JSHeapBroker* js_heap_broker, Flags flags,
                                 Handle<Context> native_context,
                                 CompilationDependencies* dependencies,
-                                Zone* zone);
+                                Zone* zone, Zone* shared_zone);
 
   const char* reducer_name() const override {
     return "JSNativeContextSpecialization";
@@ -58,6 +62,12 @@ class JSNativeContextSpecialization final : public AdvancedReducer {
 
   Reduction Reduce(Node* node) final;
 
+  // Utility for folding string constant concatenation.
+  // Supports JSAdd nodes and nodes typed as string or number.
+  // Public for the sake of unit testing.
+  static base::Optional<size_t> GetMaxStringLength(JSHeapBroker* broker,
+                                                   Node* node);
+
  private:
   Reduction ReduceJSAdd(Node* node);
   Reduction ReduceJSGetSuperConstructor(Node* node);
@@ -101,6 +111,9 @@ class JSNativeContextSpecialization final : public AdvancedReducer {
                                Node* index = nullptr);
 
   Reduction ReduceSoftDeoptimize(Node* node, DeoptimizeReason reason);
+  Reduction ReduceJSToString(Node* node);
+
+  const StringConstantBase* CreateDelayedStringConstant(Node* node);
 
   // A triple of nodes that represents a continuation.
   class ValueEffectControl final {
@@ -230,6 +243,7 @@ class JSNativeContextSpecialization final : public AdvancedReducer {
   const NativeContextRef& native_context() const { return native_context_; }
   CompilationDependencies* dependencies() const { return dependencies_; }
   Zone* zone() const { return zone_; }
+  Zone* shared_zone() const { return shared_zone_; }
 
   JSGraph* const jsgraph_;
   JSHeapBroker* const js_heap_broker_;
@@ -239,6 +253,7 @@ class JSNativeContextSpecialization final : public AdvancedReducer {
   NativeContextRef native_context_;
   CompilationDependencies* const dependencies_;
   Zone* const zone_;
+  Zone* const shared_zone_;
   TypeCache const& type_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(JSNativeContextSpecialization);
diff --git a/deps/v8/src/compiler/js-operator.cc b/deps/v8/src/compiler/js-operator.cc
index acfc0d3a19..a30b4ddcdd 100644
--- a/deps/v8/src/compiler/js-operator.cc
+++ b/deps/v8/src/compiler/js-operator.cc
@@ -266,7 +266,7 @@ NamedAccess const& NamedAccessOf(const Operator* op) {
 
 
 std::ostream& operator<<(std::ostream& os, PropertyAccess const& p) {
-  return os << p.language_mode();
+  return os << p.language_mode() << ", " << p.feedback();
 }
 
 
@@ -609,7 +609,6 @@ CompareOperationHint CompareOperationHintOf(const Operator* op) {
   V(Decrement, Operator::kNoProperties, 1, 1)                          \
   V(Increment, Operator::kNoProperties, 1, 1)                          \
   V(Negate, Operator::kNoProperties, 1, 1)                             \
-  V(ToInteger, Operator::kNoProperties, 1, 1)                          \
   V(ToLength, Operator::kNoProperties, 1, 1)                           \
   V(ToName, Operator::kNoProperties, 1, 1)                             \
   V(ToNumber, Operator::kNoProperties, 1, 1)                           \
@@ -1191,6 +1190,14 @@ const Operator* JSOperatorBuilder::CreateEmptyLiteralArray(
       parameters);                                   // parameter
 }
 
+const Operator* JSOperatorBuilder::CreateArrayFromIterable() {
+  return new (zone()) Operator(              // --
+      IrOpcode::kJSCreateArrayFromIterable,  // opcode
+      Operator::kNoProperties,               // properties
+      "JSCreateArrayFromIterable",           // name
+      1, 1, 1, 1, 1, 2);                     // counts
+}
+
 const Operator* JSOperatorBuilder::CreateLiteralObject(
     Handle<ObjectBoilerplateDescription> constant_properties,
     VectorSlotPair const& feedback, int literal_flags,
diff --git a/deps/v8/src/compiler/js-operator.h b/deps/v8/src/compiler/js-operator.h
index a81b187c7b..db38941219 100644
--- a/deps/v8/src/compiler/js-operator.h
+++ b/deps/v8/src/compiler/js-operator.h
@@ -52,6 +52,8 @@ class CallFrequency final {
     return bit_cast<uint32_t>(f.value_);
   }
 
+  static constexpr float kNoFeedbackCallFrequency = -1;
+
  private:
   float value_;
 };
@@ -703,7 +705,6 @@ class V8_EXPORT_PRIVATE JSOperatorBuilder final
   const Operator* Increment();
   const Operator* Negate();
 
-  const Operator* ToInteger();
   const Operator* ToLength();
   const Operator* ToName();
   const Operator* ToNumber();
@@ -733,6 +734,7 @@ class V8_EXPORT_PRIVATE JSOperatorBuilder final
       VectorSlotPair const& feedback, int literal_flags,
       int number_of_elements);
   const Operator* CreateEmptyLiteralArray(VectorSlotPair const& feedback);
+  const Operator* CreateArrayFromIterable();
   const Operator* CreateEmptyLiteralObject();
 
   const Operator* CreateLiteralObject(
diff --git a/deps/v8/src/compiler/js-typed-lowering.cc b/deps/v8/src/compiler/js-typed-lowering.cc
index 56b1f224c7..7b3728428b 100644
--- a/deps/v8/src/compiler/js-typed-lowering.cc
+++ b/deps/v8/src/compiler/js-typed-lowering.cc
@@ -137,15 +137,20 @@ class JSBinopReduction final {
     }
   }
 
+  // Inserts a CheckSymbol for the left input.
+  void CheckLeftInputToSymbol() {
+    Node* left_input = graph()->NewNode(simplified()->CheckSymbol(), left(),
+                                        effect(), control());
+    node_->ReplaceInput(0, left_input);
+    update_effect(left_input);
+  }
+
   // Checks that both inputs are Symbol, and if we don't know
   // statically that one side is already a Symbol, insert a
   // CheckSymbol node.
   void CheckInputsToSymbol() {
     if (!left_type().Is(Type::Symbol())) {
-      Node* left_input = graph()->NewNode(simplified()->CheckSymbol(), left(),
-                                          effect(), control());
-      node_->ReplaceInput(0, left_input);
-      update_effect(left_input);
+      CheckLeftInputToSymbol();
     }
     if (!right_type().Is(Type::Symbol())) {
       Node* right_input = graph()->NewNode(simplified()->CheckSymbol(), right(),
@@ -374,7 +379,7 @@ class JSBinopReduction final {
   Node* ConvertPlainPrimitiveToNumber(Node* node) {
     DCHECK(NodeProperties::GetType(node).Is(Type::PlainPrimitive()));
     // Avoid inserting too many eager ToNumber() operations.
-    Reduction const reduction = lowering_->ReduceJSToNumberOrNumericInput(node);
+    Reduction const reduction = lowering_->ReduceJSToNumberInput(node);
     if (reduction.Changed()) return reduction.replacement();
     if (NodeProperties::GetType(node).Is(Type::Number())) {
       return node;
@@ -509,76 +514,123 @@ Reduction JSTypedLowering::ReduceJSAdd(Node* node) {
     r.ConvertInputsToNumber();
     return r.ChangeToPureOperator(simplified()->NumberAdd(), Type::Number());
   }
+
+  // Strength-reduce if one input is already known to be a string.
+  if (r.LeftInputIs(Type::String())) {
+    // JSAdd(x:string, y) => JSAdd(x, JSToString(y))
+    Reduction const reduction = ReduceJSToStringInput(r.right());
+    if (reduction.Changed()) {
+      NodeProperties::ReplaceValueInput(node, reduction.replacement(), 1);
+    }
+  } else if (r.RightInputIs(Type::String())) {
+    // JSAdd(x, y:string) => JSAdd(JSToString(x), y)
+    Reduction const reduction = ReduceJSToStringInput(r.left());
+    if (reduction.Changed()) {
+      NodeProperties::ReplaceValueInput(node, reduction.replacement(), 0);
+    }
+  }
+
+  // Always bake in String feedback into the graph.
   if (BinaryOperationHintOf(node->op()) == BinaryOperationHint::kString) {
-    // Always bake in String feedback into the graph.
-    // TODO(bmeurer): Consider adding a SpeculativeStringAdd operator,
-    // and use that in JSTypeHintLowering instead of looking at the
-    // binary operation feedback here.
     r.CheckInputsToString();
   }
-  if (r.OneInputIs(Type::String())) {
-    // We know that (at least) one input is already a String,
-    // so try to strength-reduce the non-String input.
-    if (r.LeftInputIs(Type::String())) {
-      Reduction const reduction = ReduceJSToStringInput(r.right());
-      if (reduction.Changed()) {
-        NodeProperties::ReplaceValueInput(node, reduction.replacement(), 1);
-      }
-    } else if (r.RightInputIs(Type::String())) {
-      Reduction const reduction = ReduceJSToStringInput(r.left());
-      if (reduction.Changed()) {
-        NodeProperties::ReplaceValueInput(node, reduction.replacement(), 0);
-      }
+
+  // Strength-reduce concatenation of empty strings if both sides are
+  // primitives, as in that case the ToPrimitive on the other side is
+  // definitely going to be a no-op.
+  if (r.BothInputsAre(Type::Primitive())) {
+    if (r.LeftInputIs(empty_string_type_)) {
+      // JSAdd("", x:primitive) => JSToString(x)
+      NodeProperties::ReplaceValueInputs(node, r.right());
+      NodeProperties::ChangeOp(node, javascript()->ToString());
+      Reduction const reduction = ReduceJSToString(node);
+      return reduction.Changed() ? reduction : Changed(node);
+    } else if (r.RightInputIs(empty_string_type_)) {
+      // JSAdd(x:primitive, "") => JSToString(x)
+      NodeProperties::ReplaceValueInputs(node, r.left());
+      NodeProperties::ChangeOp(node, javascript()->ToString());
+      Reduction const reduction = ReduceJSToString(node);
+      return reduction.Changed() ? reduction : Changed(node);
     }
-    // We might be able to constant-fold the String concatenation now.
-    if (r.BothInputsAre(Type::String())) {
-      HeapObjectBinopMatcher m(node);
-      if (m.IsFoldable()) {
-        StringRef left = m.left().Ref(js_heap_broker()).AsString();
-        StringRef right = m.right().Ref(js_heap_broker()).AsString();
-        if (left.length() + right.length() > String::kMaxLength) {
-          // No point in trying to optimize this, as it will just throw.
-          return NoChange();
+  }
+
+  // Lower to string addition if both inputs are known to be strings.
+  if (r.BothInputsAre(Type::String())) {
+    Node* context = NodeProperties::GetContextInput(node);
+    Node* frame_state = NodeProperties::GetFrameStateInput(node);
+    Node* effect = NodeProperties::GetEffectInput(node);
+    Node* control = NodeProperties::GetControlInput(node);
+
+    // Compute the resulting length.
+    Node* left_length =
+        graph()->NewNode(simplified()->StringLength(), r.left());
+    Node* right_length =
+        graph()->NewNode(simplified()->StringLength(), r.right());
+    Node* length =
+        graph()->NewNode(simplified()->NumberAdd(), left_length, right_length);
+
+    if (isolate()->IsStringLengthOverflowIntact()) {
+      // We can just deoptimize if the {length} is out-of-bounds. Besides
+      // generating a shorter code sequence than the version below, this
+      // has the additional benefit of not holding on to the lazy {frame_state}
+      // and thus potentially reduces the number of live ranges and allows for
+      // more truncations.
+      length = effect = graph()->NewNode(
+          simplified()->CheckBounds(VectorSlotPair()), length,
+          jsgraph()->Constant(String::kMaxLength + 1), effect, control);
+    } else {
+      // Check if we would overflow the allowed maximum string length.
+      Node* check =
+          graph()->NewNode(simplified()->NumberLessThanOrEqual(), length,
+                           jsgraph()->Constant(String::kMaxLength));
+      Node* branch =
+          graph()->NewNode(common()->Branch(BranchHint::kTrue), check, control);
+      Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
+      Node* efalse = effect;
+      {
+        // Throw a RangeError in case of overflow.
+        Node* vfalse = efalse = if_false = graph()->NewNode(
+            javascript()->CallRuntime(Runtime::kThrowInvalidStringLength),
+            context, frame_state, efalse, if_false);
+
+        // Update potential {IfException} uses of {node} to point to the
+        // %ThrowInvalidStringLength runtime call node instead.
+        Node* on_exception = nullptr;
+        if (NodeProperties::IsExceptionalCall(node, &on_exception)) {
+          NodeProperties::ReplaceControlInput(on_exception, vfalse);
+          NodeProperties::ReplaceEffectInput(on_exception, efalse);
+          if_false = graph()->NewNode(common()->IfSuccess(), vfalse);
+          Revisit(on_exception);
         }
-        // TODO(mslekova): get rid of these allows by doing either one of:
-        // 1. remove the optimization and check if it ruins the performance
-        // 2. leave a placeholder and do the actual allocations once back on the
-        // MT
-        AllowHandleDereference allow_handle_dereference;
-        AllowHandleAllocation allow_handle_allocation;
-        AllowHeapAllocation allow_heap_allocation;
-        ObjectRef cons(
-            js_heap_broker(),
-            factory()
-                ->NewConsString(left.object<String>(), right.object<String>())
-                .ToHandleChecked());
-        Node* value = jsgraph()->Constant(cons);
-        ReplaceWithValue(node, value);
-        return Replace(value);
-      }
-    }
-    // We might know for sure that we're creating a ConsString here.
-    if (r.ShouldCreateConsString()) {
-      return ReduceCreateConsString(node);
-    }
-    // Eliminate useless concatenation of empty string.
-    if (r.BothInputsAre(Type::String())) {
-      Node* effect = NodeProperties::GetEffectInput(node);
-      Node* control = NodeProperties::GetControlInput(node);
-      if (r.LeftInputIs(empty_string_type_)) {
-        Node* value = effect =
-            graph()->NewNode(simplified()->CheckString(VectorSlotPair()),
-                             r.right(), effect, control);
-        ReplaceWithValue(node, value, effect, control);
-        return Replace(value);
-      } else if (r.RightInputIs(empty_string_type_)) {
-        Node* value = effect =
-            graph()->NewNode(simplified()->CheckString(VectorSlotPair()),
-                             r.left(), effect, control);
-        ReplaceWithValue(node, value, effect, control);
-        return Replace(value);
+
+        // The above %ThrowInvalidStringLength runtime call is an unconditional
+        // throw, making it impossible to return a successful completion in this
+        // case. We simply connect the successful completion to the graph end.
+        if_false = graph()->NewNode(common()->Throw(), efalse, if_false);
+        // TODO(bmeurer): This should be on the AdvancedReducer somehow.
+        NodeProperties::MergeControlToEnd(graph(), common(), if_false);
+        Revisit(graph()->end());
       }
+      control = graph()->NewNode(common()->IfTrue(), branch);
+      length = effect =
+          graph()->NewNode(common()->TypeGuard(type_cache_.kStringLengthType),
+                           length, effect, control);
     }
+
+    // TODO(bmeurer): Ideally this should always use StringConcat and decide to
+    // optimize to NewConsString later during SimplifiedLowering, but for that
+    // to work we need to know that it's safe to create a ConsString.
+    Operator const* const op = r.ShouldCreateConsString()
+                                   ? simplified()->NewConsString()
+                                   : simplified()->StringConcat();
+    Node* value = graph()->NewNode(op, length, r.left(), r.right());
+    ReplaceWithValue(node, value, effect, control);
+    return Replace(value);
+  }
+
+  // We never get here when we had String feedback.
+  DCHECK_NE(BinaryOperationHint::kString, BinaryOperationHintOf(node->op()));
+  if (r.OneInputIs(Type::String())) {
     StringAddFlags flags = STRING_ADD_CHECK_NONE;
     if (!r.LeftInputIs(Type::String())) {
       flags = STRING_ADD_CONVERT_LEFT;
@@ -592,12 +644,13 @@ Reduction JSTypedLowering::ReduceJSAdd(Node* node) {
       // effects; it can still throw obviously.
       properties = Operator::kNoWrite | Operator::kNoDeopt;
     }
+
     // JSAdd(x:string, y) => CallStub[StringAdd](x, y)
     // JSAdd(x, y:string) => CallStub[StringAdd](x, y)
-    Callable const callable =
-        CodeFactory::StringAdd(isolate(), flags, NOT_TENURED);
+    Callable const callable = CodeFactory::StringAdd(isolate(), flags);
     auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), 0,
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(),
         CallDescriptor::kNeedsFrameState, properties);
     DCHECK_EQ(1, OperatorProperties::GetFrameStateInputCount(node->op()));
     node->InsertInput(graph()->zone(), 0,
@@ -605,8 +658,6 @@ Reduction JSTypedLowering::ReduceJSAdd(Node* node) {
     NodeProperties::ChangeOp(node, common()->Call(call_descriptor));
     return Changed(node);
   }
-  // We never get here when we had String feedback.
-  DCHECK_NE(BinaryOperationHint::kString, BinaryOperationHintOf(node->op()));
   return NoChange();
 }
 
@@ -657,103 +708,6 @@ Reduction JSTypedLowering::ReduceUI32Shift(Node* node, Signedness signedness) {
   return NoChange();
 }
 
-Reduction JSTypedLowering::ReduceCreateConsString(Node* node) {
-  Node* first = NodeProperties::GetValueInput(node, 0);
-  Node* second = NodeProperties::GetValueInput(node, 1);
-  Node* context = NodeProperties::GetContextInput(node);
-  Node* frame_state = NodeProperties::GetFrameStateInput(node);
-  Node* effect = NodeProperties::GetEffectInput(node);
-  Node* control = NodeProperties::GetControlInput(node);
-
-  // Make sure {first} is actually a String.
-  Type first_type = NodeProperties::GetType(first);
-  if (!first_type.Is(Type::String())) {
-    first = effect = graph()->NewNode(
-        simplified()->CheckString(VectorSlotPair()), first, effect, control);
-    first_type = NodeProperties::GetType(first);
-  }
-
-  // Make sure {second} is actually a String.
-  Type second_type = NodeProperties::GetType(second);
-  if (!second_type.Is(Type::String())) {
-    second = effect = graph()->NewNode(
-        simplified()->CheckString(VectorSlotPair()), second, effect, control);
-    second_type = NodeProperties::GetType(second);
-  }
-
-  // Determine the {first} length.
-  Node* first_length = BuildGetStringLength(first);
-  Node* second_length = BuildGetStringLength(second);
-
-  // Compute the resulting length.
-  Node* length =
-      graph()->NewNode(simplified()->NumberAdd(), first_length, second_length);
-
-  if (isolate()->IsStringLengthOverflowIntact()) {
-    // We can just deoptimize if the {length} is out-of-bounds. Besides
-    // generating a shorter code sequence than the version below, this
-    // has the additional benefit of not holding on to the lazy {frame_state}
-    // and thus potentially reduces the number of live ranges and allows for
-    // more truncations.
-    length = effect = graph()->NewNode(
-        simplified()->CheckBounds(VectorSlotPair()), length,
-        jsgraph()->Constant(String::kMaxLength), effect, control);
-  } else {
-    // Check if we would overflow the allowed maximum string length.
-    Node* check =
-        graph()->NewNode(simplified()->NumberLessThanOrEqual(), length,
-                         jsgraph()->Constant(String::kMaxLength));
-    Node* branch =
-        graph()->NewNode(common()->Branch(BranchHint::kTrue), check, control);
-    Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-    Node* efalse = effect;
-    {
-      // Throw a RangeError in case of overflow.
-      Node* vfalse = efalse = if_false = graph()->NewNode(
-          javascript()->CallRuntime(Runtime::kThrowInvalidStringLength),
-          context, frame_state, efalse, if_false);
-
-      // Update potential {IfException} uses of {node} to point to the
-      // %ThrowInvalidStringLength runtime call node instead.
-      Node* on_exception = nullptr;
-      if (NodeProperties::IsExceptionalCall(node, &on_exception)) {
-        NodeProperties::ReplaceControlInput(on_exception, vfalse);
-        NodeProperties::ReplaceEffectInput(on_exception, efalse);
-        if_false = graph()->NewNode(common()->IfSuccess(), vfalse);
-        Revisit(on_exception);
-      }
-
-      // The above %ThrowInvalidStringLength runtime call is an unconditional
-      // throw, making it impossible to return a successful completion in this
-      // case. We simply connect the successful completion to the graph end.
-      if_false = graph()->NewNode(common()->Throw(), efalse, if_false);
-      // TODO(bmeurer): This should be on the AdvancedReducer somehow.
-      NodeProperties::MergeControlToEnd(graph(), common(), if_false);
-      Revisit(graph()->end());
-    }
-    control = graph()->NewNode(common()->IfTrue(), branch);
-    length = effect =
-        graph()->NewNode(common()->TypeGuard(type_cache_.kStringLengthType),
-                         length, effect, control);
-  }
-
-  Node* value =
-      graph()->NewNode(simplified()->NewConsString(), length, first, second);
-  ReplaceWithValue(node, value, effect, control);
-  return Replace(value);
-}
-
-Node* JSTypedLowering::BuildGetStringLength(Node* value) {
-  // TODO(bmeurer): Get rid of this hack and instead have a way to
-  // express the string length in the types.
-  HeapObjectMatcher m(value);
-  if (!m.HasValue() || !m.Ref(js_heap_broker()).IsString()) {
-    return graph()->NewNode(simplified()->StringLength(), value);
-  }
-
-  return jsgraph()->Constant(m.Ref(js_heap_broker()).AsString().length());
-}
-
 Reduction JSTypedLowering::ReduceSpeculativeNumberComparison(Node* node) {
   JSBinopReduction r(this, node);
   if (r.BothInputsAre(Type::Signed32()) ||
@@ -922,30 +876,22 @@ Reduction JSTypedLowering::ReduceJSStrictEqual(Node* node) {
   } else if (r.IsReceiverCompareOperation()) {
     // For strict equality, it's enough to know that one input is a Receiver,
     // as a strict equality comparison with a Receiver can only yield true if
-    // both sides refer to the same Receiver than.
+    // both sides refer to the same Receiver.
     r.CheckLeftInputToReceiver();
     return r.ChangeToPureOperator(simplified()->ReferenceEqual());
   } else if (r.IsStringCompareOperation()) {
     r.CheckInputsToString();
     return r.ChangeToPureOperator(simplified()->StringEqual());
   } else if (r.IsSymbolCompareOperation()) {
-    r.CheckInputsToSymbol();
+    // For strict equality, it's enough to know that one input is a Symbol,
+    // as a strict equality comparison with a Symbol can only yield true if
+    // both sides refer to the same Symbol.
+    r.CheckLeftInputToSymbol();
     return r.ChangeToPureOperator(simplified()->ReferenceEqual());
   }
   return NoChange();
 }
 
-Reduction JSTypedLowering::ReduceJSToInteger(Node* node) {
-  Node* const input = NodeProperties::GetValueInput(node, 0);
-  Type const input_type = NodeProperties::GetType(input);
-  if (input_type.Is(type_cache_.kIntegerOrMinusZero)) {
-    // JSToInteger(x:integer) => x
-    ReplaceWithValue(node, input);
-    return Replace(input);
-  }
-  return NoChange();
-}
-
 Reduction JSTypedLowering::ReduceJSToName(Node* node) {
   Node* const input = NodeProperties::GetValueInput(node, 0);
   Type const input_type = NodeProperties::GetType(input);
@@ -981,9 +927,8 @@ Reduction JSTypedLowering::ReduceJSToLength(Node* node) {
   return NoChange();
 }
 
-Reduction JSTypedLowering::ReduceJSToNumberOrNumericInput(Node* input) {
-  // Try constant-folding of JSToNumber/JSToNumeric with constant inputs. Here
-  // we only cover cases where ToNumber and ToNumeric coincide.
+Reduction JSTypedLowering::ReduceJSToNumberInput(Node* input) {
+  // Try constant-folding of JSToNumber with constant inputs.
   Type input_type = NodeProperties::GetType(input);
 
   if (input_type.Is(Type::String())) {
@@ -996,8 +941,8 @@ Reduction JSTypedLowering::ReduceJSToNumberOrNumericInput(Node* input) {
     }
   }
   if (input_type.IsHeapConstant()) {
-    ObjectRef input_value = input_type.AsHeapConstant()->Ref();
-    if (input_value.oddball_type() != OddballType::kNone) {
+    HeapObjectRef input_value = input_type.AsHeapConstant()->Ref();
+    if (input_value.map().oddball_type() != OddballType::kNone) {
       return Replace(jsgraph()->Constant(input_value.OddballToNumber()));
     }
   }
@@ -1016,10 +961,10 @@ Reduction JSTypedLowering::ReduceJSToNumberOrNumericInput(Node* input) {
   return NoChange();
 }
 
-Reduction JSTypedLowering::ReduceJSToNumberOrNumeric(Node* node) {
+Reduction JSTypedLowering::ReduceJSToNumber(Node* node) {
   // Try to reduce the input first.
   Node* const input = node->InputAt(0);
-  Reduction reduction = ReduceJSToNumberOrNumericInput(input);
+  Reduction reduction = ReduceJSToNumberInput(input);
   if (reduction.Changed()) {
     ReplaceWithValue(node, reduction.replacement());
     return reduction;
@@ -1035,7 +980,18 @@ Reduction JSTypedLowering::ReduceJSToNumberOrNumeric(Node* node) {
     NodeProperties::ChangeOp(node, simplified()->PlainPrimitiveToNumber());
     return Changed(node);
   }
-  // TODO(neis): Reduce ToNumeric to ToNumber if input can't be BigInt?
+  return NoChange();
+}
+
+Reduction JSTypedLowering::ReduceJSToNumeric(Node* node) {
+  Node* const input = NodeProperties::GetValueInput(node, 0);
+  Type const input_type = NodeProperties::GetType(input);
+  if (input_type.Is(Type::NonBigIntPrimitive())) {
+    // ToNumeric(x:primitive\bigint) => ToNumber(x)
+    NodeProperties::ChangeOp(node, javascript()->ToNumber());
+    Reduction const reduction = ReduceJSToNumber(node);
+    return reduction.Changed() ? reduction : Changed(node);
+  }
   return NoChange();
 }
 
@@ -1065,20 +1021,6 @@ Reduction JSTypedLowering::ReduceJSToStringInput(Node* input) {
   if (input_type.Is(Type::NaN())) {
     return Replace(jsgraph()->HeapConstant(factory()->NaN_string()));
   }
-  if (input_type.Is(Type::OrderedNumber()) &&
-      input_type.Min() == input_type.Max()) {
-    // TODO(mslekova): get rid of these allows by doing either one of:
-    // 1. remove the optimization and check if it ruins the performance
-    // 2. allocate all the ToString's from numbers before the compilation
-    // 3. leave a placeholder and do the actual allocations once back on the MT
-    AllowHandleDereference allow_handle_dereference;
-    AllowHandleAllocation allow_handle_allocation;
-    AllowHeapAllocation allow_heap_allocation;
-    // Note that we can use Type::OrderedNumber(), since
-    // both 0 and -0 map to the String "0" in JavaScript.
-    return Replace(jsgraph()->HeapConstant(
-        factory()->NumberToString(factory()->NewNumber(input_type.Min()))));
-  }
   if (input_type.Is(Type::Number())) {
     return Replace(graph()->NewNode(simplified()->NumberToString(), input));
   }
@@ -1126,7 +1068,8 @@ Reduction JSTypedLowering::ReduceJSToObject(Node* node) {
     // Convert {receiver} using the ToObjectStub.
     Callable callable = Builtins::CallableFor(isolate(), Builtins::kToObject);
     auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(), 0,
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(),
         CallDescriptor::kNeedsFrameState, node->op()->properties());
     rfalse = efalse = if_false =
         graph()->NewNode(common()->Call(call_descriptor),
@@ -1555,7 +1498,7 @@ Reduction JSTypedLowering::ReduceJSConstructForwardVarargs(Node* node) {
       target_type.AsHeapConstant()->Ref().IsJSFunction()) {
     // Only optimize [[Construct]] here if {function} is a Constructor.
     JSFunctionRef function = target_type.AsHeapConstant()->Ref().AsJSFunction();
-    if (!function.IsConstructor()) return NoChange();
+    if (!function.map().is_constructor()) return NoChange();
     // Patch {node} to an indirect call via ConstructFunctionForwardVarargs.
     Callable callable = CodeFactory::ConstructFunctionForwardVarargs(isolate());
     node->RemoveInput(arity + 1);
@@ -1591,7 +1534,7 @@ Reduction JSTypedLowering::ReduceJSConstruct(Node* node) {
     SharedFunctionInfoRef shared = function.shared();
 
     // Only optimize [[Construct]] here if {function} is a Constructor.
-    if (!function.IsConstructor()) return NoChange();
+    if (!function.map().is_constructor()) return NoChange();
 
     CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
 
@@ -1744,7 +1687,8 @@ Reduction JSTypedLowering::ReduceJSCall(Node* node) {
       node->InsertInput(graph()->zone(), arity + 3, argument_count);
       NodeProperties::ChangeOp(node,
                                common()->Call(Linkage::GetJSCallDescriptor(
-                                   graph()->zone(), false, 1 + arity, flags)));
+                                   graph()->zone(), false, 1 + arity,
+                                   flags | CallDescriptor::kCanUseRoots)));
     }
     return Changed(node);
   }
@@ -1849,7 +1793,8 @@ Reduction JSTypedLowering::ReduceJSForInNext(Node* node) {
         Callable const callable =
             Builtins::CallableFor(isolate(), Builtins::kForInFilter);
         auto call_descriptor = Linkage::GetStubCallDescriptor(
-            graph()->zone(), callable.descriptor(), 0,
+            graph()->zone(), callable.descriptor(),
+            callable.descriptor().GetStackParameterCount(),
             CallDescriptor::kNeedsFrameState);
         vfalse = efalse = if_false =
             graph()->NewNode(common()->Call(call_descriptor),
@@ -2314,16 +2259,15 @@ Reduction JSTypedLowering::Reduce(Node* node) {
       return ReduceJSHasInPrototypeChain(node);
     case IrOpcode::kJSOrdinaryHasInstance:
       return ReduceJSOrdinaryHasInstance(node);
-    case IrOpcode::kJSToInteger:
-      return ReduceJSToInteger(node);
     case IrOpcode::kJSToLength:
       return ReduceJSToLength(node);
     case IrOpcode::kJSToName:
       return ReduceJSToName(node);
     case IrOpcode::kJSToNumber:
     case IrOpcode::kJSToNumberConvertBigInt:
+      return ReduceJSToNumber(node);
     case IrOpcode::kJSToNumeric:
-      return ReduceJSToNumberOrNumeric(node);
+      return ReduceJSToNumeric(node);
     case IrOpcode::kJSToString:
       return ReduceJSToString(node);
     case IrOpcode::kJSToObject:
diff --git a/deps/v8/src/compiler/js-typed-lowering.h b/deps/v8/src/compiler/js-typed-lowering.h
index c3bef9aeed..e25e092453 100644
--- a/deps/v8/src/compiler/js-typed-lowering.h
+++ b/deps/v8/src/compiler/js-typed-lowering.h
@@ -33,7 +33,7 @@ class V8_EXPORT_PRIVATE JSTypedLowering final
  public:
   JSTypedLowering(Editor* editor, JSGraph* jsgraph,
                   JSHeapBroker* js_heap_broker, Zone* zone);
-  ~JSTypedLowering() final {}
+  ~JSTypedLowering() final = default;
 
   const char* reducer_name() const override { return "JSTypedLowering"; }
 
@@ -57,11 +57,11 @@ class V8_EXPORT_PRIVATE JSTypedLowering final
   Reduction ReduceJSStoreModule(Node* node);
   Reduction ReduceJSEqual(Node* node);
   Reduction ReduceJSStrictEqual(Node* node);
-  Reduction ReduceJSToInteger(Node* node);
   Reduction ReduceJSToLength(Node* node);
   Reduction ReduceJSToName(Node* node);
-  Reduction ReduceJSToNumberOrNumericInput(Node* input);
-  Reduction ReduceJSToNumberOrNumeric(Node* node);
+  Reduction ReduceJSToNumberInput(Node* input);
+  Reduction ReduceJSToNumber(Node* node);
+  Reduction ReduceJSToNumeric(Node* node);
   Reduction ReduceJSToStringInput(Node* input);
   Reduction ReduceJSToString(Node* node);
   Reduction ReduceJSToObject(Node* node);
@@ -81,7 +81,6 @@ class V8_EXPORT_PRIVATE JSTypedLowering final
   Reduction ReduceNumberBinop(Node* node);
   Reduction ReduceInt32Binop(Node* node);
   Reduction ReduceUI32Shift(Node* node, Signedness signedness);
-  Reduction ReduceCreateConsString(Node* node);
   Reduction ReduceSpeculativeNumberAdd(Node* node);
   Reduction ReduceSpeculativeNumberMultiply(Node* node);
   Reduction ReduceSpeculativeNumberBinop(Node* node);
@@ -92,9 +91,6 @@ class V8_EXPORT_PRIVATE JSTypedLowering final
   // Helper for ReduceJSLoadModule and ReduceJSStoreModule.
   Node* BuildGetModuleCell(Node* node);
 
-  // Helpers for ReduceJSCreateConsString.
-  Node* BuildGetStringLength(Node* value);
-
   Factory* factory() const;
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }
diff --git a/deps/v8/src/compiler/linkage.cc b/deps/v8/src/compiler/linkage.cc
index 99c52b1ade..9bba09329d 100644
--- a/deps/v8/src/compiler/linkage.cc
+++ b/deps/v8/src/compiler/linkage.cc
@@ -143,7 +143,7 @@ CallDescriptor* Linkage::ComputeIncoming(Zone* zone,
     SharedFunctionInfo* shared = info->closure()->shared();
     return GetJSCallDescriptor(zone, info->is_osr(),
                                1 + shared->internal_formal_parameter_count(),
-                               CallDescriptor::kNoFlags);
+                               CallDescriptor::kCanUseRoots);
   }
   return nullptr;  // TODO(titzer): ?
 }
@@ -167,7 +167,6 @@ bool Linkage::NeedsFrameStateInput(Runtime::FunctionId function) {
     case Runtime::kPushCatchContext:
     case Runtime::kReThrow:
     case Runtime::kStringEqual:
-    case Runtime::kStringNotEqual:
     case Runtime::kStringLessThan:
     case Runtime::kStringLessThanOrEqual:
     case Runtime::kStringGreaterThan:
@@ -180,7 +179,6 @@ bool Linkage::NeedsFrameStateInput(Runtime::FunctionId function) {
     // Some inline intrinsics are also safe to call without a FrameState.
     case Runtime::kInlineCreateIterResultObject:
     case Runtime::kInlineGeneratorClose:
-    case Runtime::kInlineGeneratorGetInputOrDebugPos:
     case Runtime::kInlineGeneratorGetResumeMode:
     case Runtime::kInlineCreateJSGeneratorObject:
     case Runtime::kInlineIsArray:
@@ -333,12 +331,16 @@ CallDescriptor* Linkage::GetJSCallDescriptor(Zone* zone, bool is_osr,
       Operator::kNoProperties,          // properties
       kNoCalleeSaved,                   // callee-saved
       kNoCalleeSaved,                   // callee-saved fp
-      CallDescriptor::kCanUseRoots |    // flags
-          flags,                        // flags
+      flags,                            // flags
       "js-call");
 }
 
 // TODO(turbofan): cache call descriptors for code stub calls.
+// TODO(jgruber): Clean up stack parameter count handling. The descriptor
+// already knows the formal stack parameter count and ideally only additional
+// stack parameters should be passed into this method. All call-sites should
+// be audited for correctness (e.g. many used to assume a stack parameter count
+// of 0).
 CallDescriptor* Linkage::GetStubCallDescriptor(
     Zone* zone, const CallInterfaceDescriptor& descriptor,
     int stack_parameter_count, CallDescriptor::Flags flags,
@@ -350,6 +352,8 @@ CallDescriptor* Linkage::GetStubCallDescriptor(
   const size_t parameter_count =
       static_cast<size_t>(js_parameter_count + context_count);
 
+  DCHECK_GE(stack_parameter_count, descriptor.GetStackParameterCount());
+
   size_t return_count = descriptor.GetReturnCount();
   LocationSignature::Builder locations(zone, return_count, parameter_count);
 
diff --git a/deps/v8/src/compiler/load-elimination.cc b/deps/v8/src/compiler/load-elimination.cc
index 6d6cfafdbf..46966b552f 100644
--- a/deps/v8/src/compiler/load-elimination.cc
+++ b/deps/v8/src/compiler/load-elimination.cc
@@ -99,8 +99,6 @@ Reduction LoadElimination::Reduce(Node* node) {
     }
   }
   switch (node->opcode()) {
-    case IrOpcode::kArrayBufferWasNeutered:
-      return ReduceArrayBufferWasNeutered(node);
     case IrOpcode::kMapGuard:
       return ReduceMapGuard(node);
     case IrOpcode::kCheckMaps:
@@ -139,74 +137,6 @@ Reduction LoadElimination::Reduce(Node* node) {
 
 namespace {
 
-bool LoadEliminationIsCompatibleCheck(Node const* a, Node const* b) {
-  if (a->op() != b->op()) return false;
-  for (int i = a->op()->ValueInputCount(); --i >= 0;) {
-    if (!MustAlias(a->InputAt(i), b->InputAt(i))) return false;
-  }
-  return true;
-}
-
-}  // namespace
-
-Node* LoadElimination::AbstractChecks::Lookup(Node* node) const {
-  for (Node* const check : nodes_) {
-    if (check && !check->IsDead() &&
-        LoadEliminationIsCompatibleCheck(check, node)) {
-      return check;
-    }
-  }
-  return nullptr;
-}
-
-bool LoadElimination::AbstractChecks::Equals(AbstractChecks const* that) const {
-  if (this == that) return true;
-  for (size_t i = 0; i < arraysize(nodes_); ++i) {
-    if (Node* this_node = this->nodes_[i]) {
-      for (size_t j = 0;; ++j) {
-        if (j == arraysize(nodes_)) return false;
-        if (that->nodes_[j] == this_node) break;
-      }
-    }
-  }
-  for (size_t i = 0; i < arraysize(nodes_); ++i) {
-    if (Node* that_node = that->nodes_[i]) {
-      for (size_t j = 0;; ++j) {
-        if (j == arraysize(nodes_)) return false;
-        if (this->nodes_[j] == that_node) break;
-      }
-    }
-  }
-  return true;
-}
-
-LoadElimination::AbstractChecks const* LoadElimination::AbstractChecks::Merge(
-    AbstractChecks const* that, Zone* zone) const {
-  if (this->Equals(that)) return this;
-  AbstractChecks* copy = new (zone) AbstractChecks(zone);
-  for (Node* const this_node : this->nodes_) {
-    if (this_node == nullptr) continue;
-    for (Node* const that_node : that->nodes_) {
-      if (this_node == that_node) {
-        copy->nodes_[copy->next_index_++] = this_node;
-        break;
-      }
-    }
-  }
-  copy->next_index_ %= arraysize(nodes_);
-  return copy;
-}
-
-void LoadElimination::AbstractChecks::Print() const {
-  for (Node* const node : nodes_) {
-    if (node != nullptr) {
-      PrintF("    #%d:%s\n", node->id(), node->op()->mnemonic());
-    }
-  }
-}
-
-namespace {
-
 bool IsCompatible(MachineRepresentation r1, MachineRepresentation r2) {
   if (r1 == r2) return true;
   return IsAnyTagged(r1) && IsAnyTagged(r2);
@@ -446,13 +376,6 @@ void LoadElimination::AbstractMaps::Print() const {
 }
 
 bool LoadElimination::AbstractState::Equals(AbstractState const* that) const {
-  if (this->checks_) {
-    if (!that->checks_ || !that->checks_->Equals(this->checks_)) {
-      return false;
-    }
-  } else if (that->checks_) {
-    return false;
-  }
   if (this->elements_) {
     if (!that->elements_ || !that->elements_->Equals(this->elements_)) {
       return false;
@@ -481,12 +404,6 @@ bool LoadElimination::AbstractState::Equals(AbstractState const* that) const {
 
 void LoadElimination::AbstractState::Merge(AbstractState const* that,
                                            Zone* zone) {
-  // Merge the information we have about the checks.
-  if (this->checks_) {
-    this->checks_ =
-        that->checks_ ? that->checks_->Merge(this->checks_, zone) : nullptr;
-  }
-
   // Merge the information we have about the elements.
   if (this->elements_) {
     this->elements_ = that->elements_
@@ -511,21 +428,6 @@ void LoadElimination::AbstractState::Merge(AbstractState const* that,
   }
 }
 
-Node* LoadElimination::AbstractState::LookupCheck(Node* node) const {
-  return this->checks_ ? this->checks_->Lookup(node) : nullptr;
-}
-
-LoadElimination::AbstractState const* LoadElimination::AbstractState::AddCheck(
-    Node* node, Zone* zone) const {
-  AbstractState* that = new (zone) AbstractState(*this);
-  if (that->checks_) {
-    that->checks_ = that->checks_->Extend(node, zone);
-  } else {
-    that->checks_ = new (zone) AbstractChecks(node, zone);
-  }
-  return that;
-}
-
 bool LoadElimination::AbstractState::LookupMaps(
     Node* object, ZoneHandleSet<Map>* object_map) const {
   return this->maps_ && this->maps_->Lookup(object, object_map);
@@ -689,10 +591,6 @@ bool LoadElimination::AliasStateInfo::MayAlias(Node* other) const {
 }
 
 void LoadElimination::AbstractState::Print() const {
-  if (checks_) {
-    PrintF("   checks:\n");
-    checks_->Print();
-  }
   if (maps_) {
     PrintF("   maps:\n");
     maps_->Print();
@@ -723,18 +621,6 @@ void LoadElimination::AbstractStateForEffectNodes::Set(
   info_for_node_[id] = state;
 }
 
-Reduction LoadElimination::ReduceArrayBufferWasNeutered(Node* node) {
-  Node* const effect = NodeProperties::GetEffectInput(node);
-  AbstractState const* state = node_states_.Get(effect);
-  if (state == nullptr) return NoChange();
-  if (Node* const check = state->LookupCheck(node)) {
-    ReplaceWithValue(node, check, effect);
-    return Replace(check);
-  }
-  state = state->AddCheck(node, zone());
-  return UpdateState(node, state);
-}
-
 Reduction LoadElimination::ReduceMapGuard(Node* node) {
   ZoneHandleSet<Map> const maps = MapGuardMapsOf(node->op()).maps();
   Node* const object = NodeProperties::GetValueInput(node, 0);
@@ -962,8 +848,9 @@ Reduction LoadElimination::ReduceStoreField(Node* node) {
     Type const new_value_type = NodeProperties::GetType(new_value);
     if (new_value_type.IsHeapConstant()) {
       // Record the new {object} map information.
+      AllowHandleDereference handle_dereference;
       ZoneHandleSet<Map> object_maps(
-          bit_cast<Handle<Map>>(new_value_type.AsHeapConstant()->Value()));
+          Handle<Map>::cast(new_value_type.AsHeapConstant()->Value()));
       state = state->SetMaps(object, object_maps, zone());
     }
   } else {
diff --git a/deps/v8/src/compiler/load-elimination.h b/deps/v8/src/compiler/load-elimination.h
index 2ce5a04397..8fa31be074 100644
--- a/deps/v8/src/compiler/load-elimination.h
+++ b/deps/v8/src/compiler/load-elimination.h
@@ -31,46 +31,13 @@ class V8_EXPORT_PRIVATE LoadElimination final
  public:
   LoadElimination(Editor* editor, JSGraph* jsgraph, Zone* zone)
       : AdvancedReducer(editor), node_states_(zone), jsgraph_(jsgraph) {}
-  ~LoadElimination() final {}
+  ~LoadElimination() final = default;
 
   const char* reducer_name() const override { return "LoadElimination"; }
 
   Reduction Reduce(Node* node) final;
 
  private:
-  static const size_t kMaxTrackedChecks = 8;
-
-  // Abstract state to approximate the current state of checks that are
-  // only invalidated by calls, i.e. array buffer neutering checks, along
-  // the effect paths through the graph.
-  class AbstractChecks final : public ZoneObject {
-   public:
-    explicit AbstractChecks(Zone* zone) {
-      for (size_t i = 0; i < arraysize(nodes_); ++i) {
-        nodes_[i] = nullptr;
-      }
-    }
-    AbstractChecks(Node* node, Zone* zone) : AbstractChecks(zone) {
-      nodes_[next_index_++] = node;
-    }
-
-    AbstractChecks const* Extend(Node* node, Zone* zone) const {
-      AbstractChecks* that = new (zone) AbstractChecks(*this);
-      that->nodes_[that->next_index_] = node;
-      that->next_index_ = (that->next_index_ + 1) % arraysize(nodes_);
-      return that;
-    }
-    Node* Lookup(Node* node) const;
-    bool Equals(AbstractChecks const* that) const;
-    AbstractChecks const* Merge(AbstractChecks const* that, Zone* zone) const;
-
-    void Print() const;
-
-   private:
-    Node* nodes_[kMaxTrackedChecks];
-    size_t next_index_ = 0;
-  };
-
   static const size_t kMaxTrackedElements = 8;
 
   // Abstract state to approximate the current state of an element along the
@@ -108,7 +75,7 @@ class V8_EXPORT_PRIVATE LoadElimination final
 
    private:
     struct Element {
-      Element() {}
+      Element() = default;
       Element(Node* object, Node* index, Node* value,
               MachineRepresentation representation)
           : object(object),
@@ -174,7 +141,7 @@ class V8_EXPORT_PRIVATE LoadElimination final
 
    private:
     struct Field {
-      Field() {}
+      Field() = default;
       Field(Node* value, MaybeHandle<Name> name) : value(value), name(name) {}
 
       bool operator==(const Field& other) const {
@@ -250,13 +217,9 @@ class V8_EXPORT_PRIVATE LoadElimination final
     Node* LookupElement(Node* object, Node* index,
                         MachineRepresentation representation) const;
 
-    AbstractState const* AddCheck(Node* node, Zone* zone) const;
-    Node* LookupCheck(Node* node) const;
-
     void Print() const;
 
    private:
-    AbstractChecks const* checks_ = nullptr;
     AbstractElements const* elements_ = nullptr;
     AbstractField const* fields_[kMaxTrackedFields];
     AbstractMaps const* maps_ = nullptr;
@@ -274,7 +237,6 @@ class V8_EXPORT_PRIVATE LoadElimination final
     ZoneVector<AbstractState const*> info_for_node_;
   };
 
-  Reduction ReduceArrayBufferWasNeutered(Node* node);
   Reduction ReduceCheckMaps(Node* node);
   Reduction ReduceCompareMaps(Node* node);
   Reduction ReduceMapGuard(Node* node);
diff --git a/deps/v8/src/compiler/loop-peeling.h b/deps/v8/src/compiler/loop-peeling.h
index 150505a5e5..a3408ec81d 100644
--- a/deps/v8/src/compiler/loop-peeling.h
+++ b/deps/v8/src/compiler/loop-peeling.h
@@ -26,7 +26,7 @@ class V8_EXPORT_PRIVATE PeeledIteration : public NON_EXPORTED_BASE(ZoneObject) {
   Node* map(Node* node);
 
  protected:
-  PeeledIteration() {}
+  PeeledIteration() = default;
 };
 
 class CommonOperatorBuilder;
diff --git a/deps/v8/src/compiler/loop-variable-optimizer.cc b/deps/v8/src/compiler/loop-variable-optimizer.cc
index 5a0fc9dbfb..9fe7fdc4f9 100644
--- a/deps/v8/src/compiler/loop-variable-optimizer.cc
+++ b/deps/v8/src/compiler/loop-variable-optimizer.cc
@@ -158,6 +158,7 @@ void LoopVariableOptimizer::VisitIf(Node* node, bool polarity) {
   // Normalize to less than comparison.
   switch (cond->opcode()) {
     case IrOpcode::kJSLessThan:
+    case IrOpcode::kNumberLessThan:
     case IrOpcode::kSpeculativeNumberLessThan:
       AddCmpToLimits(&limits, cond, InductionVariable::kStrict, polarity);
       break;
@@ -165,6 +166,7 @@ void LoopVariableOptimizer::VisitIf(Node* node, bool polarity) {
       AddCmpToLimits(&limits, cond, InductionVariable::kNonStrict, !polarity);
       break;
     case IrOpcode::kJSLessThanOrEqual:
+    case IrOpcode::kNumberLessThanOrEqual:
     case IrOpcode::kSpeculativeNumberLessThanOrEqual:
       AddCmpToLimits(&limits, cond, InductionVariable::kNonStrict, polarity);
       break;
@@ -226,10 +228,12 @@ InductionVariable* LoopVariableOptimizer::TryGetInductionVariable(Node* phi) {
   Node* arith = phi->InputAt(1);
   InductionVariable::ArithmeticType arithmeticType;
   if (arith->opcode() == IrOpcode::kJSAdd ||
+      arith->opcode() == IrOpcode::kNumberAdd ||
       arith->opcode() == IrOpcode::kSpeculativeNumberAdd ||
       arith->opcode() == IrOpcode::kSpeculativeSafeIntegerAdd) {
     arithmeticType = InductionVariable::ArithmeticType::kAddition;
   } else if (arith->opcode() == IrOpcode::kJSSubtract ||
+             arith->opcode() == IrOpcode::kNumberSubtract ||
              arith->opcode() == IrOpcode::kSpeculativeNumberSubtract ||
              arith->opcode() == IrOpcode::kSpeculativeSafeIntegerSubtract) {
     arithmeticType = InductionVariable::ArithmeticType::kSubtraction;
diff --git a/deps/v8/src/compiler/machine-graph-verifier.cc b/deps/v8/src/compiler/machine-graph-verifier.cc
index f3a5fb9023..c5769c2542 100644
--- a/deps/v8/src/compiler/machine-graph-verifier.cc
+++ b/deps/v8/src/compiler/machine-graph-verifier.cc
@@ -65,6 +65,16 @@ class MachineRepresentationInferrer {
         auto call_descriptor = CallDescriptorOf(input->op());
         return call_descriptor->GetReturnType(index).representation();
       }
+      case IrOpcode::kWord32AtomicPairLoad:
+      case IrOpcode::kWord32AtomicPairAdd:
+      case IrOpcode::kWord32AtomicPairSub:
+      case IrOpcode::kWord32AtomicPairAnd:
+      case IrOpcode::kWord32AtomicPairOr:
+      case IrOpcode::kWord32AtomicPairXor:
+      case IrOpcode::kWord32AtomicPairExchange:
+      case IrOpcode::kWord32AtomicPairCompareExchange:
+        CHECK_LE(index, static_cast<size_t>(1));
+        return MachineRepresentation::kWord32;
       default:
         return MachineRepresentation::kNone;
     }
@@ -111,6 +121,7 @@ class MachineRepresentationInferrer {
             representation_vector_[node->id()] = MachineRepresentation::kNone;
             break;
           case IrOpcode::kWord32AtomicLoad:
+          case IrOpcode::kWord64AtomicLoad:
           case IrOpcode::kLoad:
           case IrOpcode::kProtectedLoad:
           case IrOpcode::kPoisonedLoad:
@@ -144,9 +155,21 @@ class MachineRepresentationInferrer {
             break;
           }
           case IrOpcode::kWord32AtomicStore:
+          case IrOpcode::kWord64AtomicStore:
             representation_vector_[node->id()] =
                 PromoteRepresentation(AtomicStoreRepresentationOf(node->op()));
             break;
+          case IrOpcode::kWord32AtomicPairLoad:
+          case IrOpcode::kWord32AtomicPairStore:
+          case IrOpcode::kWord32AtomicPairAdd:
+          case IrOpcode::kWord32AtomicPairSub:
+          case IrOpcode::kWord32AtomicPairAnd:
+          case IrOpcode::kWord32AtomicPairOr:
+          case IrOpcode::kWord32AtomicPairXor:
+          case IrOpcode::kWord32AtomicPairExchange:
+          case IrOpcode::kWord32AtomicPairCompareExchange:
+            representation_vector_[node->id()] = MachineRepresentation::kWord32;
+            break;
           case IrOpcode::kWord32AtomicExchange:
           case IrOpcode::kWord32AtomicCompareExchange:
           case IrOpcode::kWord32AtomicAdd:
@@ -154,6 +177,13 @@ class MachineRepresentationInferrer {
           case IrOpcode::kWord32AtomicAnd:
           case IrOpcode::kWord32AtomicOr:
           case IrOpcode::kWord32AtomicXor:
+          case IrOpcode::kWord64AtomicExchange:
+          case IrOpcode::kWord64AtomicCompareExchange:
+          case IrOpcode::kWord64AtomicAdd:
+          case IrOpcode::kWord64AtomicSub:
+          case IrOpcode::kWord64AtomicAnd:
+          case IrOpcode::kWord64AtomicOr:
+          case IrOpcode::kWord64AtomicXor:
             representation_vector_[node->id()] = PromoteRepresentation(
                 AtomicOpType(node->op()).representation());
             break;
@@ -168,6 +198,7 @@ class MachineRepresentationInferrer {
             break;
           case IrOpcode::kHeapConstant:
           case IrOpcode::kNumberConstant:
+          case IrOpcode::kDelayedStringConstant:
           case IrOpcode::kChangeBitToTagged:
           case IrOpcode::kIfException:
           case IrOpcode::kOsrValue:
@@ -486,11 +517,23 @@ class MachineRepresentationChecker {
             break;
           case IrOpcode::kLoad:
           case IrOpcode::kWord32AtomicLoad:
+          case IrOpcode::kWord32AtomicPairLoad:
+          case IrOpcode::kWord64AtomicLoad:
           case IrOpcode::kPoisonedLoad:
             CheckValueInputIsTaggedOrPointer(node, 0);
             CheckValueInputRepresentationIs(
                 node, 1, MachineType::PointerRepresentation());
             break;
+          case IrOpcode::kWord32AtomicPairAdd:
+          case IrOpcode::kWord32AtomicPairSub:
+          case IrOpcode::kWord32AtomicPairAnd:
+          case IrOpcode::kWord32AtomicPairOr:
+          case IrOpcode::kWord32AtomicPairXor:
+          case IrOpcode::kWord32AtomicPairStore:
+          case IrOpcode::kWord32AtomicPairExchange:
+            CheckValueInputRepresentationIs(node, 3,
+                                            MachineRepresentation::kWord32);
+            V8_FALLTHROUGH;
           case IrOpcode::kStore:
           case IrOpcode::kWord32AtomicStore:
           case IrOpcode::kWord32AtomicExchange:
@@ -499,6 +542,13 @@ class MachineRepresentationChecker {
           case IrOpcode::kWord32AtomicAnd:
           case IrOpcode::kWord32AtomicOr:
           case IrOpcode::kWord32AtomicXor:
+          case IrOpcode::kWord64AtomicStore:
+          case IrOpcode::kWord64AtomicExchange:
+          case IrOpcode::kWord64AtomicAdd:
+          case IrOpcode::kWord64AtomicSub:
+          case IrOpcode::kWord64AtomicAnd:
+          case IrOpcode::kWord64AtomicOr:
+          case IrOpcode::kWord64AtomicXor:
             CheckValueInputIsTaggedOrPointer(node, 0);
             CheckValueInputRepresentationIs(
                 node, 1, MachineType::PointerRepresentation());
@@ -513,7 +563,14 @@ class MachineRepresentationChecker {
                     node, 2, inferrer_->GetRepresentation(node));
             }
             break;
+          case IrOpcode::kWord32AtomicPairCompareExchange:
+            CheckValueInputRepresentationIs(node, 4,
+                                            MachineRepresentation::kWord32);
+            CheckValueInputRepresentationIs(node, 5,
+                                            MachineRepresentation::kWord32);
+            V8_FALLTHROUGH;
           case IrOpcode::kWord32AtomicCompareExchange:
+          case IrOpcode::kWord64AtomicCompareExchange:
             CheckValueInputIsTaggedOrPointer(node, 0);
             CheckValueInputRepresentationIs(
                 node, 1, MachineType::PointerRepresentation());
diff --git a/deps/v8/src/compiler/machine-operator-reducer.cc b/deps/v8/src/compiler/machine-operator-reducer.cc
index 7fcba20e2e..8ef7e7ce08 100644
--- a/deps/v8/src/compiler/machine-operator-reducer.cc
+++ b/deps/v8/src/compiler/machine-operator-reducer.cc
@@ -22,7 +22,7 @@ MachineOperatorReducer::MachineOperatorReducer(MachineGraph* mcgraph,
                                                bool allow_signalling_nan)
     : mcgraph_(mcgraph), allow_signalling_nan_(allow_signalling_nan) {}
 
-MachineOperatorReducer::~MachineOperatorReducer() {}
+MachineOperatorReducer::~MachineOperatorReducer() = default;
 
 
 Node* MachineOperatorReducer::Float32Constant(volatile float value) {
@@ -618,6 +618,12 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
       if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0));
       break;
     }
+    case IrOpcode::kChangeFloat64ToInt64: {
+      Float64Matcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceInt64(static_cast<int64_t>(m.Value()));
+      if (m.IsChangeInt64ToFloat64()) return Replace(m.node()->InputAt(0));
+      break;
+    }
     case IrOpcode::kChangeFloat64ToUint32: {
       Float64Matcher m(node->InputAt(0));
       if (m.HasValue()) return ReplaceInt32(FastD2UI(m.Value()));
@@ -634,6 +640,12 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
       if (m.HasValue()) return ReplaceInt64(m.Value());
       break;
     }
+    case IrOpcode::kChangeInt64ToFloat64: {
+      Int64Matcher m(node->InputAt(0));
+      if (m.HasValue()) return ReplaceFloat64(static_cast<double>(m.Value()));
+      if (m.IsChangeFloat64ToInt64()) return Replace(m.node()->InputAt(0));
+      break;
+    }
     case IrOpcode::kChangeUint32ToFloat64: {
       Uint32Matcher m(node->InputAt(0));
       if (m.HasValue()) return ReplaceFloat64(FastUI2D(m.Value()));
@@ -1374,21 +1386,32 @@ bool IsFloat64RepresentableAsFloat32(const Float64Matcher& m) {
 
 
 Reduction MachineOperatorReducer::ReduceFloat64Compare(Node* node) {
-  DCHECK((IrOpcode::kFloat64Equal == node->opcode()) ||
-         (IrOpcode::kFloat64LessThan == node->opcode()) ||
-         (IrOpcode::kFloat64LessThanOrEqual == node->opcode()));
-  // As all Float32 values have an exact representation in Float64, comparing
-  // two Float64 values both converted from Float32 is equivalent to comparing
-  // the original Float32s, so we can ignore the conversions. We can also reduce
-  // comparisons of converted Float64 values against constants that can be
-  // represented exactly as Float32.
+  DCHECK(IrOpcode::kFloat64Equal == node->opcode() ||
+         IrOpcode::kFloat64LessThan == node->opcode() ||
+         IrOpcode::kFloat64LessThanOrEqual == node->opcode());
   Float64BinopMatcher m(node);
-  if ((m.left().IsChangeFloat32ToFloat64() &&
-       m.right().IsChangeFloat32ToFloat64()) ||
-      (m.left().IsChangeFloat32ToFloat64() &&
-       IsFloat64RepresentableAsFloat32(m.right())) ||
-      (IsFloat64RepresentableAsFloat32(m.left()) &&
-       m.right().IsChangeFloat32ToFloat64())) {
+  if (m.IsFoldable()) {
+    switch (node->opcode()) {
+      case IrOpcode::kFloat64Equal:
+        return ReplaceBool(m.left().Value() == m.right().Value());
+      case IrOpcode::kFloat64LessThan:
+        return ReplaceBool(m.left().Value() < m.right().Value());
+      case IrOpcode::kFloat64LessThanOrEqual:
+        return ReplaceBool(m.left().Value() <= m.right().Value());
+      default:
+        UNREACHABLE();
+    }
+  } else if ((m.left().IsChangeFloat32ToFloat64() &&
+              m.right().IsChangeFloat32ToFloat64()) ||
+             (m.left().IsChangeFloat32ToFloat64() &&
+              IsFloat64RepresentableAsFloat32(m.right())) ||
+             (IsFloat64RepresentableAsFloat32(m.left()) &&
+              m.right().IsChangeFloat32ToFloat64())) {
+    // As all Float32 values have an exact representation in Float64, comparing
+    // two Float64 values both converted from Float32 is equivalent to comparing
+    // the original Float32s, so we can ignore the conversions. We can also
+    // reduce comparisons of converted Float64 values against constants that
+    // can be represented exactly as Float32.
     switch (node->opcode()) {
       case IrOpcode::kFloat64Equal:
         NodeProperties::ChangeOp(node, machine()->Float32Equal());
@@ -1400,7 +1423,7 @@ Reduction MachineOperatorReducer::ReduceFloat64Compare(Node* node) {
         NodeProperties::ChangeOp(node, machine()->Float32LessThanOrEqual());
         break;
       default:
-        return NoChange();
+        UNREACHABLE();
     }
     node->ReplaceInput(
         0, m.left().HasValue()
diff --git a/deps/v8/src/compiler/machine-operator-reducer.h b/deps/v8/src/compiler/machine-operator-reducer.h
index 1dc2a0a106..c44ec5f551 100644
--- a/deps/v8/src/compiler/machine-operator-reducer.h
+++ b/deps/v8/src/compiler/machine-operator-reducer.h
@@ -25,7 +25,7 @@ class V8_EXPORT_PRIVATE MachineOperatorReducer final
  public:
   explicit MachineOperatorReducer(MachineGraph* mcgraph,
                                   bool allow_signalling_nan = true);
-  ~MachineOperatorReducer();
+  ~MachineOperatorReducer() override;
 
   const char* reducer_name() const override { return "MachineOperatorReducer"; }
 
diff --git a/deps/v8/src/compiler/machine-operator.cc b/deps/v8/src/compiler/machine-operator.cc
index 241651254b..f3fcd7758c 100644
--- a/deps/v8/src/compiler/machine-operator.cc
+++ b/deps/v8/src/compiler/machine-operator.cc
@@ -81,8 +81,7 @@ StackSlotRepresentation const& StackSlotRepresentationOf(Operator const* op) {
 
 MachineRepresentation AtomicStoreRepresentationOf(Operator const* op) {
   DCHECK(IrOpcode::kWord32AtomicStore == op->opcode() ||
-         IrOpcode::kWord64AtomicStore == op->opcode() ||
-         IrOpcode::kWord32AtomicPairStore == op->opcode());
+         IrOpcode::kWord64AtomicStore == op->opcode());
   return OpParameter<MachineRepresentation>(op);
 }
 
@@ -145,6 +144,7 @@ MachineType AtomicOpType(Operator const* op) {
   V(TruncateFloat64ToWord32, Operator::kNoProperties, 1, 0, 1)            \
   V(ChangeFloat32ToFloat64, Operator::kNoProperties, 1, 0, 1)             \
   V(ChangeFloat64ToInt32, Operator::kNoProperties, 1, 0, 1)               \
+  V(ChangeFloat64ToInt64, Operator::kNoProperties, 1, 0, 1)               \
   V(ChangeFloat64ToUint32, Operator::kNoProperties, 1, 0, 1)              \
   V(ChangeFloat64ToUint64, Operator::kNoProperties, 1, 0, 1)              \
   V(TruncateFloat64ToUint32, Operator::kNoProperties, 1, 0, 1)            \
@@ -155,6 +155,7 @@ MachineType AtomicOpType(Operator const* op) {
   V(TryTruncateFloat32ToUint64, Operator::kNoProperties, 1, 0, 2)         \
   V(TryTruncateFloat64ToUint64, Operator::kNoProperties, 1, 0, 2)         \
   V(ChangeInt32ToFloat64, Operator::kNoProperties, 1, 0, 1)               \
+  V(ChangeInt64ToFloat64, Operator::kNoProperties, 1, 0, 1)               \
   V(Float64SilenceNaN, Operator::kNoProperties, 1, 0, 1)                  \
   V(RoundFloat64ToInt32, Operator::kNoProperties, 1, 0, 1)                \
   V(RoundInt32ToFloat32, Operator::kNoProperties, 1, 0, 1)                \
@@ -342,8 +343,8 @@ MachineType AtomicOpType(Operator const* op) {
   V(Word64Ctz, Operator::kNoProperties, 1, 0, 1)            \
   V(Word32ReverseBits, Operator::kNoProperties, 1, 0, 1)    \
   V(Word64ReverseBits, Operator::kNoProperties, 1, 0, 1)    \
-  V(Int32AbsWithOverflow, Operator::kNoProperties, 1, 0, 1) \
-  V(Int64AbsWithOverflow, Operator::kNoProperties, 1, 0, 1) \
+  V(Int32AbsWithOverflow, Operator::kNoProperties, 1, 0, 2) \
+  V(Int64AbsWithOverflow, Operator::kNoProperties, 1, 0, 2) \
   V(Word32Popcnt, Operator::kNoProperties, 1, 0, 1)         \
   V(Word64Popcnt, Operator::kNoProperties, 1, 0, 1)         \
   V(Float32RoundDown, Operator::kNoProperties, 1, 0, 1)     \
@@ -718,25 +719,6 @@ struct MachineOperatorGlobalCache {
 #undef ATOMIC_PAIR_OP
 #undef ATOMIC_PAIR_BINOP_LIST
 
-#define ATOMIC64_NARROW_OP(op, type)                                           \
-  struct op##type##Operator : public Operator1<MachineType> {                  \
-    op##type##Operator()                                                       \
-        : Operator1<MachineType>(                                              \
-              IrOpcode::k##op, Operator::kNoDeopt | Operator::kNoThrow, "#op", \
-              3, 1, 1, 2, 1, 0, MachineType::type()) {}                        \
-  };                                                                           \
-  op##type##Operator k##op##type;
-#define ATOMIC_OP_LIST(type)                      \
-  ATOMIC64_NARROW_OP(Word64AtomicNarrowAdd, type) \
-  ATOMIC64_NARROW_OP(Word64AtomicNarrowSub, type) \
-  ATOMIC64_NARROW_OP(Word64AtomicNarrowAnd, type) \
-  ATOMIC64_NARROW_OP(Word64AtomicNarrowOr, type)  \
-  ATOMIC64_NARROW_OP(Word64AtomicNarrowXor, type) \
-  ATOMIC64_NARROW_OP(Word64AtomicNarrowExchange, type)
-  ATOMIC_U32_TYPE_LIST(ATOMIC_OP_LIST)
-#undef ATOMIC_OP_LIST
-#undef ATOMIC64_NARROW_OP
-
   struct Word32AtomicPairCompareExchangeOperator : public Operator {
     Word32AtomicPairCompareExchangeOperator()
         : Operator(IrOpcode::kWord32AtomicPairCompareExchange,
@@ -745,20 +727,6 @@ struct MachineOperatorGlobalCache {
   };
   Word32AtomicPairCompareExchangeOperator kWord32AtomicPairCompareExchange;
 
-#define ATOMIC_COMPARE_EXCHANGE(Type)                                          \
-  struct Word64AtomicNarrowCompareExchange##Type##Operator                     \
-      : public Operator1<MachineType> {                                        \
-    Word64AtomicNarrowCompareExchange##Type##Operator()                        \
-        : Operator1<MachineType>(IrOpcode::kWord64AtomicNarrowCompareExchange, \
-                                 Operator::kNoDeopt | Operator::kNoThrow,      \
-                                 "Word64AtomicNarrowCompareExchange", 4, 1, 1, \
-                                 2, 1, 0, MachineType::Type()) {}              \
-  };                                                                           \
-  Word64AtomicNarrowCompareExchange##Type##Operator                            \
-      kWord64AtomicNarrowCompareExchange##Type;
-  ATOMIC_TYPE_LIST(ATOMIC_COMPARE_EXCHANGE)
-#undef ATOMIC_COMPARE_EXCHANGE
-
   // The {BitcastWordToTagged} operator must not be marked as pure (especially
   // not idempotent), because otherwise the splitting logic in the Scheduler
   // might decide to split these operators, thus potentially creating live
@@ -1245,82 +1213,6 @@ const Operator* MachineOperatorBuilder::Word32AtomicPairCompareExchange() {
   return &cache_.kWord32AtomicPairCompareExchange;
 }
 
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowAdd(
-    MachineType type) {
-#define ADD(kType)                                \
-  if (type == MachineType::kType()) {             \
-    return &cache_.kWord64AtomicNarrowAdd##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(ADD)
-#undef ADD
-  UNREACHABLE();
-}
-
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowSub(
-    MachineType type) {
-#define SUB(kType)                                \
-  if (type == MachineType::kType()) {             \
-    return &cache_.kWord64AtomicNarrowSub##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(SUB)
-#undef SUB
-  UNREACHABLE();
-}
-
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowAnd(
-    MachineType type) {
-#define AND(kType)                                \
-  if (type == MachineType::kType()) {             \
-    return &cache_.kWord64AtomicNarrowAnd##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(AND)
-#undef AND
-  UNREACHABLE();
-}
-
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowOr(MachineType type) {
-#define OR(kType)                                \
-  if (type == MachineType::kType()) {            \
-    return &cache_.kWord64AtomicNarrowOr##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(OR)
-#undef OR
-  UNREACHABLE();
-}
-
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowXor(
-    MachineType type) {
-#define XOR(kType)                                \
-  if (type == MachineType::kType()) {             \
-    return &cache_.kWord64AtomicNarrowXor##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(XOR)
-#undef XOR
-  UNREACHABLE();
-}
-
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowExchange(
-    MachineType type) {
-#define EXCHANGE(kType)                                \
-  if (type == MachineType::kType()) {                  \
-    return &cache_.kWord64AtomicNarrowExchange##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(EXCHANGE)
-#undef EXCHANGE
-  UNREACHABLE();
-}
-
-const Operator* MachineOperatorBuilder::Word64AtomicNarrowCompareExchange(
-    MachineType type) {
-#define CMP_EXCHANGE(kType)                                   \
-  if (type == MachineType::kType()) {                         \
-    return &cache_.kWord64AtomicNarrowCompareExchange##kType; \
-  }
-  ATOMIC_U32_TYPE_LIST(CMP_EXCHANGE)
-#undef CMP_EXCHANGE
-  UNREACHABLE();
-}
-
 const Operator* MachineOperatorBuilder::TaggedPoisonOnSpeculation() {
   return &cache_.kTaggedPoisonOnSpeculation;
 }
diff --git a/deps/v8/src/compiler/machine-operator.h b/deps/v8/src/compiler/machine-operator.h
index 261891dcdc..a34360a375 100644
--- a/deps/v8/src/compiler/machine-operator.h
+++ b/deps/v8/src/compiler/machine-operator.h
@@ -319,6 +319,7 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   // the input value is representable in the target value.
   const Operator* ChangeFloat32ToFloat64();
   const Operator* ChangeFloat64ToInt32();   // narrowing
+  const Operator* ChangeFloat64ToInt64();
   const Operator* ChangeFloat64ToUint32();  // narrowing
   const Operator* ChangeFloat64ToUint64();
   const Operator* TruncateFloat64ToUint32();
@@ -330,6 +331,7 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* TryTruncateFloat64ToUint64();
   const Operator* ChangeInt32ToFloat64();
   const Operator* ChangeInt32ToInt64();
+  const Operator* ChangeInt64ToFloat64();
   const Operator* ChangeUint32ToFloat64();
   const Operator* ChangeUint32ToUint64();
 
@@ -648,20 +650,6 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* Word64AtomicOr(MachineType type);
   // atomic-xor [base + index], value
   const Operator* Word64AtomicXor(MachineType rep);
-  // atomic-narrow-add [base + index], value
-  const Operator* Word64AtomicNarrowAdd(MachineType type);
-  // atomic-narow-sub [base + index], value
-  const Operator* Word64AtomicNarrowSub(MachineType type);
-  // atomic-narrow-and [base + index], value
-  const Operator* Word64AtomicNarrowAnd(MachineType type);
-  // atomic-narrow-or [base + index], value
-  const Operator* Word64AtomicNarrowOr(MachineType type);
-  // atomic-narrow-xor [base + index], value
-  const Operator* Word64AtomicNarrowXor(MachineType type);
-  // atomic-narrow-exchange [base + index], value
-  const Operator* Word64AtomicNarrowExchange(MachineType type);
-  // atomic-narrow-compare-exchange [base + index], old_value, new_value
-  const Operator* Word64AtomicNarrowCompareExchange(MachineType type);
   // atomic-pair-load [base + index]
   const Operator* Word32AtomicPairLoad();
   // atomic-pair-sub [base + index], value_high, value-low
diff --git a/deps/v8/src/compiler/memory-optimizer.cc b/deps/v8/src/compiler/memory-optimizer.cc
index 3ba3dcc6b8..298a503771 100644
--- a/deps/v8/src/compiler/memory-optimizer.cc
+++ b/deps/v8/src/compiler/memory-optimizer.cc
@@ -67,7 +67,7 @@ MemoryOptimizer::AllocationState::AllocationState(AllocationGroup* group)
     : group_(group), size_(std::numeric_limits<int>::max()), top_(nullptr) {}
 
 MemoryOptimizer::AllocationState::AllocationState(AllocationGroup* group,
-                                                  int size, Node* top)
+                                                  intptr_t size, Node* top)
     : group_(group), size_(size), top_(top) {}
 
 bool MemoryOptimizer::AllocationState::IsNewSpaceAllocation() const {
@@ -175,27 +175,35 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
 
   // Check if we can fold this allocation into a previous allocation represented
   // by the incoming {state}.
-  Int32Matcher m(size);
-  if (m.HasValue() && m.Value() < kMaxRegularHeapObjectSize) {
-    int32_t const object_size = m.Value();
+  IntPtrMatcher m(size);
+  if (m.IsInRange(0, kMaxRegularHeapObjectSize)) {
+    intptr_t const object_size = m.Value();
     if (allocation_folding_ == AllocationFolding::kDoAllocationFolding &&
         state->size() <= kMaxRegularHeapObjectSize - object_size &&
         state->group()->pretenure() == pretenure) {
       // We can fold this Allocate {node} into the allocation {group}
       // represented by the given {state}. Compute the upper bound for
       // the new {state}.
-      int32_t const state_size = state->size() + object_size;
+      intptr_t const state_size = state->size() + object_size;
 
       // Update the reservation check to the actual maximum upper bound.
       AllocationGroup* const group = state->group();
-      if (OpParameter<int32_t>(group->size()->op()) < state_size) {
-        NodeProperties::ChangeOp(group->size(),
-                                 common()->Int32Constant(state_size));
+      if (machine()->Is64()) {
+        if (OpParameter<int64_t>(group->size()->op()) < state_size) {
+          NodeProperties::ChangeOp(group->size(),
+                                   common()->Int64Constant(state_size));
+        }
+      } else {
+        if (OpParameter<int32_t>(group->size()->op()) < state_size) {
+          NodeProperties::ChangeOp(
+              group->size(),
+              common()->Int32Constant(static_cast<int32_t>(state_size)));
+        }
       }
 
       // Update the allocation top with the new object allocation.
       // TODO(bmeurer): Defer writing back top as much as possible.
-      Node* top = __ IntAdd(state->top(), __ IntPtrConstant(object_size));
+      Node* top = __ IntAdd(state->top(), size);
       __ Store(StoreRepresentation(MachineType::PointerRepresentation(),
                                    kNoWriteBarrier),
                top_address, __ IntPtrConstant(0), top);
@@ -213,7 +221,7 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
 
       // Setup a mutable reservation size node; will be patched as we fold
       // additional allocations into this new group.
-      Node* size = __ UniqueInt32Constant(object_size);
+      Node* size = __ UniqueIntPtrConstant(object_size);
 
       // Load allocation top and limit.
       Node* top =
@@ -223,10 +231,7 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
 
       // Check if we need to collect garbage before we can start bump pointer
       // allocation (always done for folded allocations).
-      Node* check = __ UintLessThan(
-          __ IntAdd(top,
-                    machine()->Is64() ? __ ChangeInt32ToInt64(size) : size),
-          limit);
+      Node* check = __ UintLessThan(__ IntAdd(top, size), limit);
 
       __ GotoIfNot(check, &call_runtime);
       __ Goto(&done, top);
@@ -238,8 +243,9 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
                                      : __
                                        AllocateInOldSpaceStubConstant();
         if (!allocate_operator_.is_set()) {
+          auto descriptor = AllocateDescriptor{};
           auto call_descriptor = Linkage::GetStubCallDescriptor(
-              graph()->zone(), AllocateDescriptor{}, 0,
+              graph()->zone(), descriptor, descriptor.GetStackParameterCount(),
               CallDescriptor::kCanUseRoots, Operator::kNoThrow);
           allocate_operator_.set(common()->Call(call_descriptor));
         }
@@ -276,8 +282,7 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
         __ Load(MachineType::Pointer(), limit_address, __ IntPtrConstant(0));
 
     // Compute the new top.
-    Node* new_top =
-        __ IntAdd(top, machine()->Is64() ? __ ChangeInt32ToInt64(size) : size);
+    Node* new_top = __ IntAdd(top, size);
 
     // Check if we can do bump pointer allocation here.
     Node* check = __ UintLessThan(new_top, limit);
@@ -294,8 +299,9 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
                                  : __
                                    AllocateInOldSpaceStubConstant();
     if (!allocate_operator_.is_set()) {
+      auto descriptor = AllocateDescriptor{};
       auto call_descriptor = Linkage::GetStubCallDescriptor(
-          graph()->zone(), AllocateDescriptor{}, 0,
+          graph()->zone(), descriptor, descriptor.GetStackParameterCount(),
           CallDescriptor::kCanUseRoots, Operator::kNoThrow);
       allocate_operator_.set(common()->Call(call_descriptor));
     }
@@ -421,19 +427,7 @@ void MemoryOptimizer::VisitOtherEffect(Node* node,
   EnqueueUses(node, state);
 }
 
-Node* MemoryOptimizer::ComputeIndex(ElementAccess const& access, Node* key) {
-  Node* index;
-  if (machine()->Is64()) {
-    // On 64-bit platforms, we need to feed a Word64 index to the Load and
-    // Store operators. Since LoadElement or StoreElement don't do any bounds
-    // checking themselves, we can be sure that the {key} was already checked
-    // and is in valid range, so we can do the further address computation on
-    // Word64 below, which ideally allows us to fuse the address computation
-    // with the actual memory access operation on Intel platforms.
-    index = graph()->NewNode(machine()->ChangeUint32ToUint64(), key);
-  } else {
-    index = key;
-  }
+Node* MemoryOptimizer::ComputeIndex(ElementAccess const& access, Node* index) {
   int const element_size_shift =
       ElementSizeLog2Of(access.machine_type.representation());
   if (element_size_shift) {
diff --git a/deps/v8/src/compiler/memory-optimizer.h b/deps/v8/src/compiler/memory-optimizer.h
index 5ea79556f4..31c04e5f2f 100644
--- a/deps/v8/src/compiler/memory-optimizer.h
+++ b/deps/v8/src/compiler/memory-optimizer.h
@@ -36,7 +36,7 @@ class MemoryOptimizer final {
   MemoryOptimizer(JSGraph* jsgraph, Zone* zone,
                   PoisoningMitigationLevel poisoning_level,
                   AllocationFolding allocation_folding);
-  ~MemoryOptimizer() {}
+  ~MemoryOptimizer() = default;
 
   void Optimize();
 
@@ -48,7 +48,7 @@ class MemoryOptimizer final {
     AllocationGroup(Node* node, PretenureFlag pretenure, Zone* zone);
     AllocationGroup(Node* node, PretenureFlag pretenure, Node* size,
                     Zone* zone);
-    ~AllocationGroup() {}
+    ~AllocationGroup() = default;
 
     void Add(Node* object);
     bool Contains(Node* object) const;
@@ -74,7 +74,7 @@ class MemoryOptimizer final {
     static AllocationState const* Closed(AllocationGroup* group, Zone* zone) {
       return new (zone) AllocationState(group);
     }
-    static AllocationState const* Open(AllocationGroup* group, int size,
+    static AllocationState const* Open(AllocationGroup* group, intptr_t size,
                                        Node* top, Zone* zone) {
       return new (zone) AllocationState(group, size, top);
     }
@@ -83,17 +83,17 @@ class MemoryOptimizer final {
 
     AllocationGroup* group() const { return group_; }
     Node* top() const { return top_; }
-    int size() const { return size_; }
+    intptr_t size() const { return size_; }
 
    private:
     AllocationState();
     explicit AllocationState(AllocationGroup* group);
-    AllocationState(AllocationGroup* group, int size, Node* top);
+    AllocationState(AllocationGroup* group, intptr_t size, Node* top);
 
     AllocationGroup* const group_;
     // The upper bound of the combined allocated object size on the current path
     // (max int if allocation folding is impossible on this path).
-    int const size_;
+    intptr_t const size_;
     Node* const top_;
 
     DISALLOW_COPY_AND_ASSIGN(AllocationState);
diff --git a/deps/v8/src/compiler/mips/code-generator-mips.cc b/deps/v8/src/compiler/mips/code-generator-mips.cc
index 00575fe117..e44ffee34b 100644
--- a/deps/v8/src/compiler/mips/code-generator-mips.cc
+++ b/deps/v8/src/compiler/mips/code-generator-mips.cc
@@ -84,6 +84,9 @@ class MipsOperandConverter final : public InstructionOperandConverter {
         // TODO(plind): Maybe we should handle ExtRef & HeapObj here?
         //    maybe not done on arm due to const pool ??
         break;
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kRpoNumber:
         UNREACHABLE();  // TODO(titzer): RPO immediates on mips?
         break;
@@ -353,6 +356,41 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ sync();                                                          \
   } while (0)
 
+#define ASSEMBLE_ATOMIC64_LOGIC_BINOP(bin_instr)                               \
+  do {                                                                         \
+    if (IsMipsArchVariant(kMips32r6)) {                                        \
+      Label binop;                                                             \
+      __ sync();                                                               \
+      __ bind(&binop);                                                         \
+      __ llwp(i.TempRegister(0), i.TempRegister(1), i.InputRegister(2));       \
+      __ bin_instr(i.TempRegister(0), i.TempRegister(1), i.TempRegister(0),    \
+                   i.TempRegister(1), i.InputRegister(0), i.InputRegister(1)); \
+      __ scwp(i.TempRegister(0), i.TempRegister(1), i.InputRegister(2));       \
+      __ BranchShort(&binop, eq, i.TempRegister(1), Operand(zero_reg));        \
+      __ sync();                                                               \
+    } else {                                                                   \
+      UNREACHABLE();                                                           \
+    }                                                                          \
+  } while (0)
+
+#define ASSEMBLE_ATOMIC64_ARITH_BINOP(bin_instr)                              \
+  do {                                                                        \
+    if (IsMipsArchVariant(kMips32r6)) {                                       \
+      Label binop;                                                            \
+      __ sync();                                                              \
+      __ bind(&binop);                                                        \
+      __ llwp(i.TempRegister(0), i.TempRegister(1), i.InputRegister(2));      \
+      __ bin_instr(i.TempRegister(0), i.TempRegister(1), i.TempRegister(0),   \
+                   i.TempRegister(1), i.InputRegister(0), i.InputRegister(1), \
+                   i.TempRegister(2), i.TempRegister(3));                     \
+      __ scwp(i.TempRegister(0), i.TempRegister(1), i.InputRegister(2));      \
+      __ BranchShort(&binop, eq, i.TempRegister(1), Operand(zero_reg));       \
+      __ sync();                                                              \
+    } else {                                                                  \
+      UNREACHABLE();                                                          \
+    }                                                                         \
+  } while (0)
+
 #define ASSEMBLE_ATOMIC_BINOP_EXT(sign_extend, size, bin_instr)                \
   do {                                                                         \
     Label binop;                                                               \
@@ -1701,6 +1739,61 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ATOMIC_BINOP_CASE(Or, Or)
       ATOMIC_BINOP_CASE(Xor, Xor)
 #undef ATOMIC_BINOP_CASE
+    case kMipsWord32AtomicPairLoad: {
+      if (IsMipsArchVariant(kMips32r6)) {
+        Register second_output =
+            instr->OutputCount() == 2 ? i.OutputRegister(1) : i.TempRegister(0);
+        __ llwp(i.OutputRegister(0), second_output, i.InputRegister(0));
+        __ sync();
+      } else {
+        UNREACHABLE();
+      }
+      break;
+    }
+    case kMipsWord32AtomicPairStore: {
+      if (IsMipsArchVariant(kMips32r6)) {
+        Label store;
+        __ sync();
+        __ bind(&store);
+        __ llwp(i.TempRegister(0), i.TempRegister(1), i.InputRegister(0));
+        __ Move(i.TempRegister(0), i.InputRegister(2));
+        __ scwp(i.InputRegister(1), i.TempRegister(0), i.InputRegister(0));
+        __ BranchShort(&store, eq, i.TempRegister(0), Operand(zero_reg));
+        __ sync();
+      } else {
+        UNREACHABLE();
+      }
+      break;
+    }
+#define ATOMIC64_BINOP_ARITH_CASE(op, instr) \
+  case kMipsWord32AtomicPair##op:            \
+    ASSEMBLE_ATOMIC64_ARITH_BINOP(instr);    \
+    break;
+      ATOMIC64_BINOP_ARITH_CASE(Add, AddPair)
+      ATOMIC64_BINOP_ARITH_CASE(Sub, SubPair)
+#undef ATOMIC64_BINOP_ARITH_CASE
+#define ATOMIC64_BINOP_LOGIC_CASE(op, instr) \
+  case kMipsWord32AtomicPair##op:            \
+    ASSEMBLE_ATOMIC64_LOGIC_BINOP(instr);    \
+    break;
+      ATOMIC64_BINOP_LOGIC_CASE(And, AndPair)
+      ATOMIC64_BINOP_LOGIC_CASE(Or, OrPair)
+      ATOMIC64_BINOP_LOGIC_CASE(Xor, XorPair)
+#undef ATOMIC64_BINOP_LOGIC_CASE
+    case kMipsWord32AtomicPairExchange:
+      UNREACHABLE();
+      break;
+    case kMipsWord32AtomicPairCompareExchange: {
+      FrameScope scope(tasm(), StackFrame::MANUAL);
+      __ PushCallerSaved(kDontSaveFPRegs, v0, v1);
+      __ PrepareCallCFunction(5, 0, kScratchReg);
+      __ addu(a0, i.InputRegister(0), i.InputRegister(1));
+      __ sw(i.InputRegister(5), MemOperand(sp, 16));
+      __ CallCFunction(
+          ExternalReference::atomic_pair_compare_exchange_function(), 5, 0);
+      __ PopCallerSaved(kDontSaveFPRegs, v0, v1);
+      break;
+    }
     case kMipsS128Zero: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ xor_v(i.OutputSimd128Register(), i.OutputSimd128Register(),
@@ -3371,9 +3464,12 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ li(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ li(dst, src.ToDelayedStringConstant());
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
-          Heap::RootListIndex index;
+          RootIndex index;
           if (IsMaterializableFromRoot(src_object, &index)) {
             __ LoadRoot(dst, index);
           } else {
diff --git a/deps/v8/src/compiler/mips/instruction-codes-mips.h b/deps/v8/src/compiler/mips/instruction-codes-mips.h
index dd789d0196..4b49de36b4 100644
--- a/deps/v8/src/compiler/mips/instruction-codes-mips.h
+++ b/deps/v8/src/compiler/mips/instruction-codes-mips.h
@@ -276,7 +276,16 @@ namespace compiler {
   V(MipsI16x8UConvertI8x16Low)     \
   V(MipsI16x8UConvertI8x16High)    \
   V(MipsI8x16SConvertI16x8)        \
-  V(MipsI8x16UConvertI16x8)
+  V(MipsI8x16UConvertI16x8)        \
+  V(MipsWord32AtomicPairLoad)      \
+  V(MipsWord32AtomicPairStore)     \
+  V(MipsWord32AtomicPairAdd)       \
+  V(MipsWord32AtomicPairSub)       \
+  V(MipsWord32AtomicPairAnd)       \
+  V(MipsWord32AtomicPairOr)        \
+  V(MipsWord32AtomicPairXor)       \
+  V(MipsWord32AtomicPairExchange)  \
+  V(MipsWord32AtomicPairCompareExchange)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/mips/instruction-scheduler-mips.cc b/deps/v8/src/compiler/mips/instruction-scheduler-mips.cc
index a0fe188430..26f543d838 100644
--- a/deps/v8/src/compiler/mips/instruction-scheduler-mips.cc
+++ b/deps/v8/src/compiler/mips/instruction-scheduler-mips.cc
@@ -266,6 +266,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMipsUlhu:
     case kMipsUlw:
     case kMipsUlwc1:
+    case kMipsWord32AtomicPairLoad:
       return kIsLoadOperation;
 
     case kMipsModD:
@@ -283,6 +284,14 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMipsUsh:
     case kMipsUsw:
     case kMipsUswc1:
+    case kMipsWord32AtomicPairStore:
+    case kMipsWord32AtomicPairAdd:
+    case kMipsWord32AtomicPairSub:
+    case kMipsWord32AtomicPairAnd:
+    case kMipsWord32AtomicPairOr:
+    case kMipsWord32AtomicPairXor:
+    case kMipsWord32AtomicPairExchange:
+    case kMipsWord32AtomicPairCompareExchange:
       return kHasSideEffect;
 
 #define CASE(Name) case k##Name:
diff --git a/deps/v8/src/compiler/mips/instruction-selector-mips.cc b/deps/v8/src/compiler/mips/instruction-selector-mips.cc
index 66f38dc283..954942c9af 100644
--- a/deps/v8/src/compiler/mips/instruction-selector-mips.cc
+++ b/deps/v8/src/compiler/mips/instruction-selector-mips.cc
@@ -229,6 +229,42 @@ static void VisitBinop(InstructionSelector* selector, Node* node,
   VisitBinop(selector, node, opcode, false, kArchNop);
 }
 
+static void VisitPairAtomicBinop(InstructionSelector* selector, Node* node,
+                                 ArchOpcode opcode) {
+  MipsOperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+  Node* value_high = node->InputAt(3);
+
+  InstructionOperand addr_reg = g.TempRegister();
+
+  selector->Emit(kMipsAdd | AddressingModeField::encode(kMode_None), addr_reg,
+                 g.UseRegister(index), g.UseRegister(base));
+
+  InstructionOperand inputs[] = {g.UseRegister(value),
+                                 g.UseRegister(value_high), addr_reg};
+  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
+                                g.TempRegister(), g.TempRegister()};
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsRegister(projection0),
+                                    g.DefineAsRegister(projection1)};
+    selector->Emit(opcode | AddressingModeField::encode(kMode_None),
+                   arraysize(outputs), outputs, arraysize(inputs), inputs,
+                   arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsRegister(projection0)};
+    selector->Emit(opcode | AddressingModeField::encode(kMode_None),
+                   arraysize(outputs), outputs, arraysize(inputs), inputs,
+                   arraysize(temps), temps);
+  } else {
+    selector->Emit(opcode | AddressingModeField::encode(kMode_None), 0, nullptr,
+                   arraysize(inputs), inputs, arraysize(temps), temps);
+  }
+}
+
 void InstructionSelector::VisitStackSlot(Node* node) {
   StackSlotRepresentation rep = StackSlotRepresentationOf(node->op());
   int alignment = rep.alignment();
@@ -651,6 +687,106 @@ void InstructionSelector::VisitWord32Clz(Node* node) {
   VisitRR(this, kMipsClz, node);
 }
 
+void InstructionSelector::VisitWord32AtomicPairLoad(Node* node) {
+  MipsOperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  ArchOpcode opcode = kMipsWord32AtomicPairLoad;
+
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+
+  InstructionOperand addr_reg = g.TempRegister();
+  Emit(kMipsAdd | AddressingModeField::encode(kMode_None), addr_reg,
+       g.UseRegister(index), g.UseRegister(base));
+  InstructionOperand inputs[] = {addr_reg};
+
+  InstructionOperand temps[] = {g.TempRegister()};
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsRegister(projection0),
+                                    g.DefineAsRegister(projection1)};
+    Emit(opcode | AddressingModeField::encode(kMode_MRI), arraysize(outputs),
+         outputs, arraysize(inputs), inputs, 1, temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsRegister(projection0)};
+    Emit(opcode | AddressingModeField::encode(kMode_MRI), arraysize(outputs),
+         outputs, arraysize(inputs), inputs, 1, temps);
+  } else {
+    Emit(opcode | AddressingModeField::encode(kMode_MRI), 0, nullptr,
+         arraysize(inputs), inputs, 1, temps);
+  }
+}
+
+void InstructionSelector::VisitWord32AtomicPairStore(Node* node) {
+  MipsOperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value_low = node->InputAt(2);
+  Node* value_high = node->InputAt(3);
+
+  InstructionOperand addr_reg = g.TempRegister();
+  Emit(kMipsAdd | AddressingModeField::encode(kMode_None), addr_reg,
+       g.UseRegister(index), g.UseRegister(base));
+
+  InstructionOperand inputs[] = {addr_reg, g.UseRegister(value_low),
+                                 g.UseRegister(value_high)};
+  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+  Emit(kMipsWord32AtomicPairStore | AddressingModeField::encode(kMode_MRI), 0,
+       nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
+}
+
+void InstructionSelector::VisitWord32AtomicPairAdd(Node* node) {
+  VisitPairAtomicBinop(this, node, kMipsWord32AtomicPairAdd);
+}
+
+void InstructionSelector::VisitWord32AtomicPairSub(Node* node) {
+  VisitPairAtomicBinop(this, node, kMipsWord32AtomicPairSub);
+}
+
+void InstructionSelector::VisitWord32AtomicPairAnd(Node* node) {
+  VisitPairAtomicBinop(this, node, kMipsWord32AtomicPairAnd);
+}
+
+void InstructionSelector::VisitWord32AtomicPairOr(Node* node) {
+  VisitPairAtomicBinop(this, node, kMipsWord32AtomicPairOr);
+}
+
+void InstructionSelector::VisitWord32AtomicPairXor(Node* node) {
+  VisitPairAtomicBinop(this, node, kMipsWord32AtomicPairXor);
+}
+
+void InstructionSelector::VisitWord32AtomicPairExchange(Node* node) {
+  VisitPairAtomicBinop(this, node, kMipsWord32AtomicPairExchange);
+}
+
+void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
+  MipsOperandGenerator g(this);
+  InstructionOperand inputs[] = {
+      g.UseRegister(node->InputAt(0)),  g.UseRegister(node->InputAt(1)),
+      g.UseFixed(node->InputAt(2), a1), g.UseFixed(node->InputAt(3), a2),
+      g.UseFixed(node->InputAt(4), a3), g.UseUniqueRegister(node->InputAt(5))};
+
+  InstructionCode code = kMipsWord32AtomicPairCompareExchange |
+                         AddressingModeField::encode(kMode_MRI);
+  Node* projection0 = NodeProperties::FindProjection(node, 0);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, v0),
+                                    g.DefineAsFixed(projection1, v1)};
+    InstructionOperand temps[] = {g.TempRegister(a0)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else if (projection0) {
+    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, v0)};
+    InstructionOperand temps[] = {g.TempRegister(a0), g.TempRegister(v1)};
+    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
+         arraysize(temps), temps);
+  } else {
+    InstructionOperand temps[] = {g.TempRegister(a0), g.TempRegister(v0),
+                                  g.TempRegister(v1)};
+    Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
+  }
+}
 
 void InstructionSelector::VisitWord32ReverseBits(Node* node) { UNREACHABLE(); }
 
diff --git a/deps/v8/src/compiler/mips64/code-generator-mips64.cc b/deps/v8/src/compiler/mips64/code-generator-mips64.cc
index 7beb887b53..0e2b508a29 100644
--- a/deps/v8/src/compiler/mips64/code-generator-mips64.cc
+++ b/deps/v8/src/compiler/mips64/code-generator-mips64.cc
@@ -87,6 +87,9 @@ class MipsOperandConverter final : public InstructionOperandConverter {
         // TODO(plind): Maybe we should handle ExtRef & HeapObj here?
         //    maybe not done on arm due to const pool ??
         break;
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kRpoNumber:
         UNREACHABLE();  // TODO(titzer): RPO immediates on mips?
         break;
@@ -349,116 +352,120 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ sync();                                                 \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_BINOP(bin_instr)                                 \
-  do {                                                                   \
-    Label binop;                                                         \
-    __ Daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1)); \
-    __ sync();                                                           \
-    __ bind(&binop);                                                     \
-    __ Ll(i.OutputRegister(0), MemOperand(i.TempRegister(0), 0));        \
-    __ bin_instr(i.TempRegister(1), i.OutputRegister(0),                 \
-                 Operand(i.InputRegister(2)));                           \
-    __ Sc(i.TempRegister(1), MemOperand(i.TempRegister(0), 0));          \
-    __ BranchShort(&binop, eq, i.TempRegister(1), Operand(zero_reg));    \
-    __ sync();                                                           \
+#define ASSEMBLE_ATOMIC_BINOP(load_linked, store_conditional, bin_instr)       \
+  do {                                                                         \
+    Label binop;                                                               \
+    __ Daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));       \
+    __ sync();                                                                 \
+    __ bind(&binop);                                                           \
+    __ load_linked(i.OutputRegister(0), MemOperand(i.TempRegister(0), 0));     \
+    __ bin_instr(i.TempRegister(1), i.OutputRegister(0),                       \
+                 Operand(i.InputRegister(2)));                                 \
+    __ store_conditional(i.TempRegister(1), MemOperand(i.TempRegister(0), 0)); \
+    __ BranchShort(&binop, eq, i.TempRegister(1), Operand(zero_reg));          \
+    __ sync();                                                                 \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_BINOP_EXT(sign_extend, size, bin_instr)               \
-  do {                                                                        \
-    Label binop;                                                              \
-    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));      \
-    __ andi(i.TempRegister(3), i.TempRegister(0), 0x3);                       \
-    __ Dsubu(i.TempRegister(0), i.TempRegister(0),                            \
-             Operand(i.TempRegister(3)));                                     \
-    __ sll(i.TempRegister(3), i.TempRegister(3), 3);                          \
-    __ sync();                                                                \
-    __ bind(&binop);                                                          \
-    __ Ll(i.TempRegister(1), MemOperand(i.TempRegister(0), 0));               \
-    __ ExtractBits(i.OutputRegister(0), i.TempRegister(1), i.TempRegister(3), \
-                   size, sign_extend);                                        \
-    __ bin_instr(i.TempRegister(2), i.OutputRegister(0),                      \
-                 Operand(i.InputRegister(2)));                                \
-    __ InsertBits(i.TempRegister(1), i.TempRegister(2), i.TempRegister(3),    \
-                  size);                                                      \
-    __ Sc(i.TempRegister(1), MemOperand(i.TempRegister(0), 0));               \
-    __ BranchShort(&binop, eq, i.TempRegister(1), Operand(zero_reg));         \
-    __ sync();                                                                \
+#define ASSEMBLE_ATOMIC_BINOP_EXT(load_linked, store_conditional, sign_extend, \
+                                  size, bin_instr)                             \
+  do {                                                                         \
+    Label binop;                                                               \
+    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));       \
+    __ andi(i.TempRegister(3), i.TempRegister(0), 0x3);                        \
+    __ Dsubu(i.TempRegister(0), i.TempRegister(0),                             \
+             Operand(i.TempRegister(3)));                                      \
+    __ sll(i.TempRegister(3), i.TempRegister(3), 3);                           \
+    __ sync();                                                                 \
+    __ bind(&binop);                                                           \
+    __ load_linked(i.TempRegister(1), MemOperand(i.TempRegister(0), 0));       \
+    __ ExtractBits(i.OutputRegister(0), i.TempRegister(1), i.TempRegister(3),  \
+                   size, sign_extend);                                         \
+    __ bin_instr(i.TempRegister(2), i.OutputRegister(0),                       \
+                 Operand(i.InputRegister(2)));                                 \
+    __ InsertBits(i.TempRegister(1), i.TempRegister(2), i.TempRegister(3),     \
+                  size);                                                       \
+    __ store_conditional(i.TempRegister(1), MemOperand(i.TempRegister(0), 0)); \
+    __ BranchShort(&binop, eq, i.TempRegister(1), Operand(zero_reg));          \
+    __ sync();                                                                 \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_EXCHANGE_INTEGER()                               \
-  do {                                                                   \
-    Label exchange;                                                      \
-    __ sync();                                                           \
-    __ bind(&exchange);                                                  \
-    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1)); \
-    __ Ll(i.OutputRegister(0), MemOperand(i.TempRegister(0), 0));        \
-    __ mov(i.TempRegister(1), i.InputRegister(2));                       \
-    __ Sc(i.TempRegister(1), MemOperand(i.TempRegister(0), 0));          \
-    __ BranchShort(&exchange, eq, i.TempRegister(1), Operand(zero_reg)); \
-    __ sync();                                                           \
+#define ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(load_linked, store_conditional)       \
+  do {                                                                         \
+    Label exchange;                                                            \
+    __ sync();                                                                 \
+    __ bind(&exchange);                                                        \
+    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));       \
+    __ load_linked(i.OutputRegister(0), MemOperand(i.TempRegister(0), 0));     \
+    __ mov(i.TempRegister(1), i.InputRegister(2));                             \
+    __ store_conditional(i.TempRegister(1), MemOperand(i.TempRegister(0), 0)); \
+    __ BranchShort(&exchange, eq, i.TempRegister(1), Operand(zero_reg));       \
+    __ sync();                                                                 \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(sign_extend, size)               \
-  do {                                                                        \
-    Label exchange;                                                           \
-    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));      \
-    __ andi(i.TempRegister(1), i.TempRegister(0), 0x3);                       \
-    __ Dsubu(i.TempRegister(0), i.TempRegister(0),                            \
-             Operand(i.TempRegister(1)));                                     \
-    __ sll(i.TempRegister(1), i.TempRegister(1), 3);                          \
-    __ sync();                                                                \
-    __ bind(&exchange);                                                       \
-    __ Ll(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));               \
-    __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1), \
-                   size, sign_extend);                                        \
-    __ InsertBits(i.TempRegister(2), i.InputRegister(2), i.TempRegister(1),   \
-                  size);                                                      \
-    __ Sc(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));               \
-    __ BranchShort(&exchange, eq, i.TempRegister(2), Operand(zero_reg));      \
-    __ sync();                                                                \
+#define ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(load_linked, store_conditional,   \
+                                             sign_extend, size)                \
+  do {                                                                         \
+    Label exchange;                                                            \
+    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));       \
+    __ andi(i.TempRegister(1), i.TempRegister(0), 0x3);                        \
+    __ Dsubu(i.TempRegister(0), i.TempRegister(0),                             \
+             Operand(i.TempRegister(1)));                                      \
+    __ sll(i.TempRegister(1), i.TempRegister(1), 3);                           \
+    __ sync();                                                                 \
+    __ bind(&exchange);                                                        \
+    __ load_linked(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));       \
+    __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1),  \
+                   size, sign_extend);                                         \
+    __ InsertBits(i.TempRegister(2), i.InputRegister(2), i.TempRegister(1),    \
+                  size);                                                       \
+    __ store_conditional(i.TempRegister(2), MemOperand(i.TempRegister(0), 0)); \
+    __ BranchShort(&exchange, eq, i.TempRegister(2), Operand(zero_reg));       \
+    __ sync();                                                                 \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER()                       \
-  do {                                                                   \
-    Label compareExchange;                                               \
-    Label exit;                                                          \
-    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1)); \
-    __ sync();                                                           \
-    __ bind(&compareExchange);                                           \
-    __ Ll(i.OutputRegister(0), MemOperand(i.TempRegister(0), 0));        \
-    __ BranchShort(&exit, ne, i.InputRegister(2),                        \
-                   Operand(i.OutputRegister(0)));                        \
-    __ mov(i.TempRegister(2), i.InputRegister(3));                       \
-    __ Sc(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));          \
-    __ BranchShort(&compareExchange, eq, i.TempRegister(2),              \
-                   Operand(zero_reg));                                   \
-    __ bind(&exit);                                                      \
-    __ sync();                                                           \
+#define ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER(load_linked,                  \
+                                                 store_conditional)            \
+  do {                                                                         \
+    Label compareExchange;                                                     \
+    Label exit;                                                                \
+    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));       \
+    __ sync();                                                                 \
+    __ bind(&compareExchange);                                                 \
+    __ load_linked(i.OutputRegister(0), MemOperand(i.TempRegister(0), 0));     \
+    __ BranchShort(&exit, ne, i.InputRegister(2),                              \
+                   Operand(i.OutputRegister(0)));                              \
+    __ mov(i.TempRegister(2), i.InputRegister(3));                             \
+    __ store_conditional(i.TempRegister(2), MemOperand(i.TempRegister(0), 0)); \
+    __ BranchShort(&compareExchange, eq, i.TempRegister(2),                    \
+                   Operand(zero_reg));                                         \
+    __ bind(&exit);                                                            \
+    __ sync();                                                                 \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(sign_extend, size)       \
-  do {                                                                        \
-    Label compareExchange;                                                    \
-    Label exit;                                                               \
-    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));      \
-    __ andi(i.TempRegister(1), i.TempRegister(0), 0x3);                       \
-    __ Dsubu(i.TempRegister(0), i.TempRegister(0),                            \
-             Operand(i.TempRegister(1)));                                     \
-    __ sll(i.TempRegister(1), i.TempRegister(1), 3);                          \
-    __ sync();                                                                \
-    __ bind(&compareExchange);                                                \
-    __ Ll(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));               \
-    __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1), \
-                   size, sign_extend);                                        \
-    __ BranchShort(&exit, ne, i.InputRegister(2),                             \
-                   Operand(i.OutputRegister(0)));                             \
-    __ InsertBits(i.TempRegister(2), i.InputRegister(3), i.TempRegister(1),   \
-                  size);                                                      \
-    __ Sc(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));               \
-    __ BranchShort(&compareExchange, eq, i.TempRegister(2),                   \
-                   Operand(zero_reg));                                        \
-    __ bind(&exit);                                                           \
-    __ sync();                                                                \
+#define ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(                          \
+    load_linked, store_conditional, sign_extend, size)                         \
+  do {                                                                         \
+    Label compareExchange;                                                     \
+    Label exit;                                                                \
+    __ daddu(i.TempRegister(0), i.InputRegister(0), i.InputRegister(1));       \
+    __ andi(i.TempRegister(1), i.TempRegister(0), 0x3);                        \
+    __ Dsubu(i.TempRegister(0), i.TempRegister(0),                             \
+             Operand(i.TempRegister(1)));                                      \
+    __ sll(i.TempRegister(1), i.TempRegister(1), 3);                           \
+    __ sync();                                                                 \
+    __ bind(&compareExchange);                                                 \
+    __ load_linked(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));       \
+    __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1),  \
+                   size, sign_extend);                                         \
+    __ BranchShort(&exit, ne, i.InputRegister(2),                              \
+                   Operand(i.OutputRegister(0)));                              \
+    __ InsertBits(i.TempRegister(2), i.InputRegister(3), i.TempRegister(1),    \
+                  size);                                                       \
+    __ store_conditional(i.TempRegister(2), MemOperand(i.TempRegister(0), 0)); \
+    __ BranchShort(&compareExchange, eq, i.TempRegister(2),                    \
+                   Operand(zero_reg));                                         \
+    __ bind(&exit);                                                            \
+    __ sync();                                                                 \
   } while (0)
 
 #define ASSEMBLE_IEEE754_BINOP(name)                                        \
@@ -1845,6 +1852,18 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kWord32AtomicLoadWord32:
       ASSEMBLE_ATOMIC_LOAD_INTEGER(Lw);
       break;
+    case kMips64Word64AtomicLoadUint8:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(Lbu);
+      break;
+    case kMips64Word64AtomicLoadUint16:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(Lhu);
+      break;
+    case kMips64Word64AtomicLoadUint32:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(Lwu);
+      break;
+    case kMips64Word64AtomicLoadUint64:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(Ld);
+      break;
     case kWord32AtomicStoreWord8:
       ASSEMBLE_ATOMIC_STORE_INTEGER(Sb);
       break;
@@ -1854,52 +1873,88 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kWord32AtomicStoreWord32:
       ASSEMBLE_ATOMIC_STORE_INTEGER(Sw);
       break;
+    case kMips64Word64AtomicStoreWord8:
+      ASSEMBLE_ATOMIC_STORE_INTEGER(Sb);
+      break;
+    case kMips64Word64AtomicStoreWord16:
+      ASSEMBLE_ATOMIC_STORE_INTEGER(Sh);
+      break;
+    case kMips64Word64AtomicStoreWord32:
+      ASSEMBLE_ATOMIC_STORE_INTEGER(Sw);
+      break;
+    case kMips64Word64AtomicStoreWord64:
+      ASSEMBLE_ATOMIC_STORE_INTEGER(Sd);
+      break;
     case kWord32AtomicExchangeInt8:
-      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(true, 8);
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Ll, Sc, true, 8);
       break;
     case kWord32AtomicExchangeUint8:
-      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(false, 8);
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Ll, Sc, false, 8);
       break;
     case kWord32AtomicExchangeInt16:
-      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(true, 16);
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Ll, Sc, true, 16);
       break;
     case kWord32AtomicExchangeUint16:
-      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(false, 16);
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Ll, Sc, false, 16);
       break;
     case kWord32AtomicExchangeWord32:
-      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER();
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(Ll, Sc);
+      break;
+    case kMips64Word64AtomicExchangeUint8:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Lld, Scd, false, 8);
+      break;
+    case kMips64Word64AtomicExchangeUint16:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Lld, Scd, false, 16);
+      break;
+    case kMips64Word64AtomicExchangeUint32:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT(Lld, Scd, false, 32);
+      break;
+    case kMips64Word64AtomicExchangeUint64:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(Lld, Scd);
       break;
     case kWord32AtomicCompareExchangeInt8:
-      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(true, 8);
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Ll, Sc, true, 8);
       break;
     case kWord32AtomicCompareExchangeUint8:
-      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(false, 8);
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Ll, Sc, false, 8);
       break;
     case kWord32AtomicCompareExchangeInt16:
-      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(true, 16);
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Ll, Sc, true, 16);
       break;
     case kWord32AtomicCompareExchangeUint16:
-      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(false, 16);
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Ll, Sc, false, 16);
       break;
     case kWord32AtomicCompareExchangeWord32:
       __ sll(i.InputRegister(2), i.InputRegister(2), 0);
-      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER();
-      break;
-#define ATOMIC_BINOP_CASE(op, inst)             \
-  case kWord32Atomic##op##Int8:                 \
-    ASSEMBLE_ATOMIC_BINOP_EXT(true, 8, inst);   \
-    break;                                      \
-  case kWord32Atomic##op##Uint8:                \
-    ASSEMBLE_ATOMIC_BINOP_EXT(false, 8, inst);  \
-    break;                                      \
-  case kWord32Atomic##op##Int16:                \
-    ASSEMBLE_ATOMIC_BINOP_EXT(true, 16, inst);  \
-    break;                                      \
-  case kWord32Atomic##op##Uint16:               \
-    ASSEMBLE_ATOMIC_BINOP_EXT(false, 16, inst); \
-    break;                                      \
-  case kWord32Atomic##op##Word32:               \
-    ASSEMBLE_ATOMIC_BINOP(inst);                \
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER(Ll, Sc);
+      break;
+    case kMips64Word64AtomicCompareExchangeUint8:
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Lld, Scd, false, 8);
+      break;
+    case kMips64Word64AtomicCompareExchangeUint16:
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Lld, Scd, false, 16);
+      break;
+    case kMips64Word64AtomicCompareExchangeUint32:
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT(Lld, Scd, false, 32);
+      break;
+    case kMips64Word64AtomicCompareExchangeUint64:
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER(Lld, Scd);
+      break;
+#define ATOMIC_BINOP_CASE(op, inst)                     \
+  case kWord32Atomic##op##Int8:                         \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Ll, Sc, true, 8, inst);   \
+    break;                                              \
+  case kWord32Atomic##op##Uint8:                        \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Ll, Sc, false, 8, inst);  \
+    break;                                              \
+  case kWord32Atomic##op##Int16:                        \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Ll, Sc, true, 16, inst);  \
+    break;                                              \
+  case kWord32Atomic##op##Uint16:                       \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Ll, Sc, false, 16, inst); \
+    break;                                              \
+  case kWord32Atomic##op##Word32:                       \
+    ASSEMBLE_ATOMIC_BINOP(Ll, Sc, inst);                \
     break;
       ATOMIC_BINOP_CASE(Add, Addu)
       ATOMIC_BINOP_CASE(Sub, Subu)
@@ -1907,6 +1962,25 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ATOMIC_BINOP_CASE(Or, Or)
       ATOMIC_BINOP_CASE(Xor, Xor)
 #undef ATOMIC_BINOP_CASE
+#define ATOMIC_BINOP_CASE(op, inst)                       \
+  case kMips64Word64Atomic##op##Uint8:                    \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Lld, Scd, false, 8, inst);  \
+    break;                                                \
+  case kMips64Word64Atomic##op##Uint16:                   \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Lld, Scd, false, 16, inst); \
+    break;                                                \
+  case kMips64Word64Atomic##op##Uint32:                   \
+    ASSEMBLE_ATOMIC_BINOP_EXT(Lld, Scd, false, 32, inst); \
+    break;                                                \
+  case kMips64Word64Atomic##op##Uint64:                   \
+    ASSEMBLE_ATOMIC_BINOP(Lld, Scd, inst);                \
+    break;
+      ATOMIC_BINOP_CASE(Add, Daddu)
+      ATOMIC_BINOP_CASE(Sub, Dsubu)
+      ATOMIC_BINOP_CASE(And, And)
+      ATOMIC_BINOP_CASE(Or, Or)
+      ATOMIC_BINOP_CASE(Xor, Xor)
+#undef ATOMIC_BINOP_CASE
     case kMips64AssertEqual:
       __ Assert(eq, static_cast<AbortReason>(i.InputOperand(2).immediate()),
                 i.InputRegister(0), Operand(i.InputRegister(1)));
@@ -2496,7 +2570,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Label all_false;
       __ BranchMSA(&all_false, MSA_BRANCH_V, all_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
-      __ li(dst, 0);  // branch delay slot
+      __ li(dst, 0l);  // branch delay slot
       __ li(dst, -1);
       __ bind(&all_false);
       break;
@@ -2508,7 +2582,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ BranchMSA(&all_true, MSA_BRANCH_W, all_not_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
       __ li(dst, -1);  // branch delay slot
-      __ li(dst, 0);
+      __ li(dst, 0l);
       __ bind(&all_true);
       break;
     }
@@ -2519,7 +2593,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ BranchMSA(&all_true, MSA_BRANCH_H, all_not_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
       __ li(dst, -1);  // branch delay slot
-      __ li(dst, 0);
+      __ li(dst, 0l);
       __ bind(&all_true);
       break;
     }
@@ -2530,7 +2604,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ BranchMSA(&all_true, MSA_BRANCH_B, all_not_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
       __ li(dst, -1);  // branch delay slot
-      __ li(dst, 0);
+      __ li(dst, 0l);
       __ bind(&all_true);
       break;
     }
@@ -3174,6 +3248,8 @@ void CodeGenerator::AssembleBranchPoisoning(FlagsCondition condition,
   }
 }
 
+#undef UNSUPPORTED_COND
+
 void CodeGenerator::AssembleArchDeoptBranch(Instruction* instr,
                                             BranchInfo* branch) {
   AssembleArchBranch(instr, branch);
@@ -3621,9 +3697,12 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ li(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ li(dst, src.ToDelayedStringConstant());
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
-          Heap::RootListIndex index;
+          RootIndex index;
           if (IsMaterializableFromRoot(src_object, &index)) {
             __ LoadRoot(dst, index);
           } else {
@@ -3823,6 +3902,19 @@ void CodeGenerator::AssembleJumpTable(Label** targets, size_t target_count) {
   UNREACHABLE();
 }
 
+#undef ASSEMBLE_ATOMIC_LOAD_INTEGER
+#undef ASSEMBLE_ATOMIC_STORE_INTEGER
+#undef ASSEMBLE_ATOMIC_BINOP
+#undef ASSEMBLE_ATOMIC_BINOP_EXT
+#undef ASSEMBLE_ATOMIC_EXCHANGE_INTEGER
+#undef ASSEMBLE_ATOMIC_EXCHANGE_INTEGER_EXT
+#undef ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER
+#undef ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_INTEGER_EXT
+#undef ASSEMBLE_IEEE754_BINOP
+#undef ASSEMBLE_IEEE754_UNOP
+
+#undef TRACE_MSG
+#undef TRACE_UNIMPL
 #undef __
 
 }  // namespace compiler
diff --git a/deps/v8/src/compiler/mips64/instruction-codes-mips64.h b/deps/v8/src/compiler/mips64/instruction-codes-mips64.h
index a50d294013..7ea707db53 100644
--- a/deps/v8/src/compiler/mips64/instruction-codes-mips64.h
+++ b/deps/v8/src/compiler/mips64/instruction-codes-mips64.h
@@ -11,302 +11,338 @@ namespace compiler {
 
 // MIPS64-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
-#define TARGET_ARCH_OPCODE_LIST(V)  \
-  V(Mips64Add)                      \
-  V(Mips64Dadd)                     \
-  V(Mips64DaddOvf)                  \
-  V(Mips64Sub)                      \
-  V(Mips64Dsub)                     \
-  V(Mips64DsubOvf)                  \
-  V(Mips64Mul)                      \
-  V(Mips64MulOvf)                   \
-  V(Mips64MulHigh)                  \
-  V(Mips64DMulHigh)                 \
-  V(Mips64MulHighU)                 \
-  V(Mips64Dmul)                     \
-  V(Mips64Div)                      \
-  V(Mips64Ddiv)                     \
-  V(Mips64DivU)                     \
-  V(Mips64DdivU)                    \
-  V(Mips64Mod)                      \
-  V(Mips64Dmod)                     \
-  V(Mips64ModU)                     \
-  V(Mips64DmodU)                    \
-  V(Mips64And)                      \
-  V(Mips64And32)                    \
-  V(Mips64Or)                       \
-  V(Mips64Or32)                     \
-  V(Mips64Nor)                      \
-  V(Mips64Nor32)                    \
-  V(Mips64Xor)                      \
-  V(Mips64Xor32)                    \
-  V(Mips64Clz)                      \
-  V(Mips64Lsa)                      \
-  V(Mips64Dlsa)                     \
-  V(Mips64Shl)                      \
-  V(Mips64Shr)                      \
-  V(Mips64Sar)                      \
-  V(Mips64Ext)                      \
-  V(Mips64Ins)                      \
-  V(Mips64Dext)                     \
-  V(Mips64Dins)                     \
-  V(Mips64Dclz)                     \
-  V(Mips64Ctz)                      \
-  V(Mips64Dctz)                     \
-  V(Mips64Popcnt)                   \
-  V(Mips64Dpopcnt)                  \
-  V(Mips64Dshl)                     \
-  V(Mips64Dshr)                     \
-  V(Mips64Dsar)                     \
-  V(Mips64Ror)                      \
-  V(Mips64Dror)                     \
-  V(Mips64Mov)                      \
-  V(Mips64Tst)                      \
-  V(Mips64Cmp)                      \
-  V(Mips64CmpS)                     \
-  V(Mips64AddS)                     \
-  V(Mips64SubS)                     \
-  V(Mips64MulS)                     \
-  V(Mips64DivS)                     \
-  V(Mips64ModS)                     \
-  V(Mips64AbsS)                     \
-  V(Mips64NegS)                     \
-  V(Mips64SqrtS)                    \
-  V(Mips64MaxS)                     \
-  V(Mips64MinS)                     \
-  V(Mips64CmpD)                     \
-  V(Mips64AddD)                     \
-  V(Mips64SubD)                     \
-  V(Mips64MulD)                     \
-  V(Mips64DivD)                     \
-  V(Mips64ModD)                     \
-  V(Mips64AbsD)                     \
-  V(Mips64NegD)                     \
-  V(Mips64SqrtD)                    \
-  V(Mips64MaxD)                     \
-  V(Mips64MinD)                     \
-  V(Mips64Float64RoundDown)         \
-  V(Mips64Float64RoundTruncate)     \
-  V(Mips64Float64RoundUp)           \
-  V(Mips64Float64RoundTiesEven)     \
-  V(Mips64Float32RoundDown)         \
-  V(Mips64Float32RoundTruncate)     \
-  V(Mips64Float32RoundUp)           \
-  V(Mips64Float32RoundTiesEven)     \
-  V(Mips64CvtSD)                    \
-  V(Mips64CvtDS)                    \
-  V(Mips64TruncWD)                  \
-  V(Mips64RoundWD)                  \
-  V(Mips64FloorWD)                  \
-  V(Mips64CeilWD)                   \
-  V(Mips64TruncWS)                  \
-  V(Mips64RoundWS)                  \
-  V(Mips64FloorWS)                  \
-  V(Mips64CeilWS)                   \
-  V(Mips64TruncLS)                  \
-  V(Mips64TruncLD)                  \
-  V(Mips64TruncUwD)                 \
-  V(Mips64TruncUwS)                 \
-  V(Mips64TruncUlS)                 \
-  V(Mips64TruncUlD)                 \
-  V(Mips64CvtDW)                    \
-  V(Mips64CvtSL)                    \
-  V(Mips64CvtSW)                    \
-  V(Mips64CvtSUw)                   \
-  V(Mips64CvtSUl)                   \
-  V(Mips64CvtDL)                    \
-  V(Mips64CvtDUw)                   \
-  V(Mips64CvtDUl)                   \
-  V(Mips64Lb)                       \
-  V(Mips64Lbu)                      \
-  V(Mips64Sb)                       \
-  V(Mips64Lh)                       \
-  V(Mips64Ulh)                      \
-  V(Mips64Lhu)                      \
-  V(Mips64Ulhu)                     \
-  V(Mips64Sh)                       \
-  V(Mips64Ush)                      \
-  V(Mips64Ld)                       \
-  V(Mips64Uld)                      \
-  V(Mips64Lw)                       \
-  V(Mips64Ulw)                      \
-  V(Mips64Lwu)                      \
-  V(Mips64Ulwu)                     \
-  V(Mips64Sw)                       \
-  V(Mips64Usw)                      \
-  V(Mips64Sd)                       \
-  V(Mips64Usd)                      \
-  V(Mips64Lwc1)                     \
-  V(Mips64Ulwc1)                    \
-  V(Mips64Swc1)                     \
-  V(Mips64Uswc1)                    \
-  V(Mips64Ldc1)                     \
-  V(Mips64Uldc1)                    \
-  V(Mips64Sdc1)                     \
-  V(Mips64Usdc1)                    \
-  V(Mips64BitcastDL)                \
-  V(Mips64BitcastLD)                \
-  V(Mips64Float64ExtractLowWord32)  \
-  V(Mips64Float64ExtractHighWord32) \
-  V(Mips64Float64InsertLowWord32)   \
-  V(Mips64Float64InsertHighWord32)  \
-  V(Mips64Float32Max)               \
-  V(Mips64Float64Max)               \
-  V(Mips64Float32Min)               \
-  V(Mips64Float64Min)               \
-  V(Mips64Float64SilenceNaN)        \
-  V(Mips64Push)                     \
-  V(Mips64Peek)                     \
-  V(Mips64StoreToStackSlot)         \
-  V(Mips64ByteSwap64)               \
-  V(Mips64ByteSwap32)               \
-  V(Mips64StackClaim)               \
-  V(Mips64Seb)                      \
-  V(Mips64Seh)                      \
-  V(Mips64AssertEqual)              \
-  V(Mips64S128Zero)                 \
-  V(Mips64I32x4Splat)               \
-  V(Mips64I32x4ExtractLane)         \
-  V(Mips64I32x4ReplaceLane)         \
-  V(Mips64I32x4Add)                 \
-  V(Mips64I32x4AddHoriz)            \
-  V(Mips64I32x4Sub)                 \
-  V(Mips64F32x4Splat)               \
-  V(Mips64F32x4ExtractLane)         \
-  V(Mips64F32x4ReplaceLane)         \
-  V(Mips64F32x4SConvertI32x4)       \
-  V(Mips64F32x4UConvertI32x4)       \
-  V(Mips64I32x4Mul)                 \
-  V(Mips64I32x4MaxS)                \
-  V(Mips64I32x4MinS)                \
-  V(Mips64I32x4Eq)                  \
-  V(Mips64I32x4Ne)                  \
-  V(Mips64I32x4Shl)                 \
-  V(Mips64I32x4ShrS)                \
-  V(Mips64I32x4ShrU)                \
-  V(Mips64I32x4MaxU)                \
-  V(Mips64I32x4MinU)                \
-  V(Mips64F32x4Abs)                 \
-  V(Mips64F32x4Neg)                 \
-  V(Mips64F32x4RecipApprox)         \
-  V(Mips64F32x4RecipSqrtApprox)     \
-  V(Mips64F32x4Add)                 \
-  V(Mips64F32x4AddHoriz)            \
-  V(Mips64F32x4Sub)                 \
-  V(Mips64F32x4Mul)                 \
-  V(Mips64F32x4Max)                 \
-  V(Mips64F32x4Min)                 \
-  V(Mips64F32x4Eq)                  \
-  V(Mips64F32x4Ne)                  \
-  V(Mips64F32x4Lt)                  \
-  V(Mips64F32x4Le)                  \
-  V(Mips64I32x4SConvertF32x4)       \
-  V(Mips64I32x4UConvertF32x4)       \
-  V(Mips64I32x4Neg)                 \
-  V(Mips64I32x4GtS)                 \
-  V(Mips64I32x4GeS)                 \
-  V(Mips64I32x4GtU)                 \
-  V(Mips64I32x4GeU)                 \
-  V(Mips64I16x8Splat)               \
-  V(Mips64I16x8ExtractLane)         \
-  V(Mips64I16x8ReplaceLane)         \
-  V(Mips64I16x8Neg)                 \
-  V(Mips64I16x8Shl)                 \
-  V(Mips64I16x8ShrS)                \
-  V(Mips64I16x8ShrU)                \
-  V(Mips64I16x8Add)                 \
-  V(Mips64I16x8AddSaturateS)        \
-  V(Mips64I16x8AddHoriz)            \
-  V(Mips64I16x8Sub)                 \
-  V(Mips64I16x8SubSaturateS)        \
-  V(Mips64I16x8Mul)                 \
-  V(Mips64I16x8MaxS)                \
-  V(Mips64I16x8MinS)                \
-  V(Mips64I16x8Eq)                  \
-  V(Mips64I16x8Ne)                  \
-  V(Mips64I16x8GtS)                 \
-  V(Mips64I16x8GeS)                 \
-  V(Mips64I16x8AddSaturateU)        \
-  V(Mips64I16x8SubSaturateU)        \
-  V(Mips64I16x8MaxU)                \
-  V(Mips64I16x8MinU)                \
-  V(Mips64I16x8GtU)                 \
-  V(Mips64I16x8GeU)                 \
-  V(Mips64I8x16Splat)               \
-  V(Mips64I8x16ExtractLane)         \
-  V(Mips64I8x16ReplaceLane)         \
-  V(Mips64I8x16Neg)                 \
-  V(Mips64I8x16Shl)                 \
-  V(Mips64I8x16ShrS)                \
-  V(Mips64I8x16Add)                 \
-  V(Mips64I8x16AddSaturateS)        \
-  V(Mips64I8x16Sub)                 \
-  V(Mips64I8x16SubSaturateS)        \
-  V(Mips64I8x16Mul)                 \
-  V(Mips64I8x16MaxS)                \
-  V(Mips64I8x16MinS)                \
-  V(Mips64I8x16Eq)                  \
-  V(Mips64I8x16Ne)                  \
-  V(Mips64I8x16GtS)                 \
-  V(Mips64I8x16GeS)                 \
-  V(Mips64I8x16ShrU)                \
-  V(Mips64I8x16AddSaturateU)        \
-  V(Mips64I8x16SubSaturateU)        \
-  V(Mips64I8x16MaxU)                \
-  V(Mips64I8x16MinU)                \
-  V(Mips64I8x16GtU)                 \
-  V(Mips64I8x16GeU)                 \
-  V(Mips64S128And)                  \
-  V(Mips64S128Or)                   \
-  V(Mips64S128Xor)                  \
-  V(Mips64S128Not)                  \
-  V(Mips64S128Select)               \
-  V(Mips64S1x4AnyTrue)              \
-  V(Mips64S1x4AllTrue)              \
-  V(Mips64S1x8AnyTrue)              \
-  V(Mips64S1x8AllTrue)              \
-  V(Mips64S1x16AnyTrue)             \
-  V(Mips64S1x16AllTrue)             \
-  V(Mips64S32x4InterleaveRight)     \
-  V(Mips64S32x4InterleaveLeft)      \
-  V(Mips64S32x4PackEven)            \
-  V(Mips64S32x4PackOdd)             \
-  V(Mips64S32x4InterleaveEven)      \
-  V(Mips64S32x4InterleaveOdd)       \
-  V(Mips64S32x4Shuffle)             \
-  V(Mips64S16x8InterleaveRight)     \
-  V(Mips64S16x8InterleaveLeft)      \
-  V(Mips64S16x8PackEven)            \
-  V(Mips64S16x8PackOdd)             \
-  V(Mips64S16x8InterleaveEven)      \
-  V(Mips64S16x8InterleaveOdd)       \
-  V(Mips64S16x4Reverse)             \
-  V(Mips64S16x2Reverse)             \
-  V(Mips64S8x16InterleaveRight)     \
-  V(Mips64S8x16InterleaveLeft)      \
-  V(Mips64S8x16PackEven)            \
-  V(Mips64S8x16PackOdd)             \
-  V(Mips64S8x16InterleaveEven)      \
-  V(Mips64S8x16InterleaveOdd)       \
-  V(Mips64S8x16Shuffle)             \
-  V(Mips64S8x16Concat)              \
-  V(Mips64S8x8Reverse)              \
-  V(Mips64S8x4Reverse)              \
-  V(Mips64S8x2Reverse)              \
-  V(Mips64MsaLd)                    \
-  V(Mips64MsaSt)                    \
-  V(Mips64I32x4SConvertI16x8Low)    \
-  V(Mips64I32x4SConvertI16x8High)   \
-  V(Mips64I32x4UConvertI16x8Low)    \
-  V(Mips64I32x4UConvertI16x8High)   \
-  V(Mips64I16x8SConvertI8x16Low)    \
-  V(Mips64I16x8SConvertI8x16High)   \
-  V(Mips64I16x8SConvertI32x4)       \
-  V(Mips64I16x8UConvertI32x4)       \
-  V(Mips64I16x8UConvertI8x16Low)    \
-  V(Mips64I16x8UConvertI8x16High)   \
-  V(Mips64I8x16SConvertI16x8)       \
-  V(Mips64I8x16UConvertI16x8)
+#define TARGET_ARCH_OPCODE_LIST(V)           \
+  V(Mips64Add)                               \
+  V(Mips64Dadd)                              \
+  V(Mips64DaddOvf)                           \
+  V(Mips64Sub)                               \
+  V(Mips64Dsub)                              \
+  V(Mips64DsubOvf)                           \
+  V(Mips64Mul)                               \
+  V(Mips64MulOvf)                            \
+  V(Mips64MulHigh)                           \
+  V(Mips64DMulHigh)                          \
+  V(Mips64MulHighU)                          \
+  V(Mips64Dmul)                              \
+  V(Mips64Div)                               \
+  V(Mips64Ddiv)                              \
+  V(Mips64DivU)                              \
+  V(Mips64DdivU)                             \
+  V(Mips64Mod)                               \
+  V(Mips64Dmod)                              \
+  V(Mips64ModU)                              \
+  V(Mips64DmodU)                             \
+  V(Mips64And)                               \
+  V(Mips64And32)                             \
+  V(Mips64Or)                                \
+  V(Mips64Or32)                              \
+  V(Mips64Nor)                               \
+  V(Mips64Nor32)                             \
+  V(Mips64Xor)                               \
+  V(Mips64Xor32)                             \
+  V(Mips64Clz)                               \
+  V(Mips64Lsa)                               \
+  V(Mips64Dlsa)                              \
+  V(Mips64Shl)                               \
+  V(Mips64Shr)                               \
+  V(Mips64Sar)                               \
+  V(Mips64Ext)                               \
+  V(Mips64Ins)                               \
+  V(Mips64Dext)                              \
+  V(Mips64Dins)                              \
+  V(Mips64Dclz)                              \
+  V(Mips64Ctz)                               \
+  V(Mips64Dctz)                              \
+  V(Mips64Popcnt)                            \
+  V(Mips64Dpopcnt)                           \
+  V(Mips64Dshl)                              \
+  V(Mips64Dshr)                              \
+  V(Mips64Dsar)                              \
+  V(Mips64Ror)                               \
+  V(Mips64Dror)                              \
+  V(Mips64Mov)                               \
+  V(Mips64Tst)                               \
+  V(Mips64Cmp)                               \
+  V(Mips64CmpS)                              \
+  V(Mips64AddS)                              \
+  V(Mips64SubS)                              \
+  V(Mips64MulS)                              \
+  V(Mips64DivS)                              \
+  V(Mips64ModS)                              \
+  V(Mips64AbsS)                              \
+  V(Mips64NegS)                              \
+  V(Mips64SqrtS)                             \
+  V(Mips64MaxS)                              \
+  V(Mips64MinS)                              \
+  V(Mips64CmpD)                              \
+  V(Mips64AddD)                              \
+  V(Mips64SubD)                              \
+  V(Mips64MulD)                              \
+  V(Mips64DivD)                              \
+  V(Mips64ModD)                              \
+  V(Mips64AbsD)                              \
+  V(Mips64NegD)                              \
+  V(Mips64SqrtD)                             \
+  V(Mips64MaxD)                              \
+  V(Mips64MinD)                              \
+  V(Mips64Float64RoundDown)                  \
+  V(Mips64Float64RoundTruncate)              \
+  V(Mips64Float64RoundUp)                    \
+  V(Mips64Float64RoundTiesEven)              \
+  V(Mips64Float32RoundDown)                  \
+  V(Mips64Float32RoundTruncate)              \
+  V(Mips64Float32RoundUp)                    \
+  V(Mips64Float32RoundTiesEven)              \
+  V(Mips64CvtSD)                             \
+  V(Mips64CvtDS)                             \
+  V(Mips64TruncWD)                           \
+  V(Mips64RoundWD)                           \
+  V(Mips64FloorWD)                           \
+  V(Mips64CeilWD)                            \
+  V(Mips64TruncWS)                           \
+  V(Mips64RoundWS)                           \
+  V(Mips64FloorWS)                           \
+  V(Mips64CeilWS)                            \
+  V(Mips64TruncLS)                           \
+  V(Mips64TruncLD)                           \
+  V(Mips64TruncUwD)                          \
+  V(Mips64TruncUwS)                          \
+  V(Mips64TruncUlS)                          \
+  V(Mips64TruncUlD)                          \
+  V(Mips64CvtDW)                             \
+  V(Mips64CvtSL)                             \
+  V(Mips64CvtSW)                             \
+  V(Mips64CvtSUw)                            \
+  V(Mips64CvtSUl)                            \
+  V(Mips64CvtDL)                             \
+  V(Mips64CvtDUw)                            \
+  V(Mips64CvtDUl)                            \
+  V(Mips64Lb)                                \
+  V(Mips64Lbu)                               \
+  V(Mips64Sb)                                \
+  V(Mips64Lh)                                \
+  V(Mips64Ulh)                               \
+  V(Mips64Lhu)                               \
+  V(Mips64Ulhu)                              \
+  V(Mips64Sh)                                \
+  V(Mips64Ush)                               \
+  V(Mips64Ld)                                \
+  V(Mips64Uld)                               \
+  V(Mips64Lw)                                \
+  V(Mips64Ulw)                               \
+  V(Mips64Lwu)                               \
+  V(Mips64Ulwu)                              \
+  V(Mips64Sw)                                \
+  V(Mips64Usw)                               \
+  V(Mips64Sd)                                \
+  V(Mips64Usd)                               \
+  V(Mips64Lwc1)                              \
+  V(Mips64Ulwc1)                             \
+  V(Mips64Swc1)                              \
+  V(Mips64Uswc1)                             \
+  V(Mips64Ldc1)                              \
+  V(Mips64Uldc1)                             \
+  V(Mips64Sdc1)                              \
+  V(Mips64Usdc1)                             \
+  V(Mips64BitcastDL)                         \
+  V(Mips64BitcastLD)                         \
+  V(Mips64Float64ExtractLowWord32)           \
+  V(Mips64Float64ExtractHighWord32)          \
+  V(Mips64Float64InsertLowWord32)            \
+  V(Mips64Float64InsertHighWord32)           \
+  V(Mips64Float32Max)                        \
+  V(Mips64Float64Max)                        \
+  V(Mips64Float32Min)                        \
+  V(Mips64Float64Min)                        \
+  V(Mips64Float64SilenceNaN)                 \
+  V(Mips64Push)                              \
+  V(Mips64Peek)                              \
+  V(Mips64StoreToStackSlot)                  \
+  V(Mips64ByteSwap64)                        \
+  V(Mips64ByteSwap32)                        \
+  V(Mips64StackClaim)                        \
+  V(Mips64Seb)                               \
+  V(Mips64Seh)                               \
+  V(Mips64AssertEqual)                       \
+  V(Mips64S128Zero)                          \
+  V(Mips64I32x4Splat)                        \
+  V(Mips64I32x4ExtractLane)                  \
+  V(Mips64I32x4ReplaceLane)                  \
+  V(Mips64I32x4Add)                          \
+  V(Mips64I32x4AddHoriz)                     \
+  V(Mips64I32x4Sub)                          \
+  V(Mips64F32x4Splat)                        \
+  V(Mips64F32x4ExtractLane)                  \
+  V(Mips64F32x4ReplaceLane)                  \
+  V(Mips64F32x4SConvertI32x4)                \
+  V(Mips64F32x4UConvertI32x4)                \
+  V(Mips64I32x4Mul)                          \
+  V(Mips64I32x4MaxS)                         \
+  V(Mips64I32x4MinS)                         \
+  V(Mips64I32x4Eq)                           \
+  V(Mips64I32x4Ne)                           \
+  V(Mips64I32x4Shl)                          \
+  V(Mips64I32x4ShrS)                         \
+  V(Mips64I32x4ShrU)                         \
+  V(Mips64I32x4MaxU)                         \
+  V(Mips64I32x4MinU)                         \
+  V(Mips64F32x4Abs)                          \
+  V(Mips64F32x4Neg)                          \
+  V(Mips64F32x4RecipApprox)                  \
+  V(Mips64F32x4RecipSqrtApprox)              \
+  V(Mips64F32x4Add)                          \
+  V(Mips64F32x4AddHoriz)                     \
+  V(Mips64F32x4Sub)                          \
+  V(Mips64F32x4Mul)                          \
+  V(Mips64F32x4Max)                          \
+  V(Mips64F32x4Min)                          \
+  V(Mips64F32x4Eq)                           \
+  V(Mips64F32x4Ne)                           \
+  V(Mips64F32x4Lt)                           \
+  V(Mips64F32x4Le)                           \
+  V(Mips64I32x4SConvertF32x4)                \
+  V(Mips64I32x4UConvertF32x4)                \
+  V(Mips64I32x4Neg)                          \
+  V(Mips64I32x4GtS)                          \
+  V(Mips64I32x4GeS)                          \
+  V(Mips64I32x4GtU)                          \
+  V(Mips64I32x4GeU)                          \
+  V(Mips64I16x8Splat)                        \
+  V(Mips64I16x8ExtractLane)                  \
+  V(Mips64I16x8ReplaceLane)                  \
+  V(Mips64I16x8Neg)                          \
+  V(Mips64I16x8Shl)                          \
+  V(Mips64I16x8ShrS)                         \
+  V(Mips64I16x8ShrU)                         \
+  V(Mips64I16x8Add)                          \
+  V(Mips64I16x8AddSaturateS)                 \
+  V(Mips64I16x8AddHoriz)                     \
+  V(Mips64I16x8Sub)                          \
+  V(Mips64I16x8SubSaturateS)                 \
+  V(Mips64I16x8Mul)                          \
+  V(Mips64I16x8MaxS)                         \
+  V(Mips64I16x8MinS)                         \
+  V(Mips64I16x8Eq)                           \
+  V(Mips64I16x8Ne)                           \
+  V(Mips64I16x8GtS)                          \
+  V(Mips64I16x8GeS)                          \
+  V(Mips64I16x8AddSaturateU)                 \
+  V(Mips64I16x8SubSaturateU)                 \
+  V(Mips64I16x8MaxU)                         \
+  V(Mips64I16x8MinU)                         \
+  V(Mips64I16x8GtU)                          \
+  V(Mips64I16x8GeU)                          \
+  V(Mips64I8x16Splat)                        \
+  V(Mips64I8x16ExtractLane)                  \
+  V(Mips64I8x16ReplaceLane)                  \
+  V(Mips64I8x16Neg)                          \
+  V(Mips64I8x16Shl)                          \
+  V(Mips64I8x16ShrS)                         \
+  V(Mips64I8x16Add)                          \
+  V(Mips64I8x16AddSaturateS)                 \
+  V(Mips64I8x16Sub)                          \
+  V(Mips64I8x16SubSaturateS)                 \
+  V(Mips64I8x16Mul)                          \
+  V(Mips64I8x16MaxS)                         \
+  V(Mips64I8x16MinS)                         \
+  V(Mips64I8x16Eq)                           \
+  V(Mips64I8x16Ne)                           \
+  V(Mips64I8x16GtS)                          \
+  V(Mips64I8x16GeS)                          \
+  V(Mips64I8x16ShrU)                         \
+  V(Mips64I8x16AddSaturateU)                 \
+  V(Mips64I8x16SubSaturateU)                 \
+  V(Mips64I8x16MaxU)                         \
+  V(Mips64I8x16MinU)                         \
+  V(Mips64I8x16GtU)                          \
+  V(Mips64I8x16GeU)                          \
+  V(Mips64S128And)                           \
+  V(Mips64S128Or)                            \
+  V(Mips64S128Xor)                           \
+  V(Mips64S128Not)                           \
+  V(Mips64S128Select)                        \
+  V(Mips64S1x4AnyTrue)                       \
+  V(Mips64S1x4AllTrue)                       \
+  V(Mips64S1x8AnyTrue)                       \
+  V(Mips64S1x8AllTrue)                       \
+  V(Mips64S1x16AnyTrue)                      \
+  V(Mips64S1x16AllTrue)                      \
+  V(Mips64S32x4InterleaveRight)              \
+  V(Mips64S32x4InterleaveLeft)               \
+  V(Mips64S32x4PackEven)                     \
+  V(Mips64S32x4PackOdd)                      \
+  V(Mips64S32x4InterleaveEven)               \
+  V(Mips64S32x4InterleaveOdd)                \
+  V(Mips64S32x4Shuffle)                      \
+  V(Mips64S16x8InterleaveRight)              \
+  V(Mips64S16x8InterleaveLeft)               \
+  V(Mips64S16x8PackEven)                     \
+  V(Mips64S16x8PackOdd)                      \
+  V(Mips64S16x8InterleaveEven)               \
+  V(Mips64S16x8InterleaveOdd)                \
+  V(Mips64S16x4Reverse)                      \
+  V(Mips64S16x2Reverse)                      \
+  V(Mips64S8x16InterleaveRight)              \
+  V(Mips64S8x16InterleaveLeft)               \
+  V(Mips64S8x16PackEven)                     \
+  V(Mips64S8x16PackOdd)                      \
+  V(Mips64S8x16InterleaveEven)               \
+  V(Mips64S8x16InterleaveOdd)                \
+  V(Mips64S8x16Shuffle)                      \
+  V(Mips64S8x16Concat)                       \
+  V(Mips64S8x8Reverse)                       \
+  V(Mips64S8x4Reverse)                       \
+  V(Mips64S8x2Reverse)                       \
+  V(Mips64MsaLd)                             \
+  V(Mips64MsaSt)                             \
+  V(Mips64I32x4SConvertI16x8Low)             \
+  V(Mips64I32x4SConvertI16x8High)            \
+  V(Mips64I32x4UConvertI16x8Low)             \
+  V(Mips64I32x4UConvertI16x8High)            \
+  V(Mips64I16x8SConvertI8x16Low)             \
+  V(Mips64I16x8SConvertI8x16High)            \
+  V(Mips64I16x8SConvertI32x4)                \
+  V(Mips64I16x8UConvertI32x4)                \
+  V(Mips64I16x8UConvertI8x16Low)             \
+  V(Mips64I16x8UConvertI8x16High)            \
+  V(Mips64I8x16SConvertI16x8)                \
+  V(Mips64I8x16UConvertI16x8)                \
+  V(Mips64Word64AtomicLoadUint8)             \
+  V(Mips64Word64AtomicLoadUint16)            \
+  V(Mips64Word64AtomicLoadUint32)            \
+  V(Mips64Word64AtomicLoadUint64)            \
+  V(Mips64Word64AtomicStoreWord8)            \
+  V(Mips64Word64AtomicStoreWord16)           \
+  V(Mips64Word64AtomicStoreWord32)           \
+  V(Mips64Word64AtomicStoreWord64)           \
+  V(Mips64Word64AtomicAddUint8)              \
+  V(Mips64Word64AtomicAddUint16)             \
+  V(Mips64Word64AtomicAddUint32)             \
+  V(Mips64Word64AtomicAddUint64)             \
+  V(Mips64Word64AtomicSubUint8)              \
+  V(Mips64Word64AtomicSubUint16)             \
+  V(Mips64Word64AtomicSubUint32)             \
+  V(Mips64Word64AtomicSubUint64)             \
+  V(Mips64Word64AtomicAndUint8)              \
+  V(Mips64Word64AtomicAndUint16)             \
+  V(Mips64Word64AtomicAndUint32)             \
+  V(Mips64Word64AtomicAndUint64)             \
+  V(Mips64Word64AtomicOrUint8)               \
+  V(Mips64Word64AtomicOrUint16)              \
+  V(Mips64Word64AtomicOrUint32)              \
+  V(Mips64Word64AtomicOrUint64)              \
+  V(Mips64Word64AtomicXorUint8)              \
+  V(Mips64Word64AtomicXorUint16)             \
+  V(Mips64Word64AtomicXorUint32)             \
+  V(Mips64Word64AtomicXorUint64)             \
+  V(Mips64Word64AtomicExchangeUint8)         \
+  V(Mips64Word64AtomicExchangeUint16)        \
+  V(Mips64Word64AtomicExchangeUint32)        \
+  V(Mips64Word64AtomicExchangeUint64)        \
+  V(Mips64Word64AtomicCompareExchangeUint8)  \
+  V(Mips64Word64AtomicCompareExchangeUint16) \
+  V(Mips64Word64AtomicCompareExchangeUint32) \
+  V(Mips64Word64AtomicCompareExchangeUint64)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/mips64/instruction-scheduler-mips64.cc b/deps/v8/src/compiler/mips64/instruction-scheduler-mips64.cc
index b0f6d65bfe..8fe669fe02 100644
--- a/deps/v8/src/compiler/mips64/instruction-scheduler-mips64.cc
+++ b/deps/v8/src/compiler/mips64/instruction-scheduler-mips64.cc
@@ -293,6 +293,11 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMips64Ulw:
     case kMips64Ulwu:
     case kMips64Ulwc1:
+    case kMips64Word64AtomicLoadUint8:
+    case kMips64Word64AtomicLoadUint16:
+    case kMips64Word64AtomicLoadUint32:
+    case kMips64Word64AtomicLoadUint64:
+
       return kIsLoadOperation;
 
     case kMips64ModD:
@@ -312,6 +317,38 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMips64Ush:
     case kMips64Usw:
     case kMips64Uswc1:
+    case kMips64Word64AtomicStoreWord8:
+    case kMips64Word64AtomicStoreWord16:
+    case kMips64Word64AtomicStoreWord32:
+    case kMips64Word64AtomicStoreWord64:
+    case kMips64Word64AtomicAddUint8:
+    case kMips64Word64AtomicAddUint16:
+    case kMips64Word64AtomicAddUint32:
+    case kMips64Word64AtomicAddUint64:
+    case kMips64Word64AtomicSubUint8:
+    case kMips64Word64AtomicSubUint16:
+    case kMips64Word64AtomicSubUint32:
+    case kMips64Word64AtomicSubUint64:
+    case kMips64Word64AtomicAndUint8:
+    case kMips64Word64AtomicAndUint16:
+    case kMips64Word64AtomicAndUint32:
+    case kMips64Word64AtomicAndUint64:
+    case kMips64Word64AtomicOrUint8:
+    case kMips64Word64AtomicOrUint16:
+    case kMips64Word64AtomicOrUint32:
+    case kMips64Word64AtomicOrUint64:
+    case kMips64Word64AtomicXorUint8:
+    case kMips64Word64AtomicXorUint16:
+    case kMips64Word64AtomicXorUint32:
+    case kMips64Word64AtomicXorUint64:
+    case kMips64Word64AtomicExchangeUint8:
+    case kMips64Word64AtomicExchangeUint16:
+    case kMips64Word64AtomicExchangeUint32:
+    case kMips64Word64AtomicExchangeUint64:
+    case kMips64Word64AtomicCompareExchangeUint8:
+    case kMips64Word64AtomicCompareExchangeUint16:
+    case kMips64Word64AtomicCompareExchangeUint32:
+    case kMips64Word64AtomicCompareExchangeUint64:
       return kHasSideEffect;
 
 #define CASE(Name) case k##Name:
diff --git a/deps/v8/src/compiler/mips64/instruction-selector-mips64.cc b/deps/v8/src/compiler/mips64/instruction-selector-mips64.cc
index 9f9aebc145..f27ad218fd 100644
--- a/deps/v8/src/compiler/mips64/instruction-selector-mips64.cc
+++ b/deps/v8/src/compiler/mips64/instruction-selector-mips64.cc
@@ -1160,6 +1160,9 @@ void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRR(this, kMips64CvtDW, node);
 }
 
+void InstructionSelector::VisitChangeInt64ToFloat64(Node* node) {
+  VisitRR(this, kMips64CvtDL, node);
+}
 
 void InstructionSelector::VisitChangeUint32ToFloat64(Node* node) {
   VisitRR(this, kMips64CvtDUw, node);
@@ -1239,6 +1242,9 @@ void InstructionSelector::VisitChangeFloat64ToInt32(Node* node) {
   VisitRR(this, kMips64TruncWD, node);
 }
 
+void InstructionSelector::VisitChangeFloat64ToInt64(Node* node) {
+  VisitRR(this, kMips64TruncLD, node);
+}
 
 void InstructionSelector::VisitChangeFloat64ToUint32(Node* node) {
   VisitRR(this, kMips64TruncUwD, node);
@@ -2022,6 +2028,119 @@ void EmitWordCompareZero(InstructionSelector* selector, Node* value,
                                  g.TempImmediate(0), cont);
 }
 
+void VisitAtomicLoad(InstructionSelector* selector, Node* node,
+                     ArchOpcode opcode) {
+  Mips64OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  if (g.CanBeImmediate(index, opcode)) {
+    selector->Emit(opcode | AddressingModeField::encode(kMode_MRI),
+                   g.DefineAsRegister(node), g.UseRegister(base),
+                   g.UseImmediate(index));
+  } else {
+    InstructionOperand addr_reg = g.TempRegister();
+    selector->Emit(kMips64Dadd | AddressingModeField::encode(kMode_None),
+                   addr_reg, g.UseRegister(index), g.UseRegister(base));
+    // Emit desired load opcode, using temp addr_reg.
+    selector->Emit(opcode | AddressingModeField::encode(kMode_MRI),
+                   g.DefineAsRegister(node), addr_reg, g.TempImmediate(0));
+  }
+}
+
+void VisitAtomicStore(InstructionSelector* selector, Node* node,
+                      ArchOpcode opcode) {
+  Mips64OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  if (g.CanBeImmediate(index, opcode)) {
+    selector->Emit(opcode | AddressingModeField::encode(kMode_MRI),
+                   g.NoOutput(), g.UseRegister(base), g.UseImmediate(index),
+                   g.UseRegisterOrImmediateZero(value));
+  } else {
+    InstructionOperand addr_reg = g.TempRegister();
+    selector->Emit(kMips64Dadd | AddressingModeField::encode(kMode_None),
+                   addr_reg, g.UseRegister(index), g.UseRegister(base));
+    // Emit desired store opcode, using temp addr_reg.
+    selector->Emit(opcode | AddressingModeField::encode(kMode_MRI),
+                   g.NoOutput(), addr_reg, g.TempImmediate(0),
+                   g.UseRegisterOrImmediateZero(value));
+  }
+}
+
+void VisitAtomicExchange(InstructionSelector* selector, Node* node,
+                         ArchOpcode opcode) {
+  Mips64OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  AddressingMode addressing_mode = kMode_MRI;
+  InstructionOperand inputs[3];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionOperand outputs[1];
+  outputs[0] = g.UseUniqueRegister(node);
+  InstructionOperand temp[3];
+  temp[0] = g.TempRegister();
+  temp[1] = g.TempRegister();
+  temp[2] = g.TempRegister();
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  selector->Emit(code, 1, outputs, input_count, inputs, 3, temp);
+}
+
+void VisitAtomicCompareExchange(InstructionSelector* selector, Node* node,
+                                ArchOpcode opcode) {
+  Mips64OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* old_value = node->InputAt(2);
+  Node* new_value = node->InputAt(3);
+
+  AddressingMode addressing_mode = kMode_MRI;
+  InstructionOperand inputs[4];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(old_value);
+  inputs[input_count++] = g.UseUniqueRegister(new_value);
+  InstructionOperand outputs[1];
+  outputs[0] = g.UseUniqueRegister(node);
+  InstructionOperand temp[3];
+  temp[0] = g.TempRegister();
+  temp[1] = g.TempRegister();
+  temp[2] = g.TempRegister();
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  selector->Emit(code, 1, outputs, input_count, inputs, 3, temp);
+}
+
+void VisitAtomicBinop(InstructionSelector* selector, Node* node,
+                      ArchOpcode opcode) {
+  Mips64OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  AddressingMode addressing_mode = kMode_MRI;
+  InstructionOperand inputs[3];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionOperand outputs[1];
+  outputs[0] = g.UseUniqueRegister(node);
+  InstructionOperand temps[4];
+  temps[0] = g.TempRegister();
+  temps[1] = g.TempRegister();
+  temps[2] = g.TempRegister();
+  temps[3] = g.TempRegister();
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  selector->Emit(code, 1, outputs, input_count, inputs, 4, temps);
+}
+
 }  // namespace
 
 // Shared routine for word comparisons against zero.
@@ -2366,9 +2485,6 @@ void InstructionSelector::VisitFloat64InsertHighWord32(Node* node) {
 
 void InstructionSelector::VisitWord32AtomicLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
-  Mips64OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
   ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kWord8:
@@ -2386,25 +2502,11 @@ void InstructionSelector::VisitWord32AtomicLoad(Node* node) {
       UNREACHABLE();
       return;
   }
-  if (g.CanBeImmediate(index, opcode)) {
-    Emit(opcode | AddressingModeField::encode(kMode_MRI),
-         g.DefineAsRegister(node), g.UseRegister(base), g.UseImmediate(index));
-  } else {
-    InstructionOperand addr_reg = g.TempRegister();
-    Emit(kMips64Dadd | AddressingModeField::encode(kMode_None), addr_reg,
-         g.UseRegister(index), g.UseRegister(base));
-    // Emit desired load opcode, using temp addr_reg.
-    Emit(opcode | AddressingModeField::encode(kMode_MRI),
-         g.DefineAsRegister(node), addr_reg, g.TempImmediate(0));
-  }
+  VisitAtomicLoad(this, node, opcode);
 }
 
 void InstructionSelector::VisitWord32AtomicStore(Node* node) {
   MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
-  Mips64OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
   ArchOpcode opcode = kArchNop;
   switch (rep) {
     case MachineRepresentation::kWord8:
@@ -2421,25 +2523,57 @@ void InstructionSelector::VisitWord32AtomicStore(Node* node) {
       return;
   }
 
-  if (g.CanBeImmediate(index, opcode)) {
-    Emit(opcode | AddressingModeField::encode(kMode_MRI), g.NoOutput(),
-         g.UseRegister(base), g.UseImmediate(index),
-         g.UseRegisterOrImmediateZero(value));
-  } else {
-    InstructionOperand addr_reg = g.TempRegister();
-    Emit(kMips64Dadd | AddressingModeField::encode(kMode_None), addr_reg,
-         g.UseRegister(index), g.UseRegister(base));
-    // Emit desired store opcode, using temp addr_reg.
-    Emit(opcode | AddressingModeField::encode(kMode_MRI), g.NoOutput(),
-         addr_reg, g.TempImmediate(0), g.UseRegisterOrImmediateZero(value));
+  VisitAtomicStore(this, node, opcode);
+}
+
+void InstructionSelector::VisitWord64AtomicLoad(Node* node) {
+  LoadRepresentation load_rep = LoadRepresentationOf(node->op());
+  ArchOpcode opcode = kArchNop;
+  switch (load_rep.representation()) {
+    case MachineRepresentation::kWord8:
+      opcode = kMips64Word64AtomicLoadUint8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kMips64Word64AtomicLoadUint16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kMips64Word64AtomicLoadUint32;
+      break;
+    case MachineRepresentation::kWord64:
+      opcode = kMips64Word64AtomicLoadUint64;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+  VisitAtomicLoad(this, node, opcode);
+}
+
+void InstructionSelector::VisitWord64AtomicStore(Node* node) {
+  MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
+  ArchOpcode opcode = kArchNop;
+  switch (rep) {
+    case MachineRepresentation::kWord8:
+      opcode = kMips64Word64AtomicStoreWord8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kMips64Word64AtomicStoreWord16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kMips64Word64AtomicStoreWord32;
+      break;
+    case MachineRepresentation::kWord64:
+      opcode = kMips64Word64AtomicStoreWord64;
+      break;
+    default:
+      UNREACHABLE();
+      return;
   }
+
+  VisitAtomicStore(this, node, opcode);
 }
 
 void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
-  Mips64OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
   ArchOpcode opcode = kArchNop;
   MachineType type = AtomicOpType(node->op());
   if (type == MachineType::Int8()) {
@@ -2457,28 +2591,28 @@ void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
     return;
   }
 
-  AddressingMode addressing_mode = kMode_MRI;
-  InstructionOperand inputs[3];
-  size_t input_count = 0;
-  inputs[input_count++] = g.UseUniqueRegister(base);
-  inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(value);
-  InstructionOperand outputs[1];
-  outputs[0] = g.UseUniqueRegister(node);
-  InstructionOperand temp[3];
-  temp[0] = g.TempRegister();
-  temp[1] = g.TempRegister();
-  temp[2] = g.TempRegister();
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, 1, outputs, input_count, inputs, 3, temp);
+  VisitAtomicExchange(this, node, opcode);
+}
+
+void InstructionSelector::VisitWord64AtomicExchange(Node* node) {
+  ArchOpcode opcode = kArchNop;
+  MachineType type = AtomicOpType(node->op());
+  if (type == MachineType::Uint8()) {
+    opcode = kMips64Word64AtomicExchangeUint8;
+  } else if (type == MachineType::Uint16()) {
+    opcode = kMips64Word64AtomicExchangeUint16;
+  } else if (type == MachineType::Uint32()) {
+    opcode = kMips64Word64AtomicExchangeUint32;
+  } else if (type == MachineType::Uint64()) {
+    opcode = kMips64Word64AtomicExchangeUint64;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicExchange(this, node, opcode);
 }
 
 void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
-  Mips64OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* old_value = node->InputAt(2);
-  Node* new_value = node->InputAt(3);
   ArchOpcode opcode = kArchNop;
   MachineType type = AtomicOpType(node->op());
   if (type == MachineType::Int8()) {
@@ -2496,30 +2630,29 @@ void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
     return;
   }
 
-  AddressingMode addressing_mode = kMode_MRI;
-  InstructionOperand inputs[4];
-  size_t input_count = 0;
-  inputs[input_count++] = g.UseUniqueRegister(base);
-  inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(old_value);
-  inputs[input_count++] = g.UseUniqueRegister(new_value);
-  InstructionOperand outputs[1];
-  outputs[0] = g.UseUniqueRegister(node);
-  InstructionOperand temp[3];
-  temp[0] = g.TempRegister();
-  temp[1] = g.TempRegister();
-  temp[2] = g.TempRegister();
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, 1, outputs, input_count, inputs, 3, temp);
+  VisitAtomicCompareExchange(this, node, opcode);
 }
 
+void InstructionSelector::VisitWord64AtomicCompareExchange(Node* node) {
+  ArchOpcode opcode = kArchNop;
+  MachineType type = AtomicOpType(node->op());
+  if (type == MachineType::Uint8()) {
+    opcode = kMips64Word64AtomicCompareExchangeUint8;
+  } else if (type == MachineType::Uint16()) {
+    opcode = kMips64Word64AtomicCompareExchangeUint16;
+  } else if (type == MachineType::Uint32()) {
+    opcode = kMips64Word64AtomicCompareExchangeUint32;
+  } else if (type == MachineType::Uint64()) {
+    opcode = kMips64Word64AtomicCompareExchangeUint64;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicCompareExchange(this, node, opcode);
+}
 void InstructionSelector::VisitWord32AtomicBinaryOperation(
     Node* node, ArchOpcode int8_op, ArchOpcode uint8_op, ArchOpcode int16_op,
     ArchOpcode uint16_op, ArchOpcode word32_op) {
-  Mips64OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
   ArchOpcode opcode = kArchNop;
   MachineType type = AtomicOpType(node->op());
   if (type == MachineType::Int8()) {
@@ -2537,21 +2670,7 @@ void InstructionSelector::VisitWord32AtomicBinaryOperation(
     return;
   }
 
-  AddressingMode addressing_mode = kMode_MRI;
-  InstructionOperand inputs[3];
-  size_t input_count = 0;
-  inputs[input_count++] = g.UseUniqueRegister(base);
-  inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(value);
-  InstructionOperand outputs[1];
-  outputs[0] = g.UseUniqueRegister(node);
-  InstructionOperand temps[4];
-  temps[0] = g.TempRegister();
-  temps[1] = g.TempRegister();
-  temps[2] = g.TempRegister();
-  temps[3] = g.TempRegister();
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, 1, outputs, input_count, inputs, 4, temps);
+  VisitAtomicBinop(this, node, opcode);
 }
 
 #define VISIT_ATOMIC_BINOP(op)                                   \
@@ -2568,6 +2687,39 @@ VISIT_ATOMIC_BINOP(Or)
 VISIT_ATOMIC_BINOP(Xor)
 #undef VISIT_ATOMIC_BINOP
 
+void InstructionSelector::VisitWord64AtomicBinaryOperation(
+    Node* node, ArchOpcode uint8_op, ArchOpcode uint16_op, ArchOpcode uint32_op,
+    ArchOpcode uint64_op) {
+  ArchOpcode opcode = kArchNop;
+  MachineType type = AtomicOpType(node->op());
+  if (type == MachineType::Uint8()) {
+    opcode = uint8_op;
+  } else if (type == MachineType::Uint16()) {
+    opcode = uint16_op;
+  } else if (type == MachineType::Uint32()) {
+    opcode = uint32_op;
+  } else if (type == MachineType::Uint64()) {
+    opcode = uint64_op;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicBinop(this, node, opcode);
+}
+
+#define VISIT_ATOMIC_BINOP(op)                                                 \
+  void InstructionSelector::VisitWord64Atomic##op(Node* node) {                \
+    VisitWord64AtomicBinaryOperation(                                          \
+        node, kMips64Word64Atomic##op##Uint8, kMips64Word64Atomic##op##Uint16, \
+        kMips64Word64Atomic##op##Uint32, kMips64Word64Atomic##op##Uint64);     \
+  }
+VISIT_ATOMIC_BINOP(Add)
+VISIT_ATOMIC_BINOP(Sub)
+VISIT_ATOMIC_BINOP(And)
+VISIT_ATOMIC_BINOP(Or)
+VISIT_ATOMIC_BINOP(Xor)
+#undef VISIT_ATOMIC_BINOP
+
 void InstructionSelector::VisitInt32AbsWithOverflow(Node* node) {
   UNREACHABLE();
 }
diff --git a/deps/v8/src/compiler/move-optimizer.cc b/deps/v8/src/compiler/move-optimizer.cc
index 82f4b63276..cf6edc2b67 100644
--- a/deps/v8/src/compiler/move-optimizer.cc
+++ b/deps/v8/src/compiler/move-optimizer.cc
@@ -37,7 +37,7 @@ class OperandSet {
     set_->push_back(op);
 
     if (!kSimpleFPAliasing && op.IsFPRegister())
-      fp_reps_ |= RepBit(LocationOperand::cast(op).representation());
+      fp_reps_ |= RepresentationBit(LocationOperand::cast(op).representation());
   }
 
   bool Contains(const InstructionOperand& op) const {
@@ -55,7 +55,7 @@ class OperandSet {
       const LocationOperand& loc = LocationOperand::cast(op);
       MachineRepresentation rep = loc.representation();
       // If haven't encountered mixed rep FP registers, skip the extra checks.
-      if (!HasMixedFPReps(fp_reps_ | RepBit(rep))) return false;
+      if (!HasMixedFPReps(fp_reps_ | RepresentationBit(rep))) return false;
 
       // Check register against aliasing registers of other FP representations.
       MachineRepresentation other_rep1, other_rep2;
@@ -100,10 +100,6 @@ class OperandSet {
   }
 
  private:
-  static int RepBit(MachineRepresentation rep) {
-    return 1 << static_cast<int>(rep);
-  }
-
   static bool HasMixedFPReps(int reps) {
     return reps && !base::bits::IsPowerOfTwo(reps);
   }
diff --git a/deps/v8/src/compiler/node-cache.cc b/deps/v8/src/compiler/node-cache.cc
index fc9a44c629..6b9c8dc07d 100644
--- a/deps/v8/src/compiler/node-cache.cc
+++ b/deps/v8/src/compiler/node-cache.cc
@@ -38,7 +38,7 @@ bool NodeCache<Key, Hash, Pred>::Resize(Zone* zone) {
   size_ *= 4;
   size_t num_entries = size_ + kLinearProbe;
   entries_ = zone->NewArray<Entry>(num_entries);
-  memset(entries_, 0, sizeof(Entry) * num_entries);
+  memset(static_cast<void*>(entries_), 0, sizeof(Entry) * num_entries);
 
   // Insert the old entries into the new block.
   for (size_t i = 0; i < old_size; ++i) {
@@ -69,7 +69,7 @@ Node** NodeCache<Key, Hash, Pred>::Find(Zone* zone, Key key) {
     size_t num_entries = kInitialSize + kLinearProbe;
     entries_ = zone->NewArray<Entry>(num_entries);
     size_ = kInitialSize;
-    memset(entries_, 0, sizeof(Entry) * num_entries);
+    memset(static_cast<void*>(entries_), 0, sizeof(Entry) * num_entries);
     Entry* entry = &entries_[hash & (kInitialSize - 1)];
     entry->key_ = key;
     return &entry->value_;
diff --git a/deps/v8/src/compiler/node-cache.h b/deps/v8/src/compiler/node-cache.h
index 7063a3b0b4..72b5fdf2f3 100644
--- a/deps/v8/src/compiler/node-cache.h
+++ b/deps/v8/src/compiler/node-cache.h
@@ -27,11 +27,11 @@ class Node;
 // nodes such as constants, parameters, etc.
 template <typename Key, typename Hash = base::hash<Key>,
           typename Pred = std::equal_to<Key> >
-class NodeCache final {
+class V8_EXPORT_PRIVATE NodeCache final {
  public:
   explicit NodeCache(unsigned max = 256)
       : entries_(nullptr), size_(0), max_(max) {}
-  ~NodeCache() {}
+  ~NodeCache() = default;
 
   // Search for node associated with {key} and return a pointer to a memory
   // location in this cache that stores an entry for the key. If the location
diff --git a/deps/v8/src/compiler/node-properties.cc b/deps/v8/src/compiler/node-properties.cc
index 22cdd0b091..d72980f9fd 100644
--- a/deps/v8/src/compiler/node-properties.cc
+++ b/deps/v8/src/compiler/node-properties.cc
@@ -599,7 +599,6 @@ bool NodeProperties::CanBeNullOrUndefined(Isolate* isolate, Node* receiver,
       case IrOpcode::kCheckSmi:
       case IrOpcode::kCheckString:
       case IrOpcode::kCheckSymbol:
-      case IrOpcode::kJSToInteger:
       case IrOpcode::kJSToLength:
       case IrOpcode::kJSToName:
       case IrOpcode::kJSToNumber:
diff --git a/deps/v8/src/compiler/node.h b/deps/v8/src/compiler/node.h
index fc5a17c19d..01dca47cbe 100644
--- a/deps/v8/src/compiler/node.h
+++ b/deps/v8/src/compiler/node.h
@@ -429,8 +429,7 @@ class Node::InputEdges::iterator final {
   typedef Edge& reference;
 
   iterator() : use_(nullptr), input_ptr_(nullptr) {}
-  iterator(const iterator& other)
-      : use_(other.use_), input_ptr_(other.input_ptr_) {}
+  iterator(const iterator& other) = default;
 
   Edge operator*() const { return Edge(use_, input_ptr_); }
   bool operator==(const iterator& other) const {
@@ -488,7 +487,7 @@ class Node::Inputs::const_iterator final {
   typedef const value_type* pointer;
   typedef value_type& reference;
 
-  const_iterator(const const_iterator& other) : input_ptr_(other.input_ptr_) {}
+  const_iterator(const const_iterator& other) = default;
 
   Node* operator*() const { return *input_ptr_; }
   bool operator==(const const_iterator& other) const {
@@ -536,8 +535,7 @@ Node* Node::Inputs::operator[](int index) const { return input_root_[index]; }
 // A forward iterator to visit the uses edges of a node.
 class Node::UseEdges::iterator final {
  public:
-  iterator(const iterator& other)
-      : current_(other.current_), next_(other.next_) {}
+  iterator(const iterator& other) = default;
 
   Edge operator*() const { return Edge(current_, current_->input_ptr()); }
   bool operator==(const iterator& other) const {
@@ -584,15 +582,6 @@ class Node::Uses::const_iterator final {
   typedef Node** pointer;
   typedef Node*& reference;
 
-  const_iterator(const const_iterator& other)
-      : current_(other.current_)
-#ifdef DEBUG
-        ,
-        next_(other.next_)
-#endif
-  {
-  }
-
   Node* operator*() const { return current_->from(); }
   bool operator==(const const_iterator& other) const {
     return other.current_ == current_;
diff --git a/deps/v8/src/compiler/opcodes.h b/deps/v8/src/compiler/opcodes.h
index d6ea247fbc..b6777ac439 100644
--- a/deps/v8/src/compiler/opcodes.h
+++ b/deps/v8/src/compiler/opcodes.h
@@ -117,7 +117,6 @@
   V(JSOrdinaryHasInstance)
 
 #define JS_CONVERSION_UNOP_LIST(V) \
-  V(JSToInteger)                   \
   V(JSToLength)                    \
   V(JSToName)                      \
   V(JSToNumber)                    \
@@ -151,6 +150,7 @@
   V(JSCreateTypedArray)         \
   V(JSCreateLiteralArray)       \
   V(JSCreateEmptyLiteralArray)  \
+  V(JSCreateArrayFromIterable)  \
   V(JSCreateLiteralObject)      \
   V(JSCreateEmptyLiteralObject) \
   V(JSCloneObject)              \
@@ -179,6 +179,12 @@
   V(JSCreateWithContext)      \
   V(JSCreateBlockContext)
 
+#define JS_CALL_OP_LIST(V) \
+  V(JSCall)                \
+  V(JSCallForwardVarargs)  \
+  V(JSCallWithArrayLike)   \
+  V(JSCallWithSpread)
+
 #define JS_CONSTRUCT_OP_LIST(V) \
   V(JSConstructForwardVarargs)  \
   V(JSConstruct)                \
@@ -186,11 +192,8 @@
   V(JSConstructWithSpread)
 
 #define JS_OTHER_OP_LIST(V)            \
+  JS_CALL_OP_LIST(V)                   \
   JS_CONSTRUCT_OP_LIST(V)              \
-  V(JSCallForwardVarargs)              \
-  V(JSCall)                            \
-  V(JSCallWithArrayLike)               \
-  V(JSCallWithSpread)                  \
   V(JSCallRuntime)                     \
   V(JSForInEnumerate)                  \
   V(JSForInNext)                       \
@@ -224,13 +227,17 @@
 // Opcodes for VirtuaMachine-level operators.
 #define SIMPLIFIED_CHANGE_OP_LIST(V) \
   V(ChangeTaggedSignedToInt32)       \
+  V(ChangeTaggedSignedToInt64)       \
   V(ChangeTaggedToInt32)             \
+  V(ChangeTaggedToInt64)             \
   V(ChangeTaggedToUint32)            \
   V(ChangeTaggedToFloat64)           \
   V(ChangeTaggedToTaggedSigned)      \
   V(ChangeInt31ToTaggedSigned)       \
   V(ChangeInt32ToTagged)             \
+  V(ChangeInt64ToTagged)             \
   V(ChangeUint32ToTagged)            \
+  V(ChangeUint64ToTagged)            \
   V(ChangeFloat64ToTagged)           \
   V(ChangeFloat64ToTaggedPointer)    \
   V(ChangeTaggedToBit)               \
@@ -249,8 +256,12 @@
   V(CheckedUint32Mod)                 \
   V(CheckedInt32Mul)                  \
   V(CheckedInt32ToTaggedSigned)       \
+  V(CheckedInt64ToInt32)              \
+  V(CheckedInt64ToTaggedSigned)       \
   V(CheckedUint32ToInt32)             \
   V(CheckedUint32ToTaggedSigned)      \
+  V(CheckedUint64ToInt32)             \
+  V(CheckedUint64ToTaggedSigned)      \
   V(CheckedFloat64ToInt32)            \
   V(CheckedTaggedSignedToInt32)       \
   V(CheckedTaggedToInt32)             \
@@ -348,6 +359,7 @@
   V(PlainPrimitiveToWord32)             \
   V(PlainPrimitiveToFloat64)            \
   V(BooleanNot)                         \
+  V(StringConcat)                       \
   V(StringToNumber)                     \
   V(StringCharCodeAt)                   \
   V(StringCodePointAt)                  \
@@ -420,7 +432,7 @@
   V(NewSmiOrObjectElements)             \
   V(NewArgumentsElements)               \
   V(NewConsString)                      \
-  V(ArrayBufferWasNeutered)             \
+  V(DelayedStringConstant)              \
   V(EnsureWritableFastElements)         \
   V(MaybeGrowFastElements)              \
   V(TransitionElementsKind)             \
@@ -571,14 +583,7 @@
   V(Word64AtomicOr)                      \
   V(Word64AtomicXor)                     \
   V(Word64AtomicExchange)                \
-  V(Word64AtomicCompareExchange)         \
-  V(Word64AtomicNarrowAdd)               \
-  V(Word64AtomicNarrowSub)               \
-  V(Word64AtomicNarrowAnd)               \
-  V(Word64AtomicNarrowOr)                \
-  V(Word64AtomicNarrowXor)               \
-  V(Word64AtomicNarrowExchange)          \
-  V(Word64AtomicNarrowCompareExchange)
+  V(Word64AtomicCompareExchange)
 
 #define MACHINE_OP_LIST(V)           \
   MACHINE_UNOP_32_LIST(V)            \
@@ -610,6 +615,7 @@
   V(TruncateFloat64ToWord32)         \
   V(ChangeFloat32ToFloat64)          \
   V(ChangeFloat64ToInt32)            \
+  V(ChangeFloat64ToInt64)            \
   V(ChangeFloat64ToUint32)           \
   V(ChangeFloat64ToUint64)           \
   V(Float64SilenceNaN)               \
@@ -622,6 +628,7 @@
   V(TryTruncateFloat64ToUint64)      \
   V(ChangeInt32ToFloat64)            \
   V(ChangeInt32ToInt64)              \
+  V(ChangeInt64ToFloat64)            \
   V(ChangeUint32ToFloat64)           \
   V(ChangeUint32ToUint64)            \
   V(TruncateFloat64ToFloat32)        \
diff --git a/deps/v8/src/compiler/operation-typer.cc b/deps/v8/src/compiler/operation-typer.cc
index 67a7b138a5..313a263ebb 100644
--- a/deps/v8/src/compiler/operation-typer.cc
+++ b/deps/v8/src/compiler/operation-typer.cc
@@ -16,14 +16,11 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
-OperationTyper::OperationTyper(Isolate* isolate, JSHeapBroker* js_heap_broker,
-                               Zone* zone)
+OperationTyper::OperationTyper(JSHeapBroker* js_heap_broker, Zone* zone)
     : zone_(zone), cache_(TypeCache::Get()) {
-  Factory* factory = isolate->factory();
-  infinity_ =
-      Type::NewConstant(js_heap_broker, factory->infinity_value(), zone);
-  minus_infinity_ =
-      Type::NewConstant(js_heap_broker, factory->minus_infinity_value(), zone);
+  Factory* factory = js_heap_broker->isolate()->factory();
+  infinity_ = Type::NewConstant(V8_INFINITY, zone);
+  minus_infinity_ = Type::NewConstant(-V8_INFINITY, zone);
   Type truncating_to_zero = Type::MinusZeroOrNaN();
   DCHECK(!truncating_to_zero.Maybe(Type::Integral32()));
 
@@ -265,59 +262,61 @@ Type OperationTyper::ConvertReceiver(Type type) {
   return type;
 }
 
-// Returns the result type of converting {type} to number, if the
-// result does not depend on conversion options.
-base::Optional<Type> OperationTyper::ToNumberCommon(Type type) {
+Type OperationTyper::ToNumber(Type type) {
   if (type.Is(Type::Number())) return type;
-  if (type.Is(Type::NullOrUndefined())) {
-    if (type.Is(Type::Null())) return cache_.kSingletonZero;
-    if (type.Is(Type::Undefined())) return Type::NaN();
-    return Type::Union(Type::NaN(), cache_.kSingletonZero, zone());
-  }
-  if (type.Is(Type::Boolean())) {
-    if (type.Is(singleton_false_)) return cache_.kSingletonZero;
-    if (type.Is(singleton_true_)) return cache_.kSingletonOne;
-    return cache_.kZeroOrOne;
+
+  // If {type} includes any receivers, we cannot tell what kind of
+  // Number their callbacks might produce. Similarly in the case
+  // where {type} includes String, it's not possible at this point
+  // to tell which exact numbers are going to be produced.
+  if (type.Maybe(Type::StringOrReceiver())) return Type::Number();
+
+  // Both Symbol and BigInt primitives will cause exceptions
+  // to be thrown from ToNumber conversions, so they don't
+  // contribute to the resulting type anyways.
+  type = Type::Intersect(type, Type::PlainPrimitive(), zone());
+
+  // This leaves us with Number\/Oddball, so deal with the individual
+  // Oddball primitives below.
+  DCHECK(type.Is(Type::NumberOrOddball()));
+  if (type.Maybe(Type::Null())) {
+    // ToNumber(null) => +0
+    type = Type::Union(type, cache_.kSingletonZero, zone());
   }
-  if (type.Is(Type::NumberOrOddball())) {
-    if (type.Is(Type::NumberOrUndefined())) {
-      type = Type::Union(type, Type::NaN(), zone());
-    } else if (type.Is(Type::NullOrNumber())) {
-      type = Type::Union(type, cache_.kSingletonZero, zone());
-    } else if (type.Is(Type::BooleanOrNullOrNumber())) {
-      type = Type::Union(type, cache_.kZeroOrOne, zone());
-    } else {
-      type = Type::Union(type, cache_.kZeroOrOneOrNaN, zone());
-    }
-    return Type::Intersect(type, Type::Number(), zone());
+  if (type.Maybe(Type::Undefined())) {
+    // ToNumber(undefined) => NaN
+    type = Type::Union(type, Type::NaN(), zone());
   }
-  return base::Optional<Type>();
-}
-
-Type OperationTyper::ToNumberOrNumeric(Object::Conversion mode, Type type) {
-  if (base::Optional<Type> maybe_result_type = ToNumberCommon(type)) {
-    return *maybe_result_type;
+  if (type.Maybe(singleton_false_)) {
+    // ToNumber(false) => +0
+    type = Type::Union(type, cache_.kSingletonZero, zone());
   }
-  if (type.Is(Type::BigInt())) {
-    return mode == Object::Conversion::kToNumber ? Type::None() : type;
+  if (type.Maybe(singleton_true_)) {
+    // ToNumber(true) => +1
+    type = Type::Union(type, cache_.kSingletonOne, zone());
   }
-  return mode == Object::Conversion::kToNumber ? Type::Number()
-                                               : Type::Numeric();
-}
-
-Type OperationTyper::ToNumber(Type type) {
-  return ToNumberOrNumeric(Object::Conversion::kToNumber, type);
+  return Type::Intersect(type, Type::Number(), zone());
 }
 
 Type OperationTyper::ToNumberConvertBigInt(Type type) {
-  if (base::Optional<Type> maybe_result_type = ToNumberCommon(type)) {
-    return *maybe_result_type;
-  }
-  return Type::Number();
+  // If the {type} includes any receivers, then the callbacks
+  // might actually produce BigInt primitive values here.
+  bool maybe_bigint =
+      type.Maybe(Type::BigInt()) || type.Maybe(Type::Receiver());
+  type = ToNumber(Type::Intersect(type, Type::NonBigInt(), zone()));
+
+  // Any BigInt is rounded to an integer Number in the range [-inf, inf].
+  return maybe_bigint ? Type::Union(type, cache_.kInteger, zone()) : type;
 }
 
 Type OperationTyper::ToNumeric(Type type) {
-  return ToNumberOrNumeric(Object::Conversion::kToNumeric, type);
+  // If the {type} includes any receivers, then the callbacks
+  // might actually produce BigInt primitive values here.
+  if (type.Maybe(Type::Receiver())) {
+    type = Type::Union(type, Type::BigInt(), zone());
+  }
+  return Type::Union(ToNumber(Type::Intersect(type, Type::NonBigInt(), zone())),
+                     Type::Intersect(type, Type::BigInt(), zone()), zone());
 }
 
 Type OperationTyper::NumberAbs(Type type) {
@@ -415,7 +414,7 @@ Type OperationTyper::NumberExp(Type type) {
 
 Type OperationTyper::NumberExpm1(Type type) {
   DCHECK(type.Is(Type::Number()));
-  return Type::Union(Type::PlainNumber(), Type::NaN(), zone());
+  return Type::Number();
 }
 
 Type OperationTyper::NumberFloor(Type type) {
@@ -999,7 +998,6 @@ Type OperationTyper::NumberMax(Type lhs, Type rhs) {
   if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return Type::NaN();
 
   Type type = Type::None();
-  // TODO(turbofan): Improve minus zero handling here.
   if (lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN())) {
     type = Type::Union(type, Type::NaN(), zone());
   }
@@ -1007,10 +1005,17 @@ Type OperationTyper::NumberMax(Type lhs, Type rhs) {
   DCHECK(!lhs.IsNone());
   rhs = Type::Intersect(rhs, Type::OrderedNumber(), zone());
   DCHECK(!rhs.IsNone());
-  if (lhs.Is(cache_.kInteger) && rhs.Is(cache_.kInteger)) {
+  if (lhs.Is(cache_.kIntegerOrMinusZero) &&
+      rhs.Is(cache_.kIntegerOrMinusZero)) {
+    // TODO(turbofan): This could still be improved in ruling out -0 when
+    // one of the inputs' min is 0.
     double max = std::max(lhs.Max(), rhs.Max());
     double min = std::max(lhs.Min(), rhs.Min());
     type = Type::Union(type, Type::Range(min, max, zone()), zone());
+    if (min <= 0.0 && 0.0 <= max &&
+        (lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero()))) {
+      type = Type::Union(type, Type::MinusZero(), zone());
+    }
   } else {
     type = Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
   }
@@ -1025,7 +1030,6 @@ Type OperationTyper::NumberMin(Type lhs, Type rhs) {
   if (lhs.Is(Type::NaN()) || rhs.Is(Type::NaN())) return Type::NaN();
 
   Type type = Type::None();
-  // TODO(turbofan): Improve minus zero handling here.
   if (lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN())) {
     type = Type::Union(type, Type::NaN(), zone());
   }
@@ -1033,10 +1037,15 @@ Type OperationTyper::NumberMin(Type lhs, Type rhs) {
   DCHECK(!lhs.IsNone());
   rhs = Type::Intersect(rhs, Type::OrderedNumber(), zone());
   DCHECK(!rhs.IsNone());
-  if (lhs.Is(cache_.kInteger) && rhs.Is(cache_.kInteger)) {
+  if (lhs.Is(cache_.kIntegerOrMinusZero) &&
+      rhs.Is(cache_.kIntegerOrMinusZero)) {
     double max = std::min(lhs.Max(), rhs.Max());
     double min = std::min(lhs.Min(), rhs.Min());
     type = Type::Union(type, Type::Range(min, max, zone()), zone());
+    if (min <= 0.0 && 0.0 <= max &&
+        (lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero()))) {
+      type = Type::Union(type, Type::MinusZero(), zone());
+    }
   } else {
     type = Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
   }
@@ -1163,6 +1172,19 @@ Type OperationTyper::StrictEqual(Type lhs, Type rhs) {
   return Type::Boolean();
 }
 
+Type OperationTyper::CheckBounds(Type index, Type length) {
+  DCHECK(length.Is(Type::Unsigned31()));
+  if (index.Maybe(Type::MinusZero())) {
+    index = Type::Union(index, cache_.kSingletonZero, zone());
+  }
+  index = Type::Intersect(index, Type::Integral32(), zone());
+  if (index.IsNone() || length.IsNone()) return Type::None();
+  double min = std::max(index.Min(), 0.0);
+  double max = std::min(index.Max(), length.Max() - 1);
+  if (max < min) return Type::None();
+  return Type::Range(min, max, zone());
+}
+
 Type OperationTyper::CheckFloat64Hole(Type type) {
   if (type.Maybe(Type::Hole())) {
     // Turn "the hole" into undefined.
diff --git a/deps/v8/src/compiler/operation-typer.h b/deps/v8/src/compiler/operation-typer.h
index fb5997485c..e84e97d2a1 100644
--- a/deps/v8/src/compiler/operation-typer.h
+++ b/deps/v8/src/compiler/operation-typer.h
@@ -27,7 +27,7 @@ class TypeCache;
 
 class V8_EXPORT_PRIVATE OperationTyper {
  public:
-  OperationTyper(Isolate* isolate, JSHeapBroker* js_heap_broker, Zone* zone);
+  OperationTyper(JSHeapBroker* js_heap_broker, Zone* zone);
 
   // Typing Phi.
   Type Merge(Type left, Type right);
@@ -58,6 +58,7 @@ class V8_EXPORT_PRIVATE OperationTyper {
   Type StrictEqual(Type lhs, Type rhs);
 
   // Check operators.
+  Type CheckBounds(Type index, Type length);
   Type CheckFloat64Hole(Type type);
   Type CheckNumber(Type type);
   Type ConvertTaggedHoleToUndefined(Type type);
@@ -77,9 +78,6 @@ class V8_EXPORT_PRIVATE OperationTyper {
  private:
   typedef base::Flags<ComparisonOutcomeFlags> ComparisonOutcome;
 
-  Type ToNumberOrNumeric(Object::Conversion mode, Type type);
-  base::Optional<Type> ToNumberCommon(Type type);
-
   ComparisonOutcome Invert(ComparisonOutcome);
   Type Invert(Type);
   Type FalsifyUndefined(ComparisonOutcome);
diff --git a/deps/v8/src/compiler/operator-properties.cc b/deps/v8/src/compiler/operator-properties.cc
index a5d16053d2..8da3ccfd81 100644
--- a/deps/v8/src/compiler/operator-properties.cc
+++ b/deps/v8/src/compiler/operator-properties.cc
@@ -7,6 +7,7 @@
 #include "src/compiler/js-operator.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
+#include "src/runtime/runtime.h"
 
 namespace v8 {
 namespace internal {
@@ -18,6 +19,109 @@ bool OperatorProperties::HasContextInput(const Operator* op) {
   return IrOpcode::IsJsOpcode(opcode);
 }
 
+// static
+bool OperatorProperties::NeedsExactContext(const Operator* op) {
+  DCHECK(HasContextInput(op));
+  IrOpcode::Value const opcode = static_cast<IrOpcode::Value>(op->opcode());
+  switch (opcode) {
+#define CASE(Name) case IrOpcode::k##Name:
+    // Binary/unary operators, calls and constructor calls only
+    // need the context to generate exceptions or lookup fields
+    // on the native context, so passing any context is fine.
+    JS_SIMPLE_BINOP_LIST(CASE)
+    JS_CALL_OP_LIST(CASE)
+    JS_CONSTRUCT_OP_LIST(CASE)
+    JS_SIMPLE_UNOP_LIST(CASE)
+#undef CASE
+    case IrOpcode::kJSCloneObject:
+    case IrOpcode::kJSCreate:
+    case IrOpcode::kJSCreateLiteralArray:
+    case IrOpcode::kJSCreateEmptyLiteralArray:
+    case IrOpcode::kJSCreateLiteralObject:
+    case IrOpcode::kJSCreateEmptyLiteralObject:
+    case IrOpcode::kJSCreateArrayFromIterable:
+    case IrOpcode::kJSCreateLiteralRegExp:
+    case IrOpcode::kJSForInEnumerate:
+    case IrOpcode::kJSForInNext:
+    case IrOpcode::kJSForInPrepare:
+    case IrOpcode::kJSGeneratorRestoreContext:
+    case IrOpcode::kJSGeneratorRestoreContinuation:
+    case IrOpcode::kJSGeneratorRestoreInputOrDebugPos:
+    case IrOpcode::kJSGeneratorRestoreRegister:
+    case IrOpcode::kJSGetSuperConstructor:
+    case IrOpcode::kJSLoadGlobal:
+    case IrOpcode::kJSLoadMessage:
+    case IrOpcode::kJSStackCheck:
+    case IrOpcode::kJSStoreGlobal:
+    case IrOpcode::kJSStoreMessage:
+      return false;
+
+    case IrOpcode::kJSCallRuntime:
+      return Runtime::NeedsExactContext(CallRuntimeParametersOf(op).id());
+
+    case IrOpcode::kJSCreateArguments:
+      // For mapped arguments we need to access slots of context-allocated
+      // variables if there's aliasing with formal parameters.
+      return CreateArgumentsTypeOf(op) == CreateArgumentsType::kMappedArguments;
+
+    case IrOpcode::kJSCreateBlockContext:
+    case IrOpcode::kJSCreateClosure:
+    case IrOpcode::kJSCreateFunctionContext:
+    case IrOpcode::kJSCreateGeneratorObject:
+    case IrOpcode::kJSCreateCatchContext:
+    case IrOpcode::kJSCreateWithContext:
+    case IrOpcode::kJSDebugger:
+    case IrOpcode::kJSDeleteProperty:
+    case IrOpcode::kJSGeneratorStore:
+    case IrOpcode::kJSHasProperty:
+    case IrOpcode::kJSLoadContext:
+    case IrOpcode::kJSLoadModule:
+    case IrOpcode::kJSLoadNamed:
+    case IrOpcode::kJSLoadProperty:
+    case IrOpcode::kJSStoreContext:
+    case IrOpcode::kJSStoreDataPropertyInLiteral:
+    case IrOpcode::kJSStoreInArrayLiteral:
+    case IrOpcode::kJSStoreModule:
+    case IrOpcode::kJSStoreNamed:
+    case IrOpcode::kJSStoreNamedOwn:
+    case IrOpcode::kJSStoreProperty:
+      return true;
+
+    case IrOpcode::kJSCreateArrayIterator:
+    case IrOpcode::kJSCreateBoundFunction:
+    case IrOpcode::kJSCreateCollectionIterator:
+    case IrOpcode::kJSCreateIterResultObject:
+    case IrOpcode::kJSCreateStringIterator:
+    case IrOpcode::kJSCreateKeyValueArray:
+    case IrOpcode::kJSCreateObject:
+    case IrOpcode::kJSCreatePromise:
+    case IrOpcode::kJSCreateTypedArray:
+    case IrOpcode::kJSCreateArray:
+    case IrOpcode::kJSFulfillPromise:
+    case IrOpcode::kJSObjectIsArray:
+    case IrOpcode::kJSPerformPromiseThen:
+    case IrOpcode::kJSPromiseResolve:
+    case IrOpcode::kJSRegExpTest:
+    case IrOpcode::kJSRejectPromise:
+    case IrOpcode::kJSResolvePromise:
+      // These operators aren't introduced by BytecodeGraphBuilder and
+      // thus we don't bother checking them. If you ever introduce one
+      // of these early in the BytecodeGraphBuilder make sure to check
+      // whether they are context-sensitive.
+      break;
+
+#define CASE(Name) case IrOpcode::k##Name:
+      // Non-JavaScript operators don't have a notion of "context"
+      COMMON_OP_LIST(CASE)
+      CONTROL_OP_LIST(CASE)
+      MACHINE_OP_LIST(CASE)
+      MACHINE_SIMD_OP_LIST(CASE)
+      SIMPLIFIED_OP_LIST(CASE)
+      break;
+#undef CASE
+  }
+  UNREACHABLE();
+}
 
 // static
 bool OperatorProperties::HasFrameStateInput(const Operator* op) {
@@ -73,6 +177,7 @@ bool OperatorProperties::HasFrameStateInput(const Operator* op) {
     case IrOpcode::kJSCreateArray:
     case IrOpcode::kJSCreateTypedArray:
     case IrOpcode::kJSCreateLiteralArray:
+    case IrOpcode::kJSCreateArrayFromIterable:
     case IrOpcode::kJSCreateLiteralObject:
     case IrOpcode::kJSCreateLiteralRegExp:
     case IrOpcode::kJSCreateObject:
@@ -90,7 +195,6 @@ bool OperatorProperties::HasFrameStateInput(const Operator* op) {
     case IrOpcode::kJSDeleteProperty:
 
     // Conversions
-    case IrOpcode::kJSToInteger:
     case IrOpcode::kJSToLength:
     case IrOpcode::kJSToName:
     case IrOpcode::kJSToNumber:
diff --git a/deps/v8/src/compiler/operator-properties.h b/deps/v8/src/compiler/operator-properties.h
index b4bb8b5e73..eb9e683f63 100644
--- a/deps/v8/src/compiler/operator-properties.h
+++ b/deps/v8/src/compiler/operator-properties.h
@@ -22,6 +22,8 @@ class V8_EXPORT_PRIVATE OperatorProperties final {
     return HasContextInput(op) ? 1 : 0;
   }
 
+  static bool NeedsExactContext(const Operator* op);
+
   static bool HasFrameStateInput(const Operator* op);
   static int GetFrameStateInputCount(const Operator* op) {
     return HasFrameStateInput(op) ? 1 : 0;
diff --git a/deps/v8/src/compiler/operator.h b/deps/v8/src/compiler/operator.h
index e436ec09f4..dc94e91190 100644
--- a/deps/v8/src/compiler/operator.h
+++ b/deps/v8/src/compiler/operator.h
@@ -65,7 +65,7 @@ class V8_EXPORT_PRIVATE Operator : public NON_EXPORTED_BASE(ZoneObject) {
            size_t value_in, size_t effect_in, size_t control_in,
            size_t value_out, size_t effect_out, size_t control_out);
 
-  virtual ~Operator() {}
+  virtual ~Operator() = default;
 
   // A small integer unique to all instances of a particular kind of operator,
   // useful for quick matching for specific kinds of operators. For fast access
@@ -197,7 +197,7 @@ class Operator1 : public Operator {
     os << "[" << parameter() << "]";
   }
 
-  virtual void PrintToImpl(std::ostream& os, PrintVerbosity verbose) const {
+  void PrintToImpl(std::ostream& os, PrintVerbosity verbose) const override {
     os << mnemonic();
     PrintParameter(os, verbose);
   }
diff --git a/deps/v8/src/compiler/per-isolate-compiler-cache.h b/deps/v8/src/compiler/per-isolate-compiler-cache.h
new file mode 100644
index 0000000000..70f53c38e1
--- /dev/null
+++ b/deps/v8/src/compiler/per-isolate-compiler-cache.h
@@ -0,0 +1,64 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_COMPILER_PER_ISOLATE_COMPILER_CACHE_H_
+#define V8_COMPILER_PER_ISOLATE_COMPILER_CACHE_H_
+
+#include "src/compiler/refs-map.h"
+#include "src/isolate.h"
+#include "src/zone/zone-containers.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+class Zone;
+
+namespace compiler {
+
+class ObjectData;
+
+// This class serves as a per-isolate container of data that should be
+// persisted between compiler runs. For now it stores the code builtins
+// so they are not serialized on each compiler run.
+class PerIsolateCompilerCache : public ZoneObject {
+ public:
+  explicit PerIsolateCompilerCache(Zone* zone)
+      : zone_(zone), refs_snapshot_(nullptr) {}
+
+  RefsMap* GetSnapshot() { return refs_snapshot_; }
+  void SetSnapshot(RefsMap* refs) {
+    DCHECK_NULL(refs_snapshot_);
+    DCHECK(!refs->IsEmpty());
+    refs_snapshot_ = new (zone_) RefsMap(refs, zone_);
+  }
+
+  bool HasSnapshot() const { return refs_snapshot_; }
+
+  Zone* zone() const { return zone_; }
+
+  static void Setup(Isolate* isolate) {
+    if (isolate->compiler_cache()) return;
+
+    // The following zone is supposed to contain compiler-related objects
+    // that should live through all compilations, as opposed to the
+    // broker_zone which holds per-compilation data. It's not meant for
+    // per-compilation or heap broker data.
+    Zone* compiler_zone = new Zone(isolate->allocator(), "Compiler zone");
+    PerIsolateCompilerCache* compiler_cache =
+        new (compiler_zone) PerIsolateCompilerCache(compiler_zone);
+    isolate->set_compiler_utils(compiler_cache, compiler_zone);
+  }
+
+ private:
+  Zone* const zone_;
+
+  RefsMap* refs_snapshot_;
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_PER_ISOLATE_COMPILER_CACHE_H_
diff --git a/deps/v8/src/compiler/pipeline.cc b/deps/v8/src/compiler/pipeline.cc
index 0cc3723594..c4169266e7 100644
--- a/deps/v8/src/compiler/pipeline.cc
+++ b/deps/v8/src/compiler/pipeline.cc
@@ -137,9 +137,9 @@ class PipelineData {
     javascript_ = new (graph_zone_) JSOperatorBuilder(graph_zone_);
     jsgraph_ = new (graph_zone_)
         JSGraph(isolate_, graph_, common_, javascript_, simplified_, machine_);
-    js_heap_broker_ = new (codegen_zone_) JSHeapBroker(isolate_, codegen_zone_);
+    js_heap_broker_ = new (info_->zone()) JSHeapBroker(isolate_, info_->zone());
     dependencies_ =
-        new (codegen_zone_) CompilationDependencies(isolate_, codegen_zone_);
+        new (info_->zone()) CompilationDependencies(isolate_, info_->zone());
   }
 
   // For WebAssembly compile entry point.
@@ -147,8 +147,7 @@ class PipelineData {
                OptimizedCompilationInfo* info, MachineGraph* mcgraph,
                PipelineStatistics* pipeline_statistics,
                SourcePositionTable* source_positions,
-               NodeOriginTable* node_origins,
-               int wasm_function_index,
+               NodeOriginTable* node_origins, int wasm_function_index,
                const AssemblerOptions& assembler_options)
       : isolate_(nullptr),
         wasm_engine_(wasm_engine),
@@ -156,6 +155,7 @@ class PipelineData {
         info_(info),
         debug_name_(info_->GetDebugName()),
         wasm_function_index_(wasm_function_index),
+        may_have_unverifiable_graph_(false),
         zone_stats_(zone_stats),
         pipeline_statistics_(pipeline_statistics),
         graph_zone_scope_(zone_stats_, ZONE_NAME),
@@ -218,8 +218,11 @@ class PipelineData {
         assembler_options_(AssemblerOptions::Default(isolate)) {}
 
   ~PipelineData() {
-    delete code_generator_;  // Must happen before zones are destroyed.
+    // Must happen before zones are destroyed.
+    delete code_generator_;
     code_generator_ = nullptr;
+    DeleteTyper();
+
     DeleteRegisterAllocationZone();
     DeleteInstructionZone();
     DeleteCodegenZone();
@@ -310,6 +313,22 @@ class PipelineData {
                                    : wasm_engine_->GetCodeTracer();
   }
 
+  Typer* CreateTyper() {
+    DCHECK_NULL(typer_);
+    typer_ = new Typer(js_heap_broker(), typer_flags_, graph());
+    return typer_;
+  }
+
+  void AddTyperFlag(Typer::Flag flag) {
+    DCHECK_NULL(typer_);
+    typer_flags_ |= flag;
+  }
+
+  void DeleteTyper() {
+    delete typer_;
+    typer_ = nullptr;
+  }
+
   void DeleteGraphZone() {
     if (graph_zone_ == nullptr) return;
     graph_zone_scope_.Destroy();
@@ -433,6 +452,8 @@ class PipelineData {
   base::Optional<OsrHelper> osr_helper_;
   MaybeHandle<Code> code_;
   CodeGenerator* code_generator_ = nullptr;
+  Typer* typer_ = nullptr;
+  Typer::Flags typer_flags_ = Typer::kNoFlags;
 
   // All objects in the following group of fields are allocated in graph_zone_.
   // They are all set to nullptr when the graph_zone_ is destroyed.
@@ -658,12 +679,6 @@ void PrintCode(Isolate* isolate, Handle<Code> code,
 #endif  // ENABLE_DISASSEMBLER
 }
 
-struct TurboCfgFile : public std::ofstream {
-  explicit TurboCfgFile(Isolate* isolate)
-      : std::ofstream(isolate->GetTurboCfgFileName().c_str(),
-                      std::ios_base::app) {}
-};
-
 void TraceSchedule(OptimizedCompilationInfo* info, PipelineData* data,
                    Schedule* schedule, const char* phase_name) {
   if (info->trace_turbo_json_enabled()) {
@@ -692,7 +707,7 @@ class SourcePositionWrapper final : public Reducer {
  public:
   SourcePositionWrapper(Reducer* reducer, SourcePositionTable* table)
       : reducer_(reducer), table_(table) {}
-  ~SourcePositionWrapper() final {}
+  ~SourcePositionWrapper() final = default;
 
   const char* reducer_name() const override { return reducer_->reducer_name(); }
 
@@ -715,7 +730,7 @@ class NodeOriginsWrapper final : public Reducer {
  public:
   NodeOriginsWrapper(Reducer* reducer, NodeOriginTable* table)
       : reducer_(reducer), table_(table) {}
-  ~NodeOriginsWrapper() final {}
+  ~NodeOriginsWrapper() final = default;
 
   const char* reducer_name() const override { return reducer_->reducer_name(); }
 
@@ -896,12 +911,13 @@ PipelineCompilationJob::Status PipelineCompilationJob::PrepareJobImpl(
     compilation_info()->MarkAsAccessorInliningEnabled();
   }
 
-  // Compute and set poisoning level.
+  // This is the bottleneck for computing and setting poisoning level in the
+  // optimizing compiler.
   PoisoningMitigationLevel load_poisoning =
       PoisoningMitigationLevel::kDontPoison;
-  if (FLAG_branch_load_poisoning) {
-    load_poisoning = PoisoningMitigationLevel::kPoisonAll;
-  } else if (FLAG_untrusted_code_mitigations) {
+  if (FLAG_untrusted_code_mitigations) {
+    // For full mitigations, this can be changed to
+    // PoisoningMitigationLevel::kPoisonAll.
     load_poisoning = PoisoningMitigationLevel::kPoisonCriticalOnly;
   }
   compilation_info()->SetPoisoningMitigationLevel(load_poisoning);
@@ -1030,7 +1046,6 @@ class PipelineWasmCompilationJob final : public OptimizedCompilationJob {
 PipelineWasmCompilationJob::Status PipelineWasmCompilationJob::PrepareJobImpl(
     Isolate* isolate) {
   UNREACHABLE();  // Prepare should always be skipped for WasmCompilationJob.
-  return SUCCEEDED;
 }
 
 PipelineWasmCompilationJob::Status
@@ -1110,7 +1125,6 @@ PipelineWasmCompilationJob::ExecuteJobImpl() {
 PipelineWasmCompilationJob::Status PipelineWasmCompilationJob::FinalizeJobImpl(
     Isolate* isolate) {
   UNREACHABLE();  // Finalize should always be skipped for WasmCompilationJob.
-  return SUCCEEDED;
 }
 
 template <typename Phase>
@@ -1186,6 +1200,7 @@ struct InliningPhase {
 
   void Run(PipelineData* data, Zone* temp_zone) {
     Isolate* isolate = data->isolate();
+    OptimizedCompilationInfo* info = data->info();
     GraphReducer graph_reducer(temp_zone, data->graph(),
                                data->jsgraph()->Dead());
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
@@ -1214,9 +1229,12 @@ struct InliningPhase {
     if (data->info()->is_bailout_on_uninitialized()) {
       flags |= JSNativeContextSpecialization::kBailoutOnUninitialized;
     }
+    // Passing the OptimizedCompilationInfo's shared zone here as
+    // JSNativeContextSpecialization allocates out-of-heap objects
+    // that need to live until code generation.
     JSNativeContextSpecialization native_context_specialization(
         &graph_reducer, data->jsgraph(), data->js_heap_broker(), flags,
-        data->native_context(), data->dependencies(), temp_zone);
+        data->native_context(), data->dependencies(), temp_zone, info->zone());
     JSInliningHeuristic inlining(
         &graph_reducer, data->info()->is_inlining_enabled()
                             ? JSInliningHeuristic::kGeneralInlining
@@ -1242,6 +1260,11 @@ struct TyperPhase {
   void Run(PipelineData* data, Zone* temp_zone, Typer* typer) {
     NodeVector roots(temp_zone);
     data->jsgraph()->GetCachedNodes(&roots);
+
+    // Make sure we always type True and False. Needed for escape analysis.
+    roots.push_back(data->jsgraph()->TrueConstant());
+    roots.push_back(data->jsgraph()->FalseConstant());
+
     LoopVariableOptimizer induction_vars(data->jsgraph()->graph(),
                                          data->common(), temp_zone);
     if (FLAG_turbo_loop_variable) induction_vars.Run();
@@ -1279,10 +1302,16 @@ struct UntyperPhase {
   }
 };
 
-struct CopyMetadataForConcurrentCompilePhase {
-  static const char* phase_name() {
-    return "copy metadata for concurrent compile";
+struct SerializeStandardObjectsPhase {
+  static const char* phase_name() { return "serialize standard objects"; }
+
+  void Run(PipelineData* data, Zone* temp_zone) {
+    data->js_heap_broker()->SerializeStandardObjects();
   }
+};
+
+struct CopyMetadataForConcurrentCompilePhase {
+  static const char* phase_name() { return "serialize metadata"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     GraphReducer graph_reducer(temp_zone, data->graph(),
@@ -1290,7 +1319,11 @@ struct CopyMetadataForConcurrentCompilePhase {
     JSHeapCopyReducer heap_copy_reducer(data->js_heap_broker());
     AddReducer(data, &graph_reducer, &heap_copy_reducer);
     graph_reducer.ReduceGraph();
-    data->js_heap_broker()->StopSerializing();
+
+    // Some nodes that are no longer in the graph might still be in the cache.
+    NodeVector cached_nodes(temp_zone);
+    data->jsgraph()->GetCachedNodes(&cached_nodes);
+    for (Node* const node : cached_nodes) graph_reducer.ReduceNode(node);
   }
 };
 
@@ -1304,7 +1337,7 @@ struct TypedLoweringPhase {
                                               data->common(), temp_zone);
     JSCreateLowering create_lowering(&graph_reducer, data->dependencies(),
                                      data->jsgraph(), data->js_heap_broker(),
-                                     data->native_context(), temp_zone);
+                                     temp_zone);
     JSTypedLowering typed_lowering(&graph_reducer, data->jsgraph(),
                                    data->js_heap_broker(), temp_zone);
     ConstantFoldingReducer constant_folding_reducer(
@@ -1385,32 +1418,6 @@ struct LoopExitEliminationPhase {
   }
 };
 
-struct ConcurrentOptimizationPrepPhase {
-  static const char* phase_name() { return "concurrency preparation"; }
-
-  void Run(PipelineData* data, Zone* temp_zone) {
-    // Make sure we cache these code stubs.
-    data->jsgraph()->CEntryStubConstant(1);
-    data->jsgraph()->CEntryStubConstant(2);
-
-    // TODO(turbofan): Remove this line once the Array constructor code
-    // is a proper builtin and no longer a CodeStub.
-    data->jsgraph()->ArrayConstructorStubConstant();
-
-    // This is needed for escape analysis.
-    NodeProperties::SetType(
-        data->jsgraph()->FalseConstant(),
-        Type::HeapConstant(data->js_heap_broker(),
-                           data->isolate()->factory()->false_value(),
-                           data->jsgraph()->zone()));
-    NodeProperties::SetType(
-        data->jsgraph()->TrueConstant(),
-        Type::HeapConstant(data->js_heap_broker(),
-                           data->isolate()->factory()->true_value(),
-                           data->jsgraph()->zone()));
-  }
-};
-
 struct GenericLoweringPhase {
   static const char* phase_name() { return "generic lowering"; }
 
@@ -2009,39 +2016,36 @@ bool PipelineImpl::CreateGraph() {
   Run<EarlyGraphTrimmingPhase>();
   RunPrintAndVerify(EarlyGraphTrimmingPhase::phase_name(), true);
 
-  // Run the type-sensitive lowerings and optimizations on the graph.
+  // Determine the Typer operation flags.
   {
-    // Determine the Typer operation flags.
-    Typer::Flags flags = Typer::kNoFlags;
     if (is_sloppy(info()->shared_info()->language_mode()) &&
         info()->shared_info()->IsUserJavaScript()) {
       // Sloppy mode functions always have an Object for this.
-      flags |= Typer::kThisIsReceiver;
+      data->AddTyperFlag(Typer::kThisIsReceiver);
     }
     if (IsClassConstructor(info()->shared_info()->kind())) {
       // Class constructors cannot be [[Call]]ed.
-      flags |= Typer::kNewTargetIsReceiver;
+      data->AddTyperFlag(Typer::kNewTargetIsReceiver);
     }
+  }
 
-    // Type the graph and keep the Typer running on newly created nodes within
-    // this scope; the Typer is automatically unlinked from the Graph once we
-    // leave this scope below.
-    Typer typer(isolate(), data->js_heap_broker(), flags, data->graph());
-    Run<TyperPhase>(&typer);
-    RunPrintAndVerify(TyperPhase::phase_name());
-
-    // Do some hacky things to prepare for the optimization phase.
-    // (caching handles, etc.).
-    Run<ConcurrentOptimizationPrepPhase>();
-
+  // Run the type-sensitive lowerings and optimizations on the graph.
+  {
     if (FLAG_concurrent_compiler_frontend) {
-      data->js_heap_broker()->SerializeStandardObjects();
+      data->js_heap_broker()->StartSerializing();
+      Run<SerializeStandardObjectsPhase>();
       Run<CopyMetadataForConcurrentCompilePhase>();
+      data->js_heap_broker()->StopSerializing();
+    } else {
+      data->js_heap_broker()->SetNativeContextRef();
+      // Type the graph and keep the Typer running such that new nodes get
+      // automatically typed when they are created.
+      Run<TyperPhase>(data->CreateTyper());
+      RunPrintAndVerify(TyperPhase::phase_name());
+      Run<TypedLoweringPhase>();
+      RunPrintAndVerify(TypedLoweringPhase::phase_name());
+      data->DeleteTyper();
     }
-
-    // Lower JSOperators where we can determine types.
-    Run<TypedLoweringPhase>();
-    RunPrintAndVerify(TypedLoweringPhase::phase_name());
   }
 
   data->EndPhaseKind();
@@ -2054,6 +2058,16 @@ bool PipelineImpl::OptimizeGraph(Linkage* linkage) {
 
   data->BeginPhaseKind("lowering");
 
+  if (FLAG_concurrent_compiler_frontend) {
+    // Type the graph and keep the Typer running such that new nodes get
+    // automatically typed when they are created.
+    Run<TyperPhase>(data->CreateTyper());
+    RunPrintAndVerify(TyperPhase::phase_name());
+    Run<TypedLoweringPhase>();
+    RunPrintAndVerify(TypedLoweringPhase::phase_name());
+    data->DeleteTyper();
+  }
+
   if (data->info()->is_loop_peeling_enabled()) {
     Run<LoopPeelingPhase>();
     RunPrintAndVerify(LoopPeelingPhase::phase_name(), true);
@@ -2155,10 +2169,9 @@ MaybeHandle<Code> Pipeline::GenerateCodeForCodeStub(
 
   // Construct a pipeline for scheduling and code generation.
   ZoneStats zone_stats(isolate->allocator());
-  SourcePositionTable source_positions(graph);
   NodeOriginTable node_origins(graph);
-  PipelineData data(&zone_stats, &info, isolate, graph, schedule,
-                    &source_positions, &node_origins, jump_opt, options);
+  PipelineData data(&zone_stats, &info, isolate, graph, schedule, nullptr,
+                    &node_origins, jump_opt, options);
   data.set_verify_graph(FLAG_verify_csa);
   std::unique_ptr<PipelineStatistics> pipeline_statistics;
   if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
@@ -2193,6 +2206,49 @@ MaybeHandle<Code> Pipeline::GenerateCodeForCodeStub(
 }
 
 // static
+MaybeHandle<Code> Pipeline::GenerateCodeForWasmStub(
+    Isolate* isolate, CallDescriptor* call_descriptor, Graph* graph,
+    Code::Kind kind, const char* debug_name, const AssemblerOptions& options,
+    SourcePositionTable* source_positions) {
+  OptimizedCompilationInfo info(CStrVector(debug_name), graph->zone(), kind);
+  // Construct a pipeline for scheduling and code generation.
+  ZoneStats zone_stats(isolate->allocator());
+  NodeOriginTable* node_positions = new (graph->zone()) NodeOriginTable(graph);
+  PipelineData data(&zone_stats, &info, isolate, graph, nullptr,
+                    source_positions, node_positions, nullptr, options);
+  std::unique_ptr<PipelineStatistics> pipeline_statistics;
+  if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
+    pipeline_statistics.reset(new PipelineStatistics(
+        &info, isolate->GetTurboStatistics(), &zone_stats));
+    pipeline_statistics->BeginPhaseKind("wasm stub codegen");
+  }
+
+  PipelineImpl pipeline(&data);
+
+  if (info.trace_turbo_graph_enabled()) {  // Simple textual RPO.
+    StdoutStream{} << "-- wasm stub " << Code::Kind2String(kind) << " graph -- "
+                   << std::endl
+                   << AsRPO(*graph);
+  }
+
+  if (info.trace_turbo_json_enabled()) {
+    TurboJsonFile json_of(&info, std::ios_base::trunc);
+    json_of << "{\"function\":\"" << info.GetDebugName().get()
+            << "\", \"source\":\"\",\n\"phases\":[";
+  }
+  // TODO(rossberg): Should this really be untyped?
+  pipeline.RunPrintAndVerify("machine", true);
+  pipeline.ComputeScheduledGraph();
+
+  Handle<Code> code;
+  if (pipeline.GenerateCode(call_descriptor).ToHandle(&code) &&
+      pipeline.CommitDependencies(code)) {
+    return code;
+  }
+  return MaybeHandle<Code>();
+}
+
+// static
 MaybeHandle<Code> Pipeline::GenerateCodeForTesting(
     OptimizedCompilationInfo* info, Isolate* isolate) {
   ZoneStats zone_stats(isolate->allocator());
@@ -2220,17 +2276,12 @@ MaybeHandle<Code> Pipeline::GenerateCodeForTesting(
 MaybeHandle<Code> Pipeline::GenerateCodeForTesting(
     OptimizedCompilationInfo* info, Isolate* isolate,
     CallDescriptor* call_descriptor, Graph* graph,
-    const AssemblerOptions& options, Schedule* schedule,
-    SourcePositionTable* source_positions) {
+    const AssemblerOptions& options, Schedule* schedule) {
   // Construct a pipeline for scheduling and code generation.
   ZoneStats zone_stats(isolate->allocator());
-  // TODO(wasm): Refactor code generation to check for non-existing source
-  // table, then remove this conditional allocation.
-  if (!source_positions)
-    source_positions = new (info->zone()) SourcePositionTable(graph);
   NodeOriginTable* node_positions = new (info->zone()) NodeOriginTable(graph);
-  PipelineData data(&zone_stats, info, isolate, graph, schedule,
-                    source_positions, node_positions, nullptr, options);
+  PipelineData data(&zone_stats, info, isolate, graph, schedule, nullptr,
+                    node_positions, nullptr, options);
   std::unique_ptr<PipelineStatistics> pipeline_statistics;
   if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
     pipeline_statistics.reset(new PipelineStatistics(
@@ -2374,7 +2425,11 @@ bool PipelineImpl::SelectInstructions(Linkage* linkage) {
   if (info()->trace_turbo_json_enabled()) {
     std::ostringstream source_position_output;
     // Output source position information before the graph is deleted.
-    data_->source_positions()->PrintJson(source_position_output);
+    if (data_->source_positions() != nullptr) {
+      data_->source_positions()->PrintJson(source_position_output);
+    } else {
+      source_position_output << "{}";
+    }
     source_position_output << ",\n\"NodeOrigins\" : ";
     data_->node_origins()->PrintJson(source_position_output);
     data_->set_source_position_output(source_position_output.str());
@@ -2398,17 +2453,16 @@ bool PipelineImpl::SelectInstructions(Linkage* linkage) {
     AllocateRegisters(RegisterConfiguration::Poisoning(), call_descriptor,
                       run_verifier);
 #if defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
-  } else if (data_->assembler_options().isolate_independent_code) {
+  } else if (Builtins::IsBuiltinId(data->info()->builtin_index())) {
     // TODO(v8:6666): Extend support to user code. Ensure that
     // it is mutually exclusive with the Poisoning configuration above; and that
     // it cooperates with restricted allocatable registers above.
     static_assert(kRootRegister == kSpeculationPoisonRegister,
                   "The following checks assume root equals poison register");
-    CHECK_IMPLIES(FLAG_embedded_builtins, !FLAG_branch_load_poisoning);
     CHECK_IMPLIES(FLAG_embedded_builtins, !FLAG_untrusted_code_mitigations);
     AllocateRegisters(RegisterConfiguration::PreserveRootIA32(),
                       call_descriptor, run_verifier);
-#endif  // V8_TARGET_ARCH_IA32
+#endif  // defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
   } else {
     AllocateRegisters(RegisterConfiguration::Default(), call_descriptor,
                       run_verifier);
@@ -2512,6 +2566,9 @@ std::ostream& operator<<(std::ostream& out, const BlockStartsAsJSON& s) {
 
 MaybeHandle<Code> PipelineImpl::FinalizeCode() {
   PipelineData* data = this->data_;
+  if (data->js_heap_broker() && FLAG_concurrent_compiler_frontend) {
+    data->js_heap_broker()->Retire();
+  }
   Run<FinalizeCodePhase>();
 
   MaybeHandle<Code> maybe_code = data->code();
@@ -2578,6 +2635,29 @@ bool PipelineImpl::CommitDependencies(Handle<Code> code) {
          data_->dependencies()->Commit(code);
 }
 
+namespace {
+
+void TraceSequence(OptimizedCompilationInfo* info, PipelineData* data,
+                   const RegisterConfiguration* config,
+                   const char* phase_name) {
+  if (info->trace_turbo_json_enabled()) {
+    AllowHandleDereference allow_deref;
+    TurboJsonFile json_of(info, std::ios_base::app);
+    json_of << "{\"name\":\"" << phase_name << "\",\"type\":\"sequence\",";
+    json_of << InstructionSequenceAsJSON{config, data->sequence()};
+    json_of << "},\n";
+  }
+  if (info->trace_turbo_graph_enabled()) {
+    AllowHandleDereference allow_deref;
+    CodeTracer::Scope tracing_scope(data->GetCodeTracer());
+    OFStream os(tracing_scope.file());
+    os << "----- Instruction sequence " << phase_name << " -----\n"
+       << PrintableInstructionSequence({config, data->sequence()});
+  }
+}
+
+}  // namespace
+
 void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
                                      CallDescriptor* call_descriptor,
                                      bool run_verifier) {
@@ -2603,13 +2683,7 @@ void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
   Run<MeetRegisterConstraintsPhase>();
   Run<ResolvePhisPhase>();
   Run<BuildLiveRangesPhase>();
-  if (info()->trace_turbo_graph_enabled()) {
-    AllowHandleDereference allow_deref;
-    CodeTracer::Scope tracing_scope(data->GetCodeTracer());
-    OFStream os(tracing_scope.file());
-    os << "----- Instruction sequence before register allocation -----\n"
-       << PrintableInstructionSequence({config, data->sequence()});
-  }
+  TraceSequence(info(), data, config, "before register allocation");
   if (verifier != nullptr) {
     CHECK(!data->register_allocation_data()->ExistsUseWithoutDefinition());
     CHECK(data->register_allocation_data()
@@ -2621,7 +2695,10 @@ void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
   }
 
   Run<AllocateGeneralRegistersPhase<LinearScanAllocator>>();
-  Run<AllocateFPRegistersPhase<LinearScanAllocator>>();
+
+  if (data->sequence()->HasFPVirtualRegisters()) {
+    Run<AllocateFPRegistersPhase<LinearScanAllocator>>();
+  }
 
   if (FLAG_turbo_preprocess_ranges) {
     Run<MergeSplintersPhase>();
@@ -2647,13 +2724,7 @@ void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
 
   Run<LocateSpillSlotsPhase>();
 
-  if (info()->trace_turbo_graph_enabled()) {
-    AllowHandleDereference allow_deref;
-    CodeTracer::Scope tracing_scope(data->GetCodeTracer());
-    OFStream os(tracing_scope.file());
-    os << "----- Instruction sequence after register allocation -----\n"
-       << PrintableInstructionSequence({config, data->sequence()});
-  }
+  TraceSequence(info(), data, config, "after register allocation");
 
   if (verifier != nullptr) {
     verifier->VerifyAssignment("End of regalloc pipeline.");
diff --git a/deps/v8/src/compiler/pipeline.h b/deps/v8/src/compiler/pipeline.h
index 5e4ae8671b..a86efe840b 100644
--- a/deps/v8/src/compiler/pipeline.h
+++ b/deps/v8/src/compiler/pipeline.h
@@ -54,6 +54,13 @@ class Pipeline : public AllStatic {
       wasm::NativeModule* native_module, int function_index,
       wasm::ModuleOrigin wasm_origin);
 
+  // Run the pipeline on a machine graph and generate code.
+  static MaybeHandle<Code> GenerateCodeForWasmStub(
+      Isolate* isolate, CallDescriptor* call_descriptor, Graph* graph,
+      Code::Kind kind, const char* debug_name,
+      const AssemblerOptions& assembler_options,
+      SourcePositionTable* source_positions = nullptr);
+
   // Run the pipeline on a machine graph and generate code. The {schedule} must
   // be valid, hence the given {graph} does not need to be schedulable.
   static MaybeHandle<Code> GenerateCodeForCodeStub(
@@ -76,8 +83,7 @@ class Pipeline : public AllStatic {
   V8_EXPORT_PRIVATE static MaybeHandle<Code> GenerateCodeForTesting(
       OptimizedCompilationInfo* info, Isolate* isolate,
       CallDescriptor* call_descriptor, Graph* graph,
-      const AssemblerOptions& options, Schedule* schedule = nullptr,
-      SourcePositionTable* source_positions = nullptr);
+      const AssemblerOptions& options, Schedule* schedule = nullptr);
 
   // Run just the register allocator phases.
   V8_EXPORT_PRIVATE static bool AllocateRegistersForTesting(
diff --git a/deps/v8/src/compiler/ppc/code-generator-ppc.cc b/deps/v8/src/compiler/ppc/code-generator-ppc.cc
index 45cd95a9e0..fd2b2eefdb 100644
--- a/deps/v8/src/compiler/ppc/code-generator-ppc.cc
+++ b/deps/v8/src/compiler/ppc/code-generator-ppc.cc
@@ -74,6 +74,10 @@ class PPCOperandConverter final : public InstructionOperandConverter {
         return Operand(constant.ToInt64());
 #endif
       case Constant::kExternalReference:
+        return Operand(constant.ToExternalReference());
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kHeapObject:
       case Constant::kRpoNumber:
         break;
@@ -513,11 +517,11 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen, Instruction* instr,
     /* Min: The algorithm is: -((-L) + (-R)), which in case of L and R */ \
     /* being different registers is most efficiently expressed */         \
     /* as -((-L) - R). */                                                 \
-    __ fneg(left_reg, left_reg);                                          \
-    if (left_reg == right_reg) {                                          \
-      __ fadd(result_reg, left_reg, right_reg);                           \
+    __ fneg(kScratchDoubleReg, left_reg);                                 \
+    if (kScratchDoubleReg == right_reg) {                                 \
+      __ fadd(result_reg, kScratchDoubleReg, right_reg);                  \
     } else {                                                              \
-      __ fsub(result_reg, left_reg, right_reg);                           \
+      __ fsub(result_reg, kScratchDoubleReg, right_reg);                  \
     }                                                                     \
     __ fneg(result_reg, result_reg);                                      \
     __ b(&done);                                                          \
@@ -660,15 +664,15 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen, Instruction* instr,
     __ bne(&exchange, cr0);                                             \
   } while (0)
 
-#define ASSEMBLE_ATOMIC_BINOP(bin_inst, load_inst, store_inst)                 \
-  do {                                                                         \
-    MemOperand operand = MemOperand(i.InputRegister(0), i.InputRegister(1));   \
-    Label binop;                                                               \
-    __ bind(&binop);                                                           \
-    __ load_inst(i.OutputRegister(), operand);                                 \
-    __ bin_inst(i.InputRegister(2), i.OutputRegister(), i.InputRegister(2));   \
-    __ store_inst(i.InputRegister(2), operand);                                \
-    __ bne(&binop, cr0);                                                       \
+#define ASSEMBLE_ATOMIC_BINOP(bin_inst, load_inst, store_inst)               \
+  do {                                                                       \
+    MemOperand operand = MemOperand(i.InputRegister(0), i.InputRegister(1)); \
+    Label binop;                                                             \
+    __ bind(&binop);                                                         \
+    __ load_inst(i.OutputRegister(), operand);                               \
+    __ bin_inst(kScratchReg, i.OutputRegister(), i.InputRegister(2));        \
+    __ store_inst(kScratchReg, operand);                                     \
+    __ bne(&binop, cr0);                                                     \
   } while (false)
 
 #define ASSEMBLE_ATOMIC_BINOP_SIGN_EXT(bin_inst, load_inst,                    \
@@ -691,7 +695,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen, Instruction* instr,
     Label exit;                                                                \
     __ bind(&loop);                                                            \
     __ load_inst(i.OutputRegister(), operand);                                 \
-    __ cmp_inst(i.OutputRegister(), i.InputRegister(2));                       \
+    __ cmp_inst(i.OutputRegister(), i.InputRegister(2), cr0);                  \
     __ bne(&exit, cr0);                                                        \
     __ store_inst(i.InputRegister(3), operand);                                \
     __ bne(&loop, cr0);                                                        \
@@ -1975,32 +1979,45 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ASSEMBLE_ATOMIC_LOAD_INTEGER(lbz, lbzx);
       __ extsb(i.OutputRegister(), i.OutputRegister());
       break;
+    case kPPC_Word64AtomicLoadUint8:
     case kWord32AtomicLoadUint8:
       ASSEMBLE_ATOMIC_LOAD_INTEGER(lbz, lbzx);
       break;
     case kWord32AtomicLoadInt16:
       ASSEMBLE_ATOMIC_LOAD_INTEGER(lha, lhax);
       break;
+    case kPPC_Word64AtomicLoadUint16:
     case kWord32AtomicLoadUint16:
       ASSEMBLE_ATOMIC_LOAD_INTEGER(lhz, lhzx);
       break;
+    case kPPC_Word64AtomicLoadUint32:
     case kWord32AtomicLoadWord32:
       ASSEMBLE_ATOMIC_LOAD_INTEGER(lwz, lwzx);
       break;
+    case kPPC_Word64AtomicLoadUint64:
+      ASSEMBLE_ATOMIC_LOAD_INTEGER(ld, ldx);
+      break;
 
+    case kPPC_Word64AtomicStoreUint8:
     case kWord32AtomicStoreWord8:
       ASSEMBLE_ATOMIC_STORE_INTEGER(stb, stbx);
       break;
+    case kPPC_Word64AtomicStoreUint16:
     case kWord32AtomicStoreWord16:
       ASSEMBLE_ATOMIC_STORE_INTEGER(sth, sthx);
       break;
+    case kPPC_Word64AtomicStoreUint32:
     case kWord32AtomicStoreWord32:
       ASSEMBLE_ATOMIC_STORE_INTEGER(stw, stwx);
       break;
+    case kPPC_Word64AtomicStoreUint64:
+      ASSEMBLE_ATOMIC_STORE_INTEGER(std, stdx);
+      break;
     case kWord32AtomicExchangeInt8:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lbarx, stbcx);
       __ extsb(i.OutputRegister(0), i.OutputRegister(0));
       break;
+    case kPPC_Word64AtomicExchangeUint8:
     case kWord32AtomicExchangeUint8:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lbarx, stbcx);
       break;
@@ -2008,44 +2025,57 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lharx, sthcx);
       __ extsh(i.OutputRegister(0), i.OutputRegister(0));
       break;
+    case kPPC_Word64AtomicExchangeUint16:
     case kWord32AtomicExchangeUint16:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lharx, sthcx);
       break;
+    case kPPC_Word64AtomicExchangeUint32:
     case kWord32AtomicExchangeWord32:
       ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(lwarx, stwcx);
       break;
-
+    case kPPC_Word64AtomicExchangeUint64:
+      ASSEMBLE_ATOMIC_EXCHANGE_INTEGER(ldarx, stdcx);
+      break;
     case kWord32AtomicCompareExchangeInt8:
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_SIGN_EXT(cmp, lbarx, stbcx, extsb);
       break;
+    case kPPC_Word64AtomicCompareExchangeUint8:
     case kWord32AtomicCompareExchangeUint8:
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE(cmp, lbarx, stbcx);
       break;
     case kWord32AtomicCompareExchangeInt16:
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE_SIGN_EXT(cmp, lharx, sthcx, extsh);
       break;
+    case kPPC_Word64AtomicCompareExchangeUint16:
     case kWord32AtomicCompareExchangeUint16:
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE(cmp, lharx, sthcx);
       break;
+    case kPPC_Word64AtomicCompareExchangeUint32:
     case kWord32AtomicCompareExchangeWord32:
       ASSEMBLE_ATOMIC_COMPARE_EXCHANGE(cmpw, lwarx, stwcx);
       break;
-
-#define ATOMIC_BINOP_CASE(op, inst)                             \
-  case kWord32Atomic##op##Int8:                                 \
-    ASSEMBLE_ATOMIC_BINOP_SIGN_EXT(inst, lbarx, stbcx, extsb);  \
-    break;                                                      \
-  case kWord32Atomic##op##Uint8:                                \
-    ASSEMBLE_ATOMIC_BINOP(inst, lbarx, stbcx);                  \
-    break;                                                      \
-  case kWord32Atomic##op##Int16:                                \
-    ASSEMBLE_ATOMIC_BINOP_SIGN_EXT(inst, lharx, sthcx, extsh);  \
-    break;                                                      \
-  case kWord32Atomic##op##Uint16:                               \
-    ASSEMBLE_ATOMIC_BINOP(inst, lharx, sthcx);                  \
-    break;                                                      \
-  case kWord32Atomic##op##Word32:                               \
-    ASSEMBLE_ATOMIC_BINOP(inst, lwarx, stwcx);                  \
+    case kPPC_Word64AtomicCompareExchangeUint64:
+      ASSEMBLE_ATOMIC_COMPARE_EXCHANGE(cmp, ldarx, stdcx);
+      break;
+
+#define ATOMIC_BINOP_CASE(op, inst)                            \
+  case kWord32Atomic##op##Int8:                                \
+    ASSEMBLE_ATOMIC_BINOP_SIGN_EXT(inst, lbarx, stbcx, extsb); \
+    break;                                                     \
+  case kPPC_Word64Atomic##op##Uint8:                           \
+  case kWord32Atomic##op##Uint8:                               \
+    ASSEMBLE_ATOMIC_BINOP(inst, lbarx, stbcx);                 \
+    break;                                                     \
+  case kWord32Atomic##op##Int16:                               \
+    ASSEMBLE_ATOMIC_BINOP_SIGN_EXT(inst, lharx, sthcx, extsh); \
+    break;                                                     \
+  case kPPC_Word64Atomic##op##Uint16:                          \
+  case kWord32Atomic##op##Uint16:                              \
+    ASSEMBLE_ATOMIC_BINOP(inst, lharx, sthcx);                 \
+    break;                                                     \
+  case kPPC_Word64Atomic##op##Uint32:                          \
+  case kWord32Atomic##op##Word32:                              \
+    ASSEMBLE_ATOMIC_BINOP(inst, lwarx, stwcx);                 \
     break;
       ATOMIC_BINOP_CASE(Add, add)
       ATOMIC_BINOP_CASE(Sub, sub)
@@ -2054,6 +2084,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ATOMIC_BINOP_CASE(Xor, xor_)
 #undef ATOMIC_BINOP_CASE
 
+#define ATOMIC64_BINOP_CASE(op, inst)          \
+  case kPPC_Word64Atomic##op##Uint64:          \
+    ASSEMBLE_ATOMIC_BINOP(inst, ldarx, stdcx); \
+    break;
+      ATOMIC64_BINOP_CASE(Add, add)
+      ATOMIC64_BINOP_CASE(Sub, sub)
+      ATOMIC64_BINOP_CASE(And, and_)
+      ATOMIC64_BINOP_CASE(Or, orx)
+      ATOMIC64_BINOP_CASE(Xor, xor_)
+#undef ATOMIC64_BINOP_CASE
+
     case kPPC_ByteRev32: {
       Register input = i.InputRegister(0);
       Register output = i.OutputRegister();
@@ -2118,7 +2159,8 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
 void CodeGenerator::AssembleBranchPoisoning(FlagsCondition condition,
                                             Instruction* instr) {
   // TODO(John) Handle float comparisons (kUnordered[Not]Equal).
-  if (condition == kUnorderedEqual || condition == kUnorderedNotEqual) {
+  if (condition == kUnorderedEqual || condition == kUnorderedNotEqual ||
+      condition == kOverflow || condition == kNotOverflow) {
     return;
   }
 
@@ -2564,9 +2606,13 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ Move(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ mov(dst, Operand::EmbeddedStringConstant(
+                          src.ToDelayedStringConstant()));
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
-          Heap::RootListIndex index;
+          RootIndex index;
           if (IsMaterializableFromRoot(src_object, &index)) {
             __ LoadRoot(dst, index);
           } else {
diff --git a/deps/v8/src/compiler/ppc/instruction-codes-ppc.h b/deps/v8/src/compiler/ppc/instruction-codes-ppc.h
index 3f3270028c..e189a18543 100644
--- a/deps/v8/src/compiler/ppc/instruction-codes-ppc.h
+++ b/deps/v8/src/compiler/ppc/instruction-codes-ppc.h
@@ -11,122 +11,158 @@ namespace compiler {
 
 // PPC-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
-#define TARGET_ARCH_OPCODE_LIST(V) \
-  V(PPC_And)                       \
-  V(PPC_AndComplement)             \
-  V(PPC_Or)                        \
-  V(PPC_OrComplement)              \
-  V(PPC_Xor)                       \
-  V(PPC_ShiftLeft32)               \
-  V(PPC_ShiftLeft64)               \
-  V(PPC_ShiftLeftPair)             \
-  V(PPC_ShiftRight32)              \
-  V(PPC_ShiftRight64)              \
-  V(PPC_ShiftRightPair)            \
-  V(PPC_ShiftRightAlg32)           \
-  V(PPC_ShiftRightAlg64)           \
-  V(PPC_ShiftRightAlgPair)         \
-  V(PPC_RotRight32)                \
-  V(PPC_RotRight64)                \
-  V(PPC_Not)                       \
-  V(PPC_RotLeftAndMask32)          \
-  V(PPC_RotLeftAndClear64)         \
-  V(PPC_RotLeftAndClearLeft64)     \
-  V(PPC_RotLeftAndClearRight64)    \
-  V(PPC_Add32)                     \
-  V(PPC_Add64)                     \
-  V(PPC_AddWithOverflow32)         \
-  V(PPC_AddPair)                   \
-  V(PPC_AddDouble)                 \
-  V(PPC_Sub)                       \
-  V(PPC_SubWithOverflow32)         \
-  V(PPC_SubPair)                   \
-  V(PPC_SubDouble)                 \
-  V(PPC_Mul32)                     \
-  V(PPC_Mul32WithHigh32)           \
-  V(PPC_Mul64)                     \
-  V(PPC_MulHigh32)                 \
-  V(PPC_MulHighU32)                \
-  V(PPC_MulPair)                   \
-  V(PPC_MulDouble)                 \
-  V(PPC_Div32)                     \
-  V(PPC_Div64)                     \
-  V(PPC_DivU32)                    \
-  V(PPC_DivU64)                    \
-  V(PPC_DivDouble)                 \
-  V(PPC_Mod32)                     \
-  V(PPC_Mod64)                     \
-  V(PPC_ModU32)                    \
-  V(PPC_ModU64)                    \
-  V(PPC_ModDouble)                 \
-  V(PPC_Neg)                       \
-  V(PPC_NegDouble)                 \
-  V(PPC_SqrtDouble)                \
-  V(PPC_FloorDouble)               \
-  V(PPC_CeilDouble)                \
-  V(PPC_TruncateDouble)            \
-  V(PPC_RoundDouble)               \
-  V(PPC_MaxDouble)                 \
-  V(PPC_MinDouble)                 \
-  V(PPC_AbsDouble)                 \
-  V(PPC_Cntlz32)                   \
-  V(PPC_Cntlz64)                   \
-  V(PPC_Popcnt32)                  \
-  V(PPC_Popcnt64)                  \
-  V(PPC_Cmp32)                     \
-  V(PPC_Cmp64)                     \
-  V(PPC_CmpDouble)                 \
-  V(PPC_Tst32)                     \
-  V(PPC_Tst64)                     \
-  V(PPC_Push)                      \
-  V(PPC_PushFrame)                 \
-  V(PPC_StoreToStackSlot)          \
-  V(PPC_ExtendSignWord8)           \
-  V(PPC_ExtendSignWord16)          \
-  V(PPC_ExtendSignWord32)          \
-  V(PPC_Uint32ToUint64)            \
-  V(PPC_Int64ToInt32)              \
-  V(PPC_Int64ToFloat32)            \
-  V(PPC_Int64ToDouble)             \
-  V(PPC_Uint64ToFloat32)           \
-  V(PPC_Uint64ToDouble)            \
-  V(PPC_Int32ToFloat32)            \
-  V(PPC_Int32ToDouble)             \
-  V(PPC_Uint32ToFloat32)           \
-  V(PPC_Uint32ToDouble)            \
-  V(PPC_Float32ToDouble)           \
-  V(PPC_Float64SilenceNaN)         \
-  V(PPC_DoubleToInt32)             \
-  V(PPC_DoubleToUint32)            \
-  V(PPC_DoubleToInt64)             \
-  V(PPC_DoubleToUint64)            \
-  V(PPC_DoubleToFloat32)           \
-  V(PPC_DoubleExtractLowWord32)    \
-  V(PPC_DoubleExtractHighWord32)   \
-  V(PPC_DoubleInsertLowWord32)     \
-  V(PPC_DoubleInsertHighWord32)    \
-  V(PPC_DoubleConstruct)           \
-  V(PPC_BitcastInt32ToFloat32)     \
-  V(PPC_BitcastFloat32ToInt32)     \
-  V(PPC_BitcastInt64ToDouble)      \
-  V(PPC_BitcastDoubleToInt64)      \
-  V(PPC_LoadWordS8)                \
-  V(PPC_LoadWordU8)                \
-  V(PPC_LoadWordS16)               \
-  V(PPC_LoadWordU16)               \
-  V(PPC_LoadWordS32)               \
-  V(PPC_LoadWordU32)               \
-  V(PPC_LoadWord64)                \
-  V(PPC_LoadFloat32)               \
-  V(PPC_LoadDouble)                \
-  V(PPC_StoreWord8)                \
-  V(PPC_StoreWord16)               \
-  V(PPC_StoreWord32)               \
-  V(PPC_StoreWord64)               \
-  V(PPC_StoreFloat32)              \
-  V(PPC_StoreDouble)               \
-  V(PPC_ByteRev32)                 \
-  V(PPC_ByteRev64)
+#define TARGET_ARCH_OPCODE_LIST(V)         \
+  V(PPC_And)                               \
+  V(PPC_AndComplement)                     \
+  V(PPC_Or)                                \
+  V(PPC_OrComplement)                      \
+  V(PPC_Xor)                               \
+  V(PPC_ShiftLeft32)                       \
+  V(PPC_ShiftLeft64)                       \
+  V(PPC_ShiftLeftPair)                     \
+  V(PPC_ShiftRight32)                      \
+  V(PPC_ShiftRight64)                      \
+  V(PPC_ShiftRightPair)                    \
+  V(PPC_ShiftRightAlg32)                   \
+  V(PPC_ShiftRightAlg64)                   \
+  V(PPC_ShiftRightAlgPair)                 \
+  V(PPC_RotRight32)                        \
+  V(PPC_RotRight64)                        \
+  V(PPC_Not)                               \
+  V(PPC_RotLeftAndMask32)                  \
+  V(PPC_RotLeftAndClear64)                 \
+  V(PPC_RotLeftAndClearLeft64)             \
+  V(PPC_RotLeftAndClearRight64)            \
+  V(PPC_Add32)                             \
+  V(PPC_Add64)                             \
+  V(PPC_AddWithOverflow32)                 \
+  V(PPC_AddPair)                           \
+  V(PPC_AddDouble)                         \
+  V(PPC_Sub)                               \
+  V(PPC_SubWithOverflow32)                 \
+  V(PPC_SubPair)                           \
+  V(PPC_SubDouble)                         \
+  V(PPC_Mul32)                             \
+  V(PPC_Mul32WithHigh32)                   \
+  V(PPC_Mul64)                             \
+  V(PPC_MulHigh32)                         \
+  V(PPC_MulHighU32)                        \
+  V(PPC_MulPair)                           \
+  V(PPC_MulDouble)                         \
+  V(PPC_Div32)                             \
+  V(PPC_Div64)                             \
+  V(PPC_DivU32)                            \
+  V(PPC_DivU64)                            \
+  V(PPC_DivDouble)                         \
+  V(PPC_Mod32)                             \
+  V(PPC_Mod64)                             \
+  V(PPC_ModU32)                            \
+  V(PPC_ModU64)                            \
+  V(PPC_ModDouble)                         \
+  V(PPC_Neg)                               \
+  V(PPC_NegDouble)                         \
+  V(PPC_SqrtDouble)                        \
+  V(PPC_FloorDouble)                       \
+  V(PPC_CeilDouble)                        \
+  V(PPC_TruncateDouble)                    \
+  V(PPC_RoundDouble)                       \
+  V(PPC_MaxDouble)                         \
+  V(PPC_MinDouble)                         \
+  V(PPC_AbsDouble)                         \
+  V(PPC_Cntlz32)                           \
+  V(PPC_Cntlz64)                           \
+  V(PPC_Popcnt32)                          \
+  V(PPC_Popcnt64)                          \
+  V(PPC_Cmp32)                             \
+  V(PPC_Cmp64)                             \
+  V(PPC_CmpDouble)                         \
+  V(PPC_Tst32)                             \
+  V(PPC_Tst64)                             \
+  V(PPC_Push)                              \
+  V(PPC_PushFrame)                         \
+  V(PPC_StoreToStackSlot)                  \
+  V(PPC_ExtendSignWord8)                   \
+  V(PPC_ExtendSignWord16)                  \
+  V(PPC_ExtendSignWord32)                  \
+  V(PPC_Uint32ToUint64)                    \
+  V(PPC_Int64ToInt32)                      \
+  V(PPC_Int64ToFloat32)                    \
+  V(PPC_Int64ToDouble)                     \
+  V(PPC_Uint64ToFloat32)                   \
+  V(PPC_Uint64ToDouble)                    \
+  V(PPC_Int32ToFloat32)                    \
+  V(PPC_Int32ToDouble)                     \
+  V(PPC_Uint32ToFloat32)                   \
+  V(PPC_Uint32ToDouble)                    \
+  V(PPC_Float32ToDouble)                   \
+  V(PPC_Float64SilenceNaN)                 \
+  V(PPC_DoubleToInt32)                     \
+  V(PPC_DoubleToUint32)                    \
+  V(PPC_DoubleToInt64)                     \
+  V(PPC_DoubleToUint64)                    \
+  V(PPC_DoubleToFloat32)                   \
+  V(PPC_DoubleExtractLowWord32)            \
+  V(PPC_DoubleExtractHighWord32)           \
+  V(PPC_DoubleInsertLowWord32)             \
+  V(PPC_DoubleInsertHighWord32)            \
+  V(PPC_DoubleConstruct)                   \
+  V(PPC_BitcastInt32ToFloat32)             \
+  V(PPC_BitcastFloat32ToInt32)             \
+  V(PPC_BitcastInt64ToDouble)              \
+  V(PPC_BitcastDoubleToInt64)              \
+  V(PPC_LoadWordS8)                        \
+  V(PPC_LoadWordU8)                        \
+  V(PPC_LoadWordS16)                       \
+  V(PPC_LoadWordU16)                       \
+  V(PPC_LoadWordS32)                       \
+  V(PPC_LoadWordU32)                       \
+  V(PPC_LoadWord64)                        \
+  V(PPC_LoadFloat32)                       \
+  V(PPC_LoadDouble)                        \
+  V(PPC_StoreWord8)                        \
+  V(PPC_StoreWord16)                       \
+  V(PPC_StoreWord32)                       \
+  V(PPC_StoreWord64)                       \
+  V(PPC_StoreFloat32)                      \
+  V(PPC_StoreDouble)                       \
+  V(PPC_ByteRev32)                         \
+  V(PPC_ByteRev64)                         \
+  V(PPC_Word64AtomicStoreUint8)            \
+  V(PPC_Word64AtomicStoreUint16)           \
+  V(PPC_Word64AtomicStoreUint32)           \
+  V(PPC_Word64AtomicStoreUint64)           \
+  V(PPC_Word64AtomicLoadUint8)             \
+  V(PPC_Word64AtomicLoadUint16)            \
+  V(PPC_Word64AtomicLoadUint32)            \
+  V(PPC_Word64AtomicLoadUint64)            \
+  V(PPC_Word64AtomicExchangeUint8)         \
+  V(PPC_Word64AtomicExchangeUint16)        \
+  V(PPC_Word64AtomicExchangeUint32)        \
+  V(PPC_Word64AtomicExchangeUint64)        \
+  V(PPC_Word64AtomicCompareExchangeUint8)  \
+  V(PPC_Word64AtomicCompareExchangeUint16) \
+  V(PPC_Word64AtomicCompareExchangeUint32) \
+  V(PPC_Word64AtomicCompareExchangeUint64) \
+  V(PPC_Word64AtomicAddUint8)              \
+  V(PPC_Word64AtomicAddUint16)             \
+  V(PPC_Word64AtomicAddUint32)             \
+  V(PPC_Word64AtomicAddUint64)             \
+  V(PPC_Word64AtomicSubUint8)              \
+  V(PPC_Word64AtomicSubUint16)             \
+  V(PPC_Word64AtomicSubUint32)             \
+  V(PPC_Word64AtomicSubUint64)             \
+  V(PPC_Word64AtomicAndUint8)              \
+  V(PPC_Word64AtomicAndUint16)             \
+  V(PPC_Word64AtomicAndUint32)             \
+  V(PPC_Word64AtomicAndUint64)             \
+  V(PPC_Word64AtomicOrUint8)               \
+  V(PPC_Word64AtomicOrUint16)              \
+  V(PPC_Word64AtomicOrUint32)              \
+  V(PPC_Word64AtomicOrUint64)              \
+  V(PPC_Word64AtomicXorUint8)              \
+  V(PPC_Word64AtomicXorUint16)             \
+  V(PPC_Word64AtomicXorUint32)             \
+  V(PPC_Word64AtomicXorUint64)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/ppc/instruction-scheduler-ppc.cc b/deps/v8/src/compiler/ppc/instruction-scheduler-ppc.cc
index 51c92e8e84..6e7284f30a 100644
--- a/deps/v8/src/compiler/ppc/instruction-scheduler-ppc.cc
+++ b/deps/v8/src/compiler/ppc/instruction-scheduler-ppc.cc
@@ -135,6 +135,46 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kPPC_StoreToStackSlot:
       return kHasSideEffect;
 
+    case kPPC_Word64AtomicLoadUint8:
+    case kPPC_Word64AtomicLoadUint16:
+    case kPPC_Word64AtomicLoadUint32:
+    case kPPC_Word64AtomicLoadUint64:
+      return kIsLoadOperation;
+
+    case kPPC_Word64AtomicStoreUint8:
+    case kPPC_Word64AtomicStoreUint16:
+    case kPPC_Word64AtomicStoreUint32:
+    case kPPC_Word64AtomicStoreUint64:
+    case kPPC_Word64AtomicExchangeUint8:
+    case kPPC_Word64AtomicExchangeUint16:
+    case kPPC_Word64AtomicExchangeUint32:
+    case kPPC_Word64AtomicExchangeUint64:
+    case kPPC_Word64AtomicCompareExchangeUint8:
+    case kPPC_Word64AtomicCompareExchangeUint16:
+    case kPPC_Word64AtomicCompareExchangeUint32:
+    case kPPC_Word64AtomicCompareExchangeUint64:
+    case kPPC_Word64AtomicAddUint8:
+    case kPPC_Word64AtomicAddUint16:
+    case kPPC_Word64AtomicAddUint32:
+    case kPPC_Word64AtomicAddUint64:
+    case kPPC_Word64AtomicSubUint8:
+    case kPPC_Word64AtomicSubUint16:
+    case kPPC_Word64AtomicSubUint32:
+    case kPPC_Word64AtomicSubUint64:
+    case kPPC_Word64AtomicAndUint8:
+    case kPPC_Word64AtomicAndUint16:
+    case kPPC_Word64AtomicAndUint32:
+    case kPPC_Word64AtomicAndUint64:
+    case kPPC_Word64AtomicOrUint8:
+    case kPPC_Word64AtomicOrUint16:
+    case kPPC_Word64AtomicOrUint32:
+    case kPPC_Word64AtomicOrUint64:
+    case kPPC_Word64AtomicXorUint8:
+    case kPPC_Word64AtomicXorUint16:
+    case kPPC_Word64AtomicXorUint32:
+    case kPPC_Word64AtomicXorUint64:
+      return kHasSideEffect;
+
 #define CASE(Name) case k##Name:
     COMMON_ARCH_OPCODE_LIST(CASE)
 #undef CASE
diff --git a/deps/v8/src/compiler/ppc/instruction-selector-ppc.cc b/deps/v8/src/compiler/ppc/instruction-selector-ppc.cc
index e29ae8c7a5..5d336652c9 100644
--- a/deps/v8/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/deps/v8/src/compiler/ppc/instruction-selector-ppc.cc
@@ -1188,6 +1188,10 @@ void InstructionSelector::VisitChangeUint32ToUint64(Node* node) {
 void InstructionSelector::VisitChangeFloat64ToUint64(Node* node) {
   VisitRR(this, kPPC_DoubleToUint64, node);
 }
+
+void InstructionSelector::VisitChangeFloat64ToInt64(Node* node) {
+  VisitRR(this, kPPC_DoubleToInt64, node);
+}
 #endif
 
 
@@ -1230,6 +1234,9 @@ void InstructionSelector::VisitRoundInt64ToFloat64(Node* node) {
   VisitRR(this, kPPC_Int64ToDouble, node);
 }
 
+void InstructionSelector::VisitChangeInt64ToFloat64(Node* node) {
+  VisitRR(this, kPPC_Int64ToDouble, node);
+}
 
 void InstructionSelector::VisitRoundUint64ToFloat32(Node* node) {
   VisitRR(this, kPPC_Uint64ToFloat32, node);
@@ -1859,6 +1866,7 @@ void InstructionSelector::EmitPrepareArguments(
     // Poke any stack arguments.
     int slot = kStackFrameExtraParamSlot;
     for (PushParameter input : (*arguments)) {
+      if (input.node == nullptr) continue;
       Emit(kPPC_StoreToStackSlot, g.NoOutput(), g.UseRegister(input.node),
            g.TempImmediate(slot));
       ++slot;
@@ -1949,6 +1957,33 @@ void InstructionSelector::VisitWord32AtomicLoad(Node* node) {
       g.DefineAsRegister(node), g.UseRegister(base), g.UseRegister(index));
 }
 
+void InstructionSelector::VisitWord64AtomicLoad(Node* node) {
+  LoadRepresentation load_rep = LoadRepresentationOf(node->op());
+  PPCOperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  ArchOpcode opcode = kArchNop;
+  switch (load_rep.representation()) {
+    case MachineRepresentation::kWord8:
+      opcode = kPPC_Word64AtomicLoadUint8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kPPC_Word64AtomicLoadUint16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kPPC_Word64AtomicLoadUint32;
+      break;
+    case MachineRepresentation::kWord64:
+      opcode = kPPC_Word64AtomicLoadUint64;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+  Emit(opcode | AddressingModeField::encode(kMode_MRR),
+       g.DefineAsRegister(node), g.UseRegister(base), g.UseRegister(index));
+}
+
 void InstructionSelector::VisitWord32AtomicStore(Node* node) {
   MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
   PPCOperandGenerator g(this);
@@ -1980,12 +2015,61 @@ void InstructionSelector::VisitWord32AtomicStore(Node* node) {
       0, nullptr, input_count, inputs);
 }
 
-void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
+void InstructionSelector::VisitWord64AtomicStore(Node* node) {
+  MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
   PPCOperandGenerator g(this);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
   Node* value = node->InputAt(2);
   ArchOpcode opcode = kArchNop;
+  switch (rep) {
+    case MachineRepresentation::kWord8:
+      opcode = kPPC_Word64AtomicStoreUint8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kPPC_Word64AtomicStoreUint16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kPPC_Word64AtomicStoreUint32;
+      break;
+    case MachineRepresentation::kWord64:
+      opcode = kPPC_Word64AtomicStoreUint64;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+
+  InstructionOperand inputs[4];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  Emit(opcode | AddressingModeField::encode(kMode_MRR), 0, nullptr, input_count,
+       inputs);
+}
+
+void VisitAtomicExchange(InstructionSelector* selector, Node* node,
+                         ArchOpcode opcode) {
+  PPCOperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
+  AddressingMode addressing_mode = kMode_MRR;
+  InstructionOperand inputs[3];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionOperand outputs[1];
+  outputs[0] = g.UseUniqueRegister(node);
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  selector->Emit(code, 1, outputs, input_count, inputs);
+}
+
+void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
+  ArchOpcode opcode = kArchNop;
   MachineType type = AtomicOpType(node->op());
   if (type == MachineType::Int8()) {
     opcode = kWord32AtomicExchangeInt8;
@@ -2001,26 +2085,53 @@ void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
     UNREACHABLE();
     return;
   }
+  VisitAtomicExchange(this, node, opcode);
+}
+
+void InstructionSelector::VisitWord64AtomicExchange(Node* node) {
+  ArchOpcode opcode = kArchNop;
+  MachineType type = AtomicOpType(node->op());
+  if (type == MachineType::Uint8()) {
+    opcode = kPPC_Word64AtomicExchangeUint8;
+  } else if (type == MachineType::Uint16()) {
+    opcode = kPPC_Word64AtomicExchangeUint16;
+  } else if (type == MachineType::Uint32()) {
+    opcode = kPPC_Word64AtomicExchangeUint32;
+  } else if (type == MachineType::Uint64()) {
+    opcode = kPPC_Word64AtomicExchangeUint64;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicExchange(this, node, opcode);
+}
+
+void VisitAtomicCompareExchange(InstructionSelector* selector, Node* node,
+                                ArchOpcode opcode) {
+  PPCOperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* old_value = node->InputAt(2);
+  Node* new_value = node->InputAt(3);
 
   AddressingMode addressing_mode = kMode_MRR;
-  InstructionOperand inputs[3];
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+
+  InstructionOperand inputs[4];
   size_t input_count = 0;
   inputs[input_count++] = g.UseUniqueRegister(base);
   inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(value);
+  inputs[input_count++] = g.UseUniqueRegister(old_value);
+  inputs[input_count++] = g.UseUniqueRegister(new_value);
+
   InstructionOperand outputs[1];
-  outputs[0] = g.UseUniqueRegister(node);
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, 1, outputs, input_count, inputs);
+  size_t output_count = 0;
+  outputs[output_count++] = g.DefineAsRegister(node);
+
+  selector->Emit(code, output_count, outputs, input_count, inputs);
 }
 
 void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
-  PPCOperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* old_value = node->InputAt(2);
-  Node* new_value = node->InputAt(3);
-
   MachineType type = AtomicOpType(node->op());
   ArchOpcode opcode = kArchNop;
   if (type == MachineType::Int8()) {
@@ -2037,31 +2148,53 @@ void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
     UNREACHABLE();
     return;
   }
+  VisitAtomicCompareExchange(this, node, opcode);
+}
+
+void InstructionSelector::VisitWord64AtomicCompareExchange(Node* node) {
+  MachineType type = AtomicOpType(node->op());
+  ArchOpcode opcode = kArchNop;
+  if (type == MachineType::Uint8()) {
+    opcode = kPPC_Word64AtomicCompareExchangeUint8;
+  } else if (type == MachineType::Uint16()) {
+    opcode = kPPC_Word64AtomicCompareExchangeUint16;
+  } else if (type == MachineType::Uint32()) {
+    opcode = kPPC_Word64AtomicCompareExchangeUint32;
+  } else if (type == MachineType::Uint64()) {
+    opcode = kPPC_Word64AtomicCompareExchangeUint64;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicCompareExchange(this, node, opcode);
+}
+
+void VisitAtomicBinaryOperation(InstructionSelector* selector, Node* node,
+                                ArchOpcode opcode) {
+  PPCOperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+
   AddressingMode addressing_mode = kMode_MRR;
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  InstructionOperand inputs[3];
 
-  InstructionOperand inputs[4];
   size_t input_count = 0;
   inputs[input_count++] = g.UseUniqueRegister(base);
   inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(old_value);
-  inputs[input_count++] = g.UseUniqueRegister(new_value);
+  inputs[input_count++] = g.UseUniqueRegister(value);
 
   InstructionOperand outputs[1];
   size_t output_count = 0;
   outputs[output_count++] = g.DefineAsRegister(node);
 
-  Emit(code, output_count, outputs, input_count, inputs);
+  selector->Emit(code, output_count, outputs, input_count, inputs);
 }
 
 void InstructionSelector::VisitWord32AtomicBinaryOperation(
     Node* node, ArchOpcode int8_op, ArchOpcode uint8_op, ArchOpcode int16_op,
     ArchOpcode uint16_op, ArchOpcode word32_op) {
-  PPCOperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
-
   MachineType type = AtomicOpType(node->op());
   ArchOpcode opcode = kArchNop;
 
@@ -2079,20 +2212,7 @@ void InstructionSelector::VisitWord32AtomicBinaryOperation(
     UNREACHABLE();
     return;
   }
-  AddressingMode addressing_mode = kMode_MRR;
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  InstructionOperand inputs[3];
-
-  size_t input_count = 0;
-  inputs[input_count++] = g.UseUniqueRegister(base);
-  inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(value);
-
-  InstructionOperand outputs[1];
-  size_t output_count = 0;
-  outputs[output_count++] = g.DefineAsRegister(node);
-
-  Emit(code, output_count, outputs, input_count, inputs);
+  VisitAtomicBinaryOperation(this, node, opcode);
 }
 
 #define VISIT_ATOMIC_BINOP(op)                                   \
@@ -2109,6 +2229,39 @@ VISIT_ATOMIC_BINOP(Or)
 VISIT_ATOMIC_BINOP(Xor)
 #undef VISIT_ATOMIC_BINOP
 
+void InstructionSelector::VisitWord64AtomicBinaryOperation(
+    Node* node, ArchOpcode uint8_op, ArchOpcode uint16_op, ArchOpcode uint32_op,
+    ArchOpcode uint64_op) {
+  MachineType type = AtomicOpType(node->op());
+  ArchOpcode opcode = kArchNop;
+
+  if (type == MachineType::Uint8()) {
+    opcode = uint8_op;
+  } else if (type == MachineType::Uint16()) {
+    opcode = uint16_op;
+  } else if (type == MachineType::Uint32()) {
+    opcode = uint32_op;
+  } else if (type == MachineType::Uint64()) {
+    opcode = uint64_op;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicBinaryOperation(this, node, opcode);
+}
+
+#define VISIT_ATOMIC64_BINOP(op)                                           \
+  void InstructionSelector::VisitWord64Atomic##op(Node* node) {            \
+    VisitWord64AtomicBinaryOperation(                                      \
+        node, kPPC_Word64Atomic##op##Uint8, kPPC_Word64Atomic##op##Uint16, \
+        kPPC_Word64Atomic##op##Uint32, kPPC_Word64Atomic##op##Uint64);     \
+  }
+VISIT_ATOMIC64_BINOP(Add)
+VISIT_ATOMIC64_BINOP(Sub)
+VISIT_ATOMIC64_BINOP(And)
+VISIT_ATOMIC64_BINOP(Or)
+VISIT_ATOMIC64_BINOP(Xor)
+#undef VISIT_ATOMIC64_BINOP
 
 void InstructionSelector::VisitInt32AbsWithOverflow(Node* node) {
   UNREACHABLE();
@@ -2318,6 +2471,82 @@ void InstructionSelector::VisitF32x4AddHoriz(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI32x4AddHoriz(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI16x8AddHoriz(Node* node) { UNIMPLEMENTED(); }
 
+void InstructionSelector::VisitF32x4SConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitF32x4UConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4SConvertF32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4UConvertF32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4SConvertI16x8Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4SConvertI16x8High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4UConvertI16x8Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4UConvertI16x8High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8SConvertI8x16Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8SConvertI8x16High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8UConvertI8x16Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8UConvertI8x16High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8SConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+void InstructionSelector::VisitI16x8UConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI8x16SConvertI16x8(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI8x16UConvertI16x8(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
+void InstructionSelector::VisitS1x4AnyTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x4AllTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x8AnyTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x8AllTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x16AnyTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x16AllTrue(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/deps/v8/src/compiler/property-access-builder.cc b/deps/v8/src/compiler/property-access-builder.cc
index 42b28cfa76..31950f32f2 100644
--- a/deps/v8/src/compiler/property-access-builder.cc
+++ b/deps/v8/src/compiler/property-access-builder.cc
@@ -89,6 +89,7 @@ bool NeedsCheckHeapObject(Node* receiver) {
     case IrOpcode::kJSCreateIterResultObject:
     case IrOpcode::kJSCreateLiteralArray:
     case IrOpcode::kJSCreateEmptyLiteralArray:
+    case IrOpcode::kJSCreateArrayFromIterable:
     case IrOpcode::kJSCreateLiteralObject:
     case IrOpcode::kJSCreateEmptyLiteralObject:
     case IrOpcode::kJSCreateLiteralRegExp:
@@ -208,6 +209,7 @@ Node* PropertyAccessBuilder::TryBuildLoadConstantDataField(
           DCHECK(!it.is_dictionary_holder());
           MapRef map(js_heap_broker(),
                      handle(it.GetHolder<HeapObject>()->map(), isolate()));
+          map.SerializeOwnDescriptors();  // TODO(neis): Remove later.
           dependencies()->DependOnFieldType(map, it.GetFieldDescriptorIndex());
         }
         return value;
@@ -244,7 +246,8 @@ Node* PropertyAccessBuilder::BuildLoadDataField(
       MaybeHandle<Map>(),
       field_type,
       MachineType::TypeForRepresentation(field_representation),
-      kFullWriteBarrier};
+      kFullWriteBarrier,
+      LoadSensitivity::kCritical};
   if (field_representation == MachineRepresentation::kFloat64) {
     if (!field_index.is_inobject() || field_index.is_hidden_field() ||
         !FLAG_unbox_double_fields) {
@@ -254,7 +257,8 @@ Node* PropertyAccessBuilder::BuildLoadDataField(
                                           MaybeHandle<Map>(),
                                           Type::OtherInternal(),
                                           MachineType::TaggedPointer(),
-                                          kPointerWriteBarrier};
+                                          kPointerWriteBarrier,
+                                          LoadSensitivity::kCritical};
       storage = *effect = graph()->NewNode(
           simplified()->LoadField(storage_access), storage, *effect, *control);
       field_access.offset = HeapNumber::kValueOffset;
diff --git a/deps/v8/src/compiler/raw-machine-assembler.h b/deps/v8/src/compiler/raw-machine-assembler.h
index 304d0e4ff1..9b4806a3a6 100644
--- a/deps/v8/src/compiler/raw-machine-assembler.h
+++ b/deps/v8/src/compiler/raw-machine-assembler.h
@@ -47,7 +47,7 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
               FullUnalignedAccessSupport(),
       PoisoningMitigationLevel poisoning_level =
           PoisoningMitigationLevel::kPoisonCriticalOnly);
-  ~RawMachineAssembler() {}
+  ~RawMachineAssembler() = default;
 
   Isolate* isolate() const { return isolate_; }
   Graph* graph() const { return graph_; }
@@ -173,15 +173,51 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
 
   // Atomic memory operations.
   Node* AtomicLoad(MachineType type, Node* base, Node* index) {
+    if (type.representation() == MachineRepresentation::kWord64) {
+      if (machine()->Is64()) {
+        return AddNode(machine()->Word64AtomicLoad(type), base, index);
+      } else {
+        return AddNode(machine()->Word32AtomicPairLoad(), base, index);
+      }
+    }
     return AddNode(machine()->Word32AtomicLoad(type), base, index);
   }
+
+#if defined(V8_TARGET_BIG_ENDIAN)
+#define VALUE_HALVES value_high, value
+#else
+#define VALUE_HALVES value, value_high
+#endif
+
   Node* AtomicStore(MachineRepresentation rep, Node* base, Node* index,
-                    Node* value) {
+                    Node* value, Node* value_high) {
+    if (rep == MachineRepresentation::kWord64) {
+      if (machine()->Is64()) {
+        DCHECK_NULL(value_high);
+        return AddNode(machine()->Word64AtomicStore(rep), base, index, value);
+      } else {
+        return AddNode(machine()->Word32AtomicPairStore(), base, index,
+                       VALUE_HALVES);
+      }
+    }
+    DCHECK_NULL(value_high);
     return AddNode(machine()->Word32AtomicStore(rep), base, index, value);
   }
-#define ATOMIC_FUNCTION(name)                                                 \
-  Node* Atomic##name(MachineType rep, Node* base, Node* index, Node* value) { \
-    return AddNode(machine()->Word32Atomic##name(rep), base, index, value);   \
+#define ATOMIC_FUNCTION(name)                                               \
+  Node* Atomic##name(MachineType rep, Node* base, Node* index, Node* value, \
+                     Node* value_high) {                                    \
+    if (rep.representation() == MachineRepresentation::kWord64) {           \
+      if (machine()->Is64()) {                                              \
+        DCHECK_NULL(value_high);                                            \
+        return AddNode(machine()->Word64Atomic##name(rep), base, index,     \
+                       value);                                              \
+      } else {                                                              \
+        return AddNode(machine()->Word32AtomicPair##name(), base, index,    \
+                       VALUE_HALVES);                                       \
+      }                                                                     \
+    }                                                                       \
+    DCHECK_NULL(value_high);                                                \
+    return AddNode(machine()->Word32Atomic##name(rep), base, index, value); \
   }
   ATOMIC_FUNCTION(Exchange);
   ATOMIC_FUNCTION(Add);
@@ -190,9 +226,25 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
   ATOMIC_FUNCTION(Or);
   ATOMIC_FUNCTION(Xor);
 #undef ATOMIC_FUNCTION
+#undef VALUE_HALVES
 
   Node* AtomicCompareExchange(MachineType rep, Node* base, Node* index,
-                              Node* old_value, Node* new_value) {
+                              Node* old_value, Node* old_value_high,
+                              Node* new_value, Node* new_value_high) {
+    if (rep.representation() == MachineRepresentation::kWord64) {
+      if (machine()->Is64()) {
+        DCHECK_NULL(old_value_high);
+        DCHECK_NULL(new_value_high);
+        return AddNode(machine()->Word64AtomicCompareExchange(rep), base, index,
+                       old_value, new_value);
+      } else {
+        return AddNode(machine()->Word32AtomicPairCompareExchange(), base,
+                       index, old_value, old_value_high, new_value,
+                       new_value_high);
+      }
+    }
+    DCHECK_NULL(old_value_high);
+    DCHECK_NULL(new_value_high);
     return AddNode(machine()->Word32AtomicCompareExchange(rep), base, index,
                    old_value, new_value);
   }
@@ -605,12 +657,18 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
   Node* ChangeInt32ToFloat64(Node* a) {
     return AddNode(machine()->ChangeInt32ToFloat64(), a);
   }
+  Node* ChangeInt64ToFloat64(Node* a) {
+    return AddNode(machine()->ChangeInt64ToFloat64(), a);
+  }
   Node* ChangeUint32ToFloat64(Node* a) {
     return AddNode(machine()->ChangeUint32ToFloat64(), a);
   }
   Node* ChangeFloat64ToInt32(Node* a) {
     return AddNode(machine()->ChangeFloat64ToInt32(), a);
   }
+  Node* ChangeFloat64ToInt64(Node* a) {
+    return AddNode(machine()->ChangeFloat64ToInt64(), a);
+  }
   Node* ChangeFloat64ToUint32(Node* a) {
     return AddNode(machine()->ChangeFloat64ToUint32(), a);
   }
diff --git a/deps/v8/src/compiler/redundancy-elimination.cc b/deps/v8/src/compiler/redundancy-elimination.cc
index 5ecef0408b..fdab39fb43 100644
--- a/deps/v8/src/compiler/redundancy-elimination.cc
+++ b/deps/v8/src/compiler/redundancy-elimination.cc
@@ -14,7 +14,7 @@ namespace compiler {
 RedundancyElimination::RedundancyElimination(Editor* editor, Zone* zone)
     : AdvancedReducer(editor), node_checks_(zone), zone_(zone) {}
 
-RedundancyElimination::~RedundancyElimination() {}
+RedundancyElimination::~RedundancyElimination() = default;
 
 Reduction RedundancyElimination::Reduce(Node* node) {
   if (node_checks_.Get(node)) return NoChange();
@@ -32,31 +32,20 @@ Reduction RedundancyElimination::Reduce(Node* node) {
     case IrOpcode::kCheckSmi:
     case IrOpcode::kCheckString:
     case IrOpcode::kCheckSymbol:
-    case IrOpcode::kCheckedFloat64ToInt32:
-    case IrOpcode::kCheckedInt32Add:
-    case IrOpcode::kCheckedInt32Div:
-    case IrOpcode::kCheckedInt32Mod:
-    case IrOpcode::kCheckedInt32Mul:
-    case IrOpcode::kCheckedInt32Sub:
-    case IrOpcode::kCheckedInt32ToTaggedSigned:
-    case IrOpcode::kCheckedTaggedSignedToInt32:
-    case IrOpcode::kCheckedTaggedToFloat64:
-    case IrOpcode::kCheckedTaggedToInt32:
-    case IrOpcode::kCheckedTaggedToTaggedPointer:
-    case IrOpcode::kCheckedTaggedToTaggedSigned:
-    case IrOpcode::kCheckedTruncateTaggedToWord32:
-    case IrOpcode::kCheckedUint32Div:
-    case IrOpcode::kCheckedUint32Mod:
-    case IrOpcode::kCheckedUint32ToInt32:
-    case IrOpcode::kCheckedUint32ToTaggedSigned:
+#define SIMPLIFIED_CHECKED_OP(Opcode) case IrOpcode::k##Opcode:
+      SIMPLIFIED_CHECKED_OP_LIST(SIMPLIFIED_CHECKED_OP)
+#undef SIMPLIFIED_CHECKED_OP
       return ReduceCheckNode(node);
+    case IrOpcode::kSpeculativeNumberEqual:
+    case IrOpcode::kSpeculativeNumberLessThan:
+    case IrOpcode::kSpeculativeNumberLessThanOrEqual:
+      return ReduceSpeculativeNumberComparison(node);
     case IrOpcode::kSpeculativeNumberAdd:
     case IrOpcode::kSpeculativeNumberSubtract:
     case IrOpcode::kSpeculativeSafeIntegerAdd:
     case IrOpcode::kSpeculativeSafeIntegerSubtract:
-      // For increments and decrements by a constant, try to learn from the last
-      // bounds check.
-      return TryReuseBoundsCheckForFirstInput(node);
+    case IrOpcode::kSpeculativeToNumber:
+      return ReduceSpeculativeNumberOperation(node);
     case IrOpcode::kEffectPhi:
       return ReduceEffectPhi(node);
     case IrOpcode::kDead:
@@ -140,6 +129,12 @@ bool CheckSubsumes(Node const* a, Node const* b) {
     if (a->opcode() == IrOpcode::kCheckInternalizedString &&
         b->opcode() == IrOpcode::kCheckString) {
       // CheckInternalizedString(node) implies CheckString(node)
+    } else if (a->opcode() == IrOpcode::kCheckSmi &&
+               b->opcode() == IrOpcode::kCheckNumber) {
+      // CheckSmi(node) implies CheckNumber(node)
+    } else if (a->opcode() == IrOpcode::kCheckedTaggedSignedToInt32 &&
+               b->opcode() == IrOpcode::kCheckedTaggedToInt32) {
+      // CheckedTaggedSignedToInt32(node) implies CheckedTaggedToInt32(node)
     } else if (a->opcode() != b->opcode()) {
       return false;
     } else {
@@ -150,11 +145,15 @@ bool CheckSubsumes(Node const* a, Node const* b) {
         case IrOpcode::kCheckNumber:
           break;
         case IrOpcode::kCheckedInt32ToTaggedSigned:
+        case IrOpcode::kCheckedInt64ToInt32:
+        case IrOpcode::kCheckedInt64ToTaggedSigned:
         case IrOpcode::kCheckedTaggedSignedToInt32:
         case IrOpcode::kCheckedTaggedToTaggedPointer:
         case IrOpcode::kCheckedTaggedToTaggedSigned:
         case IrOpcode::kCheckedUint32ToInt32:
         case IrOpcode::kCheckedUint32ToTaggedSigned:
+        case IrOpcode::kCheckedUint64ToInt32:
+        case IrOpcode::kCheckedUint64ToTaggedSigned:
           break;
         case IrOpcode::kCheckedFloat64ToInt32:
         case IrOpcode::kCheckedTaggedToInt32: {
@@ -167,6 +166,20 @@ bool CheckSubsumes(Node const* a, Node const* b) {
           }
           break;
         }
+        case IrOpcode::kCheckedTaggedToFloat64:
+        case IrOpcode::kCheckedTruncateTaggedToWord32: {
+          CheckTaggedInputParameters const& ap =
+              CheckTaggedInputParametersOf(a->op());
+          CheckTaggedInputParameters const& bp =
+              CheckTaggedInputParametersOf(b->op());
+          // {a} subsumes {b} if the modes are either the same, or {a} checks
+          // for Number, in which case {b} will be subsumed no matter what.
+          if (ap.mode() != bp.mode() &&
+              ap.mode() != CheckTaggedInputMode::kNumber) {
+            return false;
+          }
+          break;
+        }
         default:
           DCHECK(!IsCheckedWithFeedback(a->op()));
           return false;
@@ -232,38 +245,6 @@ Reduction RedundancyElimination::ReduceCheckNode(Node* node) {
   return UpdateChecks(node, checks->AddCheck(zone(), node));
 }
 
-Reduction RedundancyElimination::TryReuseBoundsCheckForFirstInput(Node* node) {
-  DCHECK(node->opcode() == IrOpcode::kSpeculativeNumberAdd ||
-         node->opcode() == IrOpcode::kSpeculativeNumberSubtract ||
-         node->opcode() == IrOpcode::kSpeculativeSafeIntegerAdd ||
-         node->opcode() == IrOpcode::kSpeculativeSafeIntegerSubtract);
-
-  DCHECK_EQ(1, node->op()->EffectInputCount());
-  DCHECK_EQ(1, node->op()->EffectOutputCount());
-
-  Node* const effect = NodeProperties::GetEffectInput(node);
-  EffectPathChecks const* checks = node_checks_.Get(effect);
-
-  // If we do not know anything about the predecessor, do not propagate just yet
-  // because we will have to recompute anyway once we compute the predecessor.
-  if (checks == nullptr) return NoChange();
-
-  Node* left = node->InputAt(0);
-  Node* right = node->InputAt(1);
-  // Only use bounds checks for increments/decrements by a constant.
-  if (right->opcode() == IrOpcode::kNumberConstant) {
-    if (Node* bounds_check = checks->LookupBoundsCheckFor(left)) {
-      // Only use the bounds checked type if it is better.
-      if (NodeProperties::GetType(bounds_check)
-              .Is(NodeProperties::GetType(left))) {
-        node->ReplaceInput(0, bounds_check);
-      }
-    }
-  }
-
-  return UpdateChecks(node, checks);
-}
-
 Reduction RedundancyElimination::ReduceEffectPhi(Node* node) {
   Node* const control = NodeProperties::GetControlInput(node);
   if (control->opcode() == IrOpcode::kLoop) {
@@ -292,6 +273,97 @@ Reduction RedundancyElimination::ReduceEffectPhi(Node* node) {
   return UpdateChecks(node, checks);
 }
 
+Reduction RedundancyElimination::ReduceSpeculativeNumberComparison(Node* node) {
+  NumberOperationHint const hint = NumberOperationHintOf(node->op());
+  Node* const first = NodeProperties::GetValueInput(node, 0);
+  Type const first_type = NodeProperties::GetType(first);
+  Node* const second = NodeProperties::GetValueInput(node, 1);
+  Type const second_type = NodeProperties::GetType(second);
+  Node* const effect = NodeProperties::GetEffectInput(node);
+  EffectPathChecks const* checks = node_checks_.Get(effect);
+
+  // If we do not know anything about the predecessor, do not propagate just yet
+  // because we will have to recompute anyway once we compute the predecessor.
+  if (checks == nullptr) return NoChange();
+
+  // Avoid the potentially expensive lookups below if the {node}
+  // has seen non-Smi inputs in the past, which is a clear signal
+  // that the comparison is probably not performed on a value that
+  // already passed an array bounds check.
+  if (hint == NumberOperationHint::kSignedSmall) {
+    // Don't bother trying to find a CheckBounds for the {first} input
+    // if it's type is already in UnsignedSmall range, since the bounds
+    // check is only going to narrow that range further, but the result
+    // is not going to make the representation selection any better.
+    if (!first_type.Is(Type::UnsignedSmall())) {
+      if (Node* check = checks->LookupBoundsCheckFor(first)) {
+        if (!first_type.Is(NodeProperties::GetType(check))) {
+          // Replace the {first} input with the {check}. This is safe,
+          // despite the fact that {check} can truncate -0 to 0, because
+          // the regular Number comparisons in JavaScript also identify
+          // 0 and -0 (unlike special comparisons as Object.is).
+          NodeProperties::ReplaceValueInput(node, check, 0);
+          Reduction const reduction = ReduceSpeculativeNumberComparison(node);
+          return reduction.Changed() ? reduction : Changed(node);
+        }
+      }
+    }
+
+    // Don't bother trying to find a CheckBounds for the {second} input
+    // if it's type is already in UnsignedSmall range, since the bounds
+    // check is only going to narrow that range further, but the result
+    // is not going to make the representation selection any better.
+    if (!second_type.Is(Type::UnsignedSmall())) {
+      if (Node* check = checks->LookupBoundsCheckFor(second)) {
+        if (!second_type.Is(NodeProperties::GetType(check))) {
+          // Replace the {second} input with the {check}. This is safe,
+          // despite the fact that {check} can truncate -0 to 0, because
+          // the regular Number comparisons in JavaScript also identify
+          // 0 and -0 (unlike special comparisons as Object.is).
+          NodeProperties::ReplaceValueInput(node, check, 1);
+          Reduction const reduction = ReduceSpeculativeNumberComparison(node);
+          return reduction.Changed() ? reduction : Changed(node);
+        }
+      }
+    }
+  }
+
+  return UpdateChecks(node, checks);
+}
+
+Reduction RedundancyElimination::ReduceSpeculativeNumberOperation(Node* node) {
+  DCHECK(node->opcode() == IrOpcode::kSpeculativeNumberAdd ||
+         node->opcode() == IrOpcode::kSpeculativeNumberSubtract ||
+         node->opcode() == IrOpcode::kSpeculativeSafeIntegerAdd ||
+         node->opcode() == IrOpcode::kSpeculativeSafeIntegerSubtract ||
+         node->opcode() == IrOpcode::kSpeculativeToNumber);
+  DCHECK_EQ(1, node->op()->EffectInputCount());
+  DCHECK_EQ(1, node->op()->EffectOutputCount());
+
+  Node* const first = NodeProperties::GetValueInput(node, 0);
+  Node* const effect = NodeProperties::GetEffectInput(node);
+  EffectPathChecks const* checks = node_checks_.Get(effect);
+  // If we do not know anything about the predecessor, do not propagate just yet
+  // because we will have to recompute anyway once we compute the predecessor.
+  if (checks == nullptr) return NoChange();
+
+  // Check if there's a CheckBounds operation on {first}
+  // in the graph already, which we might be able to
+  // reuse here to improve the representation selection
+  // for the {node} later on.
+  if (Node* check = checks->LookupBoundsCheckFor(first)) {
+    // Only use the bounds {check} if its type is better
+    // than the type of the {first} node, otherwise we
+    // would end up replacing NumberConstant inputs with
+    // CheckBounds operations, which is kind of pointless.
+    if (!NodeProperties::GetType(first).Is(NodeProperties::GetType(check))) {
+      NodeProperties::ReplaceValueInput(node, check, 0);
+    }
+  }
+
+  return UpdateChecks(node, checks);
+}
+
 Reduction RedundancyElimination::ReduceStart(Node* node) {
   return UpdateChecks(node, EffectPathChecks::Empty(zone()));
 }
diff --git a/deps/v8/src/compiler/redundancy-elimination.h b/deps/v8/src/compiler/redundancy-elimination.h
index 05094a388e..e89a7b2649 100644
--- a/deps/v8/src/compiler/redundancy-elimination.h
+++ b/deps/v8/src/compiler/redundancy-elimination.h
@@ -11,7 +11,7 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
-class RedundancyElimination final : public AdvancedReducer {
+class V8_EXPORT_PRIVATE RedundancyElimination final : public AdvancedReducer {
  public:
   RedundancyElimination(Editor* editor, Zone* zone);
   ~RedundancyElimination() final;
@@ -59,14 +59,14 @@ class RedundancyElimination final : public AdvancedReducer {
 
   Reduction ReduceCheckNode(Node* node);
   Reduction ReduceEffectPhi(Node* node);
+  Reduction ReduceSpeculativeNumberComparison(Node* node);
+  Reduction ReduceSpeculativeNumberOperation(Node* node);
   Reduction ReduceStart(Node* node);
   Reduction ReduceOtherNode(Node* node);
 
   Reduction TakeChecksFromFirstEffect(Node* node);
   Reduction UpdateChecks(Node* node, EffectPathChecks const* checks);
 
-  Reduction TryReuseBoundsCheckForFirstInput(Node* node);
-
   Zone* zone() const { return zone_; }
 
   PathChecksForEffectNodes node_checks_;
diff --git a/deps/v8/src/compiler/refs-map.cc b/deps/v8/src/compiler/refs-map.cc
new file mode 100644
index 0000000000..8b176d0e4c
--- /dev/null
+++ b/deps/v8/src/compiler/refs-map.cc
@@ -0,0 +1,35 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/compiler/refs-map.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+using UnderlyingMap =
+    base::TemplateHashMapImpl<Address, ObjectData*, AddressMatcher,
+                              ZoneAllocationPolicy>;
+
+RefsMap::RefsMap(uint32_t capacity, AddressMatcher match, Zone* zone)
+    : UnderlyingMap(capacity, match, ZoneAllocationPolicy(zone)) {}
+
+RefsMap::RefsMap(const RefsMap* other, Zone* zone)
+    : UnderlyingMap(other, ZoneAllocationPolicy(zone)) {}
+
+RefsMap::Entry* RefsMap::Lookup(const Address& key) const {
+  return UnderlyingMap::Lookup(key, Hash(key));
+}
+
+RefsMap::Entry* RefsMap::LookupOrInsert(const Address& key, Zone* zone) {
+  return UnderlyingMap::LookupOrInsert(key, RefsMap::Hash(key),
+                                       []() { return nullptr; },
+                                       ZoneAllocationPolicy(zone));
+}
+
+uint32_t RefsMap::Hash(Address addr) { return static_cast<uint32_t>(addr); }
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/compiler/refs-map.h b/deps/v8/src/compiler/refs-map.h
new file mode 100644
index 0000000000..daaf433049
--- /dev/null
+++ b/deps/v8/src/compiler/refs-map.h
@@ -0,0 +1,54 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_COMPILER_REFS_MAP_H_
+#define V8_COMPILER_REFS_MAP_H_
+
+#include "src/base/hashmap.h"
+#include "src/globals.h"
+#include "src/zone/zone.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+class ObjectData;
+
+class AddressMatcher : public base::KeyEqualityMatcher<Address> {
+ public:
+  bool operator()(uint32_t hash1, uint32_t hash2, const Address& key1,
+                  const Address& key2) const {
+    return key1 == key2;
+  }
+};
+
+// This class employs our own implementation of hash map for the purpose of
+// storing the mapping between canonical Addresses and allocated ObjectData.
+// It's used as the refs map in JSHeapBroker and as the snapshot in
+// PerIsolateCompilerCache, as we need a cheap copy between the two and
+// std::unordered_map doesn't satisfy this requirement, as it rehashes the
+// whole map and copies all entries one by one.
+class RefsMap
+    : public base::TemplateHashMapImpl<Address, ObjectData*, AddressMatcher,
+                                       ZoneAllocationPolicy>,
+      public ZoneObject {
+ public:
+  RefsMap(uint32_t capacity, AddressMatcher match, Zone* zone);
+  RefsMap(const RefsMap* other, Zone* zone);
+
+  bool IsEmpty() const { return occupancy() == 0; }
+
+  // Wrappers around methods from UnderlyingMap
+  Entry* Lookup(const Address& key) const;
+  Entry* LookupOrInsert(const Address& key, Zone* zone);
+
+ private:
+  static uint32_t Hash(Address addr);
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_REFS_MAP_H_
diff --git a/deps/v8/src/compiler/register-allocator.cc b/deps/v8/src/compiler/register-allocator.cc
index 1938ef22b6..0649748a35 100644
--- a/deps/v8/src/compiler/register-allocator.cc
+++ b/deps/v8/src/compiler/register-allocator.cc
@@ -21,10 +21,10 @@ namespace compiler {
 
 namespace {
 
-static const int kFloatRepBit =
-    1 << static_cast<int>(MachineRepresentation::kFloat32);
-static const int kSimd128RepBit =
-    1 << static_cast<int>(MachineRepresentation::kSimd128);
+static constexpr int kFloat32Bit =
+    RepresentationBit(MachineRepresentation::kFloat32);
+static constexpr int kSimd128Bit =
+    RepresentationBit(MachineRepresentation::kSimd128);
 
 void RemoveElement(ZoneVector<LiveRange*>* v, LiveRange* range) {
   auto it = std::find(v->begin(), v->end(), range);
@@ -2041,8 +2041,8 @@ void LiveRangeBuilder::ProcessInstructions(const InstructionBlock* block,
   bool fixed_simd128_live_ranges = false;
   if (!kSimpleFPAliasing) {
     int mask = data()->code()->representation_mask();
-    fixed_float_live_ranges = (mask & kFloatRepBit) != 0;
-    fixed_simd128_live_ranges = (mask & kSimd128RepBit) != 0;
+    fixed_float_live_ranges = (mask & kFloat32Bit) != 0;
+    fixed_simd128_live_ranges = (mask & kSimd128Bit) != 0;
   }
 
   for (int index = block->last_instruction_index(); index >= block_start;
@@ -2556,7 +2556,7 @@ RegisterAllocator::RegisterAllocator(RegisterAllocationData* data,
       check_fp_aliasing_(false) {
   if (!kSimpleFPAliasing && kind == FP_REGISTERS) {
     check_fp_aliasing_ = (data->code()->representation_mask() &
-                          (kFloatRepBit | kSimd128RepBit)) != 0;
+                          (kFloat32Bit | kSimd128Bit)) != 0;
   }
 }
 
diff --git a/deps/v8/src/compiler/representation-change.cc b/deps/v8/src/compiler/representation-change.cc
index e3c49df7a6..ad4c5c916c 100644
--- a/deps/v8/src/compiler/representation-change.cc
+++ b/deps/v8/src/compiler/representation-change.cc
@@ -10,6 +10,7 @@
 #include "src/code-factory.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-matchers.h"
+#include "src/compiler/type-cache.h"
 #include "src/heap/factory-inl.h"
 
 namespace v8 {
@@ -24,8 +25,6 @@ const char* Truncation::description() const {
       return "truncate-to-bool";
     case TruncationKind::kWord32:
       return "truncate-to-word32";
-    case TruncationKind::kWord64:
-      return "truncate-to-word64";
     case TruncationKind::kFloat64:
       switch (identify_zeros()) {
         case kIdentifyZeros:
@@ -44,23 +43,22 @@ const char* Truncation::description() const {
   UNREACHABLE();
 }
 
-
 // Partial order for truncations:
 //
-//  kWord64       kAny <-------+
-//     ^            ^          |
-//     \            |          |
-//      \         kFloat64     |
-//       \        ^            |
-//        \       /            |
-//         kWord32           kBool
-//               ^            ^
-//               \            /
-//                \          /
-//                 \        /
-//                  \      /
-//                   \    /
-//                   kNone
+//          kAny <-------+
+//            ^          |
+//            |          |
+//          kFloat64     |
+//          ^            |
+//          /            |
+//   kWord32           kBool
+//         ^            ^
+//         \            /
+//          \          /
+//           \        /
+//            \      /
+//             \    /
+//             kNone
 //
 // TODO(jarin) We might consider making kBool < kFloat64.
 
@@ -103,10 +101,7 @@ bool Truncation::LessGeneral(TruncationKind rep1, TruncationKind rep2) {
       return rep2 == TruncationKind::kBool || rep2 == TruncationKind::kAny;
     case TruncationKind::kWord32:
       return rep2 == TruncationKind::kWord32 ||
-             rep2 == TruncationKind::kWord64 ||
              rep2 == TruncationKind::kFloat64 || rep2 == TruncationKind::kAny;
-    case TruncationKind::kWord64:
-      return rep2 == TruncationKind::kWord64;
     case TruncationKind::kFloat64:
       return rep2 == TruncationKind::kFloat64 || rep2 == TruncationKind::kAny;
     case TruncationKind::kAny:
@@ -130,6 +125,13 @@ bool IsWord(MachineRepresentation rep) {
 
 }  // namespace
 
+RepresentationChanger::RepresentationChanger(JSGraph* jsgraph, Isolate* isolate)
+    : cache_(TypeCache::Get()),
+      jsgraph_(jsgraph),
+      isolate_(isolate),
+      testing_type_errors_(false),
+      type_error_(false) {}
+
 // Changes representation from {output_rep} to {use_rep}. The {truncation}
 // parameter is only used for sanity checking - if the changer cannot figure
 // out signedness for the word32->float64 conversion, then we check that the
@@ -238,6 +240,28 @@ Node* RepresentationChanger::GetTaggedSignedRepresentationFor(
       return TypeError(node, output_rep, output_type,
                        MachineRepresentation::kTaggedSigned);
     }
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    if (output_type.Is(Type::Signed31())) {
+      // int64 -> int32 -> tagged signed
+      node = InsertTruncateInt64ToInt32(node);
+      op = simplified()->ChangeInt31ToTaggedSigned();
+    } else if (output_type.Is(Type::Signed32()) && SmiValuesAre32Bits()) {
+      // int64 -> int32 -> tagged signed
+      node = InsertTruncateInt64ToInt32(node);
+      op = simplified()->ChangeInt32ToTagged();
+    } else if (use_info.type_check() == TypeCheckKind::kSignedSmall) {
+      if (output_type.Is(cache_.kPositiveSafeInteger)) {
+        op = simplified()->CheckedUint64ToTaggedSigned(use_info.feedback());
+      } else if (output_type.Is(cache_.kSafeInteger)) {
+        op = simplified()->CheckedInt64ToTaggedSigned(use_info.feedback());
+      } else {
+        return TypeError(node, output_rep, output_type,
+                         MachineRepresentation::kTaggedSigned);
+      }
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kTaggedSigned);
+    }
   } else if (output_rep == MachineRepresentation::kFloat64) {
     if (output_type.Is(Type::Signed31())) {
       // float64 -> int32 -> tagged signed
@@ -326,6 +350,7 @@ Node* RepresentationChanger::GetTaggedPointerRepresentationFor(
   // Eagerly fold representation changes for constants.
   switch (node->opcode()) {
     case IrOpcode::kHeapConstant:
+    case IrOpcode::kDelayedStringConstant:
       return node;  // No change necessary.
     case IrOpcode::kInt32Constant:
     case IrOpcode::kFloat64Constant:
@@ -360,6 +385,16 @@ Node* RepresentationChanger::GetTaggedPointerRepresentationFor(
                        MachineRepresentation::kTaggedPointer);
     }
     op = simplified()->ChangeFloat64ToTaggedPointer();
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    if (output_type.Is(cache_.kSafeInteger)) {
+      // int64 -> float64 -> tagged pointer
+      op = machine()->ChangeInt64ToFloat64();
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = simplified()->ChangeFloat64ToTaggedPointer();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kTaggedPointer);
+    }
   } else if (output_rep == MachineRepresentation::kFloat32) {
     if (output_type.Is(Type::Number())) {
       // float32 -> float64 -> tagged
@@ -399,6 +434,7 @@ Node* RepresentationChanger::GetTaggedRepresentationFor(
   switch (node->opcode()) {
     case IrOpcode::kNumberConstant:
     case IrOpcode::kHeapConstant:
+    case IrOpcode::kDelayedStringConstant:
       return node;  // No change necessary.
     case IrOpcode::kInt32Constant:
     case IrOpcode::kFloat64Constant:
@@ -440,6 +476,29 @@ Node* RepresentationChanger::GetTaggedRepresentationFor(
       return TypeError(node, output_rep, output_type,
                        MachineRepresentation::kTagged);
     }
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    if (output_type.Is(Type::Signed31())) {
+      // int64 -> int32 -> tagged signed
+      node = InsertTruncateInt64ToInt32(node);
+      op = simplified()->ChangeInt31ToTaggedSigned();
+    } else if (output_type.Is(Type::Signed32())) {
+      // int64 -> int32 -> tagged
+      node = InsertTruncateInt64ToInt32(node);
+      op = simplified()->ChangeInt32ToTagged();
+    } else if (output_type.Is(Type::Unsigned32())) {
+      // int64 -> uint32 -> tagged
+      node = InsertTruncateInt64ToInt32(node);
+      op = simplified()->ChangeUint32ToTagged();
+    } else if (output_type.Is(cache_.kPositiveSafeInteger)) {
+      // uint64 -> tagged
+      op = simplified()->ChangeUint64ToTagged();
+    } else if (output_type.Is(cache_.kSafeInteger)) {
+      // int64 -> tagged
+      op = simplified()->ChangeInt64ToTagged();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kTagged);
+    }
   } else if (output_rep ==
              MachineRepresentation::kFloat32) {  // float32 -> float64 -> tagged
     node = InsertChangeFloat32ToFloat64(node);
@@ -526,6 +585,13 @@ Node* RepresentationChanger::GetFloat32RepresentationFor(
     }
   } else if (output_rep == MachineRepresentation::kFloat64) {
     op = machine()->TruncateFloat64ToFloat32();
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    if (output_type.Is(Type::Signed32())) {
+      // int64 -> float64 -> float32
+      op = machine()->ChangeInt64ToFloat64();
+      node = jsgraph()->graph()->NewNode(op, node);
+      op = machine()->TruncateFloat64ToFloat32();
+    }
   }
   if (op == nullptr) {
     return TypeError(node, output_rep, output_type,
@@ -559,7 +625,9 @@ Node* RepresentationChanger::GetFloat64RepresentationFor(
     return jsgraph()->graph()->NewNode(
         jsgraph()->common()->DeadValue(MachineRepresentation::kFloat64), node);
   } else if (IsWord(output_rep)) {
-    if (output_type.Is(Type::Signed32())) {
+    if (output_type.Is(Type::Signed32()) ||
+        (output_type.Is(Type::Signed32OrMinusZero()) &&
+         use_info.truncation().IdentifiesZeroAndMinusZero())) {
       op = machine()->ChangeInt32ToFloat64();
     } else if (output_type.Is(Type::Unsigned32()) ||
                use_info.truncation().IsUsedAsWord32()) {
@@ -595,6 +663,10 @@ Node* RepresentationChanger::GetFloat64RepresentationFor(
     }
   } else if (output_rep == MachineRepresentation::kFloat32) {
     op = machine()->ChangeFloat32ToFloat64();
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    if (output_type.Is(cache_.kSafeInteger)) {
+      op = machine()->ChangeInt64ToFloat64();
+    }
   }
   if (op == nullptr) {
     return TypeError(node, output_rep, output_type,
@@ -607,14 +679,17 @@ Node* RepresentationChanger::MakeTruncatedInt32Constant(double value) {
   return jsgraph()->Int32Constant(DoubleToInt32(value));
 }
 
-void RepresentationChanger::InsertUnconditionalDeopt(Node* node,
-                                                     DeoptimizeReason reason) {
+Node* RepresentationChanger::InsertUnconditionalDeopt(Node* node,
+                                                      DeoptimizeReason reason) {
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
-  Node* deopt =
+  effect =
       jsgraph()->graph()->NewNode(simplified()->CheckIf(reason),
                                   jsgraph()->Int32Constant(0), effect, control);
-  NodeProperties::ReplaceEffectInput(node, deopt);
+  Node* unreachable = effect = jsgraph()->graph()->NewNode(
+      jsgraph()->common()->Unreachable(), effect, control);
+  NodeProperties::ReplaceEffectInput(node, effect);
+  return unreachable;
 }
 
 Node* RepresentationChanger::GetWord32RepresentationFor(
@@ -623,6 +698,7 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
   // Eagerly fold representation changes for constants.
   switch (node->opcode()) {
     case IrOpcode::kInt32Constant:
+    case IrOpcode::kInt64Constant:
     case IrOpcode::kFloat32Constant:
     case IrOpcode::kFloat64Constant:
       UNREACHABLE();
@@ -655,9 +731,11 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
       CHECK(Truncation::Any(kIdentifyZeros)
                 .IsLessGeneralThan(use_info.truncation()));
       CHECK_NE(use_info.type_check(), TypeCheckKind::kNone);
-      InsertUnconditionalDeopt(use_node, DeoptimizeReason::kNotASmi);
+      Node* unreachable =
+          InsertUnconditionalDeopt(use_node, DeoptimizeReason::kNotASmi);
       return jsgraph()->graph()->NewNode(
-          jsgraph()->common()->DeadValue(MachineRepresentation::kWord32), node);
+          jsgraph()->common()->DeadValue(MachineRepresentation::kWord32),
+          unreachable);
     }
   } else if (output_rep == MachineRepresentation::kFloat64) {
     if (output_type.Is(Type::Signed32())) {
@@ -730,6 +808,12 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
                        MachineRepresentation::kWord32);
     }
   } else if (output_rep == MachineRepresentation::kWord32) {
+    if (use_info.truncation().IdentifiesZeroAndMinusZero()) {
+      if (output_type.Is(Type::Signed32OrMinusZero()) ||
+          output_type.Is(Type::Unsigned32OrMinusZero())) {
+        return node;
+      }
+    }
     // Only the checked case should get here, the non-checked case is
     // handled in GetRepresentationFor.
     if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
@@ -752,6 +836,27 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
     DCHECK(use_info.type_check() == TypeCheckKind::kSignedSmall ||
            use_info.type_check() == TypeCheckKind::kSigned32);
     return node;
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    if (output_type.Is(Type::Signed32()) ||
+        output_type.Is(Type::Unsigned32())) {
+      op = machine()->TruncateInt64ToInt32();
+    } else if (output_type.Is(cache_.kSafeInteger) &&
+               use_info.truncation().IsUsedAsWord32()) {
+      op = machine()->TruncateInt64ToInt32();
+    } else if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
+               use_info.type_check() == TypeCheckKind::kSigned32) {
+      if (output_type.Is(cache_.kPositiveSafeInteger)) {
+        op = simplified()->CheckedUint64ToInt32(use_info.feedback());
+      } else if (output_type.Is(cache_.kSafeInteger)) {
+        op = simplified()->CheckedInt64ToInt32(use_info.feedback());
+      } else {
+        return TypeError(node, output_rep, output_type,
+                         MachineRepresentation::kWord32);
+      }
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kWord32);
+    }
   }
 
   if (op == nullptr) {
@@ -822,6 +927,11 @@ Node* RepresentationChanger::GetBitRepresentationFor(
                                        jsgraph()->Int32Constant(0));
     return jsgraph()->graph()->NewNode(machine()->Word32Equal(), node,
                                        jsgraph()->Int32Constant(0));
+  } else if (output_rep == MachineRepresentation::kWord64) {
+    node = jsgraph()->graph()->NewNode(machine()->Word64Equal(), node,
+                                       jsgraph()->Int64Constant(0));
+    return jsgraph()->graph()->NewNode(machine()->Word32Equal(), node,
+                                       jsgraph()->Int32Constant(0));
   } else if (output_rep == MachineRepresentation::kFloat32) {
     node = jsgraph()->graph()->NewNode(machine()->Float32Abs(), node);
     return jsgraph()->graph()->NewNode(machine()->Float32LessThan(),
@@ -839,16 +949,84 @@ Node* RepresentationChanger::GetBitRepresentationFor(
 
 Node* RepresentationChanger::GetWord64RepresentationFor(
     Node* node, MachineRepresentation output_rep, Type output_type) {
+  // Eagerly fold representation changes for constants.
+  switch (node->opcode()) {
+    case IrOpcode::kInt32Constant:
+    case IrOpcode::kInt64Constant:
+    case IrOpcode::kFloat32Constant:
+    case IrOpcode::kFloat64Constant:
+      UNREACHABLE();
+      break;
+    case IrOpcode::kNumberConstant: {
+      double const fv = OpParameter<double>(node->op());
+      int64_t const iv = static_cast<int64_t>(fv);
+      if (static_cast<double>(iv) == fv) {
+        return jsgraph()->Int64Constant(iv);
+      }
+      break;
+    }
+    default:
+      break;
+  }
+
+  // Select the correct X -> Word64 operator.
+  const Operator* op;
   if (output_type.Is(Type::None())) {
     // This is an impossible value; it should not be used at runtime.
     return jsgraph()->graph()->NewNode(
-        jsgraph()->common()->DeadValue(MachineRepresentation::kWord32), node);
+        jsgraph()->common()->DeadValue(MachineRepresentation::kWord64), node);
   } else if (output_rep == MachineRepresentation::kBit) {
     return node;  // Sloppy comparison -> word64
+  } else if (IsWord(output_rep)) {
+    if (output_type.Is(Type::Unsigned32())) {
+      op = machine()->ChangeUint32ToUint64();
+    } else if (output_type.Is(Type::Signed32())) {
+      op = machine()->ChangeInt32ToInt64();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kWord64);
+    }
+  } else if (output_rep == MachineRepresentation::kFloat32) {
+    if (output_type.Is(cache_.kInt64)) {
+      // float32 -> float64 -> int64
+      node = InsertChangeFloat32ToFloat64(node);
+      op = machine()->ChangeFloat64ToInt64();
+    } else if (output_type.Is(cache_.kUint64)) {
+      // float32 -> float64 -> uint64
+      node = InsertChangeFloat32ToFloat64(node);
+      op = machine()->ChangeFloat64ToUint64();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kWord64);
+    }
+  } else if (output_rep == MachineRepresentation::kFloat64) {
+    if (output_type.Is(cache_.kInt64)) {
+      op = machine()->ChangeFloat64ToInt64();
+    } else if (output_type.Is(cache_.kUint64)) {
+      op = machine()->ChangeFloat64ToUint64();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kWord64);
+    }
+  } else if (output_rep == MachineRepresentation::kTaggedSigned) {
+    if (output_type.Is(Type::SignedSmall())) {
+      op = simplified()->ChangeTaggedSignedToInt64();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kWord64);
+    }
+  } else if (CanBeTaggedPointer(output_rep)) {
+    if (output_type.Is(cache_.kInt64)) {
+      op = simplified()->ChangeTaggedToInt64();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kWord64);
+    }
+  } else {
+    return TypeError(node, output_rep, output_type,
+                     MachineRepresentation::kWord64);
   }
-  // Can't really convert Word64 to anything else. Purported to be internal.
-  return TypeError(node, output_rep, output_type,
-                   MachineRepresentation::kWord64);
+  return jsgraph()->graph()->NewNode(op, node);
 }
 
 const Operator* RepresentationChanger::Int32OperatorFor(
@@ -910,6 +1088,22 @@ const Operator* RepresentationChanger::Int32OverflowOperatorFor(
   }
 }
 
+const Operator* RepresentationChanger::Int64OperatorFor(
+    IrOpcode::Value opcode) {
+  switch (opcode) {
+    case IrOpcode::kSpeculativeNumberAdd:  // Fall through.
+    case IrOpcode::kSpeculativeSafeIntegerAdd:
+    case IrOpcode::kNumberAdd:
+      return machine()->Int64Add();
+    case IrOpcode::kSpeculativeNumberSubtract:  // Fall through.
+    case IrOpcode::kSpeculativeSafeIntegerSubtract:
+    case IrOpcode::kNumberSubtract:
+      return machine()->Int64Sub();
+    default:
+      UNREACHABLE();
+  }
+}
+
 const Operator* RepresentationChanger::TaggedSignedOperatorFor(
     IrOpcode::Value opcode) {
   switch (opcode) {
@@ -1124,6 +1318,10 @@ Node* RepresentationChanger::InsertChangeUint32ToFloat64(Node* node) {
   return jsgraph()->graph()->NewNode(machine()->ChangeUint32ToFloat64(), node);
 }
 
+Node* RepresentationChanger::InsertTruncateInt64ToInt32(Node* node) {
+  return jsgraph()->graph()->NewNode(machine()->TruncateInt64ToInt32(), node);
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler/representation-change.h b/deps/v8/src/compiler/representation-change.h
index 85a69d92eb..673c062d94 100644
--- a/deps/v8/src/compiler/representation-change.h
+++ b/deps/v8/src/compiler/representation-change.h
@@ -12,6 +12,9 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+// Foward declarations.
+class TypeCache;
+
 enum IdentifyZeros { kIdentifyZeros, kDistinguishZeros };
 
 class Truncation final {
@@ -26,9 +29,6 @@ class Truncation final {
   static Truncation Word32() {
     return Truncation(TruncationKind::kWord32, kIdentifyZeros);
   }
-  static Truncation Word64() {
-    return Truncation(TruncationKind::kWord64, kIdentifyZeros);
-  }
   static Truncation Float64(IdentifyZeros identify_zeros = kDistinguishZeros) {
     return Truncation(TruncationKind::kFloat64, identify_zeros);
   }
@@ -57,10 +57,6 @@ class Truncation final {
     return LessGeneral(kind_, TruncationKind::kWord32) ||
            LessGeneral(kind_, TruncationKind::kBool);
   }
-  bool IdentifiesUndefinedAndNaN() {
-    return LessGeneral(kind_, TruncationKind::kFloat64) ||
-           LessGeneral(kind_, TruncationKind::kWord64);
-  }
   bool IdentifiesZeroAndMinusZero() const {
     return identify_zeros() == kIdentifyZeros;
   }
@@ -85,7 +81,6 @@ class Truncation final {
     kNone,
     kBool,
     kWord32,
-    kWord64,
     kFloat64,
     kAny
   };
@@ -162,8 +157,11 @@ class UseInfo {
   static UseInfo TruncatingWord32() {
     return UseInfo(MachineRepresentation::kWord32, Truncation::Word32());
   }
-  static UseInfo TruncatingWord64() {
-    return UseInfo(MachineRepresentation::kWord64, Truncation::Word64());
+  static UseInfo Word64() {
+    return UseInfo(MachineRepresentation::kWord64, Truncation::Any());
+  }
+  static UseInfo Word() {
+    return UseInfo(MachineType::PointerRepresentation(), Truncation::Any());
   }
   static UseInfo Bool() {
     return UseInfo(MachineRepresentation::kBit, Truncation::Bool());
@@ -171,11 +169,10 @@ class UseInfo {
   static UseInfo Float32() {
     return UseInfo(MachineRepresentation::kFloat32, Truncation::Any());
   }
-  static UseInfo TruncatingFloat64() {
-    return UseInfo(MachineRepresentation::kFloat64, Truncation::Float64());
-  }
-  static UseInfo PointerInt() {
-    return kPointerSize == 4 ? TruncatingWord32() : TruncatingWord64();
+  static UseInfo TruncatingFloat64(
+      IdentifyZeros identify_zeros = kDistinguishZeros) {
+    return UseInfo(MachineRepresentation::kFloat64,
+                   Truncation::Float64(identify_zeros));
   }
   static UseInfo AnyTagged() {
     return UseInfo(MachineRepresentation::kTagged, Truncation::Any());
@@ -193,9 +190,11 @@ class UseInfo {
                    TypeCheckKind::kHeapObject);
   }
   static UseInfo CheckedSignedSmallAsTaggedSigned(
-      const VectorSlotPair& feedback) {
-    return UseInfo(MachineRepresentation::kTaggedSigned, Truncation::Any(),
-                   TypeCheckKind::kSignedSmall, feedback);
+      const VectorSlotPair& feedback,
+      IdentifyZeros identify_zeros = kDistinguishZeros) {
+    return UseInfo(MachineRepresentation::kTaggedSigned,
+                   Truncation::Any(identify_zeros), TypeCheckKind::kSignedSmall,
+                   feedback);
   }
   static UseInfo CheckedSignedSmallAsWord32(IdentifyZeros identify_zeros,
                                             const VectorSlotPair& feedback) {
@@ -209,17 +208,20 @@ class UseInfo {
                    Truncation::Any(identify_zeros), TypeCheckKind::kSigned32,
                    feedback);
   }
-  static UseInfo CheckedNumberAsFloat64(const VectorSlotPair& feedback) {
-    return UseInfo(MachineRepresentation::kFloat64, Truncation::Any(),
-                   TypeCheckKind::kNumber, feedback);
+  static UseInfo CheckedNumberAsFloat64(IdentifyZeros identify_zeros,
+                                        const VectorSlotPair& feedback) {
+    return UseInfo(MachineRepresentation::kFloat64,
+                   Truncation::Any(identify_zeros), TypeCheckKind::kNumber,
+                   feedback);
   }
   static UseInfo CheckedNumberAsWord32(const VectorSlotPair& feedback) {
     return UseInfo(MachineRepresentation::kWord32, Truncation::Word32(),
                    TypeCheckKind::kNumber, feedback);
   }
   static UseInfo CheckedNumberOrOddballAsFloat64(
-      const VectorSlotPair& feedback) {
-    return UseInfo(MachineRepresentation::kFloat64, Truncation::Any(),
+      IdentifyZeros identify_zeros, const VectorSlotPair& feedback) {
+    return UseInfo(MachineRepresentation::kFloat64,
+                   Truncation::Any(identify_zeros),
                    TypeCheckKind::kNumberOrOddball, feedback);
   }
   static UseInfo CheckedNumberOrOddballAsWord32(
@@ -263,11 +265,7 @@ class UseInfo {
 // Eagerly folds any representation changes for constants.
 class RepresentationChanger final {
  public:
-  RepresentationChanger(JSGraph* jsgraph, Isolate* isolate)
-      : jsgraph_(jsgraph),
-        isolate_(isolate),
-        testing_type_errors_(false),
-        type_error_(false) {}
+  RepresentationChanger(JSGraph* jsgraph, Isolate* isolate);
 
   // Changes representation from {output_type} to {use_rep}. The {truncation}
   // parameter is only used for sanity checking - if the changer cannot figure
@@ -278,6 +276,7 @@ class RepresentationChanger final {
                              UseInfo use_info);
   const Operator* Int32OperatorFor(IrOpcode::Value opcode);
   const Operator* Int32OverflowOperatorFor(IrOpcode::Value opcode);
+  const Operator* Int64OperatorFor(IrOpcode::Value opcode);
   const Operator* TaggedSignedOperatorFor(IrOpcode::Value opcode);
   const Operator* Uint32OperatorFor(IrOpcode::Value opcode);
   const Operator* Uint32OverflowOperatorFor(IrOpcode::Value opcode);
@@ -294,6 +293,7 @@ class RepresentationChanger final {
   }
 
  private:
+  TypeCache const& cache_;
   JSGraph* jsgraph_;
   Isolate* isolate_;
 
@@ -338,7 +338,8 @@ class RepresentationChanger final {
   Node* InsertChangeTaggedToFloat64(Node* node);
   Node* InsertChangeUint32ToFloat64(Node* node);
   Node* InsertConversion(Node* node, const Operator* op, Node* use_node);
-  void InsertUnconditionalDeopt(Node* node, DeoptimizeReason reason);
+  Node* InsertTruncateInt64ToInt32(Node* node);
+  Node* InsertUnconditionalDeopt(Node* node, DeoptimizeReason reason);
 
   JSGraph* jsgraph() const { return jsgraph_; }
   Isolate* isolate() const { return isolate_; }
diff --git a/deps/v8/src/compiler/s390/code-generator-s390.cc b/deps/v8/src/compiler/s390/code-generator-s390.cc
index ab9bd16e81..03a6430ef2 100644
--- a/deps/v8/src/compiler/s390/code-generator-s390.cc
+++ b/deps/v8/src/compiler/s390/code-generator-s390.cc
@@ -67,6 +67,10 @@ class S390OperandConverter final : public InstructionOperandConverter {
         return Operand(constant.ToInt64());
 #endif
       case Constant::kExternalReference:
+        return Operand(constant.ToExternalReference());
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kHeapObject:
       case Constant::kRpoNumber:
         break;
@@ -1032,6 +1036,17 @@ static inline int AssembleUnaryOp(Instruction* instr, _R _r, _M _m, _I _i) {
     __ LoadlW(result, result);                                            \
   } while (false)
 
+#define ASSEMBLE_ATOMIC_BINOP_WORD64(load_and_op)                         \
+  do {                                                                    \
+    Register value = i.InputRegister(2);                                  \
+    Register result = i.OutputRegister(0);                                \
+    Register addr = r1;                                                   \
+    AddressingMode mode = kMode_None;                                     \
+    MemOperand op = i.MemoryOperand(&mode);                               \
+    __ lay(addr, op);                                                     \
+    __ load_and_op(result, value, MemOperand(addr));                      \
+  } while (false)
+
 #define ATOMIC_BIN_OP(bin_inst, offset, shift_amount, start, end)         \
   do {                                                                    \
     Label do_cs;                                                          \
@@ -1047,6 +1062,22 @@ static inline int AssembleUnaryOp(Instruction* instr, _R _r, _M _m, _I _i) {
     __ bne(&do_cs, Label::kNear);                                         \
   } while (false)
 
+#define ATOMIC64_BIN_OP(bin_inst, offset, shift_amount, start, end)         \
+  do {                                                                      \
+    Label do_cs;                                                            \
+    __ lg(prev, MemOperand(addr, offset));                                  \
+    __ bind(&do_cs);                                                        \
+    __ RotateInsertSelectBits(temp, value, Operand(start), Operand(end),    \
+                              Operand(static_cast<intptr_t>(shift_amount)), \
+                              true);                                        \
+    __ bin_inst(new_val, prev, temp);                                       \
+    __ lgr(temp, prev);                                                     \
+    __ RotateInsertSelectBits(temp, new_val, Operand(start), Operand(end),  \
+                              Operand::Zero(), false);                      \
+    __ CmpAndSwap64(prev, temp, MemOperand(addr, offset));                  \
+    __ bne(&do_cs, Label::kNear);                                           \
+  } while (false)
+
 #ifdef V8_TARGET_BIG_ENDIAN
 #define ATOMIC_BIN_OP_HALFWORD(bin_inst, index, extract_result)  \
   {                                                              \
@@ -1066,6 +1097,15 @@ static inline int AssembleUnaryOp(Instruction* instr, _R _r, _M _m, _I _i) {
     ATOMIC_BIN_OP(bin_inst, offset, shift_amount, start, end);   \
     extract_result();                                            \
   }
+#define ATOMIC_BIN_OP_WORD(bin_inst, index, extract_result)      \
+  {                                                              \
+    constexpr int offset = -(4 * index);                         \
+    constexpr int shift_amount = 32 - (index * 32);              \
+    constexpr int start = 32 - shift_amount;                     \
+    constexpr int end = start + 31;                              \
+    ATOMIC64_BIN_OP(bin_inst, offset, shift_amount, start, end); \
+    extract_result();                                            \
+  }
 #else
 #define ATOMIC_BIN_OP_HALFWORD(bin_inst, index, extract_result)  \
   {                                                              \
@@ -1085,6 +1125,15 @@ static inline int AssembleUnaryOp(Instruction* instr, _R _r, _M _m, _I _i) {
     ATOMIC_BIN_OP(bin_inst, offset, shift_amount, start, end);   \
     extract_result();                                            \
   }
+#define ATOMIC_BIN_OP_WORD(bin_inst, index, extract_result)      \
+  {                                                              \
+    constexpr int offset = -(4 * index);                         \
+    constexpr int shift_amount = index * 32;                     \
+    constexpr int start = 32 - shift_amount;                     \
+    constexpr int end = start + 31;                              \
+    ATOMIC64_BIN_OP(bin_inst, offset, shift_amount, start, end); \
+    extract_result();                                            \
+  }
 #endif  // V8_TARGET_BIG_ENDIAN
 
 #define ASSEMBLE_ATOMIC_BINOP_HALFWORD(bin_inst, extract_result)          \
@@ -1143,6 +1192,311 @@ static inline int AssembleUnaryOp(Instruction* instr, _R _r, _M _m, _I _i) {
     __ bind(&done);                                                       \
   } while (false)
 
+#define ASSEMBLE_ATOMIC64_BINOP_BYTE(bin_inst, extract_result)       \
+  do {                                                               \
+    Register value = i.InputRegister(2);                             \
+    Register result = i.OutputRegister(0);                           \
+    Register addr = i.TempRegister(0);                               \
+    Register prev = r0;                                              \
+    Register new_val = r1;                                           \
+    Register temp = kScratchReg;                                     \
+    AddressingMode mode = kMode_None;                                \
+    MemOperand op = i.MemoryOperand(&mode);                          \
+    Label done, leftmost0, leftmost1, two, three, four, five, seven; \
+    __ lay(addr, op);                                                \
+    __ tmll(addr, Operand(7));                                       \
+    __ b(Condition(1), &seven);                                      \
+    __ b(Condition(2), &leftmost1);                                  \
+    __ b(Condition(4), &leftmost0);                                  \
+    /* ending with 0b000 */                                          \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 0, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b001 to 0b011 */                                   \
+    __ bind(&leftmost0);                                             \
+    __ tmll(addr, Operand(3));                                       \
+    __ b(Condition(1), &three);                                      \
+    __ b(Condition(2), &two);                                        \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 1, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b010 */                                            \
+    __ bind(&two);                                                   \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 2, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b011 */                                            \
+    __ bind(&three);                                                 \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 3, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b100 to 0b110 */                                   \
+    __ bind(&leftmost1);                                             \
+    __ tmll(addr, Operand(3));                                       \
+    __ b(Condition(8), &four);                                       \
+    __ b(Condition(4), &five);                                       \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 6, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b100 */                                            \
+    __ bind(&four);                                                  \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 4, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b101 */                                            \
+    __ bind(&five);                                                  \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 5, extract_result);                 \
+    __ b(&done);                                                     \
+    /* ending in 0b111 */                                            \
+    __ bind(&seven);                                                 \
+    ATOMIC_BIN_OP_BYTE(bin_inst, 7, extract_result);                 \
+    __ bind(&done);                                                  \
+  } while (false)
+
+#define ASSEMBLE_ATOMIC64_BINOP_HALFWORD(bin_inst, extract_result)      \
+  do {                                                                  \
+    Register value = i.InputRegister(2);                                \
+    Register result = i.OutputRegister(0);                              \
+    Register prev = i.TempRegister(0);                                  \
+    Register new_val = r0;                                              \
+    Register addr = r1;                                                 \
+    Register temp = kScratchReg;                                        \
+    AddressingMode mode = kMode_None;                                   \
+    MemOperand op = i.MemoryOperand(&mode);                             \
+    Label done, one, two, three;                                        \
+    __ lay(addr, op);                                                   \
+    __ tmll(addr, Operand(6));                                          \
+    __ b(Condition(1), &three);                                         \
+    __ b(Condition(2), &two);                                           \
+    __ b(Condition(4), &one);                                           \
+    /* ending in 0b00 */                                                \
+    ATOMIC_BIN_OP_HALFWORD(bin_inst, 0, extract_result);                \
+    __ b(&done);                                                        \
+    /* ending in 0b01 */                                                \
+    __ bind(&one);                                                      \
+    ATOMIC_BIN_OP_HALFWORD(bin_inst, 1, extract_result);                \
+    __ b(&done);                                                        \
+    /* ending in 0b10 */                                                \
+    __ bind(&two);                                                      \
+    ATOMIC_BIN_OP_HALFWORD(bin_inst, 2, extract_result);                \
+    __ b(&done);                                                        \
+    /* ending in 0b11 */                                                \
+    __ bind(&three);                                                    \
+    ATOMIC_BIN_OP_HALFWORD(bin_inst, 3, extract_result);                \
+    __ bind(&done);                                                     \
+  } while (false)
+
+#define ASSEMBLE_ATOMIC64_BINOP_WORD(bin_inst, extract_result)      \
+  do {                                                              \
+    Register value = i.InputRegister(2);                            \
+    Register result = i.OutputRegister(0);                          \
+    Register prev = i.TempRegister(0);                              \
+    Register new_val = r0;                                          \
+    Register addr = r1;                                             \
+    Register temp = kScratchReg;                                    \
+    AddressingMode mode = kMode_None;                               \
+    MemOperand op = i.MemoryOperand(&mode);                         \
+    Label done, one;                                                \
+    __ lay(addr, op);                                               \
+    __ tmll(addr, Operand(4));                                      \
+    __ b(Condition(2), &one);                                       \
+    /* ending in 0b000 */                                           \
+    ATOMIC_BIN_OP_WORD(bin_inst, 0, extract_result);                \
+    __ b(&done);                                                    \
+    __ bind(&one);                                                  \
+    /* ending in 0b100 */                                           \
+    ATOMIC_BIN_OP_WORD(bin_inst, 1, extract_result);                \
+    __ bind(&done);                                                 \
+  } while (false)
+
+#define ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, offset)            \
+  {                                                                         \
+    __ lg(temp0, MemOperand(addr, offset));                                 \
+    __ lgr(temp1, temp0);                                                   \
+    __ RotateInsertSelectBits(temp0, old_val, Operand(start),               \
+             Operand(end), Operand(shift_amount), false);                   \
+    __ RotateInsertSelectBits(temp1, new_val, Operand(start),               \
+             Operand(end), Operand(shift_amount), false);                   \
+    __ CmpAndSwap64(temp0, temp1, MemOperand(addr, offset));                \
+    __ RotateInsertSelectBits(output, temp0, Operand(start+shift_amount),   \
+             Operand(end+shift_amount), Operand(64-shift_amount), true);    \
+  }
+
+#ifdef V8_TARGET_BIG_ENDIAN
+#define ATOMIC64_COMP_EXCHANGE_BYTE(i)                                  \
+  {                                                                     \
+    constexpr int idx = (i);                                            \
+    constexpr int start = 8 * idx;                                      \
+    constexpr int end = start + 7;                                      \
+    constexpr int shift_amount = (7 - idx) * 8;                         \
+    ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, -idx);             \
+  }
+#define ATOMIC64_COMP_EXCHANGE_HALFWORD(i)                              \
+  {                                                                     \
+    constexpr int idx = (i);                                            \
+    constexpr int start = 16 * idx;                                     \
+    constexpr int end = start + 15;                                     \
+    constexpr int shift_amount = (3 - idx) * 16;                        \
+    ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, -idx * 2);         \
+  }
+#define ATOMIC64_COMP_EXCHANGE_WORD(i)                                  \
+  {                                                                     \
+    constexpr int idx = (i);                                            \
+    constexpr int start = 32 * idx;                                     \
+    constexpr int end = start + 31;                                     \
+    constexpr int shift_amount = (1 - idx) * 32;                        \
+    ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, -idx * 4);         \
+  }
+#else
+#define ATOMIC64_COMP_EXCHANGE_BYTE(i)                                  \
+  {                                                                     \
+    constexpr int idx = (i);                                            \
+    constexpr int start = 32 + 8 * (3 - idx);                           \
+    constexpr int end = start + 7;                                      \
+    constexpr int shift_amount = idx * 8;                               \
+    ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, -idx);             \
+  }
+#define ATOMIC64_COMP_EXCHANGE_HALFWORD(i)                              \
+  {                                                                     \
+    constexpr int idx = (i);                                            \
+    constexpr int start = 32 + 16 * (1 - idx);                          \
+    constexpr int end = start + 15;                                     \
+    constexpr int shift_amount = idx * 16;                              \
+    ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, -idx * 2);         \
+  }
+#define ATOMIC64_COMP_EXCHANGE_WORD(i)                                  \
+  {                                                                     \
+    constexpr int idx = (i);                                            \
+    constexpr int start = 32 * (1 - idx);                               \
+    constexpr int end = start + 31;                                     \
+    constexpr int shift_amount = idx * 32;                              \
+    ATOMIC64_COMP_EXCHANGE(start, end, shift_amount, -idx * 4);         \
+  }
+#endif
+
+#define ASSEMBLE_ATOMIC64_COMP_EXCHANGE_BYTE(load_and_ext)           \
+  do {                                                               \
+    Register old_val = i.InputRegister(0);                           \
+    Register new_val = i.InputRegister(1);                           \
+    Register output = i.OutputRegister();                            \
+    Register addr = kScratchReg;                                     \
+    Register temp0 = r0;                                             \
+    Register temp1 = r1;                                             \
+    size_t index = 2;                                                \
+    AddressingMode mode = kMode_None;                                \
+    MemOperand op = i.MemoryOperand(&mode, &index);                  \
+    Label done, leftmost0, leftmost1, two, three, four, five, seven; \
+    __ lay(addr, op);                                                \
+    __ tmll(addr, Operand(7));                                       \
+    __ b(Condition(1), &seven);                                      \
+    __ b(Condition(2), &leftmost1);                                  \
+    __ b(Condition(4), &leftmost0);                                  \
+    /* ending with 0b000 */                                          \
+    ATOMIC64_COMP_EXCHANGE_BYTE(0);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b001 to 0b011 */                                   \
+    __ bind(&leftmost0);                                             \
+    __ tmll(addr, Operand(3));                                       \
+    __ b(Condition(1), &three);                                      \
+    __ b(Condition(2), &two);                                        \
+    ATOMIC64_COMP_EXCHANGE_BYTE(1);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b010 */                                            \
+    __ bind(&two);                                                   \
+    ATOMIC64_COMP_EXCHANGE_BYTE(2);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b011 */                                            \
+    __ bind(&three);                                                 \
+    ATOMIC64_COMP_EXCHANGE_BYTE(3);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b100 to 0b110 */                                   \
+    __ bind(&leftmost1);                                             \
+    __ tmll(addr, Operand(3));                                       \
+    __ b(Condition(8), &four);                                       \
+    __ b(Condition(4), &five);                                       \
+    ATOMIC64_COMP_EXCHANGE_BYTE(6);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b100 */                                            \
+    __ bind(&four);                                                  \
+    ATOMIC64_COMP_EXCHANGE_BYTE(4);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b101 */                                            \
+    __ bind(&five);                                                  \
+    ATOMIC64_COMP_EXCHANGE_BYTE(5);                                  \
+    __ b(&done);                                                     \
+    /* ending in 0b111 */                                            \
+    __ bind(&seven);                                                 \
+    ATOMIC64_COMP_EXCHANGE_BYTE(7);                                  \
+    __ bind(&done);                                                  \
+    __ load_and_ext(output, output);                                 \
+  } while (false)
+
+#define ASSEMBLE_ATOMIC64_COMP_EXCHANGE_HALFWORD(load_and_ext)       \
+  do {                                                               \
+    Register old_val = i.InputRegister(0);                           \
+    Register new_val = i.InputRegister(1);                           \
+    Register output = i.OutputRegister();                            \
+    Register addr = kScratchReg;                                     \
+    Register temp0 = r0;                                             \
+    Register temp1 = r1;                                             \
+    size_t index = 2;                                                \
+    AddressingMode mode = kMode_None;                                \
+    MemOperand op = i.MemoryOperand(&mode, &index);                  \
+    Label done, one, two, three;                                     \
+    __ lay(addr, op);                                                \
+    __ tmll(addr, Operand(6));                                       \
+    __ b(Condition(1), &three);                                      \
+    __ b(Condition(2), &two);                                        \
+    __ b(Condition(4), &one);                                        \
+    /* ending in 0b00 */                                             \
+    ATOMIC64_COMP_EXCHANGE_HALFWORD(0);                              \
+    __ b(&done);                                                     \
+    /* ending in 0b01 */                                             \
+    __ bind(&one);                                                   \
+    ATOMIC64_COMP_EXCHANGE_HALFWORD(1);                              \
+    __ b(&done);                                                     \
+    /* ending in 0b10 */                                             \
+    __ bind(&two);                                                   \
+    ATOMIC64_COMP_EXCHANGE_HALFWORD(2);                              \
+    __ b(&done);                                                     \
+    /* ending in 0b11 */                                             \
+    __ bind(&three);                                                 \
+    ATOMIC64_COMP_EXCHANGE_HALFWORD(3);                              \
+    __ bind(&done);                                                  \
+    __ load_and_ext(output, output);                                 \
+  } while (false)
+
+#define ASSEMBLE_ATOMIC64_COMP_EXCHANGE_WORD(load_and_ext)     \
+  do {                                                         \
+    Register old_val = i.InputRegister(0);                     \
+    Register new_val = i.InputRegister(1);                     \
+    Register output = i.OutputRegister();                      \
+    Register addr = kScratchReg;                               \
+    Register temp0 = r0;                                       \
+    Register temp1 = r1;                                       \
+    size_t index = 2;                                          \
+    AddressingMode mode = kMode_None;                          \
+    MemOperand op = i.MemoryOperand(&mode, &index);            \
+    Label done, one;                                           \
+    __ lay(addr, op);                                          \
+    __ tmll(addr, Operand(4));                                 \
+    __ b(Condition(2), &one);                                  \
+    /* ending in 0b000 */                                      \
+    ATOMIC64_COMP_EXCHANGE_WORD(0);                            \
+    __ b(&done);                                               \
+    __ bind(&one);                                             \
+    /* ending in 0b100 */                                      \
+    ATOMIC64_COMP_EXCHANGE_WORD(1);                            \
+    __ bind(&done);                                            \
+    __ load_and_ext(output, output);                           \
+  } while (false)
+
+#define ASSEMBLE_ATOMIC64_COMP_EXCHANGE_WORD64()                 \
+  do {                                                           \
+    Register new_val = i.InputRegister(1);                       \
+    Register output = i.OutputRegister();                        \
+    Register addr = kScratchReg;                                 \
+    size_t index = 2;                                            \
+    AddressingMode mode = kMode_None;                            \
+    MemOperand op = i.MemoryOperand(&mode, &index);              \
+    __ lay(addr, op);                                            \
+    __ CmpAndSwap64(output, new_val, MemOperand(addr));          \
+  } while (false)
+
 void CodeGenerator::AssembleDeconstructFrame() {
   __ LeaveFrame(StackFrame::MANUAL);
 }
@@ -2744,6 +3098,260 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kWord32AtomicXorWord32:
       ASSEMBLE_ATOMIC_BINOP_WORD(lax);
       break;
+    case kS390_Word64AtomicLoadUint8:
+      __ LoadlB(i.OutputRegister(), i.MemoryOperand());
+      break;
+    case kS390_Word64AtomicLoadUint16:
+      __ LoadLogicalHalfWordP(i.OutputRegister(), i.MemoryOperand());
+      break;
+    case kS390_Word64AtomicLoadUint32:
+      __ LoadlW(i.OutputRegister(), i.MemoryOperand());
+      break;
+    case kS390_Word64AtomicLoadUint64:
+      __ lg(i.OutputRegister(), i.MemoryOperand());
+      break;
+    case kS390_Word64AtomicStoreUint8:
+      __ StoreByte(i.InputRegister(0), i.MemoryOperand(nullptr, 1));
+      break;
+    case kS390_Word64AtomicStoreUint16:
+      __ StoreHalfWord(i.InputRegister(0), i.MemoryOperand(nullptr, 1));
+      break;
+    case kS390_Word64AtomicStoreUint32:
+      __ StoreW(i.InputRegister(0), i.MemoryOperand(nullptr, 1));
+      break;
+    case kS390_Word64AtomicStoreUint64:
+      __ stg(i.InputRegister(0), i.MemoryOperand(nullptr, 1));
+      break;
+#define ATOMIC64_BINOP_CASE(op, inst)                                        \
+  case kS390_Word64Atomic##op##Uint8:                                        \
+    ASSEMBLE_ATOMIC64_BINOP_BYTE(inst, [&]() {                               \
+      int rotate_left = shift_amount == 0 ? 0 : 64 - shift_amount;           \
+      __ RotateInsertSelectBits(result, prev, Operand(56), Operand(63),      \
+                                Operand(static_cast<intptr_t>(rotate_left)), \
+                                true);                                       \
+    });                                                                      \
+    break;                                                                   \
+  case kS390_Word64Atomic##op##Uint16:                                       \
+    ASSEMBLE_ATOMIC64_BINOP_HALFWORD(inst, [&]() {                           \
+      int rotate_left = shift_amount == 0 ? 0 : 64 - shift_amount;           \
+      __ RotateInsertSelectBits(result, prev, Operand(48), Operand(63),      \
+                                Operand(static_cast<intptr_t>(rotate_left)), \
+                                true);                                       \
+    });                                                                      \
+    break;                                                                   \
+  case kS390_Word64Atomic##op##Uint32:                                       \
+    ASSEMBLE_ATOMIC64_BINOP_WORD(inst, [&]() {                               \
+      int rotate_left = shift_amount == 0 ? 0 : 64 - shift_amount;           \
+      __ RotateInsertSelectBits(result, prev, Operand(32), Operand(63),      \
+                                Operand(static_cast<intptr_t>(rotate_left)), \
+                                true);                                       \
+    });                                                                      \
+    break;
+      ATOMIC64_BINOP_CASE(Add, AddP)
+      ATOMIC64_BINOP_CASE(Sub, SubP)
+      ATOMIC64_BINOP_CASE(And, AndP)
+      ATOMIC64_BINOP_CASE(Or, OrP)
+      ATOMIC64_BINOP_CASE(Xor, XorP)
+#undef ATOMIC64_BINOP_CASE
+    case kS390_Word64AtomicAddUint64:
+      ASSEMBLE_ATOMIC_BINOP_WORD64(laag);
+      break;
+    case kS390_Word64AtomicSubUint64:
+      ASSEMBLE_ATOMIC_BINOP_WORD64(LoadAndSub64);
+      break;
+    case kS390_Word64AtomicAndUint64:
+      ASSEMBLE_ATOMIC_BINOP_WORD64(lang);
+      break;
+    case kS390_Word64AtomicOrUint64:
+      ASSEMBLE_ATOMIC_BINOP_WORD64(laog);
+      break;
+    case kS390_Word64AtomicXorUint64:
+      ASSEMBLE_ATOMIC_BINOP_WORD64(laxg);
+      break;
+#define ATOMIC64_EXCHANGE(start, end, shift_amount, offset)              \
+  {                                                                      \
+    Label do_cs;                                                         \
+    __ lg(output, MemOperand(r1, offset));                               \
+    __ bind(&do_cs);                                                     \
+    __ lgr(r0, output);                                                  \
+    __ RotateInsertSelectBits(r0, value, Operand(start), Operand(end),   \
+             Operand(shift_amount), false);                              \
+    __ csg(output, r0, MemOperand(r1, offset));                          \
+    __ bne(&do_cs, Label::kNear);                                        \
+    __ srlg(output, output, Operand(shift_amount));                      \
+  }
+#ifdef V8_TARGET_BIG_ENDIAN
+#define ATOMIC64_EXCHANGE_BYTE(i)                              \
+  {                                                            \
+    constexpr int idx = (i);                                   \
+    constexpr int start = 8 * idx;                             \
+    constexpr int end = start + 7;                             \
+    constexpr int shift_amount = (7 - idx) * 8;                \
+    ATOMIC64_EXCHANGE(start, end, shift_amount, -idx);         \
+  }
+#define ATOMIC64_EXCHANGE_HALFWORD(i)                          \
+  {                                                            \
+    constexpr int idx = (i);                                   \
+    constexpr int start = 16 * idx;                            \
+    constexpr int end = start + 15;                            \
+    constexpr int shift_amount = (3 - idx) * 16;               \
+    ATOMIC64_EXCHANGE(start, end, shift_amount, -idx * 2);     \
+  }
+#define ATOMIC64_EXCHANGE_WORD(i)                              \
+  {                                                            \
+    constexpr int idx = (i);                                   \
+    constexpr int start = 32 * idx;                            \
+    constexpr int end = start + 31;                            \
+    constexpr int shift_amount = (1 - idx) * 32;               \
+    ATOMIC64_EXCHANGE(start, end, shift_amount, -idx * 4);     \
+  }
+#else
+#define ATOMIC64_EXCHANGE_BYTE(i)                              \
+  {                                                            \
+    constexpr int idx = (i);                                   \
+    constexpr int start = 32 + 8 * (3 - idx);                  \
+    constexpr int end = start + 7;                             \
+    constexpr int shift_amount = idx * 8;                      \
+    ATOMIC64_EXCHANGE(start, end, shift_amount, -idx);         \
+  }
+#define ATOMIC64_EXCHANGE_HALFWORD(i)                          \
+  {                                                            \
+    constexpr int idx = (i);                                   \
+    constexpr int start = 32 + 16 * (1 - idx);                 \
+    constexpr int end = start + 15;                            \
+    constexpr int shift_amount = idx * 16;                     \
+    ATOMIC64_EXCHANGE(start, end, shift_amount, -idx * 2);     \
+  }
+#define ATOMIC64_EXCHANGE_WORD(i)                              \
+  {                                                            \
+    constexpr int idx = (i);                                   \
+    constexpr int start = 32 * (1 - idx);                      \
+    constexpr int end = start + 31;                            \
+    constexpr int shift_amount = idx * 32;                     \
+    ATOMIC64_EXCHANGE(start, end, shift_amount, -idx * 4);     \
+  }
+#endif  // V8_TARGET_BIG_ENDIAN
+    case kS390_Word64AtomicExchangeUint8: {
+      Register base = i.InputRegister(0);
+      Register index = i.InputRegister(1);
+      Register value = i.InputRegister(2);
+      Register output = i.OutputRegister();
+      Label done, leftmost0, leftmost1, two, three, four, five, seven;
+      __ la(r1, MemOperand(base, index));
+      __ tmll(r1, Operand(7));
+      __ b(Condition(1), &seven);
+      __ b(Condition(2), &leftmost1);
+      __ b(Condition(4), &leftmost0);
+      /* ending with 0b000 */
+      ATOMIC64_EXCHANGE_BYTE(0);
+      __ b(&done);
+      /* ending in 0b001 to 0b011 */
+      __ bind(&leftmost0);
+      __ tmll(r1, Operand(3));
+      __ b(Condition(1), &three);
+      __ b(Condition(2), &two);
+      ATOMIC64_EXCHANGE_BYTE(1);
+      __ b(&done);
+      /* ending in 0b010 */
+      __ bind(&two);
+      ATOMIC64_EXCHANGE_BYTE(2);
+      __ b(&done);
+      /* ending in 0b011 */
+      __ bind(&three);
+      ATOMIC64_EXCHANGE_BYTE(3);
+      __ b(&done);
+      /* ending in 0b100 to 0b110 */
+      __ bind(&leftmost1);
+      __ tmll(r1, Operand(3));
+      __ b(Condition(8), &four);
+      __ b(Condition(4), &five);
+      ATOMIC64_EXCHANGE_BYTE(6);
+      __ b(&done);
+      /* ending in 0b100 */
+      __ bind(&four);
+      ATOMIC64_EXCHANGE_BYTE(4);
+      __ b(&done);
+      /* ending in 0b101 */
+      __ bind(&five);
+      ATOMIC64_EXCHANGE_BYTE(5);
+      __ b(&done);
+      /* ending in 0b111 */
+      __ bind(&seven);
+      ATOMIC64_EXCHANGE_BYTE(7);
+      __ bind(&done);
+      break;
+    }
+    case kS390_Word64AtomicExchangeUint16: {
+      Register base = i.InputRegister(0);
+      Register index = i.InputRegister(1);
+      Register value = i.InputRegister(2);
+      Register output = i.OutputRegister();
+      Label done, one, two, three;
+      __ la(r1, MemOperand(base, index));
+      __ tmll(r1, Operand(6));
+      __ b(Condition(1), &three);
+      __ b(Condition(2), &two);
+      __ b(Condition(4), &one);
+      /* ending in 0b00 */
+      ATOMIC64_EXCHANGE_HALFWORD(0);
+      __ b(&done);
+      /* ending in 0b01 */
+      __ bind(&one);
+      ATOMIC64_EXCHANGE_HALFWORD(1);
+      __ b(&done);
+      /* ending in 0b10 */
+      __ bind(&two);
+      ATOMIC64_EXCHANGE_HALFWORD(2);
+      __ b(&done);
+      /* ending in 0b11 */
+      __ bind(&three);
+      ATOMIC64_EXCHANGE_HALFWORD(3);
+      __ bind(&done);
+      break;
+    }
+    case kS390_Word64AtomicExchangeUint32: {
+      Register base = i.InputRegister(0);
+      Register index = i.InputRegister(1);
+      Register value = i.InputRegister(2);
+      Register output = i.OutputRegister();
+      Label done, one;
+      __ la(r1, MemOperand(base, index));
+      __ tmll(r1, Operand(4));
+      __ b(Condition(2), &one);
+      /* ending in 0b0 */
+      ATOMIC64_EXCHANGE_WORD(0);
+      __ b(&done);
+      __ bind(&one);
+      /* ending in 0b1 */
+      ATOMIC64_EXCHANGE_WORD(1);
+      __ bind(&done);
+      break;
+    }
+    case kS390_Word64AtomicExchangeUint64: {
+      Register base = i.InputRegister(0);
+      Register index = i.InputRegister(1);
+      Register value = i.InputRegister(2);
+      Register output = i.OutputRegister();
+      Label do_cs;
+      __ la(r1, MemOperand(base, index));
+      __ lg(output, MemOperand(r1));
+      __ csg(output, value, MemOperand(r1));
+      __ bind(&do_cs);
+      __ bne(&do_cs, Label::kNear);
+      break;
+    }
+    case kS390_Word64AtomicCompareExchangeUint8:
+      ASSEMBLE_ATOMIC64_COMP_EXCHANGE_BYTE(LoadlB);
+      break;
+    case kS390_Word64AtomicCompareExchangeUint16:
+      ASSEMBLE_ATOMIC64_COMP_EXCHANGE_HALFWORD(LoadLogicalHalfWordP);
+      break;
+    case kS390_Word64AtomicCompareExchangeUint32:
+      ASSEMBLE_ATOMIC64_COMP_EXCHANGE_WORD(LoadlW);
+      break;
+    case kS390_Word64AtomicCompareExchangeUint64:
+      ASSEMBLE_ATOMIC64_COMP_EXCHANGE_WORD64();
+      break;
     default:
       UNREACHABLE();
       break;
@@ -2776,7 +3384,8 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
 void CodeGenerator::AssembleBranchPoisoning(FlagsCondition condition,
                                             Instruction* instr) {
   // TODO(John) Handle float comparisons (kUnordered[Not]Equal).
-  if (condition == kUnorderedEqual || condition == kUnorderedNotEqual) {
+  if (condition == kUnorderedEqual || condition == kUnorderedNotEqual ||
+      condition == kOverflow || condition == kNotOverflow) {
     return;
   }
 
@@ -3170,9 +3779,13 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ Move(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ mov(dst, Operand::EmbeddedStringConstant(
+                          src.ToDelayedStringConstant()));
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
-          Heap::RootListIndex index;
+          RootIndex index;
           if (IsMaterializableFromRoot(src_object, &index)) {
             __ LoadRoot(dst, index);
           } else {
diff --git a/deps/v8/src/compiler/s390/instruction-codes-s390.h b/deps/v8/src/compiler/s390/instruction-codes-s390.h
index b5296f63d0..9a704f9bef 100644
--- a/deps/v8/src/compiler/s390/instruction-codes-s390.h
+++ b/deps/v8/src/compiler/s390/instruction-codes-s390.h
@@ -11,157 +11,193 @@ namespace compiler {
 
 // S390-specific opcodes that specify which assembly sequence to emit.
 // Most opcodes specify a single instruction.
-#define TARGET_ARCH_OPCODE_LIST(V) \
-  V(S390_Abs32)                    \
-  V(S390_Abs64)                    \
-  V(S390_And32)                    \
-  V(S390_And64)                    \
-  V(S390_Or32)                     \
-  V(S390_Or64)                     \
-  V(S390_Xor32)                    \
-  V(S390_Xor64)                    \
-  V(S390_ShiftLeft32)              \
-  V(S390_ShiftLeft64)              \
-  V(S390_ShiftLeftPair)            \
-  V(S390_ShiftRight32)             \
-  V(S390_ShiftRight64)             \
-  V(S390_ShiftRightPair)           \
-  V(S390_ShiftRightArith32)        \
-  V(S390_ShiftRightArith64)        \
-  V(S390_ShiftRightArithPair)      \
-  V(S390_RotRight32)               \
-  V(S390_RotRight64)               \
-  V(S390_Not32)                    \
-  V(S390_Not64)                    \
-  V(S390_RotLeftAndClear64)        \
-  V(S390_RotLeftAndClearLeft64)    \
-  V(S390_RotLeftAndClearRight64)   \
-  V(S390_Lay)                      \
-  V(S390_Add32)                    \
-  V(S390_Add64)                    \
-  V(S390_AddPair)                  \
-  V(S390_AddFloat)                 \
-  V(S390_AddDouble)                \
-  V(S390_Sub32)                    \
-  V(S390_Sub64)                    \
-  V(S390_SubFloat)                 \
-  V(S390_SubDouble)                \
-  V(S390_SubPair)                  \
-  V(S390_MulPair)                  \
-  V(S390_Mul32)                    \
-  V(S390_Mul32WithOverflow)        \
-  V(S390_Mul64)                    \
-  V(S390_MulHigh32)                \
-  V(S390_MulHighU32)               \
-  V(S390_MulFloat)                 \
-  V(S390_MulDouble)                \
-  V(S390_Div32)                    \
-  V(S390_Div64)                    \
-  V(S390_DivU32)                   \
-  V(S390_DivU64)                   \
-  V(S390_DivFloat)                 \
-  V(S390_DivDouble)                \
-  V(S390_Mod32)                    \
-  V(S390_Mod64)                    \
-  V(S390_ModU32)                   \
-  V(S390_ModU64)                   \
-  V(S390_ModDouble)                \
-  V(S390_Neg32)                    \
-  V(S390_Neg64)                    \
-  V(S390_NegDouble)                \
-  V(S390_NegFloat)                 \
-  V(S390_SqrtFloat)                \
-  V(S390_FloorFloat)               \
-  V(S390_CeilFloat)                \
-  V(S390_TruncateFloat)            \
-  V(S390_AbsFloat)                 \
-  V(S390_SqrtDouble)               \
-  V(S390_FloorDouble)              \
-  V(S390_CeilDouble)               \
-  V(S390_TruncateDouble)           \
-  V(S390_RoundDouble)              \
-  V(S390_MaxFloat)                 \
-  V(S390_MaxDouble)                \
-  V(S390_MinFloat)                 \
-  V(S390_MinDouble)                \
-  V(S390_AbsDouble)                \
-  V(S390_Cntlz32)                  \
-  V(S390_Cntlz64)                  \
-  V(S390_Popcnt32)                 \
-  V(S390_Popcnt64)                 \
-  V(S390_Cmp32)                    \
-  V(S390_Cmp64)                    \
-  V(S390_CmpFloat)                 \
-  V(S390_CmpDouble)                \
-  V(S390_Tst32)                    \
-  V(S390_Tst64)                    \
-  V(S390_Push)                     \
-  V(S390_PushFrame)                \
-  V(S390_StackClaim)               \
-  V(S390_StoreToStackSlot)         \
-  V(S390_SignExtendWord8ToInt32)   \
-  V(S390_SignExtendWord16ToInt32)  \
-  V(S390_SignExtendWord8ToInt64)   \
-  V(S390_SignExtendWord16ToInt64)  \
-  V(S390_SignExtendWord32ToInt64)  \
-  V(S390_Uint32ToUint64)           \
-  V(S390_Int64ToInt32)             \
-  V(S390_Int64ToFloat32)           \
-  V(S390_Int64ToDouble)            \
-  V(S390_Uint64ToFloat32)          \
-  V(S390_Uint64ToDouble)           \
-  V(S390_Int32ToFloat32)           \
-  V(S390_Int32ToDouble)            \
-  V(S390_Uint32ToFloat32)          \
-  V(S390_Uint32ToDouble)           \
-  V(S390_Float32ToInt64)           \
-  V(S390_Float32ToUint64)          \
-  V(S390_Float32ToInt32)           \
-  V(S390_Float32ToUint32)          \
-  V(S390_Float32ToDouble)          \
-  V(S390_Float64SilenceNaN)        \
-  V(S390_DoubleToInt32)            \
-  V(S390_DoubleToUint32)           \
-  V(S390_DoubleToInt64)            \
-  V(S390_DoubleToUint64)           \
-  V(S390_DoubleToFloat32)          \
-  V(S390_DoubleExtractLowWord32)   \
-  V(S390_DoubleExtractHighWord32)  \
-  V(S390_DoubleInsertLowWord32)    \
-  V(S390_DoubleInsertHighWord32)   \
-  V(S390_DoubleConstruct)          \
-  V(S390_BitcastInt32ToFloat32)    \
-  V(S390_BitcastFloat32ToInt32)    \
-  V(S390_BitcastInt64ToDouble)     \
-  V(S390_BitcastDoubleToInt64)     \
-  V(S390_LoadWordS8)               \
-  V(S390_LoadWordU8)               \
-  V(S390_LoadWordS16)              \
-  V(S390_LoadWordU16)              \
-  V(S390_LoadWordS32)              \
-  V(S390_LoadWordU32)              \
-  V(S390_LoadAndTestWord32)        \
-  V(S390_LoadAndTestWord64)        \
-  V(S390_LoadAndTestFloat32)       \
-  V(S390_LoadAndTestFloat64)       \
-  V(S390_LoadReverse16RR)          \
-  V(S390_LoadReverse32RR)          \
-  V(S390_LoadReverse64RR)          \
-  V(S390_LoadReverse16)            \
-  V(S390_LoadReverse32)            \
-  V(S390_LoadReverse64)            \
-  V(S390_LoadWord64)               \
-  V(S390_LoadFloat32)              \
-  V(S390_LoadDouble)               \
-  V(S390_StoreWord8)               \
-  V(S390_StoreWord16)              \
-  V(S390_StoreWord32)              \
-  V(S390_StoreWord64)              \
-  V(S390_StoreReverse16)           \
-  V(S390_StoreReverse32)           \
-  V(S390_StoreReverse64)           \
-  V(S390_StoreFloat32)             \
-  V(S390_StoreDouble)
+#define TARGET_ARCH_OPCODE_LIST(V)            \
+  V(S390_Abs32)                               \
+  V(S390_Abs64)                               \
+  V(S390_And32)                               \
+  V(S390_And64)                               \
+  V(S390_Or32)                                \
+  V(S390_Or64)                                \
+  V(S390_Xor32)                               \
+  V(S390_Xor64)                               \
+  V(S390_ShiftLeft32)                         \
+  V(S390_ShiftLeft64)                         \
+  V(S390_ShiftLeftPair)                       \
+  V(S390_ShiftRight32)                        \
+  V(S390_ShiftRight64)                        \
+  V(S390_ShiftRightPair)                      \
+  V(S390_ShiftRightArith32)                   \
+  V(S390_ShiftRightArith64)                   \
+  V(S390_ShiftRightArithPair)                 \
+  V(S390_RotRight32)                          \
+  V(S390_RotRight64)                          \
+  V(S390_Not32)                               \
+  V(S390_Not64)                               \
+  V(S390_RotLeftAndClear64)                   \
+  V(S390_RotLeftAndClearLeft64)               \
+  V(S390_RotLeftAndClearRight64)              \
+  V(S390_Lay)                                 \
+  V(S390_Add32)                               \
+  V(S390_Add64)                               \
+  V(S390_AddPair)                             \
+  V(S390_AddFloat)                            \
+  V(S390_AddDouble)                           \
+  V(S390_Sub32)                               \
+  V(S390_Sub64)                               \
+  V(S390_SubFloat)                            \
+  V(S390_SubDouble)                           \
+  V(S390_SubPair)                             \
+  V(S390_MulPair)                             \
+  V(S390_Mul32)                               \
+  V(S390_Mul32WithOverflow)                   \
+  V(S390_Mul64)                               \
+  V(S390_MulHigh32)                           \
+  V(S390_MulHighU32)                          \
+  V(S390_MulFloat)                            \
+  V(S390_MulDouble)                           \
+  V(S390_Div32)                               \
+  V(S390_Div64)                               \
+  V(S390_DivU32)                              \
+  V(S390_DivU64)                              \
+  V(S390_DivFloat)                            \
+  V(S390_DivDouble)                           \
+  V(S390_Mod32)                               \
+  V(S390_Mod64)                               \
+  V(S390_ModU32)                              \
+  V(S390_ModU64)                              \
+  V(S390_ModDouble)                           \
+  V(S390_Neg32)                               \
+  V(S390_Neg64)                               \
+  V(S390_NegDouble)                           \
+  V(S390_NegFloat)                            \
+  V(S390_SqrtFloat)                           \
+  V(S390_FloorFloat)                          \
+  V(S390_CeilFloat)                           \
+  V(S390_TruncateFloat)                       \
+  V(S390_AbsFloat)                            \
+  V(S390_SqrtDouble)                          \
+  V(S390_FloorDouble)                         \
+  V(S390_CeilDouble)                          \
+  V(S390_TruncateDouble)                      \
+  V(S390_RoundDouble)                         \
+  V(S390_MaxFloat)                            \
+  V(S390_MaxDouble)                           \
+  V(S390_MinFloat)                            \
+  V(S390_MinDouble)                           \
+  V(S390_AbsDouble)                           \
+  V(S390_Cntlz32)                             \
+  V(S390_Cntlz64)                             \
+  V(S390_Popcnt32)                            \
+  V(S390_Popcnt64)                            \
+  V(S390_Cmp32)                               \
+  V(S390_Cmp64)                               \
+  V(S390_CmpFloat)                            \
+  V(S390_CmpDouble)                           \
+  V(S390_Tst32)                               \
+  V(S390_Tst64)                               \
+  V(S390_Push)                                \
+  V(S390_PushFrame)                           \
+  V(S390_StackClaim)                          \
+  V(S390_StoreToStackSlot)                    \
+  V(S390_SignExtendWord8ToInt32)              \
+  V(S390_SignExtendWord16ToInt32)             \
+  V(S390_SignExtendWord8ToInt64)              \
+  V(S390_SignExtendWord16ToInt64)             \
+  V(S390_SignExtendWord32ToInt64)             \
+  V(S390_Uint32ToUint64)                      \
+  V(S390_Int64ToInt32)                        \
+  V(S390_Int64ToFloat32)                      \
+  V(S390_Int64ToDouble)                       \
+  V(S390_Uint64ToFloat32)                     \
+  V(S390_Uint64ToDouble)                      \
+  V(S390_Int32ToFloat32)                      \
+  V(S390_Int32ToDouble)                       \
+  V(S390_Uint32ToFloat32)                     \
+  V(S390_Uint32ToDouble)                      \
+  V(S390_Float32ToInt64)                      \
+  V(S390_Float32ToUint64)                     \
+  V(S390_Float32ToInt32)                      \
+  V(S390_Float32ToUint32)                     \
+  V(S390_Float32ToDouble)                     \
+  V(S390_Float64SilenceNaN)                   \
+  V(S390_DoubleToInt32)                       \
+  V(S390_DoubleToUint32)                      \
+  V(S390_DoubleToInt64)                       \
+  V(S390_DoubleToUint64)                      \
+  V(S390_DoubleToFloat32)                     \
+  V(S390_DoubleExtractLowWord32)              \
+  V(S390_DoubleExtractHighWord32)             \
+  V(S390_DoubleInsertLowWord32)               \
+  V(S390_DoubleInsertHighWord32)              \
+  V(S390_DoubleConstruct)                     \
+  V(S390_BitcastInt32ToFloat32)               \
+  V(S390_BitcastFloat32ToInt32)               \
+  V(S390_BitcastInt64ToDouble)                \
+  V(S390_BitcastDoubleToInt64)                \
+  V(S390_LoadWordS8)                          \
+  V(S390_LoadWordU8)                          \
+  V(S390_LoadWordS16)                         \
+  V(S390_LoadWordU16)                         \
+  V(S390_LoadWordS32)                         \
+  V(S390_LoadWordU32)                         \
+  V(S390_LoadAndTestWord32)                   \
+  V(S390_LoadAndTestWord64)                   \
+  V(S390_LoadAndTestFloat32)                  \
+  V(S390_LoadAndTestFloat64)                  \
+  V(S390_LoadReverse16RR)                     \
+  V(S390_LoadReverse32RR)                     \
+  V(S390_LoadReverse64RR)                     \
+  V(S390_LoadReverse16)                       \
+  V(S390_LoadReverse32)                       \
+  V(S390_LoadReverse64)                       \
+  V(S390_LoadWord64)                          \
+  V(S390_LoadFloat32)                         \
+  V(S390_LoadDouble)                          \
+  V(S390_StoreWord8)                          \
+  V(S390_StoreWord16)                         \
+  V(S390_StoreWord32)                         \
+  V(S390_StoreWord64)                         \
+  V(S390_StoreReverse16)                      \
+  V(S390_StoreReverse32)                      \
+  V(S390_StoreReverse64)                      \
+  V(S390_StoreFloat32)                        \
+  V(S390_StoreDouble)                         \
+  V(S390_Word64AtomicLoadUint8)               \
+  V(S390_Word64AtomicLoadUint16)              \
+  V(S390_Word64AtomicLoadUint32)              \
+  V(S390_Word64AtomicLoadUint64)              \
+  V(S390_Word64AtomicStoreUint8)              \
+  V(S390_Word64AtomicStoreUint16)             \
+  V(S390_Word64AtomicStoreUint32)             \
+  V(S390_Word64AtomicStoreUint64)             \
+  V(S390_Word64AtomicExchangeUint8)           \
+  V(S390_Word64AtomicExchangeUint16)          \
+  V(S390_Word64AtomicExchangeUint32)          \
+  V(S390_Word64AtomicExchangeUint64)          \
+  V(S390_Word64AtomicCompareExchangeUint8)    \
+  V(S390_Word64AtomicCompareExchangeUint16)   \
+  V(S390_Word64AtomicCompareExchangeUint32)   \
+  V(S390_Word64AtomicCompareExchangeUint64)   \
+  V(S390_Word64AtomicAddUint8)                \
+  V(S390_Word64AtomicAddUint16)               \
+  V(S390_Word64AtomicAddUint32)               \
+  V(S390_Word64AtomicAddUint64)               \
+  V(S390_Word64AtomicSubUint8)                \
+  V(S390_Word64AtomicSubUint16)               \
+  V(S390_Word64AtomicSubUint32)               \
+  V(S390_Word64AtomicSubUint64)               \
+  V(S390_Word64AtomicAndUint8)                \
+  V(S390_Word64AtomicAndUint16)               \
+  V(S390_Word64AtomicAndUint32)               \
+  V(S390_Word64AtomicAndUint64)               \
+  V(S390_Word64AtomicOrUint8)                 \
+  V(S390_Word64AtomicOrUint16)                \
+  V(S390_Word64AtomicOrUint32)                \
+  V(S390_Word64AtomicOrUint64)                \
+  V(S390_Word64AtomicXorUint8)                \
+  V(S390_Word64AtomicXorUint16)               \
+  V(S390_Word64AtomicXorUint32)               \
+  V(S390_Word64AtomicXorUint64)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/s390/instruction-scheduler-s390.cc b/deps/v8/src/compiler/s390/instruction-scheduler-s390.cc
index fd388a219a..fbd81e17c4 100644
--- a/deps/v8/src/compiler/s390/instruction-scheduler-s390.cc
+++ b/deps/v8/src/compiler/s390/instruction-scheduler-s390.cc
@@ -169,6 +169,46 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_StackClaim:
       return kHasSideEffect;
 
+    case kS390_Word64AtomicLoadUint8:
+    case kS390_Word64AtomicLoadUint16:
+    case kS390_Word64AtomicLoadUint32:
+    case kS390_Word64AtomicLoadUint64:
+      return kIsLoadOperation;
+
+    case kS390_Word64AtomicStoreUint8:
+    case kS390_Word64AtomicStoreUint16:
+    case kS390_Word64AtomicStoreUint32:
+    case kS390_Word64AtomicStoreUint64:
+    case kS390_Word64AtomicExchangeUint8:
+    case kS390_Word64AtomicExchangeUint16:
+    case kS390_Word64AtomicExchangeUint32:
+    case kS390_Word64AtomicExchangeUint64:
+    case kS390_Word64AtomicCompareExchangeUint8:
+    case kS390_Word64AtomicCompareExchangeUint16:
+    case kS390_Word64AtomicCompareExchangeUint32:
+    case kS390_Word64AtomicCompareExchangeUint64:
+    case kS390_Word64AtomicAddUint8:
+    case kS390_Word64AtomicAddUint16:
+    case kS390_Word64AtomicAddUint32:
+    case kS390_Word64AtomicAddUint64:
+    case kS390_Word64AtomicSubUint8:
+    case kS390_Word64AtomicSubUint16:
+    case kS390_Word64AtomicSubUint32:
+    case kS390_Word64AtomicSubUint64:
+    case kS390_Word64AtomicAndUint8:
+    case kS390_Word64AtomicAndUint16:
+    case kS390_Word64AtomicAndUint32:
+    case kS390_Word64AtomicAndUint64:
+    case kS390_Word64AtomicOrUint8:
+    case kS390_Word64AtomicOrUint16:
+    case kS390_Word64AtomicOrUint32:
+    case kS390_Word64AtomicOrUint64:
+    case kS390_Word64AtomicXorUint8:
+    case kS390_Word64AtomicXorUint16:
+    case kS390_Word64AtomicXorUint32:
+    case kS390_Word64AtomicXorUint64:
+      return kHasSideEffect;
+
 #define CASE(Name) case k##Name:
       COMMON_ARCH_OPCODE_LIST(CASE)
 #undef CASE
diff --git a/deps/v8/src/compiler/s390/instruction-selector-s390.cc b/deps/v8/src/compiler/s390/instruction-selector-s390.cc
index 8174551777..018c288939 100644
--- a/deps/v8/src/compiler/s390/instruction-selector-s390.cc
+++ b/deps/v8/src/compiler/s390/instruction-selector-s390.cc
@@ -1409,8 +1409,11 @@ static inline bool TryMatchDoubleConstructFromInsert(
   FLOAT_UNARY_OP_LIST_32(V)                                                   \
   V(Float64, ChangeFloat64ToUint64, kS390_DoubleToUint64, OperandMode::kNone, \
     null)                                                                     \
+  V(Float64, ChangeFloat64ToInt64, kS390_DoubleToInt64, OperandMode::kNone,   \
+    null)                                                                     \
   V(Float64, BitcastFloat64ToInt64, kS390_BitcastDoubleToInt64,               \
     OperandMode::kNone, null)
+
 #define WORD32_UNARY_OP_LIST(V)                                             \
   WORD32_UNARY_OP_LIST_32(V)                                                \
   V(Word32, ChangeInt32ToInt64, kS390_SignExtendWord32ToInt64,              \
@@ -1489,6 +1492,8 @@ static inline bool TryMatchDoubleConstructFromInsert(
     null)                                                                    \
   V(Word64, RoundInt64ToFloat64, kS390_Int64ToDouble, OperandMode::kNone,    \
     null)                                                                    \
+  V(Word64, ChangeInt64ToFloat64, kS390_Int64ToDouble, OperandMode::kNone,   \
+    null)                                                                    \
   V(Word64, RoundUint64ToFloat32, kS390_Uint64ToFloat32, OperandMode::kNone, \
     null)                                                                    \
   V(Word64, RoundUint64ToFloat64, kS390_Uint64ToDouble, OperandMode::kNone,  \
@@ -2157,6 +2162,7 @@ void InstructionSelector::EmitPrepareArguments(
     // Poke any stack arguments.
     int slot = kStackFrameExtraParamSlot;
     for (PushParameter input : (*arguments)) {
+      if (input.node == nullptr) continue;
       Emit(kS390_StoreToStackSlot, g.NoOutput(), g.UseRegister(input.node),
            g.TempImmediate(slot));
       ++slot;
@@ -2250,11 +2256,26 @@ void InstructionSelector::VisitWord32AtomicStore(Node* node) {
        inputs);
 }
 
-void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
-  S390OperandGenerator g(this);
+void VisitAtomicExchange(InstructionSelector* selector, Node* node,
+                         ArchOpcode opcode) {
+  S390OperandGenerator g(selector);
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);
   Node* value = node->InputAt(2);
+
+  AddressingMode addressing_mode = kMode_MRR;
+  InstructionOperand inputs[3];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  InstructionOperand outputs[1];
+  outputs[0] = g.DefineAsRegister(node);
+  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
+  selector->Emit(code, 1, outputs, input_count, inputs);
+}
+
+void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
   ArchOpcode opcode = kArchNop;
   MachineType type = AtomicOpType(node->op());
   if (type == MachineType::Int8()) {
@@ -2271,42 +2292,34 @@ void InstructionSelector::VisitWord32AtomicExchange(Node* node) {
     UNREACHABLE();
     return;
   }
-
-  AddressingMode addressing_mode = kMode_MRR;
-  InstructionOperand inputs[3];
-  size_t input_count = 0;
-  inputs[input_count++] = g.UseUniqueRegister(base);
-  inputs[input_count++] = g.UseUniqueRegister(index);
-  inputs[input_count++] = g.UseUniqueRegister(value);
-  InstructionOperand outputs[1];
-  outputs[0] = g.DefineAsRegister(node);
-  InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, 1, outputs, input_count, inputs);
+  VisitAtomicExchange(this, node, opcode);
 }
 
-void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
-  S390OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* old_value = node->InputAt(2);
-  Node* new_value = node->InputAt(3);
-
-  MachineType type = AtomicOpType(node->op());
+void InstructionSelector::VisitWord64AtomicExchange(Node* node) {
   ArchOpcode opcode = kArchNop;
-  if (type == MachineType::Int8()) {
-    opcode = kWord32AtomicCompareExchangeInt8;
-  } else if (type == MachineType::Uint8()) {
-    opcode = kWord32AtomicCompareExchangeUint8;
-  } else if (type == MachineType::Int16()) {
-    opcode = kWord32AtomicCompareExchangeInt16;
+  MachineType type = AtomicOpType(node->op());
+  if (type == MachineType::Uint8()) {
+    opcode = kS390_Word64AtomicExchangeUint8;
   } else if (type == MachineType::Uint16()) {
-    opcode = kWord32AtomicCompareExchangeUint16;
-  } else if (type == MachineType::Int32() || type == MachineType::Uint32()) {
-    opcode = kWord32AtomicCompareExchangeWord32;
+    opcode = kS390_Word64AtomicExchangeUint16;
+  } else if (type == MachineType::Uint32()) {
+    opcode = kS390_Word64AtomicExchangeUint32;
+  } else if (type == MachineType::Uint64()) {
+    opcode = kS390_Word64AtomicExchangeUint64;
   } else {
     UNREACHABLE();
     return;
   }
+  VisitAtomicExchange(this, node, opcode);
+}
+
+void VisitAtomicCompareExchange(InstructionSelector* selector, Node* node,
+                                ArchOpcode opcode) {
+  S390OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* old_value = node->InputAt(2);
+  Node* new_value = node->InputAt(3);
 
   InstructionOperand inputs[4];
   size_t input_count = 0;
@@ -2328,34 +2341,53 @@ void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
   outputs[output_count++] = g.DefineSameAsFirst(node);
 
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, output_count, outputs, input_count, inputs);
+  selector->Emit(code, output_count, outputs, input_count, inputs);
 }
 
-void InstructionSelector::VisitWord32AtomicBinaryOperation(
-    Node* node, ArchOpcode int8_op, ArchOpcode uint8_op, ArchOpcode int16_op,
-    ArchOpcode uint16_op, ArchOpcode word32_op) {
-  S390OperandGenerator g(this);
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  Node* value = node->InputAt(2);
-
+void InstructionSelector::VisitWord32AtomicCompareExchange(Node* node) {
   MachineType type = AtomicOpType(node->op());
   ArchOpcode opcode = kArchNop;
-
   if (type == MachineType::Int8()) {
-    opcode = int8_op;
+    opcode = kWord32AtomicCompareExchangeInt8;
   } else if (type == MachineType::Uint8()) {
-    opcode = uint8_op;
+    opcode = kWord32AtomicCompareExchangeUint8;
   } else if (type == MachineType::Int16()) {
-    opcode = int16_op;
+    opcode = kWord32AtomicCompareExchangeInt16;
   } else if (type == MachineType::Uint16()) {
-    opcode = uint16_op;
+    opcode = kWord32AtomicCompareExchangeUint16;
   } else if (type == MachineType::Int32() || type == MachineType::Uint32()) {
-    opcode = word32_op;
+    opcode = kWord32AtomicCompareExchangeWord32;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicCompareExchange(this, node, opcode);
+}
+
+void InstructionSelector::VisitWord64AtomicCompareExchange(Node* node) {
+  MachineType type = AtomicOpType(node->op());
+  ArchOpcode opcode = kArchNop;
+  if (type == MachineType::Uint8()) {
+    opcode = kS390_Word64AtomicCompareExchangeUint8;
+  } else if (type == MachineType::Uint16()) {
+    opcode = kS390_Word64AtomicCompareExchangeUint16;
+  } else if (type == MachineType::Uint32()) {
+    opcode = kS390_Word64AtomicCompareExchangeUint32;
+  } else  if (type == MachineType::Uint64()) {
+    opcode = kS390_Word64AtomicCompareExchangeUint64;
   } else {
     UNREACHABLE();
     return;
   }
+  VisitAtomicCompareExchange(this, node, opcode);
+}
+
+void VisitAtomicBinop(InstructionSelector* selector, Node* node,
+                      ArchOpcode opcode) {
+  S390OperandGenerator g(selector);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
 
   InstructionOperand inputs[3];
   size_t input_count = 0;
@@ -2381,7 +2413,31 @@ void InstructionSelector::VisitWord32AtomicBinaryOperation(
   temps[temp_count++] = g.TempRegister();
 
   InstructionCode code = opcode | AddressingModeField::encode(addressing_mode);
-  Emit(code, output_count, outputs, input_count, inputs, temp_count, temps);
+  selector->Emit(code, output_count, outputs, input_count, inputs, temp_count,
+                 temps);
+}
+
+void InstructionSelector::VisitWord32AtomicBinaryOperation(
+    Node* node, ArchOpcode int8_op, ArchOpcode uint8_op, ArchOpcode int16_op,
+    ArchOpcode uint16_op, ArchOpcode word32_op) {
+  MachineType type = AtomicOpType(node->op());
+  ArchOpcode opcode = kArchNop;
+
+  if (type == MachineType::Int8()) {
+    opcode = int8_op;
+  } else if (type == MachineType::Uint8()) {
+    opcode = uint8_op;
+  } else if (type == MachineType::Int16()) {
+    opcode = int16_op;
+  } else if (type == MachineType::Uint16()) {
+    opcode = uint16_op;
+  } else if (type == MachineType::Int32() || type == MachineType::Uint32()) {
+    opcode = word32_op;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicBinop(this, node, opcode);
 }
 
 #define VISIT_ATOMIC_BINOP(op)                                   \
@@ -2398,6 +2454,101 @@ VISIT_ATOMIC_BINOP(Or)
 VISIT_ATOMIC_BINOP(Xor)
 #undef VISIT_ATOMIC_BINOP
 
+void InstructionSelector::VisitWord64AtomicBinaryOperation(
+    Node* node, ArchOpcode uint8_op, ArchOpcode uint16_op, ArchOpcode word32_op,
+    ArchOpcode word64_op) {
+  MachineType type = AtomicOpType(node->op());
+  ArchOpcode opcode = kArchNop;
+
+  if (type == MachineType::Uint8()) {
+    opcode = uint8_op;
+  } else if (type == MachineType::Uint16()) {
+    opcode = uint16_op;
+  } else if (type == MachineType::Uint32()) {
+    opcode = word32_op;
+  } else if (type == MachineType::Uint64()) {
+    opcode = word64_op;
+  } else {
+    UNREACHABLE();
+    return;
+  }
+  VisitAtomicBinop(this, node, opcode);
+}
+
+#define VISIT_ATOMIC64_BINOP(op)                                             \
+  void InstructionSelector::VisitWord64Atomic##op(Node* node) {              \
+    VisitWord64AtomicBinaryOperation(                                        \
+        node, kS390_Word64Atomic##op##Uint8, kS390_Word64Atomic##op##Uint16, \
+        kS390_Word64Atomic##op##Uint32, kS390_Word64Atomic##op##Uint64);     \
+  }
+VISIT_ATOMIC64_BINOP(Add)
+VISIT_ATOMIC64_BINOP(Sub)
+VISIT_ATOMIC64_BINOP(And)
+VISIT_ATOMIC64_BINOP(Or)
+VISIT_ATOMIC64_BINOP(Xor)
+#undef VISIT_ATOMIC64_BINOP
+
+void InstructionSelector::VisitWord64AtomicLoad(Node* node) {
+  LoadRepresentation load_rep = LoadRepresentationOf(node->op());
+  S390OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  ArchOpcode opcode = kArchNop;
+  switch (load_rep.representation()) {
+    case MachineRepresentation::kWord8:
+      opcode = kS390_Word64AtomicLoadUint8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kS390_Word64AtomicLoadUint16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kS390_Word64AtomicLoadUint32;
+      break;
+    case MachineRepresentation::kWord64:
+      opcode = kS390_Word64AtomicLoadUint64;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+  Emit(opcode | AddressingModeField::encode(kMode_MRR),
+       g.DefineAsRegister(node), g.UseRegister(base), g.UseRegister(index));
+}
+
+void InstructionSelector::VisitWord64AtomicStore(Node* node) {
+  MachineRepresentation rep = AtomicStoreRepresentationOf(node->op());
+  S390OperandGenerator g(this);
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  Node* value = node->InputAt(2);
+  ArchOpcode opcode = kArchNop;
+  switch (rep) {
+    case MachineRepresentation::kWord8:
+      opcode = kS390_Word64AtomicStoreUint8;
+      break;
+    case MachineRepresentation::kWord16:
+      opcode = kS390_Word64AtomicStoreUint16;
+      break;
+    case MachineRepresentation::kWord32:
+      opcode = kS390_Word64AtomicStoreUint32;
+      break;
+    case MachineRepresentation::kWord64:
+      opcode = kS390_Word64AtomicStoreUint64;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+
+  InstructionOperand inputs[4];
+  size_t input_count = 0;
+  inputs[input_count++] = g.UseUniqueRegister(value);
+  inputs[input_count++] = g.UseUniqueRegister(base);
+  inputs[input_count++] = g.UseUniqueRegister(index);
+  Emit(opcode | AddressingModeField::encode(kMode_MRR), 0, nullptr, input_count,
+       inputs);
+}
+
 void InstructionSelector::VisitI32x4Splat(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitI32x4ExtractLane(Node* node) { UNIMPLEMENTED(); }
@@ -2598,6 +2749,82 @@ void InstructionSelector::VisitF32x4AddHoriz(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI32x4AddHoriz(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI16x8AddHoriz(Node* node) { UNIMPLEMENTED(); }
 
+void InstructionSelector::VisitF32x4SConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitF32x4UConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4SConvertF32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4UConvertF32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4SConvertI16x8Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4SConvertI16x8High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4UConvertI16x8Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI32x4UConvertI16x8High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8SConvertI8x16Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8SConvertI8x16High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8UConvertI8x16Low(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8UConvertI8x16High(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI16x8SConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+void InstructionSelector::VisitI16x8UConvertI32x4(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI8x16SConvertI16x8(Node* node) {
+  UNIMPLEMENTED();
+}
+
+void InstructionSelector::VisitI8x16UConvertI16x8(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
+void InstructionSelector::VisitS1x4AnyTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x4AllTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x8AnyTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x8AllTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x16AnyTrue(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitS1x16AllTrue(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/deps/v8/src/compiler/schedule.cc b/deps/v8/src/compiler/schedule.cc
index 01034ffb73..7632d3cc8c 100644
--- a/deps/v8/src/compiler/schedule.cc
+++ b/deps/v8/src/compiler/schedule.cc
@@ -42,48 +42,36 @@ bool BasicBlock::LoopContains(BasicBlock* block) const {
          block->rpo_number_ < loop_end_->rpo_number_;
 }
 
-
 void BasicBlock::AddSuccessor(BasicBlock* successor) {
   successors_.push_back(successor);
 }
 
-
 void BasicBlock::AddPredecessor(BasicBlock* predecessor) {
   predecessors_.push_back(predecessor);
 }
 
-
 void BasicBlock::AddNode(Node* node) { nodes_.push_back(node); }
 
-
-void BasicBlock::set_control(Control control) {
-  control_ = control;
-}
-
+void BasicBlock::set_control(Control control) { control_ = control; }
 
 void BasicBlock::set_control_input(Node* control_input) {
   control_input_ = control_input;
 }
 
-
 void BasicBlock::set_loop_depth(int32_t loop_depth) {
   loop_depth_ = loop_depth;
 }
 
-
 void BasicBlock::set_rpo_number(int32_t rpo_number) {
   rpo_number_ = rpo_number;
 }
 
-
 void BasicBlock::set_loop_end(BasicBlock* loop_end) { loop_end_ = loop_end; }
 
-
 void BasicBlock::set_loop_header(BasicBlock* loop_header) {
   loop_header_ = loop_header;
 }
 
-
 // static
 BasicBlock* BasicBlock::GetCommonDominator(BasicBlock* b1, BasicBlock* b2) {
   while (b1 != b2) {
@@ -141,12 +129,10 @@ std::ostream& operator<<(std::ostream& os, const BasicBlock::Control& c) {
   UNREACHABLE();
 }
 
-
 std::ostream& operator<<(std::ostream& os, const BasicBlock::Id& id) {
   return os << id.ToSize();
 }
 
-
 Schedule::Schedule(Zone* zone, size_t node_count_hint)
     : zone_(zone),
       all_blocks_(zone),
@@ -157,7 +143,6 @@ Schedule::Schedule(Zone* zone, size_t node_count_hint)
   nodeid_to_block_.reserve(node_count_hint);
 }
 
-
 BasicBlock* Schedule::block(Node* node) const {
   if (node->id() < static_cast<NodeId>(nodeid_to_block_.size())) {
     return nodeid_to_block_[node->id()];
@@ -165,25 +150,21 @@ BasicBlock* Schedule::block(Node* node) const {
   return nullptr;
 }
 
-
 bool Schedule::IsScheduled(Node* node) {
   if (node->id() >= nodeid_to_block_.size()) return false;
   return nodeid_to_block_[node->id()] != nullptr;
 }
 
-
 BasicBlock* Schedule::GetBlockById(BasicBlock::Id block_id) {
   DCHECK(block_id.ToSize() < all_blocks_.size());
   return all_blocks_[block_id.ToSize()];
 }
 
-
 bool Schedule::SameBasicBlock(Node* a, Node* b) const {
   BasicBlock* block = this->block(a);
   return block != nullptr && block == this->block(b);
 }
 
-
 BasicBlock* Schedule::NewBasicBlock() {
   BasicBlock* block = new (zone_)
       BasicBlock(zone_, BasicBlock::Id::FromSize(all_blocks_.size()));
@@ -191,7 +172,6 @@ BasicBlock* Schedule::NewBasicBlock() {
   return block;
 }
 
-
 void Schedule::PlanNode(BasicBlock* block, Node* node) {
   if (FLAG_trace_turbo_scheduler) {
     StdoutStream{} << "Planning #" << node->id() << ":"
@@ -202,7 +182,6 @@ void Schedule::PlanNode(BasicBlock* block, Node* node) {
   SetBlockForNode(block, node);
 }
 
-
 void Schedule::AddNode(BasicBlock* block, Node* node) {
   if (FLAG_trace_turbo_scheduler) {
     StdoutStream{} << "Adding #" << node->id() << ":" << node->op()->mnemonic()
@@ -213,7 +192,6 @@ void Schedule::AddNode(BasicBlock* block, Node* node) {
   SetBlockForNode(block, node);
 }
 
-
 void Schedule::AddGoto(BasicBlock* block, BasicBlock* succ) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
   block->set_control(BasicBlock::kGoto);
@@ -249,7 +227,6 @@ void Schedule::AddCall(BasicBlock* block, Node* call, BasicBlock* success_block,
   SetControlInput(block, call);
 }
 
-
 void Schedule::AddBranch(BasicBlock* block, Node* branch, BasicBlock* tblock,
                          BasicBlock* fblock) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
@@ -260,7 +237,6 @@ void Schedule::AddBranch(BasicBlock* block, Node* branch, BasicBlock* tblock,
   SetControlInput(block, branch);
 }
 
-
 void Schedule::AddSwitch(BasicBlock* block, Node* sw, BasicBlock** succ_blocks,
                          size_t succ_count) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
@@ -272,7 +248,6 @@ void Schedule::AddSwitch(BasicBlock* block, Node* sw, BasicBlock** succ_blocks,
   SetControlInput(block, sw);
 }
 
-
 void Schedule::AddTailCall(BasicBlock* block, Node* input) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
   block->set_control(BasicBlock::kTailCall);
@@ -280,7 +255,6 @@ void Schedule::AddTailCall(BasicBlock* block, Node* input) {
   if (block != end()) AddSuccessor(block, end());
 }
 
-
 void Schedule::AddReturn(BasicBlock* block, Node* input) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
   block->set_control(BasicBlock::kReturn);
@@ -288,7 +262,6 @@ void Schedule::AddReturn(BasicBlock* block, Node* input) {
   if (block != end()) AddSuccessor(block, end());
 }
 
-
 void Schedule::AddDeoptimize(BasicBlock* block, Node* input) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
   block->set_control(BasicBlock::kDeoptimize);
@@ -296,7 +269,6 @@ void Schedule::AddDeoptimize(BasicBlock* block, Node* input) {
   if (block != end()) AddSuccessor(block, end());
 }
 
-
 void Schedule::AddThrow(BasicBlock* block, Node* input) {
   DCHECK_EQ(BasicBlock::kNone, block->control());
   block->set_control(BasicBlock::kThrow);
@@ -304,7 +276,6 @@ void Schedule::AddThrow(BasicBlock* block, Node* input) {
   if (block != end()) AddSuccessor(block, end());
 }
 
-
 void Schedule::InsertBranch(BasicBlock* block, BasicBlock* end, Node* branch,
                             BasicBlock* tblock, BasicBlock* fblock) {
   DCHECK_NE(BasicBlock::kNone, block->control());
@@ -320,7 +291,6 @@ void Schedule::InsertBranch(BasicBlock* block, BasicBlock* end, Node* branch,
   SetControlInput(block, branch);
 }
 
-
 void Schedule::InsertSwitch(BasicBlock* block, BasicBlock* end, Node* sw,
                             BasicBlock** succ_blocks, size_t succ_count) {
   DCHECK_NE(BasicBlock::kNone, block->control());
@@ -343,7 +313,7 @@ void Schedule::EnsureCFGWellFormedness() {
   BasicBlockVector all_blocks_copy(all_blocks_);
 
   // Insert missing split edge blocks.
-  for (auto block : all_blocks_copy) {
+  for (BasicBlock* block : all_blocks_copy) {
     if (block->PredecessorCount() > 1) {
       if (block != end_) {
         EnsureSplitEdgeForm(block);
@@ -351,24 +321,42 @@ void Schedule::EnsureCFGWellFormedness() {
       if (block->deferred()) {
         EnsureDeferredCodeSingleEntryPoint(block);
       }
-    } else {
-      EliminateNoopPhiNodes(block);
     }
   }
+
+  EliminateRedundantPhiNodes();
 }
 
-void Schedule::EliminateNoopPhiNodes(BasicBlock* block) {
-  // Ensure that useless phi nodes in blocks that only have a single predecessor
+void Schedule::EliminateRedundantPhiNodes() {
+  // Ensure that useless phi nodes that only have a single input, identical
+  // inputs, or are a self-referential loop phi,
   // -- which can happen with the automatically generated code in the CSA and
   // torque -- are pruned.
-  if (block->PredecessorCount() == 1) {
-    for (size_t i = 0; i < block->NodeCount();) {
-      Node* node = block->NodeAt(i);
-      if (node->opcode() == IrOpcode::kPhi) {
-        node->ReplaceUses(node->InputAt(0));
-        block->RemoveNode(block->begin() + i);
-      } else {
-        ++i;
+  // Since we have strucured control flow, this is enough to minimize the number
+  // of phi nodes.
+  bool reached_fixed_point = false;
+  while (!reached_fixed_point) {
+    reached_fixed_point = true;
+    for (BasicBlock* block : all_blocks_) {
+      int predecessor_count = static_cast<int>(block->PredecessorCount());
+      for (size_t node_pos = 0; node_pos < block->NodeCount(); ++node_pos) {
+        Node* node = block->NodeAt(node_pos);
+        if (node->opcode() == IrOpcode::kPhi) {
+          Node* first_input = node->InputAt(0);
+          bool inputs_equal = true;
+          for (int i = 1; i < predecessor_count; ++i) {
+            Node* input = node->InputAt(i);
+            if (input != first_input && input != node) {
+              inputs_equal = false;
+              break;
+            }
+          }
+          if (!inputs_equal) continue;
+          node->ReplaceUses(first_input);
+          block->RemoveNode(block->begin() + node_pos);
+          --node_pos;
+          reached_fixed_point = false;
+        }
       }
     }
   }
@@ -481,7 +469,6 @@ void Schedule::AddSuccessor(BasicBlock* block, BasicBlock* succ) {
   succ->AddPredecessor(block);
 }
 
-
 void Schedule::MoveSuccessors(BasicBlock* from, BasicBlock* to) {
   for (BasicBlock* const successor : from->successors()) {
     to->AddSuccessor(successor);
@@ -492,13 +479,11 @@ void Schedule::MoveSuccessors(BasicBlock* from, BasicBlock* to) {
   from->ClearSuccessors();
 }
 
-
 void Schedule::SetControlInput(BasicBlock* block, Node* node) {
   block->set_control_input(node);
   SetBlockForNode(block, node);
 }
 
-
 void Schedule::SetBlockForNode(BasicBlock* block, Node* node) {
   if (node->id() >= nodeid_to_block_.size()) {
     nodeid_to_block_.resize(node->id() + 1);
@@ -506,7 +491,6 @@ void Schedule::SetBlockForNode(BasicBlock* block, Node* node) {
   nodeid_to_block_[node->id()] = block;
 }
 
-
 std::ostream& operator<<(std::ostream& os, const Schedule& s) {
   for (BasicBlock* block :
        ((s.RpoBlockCount() == 0) ? *s.all_blocks() : *s.rpo_order())) {
diff --git a/deps/v8/src/compiler/schedule.h b/deps/v8/src/compiler/schedule.h
index 74e51c5341..8d2079787e 100644
--- a/deps/v8/src/compiler/schedule.h
+++ b/deps/v8/src/compiler/schedule.h
@@ -166,12 +166,12 @@ class V8_EXPORT_PRIVATE BasicBlock final
   BasicBlock* loop_header_;  // Pointer to dominating loop header basic block,
   // nullptr if none. For loop headers, this points to
   // enclosing loop header.
-  BasicBlock* loop_end_;     // end of the loop, if this block is a loop header.
-  int32_t loop_depth_;       // loop nesting, 0 is top-level
+  BasicBlock* loop_end_;  // end of the loop, if this block is a loop header.
+  int32_t loop_depth_;    // loop nesting, 0 is top-level
 
-  Control control_;          // Control at the end of the block.
-  Node* control_input_;      // Input value for control.
-  NodeVector nodes_;         // nodes of this block in forward order.
+  Control control_;      // Control at the end of the block.
+  Node* control_input_;  // Input value for control.
+  NodeVector nodes_;     // nodes of this block in forward order.
 
   BasicBlockVector successors_;
   BasicBlockVector predecessors_;
@@ -187,7 +187,6 @@ std::ostream& operator<<(std::ostream&, const BasicBlock&);
 std::ostream& operator<<(std::ostream&, const BasicBlock::Control&);
 std::ostream& operator<<(std::ostream&, const BasicBlock::Id&);
 
-
 // A schedule represents the result of assigning nodes to basic blocks
 // and ordering them within basic blocks. Prior to computing a schedule,
 // a graph has no notion of control flow ordering other than that induced
@@ -272,12 +271,13 @@ class V8_EXPORT_PRIVATE Schedule final : public NON_EXPORTED_BASE(ZoneObject) {
   friend class BasicBlockInstrumentor;
   friend class RawMachineAssembler;
 
-  // Ensure properties of the CFG assumed by further stages.
+  // For CSA/Torque: Ensure properties of the CFG assumed by further stages.
   void EnsureCFGWellFormedness();
-  // Eliminates no-op phi nodes added for blocks that only have a single
-  // predecessor. This ensures the property required for SSA deconstruction that
-  // the target block of a control flow split has no phis.
-  void EliminateNoopPhiNodes(BasicBlock* block);
+  // For CSA/Torque: Eliminates unnecessary phi nodes, including phis with a
+  // single input. The latter is necessary to ensure the property required for
+  // SSA deconstruction that the target block of a control flow split has no
+  // phis.
+  void EliminateRedundantPhiNodes();
   // Ensure split-edge form for a hand-assembled schedule.
   void EnsureSplitEdgeForm(BasicBlock* block);
   // Ensure entry into a deferred block happens from a single hot block.
@@ -294,9 +294,9 @@ class V8_EXPORT_PRIVATE Schedule final : public NON_EXPORTED_BASE(ZoneObject) {
   void SetBlockForNode(BasicBlock* block, Node* node);
 
   Zone* zone_;
-  BasicBlockVector all_blocks_;           // All basic blocks in the schedule.
-  BasicBlockVector nodeid_to_block_;      // Map from node to containing block.
-  BasicBlockVector rpo_order_;            // Reverse-post-order block list.
+  BasicBlockVector all_blocks_;       // All basic blocks in the schedule.
+  BasicBlockVector nodeid_to_block_;  // Map from node to containing block.
+  BasicBlockVector rpo_order_;        // Reverse-post-order block list.
   BasicBlock* start_;
   BasicBlock* end_;
 
diff --git a/deps/v8/src/compiler/select-lowering.cc b/deps/v8/src/compiler/select-lowering.cc
index b1a230962f..4d5bb99053 100644
--- a/deps/v8/src/compiler/select-lowering.cc
+++ b/deps/v8/src/compiler/select-lowering.cc
@@ -17,7 +17,7 @@ namespace compiler {
 SelectLowering::SelectLowering(Graph* graph, CommonOperatorBuilder* common)
     : common_(common), graph_(graph) {}
 
-SelectLowering::~SelectLowering() {}
+SelectLowering::~SelectLowering() = default;
 
 
 Reduction SelectLowering::Reduce(Node* node) {
diff --git a/deps/v8/src/compiler/select-lowering.h b/deps/v8/src/compiler/select-lowering.h
index b66f69f986..d8c12d4d54 100644
--- a/deps/v8/src/compiler/select-lowering.h
+++ b/deps/v8/src/compiler/select-lowering.h
@@ -20,7 +20,7 @@ class Graph;
 class SelectLowering final : public Reducer {
  public:
   SelectLowering(Graph* graph, CommonOperatorBuilder* common);
-  ~SelectLowering();
+  ~SelectLowering() override;
 
   const char* reducer_name() const override { return "SelectLowering"; }
 
diff --git a/deps/v8/src/compiler/simd-scalar-lowering.cc b/deps/v8/src/compiler/simd-scalar-lowering.cc
index 882e3b9d6e..32de83061d 100644
--- a/deps/v8/src/compiler/simd-scalar-lowering.cc
+++ b/deps/v8/src/compiler/simd-scalar-lowering.cc
@@ -38,7 +38,8 @@ SimdScalarLowering::SimdScalarLowering(
   DCHECK_NOT_NULL(graph());
   DCHECK_NOT_NULL(graph()->end());
   replacements_ = zone()->NewArray<Replacement>(graph()->NodeCount());
-  memset(replacements_, 0, sizeof(Replacement) * graph()->NodeCount());
+  memset(static_cast<void*>(replacements_), 0,
+         sizeof(Replacement) * graph()->NodeCount());
 }
 
 void SimdScalarLowering::LowerGraph() {
diff --git a/deps/v8/src/compiler/simplified-lowering.cc b/deps/v8/src/compiler/simplified-lowering.cc
index 2d82fc99bc..739f81f90d 100644
--- a/deps/v8/src/compiler/simplified-lowering.cc
+++ b/deps/v8/src/compiler/simplified-lowering.cc
@@ -107,8 +107,9 @@ UseInfo CheckedUseInfoAsWord32FromHint(
   UNREACHABLE();
 }
 
-UseInfo CheckedUseInfoAsFloat64FromHint(NumberOperationHint hint,
-                                        const VectorSlotPair& feedback) {
+UseInfo CheckedUseInfoAsFloat64FromHint(
+    NumberOperationHint hint, const VectorSlotPair& feedback,
+    IdentifyZeros identify_zeros = kDistinguishZeros) {
   switch (hint) {
     case NumberOperationHint::kSignedSmall:
     case NumberOperationHint::kSignedSmallInputs:
@@ -117,9 +118,9 @@ UseInfo CheckedUseInfoAsFloat64FromHint(NumberOperationHint hint,
       UNREACHABLE();
       break;
     case NumberOperationHint::kNumber:
-      return UseInfo::CheckedNumberAsFloat64(feedback);
+      return UseInfo::CheckedNumberAsFloat64(identify_zeros, feedback);
     case NumberOperationHint::kNumberOrOddball:
-      return UseInfo::CheckedNumberOrOddballAsFloat64(feedback);
+      return UseInfo::CheckedNumberOrOddballAsFloat64(identify_zeros, feedback);
   }
   UNREACHABLE();
 }
@@ -140,7 +141,7 @@ UseInfo TruncatingUseInfoFromRepresentation(MachineRepresentation rep) {
     case MachineRepresentation::kWord32:
       return UseInfo::TruncatingWord32();
     case MachineRepresentation::kWord64:
-      return UseInfo::TruncatingWord64();
+      return UseInfo::Word64();
     case MachineRepresentation::kBit:
       return UseInfo::Bool();
     case MachineRepresentation::kSimd128:
@@ -151,11 +152,11 @@ UseInfo TruncatingUseInfoFromRepresentation(MachineRepresentation rep) {
 }
 
 UseInfo UseInfoForBasePointer(const FieldAccess& access) {
-  return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::PointerInt();
+  return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::Word();
 }
 
 UseInfo UseInfoForBasePointer(const ElementAccess& access) {
-  return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::PointerInt();
+  return access.tag() != 0 ? UseInfo::AnyTagged() : UseInfo::Word();
 }
 
 void ReplaceEffectControlUses(Node* node, Node* effect, Node* control) {
@@ -186,32 +187,6 @@ void ChangeToPureOp(Node* node, const Operator* new_op) {
   NodeProperties::ChangeOp(node, new_op);
 }
 
-#ifdef DEBUG
-// Helpers for monotonicity checking.
-class InputUseInfos {
- public:
-  explicit InputUseInfos(Zone* zone) : input_use_infos_(zone) {}
-
-  void SetAndCheckInput(Node* node, int index, UseInfo use_info) {
-    if (input_use_infos_.empty()) {
-      input_use_infos_.resize(node->InputCount(), UseInfo::None());
-    }
-    // Check that the new use informatin is a super-type of the old
-    // one.
-    DCHECK(IsUseLessGeneral(input_use_infos_[index], use_info));
-    input_use_infos_[index] = use_info;
-  }
-
- private:
-  ZoneVector<UseInfo> input_use_infos_;
-
-  static bool IsUseLessGeneral(UseInfo use1, UseInfo use2) {
-    return use1.truncation().IsLessGeneralThan(use2.truncation());
-  }
-};
-
-#endif  // DEBUG
-
 bool CanOverflowSigned32(const Operator* op, Type left, Type right,
                          Zone* type_zone) {
   // We assume the inputs are checked Signed32 (or known statically
@@ -241,6 +216,32 @@ bool IsSomePositiveOrderedNumber(Type type) {
 
 }  // namespace
 
+#ifdef DEBUG
+// Helpers for monotonicity checking.
+class InputUseInfos {
+ public:
+  explicit InputUseInfos(Zone* zone) : input_use_infos_(zone) {}
+
+  void SetAndCheckInput(Node* node, int index, UseInfo use_info) {
+    if (input_use_infos_.empty()) {
+      input_use_infos_.resize(node->InputCount(), UseInfo::None());
+    }
+    // Check that the new use informatin is a super-type of the old
+    // one.
+    DCHECK(IsUseLessGeneral(input_use_infos_[index], use_info));
+    input_use_infos_[index] = use_info;
+  }
+
+ private:
+  ZoneVector<UseInfo> input_use_infos_;
+
+  static bool IsUseLessGeneral(UseInfo use1, UseInfo use2) {
+    return use1.truncation().IsLessGeneralThan(use2.truncation());
+  }
+};
+
+#endif  // DEBUG
+
 class RepresentationSelector {
  public:
   // Information for each node tracked during the fixpoint.
@@ -306,7 +307,7 @@ class RepresentationSelector {
         source_positions_(source_positions),
         node_origins_(node_origins),
         type_cache_(TypeCache::Get()),
-        op_typer_(jsgraph->isolate(), js_heap_broker, graph_zone()) {
+        op_typer_(js_heap_broker, graph_zone()) {
   }
 
   // Forward propagation of types from type feedback.
@@ -430,64 +431,71 @@ class RepresentationSelector {
       }
     }
 
+    // We preload these values here to avoid increasing the binary size too
+    // much, which happens if we inline the calls into the macros below.
+    Type input0_type;
+    if (node->InputCount() > 0) input0_type = FeedbackTypeOf(node->InputAt(0));
+    Type input1_type;
+    if (node->InputCount() > 1) input1_type = FeedbackTypeOf(node->InputAt(1));
+
     switch (node->opcode()) {
-#define DECLARE_CASE(Name)                                       \
-  case IrOpcode::k##Name: {                                      \
-    new_type = op_typer_.Name(FeedbackTypeOf(node->InputAt(0)),  \
-                              FeedbackTypeOf(node->InputAt(1))); \
-    break;                                                       \
+#define DECLARE_CASE(Name)                               \
+  case IrOpcode::k##Name: {                              \
+    new_type = op_typer_.Name(input0_type, input1_type); \
+    break;                                               \
   }
       SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_CASE)
       DECLARE_CASE(SameValue)
 #undef DECLARE_CASE
 
-#define DECLARE_CASE(Name)                                                \
-  case IrOpcode::k##Name: {                                               \
-    new_type =                                                            \
-        Type::Intersect(op_typer_.Name(FeedbackTypeOf(node->InputAt(0)),  \
-                                       FeedbackTypeOf(node->InputAt(1))), \
-                        info->restriction_type(), graph_zone());          \
-    break;                                                                \
+#define DECLARE_CASE(Name)                                               \
+  case IrOpcode::k##Name: {                                              \
+    new_type = Type::Intersect(op_typer_.Name(input0_type, input1_type), \
+                               info->restriction_type(), graph_zone());  \
+    break;                                                               \
   }
       SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_CASE)
 #undef DECLARE_CASE
 
-#define DECLARE_CASE(Name)                                       \
-  case IrOpcode::k##Name: {                                      \
-    new_type = op_typer_.Name(FeedbackTypeOf(node->InputAt(0))); \
-    break;                                                       \
+#define DECLARE_CASE(Name)                  \
+  case IrOpcode::k##Name: {                 \
+    new_type = op_typer_.Name(input0_type); \
+    break;                                  \
   }
       SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_CASE)
 #undef DECLARE_CASE
 
-#define DECLARE_CASE(Name)                                                \
-  case IrOpcode::k##Name: {                                               \
-    new_type =                                                            \
-        Type::Intersect(op_typer_.Name(FeedbackTypeOf(node->InputAt(0))), \
-                        info->restriction_type(), graph_zone());          \
-    break;                                                                \
+#define DECLARE_CASE(Name)                                              \
+  case IrOpcode::k##Name: {                                             \
+    new_type = Type::Intersect(op_typer_.Name(input0_type),             \
+                               info->restriction_type(), graph_zone()); \
+    break;                                                              \
   }
       SIMPLIFIED_SPECULATIVE_NUMBER_UNOP_LIST(DECLARE_CASE)
 #undef DECLARE_CASE
 
       case IrOpcode::kConvertReceiver:
-        new_type = op_typer_.ConvertReceiver(FeedbackTypeOf(node->InputAt(0)));
+        new_type = op_typer_.ConvertReceiver(input0_type);
         break;
 
       case IrOpcode::kPlainPrimitiveToNumber:
-        new_type = op_typer_.ToNumber(FeedbackTypeOf(node->InputAt(0)));
+        new_type = op_typer_.ToNumber(input0_type);
+        break;
+
+      case IrOpcode::kCheckBounds:
+        new_type =
+            Type::Intersect(op_typer_.CheckBounds(input0_type, input1_type),
+                            info->restriction_type(), graph_zone());
         break;
 
       case IrOpcode::kCheckFloat64Hole:
-        new_type = Type::Intersect(
-            op_typer_.CheckFloat64Hole(FeedbackTypeOf(node->InputAt(0))),
-            info->restriction_type(), graph_zone());
+        new_type = Type::Intersect(op_typer_.CheckFloat64Hole(input0_type),
+                                   info->restriction_type(), graph_zone());
         break;
 
       case IrOpcode::kCheckNumber:
-        new_type = Type::Intersect(
-            op_typer_.CheckNumber(FeedbackTypeOf(node->InputAt(0))),
-            info->restriction_type(), graph_zone());
+        new_type = Type::Intersect(op_typer_.CheckNumber(input0_type),
+                                   info->restriction_type(), graph_zone());
         break;
 
       case IrOpcode::kPhi: {
@@ -913,6 +921,9 @@ class RepresentationSelector {
     VisitBinop(node, UseInfo::TruncatingFloat64(),
                MachineRepresentation::kFloat64);
   }
+  void VisitInt64Binop(Node* node) {
+    VisitBinop(node, UseInfo::Word64(), MachineRepresentation::kWord64);
+  }
   void VisitWord32TruncatingBinop(Node* node) {
     VisitBinop(node, UseInfo::TruncatingWord32(),
                MachineRepresentation::kWord32);
@@ -1067,16 +1078,15 @@ class RepresentationSelector {
     if (type.IsNone()) {
       return MachineType::None();
     }
-    // TODO(turbofan): Special treatment for ExternalPointer here,
-    // to avoid incompatible truncations. We really need a story
-    // for the JSFunction::entry field.
-    if (type.Is(Type::ExternalPointer())) {
-      return MachineType::Pointer();
-    }
     // Do not distinguish between various Tagged variations.
     if (IsAnyTagged(rep)) {
       return MachineType::AnyTagged();
     }
+    // Word64 representation is only valid for safe integer values.
+    if (rep == MachineRepresentation::kWord64) {
+      DCHECK(type.Is(TypeCache::Get().kSafeInteger));
+      return MachineType(rep, MachineSemantic::kInt64);
+    }
     MachineType machine_type(rep, DeoptValueSemanticOf(type));
     DCHECK(machine_type.representation() != MachineRepresentation::kWord32 ||
            machine_type.semantic() == MachineSemantic::kInt32 ||
@@ -1174,6 +1184,10 @@ class RepresentationSelector {
     return changer_->Int32OverflowOperatorFor(node->opcode());
   }
 
+  const Operator* Int64Op(Node* node) {
+    return changer_->Int64OperatorFor(node->opcode());
+  }
+
   const Operator* Uint32Op(Node* node) {
     return changer_->Uint32OperatorFor(node->opcode());
   }
@@ -1205,7 +1219,7 @@ class RepresentationSelector {
         return kNoWriteBarrier;
       }
       if (value_type.IsHeapConstant()) {
-        Heap::RootListIndex root_index;
+        RootIndex root_index;
         Heap* heap = jsgraph_->isolate()->heap();
         if (heap->IsRootHandle(value_type.AsHeapConstant()->Value(),
                                &root_index)) {
@@ -1366,7 +1380,9 @@ class RepresentationSelector {
     }
 
     // default case => Float64Add/Sub
-    VisitBinop(node, UseInfo::CheckedNumberOrOddballAsFloat64(VectorSlotPair()),
+    VisitBinop(node,
+               UseInfo::CheckedNumberOrOddballAsFloat64(kDistinguishZeros,
+                                                        VectorSlotPair()),
                MachineRepresentation::kFloat64, Type::Number());
     if (lower()) {
       ChangeToPureOp(node, Float64Op(node));
@@ -1424,17 +1440,24 @@ class RepresentationSelector {
     if (hint == NumberOperationHint::kSignedSmall ||
         hint == NumberOperationHint::kSigned32) {
       // If the result is truncated, we only need to check the inputs.
+      // For the left hand side we just propagate the identify zeros
+      // mode of the {truncation}; and for modulus the sign of the
+      // right hand side doesn't matter anyways, so in particular there's
+      // no observable difference between a 0 and a -0 then.
+      UseInfo const lhs_use = CheckedUseInfoAsWord32FromHint(
+          hint, VectorSlotPair(), truncation.identify_zeros());
+      UseInfo const rhs_use = CheckedUseInfoAsWord32FromHint(
+          hint, VectorSlotPair(), kIdentifyZeros);
       if (truncation.IsUsedAsWord32()) {
-        VisitBinop(node, CheckedUseInfoAsWord32FromHint(hint),
-                   MachineRepresentation::kWord32);
+        VisitBinop(node, lhs_use, rhs_use, MachineRepresentation::kWord32);
         if (lower()) DeferReplacement(node, lowering->Int32Mod(node));
       } else if (BothInputsAre(node, Type::Unsigned32OrMinusZeroOrNaN())) {
-        VisitBinop(node, CheckedUseInfoAsWord32FromHint(hint),
-                   MachineRepresentation::kWord32, Type::Unsigned32());
+        VisitBinop(node, lhs_use, rhs_use, MachineRepresentation::kWord32,
+                   Type::Unsigned32());
         if (lower()) DeferReplacement(node, lowering->Uint32Mod(node));
       } else {
-        VisitBinop(node, CheckedUseInfoAsWord32FromHint(hint),
-                   MachineRepresentation::kWord32, Type::Signed32());
+        VisitBinop(node, lhs_use, rhs_use, MachineRepresentation::kWord32,
+                   Type::Signed32());
         if (lower()) ChangeToInt32OverflowOp(node);
       }
       return;
@@ -1444,10 +1467,7 @@ class RepresentationSelector {
         TypeOf(node->InputAt(1)).Is(Type::Unsigned32()) &&
         (truncation.IsUsedAsWord32() ||
          NodeProperties::GetType(node).Is(Type::Unsigned32()))) {
-      // We can only promise Float64 truncation here, as the decision is
-      // based on the feedback types of the inputs.
-      VisitBinop(node,
-                 UseInfo(MachineRepresentation::kWord32, Truncation::Float64()),
+      VisitBinop(node, UseInfo::TruncatingWord32(),
                  MachineRepresentation::kWord32, Type::Number());
       if (lower()) DeferReplacement(node, lowering->Uint32Mod(node));
       return;
@@ -1456,21 +1476,51 @@ class RepresentationSelector {
         TypeOf(node->InputAt(1)).Is(Type::Signed32()) &&
         (truncation.IsUsedAsWord32() ||
          NodeProperties::GetType(node).Is(Type::Signed32()))) {
-      // We can only promise Float64 truncation here, as the decision is
-      // based on the feedback types of the inputs.
-      VisitBinop(node,
-                 UseInfo(MachineRepresentation::kWord32, Truncation::Float64()),
+      VisitBinop(node, UseInfo::TruncatingWord32(),
                  MachineRepresentation::kWord32, Type::Number());
       if (lower()) DeferReplacement(node, lowering->Int32Mod(node));
       return;
     }
+
     // default case => Float64Mod
-    VisitBinop(node, UseInfo::CheckedNumberOrOddballAsFloat64(VectorSlotPair()),
-               MachineRepresentation::kFloat64, Type::Number());
+    // For the left hand side we just propagate the identify zeros
+    // mode of the {truncation}; and for modulus the sign of the
+    // right hand side doesn't matter anyways, so in particular there's
+    // no observable difference between a 0 and a -0 then.
+    UseInfo const lhs_use = UseInfo::CheckedNumberOrOddballAsFloat64(
+        truncation.identify_zeros(), VectorSlotPair());
+    UseInfo const rhs_use = UseInfo::CheckedNumberOrOddballAsFloat64(
+        kIdentifyZeros, VectorSlotPair());
+    VisitBinop(node, lhs_use, rhs_use, MachineRepresentation::kFloat64,
+               Type::Number());
     if (lower()) ChangeToPureOp(node, Float64Op(node));
     return;
   }
 
+  void InsertUnreachableIfNecessary(Node* node) {
+    DCHECK(lower());
+    // If the node is effectful and it produces an impossible value, then we
+    // insert Unreachable node after it.
+    if (node->op()->ValueOutputCount() > 0 &&
+        node->op()->EffectOutputCount() > 0 &&
+        node->opcode() != IrOpcode::kUnreachable && TypeOf(node).IsNone()) {
+      Node* control = node->op()->ControlOutputCount() > 0
+                          ? node
+                          : NodeProperties::GetControlInput(node, 0);
+
+      Node* unreachable =
+          graph()->NewNode(common()->Unreachable(), node, control);
+
+      // Insert unreachable node and replace all the effect uses of the {node}
+      // with the new unreachable node.
+      for (Edge edge : node->use_edges()) {
+        if (NodeProperties::IsEffectEdge(edge) && edge.from() != unreachable) {
+          edge.UpdateTo(unreachable);
+        }
+      }
+    }
+  }
+
   // Dispatching routine for visiting the node {node} with the usage {use}.
   // Depending on the operator, propagate new usage info to the inputs.
   void VisitNode(Node* node, Truncation truncation,
@@ -1485,9 +1535,12 @@ class RepresentationSelector {
     // a sane state still) and we would afterwards replace that use with
     // Dead as well.
     if (node->op()->ValueInputCount() > 0 &&
-        node->op()->HasProperty(Operator::kPure)) {
-      if (truncation.IsUnused()) return VisitUnused(node);
+        node->op()->HasProperty(Operator::kPure) && truncation.IsUnused()) {
+      return VisitUnused(node);
     }
+
+    if (lower()) InsertUnreachableIfNecessary(node);
+
     switch (node->opcode()) {
       //------------------------------------------------------------------
       // Common operators.
@@ -1521,6 +1574,7 @@ class RepresentationSelector {
         return;
       }
       case IrOpcode::kHeapConstant:
+      case IrOpcode::kDelayedStringConstant:
         return VisitLeaf(node, MachineRepresentation::kTaggedPointer);
       case IrOpcode::kPointerConstant: {
         VisitLeaf(node, MachineType::PointerRepresentation());
@@ -1609,9 +1663,13 @@ class RepresentationSelector {
       case IrOpcode::kNumberEqual: {
         Type const lhs_type = TypeOf(node->InputAt(0));
         Type const rhs_type = TypeOf(node->InputAt(1));
-        // Number comparisons reduce to integer comparisons for integer inputs.
-        if ((lhs_type.Is(Type::Unsigned32()) &&
-             rhs_type.Is(Type::Unsigned32())) ||
+        // Regular number comparisons in JavaScript generally identify zeros,
+        // so we always pass kIdentifyZeros for the inputs, and in addition
+        // we can truncate -0 to 0 for otherwise Unsigned32 or Signed32 inputs.
+        // For equality we also handle the case that one side is non-zero, in
+        // which case we allow to truncate NaN to 0 on the other side.
+        if ((lhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+             rhs_type.Is(Type::Unsigned32OrMinusZero())) ||
             (lhs_type.Is(Type::Unsigned32OrMinusZeroOrNaN()) &&
              rhs_type.Is(Type::Unsigned32OrMinusZeroOrNaN()) &&
              OneInputCannotBe(node, type_cache_.kZeroish))) {
@@ -1621,7 +1679,8 @@ class RepresentationSelector {
           if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
           return;
         }
-        if ((lhs_type.Is(Type::Signed32()) && rhs_type.Is(Type::Signed32())) ||
+        if ((lhs_type.Is(Type::Signed32OrMinusZero()) &&
+             rhs_type.Is(Type::Signed32OrMinusZero())) ||
             (lhs_type.Is(Type::Signed32OrMinusZeroOrNaN()) &&
              rhs_type.Is(Type::Signed32OrMinusZeroOrNaN()) &&
              OneInputCannotBe(node, type_cache_.kZeroish))) {
@@ -1632,29 +1691,33 @@ class RepresentationSelector {
           return;
         }
         // => Float64Cmp
-        VisitBinop(node, UseInfo::TruncatingFloat64(),
+        VisitBinop(node, UseInfo::TruncatingFloat64(kIdentifyZeros),
                    MachineRepresentation::kBit);
         if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         return;
       }
       case IrOpcode::kNumberLessThan:
       case IrOpcode::kNumberLessThanOrEqual: {
-        // Number comparisons reduce to integer comparisons for integer inputs.
-        if (TypeOf(node->InputAt(0)).Is(Type::Unsigned32()) &&
-            TypeOf(node->InputAt(1)).Is(Type::Unsigned32())) {
+        Type const lhs_type = TypeOf(node->InputAt(0));
+        Type const rhs_type = TypeOf(node->InputAt(1));
+        // Regular number comparisons in JavaScript generally identify zeros,
+        // so we always pass kIdentifyZeros for the inputs, and in addition
+        // we can truncate -0 to 0 for otherwise Unsigned32 or Signed32 inputs.
+        if (lhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+            rhs_type.Is(Type::Unsigned32OrMinusZero())) {
           // => unsigned Int32Cmp
           VisitBinop(node, UseInfo::TruncatingWord32(),
                      MachineRepresentation::kBit);
           if (lower()) NodeProperties::ChangeOp(node, Uint32Op(node));
-        } else if (TypeOf(node->InputAt(0)).Is(Type::Signed32()) &&
-                   TypeOf(node->InputAt(1)).Is(Type::Signed32())) {
+        } else if (lhs_type.Is(Type::Signed32OrMinusZero()) &&
+                   rhs_type.Is(Type::Signed32OrMinusZero())) {
           // => signed Int32Cmp
           VisitBinop(node, UseInfo::TruncatingWord32(),
                      MachineRepresentation::kBit);
           if (lower()) NodeProperties::ChangeOp(node, Int32Op(node));
         } else {
           // => Float64Cmp
-          VisitBinop(node, UseInfo::TruncatingFloat64(),
+          VisitBinop(node, UseInfo::TruncatingFloat64(kIdentifyZeros),
                      MachineRepresentation::kBit);
           if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         }
@@ -1672,16 +1735,20 @@ class RepresentationSelector {
       case IrOpcode::kSpeculativeNumberLessThan:
       case IrOpcode::kSpeculativeNumberLessThanOrEqual:
       case IrOpcode::kSpeculativeNumberEqual: {
-        // Number comparisons reduce to integer comparisons for integer inputs.
-        if (TypeOf(node->InputAt(0)).Is(Type::Unsigned32()) &&
-            TypeOf(node->InputAt(1)).Is(Type::Unsigned32())) {
+        Type const lhs_type = TypeOf(node->InputAt(0));
+        Type const rhs_type = TypeOf(node->InputAt(1));
+        // Regular number comparisons in JavaScript generally identify zeros,
+        // so we always pass kIdentifyZeros for the inputs, and in addition
+        // we can truncate -0 to 0 for otherwise Unsigned32 or Signed32 inputs.
+        if (lhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+            rhs_type.Is(Type::Unsigned32OrMinusZero())) {
           // => unsigned Int32Cmp
           VisitBinop(node, UseInfo::TruncatingWord32(),
                      MachineRepresentation::kBit);
           if (lower()) ChangeToPureOp(node, Uint32Op(node));
           return;
-        } else if (TypeOf(node->InputAt(0)).Is(Type::Signed32()) &&
-                   TypeOf(node->InputAt(1)).Is(Type::Signed32())) {
+        } else if (lhs_type.Is(Type::Signed32OrMinusZero()) &&
+                   rhs_type.Is(Type::Signed32OrMinusZero())) {
           // => signed Int32Cmp
           VisitBinop(node, UseInfo::TruncatingWord32(),
                      MachineRepresentation::kBit);
@@ -1694,7 +1761,9 @@ class RepresentationSelector {
           case NumberOperationHint::kSigned32:
           case NumberOperationHint::kSignedSmall:
             if (propagate()) {
-              VisitBinop(node, CheckedUseInfoAsWord32FromHint(hint),
+              VisitBinop(node,
+                         CheckedUseInfoAsWord32FromHint(hint, VectorSlotPair(),
+                                                        kIdentifyZeros),
                          MachineRepresentation::kBit);
             } else if (retype()) {
               SetOutput(node, MachineRepresentation::kBit, Type::Any());
@@ -1704,15 +1773,17 @@ class RepresentationSelector {
               Node* rhs = node->InputAt(1);
               if (IsNodeRepresentationTagged(lhs) &&
                   IsNodeRepresentationTagged(rhs)) {
-                VisitBinop(
-                    node,
-                    UseInfo::CheckedSignedSmallAsTaggedSigned(VectorSlotPair()),
-                    MachineRepresentation::kBit);
+                VisitBinop(node,
+                           UseInfo::CheckedSignedSmallAsTaggedSigned(
+                               VectorSlotPair(), kIdentifyZeros),
+                           MachineRepresentation::kBit);
                 ChangeToPureOp(
                     node, changer_->TaggedSignedOperatorFor(node->opcode()));
 
               } else {
-                VisitBinop(node, CheckedUseInfoAsWord32FromHint(hint),
+                VisitBinop(node,
+                           CheckedUseInfoAsWord32FromHint(
+                               hint, VectorSlotPair(), kIdentifyZeros),
                            MachineRepresentation::kBit);
                 ChangeToPureOp(node, Int32Op(node));
               }
@@ -1729,7 +1800,8 @@ class RepresentationSelector {
             V8_FALLTHROUGH;
           case NumberOperationHint::kNumber:
             VisitBinop(node,
-                       CheckedUseInfoAsFloat64FromHint(hint, VectorSlotPair()),
+                       CheckedUseInfoAsFloat64FromHint(hint, VectorSlotPair(),
+                                                       kIdentifyZeros),
                        MachineRepresentation::kBit);
             if (lower()) ChangeToPureOp(node, Float64Op(node));
             return;
@@ -1740,13 +1812,22 @@ class RepresentationSelector {
 
       case IrOpcode::kNumberAdd:
       case IrOpcode::kNumberSubtract: {
-        if (BothInputsAre(node, type_cache_.kAdditiveSafeIntegerOrMinusZero) &&
-            (GetUpperBound(node).Is(Type::Signed32()) ||
-             GetUpperBound(node).Is(Type::Unsigned32()) ||
+        if (TypeOf(node->InputAt(0))
+                .Is(type_cache_.kAdditiveSafeIntegerOrMinusZero) &&
+            TypeOf(node->InputAt(1))
+                .Is(type_cache_.kAdditiveSafeIntegerOrMinusZero) &&
+            (TypeOf(node).Is(Type::Signed32()) ||
+             TypeOf(node).Is(Type::Unsigned32()) ||
              truncation.IsUsedAsWord32())) {
           // => Int32Add/Sub
           VisitWord32TruncatingBinop(node);
           if (lower()) ChangeToPureOp(node, Int32Op(node));
+        } else if (jsgraph_->machine()->Is64() &&
+                   BothInputsAre(node, type_cache_.kSafeInteger) &&
+                   GetUpperBound(node).Is(type_cache_.kSafeInteger)) {
+          // => Int64Add/Sub
+          VisitInt64Binop(node);
+          if (lower()) ChangeToPureOp(node, Int64Op(node));
         } else {
           // => Float64Add/Sub
           VisitFloat64Binop(node);
@@ -1803,18 +1884,19 @@ class RepresentationSelector {
 
         // Checked float64 x float64 => float64
         VisitBinop(node,
-                   UseInfo::CheckedNumberOrOddballAsFloat64(VectorSlotPair()),
+                   UseInfo::CheckedNumberOrOddballAsFloat64(kDistinguishZeros,
+                                                            VectorSlotPair()),
                    MachineRepresentation::kFloat64, Type::Number());
         if (lower()) ChangeToPureOp(node, Float64Op(node));
         return;
       }
       case IrOpcode::kNumberMultiply: {
-        if (BothInputsAre(node, Type::Integral32()) &&
-            (NodeProperties::GetType(node).Is(Type::Signed32()) ||
-             NodeProperties::GetType(node).Is(Type::Unsigned32()) ||
+        if (TypeOf(node->InputAt(0)).Is(Type::Integral32()) &&
+            TypeOf(node->InputAt(1)).Is(Type::Integral32()) &&
+            (TypeOf(node).Is(Type::Signed32()) ||
+             TypeOf(node).Is(Type::Unsigned32()) ||
              (truncation.IsUsedAsWord32() &&
-              NodeProperties::GetType(node).Is(
-                  type_cache_.kSafeIntegerOrMinusZero)))) {
+              TypeOf(node).Is(type_cache_.kSafeIntegerOrMinusZero)))) {
           // Multiply reduces to Int32Mul if the inputs are integers, and
           // (a) the output is either known to be Signed32, or
           // (b) the output is known to be Unsigned32, or
@@ -1898,31 +1980,30 @@ class RepresentationSelector {
 
         // default case => Float64Div
         VisitBinop(node,
-                   UseInfo::CheckedNumberOrOddballAsFloat64(VectorSlotPair()),
+                   UseInfo::CheckedNumberOrOddballAsFloat64(kDistinguishZeros,
+                                                            VectorSlotPair()),
                    MachineRepresentation::kFloat64, Type::Number());
         if (lower()) ChangeToPureOp(node, Float64Op(node));
         return;
       }
       case IrOpcode::kNumberDivide: {
-        if (BothInputsAreUnsigned32(node) && truncation.IsUsedAsWord32()) {
+        if (TypeOf(node->InputAt(0)).Is(Type::Unsigned32()) &&
+            TypeOf(node->InputAt(1)).Is(Type::Unsigned32()) &&
+            (truncation.IsUsedAsWord32() ||
+             TypeOf(node).Is(Type::Unsigned32()))) {
           // => unsigned Uint32Div
           VisitWord32TruncatingBinop(node);
           if (lower()) DeferReplacement(node, lowering->Uint32Div(node));
           return;
         }
-        if (BothInputsAreSigned32(node)) {
-          if (NodeProperties::GetType(node).Is(Type::Signed32())) {
-            // => signed Int32Div
-            VisitWord32TruncatingBinop(node);
-            if (lower()) DeferReplacement(node, lowering->Int32Div(node));
-            return;
-          }
-          if (truncation.IsUsedAsWord32()) {
-            // => signed Int32Div
-            VisitWord32TruncatingBinop(node);
-            if (lower()) DeferReplacement(node, lowering->Int32Div(node));
-            return;
-          }
+        if (TypeOf(node->InputAt(0)).Is(Type::Signed32()) &&
+            TypeOf(node->InputAt(1)).Is(Type::Signed32()) &&
+            (truncation.IsUsedAsWord32() ||
+             TypeOf(node).Is(Type::Signed32()))) {
+          // => signed Int32Div
+          VisitWord32TruncatingBinop(node);
+          if (lower()) DeferReplacement(node, lowering->Int32Div(node));
+          return;
         }
         // Number x Number => Float64Div
         VisitFloat64Binop(node);
@@ -1932,48 +2013,36 @@ class RepresentationSelector {
       case IrOpcode::kSpeculativeNumberModulus:
         return VisitSpeculativeNumberModulus(node, truncation, lowering);
       case IrOpcode::kNumberModulus: {
-        if (BothInputsAre(node, Type::Unsigned32OrMinusZeroOrNaN()) &&
+        Type const lhs_type = TypeOf(node->InputAt(0));
+        Type const rhs_type = TypeOf(node->InputAt(1));
+        if ((lhs_type.Is(Type::Unsigned32OrMinusZeroOrNaN()) &&
+             rhs_type.Is(Type::Unsigned32OrMinusZeroOrNaN())) &&
             (truncation.IsUsedAsWord32() ||
-             NodeProperties::GetType(node).Is(Type::Unsigned32()))) {
+             TypeOf(node).Is(Type::Unsigned32()))) {
           // => unsigned Uint32Mod
           VisitWord32TruncatingBinop(node);
           if (lower()) DeferReplacement(node, lowering->Uint32Mod(node));
           return;
         }
-        if (BothInputsAre(node, Type::Signed32OrMinusZeroOrNaN()) &&
-            (truncation.IsUsedAsWord32() ||
-             NodeProperties::GetType(node).Is(Type::Signed32()))) {
+        if ((lhs_type.Is(Type::Signed32OrMinusZeroOrNaN()) &&
+             rhs_type.Is(Type::Signed32OrMinusZeroOrNaN())) &&
+            (truncation.IsUsedAsWord32() || TypeOf(node).Is(Type::Signed32()) ||
+             (truncation.IdentifiesZeroAndMinusZero() &&
+              TypeOf(node).Is(Type::Signed32OrMinusZero())))) {
           // => signed Int32Mod
           VisitWord32TruncatingBinop(node);
           if (lower()) DeferReplacement(node, lowering->Int32Mod(node));
           return;
         }
-        if (TypeOf(node->InputAt(0)).Is(Type::Unsigned32()) &&
-            TypeOf(node->InputAt(1)).Is(Type::Unsigned32()) &&
-            (truncation.IsUsedAsWord32() ||
-             NodeProperties::GetType(node).Is(Type::Unsigned32()))) {
-          // We can only promise Float64 truncation here, as the decision is
-          // based on the feedback types of the inputs.
-          VisitBinop(node, UseInfo(MachineRepresentation::kWord32,
-                                   Truncation::Float64()),
-                     MachineRepresentation::kWord32);
-          if (lower()) DeferReplacement(node, lowering->Uint32Mod(node));
-          return;
-        }
-        if (TypeOf(node->InputAt(0)).Is(Type::Signed32()) &&
-            TypeOf(node->InputAt(1)).Is(Type::Signed32()) &&
-            (truncation.IsUsedAsWord32() ||
-             NodeProperties::GetType(node).Is(Type::Signed32()))) {
-          // We can only promise Float64 truncation here, as the decision is
-          // based on the feedback types of the inputs.
-          VisitBinop(node, UseInfo(MachineRepresentation::kWord32,
-                                   Truncation::Float64()),
-                     MachineRepresentation::kWord32);
-          if (lower()) DeferReplacement(node, lowering->Int32Mod(node));
-          return;
-        }
-        // default case => Float64Mod
-        VisitFloat64Binop(node);
+        // => Float64Mod
+        // For the left hand side we just propagate the identify zeros
+        // mode of the {truncation}; and for modulus the sign of the
+        // right hand side doesn't matter anyways, so in particular there's
+        // no observable difference between a 0 and a -0 then.
+        UseInfo const lhs_use =
+            UseInfo::TruncatingFloat64(truncation.identify_zeros());
+        UseInfo const rhs_use = UseInfo::TruncatingFloat64(kIdentifyZeros);
+        VisitBinop(node, lhs_use, rhs_use, MachineRepresentation::kFloat64);
         if (lower()) ChangeToPureOp(node, Float64Op(node));
         return;
       }
@@ -2096,21 +2165,24 @@ class RepresentationSelector {
         return;
       }
       case IrOpcode::kNumberAbs: {
-        if (TypeOf(node->InputAt(0)).Is(Type::Unsigned32())) {
+        // NumberAbs maps both 0 and -0 to 0, so we can generally
+        // pass the kIdentifyZeros truncation to its input, and
+        // choose to ignore minus zero in all cases.
+        Type const input_type = TypeOf(node->InputAt(0));
+        if (input_type.Is(Type::Unsigned32OrMinusZero())) {
           VisitUnop(node, UseInfo::TruncatingWord32(),
                     MachineRepresentation::kWord32);
           if (lower()) DeferReplacement(node, node->InputAt(0));
-        } else if (TypeOf(node->InputAt(0)).Is(Type::Signed32())) {
+        } else if (input_type.Is(Type::Signed32OrMinusZero())) {
           VisitUnop(node, UseInfo::TruncatingWord32(),
                     MachineRepresentation::kWord32);
           if (lower()) DeferReplacement(node, lowering->Int32Abs(node));
-        } else if (TypeOf(node->InputAt(0))
-                       .Is(type_cache_.kPositiveIntegerOrMinusZeroOrNaN)) {
-          VisitUnop(node, UseInfo::TruncatingFloat64(),
+        } else if (input_type.Is(type_cache_.kPositiveIntegerOrNaN)) {
+          VisitUnop(node, UseInfo::TruncatingFloat64(kIdentifyZeros),
                     MachineRepresentation::kFloat64);
           if (lower()) DeferReplacement(node, node->InputAt(0));
         } else {
-          VisitUnop(node, UseInfo::TruncatingFloat64(),
+          VisitUnop(node, UseInfo::TruncatingFloat64(kIdentifyZeros),
                     MachineRepresentation::kFloat64);
           if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         }
@@ -2138,32 +2210,45 @@ class RepresentationSelector {
         // It is safe to use the feedback types for left and right hand side
         // here, since we can only narrow those types and thus we can only
         // promise a more specific truncation.
+        // For NumberMax we generally propagate whether the truncation
+        // identifies zeros to the inputs, and we choose to ignore minus
+        // zero in those cases.
         Type const lhs_type = TypeOf(node->InputAt(0));
         Type const rhs_type = TypeOf(node->InputAt(1));
-        if (lhs_type.Is(Type::Unsigned32()) &&
-            rhs_type.Is(Type::Unsigned32())) {
+        if ((lhs_type.Is(Type::Unsigned32()) &&
+             rhs_type.Is(Type::Unsigned32())) ||
+            (lhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+             rhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+             truncation.IdentifiesZeroAndMinusZero())) {
           VisitWord32TruncatingBinop(node);
           if (lower()) {
             lowering->DoMax(node, lowering->machine()->Uint32LessThan(),
                             MachineRepresentation::kWord32);
           }
-        } else if (lhs_type.Is(Type::Signed32()) &&
-                   rhs_type.Is(Type::Signed32())) {
+        } else if ((lhs_type.Is(Type::Signed32()) &&
+                    rhs_type.Is(Type::Signed32())) ||
+                   (lhs_type.Is(Type::Signed32OrMinusZero()) &&
+                    rhs_type.Is(Type::Signed32OrMinusZero()) &&
+                    truncation.IdentifiesZeroAndMinusZero())) {
           VisitWord32TruncatingBinop(node);
           if (lower()) {
             lowering->DoMax(node, lowering->machine()->Int32LessThan(),
                             MachineRepresentation::kWord32);
           }
-        } else if (lhs_type.Is(Type::PlainNumber()) &&
-                   rhs_type.Is(Type::PlainNumber())) {
-          VisitFloat64Binop(node);
+        } else {
+          VisitBinop(node,
+                     UseInfo::TruncatingFloat64(truncation.identify_zeros()),
+                     MachineRepresentation::kFloat64);
           if (lower()) {
-            lowering->DoMax(node, lowering->machine()->Float64LessThan(),
-                            MachineRepresentation::kFloat64);
+            if (truncation.IdentifiesZeroAndMinusZero() ||
+                (lhs_type.Is(Type::PlainNumber()) &&
+                 rhs_type.Is(Type::PlainNumber()))) {
+              lowering->DoMax(node, lowering->machine()->Float64LessThan(),
+                              MachineRepresentation::kFloat64);
+            } else {
+              NodeProperties::ChangeOp(node, Float64Op(node));
+            }
           }
-        } else {
-          VisitFloat64Binop(node);
-          if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         }
         return;
       }
@@ -2171,32 +2256,45 @@ class RepresentationSelector {
         // It is safe to use the feedback types for left and right hand side
         // here, since we can only narrow those types and thus we can only
         // promise a more specific truncation.
+        // For NumberMin we generally propagate whether the truncation
+        // identifies zeros to the inputs, and we choose to ignore minus
+        // zero in those cases.
         Type const lhs_type = TypeOf(node->InputAt(0));
         Type const rhs_type = TypeOf(node->InputAt(1));
-        if (lhs_type.Is(Type::Unsigned32()) &&
-            rhs_type.Is(Type::Unsigned32())) {
+        if ((lhs_type.Is(Type::Unsigned32()) &&
+             rhs_type.Is(Type::Unsigned32())) ||
+            (lhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+             rhs_type.Is(Type::Unsigned32OrMinusZero()) &&
+             truncation.IdentifiesZeroAndMinusZero())) {
           VisitWord32TruncatingBinop(node);
           if (lower()) {
             lowering->DoMin(node, lowering->machine()->Uint32LessThan(),
                             MachineRepresentation::kWord32);
           }
-        } else if (lhs_type.Is(Type::Signed32()) &&
-                   rhs_type.Is(Type::Signed32())) {
+        } else if ((lhs_type.Is(Type::Signed32()) &&
+                    rhs_type.Is(Type::Signed32())) ||
+                   (lhs_type.Is(Type::Signed32OrMinusZero()) &&
+                    rhs_type.Is(Type::Signed32OrMinusZero()) &&
+                    truncation.IdentifiesZeroAndMinusZero())) {
           VisitWord32TruncatingBinop(node);
           if (lower()) {
             lowering->DoMin(node, lowering->machine()->Int32LessThan(),
                             MachineRepresentation::kWord32);
           }
-        } else if (lhs_type.Is(Type::PlainNumber()) &&
-                   rhs_type.Is(Type::PlainNumber())) {
-          VisitFloat64Binop(node);
+        } else {
+          VisitBinop(node,
+                     UseInfo::TruncatingFloat64(truncation.identify_zeros()),
+                     MachineRepresentation::kFloat64);
           if (lower()) {
-            lowering->DoMin(node, lowering->machine()->Float64LessThan(),
-                            MachineRepresentation::kFloat64);
+            if (truncation.IdentifiesZeroAndMinusZero() ||
+                (lhs_type.Is(Type::PlainNumber()) &&
+                 rhs_type.Is(Type::PlainNumber()))) {
+              lowering->DoMin(node, lowering->machine()->Float64LessThan(),
+                              MachineRepresentation::kFloat64);
+            } else {
+              NodeProperties::ChangeOp(node, Float64Op(node));
+            }
           }
-        } else {
-          VisitFloat64Binop(node);
-          if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         }
         return;
       }
@@ -2207,18 +2305,38 @@ class RepresentationSelector {
         if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         return;
       }
+      case IrOpcode::kNumberCeil:
+      case IrOpcode::kNumberFloor:
+      case IrOpcode::kNumberRound:
+      case IrOpcode::kNumberTrunc: {
+        // For NumberCeil, NumberFloor, NumberRound and NumberTrunc we propagate
+        // the zero identification part of the truncation, and we turn them into
+        // no-ops if we figure out (late) that their input is already an
+        // integer, NaN or -0.
+        Type const input_type = TypeOf(node->InputAt(0));
+        VisitUnop(node, UseInfo::TruncatingFloat64(truncation.identify_zeros()),
+                  MachineRepresentation::kFloat64);
+        if (lower()) {
+          if (input_type.Is(type_cache_.kIntegerOrMinusZeroOrNaN)) {
+            DeferReplacement(node, node->InputAt(0));
+          } else if (node->opcode() == IrOpcode::kNumberRound) {
+            DeferReplacement(node, lowering->Float64Round(node));
+          } else {
+            NodeProperties::ChangeOp(node, Float64Op(node));
+          }
+        }
+        return;
+      }
       case IrOpcode::kNumberAcos:
       case IrOpcode::kNumberAcosh:
       case IrOpcode::kNumberAsin:
       case IrOpcode::kNumberAsinh:
       case IrOpcode::kNumberAtan:
       case IrOpcode::kNumberAtanh:
-      case IrOpcode::kNumberCeil:
       case IrOpcode::kNumberCos:
       case IrOpcode::kNumberCosh:
       case IrOpcode::kNumberExp:
       case IrOpcode::kNumberExpm1:
-      case IrOpcode::kNumberFloor:
       case IrOpcode::kNumberLog:
       case IrOpcode::kNumberLog1p:
       case IrOpcode::kNumberLog2:
@@ -2227,19 +2345,12 @@ class RepresentationSelector {
       case IrOpcode::kNumberSin:
       case IrOpcode::kNumberSinh:
       case IrOpcode::kNumberTan:
-      case IrOpcode::kNumberTanh:
-      case IrOpcode::kNumberTrunc: {
+      case IrOpcode::kNumberTanh: {
         VisitUnop(node, UseInfo::TruncatingFloat64(),
                   MachineRepresentation::kFloat64);
         if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
         return;
       }
-      case IrOpcode::kNumberRound: {
-        VisitUnop(node, UseInfo::TruncatingFloat64(),
-                  MachineRepresentation::kFloat64);
-        if (lower()) DeferReplacement(node, lowering->Float64Round(node));
-        return;
-      }
       case IrOpcode::kNumberSign: {
         if (InputIs(node, Type::Signed32())) {
           VisitUnop(node, UseInfo::TruncatingWord32(),
@@ -2252,6 +2363,20 @@ class RepresentationSelector {
         }
         return;
       }
+      case IrOpcode::kNumberSilenceNaN: {
+        Type const input_type = TypeOf(node->InputAt(0));
+        if (input_type.Is(Type::OrderedNumber())) {
+          // No need to silence anything if the input cannot be NaN.
+          VisitUnop(node, UseInfo::TruncatingFloat64(),
+                    MachineRepresentation::kFloat64);
+          if (lower()) DeferReplacement(node, node->InputAt(0));
+        } else {
+          VisitUnop(node, UseInfo::TruncatingFloat64(),
+                    MachineRepresentation::kFloat64);
+          if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
+        }
+        return;
+      }
       case IrOpcode::kNumberSqrt: {
         VisitUnop(node, UseInfo::TruncatingFloat64(),
                   MachineRepresentation::kFloat64);
@@ -2259,17 +2384,22 @@ class RepresentationSelector {
         return;
       }
       case IrOpcode::kNumberToBoolean: {
+        // For NumberToBoolean we don't care whether the input is 0 or
+        // -0, since both of them are mapped to false anyways, so we
+        // can generally pass kIdentifyZeros truncation.
         Type const input_type = TypeOf(node->InputAt(0));
-        if (input_type.Is(Type::Integral32())) {
+        if (input_type.Is(Type::Integral32OrMinusZeroOrNaN())) {
+          // 0, -0 and NaN all map to false, so we can safely truncate
+          // all of them to zero here.
           VisitUnop(node, UseInfo::TruncatingWord32(),
                     MachineRepresentation::kBit);
           if (lower()) lowering->DoIntegral32ToBit(node);
         } else if (input_type.Is(Type::OrderedNumber())) {
-          VisitUnop(node, UseInfo::TruncatingFloat64(),
+          VisitUnop(node, UseInfo::TruncatingFloat64(kIdentifyZeros),
                     MachineRepresentation::kBit);
           if (lower()) lowering->DoOrderedNumberToBit(node);
         } else {
-          VisitUnop(node, UseInfo::TruncatingFloat64(),
+          VisitUnop(node, UseInfo::TruncatingFloat64(kIdentifyZeros),
                     MachineRepresentation::kBit);
           if (lower()) lowering->DoNumberToBit(node);
         }
@@ -2337,6 +2467,18 @@ class RepresentationSelector {
                          MachineRepresentation::kTaggedPointer);
       }
       case IrOpcode::kNewConsString: {
+        ProcessInput(node, 0, UseInfo::TruncatingWord32());  // length
+        ProcessInput(node, 1, UseInfo::AnyTagged());         // first
+        ProcessInput(node, 2, UseInfo::AnyTagged());         // second
+        SetOutput(node, MachineRepresentation::kTaggedPointer);
+        return;
+      }
+      case IrOpcode::kStringConcat: {
+        // TODO(turbofan): We currently depend on having this first length input
+        // to make sure that the overflow check is properly scheduled before the
+        // actual string concatenation. We should also use the length to pass it
+        // to the builtin or decide in optimized code how to construct the
+        // resulting string (i.e. cons string or sequential string).
         ProcessInput(node, 0, UseInfo::TaggedSigned());  // length
         ProcessInput(node, 1, UseInfo::AnyTagged());     // first
         ProcessInput(node, 2, UseInfo::AnyTagged());     // second
@@ -2350,13 +2492,11 @@ class RepresentationSelector {
                           MachineRepresentation::kTaggedPointer);
       }
       case IrOpcode::kStringCharCodeAt: {
-        return VisitBinop(node, UseInfo::AnyTagged(),
-                          UseInfo::TruncatingWord32(),
+        return VisitBinop(node, UseInfo::AnyTagged(), UseInfo::Word(),
                           MachineRepresentation::kWord32);
       }
       case IrOpcode::kStringCodePointAt: {
-        return VisitBinop(node, UseInfo::AnyTagged(),
-                          UseInfo::TruncatingWord32(),
+        return VisitBinop(node, UseInfo::AnyTagged(), UseInfo::Word(),
                           MachineRepresentation::kTaggedSigned);
       }
       case IrOpcode::kStringFromSingleCharCode: {
@@ -2380,8 +2520,7 @@ class RepresentationSelector {
         // TODO(bmeurer): The input representation should be TaggedPointer.
         // Fix this once we have a dedicated StringConcat/JSStringAdd
         // operator, which marks it's output as TaggedPointer properly.
-        VisitUnop(node, UseInfo::AnyTagged(),
-                  MachineRepresentation::kTaggedSigned);
+        VisitUnop(node, UseInfo::AnyTagged(), MachineRepresentation::kWord32);
         return;
       }
       case IrOpcode::kStringSubstring: {
@@ -2491,7 +2630,7 @@ class RepresentationSelector {
       }
 
       case IrOpcode::kAllocate: {
-        ProcessInput(node, 0, UseInfo::TruncatingWord32());
+        ProcessInput(node, 0, UseInfo::Word());
         ProcessRemainingInputs(node, 1);
         SetOutput(node, MachineRepresentation::kTaggedPointer);
         return;
@@ -2543,8 +2682,7 @@ class RepresentationSelector {
       case IrOpcode::kLoadElement: {
         if (truncation.IsUnused()) return VisitUnused(node);
         ElementAccess access = ElementAccessOf(node->op());
-        VisitBinop(node, UseInfoForBasePointer(access),
-                   UseInfo::TruncatingWord32(),
+        VisitBinop(node, UseInfoForBasePointer(access), UseInfo::Word(),
                    access.machine_type.representation());
         return;
       }
@@ -2564,7 +2702,7 @@ class RepresentationSelector {
             access.base_is_tagged, element_representation, access.type,
             input_info->representation(), value_node);
         ProcessInput(node, 0, UseInfoForBasePointer(access));  // base
-        ProcessInput(node, 1, UseInfo::TruncatingWord32());    // index
+        ProcessInput(node, 1, UseInfo::Word());                // index
         ProcessInput(node, 2,
                      TruncatingUseInfoFromRepresentation(
                          element_representation));  // value
@@ -2587,8 +2725,8 @@ class RepresentationSelector {
       case IrOpcode::kTransitionAndStoreElement: {
         Type value_type = TypeOf(node->InputAt(2));
 
-        ProcessInput(node, 0, UseInfo::AnyTagged());         // array
-        ProcessInput(node, 1, UseInfo::TruncatingWord32());  // index
+        ProcessInput(node, 0, UseInfo::AnyTagged());  // array
+        ProcessInput(node, 1, UseInfo::Word());       // index
 
         if (value_type.Is(Type::SignedSmall())) {
           ProcessInput(node, 2, UseInfo::TruncatingWord32());  // value
@@ -2623,10 +2761,10 @@ class RepresentationSelector {
       case IrOpcode::kLoadTypedElement: {
         MachineRepresentation const rep =
             MachineRepresentationFromArrayType(ExternalArrayTypeOf(node->op()));
-        ProcessInput(node, 0, UseInfo::AnyTagged());         // buffer
-        ProcessInput(node, 1, UseInfo::AnyTagged());         // base pointer
-        ProcessInput(node, 2, UseInfo::PointerInt());        // external pointer
-        ProcessInput(node, 3, UseInfo::TruncatingWord32());  // index
+        ProcessInput(node, 0, UseInfo::AnyTagged());  // buffer
+        ProcessInput(node, 1, UseInfo::AnyTagged());  // base pointer
+        ProcessInput(node, 2, UseInfo::Word());       // external pointer
+        ProcessInput(node, 3, UseInfo::Word());       // index
         ProcessRemainingInputs(node, 4);
         SetOutput(node, rep);
         return;
@@ -2634,10 +2772,10 @@ class RepresentationSelector {
       case IrOpcode::kLoadDataViewElement: {
         MachineRepresentation const rep =
             MachineRepresentationFromArrayType(ExternalArrayTypeOf(node->op()));
-        ProcessInput(node, 0, UseInfo::AnyTagged());         // buffer
-        ProcessInput(node, 1, UseInfo::PointerInt());        // external pointer
-        ProcessInput(node, 2, UseInfo::TruncatingWord32());  // index
-        ProcessInput(node, 3, UseInfo::Bool());              // little-endian
+        ProcessInput(node, 0, UseInfo::AnyTagged());  // buffer
+        ProcessInput(node, 1, UseInfo::Word());       // external pointer
+        ProcessInput(node, 2, UseInfo::Word());       // index
+        ProcessInput(node, 3, UseInfo::Bool());       // little-endian
         ProcessRemainingInputs(node, 4);
         SetOutput(node, rep);
         return;
@@ -2645,10 +2783,10 @@ class RepresentationSelector {
       case IrOpcode::kStoreTypedElement: {
         MachineRepresentation const rep =
             MachineRepresentationFromArrayType(ExternalArrayTypeOf(node->op()));
-        ProcessInput(node, 0, UseInfo::AnyTagged());         // buffer
-        ProcessInput(node, 1, UseInfo::AnyTagged());         // base pointer
-        ProcessInput(node, 2, UseInfo::PointerInt());        // external pointer
-        ProcessInput(node, 3, UseInfo::TruncatingWord32());  // index
+        ProcessInput(node, 0, UseInfo::AnyTagged());  // buffer
+        ProcessInput(node, 1, UseInfo::AnyTagged());  // base pointer
+        ProcessInput(node, 2, UseInfo::Word());       // external pointer
+        ProcessInput(node, 3, UseInfo::Word());       // index
         ProcessInput(node, 4,
                      TruncatingUseInfoFromRepresentation(rep));  // value
         ProcessRemainingInputs(node, 5);
@@ -2659,8 +2797,8 @@ class RepresentationSelector {
         MachineRepresentation const rep =
             MachineRepresentationFromArrayType(ExternalArrayTypeOf(node->op()));
         ProcessInput(node, 0, UseInfo::AnyTagged());         // buffer
-        ProcessInput(node, 1, UseInfo::PointerInt());        // external pointer
-        ProcessInput(node, 2, UseInfo::TruncatingWord32());  // index
+        ProcessInput(node, 1, UseInfo::Word());              // external pointer
+        ProcessInput(node, 2, UseInfo::Word());              // index
         ProcessInput(node, 3,
                      TruncatingUseInfoFromRepresentation(rep));  // value
         ProcessInput(node, 4, UseInfo::Bool());  // little-endian
@@ -2949,8 +3087,7 @@ class RepresentationSelector {
         return;
       }
       case IrOpcode::kArgumentsLength: {
-        VisitUnop(node, UseInfo::PointerInt(),
-                  MachineRepresentation::kTaggedSigned);
+        VisitUnop(node, UseInfo::Word(), MachineRepresentation::kTaggedSigned);
         return;
       }
       case IrOpcode::kNewDoubleElements:
@@ -2960,14 +3097,10 @@ class RepresentationSelector {
         return;
       }
       case IrOpcode::kNewArgumentsElements: {
-        VisitBinop(node, UseInfo::PointerInt(), UseInfo::TaggedSigned(),
+        VisitBinop(node, UseInfo::Word(), UseInfo::TaggedSigned(),
                    MachineRepresentation::kTaggedPointer);
         return;
       }
-      case IrOpcode::kArrayBufferWasNeutered: {
-        VisitUnop(node, UseInfo::AnyTagged(), MachineRepresentation::kBit);
-        return;
-      }
       case IrOpcode::kCheckFloat64Hole: {
         Type const input_type = TypeOf(node->InputAt(0));
         if (input_type.Is(Type::Number())) {
@@ -3045,20 +3178,28 @@ class RepresentationSelector {
         return VisitBinop(node, UseInfo::AnyTagged(),
                           MachineRepresentation::kTaggedPointer);
       case IrOpcode::kMaybeGrowFastElements: {
+        Type const index_type = TypeOf(node->InputAt(2));
+        Type const length_type = TypeOf(node->InputAt(3));
         ProcessInput(node, 0, UseInfo::AnyTagged());         // object
         ProcessInput(node, 1, UseInfo::AnyTagged());         // elements
         ProcessInput(node, 2, UseInfo::TruncatingWord32());  // index
         ProcessInput(node, 3, UseInfo::TruncatingWord32());  // length
         ProcessRemainingInputs(node, 4);
         SetOutput(node, MachineRepresentation::kTaggedPointer);
+        if (lower()) {
+          // If the index is known to be less than the length (or if
+          // we're in dead code), we know that we don't need to grow
+          // the elements, so we can just remove this operation all
+          // together and replace it with the elements that we have
+          // on the inputs.
+          if (index_type.IsNone() || length_type.IsNone() ||
+              index_type.Max() < length_type.Min()) {
+            DeferReplacement(node, node->InputAt(1));
+          }
+        }
         return;
       }
 
-      case IrOpcode::kNumberSilenceNaN:
-        VisitUnop(node, UseInfo::TruncatingFloat64(),
-                  MachineRepresentation::kFloat64);
-        if (lower()) NodeProperties::ChangeOp(node, Float64Op(node));
-        return;
       case IrOpcode::kDateNow:
         VisitInputs(node);
         return SetOutput(node, MachineRepresentation::kTaggedPointer);
@@ -3104,7 +3245,7 @@ class RepresentationSelector {
         Type const key_type = TypeOf(node->InputAt(1));
         if (key_type.Is(Type::Signed32OrMinusZero())) {
           VisitBinop(node, UseInfo::AnyTagged(), UseInfo::TruncatingWord32(),
-                     MachineRepresentation::kWord32);
+                     MachineType::PointerRepresentation());
           if (lower()) {
             NodeProperties::ChangeOp(
                 node,
@@ -3151,7 +3292,6 @@ class RepresentationSelector {
       case IrOpcode::kJSDecrement:
       case IrOpcode::kJSIncrement:
       case IrOpcode::kJSNegate:
-      case IrOpcode::kJSToInteger:
       case IrOpcode::kJSToLength:
       case IrOpcode::kJSToName:
       case IrOpcode::kJSToObject:
@@ -3950,7 +4090,7 @@ Node* SimplifiedLowering::ToNumberConvertBigIntCode() {
 Node* SimplifiedLowering::ToNumericCode() {
   if (!to_numeric_code_.is_set()) {
     Callable callable = Builtins::CallableFor(isolate(), Builtins::kToNumeric);
-    to_number_code_.set(jsgraph()->HeapConstant(callable.code()));
+    to_numeric_code_.set(jsgraph()->HeapConstant(callable.code()));
   }
   return to_numeric_code_.get();
 }
@@ -3959,9 +4099,10 @@ Operator const* SimplifiedLowering::ToNumberOperator() {
   if (!to_number_operator_.is_set()) {
     Callable callable = Builtins::CallableFor(isolate(), Builtins::kToNumber);
     CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
-    auto call_descriptor =
-        Linkage::GetStubCallDescriptor(graph()->zone(), callable.descriptor(),
-                                       0, flags, Operator::kNoProperties);
+    auto call_descriptor = Linkage::GetStubCallDescriptor(
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(), flags,
+        Operator::kNoProperties);
     to_number_operator_.set(common()->Call(call_descriptor));
   }
   return to_number_operator_.get();
@@ -3972,9 +4113,10 @@ Operator const* SimplifiedLowering::ToNumberConvertBigIntOperator() {
     Callable callable =
         Builtins::CallableFor(isolate(), Builtins::kToNumberConvertBigInt);
     CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
-    auto call_descriptor =
-        Linkage::GetStubCallDescriptor(graph()->zone(), callable.descriptor(),
-                                       0, flags, Operator::kNoProperties);
+    auto call_descriptor = Linkage::GetStubCallDescriptor(
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(), flags,
+        Operator::kNoProperties);
     to_number_convert_big_int_operator_.set(common()->Call(call_descriptor));
   }
   return to_number_convert_big_int_operator_.get();
@@ -3984,9 +4126,10 @@ Operator const* SimplifiedLowering::ToNumericOperator() {
   if (!to_numeric_operator_.is_set()) {
     Callable callable = Builtins::CallableFor(isolate(), Builtins::kToNumeric);
     CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
-    auto call_descriptor =
-        Linkage::GetStubCallDescriptor(graph()->zone(), callable.descriptor(),
-                                       0, flags, Operator::kNoProperties);
+    auto call_descriptor = Linkage::GetStubCallDescriptor(
+        graph()->zone(), callable.descriptor(),
+        callable.descriptor().GetStackParameterCount(), flags,
+        Operator::kNoProperties);
     to_numeric_operator_.set(common()->Call(call_descriptor));
   }
   return to_numeric_operator_.get();
diff --git a/deps/v8/src/compiler/simplified-lowering.h b/deps/v8/src/compiler/simplified-lowering.h
index 7b21b07813..ba7c9b68b7 100644
--- a/deps/v8/src/compiler/simplified-lowering.h
+++ b/deps/v8/src/compiler/simplified-lowering.h
@@ -27,7 +27,7 @@ class V8_EXPORT_PRIVATE SimplifiedLowering final {
                      SourcePositionTable* source_position,
                      NodeOriginTable* node_origins,
                      PoisoningMitigationLevel poisoning_level);
-  ~SimplifiedLowering() {}
+  ~SimplifiedLowering() = default;
 
   void LowerAllNodes();
 
diff --git a/deps/v8/src/compiler/simplified-operator-reducer.cc b/deps/v8/src/compiler/simplified-operator-reducer.cc
index ce7d18f34a..851d7927bd 100644
--- a/deps/v8/src/compiler/simplified-operator-reducer.cc
+++ b/deps/v8/src/compiler/simplified-operator-reducer.cc
@@ -38,7 +38,7 @@ SimplifiedOperatorReducer::SimplifiedOperatorReducer(
       jsgraph_(jsgraph),
       js_heap_broker_(js_heap_broker) {}
 
-SimplifiedOperatorReducer::~SimplifiedOperatorReducer() {}
+SimplifiedOperatorReducer::~SimplifiedOperatorReducer() = default;
 
 
 Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
diff --git a/deps/v8/src/compiler/simplified-operator.cc b/deps/v8/src/compiler/simplified-operator.cc
index 0c331bce5e..3aa3d30a27 100644
--- a/deps/v8/src/compiler/simplified-operator.cc
+++ b/deps/v8/src/compiler/simplified-operator.cc
@@ -79,7 +79,7 @@ std::ostream& operator<<(std::ostream& os, FieldAccess const& access) {
 #endif
   os << access.type << ", " << access.machine_type << ", "
      << access.write_barrier_kind;
-  if (FLAG_untrusted_code_mitigations || FLAG_branch_load_poisoning) {
+  if (FLAG_untrusted_code_mitigations) {
     os << ", " << access.load_sensitivity;
   }
   os << "]";
@@ -118,7 +118,7 @@ std::ostream& operator<<(std::ostream& os, ElementAccess const& access) {
   os << access.base_is_tagged << ", " << access.header_size << ", "
      << access.type << ", " << access.machine_type << ", "
      << access.write_barrier_kind;
-  if (FLAG_untrusted_code_mitigations || FLAG_branch_load_poisoning) {
+  if (FLAG_untrusted_code_mitigations) {
     os << ", " << access.load_sensitivity;
   }
   return os;
@@ -709,6 +709,7 @@ bool operator==(CheckMinusZeroParameters const& lhs,
   V(NumberToUint32, Operator::kNoProperties, 1, 0)               \
   V(NumberToUint8Clamped, Operator::kNoProperties, 1, 0)         \
   V(NumberSilenceNaN, Operator::kNoProperties, 1, 0)             \
+  V(StringConcat, Operator::kNoProperties, 3, 0)                 \
   V(StringToNumber, Operator::kNoProperties, 1, 0)               \
   V(StringFromSingleCharCode, Operator::kNoProperties, 1, 0)     \
   V(StringIndexOf, Operator::kNoProperties, 3, 0)                \
@@ -720,14 +721,18 @@ bool operator==(CheckMinusZeroParameters const& lhs,
   V(PlainPrimitiveToWord32, Operator::kNoProperties, 1, 0)       \
   V(PlainPrimitiveToFloat64, Operator::kNoProperties, 1, 0)      \
   V(ChangeTaggedSignedToInt32, Operator::kNoProperties, 1, 0)    \
+  V(ChangeTaggedSignedToInt64, Operator::kNoProperties, 1, 0)    \
   V(ChangeTaggedToInt32, Operator::kNoProperties, 1, 0)          \
+  V(ChangeTaggedToInt64, Operator::kNoProperties, 1, 0)          \
   V(ChangeTaggedToUint32, Operator::kNoProperties, 1, 0)         \
   V(ChangeTaggedToFloat64, Operator::kNoProperties, 1, 0)        \
   V(ChangeTaggedToTaggedSigned, Operator::kNoProperties, 1, 0)   \
   V(ChangeFloat64ToTaggedPointer, Operator::kNoProperties, 1, 0) \
   V(ChangeInt31ToTaggedSigned, Operator::kNoProperties, 1, 0)    \
   V(ChangeInt32ToTagged, Operator::kNoProperties, 1, 0)          \
+  V(ChangeInt64ToTagged, Operator::kNoProperties, 1, 0)          \
   V(ChangeUint32ToTagged, Operator::kNoProperties, 1, 0)         \
+  V(ChangeUint64ToTagged, Operator::kNoProperties, 1, 0)         \
   V(ChangeTaggedToBit, Operator::kNoProperties, 1, 0)            \
   V(ChangeBitToTagged, Operator::kNoProperties, 1, 0)            \
   V(TruncateTaggedToBit, Operator::kNoProperties, 1, 0)          \
@@ -798,11 +803,15 @@ bool operator==(CheckMinusZeroParameters const& lhs,
   V(CheckSmi, 1, 1)                      \
   V(CheckString, 1, 1)                   \
   V(CheckedInt32ToTaggedSigned, 1, 1)    \
+  V(CheckedInt64ToInt32, 1, 1)           \
+  V(CheckedInt64ToTaggedSigned, 1, 1)    \
   V(CheckedTaggedSignedToInt32, 1, 1)    \
   V(CheckedTaggedToTaggedPointer, 1, 1)  \
   V(CheckedTaggedToTaggedSigned, 1, 1)   \
   V(CheckedUint32ToInt32, 1, 1)          \
-  V(CheckedUint32ToTaggedSigned, 1, 1)
+  V(CheckedUint32ToTaggedSigned, 1, 1)   \
+  V(CheckedUint64ToInt32, 1, 1)          \
+  V(CheckedUint64ToTaggedSigned, 1, 1)
 
 struct SimplifiedOperatorGlobalCache final {
 #define PURE(Name, properties, value_input_count, control_input_count)     \
@@ -891,13 +900,6 @@ struct SimplifiedOperatorGlobalCache final {
   StringFromSingleCodePointOperator<UnicodeEncoding::UTF32>
       kStringFromSingleCodePointOperatorUTF32;
 
-  struct ArrayBufferWasNeuteredOperator final : public Operator {
-    ArrayBufferWasNeuteredOperator()
-        : Operator(IrOpcode::kArrayBufferWasNeutered, Operator::kEliminatable,
-                   "ArrayBufferWasNeutered", 1, 1, 1, 1, 1, 0) {}
-  };
-  ArrayBufferWasNeuteredOperator kArrayBufferWasNeutered;
-
   struct FindOrderedHashMapEntryOperator final : public Operator {
     FindOrderedHashMapEntryOperator()
         : Operator(IrOpcode::kFindOrderedHashMapEntry, Operator::kEliminatable,
@@ -1124,7 +1126,6 @@ SimplifiedOperatorBuilder::SimplifiedOperatorBuilder(Zone* zone)
 PURE_OP_LIST(GET_FROM_CACHE)
 EFFECT_DEPENDENT_OP_LIST(GET_FROM_CACHE)
 CHECKED_OP_LIST(GET_FROM_CACHE)
-GET_FROM_CACHE(ArrayBufferWasNeutered)
 GET_FROM_CACHE(ArgumentsFrame)
 GET_FROM_CACHE(FindOrderedHashMapEntry)
 GET_FROM_CACHE(FindOrderedHashMapEntryForInt32Key)
diff --git a/deps/v8/src/compiler/simplified-operator.h b/deps/v8/src/compiler/simplified-operator.h
index df44e899cd..df823fb0b0 100644
--- a/deps/v8/src/compiler/simplified-operator.h
+++ b/deps/v8/src/compiler/simplified-operator.h
@@ -228,7 +228,7 @@ enum class CheckTaggedInputMode : uint8_t {
 
 size_t hash_value(CheckTaggedInputMode);
 
-std::ostream& operator<<(std::ostream&, CheckTaggedInputMode);
+V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream&, CheckTaggedInputMode);
 
 class CheckTaggedInputParameters {
  public:
@@ -616,6 +616,7 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
 
   const Operator* ToBoolean();
 
+  const Operator* StringConcat();
   const Operator* StringEqual();
   const Operator* StringLessThan();
   const Operator* StringLessThanOrEqual();
@@ -641,13 +642,17 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   const Operator* PlainPrimitiveToFloat64();
 
   const Operator* ChangeTaggedSignedToInt32();
+  const Operator* ChangeTaggedSignedToInt64();
   const Operator* ChangeTaggedToInt32();
+  const Operator* ChangeTaggedToInt64();
   const Operator* ChangeTaggedToUint32();
   const Operator* ChangeTaggedToFloat64();
   const Operator* ChangeTaggedToTaggedSigned();
   const Operator* ChangeInt31ToTaggedSigned();
   const Operator* ChangeInt32ToTagged();
+  const Operator* ChangeInt64ToTagged();
   const Operator* ChangeUint32ToTagged();
+  const Operator* ChangeUint64ToTagged();
   const Operator* ChangeFloat64ToTagged(CheckForMinusZeroMode);
   const Operator* ChangeFloat64ToTaggedPointer();
   const Operator* ChangeTaggedToBit();
@@ -686,6 +691,8 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   const Operator* CheckedInt32Mul(CheckForMinusZeroMode);
   const Operator* CheckedInt32Sub();
   const Operator* CheckedInt32ToTaggedSigned(const VectorSlotPair& feedback);
+  const Operator* CheckedInt64ToInt32(const VectorSlotPair& feedback);
+  const Operator* CheckedInt64ToTaggedSigned(const VectorSlotPair& feedback);
   const Operator* CheckedTaggedSignedToInt32(const VectorSlotPair& feedback);
   const Operator* CheckedTaggedToFloat64(CheckTaggedInputMode,
                                          const VectorSlotPair& feedback);
@@ -699,6 +706,8 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   const Operator* CheckedUint32Mod();
   const Operator* CheckedUint32ToInt32(const VectorSlotPair& feedback);
   const Operator* CheckedUint32ToTaggedSigned(const VectorSlotPair& feedback);
+  const Operator* CheckedUint64ToInt32(const VectorSlotPair& feedback);
+  const Operator* CheckedUint64ToTaggedSigned(const VectorSlotPair& feedback);
 
   const Operator* ConvertReceiver(ConvertReceiverMode);
 
@@ -741,9 +750,6 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   // new-cons-string length, first, second
   const Operator* NewConsString();
 
-  // array-buffer-was-neutered buffer
-  const Operator* ArrayBufferWasNeutered();
-
   // ensure-writable-fast-elements object, elements
   const Operator* EnsureWritableFastElements();
 
diff --git a/deps/v8/src/compiler/store-store-elimination.cc b/deps/v8/src/compiler/store-store-elimination.cc
index ce2c71a3d7..589e3948b9 100644
--- a/deps/v8/src/compiler/store-store-elimination.cc
+++ b/deps/v8/src/compiler/store-store-elimination.cc
@@ -32,7 +32,7 @@ namespace compiler {
     if (V8_UNLIKELY(!(condition))) {                                          \
       FATAL("Check failed: %s. Extra info: " fmt, #condition, ##__VA_ARGS__); \
     }                                                                         \
-  } while (0)
+  } while (false)
 
 #ifdef DEBUG
 #define DCHECK_EXTRA(condition, fmt, ...) \
@@ -100,9 +100,9 @@ class UnobservablesSet final {
   static UnobservablesSet Unvisited();
   static UnobservablesSet VisitedEmpty(Zone* zone);
   UnobservablesSet();  // unvisited
-  UnobservablesSet(const UnobservablesSet& other) : set_(other.set_) {}
+  UnobservablesSet(const UnobservablesSet& other) = default;
 
-  UnobservablesSet Intersect(UnobservablesSet other, Zone* zone) const;
+  UnobservablesSet Intersect(const UnobservablesSet& other, Zone* zone) const;
   UnobservablesSet Add(UnobservableStore obs, Zone* zone) const;
   UnobservablesSet RemoveSameOffset(StoreOffset off, Zone* zone) const;
 
@@ -140,7 +140,7 @@ class RedundantStoreFinder final {
  private:
   void VisitEffectfulNode(Node* node);
   UnobservablesSet RecomputeUseIntersection(Node* node);
-  UnobservablesSet RecomputeSet(Node* node, UnobservablesSet uses);
+  UnobservablesSet RecomputeSet(Node* node, const UnobservablesSet& uses);
   static bool CannotObserveStoreField(Node* node);
 
   void MarkForRevisit(Node* node);
@@ -252,8 +252,8 @@ void StoreStoreElimination::Run(JSGraph* js_graph, Zone* temp_zone) {
 // Recompute unobservables-set for a node. Will also mark superfluous nodes
 // as to be removed.
 
-UnobservablesSet RedundantStoreFinder::RecomputeSet(Node* node,
-                                                    UnobservablesSet uses) {
+UnobservablesSet RedundantStoreFinder::RecomputeSet(
+    Node* node, const UnobservablesSet& uses) {
   switch (node->op()->opcode()) {
     case IrOpcode::kStoreField: {
       Node* stored_to = node->InputAt(0);
@@ -472,7 +472,7 @@ UnobservablesSet UnobservablesSet::VisitedEmpty(Zone* zone) {
 // Computes the intersection of two UnobservablesSets. May return
 // UnobservablesSet::Unvisited() instead of an empty UnobservablesSet for
 // speed.
-UnobservablesSet UnobservablesSet::Intersect(UnobservablesSet other,
+UnobservablesSet UnobservablesSet::Intersect(const UnobservablesSet& other,
                                              Zone* zone) const {
   if (IsEmpty() || other.IsEmpty()) {
     return Unvisited();
diff --git a/deps/v8/src/compiler/type-cache.h b/deps/v8/src/compiler/type-cache.h
index 7a02c9a37c..251ea08751 100644
--- a/deps/v8/src/compiler/type-cache.h
+++ b/deps/v8/src/compiler/type-cache.h
@@ -8,6 +8,7 @@
 #include "src/compiler/types.h"
 #include "src/date.h"
 #include "src/objects/code.h"
+#include "src/objects/js-array-buffer.h"
 #include "src/objects/string.h"
 
 namespace v8 {
@@ -34,6 +35,8 @@ class TypeCache final {
   Type const kUint16 = CreateRange<uint16_t>();
   Type const kInt32 = Type::Signed32();
   Type const kUint32 = Type::Unsigned32();
+  Type const kInt64 = CreateRange<int64_t>();
+  Type const kUint64 = CreateRange<uint64_t>();
   Type const kFloat32 = Type::Number();
   Type const kFloat64 = Type::Number();
   Type const kBigInt64 = Type::BigInt();
@@ -96,6 +99,20 @@ class TypeCache final {
   // [0, kMaxUInt32].
   Type const kJSArrayLengthType = Type::Unsigned32();
 
+  // The JSArrayBuffer::byte_length property is limited to safe integer range
+  // per specification, but on 32-bit architectures is implemented as uint32_t
+  // field, so it's in the [0, kMaxUInt32] range in that case.
+  Type const kJSArrayBufferByteLengthType =
+      CreateRange(0.0, JSArrayBuffer::kMaxByteLength);
+
+  // The type for the JSArrayBufferView::byte_length property is the same as
+  // JSArrayBuffer::byte_length above.
+  Type const kJSArrayBufferViewByteLengthType = kJSArrayBufferByteLengthType;
+
+  // The type for the JSArrayBufferView::byte_offset property is the same as
+  // JSArrayBuffer::byte_length above.
+  Type const kJSArrayBufferViewByteOffsetType = kJSArrayBufferByteLengthType;
+
   // The JSTypedArray::length property always contains a tagged number in the
   // range [0, kMaxSmiValue].
   Type const kJSTypedArrayLengthType = Type::UnsignedSmall();
diff --git a/deps/v8/src/compiler/type-narrowing-reducer.cc b/deps/v8/src/compiler/type-narrowing-reducer.cc
index 01afdcb911..c0343f70e7 100644
--- a/deps/v8/src/compiler/type-narrowing-reducer.cc
+++ b/deps/v8/src/compiler/type-narrowing-reducer.cc
@@ -15,9 +15,9 @@ TypeNarrowingReducer::TypeNarrowingReducer(Editor* editor, JSGraph* jsgraph,
                                            JSHeapBroker* js_heap_broker)
     : AdvancedReducer(editor),
       jsgraph_(jsgraph),
-      op_typer_(jsgraph->isolate(), js_heap_broker, zone()) {}
+      op_typer_(js_heap_broker, zone()) {}
 
-TypeNarrowingReducer::~TypeNarrowingReducer() {}
+TypeNarrowingReducer::~TypeNarrowingReducer() = default;
 
 Reduction TypeNarrowingReducer::Reduce(Node* node) {
   DisallowHeapAccess no_heap_access;
diff --git a/deps/v8/src/compiler/typed-optimization.cc b/deps/v8/src/compiler/typed-optimization.cc
index b77fc97859..6a9430bd29 100644
--- a/deps/v8/src/compiler/typed-optimization.cc
+++ b/deps/v8/src/compiler/typed-optimization.cc
@@ -32,7 +32,7 @@ TypedOptimization::TypedOptimization(Editor* editor,
                                      graph()->zone())),
       type_cache_(TypeCache::Get()) {}
 
-TypedOptimization::~TypedOptimization() {}
+TypedOptimization::~TypedOptimization() = default;
 
 Reduction TypedOptimization::Reduce(Node* node) {
   DisallowHeapAccess no_heap_access;
@@ -61,6 +61,8 @@ Reduction TypedOptimization::Reduce(Node* node) {
       return ReduceNumberRoundop(node);
     case IrOpcode::kNumberFloor:
       return ReduceNumberFloor(node);
+    case IrOpcode::kNumberSilenceNaN:
+      return ReduceNumberSilenceNaN(node);
     case IrOpcode::kNumberToUint8Clamped:
       return ReduceNumberToUint8Clamped(node);
     case IrOpcode::kPhi:
@@ -71,6 +73,8 @@ Reduction TypedOptimization::Reduce(Node* node) {
     case IrOpcode::kStringLessThan:
     case IrOpcode::kStringLessThanOrEqual:
       return ReduceStringComparison(node);
+    case IrOpcode::kStringLength:
+      return ReduceStringLength(node);
     case IrOpcode::kSameValue:
       return ReduceSameValue(node);
     case IrOpcode::kSelect:
@@ -272,6 +276,15 @@ Reduction TypedOptimization::ReduceNumberRoundop(Node* node) {
   return NoChange();
 }
 
+Reduction TypedOptimization::ReduceNumberSilenceNaN(Node* node) {
+  Node* const input = NodeProperties::GetValueInput(node, 0);
+  Type const input_type = NodeProperties::GetType(input);
+  if (input_type.Is(Type::OrderedNumber())) {
+    return Replace(input);
+  }
+  return NoChange();
+}
+
 Reduction TypedOptimization::ReduceNumberToUint8Clamped(Node* node) {
   Node* const input = NodeProperties::GetValueInput(node, 0);
   Type const input_type = NodeProperties::GetType(input);
@@ -454,6 +467,30 @@ Reduction TypedOptimization::ReduceStringComparison(Node* node) {
   return NoChange();
 }
 
+Reduction TypedOptimization::ReduceStringLength(Node* node) {
+  DCHECK_EQ(IrOpcode::kStringLength, node->opcode());
+  Node* const input = NodeProperties::GetValueInput(node, 0);
+  switch (input->opcode()) {
+    case IrOpcode::kHeapConstant: {
+      // Constant-fold the String::length of the {input}.
+      HeapObjectMatcher m(input);
+      if (m.Ref(js_heap_broker()).IsString()) {
+        uint32_t const length = m.Ref(js_heap_broker()).AsString().length();
+        Node* value = jsgraph()->Constant(length);
+        return Replace(value);
+      }
+      break;
+    }
+    case IrOpcode::kStringConcat: {
+      // The first value input to the {input} is the resulting length.
+      return Replace(input->InputAt(0));
+    }
+    default:
+      break;
+  }
+  return NoChange();
+}
+
 Reduction TypedOptimization::ReduceSameValue(Node* node) {
   DCHECK_EQ(IrOpcode::kSameValue, node->opcode());
   Node* const lhs = NodeProperties::GetValueInput(node, 0);
@@ -578,8 +615,6 @@ Reduction TypedOptimization::ReduceTypeOf(Node* node) {
   } else if (type.Is(Type::Function())) {
     return Replace(
         jsgraph()->Constant(ObjectRef(js_heap_broker(), f->function_string())));
-  } else if (type.IsHeapConstant()) {
-    return Replace(jsgraph()->Constant(type.AsHeapConstant()->Ref().TypeOf()));
   }
   return NoChange();
 }
diff --git a/deps/v8/src/compiler/typed-optimization.h b/deps/v8/src/compiler/typed-optimization.h
index baee65dd4e..b49982b4e6 100644
--- a/deps/v8/src/compiler/typed-optimization.h
+++ b/deps/v8/src/compiler/typed-optimization.h
@@ -29,7 +29,7 @@ class V8_EXPORT_PRIVATE TypedOptimization final
  public:
   TypedOptimization(Editor* editor, CompilationDependencies* dependencies,
                     JSGraph* jsgraph, JSHeapBroker* js_heap_broker);
-  ~TypedOptimization();
+  ~TypedOptimization() override;
 
   const char* reducer_name() const override { return "TypedOptimization"; }
 
@@ -46,10 +46,12 @@ class V8_EXPORT_PRIVATE TypedOptimization final
   Reduction ReduceLoadField(Node* node);
   Reduction ReduceNumberFloor(Node* node);
   Reduction ReduceNumberRoundop(Node* node);
+  Reduction ReduceNumberSilenceNaN(Node* node);
   Reduction ReduceNumberToUint8Clamped(Node* node);
   Reduction ReducePhi(Node* node);
   Reduction ReduceReferenceEqual(Node* node);
   Reduction ReduceStringComparison(Node* node);
+  Reduction ReduceStringLength(Node* node);
   Reduction ReduceSameValue(Node* node);
   Reduction ReduceSelect(Node* node);
   Reduction ReduceSpeculativeToNumber(Node* node);
diff --git a/deps/v8/src/compiler/typer.cc b/deps/v8/src/compiler/typer.cc
index 7627d27b08..eb357054e0 100644
--- a/deps/v8/src/compiler/typer.cc
+++ b/deps/v8/src/compiler/typer.cc
@@ -19,6 +19,7 @@
 #include "src/compiler/simplified-operator.h"
 #include "src/compiler/type-cache.h"
 #include "src/objects-inl.h"
+#include "src/objects/builtin-function-id.h"
 
 namespace v8 {
 namespace internal {
@@ -33,14 +34,13 @@ class Typer::Decorator final : public GraphDecorator {
   Typer* const typer_;
 };
 
-Typer::Typer(Isolate* isolate, JSHeapBroker* js_heap_broker, Flags flags,
-             Graph* graph)
+Typer::Typer(JSHeapBroker* js_heap_broker, Flags flags, Graph* graph)
     : flags_(flags),
       graph_(graph),
       decorator_(nullptr),
       cache_(TypeCache::Get()),
       js_heap_broker_(js_heap_broker),
-      operation_typer_(isolate, js_heap_broker, zone()) {
+      operation_typer_(js_heap_broker, zone()) {
   singleton_false_ = operation_typer_.singleton_false();
   singleton_true_ = operation_typer_.singleton_true();
 
@@ -1114,10 +1114,6 @@ Type Typer::Visitor::TypeToBoolean(Node* node) {
   return TypeUnaryOp(node, ToBoolean);
 }
 
-Type Typer::Visitor::TypeJSToInteger(Node* node) {
-  return TypeUnaryOp(node, ToInteger);
-}
-
 Type Typer::Visitor::TypeJSToLength(Node* node) {
   return TypeUnaryOp(node, ToLength);
 }
@@ -1215,6 +1211,10 @@ Type Typer::Visitor::TypeJSCreateEmptyLiteralArray(Node* node) {
   return Type::Array();
 }
 
+Type Typer::Visitor::TypeJSCreateArrayFromIterable(Node* node) {
+  return Type::Array();
+}
+
 Type Typer::Visitor::TypeJSCreateLiteralObject(Node* node) {
   return Type::OtherObject();
 }
@@ -1433,7 +1433,6 @@ Type Typer::Visitor::JSCallTyper(Type fun, Typer* t) {
     // Unary math functions.
     case BuiltinFunctionId::kMathAbs:
     case BuiltinFunctionId::kMathExp:
-    case BuiltinFunctionId::kMathExpm1:
       return Type::Union(Type::PlainNumber(), Type::NaN(), t->zone());
     case BuiltinFunctionId::kMathAcos:
     case BuiltinFunctionId::kMathAcosh:
@@ -1443,6 +1442,7 @@ Type Typer::Visitor::JSCallTyper(Type fun, Typer* t) {
     case BuiltinFunctionId::kMathAtanh:
     case BuiltinFunctionId::kMathCbrt:
     case BuiltinFunctionId::kMathCos:
+    case BuiltinFunctionId::kMathExpm1:
     case BuiltinFunctionId::kMathFround:
     case BuiltinFunctionId::kMathLog:
     case BuiltinFunctionId::kMathLog1p:
@@ -1490,6 +1490,10 @@ Type Typer::Visitor::JSCallTyper(Type fun, Typer* t) {
     // Symbol functions.
     case BuiltinFunctionId::kSymbolConstructor:
       return Type::Symbol();
+    case BuiltinFunctionId::kSymbolPrototypeToString:
+      return Type::String();
+    case BuiltinFunctionId::kSymbolPrototypeValueOf:
+      return Type::Symbol();
 
     // BigInt functions.
     case BuiltinFunctionId::kBigIntConstructor:
@@ -1714,16 +1718,11 @@ Type Typer::Visitor::TypeJSCallRuntime(Node* node) {
     case Runtime::kInlineIsSmi:
       return TypeUnaryOp(node, ObjectIsSmi);
     case Runtime::kInlineIsArray:
-    case Runtime::kInlineIsDate:
     case Runtime::kInlineIsTypedArray:
     case Runtime::kInlineIsRegExp:
       return Type::Boolean();
     case Runtime::kInlineCreateIterResultObject:
       return Type::OtherObject();
-    case Runtime::kInlineStringCharFromCode:
-      return Type::String();
-    case Runtime::kInlineToInteger:
-      return TypeUnaryOp(node, ToInteger);
     case Runtime::kInlineToLength:
       return TypeUnaryOp(node, ToLength);
     case Runtime::kInlineToNumber:
@@ -1855,6 +1854,8 @@ Type Typer::Visitor::TypeSpeculativeNumberLessThanOrEqual(Node* node) {
   return TypeBinaryOp(node, NumberLessThanOrEqualTyper);
 }
 
+Type Typer::Visitor::TypeStringConcat(Node* node) { return Type::String(); }
+
 Type Typer::Visitor::TypeStringToNumber(Node* node) {
   return TypeUnaryOp(node, ToNumber);
 }
@@ -1947,18 +1948,8 @@ Type Typer::Visitor::TypePoisonIndex(Node* node) {
 }
 
 Type Typer::Visitor::TypeCheckBounds(Node* node) {
-  Type index = Operand(node, 0);
-  Type length = Operand(node, 1);
-  DCHECK(length.Is(Type::Unsigned31()));
-  if (index.Maybe(Type::MinusZero())) {
-    index = Type::Union(index, typer_->cache_.kSingletonZero, zone());
-  }
-  index = Type::Intersect(index, Type::Integral32(), zone());
-  if (index.IsNone() || length.IsNone()) return Type::None();
-  double min = std::max(index.Min(), 0.0);
-  double max = std::min(index.Max(), length.Max() - 1);
-  if (max < min) return Type::None();
-  return Type::Range(min, max, zone());
+  return typer_->operation_typer_.CheckBounds(Operand(node, 0),
+                                              Operand(node, 1));
 }
 
 Type Typer::Visitor::TypeCheckHeapObject(Node* node) {
@@ -2191,8 +2182,8 @@ Type Typer::Visitor::TypeNewArgumentsElements(Node* node) {
 
 Type Typer::Visitor::TypeNewConsString(Node* node) { return Type::String(); }
 
-Type Typer::Visitor::TypeArrayBufferWasNeutered(Node* node) {
-  return Type::Boolean();
+Type Typer::Visitor::TypeDelayedStringConstant(Node* node) {
+  return Type::String();
 }
 
 Type Typer::Visitor::TypeFindOrderedHashMapEntry(Node* node) {
diff --git a/deps/v8/src/compiler/typer.h b/deps/v8/src/compiler/typer.h
index 741ca481c2..f6703fe366 100644
--- a/deps/v8/src/compiler/typer.h
+++ b/deps/v8/src/compiler/typer.h
@@ -25,8 +25,7 @@ class V8_EXPORT_PRIVATE Typer {
   };
   typedef base::Flags<Flag> Flags;
 
-  Typer(Isolate* isolate, JSHeapBroker* js_heap_broker, Flags flags,
-        Graph* graph);
+  Typer(JSHeapBroker* js_heap_broker, Flags flags, Graph* graph);
   ~Typer();
 
   void Run();
diff --git a/deps/v8/src/compiler/types.cc b/deps/v8/src/compiler/types.cc
index 968d788fcc..e8954f9202 100644
--- a/deps/v8/src/compiler/types.cc
+++ b/deps/v8/src/compiler/types.cc
@@ -132,8 +132,11 @@ Type::bitset Type::BitsetLub() const {
   UNREACHABLE();
 }
 
-Type::bitset BitsetType::Lub(HeapObjectType const& type) {
-  switch (type.instance_type()) {
+// TODO(neis): Once the broker mode kDisabled is gone, change the input type to
+// MapRef and get rid of the HeapObjectType class.
+template <typename MapRefLike>
+Type::bitset BitsetType::Lub(const MapRefLike& map) {
+  switch (map.instance_type()) {
     case CONS_STRING_TYPE:
     case CONS_ONE_BYTE_STRING_TYPE:
     case THIN_STRING_TYPE:
@@ -143,18 +146,18 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case EXTERNAL_STRING_TYPE:
     case EXTERNAL_ONE_BYTE_STRING_TYPE:
     case EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
-    case SHORT_EXTERNAL_STRING_TYPE:
-    case SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE:
-    case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
+    case UNCACHED_EXTERNAL_STRING_TYPE:
+    case UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE:
+    case UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
     case STRING_TYPE:
     case ONE_BYTE_STRING_TYPE:
       return kString;
     case EXTERNAL_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
-    case SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE:
-    case SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
-    case SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
+    case UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE:
+    case UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
+    case UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
     case INTERNALIZED_STRING_TYPE:
     case ONE_BYTE_INTERNALIZED_STRING_TYPE:
       return kInternalizedString;
@@ -163,7 +166,7 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case BIGINT_TYPE:
       return kBigInt;
     case ODDBALL_TYPE:
-      switch (type.oddball_type()) {
+      switch (map.oddball_type()) {
         case OddballType::kNone:
           break;
         case OddballType::kHole:
@@ -189,15 +192,15 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case JS_GLOBAL_PROXY_TYPE:
     case JS_API_OBJECT_TYPE:
     case JS_SPECIAL_API_OBJECT_TYPE:
-      if (type.is_undetectable()) {
+      if (map.is_undetectable()) {
         // Currently we assume that every undetectable receiver is also
         // callable, which is what we need to support document.all.  We
         // could add another Type bit to support other use cases in the
         // future if necessary.
-        DCHECK(type.is_callable());
+        DCHECK(map.is_callable());
         return kOtherUndetectable;
       }
-      if (type.is_callable()) {
+      if (map.is_callable()) {
         return kOtherCallable;
       }
       return kOtherObject;
@@ -207,11 +210,15 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case JS_MESSAGE_OBJECT_TYPE:
     case JS_DATE_TYPE:
 #ifdef V8_INTL_SUPPORT
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
     case JS_INTL_COLLATOR_TYPE:
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
     case JS_INTL_LIST_FORMAT_TYPE:
     case JS_INTL_LOCALE_TYPE:
+    case JS_INTL_NUMBER_FORMAT_TYPE:
     case JS_INTL_PLURAL_RULES_TYPE:
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
+    case JS_INTL_SEGMENTER_TYPE:
 #endif  // V8_INTL_SUPPORT
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
     case JS_GENERATOR_OBJECT_TYPE:
@@ -235,23 +242,24 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case JS_WEAK_MAP_TYPE:
     case JS_WEAK_SET_TYPE:
     case JS_PROMISE_TYPE:
-    case WASM_MODULE_TYPE:
+    case WASM_EXCEPTION_TYPE:
     case WASM_GLOBAL_TYPE:
     case WASM_INSTANCE_TYPE:
     case WASM_MEMORY_TYPE:
+    case WASM_MODULE_TYPE:
     case WASM_TABLE_TYPE:
-      DCHECK(!type.is_callable());
-      DCHECK(!type.is_undetectable());
+      DCHECK(!map.is_callable());
+      DCHECK(!map.is_undetectable());
       return kOtherObject;
     case JS_BOUND_FUNCTION_TYPE:
-      DCHECK(!type.is_undetectable());
+      DCHECK(!map.is_undetectable());
       return kBoundFunction;
     case JS_FUNCTION_TYPE:
-      DCHECK(!type.is_undetectable());
+      DCHECK(!map.is_undetectable());
       return kFunction;
     case JS_PROXY_TYPE:
-      DCHECK(!type.is_undetectable());
-      if (type.is_callable()) return kCallableProxy;
+      DCHECK(!map.is_undetectable());
+      if (map.is_callable()) return kCallableProxy;
       return kOtherProxy;
     case MAP_TYPE:
     case ALLOCATION_SITE_TYPE:
@@ -285,6 +293,7 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case FOREIGN_TYPE:
     case SCOPE_INFO_TYPE:
     case SCRIPT_CONTEXT_TABLE_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
@@ -299,6 +308,7 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
     case PROPERTY_CELL_TYPE:
     case MODULE_TYPE:
     case MODULE_INFO_ENTRY_TYPE:
+    case MICROTASK_QUEUE_TYPE:
     case CELL_TYPE:
     case PRE_PARSED_SCOPE_DATA_TYPE:
     case UNCOMPILED_DATA_WITHOUT_PRE_PARSED_SCOPE_TYPE:
@@ -347,6 +357,9 @@ Type::bitset BitsetType::Lub(HeapObjectType const& type) {
   UNREACHABLE();
 }
 
+// Explicit instantiation.
+template Type::bitset BitsetType::Lub<MapRef>(const MapRef& map);
+
 Type::bitset BitsetType::Lub(double value) {
   DisallowHeapAllocation no_allocation;
   if (IsMinusZero(value)) return kMinusZero;
@@ -1009,14 +1022,16 @@ void Type::PrintTo(std::ostream& os) const {
     os << "(";
     for (int i = 0, n = this->AsUnion()->Length(); i < n; ++i) {
       Type type_i = this->AsUnion()->Get(i);
-      if (i > 0) os << " | " << type_i;
+      if (i > 0) os << " | ";
+      os << type_i;
     }
     os << ")";
   } else if (this->IsTuple()) {
     os << "<";
     for (int i = 0, n = this->AsTuple()->Arity(); i < n; ++i) {
       Type type_i = this->AsTuple()->Element(i);
-      if (i > 0) os << ", " << type_i;
+      if (i > 0) os << ", ";
+      os << type_i;
     }
     os << ">";
   } else {
diff --git a/deps/v8/src/compiler/types.h b/deps/v8/src/compiler/types.h
index d27f6e3e75..27f38edae7 100644
--- a/deps/v8/src/compiler/types.h
+++ b/deps/v8/src/compiler/types.h
@@ -169,7 +169,8 @@ namespace compiler {
                                   kNumber | kNullOrUndefined | kBoolean) \
   V(PlainPrimitive,               kNumber | kString | kBoolean | \
                                   kNullOrUndefined) \
-  V(Primitive,                    kSymbol | kBigInt | kPlainPrimitive) \
+  V(NonBigIntPrimitive,           kSymbol | kPlainPrimitive) \
+  V(Primitive,                    kBigInt | kNonBigIntPrimitive) \
   V(OtherUndetectableOrUndefined, kOtherUndetectable | kUndefined) \
   V(Proxy,                        kCallableProxy | kOtherProxy) \
   V(ArrayOrOtherObject,           kArray | kOtherObject) \
@@ -193,7 +194,8 @@ namespace compiler {
                                   kUndefined | kReceiver) \
   V(Internal,                     kHole | kExternalPointer | kOtherInternal) \
   V(NonInternal,                  kPrimitive | kReceiver) \
-  V(NonNumber,                    kUnique | kString | kInternal) \
+  V(NonBigInt,                    kNonBigIntPrimitive | kReceiver) \
+  V(NonNumber,                    kBigInt | kUnique | kString | kInternal) \
   V(Any,                          0xfffffffeu)
 
 // clang-format on
@@ -251,7 +253,10 @@ class V8_EXPORT_PRIVATE BitsetType {
   static double Max(bitset);
 
   static bitset Glb(double min, double max);
-  static bitset Lub(HeapObjectType const& type);
+  static bitset Lub(HeapObjectType const& type) {
+    return Lub<HeapObjectType>(type);
+  }
+  static bitset Lub(MapRef const& map) { return Lub<MapRef>(map); }
   static bitset Lub(double value);
   static bitset Lub(double min, double max);
   static bitset ExpandInternals(bitset bits);
@@ -273,6 +278,9 @@ class V8_EXPORT_PRIVATE BitsetType {
   static const Boundary BoundariesArray[];
   static inline const Boundary* Boundaries();
   static inline size_t BoundariesSize();
+
+  template <typename MapRefLike>
+  static bitset Lub(MapRefLike const& map);
 };
 
 // -----------------------------------------------------------------------------
@@ -377,8 +385,10 @@ class V8_EXPORT_PRIVATE Type {
   static Type Union(Type type1, Type type2, Zone* zone);
   static Type Intersect(Type type1, Type type2, Zone* zone);
 
-  static Type For(JSHeapBroker* js_heap_broker, Handle<i::Map> map) {
-    HeapObjectType type = js_heap_broker->HeapObjectTypeFromMap(map);
+  static Type For(HeapObjectType const& type) {
+    return NewBitset(BitsetType::ExpandInternals(BitsetType::Lub(type)));
+  }
+  static Type For(MapRef const& type) {
     return NewBitset(BitsetType::ExpandInternals(BitsetType::Lub(type)));
   }
 
@@ -545,7 +555,7 @@ class V8_EXPORT_PRIVATE HeapConstantType : public NON_EXPORTED_BASE(TypeBase) {
   static HeapConstantType* New(const HeapObjectRef& heap_ref, Zone* zone) {
     DCHECK(!heap_ref.IsHeapNumber());
     DCHECK_IMPLIES(heap_ref.IsString(), heap_ref.IsInternalizedString());
-    BitsetType::bitset bitset = BitsetType::Lub(heap_ref.type());
+    BitsetType::bitset bitset = BitsetType::Lub(heap_ref.GetHeapObjectType());
     return new (zone->New(sizeof(HeapConstantType)))
         HeapConstantType(bitset, heap_ref);
   }
diff --git a/deps/v8/src/compiler/value-numbering-reducer.cc b/deps/v8/src/compiler/value-numbering-reducer.cc
index 864d33bc20..af0bc99746 100644
--- a/deps/v8/src/compiler/value-numbering-reducer.cc
+++ b/deps/v8/src/compiler/value-numbering-reducer.cc
@@ -21,7 +21,7 @@ ValueNumberingReducer::ValueNumberingReducer(Zone* temp_zone, Zone* graph_zone)
       temp_zone_(temp_zone),
       graph_zone_(graph_zone) {}
 
-ValueNumberingReducer::~ValueNumberingReducer() {}
+ValueNumberingReducer::~ValueNumberingReducer() = default;
 
 
 Reduction ValueNumberingReducer::Reduce(Node* node) {
diff --git a/deps/v8/src/compiler/value-numbering-reducer.h b/deps/v8/src/compiler/value-numbering-reducer.h
index 44195468c3..489ab71d74 100644
--- a/deps/v8/src/compiler/value-numbering-reducer.h
+++ b/deps/v8/src/compiler/value-numbering-reducer.h
@@ -17,7 +17,7 @@ class V8_EXPORT_PRIVATE ValueNumberingReducer final
     : public NON_EXPORTED_BASE(Reducer) {
  public:
   explicit ValueNumberingReducer(Zone* temp_zone, Zone* graph_zone);
-  ~ValueNumberingReducer();
+  ~ValueNumberingReducer() override;
 
   const char* reducer_name() const override { return "ValueNumberingReducer"; }
 
diff --git a/deps/v8/src/compiler/verifier.cc b/deps/v8/src/compiler/verifier.cc
index 55eaf07711..913a2631dc 100644
--- a/deps/v8/src/compiler/verifier.cc
+++ b/deps/v8/src/compiler/verifier.cc
@@ -617,10 +617,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // Type is Boolean.
       CheckTypeIs(node, Type::Boolean());
       break;
-    case IrOpcode::kJSToInteger:
-      // Type is OrderedNumber.
-      CheckTypeIs(node, Type::OrderedNumber());
-      break;
     case IrOpcode::kJSToLength:
       CheckTypeIs(node, Type::Range(0, kMaxSafeInteger, zone));
       break;
@@ -715,6 +711,10 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // Type is Array.
       CheckTypeIs(node, Type::Array());
       break;
+    case IrOpcode::kJSCreateArrayFromIterable:
+      // Type is Array.
+      CheckTypeIs(node, Type::Array());
+      break;
     case IrOpcode::kJSCreateLiteralObject:
     case IrOpcode::kJSCreateEmptyLiteralObject:
     case IrOpcode::kJSCloneObject:
@@ -730,7 +730,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kJSLoadNamed:
       // Type can be anything.
       CheckTypeIs(node, Type::Any());
-      CHECK(NamedAccessOf(node->op()).feedback().IsValid());
       break;
     case IrOpcode::kJSLoadGlobal:
       // Type can be anything.
@@ -745,7 +744,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kJSStoreNamed:
       // Type is empty.
       CheckNotTyped(node);
-      CHECK(NamedAccessOf(node->op()).feedback().IsValid());
       break;
     case IrOpcode::kJSStoreGlobal:
       // Type is empty.
@@ -1090,6 +1088,12 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       CheckValueInputIs(node, 0, Type::PlainPrimitive());
       CheckTypeIs(node, Type::Number());
       break;
+    case IrOpcode::kStringConcat:
+      CheckValueInputIs(node, 0, TypeCache::Get().kStringLengthType);
+      CheckValueInputIs(node, 1, Type::String());
+      CheckValueInputIs(node, 2, Type::String());
+      CheckTypeIs(node, Type::String());
+      break;
     case IrOpcode::kStringEqual:
     case IrOpcode::kStringLessThan:
     case IrOpcode::kStringLessThanOrEqual:
@@ -1173,7 +1177,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kObjectIsString:
     case IrOpcode::kObjectIsSymbol:
     case IrOpcode::kObjectIsUndetectable:
-    case IrOpcode::kArrayBufferWasNeutered:
       CheckValueInputIs(node, 0, Type::Any());
       CheckTypeIs(node, Type::Boolean());
       break;
@@ -1243,6 +1246,9 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       CheckValueInputIs(node, 2, Type::String());
       CheckTypeIs(node, Type::String());
       break;
+    case IrOpcode::kDelayedStringConstant:
+      CheckTypeIs(node, Type::String());
+      break;
     case IrOpcode::kAllocate:
       CheckValueInputIs(node, 0, Type::PlainNumber());
       break;
@@ -1275,6 +1281,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, to));
       break;
     }
+    case IrOpcode::kChangeTaggedSignedToInt64:
+      break;
     case IrOpcode::kChangeTaggedToInt32: {
       // Signed32 /\ Tagged -> Signed32 /\ UntaggedInt32
       // TODO(neis): Activate once ChangeRepresentation works in typer.
@@ -1284,6 +1292,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, to));
       break;
     }
+    case IrOpcode::kChangeTaggedToInt64:
+      break;
     case IrOpcode::kChangeTaggedToUint32: {
       // Unsigned32 /\ Tagged -> Unsigned32 /\ UntaggedInt32
       // TODO(neis): Activate once ChangeRepresentation works in typer.
@@ -1332,6 +1342,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, to));
       break;
     }
+    case IrOpcode::kChangeInt64ToTagged:
+      break;
     case IrOpcode::kChangeUint32ToTagged: {
       // Unsigned32 /\ UntaggedInt32 -> Unsigned32 /\ Tagged
       // TODO(neis): Activate once ChangeRepresentation works in typer.
@@ -1341,6 +1353,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, to));
       break;
     }
+    case IrOpcode::kChangeUint64ToTagged:
+      break;
     case IrOpcode::kChangeFloat64ToTagged: {
       // Number /\ UntaggedFloat64 -> Number /\ Tagged
       // TODO(neis): Activate once ChangeRepresentation works in typer.
@@ -1430,7 +1444,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       CheckValueInputIs(node, 0, Type::Any());
       CheckTypeIs(node, Type::Symbol());
       break;
-
     case IrOpcode::kConvertReceiver:
       // (Any, Any) -> Receiver
       CheckValueInputIs(node, 0, Type::Any());
@@ -1446,8 +1459,12 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kCheckedUint32Mod:
     case IrOpcode::kCheckedInt32Mul:
     case IrOpcode::kCheckedInt32ToTaggedSigned:
+    case IrOpcode::kCheckedInt64ToInt32:
+    case IrOpcode::kCheckedInt64ToTaggedSigned:
     case IrOpcode::kCheckedUint32ToInt32:
     case IrOpcode::kCheckedUint32ToTaggedSigned:
+    case IrOpcode::kCheckedUint64ToInt32:
+    case IrOpcode::kCheckedUint64ToTaggedSigned:
     case IrOpcode::kCheckedFloat64ToInt32:
     case IrOpcode::kCheckedTaggedSignedToInt32:
     case IrOpcode::kCheckedTaggedToInt32:
@@ -1689,9 +1706,11 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kChangeInt32ToInt64:
     case IrOpcode::kChangeUint32ToUint64:
     case IrOpcode::kChangeInt32ToFloat64:
+    case IrOpcode::kChangeInt64ToFloat64:
     case IrOpcode::kChangeUint32ToFloat64:
     case IrOpcode::kChangeFloat32ToFloat64:
     case IrOpcode::kChangeFloat64ToInt32:
+    case IrOpcode::kChangeFloat64ToInt64:
     case IrOpcode::kChangeFloat64ToUint32:
     case IrOpcode::kChangeFloat64ToUint64:
     case IrOpcode::kFloat64SilenceNaN:
@@ -1747,13 +1766,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kWord32AtomicPairXor:
     case IrOpcode::kWord32AtomicPairExchange:
     case IrOpcode::kWord32AtomicPairCompareExchange:
-    case IrOpcode::kWord64AtomicNarrowAdd:
-    case IrOpcode::kWord64AtomicNarrowSub:
-    case IrOpcode::kWord64AtomicNarrowAnd:
-    case IrOpcode::kWord64AtomicNarrowOr:
-    case IrOpcode::kWord64AtomicNarrowXor:
-    case IrOpcode::kWord64AtomicNarrowExchange:
-    case IrOpcode::kWord64AtomicNarrowCompareExchange:
     case IrOpcode::kSpeculationFence:
     case IrOpcode::kSignExtendWord8ToInt32:
     case IrOpcode::kSignExtendWord16ToInt32:
diff --git a/deps/v8/src/compiler/wasm-compiler.cc b/deps/v8/src/compiler/wasm-compiler.cc
index f544c2eb10..4f35476dfb 100644
--- a/deps/v8/src/compiler/wasm-compiler.cc
+++ b/deps/v8/src/compiler/wasm-compiler.cc
@@ -15,7 +15,6 @@
 #include "src/builtins/builtins.h"
 #include "src/code-factory.h"
 #include "src/compiler.h"
-#include "src/compiler/access-builder.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/compiler-source-position-table.h"
@@ -43,6 +42,7 @@
 #include "src/wasm/function-compiler.h"
 #include "src/wasm/jump-table-assembler.h"
 #include "src/wasm/memory-tracing.h"
+#include "src/wasm/object-access.h"
 #include "src/wasm/wasm-code-manager.h"
 #include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-linkage.h"
@@ -55,6 +55,8 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+namespace {
+
 // TODO(titzer): pull WASM_64 up to a common header.
 #if !V8_TARGET_ARCH_32_BIT || V8_TARGET_ARCH_X64
 #define WASM_64 1
@@ -66,27 +68,34 @@ namespace compiler {
   FATAL("Unsupported opcode 0x%x:%s", (opcode), \
         wasm::WasmOpcodes::OpcodeName(opcode));
 
+MachineType assert_size(int expected_size, MachineType type) {
+  DCHECK_EQ(expected_size, ElementSizeInBytes(type.representation()));
+  return type;
+}
+
+#define WASM_INSTANCE_OBJECT_SIZE(name)     \
+  (WasmInstanceObject::k##name##OffsetEnd - \
+   WasmInstanceObject::k##name##Offset + 1)  // NOLINT(whitespace/indent)
+
 #define WASM_INSTANCE_OBJECT_OFFSET(name) \
-  (WasmInstanceObject::k##name##Offset - kHeapObjectTag)
+  wasm::ObjectAccess::ToTagged(WasmInstanceObject::k##name##Offset)
 
 #define LOAD_INSTANCE_FIELD(name, type)                                      \
   SetEffect(graph()->NewNode(                                                \
-      mcgraph()->machine()->Load(type), instance_node_.get(),                \
+      mcgraph()->machine()->Load(                                            \
+          assert_size(WASM_INSTANCE_OBJECT_SIZE(name), type)),               \
+      instance_node_.get(),                                                  \
       mcgraph()->Int32Constant(WASM_INSTANCE_OBJECT_OFFSET(name)), Effect(), \
       Control()))
 
-#define LOAD_FIXED_ARRAY_SLOT(array_node, index)                            \
-  SetEffect(graph()->NewNode(                                               \
-      mcgraph()->machine()->Load(MachineType::TaggedPointer()), array_node, \
-      mcgraph()->Int32Constant(FixedArrayOffsetMinusTag(index)), Effect(),  \
-      Control()))
+#define LOAD_TAGGED_POINTER(base_pointer, byte_offset)                        \
+  SetEffect(graph()->NewNode(                                                 \
+      mcgraph()->machine()->Load(MachineType::TaggedPointer()), base_pointer, \
+      mcgraph()->Int32Constant(byte_offset), Effect(), Control()))
 
-int FixedArrayOffsetMinusTag(uint32_t index) {
-  auto access = AccessBuilder::ForFixedArraySlot(index);
-  return access.offset - access.tag();
-}
-
-namespace {
+#define LOAD_FIXED_ARRAY_SLOT(array_node, index) \
+  LOAD_TAGGED_POINTER(                           \
+      array_node, wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(index))
 
 constexpr uint32_t kBytesPerExceptionValuesArrayElement = 2;
 
@@ -2001,7 +2010,7 @@ Node* WasmGraphBuilder::BuildCcallConvertFloat(Node* input,
 }
 
 Node* WasmGraphBuilder::GrowMemory(Node* input) {
-  SetNeedsStackCheck();
+  needs_stack_check_ = true;
 
   WasmGrowMemoryDescriptor interface_descriptor;
   auto call_descriptor = Linkage::GetStubCallDescriptor(
@@ -2034,16 +2043,17 @@ uint32_t WasmGraphBuilder::GetExceptionEncodedSize(
   return encoded_size;
 }
 
-Node* WasmGraphBuilder::Throw(uint32_t tag,
+Node* WasmGraphBuilder::Throw(uint32_t exception_index,
                               const wasm::WasmException* exception,
                               const Vector<Node*> values) {
-  SetNeedsStackCheck();
+  needs_stack_check_ = true;
   uint32_t encoded_size = GetExceptionEncodedSize(exception);
   Node* create_parameters[] = {
-      BuildChangeUint31ToSmi(ConvertExceptionTagToRuntimeId(tag)),
+      LoadExceptionTagFromTable(exception_index),
       BuildChangeUint31ToSmi(Uint32Constant(encoded_size))};
-  BuildCallToRuntime(Runtime::kWasmThrowCreate, create_parameters,
-                     arraysize(create_parameters));
+  Node* except_obj =
+      BuildCallToRuntime(Runtime::kWasmThrowCreate, create_parameters,
+                         arraysize(create_parameters));
   uint32_t index = 0;
   const wasm::WasmExceptionSig* sig = exception->sig;
   MachineOperatorBuilder* m = mcgraph()->machine();
@@ -2054,7 +2064,7 @@ Node* WasmGraphBuilder::Throw(uint32_t tag,
         value = graph()->NewNode(m->BitcastFloat32ToInt32(), value);
         V8_FALLTHROUGH;
       case wasm::kWasmI32:
-        BuildEncodeException32BitValue(&index, value);
+        BuildEncodeException32BitValue(except_obj, &index, value);
         break;
       case wasm::kWasmF64:
         value = graph()->NewNode(m->BitcastFloat64ToInt64(), value);
@@ -2063,9 +2073,9 @@ Node* WasmGraphBuilder::Throw(uint32_t tag,
         Node* upper32 = graph()->NewNode(
             m->TruncateInt64ToInt32(),
             Binop(wasm::kExprI64ShrU, value, Int64Constant(32)));
-        BuildEncodeException32BitValue(&index, upper32);
+        BuildEncodeException32BitValue(except_obj, &index, upper32);
         Node* lower32 = graph()->NewNode(m->TruncateInt64ToInt32(), value);
-        BuildEncodeException32BitValue(&index, lower32);
+        BuildEncodeException32BitValue(except_obj, &index, lower32);
         break;
       }
       default:
@@ -2073,14 +2083,24 @@ Node* WasmGraphBuilder::Throw(uint32_t tag,
     }
   }
   DCHECK_EQ(encoded_size, index);
-  return BuildCallToRuntime(Runtime::kWasmThrow, nullptr, 0);
+  WasmThrowDescriptor interface_descriptor;
+  auto call_descriptor = Linkage::GetStubCallDescriptor(
+      mcgraph()->zone(), interface_descriptor,
+      interface_descriptor.GetStackParameterCount(), CallDescriptor::kNoFlags,
+      Operator::kNoProperties, StubCallMode::kCallWasmRuntimeStub);
+  Node* call_target = mcgraph()->RelocatableIntPtrConstant(
+      wasm::WasmCode::kWasmThrow, RelocInfo::WASM_STUB_CALL);
+  return SetEffect(SetControl(
+      graph()->NewNode(mcgraph()->common()->Call(call_descriptor), call_target,
+                       except_obj, Effect(), Control())));
 }
 
-void WasmGraphBuilder::BuildEncodeException32BitValue(uint32_t* index,
+void WasmGraphBuilder::BuildEncodeException32BitValue(Node* except_obj,
+                                                      uint32_t* index,
                                                       Node* value) {
   MachineOperatorBuilder* machine = mcgraph()->machine();
   Node* upper_parameters[] = {
-      BuildChangeUint31ToSmi(Int32Constant(*index)),
+      except_obj, BuildChangeUint31ToSmi(Int32Constant(*index)),
       BuildChangeUint31ToSmi(
           graph()->NewNode(machine->Word32Shr(), value, Int32Constant(16))),
   };
@@ -2088,7 +2108,7 @@ void WasmGraphBuilder::BuildEncodeException32BitValue(uint32_t* index,
                      arraysize(upper_parameters));
   ++(*index);
   Node* lower_parameters[] = {
-      BuildChangeUint31ToSmi(Int32Constant(*index)),
+      except_obj, BuildChangeUint31ToSmi(Int32Constant(*index)),
       BuildChangeUint31ToSmi(graph()->NewNode(machine->Word32And(), value,
                                               Int32Constant(0xFFFFu))),
   };
@@ -2109,26 +2129,40 @@ Node* WasmGraphBuilder::BuildDecodeException32BitValue(Node* const* values,
   return value;
 }
 
-Node* WasmGraphBuilder::Rethrow() {
-  SetNeedsStackCheck();
-  Node* result = BuildCallToRuntime(Runtime::kWasmThrow, nullptr, 0);
-  return result;
+Node* WasmGraphBuilder::Rethrow(Node* except_obj) {
+  needs_stack_check_ = true;
+  WasmThrowDescriptor interface_descriptor;
+  auto call_descriptor = Linkage::GetStubCallDescriptor(
+      mcgraph()->zone(), interface_descriptor,
+      interface_descriptor.GetStackParameterCount(), CallDescriptor::kNoFlags,
+      Operator::kNoProperties, StubCallMode::kCallWasmRuntimeStub);
+  Node* call_target = mcgraph()->RelocatableIntPtrConstant(
+      wasm::WasmCode::kWasmThrow, RelocInfo::WASM_STUB_CALL);
+  return SetEffect(SetControl(
+      graph()->NewNode(mcgraph()->common()->Call(call_descriptor), call_target,
+                       except_obj, Effect(), Control())));
 }
 
-Node* WasmGraphBuilder::ConvertExceptionTagToRuntimeId(uint32_t tag) {
-  // TODO(kschimpf): Handle exceptions from different modules, when they are
-  // linked at runtime.
-  return Uint32Constant(tag);
+Node* WasmGraphBuilder::ExceptionTagEqual(Node* caught_tag,
+                                          Node* expected_tag) {
+  MachineOperatorBuilder* machine = mcgraph()->machine();
+  return graph()->NewNode(machine->WordEqual(), caught_tag, expected_tag);
 }
 
-Node* WasmGraphBuilder::GetExceptionRuntimeId() {
-  SetNeedsStackCheck();
-  return BuildChangeSmiToInt32(
-      BuildCallToRuntime(Runtime::kWasmGetExceptionRuntimeId, nullptr, 0));
+Node* WasmGraphBuilder::LoadExceptionTagFromTable(uint32_t exception_index) {
+  Node* exceptions_table =
+      LOAD_INSTANCE_FIELD(ExceptionsTable, MachineType::TaggedPointer());
+  Node* tag = LOAD_FIXED_ARRAY_SLOT(exceptions_table, exception_index);
+  return tag;
+}
+
+Node* WasmGraphBuilder::GetExceptionTag(Node* except_obj) {
+  needs_stack_check_ = true;
+  return BuildCallToRuntime(Runtime::kWasmExceptionGetTag, &except_obj, 1);
 }
 
 Node** WasmGraphBuilder::GetExceptionValues(
-    const wasm::WasmException* except_decl) {
+    Node* except_obj, const wasm::WasmException* except_decl) {
   // TODO(kschimpf): We need to move this code to the function-body-decoder.cc
   // in order to build landing-pad (exception) edges in case the runtime
   // call causes an exception.
@@ -2137,7 +2171,8 @@ Node** WasmGraphBuilder::GetExceptionValues(
   uint32_t encoded_size = GetExceptionEncodedSize(except_decl);
   Node** values = Buffer(encoded_size);
   for (uint32_t i = 0; i < encoded_size; ++i) {
-    Node* parameters[] = {BuildChangeUint31ToSmi(Uint32Constant(i))};
+    Node* parameters[] = {except_obj,
+                          BuildChangeUint31ToSmi(Uint32Constant(i))};
     values[i] = BuildCallToRuntime(Runtime::kWasmExceptionGetElement,
                                    parameters, arraysize(parameters));
   }
@@ -2517,7 +2552,7 @@ Node* WasmGraphBuilder::BuildWasmCall(wasm::FunctionSig* sig, Node** args,
     DCHECK_NOT_NULL(instance_node_);
     instance_node = instance_node_.get();
   }
-  SetNeedsStackCheck();
+  needs_stack_check_ = true;
   const size_t params = sig->parameter_count();
   const size_t extra = 3;  // instance_node, effect, and control.
   const size_t count = 1 + params + extra;
@@ -2557,10 +2592,10 @@ Node* WasmGraphBuilder::BuildWasmCall(wasm::FunctionSig* sig, Node** args,
   return call;
 }
 
-Node* WasmGraphBuilder::BuildImportWasmCall(wasm::FunctionSig* sig, Node** args,
-                                            Node*** rets,
-                                            wasm::WasmCodePosition position,
-                                            int func_index) {
+Node* WasmGraphBuilder::BuildImportCall(wasm::FunctionSig* sig, Node** args,
+                                        Node*** rets,
+                                        wasm::WasmCodePosition position,
+                                        int func_index) {
   // Load the instance from the imported_instances array at a known offset.
   Node* imported_instances = LOAD_INSTANCE_FIELD(ImportedFunctionInstances,
                                                  MachineType::TaggedPointer());
@@ -2578,17 +2613,18 @@ Node* WasmGraphBuilder::BuildImportWasmCall(wasm::FunctionSig* sig, Node** args,
                        untrusted_code_mitigations_ ? kRetpoline : kNoRetpoline);
 }
 
-Node* WasmGraphBuilder::BuildImportWasmCall(wasm::FunctionSig* sig, Node** args,
-                                            Node*** rets,
-                                            wasm::WasmCodePosition position,
-                                            Node* func_index) {
+Node* WasmGraphBuilder::BuildImportCall(wasm::FunctionSig* sig, Node** args,
+                                        Node*** rets,
+                                        wasm::WasmCodePosition position,
+                                        Node* func_index) {
   // Load the instance from the imported_instances array.
   Node* imported_instances = LOAD_INSTANCE_FIELD(ImportedFunctionInstances,
                                                  MachineType::TaggedPointer());
   // Access fixed array at {header_size - tag + func_index * kPointerSize}.
-  Node* imported_instances_data =
-      graph()->NewNode(mcgraph()->machine()->IntAdd(), imported_instances,
-                       mcgraph()->IntPtrConstant(FixedArrayOffsetMinusTag(0)));
+  Node* imported_instances_data = graph()->NewNode(
+      mcgraph()->machine()->IntAdd(), imported_instances,
+      mcgraph()->IntPtrConstant(
+          wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(0)));
   Node* func_index_times_pointersize = graph()->NewNode(
       mcgraph()->machine()->IntMul(), Uint32ToUintptr(func_index),
       mcgraph()->Int32Constant(kPointerSize));
@@ -2616,7 +2652,7 @@ Node* WasmGraphBuilder::CallDirect(uint32_t index, Node** args, Node*** rets,
 
   if (env_ && index < env_->module->num_imported_functions) {
     // Call to an imported function.
-    return BuildImportWasmCall(sig, args, rets, position, index);
+    return BuildImportCall(sig, args, rets, position, index);
   }
 
   // A direct call to a wasm function defined in this module.
@@ -2687,11 +2723,11 @@ Node* WasmGraphBuilder::CallIndirect(uint32_t sig_index, Node** args,
       SetEffect(graph()->NewNode(machine->Load(MachineType::Pointer()),
                                  ift_targets, scaled_key, Effect(), Control()));
 
-  auto access = AccessBuilder::ForFixedArrayElement();
   Node* target_instance = SetEffect(graph()->NewNode(
       machine->Load(MachineType::TaggedPointer()),
       graph()->NewNode(machine->IntAdd(), ift_instances, scaled_key),
-      Int32Constant(access.header_size - access.tag()), Effect(), Control()));
+      Int32Constant(wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(0)),
+      Effect(), Control()));
 
   args[0] = target;
 
@@ -2792,11 +2828,8 @@ void WasmGraphBuilder::InitInstanceCache(
 
   if (untrusted_code_mitigations_) {
     // Load the memory mask.
-    instance_cache->mem_mask = SetEffect(graph()->NewNode(
-        mcgraph()->machine()->Load(MachineType::UintPtr()),
-        instance_node_.get(),
-        mcgraph()->Int32Constant(WASM_INSTANCE_OBJECT_OFFSET(MemoryMask)),
-        Effect(), Control()));
+    instance_cache->mem_mask =
+        LOAD_INSTANCE_FIELD(MemoryMask, MachineType::UintPtr());
   } else {
     // Explicitly set to nullptr to ensure a SEGV when we try to use it.
     instance_cache->mem_mask = nullptr;
@@ -2810,9 +2843,9 @@ void WasmGraphBuilder::PrepareInstanceCacheForLoop(
                                            instance_cache->field, control);
 
   INTRODUCE_PHI(mem_start, MachineType::PointerRepresentation());
-  INTRODUCE_PHI(mem_size, MachineRepresentation::kWord32);
+  INTRODUCE_PHI(mem_size, MachineType::PointerRepresentation());
   if (untrusted_code_mitigations_) {
-    INTRODUCE_PHI(mem_mask, MachineRepresentation::kWord32);
+    INTRODUCE_PHI(mem_mask, MachineType::PointerRepresentation());
   }
 
 #undef INTRODUCE_PHI
@@ -2958,6 +2991,14 @@ Node* WasmGraphBuilder::CurrentMemoryPages() {
   return result;
 }
 
+Node* WasmGraphBuilder::BuildLoadBuiltinFromInstance(int builtin_index) {
+  DCHECK(Builtins::IsBuiltinId(builtin_index));
+  Node* roots =
+      LOAD_INSTANCE_FIELD(RootsArrayAddress, MachineType::TaggedPointer());
+  return LOAD_TAGGED_POINTER(
+      roots, Heap::roots_to_builtins_offset() + builtin_index * kPointerSize);
+}
+
 // Only call this function for code which is not reused across instantiations,
 // as we do not patch the embedded js_context.
 Node* WasmGraphBuilder::BuildCallToRuntimeWithContext(Runtime::FunctionId f,
@@ -3226,7 +3267,7 @@ Node* WasmGraphBuilder::LoadMem(wasm::ValueType type, MachineType memtype,
     }
   }
 
-  if (FLAG_wasm_trace_memory) {
+  if (FLAG_trace_wasm_memory) {
     TraceMemoryOperation(false, memtype.representation(), index, offset,
                          position);
   }
@@ -3271,7 +3312,7 @@ Node* WasmGraphBuilder::StoreMem(MachineRepresentation mem_rep, Node* index,
 
   SetEffect(store);
 
-  if (FLAG_wasm_trace_memory) {
+  if (FLAG_trace_wasm_memory) {
     TraceMemoryOperation(true, mem_rep, index, offset, position);
   }
 
@@ -4346,8 +4387,8 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   Node* BuildLoadFunctionDataFromExportedFunction(Node* closure) {
     Node* shared = SetEffect(graph()->NewNode(
         jsgraph()->machine()->Load(MachineType::AnyTagged()), closure,
-        jsgraph()->Int32Constant(JSFunction::kSharedFunctionInfoOffset -
-                                 kHeapObjectTag),
+        jsgraph()->Int32Constant(
+            wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction()),
         Effect(), Control()));
     return SetEffect(graph()->NewNode(
         jsgraph()->machine()->Load(MachineType::AnyTagged()), shared,
@@ -4437,8 +4478,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       // Load function index from {WasmExportedFunctionData}.
       Node* function_index =
           BuildLoadFunctionIndexFromExportedFunctionData(function_data);
-      BuildImportWasmCall(sig_, args, &rets, wasm::kNoCodePosition,
-                          function_index);
+      BuildImportCall(sig_, args, &rets, wasm::kNoCodePosition, function_index);
     } else {
       // Call to a wasm function defined in this module.
       // The call target is the jump table slot for that function.
@@ -4462,9 +4502,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     Return(jsval);
   }
 
-  bool BuildWasmToJSWrapper(Handle<JSReceiver> target, int index) {
-    DCHECK(target->IsCallable());
-
+  bool BuildWasmImportCallWrapper(WasmImportCallKind kind, int func_index) {
     int wasm_count = static_cast<int>(sig_->parameter_count());
 
     // Build the start and the parameter nodes.
@@ -4473,16 +4511,13 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     // Create the instance_node from the passed parameter.
     instance_node_.set(Param(wasm::kWasmInstanceParameterIndex));
 
-    Node* callables_node = LOAD_INSTANCE_FIELD(ImportedFunctionCallables,
-                                               MachineType::TaggedPointer());
-    Node* callable_node = LOAD_FIXED_ARRAY_SLOT(callables_node, index);
-    Node* undefined_node =
-        LOAD_INSTANCE_FIELD(UndefinedValue, MachineType::TaggedPointer());
     Node* native_context =
         LOAD_INSTANCE_FIELD(NativeContext, MachineType::TaggedPointer());
 
-    if (!wasm::IsJSCompatibleSignature(sig_)) {
-      // Throw a TypeError.
+    if (kind == WasmImportCallKind::kRuntimeTypeError) {
+      // =======================================================================
+      // === Runtime TypeError =================================================
+      // =======================================================================
       BuildCallToRuntimeWithContext(Runtime::kWasmThrowTypeError,
                                     native_context, nullptr, 0);
       // We don't need to return a value here, as the runtime call will not
@@ -4491,114 +4526,156 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       return false;
     }
 
-    CallDescriptor* call_descriptor;
-    Node** args = Buffer(wasm_count + 9);
+    Node* callables_node = LOAD_INSTANCE_FIELD(ImportedFunctionCallables,
+                                               MachineType::TaggedPointer());
+    Node* callable_node = LOAD_FIXED_ARRAY_SLOT(callables_node, func_index);
+    Node* undefined_node =
+        LOAD_INSTANCE_FIELD(UndefinedValue, MachineType::TaggedPointer());
+
     Node* call = nullptr;
+    bool sloppy_receiver = true;
+
+    BuildModifyThreadInWasmFlag(false);  // exiting WASM via call.
+
+    switch (kind) {
+      // =======================================================================
+      // === JS Functions with matching arity ==================================
+      // =======================================================================
+      case WasmImportCallKind::kJSFunctionArityMatch:
+        sloppy_receiver = false;
+        V8_FALLTHROUGH;  // fallthru
+      case WasmImportCallKind::kJSFunctionArityMatchSloppy: {
+        Node** args = Buffer(wasm_count + 9);
+        int pos = 0;
+        Node* function_context = SetEffect(graph()->NewNode(
+            mcgraph()->machine()->Load(MachineType::TaggedPointer()),
+            callable_node,
+            mcgraph()->Int32Constant(
+                wasm::ObjectAccess::ContextOffsetInTaggedJSFunction()),
+            Effect(), Control()));
+        args[pos++] = callable_node;  // target callable.
+        // Receiver.
+        if (sloppy_receiver) {
+          Node* global_proxy = LOAD_FIXED_ARRAY_SLOT(
+              native_context, Context::GLOBAL_PROXY_INDEX);
+          args[pos++] = global_proxy;
+        } else {
+          args[pos++] = undefined_node;
+        }
 
-    BuildModifyThreadInWasmFlag(false);
+        auto call_descriptor = Linkage::GetJSCallDescriptor(
+            graph()->zone(), false, wasm_count + 1, CallDescriptor::kNoFlags);
 
-    if (target->IsJSFunction()) {
-      Handle<JSFunction> function = Handle<JSFunction>::cast(target);
-      FieldAccess field_access = AccessBuilder::ForJSFunctionContext();
-      Node* function_context = SetEffect(graph()->NewNode(
-          mcgraph()->machine()->Load(MachineType::TaggedPointer()),
-          callable_node,
-          mcgraph()->Int32Constant(field_access.offset - field_access.tag()),
-          Effect(), Control()));
-
-      if (!IsClassConstructor(function->shared()->kind())) {
-        if (function->shared()->internal_formal_parameter_count() ==
-            wasm_count) {
-          int pos = 0;
-          args[pos++] = callable_node;  // target callable.
-          // Receiver.
-          if (is_sloppy(function->shared()->language_mode()) &&
-              !function->shared()->native()) {
-            Node* global_proxy = LOAD_FIXED_ARRAY_SLOT(
-                native_context, Context::GLOBAL_PROXY_INDEX);
-            args[pos++] = global_proxy;
-          } else {
-            args[pos++] = undefined_node;
-          }
-
-          call_descriptor = Linkage::GetJSCallDescriptor(
-              graph()->zone(), false, wasm_count + 1, CallDescriptor::kNoFlags);
-
-          // Convert wasm numbers to JS values.
-          pos = AddArgumentNodes(args, pos, wasm_count, sig_);
-
-          args[pos++] = undefined_node;                        // new target
-          args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
-          args[pos++] = function_context;
-          args[pos++] = Effect();
-          args[pos++] = Control();
-
-          call = graph()->NewNode(mcgraph()->common()->Call(call_descriptor),
-                                  pos, args);
-        } else if (function->shared()->internal_formal_parameter_count() >= 0) {
-          int pos = 0;
-          args[pos++] = mcgraph()->RelocatableIntPtrConstant(
-              wasm::WasmCode::kWasmArgumentsAdaptor, RelocInfo::WASM_STUB_CALL);
-          args[pos++] = callable_node;   // target callable
-          args[pos++] = undefined_node;  // new target
-          args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
-          args[pos++] = mcgraph()->Int32Constant(
-              function->shared()->internal_formal_parameter_count());
-          // Receiver.
-          if (is_sloppy(function->shared()->language_mode()) &&
-              !function->shared()->native()) {
-            Node* global_proxy = LOAD_FIXED_ARRAY_SLOT(
-                native_context, Context::GLOBAL_PROXY_INDEX);
-            args[pos++] = global_proxy;
-          } else {
-            args[pos++] = undefined_node;
-          }
-
-          call_descriptor = Linkage::GetStubCallDescriptor(
-              mcgraph()->zone(), ArgumentAdaptorDescriptor{}, 1 + wasm_count,
-              CallDescriptor::kNoFlags, Operator::kNoProperties,
-              StubCallMode::kCallWasmRuntimeStub);
-
-          // Convert wasm numbers to JS values.
-          pos = AddArgumentNodes(args, pos, wasm_count, sig_);
-          args[pos++] = function_context;
-          args[pos++] = Effect();
-          args[pos++] = Control();
-          call = graph()->NewNode(mcgraph()->common()->Call(call_descriptor),
-                                  pos, args);
-        }
+        // Convert wasm numbers to JS values.
+        pos = AddArgumentNodes(args, pos, wasm_count, sig_);
+
+        args[pos++] = undefined_node;                        // new target
+        args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
+        args[pos++] = function_context;
+        args[pos++] = Effect();
+        args[pos++] = Control();
+
+        call = graph()->NewNode(mcgraph()->common()->Call(call_descriptor), pos,
+                                args);
+        break;
       }
-    }
+      // =======================================================================
+      // === JS Functions with arguments adapter ===============================
+      // =======================================================================
+      case WasmImportCallKind::kJSFunctionArityMismatch:
+        sloppy_receiver = false;
+        V8_FALLTHROUGH;  // fallthru
+      case WasmImportCallKind::kJSFunctionArityMismatchSloppy: {
+        Node** args = Buffer(wasm_count + 9);
+        int pos = 0;
+        Node* function_context = SetEffect(graph()->NewNode(
+            mcgraph()->machine()->Load(MachineType::TaggedPointer()),
+            callable_node,
+            mcgraph()->Int32Constant(
+                wasm::ObjectAccess::ContextOffsetInTaggedJSFunction()),
+            Effect(), Control()));
+        args[pos++] =
+            BuildLoadBuiltinFromInstance(Builtins::kArgumentsAdaptorTrampoline);
+        args[pos++] = callable_node;                         // target callable
+        args[pos++] = undefined_node;                        // new target
+        args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
+
+        // Load shared function info, and then the formal parameter count.
+        Node* shared_function_info = SetEffect(graph()->NewNode(
+            mcgraph()->machine()->Load(MachineType::TaggedPointer()),
+            callable_node,
+            mcgraph()->Int32Constant(
+                wasm::ObjectAccess::
+                    SharedFunctionInfoOffsetInTaggedJSFunction()),
+            Effect(), Control()));
+        Node* formal_param_count = SetEffect(graph()->NewNode(
+            mcgraph()->machine()->Load(MachineType::Uint16()),
+            shared_function_info,
+            mcgraph()->Int32Constant(
+                wasm::ObjectAccess::
+                    FormalParameterCountOffsetInSharedFunctionInfo()),
+            Effect(), Control()));
+        args[pos++] = formal_param_count;
+
+        // Receiver.
+        if (sloppy_receiver) {
+          Node* global_proxy = LOAD_FIXED_ARRAY_SLOT(
+              native_context, Context::GLOBAL_PROXY_INDEX);
+          args[pos++] = global_proxy;
+        } else {
+          args[pos++] = undefined_node;
+        }
 
-    // We cannot call the target directly, we have to use the Call builtin.
-    if (!call) {
-      int pos = 0;
-      args[pos++] = mcgraph()->RelocatableIntPtrConstant(
-          wasm::WasmCode::kWasmCallJavaScript, RelocInfo::WASM_STUB_CALL);
-      args[pos++] = callable_node;
-      args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
-      args[pos++] = undefined_node;                        // receiver
-
-      call_descriptor = Linkage::GetStubCallDescriptor(
-          graph()->zone(), CallTrampolineDescriptor{}, wasm_count + 1,
-          CallDescriptor::kNoFlags, Operator::kNoProperties,
-          StubCallMode::kCallWasmRuntimeStub);
-
-      // Convert wasm numbers to JS values.
-      pos = AddArgumentNodes(args, pos, wasm_count, sig_);
-
-      // The native_context is sufficient here, because all kind of callables
-      // which depend on the context provide their own context. The context here
-      // is only needed if the target is a constructor to throw a TypeError, if
-      // the target is a native function, or if the target is a callable
-      // JSObject, which can only be constructed by the runtime.
-      args[pos++] = native_context;
-      args[pos++] = Effect();
-      args[pos++] = Control();
-
-      call = graph()->NewNode(mcgraph()->common()->Call(call_descriptor), pos,
-                              args);
+        auto call_descriptor = Linkage::GetStubCallDescriptor(
+            mcgraph()->zone(), ArgumentsAdaptorDescriptor{}, 1 + wasm_count,
+            CallDescriptor::kNoFlags, Operator::kNoProperties);
+
+        // Convert wasm numbers to JS values.
+        pos = AddArgumentNodes(args, pos, wasm_count, sig_);
+        args[pos++] = function_context;
+        args[pos++] = Effect();
+        args[pos++] = Control();
+        call = graph()->NewNode(mcgraph()->common()->Call(call_descriptor), pos,
+                                args);
+        break;
+      }
+      // =======================================================================
+      // === General case of unknown callable ==================================
+      // =======================================================================
+      case WasmImportCallKind::kUseCallBuiltin: {
+        Node** args = Buffer(wasm_count + 9);
+        int pos = 0;
+        args[pos++] = mcgraph()->RelocatableIntPtrConstant(
+            wasm::WasmCode::kWasmCallJavaScript, RelocInfo::WASM_STUB_CALL);
+        args[pos++] = callable_node;
+        args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
+        args[pos++] = undefined_node;                        // receiver
+
+        auto call_descriptor = Linkage::GetStubCallDescriptor(
+            graph()->zone(), CallTrampolineDescriptor{}, wasm_count + 1,
+            CallDescriptor::kNoFlags, Operator::kNoProperties,
+            StubCallMode::kCallWasmRuntimeStub);
+
+        // Convert wasm numbers to JS values.
+        pos = AddArgumentNodes(args, pos, wasm_count, sig_);
+
+        // The native_context is sufficient here, because all kind of callables
+        // which depend on the context provide their own context. The context
+        // here is only needed if the target is a constructor to throw a
+        // TypeError, if the target is a native function, or if the target is a
+        // callable JSObject, which can only be constructed by the runtime.
+        args[pos++] = native_context;
+        args[pos++] = Effect();
+        args[pos++] = Control();
+
+        call = graph()->NewNode(mcgraph()->common()->Call(call_descriptor), pos,
+                                args);
+        break;
+      }
+      default:
+        UNREACHABLE();
     }
+    DCHECK_NOT_NULL(call);
 
     SetEffect(call);
     SetSourcePosition(call, 0);
@@ -4608,7 +4685,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
                     ? mcgraph()->Int32Constant(0)
                     : FromJS(call, native_context, sig_->GetReturn());
 
-    BuildModifyThreadInWasmFlag(true);
+    BuildModifyThreadInWasmFlag(true);  // reentering WASM upon return.
 
     Return(val);
     return true;
@@ -4661,9 +4738,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     // We are passing the raw arg_buffer here. To the GC and other parts, it
     // looks like a Smi (lowest bit not set). In the runtime function however,
     // don't call Smi::value on it, but just cast it to a byte pointer.
-    Node* parameters[] = {
-        jsgraph()->SmiConstant(func_index), arg_buffer,
-    };
+    Node* parameters[] = {jsgraph()->SmiConstant(func_index), arg_buffer};
     BuildCallToRuntime(Runtime::kWasmRunInterpreter, parameters,
                        arraysize(parameters));
 
@@ -4689,12 +4764,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     SetEffect(SetControl(Start(CWasmEntryParameters::kNumParameters + 5)));
 
     // Create parameter nodes (offset by 1 for the receiver parameter).
-    Node* foreign_code_obj = Param(CWasmEntryParameters::kCodeObject + 1);
-    MachineOperatorBuilder* machine = mcgraph()->machine();
-    Node* code_obj = graph()->NewNode(
-        machine->Load(MachineType::Pointer()), foreign_code_obj,
-        Int32Constant(Foreign::kForeignAddressOffset - kHeapObjectTag),
-        Effect(), Control());
+    Node* code_entry = Param(CWasmEntryParameters::kCodeEntry + 1);
     Node* instance_node = Param(CWasmEntryParameters::kWasmInstance + 1);
     Node* arg_buffer = Param(CWasmEntryParameters::kArgumentsBuffer + 1);
 
@@ -4703,7 +4773,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     Node** args = Buffer(arg_count);
 
     int pos = 0;
-    args[pos++] = code_obj;
+    args[pos++] = code_entry;
     args[pos++] = instance_node;
 
     int offset = 0;
@@ -4759,16 +4829,30 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   StubCallMode stub_mode_;
   SetOncePointer<const Operator> allocate_heap_number_operator_;
 };
+
+void AppendSignature(char* buffer, size_t max_name_len,
+                     wasm::FunctionSig* sig) {
+  size_t name_len = strlen(buffer);
+  auto append_name_char = [&](char c) {
+    if (name_len + 1 < max_name_len) buffer[name_len++] = c;
+  };
+  for (wasm::ValueType t : sig->parameters()) {
+    append_name_char(wasm::ValueTypes::ShortNameOf(t));
+  }
+  append_name_char(':');
+  for (wasm::ValueType t : sig->returns()) {
+    append_name_char(wasm::ValueTypes::ShortNameOf(t));
+  }
+  buffer[name_len] = '\0';
+}
+
 }  // namespace
 
-MaybeHandle<Code> CompileJSToWasmWrapper(
-    Isolate* isolate, const wasm::NativeModule* native_module,
-    wasm::FunctionSig* sig, bool is_import,
-    wasm::UseTrapHandler use_trap_handler) {
+MaybeHandle<Code> CompileJSToWasmWrapper(Isolate* isolate,
+                                         wasm::FunctionSig* sig,
+                                         bool is_import) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"),
                "CompileJSToWasmWrapper");
-  const wasm::WasmModule* module = native_module->module();
-
   //----------------------------------------------------------------------------
   // Create the Graph.
   //----------------------------------------------------------------------------
@@ -4784,7 +4868,8 @@ MaybeHandle<Code> CompileJSToWasmWrapper(
   Node* control = nullptr;
   Node* effect = nullptr;
 
-  wasm::ModuleEnv env(module, use_trap_handler, wasm::kRuntimeExceptionSupport);
+  wasm::ModuleEnv env(nullptr, wasm::kNoTrapHandler,
+                      wasm::kRuntimeExceptionSupport);
   WasmWrapperGraphBuilder builder(&zone, &env, &jsgraph, sig, nullptr,
                                   StubCallMode::kCallOnHeapBuiltin);
   builder.set_control_ptr(&control);
@@ -4794,28 +4879,18 @@ MaybeHandle<Code> CompileJSToWasmWrapper(
   //----------------------------------------------------------------------------
   // Run the compilation pipeline.
   //----------------------------------------------------------------------------
-#ifdef DEBUG
-  EmbeddedVector<char, 32> func_name;
-  static unsigned id = 0;
-  func_name.Truncate(SNPrintF(func_name, "js-to-wasm#%d", id++));
-#else
-  Vector<const char> func_name = CStrVector("js-to-wasm");
-#endif
-
-  OptimizedCompilationInfo info(func_name, &zone, Code::JS_TO_WASM_FUNCTION);
-
-  if (info.trace_turbo_graph_enabled()) {  // Simple textual RPO.
-    StdoutStream{} << "-- Graph after change lowering -- " << std::endl
-                   << AsRPO(graph);
-  }
+  static constexpr size_t kMaxNameLen = 128;
+  char debug_name[kMaxNameLen] = "js_to_wasm:";
+  AppendSignature(debug_name, kMaxNameLen, sig);
 
   // Schedule and compile to machine code.
   int params = static_cast<int>(sig->parameter_count());
   CallDescriptor* incoming = Linkage::GetJSCallDescriptor(
       &zone, false, params + 1, CallDescriptor::kNoFlags);
 
-  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForTesting(
-      &info, isolate, incoming, &graph, WasmAssemblerOptions());
+  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForWasmStub(
+      isolate, incoming, &graph, Code::JS_TO_WASM_FUNCTION, debug_name,
+      WasmAssemblerOptions());
   Handle<Code> code;
   if (!maybe_code.ToHandle(&code)) {
     return maybe_code;
@@ -4824,24 +4899,67 @@ MaybeHandle<Code> CompileJSToWasmWrapper(
   if (FLAG_print_opt_code) {
     CodeTracer::Scope tracing_scope(isolate->GetCodeTracer());
     OFStream os(tracing_scope.file());
-    code->Disassemble(func_name.start(), os);
+    code->Disassemble(debug_name, os);
   }
 #endif
 
   if (must_record_function_compilation(isolate)) {
-    RecordFunctionCompilation(CodeEventListener::STUB_TAG, isolate, code,
-                              "%.*s", func_name.length(), func_name.start());
+    RecordFunctionCompilation(CodeEventListener::STUB_TAG, isolate, code, "%s",
+                              debug_name);
   }
 
   return code;
 }
 
-MaybeHandle<Code> CompileWasmToJSWrapper(
-    Isolate* isolate, Handle<JSReceiver> target, wasm::FunctionSig* sig,
+WasmImportCallKind GetWasmImportCallKind(Handle<JSReceiver> target,
+                                         wasm::FunctionSig* expected_sig) {
+  if (WasmExportedFunction::IsWasmExportedFunction(*target)) {
+    auto imported_function = WasmExportedFunction::cast(*target);
+    wasm::FunctionSig* imported_sig =
+        imported_function->instance()
+            ->module()
+            ->functions[imported_function->function_index()]
+            .sig;
+    if (*imported_sig != *expected_sig) {
+      return WasmImportCallKind::kLinkError;
+    }
+    return WasmImportCallKind::kWasmToWasm;
+  }
+  // Assuming we are calling to JS, check whether this would be a runtime error.
+  if (!wasm::IsJSCompatibleSignature(expected_sig)) {
+    return WasmImportCallKind::kRuntimeTypeError;
+  }
+  // For JavaScript calls, determine whether the target has an arity match
+  // and whether it has a sloppy receiver.
+  if (target->IsJSFunction()) {
+    Handle<JSFunction> function = Handle<JSFunction>::cast(target);
+    if (IsClassConstructor(function->shared()->kind())) {
+      // Class constructor will throw anyway.
+      return WasmImportCallKind::kUseCallBuiltin;
+    }
+    bool sloppy = is_sloppy(function->shared()->language_mode()) &&
+                  !function->shared()->native();
+    if (function->shared()->internal_formal_parameter_count() ==
+        expected_sig->parameter_count()) {
+      return sloppy ? WasmImportCallKind::kJSFunctionArityMatchSloppy
+                    : WasmImportCallKind::kJSFunctionArityMatch;
+    }
+    return sloppy ? WasmImportCallKind::kJSFunctionArityMismatchSloppy
+                  : WasmImportCallKind::kJSFunctionArityMismatch;
+  }
+  // Unknown case. Use the call builtin.
+  return WasmImportCallKind::kUseCallBuiltin;
+}
+
+MaybeHandle<Code> CompileWasmImportCallWrapper(
+    Isolate* isolate, WasmImportCallKind kind, wasm::FunctionSig* sig,
     uint32_t index, wasm::ModuleOrigin origin,
     wasm::UseTrapHandler use_trap_handler) {
+  DCHECK_NE(WasmImportCallKind::kLinkError, kind);
+  DCHECK_NE(WasmImportCallKind::kWasmToWasm, kind);
+
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"),
-               "CompileWasmToJSWrapper");
+               "CompileWasmImportCallWrapper");
   //----------------------------------------------------------------------------
   // Create the Graph
   //----------------------------------------------------------------------------
@@ -4869,31 +4987,19 @@ MaybeHandle<Code> CompileWasmToJSWrapper(
                                   StubCallMode::kCallWasmRuntimeStub);
   builder.set_control_ptr(&control);
   builder.set_effect_ptr(&effect);
-  builder.BuildWasmToJSWrapper(target, index);
+  builder.BuildWasmImportCallWrapper(kind, index);
 
-#ifdef DEBUG
   EmbeddedVector<char, 32> func_name;
-  static unsigned id = 0;
-  func_name.Truncate(SNPrintF(func_name, "wasm-to-js#%d", id++));
-#else
-  Vector<const char> func_name = CStrVector("wasm-to-js");
-#endif
-
-  OptimizedCompilationInfo info(func_name, &zone, Code::WASM_TO_JS_FUNCTION);
-
-  if (info.trace_turbo_graph_enabled()) {  // Simple textual RPO.
-    StdoutStream{} << "-- Graph after change lowering -- " << std::endl
-                   << AsRPO(graph);
-  }
+  func_name.Truncate(SNPrintF(func_name, "wasm-to-js#%d", index));
 
   // Schedule and compile to machine code.
   CallDescriptor* incoming = GetWasmCallDescriptor(&zone, sig);
   if (machine.Is32()) {
     incoming = GetI32WasmCallDescriptor(&zone, incoming);
   }
-  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForTesting(
-      &info, isolate, incoming, &graph, AssemblerOptions::Default(isolate),
-      nullptr, source_position_table);
+  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForWasmStub(
+      isolate, incoming, &graph, Code::WASM_TO_JS_FUNCTION, func_name.start(),
+      AssemblerOptions::Default(isolate), source_position_table);
   Handle<Code> code;
   if (!maybe_code.ToHandle(&code)) {
     return maybe_code;
@@ -4943,24 +5049,14 @@ MaybeHandle<Code> CompileWasmInterpreterEntry(Isolate* isolate,
   if (machine.Is32()) {
     incoming = GetI32WasmCallDescriptor(&zone, incoming);
   }
-#ifdef DEBUG
+
   EmbeddedVector<char, 32> func_name;
   func_name.Truncate(
       SNPrintF(func_name, "wasm-interpreter-entry#%d", func_index));
-#else
-  Vector<const char> func_name = CStrVector("wasm-interpreter-entry");
-#endif
-
-  OptimizedCompilationInfo info(func_name, &zone, Code::WASM_INTERPRETER_ENTRY);
 
-  if (info.trace_turbo_graph_enabled()) {  // Simple textual RPO.
-    StdoutStream{} << "-- Wasm interpreter entry graph -- " << std::endl
-                   << AsRPO(graph);
-  }
-
-  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForTesting(
-      &info, isolate, incoming, &graph, AssemblerOptions::Default(isolate),
-      nullptr);
+  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForWasmStub(
+      isolate, incoming, &graph, Code::WASM_INTERPRETER_ENTRY,
+      func_name.start(), AssemblerOptions::Default(isolate));
   Handle<Code> code;
   if (!maybe_code.ToHandle(&code)) {
     return maybe_code;
@@ -5008,28 +5104,11 @@ MaybeHandle<Code> CompileCWasmEntry(Isolate* isolate, wasm::FunctionSig* sig) {
   // Build a name in the form "c-wasm-entry:<params>:<returns>".
   static constexpr size_t kMaxNameLen = 128;
   char debug_name[kMaxNameLen] = "c-wasm-entry:";
-  size_t name_len = strlen(debug_name);
-  auto append_name_char = [&](char c) {
-    if (name_len + 1 < kMaxNameLen) debug_name[name_len++] = c;
-  };
-  for (wasm::ValueType t : sig->parameters()) {
-    append_name_char(wasm::ValueTypes::ShortNameOf(t));
-  }
-  append_name_char(':');
-  for (wasm::ValueType t : sig->returns()) {
-    append_name_char(wasm::ValueTypes::ShortNameOf(t));
-  }
-  debug_name[name_len] = '\0';
-  Vector<const char> debug_name_vec(debug_name, name_len);
-
-  OptimizedCompilationInfo info(debug_name_vec, &zone, Code::C_WASM_ENTRY);
-
-  if (info.trace_turbo_graph_enabled()) {  // Simple textual RPO.
-    StdoutStream{} << "-- C Wasm entry graph -- " << std::endl << AsRPO(graph);
-  }
+  AppendSignature(debug_name, kMaxNameLen, sig);
 
-  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForTesting(
-      &info, isolate, incoming, &graph, AssemblerOptions::Default(isolate));
+  MaybeHandle<Code> maybe_code = Pipeline::GenerateCodeForWasmStub(
+      isolate, incoming, &graph, Code::C_WASM_ENTRY, debug_name,
+      AssemblerOptions::Default(isolate));
   Handle<Code> code;
   if (!maybe_code.ToHandle(&code)) {
     return maybe_code;
@@ -5100,23 +5179,17 @@ SourcePositionTable* TurbofanWasmCompilationUnit::BuildGraphForWasmFunction(
 }
 
 namespace {
-Vector<const char> GetDebugName(Zone* zone, wasm::WasmName name, int index) {
-  if (!name.is_empty()) {
-    return name;
-  }
-#ifdef DEBUG
-  constexpr int kBufferLength = 15;
+Vector<const char> GetDebugName(Zone* zone, int index) {
+  // TODO(herhut): Use name from module if available.
+  constexpr int kBufferLength = 24;
 
   EmbeddedVector<char, kBufferLength> name_vector;
-  int name_len = SNPrintF(name_vector, "wasm#%d", index);
+  int name_len = SNPrintF(name_vector, "wasm-function#%d", index);
   DCHECK(name_len > 0 && name_len < name_vector.length());
 
   char* index_name = zone->NewArray<char>(name_len);
   memcpy(index_name, name_vector.start(), name_len);
   return Vector<const char>(index_name, name_len);
-#else
-  return {};
-#endif
 }
 
 }  // namespace
@@ -5142,13 +5215,17 @@ void TurbofanWasmCompilationUnit::ExecuteCompilation(
     Zone compilation_zone(wasm_unit_->wasm_engine_->allocator(), ZONE_NAME);
 
     OptimizedCompilationInfo info(
-        GetDebugName(&compilation_zone, wasm_unit_->func_name_,
-                     wasm_unit_->func_index_),
+        GetDebugName(&compilation_zone, wasm_unit_->func_index_),
         &compilation_zone, Code::WASM_FUNCTION);
     if (wasm_unit_->env_->runtime_exception_support) {
       info.SetWasmRuntimeExceptionSupport();
     }
 
+    if (info.trace_turbo_json_enabled()) {
+      TurboCfgFile tcf;
+      tcf << AsC1VCompilation(&info);
+    }
+
     NodeOriginTable* node_origins = info.trace_turbo_json_enabled()
                                         ? new (&graph_zone)
                                               NodeOriginTable(mcgraph->graph())
@@ -5209,16 +5286,22 @@ wasm::WasmCode* TurbofanWasmCompilationUnit::FinishCompilation(
     wasm::ErrorThrower* thrower) {
   if (!ok_) {
     if (graph_construction_result_.failed()) {
-      // Add the function as another context for the exception.
+      // Add the function as another context for the exception. This is
+      // user-visible, so use official format.
       EmbeddedVector<char, 128> message;
-      if (wasm_unit_->func_name_.start() == nullptr) {
-        SNPrintF(message, "Compiling wasm function #%d failed",
-                 wasm_unit_->func_index_);
+      wasm::ModuleWireBytes wire_bytes(
+          wasm_unit_->native_module()->wire_bytes());
+      wasm::WireBytesRef name_ref =
+          wasm_unit_->native_module()->module()->LookupFunctionName(
+              wire_bytes, wasm_unit_->func_index_);
+      if (name_ref.is_set()) {
+        wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
+        SNPrintF(message, "Compiling wasm function \"%.*s\" failed",
+                 name.length(), name.start());
       } else {
-        wasm::TruncatedUserString<> trunc_name(wasm_unit_->func_name_);
-        SNPrintF(message, "Compiling wasm function #%d:%.*s failed",
-                 wasm_unit_->func_index_, trunc_name.length(),
-                 trunc_name.start());
+        SNPrintF(message,
+                 "Compiling wasm function \"wasm-function[%d]\" failed",
+                 wasm_unit_->func_index_);
       }
       thrower->CompileFailed(message.start(), graph_construction_result_);
     }
@@ -5416,8 +5499,10 @@ AssemblerOptions WasmAssemblerOptions() {
 
 #undef WASM_64
 #undef FATAL_UNSUPPORTED_OPCODE
+#undef WASM_INSTANCE_OBJECT_SIZE
 #undef WASM_INSTANCE_OBJECT_OFFSET
 #undef LOAD_INSTANCE_FIELD
+#undef LOAD_TAGGED_POINTER
 #undef LOAD_FIXED_ARRAY_SLOT
 
 }  // namespace compiler
diff --git a/deps/v8/src/compiler/wasm-compiler.h b/deps/v8/src/compiler/wasm-compiler.h
index 775c817242..f1f341c9af 100644
--- a/deps/v8/src/compiler/wasm-compiler.h
+++ b/deps/v8/src/compiler/wasm-compiler.h
@@ -68,31 +68,43 @@ class TurbofanWasmCompilationUnit {
   DISALLOW_COPY_AND_ASSIGN(TurbofanWasmCompilationUnit);
 };
 
-// Wraps a JS function, producing a code object that can be called from wasm.
-MaybeHandle<Code> CompileWasmToJSWrapper(Isolate*, Handle<JSReceiver> target,
-                                         wasm::FunctionSig*, uint32_t index,
-                                         wasm::ModuleOrigin,
-                                         wasm::UseTrapHandler);
+// Calls to WASM imports are handled in several different ways, depending
+// on the type of the target function/callable and whether the signature
+// matches the argument arity.
+enum class WasmImportCallKind {
+  kLinkError,                      // static WASM->WASM type error
+  kRuntimeTypeError,               // runtime WASM->JS type error
+  kWasmToWasm,                     // fast WASM->WASM call
+  kJSFunctionArityMatch,           // fast WASM->JS call
+  kJSFunctionArityMatchSloppy,     // fast WASM->JS call, sloppy receiver
+  kJSFunctionArityMismatch,        // WASM->JS, needs adapter frame
+  kJSFunctionArityMismatchSloppy,  // WASM->JS, needs adapter frame, sloppy
+  kUseCallBuiltin                  // everything else
+};
+
+WasmImportCallKind GetWasmImportCallKind(Handle<JSReceiver> callable,
+                                         wasm::FunctionSig* sig);
+
+// Compiles an import call wrapper, which allows WASM to call imports.
+MaybeHandle<Code> CompileWasmImportCallWrapper(Isolate*, WasmImportCallKind,
+                                               wasm::FunctionSig*,
+                                               uint32_t index,
+                                               wasm::ModuleOrigin,
+                                               wasm::UseTrapHandler);
 
 // Creates a code object calling a wasm function with the given signature,
 // callable from JS.
-// TODO(clemensh): Remove the {UseTrapHandler} parameter to make js-to-wasm
-// wrappers sharable across instances.
-V8_EXPORT_PRIVATE MaybeHandle<Code> CompileJSToWasmWrapper(
-    Isolate*, const wasm::NativeModule*, wasm::FunctionSig*, bool is_import,
-    wasm::UseTrapHandler);
+V8_EXPORT_PRIVATE MaybeHandle<Code> CompileJSToWasmWrapper(Isolate*,
+                                                           wasm::FunctionSig*,
+                                                           bool is_import);
 
 // Compiles a stub that redirects a call to a wasm function to the wasm
 // interpreter. It's ABI compatible with the compiled wasm function.
 MaybeHandle<Code> CompileWasmInterpreterEntry(Isolate*, uint32_t func_index,
                                               wasm::FunctionSig*);
 
-// Helper function to get the offset into a fixed array for a given {index}.
-// TODO(titzer): access-builder.h is not accessible outside compiler. Move?
-int FixedArrayOffsetMinusTag(uint32_t index);
-
 enum CWasmEntryParameters {
-  kCodeObject,
+  kCodeEntry,
   kWasmInstance,
   kArgumentsBuffer,
   // marker:
@@ -164,12 +176,14 @@ class WasmGraphBuilder {
   Node* Unop(wasm::WasmOpcode opcode, Node* input,
              wasm::WasmCodePosition position = wasm::kNoCodePosition);
   Node* GrowMemory(Node* input);
-  Node* Throw(uint32_t tag, const wasm::WasmException* exception,
+  Node* Throw(uint32_t exception_index, const wasm::WasmException* exception,
               const Vector<Node*> values);
-  Node* Rethrow();
-  Node* ConvertExceptionTagToRuntimeId(uint32_t tag);
-  Node* GetExceptionRuntimeId();
-  Node** GetExceptionValues(const wasm::WasmException* except_decl);
+  Node* Rethrow(Node* except_obj);
+  Node* ExceptionTagEqual(Node* caught_tag, Node* expected_tag);
+  Node* LoadExceptionTagFromTable(uint32_t exception_index);
+  Node* GetExceptionTag(Node* except_obj);
+  Node** GetExceptionValues(Node* except_obj,
+                            const wasm::WasmException* except_decl);
   bool IsPhiWithMerge(Node* phi, Node* merge);
   bool ThrowsException(Node* node, Node** if_success, Node** if_exception);
   void AppendToMerge(Node* merge, Node* from);
@@ -370,10 +384,10 @@ class WasmGraphBuilder {
   Node* BuildWasmCall(wasm::FunctionSig* sig, Node** args, Node*** rets,
                       wasm::WasmCodePosition position, Node* instance_node,
                       UseRetpoline use_retpoline);
-  Node* BuildImportWasmCall(wasm::FunctionSig* sig, Node** args, Node*** rets,
-                            wasm::WasmCodePosition position, int func_index);
-  Node* BuildImportWasmCall(wasm::FunctionSig* sig, Node** args, Node*** rets,
-                            wasm::WasmCodePosition position, Node* func_index);
+  Node* BuildImportCall(wasm::FunctionSig* sig, Node** args, Node*** rets,
+                        wasm::WasmCodePosition position, int func_index);
+  Node* BuildImportCall(wasm::FunctionSig* sig, Node** args, Node*** rets,
+                        wasm::WasmCodePosition position, Node* func_index);
 
   Node* BuildF32CopySign(Node* left, Node* right);
   Node* BuildF64CopySign(Node* left, Node* right);
@@ -436,8 +450,6 @@ class WasmGraphBuilder {
   Node* BuildSmiShiftBitsConstant();
   Node* BuildChangeSmiToInt32(Node* value);
 
-  Node* BuildLoadInstanceFromExportedFunction(Node* closure);
-
   // Asm.js specific functionality.
   Node* BuildI32AsmjsSConvertF32(Node* input);
   Node* BuildI32AsmjsSConvertF64(Node* input);
@@ -451,7 +463,8 @@ class WasmGraphBuilder {
   Node* BuildAsmjsStoreMem(MachineType type, Node* index, Node* val);
 
   uint32_t GetExceptionEncodedSize(const wasm::WasmException* exception) const;
-  void BuildEncodeException32BitValue(uint32_t* index, Node* value);
+  void BuildEncodeException32BitValue(Node* except_obj, uint32_t* index,
+                                      Node* value);
   Node* BuildDecodeException32BitValue(Node* const* values, uint32_t* index);
 
   Node** Realloc(Node* const* buffer, size_t old_count, size_t new_count) {
@@ -460,7 +473,7 @@ class WasmGraphBuilder {
     return buf;
   }
 
-  void SetNeedsStackCheck() { needs_stack_check_ = true; }
+  Node* BuildLoadBuiltinFromInstance(int builtin_index);
 
   //-----------------------------------------------------------------------
   // Operations involving the CEntry, a dependency we want to remove
@@ -471,10 +484,6 @@ class WasmGraphBuilder {
 
   Node* BuildCallToRuntimeWithContext(Runtime::FunctionId f, Node* js_context,
                                       Node** parameters, int parameter_count);
-  Node* BuildCallToRuntimeWithContextFromJS(Runtime::FunctionId f,
-                                            Node* js_context,
-                                            Node* const* parameters,
-                                            int parameter_count);
   TrapId GetTrapIdForTrap(wasm::TrapReason reason);
 };
 
diff --git a/deps/v8/src/compiler/x64/code-generator-x64.cc b/deps/v8/src/compiler/x64/code-generator-x64.cc
index 2ccb56907d..178d2b33b9 100644
--- a/deps/v8/src/compiler/x64/code-generator-x64.cc
+++ b/deps/v8/src/compiler/x64/code-generator-x64.cc
@@ -353,7 +353,6 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
 
 }  // namespace
 
-
 #define ASSEMBLE_UNOP(asm_instr)         \
   do {                                   \
     if (instr->Output()->IsRegister()) { \
@@ -361,7 +360,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     } else {                             \
       __ asm_instr(i.OutputOperand());   \
     }                                    \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_BINOP(asm_instr)                                     \
   do {                                                                \
@@ -384,7 +383,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
         }                                                             \
       }                                                               \
     }                                                                 \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_COMPARE(asm_instr)                                   \
   do {                                                                \
@@ -411,7 +410,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
         }                                                             \
       }                                                               \
     }                                                                 \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_MULT(asm_instr)                              \
   do {                                                        \
@@ -430,8 +429,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
         __ asm_instr(i.OutputRegister(), i.InputOperand(1));  \
       }                                                       \
     }                                                         \
-  } while (0)
-
+  } while (false)
 
 #define ASSEMBLE_SHIFT(asm_instr, width)                                   \
   do {                                                                     \
@@ -448,8 +446,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
         __ asm_instr##_cl(i.OutputOperand());                              \
       }                                                                    \
     }                                                                      \
-  } while (0)
-
+  } while (false)
 
 #define ASSEMBLE_MOVX(asm_instr)                            \
   do {                                                      \
@@ -460,7 +457,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     } else {                                                \
       __ asm_instr(i.OutputRegister(), i.InputOperand(0));  \
     }                                                       \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_SSE_BINOP(asm_instr)                                   \
   do {                                                                  \
@@ -469,7 +466,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     } else {                                                            \
       __ asm_instr(i.InputDoubleRegister(0), i.InputOperand(1));        \
     }                                                                   \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_SSE_UNOP(asm_instr)                                    \
   do {                                                                  \
@@ -478,7 +475,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     } else {                                                            \
       __ asm_instr(i.OutputDoubleRegister(), i.InputOperand(0));        \
     }                                                                   \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_AVX_BINOP(asm_instr)                                  \
   do {                                                                 \
@@ -490,7 +487,7 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
       __ asm_instr(i.OutputDoubleRegister(), i.InputDoubleRegister(0), \
                    i.InputOperand(1));                                 \
     }                                                                  \
-  } while (0)
+  } while (false)
 
 #define ASSEMBLE_IEEE754_BINOP(name)                                     \
   do {                                                                   \
@@ -2140,6 +2137,25 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ insertps(i.OutputSimd128Register(), i.InputDoubleRegister(2), select);
       break;
     }
+    case kX64F32x4SConvertI32x4: {
+      __ cvtdq2ps(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kX64F32x4UConvertI32x4: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      DCHECK_NE(i.OutputSimd128Register(), kScratchDoubleReg);
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      __ pxor(kScratchDoubleReg, kScratchDoubleReg);      // zeros
+      __ pblendw(kScratchDoubleReg, dst, 0x55);           // get lo 16 bits
+      __ psubd(dst, kScratchDoubleReg);                   // get hi 16 bits
+      __ cvtdq2ps(kScratchDoubleReg, kScratchDoubleReg);  // convert lo exactly
+      __ psrld(dst, 1);                  // divide by 2 to get in unsigned range
+      __ cvtdq2ps(dst, dst);             // convert hi exactly
+      __ addps(dst, dst);                // double hi, exactly
+      __ addps(dst, kScratchDoubleReg);  // add hi and lo, may round.
+      break;
+    }
     case kX64F32x4Abs: {
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(0);
@@ -2248,6 +2264,36 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
+    case kX64I32x4SConvertF32x4: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      XMMRegister dst = i.OutputSimd128Register();
+      // NAN->0
+      __ movaps(kScratchDoubleReg, dst);
+      __ cmpeqps(kScratchDoubleReg, kScratchDoubleReg);
+      __ pand(dst, kScratchDoubleReg);
+      // Set top bit if >= 0 (but not -0.0!)
+      __ pxor(kScratchDoubleReg, dst);
+      // Convert
+      __ cvttps2dq(dst, dst);
+      // Set top bit if >=0 is now < 0
+      __ pand(kScratchDoubleReg, dst);
+      __ psrad(kScratchDoubleReg, 31);
+      // Set positive overflow lanes to 0x7FFFFFFF
+      __ pxor(dst, kScratchDoubleReg);
+      break;
+    }
+    case kX64I32x4SConvertI16x8Low: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      __ pmovsxwd(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kX64I32x4SConvertI16x8High: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      __ palignr(dst, i.InputSimd128Register(0), 8);
+      __ pmovsxwd(dst, dst);
+      break;
+    }
     case kX64I32x4Neg: {
       CpuFeatureScope sse_scope(tasm(), SSSE3);
       XMMRegister dst = i.OutputSimd128Register();
@@ -2319,6 +2365,46 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ pcmpeqd(dst, src);
       break;
     }
+    case kX64I32x4UConvertF32x4: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      XMMRegister tmp = i.ToSimd128Register(instr->TempAt(0));
+      // NAN->0, negative->0
+      __ pxor(kScratchDoubleReg, kScratchDoubleReg);
+      __ maxps(dst, kScratchDoubleReg);
+      // scratch: float representation of max_signed
+      __ pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
+      __ psrld(kScratchDoubleReg, 1);                     // 0x7fffffff
+      __ cvtdq2ps(kScratchDoubleReg, kScratchDoubleReg);  // 0x4f000000
+      // tmp: convert (src-max_signed).
+      // Positive overflow lanes -> 0x7FFFFFFF
+      // Negative lanes -> 0
+      __ movaps(tmp, dst);
+      __ subps(tmp, kScratchDoubleReg);
+      __ cmpleps(kScratchDoubleReg, tmp);
+      __ cvttps2dq(tmp, tmp);
+      __ pxor(tmp, kScratchDoubleReg);
+      __ pxor(kScratchDoubleReg, kScratchDoubleReg);
+      __ pmaxsd(tmp, kScratchDoubleReg);
+      // convert. Overflow lanes above max_signed will be 0x80000000
+      __ cvttps2dq(dst, dst);
+      // Add (src-max_signed) for overflow lanes.
+      __ paddd(dst, tmp);
+      break;
+    }
+    case kX64I32x4UConvertI16x8Low: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      __ pmovzxwd(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kX64I32x4UConvertI16x8High: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      __ palignr(dst, i.InputSimd128Register(0), 8);
+      __ pmovzxwd(dst, dst);
+      break;
+    }
     case kX64I32x4ShrU: {
       __ psrld(i.OutputSimd128Register(), i.InputInt8(1));
       break;
@@ -2380,6 +2466,18 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
+    case kX64I16x8SConvertI8x16Low: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      __ pmovsxbw(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kX64I16x8SConvertI8x16High: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      __ palignr(dst, i.InputSimd128Register(0), 8);
+      __ pmovsxbw(dst, dst);
+      break;
+    }
     case kX64I16x8Neg: {
       CpuFeatureScope sse_scope(tasm(), SSSE3);
       XMMRegister dst = i.OutputSimd128Register();
@@ -2401,6 +2499,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ psraw(i.OutputSimd128Register(), i.InputInt8(1));
       break;
     }
+    case kX64I16x8SConvertI32x4: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      __ packssdw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      break;
+    }
     case kX64I16x8Add: {
       __ paddw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
@@ -2459,10 +2562,34 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ pcmpeqw(dst, src);
       break;
     }
+    case kX64I16x8UConvertI8x16Low: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      __ pmovzxbw(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kX64I16x8UConvertI8x16High: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      __ palignr(dst, i.InputSimd128Register(0), 8);
+      __ pmovzxbw(dst, dst);
+      break;
+    }
     case kX64I16x8ShrU: {
       __ psrlw(i.OutputSimd128Register(), i.InputInt8(1));
       break;
     }
+    case kX64I16x8UConvertI32x4: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      // Change negative lanes to 0x7FFFFFFF
+      __ pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
+      __ psrld(kScratchDoubleReg, 1);
+      __ pminud(dst, kScratchDoubleReg);
+      __ pminud(kScratchDoubleReg, i.InputSimd128Register(1));
+      __ packusdw(dst, kScratchDoubleReg);
+      break;
+    }
     case kX64I16x8AddSaturateU: {
       __ paddusw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
@@ -2524,6 +2651,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
+    case kX64I8x16SConvertI16x8: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      __ packsswb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      break;
+    }
     case kX64I8x16Neg: {
       CpuFeatureScope sse_scope(tasm(), SSSE3);
       XMMRegister dst = i.OutputSimd128Register();
@@ -2585,6 +2717,18 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ pcmpeqb(dst, src);
       break;
     }
+    case kX64I8x16UConvertI16x8: {
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      // Change negative lanes to 0x7FFF
+      __ pcmpeqw(kScratchDoubleReg, kScratchDoubleReg);
+      __ psrlw(kScratchDoubleReg, 1);
+      __ pminuw(dst, kScratchDoubleReg);
+      __ pminuw(kScratchDoubleReg, i.InputSimd128Register(1));
+      __ packuswb(dst, kScratchDoubleReg);
+      break;
+    }
     case kX64I8x16AddSaturateU: {
       __ paddusb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
@@ -2656,8 +2800,44 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ xorps(dst, i.InputSimd128Register(2));
       break;
     }
+    case kX64S1x4AnyTrue:
+    case kX64S1x8AnyTrue:
+    case kX64S1x16AnyTrue: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      Register dst = i.OutputRegister();
+      XMMRegister src = i.InputSimd128Register(0);
+      Register tmp = i.TempRegister(0);
+      __ xorq(tmp, tmp);
+      __ movq(dst, Immediate(-1));
+      __ ptest(src, src);
+      __ cmovq(zero, dst, tmp);
+      break;
+    }
+    case kX64S1x4AllTrue:
+    case kX64S1x8AllTrue:
+    case kX64S1x16AllTrue: {
+      CpuFeatureScope sse_scope(tasm(), SSE4_1);
+      Register dst = i.OutputRegister();
+      XMMRegister src = i.InputSimd128Register(0);
+      Register tmp = i.TempRegister(0);
+      __ movq(tmp, Immediate(-1));
+      __ xorq(dst, dst);
+      // Compare all src lanes to false.
+      __ pxor(kScratchDoubleReg, kScratchDoubleReg);
+      if (arch_opcode == kX64S1x4AllTrue) {
+        __ pcmpeqd(kScratchDoubleReg, src);
+      } else if (arch_opcode == kX64S1x8AllTrue) {
+        __ pcmpeqw(kScratchDoubleReg, src);
+      } else {
+        __ pcmpeqb(kScratchDoubleReg, src);
+      }
+      // If kScratchDoubleReg is all zero, none of src lanes are false.
+      __ ptest(kScratchDoubleReg, kScratchDoubleReg);
+      __ cmovq(zero, dst, tmp);
+      break;
+    }
     case kX64StackCheck:
-      __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
+      __ CompareRoot(rsp, RootIndex::kStackLimit);
       break;
     case kWord32AtomicExchangeInt8: {
       __ xchgb(i.InputRegister(0), i.MemoryOperand(1));
@@ -3273,7 +3453,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         break;
       case Constant::kHeapObject: {
         Handle<HeapObject> src_object = src.ToHeapObject();
-        Heap::RootListIndex index;
+        RootIndex index;
         if (IsMaterializableFromRoot(src_object, &index)) {
           __ LoadRoot(dst, index);
         } else {
@@ -3281,6 +3461,11 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         }
         break;
       }
+      case Constant::kDelayedStringConstant: {
+        const StringConstantBase* src_constant = src.ToDelayedStringConstant();
+        __ MoveStringConstant(dst, src_constant);
+        break;
+      }
       case Constant::kRpoNumber:
         UNREACHABLE();  // TODO(dcarney): load of labels on x64.
         break;
diff --git a/deps/v8/src/compiler/x64/instruction-codes-x64.h b/deps/v8/src/compiler/x64/instruction-codes-x64.h
index 6a9e313f4e..c2a194e94a 100644
--- a/deps/v8/src/compiler/x64/instruction-codes-x64.h
+++ b/deps/v8/src/compiler/x64/instruction-codes-x64.h
@@ -151,6 +151,8 @@ namespace compiler {
   V(X64F32x4Splat)                        \
   V(X64F32x4ExtractLane)                  \
   V(X64F32x4ReplaceLane)                  \
+  V(X64F32x4SConvertI32x4)                \
+  V(X64F32x4UConvertI32x4)                \
   V(X64F32x4Abs)                          \
   V(X64F32x4Neg)                          \
   V(X64F32x4RecipApprox)                  \
@@ -168,6 +170,9 @@ namespace compiler {
   V(X64I32x4Splat)                        \
   V(X64I32x4ExtractLane)                  \
   V(X64I32x4ReplaceLane)                  \
+  V(X64I32x4SConvertF32x4)                \
+  V(X64I32x4SConvertI16x8Low)             \
+  V(X64I32x4SConvertI16x8High)            \
   V(X64I32x4Neg)                          \
   V(X64I32x4Shl)                          \
   V(X64I32x4ShrS)                         \
@@ -181,6 +186,9 @@ namespace compiler {
   V(X64I32x4Ne)                           \
   V(X64I32x4GtS)                          \
   V(X64I32x4GeS)                          \
+  V(X64I32x4UConvertF32x4)                \
+  V(X64I32x4UConvertI16x8Low)             \
+  V(X64I32x4UConvertI16x8High)            \
   V(X64I32x4ShrU)                         \
   V(X64I32x4MinU)                         \
   V(X64I32x4MaxU)                         \
@@ -189,9 +197,12 @@ namespace compiler {
   V(X64I16x8Splat)                        \
   V(X64I16x8ExtractLane)                  \
   V(X64I16x8ReplaceLane)                  \
+  V(X64I16x8SConvertI8x16Low)             \
+  V(X64I16x8SConvertI8x16High)            \
   V(X64I16x8Neg)                          \
   V(X64I16x8Shl)                          \
   V(X64I16x8ShrS)                         \
+  V(X64I16x8SConvertI32x4)                \
   V(X64I16x8Add)                          \
   V(X64I16x8AddSaturateS)                 \
   V(X64I16x8AddHoriz)                     \
@@ -204,7 +215,10 @@ namespace compiler {
   V(X64I16x8Ne)                           \
   V(X64I16x8GtS)                          \
   V(X64I16x8GeS)                          \
+  V(X64I16x8UConvertI8x16Low)             \
+  V(X64I16x8UConvertI8x16High)            \
   V(X64I16x8ShrU)                         \
+  V(X64I16x8UConvertI32x4)                \
   V(X64I16x8AddSaturateU)                 \
   V(X64I16x8SubSaturateU)                 \
   V(X64I16x8MinU)                         \
@@ -214,6 +228,7 @@ namespace compiler {
   V(X64I8x16Splat)                        \
   V(X64I8x16ExtractLane)                  \
   V(X64I8x16ReplaceLane)                  \
+  V(X64I8x16SConvertI16x8)                \
   V(X64I8x16Neg)                          \
   V(X64I8x16Add)                          \
   V(X64I8x16AddSaturateS)                 \
@@ -225,6 +240,7 @@ namespace compiler {
   V(X64I8x16Ne)                           \
   V(X64I8x16GtS)                          \
   V(X64I8x16GeS)                          \
+  V(X64I8x16UConvertI16x8)                \
   V(X64I8x16AddSaturateU)                 \
   V(X64I8x16SubSaturateU)                 \
   V(X64I8x16MinU)                         \
@@ -237,6 +253,12 @@ namespace compiler {
   V(X64S128Not)                           \
   V(X64S128Select)                        \
   V(X64S128Zero)                          \
+  V(X64S1x4AnyTrue)                       \
+  V(X64S1x4AllTrue)                       \
+  V(X64S1x8AnyTrue)                       \
+  V(X64S1x8AllTrue)                       \
+  V(X64S1x16AnyTrue)                      \
+  V(X64S1x16AllTrue)                      \
   V(X64Word64AtomicLoadUint8)             \
   V(X64Word64AtomicLoadUint16)            \
   V(X64Word64AtomicLoadUint32)            \
diff --git a/deps/v8/src/compiler/x64/instruction-scheduler-x64.cc b/deps/v8/src/compiler/x64/instruction-scheduler-x64.cc
index b1f380badf..e5523fd49d 100644
--- a/deps/v8/src/compiler/x64/instruction-scheduler-x64.cc
+++ b/deps/v8/src/compiler/x64/instruction-scheduler-x64.cc
@@ -128,6 +128,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64F32x4Splat:
     case kX64F32x4ExtractLane:
     case kX64F32x4ReplaceLane:
+    case kX64F32x4SConvertI32x4:
+    case kX64F32x4UConvertI32x4:
     case kX64F32x4RecipApprox:
     case kX64F32x4RecipSqrtApprox:
     case kX64F32x4Abs:
@@ -145,6 +147,9 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I32x4Splat:
     case kX64I32x4ExtractLane:
     case kX64I32x4ReplaceLane:
+    case kX64I32x4SConvertF32x4:
+    case kX64I32x4SConvertI16x8Low:
+    case kX64I32x4SConvertI16x8High:
     case kX64I32x4Neg:
     case kX64I32x4Shl:
     case kX64I32x4ShrS:
@@ -158,6 +163,9 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I32x4Ne:
     case kX64I32x4GtS:
     case kX64I32x4GeS:
+    case kX64I32x4UConvertF32x4:
+    case kX64I32x4UConvertI16x8Low:
+    case kX64I32x4UConvertI16x8High:
     case kX64I32x4ShrU:
     case kX64I32x4MinU:
     case kX64I32x4MaxU:
@@ -166,9 +174,12 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I16x8Splat:
     case kX64I16x8ExtractLane:
     case kX64I16x8ReplaceLane:
+    case kX64I16x8SConvertI8x16Low:
+    case kX64I16x8SConvertI8x16High:
     case kX64I16x8Neg:
     case kX64I16x8Shl:
     case kX64I16x8ShrS:
+    case kX64I16x8SConvertI32x4:
     case kX64I16x8Add:
     case kX64I16x8AddSaturateS:
     case kX64I16x8AddHoriz:
@@ -181,6 +192,9 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I16x8Ne:
     case kX64I16x8GtS:
     case kX64I16x8GeS:
+    case kX64I16x8UConvertI8x16Low:
+    case kX64I16x8UConvertI8x16High:
+    case kX64I16x8UConvertI32x4:
     case kX64I16x8ShrU:
     case kX64I16x8AddSaturateU:
     case kX64I16x8SubSaturateU:
@@ -191,6 +205,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I8x16Splat:
     case kX64I8x16ExtractLane:
     case kX64I8x16ReplaceLane:
+    case kX64I8x16SConvertI16x8:
     case kX64I8x16Neg:
     case kX64I8x16Add:
     case kX64I8x16AddSaturateS:
@@ -202,6 +217,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I8x16Ne:
     case kX64I8x16GtS:
     case kX64I8x16GeS:
+    case kX64I8x16UConvertI16x8:
     case kX64I8x16AddSaturateU:
     case kX64I8x16SubSaturateU:
     case kX64I8x16MinU:
@@ -214,6 +230,12 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64S128Not:
     case kX64S128Select:
     case kX64S128Zero:
+    case kX64S1x4AnyTrue:
+    case kX64S1x4AllTrue:
+    case kX64S1x8AnyTrue:
+    case kX64S1x8AllTrue:
+    case kX64S1x16AnyTrue:
+    case kX64S1x16AllTrue:
       return (instr->addressing_mode() == kMode_None)
           ? kNoOpcodeFlags
           : kIsLoadOperation | kHasSideEffect;
diff --git a/deps/v8/src/compiler/x64/instruction-selector-x64.cc b/deps/v8/src/compiler/x64/instruction-selector-x64.cc
index b5d7fa6d55..211794ace8 100644
--- a/deps/v8/src/compiler/x64/instruction-selector-x64.cc
+++ b/deps/v8/src/compiler/x64/instruction-selector-x64.cc
@@ -1273,6 +1273,7 @@ void VisitFloatUnop(InstructionSelector* selector, Node* node, Node* input,
   V(Float64Sqrt, kSSEFloat64Sqrt)                                        \
   V(Float32Sqrt, kSSEFloat32Sqrt)                                        \
   V(ChangeFloat64ToInt32, kSSEFloat64ToInt32)                            \
+  V(ChangeFloat64ToInt64, kSSEFloat64ToInt64)                            \
   V(ChangeFloat64ToUint32, kSSEFloat64ToUint32 | MiscField::encode(1))   \
   V(TruncateFloat64ToUint32, kSSEFloat64ToUint32 | MiscField::encode(0)) \
   V(ChangeFloat64ToUint64, kSSEFloat64ToUint64)                          \
@@ -1281,6 +1282,7 @@ void VisitFloatUnop(InstructionSelector* selector, Node* node, Node* input,
   V(TruncateFloat32ToInt32, kSSEFloat32ToInt32)                          \
   V(TruncateFloat32ToUint32, kSSEFloat32ToUint32)                        \
   V(ChangeInt32ToFloat64, kSSEInt32ToFloat64)                            \
+  V(ChangeInt64ToFloat64, kSSEInt64ToFloat64)                            \
   V(ChangeUint32ToFloat64, kSSEUint32ToFloat64)                          \
   V(RoundFloat64ToInt32, kSSEFloat64ToInt32)                             \
   V(RoundInt32ToFloat32, kSSEInt32ToFloat32)                             \
@@ -1665,6 +1667,17 @@ void VisitWordCompare(InstructionSelector* selector, Node* node,
   Node* left = node->InputAt(0);
   Node* right = node->InputAt(1);
 
+  // The 32-bit comparisons automatically truncate Word64
+  // values to Word32 range, no need to do that explicitly.
+  if (opcode == kX64Cmp32 || opcode == kX64Test32) {
+    while (left->opcode() == IrOpcode::kTruncateInt64ToInt32) {
+      left = left->InputAt(0);
+    }
+    while (right->opcode() == IrOpcode::kTruncateInt64ToInt32) {
+      right = right->InputAt(0);
+    }
+  }
+
   opcode = TryNarrowOpcodeSize(opcode, left, right, cont);
 
   // If one of the two inputs is an immediate, make sure it's on the right, or
@@ -1708,7 +1721,7 @@ void VisitWord64Compare(InstructionSelector* selector, Node* node,
   X64OperandGenerator g(selector);
   if (selector->CanUseRootsRegister()) {
     Heap* const heap = selector->isolate()->heap();
-    Heap::RootListIndex root_index;
+    RootIndex root_index;
     HeapObjectBinopMatcher m(node);
     if (m.right().HasValue() &&
         heap->IsRootHandle(m.right().Value(), &root_index)) {
@@ -2483,6 +2496,7 @@ VISIT_ATOMIC_BINOP(Xor)
   V(I32x4MaxU)             \
   V(I32x4GtU)              \
   V(I32x4GeU)              \
+  V(I16x8SConvertI32x4)    \
   V(I16x8Add)              \
   V(I16x8AddSaturateS)     \
   V(I16x8AddHoriz)         \
@@ -2501,6 +2515,7 @@ VISIT_ATOMIC_BINOP(Xor)
   V(I16x8MaxU)             \
   V(I16x8GtU)              \
   V(I16x8GeU)              \
+  V(I8x16SConvertI16x8)    \
   V(I8x16Add)              \
   V(I8x16AddSaturateS)     \
   V(I8x16Sub)              \
@@ -2521,14 +2536,23 @@ VISIT_ATOMIC_BINOP(Xor)
   V(S128Or)                \
   V(S128Xor)
 
-#define SIMD_UNOP_LIST(V) \
-  V(F32x4Abs)             \
-  V(F32x4Neg)             \
-  V(F32x4RecipApprox)     \
-  V(F32x4RecipSqrtApprox) \
-  V(I32x4Neg)             \
-  V(I16x8Neg)             \
-  V(I8x16Neg)             \
+#define SIMD_UNOP_LIST(V)   \
+  V(F32x4SConvertI32x4)     \
+  V(F32x4Abs)               \
+  V(F32x4Neg)               \
+  V(F32x4RecipApprox)       \
+  V(F32x4RecipSqrtApprox)   \
+  V(I32x4SConvertI16x8Low)  \
+  V(I32x4SConvertI16x8High) \
+  V(I32x4Neg)               \
+  V(I32x4UConvertI16x8Low)  \
+  V(I32x4UConvertI16x8High) \
+  V(I16x8SConvertI8x16Low)  \
+  V(I16x8SConvertI8x16High) \
+  V(I16x8Neg)               \
+  V(I16x8UConvertI8x16Low)  \
+  V(I16x8UConvertI8x16High) \
+  V(I8x16Neg)               \
   V(S128Not)
 
 #define SIMD_SHIFT_OPCODES(V) \
@@ -2539,6 +2563,16 @@ VISIT_ATOMIC_BINOP(Xor)
   V(I16x8ShrS)                \
   V(I16x8ShrU)
 
+#define SIMD_ANYTRUE_LIST(V) \
+  V(S1x4AnyTrue)             \
+  V(S1x8AnyTrue)             \
+  V(S1x16AnyTrue)
+
+#define SIMD_ALLTRUE_LIST(V) \
+  V(S1x4AllTrue)             \
+  V(S1x8AllTrue)             \
+  V(S1x16AllTrue)
+
 void InstructionSelector::VisitS128Zero(Node* node) {
   X64OperandGenerator g(this);
   Emit(kX64S128Zero, g.DefineAsRegister(node), g.DefineAsRegister(node));
@@ -2583,6 +2617,7 @@ SIMD_TYPES(VISIT_SIMD_REPLACE_LANE)
   }
 SIMD_SHIFT_OPCODES(VISIT_SIMD_SHIFT)
 #undef VISIT_SIMD_SHIFT
+#undef SIMD_SHIFT_OPCODES
 
 #define VISIT_SIMD_UNOP(Opcode)                         \
   void InstructionSelector::Visit##Opcode(Node* node) { \
@@ -2592,6 +2627,7 @@ SIMD_SHIFT_OPCODES(VISIT_SIMD_SHIFT)
   }
 SIMD_UNOP_LIST(VISIT_SIMD_UNOP)
 #undef VISIT_SIMD_UNOP
+#undef SIMD_UNOP_LIST
 
 #define VISIT_SIMD_BINOP(Opcode)                                            \
   void InstructionSelector::Visit##Opcode(Node* node) {                     \
@@ -2601,10 +2637,30 @@ SIMD_UNOP_LIST(VISIT_SIMD_UNOP)
   }
 SIMD_BINOP_LIST(VISIT_SIMD_BINOP)
 #undef VISIT_SIMD_BINOP
-#undef SIMD_TYPES
 #undef SIMD_BINOP_LIST
-#undef SIMD_UNOP_LIST
-#undef SIMD_SHIFT_OPCODES
+
+#define VISIT_SIMD_ANYTRUE(Opcode)                                        \
+  void InstructionSelector::Visit##Opcode(Node* node) {                   \
+    X64OperandGenerator g(this);                                          \
+    InstructionOperand temps[] = {g.TempRegister()};                      \
+    Emit(kX64##Opcode, g.DefineAsRegister(node),                          \
+         g.UseUniqueRegister(node->InputAt(0)), arraysize(temps), temps); \
+  }
+SIMD_ANYTRUE_LIST(VISIT_SIMD_ANYTRUE)
+#undef VISIT_SIMD_ANYTRUE
+#undef SIMD_ANYTRUE_LIST
+
+#define VISIT_SIMD_ALLTRUE(Opcode)                                        \
+  void InstructionSelector::Visit##Opcode(Node* node) {                   \
+    X64OperandGenerator g(this);                                          \
+    InstructionOperand temps[] = {g.TempRegister()};                      \
+    Emit(kX64##Opcode, g.DefineAsRegister(node),                          \
+         g.UseUniqueRegister(node->InputAt(0)), arraysize(temps), temps); \
+  }
+SIMD_ALLTRUE_LIST(VISIT_SIMD_ALLTRUE)
+#undef VISIT_SIMD_ALLTRUE
+#undef SIMD_ALLTRUE_LIST
+#undef SIMD_TYPES
 
 void InstructionSelector::VisitS128Select(Node* node) {
   X64OperandGenerator g(this);
@@ -2613,6 +2669,36 @@ void InstructionSelector::VisitS128Select(Node* node) {
        g.UseRegister(node->InputAt(2)));
 }
 
+void InstructionSelector::VisitF32x4UConvertI32x4(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kX64F32x4UConvertI32x4, g.DefineSameAsFirst(node),
+       g.UseRegister(node->InputAt(0)));
+}
+
+void InstructionSelector::VisitI32x4SConvertF32x4(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kX64I32x4SConvertF32x4, g.DefineSameAsFirst(node),
+       g.UseRegister(node->InputAt(0)));
+}
+
+void InstructionSelector::VisitI32x4UConvertF32x4(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kX64I32x4UConvertF32x4, g.DefineSameAsFirst(node),
+       g.UseRegister(node->InputAt(0)));
+}
+
+void InstructionSelector::VisitI16x8UConvertI32x4(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kX64I16x8UConvertI32x4, g.DefineSameAsFirst(node),
+       g.UseRegister(node->InputAt(0)), g.UseRegister(node->InputAt(1)));
+}
+
+void InstructionSelector::VisitI8x16UConvertI16x8(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kX64I8x16UConvertI16x8, g.DefineSameAsFirst(node),
+       g.UseRegister(node->InputAt(0)), g.UseRegister(node->InputAt(1)));
+}
+
 void InstructionSelector::VisitInt32AbsWithOverflow(Node* node) {
   UNREACHABLE();
 }
diff --git a/deps/v8/src/contexts-inl.h b/deps/v8/src/contexts-inl.h
index 3470ff99d7..2194c6bf9b 100644
--- a/deps/v8/src/contexts-inl.h
+++ b/deps/v8/src/contexts-inl.h
@@ -99,6 +99,10 @@ bool Context::IsDebugEvaluateContext() const {
   return map()->instance_type() == DEBUG_EVALUATE_CONTEXT_TYPE;
 }
 
+bool Context::IsAwaitContext() const {
+  return map()->instance_type() == AWAIT_CONTEXT_TYPE;
+}
+
 bool Context::IsBlockContext() const {
   return map()->instance_type() == BLOCK_CONTEXT_TYPE;
 }
diff --git a/deps/v8/src/contexts.h b/deps/v8/src/contexts.h
index 709ae6164a..f33c8b16bc 100644
--- a/deps/v8/src/contexts.h
+++ b/deps/v8/src/contexts.h
@@ -10,6 +10,8 @@
 namespace v8 {
 namespace internal {
 
+class JSGlobalObject;
+class JSGlobalProxy;
 class NativeContext;
 class RegExpMatchInfo;
 
@@ -71,47 +73,45 @@ enum ContextLookupFlags {
   V(ASYNC_GENERATOR_AWAIT_CAUGHT, JSFunction, async_generator_await_caught) \
   V(ASYNC_GENERATOR_AWAIT_UNCAUGHT, JSFunction, async_generator_await_uncaught)
 
-#define NATIVE_CONTEXT_IMPORTED_FIELDS(V)                                      \
-  V(ARRAY_SHIFT_INDEX, JSFunction, array_shift)                                \
-  V(ARRAY_SPLICE_INDEX, JSFunction, array_splice)                              \
-  V(ARRAY_UNSHIFT_INDEX, JSFunction, array_unshift)                            \
-  V(ARRAY_ENTRIES_ITERATOR_INDEX, JSFunction, array_entries_iterator)          \
-  V(ARRAY_FOR_EACH_ITERATOR_INDEX, JSFunction, array_for_each_iterator)        \
-  V(ARRAY_KEYS_ITERATOR_INDEX, JSFunction, array_keys_iterator)                \
-  V(ARRAY_VALUES_ITERATOR_INDEX, JSFunction, array_values_iterator)            \
-  V(CANONICALIZE_LOCALE_LIST_FUNCTION_INDEX, JSFunction,                       \
-    canonicalize_locale_list)                                                  \
-  V(ERROR_FUNCTION_INDEX, JSFunction, error_function)                          \
-  V(ERROR_TO_STRING, JSFunction, error_to_string)                              \
-  V(EVAL_ERROR_FUNCTION_INDEX, JSFunction, eval_error_function)                \
-  V(GLOBAL_EVAL_FUN_INDEX, JSFunction, global_eval_fun)                        \
-  V(GLOBAL_PROXY_FUNCTION_INDEX, JSFunction, global_proxy_function)            \
-  V(MAP_DELETE_INDEX, JSFunction, map_delete)                                  \
-  V(MAP_GET_INDEX, JSFunction, map_get)                                        \
-  V(MAP_HAS_INDEX, JSFunction, map_has)                                        \
-  V(MAP_SET_INDEX, JSFunction, map_set)                                        \
-  V(FUNCTION_HAS_INSTANCE_INDEX, JSFunction, function_has_instance)            \
-  V(OBJECT_VALUE_OF, JSFunction, object_value_of)                              \
-  V(OBJECT_TO_STRING, JSFunction, object_to_string)                            \
-  V(PROMISE_CATCH_INDEX, JSFunction, promise_catch)                            \
-  V(PROMISE_FUNCTION_INDEX, JSFunction, promise_function)                      \
-  V(RANGE_ERROR_FUNCTION_INDEX, JSFunction, range_error_function)              \
-  V(REFERENCE_ERROR_FUNCTION_INDEX, JSFunction, reference_error_function)      \
-  V(CACHED_OR_NEW_SERVICE_LOCALE_FUNCTION_INDEX, JSFunction,                   \
-    cached_or_new_service)                                                     \
-  V(RESOLVE_LOCALE_FUNCTION_INDEX, JSFunction, resolve_locale)                 \
-  V(SET_ADD_INDEX, JSFunction, set_add)                                        \
-  V(SET_DELETE_INDEX, JSFunction, set_delete)                                  \
-  V(SET_HAS_INDEX, JSFunction, set_has)                                        \
-  V(SYNTAX_ERROR_FUNCTION_INDEX, JSFunction, syntax_error_function)            \
-  V(TYPE_ERROR_FUNCTION_INDEX, JSFunction, type_error_function)                \
-  V(URI_ERROR_FUNCTION_INDEX, JSFunction, uri_error_function)                  \
-  V(WASM_COMPILE_ERROR_FUNCTION_INDEX, JSFunction,                             \
-    wasm_compile_error_function)                                               \
-  V(WASM_LINK_ERROR_FUNCTION_INDEX, JSFunction, wasm_link_error_function)      \
-  V(WASM_RUNTIME_ERROR_FUNCTION_INDEX, JSFunction,                             \
-    wasm_runtime_error_function)                                               \
-  V(WEAKMAP_SET_INDEX, JSFunction, weakmap_set)                                \
+#define NATIVE_CONTEXT_IMPORTED_FIELDS(V)                                 \
+  V(ARRAY_ENTRIES_ITERATOR_INDEX, JSFunction, array_entries_iterator)     \
+  V(ARRAY_FOR_EACH_ITERATOR_INDEX, JSFunction, array_for_each_iterator)   \
+  V(ARRAY_KEYS_ITERATOR_INDEX, JSFunction, array_keys_iterator)           \
+  V(ARRAY_VALUES_ITERATOR_INDEX, JSFunction, array_values_iterator)       \
+  V(CANONICALIZE_LOCALE_LIST_FUNCTION_INDEX, JSFunction,                  \
+    canonicalize_locale_list)                                             \
+  V(ERROR_FUNCTION_INDEX, JSFunction, error_function)                     \
+  V(ERROR_TO_STRING, JSFunction, error_to_string)                         \
+  V(EVAL_ERROR_FUNCTION_INDEX, JSFunction, eval_error_function)           \
+  V(GLOBAL_EVAL_FUN_INDEX, JSFunction, global_eval_fun)                   \
+  V(GLOBAL_PROXY_FUNCTION_INDEX, JSFunction, global_proxy_function)       \
+  V(MAP_DELETE_INDEX, JSFunction, map_delete)                             \
+  V(MAP_GET_INDEX, JSFunction, map_get)                                   \
+  V(MAP_HAS_INDEX, JSFunction, map_has)                                   \
+  V(MAP_SET_INDEX, JSFunction, map_set)                                   \
+  V(FUNCTION_HAS_INSTANCE_INDEX, JSFunction, function_has_instance)       \
+  V(OBJECT_VALUE_OF, JSFunction, object_value_of)                         \
+  V(OBJECT_TO_STRING, JSFunction, object_to_string)                       \
+  V(PROMISE_CATCH_INDEX, JSFunction, promise_catch)                       \
+  V(PROMISE_FUNCTION_INDEX, JSFunction, promise_function)                 \
+  V(RANGE_ERROR_FUNCTION_INDEX, JSFunction, range_error_function)         \
+  V(REFERENCE_ERROR_FUNCTION_INDEX, JSFunction, reference_error_function) \
+  V(CACHED_OR_NEW_SERVICE_LOCALE_FUNCTION_INDEX, JSFunction,              \
+    cached_or_new_service)                                                \
+  V(RESOLVE_LOCALE_FUNCTION_INDEX, JSFunction, resolve_locale)            \
+  V(SET_ADD_INDEX, JSFunction, set_add)                                   \
+  V(SET_DELETE_INDEX, JSFunction, set_delete)                             \
+  V(SET_HAS_INDEX, JSFunction, set_has)                                   \
+  V(SYNTAX_ERROR_FUNCTION_INDEX, JSFunction, syntax_error_function)       \
+  V(TYPE_ERROR_FUNCTION_INDEX, JSFunction, type_error_function)           \
+  V(URI_ERROR_FUNCTION_INDEX, JSFunction, uri_error_function)             \
+  V(WASM_COMPILE_ERROR_FUNCTION_INDEX, JSFunction,                        \
+    wasm_compile_error_function)                                          \
+  V(WASM_LINK_ERROR_FUNCTION_INDEX, JSFunction, wasm_link_error_function) \
+  V(WASM_RUNTIME_ERROR_FUNCTION_INDEX, JSFunction,                        \
+    wasm_runtime_error_function)                                          \
+  V(WEAKMAP_SET_INDEX, JSFunction, weakmap_set)                           \
+  V(WEAKMAP_GET_INDEX, JSFunction, weakmap_get)                           \
   V(WEAKSET_ADD_INDEX, JSFunction, weakset_add)
 
 #define NATIVE_CONTEXT_FIELDS(V)                                               \
@@ -194,6 +194,9 @@ enum ContextLookupFlags {
   V(INITIAL_MAP_PROTOTYPE_MAP_INDEX, Map, initial_map_prototype_map)           \
   V(INITIAL_OBJECT_PROTOTYPE_INDEX, JSObject, initial_object_prototype)        \
   V(INITIAL_SET_PROTOTYPE_MAP_INDEX, Map, initial_set_prototype_map)           \
+  V(INITIAL_STRING_ITERATOR_MAP_INDEX, Map, initial_string_iterator_map)       \
+  V(INITIAL_STRING_ITERATOR_PROTOTYPE_INDEX, JSObject,                         \
+    initial_string_iterator_prototype)                                         \
   V(INITIAL_STRING_PROTOTYPE_INDEX, JSObject, initial_string_prototype)        \
   V(INITIAL_WEAKMAP_PROTOTYPE_MAP_INDEX, Map, initial_weakmap_prototype_map)   \
   V(INITIAL_WEAKSET_PROTOTYPE_MAP_INDEX, Map, initial_weakset_prototype_map)   \
@@ -204,21 +207,13 @@ enum ContextLookupFlags {
   V(ITERATOR_RESULT_MAP_INDEX, Map, iterator_result_map)                       \
   V(INTL_DATE_TIME_FORMAT_FUNCTION_INDEX, JSFunction,                          \
     intl_date_time_format_function)                                            \
-  V(INTL_DATE_FORMAT_INTERNAL_FORMAT_SHARED_FUN, SharedFunctionInfo,           \
-    date_format_internal_format_shared_fun)                                    \
   V(INTL_NUMBER_FORMAT_FUNCTION_INDEX, JSFunction,                             \
     intl_number_format_function)                                               \
-  V(INTL_NUMBER_FORMAT_INTERNAL_FORMAT_NUMBER_SHARED_FUN, SharedFunctionInfo,  \
-    number_format_internal_format_number_shared_fun)                           \
   V(INTL_LOCALE_FUNCTION_INDEX, JSFunction, intl_locale_function)              \
   V(INTL_COLLATOR_FUNCTION_INDEX, JSFunction, intl_collator_function)          \
-  V(INTL_COLLATOR_INTERNAL_COMPARE_SHARED_FUN, SharedFunctionInfo,             \
-    collator_internal_compare_shared_fun)                                      \
   V(INTL_PLURAL_RULES_FUNCTION_INDEX, JSFunction, intl_plural_rules_function)  \
   V(INTL_V8_BREAK_ITERATOR_FUNCTION_INDEX, JSFunction,                         \
     intl_v8_break_iterator_function)                                           \
-  V(INTL_V8_BREAK_ITERATOR_INTERNAL_ADOPT_TEXT_SHARED_FUN, SharedFunctionInfo, \
-    break_iterator_internal_adopt_text_shared_fun)                             \
   V(JS_ARRAY_PACKED_SMI_ELEMENTS_MAP_INDEX, Map,                               \
     js_array_packed_smi_elements_map)                                          \
   V(JS_ARRAY_HOLEY_SMI_ELEMENTS_MAP_INDEX, Map,                                \
@@ -241,7 +236,8 @@ enum ContextLookupFlags {
   V(MAP_KEY_VALUE_ITERATOR_MAP_INDEX, Map, map_key_value_iterator_map)         \
   V(MAP_VALUE_ITERATOR_MAP_INDEX, Map, map_value_iterator_map)                 \
   V(MATH_RANDOM_INDEX_INDEX, Smi, math_random_index)                           \
-  V(MATH_RANDOM_CACHE_INDEX, Object, math_random_cache)                        \
+  V(MATH_RANDOM_STATE_INDEX, ByteArray, math_random_state)                     \
+  V(MATH_RANDOM_CACHE_INDEX, FixedDoubleArray, math_random_cache)              \
   V(MESSAGE_LISTENERS_INDEX, TemplateList, message_listeners)                  \
   V(NATIVES_UTILS_OBJECT_INDEX, Object, natives_utils_object)                  \
   V(NORMALIZED_MAP_CACHE_INDEX, Object, normalized_map_cache)                  \
@@ -337,9 +333,9 @@ enum ContextLookupFlags {
   V(CLASS_FUNCTION_MAP_INDEX, Map, class_function_map)                         \
   V(STRING_FUNCTION_INDEX, JSFunction, string_function)                        \
   V(STRING_FUNCTION_PROTOTYPE_MAP_INDEX, Map, string_function_prototype_map)   \
-  V(STRING_ITERATOR_MAP_INDEX, Map, string_iterator_map)                       \
   V(SYMBOL_FUNCTION_INDEX, JSFunction, symbol_function)                        \
   V(NATIVE_FUNCTION_MAP_INDEX, Map, native_function_map)                       \
+  V(WASM_EXCEPTION_CONSTRUCTOR_INDEX, JSFunction, wasm_exception_constructor)  \
   V(WASM_GLOBAL_CONSTRUCTOR_INDEX, JSFunction, wasm_global_constructor)        \
   V(WASM_INSTANCE_CONSTRUCTOR_INDEX, JSFunction, wasm_instance_constructor)    \
   V(WASM_MEMORY_CONSTRUCTOR_INDEX, JSFunction, wasm_memory_constructor)        \
@@ -446,11 +442,6 @@ class ScriptContextTable : public FixedArray {
 
 class Context : public FixedArray, public NeverReadOnlySpaceObject {
  public:
-  // Use the mixin methods over the HeapObject methods.
-  // TODO(v8:7786) Remove once the HeapObject methods are gone.
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   // Conversions.
   static inline Context* cast(Object* context);
 
@@ -462,7 +453,8 @@ class Context : public FixedArray, public NeverReadOnlySpaceObject {
     // The extension slot is used for either the global object (in native
     // contexts), eval extension object (function contexts), subject of with
     // (with contexts), or the variable name (catch contexts), the serialized
-    // scope info (block contexts), or the module instance (module contexts).
+    // scope info (block contexts), the module instance (module contexts), or
+    // the generator object (await contexts).
     EXTENSION_INDEX,
     NATIVE_CONTEXT_INDEX,
 
@@ -549,6 +541,7 @@ class Context : public FixedArray, public NeverReadOnlySpaceObject {
   inline bool IsCatchContext() const;
   inline bool IsWithContext() const;
   inline bool IsDebugEvaluateContext() const;
+  inline bool IsAwaitContext() const;
   inline bool IsBlockContext() const;
   inline bool IsModuleContext() const;
   inline bool IsEvalContext() const;
@@ -624,12 +617,7 @@ class Context : public FixedArray, public NeverReadOnlySpaceObject {
   static const int kSize = kHeaderSize + NATIVE_CONTEXT_SLOTS * kPointerSize;
   static const int kNotFound = -1;
 
-  // GC support.
-  typedef FixedBodyDescriptor<kHeaderSize, kSize, kSize> BodyDescriptor;
-
-  typedef FixedBodyDescriptor<
-      kHeaderSize, kHeaderSize + FIRST_WEAK_SLOT * kPointerSize, kSize>
-      BodyDescriptorWeak;
+  class BodyDescriptor;
 
  private:
 #ifdef DEBUG
diff --git a/deps/v8/src/conversions.cc b/deps/v8/src/conversions.cc
index baf8b3a6d5..ee40201544 100644
--- a/deps/v8/src/conversions.cc
+++ b/deps/v8/src/conversions.cc
@@ -30,8 +30,6 @@
 namespace v8 {
 namespace internal {
 
-namespace {
-
 inline double JunkStringValue() {
   return bit_cast<double, uint64_t>(kQuietNaNMask);
 }
@@ -194,7 +192,7 @@ class StringToIntHelper {
   // buffer of one-byte digits, along with an optional radix prefix.
   StringToIntHelper(Isolate* isolate, const uint8_t* subject, int length)
       : isolate_(isolate), raw_one_byte_subject_(subject), length_(length) {}
-  virtual ~StringToIntHelper() {}
+  virtual ~StringToIntHelper() = default;
 
  protected:
   // Subclasses must implement these:
@@ -462,13 +460,13 @@ class NumberParseIntHelper : public StringToIntHelper {
   }
 
  protected:
-  virtual void AllocateResult() {}
-  virtual void ResultMultiplyAdd(uint32_t multiplier, uint32_t part) {
+  void AllocateResult() override {}
+  void ResultMultiplyAdd(uint32_t multiplier, uint32_t part) override {
     result_ = result_ * multiplier + part;
   }
 
  private:
-  virtual void HandleSpecialCases() {
+  void HandleSpecialCases() override {
     bool is_power_of_two = base::bits::IsPowerOfTwo(radix());
     if (!is_power_of_two && radix() != 10) return;
     DisallowHeapAllocation no_gc;
@@ -812,8 +810,6 @@ parsing_done:
   return (sign == NEGATIVE) ? -converted : converted;
 }
 
-}  // namespace
-
 double StringToDouble(UnicodeCache* unicode_cache,
                       const char* str, int flags, double empty_string_val) {
   // We cast to const uint8_t* here to avoid instantiating the
@@ -911,7 +907,7 @@ class StringToBigIntHelper : public StringToIntHelper {
   }
 
  protected:
-  virtual void AllocateResult() {
+  void AllocateResult() override {
     // We have to allocate a BigInt that's big enough to fit the result.
     // Conseratively assume that all remaining digits are significant.
     // Optimization opportunity: Would it makes sense to scan for trailing
@@ -928,7 +924,7 @@ class StringToBigIntHelper : public StringToIntHelper {
     }
   }
 
-  virtual void ResultMultiplyAdd(uint32_t multiplier, uint32_t part) {
+  void ResultMultiplyAdd(uint32_t multiplier, uint32_t part) override {
     BigInt::InplaceMultiplyAdd(result_, static_cast<uintptr_t>(multiplier),
                                static_cast<uintptr_t>(part));
   }
diff --git a/deps/v8/src/counters.cc b/deps/v8/src/counters.cc
index bcea9e0f42..a4b08127cd 100644
--- a/deps/v8/src/counters.cc
+++ b/deps/v8/src/counters.cc
@@ -118,7 +118,8 @@ Counters::Counters(Isolate* isolate)
       STATS_COUNTER_TS_LIST(SC)
 #undef SC
       // clang format on
-      runtime_call_stats_() {
+      runtime_call_stats_(),
+      worker_thread_runtime_call_stats_() {
   static const struct {
     Histogram Counters::*member;
     const char* caption;
@@ -529,5 +530,64 @@ void RuntimeCallStats::Dump(v8::tracing::TracedValue* value) {
   in_use_ = false;
 }
 
+WorkerThreadRuntimeCallStats::WorkerThreadRuntimeCallStats()
+    : tls_key_(base::Thread::CreateThreadLocalKey()) {}
+
+WorkerThreadRuntimeCallStats::~WorkerThreadRuntimeCallStats() {
+  base::Thread::DeleteThreadLocalKey(tls_key_);
+}
+
+RuntimeCallStats* WorkerThreadRuntimeCallStats::NewTable() {
+  DCHECK(FLAG_runtime_stats);
+  std::unique_ptr<RuntimeCallStats> new_table =
+      base::make_unique<RuntimeCallStats>();
+  RuntimeCallStats* result = new_table.get();
+
+  base::LockGuard<base::Mutex> lock(&mutex_);
+  tables_.push_back(std::move(new_table));
+  return result;
+}
+
+void WorkerThreadRuntimeCallStats::AddToMainTable(
+    RuntimeCallStats* main_call_stats) {
+  base::LockGuard<base::Mutex> lock(&mutex_);
+  for (auto& worker_stats : tables_) {
+    DCHECK_NE(main_call_stats, worker_stats.get());
+    main_call_stats->Add(worker_stats.get());
+    worker_stats->Reset();
+  }
+}
+
+WorkerThreadRuntimeCallStatsScope::WorkerThreadRuntimeCallStatsScope(
+    WorkerThreadRuntimeCallStats* worker_stats)
+    : table_(nullptr) {
+  if (V8_LIKELY(!FLAG_runtime_stats)) return;
+
+  table_ = reinterpret_cast<RuntimeCallStats*>(
+      base::Thread::GetThreadLocal(worker_stats->GetKey()));
+  if (table_ == nullptr) {
+    table_ = worker_stats->NewTable();
+    base::Thread::SetThreadLocal(worker_stats->GetKey(), table_);
+  }
+
+  if (FLAG_runtime_stats &
+      v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING) {
+    table_->Reset();
+  }
+}
+
+WorkerThreadRuntimeCallStatsScope::~WorkerThreadRuntimeCallStatsScope() {
+  if (V8_LIKELY(table_ == nullptr)) return;
+
+  if ((FLAG_runtime_stats &
+       v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
+    auto value = v8::tracing::TracedValue::Create();
+    table_->Dump(value.get());
+    TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("v8.runtime_stats"),
+                         "V8.RuntimeStats", TRACE_EVENT_SCOPE_THREAD,
+                         "runtime-call-stats", std::move(value));
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/counters.h b/deps/v8/src/counters.h
index fed7edb44a..719bcc55e0 100644
--- a/deps/v8/src/counters.h
+++ b/deps/v8/src/counters.h
@@ -98,7 +98,7 @@ class StatsCounterBase {
   const char* name_;
   int* ptr_;
 
-  StatsCounterBase() {}
+  StatsCounterBase() = default;
   StatsCounterBase(Counters* counters, const char* name)
       : counters_(counters), name_(name), ptr_(nullptr) {}
 
@@ -161,7 +161,7 @@ class StatsCounter : public StatsCounterBase {
  private:
   friend class Counters;
 
-  StatsCounter() {}
+  StatsCounter() = default;
   StatsCounter(Counters* counters, const char* name)
       : StatsCounterBase(counters, name), lookup_done_(false) {}
 
@@ -227,7 +227,7 @@ class Histogram {
   }
 
  protected:
-  Histogram() {}
+  Histogram() = default;
   Histogram(const char* name, int min, int max, int num_buckets,
             Counters* counters)
       : name_(name),
@@ -277,7 +277,7 @@ class TimedHistogram : public Histogram {
   friend class Counters;
   HistogramTimerResolution resolution_;
 
-  TimedHistogram() {}
+  TimedHistogram() = default;
   TimedHistogram(const char* name, int min, int max,
                  HistogramTimerResolution resolution, int num_buckets,
                  Counters* counters)
@@ -393,7 +393,7 @@ class HistogramTimer : public TimedHistogram {
 
   base::ElapsedTimer timer_;
 
-  HistogramTimer() {}
+  HistogramTimer() = default;
 };
 
 // Helper class for scoping a HistogramTimer.
@@ -401,7 +401,7 @@ class HistogramTimer : public TimedHistogram {
 // Parser is currently reentrant (when it throws an error, we call back
 // into JavaScript and all bets are off), but ElapsedTimer is not
 // reentry-safe. Fix this properly and remove |allow_nesting|.
-class HistogramTimerScope BASE_EMBEDDED {
+class HistogramTimerScope {
  public:
   explicit HistogramTimerScope(HistogramTimer* timer,
                                bool allow_nesting = false)
@@ -439,7 +439,7 @@ enum class OptionalHistogramTimerScopeMode { TAKE_TIME, DONT_TAKE_TIME };
 
 // Helper class for scoping a HistogramTimer.
 // It will not take time if take_time is set to false.
-class OptionalHistogramTimerScope BASE_EMBEDDED {
+class OptionalHistogramTimerScope {
  public:
   OptionalHistogramTimerScope(HistogramTimer* timer,
                               OptionalHistogramTimerScopeMode mode)
@@ -487,7 +487,7 @@ class AggregatableHistogramTimer : public Histogram {
  private:
   friend class Counters;
 
-  AggregatableHistogramTimer() {}
+  AggregatableHistogramTimer() = default;
   AggregatableHistogramTimer(const char* name, int min, int max,
                              int num_buckets, Counters* counters)
       : Histogram(name, min, max, num_buckets, counters) {}
@@ -750,6 +750,9 @@ class RuntimeCallTimer final {
   V(Map_Has)                                               \
   V(Map_New)                                               \
   V(Map_Set)                                               \
+  V(WeakMap_Get)                                           \
+  V(WeakMap_Set)                                           \
+  V(WeakMap_New)                                           \
   V(Message_GetEndColumn)                                  \
   V(Message_GetLineNumber)                                 \
   V(Message_GetSourceLine)                                 \
@@ -867,7 +870,9 @@ class RuntimeCallTimer final {
   V(BoundFunctionNameGetter)                   \
   V(BoundFunctionLengthGetter)                 \
   V(CompileBackgroundAnalyse)                  \
+  V(CompileBackgroundCompileTask)              \
   V(CompileBackgroundEval)                     \
+  V(CompileBackgroundFunction)                 \
   V(CompileBackgroundIgnition)                 \
   V(CompileBackgroundScript)                   \
   V(CompileBackgroundRewriteReturnResult)      \
@@ -875,6 +880,9 @@ class RuntimeCallTimer final {
   V(CompileDeserialize)                        \
   V(CompileEval)                               \
   V(CompileAnalyse)                            \
+  V(CompileEnqueueOnDispatcher)                \
+  V(CompileFinalizeBackgroundCompileTask)      \
+  V(CompileFinishNowOnDispatcher)              \
   V(CompileFunction)                           \
   V(CompileGetFromOptimizedCodeMap)            \
   V(CompileIgnition)                           \
@@ -1023,7 +1031,7 @@ enum RuntimeCallCounterId {
                           kNumberOfCounters
 };
 
-class RuntimeCallStats final : public ZoneObject {
+class RuntimeCallStats final {
  public:
   V8_EXPORT_PRIVATE RuntimeCallStats();
 
@@ -1075,6 +1083,42 @@ class RuntimeCallStats final : public ZoneObject {
   RuntimeCallCounter counters_[kNumberOfCounters];
 };
 
+class WorkerThreadRuntimeCallStats final {
+ public:
+  WorkerThreadRuntimeCallStats();
+  ~WorkerThreadRuntimeCallStats();
+
+  // Returns the TLS key associated with this WorkerThreadRuntimeCallStats.
+  base::Thread::LocalStorageKey GetKey() const { return tls_key_; }
+
+  // Returns a new worker thread runtime call stats table managed by this
+  // WorkerThreadRuntimeCallStats.
+  RuntimeCallStats* NewTable();
+
+  // Adds the counters from the worker thread tables to |main_call_stats|.
+  void AddToMainTable(RuntimeCallStats* main_call_stats);
+
+ private:
+  base::Mutex mutex_;
+  std::vector<std::unique_ptr<RuntimeCallStats>> tables_;
+  base::Thread::LocalStorageKey tls_key_;
+};
+
+// Creating a WorkerThreadRuntimeCallStatsScope will provide a thread-local
+// runtime call stats table, and will dump the table to an immediate trace event
+// when it is destroyed.
+class WorkerThreadRuntimeCallStatsScope final {
+ public:
+  WorkerThreadRuntimeCallStatsScope(
+      WorkerThreadRuntimeCallStats* off_thread_stats);
+  ~WorkerThreadRuntimeCallStatsScope();
+
+  RuntimeCallStats* Get() const { return table_; }
+
+ private:
+  RuntimeCallStats* table_;
+};
+
 #define CHANGE_CURRENT_RUNTIME_COUNTER(runtime_call_stats, counter_id) \
   do {                                                                 \
     if (V8_UNLIKELY(FLAG_runtime_stats) && runtime_call_stats) {       \
@@ -1136,6 +1180,8 @@ class RuntimeCallTimerScope {
   HR(gc_finalize_mark, V8.GCFinalizeMC.Mark, 0, 10000, 101)                    \
   HR(gc_finalize_prologue, V8.GCFinalizeMC.Prologue, 0, 10000, 101)            \
   HR(gc_finalize_sweep, V8.GCFinalizeMC.Sweep, 0, 10000, 101)                  \
+  HR(gc_scavenger_scavenge_main, V8.GCScavenger.ScavengeMain, 0, 10000, 101)   \
+  HR(gc_scavenger_scavenge_roots, V8.GCScavenger.ScavengeRoots, 0, 10000, 101) \
   HR(scavenge_reason, V8.GCScavengeReason, 0, 21, 22)                          \
   HR(young_generation_handling, V8.GCYoungGenerationHandling, 0, 2, 3)         \
   /* Asm/Wasm. */                                                              \
@@ -1176,7 +1222,7 @@ class RuntimeCallTimerScope {
   HR(wasm_memory_allocation_result, V8.WasmMemoryAllocationResult, 0, 3, 4)    \
   HR(wasm_address_space_usage_mb, V8.WasmAddressSpaceUsageMiB, 0, 1 << 20,     \
      128)                                                                      \
-  HR(wasm_module_code_size_mb, V8.WasmModuleCodeSizeMiB, 0, 256, 64)
+  HR(wasm_module_code_size_mb, V8.WasmModuleCodeSizeMiB, 0, 1024, 64)
 
 #define HISTOGRAM_TIMER_LIST(HT)                                               \
   /* Garbage collection timers. */                                             \
@@ -1267,6 +1313,8 @@ class RuntimeCallTimerScope {
      V8.CompileScriptMicroSeconds.NoCache.CacheTooCold, 1000000, MICROSECOND)  \
   HT(compile_script_on_background,                                             \
      V8.CompileScriptMicroSeconds.BackgroundThread, 1000000, MICROSECOND)      \
+  HT(compile_function_on_background,                                           \
+     V8.CompileFunctionMicroSeconds.BackgroundThread, 1000000, MICROSECOND)    \
   HT(gc_parallel_task_latency, V8.GC.ParallelTaskLatencyMicroSeconds, 1000000, \
      MICROSECOND)
 
@@ -1518,6 +1566,10 @@ class Counters : public std::enable_shared_from_this<Counters> {
 
   RuntimeCallStats* runtime_call_stats() { return &runtime_call_stats_; }
 
+  WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats() {
+    return &worker_thread_runtime_call_stats_;
+  }
+
  private:
   friend class StatsTable;
   friend class StatsCounterBase;
@@ -1597,6 +1649,7 @@ class Counters : public std::enable_shared_from_this<Counters> {
 #undef SC
 
   RuntimeCallStats runtime_call_stats_;
+  WorkerThreadRuntimeCallStats worker_thread_runtime_call_stats_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Counters);
 };
diff --git a/deps/v8/src/d8-console.cc b/deps/v8/src/d8-console.cc
index cb7334af78..f08aa3bfae 100644
--- a/deps/v8/src/d8-console.cc
+++ b/deps/v8/src/d8-console.cc
@@ -39,16 +39,9 @@ D8Console::D8Console(Isolate* isolate) : isolate_(isolate) {
 
 void D8Console::Assert(const debug::ConsoleCallArguments& args,
                        const v8::debug::ConsoleContext&) {
-  Local<Boolean> arg;
-  if (args.Length() > 0) {
-    if (!args[0]->ToBoolean(isolate_->GetCurrentContext()).ToLocal(&arg)) {
-      return;
-    }
-  } else {
-    // No arguments given, the "first" argument is undefined which is false-ish.
-    arg = v8::False(isolate_);
-  }
-  if (arg->IsTrue()) return;
+  // If no arguments given, the "first" argument is undefined which is
+  // false-ish.
+  if (args.Length() > 0 && args[0]->BooleanValue(isolate_)) return;
   WriteToFile("console.assert", stdout, isolate_, args);
   isolate_->ThrowException(v8::Exception::Error(
       v8::String::NewFromUtf8(isolate_, "console.assert failed",
diff --git a/deps/v8/src/d8-posix.cc b/deps/v8/src/d8-posix.cc
index a1fc3b5782..57a8a0d5a5 100644
--- a/deps/v8/src/d8-posix.cc
+++ b/deps/v8/src/d8-posix.cc
@@ -204,7 +204,7 @@ class ExecArgs {
         return;
       }
       delete [] exec_args_[i];
-      exec_args_[i] = 0;
+      exec_args_[i] = nullptr;
     }
   }
   static const unsigned kMaxArgs = 1000;
diff --git a/deps/v8/src/d8.cc b/deps/v8/src/d8.cc
index 349021d38c..5295f3957c 100644
--- a/deps/v8/src/d8.cc
+++ b/deps/v8/src/d8.cc
@@ -62,7 +62,7 @@ namespace {
 
 const int kMB = 1024 * 1024;
 
-const int kMaxWorkers = 50;
+const int kMaxWorkers = 100;
 const int kMaxSerializerMemoryUsage =
     1 * kMB;  // Arbitrary maximum for testing.
 
@@ -118,23 +118,26 @@ class ShellArrayBufferAllocator : public ArrayBufferAllocatorBase {
     // store their lengths as a SMI internally.
     if (length >= kTwoGB) return nullptr;
 
-    size_t page_size = i::AllocatePageSize();
+    v8::PageAllocator* page_allocator = i::GetPlatformPageAllocator();
+    size_t page_size = page_allocator->AllocatePageSize();
     size_t allocated = RoundUp(length, page_size);
     // Rounding up could go over the limit.
     if (allocated >= kTwoGB) return nullptr;
-    return i::AllocatePages(nullptr, allocated, page_size,
+    return i::AllocatePages(page_allocator, nullptr, allocated, page_size,
                             PageAllocator::kReadWrite);
   }
 
   void FreeVM(void* data, size_t length) {
-    size_t page_size = i::AllocatePageSize();
+    v8::PageAllocator* page_allocator = i::GetPlatformPageAllocator();
+    size_t page_size = page_allocator->AllocatePageSize();
     size_t allocated = RoundUp(length, page_size);
-    CHECK(i::FreePages(data, allocated));
+    CHECK(i::FreePages(page_allocator, data, allocated));
   }
 };
 
 // ArrayBuffer allocator that never allocates over 10MB.
 class MockArrayBufferAllocator : public ArrayBufferAllocatorBase {
+ protected:
   void* Allocate(size_t length) override {
     return ArrayBufferAllocatorBase::Allocate(Adjust(length));
   }
@@ -154,6 +157,39 @@ class MockArrayBufferAllocator : public ArrayBufferAllocatorBase {
   }
 };
 
+// ArrayBuffer allocator that can be equipped with a limit to simulate system
+// OOM.
+class MockArrayBufferAllocatiorWithLimit : public MockArrayBufferAllocator {
+ public:
+  explicit MockArrayBufferAllocatiorWithLimit(size_t allocation_limit)
+      : space_left_(allocation_limit) {}
+
+ protected:
+  void* Allocate(size_t length) override {
+    if (length > space_left_) {
+      return nullptr;
+    }
+    space_left_ -= length;
+    return MockArrayBufferAllocator::Allocate(length);
+  }
+
+  void* AllocateUninitialized(size_t length) override {
+    if (length > space_left_) {
+      return nullptr;
+    }
+    space_left_ -= length;
+    return MockArrayBufferAllocator::AllocateUninitialized(length);
+  }
+
+  void Free(void* data, size_t length) override {
+    space_left_ += length;
+    return MockArrayBufferAllocator::Free(data, length);
+  }
+
+ private:
+  std::atomic<size_t> space_left_;
+};
+
 // Predictable v8::Platform implementation. Worker threads are disabled, idle
 // tasks are disallowed, and the time reported by {MonotonicallyIncreasingTime}
 // is deterministic.
@@ -195,12 +231,14 @@ class PredictablePlatform : public Platform {
   }
 
   void CallOnForegroundThread(v8::Isolate* isolate, Task* task) override {
-    platform_->CallOnForegroundThread(isolate, task);
+    // This is a deprecated function and should not be called anymore.
+    UNREACHABLE();
   }
 
   void CallDelayedOnForegroundThread(v8::Isolate* isolate, Task* task,
                                      double delay_in_seconds) override {
-    platform_->CallDelayedOnForegroundThread(isolate, task, delay_in_seconds);
+    // This is a deprecated function and should not be called anymore.
+    UNREACHABLE();
   }
 
   void CallIdleOnForegroundThread(Isolate* isolate, IdleTask* task) override {
@@ -244,6 +282,14 @@ static Local<Value> Throw(Isolate* isolate, const char* message) {
           .ToLocalChecked());
 }
 
+static Local<Value> GetValue(v8::Isolate* isolate, Local<Context> context,
+                             Local<v8::Object> object, const char* property) {
+  Local<String> v8_str =
+      String::NewFromUtf8(isolate, property, NewStringType::kNormal)
+          .ToLocalChecked();
+  return object->Get(context, v8_str).ToLocalChecked();
+}
+
 Worker* GetWorkerFromInternalField(Isolate* isolate, Local<Object> object) {
   if (object->InternalFieldCount() != 1) {
     Throw(isolate, "this is not a Worker");
@@ -319,8 +365,7 @@ class TraceConfigParser {
                          Local<v8::Object> object, const char* property) {
     Local<Value> value = GetValue(isolate, context, object, property);
     if (value->IsNumber()) {
-      Local<Boolean> v8_boolean = value->ToBoolean(context).ToLocalChecked();
-      return v8_boolean->Value();
+      return value->BooleanValue(isolate);
     }
     return false;
   }
@@ -361,14 +406,6 @@ class TraceConfigParser {
     }
     return platform::tracing::TraceRecordMode::RECORD_UNTIL_FULL;
   }
-
-  static Local<Value> GetValue(v8::Isolate* isolate, Local<Context> context,
-                               Local<v8::Object> object, const char* property) {
-    Local<String> v8_str =
-        String::NewFromUtf8(isolate, property, NewStringType::kNormal)
-            .ToLocalChecked();
-    return object->Get(context, v8_str).ToLocalChecked();
-  }
 };
 
 }  // namespace
@@ -433,7 +470,7 @@ class DummySourceStream : public v8::ScriptCompiler::ExternalSourceStream {
                       source_length_);
   }
 
-  virtual size_t GetMoreData(const uint8_t** src) {
+  size_t GetMoreData(const uint8_t** src) override {
     if (done_) {
       return 0;
     }
@@ -1405,6 +1442,39 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
     return;
   }
 
+  // d8 honors `options={type: string}`, which means the first argument is
+  // not a filename but string of script to be run.
+  bool load_from_file = true;
+  if (args.Length() > 1 && args[1]->IsObject()) {
+    Local<Object> object = args[1].As<Object>();
+    Local<Context> context = isolate->GetCurrentContext();
+    Local<Value> value = GetValue(args.GetIsolate(), context, object, "type");
+    if (value->IsString()) {
+      Local<String> worker_type = value->ToString(context).ToLocalChecked();
+      String::Utf8Value str(isolate, worker_type);
+      if (strcmp("string", *str) == 0) {
+        load_from_file = false;
+      } else if (strcmp("classic", *str) == 0) {
+        load_from_file = true;
+      } else {
+        Throw(args.GetIsolate(), "Unsupported worker type");
+        return;
+      }
+    }
+  }
+
+  Local<Value> source;
+  if (load_from_file) {
+    String::Utf8Value filename(args.GetIsolate(), args[0]);
+    source = ReadFile(args.GetIsolate(), *filename);
+    if (source.IsEmpty()) {
+      Throw(args.GetIsolate(), "Error loading worker script");
+      return;
+    }
+  } else {
+    source = args[0];
+  }
+
   if (!args.IsConstructCall()) {
     Throw(args.GetIsolate(), "Worker must be constructed with new");
     return;
@@ -1428,7 +1498,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
     args.Holder()->SetAlignedPointerInInternalField(0, worker);
     workers_.push_back(worker);
 
-    String::Utf8Value script(args.GetIsolate(), args[0]);
+    String::Utf8Value script(args.GetIsolate(), source);
     if (!*script) {
       Throw(args.GetIsolate(), "Can't get worker script");
       return;
@@ -2016,8 +2086,9 @@ void WriteLcovDataForRange(std::vector<uint32_t>& lines, int start_line,
 }
 
 void WriteLcovDataForNamedRange(std::ostream& sink,
-                                std::vector<uint32_t>& lines, std::string name,
-                                int start_line, int end_line, uint32_t count) {
+                                std::vector<uint32_t>& lines,
+                                const std::string& name, int start_line,
+                                int end_line, uint32_t count) {
   WriteLcovDataForRange(lines, start_line, end_line, count);
   sink << "FN:" << start_line + 1 << "," << name << std::endl;
   sink << "FNDA:" << count << "," << name << std::endl;
@@ -2295,7 +2366,7 @@ class InspectorFrontend final : public v8_inspector::V8Inspector::Channel {
     isolate_ = context->GetIsolate();
     context_.Reset(isolate_, context);
   }
-  virtual ~InspectorFrontend() = default;
+  ~InspectorFrontend() override = default;
 
  private:
   void sendResponse(
@@ -2904,6 +2975,8 @@ bool Shell::SetOptions(int argc, char* argv[]) {
 
   v8::V8::SetFlagsFromCommandLine(&argc, argv, true);
   options.mock_arraybuffer_allocator = i::FLAG_mock_arraybuffer_allocator;
+  options.mock_arraybuffer_allocator_limit =
+      i::FLAG_mock_arraybuffer_allocator_limit;
 
   // Set up isolated source groups.
   options.isolate_sources = new SourceGroup[options.num_isolates];
@@ -3001,10 +3074,15 @@ void Shell::SetWaitUntilDone(Isolate* isolate, bool value) {
 }
 
 namespace {
-bool ProcessMessages(Isolate* isolate,
-                     std::function<platform::MessageLoopBehavior()> behavior) {
+bool ProcessMessages(
+    Isolate* isolate,
+    const std::function<platform::MessageLoopBehavior()>& behavior) {
   Platform* platform = GetDefaultPlatform();
   while (true) {
+    i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+    i::SaveContext saved_context(i_isolate);
+    i_isolate->set_context(nullptr);
+    SealHandleScope shs(isolate);
     while (v8::platform::PumpMessageLoop(platform, isolate, behavior())) {
       isolate->RunMicrotasks();
     }
@@ -3156,6 +3234,14 @@ class Serializer : public ValueSerializer::Delegate {
           }
 
           Local<ArrayBuffer> array_buffer = Local<ArrayBuffer>::Cast(element);
+
+          if (std::find(array_buffers_.begin(), array_buffers_.end(),
+                        array_buffer) != array_buffers_.end()) {
+            Throw(isolate_,
+                  "ArrayBuffer occurs in the transfer array more than once");
+            return Nothing<bool>();
+          }
+
           serializer_.TransferArrayBuffer(
               static_cast<uint32_t>(array_buffers_.size()), array_buffer);
           array_buffers_.emplace_back(isolate_, array_buffer);
@@ -3344,6 +3430,12 @@ int Shell::Main(int argc, char* argv[]) {
     g_platform.reset(new PredictablePlatform(std::move(g_platform)));
   }
 
+  if (i::FLAG_trace_turbo_cfg_file == nullptr) {
+    SetFlagsFromString("--trace-turbo-cfg-file=turbo.cfg");
+  }
+  if (i::FLAG_redirect_code_traces_to == nullptr) {
+    SetFlagsFromString("--redirect-code-traces-to=code.asm");
+  }
   v8::V8::InitializePlatform(g_platform.get());
   v8::V8::Initialize();
   if (options.natives_blob || options.snapshot_blob) {
@@ -3352,18 +3444,22 @@ int Shell::Main(int argc, char* argv[]) {
   } else {
     v8::V8::InitializeExternalStartupData(argv[0]);
   }
-  if (i::FLAG_trace_turbo_cfg_file == nullptr) {
-    SetFlagsFromString("--trace-turbo-cfg-file=turbo.cfg");
-  }
-  if (i::FLAG_redirect_code_traces_to == nullptr) {
-    SetFlagsFromString("--redirect-code-traces-to=code.asm");
-  }
   int result = 0;
   Isolate::CreateParams create_params;
   ShellArrayBufferAllocator shell_array_buffer_allocator;
   MockArrayBufferAllocator mock_arraybuffer_allocator;
+  const size_t memory_limit =
+      options.mock_arraybuffer_allocator_limit * options.num_isolates;
+  MockArrayBufferAllocatiorWithLimit mock_arraybuffer_allocator_with_limit(
+      memory_limit >= options.mock_arraybuffer_allocator_limit
+          ? memory_limit
+          : std::numeric_limits<size_t>::max());
   if (options.mock_arraybuffer_allocator) {
-    Shell::array_buffer_allocator = &mock_arraybuffer_allocator;
+    if (memory_limit) {
+      Shell::array_buffer_allocator = &mock_arraybuffer_allocator_with_limit;
+    } else {
+      Shell::array_buffer_allocator = &mock_arraybuffer_allocator;
+    }
   } else {
     Shell::array_buffer_allocator = &shell_array_buffer_allocator;
   }
@@ -3454,6 +3550,7 @@ int Shell::Main(int argc, char* argv[]) {
           Shell::HostInitializeImportMetaObject);
       {
         D8Console console(isolate2);
+        Initialize(isolate2);
         debug::SetConsoleDelegate(isolate2, &console);
         PerIsolateData data(isolate2);
         Isolate::Scope isolate_scope(isolate2);
diff --git a/deps/v8/src/d8.h b/deps/v8/src/d8.h
index 2d60cb8327..29f693bcb0 100644
--- a/deps/v8/src/d8.h
+++ b/deps/v8/src/d8.h
@@ -105,9 +105,7 @@ class SourceGroup {
    public:
     explicit IsolateThread(SourceGroup* group);
 
-    virtual void Run() {
-      group_->ExecuteInThread();
-    }
+    void Run() override { group_->ExecuteInThread(); }
 
    private:
     SourceGroup* group_;
@@ -257,7 +255,7 @@ class Worker {
         : base::Thread(base::Thread::Options("WorkerThread")),
           worker_(worker) {}
 
-    virtual void Run() { worker_->ExecuteInThread(); }
+    void Run() override { worker_->ExecuteInThread(); }
 
    private:
     Worker* worker_;
@@ -369,6 +367,7 @@ class ShellOptions {
   bool test_shell;
   bool expected_to_throw;
   bool mock_arraybuffer_allocator;
+  size_t mock_arraybuffer_allocator_limit = 0;
   bool enable_inspector;
   int num_isolates;
   v8::ScriptCompiler::CompileOptions compile_options;
diff --git a/deps/v8/src/d8.js b/deps/v8/src/d8.js
index a5486ccd1e..9dfb966902 100644
--- a/deps/v8/src/d8.js
+++ b/deps/v8/src/d8.js
@@ -15,7 +15,7 @@ function JSProxyGetTarget(proxy) { };
 function JSProxyGetHandler(proxy) { };
 
 try {
-  isProxy = Function(['object'], 'return %_IsJSProxy(object)');
+  isProxy = Function(['object'], 'return %IsJSProxy(object)');
   JSProxyGetTarget = Function(['proxy'],
     'return %JSProxyGetTarget(proxy)');
   JSProxyGetHandler = Function(['proxy'],
diff --git a/deps/v8/src/date.cc b/deps/v8/src/date.cc
index d98d4f6f87..88a056b367 100644
--- a/deps/v8/src/date.cc
+++ b/deps/v8/src/date.cc
@@ -27,7 +27,7 @@ static const char kDaysInMonths[] =
     {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
 
 DateCache::DateCache()
-    : stamp_(0),
+    : stamp_(nullptr),
       tz_cache_(
 #ifdef V8_INTL_SUPPORT
           FLAG_icu_timezone_data ? new ICUTimezoneCache()
diff --git a/deps/v8/src/dateparser.h b/deps/v8/src/dateparser.h
index 709c1cbaf2..e26b8688f1 100644
--- a/deps/v8/src/dateparser.h
+++ b/deps/v8/src/dateparser.h
@@ -47,7 +47,7 @@ class DateParser : public AllStatic {
 
   // InputReader provides basic string parsing and character classification.
   template <typename Char>
-  class InputReader BASE_EMBEDDED {
+  class InputReader {
    public:
     InputReader(UnicodeCache* unicode_cache, Vector<Char> s)
         : index_(0),
@@ -268,7 +268,7 @@ class DateParser : public AllStatic {
     static const int8_t array[][kEntrySize];
   };
 
-  class TimeZoneComposer BASE_EMBEDDED {
+  class TimeZoneComposer {
    public:
     TimeZoneComposer() : sign_(kNone), hour_(kNone), minute_(kNone) {}
     void Set(int offset_in_hours) {
@@ -291,7 +291,7 @@ class DateParser : public AllStatic {
     int minute_;
   };
 
-  class TimeComposer BASE_EMBEDDED {
+  class TimeComposer {
    public:
     TimeComposer() : index_(0), hour_offset_(kNone) {}
     bool IsEmpty() const { return index_ == 0; }
@@ -325,7 +325,7 @@ class DateParser : public AllStatic {
     int hour_offset_;
   };
 
-  class DayComposer BASE_EMBEDDED {
+  class DayComposer {
    public:
     DayComposer() : index_(0), named_month_(kNone), is_iso_date_(false) {}
     bool IsEmpty() const { return index_ == 0; }
diff --git a/deps/v8/src/debug/debug-coverage.cc b/deps/v8/src/debug/debug-coverage.cc
index f8b716f7c9..57c5f31079 100644
--- a/deps/v8/src/debug/debug-coverage.cc
+++ b/deps/v8/src/debug/debug-coverage.cc
@@ -81,6 +81,11 @@ std::vector<CoverageBlock> GetSortedBlockData(SharedFunctionInfo* shared) {
   std::vector<CoverageBlock> result;
   if (coverage_info->SlotCount() == 0) return result;
 
+  if (FLAG_trace_block_coverage) {
+    PrintF("Collecting coverage data\n");
+    coverage_info->Print(shared->DebugName()->ToCString());
+  }
+
   for (int i = 0; i < coverage_info->SlotCount(); i++) {
     const int start_pos = coverage_info->StartSourcePosition(i);
     const int until_pos = coverage_info->EndSourcePosition(i);
@@ -171,12 +176,6 @@ class CoverageBlockIterator final {
     return function_->blocks[read_index_ + 1];
   }
 
-  CoverageBlock& GetPreviousBlock() {
-    DCHECK(IsActive());
-    DCHECK_GT(read_index_, 0);
-    return function_->blocks[read_index_ - 1];
-  }
-
   CoverageBlock& GetParent() {
     DCHECK(IsActive());
     return nesting_stack_.back();
@@ -331,30 +330,6 @@ void MergeNestedRanges(CoverageFunction* function) {
   }
 }
 
-void FilterAliasedSingletons(CoverageFunction* function) {
-  CoverageBlockIterator iter(function);
-
-  iter.Next();  // Advance once since we reference the previous block later.
-
-  while (iter.Next()) {
-    CoverageBlock& previous_block = iter.GetPreviousBlock();
-    CoverageBlock& block = iter.GetBlock();
-
-    bool is_singleton = block.end == kNoSourcePosition;
-    bool aliases_start = block.start == previous_block.start;
-
-    if (is_singleton && aliases_start) {
-      // The previous block must have a full range since duplicate singletons
-      // have already been merged.
-      DCHECK_NE(previous_block.end, kNoSourcePosition);
-      // Likewise, the next block must have another start position since
-      // singletons are sorted to the end.
-      DCHECK_IMPLIES(iter.HasNext(), iter.GetNextBlock().start != block.start);
-      iter.DeleteBlock();
-    }
-  }
-}
-
 void FilterUncoveredRanges(CoverageFunction* function) {
   CoverageBlockIterator iter(function);
 
@@ -427,15 +402,6 @@ void CollectBlockCoverage(CoverageFunction* function, SharedFunctionInfo* info,
   // Remove duplicate singleton ranges, keeping the max count.
   MergeDuplicateSingletons(function);
 
-  // Remove singleton ranges with the same start position as a full range and
-  // throw away their counts.
-  // Singleton ranges are only intended to split existing full ranges and should
-  // never expand into a full range. Consider 'if (cond) { ... } else { ... }'
-  // as a problematic example; if the then-block produces a continuation
-  // singleton, it would incorrectly expand into the else range.
-  // For more context, see https://crbug.com/v8/8237.
-  FilterAliasedSingletons(function);
-
   // Rewrite all singletons (created e.g. by continuations and unconditional
   // control flow) to ranges.
   RewritePositionSingletonsToRanges(function);
diff --git a/deps/v8/src/debug/debug-coverage.h b/deps/v8/src/debug/debug-coverage.h
index 359a813375..13816670f7 100644
--- a/deps/v8/src/debug/debug-coverage.h
+++ b/deps/v8/src/debug/debug-coverage.h
@@ -63,7 +63,7 @@ class Coverage : public std::vector<CoverageScript> {
   static std::unique_ptr<Coverage> Collect(
       Isolate* isolate, v8::debug::Coverage::Mode collectionMode);
 
-  Coverage() {}
+  Coverage() = default;
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/debug/debug-evaluate.cc b/deps/v8/src/debug/debug-evaluate.cc
index 583b41f1b2..98e4c58fb9 100644
--- a/deps/v8/src/debug/debug-evaluate.cc
+++ b/deps/v8/src/debug/debug-evaluate.cc
@@ -16,7 +16,6 @@
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/isolate-inl.h"
-#include "src/objects/api-callbacks.h"
 #include "src/snapshot/snapshot.h"
 
 namespace v8 {
@@ -140,25 +139,13 @@ MaybeHandle<Object> DebugEvaluate::Evaluate(
       Object);
 
   Handle<Object> result;
-  bool sucess = false;
+  bool success = false;
   if (throw_on_side_effect) isolate->debug()->StartSideEffectCheckMode();
-  sucess = Execution::Call(isolate, eval_fun, receiver, 0, nullptr)
-               .ToHandle(&result);
+  success = Execution::Call(isolate, eval_fun, receiver, 0, nullptr)
+                .ToHandle(&result);
   if (throw_on_side_effect) isolate->debug()->StopSideEffectCheckMode();
-  if (!sucess) {
-    DCHECK(isolate->has_pending_exception());
-    return MaybeHandle<Object>();
-  }
-
-  // Skip the global proxy as it has no properties and always delegates to the
-  // real global object.
-  if (result->IsJSGlobalProxy()) {
-    PrototypeIterator iter(isolate, Handle<JSGlobalProxy>::cast(result));
-    // TODO(verwaest): This will crash when the global proxy is detached.
-    result = PrototypeIterator::GetCurrent<JSObject>(iter);
-  }
-
-  return result;
+  if (!success) DCHECK(isolate->has_pending_exception());
+  return success ? result : MaybeHandle<Object>();
 }
 
 Handle<SharedFunctionInfo> DebugEvaluate::ContextBuilder::outer_info() const {
@@ -254,19 +241,17 @@ void DebugEvaluate::ContextBuilder::UpdateValues() {
 namespace {
 
 bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
-// Use macro to include both inlined and non-inlined version of an intrinsic.
+// Use macro to include only the non-inlined version of an intrinsic.
 #define INTRINSIC_WHITELIST(V)                \
   /* Conversions */                           \
   V(NumberToString)                           \
   V(ToBigInt)                                 \
-  V(ToInteger)                                \
   V(ToLength)                                 \
   V(ToNumber)                                 \
   V(ToObject)                                 \
   V(ToString)                                 \
   /* Type checks */                           \
   V(IsArray)                                  \
-  V(IsDate)                                   \
   V(IsFunction)                               \
   V(IsJSProxy)                                \
   V(IsJSReceiver)                             \
@@ -292,6 +277,7 @@ bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
   V(ReThrow)                                  \
   V(ThrowCalledNonCallable)                   \
   V(ThrowInvalidStringLength)                 \
+  V(ThrowIteratorError)                       \
   V(ThrowIteratorResultNotAnObject)           \
   V(ThrowReferenceError)                      \
   V(ThrowSymbolIteratorInvalid)               \
@@ -322,7 +308,6 @@ bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
   V(ArrayIndexOf)                             \
   V(ArrayIsArray)                             \
   V(ClassOf)                                  \
-  V(GenerateRandomNumbers)                    \
   V(GetFunctionName)                          \
   V(GetOwnPropertyDescriptor)                 \
   V(GlobalPrint)                              \
@@ -363,12 +348,16 @@ bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
   V(OptimizeOsr)                              \
   V(UnblockConcurrentRecompilation)
 
-#define CASE(Name)       \
-  case Runtime::k##Name: \
-  case Runtime::kInline##Name:
+// Intrinsics with inline versions have to be whitelisted here a second time.
+#define INLINE_INTRINSIC_WHITELIST(V) \
+  V(Call)                             \
+  V(IsJSReceiver)
 
+#define CASE(Name) case Runtime::k##Name:
+#define INLINE_CASE(Name) case Runtime::kInline##Name:
   switch (id) {
     INTRINSIC_WHITELIST(CASE)
+    INLINE_INTRINSIC_WHITELIST(INLINE_CASE)
     return true;
     default:
       if (FLAG_trace_side_effect_free_debug_evaluate) {
@@ -379,7 +368,9 @@ bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
   }
 
 #undef CASE
+#undef INLINE_CASE
 #undef INTRINSIC_WHITELIST
+#undef INLINE_INTRINSIC_WHITELIST
 }
 
 #ifdef DEBUG
@@ -389,24 +380,23 @@ bool BuiltinToIntrinsicHasNoSideEffect(Builtins::Name builtin_id,
   if (IntrinsicHasNoSideEffect(intrinsic_id)) return true;
 
 // Whitelist intrinsics called from specific builtins.
-#define BUILTIN_INTRINSIC_WHITELIST(V, W)                                 \
-  /* Arrays */                                                            \
-  V(Builtins::kArrayFilter, W(CreateDataProperty))                        \
-  V(Builtins::kArrayMap, W(CreateDataProperty))                           \
-  V(Builtins::kArrayPrototypeSlice, W(CreateDataProperty) W(SetProperty)) \
-  /* TypedArrays */                                                       \
-  V(Builtins::kTypedArrayConstructor,                                     \
-    W(TypedArrayCopyElements) W(ThrowInvalidTypedArrayAlignment))         \
-  V(Builtins::kTypedArrayPrototypeFilter, W(TypedArrayCopyElements))      \
-  V(Builtins::kTypedArrayPrototypeMap, W(SetProperty))
+#define BUILTIN_INTRINSIC_WHITELIST(V, W)                            \
+  /* Arrays */                                                       \
+  V(Builtins::kArrayFilter, W(CreateDataProperty))                   \
+  V(Builtins::kArrayMap, W(CreateDataProperty))                      \
+  V(Builtins::kArrayPrototypeSlice,                                  \
+    W(CreateDataProperty) W(SetKeyedProperty) W(SetNamedProperty))   \
+  /* TypedArrays */                                                  \
+  V(Builtins::kTypedArrayConstructor,                                \
+    W(TypedArrayCopyElements) W(ThrowInvalidTypedArrayAlignment))    \
+  V(Builtins::kTypedArrayPrototypeFilter, W(TypedArrayCopyElements)) \
+  V(Builtins::kTypedArrayPrototypeMap, W(SetKeyedProperty) W(SetNamedProperty))
 
 #define CASE(Builtin, ...) \
   case Builtin:            \
     return (__VA_ARGS__ false);
 
-#define MATCH(Intrinsic)                   \
-  intrinsic_id == Runtime::k##Intrinsic || \
-      intrinsic_id == Runtime::kInline##Intrinsic ||
+#define MATCH(Intrinsic) intrinsic_id == Runtime::k##Intrinsic ||
 
   switch (builtin_id) {
     BUILTIN_INTRINSIC_WHITELIST(CASE, MATCH)
@@ -433,6 +423,7 @@ bool BytecodeHasNoSideEffect(interpreter::Bytecode bytecode) {
     case Bytecode::kLdaLookupSlot:
     case Bytecode::kLdaGlobal:
     case Bytecode::kLdaNamedProperty:
+    case Bytecode::kLdaNamedPropertyNoFeedback:
     case Bytecode::kLdaKeyedProperty:
     case Bytecode::kLdaGlobalInsideTypeof:
     case Bytecode::kLdaLookupSlotInsideTypeof:
@@ -477,6 +468,7 @@ bool BytecodeHasNoSideEffect(interpreter::Bytecode bytecode) {
     // Literals.
     case Bytecode::kCreateArrayLiteral:
     case Bytecode::kCreateEmptyArrayLiteral:
+    case Bytecode::kCreateArrayFromIterable:
     case Bytecode::kCreateObjectLiteral:
     case Bytecode::kCreateEmptyObjectLiteral:
     case Bytecode::kCreateRegExpLiteral:
@@ -561,6 +553,7 @@ DebugInfo::SideEffectState BuiltinGetSideEffectState(Builtins::Name id) {
     case Builtins::kArrayPrototypeFlat:
     case Builtins::kArrayPrototypeFlatMap:
     case Builtins::kArrayPrototypeKeys:
+    case Builtins::kArrayPrototypeLastIndexOf:
     case Builtins::kArrayPrototypeSlice:
     case Builtins::kArrayPrototypeSort:
     case Builtins::kArrayForEach:
@@ -807,7 +800,10 @@ DebugInfo::SideEffectState BuiltinGetSideEffectState(Builtins::Name id) {
     case Builtins::kMakeURIError:
     // RegExp builtins.
     case Builtins::kRegExpConstructor:
+    // Internal.
+    case Builtins::kStrictPoisonPillThrower:
       return DebugInfo::kHasNoSideEffect;
+
     // Set builtins.
     case Builtins::kSetIteratorPrototypeNext:
     case Builtins::kSetPrototypeAdd:
@@ -819,6 +815,7 @@ DebugInfo::SideEffectState BuiltinGetSideEffectState(Builtins::Name id) {
     case Builtins::kArrayPrototypePush:
     case Builtins::kArrayPrototypeReverse:
     case Builtins::kArrayPrototypeShift:
+    case Builtins::kArrayPrototypeUnshift:
     case Builtins::kArraySplice:
     case Builtins::kArrayUnshift:
     // Map builtins.
@@ -851,6 +848,7 @@ bool BytecodeRequiresRuntimeCheck(interpreter::Bytecode bytecode) {
   typedef interpreter::Bytecode Bytecode;
   switch (bytecode) {
     case Bytecode::kStaNamedProperty:
+    case Bytecode::kStaNamedPropertyNoFeedback:
     case Bytecode::kStaNamedOwnProperty:
     case Bytecode::kStaKeyedProperty:
     case Bytecode::kStaInArrayLiteral:
@@ -962,34 +960,6 @@ DebugInfo::SideEffectState DebugEvaluate::FunctionGetSideEffectState(
 }
 
 // static
-bool DebugEvaluate::CallbackHasNoSideEffect(Object* callback_info) {
-  DisallowHeapAllocation no_gc;
-  if (callback_info->IsAccessorInfo()) {
-    // List of whitelisted internal accessors can be found in accessors.h.
-    AccessorInfo* info = AccessorInfo::cast(callback_info);
-    if (info->has_no_side_effect()) return true;
-    if (FLAG_trace_side_effect_free_debug_evaluate) {
-      PrintF("[debug-evaluate] API Callback '");
-      info->name()->ShortPrint();
-      PrintF("' may cause side effect.\n");
-    }
-  } else if (callback_info->IsInterceptorInfo()) {
-    InterceptorInfo* info = InterceptorInfo::cast(callback_info);
-    if (info->has_no_side_effect()) return true;
-    if (FLAG_trace_side_effect_free_debug_evaluate) {
-      PrintF("[debug-evaluate] API Interceptor may cause side effect.\n");
-    }
-  } else if (callback_info->IsCallHandlerInfo()) {
-    CallHandlerInfo* info = CallHandlerInfo::cast(callback_info);
-    if (info->IsSideEffectFreeCallHandlerInfo()) return true;
-    if (FLAG_trace_side_effect_free_debug_evaluate) {
-      PrintF("[debug-evaluate] API CallHandlerInfo may cause side effect.\n");
-    }
-  }
-  return false;
-}
-
-// static
 void DebugEvaluate::ApplySideEffectChecks(
     Handle<BytecodeArray> bytecode_array) {
   for (interpreter::BytecodeArrayIterator it(bytecode_array); !it.done();
diff --git a/deps/v8/src/debug/debug-evaluate.h b/deps/v8/src/debug/debug-evaluate.h
index 420c6c208b..470a4900a7 100644
--- a/deps/v8/src/debug/debug-evaluate.h
+++ b/deps/v8/src/debug/debug-evaluate.h
@@ -41,7 +41,6 @@ class DebugEvaluate : public AllStatic {
 
   static DebugInfo::SideEffectState FunctionGetSideEffectState(
       Isolate* isolate, Handle<SharedFunctionInfo> info);
-  static bool CallbackHasNoSideEffect(Object* callback_info);
   static void ApplySideEffectChecks(Handle<BytecodeArray> bytecode_array);
 
  private:
diff --git a/deps/v8/src/debug/debug-frames.cc b/deps/v8/src/debug/debug-frames.cc
index e474056107..a67ca5bc6b 100644
--- a/deps/v8/src/debug/debug-frames.cc
+++ b/deps/v8/src/debug/debug-frames.cc
@@ -51,6 +51,7 @@ FrameInspector::FrameInspector(StandardFrame* frame, int inlined_frame_index,
   }
 }
 
+// NOLINTNEXTLINE
 FrameInspector::~FrameInspector() {
   // Destructor needs to be defined in the .cc file, because it instantiates
   // std::unique_ptr destructors but the types are not known in the header.
diff --git a/deps/v8/src/debug/debug-frames.h b/deps/v8/src/debug/debug-frames.h
index 6a613dbae9..34f3226890 100644
--- a/deps/v8/src/debug/debug-frames.h
+++ b/deps/v8/src/debug/debug-frames.h
@@ -19,7 +19,7 @@ class FrameInspector {
   FrameInspector(StandardFrame* frame, int inlined_frame_index,
                  Isolate* isolate);
 
-  ~FrameInspector();
+  ~FrameInspector();  // NOLINT (modernize-use-equals-default)
 
   int GetParametersCount();
   Handle<JSFunction> GetFunction() const { return function_; }
diff --git a/deps/v8/src/debug/debug-interface.h b/deps/v8/src/debug/debug-interface.h
index ac8073e02c..14ccf2c20a 100644
--- a/deps/v8/src/debug/debug-interface.h
+++ b/deps/v8/src/debug/debug-interface.h
@@ -154,9 +154,11 @@ void GetLoadedScripts(Isolate* isolate, PersistentValueVector<Script>& scripts);
 MaybeLocal<UnboundScript> CompileInspectorScript(Isolate* isolate,
                                                  Local<String> source);
 
+enum ExceptionType { kException, kPromiseRejection };
+
 class DebugDelegate {
  public:
-  virtual ~DebugDelegate() {}
+  virtual ~DebugDelegate() = default;
   virtual void ScriptCompiled(v8::Local<Script> script, bool is_live_edited,
                               bool has_compile_error) {}
   // |inspector_break_points_hit| contains id of breakpoints installed with
@@ -166,8 +168,8 @@ class DebugDelegate {
       const std::vector<debug::BreakpointId>& inspector_break_points_hit) {}
   virtual void ExceptionThrown(v8::Local<v8::Context> paused_context,
                                v8::Local<v8::Value> exception,
-                               v8::Local<v8::Value> promise, bool is_uncaught) {
-  }
+                               v8::Local<v8::Value> promise, bool is_uncaught,
+                               ExceptionType exception_type) {}
   virtual bool IsFunctionBlackboxed(v8::Local<debug::Script> script,
                                     const debug::Location& start,
                                     const debug::Location& end) {
@@ -179,7 +181,7 @@ void SetDebugDelegate(Isolate* isolate, DebugDelegate* listener);
 
 class AsyncEventDelegate {
  public:
-  virtual ~AsyncEventDelegate() {}
+  virtual ~AsyncEventDelegate() = default;
   virtual void AsyncEventOccurred(debug::DebugAsyncActionType type, int id,
                                   bool is_blackboxed) = 0;
 };
@@ -502,6 +504,20 @@ class PostponeInterruptsScope {
   std::unique_ptr<i::PostponeInterruptsScope> scope_;
 };
 
+class WeakMap : public v8::Object {
+ public:
+  V8_WARN_UNUSED_RESULT v8::MaybeLocal<v8::Value> Get(
+      v8::Local<v8::Context> context, v8::Local<v8::Value> key);
+  V8_WARN_UNUSED_RESULT v8::MaybeLocal<WeakMap> Set(
+      v8::Local<v8::Context> context, v8::Local<v8::Value> key,
+      v8::Local<v8::Value> value);
+
+  static Local<WeakMap> New(v8::Isolate* isolate);
+  V8_INLINE static WeakMap* Cast(Value* obj);
+
+ private:
+  WeakMap();
+};
 }  // namespace debug
 }  // namespace v8
 
diff --git a/deps/v8/src/debug/debug-stack-trace-iterator.cc b/deps/v8/src/debug/debug-stack-trace-iterator.cc
index 14d2850b69..5f2d657194 100644
--- a/deps/v8/src/debug/debug-stack-trace-iterator.cc
+++ b/deps/v8/src/debug/debug-stack-trace-iterator.cc
@@ -35,7 +35,7 @@ DebugStackTraceIterator::DebugStackTraceIterator(Isolate* isolate, int index)
   for (; !Done() && index > 0; --index) Advance();
 }
 
-DebugStackTraceIterator::~DebugStackTraceIterator() {}
+DebugStackTraceIterator::~DebugStackTraceIterator() = default;
 
 bool DebugStackTraceIterator::Done() const { return iterator_.done(); }
 
@@ -117,7 +117,9 @@ v8::MaybeLocal<v8::Value> DebugStackTraceIterator::GetReceiver() const {
 
 v8::Local<v8::Value> DebugStackTraceIterator::GetReturnValue() const {
   DCHECK(!Done());
-  if (frame_inspector_->IsWasm()) return v8::Local<v8::Value>();
+  if (frame_inspector_ && frame_inspector_->IsWasm()) {
+    return v8::Local<v8::Value>();
+  }
   bool is_optimized = iterator_.frame()->is_optimized();
   if (is_optimized || !is_top_frame_ ||
       !isolate_->debug()->IsBreakAtReturn(iterator_.javascript_frame())) {
diff --git a/deps/v8/src/debug/debug-type-profile.h b/deps/v8/src/debug/debug-type-profile.h
index de18951381..0d2e88a7d5 100644
--- a/deps/v8/src/debug/debug-type-profile.h
+++ b/deps/v8/src/debug/debug-type-profile.h
@@ -36,7 +36,7 @@ class TypeProfile : public std::vector<TypeProfileScript> {
   static void SelectMode(Isolate* isolate, debug::TypeProfile::Mode mode);
 
  private:
-  TypeProfile() {}
+  TypeProfile() = default;
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/debug/debug.cc b/deps/v8/src/debug/debug.cc
index 3a3a48b699..8a5a9b6eb0 100644
--- a/deps/v8/src/debug/debug.cc
+++ b/deps/v8/src/debug/debug.cc
@@ -29,6 +29,7 @@
 #include "src/isolate-inl.h"
 #include "src/log.h"
 #include "src/messages.h"
+#include "src/objects/api-callbacks-inl.h"
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/js-generator-inl.h"
 #include "src/objects/js-promise-inl.h"
@@ -42,7 +43,7 @@ namespace internal {
 class Debug::TemporaryObjectsTracker : public HeapObjectAllocationTracker {
  public:
   TemporaryObjectsTracker() = default;
-  ~TemporaryObjectsTracker() = default;
+  ~TemporaryObjectsTracker() override = default;
 
   void AllocationEvent(Address addr, int) override { objects_.insert(addr); }
 
@@ -417,9 +418,6 @@ void Debug::Break(JavaScriptFrame* frame, Handle<JSFunction> break_target) {
 
   // Enter the debugger.
   DebugScope debug_scope(this);
-
-  // Postpone interrupt during breakpoint processing.
-  PostponeInterruptsScope postpone(isolate_);
   DisableBreak no_recursive_break(this);
 
   // Return if we fail to retrieve debug info.
@@ -1142,7 +1140,7 @@ class RedirectActiveFunctions : public ThreadVisitor {
     DCHECK(shared->HasBytecodeArray());
   }
 
-  void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
+  void VisitThread(Isolate* isolate, ThreadLocalTop* top) override {
     for (JavaScriptFrameIterator it(isolate, top); !it.done(); it.Advance()) {
       JavaScriptFrame* frame = it.frame();
       JSFunction* function = frame->function();
@@ -1165,9 +1163,9 @@ void Debug::DeoptimizeFunction(Handle<SharedFunctionInfo> shared) {
   // inlining.
   isolate_->AbortConcurrentOptimization(BlockingBehavior::kBlock);
 
-  // Make sure we abort incremental marking.
-  isolate_->heap()->CollectAllGarbage(Heap::kMakeHeapIterableMask,
-                                      GarbageCollectionReason::kDebugger);
+  // TODO(mlippautz): Try to remove this call.
+  isolate_->heap()->PreciseCollectAllGarbage(
+      Heap::kNoGCFlags, GarbageCollectionReason::kDebugger);
 
   bool found_something = false;
   Code::OptimizedCodeIterator iterator(isolate_);
@@ -1542,7 +1540,7 @@ void Debug::FindDebugInfo(Handle<DebugInfo> debug_info,
   UNREACHABLE();
 }
 
-void Debug::ClearAllDebugInfos(DebugInfoClearFunction clear_function) {
+void Debug::ClearAllDebugInfos(const DebugInfoClearFunction& clear_function) {
   DebugInfoListNode* prev = nullptr;
   DebugInfoListNode* current = debug_info_list_;
   while (current != nullptr) {
@@ -1625,7 +1623,7 @@ void Debug::ScheduleFrameRestart(StackFrame* frame) {
 }
 
 Handle<FixedArray> Debug::GetLoadedScripts() {
-  isolate_->heap()->CollectAllGarbage(Heap::kFinalizeIncrementalMarkingMask,
+  isolate_->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                       GarbageCollectionReason::kDebugger);
   Factory* factory = isolate_->factory();
   if (!factory->script_list()->IsWeakArrayList()) {
@@ -1655,7 +1653,10 @@ void Debug::OnThrow(Handle<Object> exception) {
     scheduled_exception = handle(isolate_->scheduled_exception(), isolate_);
     isolate_->clear_scheduled_exception();
   }
-  OnException(exception, isolate_->GetPromiseOnStackOnThrow());
+  Handle<Object> maybe_promise = isolate_->GetPromiseOnStackOnThrow();
+  OnException(exception, maybe_promise,
+              maybe_promise->IsJSPromise() ? v8::debug::kPromiseRejection
+                                           : v8::debug::kException);
   if (!scheduled_exception.is_null()) {
     isolate_->thread_local_top()->scheduled_exception_ = *scheduled_exception;
   }
@@ -1670,7 +1671,7 @@ void Debug::OnPromiseReject(Handle<Object> promise, Handle<Object> value) {
   if (!promise->IsJSObject() ||
       JSReceiver::GetDataProperty(Handle<JSObject>::cast(promise), key)
           ->IsUndefined(isolate_)) {
-    OnException(value, promise);
+    OnException(value, promise, v8::debug::kPromiseRejection);
   }
 }
 
@@ -1695,7 +1696,8 @@ bool Debug::IsFrameBlackboxed(JavaScriptFrame* frame) {
   return true;
 }
 
-void Debug::OnException(Handle<Object> exception, Handle<Object> promise) {
+void Debug::OnException(Handle<Object> exception, Handle<Object> promise,
+                        v8::debug::ExceptionType exception_type) {
   // TODO(kozyatinskiy): regress-662674.js test fails on arm without this.
   if (!AllowJavascriptExecution::IsAllowed(isolate_)) return;
 
@@ -1741,9 +1743,9 @@ void Debug::OnException(Handle<Object> exception, Handle<Object> promise) {
   DisableBreak no_recursive_break(this);
 
   Handle<Context> native_context(isolate_->native_context());
-  debug_delegate_->ExceptionThrown(v8::Utils::ToLocal(native_context),
-                                   v8::Utils::ToLocal(exception),
-                                   v8::Utils::ToLocal(promise), uncaught);
+  debug_delegate_->ExceptionThrown(
+      v8::Utils::ToLocal(native_context), v8::Utils::ToLocal(exception),
+      v8::Utils::ToLocal(promise), uncaught, exception_type);
 }
 
 void Debug::OnDebugBreak(Handle<FixedArray> break_points_hit) {
@@ -1758,8 +1760,8 @@ void Debug::OnDebugBreak(Handle<FixedArray> break_points_hit) {
 #endif  // DEBUG
 
   if (!debug_delegate_) return;
+  DCHECK(in_debug_scope());
   HandleScope scope(isolate_);
-  PostponeInterruptsScope no_interrupts(isolate_);
   DisableBreak no_recursive_break(this);
 
   std::vector<int> inspector_break_points_hit;
@@ -2182,16 +2184,55 @@ Handle<Object> Debug::return_value_handle() {
   return handle(thread_local_.return_value_, isolate_);
 }
 
-bool Debug::PerformSideEffectCheckForCallback(Handle<Object> callback_info) {
+bool Debug::PerformSideEffectCheckForCallback(
+    Handle<Object> callback_info, Handle<Object> receiver,
+    Debug::AccessorKind accessor_kind) {
+  DCHECK_EQ(!receiver.is_null(), callback_info->IsAccessorInfo());
   DCHECK_EQ(isolate_->debug_execution_mode(), DebugInfo::kSideEffects);
   if (!callback_info.is_null() && callback_info->IsCallHandlerInfo() &&
       i::CallHandlerInfo::cast(*callback_info)->NextCallHasNoSideEffect()) {
     return true;
   }
   // TODO(7515): always pass a valid callback info object.
-  if (!callback_info.is_null() &&
-      DebugEvaluate::CallbackHasNoSideEffect(*callback_info)) {
-    return true;
+  if (!callback_info.is_null()) {
+    if (callback_info->IsAccessorInfo()) {
+      // List of whitelisted internal accessors can be found in accessors.h.
+      AccessorInfo* info = AccessorInfo::cast(*callback_info);
+      DCHECK_NE(kNotAccessor, accessor_kind);
+      switch (accessor_kind == kSetter ? info->setter_side_effect_type()
+                                       : info->getter_side_effect_type()) {
+        case SideEffectType::kHasNoSideEffect:
+          // We do not support setter accessors with no side effects, since
+          // calling set accessors go through a store bytecode. Store bytecodes
+          // are considered to cause side effects (to non-temporary objects).
+          DCHECK_NE(kSetter, accessor_kind);
+          return true;
+        case SideEffectType::kHasSideEffectToReceiver:
+          DCHECK(!receiver.is_null());
+          if (PerformSideEffectCheckForObject(receiver)) return true;
+          isolate_->OptionalRescheduleException(false);
+          return false;
+        case SideEffectType::kHasSideEffect:
+          break;
+      }
+      if (FLAG_trace_side_effect_free_debug_evaluate) {
+        PrintF("[debug-evaluate] API Callback '");
+        info->name()->ShortPrint();
+        PrintF("' may cause side effect.\n");
+      }
+    } else if (callback_info->IsInterceptorInfo()) {
+      InterceptorInfo* info = InterceptorInfo::cast(*callback_info);
+      if (info->has_no_side_effect()) return true;
+      if (FLAG_trace_side_effect_free_debug_evaluate) {
+        PrintF("[debug-evaluate] API Interceptor may cause side effect.\n");
+      }
+    } else if (callback_info->IsCallHandlerInfo()) {
+      CallHandlerInfo* info = CallHandlerInfo::cast(*callback_info);
+      if (info->IsSideEffectFreeCallHandlerInfo()) return true;
+      if (FLAG_trace_side_effect_free_debug_evaluate) {
+        PrintF("[debug-evaluate] API CallHandlerInfo may cause side effect.\n");
+      }
+    }
   }
   side_effect_check_failed_ = true;
   // Throw an uncatchable termination exception.
@@ -2228,11 +2269,14 @@ bool Debug::PerformSideEffectCheckAtBytecode(InterpretedFrame* frame) {
 bool Debug::PerformSideEffectCheckForObject(Handle<Object> object) {
   DCHECK_EQ(isolate_->debug_execution_mode(), DebugInfo::kSideEffects);
 
-  if (object->IsHeapObject()) {
-    if (temporary_objects_->HasObject(Handle<HeapObject>::cast(object))) {
-      return true;
-    }
+  // We expect no side-effects for primitives.
+  if (object->IsNumber()) return true;
+  if (object->IsName()) return true;
+
+  if (temporary_objects_->HasObject(Handle<HeapObject>::cast(object))) {
+    return true;
   }
+
   if (FLAG_trace_side_effect_free_debug_evaluate) {
     PrintF("[debug-evaluate] failed runtime side effect check.\n");
   }
diff --git a/deps/v8/src/debug/debug.h b/deps/v8/src/debug/debug.h
index a6ad7bd4da..3b6748851b 100644
--- a/deps/v8/src/debug/debug.h
+++ b/deps/v8/src/debug/debug.h
@@ -326,7 +326,11 @@ class Debug {
 
   bool PerformSideEffectCheck(Handle<JSFunction> function,
                               Handle<Object> receiver);
-  bool PerformSideEffectCheckForCallback(Handle<Object> callback_info);
+
+  enum AccessorKind { kNotAccessor, kGetter, kSetter };
+  bool PerformSideEffectCheckForCallback(Handle<Object> callback_info,
+                                         Handle<Object> receiver,
+                                         AccessorKind accessor_kind);
   bool PerformSideEffectCheckAtBytecode(InterpretedFrame* frame);
   bool PerformSideEffectCheckForObject(Handle<Object> object);
 
@@ -406,7 +410,8 @@ class Debug {
 
   bool IsExceptionBlackboxed(bool uncaught);
 
-  void OnException(Handle<Object> exception, Handle<Object> promise);
+  void OnException(Handle<Object> exception, Handle<Object> promise,
+                   v8::debug::ExceptionType exception_type);
 
   void ProcessCompileEvent(bool has_compile_error, Handle<Script> script);
 
@@ -447,7 +452,7 @@ class Debug {
 
   // Wraps logic for clearing and maybe freeing all debug infos.
   typedef std::function<void(Handle<DebugInfo>)> DebugInfoClearFunction;
-  void ClearAllDebugInfos(DebugInfoClearFunction clear_function);
+  void ClearAllDebugInfos(const DebugInfoClearFunction& clear_function);
 
   void FindDebugInfo(Handle<DebugInfo> debug_info, DebugInfoListNode** prev,
                      DebugInfoListNode** curr);
@@ -551,7 +556,7 @@ class Debug {
 
 // This scope is used to load and enter the debug context and create a new
 // break state.  Leaving the scope will restore the previous state.
-class DebugScope BASE_EMBEDDED {
+class DebugScope {
  public:
   explicit DebugScope(Debug* debug);
   ~DebugScope();
@@ -580,7 +585,7 @@ class ReturnValueScope {
 };
 
 // Stack allocated class for disabling break.
-class DisableBreak BASE_EMBEDDED {
+class DisableBreak {
  public:
   explicit DisableBreak(Debug* debug, bool disable = true)
       : debug_(debug), previous_break_disabled_(debug->break_disabled_) {
@@ -596,8 +601,7 @@ class DisableBreak BASE_EMBEDDED {
   DISALLOW_COPY_AND_ASSIGN(DisableBreak);
 };
 
-
-class SuppressDebug BASE_EMBEDDED {
+class SuppressDebug {
  public:
   explicit SuppressDebug(Debug* debug)
       : debug_(debug), old_state_(debug->is_suppressed_) {
diff --git a/deps/v8/src/debug/ia32/debug-ia32.cc b/deps/v8/src/debug/ia32/debug-ia32.cc
index 03a60d269e..1e3ab38966 100644
--- a/deps/v8/src/debug/ia32/debug-ia32.cc
+++ b/deps/v8/src/debug/ia32/debug-ia32.cc
@@ -16,6 +16,8 @@ namespace internal {
 #define __ ACCESS_MASM(masm)
 
 void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
@@ -27,24 +29,28 @@ void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
 }
 
 void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // Frame is being dropped:
-  // - Drop to the target frame specified by ebx.
+  // - Drop to the target frame specified by eax.
   // - Look up current function on the frame.
   // - Leave the frame.
   // - Restart the frame by calling the function.
-  __ mov(ebp, ebx);
+  __ mov(ebp, eax);
   __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
   __ leave();
 
-  __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+  __ mov(eax, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
   __ movzx_w(
-      ebx, FieldOperand(ebx, SharedFunctionInfo::kFormalParameterCountOffset));
+      eax, FieldOperand(eax, SharedFunctionInfo::kFormalParameterCountOffset));
 
-  ParameterCount dummy(ebx);
-  __ InvokeFunction(edi, dummy, dummy, JUMP_FUNCTION);
+  // The expected and actual argument counts don't matter as long as they match
+  // and we don't enter the ArgumentsAdaptorTrampoline.
+  ParameterCount dummy(0);
+  __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
+  __ InvokeFunctionCode(edi, no_reg, dummy, dummy, JUMP_FUNCTION);
 }
 
-
 const bool LiveEdit::kFrameDropperSupported = true;
 
 #undef __
diff --git a/deps/v8/src/debug/interface-types.h b/deps/v8/src/debug/interface-types.h
index f0b47e6238..2d38120da5 100644
--- a/deps/v8/src/debug/interface-types.h
+++ b/deps/v8/src/debug/interface-types.h
@@ -60,7 +60,7 @@ struct WasmDisassemblyOffsetTableEntry {
 
 struct WasmDisassembly {
   using OffsetTable = std::vector<WasmDisassemblyOffsetTableEntry>;
-  WasmDisassembly() {}
+  WasmDisassembly() = default;
   WasmDisassembly(std::string disassembly, OffsetTable offset_table)
       : disassembly(std::move(disassembly)),
         offset_table(std::move(offset_table)) {}
@@ -161,6 +161,8 @@ class ConsoleDelegate {
                           const ConsoleContext& context) {}
   virtual void Time(const ConsoleCallArguments& args,
                     const ConsoleContext& context) {}
+  virtual void TimeLog(const ConsoleCallArguments& args,
+                       const ConsoleContext& context) {}
   virtual void TimeEnd(const ConsoleCallArguments& args,
                        const ConsoleContext& context) {}
   virtual void TimeStamp(const ConsoleCallArguments& args,
diff --git a/deps/v8/src/deoptimizer.cc b/deps/v8/src/deoptimizer.cc
index a2e59caf15..abda40bf51 100644
--- a/deps/v8/src/deoptimizer.cc
+++ b/deps/v8/src/deoptimizer.cc
@@ -253,7 +253,7 @@ class ActivationsFinder : public ThreadVisitor {
   // Find the frames with activations of codes marked for deoptimization, search
   // for the trampoline to the deoptimizer call respective to each code, and use
   // it to replace the current pc on the stack.
-  void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
+  void VisitThread(Isolate* isolate, ThreadLocalTop* top) override {
     for (StackFrameIterator it(isolate, top); !it.done(); it.Advance()) {
       if (it.frame()->type() == StackFrame::OPTIMIZED) {
         Code* code = it.frame()->LookupCode();
@@ -1173,7 +1173,8 @@ void Deoptimizer::DoComputeConstructStubFrame(TranslatedFrame* translated_frame,
   Code* construct_stub = builtins->builtin(Builtins::kJSConstructStubGeneric);
   BailoutId bailout_id = translated_frame->node_id();
   unsigned height = translated_frame->height();
-  unsigned height_in_bytes = height * kPointerSize;
+  unsigned parameter_count = height - 1;  // Exclude the context.
+  unsigned height_in_bytes = parameter_count * kPointerSize;
 
   // If the construct frame appears to be topmost we should ensure that the
   // value of result register is preserved during continuation execution.
@@ -1185,7 +1186,6 @@ void Deoptimizer::DoComputeConstructStubFrame(TranslatedFrame* translated_frame,
     if (PadTopOfStackRegister()) height_in_bytes += kPointerSize;
   }
 
-  int parameter_count = height;
   if (ShouldPadArguments(parameter_count)) height_in_bytes += kPointerSize;
 
   TranslatedFrame::iterator function_iterator = value_iterator++;
@@ -1227,7 +1227,7 @@ void Deoptimizer::DoComputeConstructStubFrame(TranslatedFrame* translated_frame,
   TranslatedFrame::iterator receiver_iterator = value_iterator;
 
   // Compute the incoming parameter translation.
-  for (int i = 0; i < parameter_count; ++i, ++value_iterator) {
+  for (unsigned i = 0; i < parameter_count; ++i, ++value_iterator) {
     frame_writer.PushTranslatedValue(value_iterator, "stack parameter");
   }
 
@@ -1259,13 +1259,10 @@ void Deoptimizer::DoComputeConstructStubFrame(TranslatedFrame* translated_frame,
   intptr_t marker = StackFrame::TypeToMarker(StackFrame::CONSTRUCT);
   frame_writer.PushRawValue(marker, "context (construct stub sentinel)\n");
 
-  // The context can be gotten from the previous frame.
-  Object* context =
-      reinterpret_cast<Object*>(output_[frame_index - 1]->GetContext());
-  frame_writer.PushRawObject(context, "context\n");
+  frame_writer.PushTranslatedValue(value_iterator++, "context\n");
 
   // Number of incoming arguments.
-  frame_writer.PushRawObject(Smi::FromInt(height - 1), "argc\n");
+  frame_writer.PushRawObject(Smi::FromInt(parameter_count - 1), "argc\n");
 
   // The constructor function was mentioned explicitly in the
   // CONSTRUCT_STUB_FRAME.
@@ -1476,7 +1473,13 @@ void Deoptimizer::DoComputeBuiltinContinuation(
   const bool must_handle_result =
       !is_topmost || deopt_kind_ == DeoptimizeKind::kLazy;
 
+#if defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
+  // TODO(v8:6666): Fold into Default config once root is fully supported.
+  const RegisterConfiguration* config(
+      RegisterConfiguration::PreserveRootIA32());
+#else
   const RegisterConfiguration* config(RegisterConfiguration::Default());
+#endif
   const int allocatable_register_count =
       config->num_allocatable_general_registers();
   const int padding_slot_count =
@@ -1739,7 +1742,7 @@ void Deoptimizer::MaterializeHeapObjects() {
   translated_state_.Prepare(static_cast<Address>(stack_fp_));
   if (FLAG_deopt_every_n_times > 0) {
     // Doing a GC here will find problems with the deoptimized frames.
-    isolate_->heap()->CollectAllGarbage(Heap::kFinalizeIncrementalMarkingMask,
+    isolate_->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                         GarbageCollectionReason::kTesting);
   }
 
@@ -1998,6 +2001,10 @@ void Translation::StoreInt32Register(Register reg) {
   buffer_->Add(reg.code());
 }
 
+void Translation::StoreInt64Register(Register reg) {
+  buffer_->Add(INT64_REGISTER);
+  buffer_->Add(reg.code());
+}
 
 void Translation::StoreUint32Register(Register reg) {
   buffer_->Add(UINT32_REGISTER);
@@ -2032,6 +2039,10 @@ void Translation::StoreInt32StackSlot(int index) {
   buffer_->Add(index);
 }
 
+void Translation::StoreInt64StackSlot(int index) {
+  buffer_->Add(INT64_STACK_SLOT);
+  buffer_->Add(index);
+}
 
 void Translation::StoreUint32StackSlot(int index) {
   buffer_->Add(UINT32_STACK_SLOT);
@@ -2080,12 +2091,14 @@ int Translation::NumberOfOperandsFor(Opcode opcode) {
     case CAPTURED_OBJECT:
     case REGISTER:
     case INT32_REGISTER:
+    case INT64_REGISTER:
     case UINT32_REGISTER:
     case BOOL_REGISTER:
     case FLOAT_REGISTER:
     case DOUBLE_REGISTER:
     case STACK_SLOT:
     case INT32_STACK_SLOT:
+    case INT64_STACK_SLOT:
     case UINT32_STACK_SLOT:
     case BOOL_STACK_SLOT:
     case FLOAT_STACK_SLOT:
@@ -2350,6 +2363,13 @@ TranslatedValue TranslatedValue::NewInt32(TranslatedState* container,
   return slot;
 }
 
+// static
+TranslatedValue TranslatedValue::NewInt64(TranslatedState* container,
+                                          int64_t value) {
+  TranslatedValue slot(container, kInt64);
+  slot.int64_value_ = value;
+  return slot;
+}
 
 // static
 TranslatedValue TranslatedValue::NewUInt32(TranslatedState* container,
@@ -2398,6 +2418,10 @@ int32_t TranslatedValue::int32_value() const {
   return int32_value_;
 }
 
+int64_t TranslatedValue::int64_value() const {
+  DCHECK_EQ(kInt64, kind());
+  return int64_value_;
+}
 
 uint32_t TranslatedValue::uint32_value() const {
   DCHECK(kind() == kUInt32 || kind() == kBoolBit);
@@ -2446,6 +2470,15 @@ Object* TranslatedValue::GetRawValue() const {
       break;
     }
 
+    case kInt64: {
+      bool is_smi = (int64_value() >= static_cast<int64_t>(Smi::kMinValue) &&
+                     int64_value() <= static_cast<int64_t>(Smi::kMaxValue));
+      if (is_smi) {
+        return Smi::FromIntptr(static_cast<intptr_t>(int64_value()));
+      }
+      break;
+    }
+
     case kUInt32: {
       bool is_smi = (uint32_value() <= static_cast<uintptr_t>(Smi::kMaxValue));
       if (is_smi) {
@@ -2486,6 +2519,7 @@ Handle<Object> TranslatedValue::GetValue() {
   switch (kind()) {
     case TranslatedValue::kTagged:
     case TranslatedValue::kInt32:
+    case TranslatedValue::kInt64:
     case TranslatedValue::kUInt32:
     case TranslatedValue::kBoolBit:
     case TranslatedValue::kFloat:
@@ -2539,6 +2573,11 @@ void TranslatedValue::MaterializeSimple() {
           Handle<Object>(isolate()->factory()->NewNumber(int32_value())));
       return;
 
+    case kInt64:
+      set_initialized_storage(Handle<Object>(
+          isolate()->factory()->NewNumber(static_cast<double>(int64_value()))));
+      return;
+
     case kUInt32:
       set_initialized_storage(
           Handle<Object>(isolate()->factory()->NewNumber(uint32_value())));
@@ -2592,6 +2631,9 @@ int TranslatedValue::GetChildrenCount() const {
   }
 }
 
+uint64_t TranslatedState::GetUInt64Slot(Address fp, int slot_offset) {
+  return Memory<uint64_t>(fp + slot_offset);
+}
 
 uint32_t TranslatedState::GetUInt32Slot(Address fp, int slot_offset) {
   Address address = fp + slot_offset;
@@ -2611,7 +2653,7 @@ Float32 TranslatedState::GetFloatSlot(Address fp, int slot_offset) {
 }
 
 Float64 TranslatedState::GetDoubleSlot(Address fp, int slot_offset) {
-  return Float64::FromBits(Memory<uint64_t>(fp + slot_offset));
+  return Float64::FromBits(GetUInt64Slot(fp, slot_offset));
 }
 
 void TranslatedValue::Handlify() {
@@ -2814,12 +2856,14 @@ TranslatedFrame TranslatedState::CreateNextTranslatedFrame(
     case Translation::CAPTURED_OBJECT:
     case Translation::REGISTER:
     case Translation::INT32_REGISTER:
+    case Translation::INT64_REGISTER:
     case Translation::UINT32_REGISTER:
     case Translation::BOOL_REGISTER:
     case Translation::FLOAT_REGISTER:
     case Translation::DOUBLE_REGISTER:
     case Translation::STACK_SLOT:
     case Translation::INT32_STACK_SLOT:
+    case Translation::INT64_STACK_SLOT:
     case Translation::UINT32_STACK_SLOT:
     case Translation::BOOL_STACK_SLOT:
     case Translation::FLOAT_STACK_SLOT:
@@ -3029,7 +3073,7 @@ int TranslatedState::CreateNextTranslatedValue(
       }
       intptr_t value = registers->GetRegister(input_reg);
       if (trace_file != nullptr) {
-        PrintF(trace_file, "%" V8PRIdPTR " ; %s ", value,
+        PrintF(trace_file, "%" V8PRIdPTR " ; %s (int32)", value,
                converter.NameOfCPURegister(input_reg));
       }
       TranslatedValue translated_value =
@@ -3038,6 +3082,24 @@ int TranslatedState::CreateNextTranslatedValue(
       return translated_value.GetChildrenCount();
     }
 
+    case Translation::INT64_REGISTER: {
+      int input_reg = iterator->Next();
+      if (registers == nullptr) {
+        TranslatedValue translated_value = TranslatedValue::NewInvalid(this);
+        frame.Add(translated_value);
+        return translated_value.GetChildrenCount();
+      }
+      intptr_t value = registers->GetRegister(input_reg);
+      if (trace_file != nullptr) {
+        PrintF(trace_file, "%" V8PRIdPTR " ; %s (int64)", value,
+               converter.NameOfCPURegister(input_reg));
+      }
+      TranslatedValue translated_value =
+          TranslatedValue::NewInt64(this, static_cast<int64_t>(value));
+      frame.Add(translated_value);
+      return translated_value.GetChildrenCount();
+    }
+
     case Translation::UINT32_REGISTER: {
       int input_reg = iterator->Next();
       if (registers == nullptr) {
@@ -3047,7 +3109,7 @@ int TranslatedState::CreateNextTranslatedValue(
       }
       intptr_t value = registers->GetRegister(input_reg);
       if (trace_file != nullptr) {
-        PrintF(trace_file, "%" V8PRIuPTR " ; %s (uint)", value,
+        PrintF(trace_file, "%" V8PRIuPTR " ; %s (uint32)", value,
                converter.NameOfCPURegister(input_reg));
       }
       TranslatedValue translated_value =
@@ -3131,7 +3193,7 @@ int TranslatedState::CreateNextTranslatedValue(
           OptimizedFrame::StackSlotOffsetRelativeToFp(iterator->Next());
       uint32_t value = GetUInt32Slot(fp, slot_offset);
       if (trace_file != nullptr) {
-        PrintF(trace_file, "%d ; (int) [fp %c %3d] ",
+        PrintF(trace_file, "%d ; (int32) [fp %c %3d] ",
                static_cast<int32_t>(value), slot_offset < 0 ? '-' : '+',
                std::abs(slot_offset));
       }
@@ -3140,12 +3202,26 @@ int TranslatedState::CreateNextTranslatedValue(
       return translated_value.GetChildrenCount();
     }
 
+    case Translation::INT64_STACK_SLOT: {
+      int slot_offset =
+          OptimizedFrame::StackSlotOffsetRelativeToFp(iterator->Next());
+      uint64_t value = GetUInt64Slot(fp, slot_offset);
+      if (trace_file != nullptr) {
+        PrintF(trace_file, "%" V8PRIdPTR " ; (int64) [fp %c %3d] ",
+               static_cast<intptr_t>(value), slot_offset < 0 ? '-' : '+',
+               std::abs(slot_offset));
+      }
+      TranslatedValue translated_value = TranslatedValue::NewInt64(this, value);
+      frame.Add(translated_value);
+      return translated_value.GetChildrenCount();
+    }
+
     case Translation::UINT32_STACK_SLOT: {
       int slot_offset =
           OptimizedFrame::StackSlotOffsetRelativeToFp(iterator->Next());
       uint32_t value = GetUInt32Slot(fp, slot_offset);
       if (trace_file != nullptr) {
-        PrintF(trace_file, "%u ; (uint) [fp %c %3d] ", value,
+        PrintF(trace_file, "%u ; (uint32) [fp %c %3d] ", value,
                slot_offset < 0 ? '-' : '+', std::abs(slot_offset));
       }
       TranslatedValue translated_value =
@@ -3389,6 +3465,7 @@ void TranslatedState::InitializeCapturedObjectAt(
       return;
 
     case FIXED_ARRAY_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
@@ -3532,6 +3609,7 @@ void TranslatedState::EnsureCapturedObjectAllocatedAt(
 
     case FIXED_ARRAY_TYPE:
     case SCRIPT_CONTEXT_TABLE_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
diff --git a/deps/v8/src/deoptimizer.h b/deps/v8/src/deoptimizer.h
index d981a86253..0c5254e773 100644
--- a/deps/v8/src/deoptimizer.h
+++ b/deps/v8/src/deoptimizer.h
@@ -53,6 +53,7 @@ class TranslatedValue {
     kInvalid,
     kTagged,
     kInt32,
+    kInt64,
     kUInt32,
     kBoolBit,
     kFloat,
@@ -88,6 +89,7 @@ class TranslatedValue {
   static TranslatedValue NewFloat(TranslatedState* container, Float32 value);
   static TranslatedValue NewDouble(TranslatedState* container, Float64 value);
   static TranslatedValue NewInt32(TranslatedState* container, int32_t value);
+  static TranslatedValue NewInt64(TranslatedState* container, int64_t value);
   static TranslatedValue NewUInt32(TranslatedState* container, uint32_t value);
   static TranslatedValue NewBool(TranslatedState* container, uint32_t value);
   static TranslatedValue NewTagged(TranslatedState* container, Object* literal);
@@ -128,6 +130,8 @@ class TranslatedValue {
     uint32_t uint32_value_;
     // kind is kInt32.
     int32_t int32_value_;
+    // kind is kInt64.
+    int64_t int64_value_;
     // kind is kFloat
     Float32 float_value_;
     // kind is kDouble
@@ -139,6 +143,7 @@ class TranslatedValue {
   // Checked accessors for the union members.
   Object* raw_literal() const;
   int32_t int32_value() const;
+  int64_t int64_value() const;
   uint32_t uint32_value() const;
   Float32 float_value() const;
   Float64 double_value() const;
@@ -284,7 +289,7 @@ class TranslatedFrame {
 
 class TranslatedState {
  public:
-  TranslatedState() {}
+  TranslatedState() = default;
   explicit TranslatedState(const JavaScriptFrame* frame);
 
   void Prepare(Address stack_frame_pointer);
@@ -368,6 +373,7 @@ class TranslatedState {
   Handle<Object> GetValueAndAdvance(TranslatedFrame* frame, int* value_index);
 
   static uint32_t GetUInt32Slot(Address fp, int slot_index);
+  static uint64_t GetUInt64Slot(Address fp, int slot_index);
   static Float32 GetFloatSlot(Address fp, int slot_index);
   static Float64 GetDoubleSlot(Address fp, int slot_index);
 
@@ -386,10 +392,9 @@ class TranslatedState {
   FeedbackSlot feedback_slot_;
 };
 
-
-class OptimizedFunctionVisitor BASE_EMBEDDED {
+class OptimizedFunctionVisitor {
  public:
-  virtual ~OptimizedFunctionVisitor() {}
+  virtual ~OptimizedFunctionVisitor() = default;
   virtual void VisitFunction(JSFunction* function) = 0;
 };
 
@@ -501,7 +506,7 @@ class Deoptimizer : public Malloced {
   static const int kNotDeoptimizationEntry = -1;
 
   // Generators for the deoptimization entry code.
-  class TableEntryGenerator BASE_EMBEDDED {
+  class TableEntryGenerator {
    public:
     TableEntryGenerator(MacroAssembler* masm, DeoptimizeKind kind, int count)
         : masm_(masm), deopt_kind_(kind), count_(count) {}
@@ -864,8 +869,7 @@ class DeoptimizerData {
   DISALLOW_COPY_AND_ASSIGN(DeoptimizerData);
 };
 
-
-class TranslationBuffer BASE_EMBEDDED {
+class TranslationBuffer {
  public:
   explicit TranslationBuffer(Zone* zone) : contents_(zone) {}
 
@@ -878,8 +882,7 @@ class TranslationBuffer BASE_EMBEDDED {
   ZoneChunkList<uint8_t> contents_;
 };
 
-
-class TranslationIterator BASE_EMBEDDED {
+class TranslationIterator {
  public:
   TranslationIterator(ByteArray* buffer, int index);
 
@@ -910,12 +913,14 @@ class TranslationIterator BASE_EMBEDDED {
   V(CAPTURED_OBJECT)                                   \
   V(REGISTER)                                          \
   V(INT32_REGISTER)                                    \
+  V(INT64_REGISTER)                                    \
   V(UINT32_REGISTER)                                   \
   V(BOOL_REGISTER)                                     \
   V(FLOAT_REGISTER)                                    \
   V(DOUBLE_REGISTER)                                   \
   V(STACK_SLOT)                                        \
   V(INT32_STACK_SLOT)                                  \
+  V(INT64_STACK_SLOT)                                  \
   V(UINT32_STACK_SLOT)                                 \
   V(BOOL_STACK_SLOT)                                   \
   V(FLOAT_STACK_SLOT)                                  \
@@ -923,7 +928,7 @@ class TranslationIterator BASE_EMBEDDED {
   V(LITERAL)                                           \
   V(UPDATE_FEEDBACK)
 
-class Translation BASE_EMBEDDED {
+class Translation {
  public:
 #define DECLARE_TRANSLATION_OPCODE_ENUM(item) item,
   enum Opcode {
@@ -963,12 +968,14 @@ class Translation BASE_EMBEDDED {
   void DuplicateObject(int object_index);
   void StoreRegister(Register reg);
   void StoreInt32Register(Register reg);
+  void StoreInt64Register(Register reg);
   void StoreUint32Register(Register reg);
   void StoreBoolRegister(Register reg);
   void StoreFloatRegister(FloatRegister reg);
   void StoreDoubleRegister(DoubleRegister reg);
   void StoreStackSlot(int index);
   void StoreInt32StackSlot(int index);
+  void StoreInt64StackSlot(int index);
   void StoreUint32StackSlot(int index);
   void StoreBoolStackSlot(int index);
   void StoreFloatStackSlot(int index);
diff --git a/deps/v8/src/disasm.h b/deps/v8/src/disasm.h
index f8ef304d2c..81a0055cc5 100644
--- a/deps/v8/src/disasm.h
+++ b/deps/v8/src/disasm.h
@@ -16,7 +16,7 @@ typedef unsigned char byte;
 // specific.
 class NameConverter {
  public:
-  virtual ~NameConverter() {}
+  virtual ~NameConverter() = default;
   virtual const char* NameOfCPURegister(int reg) const;
   virtual const char* NameOfByteCPURegister(int reg) const;
   virtual const char* NameOfXMMRegister(int reg) const;
diff --git a/deps/v8/src/disassembler.cc b/deps/v8/src/disassembler.cc
index 4ccddc289c..0bb59ec0fd 100644
--- a/deps/v8/src/disassembler.cc
+++ b/deps/v8/src/disassembler.cc
@@ -5,6 +5,7 @@
 #include "src/disassembler.h"
 
 #include <memory>
+#include <unordered_map>
 #include <vector>
 
 #include "src/assembler-inl.h"
@@ -38,12 +39,39 @@ class V8NameConverter: public disasm::NameConverter {
   const CodeReference& code() const { return code_; }
 
  private:
+  void InitExternalRefsCache() const;
+
   Isolate* isolate_;
   CodeReference code_;
 
   EmbeddedVector<char, 128> v8_buffer_;
+
+  // Map from root-register relative offset of the external reference value to
+  // the external reference name (stored in the external reference table).
+  // This cache is used to recognize [root_reg + offs] patterns as direct
+  // access to certain external reference's value.
+  mutable std::unordered_map<int, const char*> directly_accessed_external_refs_;
 };
 
+void V8NameConverter::InitExternalRefsCache() const {
+  ExternalReferenceTable* external_reference_table =
+      isolate_->heap()->external_reference_table();
+  if (!external_reference_table->is_initialized()) return;
+
+  base::AddressRegion addressable_region =
+      isolate_->root_register_addressable_region();
+  Address roots_start =
+      reinterpret_cast<Address>(isolate_->heap()->roots_array_start());
+
+  for (uint32_t i = 0; i < external_reference_table->size(); i++) {
+    Address address = external_reference_table->address(i);
+    if (addressable_region.contains(address)) {
+      int offset = static_cast<int>(address - roots_start);
+      const char* name = external_reference_table->name(i);
+      directly_accessed_external_refs_.insert({offset, name});
+    }
+  }
+}
 
 const char* V8NameConverter::NameOfAddress(byte* pc) const {
   if (!code_.is_null()) {
@@ -90,8 +118,11 @@ const char* V8NameConverter::RootRelativeName(int offset) const {
 
   const int kRootsStart = 0;
   const int kRootsEnd = Heap::roots_to_external_reference_table_offset();
-  const int kExtRefsStart = Heap::roots_to_external_reference_table_offset();
+  const int kExtRefsStart = kRootsEnd;
   const int kExtRefsEnd = Heap::roots_to_builtins_offset();
+  const int kBuiltinsStart = kExtRefsEnd;
+  const int kBuiltinsEnd =
+      kBuiltinsStart + Builtins::builtin_count * kPointerSize;
 
   if (kRootsStart <= offset && offset < kRootsEnd) {
     uint32_t offset_in_roots_table = offset - kRootsStart;
@@ -99,8 +130,8 @@ const char* V8NameConverter::RootRelativeName(int offset) const {
     // Fail safe in the unlikely case of an arbitrary root-relative offset.
     if (offset_in_roots_table % kPointerSize != 0) return nullptr;
 
-    Heap::RootListIndex root_index =
-        static_cast<Heap::RootListIndex>(offset_in_roots_table / kPointerSize);
+    RootIndex root_index =
+        static_cast<RootIndex>(offset_in_roots_table / kPointerSize);
 
     HeapStringAllocator allocator;
     StringStream accumulator(&allocator);
@@ -109,6 +140,7 @@ const char* V8NameConverter::RootRelativeName(int offset) const {
 
     SNPrintF(v8_buffer_, "root (%s)", obj_name.get());
     return v8_buffer_.start();
+
   } else if (kExtRefsStart <= offset && offset < kExtRefsEnd) {
     uint32_t offset_in_extref_table = offset - kExtRefsStart;
 
@@ -126,8 +158,29 @@ const char* V8NameConverter::RootRelativeName(int offset) const {
              isolate_->heap()->external_reference_table()->NameFromOffset(
                  offset_in_extref_table));
     return v8_buffer_.start();
+
+  } else if (kBuiltinsStart <= offset && offset < kBuiltinsEnd) {
+    uint32_t offset_in_builtins_table = (offset - kBuiltinsStart);
+
+    Builtins::Name builtin_id =
+        static_cast<Builtins::Name>(offset_in_builtins_table / kPointerSize);
+
+    const char* name = Builtins::name(builtin_id);
+    SNPrintF(v8_buffer_, "builtin (%s)", name);
+    return v8_buffer_.start();
+
   } else {
-    return nullptr;
+    // It must be a direct access to one of the external values.
+    if (directly_accessed_external_refs_.empty()) {
+      InitExternalRefsCache();
+    }
+
+    auto iter = directly_accessed_external_refs_.find(offset);
+    if (iter != directly_accessed_external_refs_.end()) {
+      SNPrintF(v8_buffer_, "external value (%s)", iter->second);
+      return v8_buffer_.start();
+    }
+    return "WAAT??? What are we accessing here???";
   }
 }
 
@@ -142,8 +195,8 @@ static const int kRelocInfoPosition = 57;
 
 static void PrintRelocInfo(StringBuilder* out, Isolate* isolate,
                            const ExternalReferenceEncoder* ref_encoder,
-                           std::ostream* os, RelocInfo* relocinfo,
-                           bool first_reloc_info = true) {
+                           std::ostream* os, CodeReference host,
+                           RelocInfo* relocinfo, bool first_reloc_info = true) {
   // Indent the printing of the reloc info.
   if (first_reloc_info) {
     // The first reloc info is printed after the disassembled instruction.
@@ -199,6 +252,11 @@ static void PrintRelocInfo(StringBuilder* out, Isolate* isolate,
     } else {
       out->AddFormatted(" %s", Code::Kind2String(kind));
     }
+  } else if (RelocInfo::IsWasmStubCall(rmode) && !isolate) {
+    // Host is isolate-independent, try wasm native module instead.
+    wasm::WasmCode* code = host.as_wasm_code()->native_module()->Lookup(
+        relocinfo->wasm_stub_call_address());
+    out->AddFormatted("    ;; wasm stub: %s", code->GetRuntimeStubName());
   } else if (RelocInfo::IsRuntimeEntry(rmode) && isolate &&
              isolate->deoptimizer_data() != nullptr) {
     // A runtime entry relocinfo might be a deoptimization bailout.
@@ -313,7 +371,7 @@ static int DecodeIt(Isolate* isolate, ExternalReferenceEncoder* ref_encoder,
       RelocInfo relocinfo(pcs[i], rmodes[i], datas[i], nullptr, constant_pool);
 
       bool first_reloc_info = (i == 0);
-      PrintRelocInfo(&out, isolate, ref_encoder, os, &relocinfo,
+      PrintRelocInfo(&out, isolate, ref_encoder, os, code, &relocinfo,
                      first_reloc_info);
     }
 
@@ -331,7 +389,8 @@ static int DecodeIt(Isolate* isolate, ExternalReferenceEncoder* ref_encoder,
           if (reloc_it.rinfo()->IsInConstantPool() &&
               (reloc_it.rinfo()->constant_pool_entry_address() ==
                constant_pool_entry_address)) {
-            PrintRelocInfo(&out, isolate, ref_encoder, os, reloc_it.rinfo());
+            PrintRelocInfo(&out, isolate, ref_encoder, os, code,
+                           reloc_it.rinfo());
             break;
           }
           reloc_it.next();
diff --git a/deps/v8/src/elements-kind.h b/deps/v8/src/elements-kind.h
index e5d55c246a..473c4ebd85 100644
--- a/deps/v8/src/elements-kind.h
+++ b/deps/v8/src/elements-kind.h
@@ -25,7 +25,7 @@ namespace internal {
   V(BigUint64, biguint64, BIGUINT64, uint64_t)           \
   V(BigInt64, bigint64, BIGINT64, int64_t)
 
-enum ElementsKind {
+enum ElementsKind : uint8_t {
   // The "fast" kind for elements that only contain SMI values. Must be first
   // to make it possible to efficiently check maps for this kind.
   PACKED_SMI_ELEMENTS,
diff --git a/deps/v8/src/elements.cc b/deps/v8/src/elements.cc
index 6c4222385c..5fad30711d 100644
--- a/deps/v8/src/elements.cc
+++ b/deps/v8/src/elements.cc
@@ -10,6 +10,7 @@
 #include "src/heap/factory.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/isolate-inl.h"
+#include "src/keys.h"
 #include "src/messages.h"
 #include "src/objects-inl.h"
 #include "src/objects/arguments-inl.h"
@@ -529,11 +530,11 @@ class InternalElementsAccessor : public ElementsAccessor {
   explicit InternalElementsAccessor(const char* name)
       : ElementsAccessor(name) {}
 
-  virtual uint32_t GetEntryForIndex(Isolate* isolate, JSObject* holder,
-                                    FixedArrayBase* backing_store,
-                                    uint32_t index) = 0;
+  uint32_t GetEntryForIndex(Isolate* isolate, JSObject* holder,
+                            FixedArrayBase* backing_store,
+                            uint32_t index) override = 0;
 
-  virtual PropertyDetails GetDetails(JSObject* holder, uint32_t entry) = 0;
+  PropertyDetails GetDetails(JSObject* holder, uint32_t entry) override = 0;
 };
 
 // Base class for element handler implementations. Contains the
@@ -724,18 +725,6 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     UNREACHABLE();
   }
 
-  Handle<JSArray> Splice(Handle<JSArray> receiver, uint32_t start,
-                         uint32_t delete_count, Arguments* args,
-                         uint32_t add_count) final {
-    return Subclass::SpliceImpl(receiver, start, delete_count, args, add_count);
-  }
-
-  static Handle<JSArray> SpliceImpl(Handle<JSArray> receiver,
-                                    uint32_t start, uint32_t delete_count,
-                                    Arguments* args, uint32_t add_count) {
-    UNREACHABLE();
-  }
-
   Handle<Object> Pop(Handle<JSArray> receiver) final {
     return Subclass::PopImpl(receiver);
   }
@@ -1026,14 +1015,14 @@ class ElementsAccessorBase : public InternalElementsAccessor {
 
   void CopyElements(Isolate* isolate, Handle<FixedArrayBase> source,
                     ElementsKind source_kind,
-                    Handle<FixedArrayBase> destination, int size) {
+                    Handle<FixedArrayBase> destination, int size) override {
     Subclass::CopyElementsImpl(isolate, *source, 0, *destination, source_kind,
                                0, kPackedSizeNotKnown, size);
   }
 
   void CopyTypedArrayElementsSlice(JSTypedArray* source,
                                    JSTypedArray* destination, size_t start,
-                                   size_t end) {
+                                   size_t end) override {
     Subclass::CopyTypedArrayElementsSliceImpl(source, destination, start, end);
   }
 
@@ -1068,7 +1057,7 @@ class ElementsAccessorBase : public InternalElementsAccessor {
   Maybe<bool> CollectValuesOrEntries(Isolate* isolate, Handle<JSObject> object,
                                      Handle<FixedArray> values_or_entries,
                                      bool get_entries, int* nof_items,
-                                     PropertyFilter filter) {
+                                     PropertyFilter filter) override {
     return Subclass::CollectValuesOrEntriesImpl(
         isolate, object, values_or_entries, get_entries, nof_items, filter);
   }
@@ -1298,7 +1287,7 @@ class ElementsAccessorBase : public InternalElementsAccessor {
   }
 
   Object* Fill(Handle<JSObject> receiver, Handle<Object> obj_value,
-               uint32_t start, uint32_t end) {
+               uint32_t start, uint32_t end) override {
     return Subclass::FillImpl(receiver, obj_value, start, end);
   }
 
@@ -2227,58 +2216,6 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     return result_array;
   }
 
-  static Handle<JSArray> SpliceImpl(Handle<JSArray> receiver,
-                                    uint32_t start, uint32_t delete_count,
-                                    Arguments* args, uint32_t add_count) {
-    Isolate* isolate = receiver->GetIsolate();
-    Heap* heap = isolate->heap();
-    uint32_t length = Smi::ToInt(receiver->length());
-    uint32_t new_length = length - delete_count + add_count;
-
-    ElementsKind kind = KindTraits::Kind;
-    if (new_length <= static_cast<uint32_t>(receiver->elements()->length()) &&
-        IsSmiOrObjectElementsKind(kind)) {
-      HandleScope scope(isolate);
-      JSObject::EnsureWritableFastElements(receiver);
-    }
-
-    Handle<FixedArrayBase> backing_store(receiver->elements(), isolate);
-
-    if (new_length == 0) {
-      receiver->set_elements(ReadOnlyRoots(heap).empty_fixed_array());
-      receiver->set_length(Smi::kZero);
-      return isolate->factory()->NewJSArrayWithElements(
-          backing_store, KindTraits::Kind, delete_count);
-    }
-
-    // Construct the result array which holds the deleted elements.
-    Handle<JSArray> deleted_elements = isolate->factory()->NewJSArray(
-        KindTraits::Kind, delete_count, delete_count);
-    if (delete_count > 0) {
-      DisallowHeapAllocation no_gc;
-      Subclass::CopyElementsImpl(isolate, *backing_store, start,
-                                 deleted_elements->elements(), KindTraits::Kind,
-                                 0, kPackedSizeNotKnown, delete_count);
-    }
-
-    // Delete and move elements to make space for add_count new elements.
-    if (add_count < delete_count) {
-      Subclass::SpliceShrinkStep(isolate, receiver, backing_store, start,
-                                 delete_count, add_count, length, new_length);
-    } else if (add_count > delete_count) {
-      backing_store =
-          Subclass::SpliceGrowStep(isolate, receiver, backing_store, start,
-                                   delete_count, add_count, length, new_length);
-    }
-
-    // Copy over the arguments.
-    Subclass::CopyArguments(args, backing_store, add_count, 3, start);
-
-    receiver->set_length(Smi::FromInt(new_length));
-    Subclass::TryTransitionResultArrayToPacked(deleted_elements);
-    return deleted_elements;
-  }
-
   static void MoveElements(Isolate* isolate, Handle<JSArray> receiver,
                            Handle<FixedArrayBase> backing_store, int dst_index,
                            int src_index, int len, int hole_start,
@@ -2503,50 +2440,6 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     return result;
   }
 
- private:
-  // SpliceShrinkStep might modify the backing_store.
-  static void SpliceShrinkStep(Isolate* isolate, Handle<JSArray> receiver,
-                               Handle<FixedArrayBase> backing_store,
-                               uint32_t start, uint32_t delete_count,
-                               uint32_t add_count, uint32_t len,
-                               uint32_t new_length) {
-    const int move_left_count = len - delete_count - start;
-    const int move_left_dst_index = start + add_count;
-    Subclass::MoveElements(isolate, receiver, backing_store,
-                           move_left_dst_index, start + delete_count,
-                           move_left_count, new_length, len);
-  }
-
-  // SpliceGrowStep might modify the backing_store.
-  static Handle<FixedArrayBase> SpliceGrowStep(
-      Isolate* isolate, Handle<JSArray> receiver,
-      Handle<FixedArrayBase> backing_store, uint32_t start,
-      uint32_t delete_count, uint32_t add_count, uint32_t length,
-      uint32_t new_length) {
-    // Check we do not overflow the new_length.
-    DCHECK((add_count - delete_count) <= (Smi::kMaxValue - length));
-    // Check if backing_store is big enough.
-    if (new_length <= static_cast<uint32_t>(backing_store->length())) {
-      Subclass::MoveElements(isolate, receiver, backing_store,
-                             start + add_count, start + delete_count,
-                             (length - delete_count - start), 0, 0);
-      // MoveElements updates the backing_store in-place.
-      return backing_store;
-    }
-    // New backing storage is needed.
-    int capacity = JSObject::NewElementsCapacity(new_length);
-    // Partially copy all elements up to start.
-    Handle<FixedArrayBase> new_elms = Subclass::ConvertElementsWithCapacity(
-        receiver, backing_store, KindTraits::Kind, capacity, start);
-    // Copy the trailing elements after start + delete_count
-    Subclass::CopyElementsImpl(isolate, *backing_store, start + delete_count,
-                               *new_elms, KindTraits::Kind, start + add_count,
-                               kPackedSizeNotKnown,
-                               ElementsAccessor::kCopyToEndAndInitializeToHole);
-    receiver->set_elements(*new_elms);
-    return new_elms;
-  }
-
   static Handle<Object> RemoveElement(Handle<JSArray> receiver,
                                       Where remove_position) {
     Isolate* isolate = receiver->GetIsolate();
@@ -3285,8 +3178,8 @@ class TypedElementsAccessor
                                               size_t start, size_t end) {
     DisallowHeapAllocation no_gc;
     DCHECK_EQ(destination->GetElementsKind(), AccessorClass::kind());
-    DCHECK(!source->WasNeutered());
-    DCHECK(!destination->WasNeutered());
+    CHECK(!source->WasNeutered());
+    CHECK(!destination->WasNeutered());
     DCHECK_LE(start, end);
     DCHECK_LE(end, source->length_value());
 
@@ -3356,6 +3249,9 @@ class TypedElementsAccessor
     // side-effects, as the source elements will always be a number.
     DisallowHeapAllocation no_gc;
 
+    CHECK(!source->WasNeutered());
+    CHECK(!destination->WasNeutered());
+
     FixedTypedArrayBase* source_elements =
         FixedTypedArrayBase::cast(source->elements());
     BackingStore* destination_elements =
@@ -3377,8 +3273,8 @@ class TypedElementsAccessor
 
     uint8_t* source_data = static_cast<uint8_t*>(source_elements->DataPtr());
     uint8_t* dest_data = static_cast<uint8_t*>(destination_elements->DataPtr());
-    size_t source_byte_length = NumberToSize(source->byte_length());
-    size_t dest_byte_length = NumberToSize(destination->byte_length());
+    size_t source_byte_length = source->byte_length();
+    size_t dest_byte_length = destination->byte_length();
 
     // We can simply copy the backing store if the types are the same, or if
     // we are converting e.g. Uint8 <-> Int8, as the binary representation
@@ -3446,6 +3342,8 @@ class TypedElementsAccessor
     DisallowHeapAllocation no_gc;
     DisallowJavascriptExecution no_js(isolate);
 
+    CHECK(!destination->WasNeutered());
+
     size_t current_length;
     DCHECK(source->length()->IsNumber() &&
            TryNumberToSize(source->length(), &current_length) &&
@@ -3566,6 +3464,7 @@ class TypedElementsAccessor
     Handle<JSTypedArray> destination_ta =
         Handle<JSTypedArray>::cast(destination);
     DCHECK_LE(offset + length, destination_ta->length_value());
+    CHECK(!destination_ta->WasNeutered());
 
     if (length == 0) return *isolate->factory()->undefined_value();
 
@@ -3593,7 +3492,6 @@ class TypedElementsAccessor
       // If we have to copy more elements than we have in the source, we need to
       // do special handling and conversion; that happens in the slow case.
       if (length + offset <= source_ta->length_value()) {
-        DCHECK(length == 0 || !source_ta->WasNeutered());
         CopyElementsFromTypedArray(*source_ta, *destination_ta, length, offset);
         return *isolate->factory()->undefined_value();
       }
diff --git a/deps/v8/src/elements.h b/deps/v8/src/elements.h
index b0aa911f32..8cdbf331ef 100644
--- a/deps/v8/src/elements.h
+++ b/deps/v8/src/elements.h
@@ -19,7 +19,7 @@ class JSTypedArray;
 class ElementsAccessor {
  public:
   explicit ElementsAccessor(const char* name) : name_(name) { }
-  virtual ~ElementsAccessor() { }
+  virtual ~ElementsAccessor() = default;
 
   const char* name() const { return name_; }
 
@@ -135,10 +135,6 @@ class ElementsAccessor {
   virtual Handle<JSObject> Slice(Handle<JSObject> receiver, uint32_t start,
                                  uint32_t end) = 0;
 
-  virtual Handle<JSArray> Splice(Handle<JSArray> receiver,
-                                 uint32_t start, uint32_t delete_count,
-                                 Arguments* args, uint32_t add_count) = 0;
-
   virtual Handle<Object> Pop(Handle<JSArray> receiver) = 0;
 
   virtual Handle<Object> Shift(Handle<JSArray> receiver) = 0;
diff --git a/deps/v8/src/extensions/externalize-string-extension.cc b/deps/v8/src/extensions/externalize-string-extension.cc
index de1530ba27..b19128a941 100644
--- a/deps/v8/src/extensions/externalize-string-extension.cc
+++ b/deps/v8/src/extensions/externalize-string-extension.cc
@@ -20,11 +20,11 @@ class SimpleStringResource : public Base {
       : data_(data),
         length_(length) {}
 
-  virtual ~SimpleStringResource() { delete[] data_; }
+  ~SimpleStringResource() override { delete[] data_; }
 
-  virtual const Char* data() const { return data_; }
+  const Char* data() const override { return data_; }
 
-  virtual size_t length() const { return length_; }
+  size_t length() const override { return length_; }
 
  private:
   Char* const data_;
@@ -70,10 +70,7 @@ void ExternalizeStringExtension::Externalize(
   bool force_two_byte = false;
   if (args.Length() >= 2) {
     if (args[1]->IsBoolean()) {
-      force_two_byte =
-          args[1]
-              ->BooleanValue(args.GetIsolate()->GetCurrentContext())
-              .FromJust();
+      force_two_byte = args[1]->BooleanValue(args.GetIsolate());
     } else {
       args.GetIsolate()->ThrowException(
           v8::String::NewFromUtf8(
diff --git a/deps/v8/src/extensions/externalize-string-extension.h b/deps/v8/src/extensions/externalize-string-extension.h
index c8907b42ed..8d08a7474a 100644
--- a/deps/v8/src/extensions/externalize-string-extension.h
+++ b/deps/v8/src/extensions/externalize-string-extension.h
@@ -13,8 +13,8 @@ namespace internal {
 class ExternalizeStringExtension : public v8::Extension {
  public:
   ExternalizeStringExtension() : v8::Extension("v8/externalize", kSource) {}
-  virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
-      v8::Isolate* isolate, v8::Local<v8::String> name);
+  v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
+      v8::Isolate* isolate, v8::Local<v8::String> name) override;
   static void Externalize(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void IsOneByte(const v8::FunctionCallbackInfo<v8::Value>& args);
 
diff --git a/deps/v8/src/extensions/free-buffer-extension.h b/deps/v8/src/extensions/free-buffer-extension.h
index 6bc5e57cbc..51c620d171 100644
--- a/deps/v8/src/extensions/free-buffer-extension.h
+++ b/deps/v8/src/extensions/free-buffer-extension.h
@@ -14,8 +14,8 @@ class FreeBufferExtension : public v8::Extension {
  public:
   FreeBufferExtension()
       : v8::Extension("v8/free-buffer", "native function freeBuffer();") {}
-  virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
-      v8::Isolate* isolate, v8::Local<v8::String> name);
+  v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
+      v8::Isolate* isolate, v8::Local<v8::String> name) override;
   static void FreeBuffer(const v8::FunctionCallbackInfo<v8::Value>& args);
 };
 
diff --git a/deps/v8/src/extensions/gc-extension.cc b/deps/v8/src/extensions/gc-extension.cc
index 9eb453b986..4f446627fd 100644
--- a/deps/v8/src/extensions/gc-extension.cc
+++ b/deps/v8/src/extensions/gc-extension.cc
@@ -18,9 +18,7 @@ v8::Local<v8::FunctionTemplate> GCExtension::GetNativeFunctionTemplate(
 
 void GCExtension::GC(const v8::FunctionCallbackInfo<v8::Value>& args) {
   args.GetIsolate()->RequestGarbageCollectionForTesting(
-      args[0]
-              ->BooleanValue(args.GetIsolate()->GetCurrentContext())
-              .FromMaybe(false)
+      args[0]->BooleanValue(args.GetIsolate())
           ? v8::Isolate::kMinorGarbageCollection
           : v8::Isolate::kFullGarbageCollection);
 }
diff --git a/deps/v8/src/extensions/gc-extension.h b/deps/v8/src/extensions/gc-extension.h
index 9be0d4b701..4fd35d4233 100644
--- a/deps/v8/src/extensions/gc-extension.h
+++ b/deps/v8/src/extensions/gc-extension.h
@@ -16,8 +16,8 @@ class GCExtension : public v8::Extension {
   explicit GCExtension(const char* fun_name)
       : v8::Extension("v8/gc",
                       BuildSource(buffer_, sizeof(buffer_), fun_name)) {}
-  virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
-      v8::Isolate* isolate, v8::Local<v8::String> name);
+  v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
+      v8::Isolate* isolate, v8::Local<v8::String> name) override;
   static void GC(const v8::FunctionCallbackInfo<v8::Value>& args);
 
  private:
diff --git a/deps/v8/src/extensions/statistics-extension.cc b/deps/v8/src/extensions/statistics-extension.cc
index aa9d5c4364..25081b69e0 100644
--- a/deps/v8/src/extensions/statistics-extension.cc
+++ b/deps/v8/src/extensions/statistics-extension.cc
@@ -63,10 +63,7 @@ void StatisticsExtension::GetCounters(
   Heap* heap = isolate->heap();
 
   if (args.Length() > 0) {  // GC if first argument evaluates to true.
-    if (args[0]->IsBoolean() &&
-        args[0]
-            ->BooleanValue(args.GetIsolate()->GetCurrentContext())
-            .FromMaybe(false)) {
+    if (args[0]->IsBoolean() && args[0]->BooleanValue(args.GetIsolate())) {
       heap->CollectAllGarbage(Heap::kNoGCFlags,
                               GarbageCollectionReason::kCountersExtension);
     }
diff --git a/deps/v8/src/extensions/statistics-extension.h b/deps/v8/src/extensions/statistics-extension.h
index 714f86aeba..4c53cbfdea 100644
--- a/deps/v8/src/extensions/statistics-extension.h
+++ b/deps/v8/src/extensions/statistics-extension.h
@@ -13,8 +13,8 @@ namespace internal {
 class StatisticsExtension : public v8::Extension {
  public:
   StatisticsExtension() : v8::Extension("v8/statistics", kSource) {}
-  virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
-      v8::Isolate* isolate, v8::Local<v8::String> name);
+  v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
+      v8::Isolate* isolate, v8::Local<v8::String> name) override;
   static void GetCounters(const v8::FunctionCallbackInfo<v8::Value>& args);
 
  private:
diff --git a/deps/v8/src/extensions/trigger-failure-extension.h b/deps/v8/src/extensions/trigger-failure-extension.h
index 7c7ecf882c..e2cfac1eb3 100644
--- a/deps/v8/src/extensions/trigger-failure-extension.h
+++ b/deps/v8/src/extensions/trigger-failure-extension.h
@@ -13,8 +13,8 @@ namespace internal {
 class TriggerFailureExtension : public v8::Extension {
  public:
   TriggerFailureExtension() : v8::Extension("v8/trigger-failure", kSource) {}
-  virtual v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
-      v8::Isolate* isolate, v8::Local<v8::String> name);
+  v8::Local<v8::FunctionTemplate> GetNativeFunctionTemplate(
+      v8::Isolate* isolate, v8::Local<v8::String> name) override;
   static void TriggerCheckFalse(
       const v8::FunctionCallbackInfo<v8::Value>& args);
   static void TriggerAssertFalse(
diff --git a/deps/v8/src/external-reference-table.cc b/deps/v8/src/external-reference-table.cc
index 4d555e1829..47bc1b9ee4 100644
--- a/deps/v8/src/external-reference-table.cc
+++ b/deps/v8/src/external-reference-table.cc
@@ -159,10 +159,10 @@ void ExternalReferenceTable::AddAccessors(int* index) {
   };
 
   static const AccessorRefTable getters[] = {
-#define ACCESSOR_INFO_DECLARATION(accessor_name, AccessorName) \
-  {FUNCTION_ADDR(&Accessors::AccessorName##Getter),            \
+#define ACCESSOR_INFO_DECLARATION(_, accessor_name, AccessorName, ...) \
+  {FUNCTION_ADDR(&Accessors::AccessorName##Getter),                    \
    "Accessors::" #AccessorName "Getter"}, /* NOLINT(whitespace/indent) */
-      ACCESSOR_INFO_LIST(ACCESSOR_INFO_DECLARATION)
+      ACCESSOR_INFO_LIST_GENERATOR(ACCESSOR_INFO_DECLARATION, /* not used */)
 #undef ACCESSOR_INFO_DECLARATION
   };
   static const AccessorRefTable setters[] = {
diff --git a/deps/v8/src/external-reference-table.h b/deps/v8/src/external-reference-table.h
index 38acac2b7a..4fa1088ab7 100644
--- a/deps/v8/src/external-reference-table.h
+++ b/deps/v8/src/external-reference-table.h
@@ -30,7 +30,8 @@ class ExternalReferenceTable {
       BUILTIN_LIST_C(COUNT_C_BUILTIN);
 #undef COUNT_C_BUILTIN
   static constexpr int kRuntimeReferenceCount =
-      Runtime::kNumFunctions / 2;  // Don't count dupe kInline... functions.
+      Runtime::kNumFunctions -
+      Runtime::kNumInlineFunctions;  // Don't count dupe kInline... functions.
   static constexpr int kIsolateAddressReferenceCount = kIsolateAddressCount;
   static constexpr int kAccessorReferenceCount =
       Accessors::kAccessorInfoCount + Accessors::kAccessorSetterCount;
@@ -73,7 +74,7 @@ class ExternalReferenceTable {
     return OffsetOfEntry(size()) + 2 * kUInt32Size;
   }
 
-  ExternalReferenceTable() {}
+  ExternalReferenceTable() = default;
   void Init(Isolate* isolate);
 
  private:
diff --git a/deps/v8/src/external-reference.cc b/deps/v8/src/external-reference.cc
index 0fbde95a1c..806fbb8af5 100644
--- a/deps/v8/src/external-reference.cc
+++ b/deps/v8/src/external-reference.cc
@@ -16,6 +16,7 @@
 #include "src/ic/stub-cache.h"
 #include "src/interpreter/interpreter.h"
 #include "src/isolate.h"
+#include "src/math-random.h"
 #include "src/objects-inl.h"
 #include "src/regexp/regexp-stack.h"
 #include "src/simulator-base.h"
@@ -134,11 +135,6 @@ ExternalReference ExternalReference::handle_scope_implementer_address(
   return ExternalReference(isolate->handle_scope_implementer_address());
 }
 
-ExternalReference ExternalReference::pending_microtask_count_address(
-    Isolate* isolate) {
-  return ExternalReference(isolate->pending_microtask_count_address());
-}
-
 ExternalReference ExternalReference::interpreter_dispatch_table_address(
     Isolate* isolate) {
   return ExternalReference(isolate->interpreter()->dispatch_table_address());
@@ -463,6 +459,11 @@ ExternalReference ExternalReference::abort_with_reason() {
   return ExternalReference(Redirect(FUNCTION_ADDR(i::abort_with_reason)));
 }
 
+ExternalReference
+ExternalReference::address_of_harmony_await_optimization_flag() {
+  return ExternalReference(&FLAG_harmony_await_optimization);
+}
+
 ExternalReference ExternalReference::address_of_min_int() {
   return ExternalReference(reinterpret_cast<Address>(&double_min_int_constant));
 }
@@ -724,6 +725,10 @@ ExternalReference ExternalReference::printf_function() {
   return ExternalReference(Redirect(FUNCTION_ADDR(std::printf)));
 }
 
+ExternalReference ExternalReference::refill_math_random() {
+  return ExternalReference(Redirect(FUNCTION_ADDR(MathRandom::RefillCache)));
+}
+
 template <typename SubjectChar, typename PatternChar>
 ExternalReference ExternalReference::search_string_raw() {
   auto f = SearchStringRaw<SubjectChar, PatternChar>;
@@ -751,14 +756,13 @@ ExternalReference ExternalReference::orderedhashmap_gethash_raw() {
   return ExternalReference(Redirect(FUNCTION_ADDR(f)));
 }
 
-ExternalReference ExternalReference::get_or_create_hash_raw(Isolate* isolate) {
+ExternalReference ExternalReference::get_or_create_hash_raw() {
   typedef Smi* (*GetOrCreateHash)(Isolate * isolate, Object * key);
   GetOrCreateHash f = Object::GetOrCreateHash;
   return ExternalReference(Redirect(FUNCTION_ADDR(f)));
 }
 
-ExternalReference ExternalReference::jsreceiver_create_identity_hash(
-    Isolate* isolate) {
+ExternalReference ExternalReference::jsreceiver_create_identity_hash() {
   typedef Smi* (*CreateIdentityHash)(Isolate * isolate, JSReceiver * key);
   CreateIdentityHash f = JSReceiver::CreateIdentityHash;
   return ExternalReference(Redirect(FUNCTION_ADDR(f)));
@@ -795,6 +799,10 @@ ExternalReference ExternalReference::try_internalize_string_function() {
       Redirect(FUNCTION_ADDR(StringTable::LookupStringIfExists_NoAllocate)));
 }
 
+ExternalReference ExternalReference::smi_lexicographic_compare_function() {
+  return ExternalReference(Redirect(FUNCTION_ADDR(Smi::LexicographicCompare)));
+}
+
 ExternalReference ExternalReference::check_object_type() {
   return ExternalReference(Redirect(FUNCTION_ADDR(CheckObjectType)));
 }
@@ -825,8 +833,8 @@ ExternalReference ExternalReference::page_flags(Page* page) {
                            MemoryChunk::kFlagsOffset);
 }
 
-ExternalReference ExternalReference::ForDeoptEntry(Address entry) {
-  return ExternalReference(entry);
+ExternalReference ExternalReference::FromRawAddress(Address address) {
+  return ExternalReference(address);
 }
 
 ExternalReference ExternalReference::cpu_features() {
@@ -850,6 +858,11 @@ ExternalReference::promise_hook_or_async_event_delegate_address(
       isolate->promise_hook_or_async_event_delegate_address());
 }
 
+ExternalReference ExternalReference::debug_execution_mode_address(
+    Isolate* isolate) {
+  return ExternalReference(isolate->debug_execution_mode_address());
+}
+
 ExternalReference ExternalReference::debug_is_active_address(Isolate* isolate) {
   return ExternalReference(isolate->debug()->is_active_address());
 }
@@ -870,21 +883,19 @@ ExternalReference ExternalReference::invalidate_prototype_chains_function() {
       Redirect(FUNCTION_ADDR(JSObject::InvalidatePrototypeChains)));
 }
 
-double power_helper(Isolate* isolate, double x, double y) {
+double power_helper(double x, double y) {
   int y_int = static_cast<int>(y);
   if (y == y_int) {
     return power_double_int(x, y_int);  // Returns 1 if exponent is 0.
   }
   if (y == 0.5) {
-    lazily_initialize_fast_sqrt(isolate);
+    lazily_initialize_fast_sqrt();
     return (std::isinf(x)) ? V8_INFINITY
-                           : fast_sqrt(x + 0.0, isolate);  // Convert -0 to +0.
+                           : fast_sqrt(x + 0.0);  // Convert -0 to +0.
   }
   if (y == -0.5) {
-    lazily_initialize_fast_sqrt(isolate);
-    return (std::isinf(x)) ? 0
-                           : 1.0 / fast_sqrt(x + 0.0,
-                                             isolate);  // Convert -0 to +0.
+    lazily_initialize_fast_sqrt();
+    return (std::isinf(x)) ? 0 : 1.0 / fast_sqrt(x + 0.0);  // Convert -0 to +0.
   }
   return power_double_double(x, y);
 }
@@ -949,6 +960,25 @@ ExternalReference ExternalReference::fixed_typed_array_base_data_offset() {
       FixedTypedArrayBase::kDataOffset - kHeapObjectTag));
 }
 
+static uint64_t atomic_pair_compare_exchange(intptr_t address,
+                                             int old_value_low,
+                                             int old_value_high,
+                                             int new_value_low,
+                                             int new_value_high) {
+  uint64_t old_value = static_cast<uint64_t>(old_value_high) << 32 |
+                       (old_value_low & 0xFFFFFFFF);
+  uint64_t new_value = static_cast<uint64_t>(new_value_high) << 32 |
+                       (new_value_low & 0xFFFFFFFF);
+  std::atomic_compare_exchange_strong(
+      reinterpret_cast<std::atomic<uint64_t>*>(address), &old_value, new_value);
+  return old_value;
+}
+
+ExternalReference ExternalReference::atomic_pair_compare_exchange_function() {
+  return ExternalReference(
+      Redirect(FUNCTION_ADDR(atomic_pair_compare_exchange)));
+}
+
 bool operator==(ExternalReference lhs, ExternalReference rhs) {
   return lhs.address() == rhs.address();
 }
diff --git a/deps/v8/src/external-reference.h b/deps/v8/src/external-reference.h
index fb3ec07c8b..eb4b235cb0 100644
--- a/deps/v8/src/external-reference.h
+++ b/deps/v8/src/external-reference.h
@@ -27,8 +27,6 @@ class StatsCounter;
   V(builtins_address, "builtins")                                              \
   V(handle_scope_implementer_address,                                          \
     "Isolate::handle_scope_implementer_address")                               \
-  V(pending_microtask_count_address,                                           \
-    "Isolate::pending_microtask_count_address()")                              \
   V(interpreter_dispatch_counters, "Interpreter::dispatch_counters")           \
   V(interpreter_dispatch_table_address, "Interpreter::dispatch_table_address") \
   V(date_cache_stamp, "date_cache_stamp")                                      \
@@ -51,12 +49,11 @@ class StatsCounter;
   V(handle_scope_limit_address, "HandleScope::limit")                          \
   V(scheduled_exception_address, "Isolate::scheduled_exception")               \
   V(address_of_pending_message_obj, "address_of_pending_message_obj")          \
-  V(get_or_create_hash_raw, "get_or_create_hash_raw")                          \
-  V(jsreceiver_create_identity_hash, "jsreceiver_create_identity_hash")        \
   V(promise_hook_address, "Isolate::promise_hook_address()")                   \
   V(async_event_delegate_address, "Isolate::async_event_delegate_address()")   \
   V(promise_hook_or_async_event_delegate_address,                              \
     "Isolate::promise_hook_or_async_event_delegate_address()")                 \
+  V(debug_execution_mode_address, "Isolate::debug_execution_mode_address()")   \
   V(debug_is_active_address, "Debug::is_active_address()")                     \
   V(debug_hook_on_function_call_address,                                       \
     "Debug::hook_on_function_call_address()")                                  \
@@ -76,6 +73,8 @@ class StatsCounter;
   V(address_of_double_neg_constant, "double_negate_constant")                 \
   V(address_of_float_abs_constant, "float_absolute_constant")                 \
   V(address_of_float_neg_constant, "float_negate_constant")                   \
+  V(address_of_harmony_await_optimization_flag,                               \
+    "FLAG_harmony_await_optimization")                                        \
   V(address_of_min_int, "LDoubleConstant::min_int")                           \
   V(address_of_one_half, "LDoubleConstant::one_half")                         \
   V(address_of_runtime_stats_flag, "FLAG_runtime_stats")                      \
@@ -97,6 +96,7 @@ class StatsCounter;
   V(f64_mod_wrapper_function, "f64_mod_wrapper")                              \
   V(fixed_typed_array_base_data_offset, "fixed_typed_array_base_data_offset") \
   V(get_date_field_function, "JSDate::GetField")                              \
+  V(get_or_create_hash_raw, "get_or_create_hash_raw")                         \
   V(ieee754_acos_function, "base::ieee754::acos")                             \
   V(ieee754_acosh_function, "base::ieee754::acosh")                           \
   V(ieee754_asin_function, "base::ieee754::asin")                             \
@@ -123,6 +123,7 @@ class StatsCounter;
     "JSObject::InvalidatePrototypeChains()")                                  \
   V(invoke_accessor_getter_callback, "InvokeAccessorGetterCallback")          \
   V(invoke_function_callback, "InvokeFunctionCallback")                       \
+  V(jsreceiver_create_identity_hash, "jsreceiver_create_identity_hash")       \
   V(libc_memchr_function, "libc_memchr")                                      \
   V(libc_memcpy_function, "libc_memcpy")                                      \
   V(libc_memmove_function, "libc_memmove")                                    \
@@ -134,12 +135,14 @@ class StatsCounter;
   V(orderedhashmap_gethash_raw, "orderedhashmap_gethash_raw")                 \
   V(power_double_double_function, "power_double_double_function")             \
   V(printf_function, "printf")                                                \
+  V(refill_math_random, "MathRandom::RefillCache")                            \
   V(store_buffer_overflow_function, "StoreBuffer::StoreBufferOverflow")       \
   V(search_string_raw_one_one, "search_string_raw_one_one")                   \
   V(search_string_raw_one_two, "search_string_raw_one_two")                   \
   V(search_string_raw_two_one, "search_string_raw_two_one")                   \
   V(search_string_raw_two_two, "search_string_raw_two_two")                   \
   V(try_internalize_string_function, "try_internalize_string_function")       \
+  V(smi_lexicographic_compare_function, "smi_lexicographic_compare_function") \
   V(wasm_call_trap_callback_for_testing,                                      \
     "wasm::call_trap_callback_for_testing")                                   \
   V(wasm_f32_ceil, "wasm::f32_ceil_wrapper")                                  \
@@ -169,6 +172,8 @@ class StatsCounter;
   V(wasm_word32_ror, "wasm::word32_ror")                                      \
   V(wasm_word64_ctz, "wasm::word64_ctz")                                      \
   V(wasm_word64_popcnt, "wasm::word64_popcnt")                                \
+  V(atomic_pair_compare_exchange_function,                                    \
+    "atomic_pair_compare_exchange_function")                                  \
   EXTERNAL_REFERENCE_LIST_INTL(V)
 
 #ifndef V8_INTERPRETED_REGEXP
@@ -200,7 +205,7 @@ class StatsCounter;
 // in an ExternalReference instance. This is done in order to track the
 // origin of all external references in the code so that they can be bound
 // to the correct addresses when deserializing a heap.
-class ExternalReference BASE_EMBEDDED {
+class ExternalReference {
  public:
   // Used in the simulator to support different native api calls.
   enum Type {
@@ -268,7 +273,7 @@ class ExternalReference BASE_EMBEDDED {
 
   static ExternalReference page_flags(Page* page);
 
-  static ExternalReference ForDeoptEntry(Address entry);
+  static ExternalReference FromRawAddress(Address address);
 
 #define DECL_EXTERNAL_REFERENCE(name, desc) static ExternalReference name();
   EXTERNAL_REFERENCE_LIST(DECL_EXTERNAL_REFERENCE)
diff --git a/deps/v8/src/feedback-vector-inl.h b/deps/v8/src/feedback-vector-inl.h
index d539eef57b..c9cdb0a157 100644
--- a/deps/v8/src/feedback-vector-inl.h
+++ b/deps/v8/src/feedback-vector-inl.h
@@ -116,11 +116,9 @@ void FeedbackVector::increment_deopt_count() {
 
 Code* FeedbackVector::optimized_code() const {
   MaybeObject* slot = optimized_code_weak_or_smi();
-  DCHECK(slot->IsSmi() || slot->IsClearedWeakHeapObject() ||
-         slot->IsWeakHeapObject());
+  DCHECK(slot->IsSmi() || slot->IsWeakOrCleared());
   HeapObject* heap_object;
-  return slot->ToStrongOrWeakHeapObject(&heap_object) ? Code::cast(heap_object)
-                                                      : nullptr;
+  return slot->GetHeapObject(&heap_object) ? Code::cast(heap_object) : nullptr;
 }
 
 OptimizationMarker FeedbackVector::optimization_marker() const {
@@ -279,8 +277,8 @@ void FeedbackVector::ComputeCounts(int* with_type_info, int* generic,
       case FeedbackSlotKind::kStoreDataPropertyInLiteral:
       case FeedbackSlotKind::kTypeProfile: {
         HeapObject* heap_object;
-        if (obj->IsWeakOrClearedHeapObject() ||
-            (obj->ToStrongHeapObject(&heap_object) &&
+        if (obj->IsWeakOrCleared() ||
+            (obj->GetHeapObjectIfStrong(&heap_object) &&
              (heap_object->IsWeakFixedArray() || heap_object->IsString()))) {
           with++;
         } else if (obj == megamorphic_sentinel) {
@@ -291,7 +289,7 @@ void FeedbackVector::ComputeCounts(int* with_type_info, int* generic,
         break;
       }
       case FeedbackSlotKind::kBinaryOp: {
-        int const feedback = Smi::ToInt(obj->ToSmi());
+        int const feedback = Smi::ToInt(obj->cast<Smi>());
         BinaryOperationHint hint = BinaryOperationHintFromFeedback(feedback);
         if (hint == BinaryOperationHint::kAny) {
           gen++;
@@ -303,7 +301,7 @@ void FeedbackVector::ComputeCounts(int* with_type_info, int* generic,
         break;
       }
       case FeedbackSlotKind::kCompareOp: {
-        int const feedback = Smi::ToInt(obj->ToSmi());
+        int const feedback = Smi::ToInt(obj->cast<Smi>());
         CompareOperationHint hint = CompareOperationHintFromFeedback(feedback);
         if (hint == CompareOperationHint::kAny) {
           gen++;
@@ -315,7 +313,7 @@ void FeedbackVector::ComputeCounts(int* with_type_info, int* generic,
         break;
       }
       case FeedbackSlotKind::kForIn: {
-        int const feedback = Smi::ToInt(obj->ToSmi());
+        int const feedback = Smi::ToInt(obj->cast<Smi>());
         ForInHint hint = ForInHintFromFeedback(feedback);
         if (hint == ForInHint::kAny) {
           gen++;
@@ -327,7 +325,7 @@ void FeedbackVector::ComputeCounts(int* with_type_info, int* generic,
         break;
       }
       case FeedbackSlotKind::kInstanceOf: {
-        if (obj->IsWeakOrClearedHeapObject()) {
+        if (obj->IsWeakOrCleared()) {
           with++;
         } else if (obj == megamorphic_sentinel) {
           gen++;
diff --git a/deps/v8/src/feedback-vector.cc b/deps/v8/src/feedback-vector.cc
index 90ae08b0ba..eaea7a978c 100644
--- a/deps/v8/src/feedback-vector.cc
+++ b/deps/v8/src/feedback-vector.cc
@@ -42,7 +42,7 @@ bool FeedbackVectorSpec::HasTypeProfileSlot() const {
 
 static bool IsPropertyNameFeedback(MaybeObject* feedback) {
   HeapObject* heap_object;
-  if (!feedback->ToStrongHeapObject(&heap_object)) return false;
+  if (!feedback->GetHeapObjectIfStrong(&heap_object)) return false;
   if (heap_object->IsString()) return true;
   if (!heap_object->IsSymbol()) return false;
   Symbol* symbol = Symbol::cast(heap_object);
@@ -331,7 +331,7 @@ void FeedbackVector::EvictOptimizedCodeMarkedForDeoptimization(
     return;
   }
 
-  if (slot->IsClearedWeakHeapObject()) {
+  if (slot->IsCleared()) {
     ClearOptimizationMarker();
     return;
   }
@@ -373,7 +373,7 @@ bool FeedbackVector::ClearSlots(Isolate* isolate) {
 void FeedbackVector::AssertNoLegacyTypes(MaybeObject* object) {
 #ifdef DEBUG
   HeapObject* heap_object;
-  if (object->ToStrongOrWeakHeapObject(&heap_object)) {
+  if (object->GetHeapObject(&heap_object)) {
     // Instead of FixedArray, the Feedback and the Extra should contain
     // WeakFixedArrays. The only allowed FixedArray subtype is HashTable.
     DCHECK_IMPLIES(heap_object->IsFixedArray(), heap_object->IsHashTable());
@@ -384,7 +384,7 @@ void FeedbackVector::AssertNoLegacyTypes(MaybeObject* object) {
 Handle<WeakFixedArray> FeedbackNexus::EnsureArrayOfSize(int length) {
   Isolate* isolate = GetIsolate();
   HeapObject* heap_object;
-  if (GetFeedback()->ToStrongHeapObject(&heap_object) &&
+  if (GetFeedback()->GetHeapObjectIfStrong(&heap_object) &&
       heap_object->IsWeakFixedArray() &&
       WeakFixedArray::cast(heap_object)->length() == length) {
     return handle(WeakFixedArray::cast(heap_object), isolate);
@@ -397,7 +397,7 @@ Handle<WeakFixedArray> FeedbackNexus::EnsureArrayOfSize(int length) {
 Handle<WeakFixedArray> FeedbackNexus::EnsureExtraArrayOfSize(int length) {
   Isolate* isolate = GetIsolate();
   HeapObject* heap_object;
-  if (GetFeedbackExtra()->ToStrongHeapObject(&heap_object) &&
+  if (GetFeedbackExtra()->GetHeapObjectIfStrong(&heap_object) &&
       heap_object->IsWeakFixedArray() &&
       WeakFixedArray::cast(heap_object)->length() == length) {
     return handle(WeakFixedArray::cast(heap_object), isolate);
@@ -546,10 +546,11 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
 
   switch (kind()) {
     case FeedbackSlotKind::kCreateClosure:
+      return MONOMORPHIC;
+
     case FeedbackSlotKind::kLiteral:
-      // CreateClosure and literal slots don't have a notion of state.
-      UNREACHABLE();
-      break;
+      if (feedback->IsSmi()) return UNINITIALIZED;
+      return MONOMORPHIC;
 
     case FeedbackSlotKind::kStoreGlobalSloppy:
     case FeedbackSlotKind::kStoreGlobalStrict:
@@ -557,9 +558,9 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
     case FeedbackSlotKind::kLoadGlobalInsideTypeof: {
       if (feedback->IsSmi()) return MONOMORPHIC;
 
-      DCHECK(feedback->IsWeakOrClearedHeapObject());
+      DCHECK(feedback->IsWeakOrCleared());
       MaybeObject* extra = GetFeedbackExtra();
-      if (!feedback->IsClearedWeakHeapObject() ||
+      if (!feedback->IsCleared() ||
           extra != MaybeObject::FromObject(
                        *FeedbackVector::UninitializedSentinel(isolate))) {
         return MONOMORPHIC;
@@ -587,12 +588,12 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
                           *FeedbackVector::PremonomorphicSentinel(isolate))) {
         return PREMONOMORPHIC;
       }
-      if (feedback->IsWeakOrClearedHeapObject()) {
+      if (feedback->IsWeakOrCleared()) {
         // Don't check if the map is cleared.
         return MONOMORPHIC;
       }
       HeapObject* heap_object;
-      if (feedback->ToStrongHeapObject(&heap_object)) {
+      if (feedback->GetHeapObjectIfStrong(&heap_object)) {
         if (heap_object->IsWeakFixedArray()) {
           // Determine state purely by our structure, don't check if the maps
           // are cleared.
@@ -600,7 +601,7 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
         }
         if (heap_object->IsName()) {
           DCHECK(IsKeyedLoadICKind(kind()) || IsKeyedStoreICKind(kind()));
-          Object* extra = GetFeedbackExtra()->ToStrongHeapObject();
+          Object* extra = GetFeedbackExtra()->GetHeapObjectAssumeStrong();
           WeakFixedArray* extra_array = WeakFixedArray::cast(extra);
           return extra_array->length() > 2 ? POLYMORPHIC : MONOMORPHIC;
         }
@@ -612,8 +613,8 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
       if (feedback == MaybeObject::FromObject(
                           *FeedbackVector::MegamorphicSentinel(isolate))) {
         return GENERIC;
-      } else if (feedback->IsWeakOrClearedHeapObject() ||
-                 (feedback->ToStrongHeapObject(&heap_object) &&
+      } else if (feedback->IsWeakOrCleared() ||
+                 (feedback->GetHeapObjectIfStrong(&heap_object) &&
                   heap_object->IsAllocationSite())) {
         return MONOMORPHIC;
       }
@@ -666,7 +667,7 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
       if (feedback == MaybeObject::FromObject(
                           *FeedbackVector::UninitializedSentinel(isolate))) {
         return UNINITIALIZED;
-      } else if (feedback->IsWeakOrClearedHeapObject()) {
+      } else if (feedback->IsWeakOrCleared()) {
         // Don't check if the map is cleared.
         return MONOMORPHIC;
       }
@@ -690,11 +691,11 @@ InlineCacheState FeedbackNexus::StateFromFeedback() const {
                           *FeedbackVector::MegamorphicSentinel(isolate))) {
         return MEGAMORPHIC;
       }
-      if (feedback->IsWeakOrClearedHeapObject()) {
+      if (feedback->IsWeakOrCleared()) {
         return MONOMORPHIC;
       }
 
-      DCHECK(feedback->ToStrongHeapObject()->IsWeakFixedArray());
+      DCHECK(feedback->GetHeapObjectAssumeStrong()->IsWeakFixedArray());
       return POLYMORPHIC;
     }
 
@@ -744,7 +745,7 @@ void FeedbackNexus::ConfigureCloneObject(Handle<Map> source_map,
                                          Handle<Map> result_map) {
   Isolate* isolate = GetIsolate();
   MaybeObject* maybe_feedback = GetFeedback();
-  Handle<HeapObject> feedback(maybe_feedback->IsStrongOrWeakHeapObject()
+  Handle<HeapObject> feedback(maybe_feedback->IsStrongOrWeak()
                                   ? maybe_feedback->GetHeapObject()
                                   : nullptr,
                               isolate);
@@ -755,8 +756,7 @@ void FeedbackNexus::ConfigureCloneObject(Handle<Map> source_map,
       SetFeedbackExtra(*result_map);
       break;
     case MONOMORPHIC:
-      if (maybe_feedback->IsClearedWeakHeapObject() ||
-          feedback.is_identical_to(source_map) ||
+      if (maybe_feedback->IsCleared() || feedback.is_identical_to(source_map) ||
           Map::cast(*feedback)->is_deprecated()) {
         // Remain in MONOMORPHIC state if previous feedback has been collected.
         SetFeedback(HeapObjectReference::Weak(*source_map));
@@ -779,7 +779,7 @@ void FeedbackNexus::ConfigureCloneObject(Handle<Map> source_map,
       int i = 0;
       for (; i < array->length(); i += kCloneObjectPolymorphicEntrySize) {
         MaybeObject* feedback = array->Get(i);
-        if (feedback->IsClearedWeakHeapObject()) break;
+        if (feedback->IsCleared()) break;
         Handle<Map> cached_map(Map::cast(feedback->GetHeapObject()), isolate);
         if (cached_map.is_identical_to(source_map) ||
             cached_map->is_deprecated())
@@ -818,7 +818,7 @@ void FeedbackNexus::ConfigureCloneObject(Handle<Map> source_map,
 int FeedbackNexus::GetCallCount() {
   DCHECK(IsCallICKind(kind()));
 
-  Object* call_count = GetFeedbackExtra()->ToObject();
+  Object* call_count = GetFeedbackExtra()->cast<Object>();
   CHECK(call_count->IsSmi());
   uint32_t value = static_cast<uint32_t>(Smi::ToInt(call_count));
   return CallCountField::decode(value);
@@ -827,7 +827,7 @@ int FeedbackNexus::GetCallCount() {
 void FeedbackNexus::SetSpeculationMode(SpeculationMode mode) {
   DCHECK(IsCallICKind(kind()));
 
-  Object* call_count = GetFeedbackExtra()->ToObject();
+  Object* call_count = GetFeedbackExtra()->cast<Object>();
   CHECK(call_count->IsSmi());
   uint32_t count = static_cast<uint32_t>(Smi::ToInt(call_count));
   uint32_t value = CallCountField::encode(CallCountField::decode(count));
@@ -838,7 +838,7 @@ void FeedbackNexus::SetSpeculationMode(SpeculationMode mode) {
 SpeculationMode FeedbackNexus::GetSpeculationMode() {
   DCHECK(IsCallICKind(kind()));
 
-  Object* call_count = GetFeedbackExtra()->ToObject();
+  Object* call_count = GetFeedbackExtra()->cast<Object>();
   CHECK(call_count->IsSmi());
   uint32_t value = static_cast<uint32_t>(Smi::ToInt(call_count));
   return SpeculationModeField::decode(value);
@@ -910,35 +910,36 @@ int FeedbackNexus::ExtractMaps(MapHandles* maps) const {
   MaybeObject* feedback = GetFeedback();
   bool is_named_feedback = IsPropertyNameFeedback(feedback);
   HeapObject* heap_object;
-  if ((feedback->ToStrongHeapObject(&heap_object) &&
+  if ((feedback->GetHeapObjectIfStrong(&heap_object) &&
        heap_object->IsWeakFixedArray()) ||
       is_named_feedback) {
     int found = 0;
     WeakFixedArray* array;
     if (is_named_feedback) {
-      array = WeakFixedArray::cast(GetFeedbackExtra()->ToStrongHeapObject());
+      array =
+          WeakFixedArray::cast(GetFeedbackExtra()->GetHeapObjectAssumeStrong());
     } else {
       array = WeakFixedArray::cast(heap_object);
     }
     const int increment = 2;
     HeapObject* heap_object;
     for (int i = 0; i < array->length(); i += increment) {
-      DCHECK(array->Get(i)->IsWeakOrClearedHeapObject());
-      if (array->Get(i)->ToWeakHeapObject(&heap_object)) {
+      DCHECK(array->Get(i)->IsWeakOrCleared());
+      if (array->Get(i)->GetHeapObjectIfWeak(&heap_object)) {
         Map* map = Map::cast(heap_object);
         maps->push_back(handle(map, isolate));
         found++;
       }
     }
     return found;
-  } else if (feedback->ToWeakHeapObject(&heap_object)) {
+  } else if (feedback->GetHeapObjectIfWeak(&heap_object)) {
     Map* map = Map::cast(heap_object);
     maps->push_back(handle(map, isolate));
     return 1;
-  } else if (feedback->ToStrongHeapObject(&heap_object) &&
+  } else if (feedback->GetHeapObjectIfStrong(&heap_object) &&
              heap_object ==
                  heap_object->GetReadOnlyRoots().premonomorphic_symbol()) {
-    if (GetFeedbackExtra()->ToWeakHeapObject(&heap_object)) {
+    if (GetFeedbackExtra()->GetHeapObjectIfWeak(&heap_object)) {
       Map* map = Map::cast(heap_object);
       maps->push_back(handle(map, isolate));
       return 1;
@@ -957,32 +958,32 @@ MaybeObjectHandle FeedbackNexus::FindHandlerForMap(Handle<Map> map) const {
   Isolate* isolate = GetIsolate();
   bool is_named_feedback = IsPropertyNameFeedback(feedback);
   HeapObject* heap_object;
-  if ((feedback->ToStrongHeapObject(&heap_object) &&
+  if ((feedback->GetHeapObjectIfStrong(&heap_object) &&
        heap_object->IsWeakFixedArray()) ||
       is_named_feedback) {
     WeakFixedArray* array;
     if (is_named_feedback) {
-      array = WeakFixedArray::cast(GetFeedbackExtra()->ToStrongHeapObject());
+      array =
+          WeakFixedArray::cast(GetFeedbackExtra()->GetHeapObjectAssumeStrong());
     } else {
       array = WeakFixedArray::cast(heap_object);
     }
     const int increment = 2;
     HeapObject* heap_object;
     for (int i = 0; i < array->length(); i += increment) {
-      DCHECK(array->Get(i)->IsWeakOrClearedHeapObject());
-      if (array->Get(i)->ToWeakHeapObject(&heap_object)) {
+      DCHECK(array->Get(i)->IsWeakOrCleared());
+      if (array->Get(i)->GetHeapObjectIfWeak(&heap_object)) {
         Map* array_map = Map::cast(heap_object);
-        if (array_map == *map &&
-            !array->Get(i + increment - 1)->IsClearedWeakHeapObject()) {
+        if (array_map == *map && !array->Get(i + increment - 1)->IsCleared()) {
           MaybeObject* handler = array->Get(i + increment - 1);
           DCHECK(IC::IsHandler(handler));
           return handle(handler, isolate);
         }
       }
     }
-  } else if (feedback->ToWeakHeapObject(&heap_object)) {
+  } else if (feedback->GetHeapObjectIfWeak(&heap_object)) {
     Map* cell_map = Map::cast(heap_object);
-    if (cell_map == *map && !GetFeedbackExtra()->IsClearedWeakHeapObject()) {
+    if (cell_map == *map && !GetFeedbackExtra()->IsCleared()) {
       MaybeObject* handler = GetFeedbackExtra();
       DCHECK(IC::IsHandler(handler));
       return handle(handler, isolate);
@@ -1004,12 +1005,13 @@ bool FeedbackNexus::FindHandlers(MaybeObjectHandles* code_list,
   int count = 0;
   bool is_named_feedback = IsPropertyNameFeedback(feedback);
   HeapObject* heap_object;
-  if ((feedback->ToStrongHeapObject(&heap_object) &&
+  if ((feedback->GetHeapObjectIfStrong(&heap_object) &&
        heap_object->IsWeakFixedArray()) ||
       is_named_feedback) {
     WeakFixedArray* array;
     if (is_named_feedback) {
-      array = WeakFixedArray::cast(GetFeedbackExtra()->ToStrongHeapObject());
+      array =
+          WeakFixedArray::cast(GetFeedbackExtra()->GetHeapObjectAssumeStrong());
     } else {
       array = WeakFixedArray::cast(heap_object);
     }
@@ -1017,18 +1019,18 @@ bool FeedbackNexus::FindHandlers(MaybeObjectHandles* code_list,
     HeapObject* heap_object;
     for (int i = 0; i < array->length(); i += increment) {
       // Be sure to skip handlers whose maps have been cleared.
-      DCHECK(array->Get(i)->IsWeakOrClearedHeapObject());
-      if (array->Get(i)->ToWeakHeapObject(&heap_object) &&
-          !array->Get(i + increment - 1)->IsClearedWeakHeapObject()) {
+      DCHECK(array->Get(i)->IsWeakOrCleared());
+      if (array->Get(i)->GetHeapObjectIfWeak(&heap_object) &&
+          !array->Get(i + increment - 1)->IsCleared()) {
         MaybeObject* handler = array->Get(i + increment - 1);
         DCHECK(IC::IsHandler(handler));
         code_list->push_back(handle(handler, isolate));
         count++;
       }
     }
-  } else if (feedback->ToWeakHeapObject(&heap_object)) {
+  } else if (feedback->GetHeapObjectIfWeak(&heap_object)) {
     MaybeObject* extra = GetFeedbackExtra();
-    if (!extra->IsClearedWeakHeapObject()) {
+    if (!extra->IsCleared()) {
       DCHECK(IC::IsHandler(extra));
       code_list->push_back(handle(extra, isolate));
       count++;
@@ -1041,7 +1043,7 @@ Name* FeedbackNexus::FindFirstName() const {
   if (IsKeyedStoreICKind(kind()) || IsKeyedLoadICKind(kind())) {
     MaybeObject* feedback = GetFeedback();
     if (IsPropertyNameFeedback(feedback)) {
-      return Name::cast(feedback->ToStrongHeapObject());
+      return Name::cast(feedback->GetHeapObjectAssumeStrong());
     }
   }
   return nullptr;
@@ -1115,32 +1117,33 @@ IcCheckType FeedbackNexus::GetKeyType() const {
   MaybeObject* feedback = GetFeedback();
   if (feedback == MaybeObject::FromObject(
                       *FeedbackVector::MegamorphicSentinel(GetIsolate()))) {
-    return static_cast<IcCheckType>(Smi::ToInt(GetFeedbackExtra()->ToObject()));
+    return static_cast<IcCheckType>(
+        Smi::ToInt(GetFeedbackExtra()->cast<Object>()));
   }
   return IsPropertyNameFeedback(feedback) ? PROPERTY : ELEMENT;
 }
 
 BinaryOperationHint FeedbackNexus::GetBinaryOperationFeedback() const {
   DCHECK_EQ(kind(), FeedbackSlotKind::kBinaryOp);
-  int feedback = Smi::ToInt(GetFeedback()->ToSmi());
+  int feedback = Smi::ToInt(GetFeedback()->cast<Smi>());
   return BinaryOperationHintFromFeedback(feedback);
 }
 
 CompareOperationHint FeedbackNexus::GetCompareOperationFeedback() const {
   DCHECK_EQ(kind(), FeedbackSlotKind::kCompareOp);
-  int feedback = Smi::ToInt(GetFeedback()->ToSmi());
+  int feedback = Smi::ToInt(GetFeedback()->cast<Smi>());
   return CompareOperationHintFromFeedback(feedback);
 }
 
 ForInHint FeedbackNexus::GetForInFeedback() const {
   DCHECK_EQ(kind(), FeedbackSlotKind::kForIn);
-  int feedback = Smi::ToInt(GetFeedback()->ToSmi());
+  int feedback = Smi::ToInt(GetFeedback()->cast<Smi>());
   return ForInHintFromFeedback(feedback);
 }
 
 Handle<FeedbackCell> FeedbackNexus::GetFeedbackCell() const {
   DCHECK_EQ(FeedbackSlotKind::kCreateClosure, kind());
-  return handle(FeedbackCell::cast(GetFeedback()->ToObject()),
+  return handle(FeedbackCell::cast(GetFeedback()->cast<Object>()),
                 vector()->GetIsolate());
 }
 
@@ -1149,7 +1152,7 @@ MaybeHandle<JSObject> FeedbackNexus::GetConstructorFeedback() const {
   Isolate* isolate = GetIsolate();
   MaybeObject* feedback = GetFeedback();
   HeapObject* heap_object;
-  if (feedback->ToWeakHeapObject(&heap_object)) {
+  if (feedback->GetHeapObjectIfWeak(&heap_object)) {
     return handle(JSObject::cast(heap_object), isolate);
   }
   return MaybeHandle<JSObject>();
@@ -1182,8 +1185,9 @@ void FeedbackNexus::Collect(Handle<String> type, int position) {
                       *FeedbackVector::UninitializedSentinel(isolate))) {
     types = SimpleNumberDictionary::New(isolate, 1);
   } else {
-    types = handle(SimpleNumberDictionary::cast(feedback->ToStrongHeapObject()),
-                   isolate);
+    types = handle(
+        SimpleNumberDictionary::cast(feedback->GetHeapObjectAssumeStrong()),
+        isolate);
   }
 
   Handle<ArrayList> position_specific_types;
@@ -1220,7 +1224,8 @@ std::vector<int> FeedbackNexus::GetSourcePositions() const {
   }
 
   Handle<SimpleNumberDictionary> types(
-      SimpleNumberDictionary::cast(feedback->ToStrongHeapObject()), isolate);
+      SimpleNumberDictionary::cast(feedback->GetHeapObjectAssumeStrong()),
+      isolate);
 
   for (int index = SimpleNumberDictionary::kElementsStartIndex;
        index < types->length(); index += SimpleNumberDictionary::kEntrySize) {
@@ -1247,7 +1252,8 @@ std::vector<Handle<String>> FeedbackNexus::GetTypesForSourcePositions(
   }
 
   Handle<SimpleNumberDictionary> types(
-      SimpleNumberDictionary::cast(feedback->ToStrongHeapObject()), isolate);
+      SimpleNumberDictionary::cast(feedback->GetHeapObjectAssumeStrong()),
+      isolate);
 
   int entry = types->FindEntry(isolate, position);
   if (entry == SimpleNumberDictionary::kNotFound) {
@@ -1305,10 +1311,10 @@ JSObject* FeedbackNexus::GetTypeProfile() const {
     return *isolate->factory()->NewJSObject(isolate->object_function());
   }
 
-  return *ConvertToJSObject(
-      isolate,
-      handle(SimpleNumberDictionary::cast(feedback->ToStrongHeapObject()),
-             isolate));
+  return *ConvertToJSObject(isolate,
+                            handle(SimpleNumberDictionary::cast(
+                                       feedback->GetHeapObjectAssumeStrong()),
+                                   isolate));
 }
 
 void FeedbackNexus::ResetTypeProfile() {
diff --git a/deps/v8/src/feedback-vector.h b/deps/v8/src/feedback-vector.h
index 3721ffec9a..71d84534b6 100644
--- a/deps/v8/src/feedback-vector.h
+++ b/deps/v8/src/feedback-vector.h
@@ -147,11 +147,6 @@ class FeedbackMetadata;
 // metadata.
 class FeedbackVector : public HeapObject, public NeverReadOnlySpaceObject {
  public:
-  // Use the mixin methods over the HeapObject methods.
-  // TODO(v8:7786) Remove once the HeapObject methods are gone.
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   // Casting.
   static inline FeedbackVector* cast(Object* obj);
 
@@ -294,12 +289,10 @@ class FeedbackVector : public HeapObject, public NeverReadOnlySpaceObject {
 #undef FEEDBACK_VECTOR_FIELDS
 
   static const int kHeaderSize =
-      RoundUp<kPointerAlignment>(kUnalignedHeaderSize);
+      RoundUp<kPointerAlignment>(int{kUnalignedHeaderSize});
   static const int kFeedbackSlotsOffset = kHeaderSize;
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   // Garbage collection support.
   static constexpr int SizeFor(int length) {
@@ -352,11 +345,14 @@ class V8_EXPORT_PRIVATE FeedbackVectorSpec {
     return AddSlot(FeedbackSlotKind::kLoadKeyed);
   }
 
-  FeedbackSlot AddStoreICSlot(LanguageMode language_mode) {
+  FeedbackSlotKind GetStoreICSlot(LanguageMode language_mode) {
     STATIC_ASSERT(LanguageModeSize == 2);
-    return AddSlot(is_strict(language_mode)
-                       ? FeedbackSlotKind::kStoreNamedStrict
-                       : FeedbackSlotKind::kStoreNamedSloppy);
+    return is_strict(language_mode) ? FeedbackSlotKind::kStoreNamedStrict
+                                    : FeedbackSlotKind::kStoreNamedSloppy;
+  }
+
+  FeedbackSlot AddStoreICSlot(LanguageMode language_mode) {
+    return AddSlot(GetStoreICSlot(language_mode));
   }
 
   FeedbackSlot AddStoreOwnICSlot() {
@@ -370,11 +366,14 @@ class V8_EXPORT_PRIVATE FeedbackVectorSpec {
                        : FeedbackSlotKind::kStoreGlobalSloppy);
   }
 
-  FeedbackSlot AddKeyedStoreICSlot(LanguageMode language_mode) {
+  FeedbackSlotKind GetKeyedStoreICSlotKind(LanguageMode language_mode) {
     STATIC_ASSERT(LanguageModeSize == 2);
-    return AddSlot(is_strict(language_mode)
-                       ? FeedbackSlotKind::kStoreKeyedStrict
-                       : FeedbackSlotKind::kStoreKeyedSloppy);
+    return is_strict(language_mode) ? FeedbackSlotKind::kStoreKeyedStrict
+                                    : FeedbackSlotKind::kStoreKeyedSloppy;
+  }
+
+  FeedbackSlot AddKeyedStoreICSlot(LanguageMode language_mode) {
+    return AddSlot(GetKeyedStoreICSlotKind(language_mode));
   }
 
   FeedbackSlot AddStoreInArrayLiteralICSlot() {
@@ -422,6 +421,26 @@ class V8_EXPORT_PRIVATE FeedbackVectorSpec {
   }
 
   ZoneVector<unsigned char> slot_kinds_;
+
+  friend class SharedFeedbackSlot;
+};
+
+// Helper class that creates a feedback slot on-demand.
+class SharedFeedbackSlot {
+ public:
+  // FeedbackSlot default constructor constructs an invalid slot.
+  SharedFeedbackSlot(FeedbackVectorSpec* spec, FeedbackSlotKind kind)
+      : kind_(kind), spec_(spec) {}
+
+  FeedbackSlot Get() {
+    if (slot_.IsInvalid()) slot_ = spec_->AddSlot(kind_);
+    return slot_;
+  }
+
+ private:
+  FeedbackSlotKind kind_;
+  FeedbackSlot slot_;
+  FeedbackVectorSpec* spec_;
 };
 
 // FeedbackMetadata is an array-like object with a slot count (indicating how
@@ -471,8 +490,6 @@ class FeedbackMetadata : public HeapObject {
   static const int kHeaderSize = kSlotCountOffset + kInt32Size;
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   friend class AccessorAssembler;
diff --git a/deps/v8/src/flag-definitions.h b/deps/v8/src/flag-definitions.h
index 69ec7472bb..170a777c72 100644
--- a/deps/v8/src/flag-definitions.h
+++ b/deps/v8/src/flag-definitions.h
@@ -209,18 +209,18 @@ DEFINE_IMPLICATION(harmony_class_fields, harmony_private_fields)
 // Update bootstrapper.cc whenever adding a new feature flag.
 
 // Features that are still work in progress (behind individual flags).
-#define HARMONY_INPROGRESS_BASE(V)                                    \
-  V(harmony_do_expressions, "harmony do-expressions")                 \
-  V(harmony_class_fields, "harmony fields in class literals")         \
-  V(harmony_static_fields, "harmony static fields in class literals") \
-  V(harmony_await_optimization, "harmony await taking 1 tick")
+#define HARMONY_INPROGRESS_BASE(V)                             \
+  V(harmony_do_expressions, "harmony do-expressions")          \
+  V(harmony_class_fields, "harmony fields in class literals")  \
+  V(harmony_await_optimization, "harmony await taking 1 tick") \
+  V(harmony_regexp_sequence, "RegExp Unicode sequence properties")
 
 #ifdef V8_INTL_SUPPORT
 #define HARMONY_INPROGRESS(V)                    \
   HARMONY_INPROGRESS_BASE(V)                     \
   V(harmony_locale, "Intl.Locale")               \
   V(harmony_intl_list_format, "Intl.ListFormat") \
-  V(harmony_intl_relative_time_format, "Intl.RelativeTimeFormat")
+  V(harmony_intl_segmenter, "Intl.Segmenter")
 #else
 #define HARMONY_INPROGRESS(V) HARMONY_INPROGRESS_BASE(V)
 #endif
@@ -231,19 +231,26 @@ DEFINE_IMPLICATION(harmony_class_fields, harmony_private_fields)
   V(harmony_private_fields, "harmony private fields in class literals")    \
   V(harmony_numeric_separator, "harmony numeric separator between digits") \
   V(harmony_string_matchall, "harmony String.prototype.matchAll")          \
-  V(harmony_global, "harmony global")
+  V(harmony_static_fields, "harmony static fields in class literals")      \
+  V(harmony_json_stringify, "Well-formed JSON.stringify")
 
 // Features that are shipping (turned on by default, but internal flag remains).
-#define HARMONY_SHIPPING(V)                                              \
-  V(harmony_string_trimming, "harmony String.prototype.trim{Start,End}") \
+#define HARMONY_SHIPPING_BASE(V)                                         \
   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")              \
-  V(harmony_function_tostring, "harmony Function.prototype.toString")    \
   V(harmony_import_meta, "harmony import.meta property")                 \
-  V(harmony_bigint, "harmony arbitrary precision integers")              \
   V(harmony_dynamic_import, "harmony dynamic import")                    \
   V(harmony_array_prototype_values, "harmony Array.prototype.values")    \
   V(harmony_array_flat, "harmony Array.prototype.{flat,flatMap}")        \
-  V(harmony_symbol_description, "harmony Symbol.prototype.description")
+  V(harmony_symbol_description, "harmony Symbol.prototype.description")  \
+  V(harmony_global, "harmony global")
+
+#ifdef V8_INTL_SUPPORT
+#define HARMONY_SHIPPING(V) \
+  HARMONY_SHIPPING_BASE(V)  \
+  V(harmony_intl_relative_time_format, "Intl.RelativeTimeFormat")
+#else
+#define HARMONY_SHIPPING(V) HARMONY_SHIPPING_BASE(V)
+#endif
 
 // Once a shipping feature has proved stable in the wild, it will be dropped
 // from HARMONY_SHIPPING, all occurrences of the FLAG_ variable are removed,
@@ -518,9 +525,6 @@ DEFINE_BOOL(untrusted_code_mitigations, V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS,
             "Enable mitigations for executing untrusted code")
 #undef V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS
 
-DEFINE_BOOL(branch_load_poisoning, false, "Mask loads with branch conditions.")
-DEFINE_IMPLICATION(future, branch_load_poisoning)
-
 // Flags to help platform porters
 DEFINE_BOOL(minimal, false,
             "simplifies execution model to make porting "
@@ -536,11 +540,11 @@ DEFINE_BOOL(wasm_disable_structured_cloning, false,
             "disable wasm structured cloning")
 DEFINE_INT(wasm_num_compilation_tasks, 10,
            "number of parallel compilation tasks for wasm")
-DEFINE_DEBUG_BOOL(wasm_trace_native_heap, false,
+DEFINE_DEBUG_BOOL(trace_wasm_native_heap, false,
                   "trace wasm native heap events")
 DEFINE_BOOL(wasm_write_protect_code_memory, false,
             "write protect code memory on the wasm native heap")
-DEFINE_BOOL(wasm_trace_serialization, false,
+DEFINE_BOOL(trace_wasm_serialization, false,
             "trace serialization/deserialization")
 DEFINE_BOOL(wasm_async_compilation, true,
             "enable actual asynchronous compilation for WebAssembly.compile")
@@ -580,7 +584,7 @@ DEFINE_DEBUG_BOOL(trace_liftoff, false,
                   "trace Liftoff, the baseline compiler for WebAssembly")
 DEFINE_DEBUG_BOOL(wasm_break_on_decoder_error, false,
                   "debug break when wasm decoder encounters an error")
-DEFINE_BOOL(wasm_trace_memory, false,
+DEFINE_BOOL(trace_wasm_memory, false,
             "print all memory updates performed in wasm code")
 // Fuzzers use {wasm_tier_mask_for_testing} together with {liftoff} and
 // {no_wasm_tier_up} to force some functions to be compiled with Turbofan.
@@ -874,8 +878,6 @@ DEFINE_BOOL(expose_trigger_failure, false, "expose trigger-failure extension")
 DEFINE_INT(stack_trace_limit, 10, "number of stack frames to capture")
 DEFINE_BOOL(builtins_in_stack_traces, false,
             "show built-in functions in stack traces")
-DEFINE_BOOL(enable_experimental_builtins, false,
-            "enable new csa-based experimental builtins")
 DEFINE_BOOL(disallow_code_generation_from_strings, false,
             "disallow eval and friends")
 DEFINE_BOOL(expose_async_hooks, false, "expose async_hooks object")
@@ -922,11 +924,6 @@ DEFINE_BOOL(compiler_dispatcher, false, "enable compiler dispatcher")
 DEFINE_BOOL(trace_compiler_dispatcher, false,
             "trace compiler dispatcher activity")
 
-// compiler-dispatcher-job.cc
-DEFINE_BOOL(
-    trace_compiler_dispatcher_jobs, false,
-    "trace progress of individual jobs managed by the compiler dispatcher")
-
 // cpu-profiler.cc
 DEFINE_INT(cpu_profiler_sampling_interval, 1000,
            "CPU profiler sampling interval in microseconds")
@@ -1043,6 +1040,9 @@ DEFINE_BOOL(trace_sim_messages, false,
             "Trace simulator debug messages. Implied by --trace-sim.")
 
 // isolate.cc
+DEFINE_BOOL(async_stack_traces, false,
+            "include async stack traces in Error.stack")
+DEFINE_IMPLICATION(async_stack_traces, harmony_await_optimization)
 DEFINE_BOOL(stack_trace_on_illegal, false,
             "print stack trace when an illegal exception is thrown")
 DEFINE_BOOL(abort_on_uncaught_exception, false,
@@ -1093,10 +1093,6 @@ DEFINE_BOOL(print_embedded_builtin_candidates, false,
             "Prints builtins that are not yet embedded but could be.")
 DEFINE_BOOL(lazy_deserialization, true,
             "Deserialize code lazily from the snapshot.")
-DEFINE_BOOL(lazy_handler_deserialization, true,
-            "Deserialize bytecode handlers lazily from the snapshot.")
-DEFINE_IMPLICATION(lazy_handler_deserialization, lazy_deserialization)
-DEFINE_IMPLICATION(future, lazy_handler_deserialization)
 DEFINE_BOOL(trace_lazy_deserialization, false, "Trace lazy deserialization.")
 DEFINE_BOOL(profile_deserialization, false,
             "Print the time it takes to deserialize the snapshot.")
@@ -1154,6 +1150,9 @@ DEFINE_ARGS(js_arguments,
             "Pass all remaining arguments to the script. Alias for \"--\".")
 DEFINE_BOOL(mock_arraybuffer_allocator, false,
             "Use a mock ArrayBuffer allocator for testing.")
+DEFINE_SIZE_T(mock_arraybuffer_allocator_limit, 0,
+              "Memory limit for mock ArrayBuffer allocator used to simulate "
+              "OOM for testing.")
 
 //
 // GDB JIT integration flags.
diff --git a/deps/v8/src/frames.cc b/deps/v8/src/frames.cc
index 9dee01698e..a4d2561cd3 100644
--- a/deps/v8/src/frames.cc
+++ b/deps/v8/src/frames.cc
@@ -29,7 +29,7 @@ ReturnAddressLocationResolver StackFrame::return_address_location_resolver_ =
 
 // Iterator that supports traversing the stack handlers of a
 // particular frame. Needs to know the top of the handler chain.
-class StackHandlerIterator BASE_EMBEDDED {
+class StackHandlerIterator {
  public:
   StackHandlerIterator(const StackFrame* frame, StackHandler* handler)
       : limit_(frame->fp()), handler_(handler) {
diff --git a/deps/v8/src/frames.h b/deps/v8/src/frames.h
index 40fce95e7f..a8c0989036 100644
--- a/deps/v8/src/frames.h
+++ b/deps/v8/src/frames.h
@@ -42,9 +42,7 @@ class InnerPointerToCodeCache {
     Flush();
   }
 
-  void Flush() {
-    memset(&cache_[0], 0, sizeof(cache_));
-  }
+  void Flush() { memset(static_cast<void*>(&cache_[0]), 0, sizeof(cache_)); }
 
   InnerPointerToCodeCacheEntry* GetCacheEntry(Address inner_pointer);
 
@@ -69,8 +67,7 @@ class StackHandlerConstants : public AllStatic {
   static const int kSlotCount = kSize >> kPointerSizeLog2;
 };
 
-
-class StackHandler BASE_EMBEDDED {
+class StackHandler {
  public:
   // Get the address of this stack handler.
   inline Address address() const;
@@ -110,7 +107,7 @@ class StackHandler BASE_EMBEDDED {
   V(NATIVE, NativeFrame)
 
 // Abstract base class for all stack frames.
-class StackFrame BASE_EMBEDDED {
+class StackFrame {
  public:
 #define DECLARE_TYPE(type, ignore) type,
   enum Type {
@@ -262,7 +259,7 @@ class StackFrame BASE_EMBEDDED {
   }
 
   // Get the id of this stack frame.
-  Id id() const { return static_cast<Id>(OffsetFrom(caller_sp())); }
+  Id id() const { return static_cast<Id>(caller_sp()); }
 
   // Get the top handler from the current stack iterator.
   inline StackHandler* top_handler() const;
@@ -301,7 +298,7 @@ class StackFrame BASE_EMBEDDED {
 
  protected:
   inline explicit StackFrame(StackFrameIteratorBase* iterator);
-  virtual ~StackFrame() { }
+  virtual ~StackFrame() = default;
 
   // Compute the stack pointer for the calling frame.
   virtual Address GetCallerStackPointer() const = 0;
@@ -476,7 +473,7 @@ class BuiltinExitFrame : public ExitFrame {
 
 class StandardFrame;
 
-class FrameSummary BASE_EMBEDDED {
+class FrameSummary {
  public:
 // Subclasses for the different summary kinds:
 #define FRAME_SUMMARY_VARIANTS(F)                                             \
@@ -1202,7 +1199,7 @@ class JavaScriptBuiltinContinuationWithCatchFrame
   friend class StackFrameIteratorBase;
 };
 
-class StackFrameIteratorBase BASE_EMBEDDED {
+class StackFrameIteratorBase {
  public:
   Isolate* isolate() const { return isolate_; }
 
@@ -1257,7 +1254,7 @@ class StackFrameIterator: public StackFrameIteratorBase {
 };
 
 // Iterator that supports iterating through all JavaScript frames.
-class JavaScriptFrameIterator BASE_EMBEDDED {
+class JavaScriptFrameIterator {
  public:
   inline explicit JavaScriptFrameIterator(Isolate* isolate);
   inline JavaScriptFrameIterator(Isolate* isolate, ThreadLocalTop* top);
@@ -1275,7 +1272,7 @@ class JavaScriptFrameIterator BASE_EMBEDDED {
 // NOTE: The stack trace frame iterator is an iterator that only traverse proper
 // JavaScript frames that have proper JavaScript functions and WebAssembly
 // frames.
-class StackTraceFrameIterator BASE_EMBEDDED {
+class StackTraceFrameIterator {
  public:
   explicit StackTraceFrameIterator(Isolate* isolate);
   // Skip frames until the frame with the given id is reached.
diff --git a/deps/v8/src/futex-emulation.cc b/deps/v8/src/futex-emulation.cc
index c0704ee9a2..c1dd523984 100644
--- a/deps/v8/src/futex-emulation.cc
+++ b/deps/v8/src/futex-emulation.cc
@@ -89,7 +89,7 @@ void AtomicsWaitWakeHandle::Wake() {
 Object* FutexEmulation::Wait(Isolate* isolate,
                              Handle<JSArrayBuffer> array_buffer, size_t addr,
                              int32_t value, double rel_timeout_ms) {
-  DCHECK(addr < NumberToSize(array_buffer->byte_length()));
+  DCHECK_LT(addr, array_buffer->byte_length());
 
   void* backing_store = array_buffer->backing_store();
   int32_t* p =
@@ -223,7 +223,7 @@ Object* FutexEmulation::Wait(Isolate* isolate,
     }
 
     wait_list_.Pointer()->RemoveNode(node);
-  } while (0);
+  } while (false);
 
   isolate->RunAtomicsWaitCallback(callback_result, array_buffer, addr, value,
                                   rel_timeout_ms, nullptr);
@@ -238,7 +238,7 @@ Object* FutexEmulation::Wait(Isolate* isolate,
 
 Object* FutexEmulation::Wake(Handle<JSArrayBuffer> array_buffer, size_t addr,
                              uint32_t num_waiters_to_wake) {
-  DCHECK(addr < NumberToSize(array_buffer->byte_length()));
+  DCHECK_LT(addr, array_buffer->byte_length());
 
   int waiters_woken = 0;
   void* backing_store = array_buffer->backing_store();
@@ -263,7 +263,7 @@ Object* FutexEmulation::Wake(Handle<JSArrayBuffer> array_buffer, size_t addr,
 
 Object* FutexEmulation::NumWaitersForTesting(Handle<JSArrayBuffer> array_buffer,
                                              size_t addr) {
-  DCHECK(addr < NumberToSize(array_buffer->byte_length()));
+  DCHECK_LT(addr, array_buffer->byte_length());
   void* backing_store = array_buffer->backing_store();
 
   base::LockGuard<base::Mutex> lock_guard(mutex_.Pointer());
diff --git a/deps/v8/src/gdb-jit.cc b/deps/v8/src/gdb-jit.cc
index 4fa7ce0699..712408ab7e 100644
--- a/deps/v8/src/gdb-jit.cc
+++ b/deps/v8/src/gdb-jit.cc
@@ -41,7 +41,7 @@ typedef ELF DebugObject;
 typedef ELFSection DebugSection;
 #endif
 
-class Writer BASE_EMBEDDED {
+class Writer {
  public:
   explicit Writer(DebugObject* debug_object)
       : debug_object_(debug_object),
@@ -177,7 +177,7 @@ class ELFStringTable;
 template<typename THeader>
 class DebugSectionBase : public ZoneObject {
  public:
-  virtual ~DebugSectionBase() { }
+  virtual ~DebugSectionBase() = default;
 
   virtual void WriteBody(Writer::Slot<THeader> header, Writer* writer) {
     uintptr_t start = writer->position();
@@ -238,7 +238,7 @@ class MachOSection : public DebugSectionBase<MachOSectionHeader> {
     }
   }
 
-  virtual ~MachOSection() { }
+  ~MachOSection() override = default;
 
   virtual void PopulateHeader(Writer::Slot<Header> header) {
     header->addr = 0;
@@ -314,11 +314,11 @@ class ELFSection : public DebugSectionBase<ELFSectionHeader> {
   ELFSection(const char* name, Type type, uintptr_t align)
       : name_(name), type_(type), align_(align) { }
 
-  virtual ~ELFSection() { }
+  ~ELFSection() override = default;
 
   void PopulateHeader(Writer::Slot<Header> header, ELFStringTable* strtab);
 
-  virtual void WriteBody(Writer::Slot<Header> header, Writer* w) {
+  void WriteBody(Writer::Slot<Header> header, Writer* w) override {
     uintptr_t start = w->position();
     if (WriteBodyInternal(w)) {
       uintptr_t end = w->position();
@@ -327,9 +327,7 @@ class ELFSection : public DebugSectionBase<ELFSectionHeader> {
     }
   }
 
-  virtual bool WriteBodyInternal(Writer* w) {
-    return false;
-  }
+  bool WriteBodyInternal(Writer* w) override { return false; }
 
   uint16_t index() const { return index_; }
   void set_index(uint16_t index) { index_ = index; }
@@ -396,7 +394,7 @@ class FullHeaderELFSection : public ELFSection {
         flags_(flags) { }
 
  protected:
-  virtual void PopulateHeader(Writer::Slot<Header> header) {
+  void PopulateHeader(Writer::Slot<Header> header) override {
     ELFSection::PopulateHeader(header);
     header->address = addr_;
     header->offset = offset_;
@@ -438,7 +436,7 @@ class ELFStringTable : public ELFSection {
 
   void DetachWriter() { writer_ = nullptr; }
 
-  virtual void WriteBody(Writer::Slot<Header> header, Writer* w) {
+  void WriteBody(Writer::Slot<Header> header, Writer* w) override {
     DCHECK_NULL(writer_);
     header->offset = offset_;
     header->size = size_;
@@ -472,7 +470,7 @@ void ELFSection::PopulateHeader(Writer::Slot<ELFSection::Header> header,
 
 
 #if defined(__MACH_O)
-class MachO BASE_EMBEDDED {
+class MachO {
  public:
   explicit MachO(Zone* zone) : sections_(zone) {}
 
@@ -604,7 +602,7 @@ class MachO BASE_EMBEDDED {
 
 
 #if defined(__ELF)
-class ELF BASE_EMBEDDED {
+class ELF {
  public:
   explicit ELF(Zone* zone) : sections_(zone) {
     sections_.push_back(new (zone) ELFSection("", ELFSection::TYPE_NULL, 0));
@@ -746,8 +744,7 @@ class ELF BASE_EMBEDDED {
   ZoneChunkList<ELFSection*> sections_;
 };
 
-
-class ELFSymbol BASE_EMBEDDED {
+class ELFSymbol {
  public:
   enum Type {
     TYPE_NOTYPE = 0,
@@ -862,7 +859,7 @@ class ELFSymbolTable : public ELFSection {
         locals_(zone),
         globals_(zone) {}
 
-  virtual void WriteBody(Writer::Slot<Header> header, Writer* w) {
+  void WriteBody(Writer::Slot<Header> header, Writer* w) override {
     w->Align(header->alignment);
     size_t total_symbols = locals_.size() + globals_.size() + 1;
     header->offset = w->position();
@@ -899,7 +896,7 @@ class ELFSymbolTable : public ELFSection {
   }
 
  protected:
-  virtual void PopulateHeader(Writer::Slot<Header> header) {
+  void PopulateHeader(Writer::Slot<Header> header) override {
     ELFSection::PopulateHeader(header);
     // We are assuming that string table will follow symbol table.
     header->link = index() + 1;
@@ -946,8 +943,7 @@ class LineInfo : public Malloced {
   std::vector<PCInfo> pc_info_;
 };
 
-
-class CodeDescription BASE_EMBEDDED {
+class CodeDescription {
  public:
 #if V8_TARGET_ARCH_X64
   enum StackState {
@@ -1115,7 +1111,7 @@ class DebugInfoSection : public DebugSection {
     DW_ATE_SIGNED = 0x5
   };
 
-  bool WriteBodyInternal(Writer* w) {
+  bool WriteBodyInternal(Writer* w) override {
     uintptr_t cu_start = w->position();
     Writer::Slot<uint32_t> size = w->CreateSlotHere<uint32_t>();
     uintptr_t start = w->position();
@@ -1318,7 +1314,7 @@ class DebugAbbrevSection : public DebugSection {
     w->WriteULEB128(0);
   }
 
-  bool WriteBodyInternal(Writer* w) {
+  bool WriteBodyInternal(Writer* w) override {
     int current_abbreviation = 1;
     bool extra_info = desc_->has_scope_info();
     DCHECK(desc_->IsLineInfoAvailable());
@@ -1435,7 +1431,7 @@ class DebugLineSection : public DebugSection {
     DW_LNE_DEFINE_FILE = 3
   };
 
-  bool WriteBodyInternal(Writer* w) {
+  bool WriteBodyInternal(Writer* w) override {
     // Write prologue.
     Writer::Slot<uint32_t> total_length = w->CreateSlotHere<uint32_t>();
     uintptr_t start = w->position();
@@ -1571,7 +1567,7 @@ class DebugLineSection : public DebugSection {
 class UnwindInfoSection : public DebugSection {
  public:
   explicit UnwindInfoSection(CodeDescription* desc);
-  virtual bool WriteBodyInternal(Writer* w);
+  bool WriteBodyInternal(Writer* w) override;
 
   int WriteCIE(Writer* w);
   void WriteFDE(Writer* w, int);
@@ -1840,7 +1836,7 @@ extern "C" {
   // GDB will inspect contents of this descriptor.
   // Static initialization is necessary to prevent GDB from seeing
   // uninitialized descriptor.
-  JITDescriptor __jit_debug_descriptor = { 1, 0, 0, 0 };
+  JITDescriptor __jit_debug_descriptor = {1, 0, nullptr, nullptr};
 
 #ifdef OBJECT_PRINT
   void __gdb_print_v8_object(Object* object) {
diff --git a/deps/v8/src/global-handles.cc b/deps/v8/src/global-handles.cc
index a3c146cc70..e8f72c7177 100644
--- a/deps/v8/src/global-handles.cc
+++ b/deps/v8/src/global-handles.cc
@@ -500,22 +500,6 @@ class GlobalHandles::NodeIterator {
   DISALLOW_COPY_AND_ASSIGN(NodeIterator);
 };
 
-class GlobalHandles::PendingPhantomCallbacksSecondPassTask
-    : public v8::internal::CancelableTask {
- public:
-  PendingPhantomCallbacksSecondPassTask(GlobalHandles* global_handles,
-                                        Isolate* isolate)
-      : CancelableTask(isolate), global_handles_(global_handles) {}
-
-  void RunInternal() override {
-    global_handles_->InvokeSecondPassPhantomCallbacksFromTask();
-  }
-
- private:
-  GlobalHandles* global_handles_;
-  DISALLOW_COPY_AND_ASSIGN(PendingPhantomCallbacksSecondPassTask);
-};
-
 GlobalHandles::GlobalHandles(Isolate* isolate)
     : isolate_(isolate),
       number_of_global_handles_(0),
@@ -871,9 +855,10 @@ int GlobalHandles::DispatchPendingPhantomCallbacks(
           GCType::kGCTypeProcessWeakCallbacks, kNoGCCallbackFlags);
     } else if (!second_pass_callbacks_task_posted_) {
       second_pass_callbacks_task_posted_ = true;
-      auto task = new PendingPhantomCallbacksSecondPassTask(this, isolate());
-      V8::GetCurrentPlatform()->CallOnForegroundThread(
-          reinterpret_cast<v8::Isolate*>(isolate()), task);
+      auto taskrunner = V8::GetCurrentPlatform()->GetForegroundTaskRunner(
+          reinterpret_cast<v8::Isolate*>(isolate()));
+      taskrunner->PostTask(MakeCancelableLambdaTask(
+          isolate(), [this] { InvokeSecondPassPhantomCallbacksFromTask(); }));
     }
   }
   return freed_nodes;
@@ -913,6 +898,7 @@ int GlobalHandles::PostGarbageCollectionProcessing(
   const int initial_post_gc_processing_count = ++post_gc_processing_count_;
   int freed_nodes = 0;
   bool synchronous_second_pass =
+      isolate_->heap()->IsTearingDown() ||
       (gc_callback_flags &
        (kGCCallbackFlagForced | kGCCallbackFlagCollectAllAvailableGarbage |
         kGCCallbackFlagSynchronousPhantomCallbackProcessing)) != 0;
diff --git a/deps/v8/src/global-handles.h b/deps/v8/src/global-handles.h
index 246dc0c469..d5e5628c3d 100644
--- a/deps/v8/src/global-handles.h
+++ b/deps/v8/src/global-handles.h
@@ -184,7 +184,6 @@ class GlobalHandles {
   class NodeBlock;
   class NodeIterator;
   class PendingPhantomCallback;
-  class PendingPhantomCallbacksSecondPassTask;
 
   explicit GlobalHandles(Isolate* isolate);
 
diff --git a/deps/v8/src/globals.h b/deps/v8/src/globals.h
index e9142276e0..c20e6086ee 100644
--- a/deps/v8/src/globals.h
+++ b/deps/v8/src/globals.h
@@ -11,7 +11,7 @@
 #include <limits>
 #include <ostream>
 
-#include "include/v8.h"
+#include "include/v8-internal.h"
 #include "src/base/build_config.h"
 #include "src/base/flags.h"
 #include "src/base/logging.h"
@@ -55,9 +55,9 @@ namespace internal {
 // Determine whether the architecture uses an embedded constant pool
 // (contiguous constant pool embedded in code object).
 #if V8_TARGET_ARCH_PPC
-#define V8_EMBEDDED_CONSTANT_POOL 1
+#define V8_EMBEDDED_CONSTANT_POOL true
 #else
-#define V8_EMBEDDED_CONSTANT_POOL 0
+#define V8_EMBEDDED_CONSTANT_POOL false
 #endif
 
 #ifdef V8_TARGET_ARCH_ARM
@@ -76,14 +76,14 @@ constexpr int kStackSpaceRequiredForCompilation = 40;
 
 // Determine whether double field unboxing feature is enabled.
 #if V8_TARGET_ARCH_64_BIT
-#define V8_DOUBLE_FIELDS_UNBOXING 1
+#define V8_DOUBLE_FIELDS_UNBOXING true
 #else
-#define V8_DOUBLE_FIELDS_UNBOXING 0
+#define V8_DOUBLE_FIELDS_UNBOXING false
 #endif
 
 // Some types of tracing require the SFI to store a unique ID.
 #if defined(V8_TRACE_MAPS) || defined(V8_TRACE_IGNITION)
-#define V8_SFI_HAS_UNIQUE_ID 1
+#define V8_SFI_HAS_UNIQUE_ID true
 #endif
 
 // Superclass for classes only using static method functions.
@@ -95,10 +95,6 @@ class AllStatic {
 #endif
 };
 
-// DEPRECATED
-// TODO(leszeks): Delete this during a quiet period
-#define BASE_EMBEDDED
-
 typedef uint8_t byte;
 typedef uintptr_t Address;
 static const Address kNullAddress = 0;
@@ -166,13 +162,7 @@ constexpr intptr_t kIntptrSignBit =
     static_cast<intptr_t>(uintptr_t{0x8000000000000000});
 constexpr uintptr_t kUintptrAllBitsSet = uintptr_t{0xFFFFFFFFFFFFFFFF};
 constexpr bool kRequiresCodeRange = true;
-#if V8_TARGET_ARCH_MIPS64
-// To use pseudo-relative jumps such as j/jal instructions which have 28-bit
-// encoded immediate, the addresses have to be in range of 256MB aligned
-// region. Used only for large object space.
-constexpr size_t kMaximalCodeRangeSize = 256 * MB;
-constexpr size_t kCodeRangeAreaAlignment = 256 * MB;
-#elif V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
+#if V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
 constexpr size_t kMaximalCodeRangeSize = 512 * MB;
 constexpr size_t kCodeRangeAreaAlignment = 64 * KB;  // OS page on PPC Linux
 #elif V8_TARGET_ARCH_ARM64
@@ -213,8 +203,8 @@ constexpr size_t kCodeRangeAreaAlignment = 4 * KB;  // OS page.
 constexpr size_t kReservedCodeRangePages = 0;
 #endif
 
-// Trigger an incremental GCs once the external memory reaches this limit.
-constexpr int kExternalAllocationSoftLimit = 64 * MB;
+constexpr int kExternalAllocationSoftLimit =
+    internal::Internals::kExternalAllocationSoftLimit;
 
 // Maximum object size that gets allocated into regular pages. Objects larger
 // than that size are allocated in large object space and are never moved in
@@ -339,6 +329,10 @@ inline LanguageMode stricter_language_mode(LanguageMode mode1,
                                    static_cast<int>(mode2));
 }
 
+// A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
+// a keyed store is of the form a[expression] = foo.
+enum class StoreOrigin { kMaybeKeyed, kNamed };
+
 enum TypeofMode : int { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
 
 // Enums used by CEntry.
@@ -629,11 +623,13 @@ enum Movability { kMovable, kImmovable };
 
 enum VisitMode {
   VISIT_ALL,
+  VISIT_ALL_BUT_READ_ONLY,
   VISIT_ALL_IN_MINOR_MC_MARK,
   VISIT_ALL_IN_MINOR_MC_UPDATE,
   VISIT_ALL_IN_SCAVENGE,
   VISIT_ALL_IN_SWEEP_NEWSPACE,
   VISIT_ONLY_STRONG,
+  VISIT_ONLY_STRONG_FOR_SERIALIZATION,
   VISIT_FOR_SERIALIZATION,
 };
 
@@ -709,6 +705,27 @@ enum InlineCacheState {
   GENERIC,
 };
 
+// Printing support.
+inline const char* InlineCacheState2String(InlineCacheState state) {
+  switch (state) {
+    case UNINITIALIZED:
+      return "UNINITIALIZED";
+    case PREMONOMORPHIC:
+      return "PREMONOMORPHIC";
+    case MONOMORPHIC:
+      return "MONOMORPHIC";
+    case RECOMPUTE_HANDLER:
+      return "RECOMPUTE_HANDLER";
+    case POLYMORPHIC:
+      return "POLYMORPHIC";
+    case MEGAMORPHIC:
+      return "MEGAMORPHIC";
+    case GENERIC:
+      return "GENERIC";
+  }
+  UNREACHABLE();
+}
+
 enum WhereToStart { kStartAtReceiver, kStartAtPrototype };
 
 enum ResultSentinel { kNotFound = -1, kUnsupported = -2 };
@@ -930,6 +947,8 @@ enum AllocationSiteMode {
   LAST_ALLOCATION_SITE_MODE = TRACK_ALLOCATION_SITE
 };
 
+enum class AllocationSiteUpdateMode { kUpdate, kCheckOnly };
+
 // The mips architecture prior to revision 5 has inverted encoding for sNaN.
 #if (V8_TARGET_ARCH_MIPS && !defined(_MIPS_ARCH_MIPS32R6) &&           \
      (!defined(USE_SIMULATOR) || !defined(_MIPS_TARGET_SIMULATOR))) || \
@@ -1578,6 +1597,65 @@ enum class LoadSensitivity {
   V(TrapFuncInvalid)               \
   V(TrapFuncSigMismatch)
 
+enum KeyedAccessLoadMode {
+  STANDARD_LOAD,
+  LOAD_IGNORE_OUT_OF_BOUNDS,
+};
+
+enum KeyedAccessStoreMode {
+  STANDARD_STORE,
+  STORE_TRANSITION_TO_OBJECT,
+  STORE_TRANSITION_TO_DOUBLE,
+  STORE_AND_GROW_NO_TRANSITION_HANDLE_COW,
+  STORE_AND_GROW_TRANSITION_TO_OBJECT,
+  STORE_AND_GROW_TRANSITION_TO_DOUBLE,
+  STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS,
+  STORE_NO_TRANSITION_HANDLE_COW
+};
+
+enum MutableMode { MUTABLE, IMMUTABLE };
+
+static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) {
+  return store_mode == STORE_TRANSITION_TO_OBJECT ||
+         store_mode == STORE_TRANSITION_TO_DOUBLE ||
+         store_mode == STORE_AND_GROW_TRANSITION_TO_OBJECT ||
+         store_mode == STORE_AND_GROW_TRANSITION_TO_DOUBLE;
+}
+
+static inline bool IsCOWHandlingStoreMode(KeyedAccessStoreMode store_mode) {
+  return store_mode == STORE_NO_TRANSITION_HANDLE_COW ||
+         store_mode == STORE_AND_GROW_NO_TRANSITION_HANDLE_COW;
+}
+
+static inline KeyedAccessStoreMode GetNonTransitioningStoreMode(
+    KeyedAccessStoreMode store_mode, bool receiver_was_cow) {
+  switch (store_mode) {
+    case STORE_AND_GROW_NO_TRANSITION_HANDLE_COW:
+    case STORE_AND_GROW_TRANSITION_TO_OBJECT:
+    case STORE_AND_GROW_TRANSITION_TO_DOUBLE:
+      store_mode = STORE_AND_GROW_NO_TRANSITION_HANDLE_COW;
+      break;
+    case STANDARD_STORE:
+    case STORE_TRANSITION_TO_OBJECT:
+    case STORE_TRANSITION_TO_DOUBLE:
+      store_mode =
+          receiver_was_cow ? STORE_NO_TRANSITION_HANDLE_COW : STANDARD_STORE;
+      break;
+    case STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS:
+    case STORE_NO_TRANSITION_HANDLE_COW:
+      break;
+  }
+  DCHECK(!IsTransitionStoreMode(store_mode));
+  DCHECK_IMPLIES(receiver_was_cow, IsCOWHandlingStoreMode(store_mode));
+  return store_mode;
+}
+
+static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
+  return store_mode >= STORE_AND_GROW_NO_TRANSITION_HANDLE_COW &&
+         store_mode <= STORE_AND_GROW_TRANSITION_TO_DOUBLE;
+}
+
+enum IcCheckType { ELEMENT, PROPERTY };
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/handles.cc b/deps/v8/src/handles.cc
index b0ffe6a13e..a9f4a0f0b4 100644
--- a/deps/v8/src/handles.cc
+++ b/deps/v8/src/handles.cc
@@ -30,11 +30,9 @@ bool HandleBase::IsDereferenceAllowed(DereferenceCheckMode mode) const {
   Isolate* isolate;
   if (!Isolate::FromWritableHeapObject(heap_object, &isolate)) return true;
   Heap* heap = isolate->heap();
-  Object** roots_array_start = heap->roots_array_start();
-  if (roots_array_start <= location_ &&
-      location_ < roots_array_start + Heap::kStrongRootListLength &&
-      heap->RootCanBeTreatedAsConstant(
-          static_cast<Heap::RootListIndex>(location_ - roots_array_start))) {
+  RootIndex root_index;
+  if (heap->IsRootHandleLocation(location_, &root_index) &&
+      heap->RootCanBeTreatedAsConstant(root_index)) {
     return true;
   }
   if (!AllowHandleDereference::IsAllowed()) return false;
@@ -157,11 +155,9 @@ Object** CanonicalHandleScope::Lookup(Object* object) {
     return HandleScope::CreateHandle(isolate_, object);
   }
   if (object->IsHeapObject()) {
-    int index = root_index_map_->Lookup(HeapObject::cast(object));
-    if (index != RootIndexMap::kInvalidRootIndex) {
-      return isolate_->heap()
-          ->root_handle(static_cast<Heap::RootListIndex>(index))
-          .location();
+    RootIndex root_index;
+    if (root_index_map_->Lookup(HeapObject::cast(object), &root_index)) {
+      return isolate_->heap()->root_handle(root_index).location();
     }
   }
   Object*** entry = identity_map_->Get(object);
diff --git a/deps/v8/src/handles.h b/deps/v8/src/handles.h
index c0a7ac9420..f37162f70e 100644
--- a/deps/v8/src/handles.h
+++ b/deps/v8/src/handles.h
@@ -319,7 +319,7 @@ class SealHandleScope final {
  public:
 #ifndef DEBUG
   explicit SealHandleScope(Isolate* isolate) {}
-  ~SealHandleScope() {}
+  ~SealHandleScope() = default;
 #else
   explicit inline SealHandleScope(Isolate* isolate);
   inline ~SealHandleScope();
diff --git a/deps/v8/src/heap-symbols.h b/deps/v8/src/heap-symbols.h
index 9f13253219..152c894796 100644
--- a/deps/v8/src/heap-symbols.h
+++ b/deps/v8/src/heap-symbols.h
@@ -5,298 +5,334 @@
 #ifndef V8_HEAP_SYMBOLS_H_
 #define V8_HEAP_SYMBOLS_H_
 
-#define INTERNALIZED_STRING_LIST(V)                                \
-  V(add_string, "add")                                             \
-  V(always_string, "always")                                       \
-  V(anonymous_function_string, "(anonymous function)")             \
-  V(anonymous_string, "anonymous")                                 \
-  V(apply_string, "apply")                                         \
-  V(Arguments_string, "Arguments")                                 \
-  V(arguments_string, "arguments")                                 \
-  V(arguments_to_string, "[object Arguments]")                     \
-  V(Array_string, "Array")                                         \
-  V(array_to_string, "[object Array]")                             \
-  V(ArrayBuffer_string, "ArrayBuffer")                             \
-  V(ArrayIterator_string, "Array Iterator")                        \
-  V(assign_string, "assign")                                       \
-  V(async_string, "async")                                         \
-  V(auto_string, "auto")                                           \
-  V(await_string, "await")                                         \
-  V(BigInt_string, "BigInt")                                       \
-  V(bigint_string, "bigint")                                       \
-  V(BigInt64Array_string, "BigInt64Array")                         \
-  V(BigUint64Array_string, "BigUint64Array")                       \
-  V(bind_string, "bind")                                           \
-  V(Boolean_string, "Boolean")                                     \
-  V(boolean_string, "boolean")                                     \
-  V(boolean_to_string, "[object Boolean]")                         \
-  V(bound__string, "bound ")                                       \
-  V(buffer_string, "buffer")                                       \
-  V(byte_length_string, "byteLength")                              \
-  V(byte_offset_string, "byteOffset")                              \
-  V(call_string, "call")                                           \
-  V(callee_string, "callee")                                       \
-  V(caller_string, "caller")                                       \
-  V(caseFirst_string, "caseFirst")                                 \
-  V(cell_value_string, "%cell_value")                              \
-  V(char_at_string, "CharAt")                                      \
-  V(closure_string, "(closure)")                                   \
-  V(collation_string, "collation")                                 \
-  V(column_string, "column")                                       \
-  V(CompileError_string, "CompileError")                           \
-  V(configurable_string, "configurable")                           \
-  V(construct_string, "construct")                                 \
-  V(constructor_string, "constructor")                             \
-  V(conjunction_string, "conjunction")                             \
-  V(create_string, "create")                                       \
-  V(currency_string, "currency")                                   \
-  V(Date_string, "Date")                                           \
-  V(date_to_string, "[object Date]")                               \
-  V(day_string, "day")                                             \
-  V(dayperiod_string, "dayperiod")                                 \
-  V(decimal_string, "decimal")                                     \
-  V(default_string, "default")                                     \
-  V(defineProperty_string, "defineProperty")                       \
-  V(deleteProperty_string, "deleteProperty")                       \
-  V(did_handle_string, "didHandle")                                \
-  V(disjunction_string, "disjunction")                             \
-  V(display_name_string, "displayName")                            \
-  V(done_string, "done")                                           \
-  V(dot_catch_string, ".catch")                                    \
-  V(dot_for_string, ".for")                                        \
-  V(dot_generator_object_string, ".generator_object")              \
-  V(dot_iterator_string, ".iterator")                              \
-  V(dot_result_string, ".result")                                  \
-  V(dot_string, ".")                                               \
-  V(dot_switch_tag_string, ".switch_tag")                          \
-  V(dotAll_string, "dotAll")                                       \
-  V(enqueue_string, "enqueue")                                     \
-  V(entries_string, "entries")                                     \
-  V(enumerable_string, "enumerable")                               \
-  V(element_string, "element")                                     \
-  V(era_string, "era")                                             \
-  V(Error_string, "Error")                                         \
-  V(error_to_string, "[object Error]")                             \
-  V(eval_string, "eval")                                           \
-  V(EvalError_string, "EvalError")                                 \
-  V(exec_string, "exec")                                           \
-  V(false_string, "false")                                         \
-  V(flags_string, "flags")                                         \
-  V(Float32Array_string, "Float32Array")                           \
-  V(Float64Array_string, "Float64Array")                           \
-  V(fraction_string, "fraction")                                   \
-  V(Function_string, "Function")                                   \
-  V(function_native_code_string, "function () { [native code] }")  \
-  V(function_string, "function")                                   \
-  V(function_to_string, "[object Function]")                       \
-  V(Generator_string, "Generator")                                 \
-  V(get_space_string, "get ")                                      \
-  V(get_string, "get")                                             \
-  V(getOwnPropertyDescriptor_string, "getOwnPropertyDescriptor")   \
-  V(getOwnPropertyDescriptors_string, "getOwnPropertyDescriptors") \
-  V(getPrototypeOf_string, "getPrototypeOf")                       \
-  V(global_string, "global")                                       \
-  V(globalThis_string, "globalThis")                               \
-  V(group_string, "group")                                         \
-  V(groups_string, "groups")                                       \
-  V(has_string, "has")                                             \
-  V(hour_string, "hour")                                           \
-  V(ignoreCase_string, "ignoreCase")                               \
-  V(ignorePunctuation_string, "ignorePunctuation")                 \
-  V(illegal_access_string, "illegal access")                       \
-  V(illegal_argument_string, "illegal argument")                   \
-  V(index_string, "index")                                         \
-  V(Infinity_string, "Infinity")                                   \
-  V(infinity_string, "infinity")                                   \
-  V(input_string, "input")                                         \
-  V(Int16Array_string, "Int16Array")                               \
-  V(Int32Array_string, "Int32Array")                               \
-  V(Int8Array_string, "Int8Array")                                 \
-  V(integer_string, "integer")                                     \
-  V(isExtensible_string, "isExtensible")                           \
-  V(isView_string, "isView")                                       \
-  V(KeyedLoadMonomorphic_string, "KeyedLoadMonomorphic")           \
-  V(KeyedStoreMonomorphic_string, "KeyedStoreMonomorphic")         \
-  V(keys_string, "keys")                                           \
-  V(lastIndex_string, "lastIndex")                                 \
-  V(length_string, "length")                                       \
-  V(let_string, "let")                                             \
-  V(line_string, "line")                                           \
-  V(LinkError_string, "LinkError")                                 \
-  V(literal_string, "literal")                                     \
-  V(locale_string, "locale")                                       \
-  V(long_string, "long")                                           \
-  V(Map_string, "Map")                                             \
-  V(MapIterator_string, "Map Iterator")                            \
-  V(message_string, "message")                                     \
-  V(minus_Infinity_string, "-Infinity")                            \
-  V(minus_zero_string, "-0")                                       \
-  V(minusSign_string, "minusSign")                                 \
-  V(minute_string, "minute")                                       \
-  V(Module_string, "Module")                                       \
-  V(month_string, "month")                                         \
-  V(multiline_string, "multiline")                                 \
-  V(name_string, "name")                                           \
-  V(NaN_string, "NaN")                                             \
-  V(nan_string, "nan")                                             \
-  V(narrow_string, "narrow")                                       \
-  V(native_string, "native")                                       \
-  V(new_target_string, ".new.target")                              \
-  V(next_string, "next")                                           \
-  V(NFC_string, "NFC")                                             \
-  V(NFD_string, "NFD")                                             \
-  V(NFKC_string, "NFKC")                                           \
-  V(NFKD_string, "NFKD")                                           \
-  V(not_equal, "not-equal")                                        \
-  V(null_string, "null")                                           \
-  V(null_to_string, "[object Null]")                               \
-  V(Number_string, "Number")                                       \
-  V(number_string, "number")                                       \
-  V(number_to_string, "[object Number]")                           \
-  V(numeric_string, "numeric")                                     \
-  V(Object_string, "Object")                                       \
-  V(object_string, "object")                                       \
-  V(object_to_string, "[object Object]")                           \
-  V(ok, "ok")                                                      \
-  V(one_string, "1")                                               \
-  V(ownKeys_string, "ownKeys")                                     \
-  V(percentSign_string, "percentSign")                             \
-  V(plusSign_string, "plusSign")                                   \
-  V(position_string, "position")                                   \
-  V(preventExtensions_string, "preventExtensions")                 \
-  V(Promise_string, "Promise")                                     \
-  V(promise_string, "promise")                                     \
-  V(PromiseResolveThenableJob_string, "PromiseResolveThenableJob") \
-  V(proto_string, "__proto__")                                     \
-  V(prototype_string, "prototype")                                 \
-  V(proxy_string, "proxy")                                         \
-  V(Proxy_string, "Proxy")                                         \
-  V(query_colon_string, "(?:)")                                    \
-  V(RangeError_string, "RangeError")                               \
-  V(raw_string, "raw")                                             \
-  V(ReconfigureToDataProperty_string, "ReconfigureToDataProperty") \
-  V(ReferenceError_string, "ReferenceError")                       \
-  V(RegExp_string, "RegExp")                                       \
-  V(regexp_to_string, "[object RegExp]")                           \
-  V(reject_string, "reject")                                       \
-  V(resolve_string, "resolve")                                     \
-  V(return_string, "return")                                       \
-  V(revoke_string, "revoke")                                       \
-  V(RuntimeError_string, "RuntimeError")                           \
-  V(Script_string, "Script")                                       \
-  V(script_string, "script")                                       \
-  V(short_string, "short")                                         \
-  V(second_string, "second")                                       \
-  V(Set_string, "Set")                                             \
-  V(sensitivity_string, "sensitivity")                             \
-  V(set_space_string, "set ")                                      \
-  V(set_string, "set")                                             \
-  V(SetIterator_string, "Set Iterator")                            \
-  V(setPrototypeOf_string, "setPrototypeOf")                       \
-  V(SharedArrayBuffer_string, "SharedArrayBuffer")                 \
-  V(source_string, "source")                                       \
-  V(sourceText_string, "sourceText")                               \
-  V(stack_string, "stack")                                         \
-  V(stackTraceLimit_string, "stackTraceLimit")                     \
-  V(star_default_star_string, "*default*")                         \
-  V(sticky_string, "sticky")                                       \
-  V(String_string, "String")                                       \
-  V(string_string, "string")                                       \
-  V(string_to_string, "[object String]")                           \
-  V(style_string, "style")                                         \
-  V(symbol_species_string, "[Symbol.species]")                     \
-  V(Symbol_string, "Symbol")                                       \
-  V(symbol_string, "symbol")                                       \
-  V(SyntaxError_string, "SyntaxError")                             \
-  V(then_string, "then")                                           \
-  V(this_function_string, ".this_function")                        \
-  V(this_string, "this")                                           \
-  V(throw_string, "throw")                                         \
-  V(timed_out, "timed-out")                                        \
-  V(timeZoneName_string, "timeZoneName")                           \
-  V(toJSON_string, "toJSON")                                       \
-  V(toString_string, "toString")                                   \
-  V(true_string, "true")                                           \
-  V(TypeError_string, "TypeError")                                 \
-  V(type_string, "type")                                           \
-  V(Uint16Array_string, "Uint16Array")                             \
-  V(Uint32Array_string, "Uint32Array")                             \
-  V(Uint8Array_string, "Uint8Array")                               \
-  V(Uint8ClampedArray_string, "Uint8ClampedArray")                 \
-  V(undefined_string, "undefined")                                 \
-  V(undefined_to_string, "[object Undefined]")                     \
-  V(unicode_string, "unicode")                                     \
-  V(unit_string, "unit")                                           \
-  V(URIError_string, "URIError")                                   \
-  V(usage_string, "usage")                                         \
-  V(use_asm_string, "use asm")                                     \
-  V(use_strict_string, "use strict")                               \
-  V(value_string, "value")                                         \
-  V(valueOf_string, "valueOf")                                     \
-  V(values_string, "values")                                       \
-  V(WeakMap_string, "WeakMap")                                     \
-  V(WeakSet_string, "WeakSet")                                     \
-  V(weekday_string, "weekday")                                     \
-  V(will_handle_string, "willHandle")                              \
-  V(writable_string, "writable")                                   \
-  V(year_string, "year")                                           \
-  V(zero_string, "0")
+#ifdef V8_INTL_SUPPORT
+#define INTERNALIZED_STRING_LIST_GENERATOR_INTL(V, _)               \
+  V(_, caseFirst_string, "caseFirst")                               \
+  V(_, day_string, "day")                                           \
+  V(_, dayPeriod_string, "dayPeriod")                               \
+  V(_, decimal_string, "decimal")                                   \
+  V(_, era_string, "era")                                           \
+  V(_, fraction_string, "fraction")                                 \
+  V(_, group_string, "group")                                       \
+  V(_, h11_string, "h11")                                           \
+  V(_, h12_string, "h12")                                           \
+  V(_, h23_string, "h23")                                           \
+  V(_, h24_string, "h24")                                           \
+  V(_, hour_string, "hour")                                         \
+  V(_, collation_string, "collation")                               \
+  V(_, currency_string, "currency")                                 \
+  V(_, currencyDisplay_string, "currencyDisplay")                   \
+  V(_, ignorePunctuation_string, "ignorePunctuation")               \
+  V(_, integer_string, "integer")                                   \
+  V(_, literal_string, "literal")                                   \
+  V(_, locale_string, "locale")                                     \
+  V(_, lower_string, "lower")                                       \
+  V(_, maximumFractionDigits_string, "maximumFractionDigits")       \
+  V(_, maximumSignificantDigits_string, "maximumSignificantDigits") \
+  V(_, nan_string, "nan")                                           \
+  V(_, minimumFractionDigits_string, "minimumFractionDigits")       \
+  V(_, minimumIntegerDigits_string, "minimumIntegerDigits")         \
+  V(_, minimumSignificantDigits_string, "minimumSignificantDigits") \
+  V(_, minusSign_string, "minusSign")                               \
+  V(_, minute_string, "minute")                                     \
+  V(_, month_string, "month")                                       \
+  V(_, numberingSystem_string, "numberingSystem")                   \
+  V(_, numeric_string, "numeric")                                   \
+  V(_, percentSign_string, "percentSign")                           \
+  V(_, plusSign_string, "plusSign")                                 \
+  V(_, quarter_string, "quarter")                                   \
+  V(_, second_string, "second")                                     \
+  V(_, sensitivity_string, "sensitivity")                           \
+  V(_, style_string, "style")                                       \
+  V(_, timeZoneName_string, "timeZoneName")                         \
+  V(_, type_string, "type")                                         \
+  V(_, upper_string, "upper")                                       \
+  V(_, usage_string, "usage")                                       \
+  V(_, useGrouping_string, "useGrouping")                           \
+  V(_, unit_string, "unit")                                         \
+  V(_, weekday_string, "weekday")                                   \
+  V(_, year_string, "year")
+#else  // V8_INTL_SUPPORT
+#define INTERNALIZED_STRING_LIST_GENERATOR_INTL(V, _)
+#endif  // V8_INTL_SUPPORT
 
-#define PRIVATE_SYMBOL_LIST(V)         \
-  V(call_site_frame_array_symbol)      \
-  V(call_site_frame_index_symbol)      \
-  V(console_context_id_symbol)         \
-  V(console_context_name_symbol)       \
-  V(class_fields_symbol)               \
-  V(class_positions_symbol)            \
-  V(detailed_stack_trace_symbol)       \
-  V(elements_transition_symbol)        \
-  V(error_end_pos_symbol)              \
-  V(error_script_symbol)               \
-  V(error_start_pos_symbol)            \
-  V(frozen_symbol)                     \
-  V(generic_symbol)                    \
-  V(home_object_symbol)                \
-  V(intl_initialized_marker_symbol)    \
-  V(intl_pattern_symbol)               \
-  V(intl_resolved_symbol)              \
-  V(interpreter_trampoline_symbol)     \
-  V(megamorphic_symbol)                \
-  V(native_context_index_symbol)       \
-  V(nonextensible_symbol)              \
-  V(not_mapped_symbol)                 \
-  V(premonomorphic_symbol)             \
-  V(promise_async_stack_id_symbol)     \
-  V(promise_debug_marker_symbol)       \
-  V(promise_forwarding_handler_symbol) \
-  V(promise_handled_by_symbol)         \
-  V(promise_async_id_symbol)           \
-  V(sealed_symbol)                     \
-  V(stack_trace_symbol)                \
-  V(strict_function_transition_symbol) \
-  V(uninitialized_symbol)
+#define INTERNALIZED_STRING_LIST_GENERATOR(V, _)                      \
+  INTERNALIZED_STRING_LIST_GENERATOR_INTL(V, _)                       \
+  V(_, add_string, "add")                                             \
+  V(_, always_string, "always")                                       \
+  V(_, anonymous_function_string, "(anonymous function)")             \
+  V(_, anonymous_string, "anonymous")                                 \
+  V(_, apply_string, "apply")                                         \
+  V(_, Arguments_string, "Arguments")                                 \
+  V(_, arguments_string, "arguments")                                 \
+  V(_, arguments_to_string, "[object Arguments]")                     \
+  V(_, Array_string, "Array")                                         \
+  V(_, array_to_string, "[object Array]")                             \
+  V(_, ArrayBuffer_string, "ArrayBuffer")                             \
+  V(_, ArrayIterator_string, "Array Iterator")                        \
+  V(_, assign_string, "assign")                                       \
+  V(_, async_string, "async")                                         \
+  V(_, auto_string, "auto")                                           \
+  V(_, await_string, "await")                                         \
+  V(_, BigInt_string, "BigInt")                                       \
+  V(_, bigint_string, "bigint")                                       \
+  V(_, BigInt64Array_string, "BigInt64Array")                         \
+  V(_, BigUint64Array_string, "BigUint64Array")                       \
+  V(_, bind_string, "bind")                                           \
+  V(_, Boolean_string, "Boolean")                                     \
+  V(_, boolean_string, "boolean")                                     \
+  V(_, boolean_to_string, "[object Boolean]")                         \
+  V(_, bound__string, "bound ")                                       \
+  V(_, buffer_string, "buffer")                                       \
+  V(_, byte_length_string, "byteLength")                              \
+  V(_, byte_offset_string, "byteOffset")                              \
+  V(_, call_string, "call")                                           \
+  V(_, callee_string, "callee")                                       \
+  V(_, caller_string, "caller")                                       \
+  V(_, cell_value_string, "%cell_value")                              \
+  V(_, char_at_string, "CharAt")                                      \
+  V(_, character_string, "character")                                 \
+  V(_, closure_string, "(closure)")                                   \
+  V(_, code_string, "code")                                           \
+  V(_, column_string, "column")                                       \
+  V(_, CompileError_string, "CompileError")                           \
+  V(_, configurable_string, "configurable")                           \
+  V(_, construct_string, "construct")                                 \
+  V(_, constructor_string, "constructor")                             \
+  V(_, conjunction_string, "conjunction")                             \
+  V(_, create_string, "create")                                       \
+  V(_, Date_string, "Date")                                           \
+  V(_, date_to_string, "[object Date]")                               \
+  V(_, default_string, "default")                                     \
+  V(_, defineProperty_string, "defineProperty")                       \
+  V(_, deleteProperty_string, "deleteProperty")                       \
+  V(_, did_handle_string, "didHandle")                                \
+  V(_, disjunction_string, "disjunction")                             \
+  V(_, display_name_string, "displayName")                            \
+  V(_, done_string, "done")                                           \
+  V(_, dot_catch_string, ".catch")                                    \
+  V(_, dot_for_string, ".for")                                        \
+  V(_, dot_generator_object_string, ".generator_object")              \
+  V(_, dot_iterator_string, ".iterator")                              \
+  V(_, dot_promise_string, ".promise")                                \
+  V(_, dot_result_string, ".result")                                  \
+  V(_, dot_string, ".")                                               \
+  V(_, dot_switch_tag_string, ".switch_tag")                          \
+  V(_, dotAll_string, "dotAll")                                       \
+  V(_, enqueue_string, "enqueue")                                     \
+  V(_, entries_string, "entries")                                     \
+  V(_, enumerable_string, "enumerable")                               \
+  V(_, element_string, "element")                                     \
+  V(_, Error_string, "Error")                                         \
+  V(_, error_to_string, "[object Error]")                             \
+  V(_, eval_string, "eval")                                           \
+  V(_, EvalError_string, "EvalError")                                 \
+  V(_, exec_string, "exec")                                           \
+  V(_, false_string, "false")                                         \
+  V(_, flags_string, "flags")                                         \
+  V(_, Float32Array_string, "Float32Array")                           \
+  V(_, Float64Array_string, "Float64Array")                           \
+  V(_, Function_string, "Function")                                   \
+  V(_, function_native_code_string, "function () { [native code] }")  \
+  V(_, function_string, "function")                                   \
+  V(_, function_to_string, "[object Function]")                       \
+  V(_, Generator_string, "Generator")                                 \
+  V(_, get_space_string, "get ")                                      \
+  V(_, get_string, "get")                                             \
+  V(_, getOwnPropertyDescriptor_string, "getOwnPropertyDescriptor")   \
+  V(_, getOwnPropertyDescriptors_string, "getOwnPropertyDescriptors") \
+  V(_, getPrototypeOf_string, "getPrototypeOf")                       \
+  V(_, global_string, "global")                                       \
+  V(_, globalThis_string, "globalThis")                               \
+  V(_, granularity_string, "granularity")                             \
+  V(_, grapheme_string, "grapheme")                                   \
+  V(_, groups_string, "groups")                                       \
+  V(_, has_string, "has")                                             \
+  V(_, ignoreCase_string, "ignoreCase")                               \
+  V(_, illegal_access_string, "illegal access")                       \
+  V(_, illegal_argument_string, "illegal argument")                   \
+  V(_, index_string, "index")                                         \
+  V(_, Infinity_string, "Infinity")                                   \
+  V(_, infinity_string, "infinity")                                   \
+  V(_, input_string, "input")                                         \
+  V(_, Int16Array_string, "Int16Array")                               \
+  V(_, Int32Array_string, "Int32Array")                               \
+  V(_, Int8Array_string, "Int8Array")                                 \
+  V(_, isExtensible_string, "isExtensible")                           \
+  V(_, isView_string, "isView")                                       \
+  V(_, KeyedLoadMonomorphic_string, "KeyedLoadMonomorphic")           \
+  V(_, KeyedStoreMonomorphic_string, "KeyedStoreMonomorphic")         \
+  V(_, keys_string, "keys")                                           \
+  V(_, lastIndex_string, "lastIndex")                                 \
+  V(_, length_string, "length")                                       \
+  V(_, let_string, "let")                                             \
+  V(_, lineBreakStyle_string, "lineBreakStyle")                       \
+  V(_, line_string, "line")                                           \
+  V(_, LinkError_string, "LinkError")                                 \
+  V(_, long_string, "long")                                           \
+  V(_, loose_string, "loose")                                         \
+  V(_, Map_string, "Map")                                             \
+  V(_, MapIterator_string, "Map Iterator")                            \
+  V(_, message_string, "message")                                     \
+  V(_, minus_Infinity_string, "-Infinity")                            \
+  V(_, minus_zero_string, "-0")                                       \
+  V(_, Module_string, "Module")                                       \
+  V(_, multiline_string, "multiline")                                 \
+  V(_, name_string, "name")                                           \
+  V(_, NaN_string, "NaN")                                             \
+  V(_, narrow_string, "narrow")                                       \
+  V(_, native_string, "native")                                       \
+  V(_, new_target_string, ".new.target")                              \
+  V(_, next_string, "next")                                           \
+  V(_, NFC_string, "NFC")                                             \
+  V(_, NFD_string, "NFD")                                             \
+  V(_, NFKC_string, "NFKC")                                           \
+  V(_, NFKD_string, "NFKD")                                           \
+  V(_, not_equal, "not-equal")                                        \
+  V(_, normal_string, "normal")                                       \
+  V(_, null_string, "null")                                           \
+  V(_, null_to_string, "[object Null]")                               \
+  V(_, Number_string, "Number")                                       \
+  V(_, number_string, "number")                                       \
+  V(_, number_to_string, "[object Number]")                           \
+  V(_, Object_string, "Object")                                       \
+  V(_, object_string, "object")                                       \
+  V(_, object_to_string, "[object Object]")                           \
+  V(_, ok, "ok")                                                      \
+  V(_, one_string, "1")                                               \
+  V(_, ownKeys_string, "ownKeys")                                     \
+  V(_, percent_string, "percent")                                     \
+  V(_, position_string, "position")                                   \
+  V(_, preventExtensions_string, "preventExtensions")                 \
+  V(_, Promise_string, "Promise")                                     \
+  V(_, promise_string, "promise")                                     \
+  V(_, PromiseResolveThenableJob_string, "PromiseResolveThenableJob") \
+  V(_, proto_string, "__proto__")                                     \
+  V(_, prototype_string, "prototype")                                 \
+  V(_, proxy_string, "proxy")                                         \
+  V(_, Proxy_string, "Proxy")                                         \
+  V(_, query_colon_string, "(?:)")                                    \
+  V(_, RangeError_string, "RangeError")                               \
+  V(_, raw_string, "raw")                                             \
+  V(_, ReconfigureToDataProperty_string, "ReconfigureToDataProperty") \
+  V(_, ReferenceError_string, "ReferenceError")                       \
+  V(_, RegExp_string, "RegExp")                                       \
+  V(_, regexp_to_string, "[object RegExp]")                           \
+  V(_, reject_string, "reject")                                       \
+  V(_, resolve_string, "resolve")                                     \
+  V(_, return_string, "return")                                       \
+  V(_, revoke_string, "revoke")                                       \
+  V(_, RuntimeError_string, "RuntimeError")                           \
+  V(_, Script_string, "Script")                                       \
+  V(_, script_string, "script")                                       \
+  V(_, short_string, "short")                                         \
+  V(_, Set_string, "Set")                                             \
+  V(_, sentence_string, "sentence")                                   \
+  V(_, set_space_string, "set ")                                      \
+  V(_, set_string, "set")                                             \
+  V(_, SetIterator_string, "Set Iterator")                            \
+  V(_, setPrototypeOf_string, "setPrototypeOf")                       \
+  V(_, SharedArrayBuffer_string, "SharedArrayBuffer")                 \
+  V(_, source_string, "source")                                       \
+  V(_, sourceText_string, "sourceText")                               \
+  V(_, stack_string, "stack")                                         \
+  V(_, stackTraceLimit_string, "stackTraceLimit")                     \
+  V(_, star_default_star_string, "*default*")                         \
+  V(_, sticky_string, "sticky")                                       \
+  V(_, strict_string, "strict")                                       \
+  V(_, String_string, "String")                                       \
+  V(_, string_string, "string")                                       \
+  V(_, string_to_string, "[object String]")                           \
+  V(_, symbol_species_string, "[Symbol.species]")                     \
+  V(_, Symbol_string, "Symbol")                                       \
+  V(_, symbol_string, "symbol")                                       \
+  V(_, SyntaxError_string, "SyntaxError")                             \
+  V(_, then_string, "then")                                           \
+  V(_, this_function_string, ".this_function")                        \
+  V(_, this_string, "this")                                           \
+  V(_, throw_string, "throw")                                         \
+  V(_, timed_out, "timed-out")                                        \
+  V(_, toJSON_string, "toJSON")                                       \
+  V(_, toString_string, "toString")                                   \
+  V(_, true_string, "true")                                           \
+  V(_, TypeError_string, "TypeError")                                 \
+  V(_, Uint16Array_string, "Uint16Array")                             \
+  V(_, Uint32Array_string, "Uint32Array")                             \
+  V(_, Uint8Array_string, "Uint8Array")                               \
+  V(_, Uint8ClampedArray_string, "Uint8ClampedArray")                 \
+  V(_, undefined_string, "undefined")                                 \
+  V(_, undefined_to_string, "[object Undefined]")                     \
+  V(_, unicode_string, "unicode")                                     \
+  V(_, URIError_string, "URIError")                                   \
+  V(_, use_asm_string, "use asm")                                     \
+  V(_, use_strict_string, "use strict")                               \
+  V(_, value_string, "value")                                         \
+  V(_, valueOf_string, "valueOf")                                     \
+  V(_, values_string, "values")                                       \
+  V(_, WeakMap_string, "WeakMap")                                     \
+  V(_, WeakSet_string, "WeakSet")                                     \
+  V(_, week_string, "week")                                           \
+  V(_, will_handle_string, "willHandle")                              \
+  V(_, word_string, "word")                                           \
+  V(_, writable_string, "writable")                                   \
+  V(_, zero_string, "0")
 
-#define PUBLIC_SYMBOL_LIST(V)                    \
-  V(async_iterator_symbol, Symbol.asyncIterator) \
-  V(iterator_symbol, Symbol.iterator)            \
-  V(intl_fallback_symbol, IntlFallback)          \
-  V(match_all_symbol, Symbol.matchAll)           \
-  V(match_symbol, Symbol.match)                  \
-  V(replace_symbol, Symbol.replace)              \
-  V(search_symbol, Symbol.search)                \
-  V(species_symbol, Symbol.species)              \
-  V(split_symbol, Symbol.split)                  \
-  V(to_primitive_symbol, Symbol.toPrimitive)     \
-  V(unscopables_symbol, Symbol.unscopables)
+#define PRIVATE_SYMBOL_LIST_GENERATOR(V, _) \
+  V(_, call_site_frame_array_symbol)        \
+  V(_, call_site_frame_index_symbol)        \
+  V(_, console_context_id_symbol)           \
+  V(_, console_context_name_symbol)         \
+  V(_, class_fields_symbol)                 \
+  V(_, class_positions_symbol)              \
+  V(_, detailed_stack_trace_symbol)         \
+  V(_, elements_transition_symbol)          \
+  V(_, error_end_pos_symbol)                \
+  V(_, error_script_symbol)                 \
+  V(_, error_start_pos_symbol)              \
+  V(_, frozen_symbol)                       \
+  V(_, generic_symbol)                      \
+  V(_, home_object_symbol)                  \
+  V(_, intl_initialized_marker_symbol)      \
+  V(_, intl_resolved_symbol)                \
+  V(_, interpreter_trampoline_symbol)       \
+  V(_, megamorphic_symbol)                  \
+  V(_, native_context_index_symbol)         \
+  V(_, nonextensible_symbol)                \
+  V(_, not_mapped_symbol)                   \
+  V(_, premonomorphic_symbol)               \
+  V(_, promise_async_stack_id_symbol)       \
+  V(_, promise_debug_marker_symbol)         \
+  V(_, promise_forwarding_handler_symbol)   \
+  V(_, promise_handled_by_symbol)           \
+  V(_, promise_async_id_symbol)             \
+  V(_, sealed_symbol)                       \
+  V(_, stack_trace_symbol)                  \
+  V(_, strict_function_transition_symbol)   \
+  V(_, wasm_exception_tag_symbol)           \
+  V(_, wasm_exception_values_symbol)        \
+  V(_, uninitialized_symbol)
+
+#define PUBLIC_SYMBOL_LIST_GENERATOR(V, _)          \
+  V(_, async_iterator_symbol, Symbol.asyncIterator) \
+  V(_, iterator_symbol, Symbol.iterator)            \
+  V(_, intl_fallback_symbol, IntlFallback)          \
+  V(_, match_all_symbol, Symbol.matchAll)           \
+  V(_, match_symbol, Symbol.match)                  \
+  V(_, replace_symbol, Symbol.replace)              \
+  V(_, search_symbol, Symbol.search)                \
+  V(_, species_symbol, Symbol.species)              \
+  V(_, split_symbol, Symbol.split)                  \
+  V(_, to_primitive_symbol, Symbol.toPrimitive)     \
+  V(_, unscopables_symbol, Symbol.unscopables)
 
 // Well-Known Symbols are "Public" symbols, which have a bit set which causes
 // them to produce an undefined value when a load results in a failed access
 // check. Because this behaviour is not specified properly as of yet, it only
 // applies to a subset of spec-defined Well-Known Symbols.
-#define WELL_KNOWN_SYMBOL_LIST(V)                           \
-  V(has_instance_symbol, Symbol.hasInstance)                \
-  V(is_concat_spreadable_symbol, Symbol.isConcatSpreadable) \
-  V(to_string_tag_symbol, Symbol.toStringTag)
+#define WELL_KNOWN_SYMBOL_LIST_GENERATOR(V, _)                 \
+  V(_, has_instance_symbol, Symbol.hasInstance)                \
+  V(_, is_concat_spreadable_symbol, Symbol.isConcatSpreadable) \
+  V(_, to_string_tag_symbol, Symbol.toStringTag)
 
 #define INCREMENTAL_SCOPES(F)                                      \
   /* MC_INCREMENTAL is the top-level incremental marking scope. */ \
@@ -394,7 +430,8 @@
   F(SCAVENGER_SCAVENGE_PARALLEL)                     \
   F(SCAVENGER_SCAVENGE_ROOTS)                        \
   F(SCAVENGER_SCAVENGE_UPDATE_REFS)                  \
-  F(SCAVENGER_SCAVENGE_WEAK)
+  F(SCAVENGER_SCAVENGE_WEAK)                         \
+  F(SCAVENGER_SCAVENGE_FINALIZE)
 
 #define TRACER_BACKGROUND_SCOPES(F)               \
   F(BACKGROUND_ARRAY_BUFFER_FREE)                 \
diff --git a/deps/v8/src/heap/array-buffer-collector.cc b/deps/v8/src/heap/array-buffer-collector.cc
index 2c28f46a85..0cf4ae945d 100644
--- a/deps/v8/src/heap/array-buffer-collector.cc
+++ b/deps/v8/src/heap/array-buffer-collector.cc
@@ -12,50 +12,54 @@
 namespace v8 {
 namespace internal {
 
-void ArrayBufferCollector::AddGarbageAllocations(
+namespace {
+
+void FreeAllocationsHelper(
+    Heap* heap, const std::vector<JSArrayBuffer::Allocation>& allocations) {
+  for (JSArrayBuffer::Allocation alloc : allocations) {
+    JSArrayBuffer::FreeBackingStore(heap->isolate(), alloc);
+  }
+}
+
+}  // namespace
+
+void ArrayBufferCollector::QueueOrFreeGarbageAllocations(
     std::vector<JSArrayBuffer::Allocation> allocations) {
-  base::LockGuard<base::Mutex> guard(&allocations_mutex_);
-  allocations_.push_back(std::move(allocations));
+  if (heap_->ShouldReduceMemory()) {
+    FreeAllocationsHelper(heap_, allocations);
+  } else {
+    base::LockGuard<base::Mutex> guard(&allocations_mutex_);
+    allocations_.push_back(std::move(allocations));
+  }
 }
 
-void ArrayBufferCollector::FreeAllocations() {
+void ArrayBufferCollector::PerformFreeAllocations() {
   base::LockGuard<base::Mutex> guard(&allocations_mutex_);
   for (const std::vector<JSArrayBuffer::Allocation>& allocations :
        allocations_) {
-    for (JSArrayBuffer::Allocation alloc : allocations) {
-      JSArrayBuffer::FreeBackingStore(heap_->isolate(), alloc);
-    }
+    FreeAllocationsHelper(heap_, allocations);
   }
   allocations_.clear();
 }
 
-class ArrayBufferCollector::FreeingTask final : public CancelableTask {
- public:
-  explicit FreeingTask(Heap* heap)
-      : CancelableTask(heap->isolate()), heap_(heap) {}
-
-  virtual ~FreeingTask() {}
-
- private:
-  void RunInternal() final {
-    TRACE_BACKGROUND_GC(
-        heap_->tracer(),
-        GCTracer::BackgroundScope::BACKGROUND_ARRAY_BUFFER_FREE);
-    heap_->array_buffer_collector()->FreeAllocations();
-  }
-
-  Heap* heap_;
-};
-
-void ArrayBufferCollector::FreeAllocationsOnBackgroundThread() {
+void ArrayBufferCollector::FreeAllocations() {
   // TODO(wez): Remove backing-store from external memory accounting.
   heap_->account_external_memory_concurrently_freed();
-  if (!heap_->IsTearingDown() && FLAG_concurrent_array_buffer_freeing) {
+  if (!heap_->IsTearingDown() && !heap_->ShouldReduceMemory() &&
+      FLAG_concurrent_array_buffer_freeing) {
     V8::GetCurrentPlatform()->CallOnWorkerThread(
-        base::make_unique<FreeingTask>(heap_));
+        MakeCancelableLambdaTask(heap_->isolate(), [this] {
+          TRACE_BACKGROUND_GC(
+              heap_->tracer(),
+              GCTracer::BackgroundScope::BACKGROUND_ARRAY_BUFFER_FREE);
+          PerformFreeAllocations();
+        }));
   } else {
-    // Fallback for when concurrency is disabled/restricted.
-    FreeAllocations();
+    // Fallback for when concurrency is disabled/restricted. This is e.g. the
+    // case when the GC should reduce memory. For such GCs the
+    // QueueOrFreeGarbageAllocations() call would immediately free the
+    // allocations and this call would free already queued ones.
+    PerformFreeAllocations();
   }
 }
 
diff --git a/deps/v8/src/heap/array-buffer-collector.h b/deps/v8/src/heap/array-buffer-collector.h
index 74a28c3d06..784092e936 100644
--- a/deps/v8/src/heap/array-buffer-collector.h
+++ b/deps/v8/src/heap/array-buffer-collector.h
@@ -23,24 +23,27 @@ class ArrayBufferCollector {
  public:
   explicit ArrayBufferCollector(Heap* heap) : heap_(heap) {}
 
-  ~ArrayBufferCollector() { FreeAllocations(); }
-
-  // These allocations will begin to be freed once FreeAllocations() is called,
-  // or on TearDown.
-  void AddGarbageAllocations(
+  ~ArrayBufferCollector() { PerformFreeAllocations(); }
+
+  // These allocations will be either
+  // - freed immediately when under memory pressure, or
+  // - queued for freeing in FreeAllocations() or during tear down.
+  //
+  // FreeAllocations() potentially triggers a background task for processing.
+  void QueueOrFreeGarbageAllocations(
       std::vector<JSArrayBuffer::Allocation> allocations);
 
   // Calls FreeAllocations() on a background thread.
-  void FreeAllocationsOnBackgroundThread();
+  void FreeAllocations();
 
  private:
   class FreeingTask;
 
-  // Begin freeing the allocations added through AddGarbageAllocations. Also
-  // called by TearDown.
-  void FreeAllocations();
+  // Begin freeing the allocations added through QueueOrFreeGarbageAllocations.
+  // Also called by TearDown.
+  void PerformFreeAllocations();
 
-  Heap* heap_;
+  Heap* const heap_;
   base::Mutex allocations_mutex_;
   std::vector<std::vector<JSArrayBuffer::Allocation>> allocations_;
 };
diff --git a/deps/v8/src/heap/array-buffer-tracker-inl.h b/deps/v8/src/heap/array-buffer-tracker-inl.h
index e0d862aed7..814cfce63a 100644
--- a/deps/v8/src/heap/array-buffer-tracker-inl.h
+++ b/deps/v8/src/heap/array-buffer-tracker-inl.h
@@ -18,7 +18,7 @@ namespace internal {
 void ArrayBufferTracker::RegisterNew(Heap* heap, JSArrayBuffer* buffer) {
   if (buffer->backing_store() == nullptr) return;
 
-  const size_t length = NumberToSize(buffer->byte_length());
+  const size_t length = buffer->byte_length();
   Page* page = Page::FromAddress(buffer->address());
   {
     base::LockGuard<base::Mutex> guard(page->mutex());
@@ -42,7 +42,7 @@ void ArrayBufferTracker::Unregister(Heap* heap, JSArrayBuffer* buffer) {
   if (buffer->backing_store() == nullptr) return;
 
   Page* page = Page::FromAddress(buffer->address());
-  const size_t length = NumberToSize(buffer->byte_length());
+  const size_t length = buffer->byte_length();
   {
     base::LockGuard<base::Mutex> guard(page->mutex());
     LocalArrayBufferTracker* tracker = page->local_tracker();
@@ -100,6 +100,11 @@ void LocalArrayBufferTracker::Add(JSArrayBuffer* buffer, size_t length) {
   page_->IncrementExternalBackingStoreBytes(
       ExternalBackingStoreType::kArrayBuffer, length);
 
+  AddInternal(buffer, length);
+}
+
+void LocalArrayBufferTracker::AddInternal(JSArrayBuffer* buffer,
+                                          size_t length) {
   auto ret = array_buffers_.insert(
       {buffer,
        {buffer->backing_store(), length, buffer->backing_store(),
diff --git a/deps/v8/src/heap/array-buffer-tracker.cc b/deps/v8/src/heap/array-buffer-tracker.cc
index 0a158e3543..f35f2b3754 100644
--- a/deps/v8/src/heap/array-buffer-tracker.cc
+++ b/deps/v8/src/heap/array-buffer-tracker.cc
@@ -26,11 +26,10 @@ void LocalArrayBufferTracker::Process(Callback callback) {
   JSArrayBuffer* new_buffer = nullptr;
   JSArrayBuffer* old_buffer = nullptr;
   size_t freed_memory = 0;
-  size_t moved_memory = 0;
   for (TrackingData::iterator it = array_buffers_.begin();
        it != array_buffers_.end(); ++it) {
     old_buffer = it->first;
-    Page* old_page = Page::FromAddress(old_buffer->address());
+    DCHECK_EQ(page_, Page::FromAddress(old_buffer->address()));
     const CallbackResult result = callback(old_buffer, &new_buffer);
     if (result == kKeepEntry) {
       kept_array_buffers.insert(*it);
@@ -49,26 +48,25 @@ void LocalArrayBufferTracker::Process(Callback callback) {
         // We should decrement before adding to avoid potential overflows in
         // the external memory counters.
         DCHECK_EQ(it->first->is_wasm_memory(), it->second.is_wasm_memory);
-        old_page->DecrementExternalBackingStoreBytes(
-            ExternalBackingStoreType::kArrayBuffer, length);
-        tracker->Add(new_buffer, length);
+        tracker->AddInternal(new_buffer, length);
+        MemoryChunk::MoveExternalBackingStoreBytes(
+            ExternalBackingStoreType::kArrayBuffer,
+            static_cast<MemoryChunk*>(page_),
+            static_cast<MemoryChunk*>(target_page), length);
       }
-      moved_memory += it->second.length;
-
     } else if (result == kRemoveEntry) {
-      const size_t length = it->second.length;
-      freed_memory += length;
+      freed_memory += it->second.length;
       // We pass backing_store() and stored length to the collector for freeing
       // the backing store. Wasm allocations will go through their own tracker
       // based on the backing store.
       backing_stores_to_free.push_back(it->second);
-      old_page->DecrementExternalBackingStoreBytes(
-          ExternalBackingStoreType::kArrayBuffer, length);
     } else {
       UNREACHABLE();
     }
   }
-  if (moved_memory || freed_memory) {
+  if (freed_memory) {
+    page_->DecrementExternalBackingStoreBytes(
+        ExternalBackingStoreType::kArrayBuffer, freed_memory);
     // TODO(wez): Remove backing-store from external memory accounting.
     page_->heap()->update_external_memory_concurrently_freed(
         static_cast<intptr_t>(freed_memory));
@@ -76,9 +74,9 @@ void LocalArrayBufferTracker::Process(Callback callback) {
 
   array_buffers_.swap(kept_array_buffers);
 
-  // Pass the backing stores that need to be freed to the main thread for later
-  // distribution.
-  page_->heap()->array_buffer_collector()->AddGarbageAllocations(
+  // Pass the backing stores that need to be freed to the main thread for
+  // potential later distribution.
+  page_->heap()->array_buffer_collector()->QueueOrFreeGarbageAllocations(
       std::move(backing_stores_to_free));
 }
 
diff --git a/deps/v8/src/heap/array-buffer-tracker.h b/deps/v8/src/heap/array-buffer-tracker.h
index e60fe6c6c0..3c00c2c486 100644
--- a/deps/v8/src/heap/array-buffer-tracker.h
+++ b/deps/v8/src/heap/array-buffer-tracker.h
@@ -113,6 +113,10 @@ class LocalArrayBufferTracker {
   typedef std::unordered_map<JSArrayBuffer*, JSArrayBuffer::Allocation, Hasher>
       TrackingData;
 
+  // Internal version of add that does not update counters. Requires separate
+  // logic for updating external memory counters.
+  inline void AddInternal(JSArrayBuffer* buffer, size_t length);
+
   inline Space* space();
 
   Page* page_;
diff --git a/deps/v8/src/heap/concurrent-marking.cc b/deps/v8/src/heap/concurrent-marking.cc
index f6eabbb021..5e147ca9a5 100644
--- a/deps/v8/src/heap/concurrent-marking.cc
+++ b/deps/v8/src/heap/concurrent-marking.cc
@@ -74,15 +74,19 @@ class ConcurrentMarkingVisitor final
  public:
   using BaseClass = HeapVisitor<int, ConcurrentMarkingVisitor>;
 
-  explicit ConcurrentMarkingVisitor(ConcurrentMarking::MarkingWorklist* shared,
-                                    ConcurrentMarking::MarkingWorklist* bailout,
-                                    LiveBytesMap* live_bytes,
-                                    WeakObjects* weak_objects, int task_id)
+  explicit ConcurrentMarkingVisitor(
+      ConcurrentMarking::MarkingWorklist* shared,
+      ConcurrentMarking::MarkingWorklist* bailout, LiveBytesMap* live_bytes,
+      WeakObjects* weak_objects,
+      ConcurrentMarking::EmbedderTracingWorklist* embedder_objects, int task_id,
+      bool embedder_tracing_enabled)
       : shared_(shared, task_id),
         bailout_(bailout, task_id),
         weak_objects_(weak_objects),
+        embedder_objects_(embedder_objects, task_id),
         marking_state_(live_bytes),
-        task_id_(task_id) {}
+        task_id_(task_id),
+        embedder_tracing_enabled_(embedder_tracing_enabled) {}
 
   template <typename T>
   static V8_INLINE T* Cast(HeapObject* object) {
@@ -138,19 +142,24 @@ class ConcurrentMarkingVisitor final
     for (MaybeObject** slot = start; slot < end; slot++) {
       MaybeObject* object = base::AsAtomicPointer::Relaxed_Load(slot);
       HeapObject* heap_object;
-      if (object->ToStrongHeapObject(&heap_object)) {
+      if (object->GetHeapObjectIfStrong(&heap_object)) {
         // If the reference changes concurrently from strong to weak, the write
         // barrier will treat the weak reference as strong, so we won't miss the
         // weak reference.
         ProcessStrongHeapObject(host, reinterpret_cast<Object**>(slot),
                                 heap_object);
-      } else if (object->ToWeakHeapObject(&heap_object)) {
+      } else if (object->GetHeapObjectIfWeak(&heap_object)) {
         ProcessWeakHeapObject(
             host, reinterpret_cast<HeapObjectReference**>(slot), heap_object);
       }
     }
   }
 
+  // Weak list pointers should be ignored during marking. The lists are
+  // reconstructed after GC.
+  void VisitCustomWeakPointers(HeapObject* host, Object** start,
+                               Object** end) override {}
+
   void VisitPointersInSnapshot(HeapObject* host, const SlotSnapshot& snapshot) {
     for (int i = 0; i < snapshot.number_of_slots(); i++) {
       Object** slot = snapshot.slot(i);
@@ -175,31 +184,27 @@ class ConcurrentMarkingVisitor final
     return VisitJSObjectSubclass(map, object);
   }
 
-  int VisitJSArrayBuffer(Map* map, JSArrayBuffer* object) {
-    return VisitJSObjectSubclass(map, object);
-  }
-
   int VisitWasmInstanceObject(Map* map, WasmInstanceObject* object) {
     return VisitJSObjectSubclass(map, object);
   }
 
+  // Some JS objects can carry back links to embedders that contain information
+  // relevant to the garbage collectors.
+
   int VisitJSApiObject(Map* map, JSObject* object) {
-    if (marking_state_.IsGrey(object)) {
-      // The main thread will do wrapper tracing in Blink.
-      bailout_.Push(object);
-    }
-    return 0;
+    return VisitEmbedderTracingSubclass(map, object);
   }
 
-  int VisitJSFunction(Map* map, JSFunction* object) {
-    int size = JSFunction::BodyDescriptorWeak::SizeOf(map, object);
-    int used_size = map->UsedInstanceSize();
-    DCHECK_LE(used_size, size);
-    DCHECK_GE(used_size, JSObject::kHeaderSize);
-    const SlotSnapshot& snapshot = MakeSlotSnapshotWeak(map, object, used_size);
-    if (!ShouldVisit(object)) return 0;
-    VisitPointersInSnapshot(object, snapshot);
-    return size;
+  int VisitJSArrayBuffer(Map* map, JSArrayBuffer* object) {
+    return VisitEmbedderTracingSubclass(map, object);
+  }
+
+  int VisitJSDataView(Map* map, JSDataView* object) {
+    return VisitEmbedderTracingSubclass(map, object);
+  }
+
+  int VisitJSTypedArray(Map* map, JSTypedArray* object) {
+    return VisitEmbedderTracingSubclass(map, object);
   }
 
   // ===========================================================================
@@ -270,34 +275,18 @@ class ConcurrentMarkingVisitor final
   }
 
   // ===========================================================================
-  // Objects with weak fields and/or side-effectiful visitation.
+  // Side-effectful visitation.
   // ===========================================================================
 
   int VisitBytecodeArray(Map* map, BytecodeArray* object) {
     if (!ShouldVisit(object)) return 0;
-    int size = BytecodeArray::BodyDescriptorWeak::SizeOf(map, object);
+    int size = BytecodeArray::BodyDescriptor::SizeOf(map, object);
     VisitMapPointer(object, object->map_slot());
-    BytecodeArray::BodyDescriptorWeak::IterateBody(map, object, size, this);
+    BytecodeArray::BodyDescriptor::IterateBody(map, object, size, this);
     object->MakeOlder();
     return size;
   }
 
-  int VisitAllocationSite(Map* map, AllocationSite* object) {
-    if (!ShouldVisit(object)) return 0;
-    int size = AllocationSite::BodyDescriptorWeak::SizeOf(map, object);
-    VisitMapPointer(object, object->map_slot());
-    AllocationSite::BodyDescriptorWeak::IterateBody(map, object, size, this);
-    return size;
-  }
-
-  int VisitCodeDataContainer(Map* map, CodeDataContainer* object) {
-    if (!ShouldVisit(object)) return 0;
-    int size = CodeDataContainer::BodyDescriptorWeak::SizeOf(map, object);
-    VisitMapPointer(object, object->map_slot());
-    CodeDataContainer::BodyDescriptorWeak::IterateBody(map, object, size, this);
-    return size;
-  }
-
   int VisitMap(Map* meta_map, Map* map) {
     if (marking_state_.IsGrey(map)) {
       // Maps have ad-hoc weakness for descriptor arrays. They also clear the
@@ -315,14 +304,6 @@ class ConcurrentMarkingVisitor final
     return 0;
   }
 
-  int VisitNativeContext(Map* map, Context* object) {
-    if (!ShouldVisit(object)) return 0;
-    int size = Context::BodyDescriptorWeak::SizeOf(map, object);
-    VisitMapPointer(object, object->map_slot());
-    Context::BodyDescriptorWeak::IterateBody(map, object, size, this);
-    return size;
-  }
-
   int VisitTransitionArray(Map* map, TransitionArray* array) {
     if (!ShouldVisit(array)) return 0;
     VisitMapPointer(array, array->map_slot());
@@ -443,6 +424,18 @@ class ConcurrentMarkingVisitor final
   }
 
   template <typename T>
+  int VisitEmbedderTracingSubclass(Map* map, T* object) {
+    DCHECK(object->IsApiWrapper());
+    int size = VisitJSObjectSubclass(map, object);
+    if (size && embedder_tracing_enabled_) {
+      // Success: The object needs to be processed for embedder references on
+      // the main thread.
+      embedder_objects_.Push(object);
+    }
+    return size;
+  }
+
+  template <typename T>
   int VisitLeftTrimmableArray(Map* map, T* object) {
     // The synchronized_length() function checks that the length is a Smi.
     // This is not necessarily the case if the array is being left-trimmed.
@@ -466,20 +459,14 @@ class ConcurrentMarkingVisitor final
     return slot_snapshot_;
   }
 
-  template <typename T>
-  const SlotSnapshot& MakeSlotSnapshotWeak(Map* map, T* object, int size) {
-    SlotSnapshottingVisitor visitor(&slot_snapshot_);
-    visitor.VisitPointer(object,
-                         reinterpret_cast<Object**>(object->map_slot()));
-    T::BodyDescriptorWeak::IterateBody(map, object, size, &visitor);
-    return slot_snapshot_;
-  }
   ConcurrentMarking::MarkingWorklist::View shared_;
   ConcurrentMarking::MarkingWorklist::View bailout_;
   WeakObjects* weak_objects_;
+  ConcurrentMarking::EmbedderTracingWorklist::View embedder_objects_;
   ConcurrentMarkingState marking_state_;
   int task_id_;
   SlotSnapshot slot_snapshot_;
+  bool embedder_tracing_enabled_;
 };
 
 // Strings can change maps due to conversion to thin string or external strings.
@@ -524,7 +511,7 @@ class ConcurrentMarking::Task : public CancelableTask {
         task_state_(task_state),
         task_id_(task_id) {}
 
-  virtual ~Task() {}
+  ~Task() override = default;
 
  private:
   // v8::internal::CancelableTask overrides.
@@ -541,12 +528,14 @@ class ConcurrentMarking::Task : public CancelableTask {
 ConcurrentMarking::ConcurrentMarking(Heap* heap, MarkingWorklist* shared,
                                      MarkingWorklist* bailout,
                                      MarkingWorklist* on_hold,
-                                     WeakObjects* weak_objects)
+                                     WeakObjects* weak_objects,
+                                     EmbedderTracingWorklist* embedder_objects)
     : heap_(heap),
       shared_(shared),
       bailout_(bailout),
       on_hold_(on_hold),
-      weak_objects_(weak_objects) {
+      weak_objects_(weak_objects),
+      embedder_objects_(embedder_objects) {
 // The runtime flag should be set only if the compile time flag was set.
 #ifndef V8_CONCURRENT_MARKING
   CHECK(!FLAG_concurrent_marking);
@@ -558,8 +547,9 @@ void ConcurrentMarking::Run(int task_id, TaskState* task_state) {
                       GCTracer::BackgroundScope::MC_BACKGROUND_MARKING);
   size_t kBytesUntilInterruptCheck = 64 * KB;
   int kObjectsUntilInterrupCheck = 1000;
-  ConcurrentMarkingVisitor visitor(shared_, bailout_, &task_state->live_bytes,
-                                   weak_objects_, task_id);
+  ConcurrentMarkingVisitor visitor(
+      shared_, bailout_, &task_state->live_bytes, weak_objects_,
+      embedder_objects_, task_id, heap_->local_embedder_heap_tracer()->InUse());
   double time_ms;
   size_t marked_bytes = 0;
   if (FLAG_trace_concurrent_marking) {
@@ -626,6 +616,7 @@ void ConcurrentMarking::Run(int task_id, TaskState* task_state) {
     shared_->FlushToGlobal(task_id);
     bailout_->FlushToGlobal(task_id);
     on_hold_->FlushToGlobal(task_id);
+    embedder_objects_->FlushToGlobal(task_id);
 
     weak_objects_->transition_arrays.FlushToGlobal(task_id);
     weak_objects_->ephemeron_hash_tables.FlushToGlobal(task_id);
diff --git a/deps/v8/src/heap/concurrent-marking.h b/deps/v8/src/heap/concurrent-marking.h
index 0b8ffd9336..34de02fea1 100644
--- a/deps/v8/src/heap/concurrent-marking.h
+++ b/deps/v8/src/heap/concurrent-marking.h
@@ -58,10 +58,12 @@ class ConcurrentMarking {
   // task 0, reserved for the main thread).
   static constexpr int kMaxTasks = 7;
   using MarkingWorklist = Worklist<HeapObject*, 64 /* segment size */>;
+  using EmbedderTracingWorklist = Worklist<HeapObject*, 16 /* segment size */>;
 
   ConcurrentMarking(Heap* heap, MarkingWorklist* shared,
                     MarkingWorklist* bailout, MarkingWorklist* on_hold,
-                    WeakObjects* weak_objects);
+                    WeakObjects* weak_objects,
+                    EmbedderTracingWorklist* embedder_objects);
 
   // Schedules asynchronous tasks to perform concurrent marking. Objects in the
   // heap should not be moved while these are active (can be stopped safely via
@@ -108,6 +110,7 @@ class ConcurrentMarking {
   MarkingWorklist* const bailout_;
   MarkingWorklist* const on_hold_;
   WeakObjects* const weak_objects_;
+  EmbedderTracingWorklist* const embedder_objects_;
   TaskState task_state_[kMaxTasks + 1];
   std::atomic<size_t> total_marked_bytes_{0};
   std::atomic<bool> ephemeron_marked_{false};
diff --git a/deps/v8/src/heap/embedder-tracing.cc b/deps/v8/src/heap/embedder-tracing.cc
index bf6d5f3b90..198cdd4b1a 100644
--- a/deps/v8/src/heap/embedder-tracing.cc
+++ b/deps/v8/src/heap/embedder-tracing.cc
@@ -24,13 +24,6 @@ void LocalEmbedderHeapTracer::TraceEpilogue() {
   remote_tracer_->TraceEpilogue();
 }
 
-void LocalEmbedderHeapTracer::AbortTracing() {
-  if (!InUse()) return;
-
-  cached_wrappers_to_trace_.clear();
-  remote_tracer_->AbortTracing();
-}
-
 void LocalEmbedderHeapTracer::EnterFinalPause() {
   if (!InUse()) return;
 
diff --git a/deps/v8/src/heap/embedder-tracing.h b/deps/v8/src/heap/embedder-tracing.h
index ab8a46bb53..2588200db9 100644
--- a/deps/v8/src/heap/embedder-tracing.h
+++ b/deps/v8/src/heap/embedder-tracing.h
@@ -24,6 +24,8 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
     if (remote_tracer_) remote_tracer_->isolate_ = nullptr;
   }
 
+  EmbedderHeapTracer* remote_tracer() const { return remote_tracer_; }
+
   void SetRemoteTracer(EmbedderHeapTracer* tracer) {
     if (remote_tracer_) remote_tracer_->isolate_ = nullptr;
 
@@ -36,7 +38,6 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
 
   void TracePrologue();
   void TraceEpilogue();
-  void AbortTracing();
   void EnterFinalPause();
   bool Trace(double deadline);
   bool IsRemoteTracingDone();
diff --git a/deps/v8/src/heap/factory-inl.h b/deps/v8/src/heap/factory-inl.h
index 614c6ec174..eb1661aaee 100644
--- a/deps/v8/src/heap/factory-inl.h
+++ b/deps/v8/src/heap/factory-inl.h
@@ -16,73 +16,14 @@
 namespace v8 {
 namespace internal {
 
-#define ROOT_ACCESSOR(type, name, camel_name)                         \
-  Handle<type> Factory::name() {                                      \
-    return Handle<type>(bit_cast<type**>(                             \
-        &isolate()->heap()->roots_[Heap::k##camel_name##RootIndex])); \
+#define ROOT_ACCESSOR(type, name, CamelName)                   \
+  Handle<type> Factory::name() {                               \
+    return Handle<type>(bit_cast<type**>(                      \
+        &isolate()->heap()->roots_[RootIndex::k##CamelName])); \
   }
 ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
-#define STRUCT_MAP_ACCESSOR(NAME, Name, name)                      \
-  Handle<Map> Factory::name##_map() {                              \
-    return Handle<Map>(bit_cast<Map**>(                            \
-        &isolate()->heap()->roots_[Heap::k##Name##MapRootIndex])); \
-  }
-STRUCT_LIST(STRUCT_MAP_ACCESSOR)
-#undef STRUCT_MAP_ACCESSOR
-
-#define ALLOCATION_SITE_MAP_ACCESSOR(NAME, Name, Size, name)             \
-  Handle<Map> Factory::name##_map() {                                    \
-    return Handle<Map>(bit_cast<Map**>(                                  \
-        &isolate()->heap()->roots_[Heap::k##Name##Size##MapRootIndex])); \
-  }
-ALLOCATION_SITE_LIST(ALLOCATION_SITE_MAP_ACCESSOR)
-#undef ALLOCATION_SITE_MAP_ACCESSOR
-
-#define DATA_HANDLER_MAP_ACCESSOR(NAME, Name, Size, name)                \
-  Handle<Map> Factory::name##_map() {                                    \
-    return Handle<Map>(bit_cast<Map**>(                                  \
-        &isolate()->heap()->roots_[Heap::k##Name##Size##MapRootIndex])); \
-  }
-DATA_HANDLER_LIST(DATA_HANDLER_MAP_ACCESSOR)
-#undef DATA_HANDLER_MAP_ACCESSOR
-
-#define STRING_ACCESSOR(name, str)                              \
-  Handle<String> Factory::name() {                              \
-    return Handle<String>(bit_cast<String**>(                   \
-        &isolate()->heap()->roots_[Heap::k##name##RootIndex])); \
-  }
-INTERNALIZED_STRING_LIST(STRING_ACCESSOR)
-#undef STRING_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name)                                   \
-  Handle<Symbol> Factory::name() {                              \
-    return Handle<Symbol>(bit_cast<Symbol**>(                   \
-        &isolate()->heap()->roots_[Heap::k##name##RootIndex])); \
-  }
-PRIVATE_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name, description)                      \
-  Handle<Symbol> Factory::name() {                              \
-    return Handle<Symbol>(bit_cast<Symbol**>(                   \
-        &isolate()->heap()->roots_[Heap::k##name##RootIndex])); \
-  }
-PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR)
-WELL_KNOWN_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define ACCESSOR_INFO_ACCESSOR(accessor_name, AccessorName)        \
-  Handle<AccessorInfo> Factory::accessor_name##_accessor() {       \
-    return Handle<AccessorInfo>(bit_cast<AccessorInfo**>(          \
-        &isolate()                                                 \
-             ->heap()                                              \
-             ->roots_[Heap::k##AccessorName##AccessorRootIndex])); \
-  }
-ACCESSOR_INFO_LIST(ACCESSOR_INFO_ACCESSOR)
-#undef ACCESSOR_INFO_ACCESSOR
-
 Handle<String> Factory::InternalizeString(Handle<String> string) {
   if (string->IsInternalizedString()) return string;
   return StringTable::LookupString(isolate(), string);
diff --git a/deps/v8/src/heap/factory.cc b/deps/v8/src/heap/factory.cc
index c8528f9fdb..9535eb4b88 100644
--- a/deps/v8/src/heap/factory.cc
+++ b/deps/v8/src/heap/factory.cc
@@ -27,9 +27,11 @@
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/microtask-inl.h"
+#include "src/objects/microtask-queue-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
 #include "src/objects/scope-info.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/unicode-cache.h"
 #include "src/unicode-decoder.h"
 
@@ -63,9 +65,9 @@ void InitializeCode(Heap* heap, Handle<Code> code, int object_size,
                     bool is_turbofanned, int stack_slots,
                     int safepoint_table_offset, int handler_table_offset) {
   DCHECK(IsAligned(code->address(), kCodeAlignment));
-  DCHECK(!heap->memory_allocator()->code_range()->valid() ||
-         heap->memory_allocator()->code_range()->contains(code->address()) ||
-         object_size <= heap->code_space()->AreaSize());
+  DCHECK_IMPLIES(
+      !heap->memory_allocator()->code_range().is_empty(),
+      heap->memory_allocator()->code_range().contains(code->address()));
 
   bool has_unwinding_info = desc.unwinding_info != nullptr;
 
@@ -287,9 +289,9 @@ Handle<PropertyArray> Factory::NewPropertyArray(int length,
   return array;
 }
 
-Handle<FixedArray> Factory::NewFixedArrayWithFiller(
-    Heap::RootListIndex map_root_index, int length, Object* filler,
-    PretenureFlag pretenure) {
+Handle<FixedArray> Factory::NewFixedArrayWithFiller(RootIndex map_root_index,
+                                                    int length, Object* filler,
+                                                    PretenureFlag pretenure) {
   HeapObject* result = AllocateRawFixedArray(length, pretenure);
   DCHECK(Heap::RootIsImmortalImmovable(map_root_index));
   Map* map = Map::cast(isolate()->heap()->root(map_root_index));
@@ -301,8 +303,8 @@ Handle<FixedArray> Factory::NewFixedArrayWithFiller(
 }
 
 template <typename T>
-Handle<T> Factory::NewFixedArrayWithMap(Heap::RootListIndex map_root_index,
-                                        int length, PretenureFlag pretenure) {
+Handle<T> Factory::NewFixedArrayWithMap(RootIndex map_root_index, int length,
+                                        PretenureFlag pretenure) {
   static_assert(std::is_base_of<FixedArray, T>::value,
                 "T must be a descendant of FixedArray");
   // Zero-length case must be handled outside, where the knowledge about
@@ -313,7 +315,7 @@ Handle<T> Factory::NewFixedArrayWithMap(Heap::RootListIndex map_root_index,
 }
 
 template <typename T>
-Handle<T> Factory::NewWeakFixedArrayWithMap(Heap::RootListIndex map_root_index,
+Handle<T> Factory::NewWeakFixedArrayWithMap(RootIndex map_root_index,
                                             int length,
                                             PretenureFlag pretenure) {
   static_assert(std::is_base_of<WeakFixedArray, T>::value,
@@ -336,16 +338,16 @@ Handle<T> Factory::NewWeakFixedArrayWithMap(Heap::RootListIndex map_root_index,
 }
 
 template Handle<FixedArray> Factory::NewFixedArrayWithMap<FixedArray>(
-    Heap::RootListIndex, int, PretenureFlag);
+    RootIndex, int, PretenureFlag);
 
 template Handle<DescriptorArray>
-Factory::NewWeakFixedArrayWithMap<DescriptorArray>(Heap::RootListIndex, int,
+Factory::NewWeakFixedArrayWithMap<DescriptorArray>(RootIndex, int,
                                                    PretenureFlag);
 
 Handle<FixedArray> Factory::NewFixedArray(int length, PretenureFlag pretenure) {
   DCHECK_LE(0, length);
   if (length == 0) return empty_fixed_array();
-  return NewFixedArrayWithFiller(Heap::kFixedArrayMapRootIndex, length,
+  return NewFixedArrayWithFiller(RootIndex::kFixedArrayMap, length,
                                  *undefined_value(), pretenure);
 }
 
@@ -355,7 +357,7 @@ Handle<WeakFixedArray> Factory::NewWeakFixedArray(int length,
   if (length == 0) return empty_weak_fixed_array();
   HeapObject* result =
       AllocateRawArray(WeakFixedArray::SizeFor(length), pretenure);
-  DCHECK(Heap::RootIsImmortalImmovable(Heap::kWeakFixedArrayMapRootIndex));
+  DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kWeakFixedArrayMap));
   result->set_map_after_allocation(*weak_fixed_array_map(), SKIP_WRITE_BARRIER);
   Handle<WeakFixedArray> array(WeakFixedArray::cast(result), isolate());
   array->set_length(length);
@@ -391,7 +393,7 @@ Handle<FixedArray> Factory::NewFixedArrayWithHoles(int length,
                                                    PretenureFlag pretenure) {
   DCHECK_LE(0, length);
   if (length == 0) return empty_fixed_array();
-  return NewFixedArrayWithFiller(Heap::kFixedArrayMapRootIndex, length,
+  return NewFixedArrayWithFiller(RootIndex::kFixedArrayMap, length,
                                  *the_hole_value(), pretenure);
 }
 
@@ -403,7 +405,7 @@ Handle<FixedArray> Factory::NewUninitializedFixedArray(
   // TODO(ulan): As an experiment this temporarily returns an initialized fixed
   // array. After getting canary/performance coverage, either remove the
   // function or revert to returning uninitilized array.
-  return NewFixedArrayWithFiller(Heap::kFixedArrayMapRootIndex, length,
+  return NewFixedArrayWithFiller(RootIndex::kFixedArrayMap, length,
                                  *undefined_value(), pretenure);
 }
 
@@ -452,7 +454,7 @@ Handle<ObjectBoilerplateDescription> Factory::NewObjectBoilerplateDescription(
 
   Handle<ObjectBoilerplateDescription> description =
       Handle<ObjectBoilerplateDescription>::cast(NewFixedArrayWithMap(
-          Heap::kObjectBoilerplateDescriptionMapRootIndex, size, TENURED));
+          RootIndex::kObjectBoilerplateDescriptionMap, size, TENURED));
 
   if (has_different_size_backing_store) {
     DCHECK_IMPLIES((boilerplate == (all_properties - index_keys)),
@@ -773,7 +775,7 @@ Handle<SeqOneByteString> Factory::AllocateRawOneByteInternalizedString(
   // The canonical empty_string is the only zero-length string we allow.
   DCHECK_IMPLIES(
       length == 0,
-      isolate()->heap()->roots_[Heap::kempty_stringRootIndex] == nullptr);
+      isolate()->heap()->roots_[RootIndex::kempty_string] == nullptr);
 
   Map* map = *one_byte_internalized_string_map();
   int size = SeqOneByteString::SizeFor(length);
@@ -900,12 +902,12 @@ MaybeHandle<Map> GetInternalizedStringMap(Factory* f, Handle<String> string) {
       return f->external_one_byte_internalized_string_map();
     case EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
       return f->external_internalized_string_with_one_byte_data_map();
-    case SHORT_EXTERNAL_STRING_TYPE:
-      return f->short_external_internalized_string_map();
-    case SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE:
-      return f->short_external_one_byte_internalized_string_map();
-    case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
-      return f->short_external_internalized_string_with_one_byte_data_map();
+    case UNCACHED_EXTERNAL_STRING_TYPE:
+      return f->uncached_external_internalized_string_map();
+    case UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE:
+      return f->uncached_external_one_byte_internalized_string_map();
+    case UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
+      return f->uncached_external_internalized_string_with_one_byte_data_map();
     default:
       return MaybeHandle<Map>();  // No match found.
   }
@@ -1083,7 +1085,7 @@ MaybeHandle<String> Factory::NewConsString(Handle<String> left,
   bool is_one_byte_data_in_two_byte_string = false;
   if (!is_one_byte) {
     // At least one of the strings uses two-byte representation so we
-    // can't use the fast case code for short one-byte strings below, but
+    // can't use the fast case code for uncached one-byte strings below, but
     // we can try to save memory if all chars actually fit in one-byte.
     is_one_byte_data_in_two_byte_string =
         left->HasOnlyOneByteChars() && right->HasOnlyOneByteChars();
@@ -1243,9 +1245,8 @@ MaybeHandle<String> Factory::NewExternalStringFromOneByte(
   if (length == 0) return empty_string();
 
   Handle<Map> map;
-  if (resource->IsCompressible()) {
-    // TODO(hajimehoshi): Rename this to 'uncached_external_one_byte_string_map'
-    map = short_external_one_byte_string_map();
+  if (!resource->IsCacheable()) {
+    map = uncached_external_one_byte_string_map();
   } else {
     map = external_one_byte_string_map();
   }
@@ -1274,10 +1275,9 @@ MaybeHandle<String> Factory::NewExternalStringFromTwoByte(
       length <= kOneByteCheckLengthLimit &&
       String::IsOneByte(resource->data(), static_cast<int>(length));
   Handle<Map> map;
-  if (resource->IsCompressible()) {
-    // TODO(hajimehoshi): Rename these to 'uncached_external_string_...'.
-    map = is_one_byte ? short_external_string_with_one_byte_data_map()
-                      : short_external_string_map();
+  if (!resource->IsCacheable()) {
+    map = is_one_byte ? uncached_external_string_with_one_byte_data_map()
+                      : uncached_external_string_map();
   } else {
     map = is_one_byte ? external_string_with_one_byte_data_map()
                       : external_string_map();
@@ -1309,7 +1309,7 @@ Handle<ExternalOneByteString> Factory::NewNativeSourceString(
 }
 
 Handle<JSStringIterator> Factory::NewJSStringIterator(Handle<String> string) {
-  Handle<Map> map(isolate()->native_context()->string_iterator_map(),
+  Handle<Map> map(isolate()->native_context()->initial_string_iterator_map(),
                   isolate());
   Handle<String> flat_string = String::Flatten(isolate(), string);
   Handle<JSStringIterator> iterator =
@@ -1355,7 +1355,7 @@ Handle<Symbol> Factory::NewPrivateFieldSymbol() {
 
 Handle<NativeContext> Factory::NewNativeContext() {
   Handle<NativeContext> context = NewFixedArrayWithMap<NativeContext>(
-      Heap::kNativeContextMapRootIndex, Context::NATIVE_CONTEXT_SLOTS, TENURED);
+      RootIndex::kNativeContextMap, Context::NATIVE_CONTEXT_SLOTS, TENURED);
   context->set_native_context(*context);
   context->set_errors_thrown(Smi::kZero);
   context->set_math_random_index(Smi::kZero);
@@ -1367,7 +1367,7 @@ Handle<Context> Factory::NewScriptContext(Handle<NativeContext> outer,
                                           Handle<ScopeInfo> scope_info) {
   DCHECK_EQ(scope_info->scope_type(), SCRIPT_SCOPE);
   Handle<Context> context = NewFixedArrayWithMap<Context>(
-      Heap::kScriptContextMapRootIndex, scope_info->ContextLength(), TENURED);
+      RootIndex::kScriptContextMap, scope_info->ContextLength(), TENURED);
   context->set_scope_info(*scope_info);
   context->set_previous(*outer);
   context->set_extension(*the_hole_value());
@@ -1379,8 +1379,7 @@ Handle<Context> Factory::NewScriptContext(Handle<NativeContext> outer,
 Handle<ScriptContextTable> Factory::NewScriptContextTable() {
   Handle<ScriptContextTable> context_table =
       NewFixedArrayWithMap<ScriptContextTable>(
-          Heap::kScriptContextTableMapRootIndex,
-          ScriptContextTable::kMinLength);
+          RootIndex::kScriptContextTableMap, ScriptContextTable::kMinLength);
   context_table->set_used(0);
   return context_table;
 }
@@ -1390,7 +1389,7 @@ Handle<Context> Factory::NewModuleContext(Handle<Module> module,
                                           Handle<ScopeInfo> scope_info) {
   DCHECK_EQ(scope_info->scope_type(), MODULE_SCOPE);
   Handle<Context> context = NewFixedArrayWithMap<Context>(
-      Heap::kModuleContextMapRootIndex, scope_info->ContextLength(), TENURED);
+      RootIndex::kModuleContextMap, scope_info->ContextLength(), TENURED);
   context->set_scope_info(*scope_info);
   context->set_previous(*outer);
   context->set_extension(*module);
@@ -1403,13 +1402,13 @@ Handle<Context> Factory::NewFunctionContext(Handle<Context> outer,
                                             Handle<ScopeInfo> scope_info) {
   int length = scope_info->ContextLength();
   DCHECK_LE(Context::MIN_CONTEXT_SLOTS, length);
-  Heap::RootListIndex mapRootIndex;
+  RootIndex mapRootIndex;
   switch (scope_info->scope_type()) {
     case EVAL_SCOPE:
-      mapRootIndex = Heap::kEvalContextMapRootIndex;
+      mapRootIndex = RootIndex::kEvalContextMap;
       break;
     case FUNCTION_SCOPE:
-      mapRootIndex = Heap::kFunctionContextMapRootIndex;
+      mapRootIndex = RootIndex::kFunctionContextMap;
       break;
     default:
       UNREACHABLE();
@@ -1427,7 +1426,7 @@ Handle<Context> Factory::NewCatchContext(Handle<Context> previous,
                                          Handle<Object> thrown_object) {
   STATIC_ASSERT(Context::MIN_CONTEXT_SLOTS == Context::THROWN_OBJECT_INDEX);
   Handle<Context> context = NewFixedArrayWithMap<Context>(
-      Heap::kCatchContextMapRootIndex, Context::MIN_CONTEXT_SLOTS + 1);
+      RootIndex::kCatchContextMap, Context::MIN_CONTEXT_SLOTS + 1);
   context->set_scope_info(*scope_info);
   context->set_previous(*previous);
   context->set_extension(*the_hole_value());
@@ -1447,7 +1446,7 @@ Handle<Context> Factory::NewDebugEvaluateContext(Handle<Context> previous,
                                ? Handle<HeapObject>::cast(the_hole_value())
                                : Handle<HeapObject>::cast(extension);
   Handle<Context> c = NewFixedArrayWithMap<Context>(
-      Heap::kDebugEvaluateContextMapRootIndex, Context::MIN_CONTEXT_SLOTS + 2);
+      RootIndex::kDebugEvaluateContextMap, Context::MIN_CONTEXT_SLOTS + 2);
   c->set_scope_info(*scope_info);
   c->set_previous(*previous);
   c->set_native_context(previous->native_context());
@@ -1461,7 +1460,7 @@ Handle<Context> Factory::NewWithContext(Handle<Context> previous,
                                         Handle<ScopeInfo> scope_info,
                                         Handle<JSReceiver> extension) {
   Handle<Context> context = NewFixedArrayWithMap<Context>(
-      Heap::kWithContextMapRootIndex, Context::MIN_CONTEXT_SLOTS);
+      RootIndex::kWithContextMap, Context::MIN_CONTEXT_SLOTS);
   context->set_scope_info(*scope_info);
   context->set_previous(*previous);
   context->set_extension(*extension);
@@ -1473,7 +1472,7 @@ Handle<Context> Factory::NewBlockContext(Handle<Context> previous,
                                          Handle<ScopeInfo> scope_info) {
   DCHECK_EQ(scope_info->scope_type(), BLOCK_SCOPE);
   Handle<Context> context = NewFixedArrayWithMap<Context>(
-      Heap::kBlockContextMapRootIndex, scope_info->ContextLength());
+      RootIndex::kBlockContextMap, scope_info->ContextLength());
   context->set_scope_info(*scope_info);
   context->set_previous(*previous);
   context->set_extension(*the_hole_value());
@@ -1485,7 +1484,7 @@ Handle<Context> Factory::NewBuiltinContext(Handle<NativeContext> native_context,
                                            int length) {
   DCHECK_GE(length, Context::MIN_CONTEXT_SLOTS);
   Handle<Context> context =
-      NewFixedArrayWithMap<Context>(Heap::kFunctionContextMapRootIndex, length);
+      NewFixedArrayWithMap<Context>(RootIndex::kFunctionContextMap, length);
   context->set_scope_info(ReadOnlyRoots(isolate()).empty_scope_info());
   context->set_extension(*the_hole_value());
   context->set_native_context(*native_context);
@@ -1495,8 +1494,8 @@ Handle<Context> Factory::NewBuiltinContext(Handle<NativeContext> native_context,
 Handle<Struct> Factory::NewStruct(InstanceType type, PretenureFlag pretenure) {
   Map* map;
   switch (type) {
-#define MAKE_CASE(NAME, Name, name) \
-  case NAME##_TYPE:                 \
+#define MAKE_CASE(TYPE, Name, name) \
+  case TYPE:                        \
     map = *name##_map();            \
     break;
     STRUCT_LIST(MAKE_CASE)
@@ -1623,6 +1622,16 @@ Handle<PromiseResolveThenableJobTask> Factory::NewPromiseResolveThenableJobTask(
   return microtask;
 }
 
+Handle<MicrotaskQueue> Factory::NewMicrotaskQueue() {
+  // MicrotaskQueue should be TENURED, as it outlives Context, and is mostly
+  // as long-living as Context is.
+  Handle<MicrotaskQueue> microtask_queue =
+      Handle<MicrotaskQueue>::cast(NewStruct(MICROTASK_QUEUE_TYPE, TENURED));
+  microtask_queue->set_queue(*empty_fixed_array());
+  microtask_queue->set_pending_microtask_count(0);
+  return microtask_queue;
+}
+
 Handle<Foreign> Factory::NewForeign(Address addr, PretenureFlag pretenure) {
   // Statically ensure that it is safe to allocate foreigns in paged spaces.
   STATIC_ASSERT(Foreign::kSize <= kMaxRegularHeapObjectSize);
@@ -1687,7 +1696,8 @@ Handle<FixedTypedArrayBase> Factory::NewFixedTypedArrayWithExternalPointer(
   DCHECK(0 <= length && length <= Smi::kMaxValue);
   int size = FixedTypedArrayBase::kHeaderSize;
   HeapObject* result = AllocateRawWithImmortalMap(
-      size, pretenure, isolate()->heap()->MapForFixedTypedArray(array_type));
+      size, pretenure,
+      ReadOnlyRoots(isolate()).MapForFixedTypedArray(array_type));
   Handle<FixedTypedArrayBase> elements(FixedTypedArrayBase::cast(result),
                                        isolate());
   elements->set_base_pointer(Smi::kZero, SKIP_WRITE_BARRIER);
@@ -1704,7 +1714,7 @@ Handle<FixedTypedArrayBase> Factory::NewFixedTypedArray(
   CHECK(byte_length <= kMaxInt - FixedTypedArrayBase::kDataOffset);
   size_t size =
       OBJECT_POINTER_ALIGN(byte_length + FixedTypedArrayBase::kDataOffset);
-  Map* map = isolate()->heap()->MapForFixedTypedArray(array_type);
+  Map* map = ReadOnlyRoots(isolate()).MapForFixedTypedArray(array_type);
   AllocationAlignment alignment =
       array_type == kExternalFloat64Array ? kDoubleAligned : kWordAligned;
   HeapObject* object = AllocateRawWithImmortalMap(static_cast<int>(size),
@@ -1778,7 +1788,7 @@ Handle<TransitionArray> Factory::NewTransitionArray(int number_of_transitions,
                                                     int slack) {
   int capacity = TransitionArray::LengthFor(number_of_transitions + slack);
   Handle<TransitionArray> array = NewWeakFixedArrayWithMap<TransitionArray>(
-      Heap::kTransitionArrayMapRootIndex, capacity, TENURED);
+      RootIndex::kTransitionArrayMap, capacity, TENURED);
   // Transition arrays are tenured. When black allocation is on we have to
   // add the transition array to the list of encountered_transition_arrays.
   Heap* heap = isolate()->heap();
@@ -1812,7 +1822,7 @@ Handle<Map> Factory::NewMap(InstanceType type, int instance_size,
                             ElementsKind elements_kind,
                             int inobject_properties) {
   STATIC_ASSERT(LAST_JS_OBJECT_TYPE == LAST_TYPE);
-  DCHECK_IMPLIES(Map::IsJSObject(type) &&
+  DCHECK_IMPLIES(InstanceTypeChecker::IsJSObject(type) &&
                      !Map::CanHaveFastTransitionableElementsKind(type),
                  IsDictionaryElementsKind(elements_kind) ||
                      IsTerminalElementsKind(elements_kind));
@@ -2480,12 +2490,12 @@ Handle<JSFunction> Factory::NewFunctionFromSharedFunctionInfo(
 }
 
 Handle<ScopeInfo> Factory::NewScopeInfo(int length) {
-  return NewFixedArrayWithMap<ScopeInfo>(Heap::kScopeInfoMapRootIndex, length,
+  return NewFixedArrayWithMap<ScopeInfo>(RootIndex::kScopeInfoMap, length,
                                          TENURED);
 }
 
 Handle<ModuleInfo> Factory::NewModuleInfo() {
-  return NewFixedArrayWithMap<ModuleInfo>(Heap::kModuleInfoMapRootIndex,
+  return NewFixedArrayWithMap<ModuleInfo>(RootIndex::kModuleInfoMap,
                                           ModuleInfo::kLength, TENURED);
 }
 
@@ -2665,9 +2675,9 @@ Handle<Code> Factory::NewCodeForDeserialization(uint32_t size) {
   heap->ZapCodeObject(result->address(), size);
   result->set_map_after_allocation(*code_map(), SKIP_WRITE_BARRIER);
   DCHECK(IsAligned(result->address(), kCodeAlignment));
-  DCHECK(!heap->memory_allocator()->code_range()->valid() ||
-         heap->memory_allocator()->code_range()->contains(result->address()) ||
-         static_cast<int>(size) <= heap->code_space()->AreaSize());
+  DCHECK_IMPLIES(
+      !heap->memory_allocator()->code_range().is_empty(),
+      heap->memory_allocator()->code_range().contains(result->address()));
   return handle(Code::cast(result), isolate());
 }
 
@@ -2729,10 +2739,9 @@ Handle<Code> Factory::CopyCode(Handle<Code> code) {
   if (FLAG_verify_heap) new_code->ObjectVerify(isolate());
 #endif
   DCHECK(IsAligned(new_code->address(), kCodeAlignment));
-  DCHECK(
-      !heap->memory_allocator()->code_range()->valid() ||
-      heap->memory_allocator()->code_range()->contains(new_code->address()) ||
-      obj_size <= heap->code_space()->AreaSize());
+  DCHECK_IMPLIES(
+      !heap->memory_allocator()->code_range().is_empty(),
+      heap->memory_allocator()->code_range().contains(new_code->address()));
   return new_code;
 }
 
@@ -3095,26 +3104,6 @@ Handle<JSSet> Factory::NewJSSet() {
   return js_set;
 }
 
-Handle<JSMapIterator> Factory::NewJSMapIterator(Handle<Map> map,
-                                                Handle<OrderedHashMap> table,
-                                                int index) {
-  Handle<JSMapIterator> result =
-      Handle<JSMapIterator>::cast(NewJSObjectFromMap(map));
-  result->set_table(*table);
-  result->set_index(Smi::FromInt(index));
-  return result;
-}
-
-Handle<JSSetIterator> Factory::NewJSSetIterator(Handle<Map> map,
-                                                Handle<OrderedHashSet> table,
-                                                int index) {
-  Handle<JSSetIterator> result =
-      Handle<JSSetIterator>::cast(NewJSObjectFromMap(map));
-  result->set_table(*table);
-  result->set_index(Smi::FromInt(index));
-  return result;
-}
-
 void Factory::TypeAndSizeForElementsKind(ElementsKind kind,
                                          ExternalArrayType* array_type,
                                          size_t* element_size) {
@@ -3181,26 +3170,16 @@ JSFunction* GetTypedArrayFun(ElementsKind elements_kind, Isolate* isolate) {
 void SetupArrayBufferView(i::Isolate* isolate,
                           i::Handle<i::JSArrayBufferView> obj,
                           i::Handle<i::JSArrayBuffer> buffer,
-                          size_t byte_offset, size_t byte_length,
-                          PretenureFlag pretenure = NOT_TENURED) {
-  DCHECK(byte_offset + byte_length <=
-         static_cast<size_t>(buffer->byte_length()->Number()));
-
+                          size_t byte_offset, size_t byte_length) {
+  DCHECK_LE(byte_offset + byte_length, buffer->byte_length());
   DCHECK_EQ(obj->GetEmbedderFieldCount(),
             v8::ArrayBufferView::kEmbedderFieldCount);
   for (int i = 0; i < v8::ArrayBufferView::kEmbedderFieldCount; i++) {
     obj->SetEmbedderField(i, Smi::kZero);
   }
-
   obj->set_buffer(*buffer);
-
-  i::Handle<i::Object> byte_offset_object =
-      isolate->factory()->NewNumberFromSize(byte_offset, pretenure);
-  obj->set_byte_offset(*byte_offset_object);
-
-  i::Handle<i::Object> byte_length_object =
-      isolate->factory()->NewNumberFromSize(byte_length, pretenure);
-  obj->set_byte_length(*byte_length_object);
+  obj->set_byte_offset(byte_offset);
+  obj->set_byte_length(byte_length);
 }
 
 }  // namespace
@@ -3237,8 +3216,7 @@ Handle<JSTypedArray> Factory::NewJSTypedArray(ExternalArrayType type,
   // TODO(7881): Smi length check
   CHECK(length <= static_cast<size_t>(Smi::kMaxValue));
   size_t byte_length = length * element_size;
-  SetupArrayBufferView(isolate(), obj, buffer, byte_offset, byte_length,
-                       pretenure);
+  SetupArrayBufferView(isolate(), obj, buffer, byte_offset, byte_length);
 
   Handle<Object> length_object = NewNumberFromSize(length, pretenure);
   obj->set_length(*length_object);
@@ -3271,13 +3249,9 @@ Handle<JSTypedArray> Factory::NewJSTypedArray(ElementsKind elements_kind,
   CHECK(number_of_elements <= static_cast<size_t>(Smi::kMaxValue));
   size_t byte_length = number_of_elements * element_size;
 
-  obj->set_byte_offset(Smi::kZero);
-  i::Handle<i::Object> byte_length_object =
-      NewNumberFromSize(byte_length, pretenure);
-  obj->set_byte_length(*byte_length_object);
-  Handle<Object> length_object =
-      NewNumberFromSize(number_of_elements, pretenure);
-  obj->set_length(*length_object);
+  obj->set_byte_offset(0);
+  obj->set_byte_length(byte_length);
+  obj->set_length(Smi::FromIntptr(static_cast<intptr_t>(number_of_elements)));
 
   Handle<JSArrayBuffer> buffer =
       NewJSArrayBuffer(SharedFlag::kNotShared, pretenure);
@@ -3757,7 +3731,7 @@ Handle<Map> Factory::ObjectLiteralMapFromCache(Handle<NativeContext> context,
     Handle<WeakFixedArray> cache = Handle<WeakFixedArray>::cast(maybe_cache);
     MaybeObject* result = cache->Get(cache_index);
     HeapObject* heap_object;
-    if (result->ToWeakHeapObject(&heap_object)) {
+    if (result->GetHeapObjectIfWeak(&heap_object)) {
       Map* map = Map::cast(heap_object);
       DCHECK(!map->is_dictionary_map());
       return handle(map, isolate());
diff --git a/deps/v8/src/heap/factory.h b/deps/v8/src/heap/factory.h
index cd57b5bf87..8c6d32090e 100644
--- a/deps/v8/src/heap/factory.h
+++ b/deps/v8/src/heap/factory.h
@@ -44,6 +44,7 @@ class JSGeneratorObject;
 class JSMap;
 class JSMapIterator;
 class JSModuleNamespace;
+class JSPromise;
 class JSProxy;
 class JSSet;
 class JSSetIterator;
@@ -56,6 +57,7 @@ class PreParsedScopeData;
 class PromiseResolveThenableJobTask;
 class RegExpMatchInfo;
 class ScriptContextTable;
+class StackFrameInfo;
 class StoreHandler;
 class TemplateObjectDescription;
 class UncompiledDataWithoutPreParsedScope;
@@ -107,14 +109,13 @@ class V8_EXPORT_PRIVATE Factory {
   // Allocates a fixed array-like object with given map and initialized with
   // undefined values.
   template <typename T = FixedArray>
-  Handle<T> NewFixedArrayWithMap(Heap::RootListIndex map_root_index, int length,
+  Handle<T> NewFixedArrayWithMap(RootIndex map_root_index, int length,
                                  PretenureFlag pretenure = NOT_TENURED);
 
   // Allocates a weak fixed array-like object with given map and initialized
   // with undefined values.
   template <typename T = WeakFixedArray>
-  Handle<T> NewWeakFixedArrayWithMap(Heap::RootListIndex map_root_index,
-                                     int length,
+  Handle<T> NewWeakFixedArrayWithMap(RootIndex map_root_index, int length,
                                      PretenureFlag pretenure = NOT_TENURED);
 
   // Allocates a fixed array initialized with undefined values.
@@ -439,6 +440,8 @@ class V8_EXPORT_PRIVATE Factory {
       Handle<JSPromise> promise_to_resolve, Handle<JSReceiver> then,
       Handle<JSReceiver> thenable, Handle<Context> context);
 
+  Handle<MicrotaskQueue> NewMicrotaskQueue();
+
   // Foreign objects are pretenured when allocated by the bootstrapper.
   Handle<Foreign> NewForeign(Address addr,
                              PretenureFlag pretenure = NOT_TENURED);
@@ -667,13 +670,6 @@ class V8_EXPORT_PRIVATE Factory {
   Handle<JSMap> NewJSMap();
   Handle<JSSet> NewJSSet();
 
-  Handle<JSMapIterator> NewJSMapIterator(Handle<Map> map,
-                                         Handle<OrderedHashMap> table,
-                                         int index);
-  Handle<JSSetIterator> NewJSSetIterator(Handle<Map> map,
-                                         Handle<OrderedHashSet> table,
-                                         int index);
-
   // Allocates a bound function.
   MaybeHandle<JSBoundFunction> NewJSBoundFunction(
       Handle<JSReceiver> target_function, Handle<Object> bound_this,
@@ -828,45 +824,12 @@ class V8_EXPORT_PRIVATE Factory {
   Handle<String> NumberToString(Handle<Object> number, bool check_cache = true);
   Handle<String> NumberToString(Smi* number, bool check_cache = true);
 
-  inline Handle<String> Uint32ToString(uint32_t value,
-                                       bool check_cache = false);
+  inline Handle<String> Uint32ToString(uint32_t value, bool check_cache = true);
 
-#define ROOT_ACCESSOR(type, name, camel_name) inline Handle<type> name();
+#define ROOT_ACCESSOR(type, name, CamelName) inline Handle<type> name();
   ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
-#define STRUCT_MAP_ACCESSOR(NAME, Name, name) inline Handle<Map> name##_map();
-  STRUCT_LIST(STRUCT_MAP_ACCESSOR)
-#undef STRUCT_MAP_ACCESSOR
-
-#define ALLOCATION_SITE_MAP_ACCESSOR(NAME, Name, Size, name) \
-  inline Handle<Map> name##_map();
-  ALLOCATION_SITE_LIST(ALLOCATION_SITE_MAP_ACCESSOR)
-#undef ALLOCATION_SITE_MAP_ACCESSOR
-
-#define DATA_HANDLER_MAP_ACCESSOR(NAME, Name, Size, name) \
-  inline Handle<Map> name##_map();
-  DATA_HANDLER_LIST(DATA_HANDLER_MAP_ACCESSOR)
-#undef DATA_HANDLER_MAP_ACCESSOR
-
-#define STRING_ACCESSOR(name, str) inline Handle<String> name();
-  INTERNALIZED_STRING_LIST(STRING_ACCESSOR)
-#undef STRING_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name) inline Handle<Symbol> name();
-  PRIVATE_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name, description) inline Handle<Symbol> name();
-  PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR)
-  WELL_KNOWN_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define ACCESSOR_INFO_ACCESSOR(accessor_name, AccessorName) \
-  inline Handle<AccessorInfo> accessor_name##_accessor();
-  ACCESSOR_INFO_LIST(ACCESSOR_INFO_ACCESSOR)
-#undef ACCESSOR_INFO_ACCESSOR
-
   // Allocates a new SharedFunctionInfo object.
   Handle<SharedFunctionInfo> NewSharedFunctionInfoForApiFunction(
       MaybeHandle<String> maybe_name,
@@ -961,6 +924,7 @@ class V8_EXPORT_PRIVATE Factory {
     // Downcast to the privately inherited sub-class using c-style casts to
     // avoid undefined behavior (as static_cast cannot cast across private
     // bases).
+    // NOLINTNEXTLINE (google-readability-casting)
     return (Isolate*)this;  // NOLINT(readability/casting)
   }
 
@@ -975,7 +939,7 @@ class V8_EXPORT_PRIVATE Factory {
   HeapObject* AllocateRawArray(int size, PretenureFlag pretenure);
   HeapObject* AllocateRawFixedArray(int length, PretenureFlag pretenure);
   HeapObject* AllocateRawWeakArrayList(int length, PretenureFlag pretenure);
-  Handle<FixedArray> NewFixedArrayWithFiller(Heap::RootListIndex map_root_index,
+  Handle<FixedArray> NewFixedArrayWithFiller(RootIndex map_root_index,
                                              int length, Object* filler,
                                              PretenureFlag pretenure);
 
@@ -1054,7 +1018,7 @@ class NewFunctionArgs final {
   Handle<Map> GetMap(Isolate* isolate) const;
 
  private:
-  NewFunctionArgs() {}  // Use the static factory constructors.
+  NewFunctionArgs() = default;  // Use the static factory constructors.
 
   void SetShouldCreateAndSetInitialMap();
   void SetShouldSetPrototype();
diff --git a/deps/v8/src/heap/gc-tracer.cc b/deps/v8/src/heap/gc-tracer.cc
index 5ee7186c6a..7d33c68ad1 100644
--- a/deps/v8/src/heap/gc-tracer.cc
+++ b/deps/v8/src/heap/gc-tracer.cc
@@ -1093,7 +1093,7 @@ void GCTracer::AddBackgroundScopeSample(
   }
 }
 
-void GCTracer::RecordMarkCompactHistograms(HistogramTimer* gc_timer) {
+void GCTracer::RecordGCPhasesHistograms(HistogramTimer* gc_timer) {
   Counters* counters = heap_->isolate()->counters();
   if (gc_timer == counters->gc_finalize()) {
     DCHECK_EQ(Scope::FIRST_TOP_MC_SCOPE, Scope::MC_CLEAR);
@@ -1112,6 +1112,11 @@ void GCTracer::RecordMarkCompactHistograms(HistogramTimer* gc_timer) {
     counters->gc_finalize_sweep()->AddSample(
         static_cast<int>(current_.scopes[Scope::MC_SWEEP]));
     DCHECK_EQ(Scope::LAST_TOP_MC_SCOPE, Scope::MC_SWEEP);
+  } else if (gc_timer == counters->gc_scavenger()) {
+    counters->gc_scavenger_scavenge_main()->AddSample(
+        static_cast<int>(current_.scopes[Scope::SCAVENGER_SCAVENGE_PARALLEL]));
+    counters->gc_scavenger_scavenge_roots()->AddSample(
+        static_cast<int>(current_.scopes[Scope::SCAVENGER_SCAVENGE_ROOTS]));
   }
 }
 
diff --git a/deps/v8/src/heap/gc-tracer.h b/deps/v8/src/heap/gc-tracer.h
index 62e077be50..bf49586d57 100644
--- a/deps/v8/src/heap/gc-tracer.h
+++ b/deps/v8/src/heap/gc-tracer.h
@@ -321,7 +321,7 @@ class V8_EXPORT_PRIVATE GCTracer {
   void AddBackgroundScopeSample(BackgroundScope::ScopeId scope, double duration,
                                 RuntimeCallCounter* runtime_call_counter);
 
-  void RecordMarkCompactHistograms(HistogramTimer* gc_timer);
+  void RecordGCPhasesHistograms(HistogramTimer* gc_timer);
 
  private:
   FRIEND_TEST(GCTracer, AverageSpeed);
@@ -339,6 +339,7 @@ class V8_EXPORT_PRIVATE GCTracer {
   FRIEND_TEST(GCTracerTest, IncrementalMarkingSpeed);
   FRIEND_TEST(GCTracerTest, MutatorUtilization);
   FRIEND_TEST(GCTracerTest, RecordMarkCompactHistograms);
+  FRIEND_TEST(GCTracerTest, RecordScavengerHistograms);
 
   struct BackgroundCounter {
     double total_duration_ms;
diff --git a/deps/v8/src/heap/heap-controller.cc b/deps/v8/src/heap/heap-controller.cc
index 485b22902a..d515199518 100644
--- a/deps/v8/src/heap/heap-controller.cc
+++ b/deps/v8/src/heap/heap-controller.cc
@@ -10,16 +10,16 @@ namespace internal {
 
 // Given GC speed in bytes per ms, the allocation throughput in bytes per ms
 // (mutator speed), this function returns the heap growing factor that will
-// achieve the kTargetMutatorUtilisation if the GC speed and the mutator speed
+// achieve the target_mutator_utilization_ if the GC speed and the mutator speed
 // remain the same until the next GC.
 //
 // For a fixed time-frame T = TM + TG, the mutator utilization is the ratio
 // TM / (TM + TG), where TM is the time spent in the mutator and TG is the
 // time spent in the garbage collector.
 //
-// Let MU be kTargetMutatorUtilisation, the desired mutator utilization for the
-// time-frame from the end of the current GC to the end of the next GC. Based
-// on the MU we can compute the heap growing factor F as
+// Let MU be target_mutator_utilization_, the desired mutator utilization for
+// the time-frame from the end of the current GC to the end of the next GC.
+// Based on the MU we can compute the heap growing factor F as
 //
 // F = R * (1 - MU) / (R * (1 - MU) - MU), where R = gc_speed / mutator_speed.
 //
@@ -49,69 +49,44 @@ namespace internal {
 //   F = R * (1 - MU) / (R * (1 - MU) - MU)
 double MemoryController::GrowingFactor(double gc_speed, double mutator_speed,
                                        double max_factor) {
-  DCHECK_LE(kMinGrowingFactor, max_factor);
-  DCHECK_GE(kMaxGrowingFactor, max_factor);
+  DCHECK_LE(min_growing_factor_, max_factor);
+  DCHECK_GE(max_growing_factor_, max_factor);
   if (gc_speed == 0 || mutator_speed == 0) return max_factor;
 
   const double speed_ratio = gc_speed / mutator_speed;
 
-  const double a = speed_ratio * (1 - kTargetMutatorUtilization);
-  const double b =
-      speed_ratio * (1 - kTargetMutatorUtilization) - kTargetMutatorUtilization;
+  const double a = speed_ratio * (1 - target_mutator_utilization_);
+  const double b = speed_ratio * (1 - target_mutator_utilization_) -
+                   target_mutator_utilization_;
 
   // The factor is a / b, but we need to check for small b first.
   double factor = (a < b * max_factor) ? a / b : max_factor;
   factor = Min(factor, max_factor);
-  factor = Max(factor, kMinGrowingFactor);
-  return factor;
-}
-
-double MemoryController::MaxGrowingFactor(size_t curr_max_size) {
-  const double min_small_factor = 1.3;
-  const double max_small_factor = 2.0;
-  const double high_factor = 4.0;
-
-  size_t max_size_in_mb = curr_max_size / MB;
-  max_size_in_mb = Max(max_size_in_mb, kMinSize);
-
-  // If we are on a device with lots of memory, we allow a high heap
-  // growing factor.
-  if (max_size_in_mb >= kMaxSize) {
-    return high_factor;
-  }
-
-  DCHECK_GE(max_size_in_mb, kMinSize);
-  DCHECK_LT(max_size_in_mb, kMaxSize);
-
-  // On smaller devices we linearly scale the factor: (X-A)/(B-A)*(D-C)+C
-  double factor = (max_size_in_mb - kMinSize) *
-                      (max_small_factor - min_small_factor) /
-                      (kMaxSize - kMinSize) +
-                  min_small_factor;
+  factor = Max(factor, min_growing_factor_);
   return factor;
 }
 
 size_t MemoryController::CalculateAllocationLimit(
-    size_t curr_size, size_t max_size, double gc_speed, double mutator_speed,
-    size_t new_space_capacity, Heap::HeapGrowingMode growing_mode) {
-  double max_factor = MaxGrowingFactor(max_size);
+    size_t curr_size, size_t max_size, double max_factor, double gc_speed,
+    double mutator_speed, size_t new_space_capacity,
+    Heap::HeapGrowingMode growing_mode) {
   double factor = GrowingFactor(gc_speed, mutator_speed, max_factor);
 
   if (FLAG_trace_gc_verbose) {
     heap_->isolate()->PrintWithTimestamp(
         "%s factor %.1f based on mu=%.3f, speed_ratio=%.f "
         "(gc=%.f, mutator=%.f)\n",
-        ControllerName(), factor, kTargetMutatorUtilization,
+        ControllerName(), factor, target_mutator_utilization_,
         gc_speed / mutator_speed, gc_speed, mutator_speed);
   }
 
   if (growing_mode == Heap::HeapGrowingMode::kConservative ||
       growing_mode == Heap::HeapGrowingMode::kSlow) {
-    factor = Min(factor, kConservativeGrowingFactor);
+    factor = Min(factor, conservative_growing_factor_);
   }
 
   if (growing_mode == Heap::HeapGrowingMode::kMinimal) {
-    factor = kMinGrowingFactor;
+    factor = min_growing_factor_;
   }
 
   if (FLAG_heap_growing_percent > 0) {
@@ -147,5 +122,30 @@ size_t MemoryController::MinimumAllocationLimitGrowingStep(
                       : kRegularAllocationLimitGrowingStep);
 }
 
+double HeapController::MaxGrowingFactor(size_t curr_max_size) {
+  const double min_small_factor = 1.3;
+  const double max_small_factor = 2.0;
+  const double high_factor = 4.0;
+
+  size_t max_size_in_mb = curr_max_size / MB;
+  max_size_in_mb = Max(max_size_in_mb, kMinSize);
+
+  // If we are on a device with lots of memory, we allow a high heap
+  // growing factor.
+  if (max_size_in_mb >= kMaxSize) {
+    return high_factor;
+  }
+
+  DCHECK_GE(max_size_in_mb, kMinSize);
+  DCHECK_LT(max_size_in_mb, kMaxSize);
+
+  // On smaller devices we linearly scale the factor: (X-A)/(B-A)*(D-C)+C
+  double factor = (max_size_in_mb - kMinSize) *
+                      (max_small_factor - min_small_factor) /
+                      (kMaxSize - kMinSize) +
+                  min_small_factor;
+  return factor;
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/heap-controller.h b/deps/v8/src/heap/heap-controller.h
index 8aae46c279..f8625ee963 100644
--- a/deps/v8/src/heap/heap-controller.h
+++ b/deps/v8/src/heap/heap-controller.h
@@ -18,20 +18,18 @@ class V8_EXPORT_PRIVATE MemoryController {
   MemoryController(Heap* heap, double min_growing_factor,
                    double max_growing_factor,
                    double conservative_growing_factor,
-                   double target_mutator_utilization, size_t min_size,
-                   size_t max_size)
+                   double target_mutator_utilization)
       : heap_(heap),
-        kMinGrowingFactor(min_growing_factor),
-        kMaxGrowingFactor(max_growing_factor),
-        kConservativeGrowingFactor(conservative_growing_factor),
-        kTargetMutatorUtilization(target_mutator_utilization),
-        kMinSize(min_size),
-        kMaxSize(max_size) {}
-  virtual ~MemoryController() {}
+        min_growing_factor_(min_growing_factor),
+        max_growing_factor_(max_growing_factor),
+        conservative_growing_factor_(conservative_growing_factor),
+        target_mutator_utilization_(target_mutator_utilization) {}
+  virtual ~MemoryController() = default;
 
   // Computes the allocation limit to trigger the next garbage collection.
   size_t CalculateAllocationLimit(size_t curr_size, size_t max_size,
-                                  double gc_speed, double mutator_speed,
+                                  double max_factor, double gc_speed,
+                                  double mutator_speed,
                                   size_t new_space_capacity,
                                   Heap::HeapGrowingMode growing_mode);
 
@@ -41,18 +39,13 @@ class V8_EXPORT_PRIVATE MemoryController {
  protected:
   double GrowingFactor(double gc_speed, double mutator_speed,
                        double max_factor);
-  double MaxGrowingFactor(size_t curr_max_size);
   virtual const char* ControllerName() = 0;
 
   Heap* const heap_;
-
-  const double kMinGrowingFactor;
-  const double kMaxGrowingFactor;
-  const double kConservativeGrowingFactor;
-  const double kTargetMutatorUtilization;
-  // Sizes are in MB.
-  const size_t kMinSize;
-  const size_t kMaxSize;
+  const double min_growing_factor_;
+  const double max_growing_factor_;
+  const double conservative_growing_factor_;
+  const double target_mutator_utilization_;
 
   FRIEND_TEST(HeapControllerTest, HeapGrowingFactor);
   FRIEND_TEST(HeapControllerTest, MaxHeapGrowingFactor);
@@ -60,18 +53,18 @@ class V8_EXPORT_PRIVATE MemoryController {
   FRIEND_TEST(HeapControllerTest, OldGenerationAllocationLimit);
 };
 
-class HeapController : public MemoryController {
+class V8_EXPORT_PRIVATE HeapController : public MemoryController {
  public:
-  explicit HeapController(Heap* heap)
-      : MemoryController(heap, 1.1, 4.0, 1.3, 0.97, kMinHeapSize,
-                         kMaxHeapSize) {}
-
   // Sizes are in MB.
-  static const size_t kMinHeapSize = 128 * Heap::kPointerMultiplier;
-  static const size_t kMaxHeapSize = 1024 * Heap::kPointerMultiplier;
+  static constexpr size_t kMinSize = 128 * Heap::kPointerMultiplier;
+  static constexpr size_t kMaxSize = 1024 * Heap::kPointerMultiplier;
+
+  explicit HeapController(Heap* heap)
+      : MemoryController(heap, 1.1, 4.0, 1.3, 0.97) {}
+  double MaxGrowingFactor(size_t curr_max_size);
 
  protected:
-  const char* ControllerName() { return "HeapController"; }
+  const char* ControllerName() override { return "HeapController"; }
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/heap/heap-inl.h b/deps/v8/src/heap/heap-inl.h
index 62f07ea322..65b791a42f 100644
--- a/deps/v8/src/heap/heap-inl.h
+++ b/deps/v8/src/heap/heap-inl.h
@@ -13,6 +13,7 @@
 #include "src/heap/heap-write-barrier.h"
 #include "src/heap/heap.h"
 
+#include "src/base/atomic-utils.h"
 #include "src/base/platform/platform.h"
 #include "src/counters-inl.h"
 #include "src/feedback-vector.h"
@@ -24,9 +25,11 @@
 #include "src/log.h"
 #include "src/msan.h"
 #include "src/objects-inl.h"
+#include "src/objects/allocation-site-inl.h"
 #include "src/objects/api-callbacks-inl.h"
 #include "src/objects/descriptor-array.h"
 #include "src/objects/literal-objects.h"
+#include "src/objects/microtask-queue-inl.h"
 #include "src/objects/scope-info.h"
 #include "src/objects/script-inl.h"
 #include "src/profiler/heap-profiler.h"
@@ -52,33 +55,20 @@ HeapObject* AllocationResult::ToObjectChecked() {
   return HeapObject::cast(object_);
 }
 
-#define ROOT_ACCESSOR(type, name, camel_name) \
-  type* Heap::name() { return type::cast(roots_[k##camel_name##RootIndex]); }
+#define ROOT_ACCESSOR(type, name, CamelName) \
+  type* Heap::name() { return type::cast(roots_[RootIndex::k##CamelName]); }
 MUTABLE_ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
-#define DATA_HANDLER_MAP_ACCESSOR(NAME, Name, Size, name)  \
-  Map* Heap::name##_map() {                                \
-    return Map::cast(roots_[k##Name##Size##MapRootIndex]); \
-  }
-DATA_HANDLER_LIST(DATA_HANDLER_MAP_ACCESSOR)
-#undef DATA_HANDLER_MAP_ACCESSOR
-
-#define ACCESSOR_INFO_ACCESSOR(accessor_name, AccessorName)                \
-  AccessorInfo* Heap::accessor_name##_accessor() {                         \
-    return AccessorInfo::cast(roots_[k##AccessorName##AccessorRootIndex]); \
-  }
-ACCESSOR_INFO_LIST(ACCESSOR_INFO_ACCESSOR)
-#undef ACCESSOR_INFO_ACCESSOR
-
-#define ROOT_ACCESSOR(type, name, camel_name)                                 \
-  void Heap::set_##name(type* value) {                                        \
-    /* The deserializer makes use of the fact that these common roots are */  \
-    /* never in new space and never on a page that is being compacted.    */  \
-    DCHECK(!deserialization_complete() ||                                     \
-           RootCanBeWrittenAfterInitialization(k##camel_name##RootIndex));    \
-    DCHECK(k##camel_name##RootIndex >= kOldSpaceRoots || !InNewSpace(value)); \
-    roots_[k##camel_name##RootIndex] = value;                                 \
+#define ROOT_ACCESSOR(type, name, CamelName)                                   \
+  void Heap::set_##name(type* value) {                                         \
+    /* The deserializer makes use of the fact that these common roots are */   \
+    /* never in new space and never on a page that is being compacted.    */   \
+    DCHECK(!deserialization_complete() ||                                      \
+           RootCanBeWrittenAfterInitialization(RootIndex::k##CamelName));      \
+    DCHECK_IMPLIES(static_cast<int>(RootIndex::k##CamelName) < kOldSpaceRoots, \
+                   !InNewSpace(value));                                        \
+    roots_[RootIndex::k##CamelName] = value;                                   \
   }
 ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
@@ -336,8 +326,7 @@ bool Heap::InNewSpace(Object* object) {
 // static
 bool Heap::InNewSpace(MaybeObject* object) {
   HeapObject* heap_object;
-  return object->ToStrongOrWeakHeapObject(&heap_object) &&
-         InNewSpace(heap_object);
+  return object->GetHeapObject(&heap_object) && InNewSpace(heap_object);
 }
 
 // static
@@ -365,8 +354,7 @@ bool Heap::InFromSpace(Object* object) {
 // static
 bool Heap::InFromSpace(MaybeObject* object) {
   HeapObject* heap_object;
-  return object->ToStrongOrWeakHeapObject(&heap_object) &&
-         InFromSpace(heap_object);
+  return object->GetHeapObject(&heap_object) && InFromSpace(heap_object);
 }
 
 // static
@@ -384,8 +372,7 @@ bool Heap::InToSpace(Object* object) {
 // static
 bool Heap::InToSpace(MaybeObject* object) {
   HeapObject* heap_object;
-  return object->ToStrongOrWeakHeapObject(&heap_object) &&
-         InToSpace(heap_object);
+  return object->GetHeapObject(&heap_object) && InToSpace(heap_object);
 }
 
 // static
@@ -581,6 +568,19 @@ int Heap::MaxNumberToStringCacheSize() const {
   // of entries.
   return static_cast<int>(number_string_cache_size * 2);
 }
+
+void Heap::IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                              size_t amount) {
+  base::CheckedIncrement(&backing_store_bytes_, amount);
+  // TODO(mlippautz): Implement interrupt for global memory allocations that can
+  // trigger garbage collections.
+}
+
+void Heap::DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                              size_t amount) {
+  base::CheckedDecrement(&backing_store_bytes_, amount);
+}
+
 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
     : heap_(isolate->heap()) {
   heap_->always_allocate_scope_count_++;
diff --git a/deps/v8/src/heap/heap-write-barrier-inl.h b/deps/v8/src/heap/heap-write-barrier-inl.h
index 1e4550679c..b20e65d1f1 100644
--- a/deps/v8/src/heap/heap-write-barrier-inl.h
+++ b/deps/v8/src/heap/heap-write-barrier-inl.h
@@ -96,7 +96,7 @@ inline void GenerationalBarrier(HeapObject* object, Object** slot,
 inline void GenerationalBarrier(HeapObject* object, MaybeObject** slot,
                                 MaybeObject* value) {
   HeapObject* value_heap_object;
-  if (!value->ToStrongOrWeakHeapObject(&value_heap_object)) return;
+  if (!value->GetHeapObject(&value_heap_object)) return;
   heap_internals::GenerationalBarrierInternal(
       object, reinterpret_cast<Address>(slot), value_heap_object);
 }
@@ -129,7 +129,7 @@ inline void MarkingBarrier(HeapObject* object, Object** slot, Object* value) {
 inline void MarkingBarrier(HeapObject* object, MaybeObject** slot,
                            MaybeObject* value) {
   HeapObject* value_heap_object;
-  if (!value->ToStrongOrWeakHeapObject(&value_heap_object)) return;
+  if (!value->GetHeapObject(&value_heap_object)) return;
   heap_internals::MarkingBarrierInternal(
       object, reinterpret_cast<Address>(slot), value_heap_object);
 }
diff --git a/deps/v8/src/heap/heap.cc b/deps/v8/src/heap/heap.cc
index 2ec30635be..b509d21142 100644
--- a/deps/v8/src/heap/heap.cc
+++ b/deps/v8/src/heap/heap.cc
@@ -33,7 +33,6 @@
 #include "src/heap/heap-controller.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/heap/incremental-marking.h"
-#include "src/heap/item-parallel-job.h"
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/mark-compact.h"
 #include "src/heap/memory-reducer.h"
@@ -108,12 +107,7 @@ bool Heap::GCCallbackTuple::operator==(
 }
 
 Heap::GCCallbackTuple& Heap::GCCallbackTuple::operator=(
-    const Heap::GCCallbackTuple& other) {
-  callback = other.callback;
-  gc_type = other.gc_type;
-  data = other.data;
-  return *this;
-}
+    const Heap::GCCallbackTuple& other) = default;
 
 struct Heap::StrongRootsList {
   Object** start;
@@ -135,112 +129,17 @@ class IdleScavengeObserver : public AllocationObserver {
 };
 
 Heap::Heap()
-    : external_memory_(0),
-      external_memory_limit_(kExternalAllocationSoftLimit),
-      external_memory_at_last_mark_compact_(0),
-      external_memory_concurrently_freed_(0),
-      isolate_(nullptr),
-      code_range_size_(0),
-      // semispace_size_ should be a power of 2 and old_generation_size_ should
-      // be a multiple of Page::kPageSize.
-      max_semi_space_size_(8 * (kPointerSize / 4) * MB),
-      initial_semispace_size_(kMinSemiSpaceSizeInKB * KB),
-      max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
-      initial_max_old_generation_size_(max_old_generation_size_),
+    : initial_max_old_generation_size_(max_old_generation_size_),
       initial_old_generation_size_(max_old_generation_size_ /
                                    kInitalOldGenerationLimitFactor),
-      old_generation_size_configured_(false),
-      // Variables set based on semispace_size_ and old_generation_size_ in
-      // ConfigureHeap.
-      // Will be 4 * reserved_semispace_size_ to ensure that young
-      // generation can be aligned to its size.
-      maximum_committed_(0),
-      survived_since_last_expansion_(0),
-      survived_last_scavenge_(0),
-      always_allocate_scope_count_(0),
       memory_pressure_level_(MemoryPressureLevel::kNone),
-      contexts_disposed_(0),
-      number_of_disposed_maps_(0),
-      new_space_(nullptr),
-      old_space_(nullptr),
-      code_space_(nullptr),
-      map_space_(nullptr),
-      lo_space_(nullptr),
-      new_lo_space_(nullptr),
-      read_only_space_(nullptr),
-      write_protect_code_memory_(false),
-      code_space_memory_modification_scope_depth_(0),
-      gc_state_(NOT_IN_GC),
-      gc_post_processing_depth_(0),
-      allocations_count_(0),
-      raw_allocations_hash_(0),
-      stress_marking_observer_(nullptr),
-      stress_scavenge_observer_(nullptr),
-      allocation_step_in_progress_(false),
-      max_marking_limit_reached_(0.0),
-      ms_count_(0),
-      gc_count_(0),
-      consecutive_ineffective_mark_compacts_(0),
-      mmap_region_base_(0),
-      remembered_unmapped_pages_index_(0),
       old_generation_allocation_limit_(initial_old_generation_size_),
-      inline_allocation_disabled_(false),
-      tracer_(nullptr),
-      promoted_objects_size_(0),
-      promotion_ratio_(0),
-      semi_space_copied_object_size_(0),
-      previous_semi_space_copied_object_size_(0),
-      semi_space_copied_rate_(0),
-      nodes_died_in_new_space_(0),
-      nodes_copied_in_new_space_(0),
-      nodes_promoted_(0),
-      maximum_size_scavenges_(0),
-      last_idle_notification_time_(0.0),
-      last_gc_time_(0.0),
-      mark_compact_collector_(nullptr),
-      minor_mark_compact_collector_(nullptr),
-      array_buffer_collector_(nullptr),
-      memory_allocator_(nullptr),
-      store_buffer_(nullptr),
-      incremental_marking_(nullptr),
-      concurrent_marking_(nullptr),
-      gc_idle_time_handler_(nullptr),
-      memory_reducer_(nullptr),
-      live_object_stats_(nullptr),
-      dead_object_stats_(nullptr),
-      scavenge_job_(nullptr),
-      parallel_scavenge_semaphore_(0),
-      idle_scavenge_observer_(nullptr),
-      new_space_allocation_counter_(0),
-      old_generation_allocation_counter_at_last_gc_(0),
-      old_generation_size_at_last_gc_(0),
       global_pretenuring_feedback_(kInitialFeedbackCapacity),
-      is_marking_flag_(false),
-      ring_buffer_full_(false),
-      ring_buffer_end_(0),
-      configured_(false),
-      current_gc_flags_(Heap::kNoGCFlags),
       current_gc_callback_flags_(GCCallbackFlags::kNoGCCallbackFlags),
-      external_string_table_(this),
-      gc_callbacks_depth_(0),
-      deserialization_complete_(false),
-      strong_roots_list_(nullptr),
-      heap_iterator_depth_(0),
-      local_embedder_heap_tracer_(nullptr),
-      fast_promotion_mode_(false),
-      force_oom_(false),
-      delay_sweeper_tasks_for_testing_(false),
-      pending_layout_change_object_(nullptr),
-      unprotected_memory_chunks_registry_enabled_(false)
-#ifdef V8_ENABLE_ALLOCATION_TIMEOUT
-      ,
-      allocation_timeout_(0)
-#endif  // V8_ENABLE_ALLOCATION_TIMEOUT
-{
+      external_string_table_(this) {
   // Ensure old_generation_size_ is a multiple of kPageSize.
   DCHECK_EQ(0, max_old_generation_size_ & (Page::kPageSize - 1));
 
-  memset(roots_, 0, sizeof(roots_[0]) * kRootListLength);
   set_native_contexts_list(nullptr);
   set_allocation_sites_list(Smi::kZero);
   // Put a dummy entry in the remembered pages so we can find the list the
@@ -259,8 +158,8 @@ size_t Heap::ComputeMaxOldGenerationSize(uint64_t physical_memory) {
   size_t computed_size = static_cast<size_t>(physical_memory / i::MB /
                                              old_space_physical_memory_factor *
                                              kPointerMultiplier);
-  return Max(Min(computed_size, HeapController::kMaxHeapSize),
-             HeapController::kMinHeapSize);
+  return Max(Min(computed_size, HeapController::kMaxSize),
+             HeapController::kMinSize);
 }
 
 size_t Heap::Capacity() {
@@ -477,6 +376,8 @@ void Heap::PrintShortHeapStatistics() {
                CommittedMemoryOfHeapAndUnmapper() / KB);
   PrintIsolate(isolate_, "External memory reported: %6" PRId64 " KB\n",
                external_memory_ / KB);
+  PrintIsolate(isolate_, "Backing store memory: %6" PRIuS " KB\n",
+               backing_store_bytes_ / KB);
   PrintIsolate(isolate_, "External memory global %zu KB\n",
                external_memory_callback_() / KB);
   PrintIsolate(isolate_, "Total time spent in GC  : %.1f ms\n",
@@ -531,7 +432,7 @@ bool Heap::IsRetainingPathTarget(HeapObject* object,
   MaybeObject* object_to_check = HeapObjectReference::Weak(object);
   for (int i = 0; i < length; i++) {
     MaybeObject* target = targets->Get(i);
-    DCHECK(target->IsWeakOrClearedHeapObject());
+    DCHECK(target->IsWeakOrCleared());
     if (target == object_to_check) {
       DCHECK(retaining_path_target_option_.count(i));
       *option = retaining_path_target_option_[i];
@@ -705,7 +606,7 @@ const char* Heap::GetSpaceName(int idx) {
 }
 
 void Heap::SetRootCodeStubs(SimpleNumberDictionary* value) {
-  roots_[kCodeStubsRootIndex] = value;
+  roots_[RootIndex::kCodeStubs] = value;
 }
 
 void Heap::RepairFreeListsAfterDeserialization() {
@@ -1219,13 +1120,16 @@ void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) {
   // The optimizing compiler may be unnecessarily holding on to memory.
   isolate()->AbortConcurrentOptimization(BlockingBehavior::kDontBlock);
   isolate()->ClearSerializerData();
-  set_current_gc_flags(kMakeHeapIterableMask | kReduceMemoryFootprintMask);
+  set_current_gc_flags(kReduceMemoryFootprintMask);
   isolate_->compilation_cache()->Clear();
   const int kMaxNumberOfAttempts = 7;
   const int kMinNumberOfAttempts = 2;
+  const v8::GCCallbackFlags callback_flags =
+      gc_reason == GarbageCollectionReason::kLowMemoryNotification
+          ? v8::kGCCallbackFlagForced
+          : v8::kGCCallbackFlagCollectAllAvailableGarbage;
   for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) {
-    if (!CollectGarbage(OLD_SPACE, gc_reason,
-                        v8::kGCCallbackFlagCollectAllAvailableGarbage) &&
+    if (!CollectGarbage(OLD_SPACE, gc_reason, callback_flags) &&
         attempt + 1 >= kMinNumberOfAttempts) {
       break;
     }
@@ -1234,7 +1138,7 @@ void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) {
   set_current_gc_flags(kNoGCFlags);
   new_space_->Shrink();
   UncommitFromSpace();
-  memory_allocator()->unmapper()->EnsureUnmappingCompleted();
+  EagerlyFreeExternalMemory();
 
   if (FLAG_trace_duplicate_threshold_kb) {
     std::map<int, std::vector<HeapObject*>> objects_by_size;
@@ -1259,6 +1163,15 @@ void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) {
   }
 }
 
+void Heap::PreciseCollectAllGarbage(int flags,
+                                    GarbageCollectionReason gc_reason,
+                                    const GCCallbackFlags gc_callback_flags) {
+  if (!incremental_marking()->IsStopped()) {
+    FinalizeIncrementalMarkingAtomically(gc_reason);
+  }
+  CollectAllGarbage(flags, gc_reason, gc_callback_flags);
+}
+
 void Heap::ReportExternalMemoryPressure() {
   const GCCallbackFlags kGCCallbackFlagsForExternalMemory =
       static_cast<GCCallbackFlags>(
@@ -1267,7 +1180,7 @@ void Heap::ReportExternalMemoryPressure() {
   if (external_memory_ >
       (external_memory_at_last_mark_compact_ + external_memory_hard_limit())) {
     CollectAllGarbage(
-        kReduceMemoryFootprintMask | kFinalizeIncrementalMarkingMask,
+        kReduceMemoryFootprintMask,
         GarbageCollectionReason::kExternalMemoryPressure,
         static_cast<GCCallbackFlags>(kGCCallbackFlagCollectAllAvailableGarbage |
                                      kGCCallbackFlagsForExternalMemory));
@@ -1377,8 +1290,8 @@ bool Heap::CollectGarbage(AllocationSpace space,
 
       next_gc_likely_to_collect_more =
           PerformGarbageCollection(collector, gc_callback_flags);
-      if (collector == MARK_COMPACTOR) {
-        tracer()->RecordMarkCompactHistograms(gc_type_timer);
+      if (collector == MARK_COMPACTOR || collector == SCAVENGER) {
+        tracer()->RecordGCPhasesHistograms(gc_type_timer);
       }
     }
 
@@ -1416,12 +1329,9 @@ bool Heap::CollectGarbage(AllocationSpace space,
     isolate()->CountUsage(v8::Isolate::kForcedGC);
   }
 
-  // Start incremental marking for the next cycle. The heap snapshot
-  // generator needs incremental marking to stay off after it aborted.
-  // We do this only for scavenger to avoid a loop where mark-compact
-  // causes another mark-compact.
-  if (IsYoungGenerationCollector(collector) &&
-      !ShouldAbortIncrementalMarking()) {
+  // Start incremental marking for the next cycle. We do this only for scavenger
+  // to avoid a loop where mark-compact causes another mark-compact.
+  if (IsYoungGenerationCollector(collector)) {
     StartIncrementalMarkingIfAllocationLimitIsReached(
         GCFlagsForIncrementalMarking(),
         kGCCallbackScheduleIdleGarbageCollection);
@@ -1627,11 +1537,10 @@ bool Heap::ReserveSpace(Reservation* reservations, std::vector<Address>* maps) {
           CollectGarbage(NEW_SPACE, GarbageCollectionReason::kDeserializer);
         } else {
           if (counter > 1) {
-            CollectAllGarbage(
-                kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask,
-                GarbageCollectionReason::kDeserializer);
+            CollectAllGarbage(kReduceMemoryFootprintMask,
+                              GarbageCollectionReason::kDeserializer);
           } else {
-            CollectAllGarbage(kAbortIncrementalMarkingMask,
+            CollectAllGarbage(kNoGCFlags,
                               GarbageCollectionReason::kDeserializer);
           }
         }
@@ -1785,18 +1694,22 @@ bool Heap::PerformGarbageCollection(
     external_memory_at_last_mark_compact_ = external_memory_;
     external_memory_limit_ = external_memory_ + kExternalAllocationSoftLimit;
 
+    double max_factor =
+        heap_controller()->MaxGrowingFactor(max_old_generation_size_);
     size_t new_limit = heap_controller()->CalculateAllocationLimit(
-        old_gen_size, max_old_generation_size_, gc_speed, mutator_speed,
-        new_space()->Capacity(), CurrentHeapGrowingMode());
+        old_gen_size, max_old_generation_size_, max_factor, gc_speed,
+        mutator_speed, new_space()->Capacity(), CurrentHeapGrowingMode());
     old_generation_allocation_limit_ = new_limit;
 
     CheckIneffectiveMarkCompact(
         old_gen_size, tracer()->AverageMarkCompactMutatorUtilization());
   } else if (HasLowYoungGenerationAllocationRate() &&
              old_generation_size_configured_) {
+    double max_factor =
+        heap_controller()->MaxGrowingFactor(max_old_generation_size_);
     size_t new_limit = heap_controller()->CalculateAllocationLimit(
-        old_gen_size, max_old_generation_size_, gc_speed, mutator_speed,
-        new_space()->Capacity(), CurrentHeapGrowingMode());
+        old_gen_size, max_old_generation_size_, max_factor, gc_speed,
+        mutator_speed, new_space()->Capacity(), CurrentHeapGrowingMode());
     if (new_limit < old_generation_allocation_limit_) {
       old_generation_allocation_limit_ = new_limit;
     }
@@ -1940,26 +1853,6 @@ void Heap::CheckNewSpaceExpansionCriteria() {
   }
 }
 
-static bool IsUnscavengedHeapObject(Heap* heap, Object** p) {
-  return Heap::InFromSpace(*p) &&
-         !HeapObject::cast(*p)->map_word().IsForwardingAddress();
-}
-
-class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
- public:
-  virtual Object* RetainAs(Object* object) {
-    if (!Heap::InFromSpace(object)) {
-      return object;
-    }
-
-    MapWord map_word = HeapObject::cast(object)->map_word();
-    if (map_word.IsForwardingAddress()) {
-      return map_word.ToForwardingAddress();
-    }
-    return nullptr;
-  }
-};
-
 void Heap::EvacuateYoungGeneration() {
   TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_FAST_PROMOTE);
   base::LockGuard<base::Mutex> guard(relocation_mutex());
@@ -2003,79 +1896,6 @@ void Heap::EvacuateYoungGeneration() {
   SetGCState(NOT_IN_GC);
 }
 
-static bool IsLogging(Isolate* isolate) {
-  return FLAG_verify_predictable || isolate->logger()->is_logging() ||
-         isolate->is_profiling() ||
-         (isolate->heap_profiler() != nullptr &&
-          isolate->heap_profiler()->is_tracking_object_moves()) ||
-         isolate->heap()->has_heap_object_allocation_tracker();
-}
-
-class PageScavengingItem final : public ItemParallelJob::Item {
- public:
-  explicit PageScavengingItem(MemoryChunk* chunk) : chunk_(chunk) {}
-  virtual ~PageScavengingItem() {}
-
-  void Process(Scavenger* scavenger) { scavenger->ScavengePage(chunk_); }
-
- private:
-  MemoryChunk* const chunk_;
-};
-
-class ScavengingTask final : public ItemParallelJob::Task {
- public:
-  ScavengingTask(Heap* heap, Scavenger* scavenger, OneshotBarrier* barrier)
-      : ItemParallelJob::Task(heap->isolate()),
-        heap_(heap),
-        scavenger_(scavenger),
-        barrier_(barrier) {}
-
-  void RunInParallel() final {
-    TRACE_BACKGROUND_GC(
-        heap_->tracer(),
-        GCTracer::BackgroundScope::SCAVENGER_BACKGROUND_SCAVENGE_PARALLEL);
-    double scavenging_time = 0.0;
-    {
-      barrier_->Start();
-      TimedScope scope(&scavenging_time);
-      PageScavengingItem* item = nullptr;
-      while ((item = GetItem<PageScavengingItem>()) != nullptr) {
-        item->Process(scavenger_);
-        item->MarkFinished();
-      }
-      do {
-        scavenger_->Process(barrier_);
-      } while (!barrier_->Wait());
-      scavenger_->Process();
-    }
-    if (FLAG_trace_parallel_scavenge) {
-      PrintIsolate(heap_->isolate(),
-                   "scavenge[%p]: time=%.2f copied=%zu promoted=%zu\n",
-                   static_cast<void*>(this), scavenging_time,
-                   scavenger_->bytes_copied(), scavenger_->bytes_promoted());
-    }
-  };
-
- private:
-  Heap* const heap_;
-  Scavenger* const scavenger_;
-  OneshotBarrier* const barrier_;
-};
-
-int Heap::NumberOfScavengeTasks() {
-  if (!FLAG_parallel_scavenge) return 1;
-  const int num_scavenge_tasks =
-      static_cast<int>(new_space()->TotalCapacity()) / MB;
-  static int num_cores = V8::GetCurrentPlatform()->NumberOfWorkerThreads() + 1;
-  int tasks =
-      Max(1, Min(Min(num_scavenge_tasks, kMaxScavengerTasks), num_cores));
-  if (!CanExpandOldGeneration(static_cast<size_t>(tasks * Page::kPageSize))) {
-    // Optimize for memory usage near the heap limit.
-    tasks = 1;
-  }
-  return tasks;
-}
-
 void Heap::Scavenge() {
   TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE);
   base::LockGuard<base::Mutex> guard(relocation_mutex());
@@ -2088,7 +1908,6 @@ void Heap::Scavenge() {
   // Bump-pointer allocations done during scavenge are not real allocations.
   // Pause the inline allocation steps.
   PauseAllocationObserversScope pause_observers(this);
-
   IncrementalMarking::PauseBlackAllocationScope pause_black_allocation(
       incremental_marking());
 
@@ -2097,137 +1916,19 @@ void Heap::Scavenge() {
 
   SetGCState(SCAVENGE);
 
-  // Implements Cheney's copying algorithm
-  LOG(isolate_, ResourceEvent("scavenge", "begin"));
-
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
-  new_space_->Flip();
-  new_space_->ResetLinearAllocationArea();
-
-  ItemParallelJob job(isolate()->cancelable_task_manager(),
-                      &parallel_scavenge_semaphore_);
-  const int kMainThreadId = 0;
-  Scavenger* scavengers[kMaxScavengerTasks];
-  const bool is_logging = IsLogging(isolate());
-  const int num_scavenge_tasks = NumberOfScavengeTasks();
-  OneshotBarrier barrier;
-  Scavenger::CopiedList copied_list(num_scavenge_tasks);
-  Scavenger::PromotionList promotion_list(num_scavenge_tasks);
-  for (int i = 0; i < num_scavenge_tasks; i++) {
-    scavengers[i] =
-        new Scavenger(this, is_logging, &copied_list, &promotion_list, i);
-    job.AddTask(new ScavengingTask(this, scavengers[i], &barrier));
-  }
-
-  {
-    Sweeper* sweeper = mark_compact_collector()->sweeper();
-    // Pause the concurrent sweeper.
-    Sweeper::PauseOrCompleteScope pause_scope(sweeper);
-    // Filter out pages from the sweeper that need to be processed for old to
-    // new slots by the Scavenger. After processing, the Scavenger adds back
-    // pages that are still unsweeped. This way the Scavenger has exclusive
-    // access to the slots of a page and can completely avoid any locks on
-    // the page itself.
-    Sweeper::FilterSweepingPagesScope filter_scope(sweeper, pause_scope);
-    filter_scope.FilterOldSpaceSweepingPages(
-        [](Page* page) { return !page->ContainsSlots<OLD_TO_NEW>(); });
-    RememberedSet<OLD_TO_NEW>::IterateMemoryChunks(
-        this, [&job](MemoryChunk* chunk) {
-          job.AddItem(new PageScavengingItem(chunk));
-        });
-
-    RootScavengeVisitor root_scavenge_visitor(scavengers[kMainThreadId]);
-
-    {
-      // Identify weak unmodified handles. Requires an unmodified graph.
-      TRACE_GC(
-          tracer(),
-          GCTracer::Scope::SCAVENGER_SCAVENGE_WEAK_GLOBAL_HANDLES_IDENTIFY);
-      isolate()->global_handles()->IdentifyWeakUnmodifiedObjects(
-          &JSObject::IsUnmodifiedApiObject);
-    }
-    {
-      // Copy roots.
-      TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_ROOTS);
-      IterateRoots(&root_scavenge_visitor, VISIT_ALL_IN_SCAVENGE);
-    }
-    {
-      // Parallel phase scavenging all copied and promoted objects.
-      TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_PARALLEL);
-      job.Run(isolate()->async_counters());
-      DCHECK(copied_list.IsEmpty());
-      DCHECK(promotion_list.IsEmpty());
-    }
-    {
-      // Scavenge weak global handles.
-      TRACE_GC(tracer(),
-               GCTracer::Scope::SCAVENGER_SCAVENGE_WEAK_GLOBAL_HANDLES_PROCESS);
-      isolate()->global_handles()->MarkNewSpaceWeakUnmodifiedObjectsPending(
-          &IsUnscavengedHeapObject);
-      isolate()
-          ->global_handles()
-          ->IterateNewSpaceWeakUnmodifiedRootsForFinalizers(
-              &root_scavenge_visitor);
-      scavengers[kMainThreadId]->Process();
-
-      DCHECK(copied_list.IsEmpty());
-      DCHECK(promotion_list.IsEmpty());
-      isolate()
-          ->global_handles()
-          ->IterateNewSpaceWeakUnmodifiedRootsForPhantomHandles(
-              &root_scavenge_visitor, &IsUnscavengedHeapObject);
-    }
-
-    for (int i = 0; i < num_scavenge_tasks; i++) {
-      scavengers[i]->Finalize();
-      delete scavengers[i];
-    }
-  }
-
-  {
-    // Update references into new space
-    TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_UPDATE_REFS);
-    UpdateNewSpaceReferencesInExternalStringTable(
-        &UpdateNewSpaceReferenceInExternalStringTableEntry);
-
-    incremental_marking()->UpdateMarkingWorklistAfterScavenge();
-  }
-
-  if (FLAG_concurrent_marking) {
-    // Ensure that concurrent marker does not track pages that are
-    // going to be unmapped.
-    for (Page* p : PageRange(new_space()->from_space().first_page(), nullptr)) {
-      concurrent_marking()->ClearLiveness(p);
-    }
-  }
-
-  ScavengeWeakObjectRetainer weak_object_retainer;
-  ProcessYoungWeakReferences(&weak_object_retainer);
-
-  // Set age mark.
-  new_space_->set_age_mark(new_space_->top());
-
-  {
-    TRACE_GC(tracer(), GCTracer::Scope::SCAVENGER_PROCESS_ARRAY_BUFFERS);
-    ArrayBufferTracker::PrepareToFreeDeadInNewSpace(this);
-  }
-  array_buffer_collector()->FreeAllocationsOnBackgroundThread();
+  new_space()->Flip();
+  new_space()->ResetLinearAllocationArea();
 
-  RememberedSet<OLD_TO_NEW>::IterateMemoryChunks(this, [](MemoryChunk* chunk) {
-    if (chunk->SweepingDone()) {
-      RememberedSet<OLD_TO_NEW>::FreeEmptyBuckets(chunk);
-    } else {
-      RememberedSet<OLD_TO_NEW>::PreFreeEmptyBuckets(chunk);
-    }
-  });
+  // We also flip the young generation large object space. All large objects
+  // will be in the from space.
+  new_lo_space()->Flip();
 
-  // Update how much has survived scavenge.
-  IncrementYoungSurvivorsCounter(SurvivedNewSpaceObjectSize());
+  // Implements Cheney's copying algorithm
+  LOG(isolate_, ResourceEvent("scavenge", "begin"));
 
-  // Scavenger may find new wrappers by iterating objects promoted onto a black
-  // page.
-  local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer();
+  scavenger_collector_->CollectGarbage();
 
   LOG(isolate_, ResourceEvent("scavenge", "end"));
 
@@ -2285,15 +1986,6 @@ bool Heap::ExternalStringTable::Contains(HeapObject* obj) {
   return false;
 }
 
-void Heap::ProcessMovedExternalString(Page* old_page, Page* new_page,
-                                      ExternalString* string) {
-  size_t size = string->ExternalPayloadSize();
-  new_page->IncrementExternalBackingStoreBytes(
-      ExternalBackingStoreType::kExternalString, size);
-  old_page->DecrementExternalBackingStoreBytes(
-      ExternalBackingStoreType::kExternalString, size);
-}
-
 String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap,
                                                                 Object** p) {
   MapWord first_word = HeapObject::cast(*p)->map_word();
@@ -2312,18 +2004,15 @@ String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap,
 
   // String is still reachable.
   String* new_string = String::cast(first_word.ToForwardingAddress());
-  String* original_string = reinterpret_cast<String*>(*p);
-  // The length of the original string is used to disambiguate the scenario
-  // of a ThingString being forwarded to an ExternalString (which already exists
-  // in the OLD space), and an ExternalString being forwarded to its promoted
-  // copy. See Scavenger::EvacuateThinString.
-  if (new_string->IsThinString() || original_string->length() == 0) {
+  if (new_string->IsThinString()) {
     // Filtering Thin strings out of the external string table.
     return nullptr;
   } else if (new_string->IsExternalString()) {
-    heap->ProcessMovedExternalString(
+    MemoryChunk::MoveExternalBackingStoreBytes(
+        ExternalBackingStoreType::kExternalString,
         Page::FromAddress(reinterpret_cast<Address>(*p)),
-        Page::FromHeapObject(new_string), ExternalString::cast(new_string));
+        Page::FromHeapObject(new_string),
+        ExternalString::cast(new_string)->ExternalPayloadSize());
     return new_string;
   }
 
@@ -2488,8 +2177,8 @@ void Heap::ProcessWeakListRoots(WeakObjectRetainer* retainer) {
   set_allocation_sites_list(retainer->RetainAs(allocation_sites_list()));
 }
 
-void Heap::ForeachAllocationSite(Object* list,
-                                 std::function<void(AllocationSite*)> visitor) {
+void Heap::ForeachAllocationSite(
+    Object* list, const std::function<void(AllocationSite*)>& visitor) {
   DisallowHeapAllocation disallow_heap_allocation;
   Object* current = list;
   while (current->IsAllocationSite()) {
@@ -2555,8 +2244,8 @@ void Heap::VisitExternalResources(v8::ExternalResourceVisitor* visitor) {
     explicit ExternalStringTableVisitorAdapter(
         Isolate* isolate, v8::ExternalResourceVisitor* visitor)
         : isolate_(isolate), visitor_(visitor) {}
-    virtual void VisitRootPointers(Root root, const char* description,
-                                   Object** start, Object** end) {
+    void VisitRootPointers(Root root, const char* description,
+                                   Object** start, Object** end) override {
       for (Object** p = start; p < end; p++) {
         DCHECK((*p)->IsExternalString());
         visitor_->VisitExternalString(
@@ -2597,10 +2286,9 @@ int Heap::GetMaximumFillToAlign(AllocationAlignment alignment) {
 
 
 int Heap::GetFillToAlign(Address address, AllocationAlignment alignment) {
-  intptr_t offset = OffsetFrom(address);
-  if (alignment == kDoubleAligned && (offset & kDoubleAlignmentMask) != 0)
+  if (alignment == kDoubleAligned && (address & kDoubleAlignmentMask) != 0)
     return kPointerSize;
-  if (alignment == kDoubleUnaligned && (offset & kDoubleAlignmentMask) == 0)
+  if (alignment == kDoubleUnaligned && (address & kDoubleAlignmentMask) == 0)
     return kDoubleSize - kPointerSize;  // No fill if double is always aligned.
   return 0;
 }
@@ -2693,33 +2381,29 @@ void Heap::CreateFixedStubs() {
   Heap::CreateJSRunMicrotasksEntryStub();
 }
 
-bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) {
+bool Heap::RootCanBeWrittenAfterInitialization(RootIndex root_index) {
   switch (root_index) {
-    case kNumberStringCacheRootIndex:
-    case kCodeStubsRootIndex:
-    case kScriptListRootIndex:
-    case kMaterializedObjectsRootIndex:
-    case kMicrotaskQueueRootIndex:
-    case kDetachedContextsRootIndex:
-    case kRetainedMapsRootIndex:
-    case kRetainingPathTargetsRootIndex:
-    case kFeedbackVectorsForProfilingToolsRootIndex:
-    case kNoScriptSharedFunctionInfosRootIndex:
-    case kSerializedObjectsRootIndex:
-    case kSerializedGlobalProxySizesRootIndex:
-    case kPublicSymbolTableRootIndex:
-    case kApiSymbolTableRootIndex:
-    case kApiPrivateSymbolTableRootIndex:
-    case kMessageListenersRootIndex:
-    case kDeserializeLazyHandlerRootIndex:
-    case kDeserializeLazyHandlerWideRootIndex:
-    case kDeserializeLazyHandlerExtraWideRootIndex:
+    case RootIndex::kNumberStringCache:
+    case RootIndex::kCodeStubs:
+    case RootIndex::kScriptList:
+    case RootIndex::kMaterializedObjects:
+    case RootIndex::kDetachedContexts:
+    case RootIndex::kRetainedMaps:
+    case RootIndex::kRetainingPathTargets:
+    case RootIndex::kFeedbackVectorsForProfilingTools:
+    case RootIndex::kNoScriptSharedFunctionInfos:
+    case RootIndex::kSerializedObjects:
+    case RootIndex::kSerializedGlobalProxySizes:
+    case RootIndex::kPublicSymbolTable:
+    case RootIndex::kApiSymbolTable:
+    case RootIndex::kApiPrivateSymbolTable:
+    case RootIndex::kMessageListeners:
 // Smi values
-#define SMI_ENTRY(type, name, Name) case k##Name##RootIndex:
+#define SMI_ENTRY(type, name, Name) case RootIndex::k##Name:
       SMI_ROOT_LIST(SMI_ENTRY)
 #undef SMI_ENTRY
     // String table
-    case kStringTableRootIndex:
+    case RootIndex::kStringTable:
       return true;
 
     default:
@@ -2727,7 +2411,7 @@ bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) {
   }
 }
 
-bool Heap::RootCanBeTreatedAsConstant(RootListIndex root_index) {
+bool Heap::RootCanBeTreatedAsConstant(RootIndex root_index) {
   bool can_be = !RootCanBeWrittenAfterInitialization(root_index) &&
                 !InNewSpace(root(root_index));
   DCHECK_IMPLIES(can_be, IsImmovable(HeapObject::cast(root(root_index))));
@@ -2743,61 +2427,6 @@ void Heap::FlushNumberStringCache() {
   }
 }
 
-namespace {
-
-Heap::RootListIndex RootIndexForFixedTypedArray(ExternalArrayType array_type) {
-  switch (array_type) {
-#define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype) \
-  case kExternal##Type##Array:                            \
-    return Heap::kFixed##Type##ArrayMapRootIndex;
-
-    TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX)
-#undef ARRAY_TYPE_TO_ROOT_INDEX
-  }
-  UNREACHABLE();
-}
-
-Heap::RootListIndex RootIndexForFixedTypedArray(ElementsKind elements_kind) {
-  switch (elements_kind) {
-#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) \
-  case TYPE##_ELEMENTS:                           \
-    return Heap::kFixed##Type##ArrayMapRootIndex;
-    TYPED_ARRAYS(TYPED_ARRAY_CASE)
-    default:
-      UNREACHABLE();
-#undef TYPED_ARRAY_CASE
-  }
-}
-
-Heap::RootListIndex RootIndexForEmptyFixedTypedArray(
-    ElementsKind elements_kind) {
-  switch (elements_kind) {
-#define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype) \
-  case TYPE##_ELEMENTS:                                     \
-    return Heap::kEmptyFixed##Type##ArrayRootIndex;
-
-    TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX)
-#undef ELEMENT_KIND_TO_ROOT_INDEX
-    default:
-      UNREACHABLE();
-  }
-}
-
-}  // namespace
-
-Map* Heap::MapForFixedTypedArray(ExternalArrayType array_type) {
-  return Map::cast(roots_[RootIndexForFixedTypedArray(array_type)]);
-}
-
-Map* Heap::MapForFixedTypedArray(ElementsKind elements_kind) {
-  return Map::cast(roots_[RootIndexForFixedTypedArray(elements_kind)]);
-}
-
-FixedTypedArrayBase* Heap::EmptyFixedTypedArrayForMap(const Map* map) {
-  return FixedTypedArrayBase::cast(
-      roots_[RootIndexForEmptyFixedTypedArray(map->elements_kind())]);
-}
-
 HeapObject* Heap::CreateFillerObjectAt(Address addr, int size,
                                        ClearRecordedSlots clear_slots_mode,
                                        ClearFreedMemoryMode clear_memory_mode) {
@@ -2805,11 +2434,11 @@ HeapObject* Heap::CreateFillerObjectAt(Address addr, int size,
   HeapObject* filler = HeapObject::FromAddress(addr);
   if (size == kPointerSize) {
     filler->set_map_after_allocation(
-        reinterpret_cast<Map*>(root(kOnePointerFillerMapRootIndex)),
+        reinterpret_cast<Map*>(root(RootIndex::kOnePointerFillerMap)),
         SKIP_WRITE_BARRIER);
   } else if (size == 2 * kPointerSize) {
     filler->set_map_after_allocation(
-        reinterpret_cast<Map*>(root(kTwoPointerFillerMapRootIndex)),
+        reinterpret_cast<Map*>(root(RootIndex::kTwoPointerFillerMap)),
         SKIP_WRITE_BARRIER);
     if (clear_memory_mode == ClearFreedMemoryMode::kClearFreedMemory) {
       Memory<Address>(addr + kPointerSize) =
@@ -2818,7 +2447,7 @@ HeapObject* Heap::CreateFillerObjectAt(Address addr, int size,
   } else {
     DCHECK_GT(size, 2 * kPointerSize);
     filler->set_map_after_allocation(
-        reinterpret_cast<Map*>(root(kFreeSpaceMapRootIndex)),
+        reinterpret_cast<Map*>(root(RootIndex::kFreeSpaceMap)),
         SKIP_WRITE_BARRIER);
     FreeSpace::cast(filler)->relaxed_write_size(size);
     if (clear_memory_mode == ClearFreedMemoryMode::kClearFreedMemory) {
@@ -2865,8 +2494,8 @@ class LeftTrimmerVerifierRootVisitor : public RootVisitor {
   explicit LeftTrimmerVerifierRootVisitor(FixedArrayBase* to_check)
       : to_check_(to_check) {}
 
-  virtual void VisitRootPointers(Root root, const char* description,
-                                 Object** start, Object** end) {
+  void VisitRootPointers(Root root, const char* description,
+                                 Object** start, Object** end) override {
     for (Object** p = start; p < end; ++p) {
       DCHECK_NE(*p, to_check_);
     }
@@ -3532,7 +3161,7 @@ class MemoryPressureInterruptTask : public CancelableTask {
   explicit MemoryPressureInterruptTask(Heap* heap)
       : CancelableTask(heap->isolate()), heap_(heap) {}
 
-  virtual ~MemoryPressureInterruptTask() {}
+  ~MemoryPressureInterruptTask() override = default;
 
  private:
   // v8::internal::CancelableTask overrides.
@@ -3575,9 +3204,10 @@ void Heap::CollectGarbageOnMemoryPressure() {
   const double kMaxMemoryPressurePauseMs = 100;
 
   double start = MonotonicallyIncreasingTimeInMs();
-  CollectAllGarbage(kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask,
+  CollectAllGarbage(kReduceMemoryFootprintMask,
                     GarbageCollectionReason::kMemoryPressure,
                     kGCCallbackFlagCollectAllAvailableGarbage);
+  EagerlyFreeExternalMemory();
   double end = MonotonicallyIncreasingTimeInMs();
 
   // Estimate how much memory we can free.
@@ -3591,10 +3221,9 @@ void Heap::CollectGarbageOnMemoryPressure() {
     // If we spent less than half of the time budget, then perform full GC
     // Otherwise, start incremental marking.
     if (end - start < kMaxMemoryPressurePauseMs / 2) {
-      CollectAllGarbage(
-          kReduceMemoryFootprintMask | kAbortIncrementalMarkingMask,
-          GarbageCollectionReason::kMemoryPressure,
-          kGCCallbackFlagCollectAllAvailableGarbage);
+      CollectAllGarbage(kReduceMemoryFootprintMask,
+                        GarbageCollectionReason::kMemoryPressure,
+                        kGCCallbackFlagCollectAllAvailableGarbage);
     } else {
       if (FLAG_incremental_marking && incremental_marking()->IsStopped()) {
         StartIncrementalMarking(kReduceMemoryFootprintMask,
@@ -3617,13 +3246,27 @@ void Heap::MemoryPressureNotification(MemoryPressureLevel level,
     } else {
       ExecutionAccess access(isolate());
       isolate()->stack_guard()->RequestGC();
-      V8::GetCurrentPlatform()->CallOnForegroundThread(
-          reinterpret_cast<v8::Isolate*>(isolate()),
-          new MemoryPressureInterruptTask(this));
+      auto taskrunner = V8::GetCurrentPlatform()->GetForegroundTaskRunner(
+          reinterpret_cast<v8::Isolate*>(isolate()));
+      taskrunner->PostTask(
+          base::make_unique<MemoryPressureInterruptTask>(this));
     }
   }
 }
 
+void Heap::EagerlyFreeExternalMemory() {
+  for (Page* page : *old_space()) {
+    if (!page->SweepingDone()) {
+      base::LockGuard<base::Mutex> guard(page->mutex());
+      if (!page->SweepingDone()) {
+        ArrayBufferTracker::FreeDead(
+            page, mark_compact_collector()->non_atomic_marking_state());
+      }
+    }
+  }
+  memory_allocator()->unmapper()->EnsureUnmappingCompleted();
+}
+
 void Heap::AddNearHeapLimitCallback(v8::NearHeapLimitCallback callback,
                                     void* data) {
   const size_t kMaxCallbacks = 100;
@@ -3833,16 +3476,15 @@ bool Heap::IsValidAllocationSpace(AllocationSpace space) {
   }
 }
 
-
-bool Heap::RootIsImmortalImmovable(int root_index) {
+bool Heap::RootIsImmortalImmovable(RootIndex root_index) {
   switch (root_index) {
-#define IMMORTAL_IMMOVABLE_ROOT(name) case Heap::k##name##RootIndex:
+#define IMMORTAL_IMMOVABLE_ROOT(name) case RootIndex::k##name:
     IMMORTAL_IMMOVABLE_ROOT_LIST(IMMORTAL_IMMOVABLE_ROOT)
 #undef IMMORTAL_IMMOVABLE_ROOT
-#define INTERNALIZED_STRING(name, value) case Heap::k##name##RootIndex:
-    INTERNALIZED_STRING_LIST(INTERNALIZED_STRING)
+#define INTERNALIZED_STRING(_, name, value) case RootIndex::k##name:
+    INTERNALIZED_STRING_LIST_GENERATOR(INTERNALIZED_STRING, /* not used */)
 #undef INTERNALIZED_STRING
-#define STRING_TYPE(NAME, size, name, Name) case Heap::k##Name##MapRootIndex:
+#define STRING_TYPE(NAME, size, name, Name) case RootIndex::k##Name##Map:
     STRING_TYPE_LIST(STRING_TYPE)
 #undef STRING_TYPE
     return true;
@@ -3867,7 +3509,7 @@ class VerifyReadOnlyPointersVisitor : public VerifyPointersVisitor {
 
     for (MaybeObject** current = start; current < end; current++) {
       HeapObject* object;
-      if ((*current)->ToStrongOrWeakHeapObject(&object)) {
+      if ((*current)->GetHeapObject(&object)) {
         CHECK(heap_->InReadOnlySpace(object));
       }
     }
@@ -3963,10 +3605,9 @@ class OldToNewSlotVerifyingVisitor : public SlotVerifyingVisitor {
       : SlotVerifyingVisitor(untyped, typed) {}
 
   bool ShouldHaveBeenRecorded(HeapObject* host, MaybeObject* target) override {
-    DCHECK_IMPLIES(
-        target->IsStrongOrWeakHeapObject() && Heap::InNewSpace(target),
-        Heap::InToSpace(target));
-    return target->IsStrongOrWeakHeapObject() && Heap::InNewSpace(target) &&
+    DCHECK_IMPLIES(target->IsStrongOrWeak() && Heap::InNewSpace(target),
+                   Heap::InToSpace(target));
+    return target->IsStrongOrWeak() && Heap::InNewSpace(target) &&
            !Heap::InNewSpace(host);
   }
 };
@@ -4077,9 +3718,8 @@ void Heap::IterateWeakRoots(RootVisitor* v, VisitMode mode) {
   const bool isMinorGC = mode == VISIT_ALL_IN_SCAVENGE ||
                          mode == VISIT_ALL_IN_MINOR_MC_MARK ||
                          mode == VISIT_ALL_IN_MINOR_MC_UPDATE;
-  v->VisitRootPointer(
-      Root::kStringTable, nullptr,
-      reinterpret_cast<Object**>(&roots_[kStringTableRootIndex]));
+  v->VisitRootPointer(Root::kStringTable, nullptr,
+                      &roots_[RootIndex::kStringTable]);
   v->Synchronize(VisitorSynchronization::kStringTable);
   if (!isMinorGC && mode != VISIT_ALL_IN_SWEEP_NEWSPACE &&
       mode != VISIT_FOR_SERIALIZATION) {
@@ -4094,8 +3734,8 @@ void Heap::IterateWeakRoots(RootVisitor* v, VisitMode mode) {
 void Heap::IterateSmiRoots(RootVisitor* v) {
   // Acquire execution access since we are going to read stack limit values.
   ExecutionAccess access(isolate());
-  v->VisitRootPointers(Root::kSmiRootList, nullptr, &roots_[kSmiRootsStart],
-                       &roots_[kRootListLength]);
+  v->VisitRootPointers(Root::kSmiRootList, nullptr, roots_.smi_roots_begin(),
+                       roots_.smi_roots_end());
   v->Synchronize(VisitorSynchronization::kSmiRootList);
 }
 
@@ -4152,8 +3792,13 @@ void Heap::IterateStrongRoots(RootVisitor* v, VisitMode mode) {
   const bool isMinorGC = mode == VISIT_ALL_IN_SCAVENGE ||
                          mode == VISIT_ALL_IN_MINOR_MC_MARK ||
                          mode == VISIT_ALL_IN_MINOR_MC_UPDATE;
-  v->VisitRootPointers(Root::kStrongRootList, nullptr, &roots_[0],
-                       &roots_[kStrongRootListLength]);
+  // Garbage collection can skip over the read-only roots.
+  const bool isGC = mode != VISIT_ALL && mode != VISIT_FOR_SERIALIZATION &&
+                    mode != VISIT_ONLY_STRONG_FOR_SERIALIZATION;
+  Object** start =
+      isGC ? roots_.read_only_roots_end() : roots_.strong_roots_begin();
+  v->VisitRootPointers(Root::kStrongRootList, nullptr, start,
+                       roots_.strong_roots_end());
   v->Synchronize(VisitorSynchronization::kStrongRootList);
 
   isolate_->bootstrapper()->Iterate(v);
@@ -4192,17 +3837,19 @@ void Heap::IterateStrongRoots(RootVisitor* v, VisitMode mode) {
       // global handles need to be added manually.
       break;
     case VISIT_ONLY_STRONG:
+    case VISIT_ONLY_STRONG_FOR_SERIALIZATION:
       isolate_->global_handles()->IterateStrongRoots(v);
       break;
     case VISIT_ALL_IN_SCAVENGE:
       isolate_->global_handles()->IterateNewSpaceStrongAndDependentRoots(v);
       break;
     case VISIT_ALL_IN_MINOR_MC_MARK:
-      // Global handles are processed manually be the minor MC.
+      // Global handles are processed manually by the minor MC.
       break;
     case VISIT_ALL_IN_MINOR_MC_UPDATE:
-      // Global handles are processed manually be the minor MC.
+      // Global handles are processed manually by the minor MC.
       break;
+    case VISIT_ALL_BUT_READ_ONLY:
     case VISIT_ALL_IN_SWEEP_NEWSPACE:
     case VISIT_ALL:
       isolate_->global_handles()->IterateAllRoots(v);
@@ -4706,6 +4353,9 @@ void Heap::SetUp() {
   heap_controller_ = new HeapController(this);
 
   mark_compact_collector_ = new MarkCompactCollector(this);
+
+  scavenger_collector_ = new ScavengerCollector(this);
+
   incremental_marking_ =
       new IncrementalMarking(this, mark_compact_collector_->marking_worklist(),
                              mark_compact_collector_->weak_objects());
@@ -4715,10 +4365,11 @@ void Heap::SetUp() {
         mark_compact_collector_->marking_worklist();
     concurrent_marking_ = new ConcurrentMarking(
         this, marking_worklist->shared(), marking_worklist->bailout(),
-        marking_worklist->on_hold(), mark_compact_collector_->weak_objects());
+        marking_worklist->on_hold(), mark_compact_collector_->weak_objects(),
+        marking_worklist->embedder());
   } else {
-    concurrent_marking_ =
-        new ConcurrentMarking(this, nullptr, nullptr, nullptr, nullptr);
+    concurrent_marking_ = new ConcurrentMarking(this, nullptr, nullptr, nullptr,
+                                                nullptr, nullptr);
   }
 
   for (int i = FIRST_SPACE; i <= LAST_SPACE; i++) {
@@ -4727,7 +4378,8 @@ void Heap::SetUp() {
 
   space_[RO_SPACE] = read_only_space_ = new ReadOnlySpace(this);
   space_[NEW_SPACE] = new_space_ =
-      new NewSpace(this, initial_semispace_size_, max_semi_space_size_);
+      new NewSpace(this, memory_allocator_->data_page_allocator(),
+                   initial_semispace_size_, max_semi_space_size_);
   space_[OLD_SPACE] = old_space_ = new OldSpace(this);
   space_[CODE_SPACE] = code_space_ = new CodeSpace(this);
   space_[MAP_SPACE] = map_space_ = new MapSpace(this);
@@ -4809,15 +4461,15 @@ void Heap::SetStackLimits() {
 
   // Set up the special root array entries containing the stack limits.
   // These are actually addresses, but the tag makes the GC ignore it.
-  roots_[kStackLimitRootIndex] = reinterpret_cast<Object*>(
+  roots_[RootIndex::kStackLimit] = reinterpret_cast<Object*>(
       (isolate_->stack_guard()->jslimit() & ~kSmiTagMask) | kSmiTag);
-  roots_[kRealStackLimitRootIndex] = reinterpret_cast<Object*>(
+  roots_[RootIndex::kRealStackLimit] = reinterpret_cast<Object*>(
       (isolate_->stack_guard()->real_jslimit() & ~kSmiTagMask) | kSmiTag);
 }
 
 void Heap::ClearStackLimits() {
-  roots_[kStackLimitRootIndex] = Smi::kZero;
-  roots_[kRealStackLimitRootIndex] = Smi::kZero;
+  roots_[RootIndex::kStackLimit] = Smi::kZero;
+  roots_[RootIndex::kRealStackLimit] = Smi::kZero;
 }
 
 int Heap::NextAllocationTimeout(int current_timeout) {
@@ -4873,6 +4525,10 @@ void Heap::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) {
   local_embedder_heap_tracer()->SetRemoteTracer(tracer);
 }
 
+EmbedderHeapTracer* Heap::GetEmbedderHeapTracer() const {
+  return local_embedder_heap_tracer()->remote_tracer();
+}
+
 void Heap::TracePossibleWrapper(JSObject* js_object) {
   DCHECK(js_object->IsApiWrapper());
   if (js_object->GetEmbedderFieldCount() >= 2 &&
@@ -4961,6 +4617,11 @@ void Heap::TearDown() {
   }
 #endif  // ENABLE_MINOR_MC
 
+  if (scavenger_collector_ != nullptr) {
+    delete scavenger_collector_;
+    scavenger_collector_ = nullptr;
+  }
+
   if (array_buffer_collector_ != nullptr) {
     delete array_buffer_collector_;
     array_buffer_collector_ = nullptr;
@@ -5100,7 +4761,7 @@ Handle<WeakArrayList> CompactWeakArrayList(Heap* heap,
   int copy_to = 0;
   for (int i = 0; i < array->length(); i++) {
     MaybeObject* element = array->Get(i);
-    if (element->IsClearedWeakHeapObject()) continue;
+    if (element->IsCleared()) continue;
     new_array->Set(copy_to++, element);
   }
   new_array->set_length(copy_to);
@@ -5174,11 +4835,11 @@ void Heap::CompactRetainedMaps(WeakArrayList* retained_maps) {
   // This loop compacts the array by removing cleared weak cells.
   for (int i = 0; i < length; i += 2) {
     MaybeObject* maybe_object = retained_maps->Get(i);
-    if (maybe_object->IsClearedWeakHeapObject()) {
+    if (maybe_object->IsCleared()) {
       continue;
     }
 
-    DCHECK(maybe_object->IsWeakHeapObject());
+    DCHECK(maybe_object->IsWeak());
 
     MaybeObject* age = retained_maps->Get(i + 1);
     DCHECK(age->IsSmi());
@@ -5268,17 +4929,19 @@ void Heap::ClearRecordedSlot(HeapObject* object, Object** slot) {
   }
 }
 
-bool Heap::HasRecordedSlot(HeapObject* object, Object** slot) {
-  if (InNewSpace(object)) {
-    return false;
-  }
+#ifdef DEBUG
+void Heap::VerifyClearedSlot(HeapObject* object, Object** slot) {
+  if (InNewSpace(object)) return;
   Address slot_addr = reinterpret_cast<Address>(slot);
   Page* page = Page::FromAddress(slot_addr);
   DCHECK_EQ(page->owner()->identity(), OLD_SPACE);
   store_buffer()->MoveAllEntriesToRememberedSet();
-  return RememberedSet<OLD_TO_NEW>::Contains(page, slot_addr) ||
-         RememberedSet<OLD_TO_OLD>::Contains(page, slot_addr);
+  CHECK(!RememberedSet<OLD_TO_NEW>::Contains(page, slot_addr));
+  // Old to old slots are filtered with invalidated slots.
+  CHECK_IMPLIES(RememberedSet<OLD_TO_OLD>::Contains(page, slot_addr),
+                page->RegisteredObjectWithInvalidatedSlots(object));
 }
+#endif
 
 void Heap::ClearRecordedSlotRange(Address start, Address end) {
   Page* page = Page::FromAddress(start);
@@ -5308,9 +4971,7 @@ PagedSpace* PagedSpaces::next() {
 SpaceIterator::SpaceIterator(Heap* heap)
     : heap_(heap), current_space_(FIRST_SPACE - 1) {}
 
-SpaceIterator::~SpaceIterator() {
-}
-
+SpaceIterator::~SpaceIterator() = default;
 
 bool SpaceIterator::has_next() {
   // Iterate until no more spaces.
@@ -5325,7 +4986,7 @@ Space* SpaceIterator::next() {
 
 class HeapObjectsFilter {
  public:
-  virtual ~HeapObjectsFilter() {}
+  virtual ~HeapObjectsFilter() = default;
   virtual bool SkipObject(HeapObject* object) = 0;
 };
 
@@ -5336,14 +4997,14 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
     MarkReachableObjects();
   }
 
-  ~UnreachableObjectsFilter() {
+  ~UnreachableObjectsFilter() override {
     for (auto it : reachable_) {
       delete it.second;
       it.second = nullptr;
     }
   }
 
-  bool SkipObject(HeapObject* object) {
+  bool SkipObject(HeapObject* object) override {
     if (object->IsFiller()) return true;
     MemoryChunk* chunk = MemoryChunk::FromAddress(object->address());
     if (reachable_.count(chunk) == 0) return true;
@@ -5396,7 +5057,7 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
       // Treat weak references as strong.
       for (MaybeObject** p = start; p < end; p++) {
         HeapObject* heap_object;
-        if ((*p)->ToStrongOrWeakHeapObject(&heap_object)) {
+        if ((*p)->GetHeapObject(&heap_object)) {
           if (filter_->MarkAsReachable(heap_object)) {
             marking_stack_.push_back(heap_object);
           }
@@ -5411,7 +5072,7 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
 
   void MarkReachableObjects() {
     MarkingVisitor visitor(this);
-    heap_->IterateRoots(&visitor, VISIT_ALL);
+    heap_->IterateRoots(&visitor, VISIT_ALL_BUT_READ_ONLY);
     visitor.TransitiveClosure();
   }
 
@@ -5597,24 +5258,6 @@ void Heap::UnregisterStrongRoots(Object** start) {
   }
 }
 
-bool Heap::IsDeserializeLazyHandler(Code* code) {
-  return (code == deserialize_lazy_handler() ||
-          code == deserialize_lazy_handler_wide() ||
-          code == deserialize_lazy_handler_extra_wide());
-}
-
-void Heap::SetDeserializeLazyHandler(Code* code) {
-  set_deserialize_lazy_handler(code);
-}
-
-void Heap::SetDeserializeLazyHandlerWide(Code* code) {
-  set_deserialize_lazy_handler_wide(code);
-}
-
-void Heap::SetDeserializeLazyHandlerExtraWide(Code* code) {
-  set_deserialize_lazy_handler_extra_wide(code);
-}
-
 void Heap::SetBuiltinsConstantsTable(FixedArray* cache) {
   set_builtins_constants_table(cache);
 }
@@ -5723,11 +5366,11 @@ void VerifyPointersVisitor::VerifyPointers(HeapObject* host,
                                            MaybeObject** end) {
   for (MaybeObject** current = start; current < end; current++) {
     HeapObject* object;
-    if ((*current)->ToStrongOrWeakHeapObject(&object)) {
+    if ((*current)->GetHeapObject(&object)) {
       CHECK(heap_->Contains(object));
       CHECK(object->map()->IsMap());
     } else {
-      CHECK((*current)->IsSmi() || (*current)->IsClearedWeakHeapObject());
+      CHECK((*current)->IsSmi() || (*current)->IsCleared());
     }
   }
 }
diff --git a/deps/v8/src/heap/heap.h b/deps/v8/src/heap/heap.h
index 2e750d56fa..c99f0d424e 100644
--- a/deps/v8/src/heap/heap.h
+++ b/deps/v8/src/heap/heap.h
@@ -13,6 +13,7 @@
 
 // Clients of this interface shouldn't depend on lots of heap internals.
 // Do not include anything from src/heap here!
+#include "include/v8-internal.h"
 #include "include/v8.h"
 #include "src/accessors.h"
 #include "src/allocation.h"
@@ -40,6 +41,7 @@ class HeapTester;
 class TestMemoryAllocatorScope;
 }  // namespace heap
 
+class AllocationMemento;
 class ObjectBoilerplateDescription;
 class BytecodeArray;
 class CodeDataContainer;
@@ -50,6 +52,10 @@ class JSArrayBuffer;
 class ExternalString;
 using v8::MemoryPressureLevel;
 
+// Adapts PRIVATE_SYMBOL_LIST_GERNATOR entry to IMMORTAL_IMMOVABLE_ROOT_LIST
+// entry
+#define PRIVATE_SYMBOL_LIST_TO_IMMORTAL_IMMOVABLE_LIST_ADAPTER(V, name) V(name)
+
 // Heap roots that are known to be immortal immovable, for which we can safely
 // skip write barriers. This list is not complete and has omissions.
 #define IMMORTAL_IMMOVABLE_ROOT_LIST(V)     \
@@ -57,6 +63,7 @@ using v8::MemoryPressureLevel;
   V(ArgumentsMarkerMap)                     \
   V(ArrayBufferNeuteringProtector)          \
   V(ArrayIteratorProtector)                 \
+  V(AwaitContextMap)                        \
   V(BigIntMap)                              \
   V(BlockContextMap)                        \
   V(ObjectBoilerplateDescriptionMap)        \
@@ -143,6 +150,7 @@ using v8::MemoryPressureLevel;
   V(TypedArraySpeciesProtector)             \
   V(PromiseSpeciesProtector)                \
   V(StaleRegister)                          \
+  V(StringIteratorProtector)                \
   V(StringLengthProtector)                  \
   V(StringTableMap)                         \
   V(SymbolMap)                              \
@@ -162,7 +170,8 @@ using v8::MemoryPressureLevel;
   V(WeakArrayListMap)                       \
   V(WithContextMap)                         \
   V(empty_string)                           \
-  PRIVATE_SYMBOL_LIST(V)
+  PRIVATE_SYMBOL_LIST_GENERATOR(            \
+      PRIVATE_SYMBOL_LIST_TO_IMMORTAL_IMMOVABLE_LIST_ADAPTER, V)
 
 class AllocationObserver;
 class ArrayBufferCollector;
@@ -189,6 +198,7 @@ class PagedSpace;
 class RootVisitor;
 class ScavengeJob;
 class Scavenger;
+class ScavengerCollector;
 class Space;
 class StoreBuffer;
 class StressScavengeObserver;
@@ -206,6 +216,8 @@ enum class ClearRecordedSlots { kYes, kNo };
 
 enum class ClearFreedMemoryMode { kClearFreedMemory, kDontClearFreedMemory };
 
+enum ExternalBackingStoreType { kArrayBuffer, kExternalString, kNumTypes };
+
 enum class FixedArrayVisitationMode { kRegular, kIncremental };
 
 enum class TraceRetainingPathMode { kEnabled, kDisabled };
@@ -305,54 +317,6 @@ struct CommentStatistic {
 
 class Heap {
  public:
-  // Declare all the root indices.  This defines the root list order.
-  // clang-format off
-  enum RootListIndex {
-#define DECL(type, name, camel_name) k##camel_name##RootIndex,
-    STRONG_ROOT_LIST(DECL)
-#undef DECL
-
-#define DECL(name, str) k##name##RootIndex,
-    INTERNALIZED_STRING_LIST(DECL)
-#undef DECL
-
-#define DECL(name) k##name##RootIndex,
-    PRIVATE_SYMBOL_LIST(DECL)
-#undef DECL
-
-#define DECL(name, description) k##name##RootIndex,
-    PUBLIC_SYMBOL_LIST(DECL)
-    WELL_KNOWN_SYMBOL_LIST(DECL)
-#undef DECL
-
-#define DECL(accessor_name, AccessorName) k##AccessorName##AccessorRootIndex,
-    ACCESSOR_INFO_LIST(DECL)
-#undef DECL
-
-#define DECL(NAME, Name, name) k##Name##MapRootIndex,
-    STRUCT_LIST(DECL)
-#undef DECL
-
-#define DECL(NAME, Name, Size, name) k##Name##Size##MapRootIndex,
-   ALLOCATION_SITE_LIST(DECL)
-#undef DECL
-
-#define DECL(NAME, Name, Size, name) k##Name##Size##MapRootIndex,
-    DATA_HANDLER_LIST(DECL)
-#undef DECL
-
-    kStringTableRootIndex,
-
-#define DECL(type, name, camel_name) k##camel_name##RootIndex,
-    SMI_ROOT_LIST(DECL)
-#undef DECL
-
-    kRootListLength,
-    kStrongRootListLength = kStringTableRootIndex,
-    kSmiRootsStart = kStringTableRootIndex + 1
-  };
-  // clang-format on
-
   enum FindMementoMode { kForRuntime, kForGC };
 
   enum HeapState {
@@ -399,11 +363,6 @@ class Heap {
 
   static const int kNoGCFlags = 0;
   static const int kReduceMemoryFootprintMask = 1;
-  static const int kAbortIncrementalMarkingMask = 2;
-  static const int kFinalizeIncrementalMarkingMask = 4;
-
-  // Making the heap iterable requires us to abort incremental marking.
-  static const int kMakeHeapIterableMask = kAbortIncrementalMarkingMask;
 
   // The roots that have an index less than this are always in old space.
   static const int kOldSpaceRoots = 0x20;
@@ -413,13 +372,18 @@ class Heap {
 
   static const int kMinPromotedPercentForFastPromotionMode = 90;
 
-  STATIC_ASSERT(kUndefinedValueRootIndex ==
+  STATIC_ASSERT(static_cast<int>(RootIndex::kUndefinedValue) ==
                 Internals::kUndefinedValueRootIndex);
-  STATIC_ASSERT(kTheHoleValueRootIndex == Internals::kTheHoleValueRootIndex);
-  STATIC_ASSERT(kNullValueRootIndex == Internals::kNullValueRootIndex);
-  STATIC_ASSERT(kTrueValueRootIndex == Internals::kTrueValueRootIndex);
-  STATIC_ASSERT(kFalseValueRootIndex == Internals::kFalseValueRootIndex);
-  STATIC_ASSERT(kempty_stringRootIndex == Internals::kEmptyStringRootIndex);
+  STATIC_ASSERT(static_cast<int>(RootIndex::kTheHoleValue) ==
+                Internals::kTheHoleValueRootIndex);
+  STATIC_ASSERT(static_cast<int>(RootIndex::kNullValue) ==
+                Internals::kNullValueRootIndex);
+  STATIC_ASSERT(static_cast<int>(RootIndex::kTrueValue) ==
+                Internals::kTrueValueRootIndex);
+  STATIC_ASSERT(static_cast<int>(RootIndex::kFalseValue) ==
+                Internals::kFalseValueRootIndex);
+  STATIC_ASSERT(static_cast<int>(RootIndex::kempty_string) ==
+                Internals::kEmptyStringRootIndex);
 
   // Calculates the maximum amount of filler that could be required by the
   // given alignment.
@@ -430,14 +394,14 @@ class Heap {
 
   void FatalProcessOutOfMemory(const char* location);
 
-  V8_EXPORT_PRIVATE static bool RootIsImmortalImmovable(int root_index);
+  V8_EXPORT_PRIVATE static bool RootIsImmortalImmovable(RootIndex root_index);
 
   // Checks whether the space is valid.
   static bool IsValidAllocationSpace(AllocationSpace space);
 
   // Generated code can embed direct references to non-writable roots if
   // they are in new space.
-  static bool RootCanBeWrittenAfterInitialization(RootListIndex root_index);
+  static bool RootCanBeWrittenAfterInitialization(RootIndex root_index);
 
   // Zapping is needed for verify heap, and always done in debug builds.
   static inline bool ShouldZapGarbage() {
@@ -566,8 +530,8 @@ class Heap {
 
   // Traverse all the allocaions_sites [nested_site and weak_next] in the list
   // and foreach call the visitor
-  void ForeachAllocationSite(Object* list,
-                             std::function<void(AllocationSite*)> visitor);
+  void ForeachAllocationSite(
+      Object* list, const std::function<void(AllocationSite*)>& visitor);
 
   // Number of mark-sweeps.
   int ms_count() const { return ms_count_; }
@@ -688,8 +652,7 @@ class Heap {
     external_memory_concurrently_freed_ = 0;
   }
 
-  void ProcessMovedExternalString(Page* old_page, Page* new_page,
-                                  ExternalString* string);
+  size_t backing_store_bytes() const { return backing_store_bytes_; }
 
   void CompactWeakArrayLists(PretenureFlag pretenure);
 
@@ -811,36 +774,29 @@ class Heap {
   friend class ReadOnlyRoots;
 
  public:
+  RootsTable& roots_table() { return roots_; }
+
 // Heap root getters.
-#define ROOT_ACCESSOR(type, name, camel_name) inline type* name();
+#define ROOT_ACCESSOR(type, name, CamelName) inline type* name();
   MUTABLE_ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
-#define DATA_HANDLER_MAP_ACCESSOR(NAME, Name, Size, name) \
-  inline Map* name##_map();
-  DATA_HANDLER_LIST(DATA_HANDLER_MAP_ACCESSOR)
-#undef DATA_HANDLER_MAP_ACCESSOR
-
-#define ACCESSOR_INFO_ACCESSOR(accessor_name, AccessorName) \
-  inline AccessorInfo* accessor_name##_accessor();
-  ACCESSOR_INFO_LIST(ACCESSOR_INFO_ACCESSOR)
-#undef ACCESSOR_INFO_ACCESSOR
-
-  Object* root(RootListIndex index) { return roots_[index]; }
-  Handle<Object> root_handle(RootListIndex index) {
+  Object* root(RootIndex index) { return roots_[index]; }
+  Handle<Object> root_handle(RootIndex index) {
     return Handle<Object>(&roots_[index]);
   }
+
+  bool IsRootHandleLocation(Object** handle_location, RootIndex* index) const {
+    return roots_.IsRootHandleLocation(handle_location, index);
+  }
+
   template <typename T>
-  bool IsRootHandle(Handle<T> handle, RootListIndex* index) const {
-    Object** const handle_location = bit_cast<Object**>(handle.address());
-    if (handle_location >= &roots_[kRootListLength]) return false;
-    if (handle_location < &roots_[0]) return false;
-    *index = static_cast<RootListIndex>(handle_location - &roots_[0]);
-    return true;
+  bool IsRootHandle(Handle<T> handle, RootIndex* index) const {
+    return roots_.IsRootHandle(handle, index);
   }
 
   // Generated code can embed this address to get access to the roots.
-  Object** roots_array_start() { return roots_; }
+  Object** roots_array_start() { return roots_.roots_; }
 
   ExternalReferenceTable* external_reference_table() {
     DCHECK(external_reference_table_.is_initialized());
@@ -868,23 +824,23 @@ class Heap {
   void SetRootCodeStubs(SimpleNumberDictionary* value);
 
   void SetRootMaterializedObjects(FixedArray* objects) {
-    roots_[kMaterializedObjectsRootIndex] = objects;
+    roots_[RootIndex::kMaterializedObjects] = objects;
   }
 
   void SetRootScriptList(Object* value) {
-    roots_[kScriptListRootIndex] = value;
+    roots_[RootIndex::kScriptList] = value;
   }
 
   void SetRootStringTable(StringTable* value) {
-    roots_[kStringTableRootIndex] = value;
+    roots_[RootIndex::kStringTable] = value;
   }
 
   void SetRootNoScriptSharedFunctionInfos(Object* value) {
-    roots_[kNoScriptSharedFunctionInfosRootIndex] = value;
+    roots_[RootIndex::kNoScriptSharedFunctionInfos] = value;
   }
 
   void SetMessageListeners(TemplateList* value) {
-    roots_[kMessageListenersRootIndex] = value;
+    roots_[RootIndex::kMessageListeners] = value;
   }
 
   // Set the stack limit in the roots_ array.  Some architectures generate
@@ -897,20 +853,11 @@ class Heap {
   void ClearStackLimits();
 
   // Generated code can treat direct references to this root as constant.
-  bool RootCanBeTreatedAsConstant(RootListIndex root_index);
-
-  Map* MapForFixedTypedArray(ExternalArrayType array_type);
-  Map* MapForFixedTypedArray(ElementsKind elements_kind);
-  FixedTypedArrayBase* EmptyFixedTypedArrayForMap(const Map* map);
+  bool RootCanBeTreatedAsConstant(RootIndex root_index);
 
   void RegisterStrongRoots(Object** start, Object** end);
   void UnregisterStrongRoots(Object** start);
 
-  bool IsDeserializeLazyHandler(Code* code);
-  void SetDeserializeLazyHandler(Code* code);
-  void SetDeserializeLazyHandlerWide(Code* code);
-  void SetDeserializeLazyHandlerExtraWide(Code* code);
-
   void SetBuiltinsConstantsTable(FixedArray* cache);
 
   // ===========================================================================
@@ -935,9 +882,7 @@ class Heap {
       AllocationSpace space, GarbageCollectionReason gc_reason,
       const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags);
 
-  // Performs a full garbage collection.  If (flags & kMakeHeapIterableMask) is
-  // non-zero, then the slower precise sweeper is used, which leaves the heap
-  // in a state where we can iterate over the heap visiting all objects.
+  // Performs a full garbage collection.
   V8_EXPORT_PRIVATE void CollectAllGarbage(
       int flags, GarbageCollectionReason gc_reason,
       const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags);
@@ -945,6 +890,13 @@ class Heap {
   // Last hope GC, should try to squeeze as much as possible.
   void CollectAllAvailableGarbage(GarbageCollectionReason gc_reason);
 
+  // Precise garbage collection that potentially finalizes already running
+  // incremental marking before performing an atomic garbage collection.
+  // Only use if absolutely necessary or in tests to avoid floating garbage!
+  void PreciseCollectAllGarbage(
+      int flags, GarbageCollectionReason gc_reason,
+      const GCCallbackFlags gc_callback_flags = kNoGCCallbackFlags);
+
   // Reports and external memory pressure event, either performs a major GC or
   // completes incremental marking in order to free external resources.
   void ReportExternalMemoryPressure();
@@ -1002,7 +954,9 @@ class Heap {
   void ClearRecordedSlot(HeapObject* object, Object** slot);
   void ClearRecordedSlotRange(Address start, Address end);
 
-  bool HasRecordedSlot(HeapObject* object, Object** slot);
+#ifdef DEBUG
+  void VerifyClearedSlot(HeapObject* object, Object** slot);
+#endif
 
   // ===========================================================================
   // Incremental marking API. ==================================================
@@ -1084,10 +1038,13 @@ class Heap {
   // Embedder heap tracer support. =============================================
   // ===========================================================================
 
-  LocalEmbedderHeapTracer* local_embedder_heap_tracer() {
+  LocalEmbedderHeapTracer* local_embedder_heap_tracer() const {
     return local_embedder_heap_tracer_;
   }
+
   void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
+  EmbedderHeapTracer* GetEmbedderHeapTracer() const;
+
   void TracePossibleWrapper(JSObject* js_object);
   void RegisterExternallyReferencedObject(Object** object);
   void SetEmbedderStackStateForNextFinalizaton(
@@ -1109,6 +1066,9 @@ class Heap {
   // data and clearing the resource pointer.
   inline void FinalizeExternalString(String* string);
 
+  static String* UpdateNewSpaceReferenceInExternalStringTableEntry(
+      Heap* heap, Object** pointer);
+
   // ===========================================================================
   // Methods checking/returning the space of a given object/address. ===========
   // ===========================================================================
@@ -1538,18 +1498,18 @@ class Heap {
   struct StringTypeTable {
     InstanceType type;
     int size;
-    RootListIndex index;
+    RootIndex index;
   };
 
   struct ConstantStringTable {
     const char* contents;
-    RootListIndex index;
+    RootIndex index;
   };
 
   struct StructTable {
     InstanceType type;
     int size;
-    RootListIndex index;
+    RootIndex index;
   };
 
   struct GCCallbackTuple {
@@ -1584,13 +1544,8 @@ class Heap {
 
   static const int kInitialFeedbackCapacity = 256;
 
-  static const int kMaxScavengerTasks = 8;
-
   Heap();
 
-  static String* UpdateNewSpaceReferenceInExternalStringTableEntry(
-      Heap* heap, Object** pointer);
-
   // Selects the proper allocation space based on the pretenuring decision.
   static AllocationSpace SelectSpace(PretenureFlag pretenure) {
     switch (pretenure) {
@@ -1609,7 +1564,7 @@ class Heap {
     return 0;
   }
 
-#define ROOT_ACCESSOR(type, name, camel_name) \
+#define ROOT_ACCESSOR(type, name, CamelName) \
   inline void set_##name(type* value);
   ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
@@ -1618,22 +1573,12 @@ class Heap {
 
   void set_current_gc_flags(int flags) {
     current_gc_flags_ = flags;
-    DCHECK(!ShouldFinalizeIncrementalMarking() ||
-           !ShouldAbortIncrementalMarking());
   }
 
   inline bool ShouldReduceMemory() const {
     return (current_gc_flags_ & kReduceMemoryFootprintMask) != 0;
   }
 
-  inline bool ShouldAbortIncrementalMarking() const {
-    return (current_gc_flags_ & kAbortIncrementalMarkingMask) != 0;
-  }
-
-  inline bool ShouldFinalizeIncrementalMarking() const {
-    return (current_gc_flags_ & kFinalizeIncrementalMarkingMask) != 0;
-  }
-
   int NumberOfScavengeTasks();
 
   // Checks whether a global GC is necessary
@@ -1733,6 +1678,8 @@ class Heap {
 
   void CollectGarbageOnMemoryPressure();
 
+  void EagerlyFreeExternalMemory();
+
   bool InvokeNearHeapLimitCallback();
 
   void ComputeFastPromotionMode();
@@ -1841,6 +1788,12 @@ class Heap {
   void CheckIneffectiveMarkCompact(size_t old_generation_size,
                                    double mutator_utilization);
 
+  inline void IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                 size_t amount);
+
+  inline void DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                 size_t amount);
+
   // ===========================================================================
   // Growing strategy. =========================================================
   // ===========================================================================
@@ -1962,28 +1915,28 @@ class Heap {
   void PrintRetainingPath(HeapObject* object, RetainingPathOption option);
 
   // The amount of external memory registered through the API.
-  int64_t external_memory_;
+  int64_t external_memory_ = 0;
 
   // The limit when to trigger memory pressure from the API.
-  int64_t external_memory_limit_;
+  int64_t external_memory_limit_ = kExternalAllocationSoftLimit;
 
   // Caches the amount of external memory registered at the last MC.
-  int64_t external_memory_at_last_mark_compact_;
+  int64_t external_memory_at_last_mark_compact_ = 0;
 
   // The amount of memory that has been freed concurrently.
-  std::atomic<intptr_t> external_memory_concurrently_freed_;
+  std::atomic<intptr_t> external_memory_concurrently_freed_{0};
 
   // This can be calculated directly from a pointer to the heap; however, it is
   // more expedient to get at the isolate directly from within Heap methods.
-  Isolate* isolate_;
+  Isolate* isolate_ = nullptr;
 
-  Object* roots_[kRootListLength];
+  RootsTable roots_;
 
   // This table is accessed from builtin code compiled into the snapshot, and
   // thus its offset from roots_ must remain static. This is verified in
   // Isolate::Init() using runtime checks.
   static constexpr int kRootsExternalReferenceTableOffset =
-      kRootListLength * kPointerSize;
+      static_cast<int>(RootIndex::kRootListLength) * kPointerSize;
   ExternalReferenceTable external_reference_table_;
 
   // As external references above, builtins are accessed through an offset from
@@ -2000,25 +1953,28 @@ class Heap {
   static constexpr int kRootRegisterAddressableEndOffset =
       kRootsBuiltinsOffset + Builtins::builtin_count * kPointerSize;
 
-  size_t code_range_size_;
-  size_t max_semi_space_size_;
-  size_t initial_semispace_size_;
-  size_t max_old_generation_size_;
+  size_t code_range_size_ = 0;
+  size_t max_semi_space_size_ = 8 * (kPointerSize / 4) * MB;
+  size_t initial_semispace_size_ = kMinSemiSpaceSizeInKB * KB;
+  size_t max_old_generation_size_ = 700ul * (kPointerSize / 4) * MB;
   size_t initial_max_old_generation_size_;
   size_t initial_old_generation_size_;
-  bool old_generation_size_configured_;
-  size_t maximum_committed_;
+  bool old_generation_size_configured_ = false;
+  size_t maximum_committed_ = 0;
+
+  // Backing store bytes (array buffers and external strings).
+  std::atomic<size_t> backing_store_bytes_{0};
 
   // For keeping track of how much data has survived
   // scavenge since last new space expansion.
-  size_t survived_since_last_expansion_;
+  size_t survived_since_last_expansion_ = 0;
 
   // ... and since the last scavenge.
-  size_t survived_last_scavenge_;
+  size_t survived_last_scavenge_ = 0;
 
   // This is not the depth of nested AlwaysAllocateScope's but rather a single
   // count, as scopes can be acquired from multiple tasks (read: threads).
-  std::atomic<size_t> always_allocate_scope_count_;
+  std::atomic<size_t> always_allocate_scope_count_{0};
 
   // Stores the memory pressure level that set by MemoryPressureNotification
   // and reset by a mark-compact garbage collection.
@@ -2028,74 +1984,75 @@ class Heap {
       near_heap_limit_callbacks_;
 
   // For keeping track of context disposals.
-  int contexts_disposed_;
+  int contexts_disposed_ = 0;
 
   // The length of the retained_maps array at the time of context disposal.
   // This separates maps in the retained_maps array that were created before
   // and after context disposal.
-  int number_of_disposed_maps_;
-
-  NewSpace* new_space_;
-  OldSpace* old_space_;
-  CodeSpace* code_space_;
-  MapSpace* map_space_;
-  LargeObjectSpace* lo_space_;
-  NewLargeObjectSpace* new_lo_space_;
-  ReadOnlySpace* read_only_space_;
+  int number_of_disposed_maps_ = 0;
+
+  NewSpace* new_space_ = nullptr;
+  OldSpace* old_space_ = nullptr;
+  CodeSpace* code_space_ = nullptr;
+  MapSpace* map_space_ = nullptr;
+  LargeObjectSpace* lo_space_ = nullptr;
+  NewLargeObjectSpace* new_lo_space_ = nullptr;
+  ReadOnlySpace* read_only_space_ = nullptr;
   // Map from the space id to the space.
   Space* space_[LAST_SPACE + 1];
 
   // Determines whether code space is write-protected. This is essentially a
   // race-free copy of the {FLAG_write_protect_code_memory} flag.
-  bool write_protect_code_memory_;
+  bool write_protect_code_memory_ = false;
 
   // Holds the number of open CodeSpaceMemoryModificationScopes.
-  uintptr_t code_space_memory_modification_scope_depth_;
+  uintptr_t code_space_memory_modification_scope_depth_ = 0;
+
+  HeapState gc_state_ = NOT_IN_GC;
 
-  HeapState gc_state_;
-  int gc_post_processing_depth_;
+  int gc_post_processing_depth_ = 0;
 
   // Returns the amount of external memory registered since last global gc.
   uint64_t PromotedExternalMemorySize();
 
   // How many "runtime allocations" happened.
-  uint32_t allocations_count_;
+  uint32_t allocations_count_ = 0;
 
   // Running hash over allocations performed.
-  uint32_t raw_allocations_hash_;
+  uint32_t raw_allocations_hash_ = 0;
 
   // Starts marking when stress_marking_percentage_% of the marking start limit
   // is reached.
-  int stress_marking_percentage_;
+  int stress_marking_percentage_ = 0;
 
   // Observer that causes more frequent checks for reached incremental marking
   // limit.
-  AllocationObserver* stress_marking_observer_;
+  AllocationObserver* stress_marking_observer_ = nullptr;
 
   // Observer that can cause early scavenge start.
-  StressScavengeObserver* stress_scavenge_observer_;
+  StressScavengeObserver* stress_scavenge_observer_ = nullptr;
 
-  bool allocation_step_in_progress_;
+  bool allocation_step_in_progress_ = false;
 
   // The maximum percent of the marking limit reached wihout causing marking.
   // This is tracked when specyfing --fuzzer-gc-analysis.
-  double max_marking_limit_reached_;
+  double max_marking_limit_reached_ = 0.0;
 
   // How many mark-sweep collections happened.
-  unsigned int ms_count_;
+  unsigned int ms_count_ = 0;
 
   // How many gc happened.
-  unsigned int gc_count_;
+  unsigned int gc_count_ = 0;
 
   // The number of Mark-Compact garbage collections that are considered as
   // ineffective. See IsIneffectiveMarkCompact() predicate.
-  int consecutive_ineffective_mark_compacts_;
+  int consecutive_ineffective_mark_compacts_ = 0;
 
   static const uintptr_t kMmapRegionMask = 0xFFFFFFFFu;
-  uintptr_t mmap_region_base_;
+  uintptr_t mmap_region_base_ = 0;
 
   // For post mortem debugging.
-  int remembered_unmapped_pages_index_;
+  int remembered_unmapped_pages_index_ = 0;
   Address remembered_unmapped_pages_[kRememberedUnmappedPages];
 
   // Limit that triggers a global GC on the next (normally caused) GC.  This
@@ -2106,7 +2063,7 @@ class Heap {
 
   // Indicates that inline bump-pointer allocation has been globally disabled
   // for all spaces. This is used to disable allocations in generated code.
-  bool inline_allocation_disabled_;
+  bool inline_allocation_disabled_ = false;
 
   // Weak list heads, threaded through the objects.
   // List heads are initialized lazily and contain the undefined_value at start.
@@ -2120,71 +2077,62 @@ class Heap {
 
   int deferred_counters_[v8::Isolate::kUseCounterFeatureCount];
 
-  GCTracer* tracer_;
-
-  size_t promoted_objects_size_;
-  double promotion_ratio_;
-  double promotion_rate_;
-  size_t semi_space_copied_object_size_;
-  size_t previous_semi_space_copied_object_size_;
-  double semi_space_copied_rate_;
-  int nodes_died_in_new_space_;
-  int nodes_copied_in_new_space_;
-  int nodes_promoted_;
+  size_t promoted_objects_size_ = 0;
+  double promotion_ratio_ = 0.0;
+  double promotion_rate_ = 0.0;
+  size_t semi_space_copied_object_size_ = 0;
+  size_t previous_semi_space_copied_object_size_ = 0;
+  double semi_space_copied_rate_ = 0.0;
+  int nodes_died_in_new_space_ = 0;
+  int nodes_copied_in_new_space_ = 0;
+  int nodes_promoted_ = 0;
 
   // This is the pretenuring trigger for allocation sites that are in maybe
   // tenure state. When we switched to the maximum new space size we deoptimize
   // the code that belongs to the allocation site and derive the lifetime
   // of the allocation site.
-  unsigned int maximum_size_scavenges_;
+  unsigned int maximum_size_scavenges_ = 0;
 
   // Total time spent in GC.
   double total_gc_time_ms_;
 
   // Last time an idle notification happened.
-  double last_idle_notification_time_;
+  double last_idle_notification_time_ = 0.0;
 
   // Last time a garbage collection happened.
-  double last_gc_time_;
-
-  MarkCompactCollector* mark_compact_collector_;
-  MinorMarkCompactCollector* minor_mark_compact_collector_;
-
-  ArrayBufferCollector* array_buffer_collector_;
-
-  MemoryAllocator* memory_allocator_;
-
-  StoreBuffer* store_buffer_;
-
-  HeapController* heap_controller_;
-
-  IncrementalMarking* incremental_marking_;
-  ConcurrentMarking* concurrent_marking_;
-
-  GCIdleTimeHandler* gc_idle_time_handler_;
-
-  MemoryReducer* memory_reducer_;
-
-  ObjectStats* live_object_stats_;
-  ObjectStats* dead_object_stats_;
-
-  ScavengeJob* scavenge_job_;
-  base::Semaphore parallel_scavenge_semaphore_;
-
-  AllocationObserver* idle_scavenge_observer_;
+  double last_gc_time_ = 0.0;
+
+  GCTracer* tracer_ = nullptr;
+  MarkCompactCollector* mark_compact_collector_ = nullptr;
+  MinorMarkCompactCollector* minor_mark_compact_collector_ = nullptr;
+  ScavengerCollector* scavenger_collector_ = nullptr;
+  ArrayBufferCollector* array_buffer_collector_ = nullptr;
+  MemoryAllocator* memory_allocator_ = nullptr;
+  StoreBuffer* store_buffer_ = nullptr;
+  HeapController* heap_controller_ = nullptr;
+  IncrementalMarking* incremental_marking_ = nullptr;
+  ConcurrentMarking* concurrent_marking_ = nullptr;
+  GCIdleTimeHandler* gc_idle_time_handler_ = nullptr;
+  MemoryReducer* memory_reducer_ = nullptr;
+  ObjectStats* live_object_stats_ = nullptr;
+  ObjectStats* dead_object_stats_ = nullptr;
+  ScavengeJob* scavenge_job_ = nullptr;
+  AllocationObserver* idle_scavenge_observer_ = nullptr;
+  LocalEmbedderHeapTracer* local_embedder_heap_tracer_ = nullptr;
+  StrongRootsList* strong_roots_list_ = nullptr;
 
   // This counter is increased before each GC and never reset.
   // To account for the bytes allocated since the last GC, use the
   // NewSpaceAllocationCounter() function.
-  size_t new_space_allocation_counter_;
+  size_t new_space_allocation_counter_ = 0;
 
   // This counter is increased before each GC and never reset. To
   // account for the bytes allocated since the last GC, use the
   // OldGenerationAllocationCounter() function.
-  size_t old_generation_allocation_counter_at_last_gc_;
+  size_t old_generation_allocation_counter_at_last_gc_ = 0;
 
   // The size of objects in old generation after the last MarkCompact GC.
-  size_t old_generation_size_at_last_gc_;
+  size_t old_generation_size_at_last_gc_ = 0;
 
   // The feedback storage is used to store allocation sites (keys) and how often
   // they have been visited (values) by finding a memento behind an object. The
@@ -2196,20 +2144,20 @@ class Heap {
   char trace_ring_buffer_[kTraceRingBufferSize];
 
   // Used as boolean.
-  uint8_t is_marking_flag_;
+  uint8_t is_marking_flag_ = 0;
 
   // If it's not full then the data is from 0 to ring_buffer_end_.  If it's
   // full then the data is from ring_buffer_end_ to the end of the buffer and
   // from 0 to ring_buffer_end_.
-  bool ring_buffer_full_;
-  size_t ring_buffer_end_;
+  bool ring_buffer_full_ = false;
+  size_t ring_buffer_end_ = 0;
 
   // Flag is set when the heap has been configured.  The heap can be repeatedly
   // configured through the API until it is set up.
-  bool configured_;
+  bool configured_ = false;
 
   // Currently set GC flags that are respected by all GC components.
-  int current_gc_flags_;
+  int current_gc_flags_ = Heap::kNoGCFlags;
 
   // Currently set GC callback flags that are used to pass information between
   // the embedder and V8's GC.
@@ -2219,34 +2167,30 @@ class Heap {
 
   base::Mutex relocation_mutex_;
 
-  int gc_callbacks_depth_;
-
-  bool deserialization_complete_;
+  int gc_callbacks_depth_ = 0;
 
-  StrongRootsList* strong_roots_list_;
+  bool deserialization_complete_ = false;
 
   // The depth of HeapIterator nestings.
-  int heap_iterator_depth_;
+  int heap_iterator_depth_ = 0;
 
-  LocalEmbedderHeapTracer* local_embedder_heap_tracer_;
-
-  bool fast_promotion_mode_;
+  bool fast_promotion_mode_ = false;
 
   // Used for testing purposes.
-  bool force_oom_;
-  bool delay_sweeper_tasks_for_testing_;
+  bool force_oom_ = false;
+  bool delay_sweeper_tasks_for_testing_ = false;
 
-  HeapObject* pending_layout_change_object_;
+  HeapObject* pending_layout_change_object_ = nullptr;
 
   base::Mutex unprotected_memory_chunks_mutex_;
   std::unordered_set<MemoryChunk*> unprotected_memory_chunks_;
-  bool unprotected_memory_chunks_registry_enabled_;
+  bool unprotected_memory_chunks_registry_enabled_ = false;
 
 #ifdef V8_ENABLE_ALLOCATION_TIMEOUT
   // If the --gc-interval flag is set to a positive value, this
   // variable holds the value indicating the number of allocations
   // remain until the next failure and garbage collection.
-  int allocation_timeout_;
+  int allocation_timeout_ = 0;
 #endif  // V8_ENABLE_ALLOCATION_TIMEOUT
 
   std::map<HeapObject*, HeapObject*> retainer_;
@@ -2262,6 +2206,7 @@ class Heap {
 
   // Classes in "heap" can be friends.
   friend class AlwaysAllocateScope;
+  friend class ArrayBufferCollector;
   friend class ConcurrentMarking;
   friend class EphemeronHashTableMarkingTask;
   friend class GCCallbacksScope;
@@ -2283,6 +2228,8 @@ class Heap {
   friend class Page;
   friend class PagedSpace;
   friend class Scavenger;
+  friend class ScavengerCollector;
+  friend class Space;
   friend class StoreBuffer;
   friend class Sweeper;
   friend class heap::TestMemoryAllocatorScope;
@@ -2297,7 +2244,8 @@ class Heap {
   friend class heap::HeapTester;
 
   FRIEND_TEST(HeapControllerTest, OldGenerationAllocationLimit);
-
+  FRIEND_TEST(HeapTest, ExternalLimitDefault);
+  FRIEND_TEST(HeapTest, ExternalLimitStaysAboveDefaultForExplicitHandling);
   DISALLOW_COPY_AND_ASSIGN(Heap);
 };
 
@@ -2417,7 +2365,7 @@ class VerifySmisVisitor : public RootVisitor {
 // Space iterator for iterating over all the paged spaces of the heap: Map
 // space, old space, code space and optionally read only space. Returns each
 // space in turn, and null when it is done.
-class V8_EXPORT_PRIVATE PagedSpaces BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE PagedSpaces {
  public:
   enum class SpacesSpecifier { kSweepablePagedSpaces, kAllPagedSpaces };
 
@@ -2460,7 +2408,7 @@ class SpaceIterator : public Malloced {
 // nodes filtering uses GC marks, it can't be used during MS/MC GC
 // phases. Also, it is forbidden to interrupt iteration in this mode,
 // as this will leave heap objects marked (and thus, unusable).
-class HeapIterator BASE_EMBEDDED {
+class HeapIterator {
  public:
   enum HeapObjectsFiltering { kNoFiltering, kFilterUnreachable };
 
@@ -2487,7 +2435,7 @@ class HeapIterator BASE_EMBEDDED {
 // Abstract base class for checking whether a weak object should be retained.
 class WeakObjectRetainer {
  public:
-  virtual ~WeakObjectRetainer() {}
+  virtual ~WeakObjectRetainer() = default;
 
   // Return whether this object should be retained. If nullptr is returned the
   // object has no references. Otherwise the address of the retained object
@@ -2503,7 +2451,7 @@ class AllocationObserver {
       : step_size_(step_size), bytes_to_next_step_(step_size) {
     DCHECK_LE(kPointerSize, step_size);
   }
-  virtual ~AllocationObserver() {}
+  virtual ~AllocationObserver() = default;
 
   // Called each time the observed space does an allocation step. This may be
   // more frequently than the step_size we are monitoring (e.g. when there are
diff --git a/deps/v8/src/heap/incremental-marking-inl.h b/deps/v8/src/heap/incremental-marking-inl.h
index 19d6b22e4d..e19d62f4d4 100644
--- a/deps/v8/src/heap/incremental-marking-inl.h
+++ b/deps/v8/src/heap/incremental-marking-inl.h
@@ -6,6 +6,8 @@
 #define V8_HEAP_INCREMENTAL_MARKING_INL_H_
 
 #include "src/heap/incremental-marking.h"
+
+#include "src/heap/mark-compact-inl.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 #include "src/objects/maybe-object.h"
@@ -13,6 +15,23 @@
 namespace v8 {
 namespace internal {
 
+void IncrementalMarking::TransferColor(HeapObject* from, HeapObject* to) {
+  if (atomic_marking_state()->IsBlack(to)) {
+    DCHECK(black_allocation());
+    return;
+  }
+
+  DCHECK(atomic_marking_state()->IsWhite(to));
+  if (atomic_marking_state()->IsGrey(from)) {
+    bool success = atomic_marking_state()->WhiteToGrey(to);
+    DCHECK(success);
+    USE(success);
+  } else if (atomic_marking_state()->IsBlack(from)) {
+    bool success = atomic_marking_state()->WhiteToBlack(to);
+    DCHECK(success);
+    USE(success);
+  }
+}
 
 void IncrementalMarking::RecordWrite(HeapObject* obj, Object** slot,
                                      Object* value) {
@@ -30,7 +49,7 @@ void IncrementalMarking::RecordMaybeWeakWrite(HeapObject* obj,
   // When writing a weak reference, treat it as strong for the purposes of the
   // marking barrier.
   HeapObject* heap_object;
-  if (IsMarking() && value->ToStrongOrWeakHeapObject(&heap_object)) {
+  if (IsMarking() && value->GetHeapObject(&heap_object)) {
     RecordWriteSlow(obj, reinterpret_cast<HeapObjectReference**>(slot),
                     heap_object);
   }
diff --git a/deps/v8/src/heap/incremental-marking-job.cc b/deps/v8/src/heap/incremental-marking-job.cc
index 7583aaaadf..96eff0508e 100644
--- a/deps/v8/src/heap/incremental-marking-job.cc
+++ b/deps/v8/src/heap/incremental-marking-job.cc
@@ -24,8 +24,9 @@ void IncrementalMarkingJob::ScheduleTask(Heap* heap) {
   if (!task_pending_ && !heap->IsTearingDown()) {
     v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap->isolate());
     task_pending_ = true;
-    auto task = new Task(heap->isolate(), this);
-    V8::GetCurrentPlatform()->CallOnForegroundThread(isolate, task);
+    auto taskrunner =
+        V8::GetCurrentPlatform()->GetForegroundTaskRunner(isolate);
+    taskrunner->PostTask(base::make_unique<Task>(heap->isolate(), this));
   }
 }
 
diff --git a/deps/v8/src/heap/incremental-marking.cc b/deps/v8/src/heap/incremental-marking.cc
index a58d25fff4..239f416eaf 100644
--- a/deps/v8/src/heap/incremental-marking.cc
+++ b/deps/v8/src/heap/incremental-marking.cc
@@ -458,13 +458,6 @@ void IncrementalMarking::FinishBlackAllocation() {
   }
 }
 
-void IncrementalMarking::AbortBlackAllocation() {
-  if (FLAG_trace_incremental_marking) {
-    heap()->isolate()->PrintWithTimestamp(
-        "[IncrementalMarking] Black allocation aborted\n");
-  }
-}
-
 void IncrementalMarking::MarkRoots() {
   DCHECK(!finalize_marking_completed_);
   DCHECK(IsMarking());
@@ -494,7 +487,6 @@ void IncrementalMarking::RetainMaps() {
   // - memory pressure (reduce_memory_footprint_),
   // - GC is requested by tests or dev-tools (abort_incremental_marking_).
   bool map_retaining_is_disabled = heap()->ShouldReduceMemory() ||
-                                   heap()->ShouldAbortIncrementalMarking() ||
                                    FLAG_retain_maps_for_n_gc == 0;
   WeakArrayList* retained_maps = heap()->retained_maps();
   int length = retained_maps->length();
@@ -505,10 +497,10 @@ void IncrementalMarking::RetainMaps() {
   for (int i = 0; i < length; i += 2) {
     MaybeObject* value = retained_maps->Get(i);
     HeapObject* map_heap_object;
-    if (!value->ToWeakHeapObject(&map_heap_object)) {
+    if (!value->GetHeapObjectIfWeak(&map_heap_object)) {
       continue;
     }
-    int age = Smi::ToInt(retained_maps->Get(i + 1)->ToSmi());
+    int age = Smi::ToInt(retained_maps->Get(i + 1)->cast<Smi>());
     int new_age;
     Map* map = Map::cast(map_heap_object);
     if (i >= number_of_disposed_maps && !map_retaining_is_disabled &&
@@ -801,6 +793,32 @@ intptr_t IncrementalMarking::ProcessMarkingWorklist(
   return bytes_processed;
 }
 
+void IncrementalMarking::EmbedderStep(double duration_ms) {
+  constexpr int kObjectsToProcessBeforeInterrupt = 100;
+
+  TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_INCREMENTAL_WRAPPER_TRACING);
+
+  const double deadline =
+      heap_->MonotonicallyIncreasingTimeInMs() + duration_ms;
+
+  HeapObject* object;
+  int cnt = 0;
+  while (marking_worklist()->embedder()->Pop(0, &object)) {
+    heap_->TracePossibleWrapper(JSObject::cast(object));
+    if (++cnt == kObjectsToProcessBeforeInterrupt) {
+      cnt = 0;
+      if (heap_->MonotonicallyIncreasingTimeInMs() > deadline) {
+        break;
+      }
+    }
+  }
+
+  heap_->local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer();
+  if (!heap_->local_embedder_heap_tracer()
+           ->ShouldFinalizeIncrementalMarking()) {
+    heap_->local_embedder_heap_tracer()->Trace(deadline);
+  }
+}
 
 void IncrementalMarking::Hurry() {
   // A scavenge may have pushed new objects on the marking deque (due to black
@@ -930,14 +948,7 @@ double IncrementalMarking::AdvanceIncrementalMarking(
       heap_->local_embedder_heap_tracer()->InUse();
   do {
     if (incremental_wrapper_tracing && trace_wrappers_toggle_) {
-      TRACE_GC(heap()->tracer(),
-               GCTracer::Scope::MC_INCREMENTAL_WRAPPER_TRACING);
-      const double wrapper_deadline =
-          heap_->MonotonicallyIncreasingTimeInMs() + kStepSizeInMs;
-      if (!heap_->local_embedder_heap_tracer()
-               ->ShouldFinalizeIncrementalMarking()) {
-        heap_->local_embedder_heap_tracer()->Trace(wrapper_deadline);
-      }
+      EmbedderStep(kStepSizeInMs);
     } else {
       Step(step_size_in_bytes, completion_action, step_origin);
     }
diff --git a/deps/v8/src/heap/incremental-marking.h b/deps/v8/src/heap/incremental-marking.h
index 0fb5e11651..ee774c230f 100644
--- a/deps/v8/src/heap/incremental-marking.h
+++ b/deps/v8/src/heap/incremental-marking.h
@@ -100,23 +100,7 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
 
   void NotifyLeftTrimming(HeapObject* from, HeapObject* to);
 
-  V8_INLINE void TransferColor(HeapObject* from, HeapObject* to) {
-    if (atomic_marking_state()->IsBlack(to)) {
-      DCHECK(black_allocation());
-      return;
-    }
-
-    DCHECK(atomic_marking_state()->IsWhite(to));
-    if (atomic_marking_state()->IsGrey(from)) {
-      bool success = atomic_marking_state()->WhiteToGrey(to);
-      DCHECK(success);
-      USE(success);
-    } else if (atomic_marking_state()->IsBlack(from)) {
-      bool success = atomic_marking_state()->WhiteToBlack(to);
-      DCHECK(success);
-      USE(success);
-    }
-  }
+  V8_INLINE void TransferColor(HeapObject* from, HeapObject* to);
 
   State state() const {
     DCHECK(state_ == STOPPED || FLAG_incremental_marking);
@@ -193,6 +177,7 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
   size_t Step(size_t bytes_to_process, CompletionAction action,
               StepOrigin step_origin,
               WorklistToProcess worklist_to_process = WorklistToProcess::kAll);
+  void EmbedderStep(double duration);
 
   inline void RestartIfNotMarking();
 
@@ -248,8 +233,6 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
     }
   }
 
-  void AbortBlackAllocation();
-
   MarkCompactCollector::MarkingWorklist* marking_worklist() const {
     return marking_worklist_;
   }
diff --git a/deps/v8/src/heap/item-parallel-job.cc b/deps/v8/src/heap/item-parallel-job.cc
index e909ef69d7..b536ccc5d4 100644
--- a/deps/v8/src/heap/item-parallel-job.cc
+++ b/deps/v8/src/heap/item-parallel-job.cc
@@ -58,7 +58,7 @@ ItemParallelJob::~ItemParallelJob() {
   }
 }
 
-void ItemParallelJob::Run(std::shared_ptr<Counters> async_counters) {
+void ItemParallelJob::Run(const std::shared_ptr<Counters>& async_counters) {
   DCHECK_GT(tasks_.size(), 0);
   const size_t num_items = items_.size();
   const size_t num_tasks = tasks_.size();
diff --git a/deps/v8/src/heap/item-parallel-job.h b/deps/v8/src/heap/item-parallel-job.h
index 1ad9d22fa4..15351d5d84 100644
--- a/deps/v8/src/heap/item-parallel-job.h
+++ b/deps/v8/src/heap/item-parallel-job.h
@@ -71,7 +71,7 @@ class V8_EXPORT_PRIVATE ItemParallelJob {
   class V8_EXPORT_PRIVATE Task : public CancelableTask {
    public:
     explicit Task(Isolate* isolate);
-    virtual ~Task();
+    ~Task() override;
 
     virtual void RunInParallel() = 0;
 
@@ -137,7 +137,7 @@ class V8_EXPORT_PRIVATE ItemParallelJob {
 
   // Runs this job. Reporting metrics in a thread-safe manner to
   // |async_counters|.
-  void Run(std::shared_ptr<Counters> async_counters);
+  void Run(const std::shared_ptr<Counters>& async_counters);
 
  private:
   std::vector<Item*> items_;
diff --git a/deps/v8/src/heap/mark-compact-inl.h b/deps/v8/src/heap/mark-compact-inl.h
index 466a89080b..449ca43e50 100644
--- a/deps/v8/src/heap/mark-compact-inl.h
+++ b/deps/v8/src/heap/mark-compact-inl.h
@@ -14,6 +14,28 @@
 namespace v8 {
 namespace internal {
 
+template <typename ConcreteState, AccessMode access_mode>
+bool MarkingStateBase<ConcreteState, access_mode>::GreyToBlack(
+    HeapObject* obj) {
+  MemoryChunk* p = MemoryChunk::FromAddress(obj->address());
+  MarkBit markbit = MarkBitFrom(p, obj->address());
+  if (!Marking::GreyToBlack<access_mode>(markbit)) return false;
+  static_cast<ConcreteState*>(this)->IncrementLiveBytes(p, obj->Size());
+  return true;
+}
+
+template <typename ConcreteState, AccessMode access_mode>
+bool MarkingStateBase<ConcreteState, access_mode>::WhiteToGrey(
+    HeapObject* obj) {
+  return Marking::WhiteToGrey<access_mode>(MarkBitFrom(obj));
+}
+
+template <typename ConcreteState, AccessMode access_mode>
+bool MarkingStateBase<ConcreteState, access_mode>::WhiteToBlack(
+    HeapObject* obj) {
+  return WhiteToGrey(obj) && GreyToBlack(obj);
+}
+
 template <FixedArrayVisitationMode fixed_array_mode,
           TraceRetainingPathMode retaining_path_mode, typename MarkingState>
 MarkingVisitor<fixed_array_mode, retaining_path_mode,
@@ -26,16 +48,6 @@ MarkingVisitor<fixed_array_mode, retaining_path_mode,
 template <FixedArrayVisitationMode fixed_array_mode,
           TraceRetainingPathMode retaining_path_mode, typename MarkingState>
 int MarkingVisitor<fixed_array_mode, retaining_path_mode,
-                   MarkingState>::VisitAllocationSite(Map* map,
-                                                      AllocationSite* object) {
-  int size = AllocationSite::BodyDescriptorWeak::SizeOf(map, object);
-  AllocationSite::BodyDescriptorWeak::IterateBody(map, object, size, this);
-  return size;
-}
-
-template <FixedArrayVisitationMode fixed_array_mode,
-          TraceRetainingPathMode retaining_path_mode, typename MarkingState>
-int MarkingVisitor<fixed_array_mode, retaining_path_mode,
                    MarkingState>::VisitBytecodeArray(Map* map,
                                                      BytecodeArray* array) {
   int size = BytecodeArray::BodyDescriptor::SizeOf(map, array);
@@ -46,15 +58,6 @@ int MarkingVisitor<fixed_array_mode, retaining_path_mode,
 
 template <FixedArrayVisitationMode fixed_array_mode,
           TraceRetainingPathMode retaining_path_mode, typename MarkingState>
-int MarkingVisitor<fixed_array_mode, retaining_path_mode, MarkingState>::
-    VisitCodeDataContainer(Map* map, CodeDataContainer* object) {
-  int size = CodeDataContainer::BodyDescriptorWeak::SizeOf(map, object);
-  CodeDataContainer::BodyDescriptorWeak::IterateBody(map, object, size, this);
-  return size;
-}
-
-template <FixedArrayVisitationMode fixed_array_mode,
-          TraceRetainingPathMode retaining_path_mode, typename MarkingState>
 int MarkingVisitor<fixed_array_mode, retaining_path_mode,
                    MarkingState>::VisitFixedArray(Map* map,
                                                   FixedArray* object) {
@@ -65,25 +68,48 @@ int MarkingVisitor<fixed_array_mode, retaining_path_mode,
 
 template <FixedArrayVisitationMode fixed_array_mode,
           TraceRetainingPathMode retaining_path_mode, typename MarkingState>
-int MarkingVisitor<fixed_array_mode, retaining_path_mode,
-                   MarkingState>::VisitJSApiObject(Map* map, JSObject* object) {
+template <typename T>
+V8_INLINE int
+MarkingVisitor<fixed_array_mode, retaining_path_mode,
+               MarkingState>::VisitEmbedderTracingSubclass(Map* map,
+                                                           T* object) {
   if (heap_->local_embedder_heap_tracer()->InUse()) {
-    DCHECK(object->IsJSObject());
     heap_->TracePossibleWrapper(object);
   }
-  int size = JSObject::BodyDescriptor::SizeOf(map, object);
-  JSObject::BodyDescriptor::IterateBody(map, object, size, this);
+  int size = T::BodyDescriptor::SizeOf(map, object);
+  T::BodyDescriptor::IterateBody(map, object, size, this);
   return size;
 }
 
 template <FixedArrayVisitationMode fixed_array_mode,
           TraceRetainingPathMode retaining_path_mode, typename MarkingState>
 int MarkingVisitor<fixed_array_mode, retaining_path_mode,
-                   MarkingState>::VisitJSFunction(Map* map,
-                                                  JSFunction* object) {
-  int size = JSFunction::BodyDescriptorWeak::SizeOf(map, object);
-  JSFunction::BodyDescriptorWeak::IterateBody(map, object, size, this);
-  return size;
+                   MarkingState>::VisitJSApiObject(Map* map, JSObject* object) {
+  return VisitEmbedderTracingSubclass(map, object);
+}
+
+template <FixedArrayVisitationMode fixed_array_mode,
+          TraceRetainingPathMode retaining_path_mode, typename MarkingState>
+int MarkingVisitor<fixed_array_mode, retaining_path_mode,
+                   MarkingState>::VisitJSArrayBuffer(Map* map,
+                                                     JSArrayBuffer* object) {
+  return VisitEmbedderTracingSubclass(map, object);
+}
+
+template <FixedArrayVisitationMode fixed_array_mode,
+          TraceRetainingPathMode retaining_path_mode, typename MarkingState>
+int MarkingVisitor<fixed_array_mode, retaining_path_mode,
+                   MarkingState>::VisitJSDataView(Map* map,
+                                                  JSDataView* object) {
+  return VisitEmbedderTracingSubclass(map, object);
+}
+
+template <FixedArrayVisitationMode fixed_array_mode,
+          TraceRetainingPathMode retaining_path_mode, typename MarkingState>
+int MarkingVisitor<fixed_array_mode, retaining_path_mode,
+                   MarkingState>::VisitJSTypedArray(Map* map,
+                                                    JSTypedArray* object) {
+  return VisitEmbedderTracingSubclass(map, object);
 }
 
 template <FixedArrayVisitationMode fixed_array_mode,
@@ -141,16 +167,6 @@ int MarkingVisitor<fixed_array_mode, retaining_path_mode,
 template <FixedArrayVisitationMode fixed_array_mode,
           TraceRetainingPathMode retaining_path_mode, typename MarkingState>
 int MarkingVisitor<fixed_array_mode, retaining_path_mode,
-                   MarkingState>::VisitNativeContext(Map* map,
-                                                     Context* context) {
-  int size = Context::BodyDescriptorWeak::SizeOf(map, context);
-  Context::BodyDescriptorWeak::IterateBody(map, context, size, this);
-  return size;
-}
-
-template <FixedArrayVisitationMode fixed_array_mode,
-          TraceRetainingPathMode retaining_path_mode, typename MarkingState>
-int MarkingVisitor<fixed_array_mode, retaining_path_mode,
                    MarkingState>::VisitTransitionArray(Map* map,
                                                        TransitionArray* array) {
   int size = TransitionArray::BodyDescriptor::SizeOf(map, array);
@@ -175,11 +191,11 @@ void MarkingVisitor<fixed_array_mode, retaining_path_mode,
                     MarkingState>::VisitPointer(HeapObject* host,
                                                 MaybeObject** p) {
   HeapObject* target_object;
-  if ((*p)->ToStrongHeapObject(&target_object)) {
+  if ((*p)->GetHeapObjectIfStrong(&target_object)) {
     collector_->RecordSlot(host, reinterpret_cast<HeapObjectReference**>(p),
                            target_object);
     MarkObject(host, target_object);
-  } else if ((*p)->ToWeakHeapObject(&target_object)) {
+  } else if ((*p)->GetHeapObjectIfWeak(&target_object)) {
     if (marking_state()->IsBlackOrGrey(target_object)) {
       // Weak references with live values are directly processed here to reduce
       // the processing time of weak cells during the main GC pause.
diff --git a/deps/v8/src/heap/mark-compact.cc b/deps/v8/src/heap/mark-compact.cc
index dea105943a..6f46bc57bf 100644
--- a/deps/v8/src/heap/mark-compact.cc
+++ b/deps/v8/src/heap/mark-compact.cc
@@ -17,7 +17,7 @@
 #include "src/heap/array-buffer-collector.h"
 #include "src/heap/array-buffer-tracker-inl.h"
 #include "src/heap/gc-tracer.h"
-#include "src/heap/incremental-marking.h"
+#include "src/heap/incremental-marking-inl.h"
 #include "src/heap/invalidated-slots-inl.h"
 #include "src/heap/item-parallel-job.h"
 #include "src/heap/local-allocator-inl.h"
@@ -193,7 +193,7 @@ class FullMarkingVerifier : public MarkingVerifier {
   void VerifyPointers(MaybeObject** start, MaybeObject** end) override {
     for (MaybeObject** current = start; current < end; current++) {
       HeapObject* object;
-      if ((*current)->ToStrongHeapObject(&object)) {
+      if ((*current)->GetHeapObjectIfStrong(&object)) {
         CHECK(marking_state_->IsBlackOrGrey(object));
       }
     }
@@ -309,7 +309,7 @@ class FullEvacuationVerifier : public EvacuationVerifier {
   void VerifyPointers(MaybeObject** start, MaybeObject** end) override {
     for (MaybeObject** current = start; current < end; current++) {
       HeapObject* object;
-      if ((*current)->ToStrongHeapObject(&object)) {
+      if ((*current)->GetHeapObjectIfStrong(&object)) {
         if (Heap::InNewSpace(object)) {
           CHECK(Heap::InToSpace(object));
         }
@@ -514,27 +514,6 @@ void MarkCompactCollector::VerifyMarkbitsAreClean() {
 
 #endif  // VERIFY_HEAP
 
-void MarkCompactCollector::ClearMarkbitsInPagedSpace(PagedSpace* space) {
-  for (Page* p : *space) {
-    non_atomic_marking_state()->ClearLiveness(p);
-  }
-}
-
-void MarkCompactCollector::ClearMarkbitsInNewSpace(NewSpace* space) {
-  for (Page* p : *space) {
-    non_atomic_marking_state()->ClearLiveness(p);
-  }
-}
-
-
-void MarkCompactCollector::ClearMarkbits() {
-  ClearMarkbitsInPagedSpace(heap_->code_space());
-  ClearMarkbitsInPagedSpace(heap_->map_space());
-  ClearMarkbitsInPagedSpace(heap_->old_space());
-  ClearMarkbitsInNewSpace(heap_->new_space());
-  heap_->lo_space()->ClearMarkingStateOfLiveObjects();
-}
-
 void MarkCompactCollector::EnsureSweepingCompleted() {
   if (!sweeper()->sweeping_in_progress()) return;
 
@@ -773,20 +752,6 @@ void MarkCompactCollector::Prepare() {
 
   heap()->memory_allocator()->unmapper()->PrepareForMarkCompact();
 
-  // Clear marking bits if incremental marking is aborted.
-  if (was_marked_incrementally_ && heap_->ShouldAbortIncrementalMarking()) {
-    heap()->incremental_marking()->Stop();
-    heap()->incremental_marking()->AbortBlackAllocation();
-    FinishConcurrentMarking(ConcurrentMarking::StopRequest::PREEMPT_TASKS);
-    heap()->incremental_marking()->Deactivate();
-    ClearMarkbits();
-    AbortWeakObjects();
-    AbortCompaction();
-    heap_->local_embedder_heap_tracer()->AbortTracing();
-    marking_worklist()->Clear();
-    was_marked_incrementally_ = false;
-  }
-
   if (!was_marked_incrementally_) {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_PROLOGUE);
     heap_->local_embedder_heap_tracer()->TracePrologue();
@@ -1024,7 +989,7 @@ class MarkCompactWeakObjectRetainer : public WeakObjectRetainer {
       MarkCompactCollector::NonAtomicMarkingState* marking_state)
       : marking_state_(marking_state) {}
 
-  virtual Object* RetainAs(Object* object) {
+  Object* RetainAs(Object* object) override {
     HeapObject* heap_object = HeapObject::cast(object);
     DCHECK(!marking_state_->IsGrey(heap_object));
     if (marking_state_->IsBlack(heap_object)) {
@@ -1112,7 +1077,7 @@ class RecordMigratedSlotVisitor : public ObjectVisitor {
  protected:
   inline virtual void RecordMigratedSlot(HeapObject* host, MaybeObject* value,
                                          Address slot) {
-    if (value->IsStrongOrWeakHeapObject()) {
+    if (value->IsStrongOrWeak()) {
       Page* p = Page::FromAddress(reinterpret_cast<Address>(value));
       if (p->InNewSpace()) {
         DCHECK_IMPLIES(p->InToSpace(),
@@ -1133,7 +1098,7 @@ class MigrationObserver {
  public:
   explicit MigrationObserver(Heap* heap) : heap_(heap) {}
 
-  virtual ~MigrationObserver() {}
+  virtual ~MigrationObserver() = default;
   virtual void Move(AllocationSpace dest, HeapObject* src, HeapObject* dst,
                     int size) = 0;
 
@@ -1157,7 +1122,7 @@ class ProfilingMigrationObserver final : public MigrationObserver {
 
 class HeapObjectVisitor {
  public:
-  virtual ~HeapObjectVisitor() {}
+  virtual ~HeapObjectVisitor() = default;
   virtual bool Visit(HeapObject* object, int size) = 0;
 };
 
@@ -1387,7 +1352,7 @@ class EvacuateNewSpacePageVisitor final : public HeapObjectVisitor {
     }
   }
 
-  inline bool Visit(HeapObject* object, int size) {
+  inline bool Visit(HeapObject* object, int size) override {
     if (mode == NEW_TO_NEW) {
       heap_->UpdateAllocationSite(object->map(), object,
                                   local_pretenuring_feedback_);
@@ -1429,7 +1394,7 @@ class EvacuateRecordOnlyVisitor final : public HeapObjectVisitor {
  public:
   explicit EvacuateRecordOnlyVisitor(Heap* heap) : heap_(heap) {}
 
-  inline bool Visit(HeapObject* object, int size) {
+  inline bool Visit(HeapObject* object, int size) override {
     RecordMigratedSlotVisitor visitor(heap_->mark_compact_collector());
     object->IterateBodyFast(&visitor);
     return true;
@@ -1633,6 +1598,10 @@ void MarkCompactCollector::ProcessEphemeronsLinear() {
 void MarkCompactCollector::PerformWrapperTracing() {
   if (heap_->local_embedder_heap_tracer()->InUse()) {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_TRACING);
+    HeapObject* object;
+    while (marking_worklist()->embedder()->Pop(kMainThread, &object)) {
+      heap_->TracePossibleWrapper(JSObject::cast(object));
+    }
     heap_->local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer();
     heap_->local_embedder_heap_tracer()->Trace(
         std::numeric_limits<double>::infinity());
@@ -1788,10 +1757,14 @@ void MarkCompactCollector::MarkLiveObjects() {
     // through ephemerons.
     {
       TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPERS);
-      while (!heap_->local_embedder_heap_tracer()->IsRemoteTracingDone()) {
+      do {
+        // PerformWrapperTracing() also empties the work items collected by
+        // concurrent markers. As a result this call needs to happen at least
+        // once.
         PerformWrapperTracing();
         ProcessMarkingWorklist();
-      }
+      } while (!heap_->local_embedder_heap_tracer()->IsRemoteTracingDone());
+      DCHECK(marking_worklist()->IsEmbedderEmpty());
       DCHECK(marking_worklist()->IsEmpty());
     }
 
@@ -1838,6 +1811,7 @@ void MarkCompactCollector::MarkLiveObjects() {
         TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_MARK_WRAPPER_EPILOGUE);
         heap()->local_embedder_heap_tracer()->TraceEpilogue();
       }
+      DCHECK(marking_worklist()->IsEmbedderEmpty());
       DCHECK(marking_worklist()->IsEmpty());
     }
 
@@ -2092,7 +2066,7 @@ void MarkCompactCollector::ClearWeakReferences() {
   while (weak_objects_.weak_references.Pop(kMainThread, &slot)) {
     HeapObject* value;
     HeapObjectReference** location = slot.second;
-    if ((*location)->ToWeakHeapObject(&value)) {
+    if ((*location)->GetHeapObjectIfWeak(&value)) {
       DCHECK(!value->IsCell());
       if (non_atomic_marking_state()->IsBlackOrGrey(value)) {
         // The value of the weak reference is alive.
@@ -2174,9 +2148,9 @@ template <AccessMode access_mode>
 static inline SlotCallbackResult UpdateSlot(MaybeObject** slot) {
   MaybeObject* obj = base::AsAtomicPointer::Relaxed_Load(slot);
   HeapObject* heap_obj;
-  if (obj->ToWeakHeapObject(&heap_obj)) {
+  if (obj->GetHeapObjectIfWeak(&heap_obj)) {
     UpdateSlot<access_mode>(slot, obj, heap_obj, HeapObjectReferenceType::WEAK);
-  } else if (obj->ToStrongHeapObject(&heap_obj)) {
+  } else if (obj->GetHeapObjectIfStrong(&heap_obj)) {
     return UpdateSlot<access_mode>(slot, obj, heap_obj,
                                    HeapObjectReferenceType::STRONG);
   }
@@ -2185,7 +2159,7 @@ static inline SlotCallbackResult UpdateSlot(MaybeObject** slot) {
 
 template <AccessMode access_mode>
 static inline SlotCallbackResult UpdateStrongSlot(MaybeObject** maybe_slot) {
-  DCHECK((*maybe_slot)->IsSmi() || (*maybe_slot)->IsStrongHeapObject());
+  DCHECK((*maybe_slot)->IsSmi() || (*maybe_slot)->IsStrong());
   Object** slot = reinterpret_cast<Object**>(maybe_slot);
   Object* obj = base::AsAtomicPointer::Relaxed_Load(slot);
   if (obj->IsHeapObject()) {
@@ -2248,8 +2222,7 @@ class PointersUpdatingVisitor : public ObjectVisitor, public RootVisitor {
  private:
   static inline SlotCallbackResult UpdateStrongMaybeObjectSlotInternal(
       MaybeObject** slot) {
-    DCHECK(!(*slot)->IsWeakHeapObject());
-    DCHECK(!(*slot)->IsClearedWeakHeapObject());
+    DCHECK(!(*slot)->IsWeakOrCleared());
     return UpdateStrongSlotInternal(reinterpret_cast<Object**>(slot));
   }
 
@@ -2274,9 +2247,11 @@ static String* UpdateReferenceInExternalStringTableEntry(Heap* heap,
     String* new_string = String::cast(map_word.ToForwardingAddress());
 
     if (new_string->IsExternalString()) {
-      heap->ProcessMovedExternalString(
+      MemoryChunk::MoveExternalBackingStoreBytes(
+          ExternalBackingStoreType::kExternalString,
           Page::FromAddress(reinterpret_cast<Address>(*p)),
-          Page::FromHeapObject(new_string), ExternalString::cast(new_string));
+          Page::FromHeapObject(new_string),
+          ExternalString::cast(new_string)->ExternalPayloadSize());
     }
     return new_string;
   }
@@ -2364,7 +2339,7 @@ class Evacuator : public Malloced {
         duration_(0.0),
         bytes_compacted_(0) {}
 
-  virtual ~Evacuator() {}
+  virtual ~Evacuator() = default;
 
   void EvacuatePage(Page* page);
 
@@ -2520,7 +2495,7 @@ void FullEvacuator::RawEvacuatePage(Page* page, intptr_t* live_bytes) {
 class PageEvacuationItem : public ItemParallelJob::Item {
  public:
   explicit PageEvacuationItem(Page* page) : page_(page) {}
-  virtual ~PageEvacuationItem() {}
+  ~PageEvacuationItem() override = default;
   Page* page() const { return page_; }
 
  private:
@@ -2559,11 +2534,7 @@ void MarkCompactCollectorBase::CreateAndExecuteEvacuationTasks(
     compaction_speed = heap()->tracer()->CompactionSpeedInBytesPerMillisecond();
   }
 
-  const bool profiling =
-      heap()->isolate()->is_profiling() ||
-      heap()->isolate()->logger()->is_listening_to_code_events() ||
-      heap()->isolate()->heap_profiler()->is_tracking_object_moves() ||
-      heap()->has_heap_object_allocation_tracker();
+  const bool profiling = isolate()->LogObjectRelocation();
   ProfilingMigrationObserver profiling_observer(heap());
 
   const int wanted_num_tasks =
@@ -2642,7 +2613,7 @@ void MarkCompactCollector::EvacuatePagesInParallel() {
 
 class EvacuationWeakObjectRetainer : public WeakObjectRetainer {
  public:
-  virtual Object* RetainAs(Object* object) {
+  Object* RetainAs(Object* object) override {
     if (object->IsHeapObject()) {
       HeapObject* heap_object = HeapObject::cast(object);
       MapWord map_word = heap_object->map_word();
@@ -2817,7 +2788,7 @@ void MarkCompactCollector::Evacuate() {
 
 class UpdatingItem : public ItemParallelJob::Item {
  public:
-  virtual ~UpdatingItem() {}
+  ~UpdatingItem() override = default;
   virtual void Process() = 0;
 };
 
@@ -2852,7 +2823,7 @@ class ToSpaceUpdatingItem : public UpdatingItem {
         start_(start),
         end_(end),
         marking_state_(marking_state) {}
-  virtual ~ToSpaceUpdatingItem() {}
+  ~ToSpaceUpdatingItem() override = default;
 
   void Process() override {
     if (chunk_->IsFlagSet(Page::PAGE_NEW_NEW_PROMOTION)) {
@@ -2906,7 +2877,7 @@ class RememberedSetUpdatingItem : public UpdatingItem {
         marking_state_(marking_state),
         chunk_(chunk),
         updating_mode_(updating_mode) {}
-  virtual ~RememberedSetUpdatingItem() {}
+  ~RememberedSetUpdatingItem() override = default;
 
   void Process() override {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
@@ -2921,7 +2892,7 @@ class RememberedSetUpdatingItem : public UpdatingItem {
   inline SlotCallbackResult CheckAndUpdateOldToNewSlot(Address slot_address) {
     MaybeObject** slot = reinterpret_cast<MaybeObject**>(slot_address);
     HeapObject* heap_object;
-    if (!(*slot)->ToStrongOrWeakHeapObject(&heap_object)) {
+    if (!(*slot)->GetHeapObject(&heap_object)) {
       return REMOVE_SLOT;
     }
     if (Heap::InFromSpace(heap_object)) {
@@ -2931,7 +2902,7 @@ class RememberedSetUpdatingItem : public UpdatingItem {
             reinterpret_cast<HeapObjectReference**>(slot),
             map_word.ToForwardingAddress());
       }
-      bool success = (*slot)->ToStrongOrWeakHeapObject(&heap_object);
+      bool success = (*slot)->GetHeapObject(&heap_object);
       USE(success);
       DCHECK(success);
       // If the object was in from space before and is after executing the
@@ -3054,7 +3025,7 @@ class GlobalHandlesUpdatingItem : public UpdatingItem {
         global_handles_(global_handles),
         start_(start),
         end_(end) {}
-  virtual ~GlobalHandlesUpdatingItem() {}
+  ~GlobalHandlesUpdatingItem() override = default;
 
   void Process() override {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
@@ -3081,7 +3052,7 @@ class ArrayBufferTrackerUpdatingItem : public UpdatingItem {
 
   explicit ArrayBufferTrackerUpdatingItem(Page* page, EvacuationState state)
       : page_(page), state_(state) {}
-  virtual ~ArrayBufferTrackerUpdatingItem() {}
+  ~ArrayBufferTrackerUpdatingItem() override = default;
 
   void Process() override {
     TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
@@ -3255,7 +3226,7 @@ void MarkCompactCollector::UpdatePointersAfterEvacuation() {
             GCTracer::BackgroundScope::MC_BACKGROUND_EVACUATE_UPDATE_POINTERS));
       }
       updating_job.Run(isolate()->async_counters());
-      heap()->array_buffer_collector()->FreeAllocationsOnBackgroundThread();
+      heap()->array_buffer_collector()->FreeAllocations();
     }
   }
 
@@ -3426,8 +3397,9 @@ void MarkCompactCollector::MarkingWorklist::PrintWorklist(
     count[obj->map()->instance_type()]++;
   });
   std::vector<std::pair<int, InstanceType>> rank;
-  for (auto i : count) {
-    rank.push_back(std::make_pair(i.second, i.first));
+  rank.reserve(count.size());
+  for (const auto& i : count) {
+    rank.emplace_back(i.second, i.first);
   }
   std::map<InstanceType, std::string> instance_type_name;
 #define INSTANCE_TYPE_NAME(name) instance_type_name[name] = #name;
@@ -3486,7 +3458,7 @@ class YoungGenerationMarkingVerifier : public MarkingVerifier {
     for (MaybeObject** current = start; current < end; current++) {
       HeapObject* object;
       // Minor MC treats weak references as strong.
-      if ((*current)->ToStrongOrWeakHeapObject(&object)) {
+      if ((*current)->GetHeapObject(&object)) {
         if (!Heap::InNewSpace(object)) {
           continue;
         }
@@ -3524,7 +3496,7 @@ class YoungGenerationEvacuationVerifier : public EvacuationVerifier {
   void VerifyPointers(MaybeObject** start, MaybeObject** end) override {
     for (MaybeObject** current = start; current < end; current++) {
       HeapObject* object;
-      if ((*current)->ToStrongOrWeakHeapObject(&object)) {
+      if ((*current)->GetHeapObject(&object)) {
         CHECK_IMPLIES(Heap::InNewSpace(object), Heap::InToSpace(object));
       }
     }
@@ -3593,7 +3565,7 @@ class YoungGenerationMarkingVisitor final
       HeapObject* target_object;
       // Treat weak references as strong. TODO(marja): Proper weakness handling
       // for minor-mcs.
-      if (target->ToStrongOrWeakHeapObject(&target_object)) {
+      if (target->GetHeapObject(&target_object)) {
         MarkObjectViaMarkingWorklist(target_object);
       }
     }
@@ -3697,7 +3669,7 @@ class YoungGenerationRecordMigratedSlotVisitor final
 
   inline void RecordMigratedSlot(HeapObject* host, MaybeObject* value,
                                  Address slot) final {
-    if (value->IsStrongOrWeakHeapObject()) {
+    if (value->IsStrongOrWeak()) {
       Page* p = Page::FromAddress(reinterpret_cast<Address>(value));
       if (p->InNewSpace()) {
         DCHECK_IMPLIES(p->InToSpace(),
@@ -3758,7 +3730,7 @@ void MinorMarkCompactCollector::UpdatePointersAfterEvacuation() {
     TRACE_GC(heap()->tracer(),
              GCTracer::Scope::MINOR_MC_EVACUATE_UPDATE_POINTERS_SLOTS);
     updating_job.Run(isolate()->async_counters());
-    heap()->array_buffer_collector()->FreeAllocationsOnBackgroundThread();
+    heap()->array_buffer_collector()->FreeAllocations();
   }
 
   {
@@ -3949,7 +3921,7 @@ class MinorMarkCompactWeakObjectRetainer : public WeakObjectRetainer {
       MinorMarkCompactCollector* collector)
       : marking_state_(collector->non_atomic_marking_state()) {}
 
-  virtual Object* RetainAs(Object* object) {
+  Object* RetainAs(Object* object) override {
     HeapObject* heap_object = HeapObject::cast(object);
     if (!Heap::InNewSpace(heap_object)) return object;
 
@@ -4024,7 +3996,7 @@ class YoungGenerationMarkingTask;
 
 class MarkingItem : public ItemParallelJob::Item {
  public:
-  virtual ~MarkingItem() {}
+  ~MarkingItem() override = default;
   virtual void Process(YoungGenerationMarkingTask* task) = 0;
 };
 
@@ -4112,7 +4084,7 @@ class PageMarkingItem : public MarkingItem {
  public:
   explicit PageMarkingItem(MemoryChunk* chunk, std::atomic<int>* global_slots)
       : chunk_(chunk), global_slots_(global_slots), slots_(0) {}
-  virtual ~PageMarkingItem() { *global_slots_ = *global_slots_ + slots_; }
+  ~PageMarkingItem() override { *global_slots_ = *global_slots_ + slots_; }
 
   void Process(YoungGenerationMarkingTask* task) override {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
@@ -4152,7 +4124,7 @@ class PageMarkingItem : public MarkingItem {
       // has to be in ToSpace.
       DCHECK(Heap::InToSpace(object));
       HeapObject* heap_object;
-      bool success = object->ToStrongOrWeakHeapObject(&heap_object);
+      bool success = object->GetHeapObject(&heap_object);
       USE(success);
       DCHECK(success);
       task->MarkObject(heap_object);
@@ -4172,7 +4144,7 @@ class GlobalHandlesMarkingItem : public MarkingItem {
   GlobalHandlesMarkingItem(Heap* heap, GlobalHandles* global_handles,
                            size_t start, size_t end)
       : global_handles_(global_handles), start_(start), end_(end) {}
-  virtual ~GlobalHandlesMarkingItem() {}
+  ~GlobalHandlesMarkingItem() override = default;
 
   void Process(YoungGenerationMarkingTask* task) override {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.gc"),
diff --git a/deps/v8/src/heap/mark-compact.h b/deps/v8/src/heap/mark-compact.h
index d62c964336..c4ab5b2b9c 100644
--- a/deps/v8/src/heap/mark-compact.h
+++ b/deps/v8/src/heap/mark-compact.h
@@ -63,21 +63,9 @@ class MarkingStateBase {
     return Marking::IsBlackOrGrey<access_mode>(MarkBitFrom(obj));
   }
 
-  V8_INLINE bool WhiteToGrey(HeapObject* obj) {
-    return Marking::WhiteToGrey<access_mode>(MarkBitFrom(obj));
-  }
-
-  V8_INLINE bool WhiteToBlack(HeapObject* obj) {
-    return WhiteToGrey(obj) && GreyToBlack(obj);
-  }
-
-  V8_INLINE bool GreyToBlack(HeapObject* obj) {
-    MemoryChunk* p = MemoryChunk::FromAddress(obj->address());
-    MarkBit markbit = MarkBitFrom(p, obj->address());
-    if (!Marking::GreyToBlack<access_mode>(markbit)) return false;
-    static_cast<ConcreteState*>(this)->IncrementLiveBytes(p, obj->Size());
-    return true;
-  }
+  V8_INLINE bool WhiteToGrey(HeapObject* obj);
+  V8_INLINE bool WhiteToBlack(HeapObject* obj);
+  V8_INLINE bool GreyToBlack(HeapObject* obj);
 
   void ClearLiveness(MemoryChunk* chunk) {
     static_cast<ConcreteState*>(this)->bitmap(chunk)->Clear();
@@ -250,7 +238,7 @@ enum class RememberedSetUpdatingMode { ALL, OLD_TO_NEW_ONLY };
 // Base class for minor and full MC collectors.
 class MarkCompactCollectorBase {
  public:
-  virtual ~MarkCompactCollectorBase() {}
+  virtual ~MarkCompactCollectorBase() = default;
 
   virtual void SetUp() = 0;
   virtual void TearDown() = 0;
@@ -464,11 +452,14 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
 #else
   using MarkingState = MajorNonAtomicMarkingState;
 #endif  // V8_CONCURRENT_MARKING
+
   using NonAtomicMarkingState = MajorNonAtomicMarkingState;
+
   // Wrapper for the shared and bailout worklists.
   class MarkingWorklist {
    public:
     using ConcurrentMarkingWorklist = Worklist<HeapObject*, 64>;
+    using EmbedderTracingWorklist = Worklist<HeapObject*, 16>;
 
     // The heap parameter is not used but needed to match the sequential case.
     explicit MarkingWorklist(Heap* heap) {}
@@ -500,8 +491,8 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
     }
 
     HeapObject* PopBailout() {
-      HeapObject* result;
 #ifdef V8_CONCURRENT_MARKING
+      HeapObject* result;
       if (bailout_.Pop(kMainThread, &result)) return result;
 #endif
       return nullptr;
@@ -511,6 +502,7 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
       bailout_.Clear();
       shared_.Clear();
       on_hold_.Clear();
+      embedder_.Clear();
     }
 
     bool IsBailoutEmpty() { return bailout_.IsLocalEmpty(kMainThread); }
@@ -523,6 +515,11 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
              on_hold_.IsGlobalPoolEmpty();
     }
 
+    bool IsEmbedderEmpty() {
+      return embedder_.IsLocalEmpty(kMainThread) &&
+             embedder_.IsGlobalPoolEmpty();
+    }
+
     int Size() {
       return static_cast<int>(bailout_.LocalSize(kMainThread) +
                               shared_.LocalSize(kMainThread) +
@@ -538,11 +535,13 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
       bailout_.Update(callback);
       shared_.Update(callback);
       on_hold_.Update(callback);
+      embedder_.Update(callback);
     }
 
     ConcurrentMarkingWorklist* shared() { return &shared_; }
     ConcurrentMarkingWorklist* bailout() { return &bailout_; }
     ConcurrentMarkingWorklist* on_hold() { return &on_hold_; }
+    EmbedderTracingWorklist* embedder() { return &embedder_; }
 
     void Print() {
       PrintWorklist("shared", &shared_);
@@ -568,6 +567,11 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
     // for new space. This allow the compiler to remove write barriers
     // for freshly allocatd objects.
     ConcurrentMarkingWorklist on_hold_;
+
+    // Worklist for objects that potentially require embedder tracing, i.e.,
+    // these objects need to be handed over to the embedder to find the full
+    // transitive closure.
+    EmbedderTracingWorklist embedder_;
   };
 
   class RootMarkingVisitor;
@@ -626,8 +630,6 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
   void UpdateSlots(SlotsBuffer* buffer);
   void UpdateSlotsRecordedIn(SlotsBuffer* buffer);
 
-  void ClearMarkbits();
-
   bool is_compacting() const { return compacting_; }
 
   // Ensures that sweeping is finished.
@@ -703,7 +705,7 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
 
  private:
   explicit MarkCompactCollector(Heap* heap);
-  ~MarkCompactCollector();
+  ~MarkCompactCollector() override;
 
   bool WillBeDeoptimized(Code* code);
 
@@ -835,9 +837,6 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
   void PostProcessEvacuationCandidates();
   void ReportAbortedEvacuationCandidate(HeapObject* failed_object, Page* page);
 
-  void ClearMarkbitsInPagedSpace(PagedSpace* space);
-  void ClearMarkbitsInNewSpace(NewSpace* space);
-
   static const int kEphemeronChunkSize = 8 * KB;
 
   int NumberOfParallelEphemeronVisitingTasks(size_t elements);
@@ -910,15 +909,14 @@ class MarkingVisitor final
 
   V8_INLINE bool ShouldVisitMapPointer() { return false; }
 
-  V8_INLINE int VisitAllocationSite(Map* map, AllocationSite* object);
   V8_INLINE int VisitBytecodeArray(Map* map, BytecodeArray* object);
-  V8_INLINE int VisitCodeDataContainer(Map* map, CodeDataContainer* object);
   V8_INLINE int VisitEphemeronHashTable(Map* map, EphemeronHashTable* object);
   V8_INLINE int VisitFixedArray(Map* map, FixedArray* object);
   V8_INLINE int VisitJSApiObject(Map* map, JSObject* object);
-  V8_INLINE int VisitJSFunction(Map* map, JSFunction* object);
+  V8_INLINE int VisitJSArrayBuffer(Map* map, JSArrayBuffer* object);
+  V8_INLINE int VisitJSDataView(Map* map, JSDataView* object);
+  V8_INLINE int VisitJSTypedArray(Map* map, JSTypedArray* object);
   V8_INLINE int VisitMap(Map* map, Map* object);
-  V8_INLINE int VisitNativeContext(Map* map, Context* object);
   V8_INLINE int VisitTransitionArray(Map* map, TransitionArray* object);
 
   // ObjectVisitor implementation.
@@ -931,6 +929,11 @@ class MarkingVisitor final
   V8_INLINE void VisitEmbeddedPointer(Code* host, RelocInfo* rinfo) final;
   V8_INLINE void VisitCodeTarget(Code* host, RelocInfo* rinfo) final;
 
+  // Weak list pointers should be ignored during marking. The lists are
+  // reconstructed after GC.
+  void VisitCustomWeakPointers(HeapObject* host, Object** start,
+                               Object** end) final {}
+
  private:
   // Granularity in which FixedArrays are scanned if |fixed_array_mode|
   // is true.
@@ -938,6 +941,9 @@ class MarkingVisitor final
 
   V8_INLINE int VisitFixedArrayIncremental(Map* map, FixedArray* object);
 
+  template <typename T>
+  V8_INLINE int VisitEmbedderTracingSubclass(Map* map, T* object);
+
   V8_INLINE void MarkMapContents(Map* map);
 
   // Marks the object black without pushing it on the marking work list. Returns
@@ -980,7 +986,7 @@ class MinorMarkCompactCollector final : public MarkCompactCollectorBase {
   using NonAtomicMarkingState = MinorNonAtomicMarkingState;
 
   explicit MinorMarkCompactCollector(Heap* heap);
-  ~MinorMarkCompactCollector();
+  ~MinorMarkCompactCollector() override;
 
   MarkingState* marking_state() { return &marking_state_; }
 
diff --git a/deps/v8/src/heap/marking.cc b/deps/v8/src/heap/marking.cc
index 23fbdd3465..93b5c06a45 100644
--- a/deps/v8/src/heap/marking.cc
+++ b/deps/v8/src/heap/marking.cc
@@ -28,6 +28,9 @@ void Bitmap::MarkAllBits() {
 }
 
 void Bitmap::SetRange(uint32_t start_index, uint32_t end_index) {
+  if (start_index >= end_index) return;
+  end_index--;
+
   unsigned int start_cell_index = start_index >> Bitmap::kBitsPerCellLog2;
   MarkBit::CellType start_index_mask = 1u << Bitmap::IndexInCell(start_index);
   unsigned int end_cell_index = end_index >> Bitmap::kBitsPerCellLog2;
@@ -43,10 +46,11 @@ void Bitmap::SetRange(uint32_t start_index, uint32_t end_index) {
       base::Relaxed_Store(cell_base + i, ~0u);
     }
     // Finally, fill all bits until the end address in the last cell with 1s.
-    SetBitsInCell<AccessMode::ATOMIC>(end_cell_index, (end_index_mask - 1));
+    SetBitsInCell<AccessMode::ATOMIC>(end_cell_index,
+                                      end_index_mask | (end_index_mask - 1));
   } else {
-    SetBitsInCell<AccessMode::ATOMIC>(start_cell_index,
-                                      end_index_mask - start_index_mask);
+    SetBitsInCell<AccessMode::ATOMIC>(
+        start_cell_index, end_index_mask | (end_index_mask - start_index_mask));
   }
   // This fence prevents re-ordering of publishing stores with the mark-
   // bit setting stores.
@@ -54,6 +58,9 @@ void Bitmap::SetRange(uint32_t start_index, uint32_t end_index) {
 }
 
 void Bitmap::ClearRange(uint32_t start_index, uint32_t end_index) {
+  if (start_index >= end_index) return;
+  end_index--;
+
   unsigned int start_cell_index = start_index >> Bitmap::kBitsPerCellLog2;
   MarkBit::CellType start_index_mask = 1u << Bitmap::IndexInCell(start_index);
 
@@ -71,10 +78,11 @@ void Bitmap::ClearRange(uint32_t start_index, uint32_t end_index) {
       base::Relaxed_Store(cell_base + i, 0);
     }
     // Finally, set all bits until the end address in the last cell with 0s.
-    ClearBitsInCell<AccessMode::ATOMIC>(end_cell_index, (end_index_mask - 1));
+    ClearBitsInCell<AccessMode::ATOMIC>(end_cell_index,
+                                        end_index_mask | (end_index_mask - 1));
   } else {
-    ClearBitsInCell<AccessMode::ATOMIC>(start_cell_index,
-                                        (end_index_mask - start_index_mask));
+    ClearBitsInCell<AccessMode::ATOMIC>(
+        start_cell_index, end_index_mask | (end_index_mask - start_index_mask));
   }
   // This fence prevents re-ordering of publishing stores with the mark-
   // bit clearing stores.
@@ -82,6 +90,9 @@ void Bitmap::ClearRange(uint32_t start_index, uint32_t end_index) {
 }
 
 bool Bitmap::AllBitsSetInRange(uint32_t start_index, uint32_t end_index) {
+  if (start_index >= end_index) return false;
+  end_index--;
+
   unsigned int start_cell_index = start_index >> Bitmap::kBitsPerCellLog2;
   MarkBit::CellType start_index_mask = 1u << Bitmap::IndexInCell(start_index);
 
@@ -97,21 +108,18 @@ bool Bitmap::AllBitsSetInRange(uint32_t start_index, uint32_t end_index) {
     for (unsigned int i = start_cell_index + 1; i < end_cell_index; i++) {
       if (cells()[i] != ~0u) return false;
     }
-    matching_mask = (end_index_mask - 1);
-    // Check against a mask of 0 to avoid dereferencing the cell after the
-    // end of the bitmap.
-    return (matching_mask == 0) ||
-           ((cells()[end_cell_index] & matching_mask) == matching_mask);
+    matching_mask = end_index_mask | (end_index_mask - 1);
+    return ((cells()[end_cell_index] & matching_mask) == matching_mask);
   } else {
-    matching_mask = end_index_mask - start_index_mask;
-    // Check against a mask of 0 to avoid dereferencing the cell after the
-    // end of the bitmap.
-    return (matching_mask == 0) ||
-           (cells()[end_cell_index] & matching_mask) == matching_mask;
+    matching_mask = end_index_mask | (end_index_mask - start_index_mask);
+    return (cells()[end_cell_index] & matching_mask) == matching_mask;
   }
 }
 
 bool Bitmap::AllBitsClearInRange(uint32_t start_index, uint32_t end_index) {
+  if (start_index >= end_index) return true;
+  end_index--;
+
   unsigned int start_cell_index = start_index >> Bitmap::kBitsPerCellLog2;
   MarkBit::CellType start_index_mask = 1u << Bitmap::IndexInCell(start_index);
 
@@ -125,15 +133,11 @@ bool Bitmap::AllBitsClearInRange(uint32_t start_index, uint32_t end_index) {
     for (unsigned int i = start_cell_index + 1; i < end_cell_index; i++) {
       if (cells()[i]) return false;
     }
-    matching_mask = (end_index_mask - 1);
-    // Check against a mask of 0 to avoid dereferencing the cell after the
-    // end of the bitmap.
-    return (matching_mask == 0) || !(cells()[end_cell_index] & matching_mask);
+    matching_mask = end_index_mask | (end_index_mask - 1);
+    return !(cells()[end_cell_index] & matching_mask);
   } else {
-    matching_mask = end_index_mask - start_index_mask;
-    // Check against a mask of 0 to avoid dereferencing the cell after the
-    // end of the bitmap.
-    return (matching_mask == 0) || !(cells()[end_cell_index] & matching_mask);
+    matching_mask = end_index_mask | (end_index_mask - start_index_mask);
+    return !(cells()[end_cell_index] & matching_mask);
   }
 }
 
diff --git a/deps/v8/src/heap/object-stats.cc b/deps/v8/src/heap/object-stats.cc
index ac7bcb8087..bb069d19f4 100644
--- a/deps/v8/src/heap/object-stats.cc
+++ b/deps/v8/src/heap/object-stats.cc
@@ -547,7 +547,7 @@ void ObjectStatsCollectorImpl::RecordVirtualJSObjectDetails(JSObject* object) {
 
 static ObjectStats::VirtualInstanceType GetFeedbackSlotType(
     MaybeObject* maybe_obj, FeedbackSlotKind kind, Isolate* isolate) {
-  if (maybe_obj->IsClearedWeakHeapObject())
+  if (maybe_obj->IsCleared())
     return ObjectStats::FEEDBACK_VECTOR_SLOT_OTHER_TYPE;
   Object* obj = maybe_obj->GetHeapObjectOrSmi();
   switch (kind) {
@@ -623,11 +623,12 @@ void ObjectStatsCollectorImpl::RecordVirtualFeedbackVectorDetails(
       // Log the monomorphic/polymorphic helper objects that this slot owns.
       for (int i = 0; i < it.entry_size(); i++) {
         MaybeObject* raw_object = vector->get(slot.ToInt() + i);
-        if (!raw_object->IsStrongOrWeakHeapObject()) continue;
-        HeapObject* object = raw_object->GetHeapObject();
-        if (object->IsCell() || object->IsWeakFixedArray()) {
-          RecordSimpleVirtualObjectStats(
-              vector, object, ObjectStats::FEEDBACK_VECTOR_ENTRY_TYPE);
+        HeapObject* object;
+        if (raw_object->GetHeapObject(&object)) {
+          if (object->IsCell() || object->IsWeakFixedArray()) {
+            RecordSimpleVirtualObjectStats(
+                vector, object, ObjectStats::FEEDBACK_VECTOR_ENTRY_TYPE);
+          }
         }
       }
     }
@@ -677,8 +678,6 @@ void ObjectStatsCollectorImpl::CollectStatistics(
         RecordVirtualContext(Context::cast(obj));
       } else if (obj->IsScript()) {
         RecordVirtualScriptDetails(Script::cast(obj));
-      } else if (obj->IsExternalString()) {
-        RecordVirtualExternalStringDetails(ExternalString::cast(obj));
       } else if (obj->IsArrayBoilerplateDescription()) {
         RecordVirtualArrayBoilerplateDescription(
             ArrayBoilerplateDescription::cast(obj));
@@ -688,6 +687,11 @@ void ObjectStatsCollectorImpl::CollectStatistics(
       }
       break;
     case kPhase2:
+      if (obj->IsExternalString()) {
+        // This has to be in Phase2 to avoid conflicting with recording Script
+        // sources. We still want to run RecordObjectStats after though.
+        RecordVirtualExternalStringDetails(ExternalString::cast(obj));
+      }
       RecordObjectStats(obj, map->instance_type(), obj->Size());
       if (collect_field_stats == CollectFieldStats::kYes) {
         field_stats_collector_.RecordStats(obj);
@@ -808,7 +812,7 @@ void ObjectStatsCollectorImpl::RecordVirtualScriptDetails(Script* script) {
   } else if (raw_source->IsString()) {
     String* source = String::cast(raw_source);
     RecordSimpleVirtualObjectStats(
-        script, HeapObject::cast(raw_source),
+        script, source,
         source->IsOneByteRepresentation()
             ? ObjectStats::SCRIPT_SOURCE_NON_EXTERNAL_ONE_BYTE_TYPE
             : ObjectStats::SCRIPT_SOURCE_NON_EXTERNAL_TWO_BYTE_TYPE);
diff --git a/deps/v8/src/heap/objects-visiting-inl.h b/deps/v8/src/heap/objects-visiting-inl.h
index f32bbc1914..c7a4f70f01 100644
--- a/deps/v8/src/heap/objects-visiting-inl.h
+++ b/deps/v8/src/heap/objects-visiting-inl.h
@@ -170,15 +170,6 @@ ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitFreeSpace(
 }
 
 template <typename ConcreteVisitor>
-int NewSpaceVisitor<ConcreteVisitor>::VisitJSFunction(Map* map,
-                                                      JSFunction* object) {
-  ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
-  int size = JSFunction::BodyDescriptorWeak::SizeOf(map, object);
-  JSFunction::BodyDescriptorWeak::IterateBody(map, object, size, visitor);
-  return size;
-}
-
-template <typename ConcreteVisitor>
 int NewSpaceVisitor<ConcreteVisitor>::VisitNativeContext(Map* map,
                                                          Context* object) {
   ConcreteVisitor* visitor = static_cast<ConcreteVisitor*>(this);
diff --git a/deps/v8/src/heap/objects-visiting.h b/deps/v8/src/heap/objects-visiting.h
index 63ef8fb353..147af52c7e 100644
--- a/deps/v8/src/heap/objects-visiting.h
+++ b/deps/v8/src/heap/objects-visiting.h
@@ -21,7 +21,9 @@ class BigInt;
 class BytecodeArray;
 class DataHandler;
 class JSArrayBuffer;
+class JSDataView;
 class JSRegExp;
+class JSTypedArray;
 class JSWeakCollection;
 class UncompiledDataWithoutPreParsedScope;
 class UncompiledDataWithPreParsedScope;
@@ -44,8 +46,9 @@ class UncompiledDataWithPreParsedScope;
   V(FixedFloat64Array)                   \
   V(FixedTypedArrayBase)                 \
   V(JSArrayBuffer)                       \
-  V(JSFunction)                          \
+  V(JSDataView)                          \
   V(JSObject)                            \
+  V(JSTypedArray)                        \
   V(JSWeakCollection)                    \
   V(Map)                                 \
   V(Oddball)                             \
@@ -119,7 +122,6 @@ class NewSpaceVisitor : public HeapVisitor<int, ConcreteVisitor> {
 
   // Special cases for young generation.
 
-  V8_INLINE int VisitJSFunction(Map* map, JSFunction* object);
   V8_INLINE int VisitNativeContext(Map* map, Context* object);
   V8_INLINE int VisitJSApiObject(Map* map, JSObject* object);
 
diff --git a/deps/v8/src/heap/scavenge-job.cc b/deps/v8/src/heap/scavenge-job.cc
index 9feebbf4d5..5848d5342e 100644
--- a/deps/v8/src/heap/scavenge-job.cc
+++ b/deps/v8/src/heap/scavenge-job.cc
@@ -107,8 +107,9 @@ void ScavengeJob::ScheduleIdleTask(Heap* heap) {
     v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap->isolate());
     if (V8::GetCurrentPlatform()->IdleTasksEnabled(isolate)) {
       idle_task_pending_ = true;
-      auto task = new IdleTask(heap->isolate(), this);
-      V8::GetCurrentPlatform()->CallIdleOnForegroundThread(isolate, task);
+      auto task = base::make_unique<IdleTask>(heap->isolate(), this);
+      V8::GetCurrentPlatform()->GetForegroundTaskRunner(isolate)->PostIdleTask(
+          std::move(task));
     }
   }
 }
diff --git a/deps/v8/src/heap/scavenger-inl.h b/deps/v8/src/heap/scavenger-inl.h
index 649292085a..376b5e75aa 100644
--- a/deps/v8/src/heap/scavenger-inl.h
+++ b/deps/v8/src/heap/scavenger-inl.h
@@ -7,6 +7,7 @@
 
 #include "src/heap/scavenger.h"
 
+#include "src/heap/incremental-marking-inl.h"
 #include "src/heap/local-allocator-inl.h"
 #include "src/objects-inl.h"
 #include "src/objects/map.h"
@@ -14,6 +15,81 @@
 namespace v8 {
 namespace internal {
 
+void Scavenger::PromotionList::View::PushRegularObject(HeapObject* object,
+                                                       int size) {
+  promotion_list_->PushRegularObject(task_id_, object, size);
+}
+
+void Scavenger::PromotionList::View::PushLargeObject(HeapObject* object,
+                                                     Map* map, int size) {
+  promotion_list_->PushLargeObject(task_id_, object, map, size);
+}
+
+bool Scavenger::PromotionList::View::IsEmpty() {
+  return promotion_list_->IsEmpty();
+}
+
+size_t Scavenger::PromotionList::View::LocalPushSegmentSize() {
+  return promotion_list_->LocalPushSegmentSize(task_id_);
+}
+
+bool Scavenger::PromotionList::View::Pop(struct PromotionListEntry* entry) {
+  return promotion_list_->Pop(task_id_, entry);
+}
+
+bool Scavenger::PromotionList::View::IsGlobalPoolEmpty() {
+  return promotion_list_->IsGlobalPoolEmpty();
+}
+
+bool Scavenger::PromotionList::View::ShouldEagerlyProcessPromotionList() {
+  return promotion_list_->ShouldEagerlyProcessPromotionList(task_id_);
+}
+
+void Scavenger::PromotionList::PushRegularObject(int task_id,
+                                                 HeapObject* object, int size) {
+  regular_object_promotion_list_.Push(task_id, ObjectAndSize(object, size));
+}
+
+void Scavenger::PromotionList::PushLargeObject(int task_id, HeapObject* object,
+                                               Map* map, int size) {
+  large_object_promotion_list_.Push(task_id, {object, map, size});
+}
+
+bool Scavenger::PromotionList::IsEmpty() {
+  return regular_object_promotion_list_.IsEmpty() &&
+         large_object_promotion_list_.IsEmpty();
+}
+
+size_t Scavenger::PromotionList::LocalPushSegmentSize(int task_id) {
+  return regular_object_promotion_list_.LocalPushSegmentSize(task_id) +
+         large_object_promotion_list_.LocalPushSegmentSize(task_id);
+}
+
+bool Scavenger::PromotionList::Pop(int task_id,
+                                   struct PromotionListEntry* entry) {
+  ObjectAndSize regular_object;
+  if (regular_object_promotion_list_.Pop(task_id, &regular_object)) {
+    entry->heap_object = regular_object.first;
+    entry->size = regular_object.second;
+    entry->map = entry->heap_object->map();
+    return true;
+  }
+  return large_object_promotion_list_.Pop(task_id, entry);
+}
+
+bool Scavenger::PromotionList::IsGlobalPoolEmpty() {
+  return regular_object_promotion_list_.IsGlobalPoolEmpty() &&
+         large_object_promotion_list_.IsGlobalPoolEmpty();
+}
+
+bool Scavenger::PromotionList::ShouldEagerlyProcessPromotionList(int task_id) {
+  // Threshold when to prioritize processing of the promotion list. Right
+  // now we only look into the regular object list.
+  const int kProcessPromotionListThreshold =
+      kRegularObjectPromotionListSegmentSize / 2;
+  return LocalPushSegmentSize(task_id) < kProcessPromotionListThreshold;
+}
+
 // White list for objects that for sure only contain data.
 bool Scavenger::ContainsOnlyData(VisitorId visitor_id) {
   switch (visitor_id) {
@@ -38,7 +114,7 @@ void Scavenger::PageMemoryFence(MaybeObject* object) {
   // Perform a dummy acquire load to tell TSAN that there is no data race
   // with  page initialization.
   HeapObject* heap_object;
-  if (object->ToStrongOrWeakHeapObject(&heap_object)) {
+  if (object->GetHeapObject(&heap_object)) {
     MemoryChunk* chunk = MemoryChunk::FromAddress(heap_object->address());
     CHECK_NOT_NULL(chunk->synchronized_heap());
   }
@@ -71,8 +147,10 @@ bool Scavenger::MigrateObject(Map* map, HeapObject* source, HeapObject* target,
   return true;
 }
 
-bool Scavenger::SemiSpaceCopyObject(Map* map, HeapObjectReference** slot,
-                                    HeapObject* object, int object_size) {
+CopyAndForwardResult Scavenger::SemiSpaceCopyObject(Map* map,
+                                                    HeapObjectReference** slot,
+                                                    HeapObject* object,
+                                                    int object_size) {
   DCHECK(heap()->AllowedToBeMigrated(object, NEW_SPACE));
   AllocationAlignment alignment = HeapObject::RequiredAlignment(map);
   AllocationResult allocation =
@@ -85,21 +163,26 @@ bool Scavenger::SemiSpaceCopyObject(Map* map, HeapObjectReference** slot,
     const bool self_success = MigrateObject(map, object, target, object_size);
     if (!self_success) {
       allocator_.FreeLast(NEW_SPACE, target, object_size);
-      MapWord map_word = object->map_word();
+      MapWord map_word = object->synchronized_map_word();
       HeapObjectReference::Update(slot, map_word.ToForwardingAddress());
-      return true;
+      DCHECK(!Heap::InFromSpace(*slot));
+      return Heap::InToSpace(*slot)
+                 ? CopyAndForwardResult::SUCCESS_YOUNG_GENERATION
+                 : CopyAndForwardResult::SUCCESS_OLD_GENERATION;
     }
     HeapObjectReference::Update(slot, target);
 
     copied_list_.Push(ObjectAndSize(target, object_size));
     copied_size_ += object_size;
-    return true;
+    return CopyAndForwardResult::SUCCESS_YOUNG_GENERATION;
   }
-  return false;
+  return CopyAndForwardResult::FAILURE;
 }
 
-bool Scavenger::PromoteObject(Map* map, HeapObjectReference** slot,
-                              HeapObject* object, int object_size) {
+CopyAndForwardResult Scavenger::PromoteObject(Map* map,
+                                              HeapObjectReference** slot,
+                                              HeapObject* object,
+                                              int object_size) {
   AllocationAlignment alignment = HeapObject::RequiredAlignment(map);
   AllocationResult allocation =
       allocator_.Allocate(OLD_SPACE, object_size, alignment);
@@ -111,61 +194,112 @@ bool Scavenger::PromoteObject(Map* map, HeapObjectReference** slot,
     const bool self_success = MigrateObject(map, object, target, object_size);
     if (!self_success) {
       allocator_.FreeLast(OLD_SPACE, target, object_size);
-      MapWord map_word = object->map_word();
+      MapWord map_word = object->synchronized_map_word();
       HeapObjectReference::Update(slot, map_word.ToForwardingAddress());
-      return true;
+      DCHECK(!Heap::InFromSpace(*slot));
+      return Heap::InToSpace(*slot)
+                 ? CopyAndForwardResult::SUCCESS_YOUNG_GENERATION
+                 : CopyAndForwardResult::SUCCESS_OLD_GENERATION;
     }
     HeapObjectReference::Update(slot, target);
     if (!ContainsOnlyData(map->visitor_id())) {
-      promotion_list_.Push(ObjectAndSize(target, object_size));
+      promotion_list_.PushRegularObject(target, object_size);
     }
     promoted_size_ += object_size;
+    return CopyAndForwardResult::SUCCESS_OLD_GENERATION;
+  }
+  return CopyAndForwardResult::FAILURE;
+}
+
+SlotCallbackResult Scavenger::RememberedSetEntryNeeded(
+    CopyAndForwardResult result) {
+  DCHECK_NE(CopyAndForwardResult::FAILURE, result);
+  return result == CopyAndForwardResult::SUCCESS_YOUNG_GENERATION ? KEEP_SLOT
+                                                                  : REMOVE_SLOT;
+}
+
+bool Scavenger::HandleLargeObject(Map* map, HeapObject* object,
+                                  int object_size) {
+  if (V8_UNLIKELY(FLAG_young_generation_large_objects &&
+                  object_size > kMaxNewSpaceHeapObjectSize)) {
+    DCHECK_EQ(NEW_LO_SPACE,
+              MemoryChunk::FromHeapObject(object)->owner()->identity());
+    if (base::AsAtomicPointer::Release_CompareAndSwap(
+            reinterpret_cast<HeapObject**>(object->address()), map,
+            MapWord::FromForwardingAddress(object).ToMap()) == map) {
+      surviving_new_large_objects_.insert({object, map});
+
+      if (!ContainsOnlyData(map->visitor_id())) {
+        promotion_list_.PushLargeObject(object, map, object_size);
+      }
+    }
     return true;
   }
   return false;
 }
 
-void Scavenger::EvacuateObjectDefault(Map* map, HeapObjectReference** slot,
-                                      HeapObject* object, int object_size) {
+SlotCallbackResult Scavenger::EvacuateObjectDefault(Map* map,
+                                                    HeapObjectReference** slot,
+                                                    HeapObject* object,
+                                                    int object_size) {
   SLOW_DCHECK(object_size <= Page::kAllocatableMemory);
   SLOW_DCHECK(object->SizeFromMap(map) == object_size);
+  CopyAndForwardResult result;
+
+  if (HandleLargeObject(map, object, object_size)) {
+    return REMOVE_SLOT;
+  }
 
   if (!heap()->ShouldBePromoted(object->address())) {
     // A semi-space copy may fail due to fragmentation. In that case, we
     // try to promote the object.
-    if (SemiSpaceCopyObject(map, slot, object, object_size)) return;
+    result = SemiSpaceCopyObject(map, slot, object, object_size);
+    if (result != CopyAndForwardResult::FAILURE) {
+      return RememberedSetEntryNeeded(result);
+    }
   }
 
-  if (PromoteObject(map, slot, object, object_size)) return;
+  // We may want to promote this object if the object was already semi-space
+  // copied in a previes young generation GC or if the semi-space copy above
+  // failed.
+  result = PromoteObject(map, slot, object, object_size);
+  if (result != CopyAndForwardResult::FAILURE) {
+    return RememberedSetEntryNeeded(result);
+  }
 
-  // If promotion failed, we try to copy the object to the other semi-space
-  if (SemiSpaceCopyObject(map, slot, object, object_size)) return;
+  // If promotion failed, we try to copy the object to the other semi-space.
+  result = SemiSpaceCopyObject(map, slot, object, object_size);
+  if (result != CopyAndForwardResult::FAILURE) {
+    return RememberedSetEntryNeeded(result);
+  }
 
   heap()->FatalProcessOutOfMemory("Scavenger: semi-space copy");
+  UNREACHABLE();
 }
 
-void Scavenger::EvacuateThinString(Map* map, HeapObject** slot,
-                                   ThinString* object, int object_size) {
+SlotCallbackResult Scavenger::EvacuateThinString(Map* map, HeapObject** slot,
+                                                 ThinString* object,
+                                                 int object_size) {
   if (!is_incremental_marking_) {
-    // Loading actual is fine in a parallel setting is there is no write.
+    // The ThinString should die after Scavenge, so avoid writing the proper
+    // forwarding pointer and instead just signal the actual object as forwarded
+    // reference.
     String* actual = object->actual();
-    object->set_length(0);
-    *slot = actual;
-    // ThinStrings always refer to internalized strings, which are
-    // always in old space.
+    // ThinStrings always refer to internalized strings, which are always in old
+    // space.
     DCHECK(!Heap::InNewSpace(actual));
-    base::AsAtomicPointer::Relaxed_Store(
-        reinterpret_cast<Map**>(object->address()),
-        MapWord::FromForwardingAddress(actual).ToMap());
-    return;
+    *slot = actual;
+    return REMOVE_SLOT;
   }
 
-  EvacuateObjectDefault(map, reinterpret_cast<HeapObjectReference**>(slot),
-                        object, object_size);
+  return EvacuateObjectDefault(
+      map, reinterpret_cast<HeapObjectReference**>(slot), object, object_size);
 }
 
-void Scavenger::EvacuateShortcutCandidate(Map* map, HeapObject** slot,
-                                          ConsString* object, int object_size) {
+SlotCallbackResult Scavenger::EvacuateShortcutCandidate(Map* map,
+                                                        HeapObject** slot,
+                                                        ConsString* object,
+                                                        int object_size) {
   DCHECK(IsShortcutCandidate(map->instance_type()));
   if (!is_incremental_marking_ &&
       object->unchecked_second() == ReadOnlyRoots(heap()).empty_string()) {
@@ -174,37 +308,38 @@ void Scavenger::EvacuateShortcutCandidate(Map* map, HeapObject** slot,
     *slot = first;
 
     if (!Heap::InNewSpace(first)) {
-      base::AsAtomicPointer::Relaxed_Store(
+      base::AsAtomicPointer::Release_Store(
           reinterpret_cast<Map**>(object->address()),
           MapWord::FromForwardingAddress(first).ToMap());
-      return;
+      return REMOVE_SLOT;
     }
 
-    MapWord first_word = first->map_word();
+    MapWord first_word = first->synchronized_map_word();
     if (first_word.IsForwardingAddress()) {
       HeapObject* target = first_word.ToForwardingAddress();
 
       *slot = target;
-      base::AsAtomicPointer::Relaxed_Store(
+      base::AsAtomicPointer::Release_Store(
           reinterpret_cast<Map**>(object->address()),
           MapWord::FromForwardingAddress(target).ToMap());
-      return;
+      return Heap::InToSpace(target) ? KEEP_SLOT : REMOVE_SLOT;
     }
     Map* map = first_word.ToMap();
-    EvacuateObjectDefault(map, reinterpret_cast<HeapObjectReference**>(slot),
-                          first, first->SizeFromMap(map));
-    base::AsAtomicPointer::Relaxed_Store(
+    SlotCallbackResult result = EvacuateObjectDefault(
+        map, reinterpret_cast<HeapObjectReference**>(slot), first,
+        first->SizeFromMap(map));
+    base::AsAtomicPointer::Release_Store(
         reinterpret_cast<Map**>(object->address()),
         MapWord::FromForwardingAddress(*slot).ToMap());
-    return;
+    return result;
   }
 
-  EvacuateObjectDefault(map, reinterpret_cast<HeapObjectReference**>(slot),
-                        object, object_size);
+  return EvacuateObjectDefault(
+      map, reinterpret_cast<HeapObjectReference**>(slot), object, object_size);
 }
 
-void Scavenger::EvacuateObject(HeapObjectReference** slot, Map* map,
-                               HeapObject* source) {
+SlotCallbackResult Scavenger::EvacuateObject(HeapObjectReference** slot,
+                                             Map* map, HeapObject* source) {
   SLOW_DCHECK(Heap::InFromSpace(source));
   SLOW_DCHECK(!MapWord::FromMap(map).IsForwardingAddress());
   int size = source->SizeFromMap(map);
@@ -213,23 +348,22 @@ void Scavenger::EvacuateObject(HeapObjectReference** slot, Map* map,
   switch (map->visitor_id()) {
     case kVisitThinString:
       // At the moment we don't allow weak pointers to thin strings.
-      DCHECK(!(*slot)->IsWeakHeapObject());
-      EvacuateThinString(map, reinterpret_cast<HeapObject**>(slot),
-                         reinterpret_cast<ThinString*>(source), size);
-      break;
+      DCHECK(!(*slot)->IsWeak());
+      return EvacuateThinString(map, reinterpret_cast<HeapObject**>(slot),
+                                reinterpret_cast<ThinString*>(source), size);
     case kVisitShortcutCandidate:
-      DCHECK(!(*slot)->IsWeakHeapObject());
+      DCHECK(!(*slot)->IsWeak());
       // At the moment we don't allow weak pointers to cons strings.
-      EvacuateShortcutCandidate(map, reinterpret_cast<HeapObject**>(slot),
-                                reinterpret_cast<ConsString*>(source), size);
-      break;
+      return EvacuateShortcutCandidate(
+          map, reinterpret_cast<HeapObject**>(slot),
+          reinterpret_cast<ConsString*>(source), size);
     default:
-      EvacuateObjectDefault(map, slot, source, size);
-      break;
+      return EvacuateObjectDefault(map, slot, source, size);
   }
 }
 
-void Scavenger::ScavengeObject(HeapObjectReference** p, HeapObject* object) {
+SlotCallbackResult Scavenger::ScavengeObject(HeapObjectReference** p,
+                                             HeapObject* object) {
   DCHECK(Heap::InFromSpace(object));
 
   // Synchronized load that consumes the publishing CAS of MigrateObject.
@@ -240,20 +374,21 @@ void Scavenger::ScavengeObject(HeapObjectReference** p, HeapObject* object) {
   if (first_word.IsForwardingAddress()) {
     HeapObject* dest = first_word.ToForwardingAddress();
     DCHECK(Heap::InFromSpace(*p));
-    if ((*p)->IsWeakHeapObject()) {
+    if ((*p)->IsWeak()) {
       *p = HeapObjectReference::Weak(dest);
     } else {
-      DCHECK((*p)->IsStrongHeapObject());
+      DCHECK((*p)->IsStrong());
       *p = HeapObjectReference::Strong(dest);
     }
-    return;
+    DCHECK(Heap::InToSpace(dest) || !Heap::InNewSpace((dest)));
+    return Heap::InToSpace(dest) ? KEEP_SLOT : REMOVE_SLOT;
   }
 
   Map* map = first_word.ToMap();
   // AllocationMementos are unrooted and shouldn't survive a scavenge
   DCHECK_NE(ReadOnlyRoots(heap()).allocation_memento_map(), map);
   // Call the slow part of scavenge object.
-  EvacuateObject(p, map, object);
+  return EvacuateObject(p, map, object);
 }
 
 SlotCallbackResult Scavenger::CheckAndScavengeObject(Heap* heap,
@@ -261,23 +396,13 @@ SlotCallbackResult Scavenger::CheckAndScavengeObject(Heap* heap,
   MaybeObject** slot = reinterpret_cast<MaybeObject**>(slot_address);
   MaybeObject* object = *slot;
   if (Heap::InFromSpace(object)) {
-    HeapObject* heap_object;
-    bool success = object->ToStrongOrWeakHeapObject(&heap_object);
-    USE(success);
-    DCHECK(success);
+    HeapObject* heap_object = object->GetHeapObject();
     DCHECK(heap_object->IsHeapObject());
 
-    ScavengeObject(reinterpret_cast<HeapObjectReference**>(slot), heap_object);
-
-    object = *slot;
-    // If the object was in from space before and is after executing the
-    // callback in to space, the object is still live.
-    // Unfortunately, we do not know about the slot. It could be in a
-    // just freed free space object.
-    PageMemoryFence(object);
-    if (Heap::InToSpace(object)) {
-      return KEEP_SLOT;
-    }
+    SlotCallbackResult result = ScavengeObject(
+        reinterpret_cast<HeapObjectReference**>(slot), heap_object);
+    DCHECK_IMPLIES(result == REMOVE_SLOT, !Heap::InNewSpace(*slot));
+    return result;
   } else if (Heap::InToSpace(object)) {
     // Already updated slot. This can happen when processing of the work list
     // is interleaved with processing roots.
@@ -305,7 +430,7 @@ void ScavengeVisitor::VisitPointers(HeapObject* host, MaybeObject** start,
     if (!Heap::InNewSpace(object)) continue;
     // Treat the weak reference as strong.
     HeapObject* heap_object;
-    if (object->ToStrongOrWeakHeapObject(&heap_object)) {
+    if (object->GetHeapObject(&heap_object)) {
       scavenger_->ScavengeObject(reinterpret_cast<HeapObjectReference**>(p),
                                  heap_object);
     } else {
diff --git a/deps/v8/src/heap/scavenger.cc b/deps/v8/src/heap/scavenger.cc
index f8c6d496ce..4c63ed099a 100644
--- a/deps/v8/src/heap/scavenger.cc
+++ b/deps/v8/src/heap/scavenger.cc
@@ -4,17 +4,72 @@
 
 #include "src/heap/scavenger.h"
 
+#include "src/heap/array-buffer-collector.h"
 #include "src/heap/barrier.h"
+#include "src/heap/gc-tracer.h"
 #include "src/heap/heap-inl.h"
+#include "src/heap/item-parallel-job.h"
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/objects-visiting-inl.h"
 #include "src/heap/scavenger-inl.h"
 #include "src/heap/sweeper.h"
 #include "src/objects-body-descriptors-inl.h"
+#include "src/utils-inl.h"
 
 namespace v8 {
 namespace internal {
 
+class PageScavengingItem final : public ItemParallelJob::Item {
+ public:
+  explicit PageScavengingItem(MemoryChunk* chunk) : chunk_(chunk) {}
+  ~PageScavengingItem() override = default;
+
+  void Process(Scavenger* scavenger) { scavenger->ScavengePage(chunk_); }
+
+ private:
+  MemoryChunk* const chunk_;
+};
+
+class ScavengingTask final : public ItemParallelJob::Task {
+ public:
+  ScavengingTask(Heap* heap, Scavenger* scavenger, OneshotBarrier* barrier)
+      : ItemParallelJob::Task(heap->isolate()),
+        heap_(heap),
+        scavenger_(scavenger),
+        barrier_(barrier) {}
+
+  void RunInParallel() final {
+    TRACE_BACKGROUND_GC(
+        heap_->tracer(),
+        GCTracer::BackgroundScope::SCAVENGER_BACKGROUND_SCAVENGE_PARALLEL);
+    double scavenging_time = 0.0;
+    {
+      barrier_->Start();
+      TimedScope scope(&scavenging_time);
+      PageScavengingItem* item = nullptr;
+      while ((item = GetItem<PageScavengingItem>()) != nullptr) {
+        item->Process(scavenger_);
+        item->MarkFinished();
+      }
+      do {
+        scavenger_->Process(barrier_);
+      } while (!barrier_->Wait());
+      scavenger_->Process();
+    }
+    if (FLAG_trace_parallel_scavenge) {
+      PrintIsolate(heap_->isolate(),
+                   "scavenge[%p]: time=%.2f copied=%zu promoted=%zu\n",
+                   static_cast<void*>(this), scavenging_time,
+                   scavenger_->bytes_copied(), scavenger_->bytes_promoted());
+    }
+  };
+
+ private:
+  Heap* const heap_;
+  Scavenger* const scavenger_;
+  OneshotBarrier* const barrier_;
+};
+
 class IterateAndScavengePromotedObjectsVisitor final : public ObjectVisitor {
  public:
   IterateAndScavengePromotedObjectsVisitor(Heap* heap, Scavenger* scavenger,
@@ -40,7 +95,7 @@ class IterateAndScavengePromotedObjectsVisitor final : public ObjectVisitor {
     for (MaybeObject** slot = start; slot < end; ++slot) {
       MaybeObject* target = *slot;
       HeapObject* heap_object;
-      if (target->ToStrongOrWeakHeapObject(&heap_object)) {
+      if (target->GetHeapObject(&heap_object)) {
         HandleSlot(host, reinterpret_cast<Address>(slot), heap_object);
       }
     }
@@ -53,15 +108,13 @@ class IterateAndScavengePromotedObjectsVisitor final : public ObjectVisitor {
     scavenger_->PageMemoryFence(reinterpret_cast<MaybeObject*>(target));
 
     if (Heap::InFromSpace(target)) {
-      scavenger_->ScavengeObject(slot, target);
-      bool success = (*slot)->ToStrongOrWeakHeapObject(&target);
+      SlotCallbackResult result = scavenger_->ScavengeObject(slot, target);
+      bool success = (*slot)->GetHeapObject(&target);
       USE(success);
       DCHECK(success);
-      scavenger_->PageMemoryFence(reinterpret_cast<MaybeObject*>(target));
 
-      if (Heap::InNewSpace(target)) {
+      if (result == KEEP_SLOT) {
         SLOW_DCHECK(target->IsHeapObject());
-        SLOW_DCHECK(Heap::InToSpace(target));
         RememberedSet<OLD_TO_NEW>::Insert(Page::FromAddress(slot_address),
                                           slot_address);
       }
@@ -79,9 +132,204 @@ class IterateAndScavengePromotedObjectsVisitor final : public ObjectVisitor {
   const bool record_slots_;
 };
 
-Scavenger::Scavenger(Heap* heap, bool is_logging, CopiedList* copied_list,
-                     PromotionList* promotion_list, int task_id)
-    : heap_(heap),
+static bool IsUnscavengedHeapObject(Heap* heap, Object** p) {
+  return Heap::InFromSpace(*p) &&
+         !HeapObject::cast(*p)->map_word().IsForwardingAddress();
+}
+
+class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
+ public:
+  Object* RetainAs(Object* object) override {
+    if (!Heap::InFromSpace(object)) {
+      return object;
+    }
+
+    MapWord map_word = HeapObject::cast(object)->map_word();
+    if (map_word.IsForwardingAddress()) {
+      return map_word.ToForwardingAddress();
+    }
+    return nullptr;
+  }
+};
+
+ScavengerCollector::ScavengerCollector(Heap* heap)
+    : isolate_(heap->isolate()), heap_(heap), parallel_scavenge_semaphore_(0) {}
+
+void ScavengerCollector::CollectGarbage() {
+  ItemParallelJob job(isolate_->cancelable_task_manager(),
+                      &parallel_scavenge_semaphore_);
+  const int kMainThreadId = 0;
+  Scavenger* scavengers[kMaxScavengerTasks];
+  const bool is_logging = isolate_->LogObjectRelocation();
+  const int num_scavenge_tasks = NumberOfScavengeTasks();
+  OneshotBarrier barrier;
+  Scavenger::CopiedList copied_list(num_scavenge_tasks);
+  Scavenger::PromotionList promotion_list(num_scavenge_tasks);
+  for (int i = 0; i < num_scavenge_tasks; i++) {
+    scavengers[i] = new Scavenger(this, heap_, is_logging, &copied_list,
+                                  &promotion_list, i);
+    job.AddTask(new ScavengingTask(heap_, scavengers[i], &barrier));
+  }
+
+  {
+    Sweeper* sweeper = heap_->mark_compact_collector()->sweeper();
+    // Pause the concurrent sweeper.
+    Sweeper::PauseOrCompleteScope pause_scope(sweeper);
+    // Filter out pages from the sweeper that need to be processed for old to
+    // new slots by the Scavenger. After processing, the Scavenger adds back
+    // pages that are still unsweeped. This way the Scavenger has exclusive
+    // access to the slots of a page and can completely avoid any locks on
+    // the page itself.
+    Sweeper::FilterSweepingPagesScope filter_scope(sweeper, pause_scope);
+    filter_scope.FilterOldSpaceSweepingPages(
+        [](Page* page) { return !page->ContainsSlots<OLD_TO_NEW>(); });
+    RememberedSet<OLD_TO_NEW>::IterateMemoryChunks(
+        heap_, [&job](MemoryChunk* chunk) {
+          job.AddItem(new PageScavengingItem(chunk));
+        });
+
+    RootScavengeVisitor root_scavenge_visitor(scavengers[kMainThreadId]);
+
+    {
+      // Identify weak unmodified handles. Requires an unmodified graph.
+      TRACE_GC(
+          heap_->tracer(),
+          GCTracer::Scope::SCAVENGER_SCAVENGE_WEAK_GLOBAL_HANDLES_IDENTIFY);
+      isolate_->global_handles()->IdentifyWeakUnmodifiedObjects(
+          &JSObject::IsUnmodifiedApiObject);
+    }
+    {
+      // Copy roots.
+      TRACE_GC(heap_->tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_ROOTS);
+      heap_->IterateRoots(&root_scavenge_visitor, VISIT_ALL_IN_SCAVENGE);
+    }
+    {
+      // Parallel phase scavenging all copied and promoted objects.
+      TRACE_GC(heap_->tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_PARALLEL);
+      job.Run(isolate_->async_counters());
+      DCHECK(copied_list.IsEmpty());
+      DCHECK(promotion_list.IsEmpty());
+    }
+    {
+      // Scavenge weak global handles.
+      TRACE_GC(heap_->tracer(),
+               GCTracer::Scope::SCAVENGER_SCAVENGE_WEAK_GLOBAL_HANDLES_PROCESS);
+      isolate_->global_handles()->MarkNewSpaceWeakUnmodifiedObjectsPending(
+          &IsUnscavengedHeapObject);
+      isolate_->global_handles()
+          ->IterateNewSpaceWeakUnmodifiedRootsForFinalizers(
+              &root_scavenge_visitor);
+      scavengers[kMainThreadId]->Process();
+
+      DCHECK(copied_list.IsEmpty());
+      DCHECK(promotion_list.IsEmpty());
+      isolate_->global_handles()
+          ->IterateNewSpaceWeakUnmodifiedRootsForPhantomHandles(
+              &root_scavenge_visitor, &IsUnscavengedHeapObject);
+    }
+
+    {
+      // Finalize parallel scavenging.
+      TRACE_GC(heap_->tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_FINALIZE);
+
+      for (int i = 0; i < num_scavenge_tasks; i++) {
+        scavengers[i]->Finalize();
+        delete scavengers[i];
+      }
+
+      HandleSurvivingNewLargeObjects();
+    }
+  }
+
+  {
+    // Update references into new space
+    TRACE_GC(heap_->tracer(), GCTracer::Scope::SCAVENGER_SCAVENGE_UPDATE_REFS);
+    heap_->UpdateNewSpaceReferencesInExternalStringTable(
+        &Heap::UpdateNewSpaceReferenceInExternalStringTableEntry);
+
+    heap_->incremental_marking()->UpdateMarkingWorklistAfterScavenge();
+  }
+
+  if (FLAG_concurrent_marking) {
+    // Ensure that concurrent marker does not track pages that are
+    // going to be unmapped.
+    for (Page* p :
+         PageRange(heap_->new_space()->from_space().first_page(), nullptr)) {
+      heap_->concurrent_marking()->ClearLiveness(p);
+    }
+  }
+
+  ScavengeWeakObjectRetainer weak_object_retainer;
+  heap_->ProcessYoungWeakReferences(&weak_object_retainer);
+
+  // Set age mark.
+  heap_->new_space_->set_age_mark(heap_->new_space()->top());
+
+  {
+    TRACE_GC(heap_->tracer(), GCTracer::Scope::SCAVENGER_PROCESS_ARRAY_BUFFERS);
+    ArrayBufferTracker::PrepareToFreeDeadInNewSpace(heap_);
+  }
+  heap_->array_buffer_collector()->FreeAllocations();
+
+  RememberedSet<OLD_TO_NEW>::IterateMemoryChunks(heap_, [](MemoryChunk* chunk) {
+    if (chunk->SweepingDone()) {
+      RememberedSet<OLD_TO_NEW>::FreeEmptyBuckets(chunk);
+    } else {
+      RememberedSet<OLD_TO_NEW>::PreFreeEmptyBuckets(chunk);
+    }
+  });
+
+  // Update how much has survived scavenge.
+  heap_->IncrementYoungSurvivorsCounter(heap_->SurvivedNewSpaceObjectSize());
+
+  // Scavenger may find new wrappers by iterating objects promoted onto a black
+  // page.
+  heap_->local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer();
+}
+
+void ScavengerCollector::HandleSurvivingNewLargeObjects() {
+  for (SurvivingNewLargeObjectMapEntry update_info :
+       surviving_new_large_objects_) {
+    HeapObject* object = update_info.first;
+    Map* map = update_info.second;
+    // Order is important here. We have to re-install the map to have access
+    // to meta-data like size during page promotion.
+    object->set_map_word(MapWord::FromMap(map));
+    LargePage* page = LargePage::FromHeapObject(object);
+    heap_->lo_space()->PromoteNewLargeObject(page);
+  }
+  DCHECK(heap_->new_lo_space()->IsEmpty());
+}
+
+void ScavengerCollector::MergeSurvivingNewLargeObjects(
+    const SurvivingNewLargeObjectsMap& objects) {
+  for (SurvivingNewLargeObjectMapEntry object : objects) {
+    bool success = surviving_new_large_objects_.insert(object).second;
+    USE(success);
+    DCHECK(success);
+  }
+}
+
+int ScavengerCollector::NumberOfScavengeTasks() {
+  if (!FLAG_parallel_scavenge) return 1;
+  const int num_scavenge_tasks =
+      static_cast<int>(heap_->new_space()->TotalCapacity()) / MB;
+  static int num_cores = V8::GetCurrentPlatform()->NumberOfWorkerThreads() + 1;
+  int tasks =
+      Max(1, Min(Min(num_scavenge_tasks, kMaxScavengerTasks), num_cores));
+  if (!heap_->CanExpandOldGeneration(
+          static_cast<size_t>(tasks * Page::kPageSize))) {
+    // Optimize for memory usage near the heap limit.
+    tasks = 1;
+  }
+  return tasks;
+}
+
+Scavenger::Scavenger(ScavengerCollector* collector, Heap* heap, bool is_logging,
+                     CopiedList* copied_list, PromotionList* promotion_list,
+                     int task_id)
+    : collector_(collector),
+      heap_(heap),
       promotion_list_(promotion_list, task_id),
       copied_list_(copied_list, task_id),
       local_pretenuring_feedback_(kInitialLocalPretenuringFeedbackCapacity),
@@ -92,7 +340,8 @@ Scavenger::Scavenger(Heap* heap, bool is_logging, CopiedList* copied_list,
       is_incremental_marking_(heap->incremental_marking()->IsMarking()),
       is_compacting_(heap->incremental_marking()->IsCompacting()) {}
 
-void Scavenger::IterateAndScavengePromotedObject(HeapObject* target, int size) {
+void Scavenger::IterateAndScavengePromotedObject(HeapObject* target, Map* map,
+                                                 int size) {
   // We are not collecting slots on new space objects during mutation thus we
   // have to scan for pointers to evacuation candidates when we promote
   // objects. But we should not record any slots in non-black objects. Grey
@@ -103,7 +352,7 @@ void Scavenger::IterateAndScavengePromotedObject(HeapObject* target, int size) {
       is_compacting_ &&
       heap()->incremental_marking()->atomic_marking_state()->IsBlack(target);
   IterateAndScavengePromotedObjectsVisitor visitor(heap(), this, record_slots);
-  target->IterateBodyFast(target->map(), size, &visitor);
+  target->IterateBodyFast(map, size, &visitor);
 }
 
 void Scavenger::AddPageToSweeperIfNecessary(MemoryChunk* page) {
@@ -136,9 +385,6 @@ void Scavenger::ScavengePage(MemoryChunk* page) {
 
 void Scavenger::Process(OneshotBarrier* barrier) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.gc"), "Scavenger::Process");
-  // Threshold when to switch processing the promotion list to avoid
-  // allocating too much backing store in the worklist.
-  const int kProcessPromotionListThreshold = kPromotionListSegmentSize / 2;
   ScavengeVisitor scavenge_visitor(this);
 
   const bool have_barrier = barrier != nullptr;
@@ -147,8 +393,7 @@ void Scavenger::Process(OneshotBarrier* barrier) {
   do {
     done = true;
     ObjectAndSize object_and_size;
-    while ((promotion_list_.LocalPushSegmentSize() <
-            kProcessPromotionListThreshold) &&
+    while (promotion_list_.ShouldEagerlyProcessPromotionList() &&
            copied_list_.Pop(&object_and_size)) {
       scavenge_visitor.Visit(object_and_size.first);
       done = false;
@@ -159,11 +404,11 @@ void Scavenger::Process(OneshotBarrier* barrier) {
       }
     }
 
-    while (promotion_list_.Pop(&object_and_size)) {
-      HeapObject* target = object_and_size.first;
-      int size = object_and_size.second;
+    struct PromotionListEntry entry;
+    while (promotion_list_.Pop(&entry)) {
+      HeapObject* target = entry.heap_object;
       DCHECK(!target->IsMap());
-      IterateAndScavengePromotedObject(target, size);
+      IterateAndScavengePromotedObject(target, entry.map, entry.size);
       done = false;
       if (have_barrier && ((++objects % kInterruptThreshold) == 0)) {
         if (!promotion_list_.IsGlobalPoolEmpty()) {
@@ -178,6 +423,7 @@ void Scavenger::Finalize() {
   heap()->MergeAllocationSitePretenuringFeedback(local_pretenuring_feedback_);
   heap()->IncrementSemiSpaceCopiedObjectSize(copied_size_);
   heap()->IncrementPromotedObjectsSize(promoted_size_);
+  collector_->MergeSurvivingNewLargeObjects(surviving_new_large_objects_);
   allocator_.Finalize();
 }
 
diff --git a/deps/v8/src/heap/scavenger.h b/deps/v8/src/heap/scavenger.h
index 4e6753f6ce..b984102c6b 100644
--- a/deps/v8/src/heap/scavenger.h
+++ b/deps/v8/src/heap/scavenger.h
@@ -16,17 +16,101 @@ namespace internal {
 
 class OneshotBarrier;
 
+enum class CopyAndForwardResult {
+  SUCCESS_YOUNG_GENERATION,
+  SUCCESS_OLD_GENERATION,
+  FAILURE
+};
+
+using ObjectAndSize = std::pair<HeapObject*, int>;
+using SurvivingNewLargeObjectsMap = std::unordered_map<HeapObject*, Map*>;
+using SurvivingNewLargeObjectMapEntry = std::pair<HeapObject*, Map*>;
+
+class ScavengerCollector {
+ public:
+  static const int kMaxScavengerTasks = 8;
+
+  explicit ScavengerCollector(Heap* heap);
+
+  void CollectGarbage();
+
+ private:
+  void MergeSurvivingNewLargeObjects(
+      const SurvivingNewLargeObjectsMap& objects);
+
+  int NumberOfScavengeTasks();
+
+  void HandleSurvivingNewLargeObjects();
+
+  Isolate* const isolate_;
+  Heap* const heap_;
+  base::Semaphore parallel_scavenge_semaphore_;
+  SurvivingNewLargeObjectsMap surviving_new_large_objects_;
+
+  friend class Scavenger;
+};
+
 class Scavenger {
  public:
+  struct PromotionListEntry {
+    HeapObject* heap_object;
+    Map* map;
+    int size;
+  };
+
+  class PromotionList {
+   public:
+    class View {
+     public:
+      View(PromotionList* promotion_list, int task_id)
+          : promotion_list_(promotion_list), task_id_(task_id) {}
+
+      inline void PushRegularObject(HeapObject* object, int size);
+      inline void PushLargeObject(HeapObject* object, Map* map, int size);
+      inline bool IsEmpty();
+      inline size_t LocalPushSegmentSize();
+      inline bool Pop(struct PromotionListEntry* entry);
+      inline bool IsGlobalPoolEmpty();
+      inline bool ShouldEagerlyProcessPromotionList();
+
+     private:
+      PromotionList* promotion_list_;
+      int task_id_;
+    };
+
+    explicit PromotionList(int num_tasks)
+        : regular_object_promotion_list_(num_tasks),
+          large_object_promotion_list_(num_tasks) {}
+
+    inline void PushRegularObject(int task_id, HeapObject* object, int size);
+    inline void PushLargeObject(int task_id, HeapObject* object, Map* map,
+                                int size);
+    inline bool IsEmpty();
+    inline size_t LocalPushSegmentSize(int task_id);
+    inline bool Pop(int task_id, struct PromotionListEntry* entry);
+    inline bool IsGlobalPoolEmpty();
+    inline bool ShouldEagerlyProcessPromotionList(int task_id);
+
+   private:
+    static const int kRegularObjectPromotionListSegmentSize = 256;
+    static const int kLargeObjectPromotionListSegmentSize = 4;
+
+    using RegularObjectPromotionList =
+        Worklist<ObjectAndSize, kRegularObjectPromotionListSegmentSize>;
+    using LargeObjectPromotionList =
+        Worklist<PromotionListEntry, kLargeObjectPromotionListSegmentSize>;
+
+    RegularObjectPromotionList regular_object_promotion_list_;
+    LargeObjectPromotionList large_object_promotion_list_;
+  };
+
   static const int kCopiedListSegmentSize = 256;
-  static const int kPromotionListSegmentSize = 256;
 
-  using ObjectAndSize = std::pair<HeapObject*, int>;
   using CopiedList = Worklist<ObjectAndSize, kCopiedListSegmentSize>;
-  using PromotionList = Worklist<ObjectAndSize, kPromotionListSegmentSize>;
 
-  Scavenger(Heap* heap, bool is_logging, CopiedList* copied_list,
-            PromotionList* promotion_list, int task_id);
+  Scavenger(ScavengerCollector* collector, Heap* heap, bool is_logging,
+            CopiedList* copied_list, PromotionList* promotion_list,
+            int task_id);
 
   // Entry point for scavenging an old generation page. For scavenging single
   // objects see RootScavengingVisitor and ScavengeVisitor below.
@@ -61,39 +145,52 @@ class Scavenger {
 
   // Scavenges an object |object| referenced from slot |p|. |object| is required
   // to be in from space.
-  inline void ScavengeObject(HeapObjectReference** p, HeapObject* object);
+  inline SlotCallbackResult ScavengeObject(HeapObjectReference** p,
+                                           HeapObject* object);
 
   // Copies |source| to |target| and sets the forwarding pointer in |source|.
   V8_INLINE bool MigrateObject(Map* map, HeapObject* source, HeapObject* target,
                                int size);
 
-  V8_INLINE bool SemiSpaceCopyObject(Map* map, HeapObjectReference** slot,
-                                     HeapObject* object, int object_size);
+  V8_INLINE SlotCallbackResult
+  RememberedSetEntryNeeded(CopyAndForwardResult result);
 
-  V8_INLINE bool PromoteObject(Map* map, HeapObjectReference** slot,
-                               HeapObject* object, int object_size);
+  V8_INLINE CopyAndForwardResult SemiSpaceCopyObject(Map* map,
+                                                     HeapObjectReference** slot,
+                                                     HeapObject* object,
+                                                     int object_size);
 
-  V8_INLINE void EvacuateObject(HeapObjectReference** slot, Map* map,
-                                HeapObject* source);
+  V8_INLINE CopyAndForwardResult PromoteObject(Map* map,
+                                               HeapObjectReference** slot,
+                                               HeapObject* object,
+                                               int object_size);
 
-  // Different cases for object evacuation.
+  V8_INLINE SlotCallbackResult EvacuateObject(HeapObjectReference** slot,
+                                              Map* map, HeapObject* source);
 
-  V8_INLINE void EvacuateObjectDefault(Map* map, HeapObjectReference** slot,
-                                       HeapObject* object, int object_size);
+  V8_INLINE bool HandleLargeObject(Map* map, HeapObject* object,
+                                   int object_size);
 
-  V8_INLINE void EvacuateJSFunction(Map* map, HeapObject** slot,
-                                    JSFunction* object, int object_size);
+  // Different cases for object evacuation.
+  V8_INLINE SlotCallbackResult EvacuateObjectDefault(Map* map,
+                                                     HeapObjectReference** slot,
+                                                     HeapObject* object,
+                                                     int object_size);
 
-  inline void EvacuateThinString(Map* map, HeapObject** slot,
-                                 ThinString* object, int object_size);
+  inline SlotCallbackResult EvacuateThinString(Map* map, HeapObject** slot,
+                                               ThinString* object,
+                                               int object_size);
 
-  inline void EvacuateShortcutCandidate(Map* map, HeapObject** slot,
-                                        ConsString* object, int object_size);
+  inline SlotCallbackResult EvacuateShortcutCandidate(Map* map,
+                                                      HeapObject** slot,
+                                                      ConsString* object,
+                                                      int object_size);
 
-  void IterateAndScavengePromotedObject(HeapObject* target, int size);
+  void IterateAndScavengePromotedObject(HeapObject* target, Map* map, int size);
 
   static inline bool ContainsOnlyData(VisitorId visitor_id);
 
+  ScavengerCollector* const collector_;
   Heap* const heap_;
   PromotionList::View promotion_list_;
   CopiedList::View copied_list_;
@@ -101,6 +198,7 @@ class Scavenger {
   size_t copied_size_;
   size_t promoted_size_;
   LocalAllocator allocator_;
+  SurvivingNewLargeObjectsMap surviving_new_large_objects_;
   const bool is_logging_;
   const bool is_incremental_marking_;
   const bool is_compacting_;
diff --git a/deps/v8/src/heap/setup-heap-internal.cc b/deps/v8/src/heap/setup-heap-internal.cc
index 2742cd9c9d..5790b82907 100644
--- a/deps/v8/src/heap/setup-heap-internal.cc
+++ b/deps/v8/src/heap/setup-heap-internal.cc
@@ -23,11 +23,13 @@
 #include "src/objects/dictionary.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/map.h"
+#include "src/objects/microtask-queue.h"
 #include "src/objects/microtask.h"
 #include "src/objects/module.h"
 #include "src/objects/promise.h"
 #include "src/objects/script.h"
 #include "src/objects/shared-function-info.h"
+#include "src/objects/stack-frame-info.h"
 #include "src/objects/string.h"
 #include "src/regexp/jsregexp.h"
 #include "src/wasm/wasm-objects.h"
@@ -56,33 +58,34 @@ bool Heap::CreateHeapObjects() {
 }
 
 const Heap::StringTypeTable Heap::string_type_table[] = {
-#define STRING_TYPE_ELEMENT(type, size, name, camel_name) \
-  {type, size, k##camel_name##MapRootIndex},
+#define STRING_TYPE_ELEMENT(type, size, name, CamelName) \
+  {type, size, RootIndex::k##CamelName##Map},
     STRING_TYPE_LIST(STRING_TYPE_ELEMENT)
 #undef STRING_TYPE_ELEMENT
 };
 
 const Heap::ConstantStringTable Heap::constant_string_table[] = {
-    {"", kempty_stringRootIndex},
-#define CONSTANT_STRING_ELEMENT(name, contents) {contents, k##name##RootIndex},
-    INTERNALIZED_STRING_LIST(CONSTANT_STRING_ELEMENT)
+    {"", RootIndex::kempty_string},
+#define CONSTANT_STRING_ELEMENT(_, name, contents) \
+  {contents, RootIndex::k##name},
+    INTERNALIZED_STRING_LIST_GENERATOR(CONSTANT_STRING_ELEMENT, /* not used */)
 #undef CONSTANT_STRING_ELEMENT
 };
 
 const Heap::StructTable Heap::struct_table[] = {
-#define STRUCT_TABLE_ELEMENT(NAME, Name, name) \
-  {NAME##_TYPE, Name::kSize, k##Name##MapRootIndex},
+#define STRUCT_TABLE_ELEMENT(TYPE, Name, name) \
+  {TYPE, Name::kSize, RootIndex::k##Name##Map},
     STRUCT_LIST(STRUCT_TABLE_ELEMENT)
 #undef STRUCT_TABLE_ELEMENT
 
-#define ALLOCATION_SITE_ELEMENT(NAME, Name, Size, name) \
-  {NAME##_TYPE, Name::kSize##Size, k##Name##Size##MapRootIndex},
-        ALLOCATION_SITE_LIST(ALLOCATION_SITE_ELEMENT)
+#define ALLOCATION_SITE_ELEMENT(_, TYPE, Name, Size, name) \
+  {TYPE, Name::kSize##Size, RootIndex::k##Name##Size##Map},
+        ALLOCATION_SITE_LIST(ALLOCATION_SITE_ELEMENT, /* not used */)
 #undef ALLOCATION_SITE_ELEMENT
 
-#define DATA_HANDLER_ELEMENT(NAME, Name, Size, name) \
-  {NAME##_TYPE, Name::kSizeWithData##Size, k##Name##Size##MapRootIndex},
-            DATA_HANDLER_LIST(DATA_HANDLER_ELEMENT)
+#define DATA_HANDLER_ELEMENT(_, TYPE, Name, Size, name) \
+  {TYPE, Name::kSizeWithData##Size, RootIndex::k##Name##Size##Map},
+            DATA_HANDLER_LIST(DATA_HANDLER_ELEMENT, /* not used */)
 #undef DATA_HANDLER_ELEMENT
 };
 
@@ -91,7 +94,7 @@ AllocationResult Heap::AllocateMap(InstanceType instance_type,
                                    ElementsKind elements_kind,
                                    int inobject_properties) {
   STATIC_ASSERT(LAST_JS_OBJECT_TYPE == LAST_TYPE);
-  bool is_js_object = Map::IsJSObject(instance_type);
+  bool is_js_object = InstanceTypeChecker::IsJSObject(instance_type);
   DCHECK_IMPLIES(is_js_object &&
                      !Map::CanHaveFastTransitionableElementsKind(instance_type),
                  IsDictionaryElementsKind(elements_kind) ||
@@ -119,8 +122,8 @@ AllocationResult Heap::AllocatePartialMap(InstanceType instance_type,
   if (!allocation.To(&result)) return allocation;
   // Map::cast cannot be used due to uninitialized map field.
   Map* map = reinterpret_cast<Map*>(result);
-  map->set_map_after_allocation(reinterpret_cast<Map*>(root(kMetaMapRootIndex)),
-                                SKIP_WRITE_BARRIER);
+  map->set_map_after_allocation(
+      reinterpret_cast<Map*>(root(RootIndex::kMetaMap)), SKIP_WRITE_BARRIER);
   map->set_instance_type(instance_type);
   map->set_instance_size(instance_size);
   // Initialize to only containing tagged fields.
@@ -179,8 +182,9 @@ AllocationResult Heap::AllocateEmptyFixedTypedArray(
       array_type == kExternalFloat64Array ? kDoubleAligned : kWordAligned);
   if (!allocation.To(&object)) return allocation;
 
-  object->set_map_after_allocation(MapForFixedTypedArray(array_type),
-                                   SKIP_WRITE_BARRIER);
+  object->set_map_after_allocation(
+      ReadOnlyRoots(this).MapForFixedTypedArray(array_type),
+      SKIP_WRITE_BARRIER);
   FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(object);
   elements->set_base_pointer(elements, SKIP_WRITE_BARRIER);
   elements->set_external_pointer(
@@ -390,8 +394,8 @@ bool Heap::CreateInitialMaps() {
 
     {  // Create a separate external one byte string map for native sources.
       AllocationResult allocation =
-          AllocateMap(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE,
-                      ExternalOneByteString::kShortSize);
+          AllocateMap(UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE,
+                      ExternalOneByteString::kUncachedSize);
       if (!allocation.To(&obj)) return false;
       Map* map = Map::cast(obj);
       map->SetConstructorFunctionIndex(Context::STRING_FUNCTION_INDEX);
@@ -461,6 +465,7 @@ bool Heap::CreateInitialMaps() {
     ALLOCATE_VARSIZE_MAP(CATCH_CONTEXT_TYPE, catch_context)
     ALLOCATE_VARSIZE_MAP(WITH_CONTEXT_TYPE, with_context)
     ALLOCATE_VARSIZE_MAP(DEBUG_EVALUATE_CONTEXT_TYPE, debug_evaluate_context)
+    ALLOCATE_VARSIZE_MAP(AWAIT_CONTEXT_TYPE, await_context)
     ALLOCATE_VARSIZE_MAP(BLOCK_CONTEXT_TYPE, block_context)
     ALLOCATE_VARSIZE_MAP(MODULE_CONTEXT_TYPE, module_context)
     ALLOCATE_VARSIZE_MAP(EVAL_CONTEXT_TYPE, eval_context)
@@ -696,35 +701,35 @@ void Heap::CreateInitialObjects() {
 
   {
     HandleScope scope(isolate());
-#define SYMBOL_INIT(name)                                           \
+#define SYMBOL_INIT(_, name)                                        \
   {                                                                 \
     Handle<Symbol> symbol(                                          \
         isolate()->factory()->NewPrivateSymbol(TENURED_READ_ONLY)); \
-    roots_[k##name##RootIndex] = *symbol;                           \
+    roots_[RootIndex::k##name] = *symbol;                           \
   }
-    PRIVATE_SYMBOL_LIST(SYMBOL_INIT)
+    PRIVATE_SYMBOL_LIST_GENERATOR(SYMBOL_INIT, /* not used */)
 #undef SYMBOL_INIT
   }
 
   {
     HandleScope scope(isolate());
-#define SYMBOL_INIT(name, description)                                    \
+#define SYMBOL_INIT(_, name, description)                                 \
   Handle<Symbol> name = factory->NewSymbol(TENURED_READ_ONLY);            \
   Handle<String> name##d =                                                \
       factory->NewStringFromStaticChars(#description, TENURED_READ_ONLY); \
   name->set_name(*name##d);                                               \
-  roots_[k##name##RootIndex] = *name;
-    PUBLIC_SYMBOL_LIST(SYMBOL_INIT)
+  roots_[RootIndex::k##name] = *name;
+    PUBLIC_SYMBOL_LIST_GENERATOR(SYMBOL_INIT, /* not used */)
 #undef SYMBOL_INIT
 
-#define SYMBOL_INIT(name, description)                                    \
+#define SYMBOL_INIT(_, name, description)                                 \
   Handle<Symbol> name = factory->NewSymbol(TENURED_READ_ONLY);            \
   Handle<String> name##d =                                                \
       factory->NewStringFromStaticChars(#description, TENURED_READ_ONLY); \
   name->set_is_well_known_symbol(true);                                   \
   name->set_name(*name##d);                                               \
-  roots_[k##name##RootIndex] = *name;
-    WELL_KNOWN_SYMBOL_LIST(SYMBOL_INIT)
+  roots_[RootIndex::k##name] = *name;
+    WELL_KNOWN_SYMBOL_LIST_GENERATOR(SYMBOL_INIT, /* not used */)
 #undef SYMBOL_INIT
 
     // Mark "Interesting Symbols" appropriately.
@@ -754,9 +759,7 @@ void Heap::CreateInitialObjects() {
       factory->NewManyClosuresCell(factory->undefined_value());
   set_many_closures_cell(*many_closures_cell);
 
-  // Microtask queue uses the empty fixed array as a sentinel for "empty".
-  // Number of queued microtasks stored in Isolate::pending_microtask_count().
-  set_microtask_queue(roots.empty_fixed_array());
+  set_default_microtask_queue(*factory->NewMicrotaskQueue());
 
   {
     Handle<FixedArray> empty_sloppy_arguments_elements =
@@ -815,6 +818,9 @@ void Heap::CreateInitialObjects() {
   // Allocate the empty script.
   Handle<Script> script = factory->NewScript(factory->empty_string());
   script->set_type(Script::TYPE_NATIVE);
+  // This is used for exceptions thrown with no stack frames. Such exceptions
+  // can be shared everywhere.
+  script->set_origin_options(ScriptOriginOptions(true, false));
   set_empty_script(*script);
 
   Handle<Cell> array_constructor_cell = factory->NewCell(
@@ -849,6 +855,10 @@ void Heap::CreateInitialObjects() {
   cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
   set_promise_species_protector(*cell);
 
+  cell = factory->NewPropertyCell(factory->empty_string());
+  cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
+  set_string_iterator_protector(*cell);
+
   Handle<Cell> string_length_overflow_cell = factory->NewCell(
       handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_string_length_protector(*string_length_overflow_cell);
@@ -874,11 +884,6 @@ void Heap::CreateInitialObjects() {
 
   set_noscript_shared_function_infos(roots.empty_weak_array_list());
 
-  STATIC_ASSERT(interpreter::BytecodeOperands::kOperandScaleCount == 3);
-  set_deserialize_lazy_handler(Smi::kZero);
-  set_deserialize_lazy_handler_wide(Smi::kZero);
-  set_deserialize_lazy_handler_extra_wide(Smi::kZero);
-
   // Evaluate the hash values which will then be cached in the strings.
   isolate()->factory()->zero_string()->Hash();
   isolate()->factory()->one_string()->Hash();
@@ -901,16 +906,19 @@ void Heap::CreateInternalAccessorInfoObjects() {
   HandleScope scope(isolate);
   Handle<AccessorInfo> acessor_info;
 
-#define INIT_ACCESSOR_INFO(accessor_name, AccessorName)        \
-  acessor_info = Accessors::Make##AccessorName##Info(isolate); \
-  roots_[k##AccessorName##AccessorRootIndex] = *acessor_info;
-  ACCESSOR_INFO_LIST(INIT_ACCESSOR_INFO)
+#define INIT_ACCESSOR_INFO(_, accessor_name, AccessorName, ...) \
+  acessor_info = Accessors::Make##AccessorName##Info(isolate);  \
+  roots_[RootIndex::k##AccessorName##Accessor] = *acessor_info;
+  ACCESSOR_INFO_LIST_GENERATOR(INIT_ACCESSOR_INFO, /* not used */)
 #undef INIT_ACCESSOR_INFO
 
-#define INIT_SIDE_EFFECT_FLAG(AccessorName)                      \
-  AccessorInfo::cast(roots_[k##AccessorName##AccessorRootIndex]) \
-      ->set_has_no_side_effect(true);
-  SIDE_EFFECT_FREE_ACCESSOR_INFO_LIST(INIT_SIDE_EFFECT_FLAG)
+#define INIT_SIDE_EFFECT_FLAG(_, accessor_name, AccessorName, GetterType, \
+                              SetterType)                                 \
+  AccessorInfo::cast(roots_[RootIndex::k##AccessorName##Accessor])        \
+      ->set_getter_side_effect_type(SideEffectType::GetterType);          \
+  AccessorInfo::cast(roots_[RootIndex::k##AccessorName##Accessor])        \
+      ->set_setter_side_effect_type(SideEffectType::SetterType);
+  ACCESSOR_INFO_LIST_GENERATOR(INIT_SIDE_EFFECT_FLAG, /* not used */)
 #undef INIT_SIDE_EFFECT_FLAG
 }
 
diff --git a/deps/v8/src/heap/spaces-inl.h b/deps/v8/src/heap/spaces-inl.h
index 9e86905d00..7162769e5e 100644
--- a/deps/v8/src/heap/spaces-inl.h
+++ b/deps/v8/src/heap/spaces-inl.h
@@ -5,6 +5,8 @@
 #ifndef V8_HEAP_SPACES_INL_H_
 #define V8_HEAP_SPACES_INL_H_
 
+#include "src/base/atomic-utils.h"
+#include "src/base/bounded-page-allocator.h"
 #include "src/base/v8-fallthrough.h"
 #include "src/heap/incremental-marking.h"
 #include "src/heap/spaces.h"
@@ -92,6 +94,27 @@ HeapObject* HeapObjectIterator::FromCurrentPage() {
   return nullptr;
 }
 
+void Space::IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                               size_t amount) {
+  base::CheckedIncrement(&external_backing_store_bytes_[type], amount);
+  heap()->IncrementExternalBackingStoreBytes(type, amount);
+}
+
+void Space::DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                               size_t amount) {
+  base::CheckedDecrement(&external_backing_store_bytes_[type], amount);
+  heap()->DecrementExternalBackingStoreBytes(type, amount);
+}
+
+void Space::MoveExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                          Space* from, Space* to,
+                                          size_t amount) {
+  if (from == to) return;
+
+  base::CheckedDecrement(&(from->external_backing_store_bytes_[type]), amount);
+  base::CheckedIncrement(&(to->external_backing_store_bytes_[type]), amount);
+}
+
 // -----------------------------------------------------------------------------
 // SemiSpace
 
@@ -189,6 +212,28 @@ MemoryChunk* MemoryChunk::FromAnyPointerAddress(Heap* heap, Address addr) {
   return chunk;
 }
 
+void MemoryChunk::IncrementExternalBackingStoreBytes(
+    ExternalBackingStoreType type, size_t amount) {
+  base::CheckedIncrement(&external_backing_store_bytes_[type], amount);
+  owner()->IncrementExternalBackingStoreBytes(type, amount);
+}
+
+void MemoryChunk::DecrementExternalBackingStoreBytes(
+    ExternalBackingStoreType type, size_t amount) {
+  base::CheckedDecrement(&external_backing_store_bytes_[type], amount);
+  owner()->DecrementExternalBackingStoreBytes(type, amount);
+}
+
+void MemoryChunk::MoveExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                MemoryChunk* from,
+                                                MemoryChunk* to,
+                                                size_t amount) {
+  base::CheckedDecrement(&(from->external_backing_store_bytes_[type]), amount);
+  base::CheckedIncrement(&(to->external_backing_store_bytes_[type]), amount);
+  Space::MoveExternalBackingStoreBytes(type, from->owner(), to->owner(),
+                                       amount);
+}
+
 void Page::MarkNeverAllocateForTesting() {
   DCHECK(this->owner()->identity() != NEW_SPACE);
   DCHECK(!IsFlagSet(NEVER_ALLOCATE_ON_PAGE));
diff --git a/deps/v8/src/heap/spaces.cc b/deps/v8/src/heap/spaces.cc
index ff28ab56b2..dcacea0afc 100644
--- a/deps/v8/src/heap/spaces.cc
+++ b/deps/v8/src/heap/spaces.cc
@@ -15,7 +15,7 @@
 #include "src/heap/concurrent-marking.h"
 #include "src/heap/gc-tracer.h"
 #include "src/heap/heap-controller.h"
-#include "src/heap/incremental-marking.h"
+#include "src/heap/incremental-marking-inl.h"
 #include "src/heap/mark-compact.h"
 #include "src/heap/remembered-set.h"
 #include "src/heap/slot-set.h"
@@ -94,227 +94,115 @@ PauseAllocationObserversScope::~PauseAllocationObserversScope() {
   }
 }
 
-// -----------------------------------------------------------------------------
-// CodeRange
-
 static base::LazyInstance<CodeRangeAddressHint>::type code_range_address_hint =
     LAZY_INSTANCE_INITIALIZER;
 
-CodeRange::CodeRange(Isolate* isolate, size_t requested)
+Address CodeRangeAddressHint::GetAddressHint(size_t code_range_size) {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+  auto it = recently_freed_.find(code_range_size);
+  if (it == recently_freed_.end() || it->second.empty()) {
+    return reinterpret_cast<Address>(GetRandomMmapAddr());
+  }
+  Address result = it->second.back();
+  it->second.pop_back();
+  return result;
+}
+
+void CodeRangeAddressHint::NotifyFreedCodeRange(Address code_range_start,
+                                                size_t code_range_size) {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+  recently_freed_[code_range_size].push_back(code_range_start);
+}
+
+// -----------------------------------------------------------------------------
+// MemoryAllocator
+//
+
+MemoryAllocator::MemoryAllocator(Isolate* isolate, size_t capacity,
+                                 size_t code_range_size)
     : isolate_(isolate),
-      free_list_(0),
-      allocation_list_(0),
-      current_allocation_block_index_(0),
-      requested_code_range_size_(0) {
-  DCHECK(!virtual_memory_.IsReserved());
+      data_page_allocator_(GetPlatformPageAllocator()),
+      code_page_allocator_(nullptr),
+      capacity_(RoundUp(capacity, Page::kPageSize)),
+      size_(0),
+      size_executable_(0),
+      lowest_ever_allocated_(static_cast<Address>(-1ll)),
+      highest_ever_allocated_(kNullAddress),
+      unmapper_(isolate->heap(), this) {
+  InitializeCodePageAllocator(data_page_allocator_, code_range_size);
+}
+
+void MemoryAllocator::InitializeCodePageAllocator(
+    v8::PageAllocator* page_allocator, size_t requested) {
+  DCHECK_NULL(code_page_allocator_instance_.get());
+
+  code_page_allocator_ = page_allocator;
 
   if (requested == 0) {
+    if (!kRequiresCodeRange) return;
     // When a target requires the code range feature, we put all code objects
     // in a kMaximalCodeRangeSize range of virtual address space, so that
     // they can call each other with near calls.
-    if (kRequiresCodeRange) {
-      requested = kMaximalCodeRangeSize;
-    } else {
-      return;
-    }
-  }
-
-  if (requested <= kMinimumCodeRangeSize) {
+    requested = kMaximalCodeRangeSize;
+  } else if (requested <= kMinimumCodeRangeSize) {
     requested = kMinimumCodeRangeSize;
   }
 
   const size_t reserved_area =
       kReservedCodeRangePages * MemoryAllocator::GetCommitPageSize();
-  if (requested < (kMaximalCodeRangeSize - reserved_area))
-    requested += reserved_area;
-
+  if (requested < (kMaximalCodeRangeSize - reserved_area)) {
+    requested += RoundUp(reserved_area, MemoryChunk::kPageSize);
+    // Fullfilling both reserved pages requirement and huge code area
+    // alignments is not supported (requires re-implementation).
+    DCHECK_LE(kCodeRangeAreaAlignment, page_allocator->AllocatePageSize());
+  }
   DCHECK(!kRequiresCodeRange || requested <= kMaximalCodeRangeSize);
 
-  requested_code_range_size_ = requested;
-
-  VirtualMemory reservation;
-  void* hint = code_range_address_hint.Pointer()->GetAddressHint(requested);
-  if (!AlignedAllocVirtualMemory(
-          requested, Max(kCodeRangeAreaAlignment, AllocatePageSize()), hint,
-          &reservation)) {
-    V8::FatalProcessOutOfMemory(isolate,
+  Address hint =
+      RoundDown(code_range_address_hint.Pointer()->GetAddressHint(requested),
+                page_allocator->AllocatePageSize());
+  VirtualMemory reservation(
+      page_allocator, requested, reinterpret_cast<void*>(hint),
+      Max(kCodeRangeAreaAlignment, page_allocator->AllocatePageSize()));
+  if (!reservation.IsReserved()) {
+    V8::FatalProcessOutOfMemory(isolate_,
                                 "CodeRange setup: allocate virtual memory");
   }
+  code_range_ = reservation.region();
 
   // We are sure that we have mapped a block of requested addresses.
   DCHECK_GE(reservation.size(), requested);
   Address base = reservation.address();
 
   // On some platforms, specifically Win64, we need to reserve some pages at
-  // the beginning of an executable space.
+  // the beginning of an executable space. See
+  //   https://cs.chromium.org/chromium/src/components/crash/content/
+  //     app/crashpad_win.cc?rcl=fd680447881449fba2edcf0589320e7253719212&l=204
+  // for details.
   if (reserved_area > 0) {
     if (!reservation.SetPermissions(base, reserved_area,
                                     PageAllocator::kReadWrite))
-      V8::FatalProcessOutOfMemory(isolate, "CodeRange setup: set permissions");
+      V8::FatalProcessOutOfMemory(isolate_, "CodeRange setup: set permissions");
 
     base += reserved_area;
   }
-  Address aligned_base = ::RoundUp(base, MemoryChunk::kAlignment);
-  size_t size = reservation.size() - (aligned_base - base) - reserved_area;
-  allocation_list_.emplace_back(aligned_base, size);
-  current_allocation_block_index_ = 0;
+  Address aligned_base = RoundUp(base, MemoryChunk::kAlignment);
+  size_t size =
+      RoundDown(reservation.size() - (aligned_base - base) - reserved_area,
+                MemoryChunk::kPageSize);
+  DCHECK(IsAligned(aligned_base, kCodeRangeAreaAlignment));
 
   LOG(isolate_,
       NewEvent("CodeRange", reinterpret_cast<void*>(reservation.address()),
                requested));
-  virtual_memory_.TakeControl(&reservation);
-}
-
-CodeRange::~CodeRange() {
-  if (virtual_memory_.IsReserved()) {
-    Address addr = start();
-    virtual_memory_.Free();
-    code_range_address_hint.Pointer()->NotifyFreedCodeRange(
-        reinterpret_cast<void*>(addr), requested_code_range_size_);
-  }
-}
-
-bool CodeRange::CompareFreeBlockAddress(const FreeBlock& left,
-                                        const FreeBlock& right) {
-  return left.start < right.start;
-}
 
-
-bool CodeRange::GetNextAllocationBlock(size_t requested) {
-  for (current_allocation_block_index_++;
-       current_allocation_block_index_ < allocation_list_.size();
-       current_allocation_block_index_++) {
-    if (requested <= allocation_list_[current_allocation_block_index_].size) {
-      return true;  // Found a large enough allocation block.
-    }
-  }
-
-  // Sort and merge the free blocks on the free list and the allocation list.
-  free_list_.insert(free_list_.end(), allocation_list_.begin(),
-                    allocation_list_.end());
-  allocation_list_.clear();
-  std::sort(free_list_.begin(), free_list_.end(), &CompareFreeBlockAddress);
-  for (size_t i = 0; i < free_list_.size();) {
-    FreeBlock merged = free_list_[i];
-    i++;
-    // Add adjacent free blocks to the current merged block.
-    while (i < free_list_.size() &&
-           free_list_[i].start == merged.start + merged.size) {
-      merged.size += free_list_[i].size;
-      i++;
-    }
-    if (merged.size > 0) {
-      allocation_list_.push_back(merged);
-    }
-  }
-  free_list_.clear();
-
-  for (current_allocation_block_index_ = 0;
-       current_allocation_block_index_ < allocation_list_.size();
-       current_allocation_block_index_++) {
-    if (requested <= allocation_list_[current_allocation_block_index_].size) {
-      return true;  // Found a large enough allocation block.
-    }
-  }
-  current_allocation_block_index_ = 0;
-  // Code range is full or too fragmented.
-  return false;
-}
-
-
-Address CodeRange::AllocateRawMemory(const size_t requested_size,
-                                     const size_t commit_size,
-                                     size_t* allocated) {
-  // requested_size includes the header and two guard regions, while commit_size
-  // only includes the header.
-  DCHECK_LE(commit_size,
-            requested_size - 2 * MemoryAllocator::CodePageGuardSize());
-  FreeBlock current;
-  if (!ReserveBlock(requested_size, &current)) {
-    *allocated = 0;
-    return kNullAddress;
-  }
-  *allocated = current.size;
-  DCHECK(IsAddressAligned(current.start, MemoryChunk::kAlignment));
-  if (!isolate_->heap()->memory_allocator()->CommitExecutableMemory(
-          &virtual_memory_, current.start, commit_size, *allocated)) {
-    *allocated = 0;
-    ReleaseBlock(&current);
-    return kNullAddress;
-  }
-  return current.start;
-}
-
-void CodeRange::FreeRawMemory(Address address, size_t length) {
-  DCHECK(IsAddressAligned(address, MemoryChunk::kAlignment));
-  base::LockGuard<base::Mutex> guard(&code_range_mutex_);
-  free_list_.emplace_back(address, length);
-  virtual_memory_.SetPermissions(address, length, PageAllocator::kNoAccess);
-}
-
-bool CodeRange::ReserveBlock(const size_t requested_size, FreeBlock* block) {
-  base::LockGuard<base::Mutex> guard(&code_range_mutex_);
-  DCHECK(allocation_list_.empty() ||
-         current_allocation_block_index_ < allocation_list_.size());
-  if (allocation_list_.empty() ||
-      requested_size > allocation_list_[current_allocation_block_index_].size) {
-    // Find an allocation block large enough.
-    if (!GetNextAllocationBlock(requested_size)) return false;
-  }
-  // Commit the requested memory at the start of the current allocation block.
-  size_t aligned_requested = ::RoundUp(requested_size, MemoryChunk::kAlignment);
-  *block = allocation_list_[current_allocation_block_index_];
-  // Don't leave a small free block, useless for a large object or chunk.
-  if (aligned_requested < (block->size - Page::kPageSize)) {
-    block->size = aligned_requested;
-  }
-  DCHECK(IsAddressAligned(block->start, MemoryChunk::kAlignment));
-  allocation_list_[current_allocation_block_index_].start += block->size;
-  allocation_list_[current_allocation_block_index_].size -= block->size;
-  return true;
-}
-
-
-void CodeRange::ReleaseBlock(const FreeBlock* block) {
-  base::LockGuard<base::Mutex> guard(&code_range_mutex_);
-  free_list_.push_back(*block);
-}
-
-void* CodeRangeAddressHint::GetAddressHint(size_t code_range_size) {
-  base::LockGuard<base::Mutex> guard(&mutex_);
-  auto it = recently_freed_.find(code_range_size);
-  if (it == recently_freed_.end() || it->second.empty()) {
-    return GetRandomMmapAddr();
-  }
-  void* result = it->second.back();
-  it->second.pop_back();
-  return result;
-}
-
-void CodeRangeAddressHint::NotifyFreedCodeRange(void* code_range_start,
-                                                size_t code_range_size) {
-  base::LockGuard<base::Mutex> guard(&mutex_);
-  recently_freed_[code_range_size].push_back(code_range_start);
-}
-
-// -----------------------------------------------------------------------------
-// MemoryAllocator
-//
-
-MemoryAllocator::MemoryAllocator(Isolate* isolate, size_t capacity,
-                                 size_t code_range_size)
-    : isolate_(isolate),
-      code_range_(nullptr),
-      capacity_(RoundUp(capacity, Page::kPageSize)),
-      size_(0),
-      size_executable_(0),
-      lowest_ever_allocated_(static_cast<Address>(-1ll)),
-      highest_ever_allocated_(kNullAddress),
-      unmapper_(isolate->heap(), this) {
-  code_range_ = new CodeRange(isolate_, code_range_size);
+  heap_reservation_.TakeControl(&reservation);
+  code_page_allocator_instance_ = base::make_unique<base::BoundedPageAllocator>(
+      page_allocator, aligned_base, size,
+      static_cast<size_t>(MemoryChunk::kAlignment));
+  code_page_allocator_ = code_page_allocator_instance_.get();
 }
 
-
 void MemoryAllocator::TearDown() {
   unmapper()->TearDown();
 
@@ -328,8 +216,15 @@ void MemoryAllocator::TearDown() {
     last_chunk_.Free();
   }
 
-  delete code_range_;
-  code_range_ = nullptr;
+  if (code_page_allocator_instance_.get()) {
+    DCHECK(!code_range_.is_empty());
+    code_range_address_hint.Pointer()->NotifyFreedCodeRange(code_range_.begin(),
+                                                            code_range_.size());
+    code_range_ = base::AddressRegion();
+    code_page_allocator_instance_.reset();
+  }
+  code_page_allocator_ = nullptr;
+  data_page_allocator_ = nullptr;
 }
 
 class MemoryAllocator::Unmapper::UnmapFreeMemoryTask : public CancelableTask {
@@ -489,61 +384,41 @@ size_t MemoryAllocator::Unmapper::CommittedBufferedMemory() {
   return sum;
 }
 
-bool MemoryAllocator::CommitMemory(Address base, size_t size) {
-  if (!SetPermissions(base, size, PageAllocator::kReadWrite)) {
+bool MemoryAllocator::CommitMemory(VirtualMemory* reservation) {
+  Address base = reservation->address();
+  size_t size = reservation->size();
+  if (!reservation->SetPermissions(base, size, PageAllocator::kReadWrite)) {
     return false;
   }
   UpdateAllocatedSpaceLimits(base, base + size);
+  isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size));
   return true;
 }
 
-void MemoryAllocator::FreeMemory(VirtualMemory* reservation,
-                                 Executability executable) {
-  // TODO(gc) make code_range part of memory allocator?
-  // Code which is part of the code-range does not have its own VirtualMemory.
-  DCHECK(code_range() == nullptr ||
-         !code_range()->contains(reservation->address()));
-  DCHECK(executable == NOT_EXECUTABLE || !code_range()->valid() ||
-         reservation->size() <= Page::kPageSize);
-
-  reservation->Free();
-}
-
-
-void MemoryAllocator::FreeMemory(Address base, size_t size,
-                                 Executability executable) {
-  // TODO(gc) make code_range part of memory allocator?
-  if (code_range() != nullptr && code_range()->contains(base)) {
-    DCHECK(executable == EXECUTABLE);
-    code_range()->FreeRawMemory(base, size);
-  } else {
-    DCHECK(executable == NOT_EXECUTABLE || !code_range()->valid());
-    CHECK(FreePages(reinterpret_cast<void*>(base), size));
+bool MemoryAllocator::UncommitMemory(VirtualMemory* reservation) {
+  size_t size = reservation->size();
+  if (!reservation->SetPermissions(reservation->address(), size,
+                                   PageAllocator::kNoAccess)) {
+    return false;
   }
+  isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
+  return true;
 }
 
-Address MemoryAllocator::ReserveAlignedMemory(size_t size, size_t alignment,
-                                              void* hint,
-                                              VirtualMemory* controller) {
-  VirtualMemory reservation;
-  if (!AlignedAllocVirtualMemory(size, alignment, hint, &reservation)) {
-    return kNullAddress;
-  }
-
-  Address result = reservation.address();
-  size_ += reservation.size();
-  controller->TakeControl(&reservation);
-  return result;
+void MemoryAllocator::FreeMemory(v8::PageAllocator* page_allocator,
+                                 Address base, size_t size) {
+  CHECK(FreePages(page_allocator, reinterpret_cast<void*>(base), size));
 }
 
 Address MemoryAllocator::AllocateAlignedMemory(
     size_t reserve_size, size_t commit_size, size_t alignment,
     Executability executable, void* hint, VirtualMemory* controller) {
+  v8::PageAllocator* page_allocator = this->page_allocator(executable);
   DCHECK(commit_size <= reserve_size);
-  VirtualMemory reservation;
-  Address base =
-      ReserveAlignedMemory(reserve_size, alignment, hint, &reservation);
-  if (base == kNullAddress) return kNullAddress;
+  VirtualMemory reservation(page_allocator, reserve_size, hint, alignment);
+  if (!reservation.IsReserved()) return kNullAddress;
+  Address base = reservation.address();
+  size_ += reservation.size();
 
   if (executable == EXECUTABLE) {
     if (!CommitExecutableMemory(&reservation, base, commit_size,
@@ -608,8 +483,8 @@ void MemoryChunk::SetReadAndExecutable() {
     size_t page_size = MemoryAllocator::GetCommitPageSize();
     DCHECK(IsAddressAligned(protect_start, page_size));
     size_t protect_size = RoundUp(area_size(), page_size);
-    CHECK(SetPermissions(protect_start, protect_size,
-                         PageAllocator::kReadExecute));
+    CHECK(reservation_.SetPermissions(protect_start, protect_size,
+                                      PageAllocator::kReadExecute));
   }
 }
 
@@ -627,15 +502,15 @@ void MemoryChunk::SetReadAndWritable() {
     size_t page_size = MemoryAllocator::GetCommitPageSize();
     DCHECK(IsAddressAligned(unprotect_start, page_size));
     size_t unprotect_size = RoundUp(area_size(), page_size);
-    CHECK(SetPermissions(unprotect_start, unprotect_size,
-                         PageAllocator::kReadWrite));
+    CHECK(reservation_.SetPermissions(unprotect_start, unprotect_size,
+                                      PageAllocator::kReadWrite));
   }
 }
 
 MemoryChunk* MemoryChunk::Initialize(Heap* heap, Address base, size_t size,
                                      Address area_start, Address area_end,
                                      Executability executable, Space* owner,
-                                     VirtualMemory* reservation) {
+                                     VirtualMemory reservation) {
   MemoryChunk* chunk = FromAddress(base);
 
   DCHECK(base == chunk->address());
@@ -696,14 +571,12 @@ MemoryChunk* MemoryChunk::Initialize(Heap* heap, Address base, size_t size,
       size_t page_size = MemoryAllocator::GetCommitPageSize();
       DCHECK(IsAddressAligned(area_start, page_size));
       size_t area_size = RoundUp(area_end - area_start, page_size);
-      CHECK(SetPermissions(area_start, area_size,
-                           PageAllocator::kReadWriteExecute));
+      CHECK(reservation.SetPermissions(area_start, area_size,
+                                       PageAllocator::kReadWriteExecute));
     }
   }
 
-  if (reservation != nullptr) {
-    chunk->reservation_.TakeControl(reservation);
-  }
+  chunk->reservation_ = std::move(reservation);
 
   return chunk;
 }
@@ -863,29 +736,12 @@ MemoryChunk* MemoryAllocator::AllocateChunk(size_t reserve_area_size,
     // Size of header (not executable) plus area (executable).
     size_t commit_size = ::RoundUp(
         CodePageGuardStartOffset() + commit_area_size, GetCommitPageSize());
-// Allocate executable memory either from code range or from the OS.
-#ifdef V8_TARGET_ARCH_MIPS64
-    // Use code range only for large object space on mips64 to keep address
-    // range within 256-MB memory region.
-    if (code_range()->valid() && reserve_area_size > CodePageAreaSize()) {
-#else
-    if (code_range()->valid()) {
-#endif
-      base =
-          code_range()->AllocateRawMemory(chunk_size, commit_size, &chunk_size);
-      DCHECK(IsAligned(base, MemoryChunk::kAlignment));
-      if (base == kNullAddress) return nullptr;
-      size_ += chunk_size;
-      // Update executable memory size.
-      size_executable_ += chunk_size;
-    } else {
-      base = AllocateAlignedMemory(chunk_size, commit_size,
-                                   MemoryChunk::kAlignment, executable,
-                                   address_hint, &reservation);
-      if (base == kNullAddress) return nullptr;
-      // Update executable memory size.
-      size_executable_ += reservation.size();
-    }
+    base =
+        AllocateAlignedMemory(chunk_size, commit_size, MemoryChunk::kAlignment,
+                              executable, address_hint, &reservation);
+    if (base == kNullAddress) return nullptr;
+    // Update executable memory size.
+    size_executable_ += reservation.size();
 
     if (Heap::ShouldZapGarbage()) {
       ZapBlock(base, CodePageGuardStartOffset(), kZapValue);
@@ -928,7 +784,7 @@ MemoryChunk* MemoryAllocator::AllocateChunk(size_t reserve_area_size,
   if ((base + chunk_size) == 0u) {
     CHECK(!last_chunk_.IsReserved());
     last_chunk_.TakeControl(&reservation);
-    UncommitBlock(last_chunk_.address(), last_chunk_.size());
+    UncommitMemory(&last_chunk_);
     size_ -= chunk_size;
     if (executable == EXECUTABLE) {
       size_executable_ -= chunk_size;
@@ -940,7 +796,7 @@ MemoryChunk* MemoryAllocator::AllocateChunk(size_t reserve_area_size,
 
   MemoryChunk* chunk =
       MemoryChunk::Initialize(heap, base, chunk_size, area_start, area_end,
-                              executable, owner, &reservation);
+                              executable, owner, std::move(reservation));
 
   if (chunk->executable()) RegisterExecutableMemoryChunk(chunk);
   return chunk;
@@ -1128,12 +984,15 @@ void MemoryAllocator::PerformFreeMemory(MemoryChunk* chunk) {
 
   VirtualMemory* reservation = chunk->reserved_memory();
   if (chunk->IsFlagSet(MemoryChunk::POOLED)) {
-    UncommitBlock(reinterpret_cast<Address>(chunk), MemoryChunk::kPageSize);
+    UncommitMemory(reservation);
   } else {
     if (reservation->IsReserved()) {
-      FreeMemory(reservation, chunk->executable());
+      reservation->Free();
     } else {
-      FreeMemory(chunk->address(), chunk->size(), chunk->executable());
+      // Only read-only pages can have non-initialized reservation object.
+      DCHECK_EQ(RO_SPACE, chunk->owner()->identity());
+      FreeMemory(page_allocator(chunk->executable()), chunk->address(),
+                 chunk->size());
     }
   }
 }
@@ -1147,8 +1006,9 @@ void MemoryAllocator::Free(MemoryChunk* chunk) {
       break;
     case kAlreadyPooled:
       // Pooled pages cannot be touched anymore as their memory is uncommitted.
-      FreeMemory(chunk->address(), static_cast<size_t>(MemoryChunk::kPageSize),
-                 Executability::NOT_EXECUTABLE);
+      // Pooled pages are not-executable.
+      FreeMemory(data_page_allocator(), chunk->address(),
+                 static_cast<size_t>(MemoryChunk::kPageSize));
       break;
     case kPooledAndQueue:
       DCHECK_EQ(chunk->size(), static_cast<size_t>(MemoryChunk::kPageSize));
@@ -1216,34 +1076,19 @@ MemoryChunk* MemoryAllocator::AllocatePagePooled(SpaceType* owner) {
   const Address start = reinterpret_cast<Address>(chunk);
   const Address area_start = start + MemoryChunk::kObjectStartOffset;
   const Address area_end = start + size;
-  if (!CommitBlock(start, size)) {
-    return nullptr;
+  // Pooled pages are always regular data pages.
+  DCHECK_NE(CODE_SPACE, owner->identity());
+  VirtualMemory reservation(data_page_allocator(), start, size);
+  if (!CommitMemory(&reservation)) return nullptr;
+  if (Heap::ShouldZapGarbage()) {
+    ZapBlock(start, size, kZapValue);
   }
-  VirtualMemory reservation(start, size);
   MemoryChunk::Initialize(isolate_->heap(), start, size, area_start, area_end,
-                          NOT_EXECUTABLE, owner, &reservation);
+                          NOT_EXECUTABLE, owner, std::move(reservation));
   size_ += size;
   return chunk;
 }
 
-bool MemoryAllocator::CommitBlock(Address start, size_t size) {
-  if (!CommitMemory(start, size)) return false;
-
-  if (Heap::ShouldZapGarbage()) {
-    ZapBlock(start, size, kZapValue);
-  }
-
-  isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size));
-  return true;
-}
-
-
-bool MemoryAllocator::UncommitBlock(Address start, size_t size) {
-  if (!SetPermissions(start, size, PageAllocator::kNoAccess)) return false;
-  isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
-  return true;
-}
-
 void MemoryAllocator::ZapBlock(Address start, size_t size,
                                uintptr_t zap_value) {
   DCHECK_EQ(start % kPointerSize, 0);
@@ -1441,6 +1286,17 @@ void MemoryChunk::RegisterObjectWithInvalidatedSlots(HeapObject* object,
   }
 }
 
+bool MemoryChunk::RegisteredObjectWithInvalidatedSlots(HeapObject* object) {
+  if (ShouldSkipEvacuationSlotRecording()) {
+    // Invalidated slots do not matter if we are not recording slots.
+    return true;
+  }
+  if (invalidated_slots() == nullptr) {
+    return false;
+  }
+  return invalidated_slots()->find(object) != invalidated_slots()->end();
+}
+
 void MemoryChunk::MoveObjectWithInvalidatedSlots(HeapObject* old_start,
                                                  HeapObject* new_start) {
   DCHECK_LT(old_start, new_start);
@@ -1474,19 +1330,6 @@ void MemoryChunk::ReleaseYoungGenerationBitmap() {
   young_generation_bitmap_ = nullptr;
 }
 
-void MemoryChunk::IncrementExternalBackingStoreBytes(
-    ExternalBackingStoreType type, size_t amount) {
-  external_backing_store_bytes_[type] += amount;
-  owner()->IncrementExternalBackingStoreBytes(type, amount);
-}
-
-void MemoryChunk::DecrementExternalBackingStoreBytes(
-    ExternalBackingStoreType type, size_t amount) {
-  DCHECK_GE(external_backing_store_bytes_[type], amount);
-  external_backing_store_bytes_[type] -= amount;
-  owner()->DecrementExternalBackingStoreBytes(type, amount);
-}
-
 // -----------------------------------------------------------------------------
 // PagedSpace implementation
 
@@ -2027,7 +1870,7 @@ void PagedSpace::Verify(Isolate* isolate, ObjectVisitor* visitor) {
       } else if (object->IsJSArrayBuffer()) {
         JSArrayBuffer* array_buffer = JSArrayBuffer::cast(object);
         if (ArrayBufferTracker::IsTracked(array_buffer)) {
-          size_t size = NumberToSize(array_buffer->byte_length());
+          size_t size = array_buffer->byte_length();
           external_page_bytes[ExternalBackingStoreType::kArrayBuffer] += size;
         }
       }
@@ -2119,12 +1962,12 @@ void PagedSpace::VerifyCountersBeforeConcurrentSweeping() {
 // -----------------------------------------------------------------------------
 // NewSpace implementation
 
-NewSpace::NewSpace(Heap* heap, size_t initial_semispace_capacity,
+NewSpace::NewSpace(Heap* heap, v8::PageAllocator* page_allocator,
+                   size_t initial_semispace_capacity,
                    size_t max_semispace_capacity)
     : SpaceWithLinearArea(heap, NEW_SPACE),
       to_space_(heap, kToSpace),
-      from_space_(heap, kFromSpace),
-      reservation_() {
+      from_space_(heap, kFromSpace) {
   DCHECK(initial_semispace_capacity <= max_semispace_capacity);
   DCHECK(
       base::bits::IsPowerOfTwo(static_cast<uint32_t>(max_semispace_capacity)));
@@ -2515,7 +2358,7 @@ void NewSpace::Verify(Isolate* isolate) {
       } else if (object->IsJSArrayBuffer()) {
         JSArrayBuffer* array_buffer = JSArrayBuffer::cast(object);
         if (ArrayBufferTracker::IsTracked(array_buffer)) {
-          size_t size = NumberToSize(array_buffer->byte_length());
+          size_t size = array_buffer->byte_length();
           external_space_bytes[ExternalBackingStoreType::kArrayBuffer] += size;
         }
       }
@@ -3130,7 +2973,7 @@ size_t FreeListCategory::SumFreeList() {
   size_t sum = 0;
   FreeSpace* cur = top();
   while (cur != nullptr) {
-    DCHECK(cur->map() == page()->heap()->root(Heap::kFreeSpaceMapRootIndex));
+    DCHECK(cur->map() == page()->heap()->root(RootIndex::kFreeSpaceMap));
     sum += cur->relaxed_read_size();
     cur = cur->next();
   }
@@ -3337,12 +3180,18 @@ void ReadOnlyPage::MakeHeaderRelocatable() {
 void ReadOnlySpace::SetPermissionsForPages(PageAllocator::Permission access) {
   const size_t page_size = MemoryAllocator::GetCommitPageSize();
   const size_t area_start_offset = RoundUp(Page::kObjectStartOffset, page_size);
+  MemoryAllocator* memory_allocator = heap()->memory_allocator();
   for (Page* p : *this) {
     ReadOnlyPage* page = static_cast<ReadOnlyPage*>(p);
     if (access == PageAllocator::kRead) {
       page->MakeHeaderRelocatable();
     }
-    CHECK(SetPermissions(page->address() + area_start_offset,
+
+    // Read only pages don't have valid reservation object so we get proper
+    // page allocator manually.
+    v8::PageAllocator* page_allocator =
+        memory_allocator->page_allocator(page->executable());
+    CHECK(SetPermissions(page_allocator, page->address() + area_start_offset,
                          page->size() - area_start_offset, access));
   }
 }
@@ -3473,13 +3322,7 @@ LargePage* LargeObjectSpace::AllocateLargePage(int object_size,
   if (page == nullptr) return nullptr;
   DCHECK_GE(page->area_size(), static_cast<size_t>(object_size));
 
-  size_ += static_cast<int>(page->size());
-  AccountCommitted(page->size());
-  objects_size_ += object_size;
-  page_count_++;
-  memory_chunk_list_.PushBack(page);
-
-  InsertChunkMapEntries(page);
+  Register(page, object_size);
 
   HeapObject* object = page->GetObject();
 
@@ -3572,6 +3415,39 @@ void LargeObjectSpace::RemoveChunkMapEntries(LargePage* page,
   }
 }
 
+void LargeObjectSpace::PromoteNewLargeObject(LargePage* page) {
+  DCHECK_EQ(page->owner()->identity(), NEW_LO_SPACE);
+  DCHECK(page->IsFlagSet(MemoryChunk::IN_FROM_SPACE));
+  DCHECK(!page->IsFlagSet(MemoryChunk::IN_TO_SPACE));
+  size_t object_size = static_cast<size_t>(page->GetObject()->Size());
+  reinterpret_cast<NewLargeObjectSpace*>(page->owner())
+      ->Unregister(page, object_size);
+  Register(page, object_size);
+  page->ClearFlag(MemoryChunk::IN_FROM_SPACE);
+  page->SetOldGenerationPageFlags(heap()->incremental_marking()->IsMarking());
+  page->set_owner(this);
+}
+
+void LargeObjectSpace::Register(LargePage* page, size_t object_size) {
+  size_ += static_cast<int>(page->size());
+  AccountCommitted(page->size());
+  objects_size_ += object_size;
+  page_count_++;
+  memory_chunk_list_.PushBack(page);
+
+  InsertChunkMapEntries(page);
+}
+
+void LargeObjectSpace::Unregister(LargePage* page, size_t object_size) {
+  size_ -= static_cast<int>(page->size());
+  AccountUncommitted(page->size());
+  objects_size_ -= object_size;
+  page_count_--;
+  memory_chunk_list_.Remove(page);
+
+  RemoveChunkMapEntries(page);
+}
+
 void LargeObjectSpace::FreeUnmarkedObjects() {
   LargePage* current = first_page();
   IncrementalMarking::NonAtomicMarkingState* marking_state =
@@ -3759,5 +3635,13 @@ size_t NewLargeObjectSpace::Available() {
   // TODO(hpayer): Update as soon as we have a growing strategy.
   return 0;
 }
+
+void NewLargeObjectSpace::Flip() {
+  for (LargePage* chunk = first_page(); chunk != nullptr;
+       chunk = chunk->next_page()) {
+    chunk->SetFlag(MemoryChunk::IN_FROM_SPACE);
+    chunk->ClearFlag(MemoryChunk::IN_TO_SPACE);
+  }
+}
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/spaces.h b/deps/v8/src/heap/spaces.h
index 47272501f3..018e9da47b 100644
--- a/deps/v8/src/heap/spaces.h
+++ b/deps/v8/src/heap/spaces.h
@@ -14,6 +14,7 @@
 
 #include "src/allocation.h"
 #include "src/base/atomic-utils.h"
+#include "src/base/bounded-page-allocator.h"
 #include "src/base/iterator.h"
 #include "src/base/list.h"
 #include "src/base/platform/mutex.h"
@@ -32,7 +33,7 @@ namespace internal {
 
 namespace heap {
 class HeapTester;
-class TestCodeRangeScope;
+class TestCodePageAllocatorScope;
 }  // namespace heap
 
 class AllocationObserver;
@@ -109,11 +110,10 @@ class Space;
 
 // Some assertion macros used in the debugging mode.
 
-#define DCHECK_PAGE_ALIGNED(address) \
-  DCHECK((OffsetFrom(address) & kPageAlignmentMask) == 0)
+#define DCHECK_PAGE_ALIGNED(address) DCHECK_EQ(0, (address)&kPageAlignmentMask)
 
 #define DCHECK_OBJECT_ALIGNED(address) \
-  DCHECK((OffsetFrom(address) & kObjectAlignmentMask) == 0)
+  DCHECK_EQ(0, (address)&kObjectAlignmentMask)
 
 #define DCHECK_OBJECT_SIZE(size) \
   DCHECK((0 < size) && (size <= kMaxRegularHeapObjectSize))
@@ -142,12 +142,6 @@ enum FreeMode { kLinkCategory, kDoNotLinkCategory };
 
 enum class SpaceAccountingMode { kSpaceAccounted, kSpaceUnaccounted };
 
-enum ExternalBackingStoreType {
-  kArrayBuffer,
-  kExternalString,
-  kNumTypes
-};
-
 enum RememberedSetType {
   OLD_TO_NEW,
   OLD_TO_OLD,
@@ -363,7 +357,7 @@ class MemoryChunk {
       + kUIntptrSize      // uintptr_t flags_
       + kPointerSize      // Address area_start_
       + kPointerSize      // Address area_end_
-      + 2 * kPointerSize  // VirtualMemory reservation_
+      + 3 * kPointerSize  // VirtualMemory reservation_
       + kPointerSize      // Address owner_
       + kPointerSize      // Heap* heap_
       + kIntptrSize       // intptr_t progress_bar_
@@ -378,7 +372,7 @@ class MemoryChunk {
       kPointerSize  // std::atomic<ConcurrentSweepingState> concurrent_sweeping_
       + kPointerSize  // base::Mutex* page_protection_change_mutex_
       + kPointerSize  // unitptr_t write_unprotect_counter_
-      + kSizetSize * kNumTypes
+      + kSizetSize * ExternalBackingStoreType::kNumTypes
       // std::atomic<size_t> external_backing_store_bytes_
       + kSizetSize        // size_t allocated_bytes_
       + kSizetSize        // size_t wasted_memory_
@@ -416,7 +410,7 @@ class MemoryChunk {
 
   // Only works if the pointer is in the first kPageSize of the MemoryChunk.
   static MemoryChunk* FromAddress(Address a) {
-    return reinterpret_cast<MemoryChunk*>(OffsetFrom(a) & ~kAlignmentMask);
+    return reinterpret_cast<MemoryChunk*>(a & ~kAlignmentMask);
   }
   // Only works if the object is in the first kPageSize of the MemoryChunk.
   static MemoryChunk* FromHeapObject(const HeapObject* o) {
@@ -444,6 +438,10 @@ class MemoryChunk {
         !chunk->high_water_mark_.compare_exchange_weak(old_mark, new_mark));
   }
 
+  static inline void MoveExternalBackingStoreBytes(
+      ExternalBackingStoreType type, MemoryChunk* from, MemoryChunk* to,
+      size_t amount);
+
   Address address() const {
     return reinterpret_cast<Address>(const_cast<MemoryChunk*>(this));
   }
@@ -518,6 +516,7 @@ class MemoryChunk {
   // Updates invalidated_slots after array left-trimming.
   void MoveObjectWithInvalidatedSlots(HeapObject* old_start,
                                       HeapObject* new_start);
+  bool RegisteredObjectWithInvalidatedSlots(HeapObject* object);
   InvalidatedSlots* invalidated_slots() { return invalidated_slots_; }
 
   void ReleaseLocalTracker();
@@ -550,10 +549,12 @@ class MemoryChunk {
     }
   }
 
-  void IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
-                                          size_t amount);
-  void DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
-                                          size_t amount);
+  inline void IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                 size_t amount);
+
+  inline void DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                 size_t amount);
+
   size_t ExternalBackingStoreBytes(ExternalBackingStoreType type) {
     return external_backing_store_bytes_[type];
   }
@@ -652,7 +653,7 @@ class MemoryChunk {
   static MemoryChunk* Initialize(Heap* heap, Address base, size_t size,
                                  Address area_start, Address area_end,
                                  Executability executable, Space* owner,
-                                 VirtualMemory* reservation);
+                                 VirtualMemory reservation);
 
   // Should be called when memory chunk is about to be freed.
   void ReleaseAllocatedMemory();
@@ -775,7 +776,7 @@ class Page : public MemoryChunk {
   // from [page_addr .. page_addr + kPageSize[. This only works if the object
   // is in fact in a page.
   static Page* FromAddress(Address addr) {
-    return reinterpret_cast<Page*>(OffsetFrom(addr) & ~kPageAlignmentMask);
+    return reinterpret_cast<Page*>(addr & ~kPageAlignmentMask);
   }
   static Page* FromHeapObject(const HeapObject* o) {
     return reinterpret_cast<Page*>(reinterpret_cast<Address>(o) &
@@ -797,7 +798,7 @@ class Page : public MemoryChunk {
 
   // Checks whether an address is page aligned.
   static bool IsAlignedToPageSize(Address addr) {
-    return (OffsetFrom(addr) & kPageAlignmentMask) == 0;
+    return (addr & kPageAlignmentMask) == 0;
   }
 
   static bool IsAtObjectStart(Address addr) {
@@ -894,10 +895,23 @@ class ReadOnlyPage : public Page {
   // Clears any pointers in the header that point out of the page that would
   // otherwise make the header non-relocatable.
   void MakeHeaderRelocatable();
+
+ private:
+  friend class ReadOnlySpace;
 };
 
 class LargePage : public MemoryChunk {
  public:
+  // A limit to guarantee that we do not overflow typed slot offset in
+  // the old to old remembered set.
+  // Note that this limit is higher than what assembler already imposes on
+  // x64 and ia32 architectures.
+  static const int kMaxCodePageSize = 512 * MB;
+
+  static LargePage* FromHeapObject(const HeapObject* o) {
+    return static_cast<LargePage*>(MemoryChunk::FromHeapObject(o));
+  }
+
   HeapObject* GetObject() { return HeapObject::FromAddress(area_start()); }
 
   inline LargePage* next_page() {
@@ -910,12 +924,6 @@ class LargePage : public MemoryChunk {
 
   void ClearOutOfLiveRangeSlots(Address free_start);
 
-  // A limit to guarantee that we do not overflow typed slot offset in
-  // the old to old remembered set.
-  // Note that this limit is higher than what assembler already imposes on
-  // x64 and ia32 architectures.
-  static const int kMaxCodePageSize = 512 * MB;
-
  private:
   static LargePage* Initialize(Heap* heap, MemoryChunk* chunk,
                                Executability executable);
@@ -941,6 +949,9 @@ class Space : public Malloced {
         0;
   }
 
+  static inline void MoveExternalBackingStoreBytes(
+      ExternalBackingStoreType type, Space* from, Space* to, size_t amount);
+
   virtual ~Space() {
     delete[] external_backing_store_bytes_;
     external_backing_store_bytes_ = nullptr;
@@ -980,12 +991,6 @@ class Space : public Malloced {
   // (e.g. see LargeObjectSpace).
   virtual size_t SizeOfObjects() { return Size(); }
 
-  // Returns amount of off-heap memory in-use by objects in this Space.
-  virtual size_t ExternalBackingStoreBytes(
-      ExternalBackingStoreType type) const {
-    return external_backing_store_bytes_[type];
-  }
-
   // Approximate amount of physical memory committed for this space.
   virtual size_t CommittedPhysicalMemory() = 0;
 
@@ -1015,14 +1020,16 @@ class Space : public Malloced {
     committed_ -= bytes;
   }
 
-  void IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
-                                          size_t amount) {
-    external_backing_store_bytes_[type] += amount;
-  }
-  void DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
-                                          size_t amount) {
-    DCHECK_GE(external_backing_store_bytes_[type], amount);
-    external_backing_store_bytes_[type] -= amount;
+  inline void IncrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                 size_t amount);
+
+  inline void DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
+                                                 size_t amount);
+
+  // Returns amount of off-heap memory in-use by objects in this Space.
+  virtual size_t ExternalBackingStoreBytes(
+      ExternalBackingStoreType type) const {
+    return external_backing_store_bytes_[type];
   }
 
   V8_EXPORT_PRIVATE void* GetRandomMmapAddr();
@@ -1074,94 +1081,6 @@ class MemoryChunkValidator {
 };
 
 
-// ----------------------------------------------------------------------------
-// All heap objects containing executable code (code objects) must be allocated
-// from a 2 GB range of memory, so that they can call each other using 32-bit
-// displacements.  This happens automatically on 32-bit platforms, where 32-bit
-// displacements cover the entire 4GB virtual address space.  On 64-bit
-// platforms, we support this using the CodeRange object, which reserves and
-// manages a range of virtual memory.
-class CodeRange {
- public:
-  CodeRange(Isolate* isolate, size_t requested_size);
-  ~CodeRange();
-
-  bool valid() { return virtual_memory_.IsReserved(); }
-  Address start() {
-    DCHECK(valid());
-    return virtual_memory_.address();
-  }
-  size_t size() {
-    DCHECK(valid());
-    return virtual_memory_.size();
-  }
-  bool contains(Address address) {
-    if (!valid()) return false;
-    Address start = virtual_memory_.address();
-    return start <= address && address < start + virtual_memory_.size();
-  }
-
-  // Allocates a chunk of memory from the large-object portion of
-  // the code range.  On platforms with no separate code range, should
-  // not be called.
-  V8_WARN_UNUSED_RESULT Address AllocateRawMemory(const size_t requested_size,
-                                                  const size_t commit_size,
-                                                  size_t* allocated);
-  void FreeRawMemory(Address buf, size_t length);
-
- private:
-  class FreeBlock {
-   public:
-    FreeBlock() : start(0), size(0) {}
-    FreeBlock(Address start_arg, size_t size_arg)
-        : start(start_arg), size(size_arg) {
-      DCHECK(IsAddressAligned(start, MemoryChunk::kAlignment));
-      DCHECK(size >= static_cast<size_t>(Page::kPageSize));
-    }
-    FreeBlock(void* start_arg, size_t size_arg)
-        : start(reinterpret_cast<Address>(start_arg)), size(size_arg) {
-      DCHECK(IsAddressAligned(start, MemoryChunk::kAlignment));
-      DCHECK(size >= static_cast<size_t>(Page::kPageSize));
-    }
-
-    Address start;
-    size_t size;
-  };
-
-  // Finds a block on the allocation list that contains at least the
-  // requested amount of memory.  If none is found, sorts and merges
-  // the existing free memory blocks, and searches again.
-  // If none can be found, returns false.
-  bool GetNextAllocationBlock(size_t requested);
-  // Compares the start addresses of two free blocks.
-  static bool CompareFreeBlockAddress(const FreeBlock& left,
-                                      const FreeBlock& right);
-  bool ReserveBlock(const size_t requested_size, FreeBlock* block);
-  void ReleaseBlock(const FreeBlock* block);
-
-  Isolate* isolate_;
-
-  // The reserved range of virtual memory that all code objects are put in.
-  VirtualMemory virtual_memory_;
-
-  // The global mutex guards free_list_ and allocation_list_ as GC threads may
-  // access both lists concurrently to the main thread.
-  base::Mutex code_range_mutex_;
-
-  // Freed blocks of memory are added to the free list.  When the allocation
-  // list is exhausted, the free list is sorted and merged to make the new
-  // allocation list.
-  std::vector<FreeBlock> free_list_;
-
-  // Memory is allocated from the free blocks on the allocation list.
-  // The block at current_allocation_block_index_ is the current block.
-  std::vector<FreeBlock> allocation_list_;
-  size_t current_allocation_block_index_;
-  size_t requested_code_range_size_;
-
-  DISALLOW_COPY_AND_ASSIGN(CodeRange);
-};
-
 // The process-wide singleton that keeps track of code range regions with the
 // intention to reuse free code range regions as a workaround for CFG memory
 // leaks (see crbug.com/870054).
@@ -1169,9 +1088,9 @@ class CodeRangeAddressHint {
  public:
   // Returns the most recently freed code range start address for the given
   // size. If there is no such entry, then a random address is returned.
-  V8_EXPORT_PRIVATE void* GetAddressHint(size_t code_range_size);
+  V8_EXPORT_PRIVATE Address GetAddressHint(size_t code_range_size);
 
-  V8_EXPORT_PRIVATE void NotifyFreedCodeRange(void* code_range_start,
+  V8_EXPORT_PRIVATE void NotifyFreedCodeRange(Address code_range_start,
                                               size_t code_range_size);
 
  private:
@@ -1180,7 +1099,7 @@ class CodeRangeAddressHint {
   // addresses. There should be O(1) different code range sizes.
   // The length of each array is limited by the peak number of code ranges,
   // which should be also O(1).
-  std::map<size_t, std::vector<void*>> recently_freed_;
+  std::unordered_map<size_t, std::vector<Address>> recently_freed_;
 };
 
 class SkipList {
@@ -1211,7 +1130,7 @@ class SkipList {
   }
 
   static inline int RegionNumber(Address addr) {
-    return (OffsetFrom(addr) & kPageAlignmentMask) >> kRegionSizeLog2;
+    return (addr & kPageAlignmentMask) >> kRegionSizeLog2;
   }
 
   static void Update(Address addr, int size) {
@@ -1422,16 +1341,11 @@ class V8_EXPORT_PRIVATE MemoryAllocator {
   MemoryChunk* AllocateChunk(size_t reserve_area_size, size_t commit_area_size,
                              Executability executable, Space* space);
 
-  Address ReserveAlignedMemory(size_t requested, size_t alignment, void* hint,
-                               VirtualMemory* controller);
   Address AllocateAlignedMemory(size_t reserve_size, size_t commit_size,
                                 size_t alignment, Executability executable,
                                 void* hint, VirtualMemory* controller);
 
-  bool CommitMemory(Address addr, size_t size);
-
-  void FreeMemory(VirtualMemory* reservation, Executability executable);
-  void FreeMemory(Address addr, size_t size, Executability executable);
+  void FreeMemory(v8::PageAllocator* page_allocator, Address addr, size_t size);
 
   // Partially release |bytes_to_free| bytes starting at |start_free|. Note that
   // internally memory is freed from |start_free| to the end of the reservation.
@@ -1440,23 +1354,19 @@ class V8_EXPORT_PRIVATE MemoryAllocator {
   void PartialFreeMemory(MemoryChunk* chunk, Address start_free,
                          size_t bytes_to_free, Address new_area_end);
 
-  // Commit a contiguous block of memory from the initial chunk.  Assumes that
-  // the address is not kNullAddress, the size is greater than zero, and that
-  // the block is contained in the initial chunk.  Returns true if it succeeded
-  // and false otherwise.
-  bool CommitBlock(Address start, size_t size);
-
   // Checks if an allocated MemoryChunk was intended to be used for executable
   // memory.
   bool IsMemoryChunkExecutable(MemoryChunk* chunk) {
     return executable_memory_.find(chunk) != executable_memory_.end();
   }
 
-  // Uncommit a contiguous block of memory [start..(start+size)[.
-  // start is not kNullAddress, the size is greater than zero, and the
-  // block is contained in the initial chunk.  Returns true if it succeeded
-  // and false otherwise.
-  bool UncommitBlock(Address start, size_t size);
+  // Commit memory region owned by given reservation object.  Returns true if
+  // it succeeded and false otherwise.
+  bool CommitMemory(VirtualMemory* reservation);
+
+  // Uncommit memory region owned by given reservation object. Returns true if
+  // it succeeded and false otherwise.
+  bool UncommitMemory(VirtualMemory* reservation);
 
   // Zaps a contiguous block of memory [start..(start+size)[ with
   // a given zap value.
@@ -1467,10 +1377,38 @@ class V8_EXPORT_PRIVATE MemoryAllocator {
                                                     size_t commit_size,
                                                     size_t reserved_size);
 
-  CodeRange* code_range() { return code_range_; }
+  // Page allocator instance for allocating non-executable pages.
+  // Guaranteed to be a valid pointer.
+  v8::PageAllocator* data_page_allocator() { return data_page_allocator_; }
+
+  // Page allocator instance for allocating executable pages.
+  // Guaranteed to be a valid pointer.
+  v8::PageAllocator* code_page_allocator() { return code_page_allocator_; }
+
+  // Returns page allocator suitable for allocating pages with requested
+  // executability.
+  v8::PageAllocator* page_allocator(Executability executable) {
+    return executable == EXECUTABLE ? code_page_allocator_
+                                    : data_page_allocator_;
+  }
+
+  // A region of memory that may contain executable code including reserved
+  // OS page with read-write access in the beginning.
+  const base::AddressRegion& code_range() const {
+    // |code_range_| >= |optional RW pages| + |code_page_allocator_instance_|
+    DCHECK_IMPLIES(!code_range_.is_empty(), code_page_allocator_instance_);
+    DCHECK_IMPLIES(!code_range_.is_empty(),
+                   code_range_.contains(code_page_allocator_instance_->begin(),
+                                        code_page_allocator_instance_->size()));
+    return code_range_;
+  }
+
   Unmapper* unmapper() { return &unmapper_; }
 
  private:
+  void InitializeCodePageAllocator(v8::PageAllocator* page_allocator,
+                                   size_t requested);
+
   // PreFree logically frees the object, i.e., it takes care of the size
   // bookkeeping and calls the allocation callback.
   void PreFreeMemory(MemoryChunk* chunk);
@@ -1518,7 +1456,43 @@ class V8_EXPORT_PRIVATE MemoryAllocator {
   }
 
   Isolate* isolate_;
-  CodeRange* code_range_;
+
+  // This object controls virtual space reserved for V8 heap instance.
+  // Depending on the configuration it may contain the following:
+  // - no reservation (on 32-bit architectures)
+  // - code range reservation used by bounded code page allocator (on 64-bit
+  //   architectures without pointers compression in V8 heap)
+  // - data + code range reservation (on 64-bit architectures with pointers
+  //   compression in V8 heap)
+  VirtualMemory heap_reservation_;
+
+  // Page allocator used for allocating data pages. Depending on the
+  // configuration it may be a page allocator instance provided by v8::Platform
+  // or a BoundedPageAllocator (when pointer compression is enabled).
+  v8::PageAllocator* data_page_allocator_;
+
+  // Page allocator used for allocating code pages. Depending on the
+  // configuration it may be a page allocator instance provided by v8::Platform
+  // or a BoundedPageAllocator (when pointer compression is enabled or
+  // on those 64-bit architectures where pc-relative 32-bit displacement
+  // can be used for call and jump instructions).
+  v8::PageAllocator* code_page_allocator_;
+
+  // A part of the |heap_reservation_| that may contain executable code
+  // including reserved page with read-write access in the beginning.
+  // See details below.
+  base::AddressRegion code_range_;
+
+  // This unique pointer owns the instance of bounded code allocator
+  // that controls executable pages allocation. It does not control the
+  // optionally existing page in the beginning of the |code_range_|.
+  // So, summarizing all above, the following conditions hold:
+  // 1) |heap_reservation_| >= |code_range_|
+  // 2) |code_range_| >= |optional RW pages| + |code_page_allocator_instance_|.
+  // 3) |heap_reservation_| is AllocatePageSize()-aligned
+  // 4) |code_page_allocator_instance_| is MemoryChunk::kAlignment-aligned
+  // 5) |code_range_| is CommitPageSize()-aligned
+  std::unique_ptr<base::BoundedPageAllocator> code_page_allocator_instance_;
 
   // Maximum space size in bytes.
   size_t capacity_;
@@ -1542,7 +1516,7 @@ class V8_EXPORT_PRIVATE MemoryAllocator {
   // Data structure to remember allocated executable memory chunks.
   std::unordered_set<MemoryChunk*> executable_memory_;
 
-  friend class heap::TestCodeRangeScope;
+  friend class heap::TestCodePageAllocatorScope;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MemoryAllocator);
 };
@@ -1567,7 +1541,7 @@ MemoryAllocator::AllocatePage<MemoryAllocator::kPooled, SemiSpace>(
 
 class V8_EXPORT_PRIVATE ObjectIterator : public Malloced {
  public:
-  virtual ~ObjectIterator() {}
+  virtual ~ObjectIterator() = default;
   virtual HeapObject* Next() = 0;
 };
 
@@ -1701,7 +1675,7 @@ class LinearAllocationArea {
 // functions increase or decrease one of the non-capacity stats in conjunction
 // with capacity, or else they always balance increases and decreases to the
 // non-capacity stats.
-class AllocationStats BASE_EMBEDDED {
+class AllocationStats {
  public:
   AllocationStats() { Clear(); }
 
@@ -2604,8 +2578,8 @@ class NewSpace : public SpaceWithLinearArea {
  public:
   typedef PageIterator iterator;
 
-  NewSpace(Heap* heap, size_t initial_semispace_capacity,
-           size_t max_semispace_capacity);
+  NewSpace(Heap* heap, v8::PageAllocator* page_allocator,
+           size_t initial_semispace_capacity, size_t max_semispace_capacity);
 
   ~NewSpace() override { TearDown(); }
 
@@ -3037,6 +3011,8 @@ class LargeObjectSpace : public Space {
   void RemoveChunkMapEntries(LargePage* page);
   void RemoveChunkMapEntries(LargePage* page, Address free_start);
 
+  void PromoteNewLargeObject(LargePage* page);
+
   // Checks whether a heap object is in this space; O(1).
   bool Contains(HeapObject* obj);
   // Checks whether an address is in the object area in this space. Iterates
@@ -3046,6 +3022,9 @@ class LargeObjectSpace : public Space {
   // Checks whether the space is empty.
   bool IsEmpty() { return first_page() == nullptr; }
 
+  void Register(LargePage* page, size_t object_size);
+  void Unregister(LargePage* page, size_t object_size);
+
   LargePage* first_page() {
     return reinterpret_cast<LargePage*>(Space::first_page());
   }
@@ -3094,6 +3073,8 @@ class NewLargeObjectSpace : public LargeObjectSpace {
 
   // Available bytes for objects in this space.
   size_t Available() override;
+
+  void Flip();
 };
 
 class LargeObjectIterator : public ObjectIterator {
@@ -3108,7 +3089,7 @@ class LargeObjectIterator : public ObjectIterator {
 
 // Iterates over the chunks (pages and large object pages) that can contain
 // pointers to new space or to evacuation candidates.
-class MemoryChunkIterator BASE_EMBEDDED {
+class MemoryChunkIterator {
  public:
   inline explicit MemoryChunkIterator(Heap* heap);
 
diff --git a/deps/v8/src/heap/store-buffer.cc b/deps/v8/src/heap/store-buffer.cc
index b428a82046..f737eb099d 100644
--- a/deps/v8/src/heap/store-buffer.cc
+++ b/deps/v8/src/heap/store-buffer.cc
@@ -31,15 +31,15 @@ StoreBuffer::StoreBuffer(Heap* heap)
 }
 
 void StoreBuffer::SetUp() {
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   const size_t requested_size = kStoreBufferSize * kStoreBuffers;
   // Allocate buffer memory aligned at least to kStoreBufferSize. This lets us
   // use a bit test to detect the ends of the buffers.
   const size_t alignment =
-      std::max<size_t>(kStoreBufferSize, AllocatePageSize());
+      std::max<size_t>(kStoreBufferSize, page_allocator->AllocatePageSize());
   void* hint = AlignedAddress(heap_->GetRandomMmapAddr(), alignment);
-  VirtualMemory reservation;
-  if (!AlignedAllocVirtualMemory(requested_size, alignment, hint,
-                                 &reservation)) {
+  VirtualMemory reservation(page_allocator, requested_size, hint, alignment);
+  if (!reservation.IsReserved()) {
     heap_->FatalProcessOutOfMemory("StoreBuffer::SetUp");
   }
 
diff --git a/deps/v8/src/heap/store-buffer.h b/deps/v8/src/heap/store-buffer.h
index d2c0f9b75f..4dbb471b7a 100644
--- a/deps/v8/src/heap/store-buffer.h
+++ b/deps/v8/src/heap/store-buffer.h
@@ -123,7 +123,7 @@ class StoreBuffer {
         : CancelableTask(isolate),
           store_buffer_(store_buffer),
           tracer_(isolate->heap()->tracer()) {}
-    virtual ~Task() {}
+    ~Task() override = default;
 
    private:
     void RunInternal() override {
diff --git a/deps/v8/src/heap/sweeper.cc b/deps/v8/src/heap/sweeper.cc
index 9e622c3385..4f5ad18bec 100644
--- a/deps/v8/src/heap/sweeper.cc
+++ b/deps/v8/src/heap/sweeper.cc
@@ -76,7 +76,7 @@ class Sweeper::SweeperTask final : public CancelableTask {
         space_to_start_(space_to_start),
         tracer_(isolate->heap()->tracer()) {}
 
-  virtual ~SweeperTask() {}
+  ~SweeperTask() override = default;
 
  private:
   void RunInternal() final {
@@ -111,7 +111,7 @@ class Sweeper::IncrementalSweeperTask final : public CancelableTask {
   IncrementalSweeperTask(Isolate* isolate, Sweeper* sweeper)
       : CancelableTask(isolate), isolate_(isolate), sweeper_(sweeper) {}
 
-  virtual ~IncrementalSweeperTask() {}
+  ~IncrementalSweeperTask() override = default;
 
  private:
   void RunInternal() final {
@@ -447,10 +447,11 @@ int Sweeper::ParallelSweepPage(Page* page, AllocationSpace identity) {
 void Sweeper::ScheduleIncrementalSweepingTask() {
   if (!incremental_sweeper_pending_) {
     incremental_sweeper_pending_ = true;
-    IncrementalSweeperTask* task =
-        new IncrementalSweeperTask(heap_->isolate(), this);
     v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap_->isolate());
-    V8::GetCurrentPlatform()->CallOnForegroundThread(isolate, task);
+    auto taskrunner =
+        V8::GetCurrentPlatform()->GetForegroundTaskRunner(isolate);
+    taskrunner->PostTask(
+        base::make_unique<IncrementalSweeperTask>(heap_->isolate(), this));
   }
 }
 
@@ -530,7 +531,7 @@ class Sweeper::IterabilityTask final : public CancelableTask {
         pending_iterability_task_(pending_iterability_task),
         tracer_(isolate->heap()->tracer()) {}
 
-  virtual ~IterabilityTask() {}
+  ~IterabilityTask() override = default;
 
  private:
   void RunInternal() final {
diff --git a/deps/v8/src/ia32/assembler-ia32-inl.h b/deps/v8/src/ia32/assembler-ia32-inl.h
index 1ce23129e5..4598395642 100644
--- a/deps/v8/src/ia32/assembler-ia32-inl.h
+++ b/deps/v8/src/ia32/assembler-ia32-inl.h
@@ -323,6 +323,10 @@ void Assembler::deserialization_set_target_internal_reference_at(
 
 
 void Operand::set_sib(ScaleFactor scale, Register index, Register base) {
+#ifdef DEBUG
+  AddUsedRegister(index);
+  AddUsedRegister(base);
+#endif
   DCHECK_EQ(len_, 1);
   DCHECK_EQ(scale & -4, 0);
   // Use SIB with no index register only for base esp.
diff --git a/deps/v8/src/ia32/assembler-ia32.cc b/deps/v8/src/ia32/assembler-ia32.cc
index 38b65c583f..ff589c820b 100644
--- a/deps/v8/src/ia32/assembler-ia32.cc
+++ b/deps/v8/src/ia32/assembler-ia32.cc
@@ -55,6 +55,7 @@
 #include "src/deoptimizer.h"
 #include "src/disassembler.h"
 #include "src/macro-assembler.h"
+#include "src/string-constants.h"
 #include "src/v8.h"
 
 namespace v8 {
@@ -76,6 +77,13 @@ Immediate Immediate::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Immediate Immediate::EmbeddedStringConstant(const StringConstantBase* str) {
+  Immediate result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 // -----------------------------------------------------------------------------
 // Implementation of CpuFeatures
 
@@ -300,6 +308,7 @@ Register Operand::reg() const {
 }
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     switch (request.kind()) {
@@ -311,6 +320,12 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         request.code_stub()->set_isolate(isolate);
         object = request.code_stub()->GetCode();
         break;
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        object = str->AllocateStringConstant(isolate);
+        break;
+      }
     }
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     Memory<Handle<Object>>(pc) = object;
@@ -486,6 +501,7 @@ void Assembler::pushad() {
 
 void Assembler::popad() {
   EnsureSpace ensure_space(this);
+  AssertIsAddressable(ebx);
   EMIT(0x61);
 }
 
@@ -522,6 +538,7 @@ void Assembler::push_imm32(int32_t imm32) {
 
 
 void Assembler::push(Register src) {
+  AssertIsAddressable(src);
   EnsureSpace ensure_space(this);
   EMIT(0x50 | src.code());
 }
@@ -534,6 +551,7 @@ void Assembler::push(Operand src) {
 
 
 void Assembler::pop(Register dst) {
+  AssertIsAddressable(dst);
   DCHECK_NOT_NULL(reloc_info_writer.last_pc());
   EnsureSpace ensure_space(this);
   EMIT(0x58 | dst.code());
@@ -605,6 +623,7 @@ void Assembler::mov_w(Operand dst, const Immediate& src) {
 
 
 void Assembler::mov(Register dst, int32_t imm32) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0xB8 | dst.code());
   emit(imm32);
@@ -612,12 +631,14 @@ void Assembler::mov(Register dst, int32_t imm32) {
 
 
 void Assembler::mov(Register dst, const Immediate& x) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0xB8 | dst.code());
   emit(x);
 }
 
 void Assembler::mov(Register dst, Handle<HeapObject> handle) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0xB8 | dst.code());
   emit(handle);
@@ -631,6 +652,8 @@ void Assembler::mov(Register dst, Operand src) {
 
 
 void Assembler::mov(Register dst, Register src) {
+  AssertIsAddressable(src);
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0x89);
   EMIT(0xC0 | src.code() << 3 | dst.code());
@@ -735,6 +758,8 @@ void Assembler::stos() {
 
 
 void Assembler::xchg(Register dst, Register src) {
+  AssertIsAddressable(src);
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   if (src == eax || dst == eax) {  // Single-byte encoding.
     EMIT(0x90 | (src == eax ? dst.code() : src.code()));
@@ -965,6 +990,7 @@ void Assembler::cmpw_ax(Operand op) {
 
 
 void Assembler::dec_b(Register dst) {
+  AssertIsAddressable(dst);
   CHECK(dst.is_byte_register());
   EnsureSpace ensure_space(this);
   EMIT(0xFE);
@@ -979,6 +1005,7 @@ void Assembler::dec_b(Operand dst) {
 
 
 void Assembler::dec(Register dst) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0x48 | dst.code());
 }
@@ -1009,6 +1036,7 @@ void Assembler::div(Operand src) {
 
 
 void Assembler::imul(Register reg) {
+  AssertIsAddressable(reg);
   EnsureSpace ensure_space(this);
   EMIT(0xF7);
   EMIT(0xE8 | reg.code());
@@ -1041,6 +1069,7 @@ void Assembler::imul(Register dst, Operand src, int32_t imm32) {
 
 
 void Assembler::inc(Register dst) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0x40 | dst.code());
 }
@@ -1059,6 +1088,7 @@ void Assembler::lea(Register dst, Operand src) {
 
 
 void Assembler::mul(Register src) {
+  AssertIsAddressable(src);
   EnsureSpace ensure_space(this);
   EMIT(0xF7);
   EMIT(0xE0 | src.code());
@@ -1066,12 +1096,14 @@ void Assembler::mul(Register src) {
 
 
 void Assembler::neg(Register dst) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0xF7);
   EMIT(0xD8 | dst.code());
 }
 
 void Assembler::neg(Operand dst) {
+  AllowExplicitEbxAccessScope register_used_for_regcode(this);
   EnsureSpace ensure_space(this);
   EMIT(0xF7);
   emit_operand(ebx, dst);
@@ -1079,6 +1111,7 @@ void Assembler::neg(Operand dst) {
 
 
 void Assembler::not_(Register dst) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0xF7);
   EMIT(0xD0 | dst.code());
@@ -1115,6 +1148,7 @@ void Assembler::or_(Operand dst, Register src) {
 
 
 void Assembler::rcl(Register dst, uint8_t imm8) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   DCHECK(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
@@ -1129,6 +1163,7 @@ void Assembler::rcl(Register dst, uint8_t imm8) {
 
 
 void Assembler::rcr(Register dst, uint8_t imm8) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   DCHECK(is_uint5(imm8));  // illegal shift count
   if (imm8 == 1) {
@@ -1286,6 +1321,7 @@ void Assembler::test(Register reg, const Immediate& imm) {
     return;
   }
 
+  AssertIsAddressable(reg);
   EnsureSpace ensure_space(this);
   // This is not using emit_arith because test doesn't support
   // sign-extension of 8-bit operands.
@@ -1326,6 +1362,7 @@ void Assembler::test(Operand op, const Immediate& imm) {
 }
 
 void Assembler::test_b(Register reg, Immediate imm8) {
+  AssertIsAddressable(reg);
   DCHECK(imm8.is_uint8());
   EnsureSpace ensure_space(this);
   // Only use test against byte for registers that have a byte
@@ -1355,6 +1392,7 @@ void Assembler::test_b(Operand op, Immediate imm8) {
 }
 
 void Assembler::test_w(Register reg, Immediate imm16) {
+  AssertIsAddressable(reg);
   DCHECK(imm16.is_int16() || imm16.is_uint16());
   EnsureSpace ensure_space(this);
   if (reg == eax) {
@@ -1411,6 +1449,7 @@ void Assembler::xor_(Operand dst, const Immediate& x) {
 }
 
 void Assembler::bswap(Register dst) {
+  AssertIsAddressable(dst);
   EnsureSpace ensure_space(this);
   EMIT(0x0F);
   EMIT(0xC8 + dst.code());
@@ -1839,6 +1878,7 @@ void Assembler::fld_d(Operand adr) {
 }
 
 void Assembler::fstp_s(Operand adr) {
+  AllowExplicitEbxAccessScope register_used_for_regcode(this);
   EnsureSpace ensure_space(this);
   EMIT(0xD9);
   emit_operand(ebx, adr);
@@ -1851,6 +1891,7 @@ void Assembler::fst_s(Operand adr) {
 }
 
 void Assembler::fstp_d(Operand adr) {
+  AllowExplicitEbxAccessScope register_used_for_regcode(this);
   EnsureSpace ensure_space(this);
   EMIT(0xDD);
   emit_operand(ebx, adr);
@@ -1875,6 +1916,7 @@ void Assembler::fild_d(Operand adr) {
 }
 
 void Assembler::fistp_s(Operand adr) {
+  AllowExplicitEbxAccessScope register_used_for_regcode(this);
   EnsureSpace ensure_space(this);
   EMIT(0xDB);
   emit_operand(ebx, adr);
@@ -2162,6 +2204,7 @@ void Assembler::sahf() {
 
 
 void Assembler::setcc(Condition cc, Register reg) {
+  AssertIsAddressable(reg);
   DCHECK(reg.is_byte_register());
   EnsureSpace ensure_space(this);
   EMIT(0x0F);
@@ -2358,7 +2401,7 @@ void Assembler::maxps(XMMRegister dst, Operand src) {
   emit_sse_operand(dst, src);
 }
 
-void Assembler::cmpps(XMMRegister dst, Operand src, int8_t cmp) {
+void Assembler::cmpps(XMMRegister dst, Operand src, uint8_t cmp) {
   EnsureSpace ensure_space(this);
   EMIT(0x0F);
   EMIT(0xC2);
@@ -2617,7 +2660,7 @@ void Assembler::extractps(Register dst, XMMRegister src, byte imm8) {
   EMIT(imm8);
 }
 
-void Assembler::psllw(XMMRegister reg, int8_t shift) {
+void Assembler::psllw(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2626,7 +2669,7 @@ void Assembler::psllw(XMMRegister reg, int8_t shift) {
   EMIT(shift);
 }
 
-void Assembler::pslld(XMMRegister reg, int8_t shift) {
+void Assembler::pslld(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2635,7 +2678,7 @@ void Assembler::pslld(XMMRegister reg, int8_t shift) {
   EMIT(shift);
 }
 
-void Assembler::psrlw(XMMRegister reg, int8_t shift) {
+void Assembler::psrlw(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2644,7 +2687,7 @@ void Assembler::psrlw(XMMRegister reg, int8_t shift) {
   EMIT(shift);
 }
 
-void Assembler::psrld(XMMRegister reg, int8_t shift) {
+void Assembler::psrld(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2653,7 +2696,7 @@ void Assembler::psrld(XMMRegister reg, int8_t shift) {
   EMIT(shift);
 }
 
-void Assembler::psraw(XMMRegister reg, int8_t shift) {
+void Assembler::psraw(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2662,7 +2705,7 @@ void Assembler::psraw(XMMRegister reg, int8_t shift) {
   EMIT(shift);
 }
 
-void Assembler::psrad(XMMRegister reg, int8_t shift) {
+void Assembler::psrad(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2671,7 +2714,7 @@ void Assembler::psrad(XMMRegister reg, int8_t shift) {
   EMIT(shift);
 }
 
-void Assembler::psllq(XMMRegister reg, int8_t shift) {
+void Assembler::psllq(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2689,8 +2732,7 @@ void Assembler::psllq(XMMRegister dst, XMMRegister src) {
   emit_sse_operand(dst, src);
 }
 
-
-void Assembler::psrlq(XMMRegister reg, int8_t shift) {
+void Assembler::psrlq(XMMRegister reg, uint8_t shift) {
   EnsureSpace ensure_space(this);
   EMIT(0x66);
   EMIT(0x0F);
@@ -2757,7 +2799,7 @@ void Assembler::palignr(XMMRegister dst, Operand src, uint8_t mask) {
   EMIT(mask);
 }
 
-void Assembler::pextrb(Operand dst, XMMRegister src, int8_t offset) {
+void Assembler::pextrb(Operand dst, XMMRegister src, uint8_t offset) {
   DCHECK(IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2768,7 +2810,7 @@ void Assembler::pextrb(Operand dst, XMMRegister src, int8_t offset) {
   EMIT(offset);
 }
 
-void Assembler::pextrw(Operand dst, XMMRegister src, int8_t offset) {
+void Assembler::pextrw(Operand dst, XMMRegister src, uint8_t offset) {
   DCHECK(IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2779,7 +2821,7 @@ void Assembler::pextrw(Operand dst, XMMRegister src, int8_t offset) {
   EMIT(offset);
 }
 
-void Assembler::pextrd(Operand dst, XMMRegister src, int8_t offset) {
+void Assembler::pextrd(Operand dst, XMMRegister src, uint8_t offset) {
   DCHECK(IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2790,7 +2832,7 @@ void Assembler::pextrd(Operand dst, XMMRegister src, int8_t offset) {
   EMIT(offset);
 }
 
-void Assembler::insertps(XMMRegister dst, Operand src, int8_t offset) {
+void Assembler::insertps(XMMRegister dst, Operand src, uint8_t offset) {
   DCHECK(IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2801,7 +2843,7 @@ void Assembler::insertps(XMMRegister dst, Operand src, int8_t offset) {
   EMIT(offset);
 }
 
-void Assembler::pinsrb(XMMRegister dst, Operand src, int8_t offset) {
+void Assembler::pinsrb(XMMRegister dst, Operand src, uint8_t offset) {
   DCHECK(IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2812,7 +2854,7 @@ void Assembler::pinsrb(XMMRegister dst, Operand src, int8_t offset) {
   EMIT(offset);
 }
 
-void Assembler::pinsrw(XMMRegister dst, Operand src, int8_t offset) {
+void Assembler::pinsrw(XMMRegister dst, Operand src, uint8_t offset) {
   DCHECK(is_uint8(offset));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2822,7 +2864,7 @@ void Assembler::pinsrw(XMMRegister dst, Operand src, int8_t offset) {
   EMIT(offset);
 }
 
-void Assembler::pinsrd(XMMRegister dst, Operand src, int8_t offset) {
+void Assembler::pinsrd(XMMRegister dst, Operand src, uint8_t offset) {
   DCHECK(IsEnabled(SSE4_1));
   EnsureSpace ensure_space(this);
   EMIT(0x66);
@@ -2933,7 +2975,7 @@ void Assembler::vpd(byte op, XMMRegister dst, XMMRegister src1, Operand src2) {
 }
 
 void Assembler::vcmpps(XMMRegister dst, XMMRegister src1, Operand src2,
-                       int8_t cmp) {
+                       uint8_t cmp) {
   vps(0xC2, dst, src1, src2);
   EMIT(cmp);
 }
@@ -2945,37 +2987,37 @@ void Assembler::vshufps(XMMRegister dst, XMMRegister src1, Operand src2,
   EMIT(imm8);
 }
 
-void Assembler::vpsllw(XMMRegister dst, XMMRegister src, int8_t imm8) {
+void Assembler::vpsllw(XMMRegister dst, XMMRegister src, uint8_t imm8) {
   XMMRegister iop = XMMRegister::from_code(6);
   vinstr(0x71, iop, dst, Operand(src), k66, k0F, kWIG);
   EMIT(imm8);
 }
 
-void Assembler::vpslld(XMMRegister dst, XMMRegister src, int8_t imm8) {
+void Assembler::vpslld(XMMRegister dst, XMMRegister src, uint8_t imm8) {
   XMMRegister iop = XMMRegister::from_code(6);
   vinstr(0x72, iop, dst, Operand(src), k66, k0F, kWIG);
   EMIT(imm8);
 }
 
-void Assembler::vpsrlw(XMMRegister dst, XMMRegister src, int8_t imm8) {
+void Assembler::vpsrlw(XMMRegister dst, XMMRegister src, uint8_t imm8) {
   XMMRegister iop = XMMRegister::from_code(2);
   vinstr(0x71, iop, dst, Operand(src), k66, k0F, kWIG);
   EMIT(imm8);
 }
 
-void Assembler::vpsrld(XMMRegister dst, XMMRegister src, int8_t imm8) {
+void Assembler::vpsrld(XMMRegister dst, XMMRegister src, uint8_t imm8) {
   XMMRegister iop = XMMRegister::from_code(2);
   vinstr(0x72, iop, dst, Operand(src), k66, k0F, kWIG);
   EMIT(imm8);
 }
 
-void Assembler::vpsraw(XMMRegister dst, XMMRegister src, int8_t imm8) {
+void Assembler::vpsraw(XMMRegister dst, XMMRegister src, uint8_t imm8) {
   XMMRegister iop = XMMRegister::from_code(4);
   vinstr(0x71, iop, dst, Operand(src), k66, k0F, kWIG);
   EMIT(imm8);
 }
 
-void Assembler::vpsrad(XMMRegister dst, XMMRegister src, int8_t imm8) {
+void Assembler::vpsrad(XMMRegister dst, XMMRegister src, uint8_t imm8) {
   XMMRegister iop = XMMRegister::from_code(4);
   vinstr(0x72, iop, dst, Operand(src), k66, k0F, kWIG);
   EMIT(imm8);
@@ -3008,41 +3050,41 @@ void Assembler::vpalignr(XMMRegister dst, XMMRegister src1, Operand src2,
   EMIT(mask);
 }
 
-void Assembler::vpextrb(Operand dst, XMMRegister src, int8_t offset) {
+void Assembler::vpextrb(Operand dst, XMMRegister src, uint8_t offset) {
   vinstr(0x14, src, xmm0, dst, k66, k0F3A, kWIG);
   EMIT(offset);
 }
 
-void Assembler::vpextrw(Operand dst, XMMRegister src, int8_t offset) {
+void Assembler::vpextrw(Operand dst, XMMRegister src, uint8_t offset) {
   vinstr(0x15, src, xmm0, dst, k66, k0F3A, kWIG);
   EMIT(offset);
 }
 
-void Assembler::vpextrd(Operand dst, XMMRegister src, int8_t offset) {
+void Assembler::vpextrd(Operand dst, XMMRegister src, uint8_t offset) {
   vinstr(0x16, src, xmm0, dst, k66, k0F3A, kWIG);
   EMIT(offset);
 }
 
 void Assembler::vinsertps(XMMRegister dst, XMMRegister src1, Operand src2,
-                          int8_t offset) {
+                          uint8_t offset) {
   vinstr(0x21, dst, src1, src2, k66, k0F3A, kWIG);
   EMIT(offset);
 }
 
 void Assembler::vpinsrb(XMMRegister dst, XMMRegister src1, Operand src2,
-                        int8_t offset) {
+                        uint8_t offset) {
   vinstr(0x20, dst, src1, src2, k66, k0F3A, kWIG);
   EMIT(offset);
 }
 
 void Assembler::vpinsrw(XMMRegister dst, XMMRegister src1, Operand src2,
-                        int8_t offset) {
+                        uint8_t offset) {
   vinstr(0xC4, dst, src1, src2, k66, k0F, kWIG);
   EMIT(offset);
 }
 
 void Assembler::vpinsrd(XMMRegister dst, XMMRegister src1, Operand src2,
-                        int8_t offset) {
+                        uint8_t offset) {
   vinstr(0x22, dst, src1, src2, k66, k0F3A, kWIG);
   EMIT(offset);
 }
@@ -3143,6 +3185,7 @@ void Assembler::vinstr(byte op, XMMRegister dst, XMMRegister src1, Operand src2,
 }
 
 void Assembler::emit_sse_operand(XMMRegister reg, Operand adr) {
+  AllowExplicitEbxAccessScope accessing_xmm_register(this);
   Register ireg = Register::from_code(reg.code());
   emit_operand(ireg, adr);
 }
@@ -3154,11 +3197,13 @@ void Assembler::emit_sse_operand(XMMRegister dst, XMMRegister src) {
 
 
 void Assembler::emit_sse_operand(Register dst, XMMRegister src) {
+  AssertIsAddressable(dst);
   EMIT(0xC0 | dst.code() << 3 | src.code());
 }
 
 
 void Assembler::emit_sse_operand(XMMRegister dst, Register src) {
+  AssertIsAddressable(src);
   EMIT(0xC0 | (dst.code() << 3) | src.code());
 }
 
@@ -3244,6 +3289,7 @@ void Assembler::GrowBuffer() {
 
 
 void Assembler::emit_arith_b(int op1, int op2, Register dst, int imm8) {
+  AssertIsAddressable(dst);
   DCHECK(is_uint8(op1) && is_uint8(op2));  // wrong opcode
   DCHECK(is_uint8(imm8));
   DCHECK_EQ(op1 & 0x01, 0);  // should be 8bit operation
@@ -3254,6 +3300,7 @@ void Assembler::emit_arith_b(int op1, int op2, Register dst, int imm8) {
 
 
 void Assembler::emit_arith(int sel, Operand dst, const Immediate& x) {
+  AssertIsAddressable(dst);
   DCHECK((0 <= sel) && (sel <= 7));
   Register ireg = Register::from_code(sel);
   if (x.is_int8()) {
@@ -3280,6 +3327,8 @@ void Assembler::emit_operand(XMMRegister reg, Operand adr) {
 }
 
 void Assembler::emit_operand(int code, Operand adr) {
+  AssertIsAddressable(adr);
+  AssertIsAddressable(Register::from_code(code));
   // Isolate-independent code may not embed relocatable addresses.
   DCHECK(!options().isolate_independent_code ||
          adr.rmode_ != RelocInfo::CODE_TARGET);
@@ -3356,17 +3405,20 @@ void Assembler::dd(Label* label) {
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
-  DCHECK(!RelocInfo::IsNone(rmode));
-  if (options().disable_reloc_info_for_patching) return;
-  // Don't record external references unless the heap will be serialized.
-  if (RelocInfo::IsOnlyForSerializer(rmode) &&
-      !options().record_reloc_info_for_serialization && !emit_debug_code()) {
-    return;
-  }
+  if (!ShouldRecordRelocInfo(rmode)) return;
   RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
   reloc_info_writer.Write(&rinfo);
 }
 
+#ifdef DEBUG
+void Assembler::AssertIsAddressable(const Operand& operand) {
+  DCHECK(is_ebx_addressable_ || !operand.UsesEbx());
+}
+
+void Assembler::AssertIsAddressable(const Register& reg) {
+  DCHECK(is_ebx_addressable_ || reg != ebx);
+}
+#endif  // DEBUG
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/ia32/assembler-ia32.h b/deps/v8/src/ia32/assembler-ia32.h
index 69d243a749..b721542f13 100644
--- a/deps/v8/src/ia32/assembler-ia32.h
+++ b/deps/v8/src/ia32/assembler-ia32.h
@@ -140,7 +140,6 @@ typedef XMMRegister Simd128Register;
   constexpr DoubleRegister R = DoubleRegister::from_code<kDoubleCode_##R>();
 DOUBLE_REGISTERS(DEFINE_REGISTER)
 #undef DEFINE_REGISTER
-constexpr DoubleRegister no_double_reg = DoubleRegister::no_reg();
 constexpr DoubleRegister no_dreg = DoubleRegister::no_reg();
 
 // Note that the bit values must match those used in actual instruction encoding
@@ -208,7 +207,7 @@ enum RoundingMode {
 // -----------------------------------------------------------------------------
 // Machine instruction Immediates
 
-class Immediate BASE_EMBEDDED {
+class Immediate {
  public:
   // Calls where x is an Address (uintptr_t) resolve to this overload.
   inline explicit Immediate(int x, RelocInfo::Mode rmode = RelocInfo::NONE) {
@@ -224,6 +223,7 @@ class Immediate BASE_EMBEDDED {
 
   static Immediate EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Immediate EmbeddedCode(CodeStub* code);
+  static Immediate EmbeddedStringConstant(const StringConstantBase* str);
 
   static Immediate CodeRelativeOffset(Label* label) {
     return Immediate(label);
@@ -361,10 +361,17 @@ class V8_EXPORT_PRIVATE Operand {
   // register.
   Register reg() const;
 
+#ifdef DEBUG
+  bool UsesEbx() const { return uses_ebx_; }
+#endif  // DEBUG
+
  private:
   // Set the ModRM byte without an encoded 'reg' register. The
   // register is encoded later as part of the emit_operand operation.
   inline void set_modrm(int mod, Register rm) {
+#ifdef DEBUG
+    AddUsedRegister(rm);
+#endif
     DCHECK_EQ(mod & -4, 0);
     buf_[0] = mod << 6 | rm.code();
     len_ = 1;
@@ -391,12 +398,23 @@ class V8_EXPORT_PRIVATE Operand {
   // Only valid if len_ > 4.
   RelocInfo::Mode rmode_ = RelocInfo::NONE;
 
+#ifdef DEBUG
+  // TODO(v8:6666): Remove once kRootRegister support is complete.
+  bool uses_ebx_ = false;
+  void AddUsedRegister(Register reg) {
+    if (reg == ebx) uses_ebx_ = true;
+  }
+#endif  // DEBUG
+
   // TODO(clemensh): Get rid of this friendship, or make Operand immutable.
   friend class Assembler;
 };
 ASSERT_TRIVIALLY_COPYABLE(Operand);
+// TODO(v8:6666): Re-enable globally once kRootRegister support is complete.
+#ifndef DEBUG
 static_assert(sizeof(Operand) <= 2 * kPointerSize,
               "Operand must be small enough to pass it by value");
+#endif
 
 // -----------------------------------------------------------------------------
 // A Displacement describes the 32bit immediate field of an instruction which
@@ -417,7 +435,7 @@ static_assert(sizeof(Operand) <= 2 * kPointerSize,
 // |31.....2|1......0|
 // [  next  |  type  |
 
-class Displacement BASE_EMBEDDED {
+class Displacement {
  public:
   enum Type { UNCONDITIONAL_JUMP, CODE_RELATIVE, OTHER, CODE_ABSOLUTE };
 
@@ -667,7 +685,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void and_(Operand dst, Register src);
   void and_(Operand dst, const Immediate& x);
 
-  void cmpb(Register reg, Immediate imm8) { cmpb(Operand(reg), imm8); }
+  void cmpb(Register reg, Immediate imm8) {
+    DCHECK(reg.is_byte_register());
+    cmpb(Operand(reg), imm8);
+  }
   void cmpb(Operand op, Immediate imm8);
   void cmpb(Register reg, Operand op);
   void cmpb(Operand op, Register reg);
@@ -983,7 +1004,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void maxps(XMMRegister dst, Operand src);
   void maxps(XMMRegister dst, XMMRegister src) { maxps(dst, Operand(src)); }
 
-  void cmpps(XMMRegister dst, Operand src, int8_t cmp);
+  void cmpps(XMMRegister dst, Operand src, uint8_t cmp);
 #define SSE_CMP_P(instr, imm8)                       \
   void instr##ps(XMMRegister dst, XMMRegister src) { \
     cmpps(dst, Operand(src), imm8);                  \
@@ -1088,15 +1109,15 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void movss(XMMRegister dst, XMMRegister src) { movss(dst, Operand(src)); }
   void extractps(Register dst, XMMRegister src, byte imm8);
 
-  void psllw(XMMRegister reg, int8_t shift);
-  void pslld(XMMRegister reg, int8_t shift);
-  void psrlw(XMMRegister reg, int8_t shift);
-  void psrld(XMMRegister reg, int8_t shift);
-  void psraw(XMMRegister reg, int8_t shift);
-  void psrad(XMMRegister reg, int8_t shift);
-  void psllq(XMMRegister reg, int8_t shift);
+  void psllw(XMMRegister reg, uint8_t shift);
+  void pslld(XMMRegister reg, uint8_t shift);
+  void psrlw(XMMRegister reg, uint8_t shift);
+  void psrld(XMMRegister reg, uint8_t shift);
+  void psraw(XMMRegister reg, uint8_t shift);
+  void psrad(XMMRegister reg, uint8_t shift);
+  void psllq(XMMRegister reg, uint8_t shift);
   void psllq(XMMRegister dst, XMMRegister src);
-  void psrlq(XMMRegister reg, int8_t shift);
+  void psrlq(XMMRegister reg, uint8_t shift);
   void psrlq(XMMRegister dst, XMMRegister src);
 
   void pshufhw(XMMRegister dst, XMMRegister src, uint8_t shuffle) {
@@ -1122,36 +1143,36 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
   void palignr(XMMRegister dst, Operand src, uint8_t mask);
 
-  void pextrb(Register dst, XMMRegister src, int8_t offset) {
+  void pextrb(Register dst, XMMRegister src, uint8_t offset) {
     pextrb(Operand(dst), src, offset);
   }
-  void pextrb(Operand dst, XMMRegister src, int8_t offset);
+  void pextrb(Operand dst, XMMRegister src, uint8_t offset);
   // Use SSE4_1 encoding for pextrw reg, xmm, imm8 for consistency
-  void pextrw(Register dst, XMMRegister src, int8_t offset) {
+  void pextrw(Register dst, XMMRegister src, uint8_t offset) {
     pextrw(Operand(dst), src, offset);
   }
-  void pextrw(Operand dst, XMMRegister src, int8_t offset);
-  void pextrd(Register dst, XMMRegister src, int8_t offset) {
+  void pextrw(Operand dst, XMMRegister src, uint8_t offset);
+  void pextrd(Register dst, XMMRegister src, uint8_t offset) {
     pextrd(Operand(dst), src, offset);
   }
-  void pextrd(Operand dst, XMMRegister src, int8_t offset);
+  void pextrd(Operand dst, XMMRegister src, uint8_t offset);
 
-  void insertps(XMMRegister dst, XMMRegister src, int8_t offset) {
+  void insertps(XMMRegister dst, XMMRegister src, uint8_t offset) {
     insertps(dst, Operand(src), offset);
   }
-  void insertps(XMMRegister dst, Operand src, int8_t offset);
-  void pinsrb(XMMRegister dst, Register src, int8_t offset) {
+  void insertps(XMMRegister dst, Operand src, uint8_t offset);
+  void pinsrb(XMMRegister dst, Register src, uint8_t offset) {
     pinsrb(dst, Operand(src), offset);
   }
-  void pinsrb(XMMRegister dst, Operand src, int8_t offset);
-  void pinsrw(XMMRegister dst, Register src, int8_t offset) {
+  void pinsrb(XMMRegister dst, Operand src, uint8_t offset);
+  void pinsrw(XMMRegister dst, Register src, uint8_t offset) {
     pinsrw(dst, Operand(src), offset);
   }
-  void pinsrw(XMMRegister dst, Operand src, int8_t offset);
-  void pinsrd(XMMRegister dst, Register src, int8_t offset) {
+  void pinsrw(XMMRegister dst, Operand src, uint8_t offset);
+  void pinsrd(XMMRegister dst, Register src, uint8_t offset) {
     pinsrd(dst, Operand(src), offset);
   }
-  void pinsrd(XMMRegister dst, Operand src, int8_t offset);
+  void pinsrd(XMMRegister dst, Operand src, uint8_t offset);
 
   // AVX instructions
   void vfmadd132sd(XMMRegister dst, XMMRegister src1, XMMRegister src2) {
@@ -1414,12 +1435,12 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
   void vshufps(XMMRegister dst, XMMRegister src1, Operand src2, byte imm8);
 
-  void vpsllw(XMMRegister dst, XMMRegister src, int8_t imm8);
-  void vpslld(XMMRegister dst, XMMRegister src, int8_t imm8);
-  void vpsrlw(XMMRegister dst, XMMRegister src, int8_t imm8);
-  void vpsrld(XMMRegister dst, XMMRegister src, int8_t imm8);
-  void vpsraw(XMMRegister dst, XMMRegister src, int8_t imm8);
-  void vpsrad(XMMRegister dst, XMMRegister src, int8_t imm8);
+  void vpsllw(XMMRegister dst, XMMRegister src, uint8_t imm8);
+  void vpslld(XMMRegister dst, XMMRegister src, uint8_t imm8);
+  void vpsrlw(XMMRegister dst, XMMRegister src, uint8_t imm8);
+  void vpsrld(XMMRegister dst, XMMRegister src, uint8_t imm8);
+  void vpsraw(XMMRegister dst, XMMRegister src, uint8_t imm8);
+  void vpsrad(XMMRegister dst, XMMRegister src, uint8_t imm8);
 
   void vpshufhw(XMMRegister dst, XMMRegister src, uint8_t shuffle) {
     vpshufhw(dst, Operand(src), shuffle);
@@ -1446,40 +1467,40 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
   void vpalignr(XMMRegister dst, XMMRegister src1, Operand src2, uint8_t mask);
 
-  void vpextrb(Register dst, XMMRegister src, int8_t offset) {
+  void vpextrb(Register dst, XMMRegister src, uint8_t offset) {
     vpextrb(Operand(dst), src, offset);
   }
-  void vpextrb(Operand dst, XMMRegister src, int8_t offset);
-  void vpextrw(Register dst, XMMRegister src, int8_t offset) {
+  void vpextrb(Operand dst, XMMRegister src, uint8_t offset);
+  void vpextrw(Register dst, XMMRegister src, uint8_t offset) {
     vpextrw(Operand(dst), src, offset);
   }
-  void vpextrw(Operand dst, XMMRegister src, int8_t offset);
-  void vpextrd(Register dst, XMMRegister src, int8_t offset) {
+  void vpextrw(Operand dst, XMMRegister src, uint8_t offset);
+  void vpextrd(Register dst, XMMRegister src, uint8_t offset) {
     vpextrd(Operand(dst), src, offset);
   }
-  void vpextrd(Operand dst, XMMRegister src, int8_t offset);
+  void vpextrd(Operand dst, XMMRegister src, uint8_t offset);
 
   void vinsertps(XMMRegister dst, XMMRegister src1, XMMRegister src2,
-                 int8_t offset) {
+                 uint8_t offset) {
     vinsertps(dst, src1, Operand(src2), offset);
   }
   void vinsertps(XMMRegister dst, XMMRegister src1, Operand src2,
-                 int8_t offset);
+                 uint8_t offset);
   void vpinsrb(XMMRegister dst, XMMRegister src1, Register src2,
-               int8_t offset) {
+               uint8_t offset) {
     vpinsrb(dst, src1, Operand(src2), offset);
   }
-  void vpinsrb(XMMRegister dst, XMMRegister src1, Operand src2, int8_t offset);
+  void vpinsrb(XMMRegister dst, XMMRegister src1, Operand src2, uint8_t offset);
   void vpinsrw(XMMRegister dst, XMMRegister src1, Register src2,
-               int8_t offset) {
+               uint8_t offset) {
     vpinsrw(dst, src1, Operand(src2), offset);
   }
-  void vpinsrw(XMMRegister dst, XMMRegister src1, Operand src2, int8_t offset);
+  void vpinsrw(XMMRegister dst, XMMRegister src1, Operand src2, uint8_t offset);
   void vpinsrd(XMMRegister dst, XMMRegister src1, Register src2,
-               int8_t offset) {
+               uint8_t offset) {
     vpinsrd(dst, src1, Operand(src2), offset);
   }
-  void vpinsrd(XMMRegister dst, XMMRegister src1, Operand src2, int8_t offset);
+  void vpinsrd(XMMRegister dst, XMMRegister src1, Operand src2, uint8_t offset);
 
   void vcvtdq2ps(XMMRegister dst, XMMRegister src) {
     vcvtdq2ps(dst, Operand(src));
@@ -1612,7 +1633,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void vps(byte op, XMMRegister dst, XMMRegister src1, Operand src2);
   void vpd(byte op, XMMRegister dst, XMMRegister src1, Operand src2);
 
-  void vcmpps(XMMRegister dst, XMMRegister src1, Operand src2, int8_t cmp);
+  void vcmpps(XMMRegister dst, XMMRegister src1, Operand src2, uint8_t cmp);
 #define AVX_CMP_P(instr, imm8)                                          \
   void instr##ps(XMMRegister dst, XMMRegister src1, XMMRegister src2) { \
     vcmpps(dst, src1, Operand(src2), imm8);                             \
@@ -1757,6 +1778,30 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     UNREACHABLE();
   }
 
+  // Temporary helper data structures while adding kRootRegister support to ia32
+  // builtins. The SupportsRootRegisterScope is intended to mark each builtin
+  // and helper that fully supports the root register, i.e. that does not
+  // clobber ebx. The AllowExplicitEbxAccessScope marks regions that are allowed
+  // to clobber ebx, e.g. when ebx is spilled and restored.
+  // TODO(v8:6666): Remove once kRootRegister is fully supported.
+  template <bool new_value>
+  class SetRootRegisterSupportScope final {
+   public:
+    explicit SetRootRegisterSupportScope(Assembler* assembler)
+        : assembler_(assembler), old_value_(assembler->is_ebx_addressable_) {
+      assembler_->is_ebx_addressable_ = new_value;
+    }
+    ~SetRootRegisterSupportScope() {
+      assembler_->is_ebx_addressable_ = old_value_;
+    }
+
+   private:
+    Assembler* assembler_;
+    const bool old_value_;
+  };
+  typedef SetRootRegisterSupportScope<false> SupportsRootRegisterScope;
+  typedef SetRootRegisterSupportScope<true> AllowExplicitEbxAccessScope;
+
  protected:
   void emit_sse_operand(XMMRegister reg, Operand adr);
   void emit_sse_operand(XMMRegister dst, XMMRegister src);
@@ -1765,6 +1810,16 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   byte* addr_at(int pos) { return buffer_ + pos; }
 
+#ifdef DEBUG
+  // TODO(v8:6666): Remove once kRootRegister is fully supported.
+  void AssertIsAddressable(const Register& reg);
+  void AssertIsAddressable(const Operand& operand);
+#else
+  // An empty inline definition to avoid slowing down release builds.
+  void AssertIsAddressable(const Register&) {}
+  void AssertIsAddressable(const Operand&) {}
+#endif  // DEBUG
+  bool is_ebx_addressable_ = true;
 
  private:
   uint32_t long_at(int pos)  {
@@ -1868,7 +1923,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 // instructions and relocation information.  The constructor makes
 // sure that there is enough space and (in debug mode) the destructor
 // checks that we did not generate too much.
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit EnsureSpace(Assembler* assembler) : assembler_(assembler) {
     if (assembler_->buffer_overflow()) assembler_->GrowBuffer();
diff --git a/deps/v8/src/ia32/code-stubs-ia32.cc b/deps/v8/src/ia32/code-stubs-ia32.cc
index 7bfc0875cb..63cd5a9621 100644
--- a/deps/v8/src/ia32/code-stubs-ia32.cc
+++ b/deps/v8/src/ia32/code-stubs-ia32.cc
@@ -47,6 +47,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
   __ push(ebx);
 
   __ InitializeRootRegister();
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
 
   // Save copies of the top frame descriptor on the stack.
   ExternalReference c_entry_fp =
@@ -95,6 +96,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
   __ VerifyRootRegister();
 
   // Check if the current stack frame is marked as the outermost JS frame.
+  Assembler::AllowExplicitEbxAccessScope exiting_js(masm);
   __ pop(ebx);
   __ cmp(ebx, Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
   __ j(not_equal, &not_outermost_js_2);
@@ -132,6 +134,8 @@ void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
 
 
 void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // Save volatile registers.
   const int kNumSavedRegisters = 3;
   __ push(eax);
@@ -180,9 +184,8 @@ static void PrepareCallApiFunction(MacroAssembler* masm, int argc) {
   }
 }
 
-
 // Calls an API function.  Allocates HandleScope, extracts returned value
-// from handle and propagates exceptions.  Clobbers ebx, edi and
+// from handle and propagates exceptions.  Clobbers esi, edi and
 // caller-save registers.  Restores context.  On return removes
 // stack_space * kPointerSize (GCed).
 static void CallApiFunctionAndReturn(MacroAssembler* masm,
@@ -191,6 +194,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
                                      Operand thunk_last_arg, int stack_space,
                                      Operand* stack_space_operand,
                                      Operand return_value_operand) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
   Isolate* isolate = masm->isolate();
 
   ExternalReference next_address =
@@ -202,7 +206,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
 
   DCHECK(edx == function_address);
   // Allocate HandleScope in callee-save registers.
-  __ mov(ebx, __ StaticVariable(next_address));
+  __ mov(esi, __ StaticVariable(next_address));
   __ mov(edi, __ StaticVariable(limit_address));
   __ add(__ StaticVariable(level_address), Immediate(1));
 
@@ -256,7 +260,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ bind(&prologue);
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
-  __ mov(__ StaticVariable(next_address), ebx);
+  __ mov(__ StaticVariable(next_address), esi);
   __ sub(__ StaticVariable(level_address), Immediate(1));
   __ Assert(above_equal, AbortReason::kInvalidHandleScopeLevel);
   __ cmp(edi, __ StaticVariable(limit_address));
@@ -265,7 +269,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   // Leave the API exit frame.
   __ bind(&leave_exit_frame);
   if (stack_space_operand != nullptr) {
-    __ mov(ebx, *stack_space_operand);
+    __ mov(edx, *stack_space_operand);
   }
   __ LeaveApiExitFrame();
 
@@ -314,7 +318,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   if (stack_space_operand != nullptr) {
     DCHECK_EQ(0, stack_space);
     __ pop(ecx);
-    __ add(esp, ebx);
+    __ add(esp, edx);
     __ jmp(ecx);
   } else {
     __ ret(stack_space * kPointerSize);
@@ -339,8 +343,10 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
 }
 
 void CallApiCallbackStub::Generate(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // ----------- S t a t e -------------
-  //  -- ebx                 : call_data
+  //  -- eax                 : call_data
   //  -- ecx                 : holder
   //  -- edx                 : api_function_address
   //  -- esi                 : context
@@ -352,10 +358,10 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   //  -- esp[(argc + 1) * 4] : receiver
   // -----------------------------------
 
-  Register call_data = ebx;
+  Register call_data = eax;
   Register holder = ecx;
   Register api_function_address = edx;
-  Register return_address = eax;
+  Register return_address = edi;
 
   typedef FunctionCallbackArguments FCA;
 
@@ -370,15 +376,15 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   __ pop(return_address);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data
   __ push(call_data);
 
   // return value
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
   // return value default
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
   // isolate
   __ push(Immediate(ExternalReference::isolate_address(isolate())));
   // holder
@@ -429,6 +435,8 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
 
 
 void CallApiGetterStub::Generate(MacroAssembler* masm) {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm);
+
   // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
   // name below the exit frame to make GC aware of them.
   STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
@@ -443,15 +451,15 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   Register receiver = ApiGetterDescriptor::ReceiverRegister();
   Register holder = ApiGetterDescriptor::HolderRegister();
   Register callback = ApiGetterDescriptor::CallbackRegister();
-  Register scratch = ebx;
+  Register scratch = edi;
   DCHECK(!AreAliased(receiver, holder, callback, scratch));
 
   __ pop(scratch);  // Pop return address to extend the frame.
   __ push(receiver);
   __ push(FieldOperand(callback, AccessorInfo::kDataOffset));
-  __ PushRoot(Heap::kUndefinedValueRootIndex);  // ReturnValue
+  __ PushRoot(RootIndex::kUndefinedValue);  // ReturnValue
   // ReturnValue default value
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
   __ push(Immediate(ExternalReference::isolate_address(isolate())));
   __ push(holder);
   __ push(Immediate(Smi::kZero));  // should_throw_on_error -> false
diff --git a/deps/v8/src/ia32/codegen-ia32.cc b/deps/v8/src/ia32/codegen-ia32.cc
index 2a66676c9c..78790b75d0 100644
--- a/deps/v8/src/ia32/codegen-ia32.cc
+++ b/deps/v8/src/ia32/codegen-ia32.cc
@@ -7,7 +7,6 @@
 #include "src/codegen.h"
 #include "src/heap/factory-inl.h"
 #include "src/heap/heap.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 
 namespace v8 {
@@ -15,13 +14,14 @@ namespace internal {
 
 #define __ masm.
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
   // esp[1 * kPointerSize]: raw double input
   // esp[0 * kPointerSize]: return address
   // Move double input into registers.
@@ -35,12 +35,13 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   }
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 }
 
 
@@ -129,14 +130,14 @@ class LabelConverter {
   byte* buffer_;
 };
 
-
-MemMoveFunction CreateMemMoveFunction(Isolate* isolate) {
+MemMoveFunction CreateMemMoveFunction() {
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
   LabelConverter conv(buffer);
 
   // Generated code is put into a fixed, unmovable buffer, and not into
@@ -447,10 +448,11 @@ MemMoveFunction CreateMemMoveFunction(Isolate* isolate) {
   MemMoveEmitPopAndReturn(&masm);
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
   // TODO(jkummerow): It would be nice to register this code creation event
   // with the PROFILE / GDBJIT system.
   return FUNCTION_CAST<MemMoveFunction>(buffer);
diff --git a/deps/v8/src/ia32/deoptimizer-ia32.cc b/deps/v8/src/ia32/deoptimizer-ia32.cc
index c9cc71f161..2c68241fc2 100644
--- a/deps/v8/src/ia32/deoptimizer-ia32.cc
+++ b/deps/v8/src/ia32/deoptimizer-ia32.cc
@@ -18,6 +18,8 @@ const int Deoptimizer::table_entry_size_ = 10;
 #define __ masm()->
 
 void Deoptimizer::TableEntryGenerator::Generate() {
+  Assembler::SupportsRootRegisterScope supports_root_register(masm());
+
   GeneratePrologue();
 
   // Save all general purpose registers before messing with them.
@@ -53,7 +55,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
       kNumberOfRegisters * kPointerSize + kDoubleRegsSize + kFloatRegsSize;
 
   // Get the bailout id from the stack.
-  __ mov(ebx, Operand(esp, kSavedRegistersAreaSize));
+  __ mov(esi, Operand(esp, kSavedRegistersAreaSize));
 
   // Get the address of the location in the code object
   // and compute the fp-to-sp delta in register edx.
@@ -74,7 +76,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
   __ mov(Operand(esp, 0 * kPointerSize), eax);  // Function.
   __ mov(Operand(esp, 1 * kPointerSize),
          Immediate(static_cast<int>(deopt_kind())));
-  __ mov(Operand(esp, 2 * kPointerSize), ebx);  // Bailout id.
+  __ mov(Operand(esp, 2 * kPointerSize), esi);  // Bailout id.
   __ mov(Operand(esp, 3 * kPointerSize), ecx);  // Code address or 0.
   __ mov(Operand(esp, 4 * kPointerSize), edx);  // Fp-to-sp delta.
   __ mov(Operand(esp, 5 * kPointerSize),
@@ -86,19 +88,19 @@ void Deoptimizer::TableEntryGenerator::Generate() {
 
   // Preserve deoptimizer object in register eax and get the input
   // frame descriptor pointer.
-  __ mov(ebx, Operand(eax, Deoptimizer::input_offset()));
+  __ mov(esi, Operand(eax, Deoptimizer::input_offset()));
 
   // Fill in the input registers.
   for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
-    __ pop(Operand(ebx, offset));
+    __ pop(Operand(esi, offset));
   }
 
   int float_regs_offset = FrameDescription::float_registers_offset();
   // Fill in the float input registers.
   for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
     int dst_offset = i * kFloatSize + float_regs_offset;
-    __ pop(Operand(ebx, dst_offset));
+    __ pop(Operand(esi, dst_offset));
   }
 
   int double_regs_offset = FrameDescription::double_registers_offset();
@@ -108,7 +110,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
     int dst_offset = code * kDoubleSize + double_regs_offset;
     int src_offset = code * kDoubleSize;
     __ movsd(xmm0, Operand(esp, src_offset));
-    __ movsd(Operand(ebx, dst_offset), xmm0);
+    __ movsd(Operand(esi, dst_offset), xmm0);
   }
 
   // Clear FPU all exceptions.
@@ -121,13 +123,13 @@ void Deoptimizer::TableEntryGenerator::Generate() {
 
   // Compute a pointer to the unwinding limit in register ecx; that is
   // the first stack slot not part of the input frame.
-  __ mov(ecx, Operand(ebx, FrameDescription::frame_size_offset()));
+  __ mov(ecx, Operand(esi, FrameDescription::frame_size_offset()));
   __ add(ecx, esp);
 
   // Unwind the stack down to - but not including - the unwinding
   // limit and copy the contents of the activation frame to the input
   // frame description.
-  __ lea(edx, Operand(ebx, FrameDescription::frame_content_offset()));
+  __ lea(edx, Operand(esi, FrameDescription::frame_content_offset()));
   Label pop_loop_header;
   __ jmp(&pop_loop_header);
   Label pop_loop;
@@ -140,7 +142,7 @@ void Deoptimizer::TableEntryGenerator::Generate() {
 
   // Compute the output frame in the deoptimizer.
   __ push(eax);
-  __ PrepareCallCFunction(1, ebx);
+  __ PrepareCallCFunction(1, esi);
   __ mov(Operand(esp, 0 * kPointerSize), eax);
   {
     AllowExternalCallThatCantCauseGC scope(masm());
@@ -153,20 +155,21 @@ void Deoptimizer::TableEntryGenerator::Generate() {
   // Replace the current (input) frame with the output frames.
   Label outer_push_loop, inner_push_loop,
       outer_loop_header, inner_loop_header;
-  // Outer loop state: eax = current FrameDescription**, edx = one past the
-  // last FrameDescription**.
+  // Outer loop state: eax = current FrameDescription**, edx = one
+  // past the last FrameDescription**.
   __ mov(edx, Operand(eax, Deoptimizer::output_count_offset()));
   __ mov(eax, Operand(eax, Deoptimizer::output_offset()));
   __ lea(edx, Operand(eax, edx, times_4, 0));
   __ jmp(&outer_loop_header);
   __ bind(&outer_push_loop);
-  // Inner loop state: ebx = current FrameDescription*, ecx = loop index.
-  __ mov(ebx, Operand(eax, 0));
-  __ mov(ecx, Operand(ebx, FrameDescription::frame_size_offset()));
+  // Inner loop state: esi = current FrameDescription*, ecx = loop
+  // index.
+  __ mov(esi, Operand(eax, 0));
+  __ mov(ecx, Operand(esi, FrameDescription::frame_size_offset()));
   __ jmp(&inner_loop_header);
   __ bind(&inner_push_loop);
   __ sub(ecx, Immediate(sizeof(uint32_t)));
-  __ push(Operand(ebx, ecx, times_1, FrameDescription::frame_content_offset()));
+  __ push(Operand(esi, ecx, times_1, FrameDescription::frame_content_offset()));
   __ bind(&inner_loop_header);
   __ test(ecx, ecx);
   __ j(not_zero, &inner_push_loop);
@@ -180,20 +183,21 @@ void Deoptimizer::TableEntryGenerator::Generate() {
     int code = config->GetAllocatableDoubleCode(i);
     XMMRegister xmm_reg = XMMRegister::from_code(code);
     int src_offset = code * kDoubleSize + double_regs_offset;
-    __ movsd(xmm_reg, Operand(ebx, src_offset));
+    __ movsd(xmm_reg, Operand(esi, src_offset));
   }
 
   // Push pc and continuation from the last output frame.
-  __ push(Operand(ebx, FrameDescription::pc_offset()));
-  __ push(Operand(ebx, FrameDescription::continuation_offset()));
+  __ push(Operand(esi, FrameDescription::pc_offset()));
+  __ push(Operand(esi, FrameDescription::continuation_offset()));
 
   // Push the registers from the last output frame.
   for (int i = 0; i < kNumberOfRegisters; i++) {
     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
-    __ push(Operand(ebx, offset));
+    __ push(Operand(esi, offset));
   }
 
   // Restore the registers from the stack.
+  Assembler::AllowExplicitEbxAccessScope restoring_spilled_value(masm());
   __ popad();
 
   // Return to the continuation point.
diff --git a/deps/v8/src/ia32/interface-descriptors-ia32.cc b/deps/v8/src/ia32/interface-descriptors-ia32.cc
index 71205b10d0..e2c04f7525 100644
--- a/deps/v8/src/ia32/interface-descriptors-ia32.cc
+++ b/deps/v8/src/ia32/interface-descriptors-ia32.cc
@@ -13,13 +13,7 @@ const Register CallInterfaceDescriptor::ContextRegister() { return esi; }
 
 void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
     CallInterfaceDescriptorData* data, int register_parameter_count) {
-#if defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
-  // TODO(jgruber,v8:6666): Keep kRootRegister free unconditionally.
   constexpr Register default_stub_registers[] = {eax, ecx, edx, edi};
-  DCHECK(!AreAliased(eax, ecx, edx, edi, kRootRegister));
-#else
-  constexpr Register default_stub_registers[] = {eax, ebx, ecx, edx, edi};
-#endif
   STATIC_ASSERT(arraysize(default_stub_registers) == kMaxBuiltinRegisterParams);
   CHECK_LE(static_cast<size_t>(register_parameter_count),
            arraysize(default_stub_registers));
@@ -29,7 +23,7 @@ void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
 
 void RecordWriteDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
-  static const Register default_stub_registers[] = {ebx, ecx, edx, edi,
+  static const Register default_stub_registers[] = {ecx, edx, edi,
                                                     kReturnRegister0};
 
   data->RestrictAllocatableRegisters(default_stub_registers,
@@ -49,32 +43,31 @@ const Register LoadDescriptor::ReceiverRegister() { return edx; }
 const Register LoadDescriptor::NameRegister() { return ecx; }
 const Register LoadDescriptor::SlotRegister() { return eax; }
 
-const Register LoadWithVectorDescriptor::VectorRegister() { return ebx; }
+const Register LoadWithVectorDescriptor::VectorRegister() { return no_reg; }
 
 const Register StoreDescriptor::ReceiverRegister() { return edx; }
 const Register StoreDescriptor::NameRegister() { return ecx; }
-const Register StoreDescriptor::ValueRegister() { return eax; }
-const Register StoreDescriptor::SlotRegister() { return edi; }
+const Register StoreDescriptor::ValueRegister() { return no_reg; }
+const Register StoreDescriptor::SlotRegister() { return no_reg; }
 
-const Register StoreWithVectorDescriptor::VectorRegister() { return ebx; }
+const Register StoreWithVectorDescriptor::VectorRegister() { return no_reg; }
 
 const Register StoreTransitionDescriptor::SlotRegister() { return no_reg; }
-const Register StoreTransitionDescriptor::VectorRegister() { return ebx; }
+const Register StoreTransitionDescriptor::VectorRegister() { return no_reg; }
 const Register StoreTransitionDescriptor::MapRegister() { return edi; }
 
 const Register ApiGetterDescriptor::HolderRegister() { return ecx; }
 const Register ApiGetterDescriptor::CallbackRegister() { return eax; }
 
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return eax; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return ebx; }
-
+const Register GrowArrayElementsDescriptor::KeyRegister() { return ecx; }
 
 // static
 const Register TypeConversionDescriptor::ArgumentRegister() { return eax; }
 
 void TypeofDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
-  Register registers[] = {ebx};
+  Register registers[] = {ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -96,9 +89,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // eax : number of arguments (on the stack, not including receiver)
   // edi : the target to call
-  // ebx : arguments list (FixedArray)
   // ecx : arguments list length (untagged)
-  Register registers[] = {edi, eax, ebx, ecx};
+  // On the stack : arguments list (FixedArray)
+  Register registers[] = {edi, eax, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -115,16 +108,16 @@ void CallWithSpreadDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // eax : number of arguments (on the stack, not including receiver)
   // edi : the target to call
-  // ebx : the object to spread
-  Register registers[] = {edi, eax, ebx};
+  // ecx : the object to spread
+  Register registers[] = {edi, eax, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
 void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // edi : the target to call
-  // ebx : the arguments list
-  Register registers[] = {edi, ebx};
+  // edx : the arguments list
+  Register registers[] = {edi, edx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -133,9 +126,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // eax : number of arguments (on the stack, not including receiver)
   // edi : the target to call
   // edx : the new target
-  // ebx : arguments list (FixedArray)
   // ecx : arguments list length (untagged)
-  Register registers[] = {edi, edx, eax, ebx, ecx};
+  // On the stack : arguments list (FixedArray)
+  Register registers[] = {edi, edx, eax, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -154,8 +147,8 @@ void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
   // eax : number of arguments (on the stack, not including receiver)
   // edi : the target to call
   // edx : the new target
-  // ebx : the object to spread
-  Register registers[] = {edi, edx, eax, ebx};
+  // ecx : the object to spread
+  Register registers[] = {edi, edx, eax, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -163,8 +156,8 @@ void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // edi : the target to call
   // edx : the new target
-  // ebx : the arguments list
-  Register registers[] = {edi, edx, ebx};
+  // ecx : the arguments list
+  Register registers[] = {edi, edx, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -173,8 +166,9 @@ void ConstructStubDescriptor::InitializePlatformSpecific(
   // eax : number of arguments
   // edx : the new target
   // edi : the target to call
-  // ebx : allocation site or undefined
-  Register registers[] = {edi, edx, eax, ebx};
+  // ecx : allocation site or undefined
+  // TODO(jgruber): Remove the unused allocation site parameter.
+  Register registers[] = {edi, edx, eax, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -202,13 +196,13 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       edi,  // JSFunction
       edx,  // the new target
       eax,  // actual number of arguments
-      ebx,  // expected number of arguments
+      ecx,  // expected number of arguments
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
@@ -217,7 +211,7 @@ void ApiCallbackDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       JavaScriptFrame::context_register(),  // callee context
-      ebx,                                  // call_data
+      eax,                                  // call_data
       ecx,                                  // holder
       edx,                                  // api_function_address
   };
@@ -236,7 +230,7 @@ void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       eax,  // argument count (not including receiver)
-      ebx,  // address of first argument
+      ecx,  // address of first argument
       edi   // the target callable to be call
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
@@ -246,9 +240,6 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       eax,  // argument count (not including receiver)
-      edx,  // new target
-      edi,  // constructor
-      ebx,  // allocation site feedback
       ecx,  // address of first argument
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
@@ -266,7 +257,7 @@ void ResumeGeneratorDescriptor::InitializePlatformSpecific(
 void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
-      ebx,  // loaded new FP
+      eax,  // loaded new FP
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/ia32/macro-assembler-ia32.cc b/deps/v8/src/ia32/macro-assembler-ia32.cc
index bb806edebd..82cea88ac4 100644
--- a/deps/v8/src/ia32/macro-assembler-ia32.cc
+++ b/deps/v8/src/ia32/macro-assembler-ia32.cc
@@ -51,7 +51,7 @@ MacroAssembler::MacroAssembler(Isolate* isolate,
 #endif  // V8_EMBEDDED_BUILTINS
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
+void TurboAssembler::LoadRoot(Register destination, RootIndex index) {
   // TODO(jgruber, v8:6666): Support loads through the root register once it
   // exists.
   if (isolate()->heap()->RootCanBeTreatedAsConstant(index)) {
@@ -67,22 +67,20 @@ void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
   }
   ExternalReference roots_array_start =
       ExternalReference::roots_array_start(isolate());
-  mov(destination, Immediate(index));
+  mov(destination, Immediate(static_cast<int>(index)));
   mov(destination,
       StaticArray(destination, times_pointer_size, roots_array_start));
 }
 
-void MacroAssembler::CompareRoot(Register with,
-                                 Register scratch,
-                                 Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(Register with, Register scratch,
+                                 RootIndex index) {
   ExternalReference roots_array_start =
       ExternalReference::roots_array_start(isolate());
-  mov(scratch, Immediate(index));
+  mov(scratch, Immediate(static_cast<int>(index)));
   cmp(with, StaticArray(scratch, times_pointer_size, roots_array_start));
 }
 
-
-void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(Register with, RootIndex index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(index));
   Handle<Object> object = isolate()->heap()->root_handle(index);
   if (object->IsHeapObject()) {
@@ -92,7 +90,7 @@ void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
   }
 }
 
-void MacroAssembler::CompareRoot(Operand with, Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(Operand with, RootIndex index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(index));
   Handle<Object> object = isolate()->heap()->root_handle(index);
   if (object->IsHeapObject()) {
@@ -102,7 +100,7 @@ void MacroAssembler::CompareRoot(Operand with, Heap::RootListIndex index) {
   }
 }
 
-void MacroAssembler::PushRoot(Heap::RootListIndex index) {
+void MacroAssembler::PushRoot(RootIndex index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(index));
   Handle<Object> object = isolate()->heap()->root_handle(index);
   if (object->IsHeapObject()) {
@@ -114,11 +112,12 @@ void MacroAssembler::PushRoot(Heap::RootListIndex index) {
 
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
+  DCHECK(!is_ebx_addressable_);
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
+      RootIndex::kBuiltinsConstantsTable));
   // TODO(jgruber): LoadRoot should be a register-relative load once we have
   // the kRootRegister.
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   mov(destination,
       FieldOperand(destination,
                    FixedArray::kHeaderSize + constant_index * kPointerSize));
@@ -126,6 +125,7 @@ void TurboAssembler::LoadFromConstantsTable(Register destination,
 
 void TurboAssembler::LoadRootRegisterOffset(Register destination,
                                             intptr_t offset) {
+  DCHECK(!is_ebx_addressable_);
   DCHECK(is_int32(offset));
   // TODO(jgruber): Register-relative load once kRootRegister exists.
   mov(destination, Immediate(ExternalReference::roots_array_start(isolate())));
@@ -135,6 +135,7 @@ void TurboAssembler::LoadRootRegisterOffset(Register destination,
 }
 
 void TurboAssembler::LoadRootRelative(Register destination, int32_t offset) {
+  DCHECK(!is_ebx_addressable_);
   // TODO(jgruber): Register-relative load once kRootRegister exists.
   LoadRootRegisterOffset(destination, offset);
   mov(destination, Operand(destination, 0));
@@ -326,8 +327,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -339,8 +338,6 @@ void TurboAssembler::CallRecordWriteStub(
   pop(slot_parameter);
   pop(object_parameter);
 
-  mov(isolate_parameter,
-      Immediate(ExternalReference::isolate_address(isolate())));
   Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -410,8 +407,8 @@ void MacroAssembler::MaybeDropFrames() {
   // Check whether we need to drop frames to restart a function on the stack.
   ExternalReference restart_fp =
       ExternalReference::debug_restart_fp_address(isolate());
-  mov(ebx, StaticVariable(restart_fp));
-  test(ebx, ebx);
+  mov(eax, StaticVariable(restart_fp));
+  test(eax, eax);
   j(not_zero, BUILTIN_CODE(isolate(), FrameDropperTrampoline),
     RelocInfo::CODE_TARGET);
 }
@@ -733,6 +730,9 @@ void MacroAssembler::EnterExitFramePrologue(StackFrame::Type frame_type) {
   DCHECK_EQ(-3 * kPointerSize, ExitFrameConstants::kCodeOffset);
   push(Immediate(CodeObject()));  // Accessed from ExitFrame::code_slot.
 
+  STATIC_ASSERT(edx == kRuntimeCallFunctionRegister);
+  STATIC_ASSERT(esi == kContextRegister);
+
   // Save the frame pointer and the context in top.
   ExternalReference c_entry_fp_address =
       ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate());
@@ -1035,6 +1035,9 @@ void MacroAssembler::InvokePrologue(const ParameterCount& expected,
                                     bool* definitely_mismatches,
                                     InvokeFlag flag,
                                     Label::Distance done_near) {
+  DCHECK_IMPLIES(expected.is_reg(), expected.reg() == ecx);
+  DCHECK_IMPLIES(actual.is_reg(), actual.reg() == eax);
+
   bool definitely_matches = false;
   *definitely_mismatches = false;
   Label invoke;
@@ -1053,7 +1056,7 @@ void MacroAssembler::InvokePrologue(const ParameterCount& expected,
         definitely_matches = true;
       } else {
         *definitely_mismatches = true;
-        mov(ebx, expected.immediate());
+        mov(ecx, expected.immediate());
       }
     }
   } else {
@@ -1064,14 +1067,14 @@ void MacroAssembler::InvokePrologue(const ParameterCount& expected,
       mov(eax, actual.immediate());
       cmp(expected.reg(), actual.immediate());
       j(equal, &invoke);
-      DCHECK(expected.reg() == ebx);
+      DCHECK(expected.reg() == ecx);
     } else if (expected.reg() != actual.reg()) {
       // Both expected and actual are in (different) registers. This
       // is the case when we invoke functions using call and apply.
       cmp(expected.reg(), actual.reg());
       j(equal, &invoke);
       DCHECK(actual.reg() == eax);
-      DCHECK(expected.reg() == ebx);
+      DCHECK(expected.reg() == ecx);
     } else {
       definitely_matches = true;
       Move(eax, actual.reg());
@@ -1150,6 +1153,8 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   DCHECK(flag == JUMP_FUNCTION || has_frame());
   DCHECK(function == edi);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == edx);
+  DCHECK_IMPLIES(expected.is_reg(), expected.reg() == ecx);
+  DCHECK_IMPLIES(actual.is_reg(), actual.reg() == eax);
 
   // On function call, call into the debugger if necessary.
   CheckDebugHook(function, new_target, expected, actual);
@@ -1187,28 +1192,15 @@ void MacroAssembler::InvokeFunction(Register fun, Register new_target,
   DCHECK(flag == JUMP_FUNCTION || has_frame());
 
   DCHECK(fun == edi);
-  mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+  mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
   mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
-  movzx_w(ebx,
-          FieldOperand(ebx, SharedFunctionInfo::kFormalParameterCountOffset));
+  movzx_w(ecx,
+          FieldOperand(ecx, SharedFunctionInfo::kFormalParameterCountOffset));
 
-  ParameterCount expected(ebx);
+  ParameterCount expected(ecx);
   InvokeFunctionCode(edi, new_target, expected, actual, flag);
 }
 
-void MacroAssembler::InvokeFunction(Register fun,
-                                    const ParameterCount& expected,
-                                    const ParameterCount& actual,
-                                    InvokeFlag flag) {
-  // You can't call a function without a valid frame.
-  DCHECK(flag == JUMP_FUNCTION || has_frame());
-
-  DCHECK(fun == edi);
-  mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
-
-  InvokeFunctionCode(edi, no_reg, expected, actual, flag);
-}
-
 void MacroAssembler::LoadGlobalProxy(Register dst) {
   mov(dst, NativeContextOperand());
   mov(dst, ContextOperand(dst, Context::GLOBAL_PROXY_INDEX));
@@ -1365,7 +1357,7 @@ void TurboAssembler::Pshufd(XMMRegister dst, Operand src, uint8_t shuffle) {
   }
 }
 
-void TurboAssembler::Psraw(XMMRegister dst, int8_t shift) {
+void TurboAssembler::Psraw(XMMRegister dst, uint8_t shift) {
   if (CpuFeatures::IsSupported(AVX)) {
     CpuFeatureScope scope(this, AVX);
     vpsraw(dst, dst, shift);
@@ -1374,7 +1366,7 @@ void TurboAssembler::Psraw(XMMRegister dst, int8_t shift) {
   }
 }
 
-void TurboAssembler::Psrlw(XMMRegister dst, int8_t shift) {
+void TurboAssembler::Psrlw(XMMRegister dst, uint8_t shift) {
   if (CpuFeatures::IsSupported(AVX)) {
     CpuFeatureScope scope(this, AVX);
     vpsrlw(dst, dst, shift);
@@ -1394,7 +1386,7 @@ void TurboAssembler::Psignb(XMMRegister dst, Operand src) {
     psignb(dst, src);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE3 support");
 }
 
 void TurboAssembler::Psignw(XMMRegister dst, Operand src) {
@@ -1408,7 +1400,7 @@ void TurboAssembler::Psignw(XMMRegister dst, Operand src) {
     psignw(dst, src);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE3 support");
 }
 
 void TurboAssembler::Psignd(XMMRegister dst, Operand src) {
@@ -1422,7 +1414,7 @@ void TurboAssembler::Psignd(XMMRegister dst, Operand src) {
     psignd(dst, src);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE3 support");
 }
 
 void TurboAssembler::Pshufb(XMMRegister dst, Operand src) {
@@ -1436,7 +1428,7 @@ void TurboAssembler::Pshufb(XMMRegister dst, Operand src) {
     pshufb(dst, src);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE3 support");
 }
 
 void TurboAssembler::Pblendw(XMMRegister dst, Operand src, uint8_t imm8) {
@@ -1450,7 +1442,7 @@ void TurboAssembler::Pblendw(XMMRegister dst, Operand src, uint8_t imm8) {
     pblendw(dst, src, imm8);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE4.1 support");
 }
 
 void TurboAssembler::Palignr(XMMRegister dst, Operand src, uint8_t imm8) {
@@ -1464,10 +1456,10 @@ void TurboAssembler::Palignr(XMMRegister dst, Operand src, uint8_t imm8) {
     palignr(dst, src, imm8);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE3 support");
 }
 
-void TurboAssembler::Pextrb(Register dst, XMMRegister src, int8_t imm8) {
+void TurboAssembler::Pextrb(Register dst, XMMRegister src, uint8_t imm8) {
   if (CpuFeatures::IsSupported(AVX)) {
     CpuFeatureScope scope(this, AVX);
     vpextrb(dst, src, imm8);
@@ -1478,10 +1470,10 @@ void TurboAssembler::Pextrb(Register dst, XMMRegister src, int8_t imm8) {
     pextrb(dst, src, imm8);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE4.1 support");
 }
 
-void TurboAssembler::Pextrw(Register dst, XMMRegister src, int8_t imm8) {
+void TurboAssembler::Pextrw(Register dst, XMMRegister src, uint8_t imm8) {
   if (CpuFeatures::IsSupported(AVX)) {
     CpuFeatureScope scope(this, AVX);
     vpextrw(dst, src, imm8);
@@ -1492,10 +1484,10 @@ void TurboAssembler::Pextrw(Register dst, XMMRegister src, int8_t imm8) {
     pextrw(dst, src, imm8);
     return;
   }
-  UNREACHABLE();
+  FATAL("no AVX or SSE4.1 support");
 }
 
-void TurboAssembler::Pextrd(Register dst, XMMRegister src, int8_t imm8) {
+void TurboAssembler::Pextrd(Register dst, XMMRegister src, uint8_t imm8) {
   if (imm8 == 0) {
     Movd(dst, src);
     return;
@@ -1510,37 +1502,44 @@ void TurboAssembler::Pextrd(Register dst, XMMRegister src, int8_t imm8) {
     pextrd(dst, src, imm8);
     return;
   }
-  DCHECK_LT(imm8, 4);
-  pshufd(xmm0, src, imm8);
-  movd(dst, xmm0);
+  // Without AVX or SSE, we can only have 64-bit values in xmm registers.
+  // We don't have an xmm scratch register, so move the data via the stack. This
+  // path is rarely required, so it's acceptable to be slow.
+  DCHECK_LT(imm8, 2);
+  sub(esp, Immediate(kDoubleSize));
+  movsd(Operand(esp, 0), src);
+  mov(dst, Operand(esp, imm8 * kUInt32Size));
+  add(esp, Immediate(kDoubleSize));
 }
 
-void TurboAssembler::Pinsrd(XMMRegister dst, Operand src, int8_t imm8,
-                            bool is_64_bits) {
+void TurboAssembler::Pinsrd(XMMRegister dst, Operand src, uint8_t imm8) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrd(dst, dst, src, imm8);
+    return;
+  }
   if (CpuFeatures::IsSupported(SSE4_1)) {
     CpuFeatureScope sse_scope(this, SSE4_1);
     pinsrd(dst, src, imm8);
     return;
   }
-  if (is_64_bits) {
-    movd(xmm0, src);
-    if (imm8 == 1) {
-      punpckldq(dst, xmm0);
-    } else {
-      DCHECK_EQ(0, imm8);
-      psrlq(dst, 32);
-      punpckldq(xmm0, dst);
-      movaps(dst, xmm0);
-    }
+  // Without AVX or SSE, we can only have 64-bit values in xmm registers.
+  // We don't have an xmm scratch register, so move the data via the stack. This
+  // path is rarely required, so it's acceptable to be slow.
+  DCHECK_LT(imm8, 2);
+  sub(esp, Immediate(kDoubleSize));
+  // Write original content of {dst} to the stack.
+  movsd(Operand(esp, 0), dst);
+  // Overwrite the portion specified in {imm8}.
+  if (src.is_reg_only()) {
+    mov(Operand(esp, imm8 * kUInt32Size), src.reg());
   } else {
-    DCHECK_LT(imm8, 4);
-    push(eax);
-    mov(eax, src);
-    pinsrw(dst, eax, imm8 * 2);
-    shr(eax, 16);
-    pinsrw(dst, eax, imm8 * 2 + 1);
-    pop(eax);
+    movss(dst, src);
+    movss(Operand(esp, imm8 * kUInt32Size), dst);
   }
+  // Load back the full value into {dst}.
+  movsd(dst, Operand(esp, 0));
+  add(esp, Immediate(kDoubleSize));
 }
 
 void TurboAssembler::Lzcnt(Register dst, Operand src) {
@@ -1576,7 +1575,7 @@ void TurboAssembler::Popcnt(Register dst, Operand src) {
     popcnt(dst, src);
     return;
   }
-  UNREACHABLE();
+  FATAL("no POPCNT support");
 }
 
 void MacroAssembler::LoadWeakValue(Register in_out, Label* target_if_cleared) {
@@ -1719,14 +1718,16 @@ void TurboAssembler::CallCFunction(Register function, int num_arguments) {
 
 void TurboAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode) {
   if (FLAG_embedded_builtins) {
-    // TODO(jgruber): Figure out which register we can clobber here.
     // TODO(jgruber): Pc-relative builtin-to-builtin calls.
-    Register scratch = kOffHeapTrampolineRegister;
     if (root_array_available_ && options().isolate_independent_code) {
-      IndirectLoadConstant(scratch, code_object);
-      lea(scratch, FieldOperand(scratch, Code::kHeaderSize));
-      call(scratch);
-      return;
+      // TODO(jgruber): There's no scratch register on ia32. Any call that
+      // requires loading a code object from the builtins constant table must:
+      // 1) spill two scratch registers, 2) load the target into scratch1, 3)
+      // store the target into a virtual register on the isolate using scratch2,
+      // 4) restore both scratch registers, and finally 5) call through the
+      // virtual register. All affected call sites should vanish once all
+      // builtins are embedded on ia32.
+      UNREACHABLE();
     } else if (options().inline_offheap_trampolines) {
       int builtin_index = Builtins::kNoBuiltinId;
       if (isolate()->builtins()->IsBuiltinHandle(code_object, &builtin_index) &&
@@ -1747,14 +1748,16 @@ void TurboAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode) {
 
 void TurboAssembler::Jump(Handle<Code> code_object, RelocInfo::Mode rmode) {
   if (FLAG_embedded_builtins) {
-    // TODO(jgruber): Figure out which register we can clobber here.
     // TODO(jgruber): Pc-relative builtin-to-builtin calls.
-    Register scratch = kOffHeapTrampolineRegister;
     if (root_array_available_ && options().isolate_independent_code) {
-      IndirectLoadConstant(scratch, code_object);
-      lea(scratch, FieldOperand(scratch, Code::kHeaderSize));
-      jmp(scratch);
-      return;
+      // TODO(jgruber): There's no scratch register on ia32. Any call that
+      // requires loading a code object from the builtins constant table must:
+      // 1) spill two scratch registers, 2) load the target into scratch1, 3)
+      // store the target into a virtual register on the isolate using scratch2,
+      // 4) restore both scratch registers, and finally 5) call through the
+      // virtual register. All affected call sites should vanish once all
+      // builtins are embedded on ia32.
+      UNREACHABLE();
     } else if (options().inline_offheap_trampolines) {
       int builtin_index = Builtins::kNoBuiltinId;
       if (isolate()->builtins()->IsBuiltinHandle(code_object, &builtin_index) &&
diff --git a/deps/v8/src/ia32/macro-assembler-ia32.h b/deps/v8/src/ia32/macro-assembler-ia32.h
index 8ad92a9d1d..bdb04fb222 100644
--- a/deps/v8/src/ia32/macro-assembler-ia32.h
+++ b/deps/v8/src/ia32/macro-assembler-ia32.h
@@ -58,6 +58,9 @@ enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -116,6 +119,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void VerifyRootRegister() {
     if (FLAG_ia32_verify_root_register && FLAG_embedded_builtins) {
+      Assembler::AllowExplicitEbxAccessScope read_only_access(this);
       Label root_register_ok;
       cmp(kRootRegister, kRootRegisterSentinel);
       j(equal, &root_register_ok);
@@ -238,7 +242,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void Ret();
 
-  void LoadRoot(Register destination, Heap::RootListIndex index) override;
+  void LoadRoot(Register destination, RootIndex index) override;
+
+  void MoveForRootRegisterRefactoring(Register dst, Register src) {
+    // TODO(v8:6666): When rewriting ia32 ASM builtins to not clobber the
+    // kRootRegister ebx, most call sites of this wrapper function can probably
+    // be removed.
+    Move(dst, src);
+  }
 
   // Indirect root-relative loads.
   void LoadFromConstantsTable(Register destination,
@@ -248,6 +259,17 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void LoadAddress(Register destination, ExternalReference source);
 
+  void PushRootRegister() {
+    // Check that a NoRootArrayScope exists.
+    CHECK(!root_array_available());
+    push(kRootRegister);
+  }
+  void PopRootRegister() {
+    // Check that a NoRootArrayScope exists.
+    CHECK(!root_array_available());
+    pop(kRootRegister);
+  }
+
   // Wrapper functions to ensure external reference operands produce
   // isolate-independent code if needed.
   Operand StaticVariable(const ExternalReference& ext);
@@ -270,8 +292,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
     Pshufd(dst, Operand(src), shuffle);
   }
   void Pshufd(XMMRegister dst, Operand src, uint8_t shuffle);
-  void Psraw(XMMRegister dst, int8_t shift);
-  void Psrlw(XMMRegister dst, int8_t shift);
+  void Psraw(XMMRegister dst, uint8_t shift);
+  void Psrlw(XMMRegister dst, uint8_t shift);
 
 // SSE/SSE2 instructions with AVX version.
 #define AVX_OP2_WITH_TYPE(macro_name, name, dst_type, src_type) \
@@ -380,15 +402,13 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   }
   void Palignr(XMMRegister dst, Operand src, uint8_t imm8);
 
-  void Pextrb(Register dst, XMMRegister src, int8_t imm8);
-  void Pextrw(Register dst, XMMRegister src, int8_t imm8);
-  void Pextrd(Register dst, XMMRegister src, int8_t imm8);
-  void Pinsrd(XMMRegister dst, Register src, int8_t imm8,
-              bool is_64_bits = false) {
-    Pinsrd(dst, Operand(src), imm8, is_64_bits);
+  void Pextrb(Register dst, XMMRegister src, uint8_t imm8);
+  void Pextrw(Register dst, XMMRegister src, uint8_t imm8);
+  void Pextrd(Register dst, XMMRegister src, uint8_t imm8);
+  void Pinsrd(XMMRegister dst, Register src, uint8_t imm8) {
+    Pinsrd(dst, Operand(src), imm8);
   }
-  void Pinsrd(XMMRegister dst, Operand src, int8_t imm8,
-              bool is_64_bits = false);
+  void Pinsrd(XMMRegister dst, Operand src, uint8_t imm8);
 
   // Expression support
   // cvtsi2sd instruction only writes to the low 64-bit of dst register, which
@@ -460,10 +480,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -478,34 +502,32 @@ class MacroAssembler : public TurboAssembler {
   void Set(Operand dst, int32_t x) { mov(dst, Immediate(x)); }
 
   // Operations on roots in the root-array.
-  void CompareRoot(Register with, Register scratch, Heap::RootListIndex index);
+  void CompareRoot(Register with, Register scratch, RootIndex index);
   // These methods can only be used with constant roots (i.e. non-writable
   // and not in new space).
-  void CompareRoot(Register with, Heap::RootListIndex index);
-  void CompareRoot(Operand with, Heap::RootListIndex index);
-  void PushRoot(Heap::RootListIndex index);
+  void CompareRoot(Register with, RootIndex index);
+  void CompareRoot(Operand with, RootIndex index);
+  void PushRoot(RootIndex index);
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal,
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal,
                   Label::Distance if_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(equal, if_equal, if_equal_distance);
   }
-  void JumpIfRoot(Operand with, Heap::RootListIndex index, Label* if_equal,
+  void JumpIfRoot(Operand with, RootIndex index, Label* if_equal,
                   Label::Distance if_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(equal, if_equal, if_equal_distance);
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal,
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal,
                      Label::Distance if_not_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(not_equal, if_not_equal, if_not_equal_distance);
   }
-  void JumpIfNotRoot(Operand with, Heap::RootListIndex index,
-                     Label* if_not_equal,
+  void JumpIfNotRoot(Operand with, RootIndex index, Label* if_not_equal,
                      Label::Distance if_not_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(not_equal, if_not_equal, if_not_equal_distance);
@@ -585,9 +607,6 @@ class MacroAssembler : public TurboAssembler {
   void InvokeFunction(Register function, Register new_target,
                       const ParameterCount& actual, InvokeFlag flag);
 
-  void InvokeFunction(Register function, const ParameterCount& expected,
-                      const ParameterCount& actual, InvokeFlag flag);
-
   // Compare object type for heap object.
   // Incoming register is heap_object and outgoing register is map.
   void CmpObjectType(Register heap_object, InstanceType type, Register map);
diff --git a/deps/v8/src/ic/accessor-assembler.cc b/deps/v8/src/ic/accessor-assembler.cc
index 0b5e58b92e..f730c50555 100644
--- a/deps/v8/src/ic/accessor-assembler.cc
+++ b/deps/v8/src/ic/accessor-assembler.cc
@@ -4,11 +4,13 @@
 
 #include "src/ic/accessor-assembler.h"
 
+#include "src/ast/ast.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/counters.h"
 #include "src/ic/handler-configuration.h"
 #include "src/ic/ic.h"
+#include "src/ic/keyed-store-generic.h"
 #include "src/ic/stub-cache.h"
 #include "src/objects-inl.h"
 #include "src/objects/module.h"
@@ -127,7 +129,7 @@ void AccessorAssembler::HandlePolymorphicCase(
     Label next_entry(this);
     TNode<MaybeObject> maybe_cached_map =
         LoadWeakFixedArrayElement(feedback, map_index);
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_cached_map));
+    CSA_ASSERT(this, IsWeakOrCleared(maybe_cached_map));
     GotoIf(IsNotWeakReferenceTo(maybe_cached_map, CAST(receiver_map)),
            &next_entry);
 
@@ -151,7 +153,7 @@ void AccessorAssembler::HandlePolymorphicCase(
         Label next_entry(this);
         TNode<MaybeObject> maybe_cached_map =
             LoadWeakFixedArrayElement(feedback, index);
-        CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_cached_map));
+        CSA_ASSERT(this, IsWeakOrCleared(maybe_cached_map));
         GotoIf(IsNotWeakReferenceTo(maybe_cached_map, CAST(receiver_map)),
                &next_entry);
 
@@ -241,9 +243,9 @@ void AccessorAssembler::HandleLoadAccessor(
       [=] { return LoadHandlerDataField(handler, 3); },
       [=] { return LoadHandlerDataField(handler, 2); });
 
-  CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_context));
-  CSA_CHECK(this, IsNotClearedWeakHeapObject(maybe_context));
-  TNode<Object> context = ToWeakHeapObject(maybe_context);
+  CSA_ASSERT(this, IsWeakOrCleared(maybe_context));
+  CSA_CHECK(this, IsNotCleared(maybe_context));
+  TNode<Object> context = GetHeapObjectAssumeWeak(maybe_context);
 
   GotoIf(IsRuntimeCallStatsEnabled(), &runtime);
   {
@@ -700,8 +702,9 @@ Node* AccessorAssembler::HandleProtoHandler(
       BIND(&if_do_access_check);
       {
         TNode<MaybeObject> data2 = LoadHandlerDataField(handler, 2);
-        CSA_ASSERT(this, IsWeakOrClearedHeapObject(data2));
-        TNode<Object> expected_native_context = ToWeakHeapObject(data2, miss);
+        CSA_ASSERT(this, IsWeakOrCleared(data2));
+        TNode<Object> expected_native_context =
+            GetHeapObjectAssumeWeak(data2, miss);
         EmitAccessCheck(expected_native_context, p->context, p->receiver, &done,
                         miss);
       }
@@ -773,8 +776,8 @@ void AccessorAssembler::HandleLoadICProtoHandler(
     // For regular holders, having passed the receiver map check and the
     // validity cell check implies that |holder| is alive. However, for global
     // object receivers, |maybe_holder| may be cleared.
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_holder));
-    Node* holder = ToWeakHeapObject(maybe_holder, miss);
+    CSA_ASSERT(this, IsWeakOrCleared(maybe_holder));
+    Node* holder = GetHeapObjectAssumeWeak(maybe_holder, miss);
 
     var_holder->Bind(holder);
     Goto(&done);
@@ -807,9 +810,14 @@ void AccessorAssembler::EmitAccessCheck(Node* expected_native_context,
 
 void AccessorAssembler::JumpIfDataProperty(Node* details, Label* writable,
                                            Label* readonly) {
-  // Accessor properties never have the READ_ONLY attribute set.
-  GotoIf(IsSetWord32(details, PropertyDetails::kAttributesReadOnlyMask),
-         readonly);
+  if (readonly) {
+    // Accessor properties never have the READ_ONLY attribute set.
+    GotoIf(IsSetWord32(details, PropertyDetails::kAttributesReadOnlyMask),
+           readonly);
+  } else {
+    CSA_ASSERT(this, IsNotSetWord32(details,
+                                    PropertyDetails::kAttributesReadOnlyMask));
+  }
   Node* kind = DecodeWord32<PropertyDetails::KindField>(details);
   GotoIf(Word32Equal(kind, Int32Constant(kData)), writable);
   // Fall through if it's an accessor property.
@@ -907,7 +915,7 @@ void AccessorAssembler::HandleStoreICHandlerCase(
 
   BIND(&if_nonsmi_handler);
   {
-    GotoIf(IsWeakOrClearedHeapObject(handler), &store_transition_or_global);
+    GotoIf(IsWeakOrCleared(handler), &store_transition_or_global);
     TNode<HeapObject> strong_handler = CAST(handler);
     TNode<Map> handler_map = LoadMap(strong_handler);
     Branch(IsCodeMap(handler_map), &call_handler, &if_proto_handler);
@@ -930,8 +938,9 @@ void AccessorAssembler::HandleStoreICHandlerCase(
   BIND(&store_transition_or_global);
   {
     // Load value or miss if the {handler} weak cell is cleared.
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(handler));
-    TNode<HeapObject> map_or_property_cell = ToWeakHeapObject(handler, miss);
+    CSA_ASSERT(this, IsWeakOrCleared(handler));
+    TNode<HeapObject> map_or_property_cell =
+        GetHeapObjectAssumeWeak(handler, miss);
 
     Label store_global(this), store_transition(this);
     Branch(IsMap(map_or_property_cell), &store_transition, &store_global);
@@ -946,7 +955,8 @@ void AccessorAssembler::HandleStoreICHandlerCase(
     BIND(&store_transition);
     {
       TNode<Map> map = CAST(map_or_property_cell);
-      HandleStoreICTransitionMapHandlerCase(p, map, miss, false);
+      HandleStoreICTransitionMapHandlerCase(p, map, miss,
+                                            kCheckPrototypeValidity);
       Return(p->value);
     }
   }
@@ -954,10 +964,13 @@ void AccessorAssembler::HandleStoreICHandlerCase(
 
 void AccessorAssembler::HandleStoreICTransitionMapHandlerCase(
     const StoreICParameters* p, TNode<Map> transition_map, Label* miss,
-    bool validate_transition_handler) {
-  Node* maybe_validity_cell =
-      LoadObjectField(transition_map, Map::kPrototypeValidityCellOffset);
-  CheckPrototypeValidityCell(maybe_validity_cell, miss);
+    StoreTransitionMapFlags flags) {
+  DCHECK_EQ(0, flags & ~kStoreTransitionMapFlagsMask);
+  if (flags & kCheckPrototypeValidity) {
+    Node* maybe_validity_cell =
+        LoadObjectField(transition_map, Map::kPrototypeValidityCellOffset);
+    CheckPrototypeValidityCell(maybe_validity_cell, miss);
+  }
 
   TNode<Uint32T> bitfield3 = LoadMapBitField3(transition_map);
   CSA_ASSERT(this, IsClearWord32<Map::IsDictionaryMapBit>(bitfield3));
@@ -971,7 +984,7 @@ void AccessorAssembler::HandleStoreICTransitionMapHandlerCase(
   Node* factor = IntPtrConstant(DescriptorArray::kEntrySize);
   TNode<IntPtrT> last_key_index = UncheckedCast<IntPtrT>(IntPtrAdd(
       IntPtrConstant(DescriptorArray::ToKeyIndex(-1)), IntPtrMul(nof, factor)));
-  if (validate_transition_handler) {
+  if (flags & kValidateTransitionHandler) {
     Node* key = LoadWeakFixedArrayElement(descriptors, last_key_index);
     GotoIf(WordNotEqual(key, p->name), miss);
   } else {
@@ -981,16 +994,20 @@ void AccessorAssembler::HandleStoreICTransitionMapHandlerCase(
                          p->name));
   }
   Node* details = LoadDetailsByKeyIndex(descriptors, last_key_index);
-  if (validate_transition_handler) {
+  if (flags & kValidateTransitionHandler) {
     // Follow transitions only in the following cases:
     // 1) name is a non-private symbol and attributes equal to NONE,
     // 2) name is a private symbol and attributes equal to DONT_ENUM.
     Label attributes_ok(this);
-    const int kAttributesDontDeleteReadOnlyMask =
+    const int kKindAndAttributesDontDeleteReadOnlyMask =
+        PropertyDetails::KindField::kMask |
         PropertyDetails::kAttributesDontDeleteMask |
         PropertyDetails::kAttributesReadOnlyMask;
-    // Both DontDelete and ReadOnly attributes must not be set.
-    GotoIf(IsSetWord32(details, kAttributesDontDeleteReadOnlyMask), miss);
+    STATIC_ASSERT(kData == 0);
+    // Both DontDelete and ReadOnly attributes must not be set and it has to be
+    // a kData property.
+    GotoIf(IsSetWord32(details, kKindAndAttributesDontDeleteReadOnlyMask),
+           miss);
 
     // DontEnum attribute is allowed only for private symbols and vice versa.
     Branch(Word32Equal(
@@ -1035,9 +1052,8 @@ void AccessorAssembler::CheckFieldType(TNode<DescriptorArray> descriptors,
     Node* value_map = LoadMap(value);
     // While supporting mutable HeapNumbers would be straightforward, such
     // objects should not end up here anyway.
-    CSA_ASSERT(this,
-               WordNotEqual(value_map,
-                            LoadRoot(Heap::kMutableHeapNumberMapRootIndex)));
+    CSA_ASSERT(this, WordNotEqual(value_map,
+                                  LoadRoot(RootIndex::kMutableHeapNumberMap)));
     Branch(IsHeapNumberMap(value_map), &all_fine, bailout);
   }
 
@@ -1060,7 +1076,8 @@ void AccessorAssembler::CheckFieldType(TNode<DescriptorArray> descriptors,
            &all_fine);
     // Cleared weak references count as FieldType::None, which can't hold any
     // value.
-    TNode<Map> field_type_map = CAST(ToWeakHeapObject(field_type, bailout));
+    TNode<Map> field_type_map =
+        CAST(GetHeapObjectAssumeWeak(field_type, bailout));
     // FieldType::Class(...) performs a map check.
     Branch(WordEqual(LoadMap(value), field_type_map), &all_fine, bailout);
   }
@@ -1270,7 +1287,7 @@ void AccessorAssembler::HandleStoreICProtoHandler(
         TNode<MaybeObject> maybe_transition_map =
             LoadHandlerDataField(handler, 1);
         TNode<Map> transition_map =
-            CAST(ToWeakHeapObject(maybe_transition_map, miss));
+            CAST(GetHeapObjectAssumeWeak(maybe_transition_map, miss));
 
         GotoIf(IsDeprecatedMap(transition_map), miss);
 
@@ -1312,8 +1329,8 @@ void AccessorAssembler::HandleStoreICProtoHandler(
            &if_add_normal);
 
     TNode<MaybeObject> maybe_holder = LoadHandlerDataField(handler, 1);
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_holder));
-    TNode<Object> holder = ToWeakHeapObject(maybe_holder, miss);
+    CSA_ASSERT(this, IsWeakOrCleared(maybe_holder));
+    TNode<Object> holder = GetHeapObjectAssumeWeak(maybe_holder, miss);
 
     GotoIf(WordEqual(handler_kind, IntPtrConstant(StoreHandler::kGlobalProxy)),
            &if_store_global_proxy);
@@ -1374,11 +1391,10 @@ void AccessorAssembler::HandleStoreICProtoHandler(
           [=] { return LoadHandlerDataField(handler, 3); },
           [=] { return LoadHandlerDataField(handler, 2); });
 
-      CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_context));
-      TNode<Object> context =
-          Select<Object>(IsClearedWeakHeapObject(maybe_context),
-                         [=] { return SmiConstant(0); },
-                         [=] { return ToWeakHeapObject(maybe_context); });
+      CSA_ASSERT(this, IsWeakOrCleared(maybe_context));
+      TNode<Object> context = Select<Object>(
+          IsCleared(maybe_context), [=] { return SmiConstant(0); },
+          [=] { return GetHeapObjectAssumeWeak(maybe_context); });
 
       Node* foreign = LoadObjectField(call_handler_info,
                                       CallHandlerInfo::kJsCallbackOffset);
@@ -1455,7 +1471,7 @@ void AccessorAssembler::HandleStoreToProxy(const StoreICParameters* p,
     TailCallRuntime(Runtime::kSetPropertyWithReceiver, p->context, proxy,
                     p->name, p->value, p->receiver, language_mode);
   } else {
-    Node* name = ToName(p->context, p->name);
+    Node* name = CallBuiltin(Builtins::kToName, p->context, p->name);
     TailCallBuiltin(Builtins::kProxySetProperty, p->context, proxy, name,
                     p->value, p->receiver, language_mode);
   }
@@ -1575,7 +1591,7 @@ Node* AccessorAssembler::PrepareValueForStore(Node* handler_word, Node* holder,
     GotoIf(TaggedIsSmi(maybe_field_type), &done);
     // Check that value type matches the field type.
     {
-      Node* field_type = ToWeakHeapObject(maybe_field_type, bailout);
+      Node* field_type = GetHeapObjectAssumeWeak(maybe_field_type, bailout);
       Branch(WordEqual(LoadMap(value), field_type), &done, bailout);
     }
     BIND(&done);
@@ -1855,7 +1871,7 @@ void AccessorAssembler::EmitElementLoad(
     GotoIf(IsDetachedBuffer(buffer), miss);
 
     // Bounds check.
-    Node* length = SmiUntag(LoadTypedArrayLength(CAST(object)));
+    Node* length = SmiUntag(LoadJSTypedArrayLength(CAST(object)));
     GotoIfNot(UintPtrLessThan(intptr_index, length), out_of_bounds);
 
     Node* backing_store = LoadFixedTypedArrayBackingStore(CAST(elements));
@@ -2082,7 +2098,7 @@ void AccessorAssembler::GenericElementLoad(Node* receiver, Node* receiver_map,
     Comment("check if string");
     GotoIfNot(IsStringInstanceType(instance_type), slow);
     Comment("load string character");
-    Node* length = LoadAndUntagObjectField(receiver, String::kLengthOffset);
+    TNode<IntPtrT> length = LoadStringLengthAsWord(receiver);
     GotoIfNot(UintPtrLessThan(index, length), slow);
     IncrementCounter(isolate()->counters()->ic_keyed_load_generic_smi(), 1);
     TailCallBuiltin(Builtins::kStringCharAt, NoContextConstant(), receiver,
@@ -2395,7 +2411,8 @@ void AccessorAssembler::LoadIC_BytecodeHandler(const LoadICParameters* p,
 
     BIND(&try_polymorphic);
     {
-      TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+      TNode<HeapObject> strong_feedback =
+          GetHeapObjectIfStrong(feedback, &miss);
       GotoIfNot(IsWeakFixedArrayMap(LoadMap(strong_feedback)), &stub_call);
       HandlePolymorphicCase(recv_map, CAST(strong_feedback), &if_handler,
                             &var_handler, &miss, 2);
@@ -2443,7 +2460,7 @@ void AccessorAssembler::LoadIC(const LoadICParameters* p) {
   HandleLoadICHandlerCase(p, CAST(var_handler.value()), &miss, &direct_exit);
 
   BIND(&try_polymorphic);
-  TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+  TNode<HeapObject> strong_feedback = GetHeapObjectIfStrong(feedback, &miss);
   {
     // Check polymorphic case.
     Comment("LoadIC_try_polymorphic");
@@ -2480,7 +2497,7 @@ void AccessorAssembler::LoadIC_Noninlined(const LoadICParameters* p,
 
   {
     // Check megamorphic case.
-    GotoIfNot(WordEqual(feedback, LoadRoot(Heap::kmegamorphic_symbolRootIndex)),
+    GotoIfNot(WordEqual(feedback, LoadRoot(RootIndex::kmegamorphic_symbol)),
               &try_uninitialized);
 
     TryProbeStubCache(isolate()->load_stub_cache(), p->receiver, p->name,
@@ -2490,9 +2507,8 @@ void AccessorAssembler::LoadIC_Noninlined(const LoadICParameters* p,
   BIND(&try_uninitialized);
   {
     // Check uninitialized case.
-    GotoIfNot(
-        WordEqual(feedback, LoadRoot(Heap::kuninitialized_symbolRootIndex)),
-        miss);
+    GotoIfNot(WordEqual(feedback, LoadRoot(RootIndex::kuninitialized_symbol)),
+              miss);
     exit_point->ReturnCallStub(
         Builtins::CallableFor(isolate(), Builtins::kLoadIC_Uninitialized),
         p->context, p->receiver, p->name, p->slot, p->vector);
@@ -2508,7 +2524,7 @@ void AccessorAssembler::LoadIC_Uninitialized(const LoadICParameters* p) {
 
   // Optimistically write the state transition to the vector.
   StoreFeedbackVectorSlot(p->vector, p->slot,
-                          LoadRoot(Heap::kpremonomorphic_symbolRootIndex),
+                          LoadRoot(RootIndex::kpremonomorphic_symbol),
                           SKIP_WRITE_BARRIER, 0, SMI_PARAMETERS);
   StoreWeakReferenceInFeedbackVector(p->vector, p->slot, receiver_map,
                                      kPointerSize, SMI_PARAMETERS);
@@ -2534,7 +2550,7 @@ void AccessorAssembler::LoadIC_Uninitialized(const LoadICParameters* p) {
   {
     // Undo the optimistic state transition.
     StoreFeedbackVectorSlot(p->vector, p->slot,
-                            LoadRoot(Heap::kuninitialized_symbolRootIndex),
+                            LoadRoot(RootIndex::kuninitialized_symbol),
                             SKIP_WRITE_BARRIER, 0, SMI_PARAMETERS);
 
     TailCallRuntime(Runtime::kLoadIC_Miss, p->context, p->receiver, p->name,
@@ -2580,9 +2596,9 @@ void AccessorAssembler::LoadGlobalIC_TryPropertyCellCase(
   BIND(&if_property_cell);
   {
     // Load value or try handler case if the weak reference is cleared.
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_weak_ref));
+    CSA_ASSERT(this, IsWeakOrCleared(maybe_weak_ref));
     TNode<PropertyCell> property_cell =
-        CAST(ToWeakHeapObject(maybe_weak_ref, try_handler));
+        CAST(GetHeapObjectAssumeWeak(maybe_weak_ref, try_handler));
     TNode<Object> value =
         LoadObjectField(property_cell, PropertyCell::kValueOffset);
     GotoIf(WordEqual(value, TheHoleConstant()), miss);
@@ -2616,8 +2632,7 @@ void AccessorAssembler::LoadGlobalIC_TryHandlerCase(
   TNode<MaybeObject> feedback_element =
       LoadFeedbackVectorSlot(vector, slot, kPointerSize, slot_mode);
   TNode<Object> handler = CAST(feedback_element);
-  GotoIf(WordEqual(handler, LoadRoot(Heap::kuninitialized_symbolRootIndex)),
-         miss);
+  GotoIf(WordEqual(handler, LoadRoot(RootIndex::kuninitialized_symbol)), miss);
 
   OnNonExistent on_nonexistent = typeof_mode == NOT_INSIDE_TYPEOF
                                      ? OnNonExistent::kThrowReferenceError
@@ -2660,7 +2675,7 @@ void AccessorAssembler::KeyedLoadIC(const LoadICParameters* p) {
   }
 
   BIND(&try_polymorphic);
-  TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+  TNode<HeapObject> strong_feedback = GetHeapObjectIfStrong(feedback, &miss);
   {
     // Check polymorphic case.
     Comment("KeyedLoadIC_try_polymorphic");
@@ -2673,9 +2688,9 @@ void AccessorAssembler::KeyedLoadIC(const LoadICParameters* p) {
   {
     // Check megamorphic case.
     Comment("KeyedLoadIC_try_megamorphic");
-    GotoIfNot(WordEqual(strong_feedback,
-                        LoadRoot(Heap::kmegamorphic_symbolRootIndex)),
-              &try_polymorphic_name);
+    GotoIfNot(
+        WordEqual(strong_feedback, LoadRoot(RootIndex::kmegamorphic_symbol)),
+        &try_polymorphic_name);
     // TODO(jkummerow): Inline this? Or some of it?
     TailCallBuiltin(Builtins::kKeyedLoadIC_Megamorphic, p->context, p->receiver,
                     p->name, p->slot, p->vector);
@@ -2738,29 +2753,40 @@ void AccessorAssembler::KeyedLoadIC(const LoadICParameters* p) {
 
 void AccessorAssembler::KeyedLoadICGeneric(const LoadICParameters* p) {
   VARIABLE(var_index, MachineType::PointerRepresentation());
-  VARIABLE(var_unique, MachineRepresentation::kTagged);
-  var_unique.Bind(p->name);  // Dummy initialization.
-  Label if_index(this), if_unique_name(this), if_notunique(this), slow(this);
+  VARIABLE(var_unique, MachineRepresentation::kTagged, p->name);
+  Label if_index(this), if_unique_name(this), if_notunique(this),
+      if_other(this, Label::kDeferred), if_runtime(this, Label::kDeferred);
 
   Node* receiver = p->receiver;
-  GotoIf(TaggedIsSmi(receiver), &slow);
-  Node* receiver_map = LoadMap(receiver);
-  Node* instance_type = LoadMapInstanceType(receiver_map);
+  GotoIf(TaggedIsSmi(receiver), &if_runtime);
+
+  TryToName(p->name, &if_index, &var_index, &if_unique_name, &var_unique,
+            &if_other, &if_notunique);
 
-  TryToName(p->name, &if_index, &var_index, &if_unique_name, &var_unique, &slow,
-            &if_notunique);
+  BIND(&if_other);
+  {
+    Node* name = CallBuiltin(Builtins::kToName, p->context, p->name);
+    var_unique.Bind(name);
+    TryToName(name, &if_index, &var_index, &if_unique_name, &var_unique,
+              &if_runtime, &if_notunique);
+  }
 
   BIND(&if_index);
   {
+    Node* receiver_map = LoadMap(receiver);
+    Node* instance_type = LoadMapInstanceType(receiver_map);
     GenericElementLoad(receiver, receiver_map, instance_type, var_index.value(),
-                       &slow);
+                       &if_runtime);
   }
 
   BIND(&if_unique_name);
   {
     LoadICParameters pp = *p;
     pp.name = var_unique.value();
-    GenericPropertyLoad(receiver, receiver_map, instance_type, &pp, &slow);
+    Node* receiver_map = LoadMap(receiver);
+    Node* instance_type = LoadMapInstanceType(receiver_map);
+    GenericPropertyLoad(receiver, receiver_map, instance_type, &pp,
+                        &if_runtime);
   }
 
   BIND(&if_notunique);
@@ -2769,10 +2795,11 @@ void AccessorAssembler::KeyedLoadICGeneric(const LoadICParameters* p) {
       // Ideally we could return undefined directly here if the name is not
       // found in the string table, i.e. it was never internalized, but that
       // invariant doesn't hold with named property interceptors (at this
-      // point), so we take the {slow} path instead.
+      // point), so we take the {if_runtime} path instead.
       Label if_in_string_table(this);
-      TryInternalizeString(p->name, &if_index, &var_index, &if_in_string_table,
-                           &var_unique, &slow, &slow);
+      TryInternalizeString(var_unique.value(), &if_index, &var_index,
+                           &if_in_string_table, &var_unique, &if_runtime,
+                           &if_runtime);
 
       BIND(&if_in_string_table);
       {
@@ -2783,21 +2810,23 @@ void AccessorAssembler::KeyedLoadICGeneric(const LoadICParameters* p) {
         // cache. We may want to re-evaluate that in the future.
         LoadICParameters pp = *p;
         pp.name = var_unique.value();
-        GenericPropertyLoad(receiver, receiver_map, instance_type, &pp, &slow,
-                            kDontUseStubCache);
+        Node* receiver_map = LoadMap(receiver);
+        Node* instance_type = LoadMapInstanceType(receiver_map);
+        GenericPropertyLoad(receiver, receiver_map, instance_type, &pp,
+                            &if_runtime, kDontUseStubCache);
       }
     } else {
-      Goto(&slow);
+      Goto(&if_runtime);
     }
   }
 
-  BIND(&slow);
+  BIND(&if_runtime);
   {
     Comment("KeyedLoadGeneric_slow");
     IncrementCounter(isolate()->counters()->ic_keyed_load_generic_slow(), 1);
     // TODO(jkummerow): Should we use the GetProperty TF stub instead?
-    TailCallRuntime(Runtime::kKeyedGetProperty, p->context, p->receiver,
-                    p->name);
+    TailCallRuntime(Runtime::kGetProperty, p->context, p->receiver,
+                    var_unique.value());
   }
 }
 
@@ -2868,7 +2897,7 @@ void AccessorAssembler::StoreIC(const StoreICParameters* p) {
   }
 
   BIND(&try_polymorphic);
-  TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+  TNode<HeapObject> strong_feedback = GetHeapObjectIfStrong(feedback, &miss);
   {
     // Check polymorphic case.
     Comment("StoreIC_try_polymorphic");
@@ -2880,9 +2909,9 @@ void AccessorAssembler::StoreIC(const StoreICParameters* p) {
   BIND(&try_megamorphic);
   {
     // Check megamorphic case.
-    GotoIfNot(WordEqual(strong_feedback,
-                        LoadRoot(Heap::kmegamorphic_symbolRootIndex)),
-              &try_uninitialized);
+    GotoIfNot(
+        WordEqual(strong_feedback, LoadRoot(RootIndex::kmegamorphic_symbol)),
+        &try_uninitialized);
 
     TryProbeStubCache(isolate()->store_stub_cache(), p->receiver, p->name,
                       &if_handler, &var_handler, &miss);
@@ -2890,9 +2919,9 @@ void AccessorAssembler::StoreIC(const StoreICParameters* p) {
   BIND(&try_uninitialized);
   {
     // Check uninitialized case.
-    GotoIfNot(WordEqual(strong_feedback,
-                        LoadRoot(Heap::kuninitialized_symbolRootIndex)),
-              &miss);
+    GotoIfNot(
+        WordEqual(strong_feedback, LoadRoot(RootIndex::kuninitialized_symbol)),
+        &miss);
     TailCallBuiltin(Builtins::kStoreIC_Uninitialized, p->context, p->receiver,
                     p->name, p->value, p->slot, p->vector);
   }
@@ -2912,9 +2941,9 @@ void AccessorAssembler::StoreGlobalIC(const StoreICParameters* pp) {
   BIND(&if_property_cell);
   {
     Label try_handler(this), miss(this, Label::kDeferred);
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(maybe_weak_ref));
+    CSA_ASSERT(this, IsWeakOrCleared(maybe_weak_ref));
     TNode<PropertyCell> property_cell =
-        CAST(ToWeakHeapObject(maybe_weak_ref, &try_handler));
+        CAST(GetHeapObjectAssumeWeak(maybe_weak_ref, &try_handler));
 
     ExitPoint direct_exit(this);
     StoreGlobalIC_PropertyCellCase(property_cell, pp->value, &direct_exit,
@@ -2926,7 +2955,7 @@ void AccessorAssembler::StoreGlobalIC(const StoreICParameters* pp) {
       TNode<MaybeObject> handler = LoadFeedbackVectorSlot(
           pp->vector, pp->slot, kPointerSize, SMI_PARAMETERS);
 
-      GotoIf(WordEqual(handler, LoadRoot(Heap::kuninitialized_symbolRootIndex)),
+      GotoIf(WordEqual(handler, LoadRoot(RootIndex::kuninitialized_symbol)),
              &miss);
 
       StoreICParameters p = *pp;
@@ -3049,7 +3078,7 @@ void AccessorAssembler::KeyedStoreIC(const StoreICParameters* p) {
     }
 
     BIND(&try_polymorphic);
-    TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+    TNode<HeapObject> strong_feedback = GetHeapObjectIfStrong(feedback, &miss);
     {
       // CheckPolymorphic case.
       Comment("KeyedStoreIC_try_polymorphic");
@@ -3063,9 +3092,9 @@ void AccessorAssembler::KeyedStoreIC(const StoreICParameters* p) {
     {
       // Check megamorphic case.
       Comment("KeyedStoreIC_try_megamorphic");
-      GotoIfNot(WordEqual(strong_feedback,
-                          LoadRoot(Heap::kmegamorphic_symbolRootIndex)),
-                &try_polymorphic_name);
+      GotoIfNot(
+          WordEqual(strong_feedback, LoadRoot(RootIndex::kmegamorphic_symbol)),
+          &try_polymorphic_name);
       TailCallBuiltin(Builtins::kKeyedStoreIC_Megamorphic, p->context,
                       p->receiver, p->name, p->value, p->slot, p->vector);
     }
@@ -3123,7 +3152,7 @@ void AccessorAssembler::StoreInArrayLiteralIC(const StoreICParameters* p) {
         TNode<MaybeObject> maybe_transition_map =
             LoadHandlerDataField(CAST(handler), 1);
         TNode<Map> transition_map =
-            CAST(ToWeakHeapObject(maybe_transition_map, &miss));
+            CAST(GetHeapObjectAssumeWeak(maybe_transition_map, &miss));
         GotoIf(IsDeprecatedMap(transition_map), &miss);
         Node* code = LoadObjectField(handler, StoreHandler::kSmiHandlerOffset);
         CSA_ASSERT(this, IsCode(code));
@@ -3133,7 +3162,7 @@ void AccessorAssembler::StoreInArrayLiteralIC(const StoreICParameters* p) {
     }
 
     BIND(&try_polymorphic);
-    TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+    TNode<HeapObject> strong_feedback = GetHeapObjectIfStrong(feedback, &miss);
     {
       Comment("StoreInArrayLiteralIC_try_polymorphic");
       GotoIfNot(IsWeakFixedArrayMap(LoadMap(strong_feedback)),
@@ -3145,15 +3174,14 @@ void AccessorAssembler::StoreInArrayLiteralIC(const StoreICParameters* p) {
     BIND(&try_megamorphic);
     {
       Comment("StoreInArrayLiteralIC_try_megamorphic");
-      CSA_ASSERT(
-          this,
-          Word32Or(WordEqual(strong_feedback,
-                             LoadRoot(Heap::kuninitialized_symbolRootIndex)),
-                   WordEqual(strong_feedback,
-                             LoadRoot(Heap::kmegamorphic_symbolRootIndex))));
-      GotoIfNot(WordEqual(strong_feedback,
-                          LoadRoot(Heap::kmegamorphic_symbolRootIndex)),
-                &miss);
+      CSA_ASSERT(this,
+                 Word32Or(WordEqual(strong_feedback,
+                                    LoadRoot(RootIndex::kuninitialized_symbol)),
+                          WordEqual(strong_feedback,
+                                    LoadRoot(RootIndex::kmegamorphic_symbol))));
+      GotoIfNot(
+          WordEqual(strong_feedback, LoadRoot(RootIndex::kmegamorphic_symbol)),
+          &miss);
       TailCallRuntime(Runtime::kStoreInArrayLiteralIC_Slow, p->context,
                       p->value, p->receiver, p->name);
     }
@@ -3183,6 +3211,31 @@ void AccessorAssembler::GenerateLoadIC() {
   LoadIC(&p);
 }
 
+void AccessorAssembler::GenerateLoadIC_Megamorphic() {
+  typedef LoadWithVectorDescriptor Descriptor;
+
+  Node* receiver = Parameter(Descriptor::kReceiver);
+  Node* name = Parameter(Descriptor::kName);
+  Node* slot = Parameter(Descriptor::kSlot);
+  Node* vector = Parameter(Descriptor::kVector);
+  Node* context = Parameter(Descriptor::kContext);
+
+  ExitPoint direct_exit(this);
+  TVARIABLE(MaybeObject, var_handler);
+  Label if_handler(this, &var_handler), miss(this, Label::kDeferred);
+
+  TryProbeStubCache(isolate()->load_stub_cache(), receiver, name, &if_handler,
+                    &var_handler, &miss);
+
+  BIND(&if_handler);
+  LoadICParameters p(context, receiver, name, slot, vector);
+  HandleLoadICHandlerCase(&p, CAST(var_handler.value()), &miss, &direct_exit);
+
+  BIND(&miss);
+  direct_exit.ReturnCallRuntime(Runtime::kLoadIC_Miss, context, receiver, name,
+                                slot, vector);
+}
+
 void AccessorAssembler::GenerateLoadIC_Noninlined() {
   typedef LoadWithVectorDescriptor Descriptor;
 
@@ -3238,6 +3291,19 @@ void AccessorAssembler::GenerateLoadICTrampoline() {
   TailCallBuiltin(Builtins::kLoadIC, context, receiver, name, slot, vector);
 }
 
+void AccessorAssembler::GenerateLoadICTrampoline_Megamorphic() {
+  typedef LoadDescriptor Descriptor;
+
+  Node* receiver = Parameter(Descriptor::kReceiver);
+  Node* name = Parameter(Descriptor::kName);
+  Node* slot = Parameter(Descriptor::kSlot);
+  Node* context = Parameter(Descriptor::kContext);
+  Node* vector = LoadFeedbackVectorForStub();
+
+  TailCallBuiltin(Builtins::kLoadIC_Megamorphic, context, receiver, name, slot,
+                  vector);
+}
+
 void AccessorAssembler::GenerateLoadGlobalIC(TypeofMode typeof_mode) {
   typedef LoadGlobalWithVectorDescriptor Descriptor;
 
@@ -3280,6 +3346,19 @@ void AccessorAssembler::GenerateKeyedLoadIC() {
   KeyedLoadIC(&p);
 }
 
+void AccessorAssembler::GenerateKeyedLoadIC_Megamorphic() {
+  typedef LoadWithVectorDescriptor Descriptor;
+
+  Node* receiver = Parameter(Descriptor::kReceiver);
+  Node* name = Parameter(Descriptor::kName);
+  Node* slot = Parameter(Descriptor::kSlot);
+  Node* vector = Parameter(Descriptor::kVector);
+  Node* context = Parameter(Descriptor::kContext);
+
+  LoadICParameters p(context, receiver, name, slot, vector);
+  KeyedLoadICGeneric(&p);
+}
+
 void AccessorAssembler::GenerateKeyedLoadICTrampoline() {
   typedef LoadDescriptor Descriptor;
 
@@ -3293,17 +3372,17 @@ void AccessorAssembler::GenerateKeyedLoadICTrampoline() {
                   vector);
 }
 
-void AccessorAssembler::GenerateKeyedLoadIC_Megamorphic() {
-  typedef LoadWithVectorDescriptor Descriptor;
+void AccessorAssembler::GenerateKeyedLoadICTrampoline_Megamorphic() {
+  typedef LoadDescriptor Descriptor;
 
   Node* receiver = Parameter(Descriptor::kReceiver);
   Node* name = Parameter(Descriptor::kName);
   Node* slot = Parameter(Descriptor::kSlot);
-  Node* vector = Parameter(Descriptor::kVector);
   Node* context = Parameter(Descriptor::kContext);
+  Node* vector = LoadFeedbackVectorForStub();
 
-  LoadICParameters p(context, receiver, name, slot, vector);
-  KeyedLoadICGeneric(&p);
+  TailCallBuiltin(Builtins::kKeyedLoadIC_Megamorphic, context, receiver, name,
+                  slot, vector);
 }
 
 void AccessorAssembler::GenerateKeyedLoadIC_PolymorphicName() {
@@ -3414,6 +3493,76 @@ void AccessorAssembler::GenerateStoreInArrayLiteralIC() {
   StoreInArrayLiteralIC(&p);
 }
 
+void AccessorAssembler::GenerateCloneObjectIC_Slow() {
+  typedef CloneObjectWithVectorDescriptor Descriptor;
+  TNode<HeapObject> source = CAST(Parameter(Descriptor::kSource));
+  TNode<Smi> flags = CAST(Parameter(Descriptor::kFlags));
+  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
+
+  // The Slow case uses the same call interface as CloneObjectIC, so that it
+  // can be tail called from it. However, the feedback slot and vector are not
+  // used.
+
+  TNode<Context> native_context = LoadNativeContext(context);
+  TNode<JSFunction> object_fn =
+      CAST(LoadContextElement(native_context, Context::OBJECT_FUNCTION_INDEX));
+  TNode<Map> initial_map = CAST(
+      LoadObjectField(object_fn, JSFunction::kPrototypeOrInitialMapOffset));
+  CSA_ASSERT(this, IsMap(initial_map));
+
+  TNode<JSObject> result = CAST(AllocateJSObjectFromMap(initial_map));
+
+  {
+    Label did_set_proto_if_needed(this);
+    TNode<BoolT> is_null_proto = SmiNotEqual(
+        SmiAnd(flags, SmiConstant(ObjectLiteral::kHasNullPrototype)),
+        SmiConstant(Smi::kZero));
+    GotoIfNot(is_null_proto, &did_set_proto_if_needed);
+
+    CallRuntime(Runtime::kInternalSetPrototype, context, result,
+                NullConstant());
+
+    Goto(&did_set_proto_if_needed);
+    BIND(&did_set_proto_if_needed);
+  }
+
+  ReturnIf(IsNullOrUndefined(source), result);
+
+  CSA_ASSERT(this, IsJSReceiver(source));
+
+  Label call_runtime(this, Label::kDeferred);
+  Label done(this);
+
+  TNode<Map> map = LoadMap(source);
+  TNode<Int32T> type = LoadMapInstanceType(map);
+  {
+    Label cont(this);
+    GotoIf(IsJSObjectInstanceType(type), &cont);
+    GotoIfNot(IsStringInstanceType(type), &done);
+    Branch(SmiEqual(LoadStringLengthAsSmi(CAST(source)), SmiConstant(0)), &done,
+           &call_runtime);
+    BIND(&cont);
+  }
+
+  GotoIfNot(IsEmptyFixedArray(LoadElements(CAST(source))), &call_runtime);
+
+  ForEachEnumerableOwnProperty(
+      context, map, CAST(source),
+      [=](TNode<Name> key, TNode<Object> value) {
+        KeyedStoreGenericGenerator::SetPropertyInLiteral(state(), context,
+                                                         result, key, value);
+      },
+      &call_runtime);
+  Goto(&done);
+
+  BIND(&call_runtime);
+  CallRuntime(Runtime::kCopyDataProperties, context, result, source);
+
+  Goto(&done);
+  BIND(&done);
+  Return(result);
+}
+
 void AccessorAssembler::GenerateCloneObjectIC() {
   typedef CloneObjectWithVectorDescriptor Descriptor;
   Node* source = Parameter(Descriptor::kSource);
@@ -3502,7 +3651,7 @@ void AccessorAssembler::GenerateCloneObjectIC() {
   }
 
   BIND(&try_polymorphic);
-  TNode<HeapObject> strong_feedback = ToStrongHeapObject(feedback, &miss);
+  TNode<HeapObject> strong_feedback = GetHeapObjectIfStrong(feedback, &miss);
   {
     Comment("CloneObjectIC_try_polymorphic");
     GotoIfNot(IsWeakFixedArrayMap(LoadMap(strong_feedback)), &try_megamorphic);
@@ -3513,16 +3662,16 @@ void AccessorAssembler::GenerateCloneObjectIC() {
   BIND(&try_megamorphic);
   {
     Comment("CloneObjectIC_try_megamorphic");
-    CSA_ASSERT(
-        this,
-        Word32Or(WordEqual(strong_feedback,
-                           LoadRoot(Heap::kuninitialized_symbolRootIndex)),
-                 WordEqual(strong_feedback,
-                           LoadRoot(Heap::kmegamorphic_symbolRootIndex))));
-    GotoIfNot(WordEqual(strong_feedback,
-                        LoadRoot(Heap::kmegamorphic_symbolRootIndex)),
-              &miss);
-    TailCallRuntime(Runtime::kCloneObjectIC_Slow, context, source, flags);
+    CSA_ASSERT(this,
+               Word32Or(WordEqual(strong_feedback,
+                                  LoadRoot(RootIndex::kuninitialized_symbol)),
+                        WordEqual(strong_feedback,
+                                  LoadRoot(RootIndex::kmegamorphic_symbol))));
+    GotoIfNot(
+        WordEqual(strong_feedback, LoadRoot(RootIndex::kmegamorphic_symbol)),
+        &miss);
+    TailCallBuiltin(Builtins::kCloneObjectIC_Slow, context, source, flags, slot,
+                    vector);
   }
 
   BIND(&miss);
diff --git a/deps/v8/src/ic/accessor-assembler.h b/deps/v8/src/ic/accessor-assembler.h
index 0de48e021a..3d92ab26c3 100644
--- a/deps/v8/src/ic/accessor-assembler.h
+++ b/deps/v8/src/ic/accessor-assembler.h
@@ -28,18 +28,22 @@ class AccessorAssembler : public CodeStubAssembler {
       : CodeStubAssembler(state) {}
 
   void GenerateLoadIC();
+  void GenerateLoadIC_Megamorphic();
   void GenerateLoadIC_Noninlined();
   void GenerateLoadIC_Uninitialized();
   void GenerateLoadICTrampoline();
+  void GenerateLoadICTrampoline_Megamorphic();
   void GenerateKeyedLoadIC();
-  void GenerateKeyedLoadICTrampoline();
   void GenerateKeyedLoadIC_Megamorphic();
   void GenerateKeyedLoadIC_PolymorphicName();
+  void GenerateKeyedLoadICTrampoline();
+  void GenerateKeyedLoadICTrampoline_Megamorphic();
   void GenerateStoreIC();
   void GenerateStoreICTrampoline();
   void GenerateStoreGlobalIC();
   void GenerateStoreGlobalICTrampoline();
   void GenerateCloneObjectIC();
+  void GenerateCloneObjectIC_Slow();
 
   void GenerateLoadGlobalIC(TypeofMode typeof_mode);
   void GenerateLoadGlobalICTrampoline(TypeofMode typeof_mode);
@@ -106,10 +110,16 @@ class AccessorAssembler : public CodeStubAssembler {
   void HandleStoreICHandlerCase(
       const StoreICParameters* p, TNode<MaybeObject> handler, Label* miss,
       ICMode ic_mode, ElementSupport support_elements = kOnlyProperties);
+  enum StoreTransitionMapFlags {
+    kCheckPrototypeValidity = 1 << 0,
+    kValidateTransitionHandler = 1 << 1,
+    kStoreTransitionMapFlagsMask =
+        kCheckPrototypeValidity | kValidateTransitionHandler,
+  };
   void HandleStoreICTransitionMapHandlerCase(const StoreICParameters* p,
                                              TNode<Map> transition_map,
                                              Label* miss,
-                                             bool validate_transition_handler);
+                                             StoreTransitionMapFlags flags);
 
   void JumpIfDataProperty(Node* details, Label* writable, Label* readonly);
 
diff --git a/deps/v8/src/ic/binary-op-assembler.cc b/deps/v8/src/ic/binary-op-assembler.cc
index 9016e9ba18..ebe64437c6 100644
--- a/deps/v8/src/ic/binary-op-assembler.cc
+++ b/deps/v8/src/ic/binary-op-assembler.cc
@@ -162,9 +162,8 @@ Node* BinaryOpAssembler::Generate_AddWithFeedback(Node* context, Node* lhs,
                 &call_with_any_feedback);
 
       var_type_feedback.Bind(SmiConstant(BinaryOperationFeedback::kString));
-      Callable callable =
-          CodeFactory::StringAdd(isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
-      var_result.Bind(CallStub(callable, context, lhs, rhs));
+      var_result.Bind(
+          CallBuiltin(Builtins::kStringAdd_CheckNone, context, lhs, rhs));
 
       Goto(&end);
     }
diff --git a/deps/v8/src/ic/call-optimization.h b/deps/v8/src/ic/call-optimization.h
index d87ec4fdb1..e3115bdbcd 100644
--- a/deps/v8/src/ic/call-optimization.h
+++ b/deps/v8/src/ic/call-optimization.h
@@ -12,7 +12,7 @@
 namespace v8 {
 namespace internal {
 // Holds information about possible function call optimizations.
-class CallOptimization BASE_EMBEDDED {
+class CallOptimization {
  public:
   CallOptimization(Isolate* isolate, Handle<Object> function);
 
diff --git a/deps/v8/src/ic/handler-configuration.cc b/deps/v8/src/ic/handler-configuration.cc
index 86ea4f9d3b..73ab0de645 100644
--- a/deps/v8/src/ic/handler-configuration.cc
+++ b/deps/v8/src/ic/handler-configuration.cc
@@ -140,7 +140,7 @@ Handle<Object> LoadHandler::LoadFromPrototype(Isolate* isolate,
 // static
 Handle<Object> LoadHandler::LoadFullChain(Isolate* isolate,
                                           Handle<Map> receiver_map,
-                                          MaybeObjectHandle holder,
+                                          const MaybeObjectHandle& holder,
                                           Handle<Smi> smi_handler) {
   Handle<JSReceiver> end;  // null handle, means full prototype chain lookup.
   MaybeObjectHandle data1 = holder;
@@ -168,7 +168,7 @@ Handle<Object> LoadHandler::LoadFullChain(Isolate* isolate,
 KeyedAccessLoadMode LoadHandler::GetKeyedAccessLoadMode(MaybeObject* handler) {
   DisallowHeapAllocation no_gc;
   if (handler->IsSmi()) {
-    int const raw_handler = Smi::cast(handler->ToSmi())->value();
+    int const raw_handler = handler->cast<Smi>()->value();
     Kind const kind = KindBits::decode(raw_handler);
     if ((kind == kElement || kind == kIndexedString) &&
         AllowOutOfBoundsBits::decode(raw_handler)) {
diff --git a/deps/v8/src/ic/handler-configuration.h b/deps/v8/src/ic/handler-configuration.h
index 305577a2df..72ab68140e 100644
--- a/deps/v8/src/ic/handler-configuration.h
+++ b/deps/v8/src/ic/handler-configuration.h
@@ -150,7 +150,7 @@ class LoadHandler final : public DataHandler {
   // needed (e.g., for "nonexistent"), null_value() may be passed in.
   static Handle<Object> LoadFullChain(Isolate* isolate,
                                       Handle<Map> receiver_map,
-                                      MaybeObjectHandle holder,
+                                      const MaybeObjectHandle& holder,
                                       Handle<Smi> smi_handler);
 
   // Creates a data handler that represents a prototype chain check followed
diff --git a/deps/v8/src/ic/ic-inl.h b/deps/v8/src/ic/ic-inl.h
index 640bf7250c..101703dc28 100644
--- a/deps/v8/src/ic/ic-inl.h
+++ b/deps/v8/src/ic/ic-inl.h
@@ -50,11 +50,10 @@ void IC::update_receiver_map(Handle<Object> receiver) {
 bool IC::IsHandler(MaybeObject* object) {
   HeapObject* heap_object;
   return (object->IsSmi() && (object != nullptr)) ||
-         (object->ToWeakHeapObject(&heap_object) &&
+         (object->GetHeapObjectIfWeak(&heap_object) &&
           (heap_object->IsMap() || heap_object->IsPropertyCell())) ||
-         (object->ToStrongHeapObject(&heap_object) &&
-          (heap_object->IsDataHandler() ||
-           heap_object->IsCode()));
+         (object->GetHeapObjectIfStrong(&heap_object) &&
+          (heap_object->IsDataHandler() || heap_object->IsCode()));
 }
 
 bool IC::AddressIsDeoptimizedCode() const {
diff --git a/deps/v8/src/ic/ic-stats.cc b/deps/v8/src/ic/ic-stats.cc
index c305209d48..0c33863d3d 100644
--- a/deps/v8/src/ic/ic-stats.cc
+++ b/deps/v8/src/ic/ic-stats.cc
@@ -95,7 +95,7 @@ ICInfo::ICInfo()
       is_constructor(false),
       is_optimized(false),
       map(nullptr),
-      is_dictionary_map(0),
+      is_dictionary_map(false),
       number_of_own_descriptors(0) {}
 
 void ICInfo::Reset() {
diff --git a/deps/v8/src/ic/ic.cc b/deps/v8/src/ic/ic.cc
index 9237441ac9..3ca62d0bb4 100644
--- a/deps/v8/src/ic/ic.cc
+++ b/deps/v8/src/ic/ic.cc
@@ -1260,9 +1260,8 @@ MaybeHandle<Object> KeyedLoadIC::Load(Handle<Object> object,
   return result;
 }
 
-
 bool StoreIC::LookupForWrite(LookupIterator* it, Handle<Object> value,
-                             JSReceiver::StoreFromKeyed store_mode) {
+                             StoreOrigin store_origin) {
   // Disable ICs for non-JSObjects for now.
   Handle<Object> object = it->GetReceiver();
   if (object->IsJSProxy()) return true;
@@ -1319,7 +1318,7 @@ bool StoreIC::LookupForWrite(LookupIterator* it, Handle<Object> value,
 
           if (it->ExtendingNonExtensible(receiver)) return false;
           it->PrepareTransitionToDataProperty(receiver, value, NONE,
-                                              store_mode);
+                                              store_origin);
           return it->IsCacheableTransition();
         }
       }
@@ -1328,7 +1327,7 @@ bool StoreIC::LookupForWrite(LookupIterator* it, Handle<Object> value,
 
   receiver = it->GetStoreTarget<JSObject>();
   if (it->ExtendingNonExtensible(receiver)) return false;
-  it->PrepareTransitionToDataProperty(receiver, value, NONE, store_mode);
+  it->PrepareTransitionToDataProperty(receiver, value, NONE, store_origin);
   return it->IsCacheableTransition();
 }
 
@@ -1381,7 +1380,7 @@ MaybeHandle<Object> StoreGlobalIC::Store(Handle<Name> name,
 
 MaybeHandle<Object> StoreIC::Store(Handle<Object> object, Handle<Name> name,
                                    Handle<Object> value,
-                                   JSReceiver::StoreFromKeyed store_mode) {
+                                   StoreOrigin store_origin) {
   // TODO(verwaest): Let SetProperty do the migration, since storing a property
   // might deprecate the current map again, if value does not fit.
   if (MigrateDeprecated(object)) {
@@ -1424,15 +1423,15 @@ MaybeHandle<Object> StoreIC::Store(Handle<Object> object, Handle<Name> name,
       use_ic = false;
     }
   }
-  if (use_ic) UpdateCaches(&it, value, store_mode);
+  if (use_ic) UpdateCaches(&it, value, store_origin);
 
   MAYBE_RETURN_NULL(
-      Object::SetProperty(&it, value, language_mode(), store_mode));
+      Object::SetProperty(&it, value, language_mode(), store_origin));
   return value;
 }
 
 void StoreIC::UpdateCaches(LookupIterator* lookup, Handle<Object> value,
-                           JSReceiver::StoreFromKeyed store_mode) {
+                           StoreOrigin store_origin) {
   if (state() == UNINITIALIZED && !IsStoreGlobalIC()) {
     // This is the first time we execute this inline cache. Transition
     // to premonomorphic state to delay setting the monomorphic state.
@@ -1443,7 +1442,7 @@ void StoreIC::UpdateCaches(LookupIterator* lookup, Handle<Object> value,
   }
 
   MaybeObjectHandle handler;
-  if (LookupForWrite(lookup, value, store_mode)) {
+  if (LookupForWrite(lookup, value, store_origin)) {
     if (IsStoreGlobalIC()) {
       if (lookup->state() == LookupIterator::DATA &&
           lookup->GetReceiver().is_identical_to(lookup->GetHolder<Object>())) {
@@ -1988,8 +1987,9 @@ MaybeHandle<Object> KeyedStoreIC::Store(Handle<Object> object,
   if (MigrateDeprecated(object)) {
     Handle<Object> result;
     ASSIGN_RETURN_ON_EXCEPTION(
-        isolate(), result, Runtime::SetObjectProperty(isolate(), object, key,
-                                                      value, language_mode()),
+        isolate(), result,
+        Runtime::SetObjectProperty(isolate(), object, key, value,
+                                   language_mode(), StoreOrigin::kMaybeKeyed),
         Object);
     return result;
   }
@@ -2004,11 +2004,10 @@ MaybeHandle<Object> KeyedStoreIC::Store(Handle<Object> object,
   if ((key->IsInternalizedString() &&
        !String::cast(*key)->AsArrayIndex(&index)) ||
       key->IsSymbol()) {
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate(), store_handle,
-        StoreIC::Store(object, Handle<Name>::cast(key), value,
-                       JSReceiver::MAY_BE_STORE_FROM_KEYED),
-        Object);
+    ASSIGN_RETURN_ON_EXCEPTION(isolate(), store_handle,
+                               StoreIC::Store(object, Handle<Name>::cast(key),
+                                              value, StoreOrigin::kMaybeKeyed),
+                               Object);
     if (vector_needs_update()) {
       if (ConfigureVectorState(MEGAMORPHIC, key)) {
         set_slow_stub_reason("unhandled internalized string key");
@@ -2062,10 +2061,11 @@ MaybeHandle<Object> KeyedStoreIC::Store(Handle<Object> object,
   bool receiver_was_cow =
       object->IsJSArray() &&
       Handle<JSArray>::cast(object)->elements()->IsCowArray();
-  ASSIGN_RETURN_ON_EXCEPTION(isolate(), store_handle,
-                             Runtime::SetObjectProperty(isolate(), object, key,
-                                                        value, language_mode()),
-                             Object);
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate(), store_handle,
+      Runtime::SetObjectProperty(isolate(), object, key, value, language_mode(),
+                                 StoreOrigin::kMaybeKeyed),
+      Object);
 
   if (use_ic) {
     if (!old_receiver_map.is_null()) {
@@ -2359,7 +2359,8 @@ RUNTIME_FUNCTION(Runtime_StoreGlobalIC_Slow) {
   LanguageMode language_mode = vector->GetLanguageMode(vector_slot);
   RETURN_RESULT_OR_FAILURE(
       isolate,
-      Runtime::SetObjectProperty(isolate, global, name, value, language_mode));
+      Runtime::SetObjectProperty(isolate, global, name, value, language_mode,
+                                 StoreOrigin::kMaybeKeyed));
 }
 
 RUNTIME_FUNCTION(Runtime_KeyedStoreIC_Miss) {
@@ -2406,7 +2407,8 @@ RUNTIME_FUNCTION(Runtime_KeyedStoreIC_Slow) {
   LanguageMode language_mode = GetLanguageModeFromSlotKind(kind);
   RETURN_RESULT_OR_FAILURE(
       isolate,
-      Runtime::SetObjectProperty(isolate, object, key, value, language_mode));
+      Runtime::SetObjectProperty(isolate, object, key, value, language_mode,
+                                 StoreOrigin::kMaybeKeyed));
 }
 
 RUNTIME_FUNCTION(Runtime_StoreInArrayLiteralIC_Slow) {
@@ -2446,7 +2448,8 @@ RUNTIME_FUNCTION(Runtime_ElementsTransitionAndStoreIC_Miss) {
     LanguageMode language_mode = GetLanguageModeFromSlotKind(kind);
     RETURN_RESULT_OR_FAILURE(
         isolate,
-        Runtime::SetObjectProperty(isolate, object, key, value, language_mode));
+        Runtime::SetObjectProperty(isolate, object, key, value, language_mode,
+                                   StoreOrigin::kMaybeKeyed));
   }
 }
 
@@ -2595,8 +2598,9 @@ RUNTIME_FUNCTION(Runtime_StoreCallbackProperty) {
 
   if (V8_UNLIKELY(FLAG_runtime_stats)) {
     RETURN_RESULT_OR_FAILURE(
-        isolate, Runtime::SetObjectProperty(isolate, receiver, name, value,
-                                            language_mode));
+        isolate,
+        Runtime::SetObjectProperty(isolate, receiver, name, value,
+                                   language_mode, StoreOrigin::kMaybeKeyed));
   }
 
   DCHECK(info->IsCompatibleReceiver(*receiver));
@@ -2747,9 +2751,9 @@ RUNTIME_FUNCTION(Runtime_StorePropertyWithInterceptor) {
   DCHECK_EQ(LookupIterator::INTERCEPTOR, it.state());
   it.Next();
 
-  MAYBE_RETURN(Object::SetProperty(&it, value, language_mode,
-                                   JSReceiver::CERTAINLY_NOT_STORE_FROM_KEYED),
-               ReadOnlyRoots(isolate).exception());
+  MAYBE_RETURN(
+      Object::SetProperty(&it, value, language_mode, StoreOrigin::kNamed),
+      ReadOnlyRoots(isolate).exception());
   return *value;
 }
 
diff --git a/deps/v8/src/ic/ic.h b/deps/v8/src/ic/ic.h
index 0a831b757f..05bde1ff61 100644
--- a/deps/v8/src/ic/ic.h
+++ b/deps/v8/src/ic/ic.h
@@ -36,7 +36,7 @@ class IC {
   // Construct the IC structure with the given number of extra
   // JavaScript frames on the stack.
   IC(Isolate* isolate, Handle<FeedbackVector> vector, FeedbackSlot slot);
-  virtual ~IC() {}
+  virtual ~IC() = default;
 
   State state() const { return state_; }
   inline Address address() const;
@@ -88,7 +88,7 @@ class IC {
   bool vector_needs_update() {
     return (!vector_set_ &&
             (state() != MEGAMORPHIC ||
-             Smi::ToInt(nexus()->GetFeedbackExtra()->ToSmi()) != ELEMENT));
+             Smi::ToInt(nexus()->GetFeedbackExtra()->cast<Smi>()) != ELEMENT));
   }
 
   // Configure for most states.
@@ -296,11 +296,10 @@ class StoreIC : public IC {
 
   V8_WARN_UNUSED_RESULT MaybeHandle<Object> Store(
       Handle<Object> object, Handle<Name> name, Handle<Object> value,
-      JSReceiver::StoreFromKeyed store_mode =
-          JSReceiver::CERTAINLY_NOT_STORE_FROM_KEYED);
+      StoreOrigin store_origin = StoreOrigin::kNamed);
 
   bool LookupForWrite(LookupIterator* it, Handle<Object> value,
-                      JSReceiver::StoreFromKeyed store_mode);
+                      StoreOrigin store_origin);
 
  protected:
   // Stub accessors.
@@ -312,7 +311,7 @@ class StoreIC : public IC {
   // Update the inline cache and the global stub cache based on the
   // lookup result.
   void UpdateCaches(LookupIterator* lookup, Handle<Object> value,
-                    JSReceiver::StoreFromKeyed store_mode);
+                    StoreOrigin store_origin);
 
  private:
   MaybeObjectHandle ComputeHandler(LookupIterator* lookup);
diff --git a/deps/v8/src/ic/keyed-store-generic.cc b/deps/v8/src/ic/keyed-store-generic.cc
index 23c49c8d73..2b2f15bb82 100644
--- a/deps/v8/src/ic/keyed-store-generic.cc
+++ b/deps/v8/src/ic/keyed-store-generic.cc
@@ -43,6 +43,18 @@ class KeyedStoreGenericAssembler : public AccessorAssembler {
                    TNode<Object> key, TNode<Object> value,
                    LanguageMode language_mode);
 
+  // Set an own property
+  void SetPropertyInLiteral(TNode<Context> context, TNode<JSObject> receiver,
+                            TNode<Map> map, TNode<Name> key,
+                            TNode<Object> value) {
+    Label done(this);
+    ExitPoint exit_point(this,
+                         [this, &done](Node* result) { this->Goto(&done); });
+    EmitGenericPropertyStoreInLiteral(context, receiver, map, key, value,
+                                      &exit_point);
+    BIND(&done);
+  }
+
  private:
   enum UpdateLength {
     kDontChangeLength,
@@ -78,6 +90,12 @@ class KeyedStoreGenericAssembler : public AccessorAssembler {
                              Nothing<LanguageMode>());
   }
 
+  void EmitGenericPropertyStoreInLiteral(TNode<Context> context,
+                                         TNode<JSObject> receiver,
+                                         TNode<Map> map, TNode<Name> key,
+                                         TNode<Object> value,
+                                         ExitPoint* exit_point);
+
   void BranchIfPrototypesHaveNonFastElements(Node* receiver_map,
                                              Label* non_fast_elements,
                                              Label* only_fast_elements);
@@ -111,6 +129,10 @@ class KeyedStoreGenericAssembler : public AccessorAssembler {
                                       Variable* var_accessor_pair,
                                       Variable* var_accessor_holder,
                                       Label* readonly, Label* bailout);
+
+  TNode<Map> FindCandidateStoreICTransitionMapHandler(TNode<Map> map,
+                                                      TNode<Name> name,
+                                                      Label* slow);
 };
 
 void KeyedStoreGenericGenerator::Generate(compiler::CodeAssemblerState* state) {
@@ -141,6 +163,14 @@ void KeyedStoreGenericGenerator::SetProperty(
   assembler.SetProperty(context, receiver, key, value, language_mode);
 }
 
+void KeyedStoreGenericGenerator::SetPropertyInLiteral(
+    compiler::CodeAssemblerState* state, TNode<Context> context,
+    TNode<JSObject> receiver, TNode<Name> key, TNode<Object> value) {
+  KeyedStoreGenericAssembler assembler(state);
+  TNode<Map> map = assembler.LoadMap(receiver);
+  assembler.SetPropertyInLiteral(context, receiver, map, key, value);
+}
+
 void KeyedStoreGenericAssembler::BranchIfPrototypesHaveNonFastElements(
     Node* receiver_map, Label* non_fast_elements, Label* only_fast_elements) {
   VARIABLE(var_map, MachineRepresentation::kTagged);
@@ -294,7 +324,7 @@ void KeyedStoreGenericAssembler::StoreElementWithCapacity(
 
   Label check_double_elements(this), check_cow_elements(this);
   Node* elements_map = LoadMap(elements);
-  GotoIf(WordNotEqual(elements_map, LoadRoot(Heap::kFixedArrayMapRootIndex)),
+  GotoIf(WordNotEqual(elements_map, LoadRoot(RootIndex::kFixedArrayMap)),
          &check_double_elements);
 
   // FixedArray backing store -> Smi or object elements.
@@ -355,7 +385,7 @@ void KeyedStoreGenericAssembler::StoreElementWithCapacity(
     {
       Label transition_to_double(this), transition_to_object(this);
       Node* native_context = LoadNativeContext(context);
-      Branch(WordEqual(LoadMap(value), LoadRoot(Heap::kHeapNumberMapRootIndex)),
+      Branch(WordEqual(LoadMap(value), LoadRoot(RootIndex::kHeapNumberMap)),
              &transition_to_double, &transition_to_object);
       BIND(&transition_to_double);
       {
@@ -398,7 +428,7 @@ void KeyedStoreGenericAssembler::StoreElementWithCapacity(
   }
 
   BIND(&check_double_elements);
-  Node* fixed_double_array_map = LoadRoot(Heap::kFixedDoubleArrayMapRootIndex);
+  Node* fixed_double_array_map = LoadRoot(RootIndex::kFixedDoubleArrayMap);
   GotoIf(WordNotEqual(elements_map, fixed_double_array_map),
          &check_cow_elements);
   // FixedDoubleArray backing store -> double elements.
@@ -656,6 +686,71 @@ void KeyedStoreGenericAssembler::LookupPropertyOnPrototypeChain(
   BIND(&ok_to_write);
 }
 
+TNode<Map> KeyedStoreGenericAssembler::FindCandidateStoreICTransitionMapHandler(
+    TNode<Map> map, TNode<Name> name, Label* slow) {
+  TVARIABLE(Map, var_transition_map);
+  Label simple_transition(this), transition_array(this),
+      found_handler_candidate(this);
+
+  TNode<MaybeObject> maybe_handler =
+      LoadMaybeWeakObjectField(map, Map::kTransitionsOrPrototypeInfoOffset);
+
+  // Smi -> slow,
+  // Cleared weak reference -> slow
+  // weak reference -> simple_transition
+  // strong reference -> transition_array
+  TVARIABLE(Object, var_transition_map_or_array);
+  DispatchMaybeObject(maybe_handler, slow, slow, &simple_transition,
+                      &transition_array, &var_transition_map_or_array);
+
+  BIND(&simple_transition);
+  {
+    var_transition_map = CAST(var_transition_map_or_array.value());
+    Goto(&found_handler_candidate);
+  }
+
+  BIND(&transition_array);
+  {
+    TNode<Map> maybe_handler_map =
+        LoadMap(CAST(var_transition_map_or_array.value()));
+    GotoIfNot(IsTransitionArrayMap(maybe_handler_map), slow);
+
+    TVARIABLE(IntPtrT, var_name_index);
+    Label if_found_candidate(this);
+    TNode<TransitionArray> transitions =
+        CAST(var_transition_map_or_array.value());
+    TransitionLookup(name, transitions, &if_found_candidate, &var_name_index,
+                     slow);
+
+    BIND(&if_found_candidate);
+    {
+      // Given that
+      // 1) transitions with the same name are ordered in the transition
+      //    array by PropertyKind and then by PropertyAttributes values,
+      // 2) kData < kAccessor,
+      // 3) NONE == 0,
+      // 4) properties with private symbol names are guaranteed to be
+      //    non-enumerable (so DONT_ENUM bit in attributes is always set),
+      // the resulting map of transitioning store if it exists in the
+      // transition array is expected to be the first among the transitions
+      // with the same name.
+      // See TransitionArray::CompareDetails() for details.
+      STATIC_ASSERT(kData == 0);
+      STATIC_ASSERT(NONE == 0);
+      const int kKeyToTargetOffset = (TransitionArray::kEntryTargetIndex -
+                                      TransitionArray::kEntryKeyIndex) *
+                                     kPointerSize;
+      var_transition_map = CAST(GetHeapObjectAssumeWeak(
+          LoadArrayElement(transitions, WeakFixedArray::kHeaderSize,
+                           var_name_index.value(), kKeyToTargetOffset)));
+      Goto(&found_handler_candidate);
+    }
+  }
+
+  BIND(&found_handler_candidate);
+  return var_transition_map.value();
+}
+
 void KeyedStoreGenericAssembler::EmitGenericPropertyStore(
     TNode<JSReceiver> receiver, TNode<Map> receiver_map,
     const StoreICParameters* p, ExitPoint* exit_point, Label* slow,
@@ -705,71 +800,15 @@ void KeyedStoreGenericAssembler::EmitGenericPropertyStore(
     BIND(&lookup_transition);
     {
       Comment("lookup transition");
-      TVARIABLE(Map, var_transition_map);
-      Label simple_transition(this), transition_array(this),
-          found_handler_candidate(this);
-      TNode<MaybeObject> maybe_handler = LoadMaybeWeakObjectField(
-          receiver_map, Map::kTransitionsOrPrototypeInfoOffset);
-
-      // SMI -> slow
-      // cleared weak reference -> slow
-      // weak reference -> simple_transition
-      // strong reference -> transition_array
-      TVARIABLE(Object, var_transition_map_or_array);
-      DispatchMaybeObject(maybe_handler, slow, slow, &simple_transition,
-                          &transition_array, &var_transition_map_or_array);
-
-      BIND(&simple_transition);
-      {
-        var_transition_map = CAST(var_transition_map_or_array.value());
-        Goto(&found_handler_candidate);
-      }
-
-      BIND(&transition_array);
-      {
-        TNode<Map> maybe_handler_map =
-            LoadMap(CAST(var_transition_map_or_array.value()));
-        GotoIfNot(IsTransitionArrayMap(maybe_handler_map), slow);
-
-        TVARIABLE(IntPtrT, var_name_index);
-        Label if_found_candidate(this);
-        TNode<TransitionArray> transitions =
-            CAST(var_transition_map_or_array.value());
-        TransitionLookup(p->name, transitions, &if_found_candidate,
-                         &var_name_index, slow);
-
-        BIND(&if_found_candidate);
-        {
-          // Given that
-          // 1) transitions with the same name are ordered in the transition
-          //    array by PropertyKind and then by PropertyAttributes values,
-          // 2) kData < kAccessor,
-          // 3) NONE == 0,
-          // 4) properties with private symbol names are guaranteed to be
-          //    non-enumerable (so DONT_ENUM bit in attributes is always set),
-          // the resulting map of transitioning store if it exists in the
-          // transition array is expected to be the first among the transitions
-          // with the same name.
-          // See TransitionArray::CompareDetails() for details.
-          STATIC_ASSERT(kData == 0);
-          STATIC_ASSERT(NONE == 0);
-          const int kKeyToTargetOffset = (TransitionArray::kEntryTargetIndex -
-                                          TransitionArray::kEntryKeyIndex) *
-                                         kPointerSize;
-          var_transition_map = CAST(ToWeakHeapObject(
-              LoadArrayElement(transitions, WeakFixedArray::kHeaderSize,
-                               var_name_index.value(), kKeyToTargetOffset)));
-          Goto(&found_handler_candidate);
-        }
-      }
-
-      BIND(&found_handler_candidate);
-      {
-        // Validate the transition handler candidate and apply the transition.
-        HandleStoreICTransitionMapHandlerCase(p, var_transition_map.value(),
-                                              slow, true);
-        exit_point->Return(p->value);
-      }
+      TNode<Map> transition_map = FindCandidateStoreICTransitionMapHandler(
+          receiver_map, CAST(p->name), slow);
+
+      // Validate the transition handler candidate and apply the transition.
+      HandleStoreICTransitionMapHandlerCase(
+          p, transition_map, slow,
+          StoreTransitionMapFlags(kCheckPrototypeValidity |
+                                  kValidateTransitionHandler));
+      exit_point->Return(p->value);
     }
   }
 
@@ -952,7 +991,7 @@ void KeyedStoreGenericAssembler::KeyedStoreGeneric(
   {
     Comment("KeyedStoreGeneric_slow");
     if (language_mode.IsJust()) {
-      TailCallRuntime(Runtime::kSetProperty, context, receiver, key, value,
+      TailCallRuntime(Runtime::kSetKeyedProperty, context, receiver, key, value,
                       SmiConstant(language_mode.FromJust()));
     } else {
       TVARIABLE(Smi, var_language_mode, SmiConstant(LanguageMode::kStrict));
@@ -961,7 +1000,7 @@ void KeyedStoreGenericAssembler::KeyedStoreGeneric(
       var_language_mode = SmiConstant(LanguageMode::kSloppy);
       Goto(&call_runtime);
       BIND(&call_runtime);
-      TailCallRuntime(Runtime::kSetProperty, context, receiver, key, value,
+      TailCallRuntime(Runtime::kSetKeyedProperty, context, receiver, key, value,
                       var_language_mode.value());
     }
   }
@@ -1011,7 +1050,7 @@ void KeyedStoreGenericAssembler::StoreIC_Uninitialized() {
 
   // Optimistically write the state transition to the vector.
   StoreFeedbackVectorSlot(vector, slot,
-                          LoadRoot(Heap::kpremonomorphic_symbolRootIndex),
+                          LoadRoot(RootIndex::kpremonomorphic_symbol),
                           SKIP_WRITE_BARRIER, 0, SMI_PARAMETERS);
 
   StoreICParameters p(context, receiver, name, value, slot, vector);
@@ -1021,7 +1060,7 @@ void KeyedStoreGenericAssembler::StoreIC_Uninitialized() {
   {
     // Undo the optimistic state transition.
     StoreFeedbackVectorSlot(vector, slot,
-                            LoadRoot(Heap::kuninitialized_symbolRootIndex),
+                            LoadRoot(RootIndex::kuninitialized_symbol),
                             SKIP_WRITE_BARRIER, 0, SMI_PARAMETERS);
     TailCallRuntime(Runtime::kStoreIC_Miss, context, value, slot, vector,
                     receiver, name);
@@ -1048,13 +1087,132 @@ void KeyedStoreGenericAssembler::SetProperty(TNode<Context> context,
 
   BIND(&slow);
   {
-    CallRuntime(Runtime::kSetProperty, context, receiver, unique_name, value,
-                SmiConstant(language_mode));
+    CallRuntime(Runtime::kSetKeyedProperty, context, receiver, unique_name,
+                value, SmiConstant(language_mode));
     Goto(&done);
   }
 
   BIND(&done);
 }
 
+// Sets data properties as in PropertyDefinitionEvaluation --- Does not invoke
+// own setters or traverse the prototype chain.
+void KeyedStoreGenericAssembler::EmitGenericPropertyStoreInLiteral(
+    TNode<Context> context, TNode<JSObject> receiver, TNode<Map> map,
+    TNode<Name> key, TNode<Object> value, ExitPoint* exit_point) {
+  CSA_ASSERT(this, IsSimpleObjectMap(map));
+
+  // This should only be used for storing data properties  in object literals.
+  CSA_ASSERT(this, HasInstanceType(receiver, JS_OBJECT_TYPE));
+
+  Label stub_cache(this), fast_properties(this), dictionary_properties(this),
+      accessor(this), call_runtime(this, Label::kDeferred), done(this);
+  TNode<Uint32T> bit_field3 = LoadMapBitField3(map);
+  Branch(IsSetWord32<Map::IsDictionaryMapBit>(bit_field3),
+         &dictionary_properties, &fast_properties);
+
+  BIND(&fast_properties);
+  {
+    Comment("fast property store");
+    TNode<DescriptorArray> descriptors = LoadMapDescriptors(map);
+    Label descriptor_found(this), lookup_transition(this);
+
+    TVARIABLE(IntPtrT, var_name_index);
+    DescriptorLookup(key, descriptors, bit_field3, &descriptor_found,
+                     &var_name_index, &lookup_transition);
+
+    BIND(&descriptor_found);
+    {
+      TNode<IntPtrT> name_index = var_name_index.value();
+      TNode<Uint32T> details = LoadDetailsByKeyIndex(descriptors, name_index);
+      Label data_property(this);
+      JumpIfDataProperty(details, &data_property, nullptr);
+
+      // Reconfigure the accessor to a data property via runtime call.
+      // TODO(caitp): reconfigure the property details inlinr here.
+      Goto(&call_runtime);
+
+      BIND(&data_property);
+      {
+        // TODO(caitp): consider only checking for names associated with
+        // protectors that can apply to non-prototype JSObjects (currently, only
+        // [Symbol.isConcatSpreadable]), and request this behaviour with an
+        // enum parameter.
+        CheckForAssociatedProtector(key, &call_runtime);
+        OverwriteExistingFastDataProperty(receiver, map, descriptors,
+                                          name_index, details, value,
+                                          &call_runtime, false);
+        exit_point->Return(value);
+      }
+    }
+
+    BIND(&lookup_transition);
+    {
+      Comment("lookup transition");
+      TNode<Map> transition_map =
+          FindCandidateStoreICTransitionMapHandler(map, key, &call_runtime);
+
+      // Validate the transition handler candidate and apply the transition.
+      StoreICParameters p(context, receiver, key, value, nullptr, nullptr);
+      HandleStoreICTransitionMapHandlerCase(&p, transition_map, &call_runtime,
+                                            kValidateTransitionHandler);
+      exit_point->Return(value);
+    }
+  }
+
+  BIND(&dictionary_properties);
+  {
+    Comment("dictionary property store");
+    TVARIABLE(IntPtrT, var_name_index);
+    Label dictionary_found(this, &var_name_index), not_found(this);
+    TNode<NameDictionary> properties = CAST(LoadSlowProperties(receiver));
+    NameDictionaryLookup<NameDictionary>(properties, key, &dictionary_found,
+                                         &var_name_index, &not_found);
+    BIND(&dictionary_found);
+    {
+      Label overwrite(this);
+      TNode<Uint32T> details = LoadDetailsByKeyIndex<NameDictionary>(
+          properties, var_name_index.value());
+      JumpIfDataProperty(details, &overwrite, nullptr);
+
+      // Reconfigure the accessor to a data property via runtime call.
+      Goto(&call_runtime);
+
+      BIND(&overwrite);
+      {
+        // See above TODO regarding non-pertinent checks
+        CheckForAssociatedProtector(key, &call_runtime);
+        StoreValueByKeyIndex<NameDictionary>(properties, var_name_index.value(),
+                                             value);
+        exit_point->Return(value);
+      }
+    }
+
+    BIND(&not_found);
+    {
+      // See above TODO regarding non-pertinent checks
+      CheckForAssociatedProtector(key, &call_runtime);
+
+      // This method should always be invoked on a new JSObject literal ---
+      // it should be impossible for the object to be made non-extensible, or to
+      // be a prototype map/
+      CSA_ASSERT(this, IsExtensibleNonPrototypeMap(map));
+
+      Label add_dictionary_property_slow(this);
+      Add<NameDictionary>(properties, key, value,
+                          &add_dictionary_property_slow);
+      exit_point->Return(value);
+
+      BIND(&add_dictionary_property_slow);
+      exit_point->ReturnCallRuntime(Runtime::kAddDictionaryProperty, context,
+                                    receiver, key, value);
+    }
+  }
+
+  BIND(&call_runtime);
+  exit_point->ReturnCallRuntime(Runtime::kStoreDataPropertyInLiteral, context,
+                                receiver, key, value);
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/ic/keyed-store-generic.h b/deps/v8/src/ic/keyed-store-generic.h
index 0934c96cc8..9442a54935 100644
--- a/deps/v8/src/ic/keyed-store-generic.h
+++ b/deps/v8/src/ic/keyed-store-generic.h
@@ -30,6 +30,11 @@ class KeyedStoreGenericGenerator {
                           TNode<Context> context, TNode<Object> receiver,
                           TNode<Object> key, TNode<Object> value,
                           LanguageMode language_mode);
+
+  static void SetPropertyInLiteral(compiler::CodeAssemblerState* state,
+                                   TNode<Context> context,
+                                   TNode<JSObject> receiver, TNode<Name> key,
+                                   TNode<Object> value);
 };
 
 class StoreICUninitializedGenerator {
diff --git a/deps/v8/src/identity-map.h b/deps/v8/src/identity-map.h
index ec2b558dc2..8598c6c1da 100644
--- a/deps/v8/src/identity-map.h
+++ b/deps/v8/src/identity-map.h
@@ -120,7 +120,7 @@ class IdentityMap : public IdentityMapBase {
     void* v = nullptr;
     bool deleted_something = DeleteEntry(key, &v);
     if (deleted_value != nullptr && deleted_something) {
-      *deleted_value = (V) reinterpret_cast<intptr_t>(v);
+      *deleted_value = *reinterpret_cast<V*>(&v);
     }
     return deleted_something;
   }
diff --git a/deps/v8/src/inspector/injected-script-source.js b/deps/v8/src/inspector/injected-script-source.js
index ea0d871248..380091cb4a 100644
--- a/deps/v8/src/inspector/injected-script-source.js
+++ b/deps/v8/src/inspector/injected-script-source.js
@@ -661,16 +661,15 @@ InjectedScript.prototype = {
 
         if (InjectedScriptHost.subtype(obj) === "error") {
             try {
-                var stack = obj.stack;
-                var message = obj.message && obj.message.length ? ": " + obj.message : "";
-                var firstCallFrame = /^\s+at\s/m.exec(stack);
-                var stackMessageEnd = firstCallFrame ? firstCallFrame.index : -1;
-                if (stackMessageEnd !== -1) {
-                    var stackTrace = stack.substr(stackMessageEnd);
-                    return className + message + "\n" + stackTrace;
-                }
-                return className + message;
+                const stack = obj.stack;
+                if (stack.substr(0, className.length) === className)
+                    return stack;
+                const message = obj.message;
+                const index = /* suppressBlacklist */ stack.indexOf(message);
+                const messageWithStack = index !== -1 ? stack.substr(index) : message;
+                return className + ': ' + messageWithStack;
             } catch(e) {
+                return className;
             }
         }
 
diff --git a/deps/v8/src/inspector/injected-script.cc b/deps/v8/src/inspector/injected-script.cc
index 0d1b8d6e89..296dc4c631 100644
--- a/deps/v8/src/inspector/injected-script.cc
+++ b/deps/v8/src/inspector/injected-script.cc
@@ -738,7 +738,7 @@ InjectedScript::ContextScope::ContextScope(V8InspectorSessionImpl* session,
     : InjectedScript::Scope(session),
       m_executionContextId(executionContextId) {}
 
-InjectedScript::ContextScope::~ContextScope() {}
+InjectedScript::ContextScope::~ContextScope() = default;
 
 Response InjectedScript::ContextScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
@@ -749,7 +749,7 @@ InjectedScript::ObjectScope::ObjectScope(V8InspectorSessionImpl* session,
                                          const String16& remoteObjectId)
     : InjectedScript::Scope(session), m_remoteObjectId(remoteObjectId) {}
 
-InjectedScript::ObjectScope::~ObjectScope() {}
+InjectedScript::ObjectScope::~ObjectScope() = default;
 
 Response InjectedScript::ObjectScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
@@ -770,7 +770,7 @@ InjectedScript::CallFrameScope::CallFrameScope(V8InspectorSessionImpl* session,
                                                const String16& remoteObjectId)
     : InjectedScript::Scope(session), m_remoteCallFrameId(remoteObjectId) {}
 
-InjectedScript::CallFrameScope::~CallFrameScope() {}
+InjectedScript::CallFrameScope::~CallFrameScope() = default;
 
 Response InjectedScript::CallFrameScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
diff --git a/deps/v8/src/inspector/injected-script.h b/deps/v8/src/inspector/injected-script.h
index 32969a6e7c..a5fb681060 100644
--- a/deps/v8/src/inspector/injected-script.h
+++ b/deps/v8/src/inspector/injected-script.h
@@ -60,7 +60,7 @@ class EvaluateCallback {
       protocol::Maybe<protocol::Runtime::ExceptionDetails>
           exceptionDetails) = 0;
   virtual void sendFailure(const protocol::DispatchResponse& response) = 0;
-  virtual ~EvaluateCallback() {}
+  virtual ~EvaluateCallback() = default;
 };
 
 class InjectedScript final {
@@ -153,7 +153,7 @@ class InjectedScript final {
   class ContextScope : public Scope {
    public:
     ContextScope(V8InspectorSessionImpl*, int executionContextId);
-    ~ContextScope();
+    ~ContextScope() override;
 
    private:
     Response findInjectedScript(V8InspectorSessionImpl*) override;
@@ -165,7 +165,7 @@ class InjectedScript final {
   class ObjectScope : public Scope {
    public:
     ObjectScope(V8InspectorSessionImpl*, const String16& remoteObjectId);
-    ~ObjectScope();
+    ~ObjectScope() override;
     const String16& objectGroupName() const { return m_objectGroupName; }
     v8::Local<v8::Value> object() const { return m_object; }
 
@@ -181,7 +181,7 @@ class InjectedScript final {
   class CallFrameScope : public Scope {
    public:
     CallFrameScope(V8InspectorSessionImpl*, const String16& remoteCallFrameId);
-    ~CallFrameScope();
+    ~CallFrameScope() override;
     size_t frameOrdinal() const { return m_frameOrdinal; }
 
    private:
diff --git a/deps/v8/src/inspector/remote-object-id.h b/deps/v8/src/inspector/remote-object-id.h
index 923274236d..b199032359 100644
--- a/deps/v8/src/inspector/remote-object-id.h
+++ b/deps/v8/src/inspector/remote-object-id.h
@@ -17,7 +17,7 @@ class RemoteObjectIdBase {
 
  protected:
   RemoteObjectIdBase();
-  ~RemoteObjectIdBase() {}
+  ~RemoteObjectIdBase() = default;
 
   std::unique_ptr<protocol::DictionaryValue> parseInjectedScriptId(
       const String16&);
@@ -28,7 +28,7 @@ class RemoteObjectIdBase {
 class RemoteObjectId final : public RemoteObjectIdBase {
  public:
   static Response parse(const String16&, std::unique_ptr<RemoteObjectId>*);
-  ~RemoteObjectId() {}
+  ~RemoteObjectId() = default;
   int id() const { return m_id; }
 
  private:
@@ -40,7 +40,7 @@ class RemoteObjectId final : public RemoteObjectIdBase {
 class RemoteCallFrameId final : public RemoteObjectIdBase {
  public:
   static Response parse(const String16&, std::unique_ptr<RemoteCallFrameId>*);
-  ~RemoteCallFrameId() {}
+  ~RemoteCallFrameId() = default;
 
   int frameOrdinal() const { return m_frameOrdinal; }
 
diff --git a/deps/v8/src/inspector/string-16.cc b/deps/v8/src/inspector/string-16.cc
index fbcb0f4338..eb77ddd5fb 100644
--- a/deps/v8/src/inspector/string-16.cc
+++ b/deps/v8/src/inspector/string-16.cc
@@ -116,13 +116,13 @@ ConversionResult convertUTF16ToUTF8(const UChar** sourceStart,
       }
     }
     // Figure out how many bytes the result will require
-    if (ch < (UChar32)0x80) {
+    if (ch < static_cast<UChar32>(0x80)) {
       bytesToWrite = 1;
-    } else if (ch < (UChar32)0x800) {
+    } else if (ch < static_cast<UChar32>(0x800)) {
       bytesToWrite = 2;
-    } else if (ch < (UChar32)0x10000) {
+    } else if (ch < static_cast<UChar32>(0x10000)) {
       bytesToWrite = 3;
-    } else if (ch < (UChar32)0x110000) {
+    } else if (ch < static_cast<UChar32>(0x110000)) {
       bytesToWrite = 4;
     } else {
       bytesToWrite = 3;
@@ -370,10 +370,9 @@ static inline void putUTF8Triple(char*& buffer, UChar ch) {
 
 }  // namespace
 
-String16::String16() {}
+String16::String16() = default;
 
-String16::String16(const String16& other)
-    : m_impl(other.m_impl), hash_code(other.hash_code) {}
+String16::String16(const String16& other) = default;
 
 String16::String16(String16&& other) V8_NOEXCEPT
     : m_impl(std::move(other.m_impl)),
@@ -394,11 +393,7 @@ String16::String16(const char* characters, size_t size) {
 
 String16::String16(const std::basic_string<UChar>& impl) : m_impl(impl) {}
 
-String16& String16::operator=(const String16& other) {
-  m_impl = other.m_impl;
-  hash_code = other.hash_code;
-  return *this;
-}
+String16& String16::operator=(const String16& other) = default;
 
 String16& String16::operator=(String16&& other) V8_NOEXCEPT {
   m_impl = std::move(other.m_impl);
@@ -471,7 +466,7 @@ String16 String16::stripWhiteSpace() const {
   return String16(characters16() + start, end + 1 - start);
 }
 
-String16Builder::String16Builder() {}
+String16Builder::String16Builder() = default;
 
 void String16Builder::append(const String16& s) {
   m_buffer.insert(m_buffer.end(), s.characters16(),
@@ -547,7 +542,7 @@ String16 String16::fromUTF8(const char* stringStart, size_t length) {
   UChar* bufferCurrent = bufferStart;
   const char* stringCurrent = stringStart;
   if (convertUTF8ToUTF16(&stringCurrent, stringStart + length, &bufferCurrent,
-                         bufferCurrent + buffer.size(), 0,
+                         bufferCurrent + buffer.size(), nullptr,
                          true) != conversionOK)
     return String16();
 
diff --git a/deps/v8/src/inspector/v8-console-agent-impl.cc b/deps/v8/src/inspector/v8-console-agent-impl.cc
index 96ffdc593c..66c96110d7 100644
--- a/deps/v8/src/inspector/v8-console-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-console-agent-impl.cc
@@ -24,7 +24,7 @@ V8ConsoleAgentImpl::V8ConsoleAgentImpl(
       m_frontend(frontendChannel),
       m_enabled(false) {}
 
-V8ConsoleAgentImpl::~V8ConsoleAgentImpl() {}
+V8ConsoleAgentImpl::~V8ConsoleAgentImpl() = default;
 
 Response V8ConsoleAgentImpl::enable() {
   if (m_enabled) return Response::OK();
diff --git a/deps/v8/src/inspector/v8-console-message.cc b/deps/v8/src/inspector/v8-console-message.cc
index 4bb0bf904e..6d39deeb4c 100644
--- a/deps/v8/src/inspector/v8-console-message.cc
+++ b/deps/v8/src/inspector/v8-console-message.cc
@@ -13,6 +13,7 @@
 #include "src/inspector/v8-inspector-session-impl.h"
 #include "src/inspector/v8-runtime-agent-impl.h"
 #include "src/inspector/v8-stack-trace-impl.h"
+#include "src/tracing/trace-event.h"
 
 #include "include/v8-inspector.h"
 
@@ -202,7 +203,7 @@ V8ConsoleMessage::V8ConsoleMessage(V8MessageOrigin origin, double timestamp,
       m_exceptionId(0),
       m_revokedExceptionId(0) {}
 
-V8ConsoleMessage::~V8ConsoleMessage() {}
+V8ConsoleMessage::~V8ConsoleMessage() = default;
 
 void V8ConsoleMessage::setLocation(const String16& url, unsigned lineNumber,
                                    unsigned columnNumber,
@@ -477,12 +478,34 @@ V8ConsoleMessageStorage::V8ConsoleMessageStorage(V8InspectorImpl* inspector,
 
 V8ConsoleMessageStorage::~V8ConsoleMessageStorage() { clear(); }
 
+namespace {
+
+void TraceV8ConsoleMessageEvent(V8MessageOrigin origin, ConsoleAPIType type) {
+  // Change in this function requires adjustment of Catapult/Telemetry metric
+  // tracing/tracing/metrics/console_error_metric.html.
+  // See https://crbug.com/880432
+  if (origin == V8MessageOrigin::kException) {
+    TRACE_EVENT_INSTANT0("v8.console", "V8ConsoleMessage::Exception",
+                         TRACE_EVENT_SCOPE_THREAD);
+  } else if (type == ConsoleAPIType::kError) {
+    TRACE_EVENT_INSTANT0("v8.console", "V8ConsoleMessage::Error",
+                         TRACE_EVENT_SCOPE_THREAD);
+  } else if (type == ConsoleAPIType::kAssert) {
+    TRACE_EVENT_INSTANT0("v8.console", "V8ConsoleMessage::Assert",
+                         TRACE_EVENT_SCOPE_THREAD);
+  }
+}
+
+}  // anonymous namespace
+
 void V8ConsoleMessageStorage::addMessage(
     std::unique_ptr<V8ConsoleMessage> message) {
   int contextGroupId = m_contextGroupId;
   V8InspectorImpl* inspector = m_inspector;
   if (message->type() == ConsoleAPIType::kClear) clear();
 
+  TraceV8ConsoleMessageEvent(message->origin(), message->type());
+
   inspector->forEachSession(
       contextGroupId, [&message](V8InspectorSessionImpl* session) {
         if (message->origin() == V8MessageOrigin::kConsole)
@@ -542,6 +565,13 @@ bool V8ConsoleMessageStorage::countReset(int contextId, const String16& id) {
   return true;
 }
 
+double V8ConsoleMessageStorage::timeLog(int contextId, const String16& id) {
+  std::map<String16, double>& time = m_data[contextId].m_time;
+  auto it = time.find(id);
+  if (it == time.end()) return 0.0;
+  return m_inspector->client()->currentTimeMS() - it->second;
+}
+
 double V8ConsoleMessageStorage::timeEnd(int contextId, const String16& id) {
   std::map<String16, double>& time = m_data[contextId].m_time;
   auto it = time.find(id);
diff --git a/deps/v8/src/inspector/v8-console-message.h b/deps/v8/src/inspector/v8-console-message.h
index d030778a5b..cca5b47265 100644
--- a/deps/v8/src/inspector/v8-console-message.h
+++ b/deps/v8/src/inspector/v8-console-message.h
@@ -120,6 +120,7 @@ class V8ConsoleMessageStorage {
   int count(int contextId, const String16& id);
   bool countReset(int contextId, const String16& id);
   void time(int contextId, const String16& id);
+  double timeLog(int contextId, const String16& id);
   double timeEnd(int contextId, const String16& id);
   bool hasTimer(int contextId, const String16& id);
 
diff --git a/deps/v8/src/inspector/v8-console.cc b/deps/v8/src/inspector/v8-console.cc
index 752b50fa36..ef4c7ccd1d 100644
--- a/deps/v8/src/inspector/v8-console.cc
+++ b/deps/v8/src/inspector/v8-console.cc
@@ -63,6 +63,7 @@ class ConsoleHelper {
   void reportCall(ConsoleAPIType type) {
     if (!m_info.Length()) return;
     std::vector<v8::Local<v8::Value>> arguments;
+    arguments.reserve(m_info.Length());
     for (int i = 0; i < m_info.Length(); ++i) arguments.push_back(m_info[i]);
     reportCall(type, arguments);
   }
@@ -75,6 +76,14 @@ class ConsoleHelper {
     reportCall(type, arguments);
   }
 
+  void reportCallAndReplaceFirstArgument(ConsoleAPIType type,
+                                         const String16& message) {
+    std::vector<v8::Local<v8::Value>> arguments;
+    arguments.push_back(toV8String(m_isolate, message));
+    for (int i = 1; i < m_info.Length(); ++i) arguments.push_back(m_info[i]);
+    reportCall(type, arguments);
+  }
+
   void reportCallWithArgument(ConsoleAPIType type, const String16& message) {
     std::vector<v8::Local<v8::Value>> arguments(1,
                                                 toV8String(m_isolate, message));
@@ -106,7 +115,7 @@ class ConsoleHelper {
   bool firstArgToBoolean(bool defaultValue) {
     if (m_info.Length() < 1) return defaultValue;
     if (m_info[0]->IsBoolean()) return m_info[0].As<v8::Boolean>()->Value();
-    return m_info[0]->BooleanValue(m_context).FromMaybe(defaultValue);
+    return m_info[0]->BooleanValue(m_context->GetIsolate());
   }
 
   String16 firstArgToString(const String16& defaultValue,
@@ -143,7 +152,7 @@ class ConsoleHelper {
   }
 
   void forEachSession(std::function<void(V8InspectorSessionImpl*)> callback) {
-    m_inspector->forEachSession(m_groupId, callback);
+    m_inspector->forEachSession(m_groupId, std::move(callback));
   }
 
  private:
@@ -385,10 +394,9 @@ static void timeFunction(const v8::debug::ConsoleCallArguments& info,
 
 static void timeEndFunction(const v8::debug::ConsoleCallArguments& info,
                             const v8::debug::ConsoleContext& consoleContext,
-                            bool timelinePrefix, V8InspectorImpl* inspector) {
+                            bool timeLog, V8InspectorImpl* inspector) {
   ConsoleHelper helper(info, consoleContext, inspector);
   String16 protocolTitle = helper.firstArgToString("default", false);
-  if (timelinePrefix) protocolTitle = "Timeline '" + protocolTitle + "'";
   const String16& timerId =
       protocolTitle + "@" +
       consoleContextToString(inspector->isolate(), consoleContext);
@@ -399,13 +407,22 @@ static void timeEndFunction(const v8::debug::ConsoleCallArguments& info,
     return;
   }
   inspector->client()->consoleTimeEnd(toStringView(protocolTitle));
-  double elapsed = helper.consoleMessageStorage()->timeEnd(
-      helper.contextId(),
-      protocolTitle + "@" +
-          consoleContextToString(inspector->isolate(), consoleContext));
+  String16 title = protocolTitle + "@" +
+                   consoleContextToString(inspector->isolate(), consoleContext);
+  double elapsed;
+  if (timeLog) {
+    elapsed =
+        helper.consoleMessageStorage()->timeLog(helper.contextId(), title);
+  } else {
+    elapsed =
+        helper.consoleMessageStorage()->timeEnd(helper.contextId(), title);
+  }
   String16 message =
       protocolTitle + ": " + String16::fromDouble(elapsed) + "ms";
-  helper.reportCallWithArgument(ConsoleAPIType::kTimeEnd, message);
+  if (timeLog)
+    helper.reportCallAndReplaceFirstArgument(ConsoleAPIType::kLog, message);
+  else
+    helper.reportCallWithArgument(ConsoleAPIType::kTimeEnd, message);
 }
 
 void V8Console::Time(const v8::debug::ConsoleCallArguments& info,
@@ -413,6 +430,11 @@ void V8Console::Time(const v8::debug::ConsoleCallArguments& info,
   timeFunction(info, consoleContext, false, m_inspector);
 }
 
+void V8Console::TimeLog(const v8::debug::ConsoleCallArguments& info,
+                        const v8::debug::ConsoleContext& consoleContext) {
+  timeEndFunction(info, consoleContext, true, m_inspector);
+}
+
 void V8Console::TimeEnd(const v8::debug::ConsoleCallArguments& info,
                         const v8::debug::ConsoleContext& consoleContext) {
   timeEndFunction(info, consoleContext, false, m_inspector);
diff --git a/deps/v8/src/inspector/v8-console.h b/deps/v8/src/inspector/v8-console.h
index 2e47012807..03d89ced10 100644
--- a/deps/v8/src/inspector/v8-console.h
+++ b/deps/v8/src/inspector/v8-console.h
@@ -88,6 +88,8 @@ class V8Console : public v8::debug::ConsoleDelegate {
                   const v8::debug::ConsoleContext& consoleContext) override;
   void Time(const v8::debug::ConsoleCallArguments&,
             const v8::debug::ConsoleContext& consoleContext) override;
+  void TimeLog(const v8::debug::ConsoleCallArguments&,
+               const v8::debug::ConsoleContext& consoleContext) override;
   void TimeEnd(const v8::debug::ConsoleCallArguments&,
                const v8::debug::ConsoleContext& consoleContext) override;
   void TimeStamp(const v8::debug::ConsoleCallArguments&,
diff --git a/deps/v8/src/inspector/v8-debugger-agent-impl.cc b/deps/v8/src/inspector/v8-debugger-agent-impl.cc
index a27af98d8d..d227526d64 100644
--- a/deps/v8/src/inspector/v8-debugger-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-debugger-agent-impl.cc
@@ -160,9 +160,8 @@ String16 breakpointHint(const V8DebuggerScript& script, int lineNumber,
                         int columnNumber) {
   int offset = script.offset(lineNumber, columnNumber);
   if (offset == V8DebuggerScript::kNoOffset) return String16();
-  const String16& source = script.source();
   String16 hint =
-      source.substring(offset, kBreakpointHintMaxLength).stripWhiteSpace();
+      script.source(offset, kBreakpointHintMaxLength).stripWhiteSpace();
   for (size_t i = 0; i < hint.length(); ++i) {
     if (hint[i] == '\r' || hint[i] == '\n' || hint[i] == ';') {
       return hint.substring(0, i);
@@ -183,8 +182,8 @@ void adjustBreakpointLocation(const V8DebuggerScript& script,
   intptr_t searchRegionOffset = std::max(
       sourceOffset - kBreakpointHintMaxSearchOffset, static_cast<intptr_t>(0));
   size_t offset = sourceOffset - searchRegionOffset;
-  String16 searchArea = script.source().substring(
-      searchRegionOffset, offset + kBreakpointHintMaxSearchOffset);
+  String16 searchArea = script.source(searchRegionOffset,
+                                      offset + kBreakpointHintMaxSearchOffset);
 
   size_t nextMatch = searchArea.find(hint, offset);
   size_t prevMatch = searchArea.reverseFind(hint, offset);
@@ -317,7 +316,7 @@ V8DebuggerAgentImpl::V8DebuggerAgentImpl(
       m_frontend(frontendChannel),
       m_isolate(m_inspector->isolate()) {}
 
-V8DebuggerAgentImpl::~V8DebuggerAgentImpl() {}
+V8DebuggerAgentImpl::~V8DebuggerAgentImpl() = default;
 
 void V8DebuggerAgentImpl::enableImpl() {
   m_enabled = true;
@@ -334,7 +333,7 @@ void V8DebuggerAgentImpl::enableImpl() {
 
   if (isPaused()) {
     didPause(0, v8::Local<v8::Value>(), std::vector<v8::debug::BreakpointId>(),
-             false, false, false, false);
+             v8::debug::kException, false, false, false);
   }
 }
 
@@ -837,7 +836,7 @@ Response V8DebuggerAgentImpl::searchInContent(
     return Response::Error("No script for id: " + scriptId);
 
   std::vector<std::unique_ptr<protocol::Debugger::SearchMatch>> matches =
-      searchInTextByLinesImpl(m_session, it->second->source(), query,
+      searchInTextByLinesImpl(m_session, it->second->source(0), query,
                               optionalCaseSensitive.fromMaybe(false),
                               optionalIsRegex.fromMaybe(false));
   *results = protocol::Array<protocol::Debugger::SearchMatch>::create();
@@ -859,10 +858,6 @@ Response V8DebuggerAgentImpl::setScriptSource(
   if (it == m_scripts.end()) {
     return Response::Error("No script with given id found");
   }
-  if (it->second->isModule()) {
-    // TODO(kozyatinskiy): LiveEdit should support ES6 module
-    return Response::Error("Editing module's script is not supported.");
-  }
   int contextId = it->second->executionContextId();
   InspectedContext* inspected = m_inspector->getContext(contextId);
   if (!inspected) {
@@ -927,7 +922,7 @@ Response V8DebuggerAgentImpl::getScriptSource(const String16& scriptId,
   ScriptsMap::iterator it = m_scripts.find(scriptId);
   if (it == m_scripts.end())
     return Response::Error("No script for id: " + scriptId);
-  *scriptSource = it->second->source();
+  *scriptSource = it->second->source(0);
   return Response::OK();
 }
 
@@ -1380,7 +1375,7 @@ void V8DebuggerAgentImpl::didParseSource(
   v8::HandleScope handles(m_isolate);
   if (!success) {
     DCHECK(!script->isSourceLoadedLazily());
-    String16 scriptSource = script->source();
+    String16 scriptSource = script->source(0);
     script->setSourceURL(findSourceURL(scriptSource, false));
     script->setSourceMappingURL(findSourceMapURL(scriptSource, false));
   }
@@ -1440,8 +1435,7 @@ void V8DebuggerAgentImpl::didParseSource(
           scriptRef->endLine(), scriptRef->endColumn(), contextId,
           scriptRef->hash(), std::move(executionContextAuxDataParam),
           isLiveEditParam, std::move(sourceMapURLParam), hasSourceURLParam,
-          isModuleParam, static_cast<int>(scriptRef->source().length()),
-          std::move(stackTrace));
+          isModuleParam, scriptRef->length(), std::move(stackTrace));
     }
   } else {
     m_frontend.scriptFailedToParse(
@@ -1449,7 +1443,7 @@ void V8DebuggerAgentImpl::didParseSource(
         scriptRef->endLine(), scriptRef->endColumn(), contextId,
         scriptRef->hash(), std::move(executionContextAuxDataParam),
         std::move(sourceMapURLParam), hasSourceURLParam, isModuleParam,
-        static_cast<int>(scriptRef->source().length()), std::move(stackTrace));
+        scriptRef->length(), std::move(stackTrace));
   }
 
   if (!success) {
@@ -1512,7 +1506,8 @@ void V8DebuggerAgentImpl::didParseSource(
 void V8DebuggerAgentImpl::didPause(
     int contextId, v8::Local<v8::Value> exception,
     const std::vector<v8::debug::BreakpointId>& hitBreakpoints,
-    bool isPromiseRejection, bool isUncaught, bool isOOMBreak, bool isAssert) {
+    v8::debug::ExceptionType exceptionType, bool isUncaught, bool isOOMBreak,
+    bool isAssert) {
   v8::HandleScope handles(m_isolate);
 
   std::vector<BreakReason> hitReasons;
@@ -1528,7 +1523,7 @@ void V8DebuggerAgentImpl::didPause(
     m_session->findInjectedScript(contextId, injectedScript);
     if (injectedScript) {
       String16 breakReason =
-          isPromiseRejection
+          exceptionType == v8::debug::kPromiseRejection
               ? protocol::Debugger::Paused::ReasonEnum::PromiseRejection
               : protocol::Debugger::Paused::ReasonEnum::Exception;
       std::unique_ptr<protocol::Runtime::RemoteObject> obj;
diff --git a/deps/v8/src/inspector/v8-debugger-agent-impl.h b/deps/v8/src/inspector/v8-debugger-agent-impl.h
index 65f7677b47..9806c85f48 100644
--- a/deps/v8/src/inspector/v8-debugger-agent-impl.h
+++ b/deps/v8/src/inspector/v8-debugger-agent-impl.h
@@ -142,8 +142,8 @@ class V8DebuggerAgentImpl : public protocol::Debugger::Backend {
   // Interface for V8InspectorImpl
   void didPause(int contextId, v8::Local<v8::Value> exception,
                 const std::vector<v8::debug::BreakpointId>& hitBreakpoints,
-                bool isPromiseRejection, bool isUncaught, bool isOOMBreak,
-                bool isAssert);
+                v8::debug::ExceptionType exceptionType, bool isUncaught,
+                bool isOOMBreak, bool isAssert);
   void didContinue();
   void didParseSource(std::unique_ptr<V8DebuggerScript>, bool success);
 
diff --git a/deps/v8/src/inspector/v8-debugger-script.cc b/deps/v8/src/inspector/v8-debugger-script.cc
index babb7700c6..c1efd2dba1 100644
--- a/deps/v8/src/inspector/v8-debugger-script.cc
+++ b/deps/v8/src/inspector/v8-debugger-script.cc
@@ -20,7 +20,7 @@ const char kGlobalDebuggerScriptHandleLabel[] = "DevTools debugger";
 // Multiplikation in
 // eingeschränkten Branchingprogrammmodellen" by Woelfe.
 // http://opendatastructures.org/versions/edition-0.1d/ods-java/node33.html#SECTION00832000000000000000
-String16 calculateHash(const String16& str) {
+String16 calculateHash(v8::Isolate* isolate, v8::Local<v8::String> source) {
   static uint64_t prime[] = {0x3FB75161, 0xAB1F4E4F, 0x82675BC5, 0xCD924D35,
                              0x81ABE279};
   static uint64_t random[] = {0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476,
@@ -34,9 +34,14 @@ String16 calculateHash(const String16& str) {
   const size_t hashesSize = arraysize(hashes);
 
   size_t current = 0;
+
+  std::unique_ptr<UChar[]> buffer(new UChar[source->Length()]);
+  int written = source->Write(
+      isolate, reinterpret_cast<uint16_t*>(buffer.get()), 0, source->Length());
+
   const uint32_t* data = nullptr;
-  size_t sizeInBytes = sizeof(UChar) * str.length();
-  data = reinterpret_cast<const uint32_t*>(str.characters16());
+  size_t sizeInBytes = sizeof(UChar) * written;
+  data = reinterpret_cast<const uint32_t*>(buffer.get());
   for (size_t i = 0; i < sizeInBytes / 4; ++i) {
     uint32_t d = v8::internal::ReadUnalignedUInt32(
         reinterpret_cast<v8::internal::Address>(data + i));
@@ -76,7 +81,7 @@ String16 calculateHash(const String16& str) {
 
   String16Builder hash;
   for (size_t i = 0; i < hashesSize; ++i)
-    hash.appendUnsignedAsHex((uint32_t)hashes[i]);
+    hash.appendUnsignedAsHex(static_cast<uint32_t>(hashes[i]));
   return hash.toString();
 }
 
@@ -121,12 +126,29 @@ class ActualScript : public V8DebuggerScript {
   bool isLiveEdit() const override { return m_isLiveEdit; }
   bool isModule() const override { return m_isModule; }
 
-  const String16& source() const override { return m_source; }
+  String16 source(size_t pos, size_t len) const override {
+    v8::HandleScope scope(m_isolate);
+    v8::Local<v8::String> v8Source;
+    if (!script()->Source().ToLocal(&v8Source)) return String16();
+    if (pos >= static_cast<size_t>(v8Source->Length())) return String16();
+    size_t substringLength =
+        std::min(len, static_cast<size_t>(v8Source->Length()) - pos);
+    std::unique_ptr<UChar[]> buffer(new UChar[substringLength]);
+    v8Source->Write(m_isolate, reinterpret_cast<uint16_t*>(buffer.get()),
+                    static_cast<int>(pos), static_cast<int>(substringLength));
+    return String16(buffer.get(), substringLength);
+  }
   int startLine() const override { return m_startLine; }
   int startColumn() const override { return m_startColumn; }
   int endLine() const override { return m_endLine; }
   int endColumn() const override { return m_endColumn; }
   bool isSourceLoadedLazily() const override { return false; }
+  int length() const override {
+    v8::HandleScope scope(m_isolate);
+    v8::Local<v8::String> v8Source;
+    if (!script()->Source().ToLocal(&v8Source)) return 0;
+    return v8Source->Length();
+  }
 
   const String16& sourceMappingURL() const override {
     return m_sourceMappingURL;
@@ -138,7 +160,6 @@ class ActualScript : public V8DebuggerScript {
 
   void setSource(const String16& newSource, bool preview,
                  v8::debug::LiveEditResult* result) override {
-    DCHECK(!isModule());
     v8::EscapableHandleScope scope(m_isolate);
     v8::Local<v8::String> v8Source = toV8String(m_isolate, newSource);
     if (!m_script.Get(m_isolate)->SetScriptSource(v8Source, preview, result)) {
@@ -213,7 +234,13 @@ class ActualScript : public V8DebuggerScript {
   }
 
   const String16& hash() const override {
-    if (m_hash.isEmpty()) m_hash = calculateHash(source());
+    if (m_hash.isEmpty()) {
+      v8::HandleScope scope(m_isolate);
+      v8::Local<v8::String> v8Source;
+      if (script()->Source().ToLocal(&v8Source)) {
+        m_hash = calculateHash(m_isolate, v8Source);
+      }
+    }
     DCHECK(!m_hash.isEmpty());
     return m_hash;
   }
@@ -264,10 +291,6 @@ class ActualScript : public V8DebuggerScript {
 
     USE(script->ContextId().To(&m_executionContextId));
 
-    if (script->Source().ToLocal(&tmp)) {
-      m_source = toProtocolString(m_isolate, tmp);
-    }
-
     m_isModule = script->IsModule();
 
     m_script.Reset(m_isolate, script);
@@ -277,7 +300,6 @@ class ActualScript : public V8DebuggerScript {
   String16 m_sourceMappingURL;
   bool m_isLiveEdit = false;
   bool m_isModule = false;
-  String16 m_source;
   mutable String16 m_hash;
   int m_startLine = 0;
   int m_startColumn = 0;
@@ -309,8 +331,9 @@ class WasmVirtualScript : public V8DebuggerScript {
     UNREACHABLE();
   }
   bool isSourceLoadedLazily() const override { return true; }
-  const String16& source() const override {
-    return m_wasmTranslation->GetSource(m_id, m_functionIndex);
+  String16 source(size_t pos, size_t len) const override {
+    return m_wasmTranslation->GetSource(m_id, m_functionIndex)
+        .substring(pos, len);
   }
   int startLine() const override {
     return m_wasmTranslation->GetStartLine(m_id, m_functionIndex);
@@ -324,6 +347,9 @@ class WasmVirtualScript : public V8DebuggerScript {
   int endColumn() const override {
     return m_wasmTranslation->GetEndColumn(m_id, m_functionIndex);
   }
+  int length() const override {
+    return static_cast<int>(source(0, UINT_MAX).length());
+  }
 
   bool getPossibleBreakpoints(
       const v8::debug::Location& start, const v8::debug::Location& end,
@@ -427,7 +453,7 @@ V8DebuggerScript::V8DebuggerScript(v8::Isolate* isolate, String16 id,
                                    String16 url)
     : m_id(std::move(id)), m_url(std::move(url)), m_isolate(isolate) {}
 
-V8DebuggerScript::~V8DebuggerScript() {}
+V8DebuggerScript::~V8DebuggerScript() = default;
 
 void V8DebuggerScript::setSourceURL(const String16& sourceURL) {
   if (sourceURL.length() > 0) {
diff --git a/deps/v8/src/inspector/v8-debugger-script.h b/deps/v8/src/inspector/v8-debugger-script.h
index 38e6448f48..116b965afc 100644
--- a/deps/v8/src/inspector/v8-debugger-script.h
+++ b/deps/v8/src/inspector/v8-debugger-script.h
@@ -60,7 +60,7 @@ class V8DebuggerScript {
   const String16& sourceURL() const { return m_url; }
 
   virtual const String16& sourceMappingURL() const = 0;
-  virtual const String16& source() const = 0;
+  virtual String16 source(size_t pos, size_t len = UINT_MAX) const = 0;
   virtual const String16& hash() const = 0;
   virtual int startLine() const = 0;
   virtual int startColumn() const = 0;
@@ -70,6 +70,7 @@ class V8DebuggerScript {
   virtual bool isLiveEdit() const = 0;
   virtual bool isModule() const = 0;
   virtual bool isSourceLoadedLazily() const = 0;
+  virtual int length() const = 0;
 
   void setSourceURL(const String16&);
   virtual void setSourceMappingURL(const String16&) = 0;
diff --git a/deps/v8/src/inspector/v8-debugger.cc b/deps/v8/src/inspector/v8-debugger.cc
index ccc674af43..5f826b56a9 100644
--- a/deps/v8/src/inspector/v8-debugger.cc
+++ b/deps/v8/src/inspector/v8-debugger.cc
@@ -480,7 +480,7 @@ void V8Debugger::clearContinueToLocation() {
 void V8Debugger::handleProgramBreak(
     v8::Local<v8::Context> pausedContext, v8::Local<v8::Value> exception,
     const std::vector<v8::debug::BreakpointId>& breakpointIds,
-    bool isPromiseRejection, bool isUncaught) {
+    v8::debug::ExceptionType exceptionType, bool isUncaught) {
   // Don't allow nested breaks.
   if (isPaused()) return;
 
@@ -523,12 +523,12 @@ void V8Debugger::handleProgramBreak(
 
   m_inspector->forEachSession(
       contextGroupId, [&pausedContext, &exception, &breakpointIds,
-                       &isPromiseRejection, &isUncaught, &scheduledOOMBreak,
+                       &exceptionType, &isUncaught, &scheduledOOMBreak,
                        &scheduledAssertBreak](V8InspectorSessionImpl* session) {
         if (session->debuggerAgent()->acceptsPause(scheduledOOMBreak)) {
           session->debuggerAgent()->didPause(
               InspectedContext::contextId(pausedContext), exception,
-              breakpointIds, isPromiseRejection, isUncaught, scheduledOOMBreak,
+              breakpointIds, exceptionType, isUncaught, scheduledOOMBreak,
               scheduledAssertBreak);
         }
       });
@@ -576,7 +576,7 @@ void V8Debugger::ScriptCompiled(v8::Local<v8::debug::Script> script,
                                 bool is_live_edited, bool has_compile_error) {
   int contextId;
   if (!script->ContextId().To(&contextId)) return;
-  if (script->IsWasm()) {
+  if (script->IsWasm() && script->SourceMappingURL().IsEmpty()) {
     WasmTranslation* wasmTranslation = &m_wasmTranslation;
     m_inspector->forEachSession(
         m_inspector->contextGroupId(contextId),
@@ -608,12 +608,11 @@ void V8Debugger::BreakProgramRequested(
 
 void V8Debugger::ExceptionThrown(v8::Local<v8::Context> pausedContext,
                                  v8::Local<v8::Value> exception,
-                                 v8::Local<v8::Value> promise,
-                                 bool isUncaught) {
-  bool isPromiseRejection = promise->IsPromise();
+                                 v8::Local<v8::Value> promise, bool isUncaught,
+                                 v8::debug::ExceptionType exceptionType) {
   std::vector<v8::debug::BreakpointId> break_points_hit;
-  handleProgramBreak(pausedContext, exception, break_points_hit,
-                     isPromiseRejection, isUncaught);
+  handleProgramBreak(pausedContext, exception, break_points_hit, exceptionType,
+                     isUncaught);
 }
 
 bool V8Debugger::IsFunctionBlackboxed(v8::Local<v8::debug::Script> script,
@@ -751,11 +750,37 @@ v8::MaybeLocal<v8::Value> V8Debugger::generatorScopes(
   return getTargetScopes(context, generator, GENERATOR);
 }
 
+v8::MaybeLocal<v8::Uint32> V8Debugger::stableObjectId(
+    v8::Local<v8::Context> context, v8::Local<v8::Value> value) {
+  DCHECK(value->IsObject());
+  if (m_stableObjectId.IsEmpty()) {
+    m_stableObjectId.Reset(m_isolate, v8::debug::WeakMap::New(m_isolate));
+  }
+  v8::Local<v8::debug::WeakMap> stableObjectId =
+      m_stableObjectId.Get(m_isolate);
+  v8::Local<v8::Value> idValue;
+  if (!stableObjectId->Get(context, value).ToLocal(&idValue) ||
+      !idValue->IsUint32()) {
+    idValue = v8::Integer::NewFromUnsigned(m_isolate, ++m_lastStableObjectId);
+    stableObjectId->Set(context, value, idValue).ToLocalChecked();
+  }
+  return idValue.As<v8::Uint32>();
+}
+
 v8::MaybeLocal<v8::Array> V8Debugger::internalProperties(
     v8::Local<v8::Context> context, v8::Local<v8::Value> value) {
   v8::Local<v8::Array> properties;
   if (!v8::debug::GetInternalProperties(m_isolate, value).ToLocal(&properties))
     return v8::MaybeLocal<v8::Array>();
+  if (value->IsObject()) {
+    v8::Local<v8::Uint32> id;
+    if (stableObjectId(context, value).ToLocal(&id)) {
+      createDataProperty(
+          context, properties, properties->Length(),
+          toV8StringInternalized(m_isolate, "[[StableObjectId]]"));
+      createDataProperty(context, properties, properties->Length(), id);
+    }
+  }
   if (value->IsFunction()) {
     v8::Local<v8::Function> function = value.As<v8::Function>();
     v8::Local<v8::Object> location;
diff --git a/deps/v8/src/inspector/v8-debugger.h b/deps/v8/src/inspector/v8-debugger.h
index 72962dde31..a99653add6 100644
--- a/deps/v8/src/inspector/v8-debugger.h
+++ b/deps/v8/src/inspector/v8-debugger.h
@@ -40,7 +40,7 @@ class V8Debugger : public v8::debug::DebugDelegate,
                    public v8::debug::AsyncEventDelegate {
  public:
   V8Debugger(v8::Isolate*, V8InspectorImpl*);
-  ~V8Debugger();
+  ~V8Debugger() override;
 
   bool enabled() const;
   v8::Isolate* isolate() const { return m_isolate; }
@@ -145,7 +145,8 @@ class V8Debugger : public v8::debug::DebugDelegate,
   void handleProgramBreak(
       v8::Local<v8::Context> pausedContext, v8::Local<v8::Value> exception,
       const std::vector<v8::debug::BreakpointId>& hitBreakpoints,
-      bool isPromiseRejection = false, bool isUncaught = false);
+      v8::debug::ExceptionType exception_type = v8::debug::kException,
+      bool isUncaught = false);
 
   enum ScopeTargetKind {
     FUNCTION,
@@ -181,7 +182,8 @@ class V8Debugger : public v8::debug::DebugDelegate,
       const std::vector<v8::debug::BreakpointId>& break_points_hit) override;
   void ExceptionThrown(v8::Local<v8::Context> paused_context,
                        v8::Local<v8::Value> exception,
-                       v8::Local<v8::Value> promise, bool is_uncaught) override;
+                       v8::Local<v8::Value> promise, bool is_uncaught,
+                       v8::debug::ExceptionType exception_type) override;
   bool IsFunctionBlackboxed(v8::Local<v8::debug::Script> script,
                             const v8::debug::Location& start,
                             const v8::debug::Location& end) override;
@@ -189,6 +191,9 @@ class V8Debugger : public v8::debug::DebugDelegate,
   int currentContextGroupId();
   bool asyncStepOutOfFunction(int targetContextGroupId, bool onlyAtReturn);
 
+  v8::MaybeLocal<v8::Uint32> stableObjectId(v8::Local<v8::Context>,
+                                            v8::Local<v8::Value>);
+
   v8::Isolate* m_isolate;
   V8InspectorImpl* m_inspector;
   int m_enableCount;
@@ -245,6 +250,9 @@ class V8Debugger : public v8::debug::DebugDelegate,
 
   std::unique_ptr<TerminateExecutionCallback> m_terminateExecutionCallback;
 
+  uint32_t m_lastStableObjectId = 0;
+  v8::Global<v8::debug::WeakMap> m_stableObjectId;
+
   WasmTranslation m_wasmTranslation;
 
   DISALLOW_COPY_AND_ASSIGN(V8Debugger);
diff --git a/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc b/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc
index f255287c03..e50fe0e893 100644
--- a/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc
@@ -153,7 +153,7 @@ V8HeapProfilerAgentImpl::V8HeapProfilerAgentImpl(
       m_state(state),
       m_hasTimer(false) {}
 
-V8HeapProfilerAgentImpl::~V8HeapProfilerAgentImpl() {}
+V8HeapProfilerAgentImpl::~V8HeapProfilerAgentImpl() = default;
 
 void V8HeapProfilerAgentImpl::restore() {
   if (m_state->booleanProperty(HeapProfilerAgentState::heapProfilerEnabled,
diff --git a/deps/v8/src/inspector/v8-inspector-impl.cc b/deps/v8/src/inspector/v8-inspector-impl.cc
index 62790a6335..5422b5e12f 100644
--- a/deps/v8/src/inspector/v8-inspector-impl.cc
+++ b/deps/v8/src/inspector/v8-inspector-impl.cc
@@ -359,7 +359,8 @@ V8Console* V8InspectorImpl::console() {
 }
 
 void V8InspectorImpl::forEachContext(
-    int contextGroupId, std::function<void(InspectedContext*)> callback) {
+    int contextGroupId,
+    const std::function<void(InspectedContext*)>& callback) {
   auto it = m_contexts.find(contextGroupId);
   if (it == m_contexts.end()) return;
   std::vector<int> ids;
@@ -376,7 +377,8 @@ void V8InspectorImpl::forEachContext(
 }
 
 void V8InspectorImpl::forEachSession(
-    int contextGroupId, std::function<void(V8InspectorSessionImpl*)> callback) {
+    int contextGroupId,
+    const std::function<void(V8InspectorSessionImpl*)>& callback) {
   auto it = m_sessions.find(contextGroupId);
   if (it == m_sessions.end()) return;
   std::vector<int> ids;
@@ -411,9 +413,9 @@ V8InspectorImpl::EvaluateScope::~EvaluateScope() {
 class V8InspectorImpl::EvaluateScope::TerminateTask : public v8::Task {
  public:
   TerminateTask(v8::Isolate* isolate, std::shared_ptr<CancelToken> token)
-      : m_isolate(isolate), m_token(token) {}
+      : m_isolate(isolate), m_token(std::move(token)) {}
 
-  void Run() {
+  void Run() override {
     // CancelToken contains m_canceled bool which may be changed from main
     // thread, so lock mutex first.
     v8::base::LockGuard<v8::base::Mutex> lock(&m_token->m_mutex);
diff --git a/deps/v8/src/inspector/v8-inspector-impl.h b/deps/v8/src/inspector/v8-inspector-impl.h
index 2124ba6250..70eaf0eb20 100644
--- a/deps/v8/src/inspector/v8-inspector-impl.h
+++ b/deps/v8/src/inspector/v8-inspector-impl.h
@@ -120,9 +120,10 @@ class V8InspectorImpl : public V8Inspector {
   InspectedContext* getContext(int contextId) const;
   V8Console* console();
   void forEachContext(int contextGroupId,
-                      std::function<void(InspectedContext*)> callback);
-  void forEachSession(int contextGroupId,
-                      std::function<void(V8InspectorSessionImpl*)> callback);
+                      const std::function<void(InspectedContext*)>& callback);
+  void forEachSession(
+      int contextGroupId,
+      const std::function<void(V8InspectorSessionImpl*)>& callback);
 
   class EvaluateScope {
    public:
diff --git a/deps/v8/src/inspector/v8-inspector-session-impl.h b/deps/v8/src/inspector/v8-inspector-session-impl.h
index 85861a05bf..5053d4dd78 100644
--- a/deps/v8/src/inspector/v8-inspector-session-impl.h
+++ b/deps/v8/src/inspector/v8-inspector-session-impl.h
@@ -34,7 +34,7 @@ class V8InspectorSessionImpl : public V8InspectorSession,
   static std::unique_ptr<V8InspectorSessionImpl> create(
       V8InspectorImpl*, int contextGroupId, int sessionId,
       V8Inspector::Channel*, const StringView& state);
-  ~V8InspectorSessionImpl();
+  ~V8InspectorSessionImpl() override;
 
   V8InspectorImpl* inspector() const { return m_inspector; }
   V8ConsoleAgentImpl* consoleAgent() { return m_consoleAgent.get(); }
diff --git a/deps/v8/src/inspector/v8-regex.h b/deps/v8/src/inspector/v8-regex.h
index 0c4136fc8b..0ce779542d 100644
--- a/deps/v8/src/inspector/v8-regex.h
+++ b/deps/v8/src/inspector/v8-regex.h
@@ -20,7 +20,8 @@ class V8Regex {
  public:
   V8Regex(V8InspectorImpl*, const String16&, bool caseSensitive,
           bool multiline = false);
-  int match(const String16&, int startFrom = 0, int* matchLength = 0) const;
+  int match(const String16&, int startFrom = 0,
+            int* matchLength = nullptr) const;
   bool isValid() const { return !m_regex.IsEmpty(); }
   const String16& errorMessage() const { return m_errorMessage; }
 
diff --git a/deps/v8/src/inspector/v8-runtime-agent-impl.cc b/deps/v8/src/inspector/v8-runtime-agent-impl.cc
index d0ae633945..9e3697cf9e 100644
--- a/deps/v8/src/inspector/v8-runtime-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-runtime-agent-impl.cc
@@ -226,7 +226,7 @@ V8RuntimeAgentImpl::V8RuntimeAgentImpl(
       m_inspector(session->inspector()),
       m_enabled(false) {}
 
-V8RuntimeAgentImpl::~V8RuntimeAgentImpl() {}
+V8RuntimeAgentImpl::~V8RuntimeAgentImpl() = default;
 
 void V8RuntimeAgentImpl::evaluate(
     const String16& expression, Maybe<String16> objectGroup,
diff --git a/deps/v8/src/inspector/v8-schema-agent-impl.cc b/deps/v8/src/inspector/v8-schema-agent-impl.cc
index d7b6cdcb01..07bbd35d97 100644
--- a/deps/v8/src/inspector/v8-schema-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-schema-agent-impl.cc
@@ -14,7 +14,7 @@ V8SchemaAgentImpl::V8SchemaAgentImpl(V8InspectorSessionImpl* session,
                                      protocol::DictionaryValue* state)
     : m_session(session), m_frontend(frontendChannel) {}
 
-V8SchemaAgentImpl::~V8SchemaAgentImpl() {}
+V8SchemaAgentImpl::~V8SchemaAgentImpl() = default;
 
 Response V8SchemaAgentImpl::getDomains(
     std::unique_ptr<protocol::Array<protocol::Schema::Domain>>* result) {
diff --git a/deps/v8/src/inspector/v8-stack-trace-impl.cc b/deps/v8/src/inspector/v8-stack-trace-impl.cc
index 21ca98d911..ae41344a7b 100644
--- a/deps/v8/src/inspector/v8-stack-trace-impl.cc
+++ b/deps/v8/src/inspector/v8-stack-trace-impl.cc
@@ -223,10 +223,10 @@ V8StackTraceImpl::V8StackTraceImpl(
     const V8StackTraceId& externalParent)
     : m_frames(std::move(frames)),
       m_maxAsyncDepth(maxAsyncDepth),
-      m_asyncParent(asyncParent),
+      m_asyncParent(std::move(asyncParent)),
       m_externalParent(externalParent) {}
 
-V8StackTraceImpl::~V8StackTraceImpl() {}
+V8StackTraceImpl::~V8StackTraceImpl() = default;
 
 std::unique_ptr<V8StackTrace> V8StackTraceImpl::clone() {
   return std::unique_ptr<V8StackTrace>(new V8StackTraceImpl(
@@ -392,7 +392,7 @@ AsyncStackTrace::AsyncStackTrace(
       m_suspendedTaskId(nullptr),
       m_description(description),
       m_frames(std::move(frames)),
-      m_asyncParent(asyncParent),
+      m_asyncParent(std::move(asyncParent)),
       m_externalParent(externalParent) {
   DCHECK(m_contextGroupId || (!externalParent.IsInvalid() && m_frames.empty()));
 }
diff --git a/deps/v8/src/inspector/wasm-translation.cc b/deps/v8/src/inspector/wasm-translation.cc
index f049871202..c5d1f8c6a2 100644
--- a/deps/v8/src/inspector/wasm-translation.cc
+++ b/deps/v8/src/inspector/wasm-translation.cc
@@ -62,7 +62,7 @@ class WasmTranslation::TranslatorImpl {
     TransLocation(WasmTranslation* translation, String16 script_id, int line,
                   int column)
         : translation(translation),
-          script_id(script_id),
+          script_id(std::move(script_id)),
           line(line),
           column(column) {}
   };
@@ -74,7 +74,7 @@ class WasmTranslation::TranslatorImpl {
                                                             int index) = 0;
   virtual const String16 GetHash(v8::Isolate*, int index) = 0;
 
-  virtual ~TranslatorImpl() {}
+  virtual ~TranslatorImpl() = default;
 
   class RawTranslator;
   class DisassemblingTranslator;
@@ -238,7 +238,7 @@ class WasmTranslation::TranslatorImpl::DisassemblingTranslator
     return builder.toString();
   }
 
-  String16 GetFakeScriptId(const String16 script_id, int func_index) {
+  String16 GetFakeScriptId(const String16& script_id, int func_index) {
     return String16::concat(script_id, '-', String16::fromInteger(func_index));
   }
   String16 GetFakeScriptId(const TransLocation* loc) {
diff --git a/deps/v8/src/instruction-stream.cc b/deps/v8/src/instruction-stream.cc
index 4b2a9012d6..20cb4ece16 100644
--- a/deps/v8/src/instruction-stream.cc
+++ b/deps/v8/src/instruction-stream.cc
@@ -51,16 +51,18 @@ void InstructionStream::CreateOffHeapInstructionStream(Isolate* isolate,
                                                        uint32_t* size) {
   EmbeddedData d = EmbeddedData::FromIsolate(isolate);
 
-  const uint32_t page_size = static_cast<uint32_t>(AllocatePageSize());
+  v8::PageAllocator* page_allocator = v8::internal::GetPlatformPageAllocator();
+  const uint32_t page_size =
+      static_cast<uint32_t>(page_allocator->AllocatePageSize());
   const uint32_t allocated_size = RoundUp(d.size(), page_size);
 
   uint8_t* allocated_bytes = static_cast<uint8_t*>(
-      AllocatePages(GetRandomMmapAddr(), allocated_size, page_size,
-                    PageAllocator::kReadWrite));
+      AllocatePages(page_allocator, isolate->heap()->GetRandomMmapAddr(),
+                    allocated_size, page_size, PageAllocator::kReadWrite));
   CHECK_NOT_NULL(allocated_bytes);
 
   std::memcpy(allocated_bytes, d.data(), d.size());
-  CHECK(SetPermissions(allocated_bytes, allocated_size,
+  CHECK(SetPermissions(page_allocator, allocated_bytes, allocated_size,
                        PageAllocator::kReadExecute));
 
   *data = allocated_bytes;
@@ -72,8 +74,10 @@ void InstructionStream::CreateOffHeapInstructionStream(Isolate* isolate,
 // static
 void InstructionStream::FreeOffHeapInstructionStream(uint8_t* data,
                                                      uint32_t size) {
-  const uint32_t page_size = static_cast<uint32_t>(AllocatePageSize());
-  CHECK(FreePages(data, RoundUp(size, page_size)));
+  v8::PageAllocator* page_allocator = v8::internal::GetPlatformPageAllocator();
+  const uint32_t page_size =
+      static_cast<uint32_t>(page_allocator->AllocatePageSize());
+  CHECK(FreePages(page_allocator, data, RoundUp(size, page_size)));
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/interface-descriptors.cc b/deps/v8/src/interface-descriptors.cc
index 7438731c20..3eca6f65b4 100644
--- a/deps/v8/src/interface-descriptors.cc
+++ b/deps/v8/src/interface-descriptors.cc
@@ -16,6 +16,9 @@ void CallInterfaceDescriptorData::InitializePlatformSpecific(
   // InterfaceDescriptor owns a copy of the registers array.
   register_params_ = NewArray<Register>(register_parameter_count, no_reg);
   for (int i = 0; i < register_parameter_count; i++) {
+    // The value of the root register must be reserved, thus any uses
+    // within the calling convention are disallowed.
+    DCHECK_NE(registers[i], kRootRegister);
     register_params_[i] = registers[i];
   }
 }
@@ -260,13 +263,21 @@ void LoadWithVectorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {ReceiverRegister(), NameRegister(), SlotRegister(),
                           VectorRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
+  // TODO(jgruber): This DCHECK could be enabled if RegisterBase::ListOf were
+  // to allow no_reg entries.
+  // DCHECK(!AreAliased(ReceiverRegister(), NameRegister(), SlotRegister(),
+  //                    VectorRegister(), kRootRegister));
+  int len = arraysize(registers) - kStackArgumentsCount;
+  data->InitializePlatformSpecific(len, registers);
 }
 
 void StoreWithVectorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {ReceiverRegister(), NameRegister(), ValueRegister(),
                           SlotRegister(), VectorRegister()};
+  // TODO(jgruber): This DCHECK could be enabled if RegisterBase::ListOf were
+  // to allow no_reg entries.
+  // DCHECK(!AreAliased(ReceiverRegister(), NameRegister(), kRootRegister));
   int len = arraysize(registers) - kStackArgumentsCount;
   data->InitializePlatformSpecific(len, registers);
 }
@@ -333,6 +344,11 @@ void WasmGrowMemoryDescriptor::InitializePlatformSpecific(
   DefaultInitializePlatformSpecific(data, kParameterCount);
 }
 
+void WasmThrowDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  DefaultInitializePlatformSpecific(data, kParameterCount);
+}
+
 void CloneObjectWithVectorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   DefaultInitializePlatformSpecific(data, kParameterCount);
diff --git a/deps/v8/src/interface-descriptors.h b/deps/v8/src/interface-descriptors.h
index ee9abac9ea..ae64b05582 100644
--- a/deps/v8/src/interface-descriptors.h
+++ b/deps/v8/src/interface-descriptors.h
@@ -60,7 +60,7 @@ namespace internal {
   V(StringAt)                         \
   V(StringSubstring)                  \
   V(GetProperty)                      \
-  V(ArgumentAdaptor)                  \
+  V(ArgumentsAdaptor)                 \
   V(ApiCallback)                      \
   V(ApiGetter)                        \
   V(GrowArrayElements)                \
@@ -74,6 +74,7 @@ namespace internal {
   V(FrameDropperTrampoline)           \
   V(RunMicrotasks)                    \
   V(WasmGrowMemory)                   \
+  V(WasmThrow)                        \
   V(CloneObjectWithVector)            \
   BUILTIN_LIST_TFS(V)
 
@@ -211,7 +212,7 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
   typedef CallInterfaceDescriptorData::Flags Flags;
 
   CallInterfaceDescriptor() : data_(nullptr) {}
-  virtual ~CallInterfaceDescriptor() {}
+  virtual ~CallInterfaceDescriptor() = default;
 
   CallInterfaceDescriptor(CallDescriptors::Key key)
       : data_(CallDescriptors::call_descriptor_data(key)) {}
@@ -306,19 +307,32 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
   explicit name() : base(key()) {}               \
   static inline CallDescriptors::Key key();
 
-#if defined(V8_TARGET_ARCH_IA32) && defined(V8_EMBEDDED_BUILTINS)
-// TODO(jgruber,v8:6666): Keep kRootRegister free unconditionally.
+#if defined(V8_TARGET_ARCH_IA32)
+// To support all possible cases, we must limit the number of register args for
+// TFS builtins on ia32 to 3. Out of the 6 allocatable registers, esi is taken
+// as the context register and ebx is the root register. One register must
+// remain available to store the jump/call target. Thus 3 registers remain for
+// arguments. The reason this applies to TFS builtins specifically is because
+// this becomes relevant for builtins used as targets of Torque function
+// pointers (which must have a register available to store the target).
+// TODO(jgruber): Ideally we should just decrement kMaxBuiltinRegisterParams but
+// that comes with its own set of complications. It's possible, but requires
+// refactoring the calling convention of other existing stubs.
 constexpr int kMaxBuiltinRegisterParams = 4;
+constexpr int kMaxTFSBuiltinRegisterParams = 3;
 #else
 constexpr int kMaxBuiltinRegisterParams = 5;
+constexpr int kMaxTFSBuiltinRegisterParams = kMaxBuiltinRegisterParams;
 #endif
+STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
 
 #define DECLARE_DEFAULT_DESCRIPTOR(name, base)                                 \
   DECLARE_DESCRIPTOR_WITH_BASE(name, base)                                     \
  protected:                                                                    \
   static const int kRegisterParams =                                           \
-      kParameterCount > kMaxBuiltinRegisterParams ? kMaxBuiltinRegisterParams  \
-                                                  : kParameterCount;           \
+      kParameterCount > kMaxTFSBuiltinRegisterParams                           \
+          ? kMaxTFSBuiltinRegisterParams                                       \
+          : kParameterCount;                                                   \
   static const int kStackParams = kParameterCount - kRegisterParams;           \
   void InitializePlatformSpecific(CallInterfaceDescriptorData* data)           \
       override {                                                               \
@@ -428,7 +442,7 @@ class AllocateDescriptor : public CallInterfaceDescriptor {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kRequestedSize)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::TaggedPointer(),  // result 1
-                                    MachineType::Int32())  // kRequestedSize
+                                    MachineType::IntPtr())  // kRequestedSize
   DECLARE_DESCRIPTOR(AllocateDescriptor, CallInterfaceDescriptor)
 };
 
@@ -601,6 +615,15 @@ class LoadWithVectorDescriptor : public LoadDescriptor {
   DECLARE_DESCRIPTOR(LoadWithVectorDescriptor, LoadDescriptor)
 
   static const Register VectorRegister();
+
+#if V8_TARGET_ARCH_IA32
+  static const bool kPassLastArgsOnStack = true;
+#else
+  static const bool kPassLastArgsOnStack = false;
+#endif
+
+  // Pass vector through the stack.
+  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 1 : 0;
 };
 
 class LoadGlobalWithVectorDescriptor : public LoadGlobalDescriptor {
@@ -611,9 +634,15 @@ class LoadGlobalWithVectorDescriptor : public LoadGlobalDescriptor {
                          MachineType::AnyTagged())     // kVector
   DECLARE_DESCRIPTOR(LoadGlobalWithVectorDescriptor, LoadGlobalDescriptor)
 
+#if V8_TARGET_ARCH_IA32
+  // On ia32, LoadWithVectorDescriptor passes vector on the stack and thus we
+  // need to choose a new register here.
+  static const Register VectorRegister() { return edx; }
+#else
   static const Register VectorRegister() {
     return LoadWithVectorDescriptor::VectorRegister();
   }
+#endif
 };
 
 class FastNewFunctionContextDescriptor : public CallInterfaceDescriptor {
@@ -639,10 +668,9 @@ class FastNewObjectDescriptor : public CallInterfaceDescriptor {
 
 class RecordWriteDescriptor final : public CallInterfaceDescriptor {
  public:
-  DEFINE_PARAMETERS(kObject, kSlot, kIsolate, kRememberedSet, kFPMode)
+  DEFINE_PARAMETERS(kObject, kSlot, kRememberedSet, kFPMode)
   DEFINE_PARAMETER_TYPES(MachineType::TaggedPointer(),  // kObject
                          MachineType::Pointer(),        // kSlot
-                         MachineType::Pointer(),        // kIsolate
                          MachineType::TaggedSigned(),   // kRememberedSet
                          MachineType::TaggedSigned())   // kFPMode
 
@@ -690,12 +718,12 @@ class CallTrampolineDescriptor : public CallInterfaceDescriptor {
 
 class CallVarargsDescriptor : public CallInterfaceDescriptor {
  public:
-  DEFINE_PARAMETERS(kTarget, kActualArgumentsCount, kArgumentsList,
-                    kArgumentsLength)
+  DEFINE_PARAMETERS(kTarget, kActualArgumentsCount, kArgumentsLength,
+                    kArgumentsList)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::Int32(),      // kActualArgumentsCount
-                         MachineType::AnyTagged(),  // kArgumentsList
-                         MachineType::Int32())      // kArgumentsLength
+                         MachineType::Int32(),      // kArgumentsLength
+                         MachineType::AnyTagged())  // kArgumentsList
   DECLARE_DESCRIPTOR(CallVarargsDescriptor, CallInterfaceDescriptor)
 };
 
@@ -727,9 +755,10 @@ class CallWithArrayLikeDescriptor : public CallInterfaceDescriptor {
 
 class ConstructVarargsDescriptor : public CallInterfaceDescriptor {
  public:
-  DEFINE_JS_PARAMETERS(kArgumentsList, kArgumentsLength)
-  DEFINE_JS_PARAMETER_TYPES(MachineType::AnyTagged(),  // kArgumentsList
-                            MachineType::Int32())      // kArgumentsLength
+  DEFINE_JS_PARAMETERS(kArgumentsLength, kArgumentsList)
+  DEFINE_JS_PARAMETER_TYPES(MachineType::Int32(),      // kArgumentsLength
+                            MachineType::AnyTagged())  // kArgumentsList
+
   DECLARE_DESCRIPTOR(ConstructVarargsDescriptor, CallInterfaceDescriptor)
 };
 
@@ -759,6 +788,7 @@ class ConstructWithArrayLikeDescriptor : public CallInterfaceDescriptor {
 // TODO(ishell): consider merging this with ArrayConstructorDescriptor
 class ConstructStubDescriptor : public CallInterfaceDescriptor {
  public:
+  // TODO(jgruber): Remove the unused allocation site parameter.
   DEFINE_JS_PARAMETERS(kAllocationSite)
   DEFINE_JS_PARAMETER_TYPES(MachineType::AnyTagged());
 
@@ -879,11 +909,11 @@ class StringSubstringDescriptor final : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(StringSubstringDescriptor, CallInterfaceDescriptor)
 };
 
-class ArgumentAdaptorDescriptor : public CallInterfaceDescriptor {
+class ArgumentsAdaptorDescriptor : public CallInterfaceDescriptor {
  public:
   DEFINE_JS_PARAMETERS(kExpectedArgumentsCount)
   DEFINE_JS_PARAMETER_TYPES(MachineType::Int32())
-  DECLARE_DESCRIPTOR(ArgumentAdaptorDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ArgumentsAdaptorDescriptor, CallInterfaceDescriptor)
 };
 
 class CppBuiltinAdaptorDescriptor : public CallInterfaceDescriptor {
@@ -913,6 +943,9 @@ class CEntry1ArgvOnStackDescriptor : public CallInterfaceDescriptor {
 
 class ApiCallbackDescriptor : public CallInterfaceDescriptor {
  public:
+  // TODO(jgruber): This could be simplified to pass call data on the stack
+  // since this is what the CallApiCallbackStub anyways. This would free a
+  // register.
   DEFINE_PARAMETERS_NO_CONTEXT(kTargetContext, kCallData, kHolder,
                                kApiFunctionAddress)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTargetContext
@@ -981,15 +1014,24 @@ class InterpreterPushArgsThenCallDescriptor : public CallInterfaceDescriptor {
 class InterpreterPushArgsThenConstructDescriptor
     : public CallInterfaceDescriptor {
  public:
-  DEFINE_PARAMETERS(kNumberOfArguments, kNewTarget, kConstructor,
-                    kFeedbackElement, kFirstArgument)
+  DEFINE_PARAMETERS(kNumberOfArguments, kFirstArgument, kConstructor,
+                    kNewTarget, kFeedbackElement)
   DEFINE_PARAMETER_TYPES(MachineType::Int32(),      // kNumberOfArguments
-                         MachineType::AnyTagged(),  // kNewTarget
+                         MachineType::Pointer(),    // kFirstArgument
                          MachineType::AnyTagged(),  // kConstructor
-                         MachineType::AnyTagged(),  // kFeedbackElement
-                         MachineType::Pointer())    // kFirstArgument
+                         MachineType::AnyTagged(),  // kNewTarget
+                         MachineType::AnyTagged())  // kFeedbackElement
   DECLARE_DESCRIPTOR(InterpreterPushArgsThenConstructDescriptor,
                      CallInterfaceDescriptor)
+
+#if V8_TARGET_ARCH_IA32
+  static const bool kPassLastArgsOnStack = true;
+#else
+  static const bool kPassLastArgsOnStack = false;
+#endif
+
+  // Pass constructor, new target and feedback element through the stack.
+  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 3 : 0;
 };
 
 class InterpreterCEntry1Descriptor : public CallInterfaceDescriptor {
@@ -1044,6 +1086,14 @@ class WasmGrowMemoryDescriptor final : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(WasmGrowMemoryDescriptor, CallInterfaceDescriptor)
 };
 
+class WasmThrowDescriptor final : public CallInterfaceDescriptor {
+ public:
+  DEFINE_PARAMETERS_NO_CONTEXT(kException)
+  DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::AnyTagged(),  // result 1
+                                    MachineType::AnyTagged())  // kException
+  DECLARE_DESCRIPTOR(WasmThrowDescriptor, CallInterfaceDescriptor)
+};
+
 class CloneObjectWithVectorDescriptor final : public CallInterfaceDescriptor {
  public:
   DEFINE_PARAMETERS(kSource, kFlags, kSlot, kVector)
diff --git a/deps/v8/src/interpreter/bytecode-array-builder.cc b/deps/v8/src/interpreter/bytecode-array-builder.cc
index 33731599c8..a7c95aae7b 100644
--- a/deps/v8/src/interpreter/bytecode-array-builder.cc
+++ b/deps/v8/src/interpreter/bytecode-array-builder.cc
@@ -23,7 +23,7 @@ class RegisterTransferWriter final
       public NON_EXPORTED_BASE(ZoneObject) {
  public:
   RegisterTransferWriter(BytecodeArrayBuilder* builder) : builder_(builder) {}
-  ~RegisterTransferWriter() override {}
+  ~RegisterTransferWriter() override = default;
 
   void EmitLdar(Register input) override { builder_->OutputLdarRaw(input); }
 
@@ -797,6 +797,13 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::LoadNamedProperty(
   return *this;
 }
 
+BytecodeArrayBuilder& BytecodeArrayBuilder::LoadNamedPropertyNoFeedback(
+    Register object, const AstRawString* name) {
+  size_t name_index = GetConstantPoolEntry(name);
+  OutputLdaNamedPropertyNoFeedback(object, name_index);
+  return *this;
+}
+
 BytecodeArrayBuilder& BytecodeArrayBuilder::LoadKeyedProperty(
     Register object, int feedback_slot) {
   OutputLdaKeyedProperty(object, feedback_slot);
@@ -847,6 +854,14 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::StoreNamedProperty(
   return StoreNamedProperty(object, name_index, feedback_slot, language_mode);
 }
 
+BytecodeArrayBuilder& BytecodeArrayBuilder::StoreNamedPropertyNoFeedback(
+    Register object, const AstRawString* name, LanguageMode language_mode) {
+  size_t name_index = GetConstantPoolEntry(name);
+  OutputStaNamedPropertyNoFeedback(object, name_index,
+                                   static_cast<uint8_t>(language_mode));
+  return *this;
+}
+
 BytecodeArrayBuilder& BytecodeArrayBuilder::StoreNamedOwnProperty(
     Register object, const AstRawString* name, int feedback_slot) {
   size_t name_index = GetConstantPoolEntry(name);
@@ -973,6 +988,11 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::CreateArrayLiteral(
   return *this;
 }
 
+BytecodeArrayBuilder& BytecodeArrayBuilder::CreateArrayFromIterable() {
+  OutputCreateArrayFromIterable();
+  return *this;
+}
+
 BytecodeArrayBuilder& BytecodeArrayBuilder::CreateObjectLiteral(
     size_t constant_properties_entry, int literal_index, int flags,
     Register output) {
@@ -1375,6 +1395,12 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::CallAnyReceiver(Register callable,
   return *this;
 }
 
+BytecodeArrayBuilder& BytecodeArrayBuilder::CallNoFeedback(Register callable,
+                                                           RegisterList args) {
+  OutputCallNoFeedback(callable, args, args.register_count());
+  return *this;
+}
+
 BytecodeArrayBuilder& BytecodeArrayBuilder::CallWithSpread(Register callable,
                                                            RegisterList args,
                                                            int feedback_slot) {
diff --git a/deps/v8/src/interpreter/bytecode-array-builder.h b/deps/v8/src/interpreter/bytecode-array-builder.h
index 3feda90495..bf5909d8e4 100644
--- a/deps/v8/src/interpreter/bytecode-array-builder.h
+++ b/deps/v8/src/interpreter/bytecode-array-builder.h
@@ -120,6 +120,10 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
   BytecodeArrayBuilder& LoadNamedProperty(Register object,
                                           const AstRawString* name,
                                           int feedback_slot);
+  // Named load property without feedback
+  BytecodeArrayBuilder& LoadNamedPropertyNoFeedback(Register object,
+                                                    const AstRawString* name);
+
   // Keyed load property. The key should be in the accumulator.
   BytecodeArrayBuilder& LoadKeyedProperty(Register object, int feedback_slot);
   // Named load property of the @@iterator symbol.
@@ -145,6 +149,12 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
                                            const AstRawString* name,
                                            int feedback_slot,
                                            LanguageMode language_mode);
+
+  // Store a property named by a property name without feedback slot. The value
+  // to be stored should be in the accumulator.
+  BytecodeArrayBuilder& StoreNamedPropertyNoFeedback(
+      Register object, const AstRawString* name, LanguageMode language_mode);
+
   // Store a property named by a constant from the constant pool. The value to
   // be stored should be in the accumulator.
   BytecodeArrayBuilder& StoreNamedProperty(Register object,
@@ -234,6 +244,7 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
   BytecodeArrayBuilder& CreateArrayLiteral(size_t constant_elements_entry,
                                            int literal_index, int flags);
   BytecodeArrayBuilder& CreateEmptyArrayLiteral(int literal_index);
+  BytecodeArrayBuilder& CreateArrayFromIterable();
   BytecodeArrayBuilder& CreateObjectLiteral(size_t constant_properties_entry,
                                             int literal_index, int flags,
                                             Register output);
@@ -276,6 +287,11 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
   BytecodeArrayBuilder& CallAnyReceiver(Register callable, RegisterList args,
                                         int feedback_slot);
 
+  // Call a JS function with an any receiver, possibly (but not necessarily)
+  // undefined. The JSFunction or Callable to be called should be in |callable|.
+  // The arguments should be in |args|, with the receiver in |args[0]|.
+  BytecodeArrayBuilder& CallNoFeedback(Register callable, RegisterList args);
+
   // Tail call into a JS function. The JSFunction or Callable to be called
   // should be in |callable|. The arguments should be in |args|, with the
   // receiver in |args[0]|. Type feedback is recorded in the |feedback_slot| in
diff --git a/deps/v8/src/interpreter/bytecode-decoder.cc b/deps/v8/src/interpreter/bytecode-decoder.cc
index e684eb410b..fa0ff9e4a8 100644
--- a/deps/v8/src/interpreter/bytecode-decoder.cc
+++ b/deps/v8/src/interpreter/bytecode-decoder.cc
@@ -71,18 +71,8 @@ uint32_t BytecodeDecoder::DecodeUnsignedOperand(Address operand_start,
 
 namespace {
 
-const char* NameForRuntimeId(uint32_t idx) {
-  switch (idx) {
-#define CASE(name, nargs, ressize) \
-  case Runtime::k##name:           \
-    return #name;                  \
-  case Runtime::kInline##name:     \
-    return "_" #name;
-    FOR_EACH_INTRINSIC(CASE)
-#undef CASE
-    default:
-      UNREACHABLE();
-  }
+const char* NameForRuntimeId(Runtime::FunctionId idx) {
+  return Runtime::FunctionForId(idx)->name;
 }
 
 const char* NameForNativeContextIndex(uint32_t idx) {
@@ -160,8 +150,9 @@ std::ostream& BytecodeDecoder::Decode(std::ostream& os,
         break;
       }
       case interpreter::OperandType::kRuntimeId:
-        os << "[" << NameForRuntimeId(DecodeUnsignedOperand(
-                         operand_start, op_type, operand_scale))
+        os << "["
+           << NameForRuntimeId(static_cast<Runtime::FunctionId>(
+                  DecodeUnsignedOperand(operand_start, op_type, operand_scale)))
            << "]";
         break;
       case interpreter::OperandType::kImm:
diff --git a/deps/v8/src/interpreter/bytecode-generator.cc b/deps/v8/src/interpreter/bytecode-generator.cc
index 11a19443e1..b00d3773cd 100644
--- a/deps/v8/src/interpreter/bytecode-generator.cc
+++ b/deps/v8/src/interpreter/bytecode-generator.cc
@@ -29,7 +29,7 @@ namespace interpreter {
 // Scoped class tracking context objects created by the visitor. Represents
 // mutations of the context chain within the function body, allowing pushing and
 // popping of the current {context_register} during visitation.
-class BytecodeGenerator::ContextScope BASE_EMBEDDED {
+class BytecodeGenerator::ContextScope {
  public:
   ContextScope(BytecodeGenerator* generator, Scope* scope)
       : generator_(generator),
@@ -94,7 +94,7 @@ class BytecodeGenerator::ContextScope BASE_EMBEDDED {
 
 // Scoped class for tracking control statements entered by the
 // visitor. The pattern derives AstGraphBuilder::ControlScope.
-class BytecodeGenerator::ControlScope BASE_EMBEDDED {
+class BytecodeGenerator::ControlScope {
  public:
   explicit ControlScope(BytecodeGenerator* generator)
       : generator_(generator), outer_(generator->execution_control()),
@@ -402,7 +402,7 @@ class BytecodeGenerator::ControlScopeForIteration final
         loop_builder_(loop_builder) {
     generator->loop_depth_++;
   }
-  ~ControlScopeForIteration() { generator()->loop_depth_--; }
+  ~ControlScopeForIteration() override { generator()->loop_depth_--; }
 
  protected:
   bool Execute(Command command, Statement* statement,
@@ -908,7 +908,7 @@ BytecodeGenerator::BytecodeGenerator(
       execution_context_(nullptr),
       execution_result_(nullptr),
       incoming_new_target_or_generator_(),
-      dummy_feedback_slot_(),
+      dummy_feedback_slot_(feedback_spec(), FeedbackSlotKind::kCompareOp),
       generator_jump_table_(nullptr),
       suspend_count_(0),
       loop_depth_(0),
@@ -1820,7 +1820,11 @@ bool BytecodeGenerator::ShouldOptimizeAsOneShot() const {
 
   if (loop_depth_ > 0) return false;
 
-  return info()->literal()->is_top_level() || info()->literal()->is_iife();
+  // A non-top-level iife is likely to be executed multiple times and so
+  // shouldn`t be optimized as one-shot.
+  bool is_toplevel_iife = info()->literal()->is_iife() &&
+                          current_scope()->outer_scope()->is_script_scope();
+  return info()->literal()->is_toplevel() || is_toplevel_iife;
 }
 
 void BytecodeGenerator::BuildClassLiteral(ClassLiteral* expr) {
@@ -1859,6 +1863,7 @@ void BytecodeGenerator::BuildClassLiteral(ClassLiteral* expr) {
         DCHECK_NE(property->kind(), ClassLiteral::Property::PRIVATE_FIELD);
         Register key = register_allocator()->GrowRegisterList(&args);
 
+        builder()->SetExpressionAsStatementPosition(property->key());
         BuildLoadPropertyKey(property, key);
         if (property->is_static()) {
           // The static prototype property is read only. We handle the non
@@ -1968,13 +1973,13 @@ void BytecodeGenerator::VisitClassLiteral(ClassLiteral* expr) {
 }
 
 void BytecodeGenerator::VisitInitializeClassFieldsStatement(
-    InitializeClassFieldsStatement* expr) {
+    InitializeClassFieldsStatement* stmt) {
   RegisterList args = register_allocator()->NewRegisterList(3);
   Register constructor = args[0], key = args[1], value = args[2];
   builder()->MoveRegister(builder()->Receiver(), constructor);
 
-  for (int i = 0; i < expr->fields()->length(); i++) {
-    ClassLiteral::Property* property = expr->fields()->at(i);
+  for (int i = 0; i < stmt->fields()->length(); i++) {
+    ClassLiteral::Property* property = stmt->fields()->at(i);
 
     if (property->is_computed_name()) {
       DCHECK_EQ(property->kind(), ClassLiteral::Property::PUBLIC_FIELD);
@@ -1993,6 +1998,7 @@ void BytecodeGenerator::VisitInitializeClassFieldsStatement(
       BuildLoadPropertyKey(property, key);
     }
 
+    builder()->SetExpressionAsStatementPosition(property->value());
     VisitForRegisterValue(property->value(), value);
     VisitSetHomeObject(value, constructor, property);
 
@@ -2231,7 +2237,7 @@ void BytecodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
             builder()
                 ->LoadLiteral(Smi::FromEnum(LanguageMode::kSloppy))
                 .StoreAccumulatorInRegister(args[3])
-                .CallRuntime(Runtime::kSetProperty, args);
+                .CallRuntime(Runtime::kSetKeyedProperty, args);
             Register value = args[2];
             VisitSetHomeObject(value, literal, property);
           }
@@ -2364,116 +2370,6 @@ void BytecodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   builder()->LoadAccumulatorWithRegister(literal);
 }
 
-void BytecodeGenerator::BuildArrayLiteralElementsInsertion(
-    Register array, int first_spread_index, ZonePtrList<Expression>* elements,
-    bool skip_constants) {
-  DCHECK_LT(first_spread_index, elements->length());
-
-  Register index = register_allocator()->NewRegister();
-  int array_index = 0;
-
-  ZonePtrList<Expression>::iterator iter = elements->begin();
-  ZonePtrList<Expression>::iterator first_spread_or_end =
-      first_spread_index >= 0 ? elements->begin() + first_spread_index
-                              : elements->end();
-
-  // Evaluate subexpressions and store them into the array.
-  FeedbackSlot keyed_store_slot;
-  for (; iter != first_spread_or_end; ++iter, array_index++) {
-    Expression* subexpr = *iter;
-    DCHECK(!subexpr->IsSpread());
-    if (skip_constants && subexpr->IsCompileTimeValue()) continue;
-    if (keyed_store_slot.IsInvalid()) {
-      keyed_store_slot = feedback_spec()->AddKeyedStoreICSlot(language_mode());
-    }
-    builder()
-        ->LoadLiteral(Smi::FromInt(array_index))
-        .StoreAccumulatorInRegister(index);
-    VisitForAccumulatorValue(subexpr);
-    builder()->StoreKeyedProperty(
-        array, index, feedback_index(keyed_store_slot), language_mode());
-  }
-  if (iter != elements->end()) {
-    builder()->LoadLiteral(array_index).StoreAccumulatorInRegister(index);
-
-    // Handle the first spread element and everything that follows.
-    FeedbackSlot element_slot = feedback_spec()->AddStoreInArrayLiteralICSlot();
-    FeedbackSlot index_slot = feedback_spec()->AddBinaryOpICSlot();
-    // TODO(neis): Only create length_slot when there are holes.
-    FeedbackSlot length_slot =
-        feedback_spec()->AddStoreICSlot(LanguageMode::kStrict);
-    for (; iter != elements->end(); ++iter) {
-      Expression* subexpr = *iter;
-      if (subexpr->IsSpread()) {
-        BuildArrayLiteralSpread(subexpr->AsSpread(), array, index, index_slot,
-                                element_slot);
-      } else if (!subexpr->IsTheHoleLiteral()) {
-        // literal[index++] = subexpr
-        VisitForAccumulatorValue(subexpr);
-        builder()
-            ->StoreInArrayLiteral(array, index, feedback_index(element_slot))
-            .LoadAccumulatorWithRegister(index)
-            .UnaryOperation(Token::INC, feedback_index(index_slot))
-            .StoreAccumulatorInRegister(index);
-      } else {
-        // literal.length = ++index
-        auto length = ast_string_constants()->length_string();
-        builder()
-            ->LoadAccumulatorWithRegister(index)
-            .UnaryOperation(Token::INC, feedback_index(index_slot))
-            .StoreAccumulatorInRegister(index)
-            .StoreNamedProperty(array, length, feedback_index(length_slot),
-                                LanguageMode::kStrict);
-      }
-    }
-  }
-  builder()->LoadAccumulatorWithRegister(array);
-}
-
-void BytecodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
-  expr->InitDepthAndFlags();
-  uint8_t flags = CreateArrayLiteralFlags::Encode(
-      expr->IsFastCloningSupported(), expr->ComputeFlags());
-
-  bool is_empty = expr->is_empty();
-  bool optimize_as_one_shot = ShouldOptimizeAsOneShot();
-  size_t entry;
-  if (is_empty && optimize_as_one_shot) {
-    entry = builder()->EmptyArrayBoilerplateDescriptionConstantPoolEntry();
-  } else if (!is_empty) {
-    entry = builder()->AllocateDeferredConstantPoolEntry();
-    array_literals_.push_back(std::make_pair(expr, entry));
-  }
-
-  if (optimize_as_one_shot) {
-    // Create array literal without any allocation sites
-    RegisterAllocationScope register_scope(this);
-    RegisterList args = register_allocator()->NewRegisterList(2);
-    builder()
-        ->LoadConstantPoolEntry(entry)
-        .StoreAccumulatorInRegister(args[0])
-        .LoadLiteral(Smi::FromInt(flags))
-        .StoreAccumulatorInRegister(args[1])
-        .CallRuntime(Runtime::kCreateArrayLiteralWithoutAllocationSite, args);
-  } else if (is_empty) {
-    // Empty array literal fast-path.
-    int literal_index = feedback_index(feedback_spec()->AddLiteralSlot());
-    DCHECK(expr->IsFastCloningSupported());
-    builder()->CreateEmptyArrayLiteral(literal_index);
-    return;
-  } else {
-    // Deep-copy the literal boilerplate
-    int literal_index = feedback_index(feedback_spec()->AddLiteralSlot());
-    builder()->CreateArrayLiteral(entry, literal_index, flags);
-  }
-
-  Register literal = register_allocator()->NewRegister();
-  builder()->StoreAccumulatorInRegister(literal);
-  // Insert all elements except the constant ones, since they are already there.
-  BuildArrayLiteralElementsInsertion(literal, expr->first_spread_index(),
-                                     expr->values(), true);
-}
-
 void BytecodeGenerator::BuildArrayLiteralSpread(Spread* spread, Register array,
                                                 Register index,
                                                 FeedbackSlot index_slot,
@@ -2513,6 +2409,154 @@ void BytecodeGenerator::BuildArrayLiteralSpread(Spread* spread, Register array,
   loop_builder.JumpToHeader(loop_depth_);
 }
 
+void BytecodeGenerator::BuildCreateArrayLiteral(
+    ZonePtrList<Expression>* elements, ArrayLiteral* expr) {
+  RegisterAllocationScope register_scope(this);
+  Register index = register_allocator()->NewRegister();
+  Register array = register_allocator()->NewRegister();
+  SharedFeedbackSlot element_slot(feedback_spec(),
+                                  FeedbackSlotKind::kStoreInArrayLiteral);
+  ZonePtrList<Expression>::iterator current = elements->begin();
+  ZonePtrList<Expression>::iterator end = elements->end();
+  bool is_empty = elements->is_empty();
+
+  if (!is_empty && (*current)->IsSpread()) {
+    // If we have a leading spread, use CreateArrayFromIterable to create
+    // an array from it and then add the remaining components to that array.
+    VisitForAccumulatorValue(*current);
+    builder()->CreateArrayFromIterable().StoreAccumulatorInRegister(array);
+
+    if (++current != end) {
+      // If there are remaning elements, prepare the index register that is
+      // used for adding those elements. The next index is the length of the
+      // newly created array.
+      auto length = ast_string_constants()->length_string();
+      int length_load_slot = feedback_index(feedback_spec()->AddLoadICSlot());
+      builder()
+          ->LoadNamedProperty(array, length, length_load_slot)
+          .StoreAccumulatorInRegister(index);
+    }
+  } else if (expr != nullptr) {
+    // There are some elements before the first (if any) spread, and we can
+    // use a boilerplate when creating the initial array from those elements.
+
+    // First, allocate a constant pool entry for the boilerplate that will
+    // be created during finalization, and will contain all the constant
+    // elements before the first spread. This also handle the empty array case
+    // and one-shot optimization.
+    uint8_t flags = CreateArrayLiteralFlags::Encode(
+        expr->IsFastCloningSupported(), expr->ComputeFlags());
+    bool optimize_as_one_shot = ShouldOptimizeAsOneShot();
+    size_t entry;
+    if (is_empty && optimize_as_one_shot) {
+      entry = builder()->EmptyArrayBoilerplateDescriptionConstantPoolEntry();
+    } else if (!is_empty) {
+      entry = builder()->AllocateDeferredConstantPoolEntry();
+      array_literals_.push_back(std::make_pair(expr, entry));
+    }
+
+    if (optimize_as_one_shot) {
+      RegisterList args = register_allocator()->NewRegisterList(2);
+      builder()
+          ->LoadConstantPoolEntry(entry)
+          .StoreAccumulatorInRegister(args[0])
+          .LoadLiteral(Smi::FromInt(flags))
+          .StoreAccumulatorInRegister(args[1])
+          .CallRuntime(Runtime::kCreateArrayLiteralWithoutAllocationSite, args);
+    } else if (is_empty) {
+      // Empty array literal fast-path.
+      int literal_index = feedback_index(feedback_spec()->AddLiteralSlot());
+      DCHECK(expr->IsFastCloningSupported());
+      builder()->CreateEmptyArrayLiteral(literal_index);
+    } else {
+      // Create array literal from boilerplate.
+      int literal_index = feedback_index(feedback_spec()->AddLiteralSlot());
+      builder()->CreateArrayLiteral(entry, literal_index, flags);
+    }
+    builder()->StoreAccumulatorInRegister(array);
+
+    // Insert the missing non-constant elements, up until the first spread
+    // index, into the initial array (the remaining elements will be inserted
+    // below).
+    DCHECK_EQ(current, elements->begin());
+    ZonePtrList<Expression>::iterator first_spread_or_end =
+        expr->first_spread_index() >= 0 ? current + expr->first_spread_index()
+                                        : end;
+    int array_index = 0;
+    for (; current != first_spread_or_end; ++current, array_index++) {
+      Expression* subexpr = *current;
+      DCHECK(!subexpr->IsSpread());
+      // Skip the constants.
+      if (subexpr->IsCompileTimeValue()) continue;
+
+      builder()
+          ->LoadLiteral(Smi::FromInt(array_index))
+          .StoreAccumulatorInRegister(index);
+      VisitForAccumulatorValue(subexpr);
+      builder()->StoreInArrayLiteral(array, index,
+                                     feedback_index(element_slot.Get()));
+    }
+
+    if (current != end) {
+      // If there are remaining elements, prepare the index register
+      // to store the next element, which comes from the first spread.
+      builder()->LoadLiteral(array_index).StoreAccumulatorInRegister(index);
+    }
+  } else {
+    // In other cases, we prepare an empty array to be filled in below.
+    DCHECK(!elements->is_empty());
+    int literal_index = feedback_index(feedback_spec()->AddLiteralSlot());
+    builder()
+        ->CreateEmptyArrayLiteral(literal_index)
+        .StoreAccumulatorInRegister(array);
+    // Prepare the index for the first element.
+    builder()->LoadLiteral(Smi::FromInt(0)).StoreAccumulatorInRegister(index);
+  }
+
+  // Now build insertions for the remaining elements from current to end.
+  SharedFeedbackSlot index_slot(feedback_spec(), FeedbackSlotKind::kBinaryOp);
+  SharedFeedbackSlot length_slot(
+      feedback_spec(), feedback_spec()->GetStoreICSlot(LanguageMode::kStrict));
+  for (; current != end; ++current) {
+    Expression* subexpr = *current;
+    if (subexpr->IsSpread()) {
+      FeedbackSlot real_index_slot = index_slot.Get();
+      BuildArrayLiteralSpread(subexpr->AsSpread(), array, index,
+                              real_index_slot, element_slot.Get());
+    } else if (!subexpr->IsTheHoleLiteral()) {
+      // literal[index++] = subexpr
+      VisitForAccumulatorValue(subexpr);
+      builder()
+          ->StoreInArrayLiteral(array, index,
+                                feedback_index(element_slot.Get()))
+          .LoadAccumulatorWithRegister(index);
+      // Only increase the index if we are not the last element.
+      if (current + 1 != end) {
+        builder()
+            ->UnaryOperation(Token::INC, feedback_index(index_slot.Get()))
+            .StoreAccumulatorInRegister(index);
+      }
+    } else {
+      // literal.length = ++index
+      // length_slot is only used when there are holes.
+      auto length = ast_string_constants()->length_string();
+      builder()
+          ->LoadAccumulatorWithRegister(index)
+          .UnaryOperation(Token::INC, feedback_index(index_slot.Get()))
+          .StoreAccumulatorInRegister(index)
+          .StoreNamedProperty(array, length, feedback_index(length_slot.Get()),
+                              LanguageMode::kStrict);
+    }
+  }
+
+  builder()->LoadAccumulatorWithRegister(array);
+}
+
+void BytecodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
+  expr->InitDepthAndFlags();
+  BuildCreateArrayLiteral(expr->values(), expr);
+}
+
 void BytecodeGenerator::VisitStoreInArrayLiteral(StoreInArrayLiteral* expr) {
   builder()->SetExpressionAsStatementPosition(expr);
   RegisterAllocationScope register_scope(this);
@@ -2824,13 +2868,7 @@ void BytecodeGenerator::BuildLoadNamedProperty(Property* property,
                                                Register object,
                                                const AstRawString* name) {
   if (ShouldOptimizeAsOneShot()) {
-    RegisterList args = register_allocator()->NewRegisterList(2);
-    size_t name_index = builder()->GetConstantPoolEntry(name);
-    builder()
-        ->MoveRegister(object, args[0])
-        .LoadConstantPoolEntry(name_index)
-        .StoreAccumulatorInRegister(args[1])
-        .CallRuntime(Runtime::kInlineGetProperty, args);
+    builder()->LoadNamedPropertyNoFeedback(object, name);
   } else {
     FeedbackSlot slot = GetCachedLoadICSlot(property->obj(), name);
     builder()->LoadNamedProperty(object, name, feedback_index(slot));
@@ -2847,16 +2885,7 @@ void BytecodeGenerator::BuildStoreNamedProperty(Property* property,
   }
 
   if (ShouldOptimizeAsOneShot()) {
-    RegisterList args = register_allocator()->NewRegisterList(4);
-    size_t name_index = builder()->GetConstantPoolEntry(name);
-    builder()
-        ->MoveRegister(object, args[0])
-        .StoreAccumulatorInRegister(args[2])
-        .LoadConstantPoolEntry(name_index)
-        .StoreAccumulatorInRegister(args[1])
-        .LoadLiteral(Smi::FromEnum(language_mode()))
-        .StoreAccumulatorInRegister(args[3])
-        .CallRuntime(Runtime::kSetProperty, args);
+    builder()->StoreNamedPropertyNoFeedback(object, name, language_mode());
   } else {
     FeedbackSlot slot = GetCachedStoreICSlot(property->obj(), name);
     builder()->StoreNamedProperty(object, name, feedback_index(slot),
@@ -3555,6 +3584,7 @@ void BytecodeGenerator::VisitCall(Call* expr) {
   // When a call contains a spread, a Call AST node is only created if there is
   // exactly one spread, and it is the last argument.
   bool is_spread_call = expr->only_last_arg_is_spread();
+  bool optimize_as_one_shot = ShouldOptimizeAsOneShot();
 
   // TODO(petermarshall): We have a lot of call bytecodes that are very similar,
   // see if we can reduce the number by adding a separate argument which
@@ -3579,7 +3609,7 @@ void BytecodeGenerator::VisitCall(Call* expr) {
     }
     case Call::GLOBAL_CALL: {
       // Receiver is undefined for global calls.
-      if (!is_spread_call) {
+      if (!is_spread_call && !optimize_as_one_shot) {
         implicit_undefined_receiver = true;
       } else {
         // TODO(leszeks): There's no special bytecode for tail calls or spread
@@ -3615,7 +3645,7 @@ void BytecodeGenerator::VisitCall(Call* expr) {
     }
     case Call::OTHER_CALL: {
       // Receiver is undefined for other calls.
-      if (!is_spread_call) {
+      if (!is_spread_call && !optimize_as_one_shot) {
         implicit_undefined_receiver = true;
       } else {
         // TODO(leszeks): There's no special bytecode for tail calls or spread
@@ -3679,20 +3709,25 @@ void BytecodeGenerator::VisitCall(Call* expr) {
 
   builder()->SetExpressionPosition(expr);
 
-  int feedback_slot_index = feedback_index(feedback_spec()->AddCallICSlot());
-
   if (is_spread_call) {
     DCHECK(!implicit_undefined_receiver);
-    builder()->CallWithSpread(callee, args, feedback_slot_index);
+    builder()->CallWithSpread(callee, args,
+                              feedback_index(feedback_spec()->AddCallICSlot()));
+  } else if (optimize_as_one_shot) {
+    DCHECK(!implicit_undefined_receiver);
+    builder()->CallNoFeedback(callee, args);
   } else if (call_type == Call::NAMED_PROPERTY_CALL ||
              call_type == Call::KEYED_PROPERTY_CALL ||
              call_type == Call::RESOLVED_PROPERTY_CALL) {
     DCHECK(!implicit_undefined_receiver);
-    builder()->CallProperty(callee, args, feedback_slot_index);
+    builder()->CallProperty(callee, args,
+                            feedback_index(feedback_spec()->AddCallICSlot()));
   } else if (implicit_undefined_receiver) {
-    builder()->CallUndefinedReceiver(callee, args, feedback_slot_index);
+    builder()->CallUndefinedReceiver(
+        callee, args, feedback_index(feedback_spec()->AddCallICSlot()));
   } else {
-    builder()->CallAnyReceiver(callee, args, feedback_slot_index);
+    builder()->CallAnyReceiver(
+        callee, args, feedback_index(feedback_spec()->AddCallICSlot()));
   }
 }
 
@@ -3722,17 +3757,12 @@ void BytecodeGenerator::VisitCallSuper(Call* expr) {
     // mechanism for spreads in array literals.
 
     // First generate the array containing all arguments.
-    Register array = register_allocator()->NewRegister();
-    int literal_index = feedback_index(feedback_spec()->AddLiteralSlot());
-    builder()
-        ->CreateEmptyArrayLiteral(literal_index)
-        .StoreAccumulatorInRegister(array);
-    BuildArrayLiteralElementsInsertion(array, first_spread_index, args, false);
+    BuildCreateArrayLiteral(args, nullptr);
 
     // Now pass that array to %reflect_construct.
     RegisterList construct_args = register_allocator()->NewRegisterList(3);
+    builder()->StoreAccumulatorInRegister(construct_args[1]);
     builder()->MoveRegister(constructor, construct_args[0]);
-    builder()->MoveRegister(array, construct_args[1]);
     VisitForRegisterValue(super->new_target_var(), construct_args[2]);
     builder()->CallJSRuntime(Context::REFLECT_CONSTRUCT_INDEX, construct_args);
   } else {
@@ -5175,11 +5205,7 @@ FeedbackSlot BytecodeGenerator::GetCachedCreateClosureSlot(
 }
 
 FeedbackSlot BytecodeGenerator::GetDummyCompareICSlot() {
-  if (!dummy_feedback_slot_.IsInvalid()) {
-    return dummy_feedback_slot_;
-  }
-  dummy_feedback_slot_ = feedback_spec()->AddCompareICSlot();
-  return dummy_feedback_slot_;
+  return dummy_feedback_slot_.Get();
 }
 
 Runtime::FunctionId BytecodeGenerator::StoreToSuperRuntimeId() {
diff --git a/deps/v8/src/interpreter/bytecode-generator.h b/deps/v8/src/interpreter/bytecode-generator.h
index 47f1f83e12..3150245b0b 100644
--- a/deps/v8/src/interpreter/bytecode-generator.h
+++ b/deps/v8/src/interpreter/bytecode-generator.h
@@ -6,6 +6,7 @@
 #define V8_INTERPRETER_BYTECODE_GENERATOR_H_
 
 #include "src/ast/ast.h"
+#include "src/feedback-vector.h"
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-label.h"
 #include "src/interpreter/bytecode-register.h"
@@ -182,11 +183,11 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   void BuildArrayLiteralSpread(Spread* spread, Register array, Register index,
                                FeedbackSlot index_slot,
                                FeedbackSlot element_slot);
-  void BuildArrayLiteralElementsInsertion(Register array,
-                                          int first_spread_index,
-                                          ZonePtrList<Expression>* elements,
-                                          bool skip_constants);
-
+  // Create Array literals. |expr| can be nullptr, but if provided,
+  // a boilerplate will be used to create an initial array for elements
+  // before the first spread.
+  void BuildCreateArrayLiteral(ZonePtrList<Expression>* elements,
+                               ArrayLiteral* expr);
   void BuildCreateObjectLiteral(Register literal, uint8_t flags, size_t entry);
   void AllocateTopLevelRegisters();
   void VisitArgumentsObject(Variable* variable);
@@ -373,7 +374,7 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 
   // Dummy feedback slot for compare operations, where we don't care about
   // feedback
-  FeedbackSlot dummy_feedback_slot_;
+  SharedFeedbackSlot dummy_feedback_slot_;
 
   BytecodeJumpTable* generator_jump_table_;
   int suspend_count_;
diff --git a/deps/v8/src/interpreter/bytecode-operands.h b/deps/v8/src/interpreter/bytecode-operands.h
index 04d1e35821..a2730cb64c 100644
--- a/deps/v8/src/interpreter/bytecode-operands.h
+++ b/deps/v8/src/interpreter/bytecode-operands.h
@@ -145,6 +145,19 @@ class BytecodeOperands : public AllStatic {
       0 OPERAND_SCALE_LIST(OPERAND_SCALE_COUNT);
 #undef OPERAND_SCALE_COUNT
 
+  static int OperandScaleAsIndex(OperandScale operand_scale) {
+    switch (operand_scale) {
+      case OperandScale::kSingle:
+        return 0;
+      case OperandScale::kDouble:
+        return 1;
+      case OperandScale::kQuadruple:
+        return 2;
+      default:
+        UNREACHABLE();
+    }
+  }
+
   // Returns true if |accumulator_use| reads the accumulator.
   static constexpr bool ReadsAccumulator(AccumulatorUse accumulator_use) {
     return accumulator_use == AccumulatorUse::kRead ||
diff --git a/deps/v8/src/interpreter/bytecode-register-allocator.h b/deps/v8/src/interpreter/bytecode-register-allocator.h
index 8509bd43e0..b270e3d38b 100644
--- a/deps/v8/src/interpreter/bytecode-register-allocator.h
+++ b/deps/v8/src/interpreter/bytecode-register-allocator.h
@@ -19,7 +19,7 @@ class BytecodeRegisterAllocator final {
   // Enables observation of register allocation and free events.
   class Observer {
    public:
-    virtual ~Observer() {}
+    virtual ~Observer() = default;
     virtual void RegisterAllocateEvent(Register reg) = 0;
     virtual void RegisterListAllocateEvent(RegisterList reg_list) = 0;
     virtual void RegisterListFreeEvent(RegisterList reg_list) = 0;
@@ -29,7 +29,7 @@ class BytecodeRegisterAllocator final {
       : next_register_index_(start_index),
         max_register_count_(start_index),
         observer_(nullptr) {}
-  ~BytecodeRegisterAllocator() {}
+  ~BytecodeRegisterAllocator() = default;
 
   // Returns a new register.
   Register NewRegister() {
diff --git a/deps/v8/src/interpreter/bytecode-register-optimizer.h b/deps/v8/src/interpreter/bytecode-register-optimizer.h
index 11794274b9..7ba7d3b602 100644
--- a/deps/v8/src/interpreter/bytecode-register-optimizer.h
+++ b/deps/v8/src/interpreter/bytecode-register-optimizer.h
@@ -23,8 +23,8 @@ class V8_EXPORT_PRIVATE BytecodeRegisterOptimizer final
  public:
   class BytecodeWriter {
    public:
-    BytecodeWriter() {}
-    virtual ~BytecodeWriter() {}
+    BytecodeWriter() = default;
+    virtual ~BytecodeWriter() = default;
 
     // Called to emit a register transfer bytecode.
     virtual void EmitLdar(Register input) = 0;
@@ -39,7 +39,7 @@ class V8_EXPORT_PRIVATE BytecodeRegisterOptimizer final
                             BytecodeRegisterAllocator* register_allocator,
                             int fixed_registers_count, int parameter_count,
                             BytecodeWriter* bytecode_writer);
-  virtual ~BytecodeRegisterOptimizer() {}
+  ~BytecodeRegisterOptimizer() override = default;
 
   // Perform explicit register transfer operations.
   void DoLdar(Register input) {
diff --git a/deps/v8/src/interpreter/bytecodes.cc b/deps/v8/src/interpreter/bytecodes.cc
index 88cdae6ce5..60f30ee1d9 100644
--- a/deps/v8/src/interpreter/bytecodes.cc
+++ b/deps/v8/src/interpreter/bytecodes.cc
@@ -107,14 +107,13 @@ const char* Bytecodes::ToString(Bytecode bytecode) {
 }
 
 // static
-std::string Bytecodes::ToString(Bytecode bytecode, OperandScale operand_scale) {
-  static const char kSeparator = '.';
-
+std::string Bytecodes::ToString(Bytecode bytecode, OperandScale operand_scale,
+                                const char* separator) {
   std::string value(ToString(bytecode));
   if (operand_scale > OperandScale::kSingle) {
     Bytecode prefix_bytecode = OperandScaleToPrefixBytecode(operand_scale);
     std::string suffix = ToString(prefix_bytecode);
-    return value.append(1, kSeparator).append(suffix);
+    return value.append(separator).append(suffix);
   } else {
     return value;
   }
@@ -284,6 +283,7 @@ bool Bytecodes::IsStarLookahead(Bytecode bytecode, OperandScale operand_scale) {
       case Bytecode::kDec:
       case Bytecode::kTypeOf:
       case Bytecode::kCallAnyReceiver:
+      case Bytecode::kCallNoFeedback:
       case Bytecode::kCallProperty:
       case Bytecode::kCallProperty0:
       case Bytecode::kCallProperty1:
diff --git a/deps/v8/src/interpreter/bytecodes.h b/deps/v8/src/interpreter/bytecodes.h
index 0e543877f7..39f61eb9bd 100644
--- a/deps/v8/src/interpreter/bytecodes.h
+++ b/deps/v8/src/interpreter/bytecodes.h
@@ -98,6 +98,8 @@ namespace interpreter {
   /* Property loads (LoadIC) operations */                                     \
   V(LdaNamedProperty, AccumulatorUse::kWrite, OperandType::kReg,               \
     OperandType::kIdx, OperandType::kIdx)                                      \
+  V(LdaNamedPropertyNoFeedback, AccumulatorUse::kWrite, OperandType::kReg,     \
+    OperandType::kIdx)                                                         \
   V(LdaKeyedProperty, AccumulatorUse::kReadWrite, OperandType::kReg,           \
     OperandType::kIdx)                                                         \
                                                                                \
@@ -110,6 +112,8 @@ namespace interpreter {
   /* Propery stores (StoreIC) operations */                                    \
   V(StaNamedProperty, AccumulatorUse::kReadWrite, OperandType::kReg,           \
     OperandType::kIdx, OperandType::kIdx)                                      \
+  V(StaNamedPropertyNoFeedback, AccumulatorUse::kReadWrite, OperandType::kReg, \
+    OperandType::kIdx, OperandType::kFlag8)                                    \
   V(StaNamedOwnProperty, AccumulatorUse::kReadWrite, OperandType::kReg,        \
     OperandType::kIdx, OperandType::kIdx)                                      \
   V(StaKeyedProperty, AccumulatorUse::kReadWrite, OperandType::kReg,           \
@@ -194,6 +198,8 @@ namespace interpreter {
     OperandType::kReg, OperandType::kIdx)                                      \
   V(CallUndefinedReceiver2, AccumulatorUse::kWrite, OperandType::kReg,         \
     OperandType::kReg, OperandType::kReg, OperandType::kIdx)                   \
+  V(CallNoFeedback, AccumulatorUse::kWrite, OperandType::kReg,                 \
+    OperandType::kRegList, OperandType::kRegCount)                             \
   V(CallWithSpread, AccumulatorUse::kWrite, OperandType::kReg,                 \
     OperandType::kRegList, OperandType::kRegCount, OperandType::kIdx)          \
   V(CallRuntime, AccumulatorUse::kWrite, OperandType::kRuntimeId,              \
@@ -247,6 +253,7 @@ namespace interpreter {
     OperandType::kIdx, OperandType::kFlag8)                                    \
   V(CreateArrayLiteral, AccumulatorUse::kWrite, OperandType::kIdx,             \
     OperandType::kIdx, OperandType::kFlag8)                                    \
+  V(CreateArrayFromIterable, AccumulatorUse::kReadWrite)                       \
   V(CreateEmptyArrayLiteral, AccumulatorUse::kWrite, OperandType::kIdx)        \
   V(CreateObjectLiteral, AccumulatorUse::kNone, OperandType::kIdx,             \
     OperandType::kIdx, OperandType::kFlag8, OperandType::kRegOut)              \
@@ -468,8 +475,10 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
   // Returns string representation of |bytecode|.
   static const char* ToString(Bytecode bytecode);
 
-  // Returns string representation of |bytecode|.
-  static std::string ToString(Bytecode bytecode, OperandScale operand_scale);
+  // Returns string representation of |bytecode| combined with |operand_scale|
+  // using the optionally provided |separator|.
+  static std::string ToString(Bytecode bytecode, OperandScale operand_scale,
+                              const char* separator = ".");
 
   // Returns byte value of bytecode.
   static uint8_t ToByte(Bytecode bytecode) {
@@ -664,6 +673,7 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
            bytecode == Bytecode::kCallUndefinedReceiver0 ||
            bytecode == Bytecode::kCallUndefinedReceiver1 ||
            bytecode == Bytecode::kCallUndefinedReceiver2 ||
+           bytecode == Bytecode::kCallNoFeedback ||
            bytecode == Bytecode::kConstruct ||
            bytecode == Bytecode::kCallWithSpread ||
            bytecode == Bytecode::kConstructWithSpread ||
@@ -684,12 +694,6 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
            bytecode == Bytecode::kDebugBreakWide;
   }
 
-  // Returns true if the bytecode can be lazily deserialized.
-  static constexpr bool IsLazy(Bytecode bytecode) {
-    // Currently, all handlers are deserialized lazily.
-    return true;
-  }
-
   // Returns true if the bytecode returns.
   static constexpr bool Returns(Bytecode bytecode) {
 #define OR_BYTECODE(NAME) || bytecode == Bytecode::k##NAME
@@ -801,6 +805,7 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
       case Bytecode::kCallJSRuntime:
         return ConvertReceiverMode::kNullOrUndefined;
       case Bytecode::kCallAnyReceiver:
+      case Bytecode::kCallNoFeedback:
       case Bytecode::kConstruct:
       case Bytecode::kCallWithSpread:
       case Bytecode::kConstructWithSpread:
diff --git a/deps/v8/src/interpreter/constant-array-builder.h b/deps/v8/src/interpreter/constant-array-builder.h
index 3f3d38ce6e..f06983abfa 100644
--- a/deps/v8/src/interpreter/constant-array-builder.h
+++ b/deps/v8/src/interpreter/constant-array-builder.h
@@ -36,7 +36,7 @@ namespace interpreter {
 // interpreter. Each instance of this class is intended to be used to
 // generate exactly one FixedArray of constants via the ToFixedArray
 // method.
-class V8_EXPORT_PRIVATE ConstantArrayBuilder final BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
  public:
   // Capacity of the 8-bit operand slice.
   static const size_t k8BitCapacity = 1u << kBitsPerByte;
diff --git a/deps/v8/src/interpreter/control-flow-builders.h b/deps/v8/src/interpreter/control-flow-builders.h
index 405e81bc76..fdc57776a8 100644
--- a/deps/v8/src/interpreter/control-flow-builders.h
+++ b/deps/v8/src/interpreter/control-flow-builders.h
@@ -16,11 +16,11 @@ namespace v8 {
 namespace internal {
 namespace interpreter {
 
-class V8_EXPORT_PRIVATE ControlFlowBuilder BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE ControlFlowBuilder {
  public:
   explicit ControlFlowBuilder(BytecodeArrayBuilder* builder)
       : builder_(builder) {}
-  virtual ~ControlFlowBuilder() {}
+  virtual ~ControlFlowBuilder() = default;
 
  protected:
   BytecodeArrayBuilder* builder() const { return builder_; }
@@ -41,7 +41,7 @@ class V8_EXPORT_PRIVATE BreakableControlFlowBuilder
         break_labels_(builder->zone()),
         node_(node),
         block_coverage_builder_(block_coverage_builder) {}
-  virtual ~BreakableControlFlowBuilder();
+  ~BreakableControlFlowBuilder() override;
 
   // This method is called when visiting break statements in the AST.
   // Inserts a jump to an unbound label that is patched when the corresponding
@@ -113,7 +113,7 @@ class V8_EXPORT_PRIVATE LoopBuilder final : public BreakableControlFlowBuilder {
               node, SourceRangeKind::kBody);
     }
   }
-  ~LoopBuilder();
+  ~LoopBuilder() override;
 
   void LoopHeader();
   void LoopBody();
@@ -149,7 +149,7 @@ class V8_EXPORT_PRIVATE SwitchBuilder final
         case_sites_(builder->zone()) {
     case_sites_.resize(number_of_cases);
   }
-  ~SwitchBuilder();
+  ~SwitchBuilder() override;  // NOLINT (modernize-use-equals-default)
 
   // This method should be called by the SwitchBuilder owner when the case
   // statement with |index| is emitted to update the case jump site.
@@ -186,7 +186,7 @@ class V8_EXPORT_PRIVATE TryCatchBuilder final : public ControlFlowBuilder {
         block_coverage_builder_(block_coverage_builder),
         statement_(statement) {}
 
-  ~TryCatchBuilder();
+  ~TryCatchBuilder() override;
 
   void BeginTry(Register context);
   void EndTry();
@@ -217,7 +217,7 @@ class V8_EXPORT_PRIVATE TryFinallyBuilder final : public ControlFlowBuilder {
         block_coverage_builder_(block_coverage_builder),
         statement_(statement) {}
 
-  ~TryFinallyBuilder();
+  ~TryFinallyBuilder() override;
 
   void BeginTry(Register context);
   void LeaveTry();
@@ -260,7 +260,7 @@ class V8_EXPORT_PRIVATE ConditionalControlFlowBuilder final
               node, SourceRangeKind::kElse);
     }
   }
-  ~ConditionalControlFlowBuilder();
+  ~ConditionalControlFlowBuilder() override;
 
   BytecodeLabels* then_labels() { return &then_labels_; }
   BytecodeLabels* else_labels() { return &else_labels_; }
diff --git a/deps/v8/src/interpreter/handler-table-builder.h b/deps/v8/src/interpreter/handler-table-builder.h
index 021fefad29..029c8dd1a6 100644
--- a/deps/v8/src/interpreter/handler-table-builder.h
+++ b/deps/v8/src/interpreter/handler-table-builder.h
@@ -21,7 +21,7 @@ class Isolate;
 namespace interpreter {
 
 // A helper class for constructing exception handler tables for the interpreter.
-class V8_EXPORT_PRIVATE HandlerTableBuilder final BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE HandlerTableBuilder final {
  public:
   explicit HandlerTableBuilder(Zone* zone);
 
diff --git a/deps/v8/src/interpreter/interpreter-assembler.cc b/deps/v8/src/interpreter/interpreter-assembler.cc
index 15e2b1f091..cc8dfb1a30 100644
--- a/deps/v8/src/interpreter/interpreter-assembler.cc
+++ b/deps/v8/src/interpreter/interpreter-assembler.cc
@@ -744,12 +744,12 @@ void InterpreterAssembler::CollectCallableFeedback(Node* target, Node* context,
         feedback,
         HeapConstant(FeedbackVector::UninitializedSentinel(isolate())));
     GotoIf(is_uninitialized, &initialize);
-    CSA_ASSERT(this, IsWeakOrClearedHeapObject(feedback));
+    CSA_ASSERT(this, IsWeakOrCleared(feedback));
 
     // If the weak reference is cleared, we have a new chance to become
     // monomorphic.
     Comment("check if weak reference is cleared");
-    Branch(IsClearedWeakHeapObject(feedback), &initialize, &mark_megamorphic);
+    Branch(IsCleared(feedback), &initialize, &mark_megamorphic);
 
     BIND(&initialize);
     {
@@ -803,7 +803,7 @@ void InterpreterAssembler::CollectCallableFeedback(Node* target, Node* context,
       // MegamorphicSentinel is an immortal immovable object so
       // write-barrier is not needed.
       Comment("transition to megamorphic");
-      DCHECK(Heap::RootIsImmortalImmovable(Heap::kmegamorphic_symbolRootIndex));
+      DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kmegamorphic_symbol));
       StoreFeedbackVectorSlot(
           feedback_vector, slot_id,
           HeapConstant(FeedbackVector::MegamorphicSentinel(isolate())),
@@ -948,12 +948,12 @@ Node* InterpreterAssembler::Construct(Node* target, Node* context,
     GotoIf(is_megamorphic, &construct);
 
     Comment("check if weak reference");
-    GotoIfNot(IsWeakOrClearedHeapObject(feedback), &check_allocation_site);
+    GotoIfNot(IsWeakOrCleared(feedback), &check_allocation_site);
 
     // If the weak reference is cleared, we have a new chance to become
     // monomorphic.
     Comment("check if weak reference is cleared");
-    Branch(IsClearedWeakHeapObject(feedback), &initialize, &mark_megamorphic);
+    Branch(IsCleared(feedback), &initialize, &mark_megamorphic);
 
     BIND(&check_allocation_site);
     {
@@ -976,7 +976,7 @@ Node* InterpreterAssembler::Construct(Node* target, Node* context,
       // Check if it is uninitialized.
       Comment("check if uninitialized");
       Node* is_uninitialized =
-          WordEqual(feedback, LoadRoot(Heap::kuninitialized_symbolRootIndex));
+          WordEqual(feedback, LoadRoot(RootIndex::kuninitialized_symbol));
       Branch(is_uninitialized, &initialize, &mark_megamorphic);
     }
 
@@ -1054,7 +1054,7 @@ Node* InterpreterAssembler::Construct(Node* target, Node* context,
       // MegamorphicSentinel is an immortal immovable object so
       // write-barrier is not needed.
       Comment("transition to megamorphic");
-      DCHECK(Heap::RootIsImmortalImmovable(Heap::kmegamorphic_symbolRootIndex));
+      DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kmegamorphic_symbol));
       StoreFeedbackVectorSlot(
           feedback_vector, slot_id,
           HeapConstant(FeedbackVector::MegamorphicSentinel(isolate())),
@@ -1074,8 +1074,8 @@ Node* InterpreterAssembler::Construct(Node* target, Node* context,
         isolate(), InterpreterPushArgsMode::kArrayFunction);
     Node* code_target = HeapConstant(callable.code());
     var_result.Bind(CallStub(callable.descriptor(), code_target, context,
-                             args.reg_count(), new_target, target,
-                             var_site.value(), args.base_reg_location()));
+                             args.reg_count(), args.base_reg_location(), target,
+                             new_target, var_site.value()));
     Goto(&return_result);
   }
 
@@ -1087,8 +1087,8 @@ Node* InterpreterAssembler::Construct(Node* target, Node* context,
         isolate(), InterpreterPushArgsMode::kOther);
     Node* code_target = HeapConstant(callable.code());
     var_result.Bind(CallStub(callable.descriptor(), code_target, context,
-                             args.reg_count(), new_target, target,
-                             UndefinedConstant(), args.base_reg_location()));
+                             args.reg_count(), args.base_reg_location(), target,
+                             new_target, UndefinedConstant()));
     Goto(&return_result);
   }
 
@@ -1127,19 +1127,19 @@ Node* InterpreterAssembler::ConstructWithSpread(Node* target, Node* context,
     GotoIf(is_megamorphic, &construct);
 
     Comment("check if weak reference");
-    GotoIfNot(IsWeakOrClearedHeapObject(feedback), &check_initialized);
+    GotoIfNot(IsWeakOrCleared(feedback), &check_initialized);
 
     // If the weak reference is cleared, we have a new chance to become
     // monomorphic.
     Comment("check if weak reference is cleared");
-    Branch(IsClearedWeakHeapObject(feedback), &initialize, &mark_megamorphic);
+    Branch(IsCleared(feedback), &initialize, &mark_megamorphic);
 
     BIND(&check_initialized);
     {
       // Check if it is uninitialized.
       Comment("check if uninitialized");
       Node* is_uninitialized =
-          WordEqual(feedback, LoadRoot(Heap::kuninitialized_symbolRootIndex));
+          WordEqual(feedback, LoadRoot(RootIndex::kuninitialized_symbol));
       Branch(is_uninitialized, &initialize, &mark_megamorphic);
     }
 
@@ -1195,7 +1195,7 @@ Node* InterpreterAssembler::ConstructWithSpread(Node* target, Node* context,
       // MegamorphicSentinel is an immortal immovable object so
       // write-barrier is not needed.
       Comment("transition to megamorphic");
-      DCHECK(Heap::RootIsImmortalImmovable(Heap::kmegamorphic_symbolRootIndex));
+      DCHECK(Heap::RootIsImmortalImmovable(RootIndex::kmegamorphic_symbol));
       StoreFeedbackVectorSlot(
           feedback_vector, slot_id,
           HeapConstant(FeedbackVector::MegamorphicSentinel(isolate())),
@@ -1212,8 +1212,8 @@ Node* InterpreterAssembler::ConstructWithSpread(Node* target, Node* context,
       isolate(), InterpreterPushArgsMode::kWithFinalSpread);
   Node* code_target = HeapConstant(callable.code());
   return CallStub(callable.descriptor(), code_target, context, args.reg_count(),
-                  new_target, target, UndefinedConstant(),
-                  args.base_reg_location());
+                  args.base_reg_location(), target, new_target,
+                  UndefinedConstant());
 }
 
 Node* InterpreterAssembler::CallRuntimeN(Node* function_id, Node* context,
@@ -1705,7 +1705,7 @@ Node* InterpreterAssembler::ImportRegisterFile(
     StoreRegister(value, reg_index);
 
     StoreFixedArrayElement(array, array_index,
-                           LoadRoot(Heap::kStaleRegisterRootIndex));
+                           LoadRoot(RootIndex::kStaleRegister));
 
     var_index = IntPtrAdd(index, IntPtrConstant(1));
     Goto(&loop);
diff --git a/deps/v8/src/interpreter/interpreter-generator.cc b/deps/v8/src/interpreter/interpreter-generator.cc
index afca2a8a32..d2dab6d8d8 100644
--- a/deps/v8/src/interpreter/interpreter-generator.cc
+++ b/deps/v8/src/interpreter/interpreter-generator.cc
@@ -9,6 +9,7 @@
 
 #include "src/builtins/builtins-arguments-gen.h"
 #include "src/builtins/builtins-constructor-gen.h"
+#include "src/builtins/builtins-iterator-gen.h"
 #include "src/code-events.h"
 #include "src/code-factory.h"
 #include "src/debug/debug.h"
@@ -517,6 +518,18 @@ IGNITION_HANDLER(LdaNamedProperty, InterpreterAssembler) {
   }
 }
 
+// LdaPropertyNofeedback <object> <slot>
+//
+// Calls the GetProperty builtin for <object> and the key in the accumulator.
+IGNITION_HANDLER(LdaNamedPropertyNoFeedback, InterpreterAssembler) {
+  Node* object = LoadRegisterAtOperandIndex(0);
+  Node* name = LoadConstantPoolEntryAtOperandIndex(1);
+  Node* context = GetContext();
+  Node* result = CallBuiltin(Builtins::kGetProperty, context, object, name);
+  SetAccumulator(result);
+  Dispatch();
+}
+
 // KeyedLoadIC <object> <slot>
 //
 // Calls the KeyedLoadIC at FeedBackVector slot <slot> for <object> and the key
@@ -582,6 +595,24 @@ IGNITION_HANDLER(StaNamedOwnProperty, InterpreterStoreNamedPropertyAssembler) {
   StaNamedProperty(ic);
 }
 
+// StaNamedPropertyNoFeedback <object> <name_index>
+//
+// Calls the SetPropertyBuiltin for <object> and the name in constant pool entry
+// <name_index> with the value in the accumulator.
+IGNITION_HANDLER(StaNamedPropertyNoFeedback,
+                 InterpreterStoreNamedPropertyAssembler) {
+  Node* object = LoadRegisterAtOperandIndex(0);
+  Node* name = LoadConstantPoolEntryAtOperandIndex(1);
+  Node* value = GetAccumulator();
+  Node* language_mode = SmiFromInt32(BytecodeOperandFlag(2));
+  Node* context = GetContext();
+
+  Node* result = CallRuntime(Runtime::kSetNamedProperty, context, object, name,
+                             value, language_mode);
+  SetAccumulator(result);
+  Dispatch();
+}
+
 // StaKeyedProperty <object> <key> <slot>
 //
 // Calls the KeyedStoreIC at FeedbackVector slot <slot> for <object> and
@@ -1122,7 +1153,7 @@ class UnaryNumericOpAssembler : public InterpreterAssembler {
                           OperandScale operand_scale)
       : InterpreterAssembler(state, bytecode, operand_scale) {}
 
-  virtual ~UnaryNumericOpAssembler() {}
+  virtual ~UnaryNumericOpAssembler() = default;
 
   // Must return a tagged value.
   virtual TNode<Number> SmiOp(TNode<Smi> smi_value, Variable* var_feedback,
@@ -1273,7 +1304,7 @@ IGNITION_HANDLER(Negate, NegateAssemblerImpl) { UnaryOpWithFeedback(); }
 IGNITION_HANDLER(ToName, InterpreterAssembler) {
   Node* object = GetAccumulator();
   Node* context = GetContext();
-  Node* result = ToName(context, object);
+  Node* result = CallBuiltin(Builtins::kToName, context, object);
   StoreRegisterAtOperandIndex(result, 0);
   Dispatch();
 }
@@ -1501,6 +1532,16 @@ class InterpreterJSCallAssembler : public InterpreterAssembler {
     CallJSAndDispatch(function, context, args, receiver_mode);
   }
 
+  // Generates code to perform a JS call without collecting feedback.
+  void JSCallNoFeedback(ConvertReceiverMode receiver_mode) {
+    Node* function = LoadRegisterAtOperandIndex(0);
+    RegListNodePair args = GetRegisterListAtOperandIndex(1);
+    Node* context = GetContext();
+
+    // Call the function and dispatch to the next handler.
+    CallJSAndDispatch(function, context, args, receiver_mode);
+  }
+
   // Generates code to perform a JS call with a known number of arguments that
   // collects type feedback.
   void JSCallN(int arg_count, ConvertReceiverMode receiver_mode) {
@@ -1590,6 +1631,10 @@ IGNITION_HANDLER(CallUndefinedReceiver2, InterpreterJSCallAssembler) {
   JSCallN(2, ConvertReceiverMode::kNullOrUndefined);
 }
 
+IGNITION_HANDLER(CallNoFeedback, InterpreterJSCallAssembler) {
+  JSCallNoFeedback(ConvertReceiverMode::kAny);
+}
+
 // CallRuntime <function_id> <first_arg> <arg_count>
 //
 // Call the runtime function |function_id| with the first argument in
@@ -2381,6 +2426,18 @@ IGNITION_HANDLER(CreateEmptyArrayLiteral, InterpreterAssembler) {
   Dispatch();
 }
 
+// CreateArrayFromIterable
+//
+// Spread the given iterable from the accumulator into a new JSArray.
+IGNITION_HANDLER(CreateArrayFromIterable, InterpreterAssembler) {
+  Node* iterable = GetAccumulator();
+  Node* context = GetContext();
+  Node* result =
+      CallBuiltin(Builtins::kIterableToListWithSymbolLookup, context, iterable);
+  SetAccumulator(result);
+  Dispatch();
+}
+
 // CreateObjectLiteral <element_idx> <literal_idx> <flags>
 //
 // Creates an object literal for literal index <literal_idx> with
@@ -3128,7 +3185,8 @@ IGNITION_HANDLER(ResumeGenerator, InterpreterAssembler) {
 
 Handle<Code> GenerateBytecodeHandler(Isolate* isolate, Bytecode bytecode,
                                      OperandScale operand_scale,
-                                     int builtin_index) {
+                                     int builtin_index,
+                                     const AssemblerOptions& options) {
   Zone zone(isolate->allocator(), ZONE_NAME);
   compiler::CodeAssemblerState state(
       isolate, &zone, InterpreterDispatchDescriptor{}, Code::BYTECODE_HANDLER,
@@ -3147,8 +3205,7 @@ Handle<Code> GenerateBytecodeHandler(Isolate* isolate, Bytecode bytecode,
 #undef CALL_GENERATOR
   }
 
-  Handle<Code> code = compiler::CodeAssembler::GenerateCode(
-      &state, AssemblerOptions::Default(isolate));
+  Handle<Code> code = compiler::CodeAssembler::GenerateCode(&state, options);
   PROFILE(isolate, CodeCreateEvent(
                        CodeEventListener::BYTECODE_HANDLER_TAG,
                        AbstractCode::cast(*code),
@@ -3195,7 +3252,9 @@ class DeserializeLazyAssembler : public InterpreterAssembler {
 }  // namespace
 
 Handle<Code> GenerateDeserializeLazyHandler(Isolate* isolate,
-                                            OperandScale operand_scale) {
+                                            OperandScale operand_scale,
+                                            int builtin_index,
+                                            const AssemblerOptions& options) {
   Zone zone(isolate->allocator(), ZONE_NAME);
 
   std::string debug_name = std::string("DeserializeLazy");
@@ -3210,11 +3269,11 @@ Handle<Code> GenerateDeserializeLazyHandler(Isolate* isolate,
       debug_name.c_str(),
       FLAG_untrusted_code_mitigations
           ? PoisoningMitigationLevel::kPoisonCriticalOnly
-          : PoisoningMitigationLevel::kDontPoison);
+          : PoisoningMitigationLevel::kDontPoison,
+      0, builtin_index);
 
   DeserializeLazyAssembler::Generate(&state, operand_scale);
-  Handle<Code> code = compiler::CodeAssembler::GenerateCode(
-      &state, AssemblerOptions::Default(isolate));
+  Handle<Code> code = compiler::CodeAssembler::GenerateCode(&state, options);
   PROFILE(isolate,
           CodeCreateEvent(CodeEventListener::BYTECODE_HANDLER_TAG,
                           AbstractCode::cast(*code), debug_name.c_str()));
diff --git a/deps/v8/src/interpreter/interpreter-generator.h b/deps/v8/src/interpreter/interpreter-generator.h
index bc3793a45f..a41e89f250 100644
--- a/deps/v8/src/interpreter/interpreter-generator.h
+++ b/deps/v8/src/interpreter/interpreter-generator.h
@@ -10,14 +10,19 @@
 
 namespace v8 {
 namespace internal {
+
+struct AssemblerOptions;
+
 namespace interpreter {
 
 extern Handle<Code> GenerateBytecodeHandler(Isolate* isolate, Bytecode bytecode,
                                             OperandScale operand_scale,
-                                            int builtin_index);
+                                            int builtin_index,
+                                            const AssemblerOptions& options);
 
-extern Handle<Code> GenerateDeserializeLazyHandler(Isolate* isolate,
-                                                   OperandScale operand_scale);
+extern Handle<Code> GenerateDeserializeLazyHandler(
+    Isolate* isolate, OperandScale operand_scale, int builtin_index,
+    const AssemblerOptions& options);
 
 }  // namespace interpreter
 }  // namespace internal
diff --git a/deps/v8/src/interpreter/interpreter-intrinsics-generator.cc b/deps/v8/src/interpreter/interpreter-intrinsics-generator.cc
index 55e554e2e0..3e261bea9f 100644
--- a/deps/v8/src/interpreter/interpreter-intrinsics-generator.cc
+++ b/deps/v8/src/interpreter/interpreter-intrinsics-generator.cc
@@ -159,12 +159,6 @@ Node* IntrinsicsGenerator::IsArray(
   return IsInstanceType(input, JS_ARRAY_TYPE);
 }
 
-Node* IntrinsicsGenerator::IsJSProxy(
-    const InterpreterAssembler::RegListNodePair& args, Node* context) {
-  Node* input = __ LoadRegisterFromRegisterList(args, 0);
-  return IsInstanceType(input, JS_PROXY_TYPE);
-}
-
 Node* IntrinsicsGenerator::IsTypedArray(
     const InterpreterAssembler::RegListNodePair& args, Node* context) {
   Node* input = __ LoadRegisterFromRegisterList(args, 0);
@@ -212,12 +206,6 @@ Node* IntrinsicsGenerator::HasProperty(
       args, context, Builtins::CallableFor(isolate(), Builtins::kHasProperty));
 }
 
-Node* IntrinsicsGenerator::GetProperty(
-    const InterpreterAssembler::RegListNodePair& args, Node* context) {
-  return IntrinsicAsStubCall(
-      args, context, Builtins::CallableFor(isolate(), Builtins::kGetProperty));
-}
-
 Node* IntrinsicsGenerator::RejectPromise(
     const InterpreterAssembler::RegListNodePair& args, Node* context) {
   return IntrinsicAsStubCall(
@@ -244,18 +232,6 @@ Node* IntrinsicsGenerator::ToLength(
       args, context, Builtins::CallableFor(isolate(), Builtins::kToLength));
 }
 
-Node* IntrinsicsGenerator::ToInteger(
-    const InterpreterAssembler::RegListNodePair& args, Node* context) {
-  return IntrinsicAsStubCall(
-      args, context, Builtins::CallableFor(isolate(), Builtins::kToInteger));
-}
-
-Node* IntrinsicsGenerator::ToNumber(
-    const InterpreterAssembler::RegListNodePair& args, Node* context) {
-  return IntrinsicAsStubCall(
-      args, context, Builtins::CallableFor(isolate(), Builtins::kToNumber));
-}
-
 Node* IntrinsicsGenerator::ToObject(
     const InterpreterAssembler::RegListNodePair& args, Node* context) {
   return IntrinsicAsStubCall(
@@ -336,15 +312,6 @@ Node* IntrinsicsGenerator::CreateJSGeneratorObject(
                                 Builtins::kCreateGeneratorObject);
 }
 
-Node* IntrinsicsGenerator::GeneratorGetInputOrDebugPos(
-    const InterpreterAssembler::RegListNodePair& args, Node* context) {
-  Node* generator = __ LoadRegisterFromRegisterList(args, 0);
-  Node* const value =
-      __ LoadObjectField(generator, JSGeneratorObject::kInputOrDebugPosOffset);
-
-  return value;
-}
-
 Node* IntrinsicsGenerator::GeneratorGetResumeMode(
     const InterpreterAssembler::RegListNodePair& args, Node* context) {
   Node* generator = __ LoadRegisterFromRegisterList(args, 0);
diff --git a/deps/v8/src/interpreter/interpreter-intrinsics.h b/deps/v8/src/interpreter/interpreter-intrinsics.h
index 04f662f0df..608b0afcac 100644
--- a/deps/v8/src/interpreter/interpreter-intrinsics.h
+++ b/deps/v8/src/interpreter/interpreter-intrinsics.h
@@ -19,16 +19,13 @@ namespace interpreter {
   V(AsyncGeneratorYield, async_generator_yield, 3)                    \
   V(CreateJSGeneratorObject, create_js_generator_object, 2)           \
   V(GeneratorGetResumeMode, generator_get_resume_mode, 1)             \
-  V(GeneratorGetInputOrDebugPos, generator_get_input_or_debug_pos, 1) \
   V(GeneratorClose, generator_close, 1)                               \
   V(GetImportMetaObject, get_import_meta_object, 0)                   \
   V(Call, call, -1)                                                   \
   V(CreateIterResultObject, create_iter_result_object, 2)             \
   V(CreateAsyncFromSyncIterator, create_async_from_sync_iterator, 1)  \
   V(HasProperty, has_property, 2)                                     \
-  V(GetProperty, get_property, 2)                                     \
   V(IsArray, is_array, 1)                                             \
-  V(IsJSProxy, is_js_proxy, 1)                                        \
   V(IsJSReceiver, is_js_receiver, 1)                                  \
   V(IsSmi, is_smi, 1)                                                 \
   V(IsTypedArray, is_typed_array, 1)                                  \
@@ -36,8 +33,6 @@ namespace interpreter {
   V(ResolvePromise, resolve_promise, 2)                               \
   V(ToString, to_string, 1)                                           \
   V(ToLength, to_length, 1)                                           \
-  V(ToInteger, to_integer, 1)                                         \
-  V(ToNumber, to_number, 1)                                           \
   V(ToObject, to_object, 1)
 
 class IntrinsicsHelper {
diff --git a/deps/v8/src/interpreter/interpreter.cc b/deps/v8/src/interpreter/interpreter.cc
index 0446ed494d..ca53fa674c 100644
--- a/deps/v8/src/interpreter/interpreter.cc
+++ b/deps/v8/src/interpreter/interpreter.cc
@@ -7,6 +7,7 @@
 #include <fstream>
 #include <memory>
 
+#include "builtins-generated/bytecodes-builtins-list.h"
 #include "src/ast/prettyprinter.h"
 #include "src/bootstrapper.h"
 #include "src/compiler.h"
@@ -59,41 +60,47 @@ Interpreter::Interpreter(Isolate* isolate) : isolate_(isolate) {
   }
 }
 
+namespace {
+
+int BuiltinIndexFromBytecode(Bytecode bytecode, OperandScale operand_scale) {
+  int index = BytecodeOperands::OperandScaleAsIndex(operand_scale) *
+                  kNumberOfBytecodeHandlers +
+              static_cast<int>(bytecode);
+  int offset = kBytecodeToBuiltinsMapping[index];
+  return offset >= 0 ? Builtins::kFirstBytecodeHandler + offset
+                     : Builtins::kIllegalHandler;
+}
+
+}  // namespace
+
 Code* Interpreter::GetAndMaybeDeserializeBytecodeHandler(
     Bytecode bytecode, OperandScale operand_scale) {
-  Code* code = GetBytecodeHandler(bytecode, operand_scale);
+  int builtin_index = BuiltinIndexFromBytecode(bytecode, operand_scale);
+  Builtins* builtins = isolate_->builtins();
+  Code* code = builtins->builtin(builtin_index);
 
   // Already deserialized? Then just return the handler.
-  if (!isolate_->heap()->IsDeserializeLazyHandler(code)) return code;
+  if (!Builtins::IsLazyDeserializer(code)) return code;
 
-  DCHECK(FLAG_lazy_handler_deserialization);
+  DCHECK(FLAG_lazy_deserialization);
   DCHECK(Bytecodes::BytecodeHasHandler(bytecode, operand_scale));
-  code = Snapshot::DeserializeHandler(isolate_, bytecode, operand_scale);
+  code = Snapshot::DeserializeBuiltin(isolate_, builtin_index);
 
   DCHECK(code->IsCode());
   DCHECK_EQ(code->kind(), Code::BYTECODE_HANDLER);
-  DCHECK(!isolate_->heap()->IsDeserializeLazyHandler(code));
+  DCHECK(!Builtins::IsLazyDeserializer(code));
 
   SetBytecodeHandler(bytecode, operand_scale, code);
 
   return code;
 }
 
-Code* Interpreter::GetBytecodeHandler(Bytecode bytecode,
-                                      OperandScale operand_scale) {
-  DCHECK(IsDispatchTableInitialized());
-  DCHECK(Bytecodes::BytecodeHasHandler(bytecode, operand_scale));
-  size_t index = GetDispatchTableIndex(bytecode, operand_scale);
-  Address code_entry = dispatch_table_[index];
-  return Code::GetCodeFromTargetAddress(code_entry);
-}
-
 void Interpreter::SetBytecodeHandler(Bytecode bytecode,
                                      OperandScale operand_scale,
                                      Code* handler) {
   DCHECK(handler->kind() == Code::BYTECODE_HANDLER);
   size_t index = GetDispatchTableIndex(bytecode, operand_scale);
-  dispatch_table_[index] = handler->entry();
+  dispatch_table_[index] = handler->InstructionStart();
 }
 
 // static
@@ -101,20 +108,17 @@ size_t Interpreter::GetDispatchTableIndex(Bytecode bytecode,
                                           OperandScale operand_scale) {
   static const size_t kEntriesPerOperandScale = 1u << kBitsPerByte;
   size_t index = static_cast<size_t>(bytecode);
-  switch (operand_scale) {
-    case OperandScale::kSingle:
-      return index;
-    case OperandScale::kDouble:
-      return index + kEntriesPerOperandScale;
-    case OperandScale::kQuadruple:
-      return index + 2 * kEntriesPerOperandScale;
-  }
-  UNREACHABLE();
+  return index + BytecodeOperands::OperandScaleAsIndex(operand_scale) *
+                     kEntriesPerOperandScale;
 }
 
 void Interpreter::IterateDispatchTable(RootVisitor* v) {
   for (int i = 0; i < kDispatchTableSize; i++) {
     Address code_entry = dispatch_table_[i];
+
+    // If the handler is embedded, it is immovable.
+    if (InstructionStream::PcIsOffHeap(isolate_, code_entry)) continue;
+
     Object* code = code_entry == kNullAddress
                        ? nullptr
                        : Code::GetCodeFromTargetAddress(code_entry);
@@ -229,6 +233,52 @@ UnoptimizedCompilationJob* Interpreter::NewCompilationJob(
                                        eager_inner_literals);
 }
 
+void Interpreter::ForEachBytecode(
+    const std::function<void(Bytecode, OperandScale)>& f) {
+  constexpr OperandScale kOperandScales[] = {
+#define VALUE(Name, _) OperandScale::k##Name,
+      OPERAND_SCALE_LIST(VALUE)
+#undef VALUE
+  };
+
+  for (OperandScale operand_scale : kOperandScales) {
+    for (int i = 0; i < Bytecodes::kBytecodeCount; i++) {
+      f(Bytecodes::FromByte(i), operand_scale);
+    }
+  }
+}
+
+void Interpreter::InitializeDispatchTable() {
+  Builtins* builtins = isolate_->builtins();
+  Code* illegal = builtins->builtin(Builtins::kIllegalHandler);
+  int builtin_id = Builtins::kFirstBytecodeHandler;
+  ForEachBytecode([=, &builtin_id](Bytecode bytecode,
+                                   OperandScale operand_scale) {
+    Code* handler = illegal;
+    if (Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) {
+#ifdef DEBUG
+      std::string builtin_name(Builtins::name(builtin_id));
+      std::string expected_name =
+          Bytecodes::ToString(bytecode, operand_scale, "") + "Handler";
+      DCHECK_EQ(expected_name, builtin_name);
+#endif
+      handler = builtins->builtin(builtin_id++);
+    }
+    SetBytecodeHandler(bytecode, operand_scale, handler);
+  });
+  DCHECK(builtin_id == Builtins::builtin_count);
+  DCHECK(IsDispatchTableInitialized());
+
+#if defined(V8_USE_SNAPSHOT) && !defined(V8_USE_SNAPSHOT_WITH_UNWINDING_INFO)
+  if (!isolate_->serializer_enabled() && FLAG_perf_prof_unwinding_info) {
+    StdoutStream{}
+        << "Warning: The --perf-prof-unwinding-info flag can be passed at "
+           "mksnapshot time to get better results."
+        << std::endl;
+  }
+#endif
+}
+
 bool Interpreter::IsDispatchTableInitialized() const {
   return dispatch_table_[0] != kNullAddress;
 }
diff --git a/deps/v8/src/interpreter/interpreter.h b/deps/v8/src/interpreter/interpreter.h
index 5ded893798..5023b0ef00 100644
--- a/deps/v8/src/interpreter/interpreter.h
+++ b/deps/v8/src/interpreter/interpreter.h
@@ -36,7 +36,7 @@ class InterpreterAssembler;
 class Interpreter {
  public:
   explicit Interpreter(Isolate* isolate);
-  virtual ~Interpreter() {}
+  virtual ~Interpreter() = default;
 
   // Returns the interrupt budget which should be used for the profiler counter.
   static int InterruptBudget();
@@ -54,9 +54,6 @@ class Interpreter {
   Code* GetAndMaybeDeserializeBytecodeHandler(Bytecode bytecode,
                                               OperandScale operand_scale);
 
-  // Return bytecode handler for |bytecode| and |operand_scale|.
-  Code* GetBytecodeHandler(Bytecode bytecode, OperandScale operand_scale);
-
   // Set the bytecode handler for |bytecode| and |operand_scale|.
   void SetBytecodeHandler(Bytecode bytecode, OperandScale operand_scale,
                           Code* handler);
@@ -69,6 +66,10 @@ class Interpreter {
 
   V8_EXPORT_PRIVATE Local<v8::Object> GetDispatchCountersObject();
 
+  void ForEachBytecode(const std::function<void(Bytecode, OperandScale)>& f);
+
+  void InitializeDispatchTable();
+
   bool IsDispatchTableInitialized() const;
 
   Address dispatch_table_address() {
diff --git a/deps/v8/src/interpreter/setup-interpreter-internal.cc b/deps/v8/src/interpreter/setup-interpreter-internal.cc
deleted file mode 100644
index 8f2b565c00..0000000000
--- a/deps/v8/src/interpreter/setup-interpreter-internal.cc
+++ /dev/null
@@ -1,102 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/interpreter/setup-interpreter.h"
-
-#include "src/handles-inl.h"
-#include "src/interpreter/bytecodes.h"
-#include "src/interpreter/interpreter-generator.h"
-#include "src/interpreter/interpreter.h"
-#include "src/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-namespace interpreter {
-
-namespace {
-void PrintBuiltinSize(Bytecode bytecode, OperandScale operand_scale,
-                      Handle<Code> code) {
-  PrintF(stdout, "Ignition Handler, %s, %d\n",
-         Bytecodes::ToString(bytecode, operand_scale).c_str(),
-         code->InstructionSize());
-}
-}  // namespace
-
-// static
-void SetupInterpreter::InstallBytecodeHandlers(Interpreter* interpreter) {
-  DCHECK(!interpreter->IsDispatchTableInitialized());
-  HandleScope scope(interpreter->isolate_);
-  // Canonicalize handles, so that we can share constant pool entries pointing
-  // to code targets without dereferencing their handles.
-  CanonicalHandleScope canonical(interpreter->isolate_);
-  Address* dispatch_table = interpreter->dispatch_table_;
-
-  // Generate bytecode handlers for all bytecodes and scales.
-  const OperandScale kOperandScales[] = {
-#define VALUE(Name, _) OperandScale::k##Name,
-      OPERAND_SCALE_LIST(VALUE)
-#undef VALUE
-  };
-
-  for (OperandScale operand_scale : kOperandScales) {
-#define GENERATE_CODE(Name, ...)                                \
-  InstallBytecodeHandler(interpreter->isolate_, dispatch_table, \
-                         Bytecode::k##Name, operand_scale);
-    BYTECODE_LIST(GENERATE_CODE)
-#undef GENERATE_CODE
-  }
-
-  // Fill unused entries will the illegal bytecode handler.
-  size_t illegal_index = Interpreter::GetDispatchTableIndex(
-      Bytecode::kIllegal, OperandScale::kSingle);
-  for (size_t index = 0; index < Interpreter::kDispatchTableSize; ++index) {
-    if (dispatch_table[index] == kNullAddress) {
-      dispatch_table[index] = dispatch_table[illegal_index];
-    }
-  }
-
-  // Generate the DeserializeLazy handlers, one for each operand scale.
-  Heap* heap = interpreter->isolate_->heap();
-  DCHECK_EQ(Smi::kZero, heap->deserialize_lazy_handler());
-  heap->SetDeserializeLazyHandler(*GenerateDeserializeLazyHandler(
-      interpreter->isolate_, OperandScale::kSingle));
-  DCHECK_EQ(Smi::kZero, heap->deserialize_lazy_handler_wide());
-  heap->SetDeserializeLazyHandlerWide(*GenerateDeserializeLazyHandler(
-      interpreter->isolate_, OperandScale::kDouble));
-  DCHECK_EQ(Smi::kZero, heap->deserialize_lazy_handler_extra_wide());
-  heap->SetDeserializeLazyHandlerExtraWide(*GenerateDeserializeLazyHandler(
-      interpreter->isolate_, OperandScale::kQuadruple));
-
-  // Initialization should have been successful.
-  DCHECK(interpreter->IsDispatchTableInitialized());
-}
-
-// static
-void SetupInterpreter::InstallBytecodeHandler(Isolate* isolate,
-                                              Address* dispatch_table,
-                                              Bytecode bytecode,
-                                              OperandScale operand_scale) {
-  if (!Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) return;
-
-  size_t index = Interpreter::GetDispatchTableIndex(bytecode, operand_scale);
-  // Here we explicitly set the bytecode handler to not be a builtin with an
-  // index of kNoBuiltinId.
-  // TODO(delphick): Use builtins version instead.
-  Handle<Code> code = GenerateBytecodeHandler(isolate, bytecode, operand_scale,
-                                              Builtins::kNoBuiltinId);
-  dispatch_table[index] = code->entry();
-
-  if (FLAG_print_builtin_size) PrintBuiltinSize(bytecode, operand_scale, code);
-
-#ifdef ENABLE_DISASSEMBLER
-  if (FLAG_print_builtin_code) {
-    std::string name = Bytecodes::ToString(bytecode, operand_scale);
-    code->PrintBuiltinCode(isolate, name.c_str());
-  }
-#endif  // ENABLE_DISASSEMBLER
-}
-
-}  // namespace interpreter
-}  // namespace internal
-}  // namespace v8
diff --git a/deps/v8/src/interpreter/setup-interpreter.h b/deps/v8/src/interpreter/setup-interpreter.h
deleted file mode 100644
index 19b03f7f7f..0000000000
--- a/deps/v8/src/interpreter/setup-interpreter.h
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_INTERPRETER_SETUP_INTERPRETER_H_
-#define V8_INTERPRETER_SETUP_INTERPRETER_H_
-
-#include "src/interpreter/bytecode-operands.h"
-#include "src/interpreter/bytecodes.h"
-
-namespace v8 {
-namespace internal {
-namespace interpreter {
-
-class Interpreter;
-
-class SetupInterpreter {
- public:
-  static void InstallBytecodeHandlers(Interpreter* interpreter);
-
- private:
-  // Generates handler for given |bytecode| and |operand_scale|
-  // and installs it into the |dispatch_table|.
-  static void InstallBytecodeHandler(Isolate* isolate, Address* dispatch_table,
-                                     Bytecode bytecode,
-                                     OperandScale operand_scale);
-};
-
-}  // namespace interpreter
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_INTERPRETER_SETUP_INTERPRETER_H_
diff --git a/deps/v8/src/intl.h b/deps/v8/src/intl.h
index 5ec5381f40..a2b393bdaa 100644
--- a/deps/v8/src/intl.h
+++ b/deps/v8/src/intl.h
@@ -23,15 +23,15 @@ class TimeZone;
 namespace v8 {
 namespace internal {
 
-enum class IcuService {
+enum class ICUService {
   kBreakIterator,
   kCollator,
   kDateFormat,
   kNumberFormat,
   kPluralRules,
-  kResourceBundle,
   kRelativeDateTimeFormatter,
-  kListFormatter
+  kListFormatter,
+  kSegmenter
 };
 
 const UChar* GetUCharBufferFromFlat(const String::FlatContent& flat,
diff --git a/deps/v8/src/isolate-inl.h b/deps/v8/src/isolate-inl.h
index 017032c320..dcbe5bea23 100644
--- a/deps/v8/src/isolate-inl.h
+++ b/deps/v8/src/isolate-inl.h
@@ -11,6 +11,12 @@
 namespace v8 {
 namespace internal {
 
+base::AddressRegion Isolate::root_register_addressable_region() {
+  Address start = reinterpret_cast<Address>(this);
+  Address end = heap_.root_register_addressable_end();
+  return base::AddressRegion(start, end - start);
+}
+
 bool Isolate::FromWritableHeapObject(HeapObject* obj, Isolate** isolate) {
   i::MemoryChunk* chunk = i::MemoryChunk::FromHeapObject(obj);
   if (chunk->owner()->identity() == i::RO_SPACE) {
@@ -58,17 +64,6 @@ bool Isolate::has_pending_exception() {
   return !thread_local_top_.pending_exception_->IsTheHole(this);
 }
 
-Object* Isolate::get_wasm_caught_exception() {
-  return thread_local_top_.wasm_caught_exception_;
-}
-
-void Isolate::set_wasm_caught_exception(Object* exception) {
-  thread_local_top_.wasm_caught_exception_ = exception;
-}
-
-void Isolate::clear_wasm_caught_exception() {
-  thread_local_top_.wasm_caught_exception_ = nullptr;
-}
 
 void Isolate::clear_pending_message() {
   thread_local_top_.pending_message_obj_ = ReadOnlyRoots(this).the_hole_value();
@@ -190,6 +185,11 @@ bool Isolate::IsArrayIteratorLookupChainIntact() {
   return array_iterator_cell->value() == Smi::FromInt(kProtectorValid);
 }
 
+bool Isolate::IsStringIteratorLookupChainIntact() {
+  PropertyCell* string_iterator_cell = heap()->string_iterator_protector();
+  return string_iterator_cell->value() == Smi::FromInt(kProtectorValid);
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/isolate.cc b/deps/v8/src/isolate.cc
index eed52d9c19..94033f446b 100644
--- a/deps/v8/src/isolate.cc
+++ b/deps/v8/src/isolate.cc
@@ -15,6 +15,7 @@
 #include "src/assembler-inl.h"
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/context-slot-cache.h"
+#include "src/ast/scopes.h"
 #include "src/base/adapters.h"
 #include "src/base/hashmap.h"
 #include "src/base/platform/platform.h"
@@ -28,6 +29,7 @@
 #include "src/compilation-statistics.h"
 #include "src/compiler-dispatcher/compiler-dispatcher.h"
 #include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
+#include "src/debug/debug-frames.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/elements.h"
@@ -42,8 +44,10 @@
 #include "src/objects/frame-array-inl.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-inl.h"
+#include "src/objects/js-generator-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/profiler/tracing-cpu-profiler.h"
 #include "src/prototype.h"
 #include "src/regexp/regexp-stack.h"
@@ -161,7 +165,6 @@ void ThreadLocalTop::Initialize(Isolate* isolate) {
 }
 
 void ThreadLocalTop::Free() {
-  wasm_caught_exception_ = nullptr;
   // Match unmatched PopPromise calls.
   while (promise_on_stack_) isolate_->PopPromise();
 }
@@ -252,7 +255,6 @@ void Isolate::IterateThread(ThreadVisitor* v, char* t) {
 void Isolate::Iterate(RootVisitor* v, ThreadLocalTop* thread) {
   // Visit the roots from the top for a given thread.
   v->VisitRootPointer(Root::kTop, nullptr, &thread->pending_exception_);
-  v->VisitRootPointer(Root::kTop, nullptr, &thread->wasm_caught_exception_);
   v->VisitRootPointer(Root::kTop, nullptr, &thread->pending_message_obj_);
   v->VisitRootPointer(Root::kTop, nullptr,
                       bit_cast<Object**>(&(thread->context_)));
@@ -409,82 +411,87 @@ class FrameArrayBuilder {
     elements_ = isolate->factory()->NewFrameArray(Min(limit, 10));
   }
 
-  void AppendStandardFrame(StandardFrame* frame) {
-    std::vector<FrameSummary> frames;
-    frame->Summarize(&frames);
-    // A standard frame may include many summarized frames (due to inlining).
-    for (size_t i = frames.size(); i != 0 && !full(); i--) {
-      const auto& summ = frames[i - 1];
-      if (summ.IsJavaScript()) {
-        //====================================================================
-        // Handle a JavaScript frame.
-        //====================================================================
-        const auto& summary = summ.AsJavaScript();
-
-        // Filter out internal frames that we do not want to show.
-        if (!IsVisibleInStackTrace(summary.function())) continue;
-
-        Handle<AbstractCode> abstract_code = summary.abstract_code();
-        const int offset = summary.code_offset();
-
-        bool is_constructor = summary.is_constructor();
-        // Help CallSite::IsConstructor correctly detect hand-written
-        // construct stubs.
-        if (abstract_code->IsCode() &&
-            Code::cast(*abstract_code)->is_construct_stub()) {
-          is_constructor = true;
-        }
+  void AppendAsyncFrame(Handle<JSGeneratorObject> generator_object) {
+    if (full()) return;
+    Handle<JSFunction> function(generator_object->function(), isolate_);
+    if (!IsVisibleInStackTrace(function)) return;
+    int flags = FrameArray::kIsAsync;
+    if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
 
-        int flags = 0;
-        Handle<JSFunction> function = summary.function();
-        if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
-        if (is_constructor) flags |= FrameArray::kIsConstructor;
-
-        elements_ = FrameArray::AppendJSFrame(
-            elements_, TheHoleToUndefined(isolate_, summary.receiver()),
-            function, abstract_code, offset, flags);
-      } else if (summ.IsWasmCompiled()) {
-        //====================================================================
-        // Handle a WASM compiled frame.
-        //====================================================================
-        const auto& summary = summ.AsWasmCompiled();
-        if (summary.code()->kind() != wasm::WasmCode::kFunction) {
-          continue;
-        }
-        Handle<WasmInstanceObject> instance = summary.wasm_instance();
-        int flags = 0;
-        if (instance->module_object()->is_asm_js()) {
-          flags |= FrameArray::kIsAsmJsWasmFrame;
-          if (WasmCompiledFrame::cast(frame)->at_to_number_conversion()) {
-            flags |= FrameArray::kAsmJsAtNumberConversion;
-          }
-        } else {
-          flags |= FrameArray::kIsWasmFrame;
-        }
+    Handle<Object> receiver(generator_object->receiver(), isolate_);
+    Handle<AbstractCode> code(
+        AbstractCode::cast(function->shared()->GetBytecodeArray()), isolate_);
+    int offset = Smi::ToInt(generator_object->input_or_debug_pos());
+    // The stored bytecode offset is relative to a different base than what
+    // is used in the source position table, hence the subtraction.
+    offset -= BytecodeArray::kHeaderSize - kHeapObjectTag;
+    elements_ = FrameArray::AppendJSFrame(elements_, receiver, function, code,
+                                          offset, flags);
+  }
+
+  bool AppendJavaScriptFrame(
+      FrameSummary::JavaScriptFrameSummary const& summary) {
+    // Filter out internal frames that we do not want to show.
+    if (!IsVisibleInStackTrace(summary.function())) return false;
+
+    Handle<AbstractCode> abstract_code = summary.abstract_code();
+    const int offset = summary.code_offset();
+
+    bool is_constructor = summary.is_constructor();
+    // Help CallSite::IsConstructor correctly detect hand-written
+    // construct stubs.
+    if (abstract_code->IsCode() &&
+        Code::cast(*abstract_code)->is_construct_stub()) {
+      is_constructor = true;
+    }
 
-        elements_ = FrameArray::AppendWasmFrame(
-            elements_, instance, summary.function_index(), summary.code(),
-            summary.code_offset(), flags);
-      } else if (summ.IsWasmInterpreted()) {
-        //====================================================================
-        // Handle a WASM interpreted frame.
-        //====================================================================
-        const auto& summary = summ.AsWasmInterpreted();
-        Handle<WasmInstanceObject> instance = summary.wasm_instance();
-        int flags = FrameArray::kIsWasmInterpretedFrame;
-        DCHECK(!instance->module_object()->is_asm_js());
-        elements_ = FrameArray::AppendWasmFrame(elements_, instance,
-                                                summary.function_index(), {},
-                                                summary.byte_offset(), flags);
+    int flags = 0;
+    Handle<JSFunction> function = summary.function();
+    if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
+    if (is_constructor) flags |= FrameArray::kIsConstructor;
+
+    elements_ = FrameArray::AppendJSFrame(
+        elements_, TheHoleToUndefined(isolate_, summary.receiver()), function,
+        abstract_code, offset, flags);
+    return true;
+  }
+
+  bool AppendWasmCompiledFrame(
+      FrameSummary::WasmCompiledFrameSummary const& summary) {
+    if (summary.code()->kind() != wasm::WasmCode::kFunction) return false;
+    Handle<WasmInstanceObject> instance = summary.wasm_instance();
+    int flags = 0;
+    if (instance->module_object()->is_asm_js()) {
+      flags |= FrameArray::kIsAsmJsWasmFrame;
+      if (summary.at_to_number_conversion()) {
+        flags |= FrameArray::kAsmJsAtNumberConversion;
       }
+    } else {
+      flags |= FrameArray::kIsWasmFrame;
     }
+
+    elements_ = FrameArray::AppendWasmFrame(
+        elements_, instance, summary.function_index(), summary.code(),
+        summary.code_offset(), flags);
+    return true;
   }
 
-  void AppendBuiltinExitFrame(BuiltinExitFrame* exit_frame) {
+  bool AppendWasmInterpretedFrame(
+      FrameSummary::WasmInterpretedFrameSummary const& summary) {
+    Handle<WasmInstanceObject> instance = summary.wasm_instance();
+    int flags = FrameArray::kIsWasmInterpretedFrame;
+    DCHECK(!instance->module_object()->is_asm_js());
+    elements_ = FrameArray::AppendWasmFrame(elements_, instance,
+                                            summary.function_index(), {},
+                                            summary.byte_offset(), flags);
+    return true;
+  }
+
+  bool AppendBuiltinExitFrame(BuiltinExitFrame* exit_frame) {
     Handle<JSFunction> function = handle(exit_frame->function(), isolate_);
 
     // Filter out internal frames that we do not want to show.
-    if (!IsVisibleInStackTrace(function)) return;
+    if (!IsVisibleInStackTrace(function)) return false;
 
     Handle<Object> receiver(exit_frame->receiver(), isolate_);
     Handle<Code> code(exit_frame->LookupCode(), isolate_);
@@ -498,6 +505,8 @@ class FrameArrayBuilder {
     elements_ = FrameArray::AppendJSFrame(elements_, receiver, function,
                                           Handle<AbstractCode>::cast(code),
                                           offset, flags);
+
+    return true;
   }
 
   bool full() { return elements_->FrameCount() >= limit_; }
@@ -600,6 +609,89 @@ bool GetStackTraceLimit(Isolate* isolate, int* result) {
 }
 
 bool NoExtension(const v8::FunctionCallbackInfo<v8::Value>&) { return false; }
+
+bool IsBuiltinFunction(Isolate* isolate, HeapObject* object,
+                       Builtins::Name builtin_index) {
+  if (!object->IsJSFunction()) return false;
+  JSFunction* const function = JSFunction::cast(object);
+  return function->code() == isolate->builtins()->builtin(builtin_index);
+}
+
+void CaptureAsyncStackTrace(Isolate* isolate, Handle<JSPromise> promise,
+                            FrameArrayBuilder* builder) {
+  CHECK_EQ(Promise::kPending, promise->status());
+
+  while (!builder->full()) {
+    // Check that we have exactly one PromiseReaction on the {promise}.
+    if (!promise->reactions()->IsPromiseReaction()) return;
+    Handle<PromiseReaction> reaction(
+        PromiseReaction::cast(promise->reactions()), isolate);
+    if (!reaction->next()->IsSmi()) return;
+
+    // Check if the {reaction} has one of the known async function or
+    // async generator continuations as its fulfill handler.
+    if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
+                          Builtins::kAsyncFunctionAwaitResolveClosure) ||
+        IsBuiltinFunction(isolate, reaction->fulfill_handler(),
+                          Builtins::kAsyncGeneratorAwaitResolveClosure) ||
+        IsBuiltinFunction(isolate, reaction->fulfill_handler(),
+                          Builtins::kAsyncGeneratorYieldResolveClosure)) {
+      // Now peak into the handlers' AwaitContext to get to
+      // the JSGeneratorObject for the async function.
+      Handle<Context> context(
+          JSFunction::cast(reaction->fulfill_handler())->context(), isolate);
+      Handle<JSGeneratorObject> generator_object(
+          JSGeneratorObject::cast(context->extension()), isolate);
+      CHECK(generator_object->is_suspended());
+
+      // Append async frame corresponding to the {generator_object}.
+      builder->AppendAsyncFrame(generator_object);
+
+      // Try to continue from here.
+      Handle<JSFunction> function(generator_object->function(), isolate);
+      Handle<SharedFunctionInfo> shared(function->shared(), isolate);
+      if (IsAsyncGeneratorFunction(shared->kind())) {
+        Handle<Object> dot_generator_object(
+            generator_object->parameters_and_registers()->get(
+                DeclarationScope::kGeneratorObjectVarIndex +
+                shared->scope_info()->ParameterCount()),
+            isolate);
+        if (!dot_generator_object->IsJSAsyncGeneratorObject()) return;
+        Handle<JSAsyncGeneratorObject> async_generator_object =
+            Handle<JSAsyncGeneratorObject>::cast(dot_generator_object);
+        Handle<AsyncGeneratorRequest> async_generator_request(
+            AsyncGeneratorRequest::cast(async_generator_object->queue()),
+            isolate);
+        promise = handle(JSPromise::cast(async_generator_request->promise()),
+                         isolate);
+      } else {
+        CHECK(IsAsyncFunction(shared->kind()));
+        Handle<Object> dot_promise(
+            generator_object->parameters_and_registers()->get(
+                DeclarationScope::kPromiseVarIndex +
+                shared->scope_info()->ParameterCount()),
+            isolate);
+        if (!dot_promise->IsJSPromise()) return;
+        promise = Handle<JSPromise>::cast(dot_promise);
+      }
+    } else {
+      // We have some generic promise chain here, so try to
+      // continue with the chained promise on the reaction
+      // (only works for native promise chains).
+      Handle<HeapObject> promise_or_capability(
+          reaction->promise_or_capability(), isolate);
+      if (promise_or_capability->IsJSPromise()) {
+        promise = Handle<JSPromise>::cast(promise_or_capability);
+      } else {
+        Handle<PromiseCapability> capability =
+            Handle<PromiseCapability>::cast(promise_or_capability);
+        if (!capability->promise()->IsJSPromise()) return;
+        promise = handle(JSPromise::cast(capability->promise()), isolate);
+      }
+    }
+  }
+}
+
 }  // namespace
 
 Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSReceiver> error_object,
@@ -612,28 +704,72 @@ Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSReceiver> error_object,
 
   FrameArrayBuilder builder(this, mode, limit, caller);
 
-  for (StackFrameIterator iter(this); !iter.done() && !builder.full();
-       iter.Advance()) {
-    StackFrame* frame = iter.frame();
-
+  // Build the regular stack trace, and remember the last relevant
+  // frame ID and inlined index (for the async stack trace handling
+  // below, which starts from this last frame).
+  int last_frame_index = 0;
+  StackFrame::Id last_frame_id = StackFrame::NO_ID;
+  for (StackFrameIterator it(this); !it.done() && !builder.full();
+       it.Advance()) {
+    StackFrame* const frame = it.frame();
     switch (frame->type()) {
       case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION:
       case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH:
       case StackFrame::OPTIMIZED:
       case StackFrame::INTERPRETED:
       case StackFrame::BUILTIN:
-        builder.AppendStandardFrame(JavaScriptFrame::cast(frame));
+      case StackFrame::WASM_COMPILED:
+      case StackFrame::WASM_INTERPRETER_ENTRY: {
+        // A standard frame may include many summarized frames (due to
+        // inlining).
+        std::vector<FrameSummary> frames;
+        StandardFrame::cast(frame)->Summarize(&frames);
+        for (size_t i = frames.size(); i-- != 0 && !builder.full();) {
+          const auto& summary = frames[i];
+          if (summary.IsJavaScript()) {
+            //====================================================================
+            // Handle a JavaScript frame.
+            //====================================================================
+            auto const& java_script = summary.AsJavaScript();
+            if (builder.AppendJavaScriptFrame(java_script)) {
+              if (IsAsyncFunction(java_script.function()->shared()->kind())) {
+                last_frame_id = frame->id();
+                last_frame_index = static_cast<int>(i);
+              } else {
+                last_frame_id = StackFrame::NO_ID;
+                last_frame_index = 0;
+              }
+            }
+          } else if (summary.IsWasmCompiled()) {
+            //====================================================================
+            // Handle a WASM compiled frame.
+            //====================================================================
+            auto const& wasm_compiled = summary.AsWasmCompiled();
+            if (builder.AppendWasmCompiledFrame(wasm_compiled)) {
+              last_frame_id = StackFrame::NO_ID;
+              last_frame_index = 0;
+            }
+          } else if (summary.IsWasmInterpreted()) {
+            //====================================================================
+            // Handle a WASM interpreted frame.
+            //====================================================================
+            auto const& wasm_interpreted = summary.AsWasmInterpreted();
+            if (builder.AppendWasmInterpretedFrame(wasm_interpreted)) {
+              last_frame_id = StackFrame::NO_ID;
+              last_frame_index = 0;
+            }
+          }
+        }
         break;
+      }
+
       case StackFrame::BUILTIN_EXIT:
         // BuiltinExitFrames are not standard frames, so they do not have
         // Summarize(). However, they may have one JS frame worth showing.
-        builder.AppendBuiltinExitFrame(BuiltinExitFrame::cast(frame));
-        break;
-      case StackFrame::WASM_COMPILED:
-        builder.AppendStandardFrame(WasmCompiledFrame::cast(frame));
-        break;
-      case StackFrame::WASM_INTERPRETER_ENTRY:
-        builder.AppendStandardFrame(WasmInterpreterEntryFrame::cast(frame));
+        if (builder.AppendBuiltinExitFrame(BuiltinExitFrame::cast(frame))) {
+          last_frame_id = StackFrame::NO_ID;
+          last_frame_index = 0;
+        }
         break;
 
       default:
@@ -641,6 +777,55 @@ Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSReceiver> error_object,
     }
   }
 
+  // If --async-stack-traces is enabled, and we ended on a regular JavaScript
+  // frame above, we can enrich the stack trace with async frames (if this
+  // last frame corresponds to an async function).
+  if (FLAG_async_stack_traces && last_frame_id != StackFrame::NO_ID) {
+    StackFrameIterator it(this);
+    while (it.frame()->id() != last_frame_id) it.Advance();
+    FrameInspector inspector(StandardFrame::cast(it.frame()), last_frame_index,
+                             this);
+    FunctionKind const kind = inspector.GetFunction()->shared()->kind();
+    if (IsAsyncGeneratorFunction(kind)) {
+      Handle<Object> const dot_generator_object =
+          inspector.GetExpression(DeclarationScope::kGeneratorObjectVarIndex);
+      if (dot_generator_object->IsUndefined(this)) {
+        // The .generator_object was not yet initialized (i.e. we see a
+        // really early exception in the setup of the async generator).
+      } else {
+        // Check if there's a pending async request on the generator object.
+        Handle<JSAsyncGeneratorObject> async_generator_object =
+            Handle<JSAsyncGeneratorObject>::cast(dot_generator_object);
+        if (!async_generator_object->queue()->IsUndefined(this)) {
+          // Take the promise from the first async generatot request.
+          Handle<AsyncGeneratorRequest> request(
+              AsyncGeneratorRequest::cast(async_generator_object->queue()),
+              this);
+
+          // We can start collecting an async stack trace from the
+          // promise on the {request}.
+          Handle<JSPromise> promise(JSPromise::cast(request->promise()), this);
+          CaptureAsyncStackTrace(this, promise, &builder);
+        }
+      }
+    } else {
+      DCHECK(IsAsyncFunction(kind));
+      Handle<Object> const dot_promise =
+          inspector.GetExpression(DeclarationScope::kPromiseVarIndex);
+      if (dot_promise->IsJSPromise()) {
+        // We can start collecting an async stack trace from .promise here.
+        CaptureAsyncStackTrace(this, Handle<JSPromise>::cast(dot_promise),
+                               &builder);
+      } else {
+        // If .promise was not yet initialized (i.e. we see a really
+        // early exception in the setup of the function), it holds
+        // the value undefined. Sanity check here to make sure that
+        // we're not peaking into the completely wrong stack slot.
+        CHECK(dot_promise->IsUndefined(this));
+      }
+    }
+  }
+
   // TODO(yangguo): Queue this structured stack trace for preprocessing on GC.
   return factory()->NewJSArrayWithElements(builder.GetElements());
 }
@@ -1124,19 +1309,6 @@ void ReportBootstrappingException(Handle<Object> exception,
 #endif
 }
 
-bool Isolate::is_catchable_by_wasm(Object* exception) {
-  // TODO(titzer): thread WASM features here, or just remove this check?
-  if (!FLAG_experimental_wasm_eh) return false;
-  if (!is_catchable_by_javascript(exception) || !exception->IsJSError())
-    return false;
-  HandleScope scope(this);
-  Handle<Object> exception_handle(exception, this);
-  return JSReceiver::HasProperty(Handle<JSReceiver>::cast(exception_handle),
-                                 factory()->InternalizeUtf8String(
-                                     wasm::WasmException::kRuntimeIdStr))
-      .IsJust();
-}
-
 Object* Isolate::Throw(Object* raw_exception, MessageLocation* location) {
   DCHECK(!has_pending_exception());
 
@@ -1310,11 +1482,10 @@ Object* Isolate::UnwindAndFindHandler() {
           trap_handler::ClearThreadInWasm();
         }
 
-        if (!is_catchable_by_wasm(exception)) {
-          break;
-        }
-        int stack_slots = 0;  // Will contain stack slot count of frame.
+        // For WebAssembly frames we perform a lookup in the handler table.
+        if (!catchable_by_js) break;
         WasmCompiledFrame* wasm_frame = static_cast<WasmCompiledFrame*>(frame);
+        int stack_slots = 0;  // Will contain stack slot count of frame.
         int offset = wasm_frame->LookupExceptionHandlerInTable(&stack_slots);
         if (offset < 0) break;
         // Compute the stack pointer from the frame pointer. This ensures that
@@ -1324,10 +1495,10 @@ Object* Isolate::UnwindAndFindHandler() {
                             stack_slots * kPointerSize;
 
         // This is going to be handled by Wasm, so we need to set the TLS flag
-        // again.
+        // again. It was cleared above assuming the frame would be unwound.
         trap_handler::SetThreadInWasm();
 
-        set_wasm_caught_exception(exception);
+        // Gather information from the frame.
         wasm::WasmCode* wasm_code =
             wasm_engine()->code_manager()->LookupCode(frame->pc());
         return FoundHandler(nullptr, wasm_code->instruction_start(), offset,
@@ -2229,9 +2400,16 @@ Handle<Context> Isolate::GetIncumbentContext() {
 
   // 1st candidate: most-recently-entered author function's context
   // if it's newer than the last Context::BackupIncumbentScope entry.
-  if (!it.done() &&
-      static_cast<const void*>(it.frame()) >
-          static_cast<const void*>(top_backup_incumbent_scope())) {
+  //
+  // NOTE: This code assumes that the stack grows downward.
+  // This code doesn't work with ASAN because ASAN seems allocating stack
+  // separated for native C++ code and compiled JS code, and the following
+  // comparison doesn't make sense in ASAN.
+  // TODO(yukishiino): Make the implementation of BackupIncumbentScope more
+  // robust.
+  if (!it.done() && (!top_backup_incumbent_scope() ||
+                     it.frame()->sp() < reinterpret_cast<Address>(
+                                            top_backup_incumbent_scope()))) {
     Context* context = Context::cast(it.frame()->context());
     return Handle<Context>(context->native_context(), this);
   }
@@ -2274,10 +2452,6 @@ char* Isolate::RestoreThread(char* from) {
   return from + sizeof(ThreadLocalTop);
 }
 
-Isolate::ThreadDataTable::ThreadDataTable() : table_() {}
-
-Isolate::ThreadDataTable::~ThreadDataTable() {}
-
 void Isolate::ReleaseSharedPtrs() {
   while (managed_ptr_destructors_head_) {
     ManagedPtrDestructor* l = managed_ptr_destructors_head_;
@@ -2313,6 +2487,14 @@ void Isolate::UnregisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
   destructor->next_ = nullptr;
 }
 
+void Isolate::SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine) {
+  DCHECK_NULL(wasm_engine_);  // Only call once before {Init}.
+  wasm_engine_ = std::move(engine);
+  wasm_engine_->AddIsolate(this);
+  wasm::WasmCodeManager::InstallSamplingGCCallback(this);
+}
+
+// NOLINTNEXTLINE
 Isolate::PerIsolateThreadData::~PerIsolateThreadData() {
 #if defined(USE_SIMULATOR)
   delete simulator_;
@@ -2483,9 +2665,11 @@ Isolate::Isolate()
       host_initialize_import_meta_object_callback_(nullptr),
       load_start_time_ms_(0),
 #ifdef V8_INTL_SUPPORT
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
       language_singleton_regexp_matcher_(nullptr),
       language_tag_regexp_matcher_(nullptr),
       language_variant_regexp_matcher_(nullptr),
+#endif  // USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
       default_locale_(""),
 #endif  // V8_INTL_SUPPORT
       serializer_enabled_(false),
@@ -2543,9 +2727,7 @@ Isolate::Isolate()
   InitializeLoggingAndCounters();
   debug_ = new Debug(this);
 
-  tracing_cpu_profiler_.reset(new TracingCpuProfilerImpl(this));
-
-  init_memcopy_functions(this);
+  init_memcopy_functions();
 
   if (FLAG_embedded_builtins) {
 #ifdef V8_MULTI_SNAPSHOTS
@@ -2602,20 +2784,27 @@ void Isolate::ClearSerializerData() {
   external_reference_map_ = nullptr;
 }
 
+bool Isolate::LogObjectRelocation() {
+  return FLAG_verify_predictable || logger()->is_logging() || is_profiling() ||
+         heap()->isolate()->logger()->is_listening_to_code_events() ||
+         (heap_profiler() != nullptr &&
+          heap_profiler()->is_tracking_object_moves()) ||
+         heap()->has_heap_object_allocation_tracker();
+}
 
 void Isolate::Deinit() {
   TRACE_ISOLATE(deinit);
 
   debug()->Unload();
 
+  wasm_engine()->DeleteCompileJobsOnIsolate(this);
+
   if (concurrent_recompilation_enabled()) {
     optimizing_compile_dispatcher_->Stop();
     delete optimizing_compile_dispatcher_;
     optimizing_compile_dispatcher_ = nullptr;
   }
 
-  wasm_engine()->DeleteCompileJobsOnIsolate(this);
-
   heap_.mark_compact_collector()->EnsureSweepingCompleted();
   heap_.memory_allocator()->unmapper()->EnsureUnmappingCompleted();
 
@@ -2661,7 +2850,10 @@ void Isolate::Deinit() {
   heap_.TearDown();
   logger_->TearDown();
 
-  wasm_engine_.reset();
+  if (wasm_engine_) {
+    wasm_engine_->RemoveIsolate(this);
+    wasm_engine_.reset();
+  }
 
   if (FLAG_embedded_builtins) {
     if (DefaultEmbeddedBlob() == nullptr && embedded_blob() != nullptr) {
@@ -2683,6 +2875,10 @@ void Isolate::Deinit() {
   delete root_index_map_;
   root_index_map_ = nullptr;
 
+  delete compiler_zone_;
+  compiler_zone_ = nullptr;
+  compiler_cache_ = nullptr;
+
   ClearSerializerData();
 }
 
@@ -2710,6 +2906,7 @@ Isolate::~Isolate() {
   date_cache_ = nullptr;
 
 #ifdef V8_INTL_SUPPORT
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
   delete language_singleton_regexp_matcher_;
   language_singleton_regexp_matcher_ = nullptr;
 
@@ -2718,6 +2915,7 @@ Isolate::~Isolate() {
 
   delete language_variant_regexp_matcher_;
   language_variant_regexp_matcher_ = nullptr;
+#endif  // USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
 #endif  // V8_INTL_SUPPORT
 
   delete regexp_stack_;
@@ -2958,6 +3156,7 @@ bool Isolate::Init(StartupDeserializer* des) {
   date_cache_ = new DateCache();
   heap_profiler_ = new HeapProfiler(heap());
   interpreter_ = new interpreter::Interpreter(this);
+
   compiler_dispatcher_ =
       new CompilerDispatcher(this, V8::GetCurrentPlatform(), FLAG_stack_size);
 
@@ -2978,9 +3177,9 @@ bool Isolate::Init(StartupDeserializer* des) {
 
   // Setup the wasm engine.
   if (wasm_engine_ == nullptr) {
-    wasm_engine_ = wasm::WasmEngine::GetWasmEngine();
-    wasm::WasmCodeManager::InstallSamplingGCCallback(this);
+    SetWasmEngine(wasm::WasmEngine::GetWasmEngine());
   }
+  DCHECK_NOT_NULL(wasm_engine_);
 
   deoptimizer_data_ = new DeoptimizerData(heap());
 
@@ -3001,6 +3200,10 @@ bool Isolate::Init(StartupDeserializer* des) {
 
   InitializeThreadLocal();
 
+  // Profiler has to be created after ThreadLocal is initialized
+  // because it makes use of interrupts.
+  tracing_cpu_profiler_.reset(new TracingCpuProfilerImpl(this));
+
   bootstrapper_->Initialize(create_heap_objects);
 
   if (FLAG_embedded_builtins) {
@@ -3042,8 +3245,7 @@ bool Isolate::Init(StartupDeserializer* des) {
     if (!create_heap_objects) des->DeserializeInto(this);
     load_stub_cache_->Initialize();
     store_stub_cache_->Initialize();
-    setup_delegate_->SetupInterpreter(interpreter_);
-
+    interpreter_->InitializeDispatchTable();
     heap_.NotifyDeserializationComplete();
   }
   delete setup_delegate_;
@@ -3069,7 +3271,7 @@ bool Isolate::Init(StartupDeserializer* des) {
 
   if (FLAG_trace_turbo) {
     // Create an empty file.
-    std::ofstream(GetTurboCfgFileName().c_str(), std::ios_base::trunc);
+    std::ofstream(GetTurboCfgFileName(this).c_str(), std::ios_base::trunc);
   }
 
   CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, embedder_data_)),
@@ -3227,6 +3429,8 @@ void Isolate::DumpAndResetStats() {
   }
   if (V8_UNLIKELY(FLAG_runtime_stats ==
                   v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE)) {
+    counters()->worker_thread_runtime_call_stats()->AddToMainTable(
+        counters()->runtime_call_stats());
     counters()->runtime_call_stats()->Print();
     counters()->runtime_call_stats()->Reset();
   }
@@ -3257,8 +3461,7 @@ bool Isolate::use_optimizer() {
 }
 
 bool Isolate::NeedsDetailedOptimizedCodeLineInfo() const {
-  return NeedsSourcePositionsForProfiling() ||
-         detailed_source_positions_for_profiling();
+  return NeedsSourcePositionsForProfiling() || FLAG_detailed_line_info;
 }
 
 bool Isolate::NeedsSourcePositionsForProfiling() const {
@@ -3552,6 +3755,15 @@ void Isolate::InvalidateArrayIteratorProtector() {
   DCHECK(!IsArrayIteratorLookupChainIntact());
 }
 
+void Isolate::InvalidateStringIteratorProtector() {
+  DCHECK(factory()->string_iterator_protector()->value()->IsSmi());
+  DCHECK(IsStringIteratorLookupChainIntact());
+  PropertyCell::SetValueWithInvalidation(
+      this, factory()->string_iterator_protector(),
+      handle(Smi::FromInt(kProtectorInvalid), this));
+  DCHECK(!IsStringIteratorLookupChainIntact());
+}
+
 void Isolate::InvalidateArrayBufferNeuteringProtector() {
   DCHECK(factory()->array_buffer_neutering_protector()->value()->IsSmi());
   DCHECK(IsArrayBufferNeuteringIntact());
@@ -3643,7 +3855,7 @@ ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
-Handle<Symbol> Isolate::SymbolFor(Heap::RootListIndex dictionary_index,
+Handle<Symbol> Isolate::SymbolFor(RootIndex dictionary_index,
                                   Handle<String> name, bool private_symbol) {
   Handle<String> key = factory()->InternalizeString(name);
   Handle<NameDictionary> dictionary =
@@ -3657,14 +3869,14 @@ Handle<Symbol> Isolate::SymbolFor(Heap::RootListIndex dictionary_index,
     dictionary = NameDictionary::Add(this, dictionary, key, symbol,
                                      PropertyDetails::Empty(), &entry);
     switch (dictionary_index) {
-      case Heap::kPublicSymbolTableRootIndex:
+      case RootIndex::kPublicSymbolTable:
         symbol->set_is_public(true);
         heap()->set_public_symbol_table(*dictionary);
         break;
-      case Heap::kApiSymbolTableRootIndex:
+      case RootIndex::kApiSymbolTable:
         heap()->set_api_symbol_table(*dictionary);
         break;
-      case Heap::kApiPrivateSymbolTableRootIndex:
+      case RootIndex::kApiPrivateSymbolTable:
         heap()->set_api_private_symbol_table(*dictionary);
         break;
       default:
@@ -3725,7 +3937,7 @@ void Isolate::FireCallCompletedCallback() {
   if (!handle_scope_implementer()->CallDepthIsZero()) return;
 
   bool run_microtasks =
-      pending_microtask_count() &&
+      heap()->default_microtask_queue()->pending_microtask_count() &&
       !handle_scope_implementer()->HasMicrotasksSuppressions() &&
       handle_scope_implementer()->microtasks_policy() ==
           v8::MicrotasksPolicy::kAuto;
@@ -3829,6 +4041,29 @@ void Isolate::SetHostInitializeImportMetaObjectCallback(
   host_initialize_import_meta_object_callback_ = callback;
 }
 
+MaybeHandle<Object> Isolate::RunPrepareStackTraceCallback(
+    Handle<Context> context, Handle<JSObject> error) {
+  v8::Local<v8::Context> api_context = Utils::ToLocal(context);
+
+  v8::Local<StackTrace> trace =
+      Utils::StackTraceToLocal(GetDetailedStackTrace(error));
+
+  v8::Local<v8::Value> stack;
+  ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
+      this, stack,
+      prepare_stack_trace_callback_(api_context, Utils::ToLocal(error), trace),
+      MaybeHandle<Object>());
+  return Utils::OpenHandle(*stack);
+}
+
+void Isolate::SetPrepareStackTraceCallback(PrepareStackTraceCallback callback) {
+  prepare_stack_trace_callback_ = callback;
+}
+
+bool Isolate::HasPrepareStackTraceCallback() const {
+  return prepare_stack_trace_callback_ != nullptr;
+}
+
 void Isolate::SetAtomicsWaitCallback(v8::Isolate::AtomicsWaitCallback callback,
                                      void* data) {
   atomics_wait_callback_ = callback;
@@ -3945,18 +4180,9 @@ void Isolate::ReportPromiseReject(Handle<JSPromise> promise,
 }
 
 void Isolate::EnqueueMicrotask(Handle<Microtask> microtask) {
-  Handle<FixedArray> queue(heap()->microtask_queue(), this);
-  int num_tasks = pending_microtask_count();
-  DCHECK_LE(num_tasks, queue->length());
-  if (num_tasks == queue->length()) {
-    queue = factory()->CopyFixedArrayAndGrow(queue, std::max(num_tasks, 8));
-    heap()->set_microtask_queue(*queue);
-  }
-  DCHECK_LE(8, queue->length());
-  DCHECK_LT(num_tasks, queue->length());
-  DCHECK(queue->get(num_tasks)->IsUndefined(this));
-  queue->set(num_tasks, *microtask);
-  set_pending_microtask_count(num_tasks + 1);
+  Handle<MicrotaskQueue> microtask_queue(heap()->default_microtask_queue(),
+                                         this);
+  MicrotaskQueue::EnqueueMicrotask(this, microtask_queue, microtask);
 }
 
 
@@ -3964,25 +4190,27 @@ void Isolate::RunMicrotasks() {
   // Increase call depth to prevent recursive callbacks.
   v8::Isolate::SuppressMicrotaskExecutionScope suppress(
       reinterpret_cast<v8::Isolate*>(this));
-  if (pending_microtask_count()) {
+  HandleScope scope(this);
+  Handle<MicrotaskQueue> microtask_queue(heap()->default_microtask_queue(),
+                                         this);
+  if (microtask_queue->pending_microtask_count()) {
     is_running_microtasks_ = true;
     TRACE_EVENT0("v8.execute", "RunMicrotasks");
     TRACE_EVENT_CALL_STATS_SCOPED(this, "v8", "V8.RunMicrotasks");
 
-    HandleScope scope(this);
     MaybeHandle<Object> maybe_exception;
     MaybeHandle<Object> maybe_result = Execution::RunMicrotasks(
         this, Execution::MessageHandling::kReport, &maybe_exception);
     // If execution is terminating, bail out, clean up, and propagate to
     // TryCatch scope.
     if (maybe_result.is_null() && maybe_exception.is_null()) {
-      heap()->set_microtask_queue(ReadOnlyRoots(heap()).empty_fixed_array());
-      set_pending_microtask_count(0);
+      microtask_queue->set_queue(ReadOnlyRoots(heap()).empty_fixed_array());
+      microtask_queue->set_pending_microtask_count(0);
       handle_scope_implementer()->LeaveMicrotaskContext();
       SetTerminationOnExternalTryCatch();
     }
-    CHECK_EQ(0, pending_microtask_count());
-    CHECK_EQ(0, heap()->microtask_queue()->length());
+    CHECK_EQ(0, microtask_queue->pending_microtask_count());
+    CHECK_EQ(0, microtask_queue->queue()->length());
     is_running_microtasks_ = false;
   }
   FireMicrotasksCompletedCallback();
@@ -4007,10 +4235,17 @@ void Isolate::CountUsage(v8::Isolate::UseCounterFeature feature) {
   }
 }
 
-std::string Isolate::GetTurboCfgFileName() {
+// static
+std::string Isolate::GetTurboCfgFileName(Isolate* isolate) {
   if (FLAG_trace_turbo_cfg_file == nullptr) {
     std::ostringstream os;
-    os << "turbo-" << base::OS::GetCurrentProcessId() << "-" << id() << ".cfg";
+    os << "turbo-" << base::OS::GetCurrentProcessId() << "-";
+    if (isolate != nullptr) {
+      os << isolate->id();
+    } else {
+      os << "any";
+    }
+    os << ".cfg";
     return os.str();
   } else {
     return FLAG_trace_turbo_cfg_file;
@@ -4037,10 +4272,10 @@ void Isolate::CheckDetachedContextsAfterGC() {
   if (length == 0) return;
   int new_length = 0;
   for (int i = 0; i < length; i += 2) {
-    int mark_sweeps = Smi::ToInt(detached_contexts->Get(i)->ToSmi());
+    int mark_sweeps = Smi::ToInt(detached_contexts->Get(i)->cast<Smi>());
     MaybeObject* context = detached_contexts->Get(i + 1);
-    DCHECK(context->IsWeakHeapObject() || context->IsClearedWeakHeapObject());
-    if (!context->IsClearedWeakHeapObject()) {
+    DCHECK(context->IsWeakOrCleared());
+    if (!context->IsCleared()) {
       detached_contexts->Set(
           new_length, MaybeObject::FromSmi(Smi::FromInt(mark_sweeps + 1)));
       detached_contexts->Set(new_length + 1, context);
@@ -4057,9 +4292,9 @@ void Isolate::CheckDetachedContextsAfterGC() {
     PrintF("%d detached contexts are collected out of %d\n",
            length - new_length, length);
     for (int i = 0; i < new_length; i += 2) {
-      int mark_sweeps = Smi::ToInt(detached_contexts->Get(i)->ToSmi());
+      int mark_sweeps = Smi::ToInt(detached_contexts->Get(i)->cast<Smi>());
       MaybeObject* context = detached_contexts->Get(i + 1);
-      DCHECK(context->IsWeakHeapObject() || context->IsClearedWeakHeapObject());
+      DCHECK(context->IsWeakOrCleared());
       if (mark_sweeps > 3) {
         PrintF("detached context %p\n survived %d GCs (leak?)\n",
                static_cast<void*>(context), mark_sweeps);
diff --git a/deps/v8/src/isolate.h b/deps/v8/src/isolate.h
index efd479c41e..ad124586cc 100644
--- a/deps/v8/src/isolate.h
+++ b/deps/v8/src/isolate.h
@@ -12,6 +12,7 @@
 #include <vector>
 
 #include "include/v8-inspector.h"
+#include "include/v8-internal.h"
 #include "include/v8.h"
 #include "src/allocation.h"
 #include "src/base/atomicops.h"
@@ -58,42 +59,32 @@ namespace heap {
 class HeapTester;
 }  // namespace heap
 
-class AccessCompilerData;
 class AddressToIndexHashMap;
 class AstStringConstants;
 class Bootstrapper;
 class BuiltinsConstantsTableBuilder;
 class CancelableTaskManager;
 class CodeEventDispatcher;
-class ExternalCodeEventListener;
-class CodeGenerator;
-class CodeRange;
-class CodeStubDescriptor;
 class CodeTracer;
 class CompilationCache;
 class CompilationStatistics;
 class CompilerDispatcher;
 class ContextSlotCache;
 class Counters;
-class CpuFeatures;
 class Debug;
 class DeoptimizerData;
 class DescriptorLookupCache;
-class EmptyStatement;
 class EternalHandles;
 class ExternalCallbackScope;
 class HandleScopeImplementer;
 class HeapObjectToIndexHashMap;
 class HeapProfiler;
-class InlineRuntimeFunctionsTable;
 class InnerPointerToCodeCache;
-class InstructionStream;
 class Logger;
 class MaterializedObjectStore;
 class Microtask;
 class OptimizingCompileDispatcher;
 class PromiseOnStack;
-class Redirection;
 class RegExpStack;
 class RootVisitor;
 class RuntimeProfiler;
@@ -102,10 +93,7 @@ class SetupIsolateDelegate;
 class Simulator;
 class StartupDeserializer;
 class StandardFrame;
-class StatsTable;
-class StringTracker;
 class StubCache;
-class SweeperThread;
 class ThreadManager;
 class ThreadState;
 class ThreadVisitor;  // Defined in v8threads.h
@@ -119,6 +107,10 @@ namespace interpreter {
 class Interpreter;
 }
 
+namespace compiler {
+class PerIsolateCompilerCache;
+}
+
 namespace wasm {
 class WasmEngine;
 }
@@ -395,8 +387,7 @@ class ThreadId {
   inline void set_##name(type v) { name##_ = v; }  \
   inline type name() const { return name##_; }
 
-
-class ThreadLocalTop BASE_EMBEDDED {
+class ThreadLocalTop {
  public:
   // Does early low-level initialization that does not depend on the
   // isolate being present.
@@ -435,9 +426,6 @@ class ThreadLocalTop BASE_EMBEDDED {
   Context* context_ = nullptr;
   ThreadId thread_id_ = ThreadId::Invalid();
   Object* pending_exception_ = nullptr;
-  // TODO(kschimpf): Change this to a stack of caught exceptions (rather than
-  // just innermost catching try block).
-  Object* wasm_caught_exception_ = nullptr;
 
   // Communication channel between Isolate::FindHandler and the CEntry.
   Context* pending_handler_context_ = nullptr;
@@ -531,7 +519,6 @@ typedef std::vector<HeapObject*> DebugObjectCache;
   V(const intptr_t*, api_external_references, nullptr)                        \
   V(AddressToIndexHashMap*, external_reference_map, nullptr)                  \
   V(HeapObjectToIndexHashMap*, root_index_map, nullptr)                       \
-  V(int, pending_microtask_count, 0)                                          \
   V(CompilationStatistics*, turbo_statistics, nullptr)                        \
   V(CodeTracer*, code_tracer, nullptr)                                        \
   V(uint32_t, per_isolate_assert_data, 0xFFFFFFFFu)                           \
@@ -553,8 +540,7 @@ typedef std::vector<HeapObject*> DebugObjectCache;
   V(int, last_console_context_id, 0)                                          \
   V(v8_inspector::V8Inspector*, inspector, nullptr)                           \
   V(bool, next_v8_call_is_safe_for_termination, false)                        \
-  V(bool, only_terminate_in_safe_scope, false)                                \
-  V(bool, detailed_source_positions_for_profiling, FLAG_detailed_line_info)
+  V(bool, only_terminate_in_safe_scope, false)
 
 #define THREAD_LOCAL_TOP_ACCESSOR(type, name)                        \
   inline void set_##name(type v) { thread_local_top_.name##_ = v; }  \
@@ -671,6 +657,8 @@ class Isolate : private HiddenFactory {
 
   void ClearSerializerData();
 
+  bool LogObjectRelocation();
+
   // Find the PerThread for this particular (isolate, thread) combination
   // If one does not yet exist, return null.
   PerIsolateThreadData* FindPerThreadDataForThisThread();
@@ -717,11 +705,6 @@ class Isolate : private HiddenFactory {
   inline void set_pending_exception(Object* exception_obj);
   inline void clear_pending_exception();
 
-  // Interface to wasm caught exception.
-  inline Object* get_wasm_caught_exception();
-  inline void set_wasm_caught_exception(Object* exception);
-  inline void clear_wasm_caught_exception();
-
   bool AreWasmThreadsEnabled(Handle<Context> context);
 
   THREAD_LOCAL_TOP_ADDRESS(Object*, pending_exception)
@@ -758,7 +741,6 @@ class Isolate : private HiddenFactory {
   bool IsExternalHandlerOnTop(Object* exception);
 
   inline bool is_catchable_by_javascript(Object* exception);
-  bool is_catchable_by_wasm(Object* exception);
 
   // JS execution stack (see frames.h).
   static Address c_entry_fp(ThreadLocalTop* thread) {
@@ -1016,6 +998,12 @@ class Isolate : private HiddenFactory {
   }
   StackGuard* stack_guard() { return &stack_guard_; }
   Heap* heap() { return &heap_; }
+
+  // kRootRegister may be used to address any location that falls into this
+  // region. Fields outside this region are not guaranteed to live at a static
+  // offset from kRootRegister.
+  inline base::AddressRegion root_register_addressable_region();
+
   StubCache* load_stub_cache() { return load_stub_cache_; }
   StubCache* store_stub_cache() { return store_stub_cache_; }
   DeoptimizerData* deoptimizer_data() { return deoptimizer_data_; }
@@ -1103,6 +1091,7 @@ class Isolate : private HiddenFactory {
   v8::internal::Factory* factory() {
     // Upcast to the privately inherited base-class using c-style casts to avoid
     // undefined behavior (as static_cast cannot cast across private bases).
+    // NOLINTNEXTLINE (google-readability-casting)
     return (v8::internal::Factory*)this;  // NOLINT(readability/casting)
   }
 
@@ -1193,6 +1182,7 @@ class Isolate : private HiddenFactory {
   }
 
 #ifdef V8_INTL_SUPPORT
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
   icu::RegexMatcher* language_singleton_regexp_matcher() {
     return language_singleton_regexp_matcher_;
   }
@@ -1204,6 +1194,7 @@ class Isolate : private HiddenFactory {
   icu::RegexMatcher* language_variant_regexp_matcher() {
     return language_variant_regexp_matcher_;
   }
+#endif  // USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
 
   const std::string& default_locale() { return default_locale_; }
 
@@ -1212,6 +1203,7 @@ class Isolate : private HiddenFactory {
     default_locale_ = locale;
   }
 
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
   void set_language_tag_regexp_matchers(
       icu::RegexMatcher* language_singleton_regexp_matcher,
       icu::RegexMatcher* language_tag_regexp_matcher,
@@ -1223,6 +1215,7 @@ class Isolate : private HiddenFactory {
     language_tag_regexp_matcher_ = language_tag_regexp_matcher;
     language_variant_regexp_matcher_ = language_variant_regexp_matcher;
   }
+#endif  // USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
 #endif  // V8_INTL_SUPPORT
 
   static const int kProtectorValid = 1;
@@ -1244,6 +1237,18 @@ class Isolate : private HiddenFactory {
   inline bool IsStringLengthOverflowIntact();
   inline bool IsArrayIteratorLookupChainIntact();
 
+  // The StringIteratorProtector protects the original string iterating behavior
+  // for primitive strings. As long as the StringIteratorProtector is valid,
+  // iterating over a primitive string is guaranteed to be unobservable from
+  // user code and can thus be cut short. More specifically, the protector gets
+  // invalidated as soon as either String.prototype[Symbol.iterator] or
+  // String.prototype[Symbol.iterator]().next is modified. This guarantee does
+  // not apply to string objects (as opposed to primitives), since they could
+  // define their own Symbol.iterator.
+  // String.prototype itself does not need to be protected, since it is
+  // non-configurable and non-writable.
+  inline bool IsStringIteratorLookupChainIntact();
+
   // Make sure we do check for neutered array buffers.
   inline bool IsArrayBufferNeuteringIntact();
 
@@ -1284,6 +1289,7 @@ class Isolate : private HiddenFactory {
   void InvalidateIsConcatSpreadableProtector();
   void InvalidateStringLengthOverflowProtector();
   void InvalidateArrayIteratorProtector();
+  void InvalidateStringIteratorProtector();
   void InvalidateArrayBufferNeuteringProtector();
   V8_EXPORT_PRIVATE void InvalidatePromiseHookProtector();
   void InvalidatePromiseResolveProtector();
@@ -1332,6 +1338,10 @@ class Isolate : private HiddenFactory {
   bool force_slow_path() const { return force_slow_path_; }
   bool* force_slow_path_address() { return &force_slow_path_; }
 
+  DebugInfo::ExecutionMode* debug_execution_mode_address() {
+    return &debug_execution_mode_;
+  }
+
   V8_EXPORT_PRIVATE base::RandomNumberGenerator* random_number_generator();
 
   V8_EXPORT_PRIVATE base::RandomNumberGenerator* fuzzer_rng();
@@ -1374,13 +1384,13 @@ class Isolate : private HiddenFactory {
   void RunMicrotasks();
   bool IsRunningMicrotasks() const { return is_running_microtasks_; }
 
-  Handle<Symbol> SymbolFor(Heap::RootListIndex dictionary_index,
-                           Handle<String> name, bool private_symbol);
+  Handle<Symbol> SymbolFor(RootIndex dictionary_index, Handle<String> name,
+                           bool private_symbol);
 
   void SetUseCounterCallback(v8::Isolate::UseCounterCallback callback);
   void CountUsage(v8::Isolate::UseCounterFeature feature);
 
-  std::string GetTurboCfgFileName();
+  static std::string GetTurboCfgFileName(Isolate* isolate);
 
 #if V8_SFI_HAS_UNIQUE_ID
   int GetNextUniqueSharedFunctionInfoId() { return next_unique_sfi_id_++; }
@@ -1398,10 +1408,6 @@ class Isolate : private HiddenFactory {
     return reinterpret_cast<Address>(&promise_hook_or_async_event_delegate_);
   }
 
-  Address pending_microtask_count_address() {
-    return reinterpret_cast<Address>(&pending_microtask_count_);
-  }
-
   Address handle_scope_implementer_address() {
     return reinterpret_cast<Address>(&handle_scope_implementer_);
   }
@@ -1472,6 +1478,15 @@ class Isolate : private HiddenFactory {
 
   interpreter::Interpreter* interpreter() const { return interpreter_; }
 
+  compiler::PerIsolateCompilerCache* compiler_cache() const {
+    return compiler_cache_;
+  }
+  void set_compiler_utils(compiler::PerIsolateCompilerCache* cache,
+                          Zone* zone) {
+    compiler_cache_ = cache;
+    compiler_zone_ = zone;
+  }
+
   AccountingAllocator* allocator() { return allocator_; }
 
   CompilerDispatcher* compiler_dispatcher() const {
@@ -1490,6 +1505,11 @@ class Isolate : private HiddenFactory {
   Handle<JSObject> RunHostInitializeImportMetaObjectCallback(
       Handle<Module> module);
 
+  void SetPrepareStackTraceCallback(PrepareStackTraceCallback callback);
+  MaybeHandle<Object> RunPrepareStackTraceCallback(Handle<Context>,
+                                                   Handle<JSObject> Error);
+  bool HasPrepareStackTraceCallback() const;
+
   void SetRAILMode(RAILMode rail_mode);
 
   RAILMode rail_mode() { return rail_mode_.Value(); }
@@ -1525,10 +1545,7 @@ class Isolate : private HiddenFactory {
   }
 
   wasm::WasmEngine* wasm_engine() const { return wasm_engine_.get(); }
-  void set_wasm_engine(std::shared_ptr<wasm::WasmEngine> engine) {
-    DCHECK_NULL(wasm_engine_);  // Only call once before {Init}.
-    wasm_engine_ = std::move(engine);
-  }
+  void SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine);
 
   const v8::Context::BackupIncumbentScope* top_backup_incumbent_scope() const {
     return top_backup_incumbent_scope_;
@@ -1556,8 +1573,7 @@ class Isolate : private HiddenFactory {
 
   class ThreadDataTable {
    public:
-    ThreadDataTable();
-    ~ThreadDataTable();
+    ThreadDataTable() = default;
 
     PerIsolateThreadData* Lookup(ThreadId thread_id);
     void Insert(PerIsolateThreadData* data);
@@ -1718,9 +1734,11 @@ class Isolate : private HiddenFactory {
   double load_start_time_ms_;
 
 #ifdef V8_INTL_SUPPORT
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
   icu::RegexMatcher* language_singleton_regexp_matcher_;
   icu::RegexMatcher* language_tag_regexp_matcher_;
   icu::RegexMatcher* language_variant_regexp_matcher_;
+#endif  // USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
   std::string default_locale_;
 #endif  // V8_INTL_SUPPORT
 
@@ -1762,6 +1780,9 @@ class Isolate : private HiddenFactory {
 
   interpreter::Interpreter* interpreter_;
 
+  compiler::PerIsolateCompilerCache* compiler_cache_ = nullptr;
+  Zone* compiler_zone_ = nullptr;
+
   CompilerDispatcher* compiler_dispatcher_;
 
   typedef std::pair<InterruptCallback, void*> InterruptEntry;
@@ -1856,6 +1877,8 @@ class Isolate : private HiddenFactory {
   const v8::Context::BackupIncumbentScope* top_backup_incumbent_scope_ =
       nullptr;
 
+  PrepareStackTraceCallback prepare_stack_trace_callback_ = nullptr;
+
   // TODO(kenton@cloudflare.com): This mutex can be removed if
   // thread_data_table_ is always accessed under the isolate lock. I do not
   // know if this is the case, so I'm preserving it for now.
@@ -1901,7 +1924,7 @@ class PromiseOnStack {
 // If the GCC version is 4.1.x or 4.2.x an additional field is added to the
 // class as a work around for a bug in the generated code found with these
 // versions of GCC. See V8 issue 122 for details.
-class SaveContext BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE SaveContext {
  public:
   explicit SaveContext(Isolate* isolate);
   ~SaveContext();
@@ -1919,8 +1942,7 @@ class SaveContext BASE_EMBEDDED {
   Address c_entry_fp_;
 };
 
-
-class AssertNoContextChange BASE_EMBEDDED {
+class AssertNoContextChange {
 #ifdef DEBUG
  public:
   explicit AssertNoContextChange(Isolate* isolate);
@@ -1937,8 +1959,7 @@ class AssertNoContextChange BASE_EMBEDDED {
 #endif
 };
 
-
-class ExecutionAccess BASE_EMBEDDED {
+class ExecutionAccess {
  public:
   explicit ExecutionAccess(Isolate* isolate) : isolate_(isolate) {
     Lock(isolate);
@@ -1958,7 +1979,7 @@ class ExecutionAccess BASE_EMBEDDED {
 
 
 // Support for checking for stack-overflows.
-class StackLimitCheck BASE_EMBEDDED {
+class StackLimitCheck {
  public:
   explicit StackLimitCheck(Isolate* isolate) : isolate_(isolate) { }
 
@@ -2034,7 +2055,7 @@ class PostponeInterruptsScope : public InterruptsScope {
                           int intercept_mask = StackGuard::ALL_INTERRUPTS)
       : InterruptsScope(isolate, intercept_mask,
                         InterruptsScope::kPostponeInterrupts) {}
-  virtual ~PostponeInterruptsScope() = default;
+  ~PostponeInterruptsScope() override = default;
 };
 
 // Support for overriding PostponeInterruptsScope. Interrupt is not ignored if
@@ -2046,7 +2067,7 @@ class SafeForInterruptsScope : public InterruptsScope {
                          int intercept_mask = StackGuard::ALL_INTERRUPTS)
       : InterruptsScope(isolate, intercept_mask,
                         InterruptsScope::kRunInterrupts) {}
-  virtual ~SafeForInterruptsScope() = default;
+  ~SafeForInterruptsScope() override = default;
 };
 
 class StackTraceFailureMessage {
diff --git a/deps/v8/src/js/array.js b/deps/v8/src/js/array.js
index fe02afceea..16b140bb38 100644
--- a/deps/v8/src/js/array.js
+++ b/deps/v8/src/js/array.js
@@ -13,19 +13,12 @@
 
 var GlobalArray = global.Array;
 var InternalArray = utils.InternalArray;
-var MathMax = global.Math.max;
-var MathMin = global.Math.min;
-var ObjectHasOwnProperty = global.Object.prototype.hasOwnProperty;
 var ObjectToString = global.Object.prototype.toString;
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
 var unscopablesSymbol = utils.ImportNow("unscopables_symbol");
 
 // -------------------------------------------------------------------
 
-macro IS_PROXY(arg)
-(%_IsJSProxy(arg))
-endmacro
-
 macro INVERT_NEG_ZERO(arg)
 ((arg) + 0)
 endmacro
@@ -201,140 +194,6 @@ function ConvertToString(use_locale, x, locales, options) {
 }
 
 
-// This function implements the optimized splice implementation that can use
-// special array operations to handle sparse arrays in a sensible fashion.
-function SparseSlice(array, start_i, del_count, len, deleted_elements) {
-  // Move deleted elements to a new array (the return value from splice).
-  var indices = %GetArrayKeys(array, start_i + del_count);
-  if (IS_NUMBER(indices)) {
-    var limit = indices;
-    for (var i = start_i; i < limit; ++i) {
-      var current = array[i];
-      if (!IS_UNDEFINED(current) || i in array) {
-        %CreateDataProperty(deleted_elements, i - start_i, current);
-      }
-    }
-  } else {
-    var length = indices.length;
-    for (var k = 0; k < length; ++k) {
-      var key = indices[k];
-      if (key >= start_i) {
-        var current = array[key];
-        if (!IS_UNDEFINED(current) || key in array) {
-          %CreateDataProperty(deleted_elements, key - start_i, current);
-        }
-      }
-    }
-  }
-}
-
-
-// This function implements the optimized splice implementation that can use
-// special array operations to handle sparse arrays in a sensible fashion.
-function SparseMove(array, start_i, del_count, len, num_additional_args) {
-  // Bail out if no moving is necessary.
-  if (num_additional_args === del_count) return;
-  // Move data to new array.
-  var new_array = new InternalArray(
-      // Clamp array length to 2^32-1 to avoid early RangeError.
-      MathMin(len - del_count + num_additional_args, 0xffffffff));
-  var big_indices;
-  var indices = %GetArrayKeys(array, len);
-  if (IS_NUMBER(indices)) {
-    var limit = indices;
-    for (var i = 0; i < start_i && i < limit; ++i) {
-      var current = array[i];
-      if (!IS_UNDEFINED(current) || i in array) {
-        new_array[i] = current;
-      }
-    }
-    for (var i = start_i + del_count; i < limit; ++i) {
-      var current = array[i];
-      if (!IS_UNDEFINED(current) || i in array) {
-        new_array[i - del_count + num_additional_args] = current;
-      }
-    }
-  } else {
-    var length = indices.length;
-    for (var k = 0; k < length; ++k) {
-      var key = indices[k];
-      if (key < start_i) {
-        var current = array[key];
-        if (!IS_UNDEFINED(current) || key in array) {
-          new_array[key] = current;
-        }
-      } else if (key >= start_i + del_count) {
-        var current = array[key];
-        if (!IS_UNDEFINED(current) || key in array) {
-          var new_key = key - del_count + num_additional_args;
-          new_array[new_key] = current;
-          if (new_key > 0xfffffffe) {
-            big_indices = big_indices || new InternalArray();
-            big_indices.push(new_key);
-          }
-        }
-      }
-    }
-  }
-  // Move contents of new_array into this array
-  %MoveArrayContents(new_array, array);
-  // Add any moved values that aren't elements anymore.
-  if (!IS_UNDEFINED(big_indices)) {
-    var length = big_indices.length;
-    for (var i = 0; i < length; ++i) {
-      var key = big_indices[i];
-      array[key] = new_array[key];
-    }
-  }
-}
-
-
-// This is part of the old simple-minded splice.  We are using it either
-// because the receiver is not an array (so we have no choice) or because we
-// know we are not deleting or moving a lot of elements.
-function SimpleSlice(array, start_i, del_count, len, deleted_elements) {
-  for (var i = 0; i < del_count; i++) {
-    var index = start_i + i;
-    if (index in array) {
-      var current = array[index];
-      %CreateDataProperty(deleted_elements, i, current);
-    }
-  }
-}
-
-
-function SimpleMove(array, start_i, del_count, len, num_additional_args) {
-  if (num_additional_args !== del_count) {
-    // Move the existing elements after the elements to be deleted
-    // to the right position in the resulting array.
-    if (num_additional_args > del_count) {
-      for (var i = len - del_count; i > start_i; i--) {
-        var from_index = i + del_count - 1;
-        var to_index = i + num_additional_args - 1;
-        if (from_index in array) {
-          array[to_index] = array[from_index];
-        } else {
-          delete array[to_index];
-        }
-      }
-    } else {
-      for (var i = start_i; i < len - del_count; i++) {
-        var from_index = i + del_count;
-        var to_index = i + num_additional_args;
-        if (from_index in array) {
-          array[to_index] = array[from_index];
-        } else {
-          delete array[to_index];
-        }
-      }
-      for (var i = len; i > len - del_count + num_additional_args; i--) {
-        delete array[i - 1];
-      }
-    }
-  }
-}
-
-
 // -------------------------------------------------------------------
 
 var ArrayJoin;
@@ -408,55 +267,6 @@ DEFINE_METHOD(
 );
 
 
-function ArrayShiftFallback() {
-  var array = TO_OBJECT(this);
-  var len = TO_LENGTH(array.length);
-
-  if (len === 0) {
-    array.length = 0;
-    return;
-  }
-
-  var first = array[0];
-
-  if (UseSparseVariant(array, len, IS_ARRAY(array), len)) {
-    SparseMove(array, 0, 1, len, 0);
-  } else {
-    SimpleMove(array, 0, 1, len, 0);
-  }
-
-  array.length = len - 1;
-
-  return first;
-}
-
-
-function ArrayUnshiftFallback(arg1) {  // length == 1
-  var array = TO_OBJECT(this);
-  var len = TO_LENGTH(array.length);
-  var num_arguments = arguments.length;
-
-  const new_len = len + num_arguments;
-  if (num_arguments > 0) {
-    if (new_len >= 2**53) throw %make_type_error(kInvalidArrayLength);
-
-    if (len > 0 && UseSparseVariant(array, len, IS_ARRAY(array), len) &&
-        !%object_is_sealed(array)) {
-      SparseMove(array, 0, 0, len, num_arguments);
-    } else {
-      SimpleMove(array, 0, 0, len, num_arguments);
-    }
-
-    for (var i = 0; i < num_arguments; i++) {
-      array[i] = arguments[i];
-    }
-  }
-
-  array.length = new_len;
-  return new_len;
-}
-
-
 // Oh the humanity... don't remove the following function because js2c for some
 // reason gets symbol minifiation wrong if it's not there. Instead of spending
 // the time fixing js2c (which will go away when all of the internal .js runtime
@@ -465,83 +275,6 @@ function ArraySliceFallback(start, end) {
   return null;
 }
 
-function ComputeSpliceStartIndex(start_i, len) {
-  if (start_i < 0) {
-    start_i += len;
-    return start_i < 0 ? 0 : start_i;
-  }
-
-  return start_i > len ? len : start_i;
-}
-
-
-function ComputeSpliceDeleteCount(delete_count, num_arguments, len, start_i) {
-  // SpiderMonkey, TraceMonkey and JSC treat the case where no delete count is
-  // given as a request to delete all the elements from the start.
-  // And it differs from the case of undefined delete count.
-  // This does not follow ECMA-262, but we do the same for
-  // compatibility.
-  var del_count = 0;
-  if (num_arguments == 1)
-    return len - start_i;
-
-  del_count = TO_INTEGER(delete_count);
-  if (del_count < 0)
-    return 0;
-
-  if (del_count > len - start_i)
-    return len - start_i;
-
-  return del_count;
-}
-
-
-function ArraySpliceFallback(start, delete_count) {
-  var num_arguments = arguments.length;
-  var array = TO_OBJECT(this);
-  var len = TO_LENGTH(array.length);
-  var start_i = ComputeSpliceStartIndex(TO_INTEGER(start), len);
-  var del_count = ComputeSpliceDeleteCount(delete_count, num_arguments, len,
-                                           start_i);
-  var num_elements_to_add = num_arguments > 2 ? num_arguments - 2 : 0;
-
-  const new_len = len - del_count + num_elements_to_add;
-  if (new_len >= 2**53) throw %make_type_error(kInvalidArrayLength);
-
-  var deleted_elements = ArraySpeciesCreate(array, del_count);
-  deleted_elements.length = del_count;
-
-  var changed_elements = del_count;
-  if (num_elements_to_add != del_count) {
-    // If the slice needs to do a actually move elements after the insertion
-    // point, then include those in the estimate of changed elements.
-    changed_elements += len - start_i - del_count;
-  }
-  if (UseSparseVariant(array, len, IS_ARRAY(array), changed_elements)) {
-    %NormalizeElements(array);
-    if (IS_ARRAY(deleted_elements)) %NormalizeElements(deleted_elements);
-    SparseSlice(array, start_i, del_count, len, deleted_elements);
-    SparseMove(array, start_i, del_count, len, num_elements_to_add);
-  } else {
-    SimpleSlice(array, start_i, del_count, len, deleted_elements);
-    SimpleMove(array, start_i, del_count, len, num_elements_to_add);
-  }
-
-  // Insert the arguments into the resulting array in
-  // place of the deleted elements.
-  var i = start_i;
-  var arguments_index = 2;
-  var arguments_length = arguments.length;
-  while (arguments_index < arguments_length) {
-    array[i++] = arguments[arguments_index++];
-  }
-  array.length = new_len;
-
-  // Return the deleted elements.
-  return deleted_elements;
-}
-
-
 function InnerArraySort(array, length, comparefn) {
   // In-place QuickSort algorithm.
   // For short (length <= 10) arrays, insertion sort is used for efficiency.
@@ -700,56 +433,6 @@ function InnerArraySort(array, length, comparefn) {
 }
 
 
-DEFINE_METHOD_LEN(
-  GlobalArray.prototype,
-  lastIndexOf(element, index) {
-    var array = TO_OBJECT(this);
-    var length = TO_LENGTH(this.length);
-
-    if (length == 0) return -1;
-    if (arguments.length < 2) {
-      index = length - 1;
-    } else {
-      index = INVERT_NEG_ZERO(TO_INTEGER(index));
-      // If index is negative, index from end of the array.
-      if (index < 0) index += length;
-      // If index is still negative, do not search the array.
-      if (index < 0) return -1;
-      else if (index >= length) index = length - 1;
-    }
-    var min = 0;
-    var max = index;
-    if (UseSparseVariant(array, length, IS_ARRAY(array), index)) {
-      %NormalizeElements(array);
-      var indices = %GetArrayKeys(array, index + 1);
-      if (IS_NUMBER(indices)) {
-        // It's an interval.
-        max = indices;  // Capped by index already.
-        // Fall through to loop below.
-      } else {
-        if (indices.length == 0) return -1;
-        // Get all the keys in sorted order.
-        var sortedKeys = GetSortedArrayKeys(array, indices);
-        var i = sortedKeys.length - 1;
-        while (i >= 0) {
-          var key = sortedKeys[i];
-          if (array[key] === element) return key;
-          i--;
-        }
-        return -1;
-      }
-    }
-    // Lookup through the array.
-    for (var i = max; i >= min; i--) {
-      if (i in array && array[i] === element) return i;
-    }
-    return -1;
-  },
-  1  /* Set function length */
-);
-
-
-
 // Set up unscopable properties on the Array.prototype object.
 var unscopables = {
   __proto__: null,
@@ -827,10 +510,6 @@ utils.Export(function(to) {
   "array_for_each_iterator", ArrayForEach,
   "array_keys_iterator", ArrayKeys,
   "array_values_iterator", ArrayValues,
-  // Fallback implementations of Array builtins.
-  "array_shift", ArrayShiftFallback,
-  "array_splice", ArraySpliceFallback,
-  "array_unshift", ArrayUnshiftFallback,
 ]);
 
 });
diff --git a/deps/v8/src/js/intl.js b/deps/v8/src/js/intl.js
index db4d45c563..43119a490d 100644
--- a/deps/v8/src/js/intl.js
+++ b/deps/v8/src/js/intl.js
@@ -34,7 +34,6 @@ var InternalArray = utils.InternalArray;
 var MathMax = global.Math.max;
 var ObjectHasOwnProperty = global.Object.prototype.hasOwnProperty;
 var ObjectKeys = global.Object.keys;
-var patternSymbol = utils.ImportNow("intl_pattern_symbol");
 var resolvedSymbol = utils.ImportNow("intl_resolved_symbol");
 var StringSubstr = GlobalString.prototype.substr;
 var StringSubstring = GlobalString.prototype.substring;
@@ -44,77 +43,6 @@ utils.Import(function(from) {
   ArrayPush = from.ArrayPush;
 });
 
-// Utilities for definitions
-
-macro NUMBER_IS_NAN(arg)
-(%IS_VAR(arg) !== arg)
-endmacro
-
-// To avoid ES2015 Function name inference.
-
-macro ANONYMOUS_FUNCTION(fn)
-(0, (fn))
-endmacro
-
-/**
- * Adds bound method to the prototype of the given object.
- */
-function AddBoundMethod(obj, methodName, implementation, length, type,
-                        compat) {
-  %CheckIsBootstrapping();
-  var internalName = %CreatePrivateSymbol(methodName);
-
-  DEFINE_METHOD(
-    obj.prototype,
-    get [methodName]() {
-      if(!IS_RECEIVER(this)) {
-        throw %make_type_error(kIncompatibleMethodReceiver, methodName, this);
-      }
-      var receiver = %IntlUnwrapReceiver(this, type, obj, methodName, compat);
-      if (IS_UNDEFINED(receiver[internalName])) {
-        var boundMethod;
-        if (IS_UNDEFINED(length) || length === 2) {
-          boundMethod =
-            ANONYMOUS_FUNCTION((fst, snd) => implementation(receiver, fst, snd));
-        } else if (length === 1) {
-          boundMethod = ANONYMOUS_FUNCTION(fst => implementation(receiver, fst));
-        } else {
-          boundMethod = ANONYMOUS_FUNCTION((...args) => {
-            // DateTimeFormat.format needs to be 0 arg method, but can still
-            // receive an optional dateValue param. If one was provided, pass it
-            // along.
-            if (args.length > 0) {
-              return implementation(receiver, args[0]);
-            } else {
-              return implementation(receiver);
-            }
-          });
-        }
-        %SetNativeFlag(boundMethod);
-        receiver[internalName] = boundMethod;
-      }
-      return receiver[internalName];
-    }
-  );
-}
-
-function IntlConstruct(receiver, constructor, create, newTarget, args,
-                       compat) {
-  var locales = args[0];
-  var options = args[1];
-
-  var instance = create(locales, options);
-
-  if (compat && IS_UNDEFINED(newTarget) && receiver instanceof constructor) {
-    %object_define_property(receiver, IntlFallbackSymbol, { value: instance });
-    return receiver;
-  }
-
-  return instance;
-}
-
-
-
 // -------------------------------------------------------------------
 
 /**
@@ -129,6 +57,7 @@ var AVAILABLE_LOCALES = {
   'pluralrules': UNDEFINED,
   'relativetimeformat': UNDEFINED,
   'listformat': UNDEFINED,
+  'segmenter': UNDEFINED,
 };
 
 /**
@@ -156,18 +85,6 @@ function GetAnyExtensionRE() {
 }
 
 /**
- * Replace quoted text (single quote, anything but the quote and quote again).
- */
-var QUOTED_STRING_RE = UNDEFINED;
-
-function GetQuotedStringRE() {
-  if (IS_UNDEFINED(QUOTED_STRING_RE)) {
-    QUOTED_STRING_RE = new GlobalRegExp("'[^']+'", 'g');
-  }
-  return QUOTED_STRING_RE;
-}
-
-/**
  * Matches valid service name.
  */
 var SERVICE_RE = UNDEFINED;
@@ -181,42 +98,6 @@ function GetServiceRE() {
 }
 
 /**
- * Matches valid IANA time zone names.
- */
-var TIMEZONE_NAME_CHECK_RE = UNDEFINED;
-var GMT_OFFSET_TIMEZONE_NAME_CHECK_RE = UNDEFINED;
-
-function GetTimezoneNameCheckRE() {
-  if (IS_UNDEFINED(TIMEZONE_NAME_CHECK_RE)) {
-    TIMEZONE_NAME_CHECK_RE = new GlobalRegExp(
-        '^([A-Za-z]+)/([A-Za-z_-]+)((?:\/[A-Za-z_-]+)+)*$');
-  }
-  return TIMEZONE_NAME_CHECK_RE;
-}
-
-function GetGMTOffsetTimezoneNameCheckRE() {
-  if (IS_UNDEFINED(GMT_OFFSET_TIMEZONE_NAME_CHECK_RE)) {
-     GMT_OFFSET_TIMEZONE_NAME_CHECK_RE = new GlobalRegExp(
-         '^(?:ETC/GMT)(?<offset>0|[+-](?:[0-9]|1[0-4]))$');
-  }
-  return GMT_OFFSET_TIMEZONE_NAME_CHECK_RE;
-}
-
-/**
- * Matches valid location parts of IANA time zone names.
- */
-var TIMEZONE_NAME_LOCATION_PART_RE = UNDEFINED;
-
-function GetTimezoneNameLocationPartRE() {
-  if (IS_UNDEFINED(TIMEZONE_NAME_LOCATION_PART_RE)) {
-    TIMEZONE_NAME_LOCATION_PART_RE =
-        new GlobalRegExp('^([A-Za-z]+)((?:[_-][A-Za-z]+)+)*$');
-  }
-  return TIMEZONE_NAME_LOCATION_PART_RE;
-}
-
-
-/**
  * Returns a getOption function that extracts property value for given
  * options object. If property is missing it returns defaultValue. If value
  * is out of range for that property it throws RangeError.
@@ -391,69 +272,6 @@ function bestFitMatcher(service, requestedLocales) {
 }
 
 /**
- * Populates internalOptions object with boolean key-value pairs
- * from extensionMap and options.
- * Returns filtered extension (number and date format constructors use
- * Unicode extensions for passing parameters to ICU).
- * It's used for extension-option pairs only, e.g. kn-normalization, but not
- * for 'sensitivity' since it doesn't have extension equivalent.
- * Extensions like nu and ca don't have options equivalent, so we place
- * undefined in the map.property to denote that.
- */
-function setOptions(inOptions, extensionMap, keyValues, getOption, outOptions) {
-  var extension = '';
-
-  var updateExtension = function updateExtension(key, value) {
-    return '-' + key + '-' + TO_STRING(value);
-  }
-
-  var updateProperty = function updateProperty(property, type, value) {
-    if (type === 'boolean' && (typeof value === 'string')) {
-      value = (value === 'true') ? true : false;
-    }
-
-    if (!IS_UNDEFINED(property)) {
-      %DefineWEProperty(outOptions, property, value);
-    }
-  }
-
-  for (var key in keyValues) {
-    if (HAS_OWN_PROPERTY(keyValues, key)) {
-      var value = UNDEFINED;
-      var map = keyValues[key];
-      if (!IS_UNDEFINED(map.property)) {
-        // This may return true if user specifies numeric: 'false', since
-        // Boolean('nonempty') === true.
-        value = getOption(map.property, map.type, map.values);
-      }
-      if (!IS_UNDEFINED(value)) {
-        updateProperty(map.property, map.type, value);
-        extension += updateExtension(key, value);
-        continue;
-      }
-      // User options didn't have it, check Unicode extension.
-      // Here we want to convert strings 'true', 'false' into proper Boolean
-      // values (not a user error).
-      if (HAS_OWN_PROPERTY(extensionMap, key)) {
-        value = extensionMap[key];
-        if (!IS_UNDEFINED(value)) {
-          updateProperty(map.property, map.type, value);
-          extension += updateExtension(key, value);
-        } else if (map.type === 'boolean') {
-          // Boolean keys are allowed not to have values in Unicode extension.
-          // Those default to true.
-          updateProperty(map.property, map.type, true);
-          extension += updateExtension(key, true);
-        }
-      }
-    }
-  }
-
-  return extension === ''? '' : '-u' + extension;
-}
-
-
-/**
  * Given an array-like, outputs an Array with the numbered
  * properties copied over and defined
  * configurable: false, writable: false, enumerable: true.
@@ -513,66 +331,6 @@ function getAvailableLocalesOf(service) {
   return available;
 }
 
-
-/**
- * Defines a property and sets writable, enumerable and configurable to true.
- */
-function defineWECProperty(object, property, value) {
-  %object_define_property(object, property, {value: value,
-                                             writable: true,
-                                             enumerable: true,
-                                             configurable: true});
-}
-
-
-/**
- * Adds property to an object if the value is not undefined.
- * Sets all descriptors to true.
- */
-function addWECPropertyIfDefined(object, property, value) {
-  if (!IS_UNDEFINED(value)) {
-    defineWECProperty(object, property, value);
-  }
-}
-
-
-/**
- * Returns titlecased word, aMeRricA -> America.
- */
-function toTitleCaseWord(word) {
-  return %StringToUpperCaseIntl(%_Call(StringSubstr, word, 0, 1)) +
-         %StringToLowerCaseIntl(%_Call(StringSubstr, word, 1));
-}
-
-/**
- * Returns titlecased location, bueNos_airES -> Buenos_Aires
- * or ho_cHi_minH -> Ho_Chi_Minh. It is locale-agnostic and only
- * deals with ASCII only characters.
- * 'of', 'au' and 'es' are special-cased and lowercased.
- */
-function toTitleCaseTimezoneLocation(location) {
-  var match = %regexp_internal_match(GetTimezoneNameLocationPartRE(), location)
-  if (IS_NULL(match)) throw %make_range_error(kExpectedLocation, location);
-
-  var result = toTitleCaseWord(match[1]);
-  if (!IS_UNDEFINED(match[2]) && 2 < match.length) {
-    // The first character is a separator, '_' or '-'.
-    // None of IANA zone names has both '_' and '-'.
-    var separator = %_Call(StringSubstring, match[2], 0, 1);
-    var parts = %StringSplit(match[2], separator, kMaxUint32);
-    for (var i = 1; i < parts.length; i++) {
-      var part = parts[i]
-      var lowercasedPart = %StringToLowerCaseIntl(part);
-      result = result + separator +
-          ((lowercasedPart !== 'es' &&
-            lowercasedPart !== 'of' && lowercasedPart !== 'au') ?
-          toTitleCaseWord(part) : lowercasedPart);
-    }
-  }
-  return result;
-}
-
-
 /**
  * Returns an InternalArray where all locales are canonicalized and duplicates
  * removed.
@@ -627,797 +385,6 @@ DEFINE_METHOD(
   }
 );
 
-/**
- * Collator resolvedOptions method.
- */
-DEFINE_METHOD(
-  GlobalIntlCollator.prototype,
-  resolvedOptions() {
-    return %CollatorResolvedOptions(this);
-  }
-);
-
-
-/**
- * Returns the subset of the given locale list for which this locale list
- * has a matching (possibly fallback) locale. Locales appear in the same
- * order in the returned list as in the input list.
- * Options are optional parameter.
- */
-DEFINE_METHOD(
-  GlobalIntlCollator,
-  supportedLocalesOf(locales) {
-    return %SupportedLocalesOf('collator', locales, arguments[1]);
-  }
-);
-
-
-DEFINE_METHOD(
-  GlobalIntlPluralRules.prototype,
-  resolvedOptions() {
-    return %PluralRulesResolvedOptions(this);
-  }
-);
-
-DEFINE_METHOD(
-  GlobalIntlPluralRules,
-  supportedLocalesOf(locales) {
-    return %SupportedLocalesOf('pluralrules', locales, arguments[1]);
-  }
-);
-
-DEFINE_METHOD(
-  GlobalIntlPluralRules.prototype,
-  select(value) {
-    return %PluralRulesSelect(this, TO_NUMBER(value) + 0);
-  }
-);
-
-// ECMA 402 #sec-setnfdigitoptions
-// SetNumberFormatDigitOptions ( intlObj, options, mnfdDefault, mxfdDefault )
-function SetNumberFormatDigitOptions(internalOptions, options,
-                                     mnfdDefault, mxfdDefault) {
-  // Digit ranges.
-  var mnid = %GetNumberOption(options, 'minimumIntegerDigits', 1, 21, 1);
-  %DefineWEProperty(internalOptions, 'minimumIntegerDigits', mnid);
-
-  var mnfd = %GetNumberOption(options, 'minimumFractionDigits', 0, 20,
-                             mnfdDefault);
-  %DefineWEProperty(internalOptions, 'minimumFractionDigits', mnfd);
-
-  var mxfdActualDefault = MathMax(mnfd, mxfdDefault);
-
-  var mxfd = %GetNumberOption(options, 'maximumFractionDigits', mnfd, 20,
-                             mxfdActualDefault);
-
-  %DefineWEProperty(internalOptions, 'maximumFractionDigits', mxfd);
-
-  var mnsd = options['minimumSignificantDigits'];
-  var mxsd = options['maximumSignificantDigits'];
-  if (!IS_UNDEFINED(mnsd) || !IS_UNDEFINED(mxsd)) {
-    mnsd = %DefaultNumberOption(mnsd, 1, 21, 1, 'minimumSignificantDigits');
-    %DefineWEProperty(internalOptions, 'minimumSignificantDigits', mnsd);
-
-    mxsd = %DefaultNumberOption(mxsd, mnsd, 21, 21, 'maximumSignificantDigits');
-    %DefineWEProperty(internalOptions, 'maximumSignificantDigits', mxsd);
-  }
-}
-
-/**
- * Initializes the given object so it's a valid NumberFormat instance.
- * Useful for subclassing.
- */
-function CreateNumberFormat(locales, options) {
-  if (IS_UNDEFINED(options)) {
-    options = {__proto__: null};
-  } else {
-    options = TO_OBJECT(options);
-  }
-
-  var getOption = getGetOption(options, 'numberformat');
-
-  var locale = resolveLocale('numberformat', locales, options);
-
-  var internalOptions = {__proto__: null};
-  %DefineWEProperty(internalOptions, 'style', getOption(
-    'style', 'string', ['decimal', 'percent', 'currency'], 'decimal'));
-
-  var currency = getOption('currency', 'string');
-  if (!IS_UNDEFINED(currency) && !%IsWellFormedCurrencyCode(currency)) {
-    throw %make_range_error(kInvalidCurrencyCode, currency);
-  }
-
-  if (internalOptions.style === 'currency' && IS_UNDEFINED(currency)) {
-    throw %make_type_error(kCurrencyCode);
-  }
-
-  var mnfdDefault, mxfdDefault;
-
-  var currencyDisplay = getOption(
-      'currencyDisplay', 'string', ['code', 'symbol', 'name'], 'symbol');
-  if (internalOptions.style === 'currency') {
-    %DefineWEProperty(internalOptions, 'currency', %StringToUpperCaseIntl(currency));
-    %DefineWEProperty(internalOptions, 'currencyDisplay', currencyDisplay);
-
-    mnfdDefault = mxfdDefault = %CurrencyDigits(internalOptions.currency);
-  } else {
-    mnfdDefault = 0;
-    mxfdDefault = internalOptions.style === 'percent' ? 0 : 3;
-  }
-
-  SetNumberFormatDigitOptions(internalOptions, options, mnfdDefault,
-                              mxfdDefault);
-
-  // Grouping.
-  %DefineWEProperty(internalOptions, 'useGrouping', getOption(
-    'useGrouping', 'boolean', UNDEFINED, true));
-
-  // ICU prefers options to be passed using -u- extension key/values for
-  // number format, so we need to build that.
-  var extensionMap = %ParseExtension(locale.extension);
-
-  /**
-   * Map of Unicode extensions to option properties, and their values and types,
-   * for a number format.
-   */
-  var NUMBER_FORMAT_KEY_MAP = {
-    __proto__: null,
-    'nu': {__proto__: null, 'property': UNDEFINED, 'type': 'string'}
-  };
-
-  var extension = setOptions(options, extensionMap, NUMBER_FORMAT_KEY_MAP,
-                             getOption, internalOptions);
-
-  var requestedLocale = locale.locale + extension;
-  var resolved = %object_define_properties({__proto__: null}, {
-    currency: {writable: true},
-    currencyDisplay: {writable: true},
-    locale: {writable: true},
-    maximumFractionDigits: {writable: true},
-    minimumFractionDigits: {writable: true},
-    minimumIntegerDigits: {writable: true},
-    numberingSystem: {writable: true},
-    requestedLocale: {value: requestedLocale, writable: true},
-    style: {value: internalOptions.style, writable: true},
-    useGrouping: {writable: true}
-  });
-  if (HAS_OWN_PROPERTY(internalOptions, 'minimumSignificantDigits')) {
-    %DefineWEProperty(resolved, 'minimumSignificantDigits', UNDEFINED);
-  }
-  if (HAS_OWN_PROPERTY(internalOptions, 'maximumSignificantDigits')) {
-    %DefineWEProperty(resolved, 'maximumSignificantDigits', UNDEFINED);
-  }
-  var numberFormat = %CreateNumberFormat(requestedLocale, internalOptions,
-                                         resolved);
-
-  if (internalOptions.style === 'currency') {
-    %object_define_property(resolved, 'currencyDisplay',
-        {value: currencyDisplay, writable: true});
-  }
-
-  %MarkAsInitializedIntlObjectOfType(numberFormat, NUMBER_FORMAT_TYPE);
-  numberFormat[resolvedSymbol] = resolved;
-
-  return numberFormat;
-}
-
-
-/**
- * Constructs Intl.NumberFormat object given optional locales and options
- * parameters.
- *
- * @constructor
- */
-function NumberFormatConstructor() {
-  return IntlConstruct(this, GlobalIntlNumberFormat, CreateNumberFormat,
-                       new.target, arguments, true);
-}
-%SetCode(GlobalIntlNumberFormat, NumberFormatConstructor);
-
-
-/**
- * NumberFormat resolvedOptions method.
- */
-DEFINE_METHOD(
-  GlobalIntlNumberFormat.prototype,
-  resolvedOptions() {
-    var methodName = 'resolvedOptions';
-    if(!IS_RECEIVER(this)) {
-      throw %make_type_error(kIncompatibleMethodReceiver, methodName, this);
-    }
-    var format = %IntlUnwrapReceiver(this, NUMBER_FORMAT_TYPE,
-                                     GlobalIntlNumberFormat,
-                                     methodName, true);
-    var result = {
-      locale: format[resolvedSymbol].locale,
-      numberingSystem: format[resolvedSymbol].numberingSystem,
-      style: format[resolvedSymbol].style,
-      useGrouping: format[resolvedSymbol].useGrouping,
-      minimumIntegerDigits: format[resolvedSymbol].minimumIntegerDigits,
-      minimumFractionDigits: format[resolvedSymbol].minimumFractionDigits,
-      maximumFractionDigits: format[resolvedSymbol].maximumFractionDigits,
-    };
-
-    if (result.style === 'currency') {
-      defineWECProperty(result, 'currency', format[resolvedSymbol].currency);
-      defineWECProperty(result, 'currencyDisplay',
-                        format[resolvedSymbol].currencyDisplay);
-    }
-
-    if (HAS_OWN_PROPERTY(format[resolvedSymbol], 'minimumSignificantDigits')) {
-      defineWECProperty(result, 'minimumSignificantDigits',
-                        format[resolvedSymbol].minimumSignificantDigits);
-    }
-
-    if (HAS_OWN_PROPERTY(format[resolvedSymbol], 'maximumSignificantDigits')) {
-      defineWECProperty(result, 'maximumSignificantDigits',
-                        format[resolvedSymbol].maximumSignificantDigits);
-    }
-
-    return result;
-  }
-);
-
-
-/**
- * Returns the subset of the given locale list for which this locale list
- * has a matching (possibly fallback) locale. Locales appear in the same
- * order in the returned list as in the input list.
- * Options are optional parameter.
- */
-DEFINE_METHOD(
-  GlobalIntlNumberFormat,
-  supportedLocalesOf(locales) {
-    return %SupportedLocalesOf('numberformat', locales, arguments[1]);
-  }
-);
-
-/**
- * Returns a string that matches LDML representation of the options object.
- */
-function toLDMLString(options) {
-  var getOption = getGetOption(options, 'dateformat');
-
-  var ldmlString = '';
-
-  var option = getOption('weekday', 'string', ['narrow', 'short', 'long']);
-  ldmlString += appendToLDMLString(
-      option, {narrow: 'EEEEE', short: 'EEE', long: 'EEEE'});
-
-  option = getOption('era', 'string', ['narrow', 'short', 'long']);
-  ldmlString += appendToLDMLString(
-      option, {narrow: 'GGGGG', short: 'GGG', long: 'GGGG'});
-
-  option = getOption('year', 'string', ['2-digit', 'numeric']);
-  ldmlString += appendToLDMLString(option, {'2-digit': 'yy', 'numeric': 'y'});
-
-  option = getOption('month', 'string',
-                     ['2-digit', 'numeric', 'narrow', 'short', 'long']);
-  ldmlString += appendToLDMLString(option, {'2-digit': 'MM', 'numeric': 'M',
-          'narrow': 'MMMMM', 'short': 'MMM', 'long': 'MMMM'});
-
-  option = getOption('day', 'string', ['2-digit', 'numeric']);
-  ldmlString += appendToLDMLString(
-      option, {'2-digit': 'dd', 'numeric': 'd'});
-
-  var hr12 = getOption('hour12', 'boolean');
-  option = getOption('hour', 'string', ['2-digit', 'numeric']);
-  if (IS_UNDEFINED(hr12)) {
-    ldmlString += appendToLDMLString(option, {'2-digit': 'jj', 'numeric': 'j'});
-  } else if (hr12 === true) {
-    ldmlString += appendToLDMLString(option, {'2-digit': 'hh', 'numeric': 'h'});
-  } else {
-    ldmlString += appendToLDMLString(option, {'2-digit': 'HH', 'numeric': 'H'});
-  }
-
-  option = getOption('minute', 'string', ['2-digit', 'numeric']);
-  ldmlString += appendToLDMLString(option, {'2-digit': 'mm', 'numeric': 'm'});
-
-  option = getOption('second', 'string', ['2-digit', 'numeric']);
-  ldmlString += appendToLDMLString(option, {'2-digit': 'ss', 'numeric': 's'});
-
-  option = getOption('timeZoneName', 'string', ['short', 'long']);
-  ldmlString += appendToLDMLString(option, {short: 'z', long: 'zzzz'});
-
-  return ldmlString;
-}
-
-
-/**
- * Returns either LDML equivalent of the current option or empty string.
- */
-function appendToLDMLString(option, pairs) {
-  if (!IS_UNDEFINED(option)) {
-    return pairs[option];
-  } else {
-    return '';
-  }
-}
-
-
-/**
- * Returns object that matches LDML representation of the date.
- */
-function fromLDMLString(ldmlString) {
-  // First remove '' quoted text, so we lose 'Uhr' strings.
-  ldmlString = %RegExpInternalReplace(GetQuotedStringRE(), ldmlString, '');
-
-  var options = {__proto__: null};
-  var match = %regexp_internal_match(/E{3,5}/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'weekday', match, {EEEEE: 'narrow', EEE: 'short', EEEE: 'long'});
-
-  match = %regexp_internal_match(/G{3,5}/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'era', match, {GGGGG: 'narrow', GGG: 'short', GGGG: 'long'});
-
-  match = %regexp_internal_match(/y{1,2}/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'year', match, {y: 'numeric', yy: '2-digit'});
-
-  match = %regexp_internal_match(/M{1,5}/, ldmlString);
-  options = appendToDateTimeObject(options, 'month', match, {MM: '2-digit',
-      M: 'numeric', MMMMM: 'narrow', MMM: 'short', MMMM: 'long'});
-
-  // Sometimes we get L instead of M for month - standalone name.
-  match = %regexp_internal_match(/L{1,5}/, ldmlString);
-  options = appendToDateTimeObject(options, 'month', match, {LL: '2-digit',
-      L: 'numeric', LLLLL: 'narrow', LLL: 'short', LLLL: 'long'});
-
-  match = %regexp_internal_match(/d{1,2}/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'day', match, {d: 'numeric', dd: '2-digit'});
-
-  match = %regexp_internal_match(/h{1,2}/, ldmlString);
-  if (match !== null) {
-    options['hour12'] = true;
-  }
-  options = appendToDateTimeObject(
-      options, 'hour', match, {h: 'numeric', hh: '2-digit'});
-
-  match = %regexp_internal_match(/H{1,2}/, ldmlString);
-  if (match !== null) {
-    options['hour12'] = false;
-  }
-  options = appendToDateTimeObject(
-      options, 'hour', match, {H: 'numeric', HH: '2-digit'});
-
-  match = %regexp_internal_match(/m{1,2}/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'minute', match, {m: 'numeric', mm: '2-digit'});
-
-  match = %regexp_internal_match(/s{1,2}/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'second', match, {s: 'numeric', ss: '2-digit'});
-
-  match = %regexp_internal_match(/z|zzzz/, ldmlString);
-  options = appendToDateTimeObject(
-      options, 'timeZoneName', match, {z: 'short', zzzz: 'long'});
-
-  return options;
-}
-
-
-function appendToDateTimeObject(options, option, match, pairs) {
-  if (IS_NULL(match)) {
-    if (!HAS_OWN_PROPERTY(options, option)) {
-      %DefineWEProperty(options, option, UNDEFINED);
-    }
-    return options;
-  }
-
-  var property = match[0];
-  %DefineWEProperty(options, option, pairs[property]);
-
-  return options;
-}
-
-
-/**
- * Returns options with at least default values in it.
- */
-function toDateTimeOptions(options, required, defaults) {
-  if (IS_UNDEFINED(options)) {
-    options = {__proto__: null};
-  } else {
-    options = TO_OBJECT(options);
-  }
-
-  options = %object_create(options);
-
-  var needsDefault = true;
-  if ((required === 'date' || required === 'any') &&
-      (!IS_UNDEFINED(options.weekday) || !IS_UNDEFINED(options.year) ||
-       !IS_UNDEFINED(options.month) || !IS_UNDEFINED(options.day))) {
-    needsDefault = false;
-  }
-
-  if ((required === 'time' || required === 'any') &&
-      (!IS_UNDEFINED(options.hour) || !IS_UNDEFINED(options.minute) ||
-       !IS_UNDEFINED(options.second))) {
-    needsDefault = false;
-  }
-
-  if (needsDefault && (defaults === 'date' || defaults === 'all')) {
-    %object_define_property(options, 'year', {value: 'numeric',
-                                              writable: true,
-                                              enumerable: true,
-                                              configurable: true});
-    %object_define_property(options, 'month', {value: 'numeric',
-                                               writable: true,
-                                               enumerable: true,
-                                               configurable: true});
-    %object_define_property(options, 'day', {value: 'numeric',
-                                             writable: true,
-                                             enumerable: true,
-                                             configurable: true});
-  }
-
-  if (needsDefault && (defaults === 'time' || defaults === 'all')) {
-    %object_define_property(options, 'hour', {value: 'numeric',
-                                              writable: true,
-                                              enumerable: true,
-                                              configurable: true});
-    %object_define_property(options, 'minute', {value: 'numeric',
-                                                writable: true,
-                                                enumerable: true,
-                                                configurable: true});
-    %object_define_property(options, 'second', {value: 'numeric',
-                                                writable: true,
-                                                enumerable: true,
-                                                configurable: true});
-  }
-
-  return options;
-}
-
-
-/**
- * Initializes the given object so it's a valid DateTimeFormat instance.
- * Useful for subclassing.
- */
-function CreateDateTimeFormat(locales, options) {
-  if (IS_UNDEFINED(options)) {
-    options = {__proto__: null};
-  }
-
-  var locale = resolveLocale('dateformat', locales, options);
-
-  options = %ToDateTimeOptions(options, 'any', 'date');
-
-  var getOption = getGetOption(options, 'dateformat');
-
-  // We implement only best fit algorithm, but still need to check
-  // if the formatMatcher values are in range.
-  var matcher = getOption('formatMatcher', 'string',
-                          ['basic', 'best fit'], 'best fit');
-
-  // Build LDML string for the skeleton that we pass to the formatter.
-  var ldmlString = toLDMLString(options);
-
-  // Filter out supported extension keys so we know what to put in resolved
-  // section later on.
-  // We need to pass calendar and number system to the method.
-  var tz = canonicalizeTimeZoneID(options.timeZone);
-
-  // ICU prefers options to be passed using -u- extension key/values, so
-  // we need to build that.
-  var internalOptions = {__proto__: null};
-  var extensionMap = %ParseExtension(locale.extension);
-
-  /**
-   * Map of Unicode extensions to option properties, and their values and types,
-   * for a date/time format.
-   */
-  var DATETIME_FORMAT_KEY_MAP = {
-    __proto__: null,
-    'ca': {__proto__: null, 'property': UNDEFINED, 'type': 'string'},
-    'nu': {__proto__: null, 'property': UNDEFINED, 'type': 'string'}
-  };
-
-  var extension = setOptions(options, extensionMap, DATETIME_FORMAT_KEY_MAP,
-                             getOption, internalOptions);
-
-  var requestedLocale = locale.locale + extension;
-  var resolved = %object_define_properties({__proto__: null}, {
-    calendar: {writable: true},
-    day: {writable: true},
-    era: {writable: true},
-    hour12: {writable: true},
-    hour: {writable: true},
-    locale: {writable: true},
-    minute: {writable: true},
-    month: {writable: true},
-    numberingSystem: {writable: true},
-    [patternSymbol]: {writable: true},
-    requestedLocale: {value: requestedLocale, writable: true},
-    second: {writable: true},
-    timeZone: {writable: true},
-    timeZoneName: {writable: true},
-    tz: {value: tz, writable: true},
-    weekday: {writable: true},
-    year: {writable: true}
-  });
-
-  var dateFormat = %CreateDateTimeFormat(
-    requestedLocale,
-    {__proto__: null, skeleton: ldmlString, timeZone: tz}, resolved);
-
-  if (resolved.timeZone === "Etc/Unknown") {
-    throw %make_range_error(kInvalidTimeZone, tz);
-  }
-
-  %MarkAsInitializedIntlObjectOfType(dateFormat, DATE_TIME_FORMAT_TYPE);
-  dateFormat[resolvedSymbol] = resolved;
-
-  return dateFormat;
-}
-
-
-/**
- * Constructs Intl.DateTimeFormat object given optional locales and options
- * parameters.
- *
- * @constructor
- */
-function DateTimeFormatConstructor() {
-  return IntlConstruct(this, GlobalIntlDateTimeFormat, CreateDateTimeFormat,
-                       new.target, arguments, true);
-}
-%SetCode(GlobalIntlDateTimeFormat, DateTimeFormatConstructor);
-
-
-/**
- * DateTimeFormat resolvedOptions method.
- */
-DEFINE_METHOD(
-  GlobalIntlDateTimeFormat.prototype,
-  resolvedOptions() {
-    var methodName = 'resolvedOptions';
-    if(!IS_RECEIVER(this)) {
-      throw %make_type_error(kIncompatibleMethodReceiver, methodName, this);
-    }
-    var format = %IntlUnwrapReceiver(this, DATE_TIME_FORMAT_TYPE,
-                                     GlobalIntlDateTimeFormat,
-                                     methodName, true);
-
-    /**
-     * Maps ICU calendar names to LDML/BCP47 types for key 'ca'.
-     * See typeMap section in third_party/icu/source/data/misc/keyTypeData.txt
-     * and
-     * http://www.unicode.org/repos/cldr/tags/latest/common/bcp47/calendar.xml
-     */
-    var ICU_CALENDAR_MAP = {
-      __proto__: null,
-      'gregorian': 'gregory',
-      'ethiopic-amete-alem': 'ethioaa'
-    };
-
-    var fromPattern = fromLDMLString(format[resolvedSymbol][patternSymbol]);
-    var userCalendar = ICU_CALENDAR_MAP[format[resolvedSymbol].calendar];
-    if (IS_UNDEFINED(userCalendar)) {
-      // No match means that ICU's legacy name is identical to LDML/BCP type.
-      userCalendar = format[resolvedSymbol].calendar;
-    }
-
-    var result = {
-      locale: format[resolvedSymbol].locale,
-      numberingSystem: format[resolvedSymbol].numberingSystem,
-      calendar: userCalendar,
-      timeZone: format[resolvedSymbol].timeZone
-    };
-
-    addWECPropertyIfDefined(result, 'timeZoneName', fromPattern.timeZoneName);
-    addWECPropertyIfDefined(result, 'era', fromPattern.era);
-    addWECPropertyIfDefined(result, 'year', fromPattern.year);
-    addWECPropertyIfDefined(result, 'month', fromPattern.month);
-    addWECPropertyIfDefined(result, 'day', fromPattern.day);
-    addWECPropertyIfDefined(result, 'weekday', fromPattern.weekday);
-    addWECPropertyIfDefined(result, 'hour12', fromPattern.hour12);
-    addWECPropertyIfDefined(result, 'hour', fromPattern.hour);
-    addWECPropertyIfDefined(result, 'minute', fromPattern.minute);
-    addWECPropertyIfDefined(result, 'second', fromPattern.second);
-
-    return result;
-  }
-);
-
-
-/**
- * Returns the subset of the given locale list for which this locale list
- * has a matching (possibly fallback) locale. Locales appear in the same
- * order in the returned list as in the input list.
- * Options are optional parameter.
- */
-DEFINE_METHOD(
-  GlobalIntlDateTimeFormat,
-  supportedLocalesOf(locales) {
-    return %SupportedLocalesOf('dateformat', locales, arguments[1]);
-  }
-);
-
-
-/**
- * Returns canonical Area/Location(/Location) name, or throws an exception
- * if the zone name is invalid IANA name.
- */
-function canonicalizeTimeZoneID(tzID) {
-  // Skip undefined zones.
-  if (IS_UNDEFINED(tzID)) {
-    return tzID;
-  }
-
-  // Convert zone name to string.
-  tzID = TO_STRING(tzID);
-
-  // Special case handling (UTC, GMT).
-  var upperID = %StringToUpperCaseIntl(tzID);
-  if (upperID === 'UTC' || upperID === 'GMT' ||
-      upperID === 'ETC/UTC' || upperID === 'ETC/GMT') {
-    return 'UTC';
-  }
-
-  // We expect only _, '-' and / beside ASCII letters.
-  // All inputs should conform to Area/Location(/Location)*, or Etc/GMT* .
-  // TODO(jshin): 1. Support 'GB-Eire", 'EST5EDT", "ROK', 'US/*', 'NZ' and many
-  // other aliases/linked names when moving timezone validation code to C++.
-  // See crbug.com/364374 and crbug.com/v8/8007 .
-  // 2. Resolve the difference betwee CLDR/ICU and IANA time zone db.
-  // See http://unicode.org/cldr/trac/ticket/9892 and crbug.com/645807 .
-  let match = %regexp_internal_match(GetTimezoneNameCheckRE(), tzID);
-  if (IS_NULL(match)) {
-    let match =
-      %regexp_internal_match(GetGMTOffsetTimezoneNameCheckRE(), upperID);
-     if (!IS_NULL(match) && match.length == 2)
-       return "Etc/GMT" + match.groups.offset;
-     else
-       throw %make_range_error(kInvalidTimeZone, tzID);
-  }
-
-  let result = toTitleCaseTimezoneLocation(match[1]) + '/' +
-               toTitleCaseTimezoneLocation(match[2]);
-
-  if (!IS_UNDEFINED(match[3]) && 3 < match.length) {
-    let locations = %StringSplit(match[3], '/', kMaxUint32);
-    // The 1st element is empty. Starts with i=1.
-    for (var i = 1; i < locations.length; i++) {
-      result = result + '/' + toTitleCaseTimezoneLocation(locations[i]);
-    }
-  }
-
-  return result;
-}
-
-/**
- * Initializes the given object so it's a valid BreakIterator instance.
- * Useful for subclassing.
- */
-function CreateBreakIterator(locales, options) {
-  if (IS_UNDEFINED(options)) {
-    options = {__proto__: null};
-  }
-
-  var getOption = getGetOption(options, 'breakiterator');
-
-  var internalOptions = {__proto__: null};
-
-  %DefineWEProperty(internalOptions, 'type', getOption(
-    'type', 'string', ['character', 'word', 'sentence', 'line'], 'word'));
-
-  var locale = resolveLocale('breakiterator', locales, options);
-  var resolved = %object_define_properties({__proto__: null}, {
-    requestedLocale: {value: locale.locale, writable: true},
-    type: {value: internalOptions.type, writable: true},
-    locale: {writable: true}
-  });
-
-  var iterator = %CreateBreakIterator(locale.locale, internalOptions, resolved);
-
-  %MarkAsInitializedIntlObjectOfType(iterator, BREAK_ITERATOR_TYPE);
-  iterator[resolvedSymbol] = resolved;
-
-  return iterator;
-}
-
-
-/**
- * Constructs Intl.v8BreakIterator object given optional locales and options
- * parameters.
- *
- * @constructor
- */
-function v8BreakIteratorConstructor() {
-  return IntlConstruct(this, GlobalIntlv8BreakIterator, CreateBreakIterator,
-                       new.target, arguments);
-}
-%SetCode(GlobalIntlv8BreakIterator, v8BreakIteratorConstructor);
-
-
-/**
- * BreakIterator resolvedOptions method.
- */
-DEFINE_METHOD(
-  GlobalIntlv8BreakIterator.prototype,
-  resolvedOptions() {
-    if (!IS_UNDEFINED(new.target)) {
-      throw %make_type_error(kOrdinaryFunctionCalledAsConstructor);
-    }
-
-    var methodName = 'resolvedOptions';
-    if(!IS_RECEIVER(this)) {
-      throw %make_type_error(kIncompatibleMethodReceiver, methodName, this);
-    }
-    var segmenter = %IntlUnwrapReceiver(this, BREAK_ITERATOR_TYPE,
-                                        GlobalIntlv8BreakIterator, methodName,
-                                        false);
-
-    return {
-      locale: segmenter[resolvedSymbol].locale,
-      type: segmenter[resolvedSymbol].type
-    };
-  }
-);
-
-
-/**
- * Returns the subset of the given locale list for which this locale list
- * has a matching (possibly fallback) locale. Locales appear in the same
- * order in the returned list as in the input list.
- * Options are optional parameter.
- */
-DEFINE_METHOD(
-  GlobalIntlv8BreakIterator,
-  supportedLocalesOf(locales) {
-    if (!IS_UNDEFINED(new.target)) {
-      throw %make_type_error(kOrdinaryFunctionCalledAsConstructor);
-    }
-
-    return %SupportedLocalesOf('breakiterator', locales, arguments[1]);
-  }
-);
-
-
-/**
- * Returns index of the first break in the string and moves current pointer.
- */
-function first(iterator) {
-  return %BreakIteratorFirst(iterator);
-}
-
-
-/**
- * Returns the index of the next break and moves the pointer.
- */
-function next(iterator) {
-  return %BreakIteratorNext(iterator);
-}
-
-
-/**
- * Returns index of the current break.
- */
-function current(iterator) {
-  return %BreakIteratorCurrent(iterator);
-}
-
-
-/**
- * Returns type of the current break.
- */
-function breakType(iterator) {
-  return %BreakIteratorBreakType(iterator);
-}
-
-
-AddBoundMethod(GlobalIntlv8BreakIterator, 'first', first, 0,
-               BREAK_ITERATOR_TYPE, false);
-AddBoundMethod(GlobalIntlv8BreakIterator, 'next', next, 0,
-               BREAK_ITERATOR_TYPE, false);
-AddBoundMethod(GlobalIntlv8BreakIterator, 'current', current, 0,
-               BREAK_ITERATOR_TYPE, false);
-AddBoundMethod(GlobalIntlv8BreakIterator, 'breakType', breakType, 0,
-               BREAK_ITERATOR_TYPE, false);
-
 // Save references to Intl objects and methods we use, for added security.
 var savedObjects = {
   __proto__: null,
@@ -1480,51 +447,4 @@ function cachedOrNewService(service, locales, options, defaults) {
   "cached_or_new_service", cachedOrNewService
 ]);
 
-/**
- * Formats a Date object (this) using locale and options values.
- * If locale or options are omitted, defaults are used - both date and time are
- * present in the output.
- */
-DEFINE_METHOD(
-  GlobalDate.prototype,
-  toLocaleString() {
-    var locales = arguments[0];
-    var options = arguments[1];
-    return %ToLocaleDateTime(
-        this, locales, options, 'any', 'all', 'dateformatall');
-  }
-);
-
-
-/**
- * Formats a Date object (this) using locale and options values.
- * If locale or options are omitted, defaults are used - only date is present
- * in the output.
- */
-DEFINE_METHOD(
-  GlobalDate.prototype,
-  toLocaleDateString() {
-    var locales = arguments[0];
-    var options = arguments[1];
-    return %ToLocaleDateTime(
-        this, locales, options, 'date', 'date', 'dateformatdate');
-  }
-);
-
-
-/**
- * Formats a Date object (this) using locale and options values.
- * If locale or options are omitted, defaults are used - only time is present
- * in the output.
- */
-DEFINE_METHOD(
-  GlobalDate.prototype,
-  toLocaleTimeString() {
-    var locales = arguments[0];
-    var options = arguments[1];
-    return %ToLocaleDateTime(
-        this, locales, options, 'time', 'time', 'dateformattime');
-  }
-);
-
 })
diff --git a/deps/v8/src/js/macros.py b/deps/v8/src/js/macros.py
index 8e533c38bc..4eaf990a58 100644
--- a/deps/v8/src/js/macros.py
+++ b/deps/v8/src/js/macros.py
@@ -62,10 +62,8 @@ macro REQUIRE_OBJECT_COERCIBLE(arg, functionName) = if (IS_NULL(%IS_VAR(arg)) ||
 
 # Inline macros. Use %IS_VAR to make sure arg is evaluated only once.
 macro TO_BOOLEAN(arg) = (!!(arg));
-macro TO_INTEGER(arg) = (%_ToInteger(arg));
 macro TO_LENGTH(arg) = (%_ToLength(arg));
 macro TO_STRING(arg) = (%_ToString(arg));
-macro TO_NUMBER(arg) = (%_ToNumber(arg));
 macro TO_OBJECT(arg) = (%_ToObject(arg));
 macro HAS_OWN_PROPERTY(obj, key) = (%_Call(ObjectHasOwnProperty, obj, key));
 
diff --git a/deps/v8/src/json-parser.h b/deps/v8/src/json-parser.h
index ac1442b414..67ad58c206 100644
--- a/deps/v8/src/json-parser.h
+++ b/deps/v8/src/json-parser.h
@@ -15,7 +15,7 @@ namespace internal {
 
 enum ParseElementResult { kElementFound, kElementNotFound, kNullHandle };
 
-class JsonParseInternalizer BASE_EMBEDDED {
+class JsonParseInternalizer {
  public:
   static MaybeHandle<Object> Internalize(Isolate* isolate,
                                          Handle<Object> object,
@@ -36,7 +36,7 @@ class JsonParseInternalizer BASE_EMBEDDED {
 
 // A simple json parser.
 template <bool seq_one_byte>
-class JsonParser BASE_EMBEDDED {
+class JsonParser {
  public:
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> Parse(
       Isolate* isolate, Handle<String> source, Handle<Object> reviver) {
diff --git a/deps/v8/src/json-stringifier.cc b/deps/v8/src/json-stringifier.cc
index 91a1b7201b..fe9a1468b1 100644
--- a/deps/v8/src/json-stringifier.cc
+++ b/deps/v8/src/json-stringifier.cc
@@ -16,7 +16,7 @@
 namespace v8 {
 namespace internal {
 
-class JsonStringifier BASE_EMBEDDED {
+class JsonStringifier {
  public:
   explicit JsonStringifier(Isolate* isolate);
 
@@ -755,11 +755,49 @@ void JsonStringifier::SerializeStringUnchecked_(
   // Assert that uc16 character is not truncated down to 8 bit.
   // The <uc16, char> version of this method must not be called.
   DCHECK(sizeof(DestChar) >= sizeof(SrcChar));
-
   for (int i = 0; i < src.length(); i++) {
     SrcChar c = src[i];
     if (DoNotEscape(c)) {
       dest->Append(c);
+    } else if (FLAG_harmony_json_stringify && c >= 0xD800 && c <= 0xDFFF) {
+      // The current character is a surrogate.
+      if (c <= 0xDBFF) {
+        // The current character is a leading surrogate.
+        if (i + 1 < src.length()) {
+          // There is a next character.
+          SrcChar next = src[i + 1];
+          if (next >= 0xDC00 && next <= 0xDFFF) {
+            // The next character is a trailing surrogate, meaning this is a
+            // surrogate pair.
+            dest->Append(c);
+            dest->Append(next);
+            i++;
+          } else {
+            // The next character is not a trailing surrogate. Thus, the
+            // current character is a lone leading surrogate.
+            dest->AppendCString("\\u");
+            char* const hex = DoubleToRadixCString(c, 16);
+            dest->AppendCString(hex);
+            DeleteArray(hex);
+          }
+        } else {
+          // There is no next character. Thus, the current character is a lone
+          // leading surrogate.
+          dest->AppendCString("\\u");
+          char* const hex = DoubleToRadixCString(c, 16);
+          dest->AppendCString(hex);
+          DeleteArray(hex);
+        }
+      } else {
+        // The current character is a lone trailing surrogate. (If it had been
+        // preceded by a leading surrogate, we would've ended up in the other
+        // branch earlier on, and the current character would've been handled
+        // as part of the surrogate pair already.)
+        dest->AppendCString("\\u");
+        char* const hex = DoubleToRadixCString(c, 16);
+        dest->AppendCString(hex);
+        DeleteArray(hex);
+      }
     } else {
       dest->AppendCString(&JsonEscapeTable[c * kJsonEscapeTableEntrySize]);
     }
@@ -784,6 +822,45 @@ void JsonStringifier::SerializeString_(Handle<String> string) {
       SrcChar c = reader.Get<SrcChar>(i);
       if (DoNotEscape(c)) {
         builder_.Append<SrcChar, DestChar>(c);
+      } else if (FLAG_harmony_json_stringify && c >= 0xD800 && c <= 0xDFFF) {
+        // The current character is a surrogate.
+        if (c <= 0xDBFF) {
+          // The current character is a leading surrogate.
+          if (i + 1 < reader.length()) {
+            // There is a next character.
+            SrcChar next = reader.Get<SrcChar>(i + 1);
+            if (next >= 0xDC00 && next <= 0xDFFF) {
+              // The next character is a trailing surrogate, meaning this is a
+              // surrogate pair.
+              builder_.Append<SrcChar, DestChar>(c);
+              builder_.Append<SrcChar, DestChar>(next);
+              i++;
+            } else {
+              // The next character is not a trailing surrogate. Thus, the
+              // current character is a lone leading surrogate.
+              builder_.AppendCString("\\u");
+              char* const hex = DoubleToRadixCString(c, 16);
+              builder_.AppendCString(hex);
+              DeleteArray(hex);
+            }
+          } else {
+            // There is no next character. Thus, the current character is a
+            // lone leading surrogate.
+            builder_.AppendCString("\\u");
+            char* const hex = DoubleToRadixCString(c, 16);
+            builder_.AppendCString(hex);
+            DeleteArray(hex);
+          }
+        } else {
+          // The current character is a lone trailing surrogate. (If it had
+          // been preceded by a leading surrogate, we would've ended up in the
+          // other branch earlier on, and the current character would've been
+          // handled as part of the surrogate pair already.)
+          builder_.AppendCString("\\u");
+          char* const hex = DoubleToRadixCString(c, 16);
+          builder_.AppendCString(hex);
+          DeleteArray(hex);
+        }
       } else {
         builder_.AppendCString(&JsonEscapeTable[c * kJsonEscapeTableEntrySize]);
       }
@@ -794,12 +871,15 @@ void JsonStringifier::SerializeString_(Handle<String> string) {
 
 template <>
 bool JsonStringifier::DoNotEscape(uint8_t c) {
-  return c >= '#' && c <= '~' && c != '\\';
+  // https://tc39.github.io/ecma262/#table-json-single-character-escapes
+  return c >= 0x23 && c <= 0x7E && c != 0x5C;
 }
 
 template <>
 bool JsonStringifier::DoNotEscape(uint16_t c) {
-  return c >= '#' && c != '\\' && c != 0x7F;
+  // https://tc39.github.io/ecma262/#table-json-single-character-escapes
+  return c >= 0x23 && c != 0x5C && c != 0x7F &&
+         (!FLAG_harmony_json_stringify || (c < 0xD800 || c > 0xDFFF));
 }
 
 void JsonStringifier::NewLine() {
diff --git a/deps/v8/src/keys.cc b/deps/v8/src/keys.cc
index e92902cfb5..ab893d5df9 100644
--- a/deps/v8/src/keys.cc
+++ b/deps/v8/src/keys.cc
@@ -20,9 +20,6 @@
 namespace v8 {
 namespace internal {
 
-KeyAccumulator::~KeyAccumulator() {
-}
-
 namespace {
 
 static bool ContainsOnlyValidKeys(Handle<FixedArray> array) {
@@ -634,10 +631,10 @@ Handle<FixedArray> GetOwnEnumPropertyDictionaryKeys(Isolate* isolate,
                                                     Handle<JSObject> object,
                                                     T* raw_dictionary) {
   Handle<T> dictionary(raw_dictionary, isolate);
-  int length = dictionary->NumberOfEnumerableProperties();
-  if (length == 0) {
+  if (dictionary->NumberOfElements() == 0) {
     return isolate->factory()->empty_fixed_array();
   }
+  int length = dictionary->NumberOfEnumerableProperties();
   Handle<FixedArray> storage = isolate->factory()->NewFixedArray(length);
   T::CopyEnumKeysTo(isolate, dictionary, storage, mode, accumulator);
   return storage;
diff --git a/deps/v8/src/keys.h b/deps/v8/src/keys.h
index c8db24a217..7ec7127aa5 100644
--- a/deps/v8/src/keys.h
+++ b/deps/v8/src/keys.h
@@ -32,12 +32,12 @@ enum AddKeyConversion { DO_NOT_CONVERT, CONVERT_TO_ARRAY_INDEX };
 // Only unique keys are kept by the KeyAccumulator, strings are stored in a
 // HashSet for inexpensive lookups. Integer keys are kept in sorted lists which
 // are more compact and allow for reasonably fast includes check.
-class KeyAccumulator final BASE_EMBEDDED {
+class KeyAccumulator final {
  public:
   KeyAccumulator(Isolate* isolate, KeyCollectionMode mode,
                  PropertyFilter filter)
       : isolate_(isolate), mode_(mode), filter_(filter) {}
-  ~KeyAccumulator();
+  ~KeyAccumulator() = default;
 
   static MaybeHandle<FixedArray> GetKeys(
       Handle<JSReceiver> object, KeyCollectionMode mode, PropertyFilter filter,
diff --git a/deps/v8/src/libplatform/default-platform.cc b/deps/v8/src/libplatform/default-platform.cc
index 3c29bd7eaa..c23616116e 100644
--- a/deps/v8/src/libplatform/default-platform.cc
+++ b/deps/v8/src/libplatform/default-platform.cc
@@ -140,11 +140,9 @@ bool DefaultPlatform::PumpMessageLoop(v8::Isolate* isolate,
   std::shared_ptr<DefaultForegroundTaskRunner> task_runner;
   {
     base::LockGuard<base::Mutex> guard(&lock_);
-    if (foreground_task_runner_map_.find(isolate) ==
-        foreground_task_runner_map_.end()) {
-      return failed_result;
-    }
-    task_runner = foreground_task_runner_map_[isolate];
+    auto it = foreground_task_runner_map_.find(isolate);
+    if (it == foreground_task_runner_map_.end()) return failed_result;
+    task_runner = it->second;
   }
 
   std::unique_ptr<Task> task = task_runner->PopTaskFromQueue(wait_for_work);
diff --git a/deps/v8/src/libplatform/default-platform.h b/deps/v8/src/libplatform/default-platform.h
index 1c844f0f09..40a945fd8a 100644
--- a/deps/v8/src/libplatform/default-platform.h
+++ b/deps/v8/src/libplatform/default-platform.h
@@ -35,7 +35,7 @@ class V8_PLATFORM_EXPORT DefaultPlatform : public NON_EXPORTED_BASE(Platform) {
       IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
       std::unique_ptr<v8::TracingController> tracing_controller = {});
 
-  virtual ~DefaultPlatform();
+  ~DefaultPlatform() override;
 
   void SetThreadPoolSize(int thread_pool_size);
 
diff --git a/deps/v8/src/libplatform/default-worker-threads-task-runner.cc b/deps/v8/src/libplatform/default-worker-threads-task-runner.cc
index 4251d8076e..f3338acfe3 100644
--- a/deps/v8/src/libplatform/default-worker-threads-task-runner.cc
+++ b/deps/v8/src/libplatform/default-worker-threads-task-runner.cc
@@ -17,6 +17,7 @@ DefaultWorkerThreadsTaskRunner::DefaultWorkerThreadsTaskRunner(
   }
 }
 
+// NOLINTNEXTLINE
 DefaultWorkerThreadsTaskRunner::~DefaultWorkerThreadsTaskRunner() {
   // This destructor is needed because we have unique_ptr to the WorkerThreads,
   // und the {WorkerThread} class is forward declared in the header file.
diff --git a/deps/v8/src/libplatform/default-worker-threads-task-runner.h b/deps/v8/src/libplatform/default-worker-threads-task-runner.h
index 5e46e3dd41..0b146a509c 100644
--- a/deps/v8/src/libplatform/default-worker-threads-task-runner.h
+++ b/deps/v8/src/libplatform/default-worker-threads-task-runner.h
@@ -19,7 +19,7 @@ class V8_PLATFORM_EXPORT DefaultWorkerThreadsTaskRunner
  public:
   DefaultWorkerThreadsTaskRunner(uint32_t thread_pool_size);
 
-  ~DefaultWorkerThreadsTaskRunner();
+  ~DefaultWorkerThreadsTaskRunner() override;
 
   void Terminate();
 
diff --git a/deps/v8/src/libplatform/tracing/trace-buffer.cc b/deps/v8/src/libplatform/tracing/trace-buffer.cc
index c7142ea520..8bec153440 100644
--- a/deps/v8/src/libplatform/tracing/trace-buffer.cc
+++ b/deps/v8/src/libplatform/tracing/trace-buffer.cc
@@ -15,8 +15,6 @@ TraceBufferRingBuffer::TraceBufferRingBuffer(size_t max_chunks,
   chunks_.resize(max_chunks);
 }
 
-TraceBufferRingBuffer::~TraceBufferRingBuffer() {}
-
 TraceObject* TraceBufferRingBuffer::AddTraceEvent(uint64_t* handle) {
   base::LockGuard<base::Mutex> guard(&mutex_);
   if (is_empty_ || chunks_[chunk_index_]->IsFull()) {
diff --git a/deps/v8/src/libplatform/tracing/trace-buffer.h b/deps/v8/src/libplatform/tracing/trace-buffer.h
index 3c756b7a69..95b9313338 100644
--- a/deps/v8/src/libplatform/tracing/trace-buffer.h
+++ b/deps/v8/src/libplatform/tracing/trace-buffer.h
@@ -18,7 +18,7 @@ namespace tracing {
 class TraceBufferRingBuffer : public TraceBuffer {
  public:
   TraceBufferRingBuffer(size_t max_chunks, TraceWriter* trace_writer);
-  ~TraceBufferRingBuffer();
+  ~TraceBufferRingBuffer() override = default;
 
   TraceObject* AddTraceEvent(uint64_t* handle) override;
   TraceObject* GetEventByHandle(uint64_t handle) override;
diff --git a/deps/v8/src/libplatform/tracing/trace-writer.h b/deps/v8/src/libplatform/tracing/trace-writer.h
index d811351389..df48c5a377 100644
--- a/deps/v8/src/libplatform/tracing/trace-writer.h
+++ b/deps/v8/src/libplatform/tracing/trace-writer.h
@@ -15,7 +15,7 @@ class JSONTraceWriter : public TraceWriter {
  public:
   explicit JSONTraceWriter(std::ostream& stream);
   JSONTraceWriter(std::ostream& stream, const std::string& tag);
-  ~JSONTraceWriter();
+  ~JSONTraceWriter() override;
   void AppendTraceEvent(TraceObject* trace_event) override;
   void Flush() override;
 
diff --git a/deps/v8/src/libplatform/tracing/tracing-controller.cc b/deps/v8/src/libplatform/tracing/tracing-controller.cc
index aa8789fa07..3d02347216 100644
--- a/deps/v8/src/libplatform/tracing/tracing-controller.cc
+++ b/deps/v8/src/libplatform/tracing/tracing-controller.cc
@@ -40,7 +40,7 @@ const int g_num_builtin_categories = 3;
 // Skip default categories.
 v8::base::AtomicWord g_category_index = g_num_builtin_categories;
 
-TracingController::TracingController() {}
+TracingController::TracingController() = default;
 
 TracingController::~TracingController() {
   StopTracing();
diff --git a/deps/v8/src/libplatform/worker-thread.h b/deps/v8/src/libplatform/worker-thread.h
index 22b0626024..abf0383e03 100644
--- a/deps/v8/src/libplatform/worker-thread.h
+++ b/deps/v8/src/libplatform/worker-thread.h
@@ -21,7 +21,7 @@ class TaskQueue;
 class V8_PLATFORM_EXPORT WorkerThread : public NON_EXPORTED_BASE(base::Thread) {
  public:
   explicit WorkerThread(TaskQueue* queue);
-  virtual ~WorkerThread();
+  ~WorkerThread() override;
 
   // Thread implementation.
   void Run() override;
diff --git a/deps/v8/src/libsampler/sampler.cc b/deps/v8/src/libsampler/sampler.cc
index f374ccddaf..464b4de32a 100644
--- a/deps/v8/src/libsampler/sampler.cc
+++ b/deps/v8/src/libsampler/sampler.cc
@@ -21,20 +21,12 @@
 #include <mach/mach.h>
 // OpenBSD doesn't have <ucontext.h>. ucontext_t lives in <signal.h>
 // and is a typedef for struct sigcontext. There is no uc_mcontext.
-#elif(!V8_OS_ANDROID || defined(__BIONIC_HAVE_UCONTEXT_T)) && !V8_OS_OPENBSD
+#elif !V8_OS_OPENBSD
 #include <ucontext.h>
 #endif
 
 #include <unistd.h>
 
-// GLibc on ARM defines mcontext_t has a typedef for 'struct sigcontext'.
-// Old versions of the C library <signal.h> didn't define the type.
-#if V8_OS_ANDROID && !defined(__BIONIC_HAVE_UCONTEXT_T) && \
-    (defined(__arm__) || defined(__aarch64__)) && \
-    !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT)
-#include <asm/sigcontext.h>  // NOLINT
-#endif
-
 #elif V8_OS_WIN || V8_OS_CYGWIN
 
 #include "src/base/win32-headers.h"
@@ -423,7 +415,7 @@ class SignalHandler {
 
   static void Restore() {
     if (signal_handler_installed_) {
-      sigaction(SIGPROF, &old_signal_handler_, 0);
+      sigaction(SIGPROF, &old_signal_handler_, nullptr);
       signal_handler_installed_ = false;
     }
   }
diff --git a/deps/v8/src/locked-queue.h b/deps/v8/src/locked-queue.h
index 1667917329..5bcab57b0c 100644
--- a/deps/v8/src/locked-queue.h
+++ b/deps/v8/src/locked-queue.h
@@ -17,7 +17,7 @@ namespace internal {
 // See:
 // https://www.cs.rochester.edu/research/synchronization/pseudocode/queues.html
 template <typename Record>
-class LockedQueue final BASE_EMBEDDED {
+class LockedQueue final {
  public:
   inline LockedQueue();
   inline ~LockedQueue();
diff --git a/deps/v8/src/log-utils.h b/deps/v8/src/log-utils.h
index bd56aaf418..e30b32b875 100644
--- a/deps/v8/src/log-utils.h
+++ b/deps/v8/src/log-utils.h
@@ -58,12 +58,12 @@ class Log {
 
   // Utility class for formatting log messages. It escapes the given messages
   // and then appends them to the static buffer in Log.
-  class MessageBuilder BASE_EMBEDDED {
+  class MessageBuilder {
    public:
     // Create a message builder starting from position 0.
     // This acquires the mutex in the log as well.
     explicit MessageBuilder(Log* log);
-    ~MessageBuilder() { }
+    ~MessageBuilder() = default;
 
     void AppendString(String* str,
                       base::Optional<int> length_limit = base::nullopt);
diff --git a/deps/v8/src/log.cc b/deps/v8/src/log.cc
index a3f484fd59..d78625a46a 100644
--- a/deps/v8/src/log.cc
+++ b/deps/v8/src/log.cc
@@ -349,7 +349,6 @@ void ExternalCodeEventListener::LogExistingCode() {
   HandleScope scope(isolate_);
   ExistingCodeLogger logger(isolate_, this);
   logger.LogCodeObjects();
-  logger.LogBytecodeHandlers();
   logger.LogCompiledFunctions();
 }
 
@@ -655,7 +654,7 @@ void JitLogger::LogRecordedBuffer(AbstractCode* code,
                                   SharedFunctionInfo* shared, const char* name,
                                   int length) {
   JitCodeEvent event;
-  memset(&event, 0, sizeof(event));
+  memset(static_cast<void*>(&event), 0, sizeof(event));
   event.type = JitCodeEvent::CODE_ADDED;
   event.code_start = reinterpret_cast<void*>(code->InstructionStart());
   event.code_type =
@@ -676,7 +675,7 @@ void JitLogger::LogRecordedBuffer(AbstractCode* code,
 void JitLogger::LogRecordedBuffer(const wasm::WasmCode* code, const char* name,
                                   int length) {
   JitCodeEvent event;
-  memset(&event, 0, sizeof(event));
+  memset(static_cast<void*>(&event), 0, sizeof(event));
   event.type = JitCodeEvent::CODE_ADDED;
   event.code_type = JitCodeEvent::JIT_CODE;
   event.code_start = code->instructions().start();
@@ -708,7 +707,7 @@ void JitLogger::AddCodeLinePosInfoEvent(
     int position,
     JitCodeEvent::PositionType position_type) {
   JitCodeEvent event;
-  memset(&event, 0, sizeof(event));
+  memset(static_cast<void*>(&event), 0, sizeof(event));
   event.type = JitCodeEvent::CODE_ADD_LINE_POS_INFO;
   event.user_data = jit_handler_data;
   event.line_info.offset = pc_offset;
@@ -722,7 +721,7 @@ void JitLogger::AddCodeLinePosInfoEvent(
 
 void* JitLogger::StartCodePosInfoEvent() {
   JitCodeEvent event;
-  memset(&event, 0, sizeof(event));
+  memset(static_cast<void*>(&event), 0, sizeof(event));
   event.type = JitCodeEvent::CODE_START_LINE_INFO_RECORDING;
   event.isolate = reinterpret_cast<v8::Isolate*>(isolate_);
 
@@ -733,7 +732,7 @@ void* JitLogger::StartCodePosInfoEvent() {
 void JitLogger::EndCodePosInfoEvent(Address start_address,
                                     void* jit_handler_data) {
   JitCodeEvent event;
-  memset(&event, 0, sizeof(event));
+  memset(static_cast<void*>(&event), 0, sizeof(event));
   event.type = JitCodeEvent::CODE_END_LINE_INFO_RECORDING;
   event.code_start = reinterpret_cast<void*>(start_address);
   event.user_data = jit_handler_data;
@@ -794,7 +793,7 @@ class Profiler: public base::Thread {
     }
   }
 
-  virtual void Run();
+  void Run() override;
 
   // Pause and Resume TickSample data collection.
   void Pause() { paused_ = true; }
@@ -848,7 +847,7 @@ class Ticker: public sampler::Sampler {
         profiler_(nullptr),
         sampling_thread_(new SamplingThread(this, interval_microseconds)) {}
 
-  ~Ticker() {
+  ~Ticker() override {
     if (IsActive()) Stop();
     delete sampling_thread_;
   }
@@ -1323,7 +1322,7 @@ void Logger::CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
   //        <script-offset> is the position within the script
   //        <inlining-id> is the offset in the <inlining> table
   //   <inlining> table is a sequence of strings of the form
-  //      F<function-id>O<script-offset>[I<inlining-id>
+  //      F<function-id>O<script-offset>[I<inlining-id>]
   //      where
   //         <function-id> is an index into the <fns> function table
   //   <fns> is the function table encoded as a sequence of strings
@@ -1335,12 +1334,8 @@ void Logger::CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
       << shared->EndPosition() << kNext;
 
   SourcePositionTableIterator iterator(code->source_position_table());
-  bool is_first = true;
   bool hasInlined = false;
   for (; !iterator.done(); iterator.Advance()) {
-    if (is_first) {
-      is_first = false;
-    }
     SourcePosition pos = iterator.source_position();
     msg << "C" << iterator.code_offset() << "O" << pos.ScriptOffset();
     if (pos.isInlined()) {
@@ -1604,7 +1599,7 @@ bool Logger::EnsureLogScriptSource(Script* script) {
   // Make sure the script is written to the log file.
   int script_id = script->id();
   if (logged_source_code_.find(script_id) != logged_source_code_.end()) {
-    return false;
+    return true;
   }
   // This script has not been logged yet.
   logged_source_code_.insert(script_id);
@@ -1838,16 +1833,6 @@ void Logger::LogCodeObject(Object* object) {
 
 void Logger::LogCodeObjects() { existing_code_logger_.LogCodeObjects(); }
 
-void Logger::LogBytecodeHandler(interpreter::Bytecode bytecode,
-                                interpreter::OperandScale operand_scale,
-                                Code* code) {
-  existing_code_logger_.LogBytecodeHandler(bytecode, operand_scale, code);
-}
-
-void Logger::LogBytecodeHandlers() {
-  existing_code_logger_.LogBytecodeHandlers();
-}
-
 void Logger::LogExistingFunction(Handle<SharedFunctionInfo> shared,
                                  Handle<AbstractCode> code) {
   existing_code_logger_.LogExistingFunction(shared, code);
@@ -2162,37 +2147,6 @@ void ExistingCodeLogger::LogCompiledFunctions() {
   }
 }
 
-void ExistingCodeLogger::LogBytecodeHandler(
-    interpreter::Bytecode bytecode, interpreter::OperandScale operand_scale,
-    Code* code) {
-  std::string bytecode_name =
-      interpreter::Bytecodes::ToString(bytecode, operand_scale);
-  CALL_CODE_EVENT_HANDLER(
-      CodeCreateEvent(CodeEventListener::BYTECODE_HANDLER_TAG,
-                      AbstractCode::cast(code), bytecode_name.c_str()))
-}
-
-void ExistingCodeLogger::LogBytecodeHandlers() {
-  const interpreter::OperandScale kOperandScales[] = {
-#define VALUE(Name, _) interpreter::OperandScale::k##Name,
-      OPERAND_SCALE_LIST(VALUE)
-#undef VALUE
-  };
-
-  const int last_index = static_cast<int>(interpreter::Bytecode::kLast);
-  interpreter::Interpreter* interpreter = isolate_->interpreter();
-  for (auto operand_scale : kOperandScales) {
-    for (int index = 0; index <= last_index; ++index) {
-      interpreter::Bytecode bytecode = interpreter::Bytecodes::FromByte(index);
-      if (interpreter::Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) {
-        Code* code = interpreter->GetBytecodeHandler(bytecode, operand_scale);
-        if (isolate_->heap()->IsDeserializeLazyHandler(code)) continue;
-        LogBytecodeHandler(bytecode, operand_scale, code);
-      }
-    }
-  }
-}
-
 void ExistingCodeLogger::LogExistingFunction(
     Handle<SharedFunctionInfo> shared, Handle<AbstractCode> code,
     CodeEventListener::LogEventsAndTags tag) {
diff --git a/deps/v8/src/log.h b/deps/v8/src/log.h
index 5ce7418364..8ec63a9b46 100644
--- a/deps/v8/src/log.h
+++ b/deps/v8/src/log.h
@@ -75,15 +75,6 @@ class Profiler;
 class RuntimeCallTimer;
 class Ticker;
 
-namespace interpreter {
-enum class Bytecode : uint8_t;
-enum class OperandScale : uint8_t;
-}  // namespace interpreter
-
-namespace wasm {
-class WasmCode;
-}
-
 #undef LOG
 #define LOG(isolate, Call)                              \
   do {                                                  \
@@ -104,7 +95,6 @@ class ExistingCodeLogger {
       : isolate_(isolate), listener_(listener) {}
 
   void LogCodeObjects();
-  void LogBytecodeHandlers();
 
   void LogCompiledFunctions();
   void LogExistingFunction(Handle<SharedFunctionInfo> shared,
@@ -112,8 +102,6 @@ class ExistingCodeLogger {
                            CodeEventListener::LogEventsAndTags tag =
                                CodeEventListener::LAZY_COMPILE_TAG);
   void LogCodeObject(Object* object);
-  void LogBytecodeHandler(interpreter::Bytecode bytecode,
-                          interpreter::OperandScale operand_scale, Code* code);
 
  private:
   Isolate* isolate_;
@@ -202,41 +190,43 @@ class Logger : public CodeEventListener {
   void RemoveCodeEventListener(CodeEventListener* listener);
 
   // Emits a code event for a callback function.
-  void CallbackEvent(Name* name, Address entry_point);
-  void GetterCallbackEvent(Name* name, Address entry_point);
-  void SetterCallbackEvent(Name* name, Address entry_point);
+  void CallbackEvent(Name* name, Address entry_point) override;
+  void GetterCallbackEvent(Name* name, Address entry_point) override;
+  void SetterCallbackEvent(Name* name, Address entry_point) override;
   // Emits a code create event.
   void CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
-                       AbstractCode* code, const char* source);
+                       AbstractCode* code, const char* source) override;
   void CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
-                       AbstractCode* code, Name* name);
+                       AbstractCode* code, Name* name) override;
   void CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
                        AbstractCode* code, SharedFunctionInfo* shared,
-                       Name* name);
+                       Name* name) override;
   void CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
                        AbstractCode* code, SharedFunctionInfo* shared,
-                       Name* source, int line, int column);
+                       Name* source, int line, int column) override;
   void CodeCreateEvent(CodeEventListener::LogEventsAndTags tag,
-                       const wasm::WasmCode* code, wasm::WasmName name);
+                       const wasm::WasmCode* code,
+                       wasm::WasmName name) override;
   // Emits a code deoptimization event.
-  void CodeDisableOptEvent(AbstractCode* code, SharedFunctionInfo* shared);
-  void CodeMovingGCEvent();
+  void CodeDisableOptEvent(AbstractCode* code,
+                           SharedFunctionInfo* shared) override;
+  void CodeMovingGCEvent() override;
   // Emits a code create event for a RegExp.
-  void RegExpCodeCreateEvent(AbstractCode* code, String* source);
+  void RegExpCodeCreateEvent(AbstractCode* code, String* source) override;
   // Emits a code move event.
-  void CodeMoveEvent(AbstractCode* from, AbstractCode* to);
+  void CodeMoveEvent(AbstractCode* from, AbstractCode* to) override;
   // Emits a code line info record event.
   void CodeLinePosInfoRecordEvent(Address code_start,
                                   ByteArray* source_position_table);
   void CodeLinePosInfoRecordEvent(Address code_start,
                                   Vector<const byte> source_position_table);
 
-  void SharedFunctionInfoMoveEvent(Address from, Address to);
+  void SharedFunctionInfoMoveEvent(Address from, Address to) override;
 
   void CodeNameEvent(Address addr, int pos, const char* code_name);
 
   void CodeDeoptEvent(Code* code, DeoptimizeKind kind, Address pc,
-                      int fp_to_sp_delta);
+                      int fp_to_sp_delta) override;
 
   void ICEvent(const char* type, bool keyed, Map* map, Object* key,
                char old_state, char new_state, const char* modifier,
@@ -268,7 +258,7 @@ class Logger : public CodeEventListener {
     return is_logging_;
   }
 
-  bool is_listening_to_code_events() {
+  bool is_listening_to_code_events() override {
     return is_logging() || jit_logger_ != nullptr;
   }
 
@@ -284,10 +274,6 @@ class Logger : public CodeEventListener {
   void LogAccessorCallbacks();
   // Used for logging stubs found in the snapshot.
   void LogCodeObjects();
-  // Used for logging bytecode handlers found in the snapshot.
-  void LogBytecodeHandlers();
-  void LogBytecodeHandler(interpreter::Bytecode bytecode,
-                          interpreter::OperandScale operand_scale, Code* code);
   // Logs all Mpas foind in the heap.
   void LogMaps();
 
@@ -303,7 +289,7 @@ class Logger : public CodeEventListener {
 
  private:
   explicit Logger(Isolate* isolate);
-  ~Logger();
+  ~Logger() override;
 
   // Emits the profiler's first message.
   void ProfilerBeginEvent();
diff --git a/deps/v8/src/lookup.cc b/deps/v8/src/lookup.cc
index fb3d1263d7..c6cc06eeae 100644
--- a/deps/v8/src/lookup.cc
+++ b/deps/v8/src/lookup.cc
@@ -323,12 +323,19 @@ void LookupIterator::InternalUpdateProtector() {
       }
     }
   } else if (*name_ == roots.next_string()) {
-    if (!isolate_->IsArrayIteratorLookupChainIntact()) return;
-    // Setting the next property of %ArrayIteratorPrototype% also needs to
-    // invalidate the array iterator protector.
     if (isolate_->IsInAnyContext(
             *holder_, Context::INITIAL_ARRAY_ITERATOR_PROTOTYPE_INDEX)) {
+      // Setting the next property of %ArrayIteratorPrototype% also needs to
+      // invalidate the array iterator protector.
+      if (!isolate_->IsArrayIteratorLookupChainIntact()) return;
       isolate_->InvalidateArrayIteratorProtector();
+    } else if (isolate_->IsInAnyContext(
+                   *receiver_,
+                   Context::INITIAL_STRING_ITERATOR_PROTOTYPE_INDEX)) {
+      // Setting the next property of %StringIteratorPrototype% invalidates the
+      // string iterator protector.
+      if (!isolate_->IsStringIteratorLookupChainIntact()) return;
+      isolate_->InvalidateStringIteratorProtector();
     }
   } else if (*name_ == roots.species_symbol()) {
     if (!isolate_->IsArraySpeciesLookupChainIntact() &&
@@ -354,9 +361,17 @@ void LookupIterator::InternalUpdateProtector() {
     if (!isolate_->IsIsConcatSpreadableLookupChainIntact()) return;
     isolate_->InvalidateIsConcatSpreadableProtector();
   } else if (*name_ == roots.iterator_symbol()) {
-    if (!isolate_->IsArrayIteratorLookupChainIntact()) return;
     if (holder_->IsJSArray()) {
+      if (!isolate_->IsArrayIteratorLookupChainIntact()) return;
       isolate_->InvalidateArrayIteratorProtector();
+    } else if (isolate_->IsInAnyContext(
+                   *receiver_, Context::INITIAL_STRING_PROTOTYPE_INDEX)) {
+      // Setting the Symbol.iterator property of String.prototype invalidates
+      // the string iterator protector. Symbol.iterator can also be set on a
+      // String wrapper, but not on a primitive string. We only support
+      // protector for primitive strings.
+      if (!isolate_->IsStringIteratorLookupChainIntact()) return;
+      isolate_->InvalidateStringIteratorProtector();
     }
   } else if (*name_ == roots.resolve_string()) {
     if (!isolate_->IsPromiseResolveLookupChainIntact()) return;
@@ -535,7 +550,7 @@ void LookupIterator::ReconfigureDataProperty(Handle<Object> value,
 // via a trap. Adding properties to primitive values is not observable.
 void LookupIterator::PrepareTransitionToDataProperty(
     Handle<JSReceiver> receiver, Handle<Object> value,
-    PropertyAttributes attributes, Object::StoreFromKeyed store_mode) {
+    PropertyAttributes attributes, StoreOrigin store_origin) {
   DCHECK_IMPLIES(receiver->IsJSProxy(), name()->IsPrivate());
   DCHECK(receiver.is_identical_to(GetStoreTarget<JSReceiver>()));
   if (state_ == TRANSITION) return;
@@ -589,7 +604,7 @@ void LookupIterator::PrepareTransitionToDataProperty(
 
   Handle<Map> transition =
       Map::TransitionToDataProperty(isolate_, map, name_, value, attributes,
-                                    kDefaultFieldConstness, store_mode);
+                                    kDefaultFieldConstness, store_origin);
   state_ = TRANSITION;
   transition_ = transition;
 
diff --git a/deps/v8/src/lookup.h b/deps/v8/src/lookup.h
index c1d4dd4460..1c55d2769c 100644
--- a/deps/v8/src/lookup.h
+++ b/deps/v8/src/lookup.h
@@ -15,7 +15,7 @@
 namespace v8 {
 namespace internal {
 
-class V8_EXPORT_PRIVATE LookupIterator final BASE_EMBEDDED {
+class V8_EXPORT_PRIVATE LookupIterator final {
  public:
   enum Configuration {
     // Configuration bits.
@@ -160,7 +160,7 @@ class V8_EXPORT_PRIVATE LookupIterator final BASE_EMBEDDED {
   void PrepareTransitionToDataProperty(Handle<JSReceiver> receiver,
                                        Handle<Object> value,
                                        PropertyAttributes attributes,
-                                       Object::StoreFromKeyed store_mode);
+                                       StoreOrigin store_origin);
   inline bool IsCacheableTransition();
   void ApplyTransitionToDataProperty(Handle<JSReceiver> receiver);
   void ReconfigureDataProperty(Handle<Object> value,
diff --git a/deps/v8/src/machine-type.h b/deps/v8/src/machine-type.h
index 68db01a4ef..37c2623f89 100644
--- a/deps/v8/src/machine-type.h
+++ b/deps/v8/src/machine-type.h
@@ -298,6 +298,12 @@ V8_EXPORT_PRIVATE inline int ElementSizeInBytes(MachineRepresentation rep) {
   return 1 << ElementSizeLog2Of(rep);
 }
 
+// Converts representation to bit for representation masks.
+V8_EXPORT_PRIVATE inline constexpr int RepresentationBit(
+    MachineRepresentation rep) {
+  return 1 << static_cast<int>(rep);
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/macro-assembler.h b/deps/v8/src/macro-assembler.h
index af5c60536b..33ca113da0 100644
--- a/deps/v8/src/macro-assembler.h
+++ b/deps/v8/src/macro-assembler.h
@@ -209,7 +209,7 @@ class NoRootArrayScope {
 // either registers or immediate values. Used to make sure that the
 // caller provides exactly the expected number of parameters to the
 // callee.
-class ParameterCount BASE_EMBEDDED {
+class ParameterCount {
  public:
   explicit ParameterCount(Register reg) : reg_(reg), immediate_(0) {}
   explicit ParameterCount(uint16_t imm) : reg_(no_reg), immediate_(imm) {}
diff --git a/deps/v8/src/math-random.cc b/deps/v8/src/math-random.cc
new file mode 100644
index 0000000000..932d4b9d2a
--- /dev/null
+++ b/deps/v8/src/math-random.cc
@@ -0,0 +1,70 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/math-random.h"
+
+#include "src/assert-scope.h"
+#include "src/base/utils/random-number-generator.h"
+#include "src/contexts-inl.h"
+#include "src/isolate.h"
+#include "src/objects/fixed-array.h"
+
+namespace v8 {
+namespace internal {
+
+void MathRandom::InitializeContext(Isolate* isolate,
+                                   Handle<Context> native_context) {
+  Handle<FixedDoubleArray> cache = Handle<FixedDoubleArray>::cast(
+      isolate->factory()->NewFixedDoubleArray(kCacheSize, TENURED));
+  for (int i = 0; i < kCacheSize; i++) cache->set(i, 0);
+  native_context->set_math_random_cache(*cache);
+  Handle<PodArray<State>> pod = PodArray<State>::New(isolate, 1, TENURED);
+  native_context->set_math_random_state(*pod);
+  ResetContext(*native_context);
+}
+
+void MathRandom::ResetContext(Context* native_context) {
+  native_context->set_math_random_index(Smi::kZero);
+  State state = {0, 0};
+  PodArray<State>::cast(native_context->math_random_state())->set(0, state);
+}
+
+Smi* MathRandom::RefillCache(Isolate* isolate, Context* native_context) {
+  DisallowHeapAllocation no_gc;
+  PodArray<State>* pod =
+      PodArray<State>::cast(native_context->math_random_state());
+  State state = pod->get(0);
+  // Initialize state if not yet initialized. If a fixed random seed was
+  // requested, use it to reset our state the first time a script asks for
+  // random numbers in this context. This ensures the script sees a consistent
+  // sequence.
+  if (state.s0 == 0 && state.s1 == 0) {
+    uint64_t seed;
+    if (FLAG_random_seed != 0) {
+      seed = FLAG_random_seed;
+    } else {
+      isolate->random_number_generator()->NextBytes(&seed, sizeof(seed));
+    }
+    state.s0 = base::RandomNumberGenerator::MurmurHash3(seed);
+    state.s1 = base::RandomNumberGenerator::MurmurHash3(~seed);
+    CHECK(state.s0 != 0 || state.s1 != 0);
+  }
+
+  FixedDoubleArray* cache =
+      FixedDoubleArray::cast(native_context->math_random_cache());
+  // Create random numbers.
+  for (int i = 0; i < kCacheSize; i++) {
+    // Generate random numbers using xorshift128+.
+    base::RandomNumberGenerator::XorShift128(&state.s0, &state.s1);
+    cache->set(i, base::RandomNumberGenerator::ToDouble(state.s0));
+  }
+  pod->set(0, state);
+
+  Smi* new_index = Smi::FromInt(kCacheSize);
+  native_context->set_math_random_index(new_index);
+  return new_index;
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/math-random.h b/deps/v8/src/math-random.h
new file mode 100644
index 0000000000..a720c75757
--- /dev/null
+++ b/deps/v8/src/math-random.h
@@ -0,0 +1,33 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_MATH_RANDOM_H_
+#define V8_MATH_RANDOM_H_
+
+#include "src/contexts.h"
+#include "src/globals.h"
+
+namespace v8 {
+namespace internal {
+
+class MathRandom : public AllStatic {
+ public:
+  static void InitializeContext(Isolate* isolate,
+                                Handle<Context> native_context);
+
+  static void ResetContext(Context* native_context);
+  static Smi* RefillCache(Isolate* isolate, Context* native_context);
+
+  static const int kCacheSize = 64;
+  static const int kStateSize = 2 * kInt64Size;
+
+  struct State {
+    uint64_t s0;
+    uint64_t s1;
+  };
+};
+
+}  // namespace internal
+}  // namespace v8
+#endif  // V8_MATH_RANDOM_H_
diff --git a/deps/v8/src/maybe-handles-inl.h b/deps/v8/src/maybe-handles-inl.h
index c9c8c88700..1743af41a4 100644
--- a/deps/v8/src/maybe-handles-inl.h
+++ b/deps/v8/src/maybe-handles-inl.h
@@ -22,12 +22,12 @@ MaybeObjectHandle::MaybeObjectHandle()
 
 MaybeObjectHandle::MaybeObjectHandle(MaybeObject* object, Isolate* isolate) {
   HeapObject* heap_object;
-  DCHECK(!object->IsClearedWeakHeapObject());
-  if (object->ToWeakHeapObject(&heap_object)) {
+  DCHECK(!object->IsCleared());
+  if (object->GetHeapObjectIfWeak(&heap_object)) {
     handle_ = handle(heap_object, isolate);
     reference_type_ = HeapObjectReferenceType::WEAK;
   } else {
-    handle_ = handle(object->ToObject(), isolate);
+    handle_ = handle(object->cast<Object>(), isolate);
     reference_type_ = HeapObjectReferenceType::STRONG;
   }
 }
diff --git a/deps/v8/src/maybe-handles.h b/deps/v8/src/maybe-handles.h
index d4b639e18e..231e4d78fb 100644
--- a/deps/v8/src/maybe-handles.h
+++ b/deps/v8/src/maybe-handles.h
@@ -23,7 +23,7 @@ namespace internal {
 template <typename T>
 class MaybeHandle final {
  public:
-  V8_INLINE MaybeHandle() {}
+  V8_INLINE MaybeHandle() = default;
 
   // Constructor for handling automatic up casting from Handle.
   // Ex. Handle<JSArray> can be passed when MaybeHandle<Object> is expected.
diff --git a/deps/v8/src/messages.cc b/deps/v8/src/messages.cc
index a1c228ec59..3d98da4e63 100644
--- a/deps/v8/src/messages.cc
+++ b/deps/v8/src/messages.cc
@@ -305,10 +305,9 @@ void JSStackFrame::FromFrameArray(Isolate* isolate, Handle<FrameArray> array,
   const int flags = array->Flags(frame_ix)->value();
   is_constructor_ = (flags & FrameArray::kIsConstructor) != 0;
   is_strict_ = (flags & FrameArray::kIsStrict) != 0;
+  is_async_ = (flags & FrameArray::kIsAsync) != 0;
 }
 
-JSStackFrame::JSStackFrame() {}
-
 JSStackFrame::JSStackFrame(Isolate* isolate, Handle<Object> receiver,
                            Handle<JSFunction> function,
                            Handle<AbstractCode> code, int offset)
@@ -317,6 +316,7 @@ JSStackFrame::JSStackFrame(Isolate* isolate, Handle<Object> receiver,
       function_(function),
       code_(code),
       offset_(offset),
+      is_async_(false),
       is_constructor_(false),
       is_strict_(false) {}
 
@@ -386,6 +386,13 @@ Handle<Object> JSStackFrame::GetMethodName() {
   }
 
   Handle<String> name(function_->shared()->Name(), isolate_);
+
+  // The static initializer function is not a method, so don't add a
+  // class name, just return the function name.
+  if (name->IsUtf8EqualTo(CStrVector("<static_fields_initializer>"), true)) {
+    return name;
+  }
+
   // ES2015 gives getters and setters name prefixes which must
   // be stripped to find the property name.
   if (name->IsUtf8EqualTo(CStrVector("get "), true) ||
@@ -599,9 +606,13 @@ MaybeHandle<String> JSStackFrame::ToString() {
   Handle<Object> function_name = GetFunctionName();
 
   const bool is_toplevel = IsToplevel();
+  const bool is_async = IsAsync();
   const bool is_constructor = IsConstructor();
   const bool is_method_call = !(is_toplevel || is_constructor);
 
+  if (is_async) {
+    builder.AppendCString("async ");
+  }
   if (is_method_call) {
     AppendMethodCall(isolate_, this, &builder);
   } else if (is_constructor) {
@@ -635,8 +646,6 @@ Handle<Script> JSStackFrame::GetScript() const {
   return handle(Script::cast(function_->shared()->script()), isolate_);
 }
 
-WasmStackFrame::WasmStackFrame() {}
-
 void WasmStackFrame::FromFrameArray(Isolate* isolate, Handle<FrameArray> array,
                                     int frame_ix) {
   // This function is called for compiled and interpreted wasm frames, and for
@@ -728,8 +737,6 @@ Handle<Script> WasmStackFrame::GetScript() const {
   return handle(wasm_instance_->module_object()->script(), isolate_);
 }
 
-AsmJsWasmStackFrame::AsmJsWasmStackFrame() {}
-
 void AsmJsWasmStackFrame::FromFrameArray(Isolate* isolate,
                                          Handle<FrameArray> array,
                                          int frame_ix) {
@@ -851,8 +858,9 @@ MaybeHandle<Object> ConstructCallSite(Isolate* isolate,
       handle(isolate->native_context()->callsite_function(), isolate);
 
   Handle<JSObject> obj;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, obj, JSObject::New(target, target),
-                             Object);
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, obj,
+      JSObject::New(target, target, Handle<AllocationSite>::null()), Object);
 
   Handle<Symbol> key = isolate->factory()->call_site_frame_array_symbol();
   RETURN_ON_EXCEPTION(isolate, JSObject::SetOwnPropertyIgnoreAttributes(
@@ -947,39 +955,55 @@ MaybeHandle<Object> ErrorUtils::FormatStackTrace(Isolate* isolate,
   Handle<FrameArray> elems(FrameArray::cast(raw_stack_array->elements()),
                            isolate);
 
-  // If there's a user-specified "prepareStackFrames" function, call it on the
-  // frames and use its result.
+  const bool in_recursion = isolate->formatting_stack_trace();
+  if (!in_recursion) {
+    if (isolate->HasPrepareStackTraceCallback()) {
+      Handle<Context> error_context = error->GetCreationContext();
+      DCHECK(!error_context.is_null() && error_context->IsNativeContext());
+      PrepareStackTraceScope scope(isolate);
 
-  Handle<JSFunction> global_error = isolate->error_function();
-  Handle<Object> prepare_stack_trace;
-  ASSIGN_RETURN_ON_EXCEPTION(
-      isolate, prepare_stack_trace,
-      JSFunction::GetProperty(isolate, global_error, "prepareStackTrace"),
-      Object);
+      Handle<Object> result;
+      ASSIGN_RETURN_ON_EXCEPTION(
+          isolate, result,
+          isolate->RunPrepareStackTraceCallback(error_context, error), Object);
+      return result;
+    } else {
+      Handle<JSFunction> global_error = isolate->error_function();
 
-  const bool in_recursion = isolate->formatting_stack_trace();
-  if (prepare_stack_trace->IsJSFunction() && !in_recursion) {
-    PrepareStackTraceScope scope(isolate);
+      // If there's a user-specified "prepareStackTrace" function, call it on
+      // the frames and use its result.
 
-    isolate->CountUsage(v8::Isolate::kErrorPrepareStackTrace);
+      Handle<Object> prepare_stack_trace;
+      ASSIGN_RETURN_ON_EXCEPTION(
+          isolate, prepare_stack_trace,
+          JSFunction::GetProperty(isolate, global_error, "prepareStackTrace"),
+          Object);
 
-    Handle<JSArray> sites;
-    ASSIGN_RETURN_ON_EXCEPTION(isolate, sites, GetStackFrames(isolate, elems),
-                               Object);
+      if (prepare_stack_trace->IsJSFunction()) {
+        PrepareStackTraceScope scope(isolate);
 
-    const int argc = 2;
-    ScopedVector<Handle<Object>> argv(argc);
+        isolate->CountUsage(v8::Isolate::kErrorPrepareStackTrace);
 
-    argv[0] = error;
-    argv[1] = sites;
+        Handle<JSArray> sites;
+        ASSIGN_RETURN_ON_EXCEPTION(isolate, sites,
+                                   GetStackFrames(isolate, elems), Object);
 
-    Handle<Object> result;
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, result, Execution::Call(isolate, prepare_stack_trace,
-                                         global_error, argc, argv.start()),
-        Object);
+        const int argc = 2;
+        ScopedVector<Handle<Object>> argv(argc);
+        argv[0] = error;
+        argv[1] = sites;
+
+        Handle<Object> result;
 
-    return result;
+        ASSIGN_RETURN_ON_EXCEPTION(
+            isolate, result,
+            Execution::Call(isolate, prepare_stack_trace, global_error, argc,
+                            argv.start()),
+            Object);
+
+        return result;
+      }
+    }
   }
 
   // Otherwise, run our internal formatting logic.
@@ -1107,8 +1131,10 @@ MaybeHandle<Object> ErrorUtils::Construct(
   // 2. Let O be ? OrdinaryCreateFromConstructor(newTarget, "%ErrorPrototype%",
   //    « [[ErrorData]] »).
   Handle<JSObject> err;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, err,
-                             JSObject::New(target, new_target_recv), Object);
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, err,
+      JSObject::New(target, new_target_recv, Handle<AllocationSite>::null()),
+      Object);
 
   // 3. If message is not undefined, then
   //  a. Let msg be ? ToString(message).
diff --git a/deps/v8/src/messages.h b/deps/v8/src/messages.h
index 030fc0b926..05d287faae 100644
--- a/deps/v8/src/messages.h
+++ b/deps/v8/src/messages.h
@@ -50,7 +50,7 @@ class MessageLocation {
 
 class StackFrameBase {
  public:
-  virtual ~StackFrameBase() {}
+  virtual ~StackFrameBase() = default;
 
   virtual Handle<Object> GetReceiver() const = 0;
   virtual Handle<Object> GetFunction() const = 0;
@@ -71,13 +71,14 @@ class StackFrameBase {
   virtual bool IsNative() = 0;
   virtual bool IsToplevel() = 0;
   virtual bool IsEval();
+  virtual bool IsAsync() const = 0;
   virtual bool IsConstructor() = 0;
   virtual bool IsStrict() const = 0;
 
   virtual MaybeHandle<String> ToString() = 0;
 
  protected:
-  StackFrameBase() {}
+  StackFrameBase() = default;
   explicit StackFrameBase(Isolate* isolate) : isolate_(isolate) {}
   Isolate* isolate_;
 
@@ -91,7 +92,7 @@ class JSStackFrame : public StackFrameBase {
   JSStackFrame(Isolate* isolate, Handle<Object> receiver,
                Handle<JSFunction> function, Handle<AbstractCode> code,
                int offset);
-  virtual ~JSStackFrame() {}
+  ~JSStackFrame() override = default;
 
   Handle<Object> GetReceiver() const override { return receiver_; }
   Handle<Object> GetFunction() const override;
@@ -108,13 +109,14 @@ class JSStackFrame : public StackFrameBase {
 
   bool IsNative() override;
   bool IsToplevel() override;
+  bool IsAsync() const override { return is_async_; }
   bool IsConstructor() override { return is_constructor_; }
   bool IsStrict() const override { return is_strict_; }
 
   MaybeHandle<String> ToString() override;
 
  private:
-  JSStackFrame();
+  JSStackFrame() = default;
   void FromFrameArray(Isolate* isolate, Handle<FrameArray> array, int frame_ix);
 
   bool HasScript() const override;
@@ -125,15 +127,16 @@ class JSStackFrame : public StackFrameBase {
   Handle<AbstractCode> code_;
   int offset_;
 
-  bool is_constructor_;
-  bool is_strict_;
+  bool is_async_ : 1;
+  bool is_constructor_ : 1;
+  bool is_strict_ : 1;
 
   friend class FrameArrayIterator;
 };
 
 class WasmStackFrame : public StackFrameBase {
  public:
-  virtual ~WasmStackFrame() {}
+  ~WasmStackFrame() override = default;
 
   Handle<Object> GetReceiver() const override;
   Handle<Object> GetFunction() const override;
@@ -150,6 +153,7 @@ class WasmStackFrame : public StackFrameBase {
 
   bool IsNative() override { return false; }
   bool IsToplevel() override { return false; }
+  bool IsAsync() const override { return false; }
   bool IsConstructor() override { return false; }
   bool IsStrict() const override { return false; }
   bool IsInterpreted() const { return code_ == nullptr; }
@@ -168,7 +172,7 @@ class WasmStackFrame : public StackFrameBase {
   int offset_;
 
  private:
-  WasmStackFrame();
+  WasmStackFrame() = default;
   void FromFrameArray(Isolate* isolate, Handle<FrameArray> array, int frame_ix);
 
   friend class FrameArrayIterator;
@@ -177,7 +181,7 @@ class WasmStackFrame : public StackFrameBase {
 
 class AsmJsWasmStackFrame : public WasmStackFrame {
  public:
-  virtual ~AsmJsWasmStackFrame() {}
+  ~AsmJsWasmStackFrame() override = default;
 
   Handle<Object> GetReceiver() const override;
   Handle<Object> GetFunction() const override;
@@ -193,7 +197,7 @@ class AsmJsWasmStackFrame : public WasmStackFrame {
 
  private:
   friend class FrameArrayIterator;
-  AsmJsWasmStackFrame();
+  AsmJsWasmStackFrame() = default;
   void FromFrameArray(Isolate* isolate, Handle<FrameArray> array, int frame_ix);
 
   bool is_at_number_conversion_;
@@ -377,6 +381,7 @@ class ErrorUtils : public AllStatic {
     "% is not a function or its return value is not async iterable")           \
   T(NotFiniteNumber, "Value need to be finite number for %()")                 \
   T(NotIterable, "% is not iterable")                                          \
+  T(NotIterableNoSymbolLoad, "% is not iterable (cannot read property %)")     \
   T(NotAsyncIterable, "% is not async iterable")                               \
   T(NotPropertyName, "% is not a valid property name")                         \
   T(NotTypedArray, "this is not a typed array.")                               \
diff --git a/deps/v8/src/mips/assembler-mips.cc b/deps/v8/src/mips/assembler-mips.cc
index 2c04430509..ee39c524f6 100644
--- a/deps/v8/src/mips/assembler-mips.cc
+++ b/deps/v8/src/mips/assembler-mips.cc
@@ -41,6 +41,7 @@
 #include "src/code-stubs.h"
 #include "src/deoptimizer.h"
 #include "src/mips/assembler-mips-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -248,6 +249,13 @@ Operand Operand::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rm, int32_t offset) : Operand(rm) {
   offset_ = offset;
 }
@@ -259,6 +267,7 @@ MemOperand::MemOperand(Register rm, int32_t unit, int32_t multiplier,
 }
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     switch (request.kind()) {
@@ -270,6 +279,11 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         request.code_stub()->set_isolate(isolate);
         object = request.code_stub()->GetCode();
         break;
+      case HeapObjectRequest::kStringConstant:
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        object = str->AllocateStringConstant(isolate);
+        break;
     }
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     set_target_value_at(pc, reinterpret_cast<uint32_t>(object.location()));
@@ -2321,6 +2335,16 @@ void Assembler::sc(Register rd, const MemOperand& rs) {
   }
 }
 
+void Assembler::llwp(Register rd, Register rt, Register base) {
+  DCHECK(IsMipsArchVariant(kMips32r6));
+  GenInstrRegister(SPECIAL3, base, rt, rd, 1, LL_R6);
+}
+
+void Assembler::scwp(Register rd, Register rt, Register base) {
+  DCHECK(IsMipsArchVariant(kMips32r6));
+  GenInstrRegister(SPECIAL3, base, rt, rd, 1, SC_R6);
+}
+
 void Assembler::lui(Register rd, int32_t j) {
   DCHECK(is_uint16(j) || is_int16(j));
   GenInstrImmediate(LUI, zero_reg, rd, j);
@@ -3873,17 +3897,11 @@ void Assembler::dd(Label* label) {
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
+  if (!ShouldRecordRelocInfo(rmode)) return;
   // We do not try to reuse pool constants.
   RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
-  if (!RelocInfo::IsNone(rinfo.rmode())) {
-    if (options().disable_reloc_info_for_patching) return;
-    if (RelocInfo::IsOnlyForSerializer(rmode) &&
-        !options().record_reloc_info_for_serialization && !emit_debug_code()) {
-      return;
-    }
-    DCHECK_GE(buffer_space(), kMaxRelocSize);  // Too late to grow buffer here.
-    reloc_info_writer.Write(&rinfo);
-  }
+  DCHECK_GE(buffer_space(), kMaxRelocSize);  // Too late to grow buffer here.
+  reloc_info_writer.Write(&rinfo);
 }
 
 void Assembler::BlockTrampolinePoolFor(int instructions) {
diff --git a/deps/v8/src/mips/assembler-mips.h b/deps/v8/src/mips/assembler-mips.h
index 5a51522940..d535f1e923 100644
--- a/deps/v8/src/mips/assembler-mips.h
+++ b/deps/v8/src/mips/assembler-mips.h
@@ -304,7 +304,6 @@ typedef FPURegister DoubleRegister;
 DOUBLE_REGISTERS(DECLARE_DOUBLE_REGISTER)
 #undef DECLARE_DOUBLE_REGISTER
 
-constexpr DoubleRegister no_freg = DoubleRegister::no_reg();
 constexpr DoubleRegister no_dreg = DoubleRegister::no_reg();
 
 // SIMD registers.
@@ -385,7 +384,7 @@ constexpr MSAControlRegister MSACSR = {kMSACSRRegister};
 // Machine instruction Operands.
 
 // Class Operand represents a shifter operand in data processing instructions.
-class Operand BASE_EMBEDDED {
+class Operand {
  public:
   // Immediate.
   V8_INLINE explicit Operand(int32_t immediate,
@@ -408,6 +407,7 @@ class Operand BASE_EMBEDDED {
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Operand EmbeddedCode(CodeStub* stub);
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Register.
   V8_INLINE explicit Operand(Register rm) : rm_(rm) {}
@@ -883,6 +883,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   void ll(Register rd, const MemOperand& rs);
   void sc(Register rd, const MemOperand& rs);
+  void llwp(Register rd, Register rt, Register base);
+  void scwp(Register rd, Register rt, Register base);
 
   // ---------PC-Relative-instructions-----------
 
@@ -2212,8 +2214,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   friend class EnsureSpace;
 };
 
-
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit inline EnsureSpace(Assembler* assembler);
 };
diff --git a/deps/v8/src/mips/code-stubs-mips.cc b/deps/v8/src/mips/code-stubs-mips.cc
index 3da00d4748..1650458d19 100644
--- a/deps/v8/src/mips/code-stubs-mips.cc
+++ b/deps/v8/src/mips/code-stubs-mips.cc
@@ -119,7 +119,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
   __ li(t0, ExternalReference::Create(
                 IsolateAddressId::kPendingExceptionAddress, isolate));
   __ sw(v0, MemOperand(t0));  // We come back from 'invoke'. result is in v0.
-  __ LoadRoot(v0, Heap::kExceptionRootIndex);
+  __ LoadRoot(v0, RootIndex::kException);
   __ b(&exit);  // b exposes branch delay slot.
   __ nop();   // Branch delay slot nop.
 
@@ -415,7 +415,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
                     stack_space_offset != kInvalidStackOffset);
 
   // Check if the function scheduled an exception.
-  __ LoadRoot(t0, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(t0, RootIndex::kTheHoleValue);
   __ li(kScratchReg, ExternalReference::scheduled_exception_address(isolate));
   __ lw(t1, MemOperand(kScratchReg));
   __ Branch(&promote_scheduled_exception, ne, t0, Operand(t1));
@@ -466,13 +466,13 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data.
   __ Push(call_data);
 
   Register scratch = call_data;
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   // Push return value and default return value.
   __ Push(scratch, scratch);
   __ li(scratch, ExternalReference::isolate_address(masm->isolate()));
@@ -543,7 +543,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   __ sw(receiver, MemOperand(sp, (PCA::kThisIndex + 1) * kPointerSize));
   __ lw(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
   __ sw(scratch, MemOperand(sp, (PCA::kDataIndex + 1) * kPointerSize));
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   __ sw(scratch, MemOperand(sp, (PCA::kReturnValueOffset + 1) * kPointerSize));
   __ sw(scratch, MemOperand(sp, (PCA::kReturnValueDefaultValueIndex + 1) *
                                     kPointerSize));
diff --git a/deps/v8/src/mips/codegen-mips.cc b/deps/v8/src/mips/codegen-mips.cc
index d6b47990f8..86546668db 100644
--- a/deps/v8/src/mips/codegen-mips.cc
+++ b/deps/v8/src/mips/codegen-mips.cc
@@ -7,7 +7,6 @@
 #include <memory>
 
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 #include "src/mips/simulator-mips.h"
 
@@ -18,18 +17,18 @@ namespace internal {
 
 #if defined(V8_HOST_ARCH_MIPS)
 
-MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
-                                                MemCopyUint8Function stub) {
+MemCopyUint8Function CreateMemCopyUint8Function(MemCopyUint8Function stub) {
 #if defined(USE_SIMULATOR) || defined(_MIPS_ARCH_MIPS32R6) || \
     defined(_MIPS_ARCH_MIPS32RX)
   return stub;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   // This code assumes that cache lines are 32 bytes and if the cache line is
   // larger it will not work correctly.
@@ -541,26 +540,28 @@ MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
     __ nop();
   }
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
   return FUNCTION_CAST<MemCopyUint8Function>(buffer);
 #endif
 }
 #endif
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
 #if defined(USE_SIMULATOR)
   return nullptr;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   __ MovFromFloatParameter(f12);
   __ sqrt_d(f0, f12);
@@ -568,12 +569,13 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 #endif
 }
 
diff --git a/deps/v8/src/mips/disasm-mips.cc b/deps/v8/src/mips/disasm-mips.cc
index 0049f9fa91..e7ec95b7ac 100644
--- a/deps/v8/src/mips/disasm-mips.cc
+++ b/deps/v8/src/mips/disasm-mips.cc
@@ -1546,6 +1546,16 @@ void Decoder::DecodeTypeRegisterSPECIAL3(Instruction* instr) {
           }
           break;
         }
+        case LL_R6: {
+          DCHECK(IsMipsArchVariant(kMips32r6));
+          Format(instr, "llwp    'rd, 'rt, 0('rs)");
+          break;
+        }
+        case SC_R6: {
+          DCHECK(IsMipsArchVariant(kMips32r6));
+          Format(instr, "scwp    'rd, 'rt, 0('rs)");
+          break;
+        }
         default: {
           sa >>= kBp2Bits;
           switch (sa) {
diff --git a/deps/v8/src/mips/interface-descriptors-mips.cc b/deps/v8/src/mips/interface-descriptors-mips.cc
index 31b5f82895..1ece4812a3 100644
--- a/deps/v8/src/mips/interface-descriptors-mips.cc
+++ b/deps/v8/src/mips/interface-descriptors-mips.cc
@@ -88,9 +88,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // a0 : number of arguments (on the stack, not including receiver)
   // a1 : the target to call
-  // a2 : arguments list (FixedArray)
   // t0 : arguments list length (untagged)
-  Register registers[] = {a1, a0, a2, t0};
+  // a2 : arguments list (FixedArray)
+  Register registers[] = {a1, a0, t0, a2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -125,9 +125,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // a0 : number of arguments (on the stack, not including receiver)
   // a1 : the target to call
   // a3 : the new target
-  // a2 : arguments list (FixedArray)
   // t0 : arguments list length (untagged)
-  Register registers[] = {a1, a3, a0, a2, t0};
+  // a2 : arguments list (FixedArray)
+  Register registers[] = {a1, a3, a0, t0, a2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -194,7 +194,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a1,  // JSFunction
@@ -238,10 +238,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a0,  // argument count (not including receiver)
-      a3,  // new target
+      t4,  // address of the first argument
       a1,  // constructor to call
-      a2,  // allocation site feedback if available, undefined otherwise.
-      t4   // address of the first argument
+      a3,  // new target
+      a2,  // allocation site feedback if available, undefined otherwise
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/mips/macro-assembler-mips.cc b/deps/v8/src/mips/macro-assembler-mips.cc
index 35a9959ddb..c10602df48 100644
--- a/deps/v8/src/mips/macro-assembler-mips.cc
+++ b/deps/v8/src/mips/macro-assembler-mips.cc
@@ -127,11 +127,11 @@ int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   return bytes;
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
+void TurboAssembler::LoadRoot(Register destination, RootIndex index) {
   lw(destination, MemOperand(kRootRegister, RootRegisterOffset(index)));
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index,
+void TurboAssembler::LoadRoot(Register destination, RootIndex index,
                               Condition cond, Register src1,
                               const Operand& src2) {
   Branch(2, NegateCondition(cond), src1, src2);
@@ -273,8 +273,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -286,7 +284,6 @@ void TurboAssembler::CallRecordWriteStub(
   Pop(slot_parameter);
   Pop(object_parameter);
 
-  li(isolate_parameter, ExternalReference::isolate_address(isolate()));
   Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -1347,6 +1344,11 @@ void TurboAssembler::li(Register dst, ExternalReference value, LiFlags mode) {
   li(dst, Operand(value), mode);
 }
 
+void TurboAssembler::li(Register dst, const StringConstantBase* string,
+                        LiFlags mode) {
+  li(dst, Operand::EmbeddedStringConstant(string), mode);
+}
+
 void TurboAssembler::li(Register rd, Operand j, LiFlags mode) {
   DCHECK(!j.is_reg());
   BlockTrampolinePoolScope block_trampoline_pool(this);
@@ -1461,6 +1463,26 @@ void TurboAssembler::SubPair(Register dst_low, Register dst_high,
   Move(dst_low, scratch1);
 }
 
+void TurboAssembler::AndPair(Register dst_low, Register dst_high,
+                             Register left_low, Register left_high,
+                             Register right_low, Register right_high) {
+  And(dst_low, left_low, right_low);
+  And(dst_high, left_high, right_high);
+}
+
+void TurboAssembler::OrPair(Register dst_low, Register dst_high,
+                            Register left_low, Register left_high,
+                            Register right_low, Register right_high) {
+  Or(dst_low, left_low, right_low);
+  Or(dst_high, left_high, right_high);
+}
+void TurboAssembler::XorPair(Register dst_low, Register dst_high,
+                             Register left_low, Register left_high,
+                             Register right_low, Register right_high) {
+  Xor(dst_low, left_low, right_low);
+  Xor(dst_high, left_high, right_high);
+}
+
 void TurboAssembler::MulPair(Register dst_low, Register dst_high,
                              Register left_low, Register left_high,
                              Register right_low, Register right_high,
@@ -2814,7 +2836,7 @@ void TurboAssembler::Branch(Label* L, Condition cond, Register rs,
 }
 
 void TurboAssembler::Branch(Label* L, Condition cond, Register rs,
-                            Heap::RootListIndex index, BranchDelaySlot bdslot) {
+                            RootIndex index, BranchDelaySlot bdslot) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
   LoadRoot(scratch, index);
@@ -3623,8 +3645,8 @@ bool TurboAssembler::BranchAndLinkShortCheck(int32_t offset, Label* L,
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+      RootIndex::kBuiltinsConstantsTable));
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   lw(destination,
      FieldMemOperand(destination,
                      FixedArray::kHeaderSize + constant_index * kPointerSize));
@@ -4326,7 +4348,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(a3, Heap::kUndefinedValueRootIndex);
+    LoadRoot(a3, RootIndex::kUndefinedValue);
   }
 
   Label done;
@@ -5032,7 +5054,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
   if (emit_debug_code()) {
     Label done_checking;
     AssertNotSmi(object);
-    LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    LoadRoot(scratch, RootIndex::kUndefinedValue);
     Branch(&done_checking, eq, object, Operand(scratch));
     GetObjectType(object, scratch, scratch);
     Assert(eq, AbortReason::kExpectedUndefinedOrCell, scratch,
diff --git a/deps/v8/src/mips/macro-assembler-mips.h b/deps/v8/src/mips/macro-assembler-mips.h
index f6c371923f..ae3138f85f 100644
--- a/deps/v8/src/mips/macro-assembler-mips.h
+++ b/deps/v8/src/mips/macro-assembler-mips.h
@@ -118,6 +118,9 @@ inline MemOperand CFunctionArgumentOperand(int index) {
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -223,7 +226,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void BranchMSA(Label* target, MSABranchDF df, MSABranchCondition cond,
                  MSARegister wt, BranchDelaySlot bd = PROTECT);
 
-  void Branch(Label* L, Condition cond, Register rs, Heap::RootListIndex index,
+  void Branch(Label* L, Condition cond, Register rs, RootIndex index,
               BranchDelaySlot bdslot = PROTECT);
 
   // Load int32 in the rd register.
@@ -233,6 +236,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   }
   void li(Register dst, Handle<HeapObject> value, LiFlags mode = OPTIMIZE_SIZE);
   void li(Register dst, ExternalReference value, LiFlags mode = OPTIMIZE_SIZE);
+  void li(Register dst, const StringConstantBase* string,
+          LiFlags mode = OPTIMIZE_SIZE);
 
   void LoadFromConstantsTable(Register destination,
                               int constant_index) override;
@@ -577,6 +582,15 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                Register left_high, Register right_low, Register right_high,
                Register scratch1, Register scratch2);
 
+  void AndPair(Register dst_low, Register dst_high, Register left_low,
+               Register left_high, Register right_low, Register right_high);
+
+  void OrPair(Register dst_low, Register dst_high, Register left_low,
+              Register left_high, Register right_low, Register right_high);
+
+  void XorPair(Register dst_low, Register dst_high, Register left_low,
+               Register left_high, Register right_low, Register right_high);
+
   void MulPair(Register dst_low, Register dst_high, Register left_low,
                Register left_high, Register right_low, Register right_high,
                Register scratch1, Register scratch2);
@@ -793,8 +807,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                            Func GetLabelFunction);
 
   // Load an object from the root table.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override;
-  void LoadRoot(Register destination, Heap::RootListIndex index, Condition cond,
+  void LoadRoot(Register destination, RootIndex index) override;
+  void LoadRoot(Register destination, RootIndex index, Condition cond,
                 Register src1, const Operand& src2);
 
   // If the value is a NaN, canonicalize the value else, do nothing.
@@ -901,10 +915,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -912,7 +930,7 @@ class MacroAssembler : public TurboAssembler {
   // less efficient form using xor instead of mov is emitted.
   void Swap(Register reg1, Register reg2, Register scratch = no_reg);
 
-  void PushRoot(Heap::RootListIndex index) {
+  void PushRoot(RootIndex index) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
@@ -920,7 +938,7 @@ class MacroAssembler : public TurboAssembler {
   }
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal) {
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
@@ -928,8 +946,7 @@ class MacroAssembler : public TurboAssembler {
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal) {
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
diff --git a/deps/v8/src/mips/simulator-mips.cc b/deps/v8/src/mips/simulator-mips.cc
index 13f5f38f0d..b759176db3 100644
--- a/deps/v8/src/mips/simulator-mips.cc
+++ b/deps/v8/src/mips/simulator-mips.cc
@@ -4240,6 +4240,21 @@ void Simulator::DecodeTypeRegisterSPECIAL3() {
       SetResult(rd_reg(), alu_out);
       break;
     }
+    case LL_R6: {
+      // LLWP/SCWP sequence cannot be simulated properly
+      DCHECK(IsMipsArchVariant(kMips32r6));
+      set_register(rd_reg(), ReadW(rs() + 4, instr_.instr()));
+      set_register(rt(), ReadW(rs(), instr_.instr()));
+      break;
+    }
+    case SC_R6: {
+      // LLWP/SCWP sequence cannot be simulated properly
+      DCHECK(IsMipsArchVariant(kMips32r6));
+      WriteW(rs() + 4, rd_reg(), instr_.instr());
+      WriteW(rs(), rt(), instr_.instr());
+      set_register(rt(), 1);
+      break;
+    }
     default:
       UNREACHABLE();
   }
diff --git a/deps/v8/src/mips64/assembler-mips64.cc b/deps/v8/src/mips64/assembler-mips64.cc
index 4abd272a5e..3449537626 100644
--- a/deps/v8/src/mips64/assembler-mips64.cc
+++ b/deps/v8/src/mips64/assembler-mips64.cc
@@ -40,6 +40,7 @@
 #include "src/code-stubs.h"
 #include "src/deoptimizer.h"
 #include "src/mips64/assembler-mips64-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -226,6 +227,13 @@ Operand Operand::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rm, int32_t offset) : Operand(rm) {
   offset_ = offset;
 }
@@ -238,6 +246,7 @@ MemOperand::MemOperand(Register rm, int32_t unit, int32_t multiplier,
 }
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     switch (request.kind()) {
@@ -249,6 +258,11 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         request.code_stub()->set_isolate(isolate);
         object = request.code_stub()->GetCode();
         break;
+      case HeapObjectRequest::kStringConstant:
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        object = str->AllocateStringConstant(isolate);
+        break;
     }
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     set_target_value_at(pc, reinterpret_cast<uint64_t>(object.location()));
@@ -1819,35 +1833,25 @@ void Assembler::bnezc(Register rs, int32_t offset) {
 
 
 void Assembler::j(int64_t target) {
-  BlockTrampolinePoolScope block_trampoline_pool(this);
-  GenInstrJump(J, static_cast<uint32_t>(target >> 2) & kImm26Mask);
-  BlockTrampolinePoolFor(1);  // For associated delay slot.
+  // Deprecated. Use PC-relative jumps instead.
+  UNREACHABLE();
 }
 
 
 void Assembler::j(Label* target) {
-  uint64_t imm = jump_offset(target);
-  if (target->is_bound()) {
-    BlockTrampolinePoolScope block_trampoline_pool(this);
-    GenInstrJump(static_cast<Opcode>(kJRawMark),
-                 static_cast<uint32_t>(imm >> 2) & kImm26Mask);
-    BlockTrampolinePoolFor(1);  // For associated delay slot.
-  } else {
-    j(imm);
-  }
+  // Deprecated. Use PC-relative jumps instead.
+  UNREACHABLE();
 }
 
 
 void Assembler::jal(Label* target) {
-  uint64_t imm = jump_offset(target);
-  if (target->is_bound()) {
-    BlockTrampolinePoolScope block_trampoline_pool(this);
-    GenInstrJump(static_cast<Opcode>(kJalRawMark),
-                 static_cast<uint32_t>(imm >> 2) & kImm26Mask);
-    BlockTrampolinePoolFor(1);  // For associated delay slot.
-  } else {
-    jal(imm);
-  }
+  // Deprecated. Use PC-relative jumps instead.
+  UNREACHABLE();
+}
+
+void Assembler::jal(int64_t target) {
+  // Deprecated. Use PC-relative jumps instead.
+  UNREACHABLE();
 }
 
 
@@ -1862,13 +1866,6 @@ void Assembler::jr(Register rs) {
 }
 
 
-void Assembler::jal(int64_t target) {
-  BlockTrampolinePoolScope block_trampoline_pool(this);
-  GenInstrJump(JAL, static_cast<uint32_t>(target >> 2) & kImm26Mask);
-  BlockTrampolinePoolFor(1);  // For associated delay slot.
-}
-
-
 void Assembler::jalr(Register rs, Register rd) {
   DCHECK(rs.code() != rd.code());
   BlockTrampolinePoolScope block_trampoline_pool(this);
@@ -4218,18 +4215,11 @@ void Assembler::dd(Label* label) {
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
+  if (!ShouldRecordRelocInfo(rmode)) return;
   // We do not try to reuse pool constants.
   RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
-  if (!RelocInfo::IsNone(rinfo.rmode())) {
-    if (options().disable_reloc_info_for_patching) return;
-    // Don't record external references unless the heap will be serialized.
-    if (RelocInfo::IsOnlyForSerializer(rmode) &&
-        !options().record_reloc_info_for_serialization && !emit_debug_code()) {
-      return;
-    }
-    DCHECK_GE(buffer_space(), kMaxRelocSize);  // Too late to grow buffer here.
-    reloc_info_writer.Write(&rinfo);
-  }
+  DCHECK_GE(buffer_space(), kMaxRelocSize);  // Too late to grow buffer here.
+  reloc_info_writer.Write(&rinfo);
 }
 
 
diff --git a/deps/v8/src/mips64/assembler-mips64.h b/deps/v8/src/mips64/assembler-mips64.h
index 868882eb4a..814f3eacba 100644
--- a/deps/v8/src/mips64/assembler-mips64.h
+++ b/deps/v8/src/mips64/assembler-mips64.h
@@ -309,7 +309,6 @@ typedef FPURegister DoubleRegister;
 DOUBLE_REGISTERS(DECLARE_DOUBLE_REGISTER)
 #undef DECLARE_DOUBLE_REGISTER
 
-constexpr DoubleRegister no_freg = DoubleRegister::no_reg();
 constexpr DoubleRegister no_dreg = DoubleRegister::no_reg();
 
 // SIMD registers.
@@ -392,7 +391,7 @@ constexpr MSAControlRegister MSACSR = {kMSACSRRegister};
 constexpr int kSmiShift = kSmiTagSize + kSmiShiftSize;
 constexpr uint64_t kSmiShiftMask = (1UL << kSmiShift) - 1;
 // Class Operand represents a shifter operand in data processing instructions.
-class Operand BASE_EMBEDDED {
+class Operand {
  public:
   // Immediate.
   V8_INLINE explicit Operand(int64_t immediate,
@@ -415,6 +414,7 @@ class Operand BASE_EMBEDDED {
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Operand EmbeddedCode(CodeStub* stub);
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Register.
   V8_INLINE explicit Operand(Register rm) : rm_(rm) {}
@@ -820,16 +820,17 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Never use the int16_t b(l)cond version with a branch offset
   // instead of using the Label* version.
 
-  // Jump targets must be in the current 256 MB-aligned region. i.e. 28 bits.
-  void j(int64_t target);
-  void jal(int64_t target);
-  void j(Label* target);
-  void jal(Label* target);
   void jalr(Register rs, Register rd = ra);
   void jr(Register target);
   void jic(Register rt, int16_t offset);
   void jialc(Register rt, int16_t offset);
 
+  // Following instructions are deprecated and require 256 MB
+  // code alignment. Use PC-relative instructions instead.
+  void j(int64_t target);
+  void jal(int64_t target);
+  void j(Label* target);
+  void jal(Label* target);
 
   // -------Data-processing-instructions---------
 
@@ -2279,8 +2280,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   friend class EnsureSpace;
 };
 
-
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit inline EnsureSpace(Assembler* assembler);
 };
diff --git a/deps/v8/src/mips64/code-stubs-mips64.cc b/deps/v8/src/mips64/code-stubs-mips64.cc
index cd02bea0f1..bb51ac7cf3 100644
--- a/deps/v8/src/mips64/code-stubs-mips64.cc
+++ b/deps/v8/src/mips64/code-stubs-mips64.cc
@@ -118,7 +118,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
   __ li(a4, ExternalReference::Create(
                 IsolateAddressId::kPendingExceptionAddress, isolate));
   __ Sd(v0, MemOperand(a4));  // We come back from 'invoke'. result is in v0.
-  __ LoadRoot(v0, Heap::kExceptionRootIndex);
+  __ LoadRoot(v0, RootIndex::kException);
   __ b(&exit);  // b exposes branch delay slot.
   __ nop();   // Branch delay slot nop.
 
@@ -418,7 +418,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
                     stack_space_offset != kInvalidStackOffset);
 
   // Check if the function scheduled an exception.
-  __ LoadRoot(a4, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(a4, RootIndex::kTheHoleValue);
   __ li(kScratchReg, ExternalReference::scheduled_exception_address(isolate));
   __ Ld(a5, MemOperand(kScratchReg));
   __ Branch(&promote_scheduled_exception, ne, a4, Operand(a5));
@@ -469,13 +469,13 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data.
   __ Push(call_data);
 
   Register scratch = call_data;
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   // Push return value and default return value.
   __ Push(scratch, scratch);
   __ li(scratch, ExternalReference::isolate_address(masm->isolate()));
@@ -548,7 +548,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   __ Sd(receiver, MemOperand(sp, (PCA::kThisIndex + 1) * kPointerSize));
   __ Ld(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
   __ Sd(scratch, MemOperand(sp, (PCA::kDataIndex + 1) * kPointerSize));
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   __ Sd(scratch, MemOperand(sp, (PCA::kReturnValueOffset + 1) * kPointerSize));
   __ Sd(scratch, MemOperand(sp, (PCA::kReturnValueDefaultValueIndex + 1) *
                                     kPointerSize));
diff --git a/deps/v8/src/mips64/codegen-mips64.cc b/deps/v8/src/mips64/codegen-mips64.cc
index 81a6cd4342..ac143dd3e5 100644
--- a/deps/v8/src/mips64/codegen-mips64.cc
+++ b/deps/v8/src/mips64/codegen-mips64.cc
@@ -7,7 +7,6 @@
 #include <memory>
 
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 #include "src/mips64/simulator-mips64.h"
 
@@ -18,18 +17,17 @@ namespace internal {
 
 #if defined(V8_HOST_ARCH_MIPS)
 
-MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
-                                                MemCopyUint8Function stub) {
+MemCopyUint8Function CreateMemCopyUint8Function(MemCopyUint8Function stub) {
 #if defined(USE_SIMULATOR)
   return stub;
 #else
-
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return stub;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   // This code assumes that cache lines are 32 bytes and if the cache line is
   // larger it will not work correctly.
@@ -542,26 +540,28 @@ MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
     __ nop();
   }
   CodeDesc desc;
-  masm.GetCode(isolte, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
   return FUNCTION_CAST<MemCopyUint8Function>(buffer);
 #endif
 }
 #endif
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
 #if defined(USE_SIMULATOR)
   return nullptr;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   __ MovFromFloatParameter(f12);
   __ sqrt_d(f0, f12);
@@ -569,12 +569,13 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 #endif
 }
 
diff --git a/deps/v8/src/mips64/interface-descriptors-mips64.cc b/deps/v8/src/mips64/interface-descriptors-mips64.cc
index 8f4fdcc905..a6c7bfa4ba 100644
--- a/deps/v8/src/mips64/interface-descriptors-mips64.cc
+++ b/deps/v8/src/mips64/interface-descriptors-mips64.cc
@@ -88,9 +88,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // a0 : number of arguments (on the stack, not including receiver)
   // a1 : the target to call
-  // a2 : arguments list (FixedArray)
   // a4 : arguments list length (untagged)
-  Register registers[] = {a1, a0, a2, a4};
+  // a2 : arguments list (FixedArray)
+  Register registers[] = {a1, a0, a4, a2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -125,9 +125,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // a0 : number of arguments (on the stack, not including receiver)
   // a1 : the target to call
   // a3 : the new target
-  // a2 : arguments list (FixedArray)
   // a4 : arguments list length (untagged)
-  Register registers[] = {a1, a3, a0, a2, a4};
+  // a2 : arguments list (FixedArray)
+  Register registers[] = {a1, a3, a0, a4, a2};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -194,7 +194,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a1,  // JSFunction
@@ -238,10 +238,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a0,  // argument count (not including receiver)
-      a3,  // new target
+      a4,  // address of the first argument
       a1,  // constructor to call
-      a2,  // allocation site feedback if available, undefined otherwise.
-      a4   // address of the first argument
+      a3,  // new target
+      a2,  // allocation site feedback if available, undefined otherwise
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/mips64/macro-assembler-mips64.cc b/deps/v8/src/mips64/macro-assembler-mips64.cc
index b55b47a2ed..dd3b51eba5 100644
--- a/deps/v8/src/mips64/macro-assembler-mips64.cc
+++ b/deps/v8/src/mips64/macro-assembler-mips64.cc
@@ -127,11 +127,11 @@ int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   return bytes;
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
+void TurboAssembler::LoadRoot(Register destination, RootIndex index) {
   Ld(destination, MemOperand(s6, RootRegisterOffset(index)));
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index,
+void TurboAssembler::LoadRoot(Register destination, RootIndex index,
                               Condition cond, Register src1,
                               const Operand& src2) {
   Branch(2, NegateCondition(cond), src1, src2);
@@ -273,8 +273,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -286,7 +284,6 @@ void TurboAssembler::CallRecordWriteStub(
   Pop(slot_parameter);
   Pop(object_parameter);
 
-  li(isolate_parameter, ExternalReference::isolate_address(isolate()));
   Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -1573,6 +1570,11 @@ void TurboAssembler::li(Register dst, ExternalReference value, LiFlags mode) {
   li(dst, Operand(value), mode);
 }
 
+void TurboAssembler::li(Register dst, const StringConstantBase* string,
+                        LiFlags mode) {
+  li(dst, Operand::EmbeddedStringConstant(string), mode);
+}
+
 static inline int InstrCountForLiLower32Bit(int64_t value) {
   if (!is_int16(static_cast<int32_t>(value)) && (value & kUpper16MaskOf64) &&
       (value & kImm16Mask)) {
@@ -3311,7 +3313,7 @@ void TurboAssembler::Branch(Label* L, Condition cond, Register rs,
 }
 
 void TurboAssembler::Branch(Label* L, Condition cond, Register rs,
-                            Heap::RootListIndex index, BranchDelaySlot bdslot) {
+                            RootIndex index, BranchDelaySlot bdslot) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
   LoadRoot(scratch, index);
@@ -4124,8 +4126,8 @@ bool TurboAssembler::BranchAndLinkShortCheck(int32_t offset, Label* L,
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+      RootIndex::kBuiltinsConstantsTable));
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   Ld(destination,
      FieldMemOperand(destination,
                      FixedArray::kHeaderSize + constant_index * kPointerSize));
@@ -4708,7 +4710,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(a3, Heap::kUndefinedValueRootIndex);
+    LoadRoot(a3, RootIndex::kUndefinedValue);
   }
 
   Label done;
@@ -5434,7 +5436,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
   if (emit_debug_code()) {
     Label done_checking;
     AssertNotSmi(object);
-    LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+    LoadRoot(scratch, RootIndex::kUndefinedValue);
     Branch(&done_checking, eq, object, Operand(scratch));
     GetObjectType(object, scratch, scratch);
     Assert(eq, AbortReason::kExpectedUndefinedOrCell, scratch,
diff --git a/deps/v8/src/mips64/macro-assembler-mips64.h b/deps/v8/src/mips64/macro-assembler-mips64.h
index 7dd5761571..9160b26e01 100644
--- a/deps/v8/src/mips64/macro-assembler-mips64.h
+++ b/deps/v8/src/mips64/macro-assembler-mips64.h
@@ -135,6 +135,9 @@ inline MemOperand CFunctionArgumentOperand(int index) {
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -240,7 +243,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void BranchMSA(Label* target, MSABranchDF df, MSABranchCondition cond,
                  MSARegister wt, BranchDelaySlot bd = PROTECT);
 
-  void Branch(Label* L, Condition cond, Register rs, Heap::RootListIndex index,
+  void Branch(Label* L, Condition cond, Register rs, RootIndex index,
               BranchDelaySlot bdslot = PROTECT);
 
   static int InstrCountForLi64Bit(int64_t value);
@@ -251,8 +254,13 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   inline void li(Register rd, int64_t j, LiFlags mode = OPTIMIZE_SIZE) {
     li(rd, Operand(j), mode);
   }
+  // inline void li(Register rd, int32_t j, LiFlags mode = OPTIMIZE_SIZE) {
+  //   li(rd, Operand(static_cast<int64_t>(j)), mode);
+  // }
   void li(Register dst, Handle<HeapObject> value, LiFlags mode = OPTIMIZE_SIZE);
   void li(Register dst, ExternalReference value, LiFlags mode = OPTIMIZE_SIZE);
+  void li(Register dst, const StringConstantBase* string,
+          LiFlags mode = OPTIMIZE_SIZE);
 
   void LoadFromConstantsTable(Register destination,
                               int constant_index) override;
@@ -763,8 +771,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                            Func GetLabelFunction);
 
   // Load an object from the root table.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override;
-  void LoadRoot(Register destination, Heap::RootListIndex index, Condition cond,
+  void LoadRoot(Register destination, RootIndex index) override;
+  void LoadRoot(Register destination, RootIndex index, Condition cond,
                 Register src1, const Operand& src2);
 
   // If the value is a NaN, canonicalize the value else, do nothing.
@@ -914,10 +922,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -927,7 +939,7 @@ class MacroAssembler : public TurboAssembler {
   // less efficient form using xor instead of mov is emitted.
   void Swap(Register reg1, Register reg2, Register scratch = no_reg);
 
-  void PushRoot(Heap::RootListIndex index) {
+  void PushRoot(RootIndex index) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
@@ -935,7 +947,7 @@ class MacroAssembler : public TurboAssembler {
   }
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal) {
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
@@ -943,8 +955,7 @@ class MacroAssembler : public TurboAssembler {
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal) {
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     LoadRoot(scratch, index);
diff --git a/deps/v8/src/objects-body-descriptors-inl.h b/deps/v8/src/objects-body-descriptors-inl.h
index 122cdde5bf..e91de2bac3 100644
--- a/deps/v8/src/objects-body-descriptors-inl.h
+++ b/deps/v8/src/objects-body-descriptors-inl.h
@@ -86,6 +86,19 @@ void BodyDescriptorBase::IterateMaybeWeakPointer(HeapObject* obj, int offset,
   v->VisitPointer(obj, HeapObject::RawMaybeWeakField(obj, offset));
 }
 
+template <typename ObjectVisitor>
+DISABLE_CFI_PERF void BodyDescriptorBase::IterateCustomWeakPointers(
+    HeapObject* obj, int start_offset, int end_offset, ObjectVisitor* v) {
+  v->VisitCustomWeakPointers(obj, HeapObject::RawField(obj, start_offset),
+                             HeapObject::RawField(obj, end_offset));
+}
+
+template <typename ObjectVisitor>
+void BodyDescriptorBase::IterateCustomWeakPointer(HeapObject* obj, int offset,
+                                                  ObjectVisitor* v) {
+  v->VisitCustomWeakPointer(obj, HeapObject::RawField(obj, offset));
+}
+
 class JSObject::BodyDescriptor final : public BodyDescriptorBase {
  public:
   static const int kStartOffset = JSReceiver::kPropertiesOrHashOffset;
@@ -149,8 +162,7 @@ class JSFunction::BodyDescriptor final : public BodyDescriptorBase {
   }
 };
 
-template <bool includeWeakNext>
-class AllocationSite::BodyDescriptorImpl final : public BodyDescriptorBase {
+class AllocationSite::BodyDescriptor final : public BodyDescriptorBase {
  public:
   STATIC_ASSERT(AllocationSite::kCommonPointerFieldEndOffset ==
                 AllocationSite::kPretenureDataOffset);
@@ -165,8 +177,7 @@ class AllocationSite::BodyDescriptorImpl final : public BodyDescriptorBase {
       return true;
     }
     // check for weak_next offset
-    if (includeWeakNext &&
-        map->instance_size() == AllocationSite::kSizeWithWeakNext &&
+    if (map->instance_size() == AllocationSite::kSizeWithWeakNext &&
         offset == AllocationSite::kWeakNextOffset) {
       return true;
     }
@@ -179,12 +190,12 @@ class AllocationSite::BodyDescriptorImpl final : public BodyDescriptorBase {
     // Iterate over all the common pointer fields
     IteratePointers(obj, AllocationSite::kStartOffset,
                     AllocationSite::kCommonPointerFieldEndOffset, v);
-    // Skip PretenureDataOffset and PretenureCreateCount which are Int32 fields
-    // Visit weak_next only for full body descriptor and if it has weak_next
-    // field
-    if (includeWeakNext && object_size == AllocationSite::kSizeWithWeakNext)
-      IteratePointers(obj, AllocationSite::kWeakNextOffset,
-                      AllocationSite::kSizeWithWeakNext, v);
+    // Skip PretenureDataOffset and PretenureCreateCount which are Int32 fields.
+    // Visit weak_next only if it has weak_next field.
+    if (object_size == AllocationSite::kSizeWithWeakNext) {
+      IterateCustomWeakPointers(obj, AllocationSite::kWeakNextOffset,
+                                AllocationSite::kSizeWithWeakNext, v);
+    }
   }
 
   static inline int SizeOf(Map* map, HeapObject* object) {
@@ -207,10 +218,8 @@ class JSArrayBuffer::BodyDescriptor final : public BodyDescriptorBase {
   template <typename ObjectVisitor>
   static inline void IterateBody(Map* map, HeapObject* obj, int object_size,
                                  ObjectVisitor* v) {
-    // Array buffers contain raw pointers that the GC does not know about. These
-    // are stored at kBackStoreOffset and later, so we do not iterate over
-    // those.
-    IteratePointers(obj, kPropertiesOrHashOffset, kBackingStoreOffset, v);
+    // JSArrayBuffer instances contain raw data that the GC does not know about.
+    IteratePointers(obj, kPropertiesOrHashOffset, kByteLengthOffset, v);
     IterateBodyImpl(map, obj, kSize, object_size, v);
   }
 
@@ -219,6 +228,31 @@ class JSArrayBuffer::BodyDescriptor final : public BodyDescriptorBase {
   }
 };
 
+class JSArrayBufferView::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  STATIC_ASSERT(kBufferOffset + kPointerSize == kByteOffsetOffset);
+  STATIC_ASSERT(kByteOffsetOffset + kUIntptrSize == kByteLengthOffset);
+  STATIC_ASSERT(kByteLengthOffset + kUIntptrSize == kHeaderSize);
+
+  static bool IsValidSlot(Map* map, HeapObject* obj, int offset) {
+    if (offset < kByteOffsetOffset) return true;
+    if (offset < kHeaderSize) return false;
+    return IsValidSlotImpl(map, obj, offset);
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map* map, HeapObject* obj, int object_size,
+                                 ObjectVisitor* v) {
+    // JSArrayBufferView contains raw data that the GC does not know about.
+    IteratePointers(obj, kPropertiesOrHashOffset, kByteOffsetOffset, v);
+    IterateBodyImpl(map, obj, kHeaderSize, object_size, v);
+  }
+
+  static inline int SizeOf(Map* map, HeapObject* object) {
+    return map->instance_size();
+  }
+};
+
 template <typename Derived>
 class SmallOrderedHashTable<Derived>::BodyDescriptor final
     : public BodyDescriptorBase {
@@ -624,6 +658,49 @@ class DataHandler::BodyDescriptor final : public BodyDescriptorBase {
   }
 };
 
+class Context::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map* map, HeapObject* obj, int offset) {
+    return offset >= Context::kHeaderSize && offset < Context::kSize;
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map* map, HeapObject* obj, int object_size,
+                                 ObjectVisitor* v) {
+    IteratePointers(obj, Context::kHeaderSize,
+                    Context::kHeaderSize + FIRST_WEAK_SLOT * kPointerSize, v);
+    IterateCustomWeakPointers(
+        obj, Context::kHeaderSize + FIRST_WEAK_SLOT * kPointerSize,
+        Context::kSize, v);
+  }
+
+  static inline int SizeOf(Map* map, HeapObject* object) {
+    return Context::kSize;
+  }
+};
+
+class CodeDataContainer::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map* map, HeapObject* obj, int offset) {
+    return offset >= CodeDataContainer::kHeaderSize &&
+           offset < CodeDataContainer::kSize;
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map* map, HeapObject* obj, int object_size,
+                                 ObjectVisitor* v) {
+    IteratePointers(obj, CodeDataContainer::kHeaderSize,
+                    CodeDataContainer::kPointerFieldsStrongEndOffset, v);
+    IterateCustomWeakPointers(
+        obj, CodeDataContainer::kPointerFieldsStrongEndOffset,
+        CodeDataContainer::kPointerFieldsWeakEndOffset, v);
+  }
+
+  static inline int SizeOf(Map* map, HeapObject* object) {
+    return CodeDataContainer::kSize;
+  }
+};
+
 template <typename Op, typename ReturnType, typename T1, typename T2,
           typename T3, typename T4>
 ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
@@ -663,6 +740,7 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case EPHEMERON_HASH_TABLE_TYPE:
     case SCOPE_INFO_TYPE:
     case SCRIPT_CONTEXT_TABLE_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
@@ -707,8 +785,6 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case JS_ARRAY_TYPE:
     case JS_ARRAY_ITERATOR_TYPE:
     case JS_MODULE_NAMESPACE_TYPE:
-    case JS_TYPED_ARRAY_TYPE:
-    case JS_DATA_VIEW_TYPE:
     case JS_SET_TYPE:
     case JS_MAP_TYPE:
     case JS_SET_KEY_VALUE_ITERATOR_TYPE:
@@ -726,12 +802,17 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case JS_MESSAGE_OBJECT_TYPE:
     case JS_BOUND_FUNCTION_TYPE:
 #ifdef V8_INTL_SUPPORT
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
     case JS_INTL_COLLATOR_TYPE:
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
     case JS_INTL_LIST_FORMAT_TYPE:
     case JS_INTL_LOCALE_TYPE:
+    case JS_INTL_NUMBER_FORMAT_TYPE:
     case JS_INTL_PLURAL_RULES_TYPE:
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
+    case JS_INTL_SEGMENTER_TYPE:
 #endif  // V8_INTL_SUPPORT
+    case WASM_EXCEPTION_TYPE:
     case WASM_GLOBAL_TYPE:
     case WASM_MEMORY_TYPE:
     case WASM_MODULE_TYPE:
@@ -746,6 +827,10 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
                                                                   p4);
     case JS_ARRAY_BUFFER_TYPE:
       return Op::template apply<JSArrayBuffer::BodyDescriptor>(p1, p2, p3, p4);
+    case JS_DATA_VIEW_TYPE:
+      return Op::template apply<JSDataView::BodyDescriptor>(p1, p2, p3, p4);
+    case JS_TYPED_ARRAY_TYPE:
+      return Op::template apply<JSTypedArray::BodyDescriptor>(p1, p2, p3, p4);
     case JS_FUNCTION_TYPE:
       return Op::template apply<JSFunction::BodyDescriptor>(p1, p2, p3, p4);
     case ODDBALL_TYPE:
@@ -808,7 +893,7 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case ALLOCATION_SITE_TYPE:
       return Op::template apply<AllocationSite::BodyDescriptor>(p1, p2, p3, p4);
 
-#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE:
+#define MAKE_STRUCT_CASE(TYPE, Name, name) case TYPE:
       STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
       if (type == PROTOTYPE_INFO_TYPE) {
diff --git a/deps/v8/src/objects-body-descriptors.h b/deps/v8/src/objects-body-descriptors.h
index 6277f9d8bd..a1dc0f7ffa 100644
--- a/deps/v8/src/objects-body-descriptors.h
+++ b/deps/v8/src/objects-body-descriptors.h
@@ -26,7 +26,7 @@ namespace internal {
 //   template <typename ObjectVisitor>
 //   static inline void IterateBody(Map* map, HeapObject* obj, int object_size,
 //                                  ObjectVisitor* v);
-class BodyDescriptorBase BASE_EMBEDDED {
+class BodyDescriptorBase {
  public:
   template <typename ObjectVisitor>
   static inline void IteratePointers(HeapObject* obj, int start_offset,
@@ -37,6 +37,15 @@ class BodyDescriptorBase BASE_EMBEDDED {
                                     ObjectVisitor* v);
 
   template <typename ObjectVisitor>
+  static inline void IterateCustomWeakPointers(HeapObject* obj,
+                                               int start_offset, int end_offset,
+                                               ObjectVisitor* v);
+
+  template <typename ObjectVisitor>
+  static inline void IterateCustomWeakPointer(HeapObject* obj, int offset,
+                                              ObjectVisitor* v);
+
+  template <typename ObjectVisitor>
   static inline void IterateMaybeWeakPointers(HeapObject* obj, int start_offset,
                                               int end_offset, ObjectVisitor* v);
 
diff --git a/deps/v8/src/objects-debug.cc b/deps/v8/src/objects-debug.cc
index 3ce26f95c9..b4e50843a1 100644
--- a/deps/v8/src/objects-debug.cc
+++ b/deps/v8/src/objects-debug.cc
@@ -15,30 +15,38 @@
 #include "src/objects-inl.h"
 #include "src/objects/arguments-inl.h"
 #include "src/objects/bigint.h"
-#ifdef V8_INTL_SUPPORT
-#include "src/objects/js-collator-inl.h"
-#endif  // V8_INTL_SUPPORT
 #include "src/objects/data-handler-inl.h"
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/js-break-iterator-inl.h"
+#include "src/objects/js-collator-inl.h"
+#endif  // V8_INTL_SUPPORT
 #include "src/objects/js-collection-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/js-date-time-format-inl.h"
+#endif  // V8_INTL_SUPPORT
 #include "src/objects/js-generator-inl.h"
-#include "src/objects/literal-objects-inl.h"
 #ifdef V8_INTL_SUPPORT
 #include "src/objects/js-list-format-inl.h"
 #include "src/objects/js-locale-inl.h"
+#include "src/objects/js-number-format-inl.h"
+#include "src/objects/js-plural-rules-inl.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/js-regexp-string-iterator-inl.h"
 #ifdef V8_INTL_SUPPORT
-#include "src/objects/js-plural-rules-inl.h"
 #include "src/objects/js-relative-time-format-inl.h"
+#include "src/objects/js-segmenter-inl.h"
 #endif  // V8_INTL_SUPPORT
+#include "src/objects/literal-objects-inl.h"
 #include "src/objects/maybe-object.h"
 #include "src/objects/microtask-inl.h"
+#include "src/objects/microtask-queue-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/ostreams.h"
 #include "src/regexp/jsregexp.h"
 #include "src/transitions.h"
@@ -90,10 +98,10 @@ void Object::VerifyPointer(Isolate* isolate, Object* p) {
 
 void MaybeObject::VerifyMaybeObjectPointer(Isolate* isolate, MaybeObject* p) {
   HeapObject* heap_object;
-  if (p->ToStrongOrWeakHeapObject(&heap_object)) {
+  if (p->GetHeapObject(&heap_object)) {
     HeapObject::VerifyHeapPointer(isolate, heap_object);
   } else {
-    CHECK(p->IsSmi() || p->IsClearedWeakHeapObject());
+    CHECK(p->IsSmi() || p->IsCleared());
   }
 }
 
@@ -115,7 +123,7 @@ void HeapObject::HeapObjectVerify(Isolate* isolate) {
   CHECK(map()->IsMap());
 
   switch (map()->instance_type()) {
-#define STRING_TYPE_CASE(TYPE, size, name, camel_name) case TYPE:
+#define STRING_TYPE_CASE(TYPE, size, name, CamelName) case TYPE:
     STRING_TYPE_LIST(STRING_TYPE_CASE)
 #undef STRING_TYPE_CASE
     String::cast(this)->StringVerify(isolate);
@@ -155,6 +163,7 @@ void HeapObject::HeapObjectVerify(Isolate* isolate) {
     case FIXED_ARRAY_TYPE:
     case SCOPE_INFO_TYPE:
     case SCRIPT_CONTEXT_TABLE_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
@@ -222,6 +231,7 @@ void HeapObject::HeapObjectVerify(Isolate* isolate) {
     case JS_API_OBJECT_TYPE:
     case JS_SPECIAL_API_OBJECT_TYPE:
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
+    case WASM_EXCEPTION_TYPE:
     case WASM_GLOBAL_TYPE:
     case WASM_MEMORY_TYPE:
     case WASM_TABLE_TYPE:
@@ -356,25 +366,37 @@ void HeapObject::HeapObjectVerify(Isolate* isolate) {
       CodeDataContainer::cast(this)->CodeDataContainerVerify(isolate);
       break;
 #ifdef V8_INTL_SUPPORT
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
+      JSV8BreakIterator::cast(this)->JSV8BreakIteratorVerify(isolate);
+      break;
     case JS_INTL_COLLATOR_TYPE:
       JSCollator::cast(this)->JSCollatorVerify(isolate);
       break;
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
+      JSDateTimeFormat::cast(this)->JSDateTimeFormatVerify(isolate);
+      break;
     case JS_INTL_LIST_FORMAT_TYPE:
       JSListFormat::cast(this)->JSListFormatVerify(isolate);
       break;
     case JS_INTL_LOCALE_TYPE:
       JSLocale::cast(this)->JSLocaleVerify(isolate);
       break;
+    case JS_INTL_NUMBER_FORMAT_TYPE:
+      JSNumberFormat::cast(this)->JSNumberFormatVerify(isolate);
+      break;
     case JS_INTL_PLURAL_RULES_TYPE:
       JSPluralRules::cast(this)->JSPluralRulesVerify(isolate);
       break;
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
       JSRelativeTimeFormat::cast(this)->JSRelativeTimeFormatVerify(isolate);
       break;
+    case JS_INTL_SEGMENTER_TYPE:
+      JSSegmenter::cast(this)->JSSegmenterVerify(isolate);
+      break;
 #endif  // V8_INTL_SUPPORT
 
-#define MAKE_STRUCT_CASE(NAME, Name, name)   \
-  case NAME##_TYPE:                          \
+#define MAKE_STRUCT_CASE(TYPE, Name, name)   \
+  case TYPE:                                 \
     Name::cast(this)->Name##Verify(isolate); \
     break;
       STRUCT_LIST(MAKE_STRUCT_CASE)
@@ -434,8 +456,7 @@ void FeedbackVector::FeedbackVectorVerify(Isolate* isolate) {
   CHECK(IsFeedbackVector());
   MaybeObject* code = optimized_code_weak_or_smi();
   MaybeObject::VerifyMaybeObjectPointer(isolate, code);
-  CHECK(code->IsSmi() || code->IsClearedWeakHeapObject() ||
-        code->IsWeakHeapObject());
+  CHECK(code->IsSmi() || code->IsWeakOrCleared());
 }
 
 template <class Traits>
@@ -703,7 +724,7 @@ void DescriptorArray::DescriptorArrayVerify(Isolate* isolate) {
 
     // Check that properties with private symbols names are non-enumerable.
     for (int descriptor = 0; descriptor < nof_descriptors; descriptor++) {
-      Object* key = get(ToKeyIndex(descriptor))->ToObject();
+      Object* key = get(ToKeyIndex(descriptor))->cast<Object>();
       // number_of_descriptors() may be out of sync with the actual descriptors
       // written during descriptor array construction.
       if (key->IsUndefined(isolate)) continue;
@@ -714,13 +735,14 @@ void DescriptorArray::DescriptorArrayVerify(Isolate* isolate) {
       MaybeObject* value = get(ToValueIndex(descriptor));
       HeapObject* heap_object;
       if (details.location() == kField) {
-        CHECK(value == MaybeObject::FromObject(FieldType::None()) ||
-              value == MaybeObject::FromObject(FieldType::Any()) ||
-              value->IsClearedWeakHeapObject() ||
-              (value->ToWeakHeapObject(&heap_object) && heap_object->IsMap()));
+        CHECK(
+            value == MaybeObject::FromObject(FieldType::None()) ||
+            value == MaybeObject::FromObject(FieldType::Any()) ||
+            value->IsCleared() ||
+            (value->GetHeapObjectIfWeak(&heap_object) && heap_object->IsMap()));
       } else {
-        CHECK(!value->IsWeakOrClearedHeapObject());
-        CHECK(!value->ToObject()->IsMap());
+        CHECK(!value->IsWeakOrCleared());
+        CHECK(!value->cast<Object>()->IsMap());
       }
     }
   }
@@ -1269,6 +1291,13 @@ void PromiseReactionJobTask::PromiseReactionJobTaskVerify(Isolate* isolate) {
         promise_or_capability()->IsPromiseCapability());
 }
 
+void MicrotaskQueue::MicrotaskQueueVerify(Isolate* isolate) {
+  CHECK(IsMicrotaskQueue());
+  VerifyHeapPointer(isolate, queue());
+  VerifySmiField(kPendingMicrotaskCountOffset);
+  CHECK_LE(pending_microtask_count(), queue()->length());
+}
+
 void PromiseFulfillReactionJobTask::PromiseFulfillReactionJobTaskVerify(
     Isolate* isolate) {
   CHECK(IsPromiseFulfillReactionJobTask());
@@ -1444,9 +1473,6 @@ void JSProxy::JSProxyVerify(Isolate* isolate) {
 void JSArrayBuffer::JSArrayBufferVerify(Isolate* isolate) {
   CHECK(IsJSArrayBuffer());
   JSObjectVerify(isolate);
-  VerifyPointer(isolate, byte_length());
-  CHECK(byte_length()->IsSmi() || byte_length()->IsHeapNumber() ||
-        byte_length()->IsUndefined(isolate));
 }
 
 void JSArrayBufferView::JSArrayBufferViewVerify(Isolate* isolate) {
@@ -1455,14 +1481,8 @@ void JSArrayBufferView::JSArrayBufferViewVerify(Isolate* isolate) {
   VerifyPointer(isolate, buffer());
   CHECK(buffer()->IsJSArrayBuffer() || buffer()->IsUndefined(isolate) ||
         buffer() == Smi::kZero);
-
-  VerifyPointer(isolate, raw_byte_offset());
-  CHECK(raw_byte_offset()->IsSmi() || raw_byte_offset()->IsHeapNumber() ||
-        raw_byte_offset()->IsUndefined(isolate));
-
-  VerifyPointer(isolate, raw_byte_length());
-  CHECK(raw_byte_length()->IsSmi() || raw_byte_length()->IsHeapNumber() ||
-        raw_byte_length()->IsUndefined(isolate));
+  CHECK_LE(byte_length(), JSArrayBuffer::kMaxByteLength);
+  CHECK_LE(byte_offset(), JSArrayBuffer::kMaxByteLength);
 }
 
 void JSTypedArray::JSTypedArrayVerify(Isolate* isolate) {
@@ -1575,7 +1595,7 @@ void PrototypeUsers::Verify(WeakArrayList* array) {
   while (empty_slot != kNoEmptySlotsMarker) {
     CHECK_GT(empty_slot, 0);
     CHECK_LT(empty_slot, array->length());
-    empty_slot = Smi::ToInt(array->Get(empty_slot)->ToSmi());
+    empty_slot = Smi::ToInt(array->Get(empty_slot)->cast<Smi>());
     ++empty_slots_count;
   }
 
@@ -1585,8 +1605,8 @@ void PrototypeUsers::Verify(WeakArrayList* array) {
   for (int i = kFirstIndex; i < array->length(); ++i) {
     HeapObject* heap_object;
     MaybeObject* object = array->Get(i);
-    if ((object->ToWeakHeapObject(&heap_object) && heap_object->IsMap()) ||
-        object->IsClearedWeakHeapObject()) {
+    if ((object->GetHeapObjectIfWeak(&heap_object) && heap_object->IsMap()) ||
+        object->IsCleared()) {
       ++weak_maps_count;
     } else {
       CHECK(object->IsSmi());
@@ -1800,9 +1820,8 @@ void Script::ScriptVerify(Isolate* isolate) {
   for (int i = 0; i < shared_function_infos()->length(); ++i) {
     MaybeObject* maybe_object = shared_function_infos()->Get(i);
     HeapObject* heap_object;
-    CHECK(maybe_object->IsWeakHeapObject() ||
-          maybe_object->IsClearedWeakHeapObject() ||
-          (maybe_object->ToStrongHeapObject(&heap_object) &&
+    CHECK(maybe_object->IsWeak() || maybe_object->IsCleared() ||
+          (maybe_object->GetHeapObjectIfStrong(&heap_object) &&
            heap_object->IsUndefined(isolate)));
   }
 }
@@ -1813,12 +1832,11 @@ void NormalizedMapCache::NormalizedMapCacheVerify(Isolate* isolate) {
     for (int i = 0; i < length(); i++) {
       MaybeObject* e = WeakFixedArray::Get(i);
       HeapObject* heap_object;
-      if (e->ToWeakHeapObject(&heap_object)) {
+      if (e->GetHeapObjectIfWeak(&heap_object)) {
         Map::cast(heap_object)->DictionaryMapVerify(isolate);
       } else {
-        CHECK(e->IsClearedWeakHeapObject() ||
-              (e->ToStrongHeapObject(&heap_object) &&
-               heap_object->IsUndefined(isolate)));
+        CHECK(e->IsCleared() || (e->GetHeapObjectIfStrong(&heap_object) &&
+                                 heap_object->IsUndefined(isolate)));
       }
     }
   }
@@ -1871,18 +1889,37 @@ void InterpreterData::InterpreterDataVerify(Isolate* isolate) {
 }
 
 #ifdef V8_INTL_SUPPORT
+void JSV8BreakIterator::JSV8BreakIteratorVerify(Isolate* isolate) {
+  JSObjectVerify(isolate);
+  VerifyObjectField(isolate, kLocaleOffset);
+  VerifyObjectField(isolate, kTypeOffset);
+  VerifyObjectField(isolate, kBreakIteratorOffset);
+  VerifyObjectField(isolate, kUnicodeStringOffset);
+  VerifyObjectField(isolate, kBoundAdoptTextOffset);
+  VerifyObjectField(isolate, kBoundFirstOffset);
+  VerifyObjectField(isolate, kBoundNextOffset);
+  VerifyObjectField(isolate, kBoundCurrentOffset);
+  VerifyObjectField(isolate, kBoundBreakTypeOffset);
+}
+
 void JSCollator::JSCollatorVerify(Isolate* isolate) {
   CHECK(IsJSCollator());
   JSObjectVerify(isolate);
   VerifyObjectField(isolate, kICUCollatorOffset);
-  VerifyObjectField(isolate, kFlagsOffset);
   VerifyObjectField(isolate, kBoundCompareOffset);
 }
 
+void JSDateTimeFormat::JSDateTimeFormatVerify(Isolate* isolate) {
+  JSObjectVerify(isolate);
+  VerifyObjectField(isolate, kICULocaleOffset);
+  VerifyObjectField(isolate, kICUSimpleDateFormatOffset);
+  VerifyObjectField(isolate, kBoundFormatOffset);
+}
+
 void JSListFormat::JSListFormatVerify(Isolate* isolate) {
   JSObjectVerify(isolate);
   VerifyObjectField(isolate, kLocaleOffset);
-  VerifyObjectField(isolate, kFormatterOffset);
+  VerifyObjectField(isolate, kICUFormatterOffset);
   VerifyObjectField(isolate, kFlagsOffset);
 }
 
@@ -1894,14 +1931,21 @@ void JSLocale::JSLocaleVerify(Isolate* isolate) {
   VerifyObjectField(isolate, kBaseNameOffset);
   VerifyObjectField(isolate, kLocaleOffset);
   // Unicode extension fields.
+  VerifyObjectField(isolate, kFlagsOffset);
   VerifyObjectField(isolate, kCalendarOffset);
-  VerifyObjectField(isolate, kCaseFirstOffset);
   VerifyObjectField(isolate, kCollationOffset);
-  VerifyObjectField(isolate, kHourCycleOffset);
-  VerifyObjectField(isolate, kNumericOffset);
   VerifyObjectField(isolate, kNumberingSystemOffset);
 }
 
+void JSNumberFormat::JSNumberFormatVerify(Isolate* isolate) {
+  CHECK(IsJSNumberFormat());
+  JSObjectVerify(isolate);
+  VerifyObjectField(isolate, kLocaleOffset);
+  VerifyObjectField(isolate, kICUNumberFormatOffset);
+  VerifyObjectField(isolate, kBoundFormatOffset);
+  VerifyObjectField(isolate, kFlagsOffset);
+}
+
 void JSPluralRules::JSPluralRulesVerify(Isolate* isolate) {
   CHECK(IsJSPluralRules());
   JSObjectVerify(isolate);
@@ -1914,7 +1958,14 @@ void JSPluralRules::JSPluralRulesVerify(Isolate* isolate) {
 void JSRelativeTimeFormat::JSRelativeTimeFormatVerify(Isolate* isolate) {
   JSObjectVerify(isolate);
   VerifyObjectField(isolate, kLocaleOffset);
-  VerifyObjectField(isolate, kFormatterOffset);
+  VerifyObjectField(isolate, kICUFormatterOffset);
+  VerifyObjectField(isolate, kFlagsOffset);
+}
+
+void JSSegmenter::JSSegmenterVerify(Isolate* isolate) {
+  JSObjectVerify(isolate);
+  VerifyObjectField(isolate, kLocaleOffset);
+  VerifyObjectField(isolate, kICUBreakIteratorOffset);
   VerifyObjectField(isolate, kFlagsOffset);
 }
 #endif  // V8_INTL_SUPPORT
@@ -2119,8 +2170,8 @@ bool CanLeak(Object* obj, Heap* heap) {
   if (obj->IsContext()) return true;
   if (obj->IsMap()) {
     Map* map = Map::cast(obj);
-    for (int i = 0; i < Heap::kStrongRootListLength; i++) {
-      Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(i);
+    for (RootIndex root_index = RootIndex::kFirstStrongRoot;
+         root_index <= RootIndex::kLastStrongRoot; ++root_index) {
       if (map == heap->root(root_index)) return false;
     }
     return true;
diff --git a/deps/v8/src/objects-definitions.h b/deps/v8/src/objects-definitions.h
index 3b0a379632..8b8d50f2a7 100644
--- a/deps/v8/src/objects-definitions.h
+++ b/deps/v8/src/objects-definitions.h
@@ -38,173 +38,177 @@ namespace internal {
 // NOTE: List had to be split into two, because of conditional item(s) from
 // INTL namespace. They can't just be appended to the end, because of the
 // checks we do in tests (expecting JS_FUNCTION_TYPE to be last).
-#define INSTANCE_TYPE_LIST_BEFORE_INTL(V)                       \
-  V(INTERNALIZED_STRING_TYPE)                                   \
-  V(EXTERNAL_INTERNALIZED_STRING_TYPE)                          \
-  V(ONE_BYTE_INTERNALIZED_STRING_TYPE)                          \
-  V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE)                 \
-  V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE)       \
-  V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE)                    \
-  V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE)           \
-  V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
-  V(STRING_TYPE)                                                \
-  V(CONS_STRING_TYPE)                                           \
-  V(EXTERNAL_STRING_TYPE)                                       \
-  V(SLICED_STRING_TYPE)                                         \
-  V(THIN_STRING_TYPE)                                           \
-  V(ONE_BYTE_STRING_TYPE)                                       \
-  V(CONS_ONE_BYTE_STRING_TYPE)                                  \
-  V(EXTERNAL_ONE_BYTE_STRING_TYPE)                              \
-  V(SLICED_ONE_BYTE_STRING_TYPE)                                \
-  V(THIN_ONE_BYTE_STRING_TYPE)                                  \
-  V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE)                    \
-  V(SHORT_EXTERNAL_STRING_TYPE)                                 \
-  V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE)                        \
-  V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE)              \
-                                                                \
-  V(SYMBOL_TYPE)                                                \
-  V(HEAP_NUMBER_TYPE)                                           \
-  V(BIGINT_TYPE)                                                \
-  V(ODDBALL_TYPE)                                               \
-                                                                \
-  V(MAP_TYPE)                                                   \
-  V(CODE_TYPE)                                                  \
-  V(MUTABLE_HEAP_NUMBER_TYPE)                                   \
-  V(FOREIGN_TYPE)                                               \
-  V(BYTE_ARRAY_TYPE)                                            \
-  V(BYTECODE_ARRAY_TYPE)                                        \
-  V(FREE_SPACE_TYPE)                                            \
-                                                                \
-  V(FIXED_INT8_ARRAY_TYPE)                                      \
-  V(FIXED_UINT8_ARRAY_TYPE)                                     \
-  V(FIXED_INT16_ARRAY_TYPE)                                     \
-  V(FIXED_UINT16_ARRAY_TYPE)                                    \
-  V(FIXED_INT32_ARRAY_TYPE)                                     \
-  V(FIXED_UINT32_ARRAY_TYPE)                                    \
-  V(FIXED_FLOAT32_ARRAY_TYPE)                                   \
-  V(FIXED_FLOAT64_ARRAY_TYPE)                                   \
-  V(FIXED_UINT8_CLAMPED_ARRAY_TYPE)                             \
-  V(FIXED_BIGINT64_ARRAY_TYPE)                                  \
-  V(FIXED_BIGUINT64_ARRAY_TYPE)                                 \
-                                                                \
-  V(FIXED_DOUBLE_ARRAY_TYPE)                                    \
-  V(FEEDBACK_METADATA_TYPE)                                     \
-  V(FILLER_TYPE)                                                \
-                                                                \
-  V(ACCESS_CHECK_INFO_TYPE)                                     \
-  V(ACCESSOR_INFO_TYPE)                                         \
-  V(ACCESSOR_PAIR_TYPE)                                         \
-  V(ALIASED_ARGUMENTS_ENTRY_TYPE)                               \
-  V(ALLOCATION_MEMENTO_TYPE)                                    \
-  V(ASYNC_GENERATOR_REQUEST_TYPE)                               \
-  V(DEBUG_INFO_TYPE)                                            \
-  V(FUNCTION_TEMPLATE_INFO_TYPE)                                \
-  V(INTERCEPTOR_INFO_TYPE)                                      \
-  V(INTERPRETER_DATA_TYPE)                                      \
-  V(MODULE_INFO_ENTRY_TYPE)                                     \
-  V(MODULE_TYPE)                                                \
-  V(OBJECT_TEMPLATE_INFO_TYPE)                                  \
-  V(PROMISE_CAPABILITY_TYPE)                                    \
-  V(PROMISE_REACTION_TYPE)                                      \
-  V(PROTOTYPE_INFO_TYPE)                                        \
-  V(SCRIPT_TYPE)                                                \
-  V(STACK_FRAME_INFO_TYPE)                                      \
-  V(TUPLE2_TYPE)                                                \
-  V(TUPLE3_TYPE)                                                \
-  V(ARRAY_BOILERPLATE_DESCRIPTION_TYPE)                         \
-  V(WASM_DEBUG_INFO_TYPE)                                       \
-  V(WASM_EXPORTED_FUNCTION_DATA_TYPE)                           \
-                                                                \
-  V(CALLABLE_TASK_TYPE)                                         \
-  V(CALLBACK_TASK_TYPE)                                         \
-  V(PROMISE_FULFILL_REACTION_JOB_TASK_TYPE)                     \
-  V(PROMISE_REJECT_REACTION_JOB_TASK_TYPE)                      \
-  V(PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE)                     \
-                                                                \
-  V(ALLOCATION_SITE_TYPE)                                       \
-                                                                \
-  V(FIXED_ARRAY_TYPE)                                           \
-  V(OBJECT_BOILERPLATE_DESCRIPTION_TYPE)                        \
-  V(HASH_TABLE_TYPE)                                            \
-  V(ORDERED_HASH_MAP_TYPE)                                      \
-  V(ORDERED_HASH_SET_TYPE)                                      \
-  V(NAME_DICTIONARY_TYPE)                                       \
-  V(GLOBAL_DICTIONARY_TYPE)                                     \
-  V(NUMBER_DICTIONARY_TYPE)                                     \
-  V(SIMPLE_NUMBER_DICTIONARY_TYPE)                              \
-  V(STRING_TABLE_TYPE)                                          \
-  V(EPHEMERON_HASH_TABLE_TYPE)                                  \
-  V(SCOPE_INFO_TYPE)                                            \
-  V(SCRIPT_CONTEXT_TABLE_TYPE)                                  \
-                                                                \
-  V(BLOCK_CONTEXT_TYPE)                                         \
-  V(CATCH_CONTEXT_TYPE)                                         \
-  V(DEBUG_EVALUATE_CONTEXT_TYPE)                                \
-  V(EVAL_CONTEXT_TYPE)                                          \
-  V(FUNCTION_CONTEXT_TYPE)                                      \
-  V(MODULE_CONTEXT_TYPE)                                        \
-  V(NATIVE_CONTEXT_TYPE)                                        \
-  V(SCRIPT_CONTEXT_TYPE)                                        \
-  V(WITH_CONTEXT_TYPE)                                          \
-                                                                \
-  V(WEAK_FIXED_ARRAY_TYPE)                                      \
-  V(DESCRIPTOR_ARRAY_TYPE)                                      \
-  V(TRANSITION_ARRAY_TYPE)                                      \
-                                                                \
-  V(CALL_HANDLER_INFO_TYPE)                                     \
-  V(CELL_TYPE)                                                  \
-  V(CODE_DATA_CONTAINER_TYPE)                                   \
-  V(FEEDBACK_CELL_TYPE)                                         \
-  V(FEEDBACK_VECTOR_TYPE)                                       \
-  V(LOAD_HANDLER_TYPE)                                          \
-  V(PRE_PARSED_SCOPE_DATA_TYPE)                                 \
-  V(PROPERTY_ARRAY_TYPE)                                        \
-  V(PROPERTY_CELL_TYPE)                                         \
-  V(SHARED_FUNCTION_INFO_TYPE)                                  \
-  V(SMALL_ORDERED_HASH_MAP_TYPE)                                \
-  V(SMALL_ORDERED_HASH_SET_TYPE)                                \
-  V(STORE_HANDLER_TYPE)                                         \
-  V(UNCOMPILED_DATA_WITHOUT_PRE_PARSED_SCOPE_TYPE)              \
-  V(UNCOMPILED_DATA_WITH_PRE_PARSED_SCOPE_TYPE)                 \
-  V(WEAK_ARRAY_LIST_TYPE)                                       \
-                                                                \
-  V(JS_PROXY_TYPE)                                              \
-  V(JS_GLOBAL_OBJECT_TYPE)                                      \
-  V(JS_GLOBAL_PROXY_TYPE)                                       \
-  V(JS_MODULE_NAMESPACE_TYPE)                                   \
-  V(JS_SPECIAL_API_OBJECT_TYPE)                                 \
-  V(JS_VALUE_TYPE)                                              \
-  V(JS_API_OBJECT_TYPE)                                         \
-  V(JS_OBJECT_TYPE)                                             \
-                                                                \
-  V(JS_ARGUMENTS_TYPE)                                          \
-  V(JS_ARRAY_BUFFER_TYPE)                                       \
-  V(JS_ARRAY_ITERATOR_TYPE)                                     \
-  V(JS_ARRAY_TYPE)                                              \
-  V(JS_ASYNC_FROM_SYNC_ITERATOR_TYPE)                           \
-  V(JS_ASYNC_GENERATOR_OBJECT_TYPE)                             \
-  V(JS_CONTEXT_EXTENSION_OBJECT_TYPE)                           \
-  V(JS_DATE_TYPE)                                               \
-  V(JS_ERROR_TYPE)                                              \
-  V(JS_GENERATOR_OBJECT_TYPE)                                   \
-  V(JS_MAP_TYPE)                                                \
-  V(JS_MAP_KEY_ITERATOR_TYPE)                                   \
-  V(JS_MAP_KEY_VALUE_ITERATOR_TYPE)                             \
-  V(JS_MAP_VALUE_ITERATOR_TYPE)                                 \
-  V(JS_MESSAGE_OBJECT_TYPE)                                     \
-  V(JS_PROMISE_TYPE)                                            \
-  V(JS_REGEXP_TYPE)                                             \
-  V(JS_REGEXP_STRING_ITERATOR_TYPE)                             \
-  V(JS_SET_TYPE)                                                \
-  V(JS_SET_KEY_VALUE_ITERATOR_TYPE)                             \
-  V(JS_SET_VALUE_ITERATOR_TYPE)                                 \
-  V(JS_STRING_ITERATOR_TYPE)                                    \
-  V(JS_WEAK_MAP_TYPE)                                           \
-  V(JS_WEAK_SET_TYPE)                                           \
-  V(JS_TYPED_ARRAY_TYPE)                                        \
+#define INSTANCE_TYPE_LIST_BEFORE_INTL(V)                          \
+  V(INTERNALIZED_STRING_TYPE)                                      \
+  V(EXTERNAL_INTERNALIZED_STRING_TYPE)                             \
+  V(ONE_BYTE_INTERNALIZED_STRING_TYPE)                             \
+  V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE)                    \
+  V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE)          \
+  V(UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE)                    \
+  V(UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE)           \
+  V(UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE) \
+  V(STRING_TYPE)                                                   \
+  V(CONS_STRING_TYPE)                                              \
+  V(EXTERNAL_STRING_TYPE)                                          \
+  V(SLICED_STRING_TYPE)                                            \
+  V(THIN_STRING_TYPE)                                              \
+  V(ONE_BYTE_STRING_TYPE)                                          \
+  V(CONS_ONE_BYTE_STRING_TYPE)                                     \
+  V(EXTERNAL_ONE_BYTE_STRING_TYPE)                                 \
+  V(SLICED_ONE_BYTE_STRING_TYPE)                                   \
+  V(THIN_ONE_BYTE_STRING_TYPE)                                     \
+  V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE)                       \
+  V(UNCACHED_EXTERNAL_STRING_TYPE)                                 \
+  V(UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE)                        \
+  V(UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE)              \
+                                                                   \
+  V(SYMBOL_TYPE)                                                   \
+  V(HEAP_NUMBER_TYPE)                                              \
+  V(BIGINT_TYPE)                                                   \
+  V(ODDBALL_TYPE)                                                  \
+                                                                   \
+  V(MAP_TYPE)                                                      \
+  V(CODE_TYPE)                                                     \
+  V(MUTABLE_HEAP_NUMBER_TYPE)                                      \
+  V(FOREIGN_TYPE)                                                  \
+  V(BYTE_ARRAY_TYPE)                                               \
+  V(BYTECODE_ARRAY_TYPE)                                           \
+  V(FREE_SPACE_TYPE)                                               \
+                                                                   \
+  V(FIXED_INT8_ARRAY_TYPE)                                         \
+  V(FIXED_UINT8_ARRAY_TYPE)                                        \
+  V(FIXED_INT16_ARRAY_TYPE)                                        \
+  V(FIXED_UINT16_ARRAY_TYPE)                                       \
+  V(FIXED_INT32_ARRAY_TYPE)                                        \
+  V(FIXED_UINT32_ARRAY_TYPE)                                       \
+  V(FIXED_FLOAT32_ARRAY_TYPE)                                      \
+  V(FIXED_FLOAT64_ARRAY_TYPE)                                      \
+  V(FIXED_UINT8_CLAMPED_ARRAY_TYPE)                                \
+  V(FIXED_BIGINT64_ARRAY_TYPE)                                     \
+  V(FIXED_BIGUINT64_ARRAY_TYPE)                                    \
+                                                                   \
+  V(FIXED_DOUBLE_ARRAY_TYPE)                                       \
+  V(FEEDBACK_METADATA_TYPE)                                        \
+  V(FILLER_TYPE)                                                   \
+                                                                   \
+  V(ACCESS_CHECK_INFO_TYPE)                                        \
+  V(ACCESSOR_INFO_TYPE)                                            \
+  V(ACCESSOR_PAIR_TYPE)                                            \
+  V(ALIASED_ARGUMENTS_ENTRY_TYPE)                                  \
+  V(ALLOCATION_MEMENTO_TYPE)                                       \
+  V(ASYNC_GENERATOR_REQUEST_TYPE)                                  \
+  V(DEBUG_INFO_TYPE)                                               \
+  V(FUNCTION_TEMPLATE_INFO_TYPE)                                   \
+  V(INTERCEPTOR_INFO_TYPE)                                         \
+  V(INTERPRETER_DATA_TYPE)                                         \
+  V(MODULE_INFO_ENTRY_TYPE)                                        \
+  V(MODULE_TYPE)                                                   \
+  V(OBJECT_TEMPLATE_INFO_TYPE)                                     \
+  V(PROMISE_CAPABILITY_TYPE)                                       \
+  V(PROMISE_REACTION_TYPE)                                         \
+  V(PROTOTYPE_INFO_TYPE)                                           \
+  V(SCRIPT_TYPE)                                                   \
+  V(STACK_FRAME_INFO_TYPE)                                         \
+  V(TUPLE2_TYPE)                                                   \
+  V(TUPLE3_TYPE)                                                   \
+  V(ARRAY_BOILERPLATE_DESCRIPTION_TYPE)                            \
+  V(WASM_DEBUG_INFO_TYPE)                                          \
+  V(WASM_EXPORTED_FUNCTION_DATA_TYPE)                              \
+                                                                   \
+  V(CALLABLE_TASK_TYPE)                                            \
+  V(CALLBACK_TASK_TYPE)                                            \
+  V(PROMISE_FULFILL_REACTION_JOB_TASK_TYPE)                        \
+  V(PROMISE_REJECT_REACTION_JOB_TASK_TYPE)                         \
+  V(PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE)                        \
+                                                                   \
+  V(MICROTASK_QUEUE_TYPE)                                          \
+                                                                   \
+  V(ALLOCATION_SITE_TYPE)                                          \
+                                                                   \
+  V(FIXED_ARRAY_TYPE)                                              \
+  V(OBJECT_BOILERPLATE_DESCRIPTION_TYPE)                           \
+  V(HASH_TABLE_TYPE)                                               \
+  V(ORDERED_HASH_MAP_TYPE)                                         \
+  V(ORDERED_HASH_SET_TYPE)                                         \
+  V(NAME_DICTIONARY_TYPE)                                          \
+  V(GLOBAL_DICTIONARY_TYPE)                                        \
+  V(NUMBER_DICTIONARY_TYPE)                                        \
+  V(SIMPLE_NUMBER_DICTIONARY_TYPE)                                 \
+  V(STRING_TABLE_TYPE)                                             \
+  V(EPHEMERON_HASH_TABLE_TYPE)                                     \
+  V(SCOPE_INFO_TYPE)                                               \
+  V(SCRIPT_CONTEXT_TABLE_TYPE)                                     \
+                                                                   \
+  V(AWAIT_CONTEXT_TYPE)                                            \
+  V(BLOCK_CONTEXT_TYPE)                                            \
+  V(CATCH_CONTEXT_TYPE)                                            \
+  V(DEBUG_EVALUATE_CONTEXT_TYPE)                                   \
+  V(EVAL_CONTEXT_TYPE)                                             \
+  V(FUNCTION_CONTEXT_TYPE)                                         \
+  V(MODULE_CONTEXT_TYPE)                                           \
+  V(NATIVE_CONTEXT_TYPE)                                           \
+  V(SCRIPT_CONTEXT_TYPE)                                           \
+  V(WITH_CONTEXT_TYPE)                                             \
+                                                                   \
+  V(WEAK_FIXED_ARRAY_TYPE)                                         \
+  V(DESCRIPTOR_ARRAY_TYPE)                                         \
+  V(TRANSITION_ARRAY_TYPE)                                         \
+                                                                   \
+  V(CALL_HANDLER_INFO_TYPE)                                        \
+  V(CELL_TYPE)                                                     \
+  V(CODE_DATA_CONTAINER_TYPE)                                      \
+  V(FEEDBACK_CELL_TYPE)                                            \
+  V(FEEDBACK_VECTOR_TYPE)                                          \
+  V(LOAD_HANDLER_TYPE)                                             \
+  V(PRE_PARSED_SCOPE_DATA_TYPE)                                    \
+  V(PROPERTY_ARRAY_TYPE)                                           \
+  V(PROPERTY_CELL_TYPE)                                            \
+  V(SHARED_FUNCTION_INFO_TYPE)                                     \
+  V(SMALL_ORDERED_HASH_MAP_TYPE)                                   \
+  V(SMALL_ORDERED_HASH_SET_TYPE)                                   \
+  V(STORE_HANDLER_TYPE)                                            \
+  V(UNCOMPILED_DATA_WITHOUT_PRE_PARSED_SCOPE_TYPE)                 \
+  V(UNCOMPILED_DATA_WITH_PRE_PARSED_SCOPE_TYPE)                    \
+  V(WEAK_ARRAY_LIST_TYPE)                                          \
+                                                                   \
+  V(JS_PROXY_TYPE)                                                 \
+  V(JS_GLOBAL_OBJECT_TYPE)                                         \
+  V(JS_GLOBAL_PROXY_TYPE)                                          \
+  V(JS_MODULE_NAMESPACE_TYPE)                                      \
+  V(JS_SPECIAL_API_OBJECT_TYPE)                                    \
+  V(JS_VALUE_TYPE)                                                 \
+  V(JS_API_OBJECT_TYPE)                                            \
+  V(JS_OBJECT_TYPE)                                                \
+                                                                   \
+  V(JS_ARGUMENTS_TYPE)                                             \
+  V(JS_ARRAY_BUFFER_TYPE)                                          \
+  V(JS_ARRAY_ITERATOR_TYPE)                                        \
+  V(JS_ARRAY_TYPE)                                                 \
+  V(JS_ASYNC_FROM_SYNC_ITERATOR_TYPE)                              \
+  V(JS_ASYNC_GENERATOR_OBJECT_TYPE)                                \
+  V(JS_CONTEXT_EXTENSION_OBJECT_TYPE)                              \
+  V(JS_DATE_TYPE)                                                  \
+  V(JS_ERROR_TYPE)                                                 \
+  V(JS_GENERATOR_OBJECT_TYPE)                                      \
+  V(JS_MAP_TYPE)                                                   \
+  V(JS_MAP_KEY_ITERATOR_TYPE)                                      \
+  V(JS_MAP_KEY_VALUE_ITERATOR_TYPE)                                \
+  V(JS_MAP_VALUE_ITERATOR_TYPE)                                    \
+  V(JS_MESSAGE_OBJECT_TYPE)                                        \
+  V(JS_PROMISE_TYPE)                                               \
+  V(JS_REGEXP_TYPE)                                                \
+  V(JS_REGEXP_STRING_ITERATOR_TYPE)                                \
+  V(JS_SET_TYPE)                                                   \
+  V(JS_SET_KEY_VALUE_ITERATOR_TYPE)                                \
+  V(JS_SET_VALUE_ITERATOR_TYPE)                                    \
+  V(JS_STRING_ITERATOR_TYPE)                                       \
+  V(JS_WEAK_MAP_TYPE)                                              \
+  V(JS_WEAK_SET_TYPE)                                              \
+  V(JS_TYPED_ARRAY_TYPE)                                           \
   V(JS_DATA_VIEW_TYPE)
 
 #define INSTANCE_TYPE_LIST_AFTER_INTL(V) \
+  V(WASM_EXCEPTION_TYPE)                 \
   V(WASM_GLOBAL_TYPE)                    \
   V(WASM_INSTANCE_TYPE)                  \
   V(WASM_MEMORY_TYPE)                    \
@@ -216,11 +220,15 @@ namespace internal {
 #ifdef V8_INTL_SUPPORT
 #define INSTANCE_TYPE_LIST(V)          \
   INSTANCE_TYPE_LIST_BEFORE_INTL(V)    \
+  V(JS_INTL_V8_BREAK_ITERATOR_TYPE)    \
   V(JS_INTL_COLLATOR_TYPE)             \
+  V(JS_INTL_DATE_TIME_FORMAT_TYPE)     \
   V(JS_INTL_LIST_FORMAT_TYPE)          \
   V(JS_INTL_LOCALE_TYPE)               \
+  V(JS_INTL_NUMBER_FORMAT_TYPE)        \
   V(JS_INTL_PLURAL_RULES_TYPE)         \
   V(JS_INTL_RELATIVE_TIME_FORMAT_TYPE) \
+  V(JS_INTL_SEGMENTER_TYPE)            \
   INSTANCE_TYPE_LIST_AFTER_INTL(V)
 #else
 #define INSTANCE_TYPE_LIST(V)       \
@@ -230,56 +238,57 @@ namespace internal {
 
 // Since string types are not consecutive, this macro is used to
 // iterate over them.
-#define STRING_TYPE_LIST(V)                                                   \
-  V(STRING_TYPE, kVariableSizeSentinel, string, String)                       \
-  V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string,             \
-    OneByteString)                                                            \
-  V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString)             \
-  V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string,       \
-    ConsOneByteString)                                                        \
-  V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString)     \
-  V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string, \
-    SlicedOneByteString)                                                      \
-  V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string,      \
-    ExternalString)                                                           \
-  V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize,              \
-    external_one_byte_string, ExternalOneByteString)                          \
-  V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize,    \
-    external_string_with_one_byte_data, ExternalStringWithOneByteData)        \
-  V(SHORT_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kShortSize,            \
-    short_external_string, ShortExternalString)                               \
-  V(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kShortSize,   \
-    short_external_one_byte_string, ShortExternalOneByteString)               \
-  V(SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE,                            \
-    ExternalTwoByteString::kShortSize,                                        \
-    short_external_string_with_one_byte_data,                                 \
-    ShortExternalStringWithOneByteData)                                       \
-                                                                              \
-  V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string,     \
-    InternalizedString)                                                       \
-  V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel,                 \
-    one_byte_internalized_string, OneByteInternalizedString)                  \
-  V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize,          \
-    external_internalized_string, ExternalInternalizedString)                 \
-  V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize, \
-    external_one_byte_internalized_string, ExternalOneByteInternalizedString) \
-  V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE,                     \
-    ExternalTwoByteString::kSize,                                             \
-    external_internalized_string_with_one_byte_data,                          \
-    ExternalInternalizedStringWithOneByteData)                                \
-  V(SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE,                                  \
-    ExternalTwoByteString::kShortSize, short_external_internalized_string,    \
-    ShortExternalInternalizedString)                                          \
-  V(SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE,                         \
-    ExternalOneByteString::kShortSize,                                        \
-    short_external_one_byte_internalized_string,                              \
-    ShortExternalOneByteInternalizedString)                                   \
-  V(SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE,               \
-    ExternalTwoByteString::kShortSize,                                        \
-    short_external_internalized_string_with_one_byte_data,                    \
-    ShortExternalInternalizedStringWithOneByteData)                           \
-  V(THIN_STRING_TYPE, ThinString::kSize, thin_string, ThinString)             \
-  V(THIN_ONE_BYTE_STRING_TYPE, ThinString::kSize, thin_one_byte_string,       \
+#define STRING_TYPE_LIST(V)                                                    \
+  V(STRING_TYPE, kVariableSizeSentinel, string, String)                        \
+  V(ONE_BYTE_STRING_TYPE, kVariableSizeSentinel, one_byte_string,              \
+    OneByteString)                                                             \
+  V(CONS_STRING_TYPE, ConsString::kSize, cons_string, ConsString)              \
+  V(CONS_ONE_BYTE_STRING_TYPE, ConsString::kSize, cons_one_byte_string,        \
+    ConsOneByteString)                                                         \
+  V(SLICED_STRING_TYPE, SlicedString::kSize, sliced_string, SlicedString)      \
+  V(SLICED_ONE_BYTE_STRING_TYPE, SlicedString::kSize, sliced_one_byte_string,  \
+    SlicedOneByteString)                                                       \
+  V(EXTERNAL_STRING_TYPE, ExternalTwoByteString::kSize, external_string,       \
+    ExternalString)                                                            \
+  V(EXTERNAL_ONE_BYTE_STRING_TYPE, ExternalOneByteString::kSize,               \
+    external_one_byte_string, ExternalOneByteString)                           \
+  V(EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE, ExternalTwoByteString::kSize,     \
+    external_string_with_one_byte_data, ExternalStringWithOneByteData)         \
+  V(UNCACHED_EXTERNAL_STRING_TYPE, ExternalTwoByteString::kUncachedSize,       \
+    uncached_external_string, UncachedExternalString)                          \
+  V(UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE,                                    \
+    ExternalOneByteString::kUncachedSize, uncached_external_one_byte_string,   \
+    UncachedExternalOneByteString)                                             \
+  V(UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE,                          \
+    ExternalTwoByteString::kUncachedSize,                                      \
+    uncached_external_string_with_one_byte_data,                               \
+    UncachedExternalStringWithOneByteData)                                     \
+                                                                               \
+  V(INTERNALIZED_STRING_TYPE, kVariableSizeSentinel, internalized_string,      \
+    InternalizedString)                                                        \
+  V(ONE_BYTE_INTERNALIZED_STRING_TYPE, kVariableSizeSentinel,                  \
+    one_byte_internalized_string, OneByteInternalizedString)                   \
+  V(EXTERNAL_INTERNALIZED_STRING_TYPE, ExternalTwoByteString::kSize,           \
+    external_internalized_string, ExternalInternalizedString)                  \
+  V(EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE, ExternalOneByteString::kSize,  \
+    external_one_byte_internalized_string, ExternalOneByteInternalizedString)  \
+  V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE,                      \
+    ExternalTwoByteString::kSize,                                              \
+    external_internalized_string_with_one_byte_data,                           \
+    ExternalInternalizedStringWithOneByteData)                                 \
+  V(UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE,                                \
+    ExternalTwoByteString::kUncachedSize,                                      \
+    uncached_external_internalized_string, UncachedExternalInternalizedString) \
+  V(UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE,                       \
+    ExternalOneByteString::kUncachedSize,                                      \
+    uncached_external_one_byte_internalized_string,                            \
+    UncachedExternalOneByteInternalizedString)                                 \
+  V(UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE,             \
+    ExternalTwoByteString::kUncachedSize,                                      \
+    uncached_external_internalized_string_with_one_byte_data,                  \
+    UncachedExternalInternalizedStringWithOneByteData)                         \
+  V(THIN_STRING_TYPE, ThinString::kSize, thin_string, ThinString)              \
+  V(THIN_ONE_BYTE_STRING_TYPE, ThinString::kSize, thin_one_byte_string,        \
     ThinOneByteString)
 
 // A struct is a simple object a set of object-valued fields.  Including an
@@ -291,54 +300,95 @@ namespace internal {
 // Note that for subtle reasons related to the ordering or numerical values of
 // type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST
 // manually.
-#define STRUCT_LIST(V)                                                       \
-  V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info)                   \
-  V(ACCESSOR_INFO, AccessorInfo, accessor_info)                              \
-  V(ACCESSOR_PAIR, AccessorPair, accessor_pair)                              \
-  V(ALIASED_ARGUMENTS_ENTRY, AliasedArgumentsEntry, aliased_arguments_entry) \
-  V(ALLOCATION_MEMENTO, AllocationMemento, allocation_memento)               \
-  V(ASYNC_GENERATOR_REQUEST, AsyncGeneratorRequest, async_generator_request) \
-  V(DEBUG_INFO, DebugInfo, debug_info)                                       \
-  V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info)    \
-  V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info)                     \
-  V(INTERPRETER_DATA, InterpreterData, interpreter_data)                     \
-  V(MODULE_INFO_ENTRY, ModuleInfoEntry, module_info_entry)                   \
-  V(MODULE, Module, module)                                                  \
-  V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info)          \
-  V(PROMISE_CAPABILITY, PromiseCapability, promise_capability)               \
-  V(PROMISE_REACTION, PromiseReaction, promise_reaction)                     \
-  V(PROTOTYPE_INFO, PrototypeInfo, prototype_info)                           \
-  V(SCRIPT, Script, script)                                                  \
-  V(STACK_FRAME_INFO, StackFrameInfo, stack_frame_info)                      \
-  V(TUPLE2, Tuple2, tuple2)                                                  \
-  V(TUPLE3, Tuple3, tuple3)                                                  \
-  V(ARRAY_BOILERPLATE_DESCRIPTION, ArrayBoilerplateDescription,              \
-    array_boilerplate_description)                                           \
-  V(WASM_DEBUG_INFO, WasmDebugInfo, wasm_debug_info)                         \
-  V(WASM_EXPORTED_FUNCTION_DATA, WasmExportedFunctionData,                   \
-    wasm_exported_function_data)                                             \
-  V(CALLABLE_TASK, CallableTask, callable_task)                              \
-  V(CALLBACK_TASK, CallbackTask, callback_task)                              \
-  V(PROMISE_FULFILL_REACTION_JOB_TASK, PromiseFulfillReactionJobTask,        \
-    promise_fulfill_reaction_job_task)                                       \
-  V(PROMISE_REJECT_REACTION_JOB_TASK, PromiseRejectReactionJobTask,          \
-    promise_reject_reaction_job_task)                                        \
-  V(PROMISE_RESOLVE_THENABLE_JOB_TASK, PromiseResolveThenableJobTask,        \
-    promise_resolve_thenable_job_task)
+#define STRUCT_LIST_GENERATOR(V, _)                                           \
+  V(_, ACCESS_CHECK_INFO_TYPE, AccessCheckInfo, access_check_info)            \
+  V(_, ACCESSOR_INFO_TYPE, AccessorInfo, accessor_info)                       \
+  V(_, ACCESSOR_PAIR_TYPE, AccessorPair, accessor_pair)                       \
+  V(_, ALIASED_ARGUMENTS_ENTRY_TYPE, AliasedArgumentsEntry,                   \
+    aliased_arguments_entry)                                                  \
+  V(_, ALLOCATION_MEMENTO_TYPE, AllocationMemento, allocation_memento)        \
+  V(_, ASYNC_GENERATOR_REQUEST_TYPE, AsyncGeneratorRequest,                   \
+    async_generator_request)                                                  \
+  V(_, DEBUG_INFO_TYPE, DebugInfo, debug_info)                                \
+  V(_, FUNCTION_TEMPLATE_INFO_TYPE, FunctionTemplateInfo,                     \
+    function_template_info)                                                   \
+  V(_, INTERCEPTOR_INFO_TYPE, InterceptorInfo, interceptor_info)              \
+  V(_, INTERPRETER_DATA_TYPE, InterpreterData, interpreter_data)              \
+  V(_, MODULE_INFO_ENTRY_TYPE, ModuleInfoEntry, module_info_entry)            \
+  V(_, MODULE_TYPE, Module, module)                                           \
+  V(_, OBJECT_TEMPLATE_INFO_TYPE, ObjectTemplateInfo, object_template_info)   \
+  V(_, PROMISE_CAPABILITY_TYPE, PromiseCapability, promise_capability)        \
+  V(_, PROMISE_REACTION_TYPE, PromiseReaction, promise_reaction)              \
+  V(_, PROTOTYPE_INFO_TYPE, PrototypeInfo, prototype_info)                    \
+  V(_, SCRIPT_TYPE, Script, script)                                           \
+  V(_, STACK_FRAME_INFO_TYPE, StackFrameInfo, stack_frame_info)               \
+  V(_, TUPLE2_TYPE, Tuple2, tuple2)                                           \
+  V(_, TUPLE3_TYPE, Tuple3, tuple3)                                           \
+  V(_, ARRAY_BOILERPLATE_DESCRIPTION_TYPE, ArrayBoilerplateDescription,       \
+    array_boilerplate_description)                                            \
+  V(_, WASM_DEBUG_INFO_TYPE, WasmDebugInfo, wasm_debug_info)                  \
+  V(_, WASM_EXPORTED_FUNCTION_DATA_TYPE, WasmExportedFunctionData,            \
+    wasm_exported_function_data)                                              \
+  V(_, CALLABLE_TASK_TYPE, CallableTask, callable_task)                       \
+  V(_, CALLBACK_TASK_TYPE, CallbackTask, callback_task)                       \
+  V(_, PROMISE_FULFILL_REACTION_JOB_TASK_TYPE, PromiseFulfillReactionJobTask, \
+    promise_fulfill_reaction_job_task)                                        \
+  V(_, PROMISE_REJECT_REACTION_JOB_TASK_TYPE, PromiseRejectReactionJobTask,   \
+    promise_reject_reaction_job_task)                                         \
+  V(_, PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE, PromiseResolveThenableJobTask, \
+    promise_resolve_thenable_job_task)                                        \
+  V(_, MICROTASK_QUEUE_TYPE, MicrotaskQueue, microtask_queue)
 
-#define ALLOCATION_SITE_LIST(V)                                     \
-  V(ALLOCATION_SITE, AllocationSite, WithWeakNext, allocation_site) \
-  V(ALLOCATION_SITE, AllocationSite, WithoutWeakNext,               \
+// Adapts one STRUCT_LIST_GENERATOR entry to the STRUCT_LIST entry
+#define STRUCT_LIST_ADAPTER(V, NAME, Name, name) V(NAME, Name, name)
+
+// Produces (NAME, Name, name) entries.
+#define STRUCT_LIST(V) STRUCT_LIST_GENERATOR(STRUCT_LIST_ADAPTER, V)
+
+// Adapts one STRUCT_LIST_GENERATOR entry to the STRUCT_MAPS_LIST entry
+#define STRUCT_MAPS_LIST_ADAPTER(V, NAME, Name, name) \
+  V(Map, name##_map, Name##Map)
+
+// Produces (Map, struct_name_map, StructNameMap) entries
+#define STRUCT_MAPS_LIST(V) STRUCT_LIST_GENERATOR(STRUCT_MAPS_LIST_ADAPTER, V)
+
+//
+// The following macros define list of allocation size objects and list of
+// their maps.
+//
+#define ALLOCATION_SITE_LIST(V, _)                                          \
+  V(_, ALLOCATION_SITE_TYPE, AllocationSite, WithWeakNext, allocation_site) \
+  V(_, ALLOCATION_SITE_TYPE, AllocationSite, WithoutWeakNext,               \
     allocation_site_without_weaknext)
 
-#define DATA_HANDLER_LIST(V)                        \
-  V(LOAD_HANDLER, LoadHandler, 1, load_handler1)    \
-  V(LOAD_HANDLER, LoadHandler, 2, load_handler2)    \
-  V(LOAD_HANDLER, LoadHandler, 3, load_handler3)    \
-  V(STORE_HANDLER, StoreHandler, 0, store_handler0) \
-  V(STORE_HANDLER, StoreHandler, 1, store_handler1) \
-  V(STORE_HANDLER, StoreHandler, 2, store_handler2) \
-  V(STORE_HANDLER, StoreHandler, 3, store_handler3)
+// Adapts one ALLOCATION_SITE_LIST entry to the ALLOCATION_SITE_MAPS_LIST entry
+#define ALLOCATION_SITE_MAPS_LIST_ADAPTER(V, TYPE, Name, Size, name_size) \
+  V(Map, name_size##_map, Name##Size##Map)
+
+// Produces (Map, allocation_site_name_map, AllocationSiteNameMap) entries
+#define ALLOCATION_SITE_MAPS_LIST(V) \
+  ALLOCATION_SITE_LIST(ALLOCATION_SITE_MAPS_LIST_ADAPTER, V)
+
+//
+// The following macros define list of data handler objects and list of their
+// maps.
+//
+#define DATA_HANDLER_LIST(V, _)                             \
+  V(_, LOAD_HANDLER_TYPE, LoadHandler, 1, load_handler1)    \
+  V(_, LOAD_HANDLER_TYPE, LoadHandler, 2, load_handler2)    \
+  V(_, LOAD_HANDLER_TYPE, LoadHandler, 3, load_handler3)    \
+  V(_, STORE_HANDLER_TYPE, StoreHandler, 0, store_handler0) \
+  V(_, STORE_HANDLER_TYPE, StoreHandler, 1, store_handler1) \
+  V(_, STORE_HANDLER_TYPE, StoreHandler, 2, store_handler2) \
+  V(_, STORE_HANDLER_TYPE, StoreHandler, 3, store_handler3)
+
+// Adapts one DATA_HANDLER_LIST entry to the DATA_HANDLER_MAPS_LIST entry.
+#define DATA_HANDLER_MAPS_LIST_ADAPTER(V, TYPE, Name, Size, name_size) \
+  V(Map, name_size##_map, Name##Size##Map)
+
+// Produces (Map, handler_name_map, HandlerNameMap) entries
+#define DATA_HANDLER_MAPS_LIST(V) \
+  DATA_HANDLER_LIST(DATA_HANDLER_MAPS_LIST_ADAPTER, V)
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/objects-inl.h b/deps/v8/src/objects-inl.h
index ed3e15ed9e..5c66d5f60a 100644
--- a/deps/v8/src/objects-inl.h
+++ b/deps/v8/src/objects-inl.h
@@ -83,8 +83,8 @@ INSTANCE_TYPE_CHECKERS_SINGLE(INSTANCE_TYPE_CHECKER);
 TYPED_ARRAYS(TYPED_ARRAY_INSTANCE_TYPE_CHECKER)
 #undef TYPED_ARRAY_INSTANCE_TYPE_CHECKER
 
-#define STRUCT_INSTANCE_TYPE_CHECKER(NAME, Name, name) \
-  INSTANCE_TYPE_CHECKER(Name, NAME##_TYPE)
+#define STRUCT_INSTANCE_TYPE_CHECKER(TYPE, Name, name) \
+  INSTANCE_TYPE_CHECKER(Name, TYPE)
 STRUCT_LIST(STRUCT_INSTANCE_TYPE_CHECKER)
 #undef STRUCT_INSTANCE_TYPE_CHECKER
 
@@ -116,6 +116,11 @@ V8_INLINE bool IsJSObject(InstanceType instance_type) {
   return instance_type >= FIRST_JS_OBJECT_TYPE;
 }
 
+V8_INLINE bool IsJSReceiver(InstanceType instance_type) {
+  STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
+  return instance_type >= FIRST_JS_RECEIVER_TYPE;
+}
+
 }  // namespace InstanceTypeChecker
 
 // TODO(v8:7786): For instance types that have a single map instance on the
@@ -286,13 +291,6 @@ bool HeapObject::IsFiller() const {
   return instance_type == FREE_SPACE_TYPE || instance_type == FILLER_TYPE;
 }
 
-bool HeapObject::IsJSReceiver() const {
-  STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
-  return map()->instance_type() >= FIRST_JS_RECEIVER_TYPE;
-}
-
-bool HeapObject::IsJSProxy() const { return map()->IsJSProxyMap(); }
-
 bool HeapObject::IsJSWeakCollection() const {
   return IsJSWeakMap() || IsJSWeakSet();
 }
@@ -434,8 +432,8 @@ bool HeapObject::IsAccessCheckNeeded() const {
 
 bool HeapObject::IsStruct() const {
   switch (map()->instance_type()) {
-#define MAKE_STRUCT_CASE(NAME, Name, name) \
-  case NAME##_TYPE:                        \
+#define MAKE_STRUCT_CASE(TYPE, Name, name) \
+  case TYPE:                               \
     return true;
     STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
@@ -472,8 +470,6 @@ bool Object::IsMinusZero() const {
 // Cast operations
 
 CAST_ACCESSOR(AccessorPair)
-CAST_ACCESSOR(AllocationMemento)
-CAST_ACCESSOR(AllocationSite)
 CAST_ACCESSOR(AsyncGeneratorRequest)
 CAST_ACCESSOR(BigInt)
 CAST_ACCESSOR(ObjectBoilerplateDescription)
@@ -487,18 +483,6 @@ CAST_ACCESSOR(FeedbackCell)
 CAST_ACCESSOR(Foreign)
 CAST_ACCESSOR(GlobalDictionary)
 CAST_ACCESSOR(HeapObject)
-CAST_ACCESSOR(JSAsyncFromSyncIterator)
-CAST_ACCESSOR(JSBoundFunction)
-CAST_ACCESSOR(JSDataView)
-CAST_ACCESSOR(JSDate)
-CAST_ACCESSOR(JSFunction)
-CAST_ACCESSOR(JSGlobalObject)
-CAST_ACCESSOR(JSGlobalProxy)
-CAST_ACCESSOR(JSMessageObject)
-CAST_ACCESSOR(JSObject)
-CAST_ACCESSOR(JSReceiver)
-CAST_ACCESSOR(JSStringIterator)
-CAST_ACCESSOR(JSValue)
 CAST_ACCESSOR(HeapNumber)
 CAST_ACCESSOR(LayoutDescriptor)
 CAST_ACCESSOR(MutableHeapNumber)
@@ -511,7 +495,6 @@ CAST_ACCESSOR(ObjectHashTable)
 CAST_ACCESSOR(Oddball)
 CAST_ACCESSOR(OrderedHashMap)
 CAST_ACCESSOR(OrderedHashSet)
-CAST_ACCESSOR(PropertyArray)
 CAST_ACCESSOR(PropertyCell)
 CAST_ACCESSOR(RegExpMatchInfo)
 CAST_ACCESSOR(ScopeInfo)
@@ -519,8 +502,6 @@ CAST_ACCESSOR(SimpleNumberDictionary)
 CAST_ACCESSOR(SmallOrderedHashMap)
 CAST_ACCESSOR(SmallOrderedHashSet)
 CAST_ACCESSOR(Smi)
-CAST_ACCESSOR(SourcePositionTableWithFrameCache)
-CAST_ACCESSOR(StackFrameInfo)
 CAST_ACCESSOR(StringSet)
 CAST_ACCESSOR(StringTable)
 CAST_ACCESSOR(Struct)
@@ -727,14 +708,6 @@ MaybeHandle<Object> Object::GetProperty(Isolate* isolate, Handle<Object> object,
   return GetProperty(&it);
 }
 
-MaybeHandle<Object> JSReceiver::GetProperty(Isolate* isolate,
-                                            Handle<JSReceiver> receiver,
-                                            Handle<Name> name) {
-  LookupIterator it(isolate, receiver, name, receiver);
-  if (!it.IsFound()) return it.factory()->undefined_value();
-  return Object::GetProperty(&it);
-}
-
 MaybeHandle<Object> Object::GetElement(Isolate* isolate, Handle<Object> object,
                                        uint32_t index) {
   LookupIterator it(isolate, object, index);
@@ -742,79 +715,15 @@ MaybeHandle<Object> Object::GetElement(Isolate* isolate, Handle<Object> object,
   return GetProperty(&it);
 }
 
-MaybeHandle<Object> JSReceiver::GetElement(Isolate* isolate,
-                                           Handle<JSReceiver> receiver,
-                                           uint32_t index) {
-  LookupIterator it(isolate, receiver, index, receiver);
-  if (!it.IsFound()) return it.factory()->undefined_value();
-  return Object::GetProperty(&it);
-}
-
-Handle<Object> JSReceiver::GetDataProperty(Handle<JSReceiver> object,
-                                           Handle<Name> name) {
-  LookupIterator it(object, name, object,
-                    LookupIterator::PROTOTYPE_CHAIN_SKIP_INTERCEPTOR);
-  if (!it.IsFound()) return it.factory()->undefined_value();
-  return GetDataProperty(&it);
-}
-
 MaybeHandle<Object> Object::SetElement(Isolate* isolate, Handle<Object> object,
                                        uint32_t index, Handle<Object> value,
                                        LanguageMode language_mode) {
   LookupIterator it(isolate, object, index);
   MAYBE_RETURN_NULL(
-      SetProperty(&it, value, language_mode, MAY_BE_STORE_FROM_KEYED));
+      SetProperty(&it, value, language_mode, StoreOrigin::kMaybeKeyed));
   return value;
 }
 
-MaybeHandle<Object> JSReceiver::GetPrototype(Isolate* isolate,
-                                             Handle<JSReceiver> receiver) {
-  // We don't expect access checks to be needed on JSProxy objects.
-  DCHECK(!receiver->IsAccessCheckNeeded() || receiver->IsJSObject());
-  PrototypeIterator iter(isolate, receiver, kStartAtReceiver,
-                         PrototypeIterator::END_AT_NON_HIDDEN);
-  do {
-    if (!iter.AdvanceFollowingProxies()) return MaybeHandle<Object>();
-  } while (!iter.IsAtEnd());
-  return PrototypeIterator::GetCurrent(iter);
-}
-
-MaybeHandle<Object> JSReceiver::GetProperty(Isolate* isolate,
-                                            Handle<JSReceiver> receiver,
-                                            const char* name) {
-  Handle<String> str = isolate->factory()->InternalizeUtf8String(name);
-  return GetProperty(isolate, receiver, str);
-}
-
-// static
-V8_WARN_UNUSED_RESULT MaybeHandle<FixedArray> JSReceiver::OwnPropertyKeys(
-    Handle<JSReceiver> object) {
-  return KeyAccumulator::GetKeys(object, KeyCollectionMode::kOwnOnly,
-                                 ALL_PROPERTIES,
-                                 GetKeysConversion::kConvertToString);
-}
-
-bool JSObject::PrototypeHasNoElements(Isolate* isolate, JSObject* object) {
-  DisallowHeapAllocation no_gc;
-  HeapObject* prototype = HeapObject::cast(object->map()->prototype());
-  ReadOnlyRoots roots(isolate);
-  HeapObject* null = roots.null_value();
-  HeapObject* empty_fixed_array = roots.empty_fixed_array();
-  HeapObject* empty_slow_element_dictionary =
-      roots.empty_slow_element_dictionary();
-  while (prototype != null) {
-    Map* map = prototype->map();
-    if (map->IsCustomElementsReceiverMap()) return false;
-    HeapObject* elements = JSObject::cast(prototype)->elements();
-    if (elements != empty_fixed_array &&
-        elements != empty_slow_element_dictionary) {
-      return false;
-    }
-    prototype = HeapObject::cast(map->prototype());
-  }
-  return true;
-}
-
 Object** HeapObject::RawField(const HeapObject* obj, int byte_offset) {
   return reinterpret_cast<Object**>(FIELD_ADDR(obj, byte_offset));
 }
@@ -995,282 +904,6 @@ int HeapNumberBase::get_sign() {
   return READ_INT_FIELD(this, kExponentOffset) & kSignMask;
 }
 
-ACCESSORS(JSReceiver, raw_properties_or_hash, Object, kPropertiesOrHashOffset)
-
-FixedArrayBase* JSObject::elements() const {
-  Object* array = READ_FIELD(this, kElementsOffset);
-  return static_cast<FixedArrayBase*>(array);
-}
-
-bool AllocationSite::HasWeakNext() const {
-  return map() == GetReadOnlyRoots().allocation_site_map();
-}
-
-void AllocationSite::Initialize() {
-  set_transition_info_or_boilerplate(Smi::kZero);
-  SetElementsKind(GetInitialFastElementsKind());
-  set_nested_site(Smi::kZero);
-  set_pretenure_data(0);
-  set_pretenure_create_count(0);
-  set_dependent_code(
-      DependentCode::cast(GetReadOnlyRoots().empty_weak_fixed_array()),
-      SKIP_WRITE_BARRIER);
-}
-
-bool AllocationSite::IsZombie() const {
-  return pretenure_decision() == kZombie;
-}
-
-bool AllocationSite::IsMaybeTenure() const {
-  return pretenure_decision() == kMaybeTenure;
-}
-
-bool AllocationSite::PretenuringDecisionMade() const {
-  return pretenure_decision() != kUndecided;
-}
-
-
-void AllocationSite::MarkZombie() {
-  DCHECK(!IsZombie());
-  Initialize();
-  set_pretenure_decision(kZombie);
-}
-
-ElementsKind AllocationSite::GetElementsKind() const {
-  return ElementsKindBits::decode(transition_info());
-}
-
-
-void AllocationSite::SetElementsKind(ElementsKind kind) {
-  set_transition_info(ElementsKindBits::update(transition_info(), kind));
-}
-
-bool AllocationSite::CanInlineCall() const {
-  return DoNotInlineBit::decode(transition_info()) == 0;
-}
-
-
-void AllocationSite::SetDoNotInlineCall() {
-  set_transition_info(DoNotInlineBit::update(transition_info(), true));
-}
-
-bool AllocationSite::PointsToLiteral() const {
-  Object* raw_value = transition_info_or_boilerplate();
-  DCHECK_EQ(!raw_value->IsSmi(),
-            raw_value->IsJSArray() || raw_value->IsJSObject());
-  return !raw_value->IsSmi();
-}
-
-
-// Heuristic: We only need to create allocation site info if the boilerplate
-// elements kind is the initial elements kind.
-bool AllocationSite::ShouldTrack(ElementsKind boilerplate_elements_kind) {
-  return IsSmiElementsKind(boilerplate_elements_kind);
-}
-
-inline bool AllocationSite::CanTrack(InstanceType type) {
-  if (FLAG_allocation_site_pretenuring) {
-    // TurboFan doesn't care at all about String pretenuring feedback,
-    // so don't bother even trying to track that.
-    return type == JS_ARRAY_TYPE || type == JS_OBJECT_TYPE;
-  }
-  return type == JS_ARRAY_TYPE;
-}
-
-AllocationSite::PretenureDecision AllocationSite::pretenure_decision() const {
-  return PretenureDecisionBits::decode(pretenure_data());
-}
-
-void AllocationSite::set_pretenure_decision(PretenureDecision decision) {
-  int32_t value = pretenure_data();
-  set_pretenure_data(PretenureDecisionBits::update(value, decision));
-}
-
-bool AllocationSite::deopt_dependent_code() const {
-  return DeoptDependentCodeBit::decode(pretenure_data());
-}
-
-void AllocationSite::set_deopt_dependent_code(bool deopt) {
-  int32_t value = pretenure_data();
-  set_pretenure_data(DeoptDependentCodeBit::update(value, deopt));
-}
-
-int AllocationSite::memento_found_count() const {
-  return MementoFoundCountBits::decode(pretenure_data());
-}
-
-inline void AllocationSite::set_memento_found_count(int count) {
-  int32_t value = pretenure_data();
-  // Verify that we can count more mementos than we can possibly find in one
-  // new space collection.
-  DCHECK((GetHeap()->MaxSemiSpaceSize() /
-          (Heap::kMinObjectSizeInWords * kPointerSize +
-           AllocationMemento::kSize)) < MementoFoundCountBits::kMax);
-  DCHECK_LT(count, MementoFoundCountBits::kMax);
-  set_pretenure_data(MementoFoundCountBits::update(value, count));
-}
-
-int AllocationSite::memento_create_count() const {
-  return pretenure_create_count();
-}
-
-void AllocationSite::set_memento_create_count(int count) {
-  set_pretenure_create_count(count);
-}
-
-bool AllocationSite::IncrementMementoFoundCount(int increment) {
-  if (IsZombie()) return false;
-
-  int value = memento_found_count();
-  set_memento_found_count(value + increment);
-  return memento_found_count() >= kPretenureMinimumCreated;
-}
-
-
-inline void AllocationSite::IncrementMementoCreateCount() {
-  DCHECK(FLAG_allocation_site_pretenuring);
-  int value = memento_create_count();
-  set_memento_create_count(value + 1);
-}
-
-bool AllocationMemento::IsValid() const {
-  return allocation_site()->IsAllocationSite() &&
-         !AllocationSite::cast(allocation_site())->IsZombie();
-}
-
-AllocationSite* AllocationMemento::GetAllocationSite() const {
-  DCHECK(IsValid());
-  return AllocationSite::cast(allocation_site());
-}
-
-Address AllocationMemento::GetAllocationSiteUnchecked() const {
-  return reinterpret_cast<Address>(allocation_site());
-}
-
-void JSObject::EnsureCanContainHeapObjectElements(Handle<JSObject> object) {
-  JSObject::ValidateElements(*object);
-  ElementsKind elements_kind = object->map()->elements_kind();
-  if (!IsObjectElementsKind(elements_kind)) {
-    if (IsHoleyElementsKind(elements_kind)) {
-      TransitionElementsKind(object, HOLEY_ELEMENTS);
-    } else {
-      TransitionElementsKind(object, PACKED_ELEMENTS);
-    }
-  }
-}
-
-
-void JSObject::EnsureCanContainElements(Handle<JSObject> object,
-                                        Object** objects,
-                                        uint32_t count,
-                                        EnsureElementsMode mode) {
-  ElementsKind current_kind = object->GetElementsKind();
-  ElementsKind target_kind = current_kind;
-  {
-    DisallowHeapAllocation no_allocation;
-    DCHECK(mode != ALLOW_COPIED_DOUBLE_ELEMENTS);
-    bool is_holey = IsHoleyElementsKind(current_kind);
-    if (current_kind == HOLEY_ELEMENTS) return;
-    Object* the_hole = object->GetReadOnlyRoots().the_hole_value();
-    for (uint32_t i = 0; i < count; ++i) {
-      Object* current = *objects++;
-      if (current == the_hole) {
-        is_holey = true;
-        target_kind = GetHoleyElementsKind(target_kind);
-      } else if (!current->IsSmi()) {
-        if (mode == ALLOW_CONVERTED_DOUBLE_ELEMENTS && current->IsNumber()) {
-          if (IsSmiElementsKind(target_kind)) {
-            if (is_holey) {
-              target_kind = HOLEY_DOUBLE_ELEMENTS;
-            } else {
-              target_kind = PACKED_DOUBLE_ELEMENTS;
-            }
-          }
-        } else if (is_holey) {
-          target_kind = HOLEY_ELEMENTS;
-          break;
-        } else {
-          target_kind = PACKED_ELEMENTS;
-        }
-      }
-    }
-  }
-  if (target_kind != current_kind) {
-    TransitionElementsKind(object, target_kind);
-  }
-}
-
-
-void JSObject::EnsureCanContainElements(Handle<JSObject> object,
-                                        Handle<FixedArrayBase> elements,
-                                        uint32_t length,
-                                        EnsureElementsMode mode) {
-  ReadOnlyRoots roots = object->GetReadOnlyRoots();
-  if (elements->map() != roots.fixed_double_array_map()) {
-    DCHECK(elements->map() == roots.fixed_array_map() ||
-           elements->map() == roots.fixed_cow_array_map());
-    if (mode == ALLOW_COPIED_DOUBLE_ELEMENTS) {
-      mode = DONT_ALLOW_DOUBLE_ELEMENTS;
-    }
-    Object** objects =
-        Handle<FixedArray>::cast(elements)->GetFirstElementAddress();
-    EnsureCanContainElements(object, objects, length, mode);
-    return;
-  }
-
-  DCHECK(mode == ALLOW_COPIED_DOUBLE_ELEMENTS);
-  if (object->GetElementsKind() == HOLEY_SMI_ELEMENTS) {
-    TransitionElementsKind(object, HOLEY_DOUBLE_ELEMENTS);
-  } else if (object->GetElementsKind() == PACKED_SMI_ELEMENTS) {
-    Handle<FixedDoubleArray> double_array =
-        Handle<FixedDoubleArray>::cast(elements);
-    for (uint32_t i = 0; i < length; ++i) {
-      if (double_array->is_the_hole(i)) {
-        TransitionElementsKind(object, HOLEY_DOUBLE_ELEMENTS);
-        return;
-      }
-    }
-    TransitionElementsKind(object, PACKED_DOUBLE_ELEMENTS);
-  }
-}
-
-
-void JSObject::SetMapAndElements(Handle<JSObject> object,
-                                 Handle<Map> new_map,
-                                 Handle<FixedArrayBase> value) {
-  JSObject::MigrateToMap(object, new_map);
-  DCHECK((object->map()->has_fast_smi_or_object_elements() ||
-          (*value == object->GetReadOnlyRoots().empty_fixed_array()) ||
-          object->map()->has_fast_string_wrapper_elements()) ==
-         (value->map() == object->GetReadOnlyRoots().fixed_array_map() ||
-          value->map() == object->GetReadOnlyRoots().fixed_cow_array_map()));
-  DCHECK((*value == object->GetReadOnlyRoots().empty_fixed_array()) ||
-         (object->map()->has_fast_double_elements() ==
-          value->IsFixedDoubleArray()));
-  object->set_elements(*value);
-}
-
-
-void JSObject::set_elements(FixedArrayBase* value, WriteBarrierMode mode) {
-  WRITE_FIELD(this, kElementsOffset, value);
-  CONDITIONAL_WRITE_BARRIER(this, kElementsOffset, value, mode);
-}
-
-
-void JSObject::initialize_elements() {
-  FixedArrayBase* elements = map()->GetInitialElements();
-  WRITE_FIELD(this, kElementsOffset, elements);
-}
-
-
-InterceptorInfo* JSObject::GetIndexedInterceptor() {
-  return map()->GetIndexedInterceptor();
-}
-
-InterceptorInfo* JSObject::GetNamedInterceptor() {
-  return map()->GetNamedInterceptor();
-}
-
 double Oddball::to_number_raw() const {
   return READ_DOUBLE_FIELD(this, kToNumberRawOffset);
 }
@@ -1316,18 +949,6 @@ void PropertyCell::set_property_details(PropertyDetails details) {
   set_property_details_raw(details.AsSmi());
 }
 
-int JSObject::GetHeaderSize() const { return GetHeaderSize(map()); }
-
-int JSObject::GetHeaderSize(const Map* map) {
-  // Check for the most common kind of JavaScript object before
-  // falling into the generic switch. This speeds up the internal
-  // field operations considerably on average.
-  InstanceType instance_type = map->instance_type();
-  return instance_type == JS_OBJECT_TYPE
-             ? JSObject::kHeaderSize
-             : GetHeaderSize(instance_type, map->has_prototype_slot());
-}
-
 inline bool IsSpecialReceiverInstanceType(InstanceType instance_type) {
   return instance_type <= LAST_SPECIAL_RECEIVER_TYPE;
 }
@@ -1351,187 +972,6 @@ bool Map::IsCustomElementsReceiverMap() const {
   return IsCustomElementsReceiverInstanceType(instance_type());
 }
 
-// static
-int JSObject::GetEmbedderFieldCount(const Map* map) {
-  int instance_size = map->instance_size();
-  if (instance_size == kVariableSizeSentinel) return 0;
-  return ((instance_size - GetHeaderSize(map)) >> kPointerSizeLog2) -
-         map->GetInObjectProperties();
-}
-
-int JSObject::GetEmbedderFieldCount() const {
-  return GetEmbedderFieldCount(map());
-}
-
-int JSObject::GetEmbedderFieldOffset(int index) {
-  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
-  return GetHeaderSize() + (kPointerSize * index);
-}
-
-Object* JSObject::GetEmbedderField(int index) {
-  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
-  // Internal objects do follow immediately after the header, whereas in-object
-  // properties are at the end of the object. Therefore there is no need
-  // to adjust the index here.
-  return READ_FIELD(this, GetHeaderSize() + (kPointerSize * index));
-}
-
-void JSObject::SetEmbedderField(int index, Object* value) {
-  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
-  // Internal objects do follow immediately after the header, whereas in-object
-  // properties are at the end of the object. Therefore there is no need
-  // to adjust the index here.
-  int offset = GetHeaderSize() + (kPointerSize * index);
-  WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
-}
-
-void JSObject::SetEmbedderField(int index, Smi* value) {
-  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
-  // Internal objects do follow immediately after the header, whereas in-object
-  // properties are at the end of the object. Therefore there is no need
-  // to adjust the index here.
-  int offset = GetHeaderSize() + (kPointerSize * index);
-  WRITE_FIELD(this, offset, value);
-}
-
-
-bool JSObject::IsUnboxedDoubleField(FieldIndex index) {
-  if (!FLAG_unbox_double_fields) return false;
-  return map()->IsUnboxedDoubleField(index);
-}
-
-// Access fast-case object properties at index. The use of these routines
-// is needed to correctly distinguish between properties stored in-object and
-// properties stored in the properties array.
-Object* JSObject::RawFastPropertyAt(FieldIndex index) {
-  DCHECK(!IsUnboxedDoubleField(index));
-  if (index.is_inobject()) {
-    return READ_FIELD(this, index.offset());
-  } else {
-    return property_array()->get(index.outobject_array_index());
-  }
-}
-
-
-double JSObject::RawFastDoublePropertyAt(FieldIndex index) {
-  DCHECK(IsUnboxedDoubleField(index));
-  return READ_DOUBLE_FIELD(this, index.offset());
-}
-
-uint64_t JSObject::RawFastDoublePropertyAsBitsAt(FieldIndex index) {
-  DCHECK(IsUnboxedDoubleField(index));
-  return READ_UINT64_FIELD(this, index.offset());
-}
-
-void JSObject::RawFastPropertyAtPut(FieldIndex index, Object* value) {
-  if (index.is_inobject()) {
-    int offset = index.offset();
-    WRITE_FIELD(this, offset, value);
-    WRITE_BARRIER(this, offset, value);
-  } else {
-    property_array()->set(index.outobject_array_index(), value);
-  }
-}
-
-void JSObject::RawFastDoublePropertyAsBitsAtPut(FieldIndex index,
-                                                uint64_t bits) {
-  // Double unboxing is enabled only on 64-bit platforms.
-  DCHECK_EQ(kDoubleSize, kPointerSize);
-  Address field_addr = FIELD_ADDR(this, index.offset());
-  base::Relaxed_Store(reinterpret_cast<base::AtomicWord*>(field_addr),
-                      static_cast<base::AtomicWord>(bits));
-}
-
-void JSObject::FastPropertyAtPut(FieldIndex index, Object* value) {
-  if (IsUnboxedDoubleField(index)) {
-    DCHECK(value->IsMutableHeapNumber());
-    // Ensure that all bits of the double value are preserved.
-    RawFastDoublePropertyAsBitsAtPut(
-        index, MutableHeapNumber::cast(value)->value_as_bits());
-  } else {
-    RawFastPropertyAtPut(index, value);
-  }
-}
-
-void JSObject::WriteToField(int descriptor, PropertyDetails details,
-                            Object* value) {
-  DCHECK_EQ(kField, details.location());
-  DCHECK_EQ(kData, details.kind());
-  DisallowHeapAllocation no_gc;
-  FieldIndex index = FieldIndex::ForDescriptor(map(), descriptor);
-  if (details.representation().IsDouble()) {
-    // Nothing more to be done.
-    if (value->IsUninitialized()) {
-      return;
-    }
-    // Manipulating the signaling NaN used for the hole and uninitialized
-    // double field sentinel in C++, e.g. with bit_cast or value()/set_value(),
-    // will change its value on ia32 (the x87 stack is used to return values
-    // and stores to the stack silently clear the signalling bit).
-    uint64_t bits;
-    if (value->IsSmi()) {
-      bits = bit_cast<uint64_t>(static_cast<double>(Smi::ToInt(value)));
-    } else {
-      DCHECK(value->IsHeapNumber());
-      bits = HeapNumber::cast(value)->value_as_bits();
-    }
-    if (IsUnboxedDoubleField(index)) {
-      RawFastDoublePropertyAsBitsAtPut(index, bits);
-    } else {
-      auto box = MutableHeapNumber::cast(RawFastPropertyAt(index));
-      box->set_value_as_bits(bits);
-    }
-  } else {
-    RawFastPropertyAtPut(index, value);
-  }
-}
-
-int JSObject::GetInObjectPropertyOffset(int index) {
-  return map()->GetInObjectPropertyOffset(index);
-}
-
-
-Object* JSObject::InObjectPropertyAt(int index) {
-  int offset = GetInObjectPropertyOffset(index);
-  return READ_FIELD(this, offset);
-}
-
-
-Object* JSObject::InObjectPropertyAtPut(int index,
-                                        Object* value,
-                                        WriteBarrierMode mode) {
-  // Adjust for the number of properties stored in the object.
-  int offset = GetInObjectPropertyOffset(index);
-  WRITE_FIELD(this, offset, value);
-  CONDITIONAL_WRITE_BARRIER(this, offset, value, mode);
-  return value;
-}
-
-
-void JSObject::InitializeBody(Map* map, int start_offset,
-                              Object* pre_allocated_value,
-                              Object* filler_value) {
-  DCHECK(!filler_value->IsHeapObject() || !Heap::InNewSpace(filler_value));
-  DCHECK(!pre_allocated_value->IsHeapObject() ||
-         !Heap::InNewSpace(pre_allocated_value));
-  int size = map->instance_size();
-  int offset = start_offset;
-  if (filler_value != pre_allocated_value) {
-    int end_of_pre_allocated_offset =
-        size - (map->UnusedPropertyFields() * kPointerSize);
-    DCHECK_LE(kHeaderSize, end_of_pre_allocated_offset);
-    while (offset < end_of_pre_allocated_offset) {
-      WRITE_FIELD(this, offset, pre_allocated_value);
-      offset += kPointerSize;
-    }
-  }
-  while (offset < size) {
-    WRITE_FIELD(this, offset, filler_value);
-    offset += kPointerSize;
-  }
-}
-
 void Struct::InitializeBody(int object_size) {
   Object* value = GetReadOnlyRoots().undefined_value();
   for (int offset = kHeaderSize; offset < object_size; offset += kPointerSize) {
@@ -1559,21 +999,6 @@ void Object::VerifyApiCallResultType() {
 #endif  // DEBUG
 }
 
-Object* PropertyArray::get(int index) const {
-  DCHECK_GE(index, 0);
-  DCHECK_LE(index, this->length());
-  return RELAXED_READ_FIELD(this, kHeaderSize + index * kPointerSize);
-}
-
-void PropertyArray::set(int index, Object* value) {
-  DCHECK(IsPropertyArray());
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, this->length());
-  int offset = kHeaderSize + index * kPointerSize;
-  RELAXED_WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
-}
-
 int RegExpMatchInfo::NumberOfCaptureRegisters() {
   DCHECK_GE(length(), kLastMatchOverhead);
   Object* obj = get(kNumberOfCapturesIndex);
@@ -1665,23 +1090,11 @@ Address HeapObject::GetFieldAddress(int field_offset) const {
   return FIELD_ADDR(this, field_offset);
 }
 
-void PropertyArray::set(int index, Object* value, WriteBarrierMode mode) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, this->length());
-  int offset = kHeaderSize + index * kPointerSize;
-  RELAXED_WRITE_FIELD(this, offset, value);
-  CONDITIONAL_WRITE_BARRIER(this, offset, value, mode);
-}
-
-Object** PropertyArray::data_start() {
-  return HeapObject::RawField(this, kHeaderSize);
-}
-
 ACCESSORS(EnumCache, keys, FixedArray, kKeysOffset)
 ACCESSORS(EnumCache, indices, FixedArray, kIndicesOffset)
 
 int DescriptorArray::number_of_descriptors() const {
-  return Smi::ToInt(get(kDescriptorLengthIndex)->ToSmi());
+  return Smi::ToInt(get(kDescriptorLengthIndex)->cast<Smi>());
 }
 
 int DescriptorArray::number_of_descriptors_storage() const {
@@ -1707,7 +1120,7 @@ void DescriptorArray::CopyEnumCacheFrom(DescriptorArray* array) {
 }
 
 EnumCache* DescriptorArray::GetEnumCache() {
-  return EnumCache::cast(get(kEnumCacheIndex)->ToStrongHeapObject());
+  return EnumCache::cast(get(kEnumCacheIndex)->GetHeapObjectAssumeStrong());
 }
 
 // Perform a binary search in a fixed array.
@@ -1861,7 +1274,8 @@ MaybeObject** DescriptorArray::GetDescriptorEndSlot(int descriptor_number) {
 
 Name* DescriptorArray::GetKey(int descriptor_number) {
   DCHECK(descriptor_number < number_of_descriptors());
-  return Name::cast(get(ToKeyIndex(descriptor_number))->ToStrongHeapObject());
+  return Name::cast(
+      get(ToKeyIndex(descriptor_number))->GetHeapObjectAssumeStrong());
 }
 
 
@@ -1893,7 +1307,7 @@ int DescriptorArray::GetValueOffset(int descriptor_number) {
 
 Object* DescriptorArray::GetStrongValue(int descriptor_number) {
   DCHECK(descriptor_number < number_of_descriptors());
-  return get(ToValueIndex(descriptor_number))->ToObject();
+  return get(ToValueIndex(descriptor_number))->cast<Object>();
 }
 
 
@@ -1909,7 +1323,7 @@ MaybeObject* DescriptorArray::GetValue(int descriptor_number) {
 PropertyDetails DescriptorArray::GetDetails(int descriptor_number) {
   DCHECK(descriptor_number < number_of_descriptors());
   MaybeObject* details = get(ToDetailsIndex(descriptor_number));
-  return PropertyDetails(details->ToSmi());
+  return PropertyDetails(details->cast<Smi>());
 }
 
 int DescriptorArray::GetFieldIndex(int descriptor_number) {
@@ -2004,8 +1418,8 @@ uint32_t StringTableShape::HashForObject(Isolate* isolate, Object* object) {
   return String::cast(object)->Hash();
 }
 
-int StringTableShape::GetMapRootIndex() {
-  return Heap::kStringTableMapRootIndex;
+RootIndex StringTableShape::GetMapRootIndex() {
+  return RootIndex::kStringTableMap;
 }
 
 bool NumberDictionary::requires_slow_elements() {
@@ -2038,37 +1452,6 @@ DEFINE_DEOPT_ENTRY_ACCESSORS(BytecodeOffsetRaw, Smi)
 DEFINE_DEOPT_ENTRY_ACCESSORS(TranslationIndex, Smi)
 DEFINE_DEOPT_ENTRY_ACCESSORS(Pc, Smi)
 
-int PropertyArray::length() const {
-  Object* value_obj = READ_FIELD(this, kLengthAndHashOffset);
-  int value = Smi::ToInt(value_obj);
-  return LengthField::decode(value);
-}
-
-void PropertyArray::initialize_length(int len) {
-  SLOW_DCHECK(len >= 0);
-  SLOW_DCHECK(len < LengthField::kMax);
-  WRITE_FIELD(this, kLengthAndHashOffset, Smi::FromInt(len));
-}
-
-int PropertyArray::synchronized_length() const {
-  Object* value_obj = ACQUIRE_READ_FIELD(this, kLengthAndHashOffset);
-  int value = Smi::ToInt(value_obj);
-  return LengthField::decode(value);
-}
-
-int PropertyArray::Hash() const {
-  Object* value_obj = READ_FIELD(this, kLengthAndHashOffset);
-  int value = Smi::ToInt(value_obj);
-  return HashField::decode(value);
-}
-
-void PropertyArray::SetHash(int hash) {
-  Object* value_obj = READ_FIELD(this, kLengthAndHashOffset);
-  int value = Smi::ToInt(value_obj);
-  value = HashField::update(value, hash);
-  WRITE_FIELD(this, kLengthAndHashOffset, Smi::FromInt(value));
-}
-
 SMI_ACCESSORS(FreeSpace, size, kSizeOffset)
 RELAXED_SMI_ACCESSORS(FreeSpace, size, kSizeOffset)
 
@@ -2078,7 +1461,7 @@ int FreeSpace::Size() { return size(); }
 
 FreeSpace* FreeSpace::next() {
   DCHECK(map() == Heap::FromWritableHeapObject(this)->root(
-                      Heap::kFreeSpaceMapRootIndex) ||
+                      RootIndex::kFreeSpaceMap) ||
          (!Heap::FromWritableHeapObject(this)->deserialization_complete() &&
           map() == nullptr));
   DCHECK_LE(kNextOffset + kPointerSize, relaxed_read_size());
@@ -2088,7 +1471,7 @@ FreeSpace* FreeSpace::next() {
 
 void FreeSpace::set_next(FreeSpace* next) {
   DCHECK(map() == Heap::FromWritableHeapObject(this)->root(
-                      Heap::kFreeSpaceMapRootIndex) ||
+                      RootIndex::kFreeSpaceMap) ||
          (!Heap::FromWritableHeapObject(this)->deserialization_complete() &&
           map() == nullptr));
   DCHECK_LE(kNextOffset + kPointerSize, relaxed_read_size());
@@ -2189,22 +1572,6 @@ int HeapObject::SizeFromMap(Map* map) const {
   return reinterpret_cast<const Code*>(this)->CodeSize();
 }
 
-Object* JSBoundFunction::raw_bound_target_function() const {
-  return READ_FIELD(this, kBoundTargetFunctionOffset);
-}
-
-ACCESSORS(JSBoundFunction, bound_target_function, JSReceiver,
-          kBoundTargetFunctionOffset)
-ACCESSORS(JSBoundFunction, bound_this, Object, kBoundThisOffset)
-ACCESSORS(JSBoundFunction, bound_arguments, FixedArray, kBoundArgumentsOffset)
-
-ACCESSORS(JSFunction, shared, SharedFunctionInfo, kSharedFunctionInfoOffset)
-ACCESSORS(JSFunction, feedback_cell, FeedbackCell, kFeedbackCellOffset)
-
-ACCESSORS(JSGlobalObject, native_context, Context, kNativeContextOffset)
-ACCESSORS(JSGlobalObject, global_proxy, JSObject, kGlobalProxyOffset)
-
-ACCESSORS(JSGlobalProxy, native_context, Object, kNativeContextOffset)
 
 ACCESSORS(AsyncGeneratorRequest, next, Object, kNextOffset)
 SMI_ACCESSORS(AsyncGeneratorRequest, resume_mode, kResumeModeOffset)
@@ -2222,256 +1589,6 @@ ACCESSORS(TemplateObjectDescription, cooked_strings, FixedArray,
 ACCESSORS(AccessorPair, getter, Object, kGetterOffset)
 ACCESSORS(AccessorPair, setter, Object, kSetterOffset)
 
-ACCESSORS(AllocationSite, transition_info_or_boilerplate, Object,
-          kTransitionInfoOrBoilerplateOffset)
-
-JSObject* AllocationSite::boilerplate() const {
-  DCHECK(PointsToLiteral());
-  return JSObject::cast(transition_info_or_boilerplate());
-}
-
-void AllocationSite::set_boilerplate(JSObject* object, WriteBarrierMode mode) {
-  set_transition_info_or_boilerplate(object, mode);
-}
-
-int AllocationSite::transition_info() const {
-  DCHECK(!PointsToLiteral());
-  return Smi::cast(transition_info_or_boilerplate())->value();
-}
-
-void AllocationSite::set_transition_info(int value) {
-  DCHECK(!PointsToLiteral());
-  set_transition_info_or_boilerplate(Smi::FromInt(value), SKIP_WRITE_BARRIER);
-}
-
-ACCESSORS(AllocationSite, nested_site, Object, kNestedSiteOffset)
-INT32_ACCESSORS(AllocationSite, pretenure_data, kPretenureDataOffset)
-INT32_ACCESSORS(AllocationSite, pretenure_create_count,
-                kPretenureCreateCountOffset)
-ACCESSORS(AllocationSite, dependent_code, DependentCode,
-          kDependentCodeOffset)
-ACCESSORS_CHECKED(AllocationSite, weak_next, Object, kWeakNextOffset,
-                  HasWeakNext())
-ACCESSORS(AllocationMemento, allocation_site, Object, kAllocationSiteOffset)
-
-SMI_ACCESSORS(StackFrameInfo, line_number, kLineNumberIndex)
-SMI_ACCESSORS(StackFrameInfo, column_number, kColumnNumberIndex)
-SMI_ACCESSORS(StackFrameInfo, script_id, kScriptIdIndex)
-ACCESSORS(StackFrameInfo, script_name, Object, kScriptNameIndex)
-ACCESSORS(StackFrameInfo, script_name_or_source_url, Object,
-          kScriptNameOrSourceUrlIndex)
-ACCESSORS(StackFrameInfo, function_name, Object, kFunctionNameIndex)
-SMI_ACCESSORS(StackFrameInfo, flag, kFlagIndex)
-BOOL_ACCESSORS(StackFrameInfo, flag, is_eval, kIsEvalBit)
-BOOL_ACCESSORS(StackFrameInfo, flag, is_constructor, kIsConstructorBit)
-BOOL_ACCESSORS(StackFrameInfo, flag, is_wasm, kIsWasmBit)
-SMI_ACCESSORS(StackFrameInfo, id, kIdIndex)
-
-ACCESSORS(SourcePositionTableWithFrameCache, source_position_table, ByteArray,
-          kSourcePositionTableIndex)
-ACCESSORS(SourcePositionTableWithFrameCache, stack_frame_cache,
-          SimpleNumberDictionary, kStackFrameCacheIndex)
-
-
-FeedbackVector* JSFunction::feedback_vector() const {
-  DCHECK(has_feedback_vector());
-  return FeedbackVector::cast(feedback_cell()->value());
-}
-
-// Code objects that are marked for deoptimization are not considered to be
-// optimized. This is because the JSFunction might have been already
-// deoptimized but its code() still needs to be unlinked, which will happen on
-// its next activation.
-// TODO(jupvfranco): rename this function. Maybe RunOptimizedCode,
-// or IsValidOptimizedCode.
-bool JSFunction::IsOptimized() {
-  return code()->kind() == Code::OPTIMIZED_FUNCTION &&
-         !code()->marked_for_deoptimization();
-}
-
-bool JSFunction::HasOptimizedCode() {
-  return IsOptimized() ||
-         (has_feedback_vector() && feedback_vector()->has_optimized_code() &&
-          !feedback_vector()->optimized_code()->marked_for_deoptimization());
-}
-
-bool JSFunction::HasOptimizationMarker() {
-  return has_feedback_vector() && feedback_vector()->has_optimization_marker();
-}
-
-void JSFunction::ClearOptimizationMarker() {
-  DCHECK(has_feedback_vector());
-  feedback_vector()->ClearOptimizationMarker();
-}
-
-// Optimized code marked for deoptimization will tier back down to running
-// interpreted on its next activation, and already doesn't count as IsOptimized.
-bool JSFunction::IsInterpreted() {
-  return code()->is_interpreter_trampoline_builtin() ||
-         (code()->kind() == Code::OPTIMIZED_FUNCTION &&
-          code()->marked_for_deoptimization());
-}
-
-bool JSFunction::ChecksOptimizationMarker() {
-  return code()->checks_optimization_marker();
-}
-
-bool JSFunction::IsMarkedForOptimization() {
-  return has_feedback_vector() && feedback_vector()->optimization_marker() ==
-                                      OptimizationMarker::kCompileOptimized;
-}
-
-
-bool JSFunction::IsMarkedForConcurrentOptimization() {
-  return has_feedback_vector() &&
-         feedback_vector()->optimization_marker() ==
-             OptimizationMarker::kCompileOptimizedConcurrent;
-}
-
-
-bool JSFunction::IsInOptimizationQueue() {
-  return has_feedback_vector() && feedback_vector()->optimization_marker() ==
-                                      OptimizationMarker::kInOptimizationQueue;
-}
-
-
-void JSFunction::CompleteInobjectSlackTrackingIfActive() {
-  if (!has_prototype_slot()) return;
-  if (has_initial_map() && initial_map()->IsInobjectSlackTrackingInProgress()) {
-    initial_map()->CompleteInobjectSlackTracking(GetIsolate());
-  }
-}
-
-AbstractCode* JSFunction::abstract_code() {
-  if (IsInterpreted()) {
-    return AbstractCode::cast(shared()->GetBytecodeArray());
-  } else {
-    return AbstractCode::cast(code());
-  }
-}
-
-Code* JSFunction::code() { return Code::cast(READ_FIELD(this, kCodeOffset)); }
-
-void JSFunction::set_code(Code* value) {
-  DCHECK(!Heap::InNewSpace(value));
-  WRITE_FIELD(this, kCodeOffset, value);
-  MarkingBarrier(this, HeapObject::RawField(this, kCodeOffset), value);
-}
-
-
-void JSFunction::set_code_no_write_barrier(Code* value) {
-  DCHECK(!Heap::InNewSpace(value));
-  WRITE_FIELD(this, kCodeOffset, value);
-}
-
-void JSFunction::ClearOptimizedCodeSlot(const char* reason) {
-  if (has_feedback_vector() && feedback_vector()->has_optimized_code()) {
-    if (FLAG_trace_opt) {
-      PrintF("[evicting entry from optimizing code feedback slot (%s) for ",
-             reason);
-      ShortPrint();
-      PrintF("]\n");
-    }
-    feedback_vector()->ClearOptimizedCode();
-  }
-}
-
-void JSFunction::SetOptimizationMarker(OptimizationMarker marker) {
-  DCHECK(has_feedback_vector());
-  DCHECK(ChecksOptimizationMarker());
-  DCHECK(!HasOptimizedCode());
-
-  feedback_vector()->SetOptimizationMarker(marker);
-}
-
-bool JSFunction::has_feedback_vector() const {
-  return !feedback_cell()->value()->IsUndefined();
-}
-
-Context* JSFunction::context() {
-  return Context::cast(READ_FIELD(this, kContextOffset));
-}
-
-bool JSFunction::has_context() const {
-  return READ_FIELD(this, kContextOffset)->IsContext();
-}
-
-JSGlobalProxy* JSFunction::global_proxy() { return context()->global_proxy(); }
-
-Context* JSFunction::native_context() { return context()->native_context(); }
-
-
-void JSFunction::set_context(Object* value) {
-  DCHECK(value->IsUndefined() || value->IsContext());
-  WRITE_FIELD(this, kContextOffset, value);
-  WRITE_BARRIER(this, kContextOffset, value);
-}
-
-ACCESSORS_CHECKED(JSFunction, prototype_or_initial_map, Object,
-                  kPrototypeOrInitialMapOffset, map()->has_prototype_slot())
-
-bool JSFunction::has_prototype_slot() const {
-  return map()->has_prototype_slot();
-}
-
-Map* JSFunction::initial_map() {
-  return Map::cast(prototype_or_initial_map());
-}
-
-
-bool JSFunction::has_initial_map() {
-  DCHECK(has_prototype_slot());
-  return prototype_or_initial_map()->IsMap();
-}
-
-
-bool JSFunction::has_instance_prototype() {
-  DCHECK(has_prototype_slot());
-  return has_initial_map() || !prototype_or_initial_map()->IsTheHole();
-}
-
-bool JSFunction::has_prototype() {
-  DCHECK(has_prototype_slot());
-  return map()->has_non_instance_prototype() || has_instance_prototype();
-}
-
-bool JSFunction::has_prototype_property() {
-  return (has_prototype_slot() && IsConstructor()) ||
-         IsGeneratorFunction(shared()->kind());
-}
-
-bool JSFunction::PrototypeRequiresRuntimeLookup() {
-  return !has_prototype_property() || map()->has_non_instance_prototype();
-}
-
-Object* JSFunction::instance_prototype() {
-  DCHECK(has_instance_prototype());
-  if (has_initial_map()) return initial_map()->prototype();
-  // When there is no initial map and the prototype is a JSReceiver, the
-  // initial map field is used for the prototype field.
-  return prototype_or_initial_map();
-}
-
-
-Object* JSFunction::prototype() {
-  DCHECK(has_prototype());
-  // If the function's prototype property has been set to a non-JSReceiver
-  // value, that value is stored in the constructor field of the map.
-  if (map()->has_non_instance_prototype()) {
-    Object* prototype = map()->GetConstructor();
-    // The map must have a prototype in that field, not a back pointer.
-    DCHECK(!prototype->IsMap());
-    DCHECK(!prototype->IsFunctionTemplateInfo());
-    return prototype;
-  }
-  return instance_prototype();
-}
-
-
-bool JSFunction::is_compiled() {
-  return code()->builtin_index() != Builtins::kCompileLazy;
-}
-
 // static
 bool Foreign::IsNormalized(Object* value) {
   if (value == Smi::kZero) return true;
@@ -2479,11 +1596,11 @@ bool Foreign::IsNormalized(Object* value) {
 }
 
 Address Foreign::foreign_address() {
-  return AddressFrom<Address>(READ_INTPTR_FIELD(this, kForeignAddressOffset));
+  return READ_UINTPTR_FIELD(this, kForeignAddressOffset);
 }
 
 void Foreign::set_foreign_address(Address value) {
-  WRITE_INTPTR_FIELD(this, kForeignAddressOffset, OffsetFrom(value));
+  WRITE_UINTPTR_FIELD(this, kForeignAddressOffset, value);
 }
 
 template <class Derived>
@@ -2494,158 +1611,6 @@ void SmallOrderedHashTable<Derived>::SetDataEntry(int entry, int relative_index,
   WRITE_BARRIER(this, static_cast<int>(entry_offset), value);
 }
 
-ACCESSORS(JSValue, value, Object, kValueOffset)
-
-
-ACCESSORS(JSDate, value, Object, kValueOffset)
-ACCESSORS(JSDate, cache_stamp, Object, kCacheStampOffset)
-ACCESSORS(JSDate, year, Object, kYearOffset)
-ACCESSORS(JSDate, month, Object, kMonthOffset)
-ACCESSORS(JSDate, day, Object, kDayOffset)
-ACCESSORS(JSDate, weekday, Object, kWeekdayOffset)
-ACCESSORS(JSDate, hour, Object, kHourOffset)
-ACCESSORS(JSDate, min, Object, kMinOffset)
-ACCESSORS(JSDate, sec, Object, kSecOffset)
-
-
-SMI_ACCESSORS(JSMessageObject, type, kTypeOffset)
-ACCESSORS(JSMessageObject, argument, Object, kArgumentsOffset)
-ACCESSORS(JSMessageObject, script, Script, kScriptOffset)
-ACCESSORS(JSMessageObject, stack_frames, Object, kStackFramesOffset)
-SMI_ACCESSORS(JSMessageObject, start_position, kStartPositionOffset)
-SMI_ACCESSORS(JSMessageObject, end_position, kEndPositionOffset)
-SMI_ACCESSORS(JSMessageObject, error_level, kErrorLevelOffset)
-
-ElementsKind JSObject::GetElementsKind() const {
-  ElementsKind kind = map()->elements_kind();
-#if VERIFY_HEAP && DEBUG
-  FixedArrayBase* fixed_array =
-      reinterpret_cast<FixedArrayBase*>(READ_FIELD(this, kElementsOffset));
-
-  // If a GC was caused while constructing this object, the elements
-  // pointer may point to a one pointer filler map.
-  if (ElementsAreSafeToExamine()) {
-    Map* map = fixed_array->map();
-    if (IsSmiOrObjectElementsKind(kind)) {
-      DCHECK(map == GetReadOnlyRoots().fixed_array_map() ||
-             map == GetReadOnlyRoots().fixed_cow_array_map());
-    } else if (IsDoubleElementsKind(kind)) {
-      DCHECK(fixed_array->IsFixedDoubleArray() ||
-             fixed_array == GetReadOnlyRoots().empty_fixed_array());
-    } else if (kind == DICTIONARY_ELEMENTS) {
-      DCHECK(fixed_array->IsFixedArray());
-      DCHECK(fixed_array->IsDictionary());
-    } else {
-      DCHECK(kind > DICTIONARY_ELEMENTS);
-    }
-    DCHECK(!IsSloppyArgumentsElementsKind(kind) ||
-           (elements()->IsFixedArray() && elements()->length() >= 2));
-  }
-#endif
-  return kind;
-}
-
-bool JSObject::HasObjectElements() {
-  return IsObjectElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasSmiElements() { return IsSmiElementsKind(GetElementsKind()); }
-
-bool JSObject::HasSmiOrObjectElements() {
-  return IsSmiOrObjectElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasDoubleElements() {
-  return IsDoubleElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasHoleyElements() {
-  return IsHoleyElementsKind(GetElementsKind());
-}
-
-
-bool JSObject::HasFastElements() {
-  return IsFastElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasFastPackedElements() {
-  return IsFastPackedElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasDictionaryElements() {
-  return GetElementsKind() == DICTIONARY_ELEMENTS;
-}
-
-
-bool JSObject::HasFastArgumentsElements() {
-  return GetElementsKind() == FAST_SLOPPY_ARGUMENTS_ELEMENTS;
-}
-
-
-bool JSObject::HasSlowArgumentsElements() {
-  return GetElementsKind() == SLOW_SLOPPY_ARGUMENTS_ELEMENTS;
-}
-
-
-bool JSObject::HasSloppyArgumentsElements() {
-  return IsSloppyArgumentsElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasStringWrapperElements() {
-  return IsStringWrapperElementsKind(GetElementsKind());
-}
-
-bool JSObject::HasFastStringWrapperElements() {
-  return GetElementsKind() == FAST_STRING_WRAPPER_ELEMENTS;
-}
-
-bool JSObject::HasSlowStringWrapperElements() {
-  return GetElementsKind() == SLOW_STRING_WRAPPER_ELEMENTS;
-}
-
-bool JSObject::HasFixedTypedArrayElements() {
-  DCHECK_NOT_NULL(elements());
-  return map()->has_fixed_typed_array_elements();
-}
-
-#define FIXED_TYPED_ELEMENTS_CHECK(Type, type, TYPE, ctype)            \
-  bool JSObject::HasFixed##Type##Elements() {                          \
-    HeapObject* array = elements();                                    \
-    DCHECK_NOT_NULL(array);                                            \
-    if (!array->IsHeapObject()) return false;                          \
-    return array->map()->instance_type() == FIXED_##TYPE##_ARRAY_TYPE; \
-  }
-
-TYPED_ARRAYS(FIXED_TYPED_ELEMENTS_CHECK)
-
-#undef FIXED_TYPED_ELEMENTS_CHECK
-
-
-bool JSObject::HasNamedInterceptor() {
-  return map()->has_named_interceptor();
-}
-
-
-bool JSObject::HasIndexedInterceptor() {
-  return map()->has_indexed_interceptor();
-}
-
-void JSGlobalObject::set_global_dictionary(GlobalDictionary* dictionary) {
-  DCHECK(IsJSGlobalObject());
-  set_raw_properties_or_hash(dictionary);
-}
-
-GlobalDictionary* JSGlobalObject::global_dictionary() {
-  DCHECK(!HasFastProperties());
-  DCHECK(IsJSGlobalObject());
-  return GlobalDictionary::cast(raw_properties_or_hash());
-}
-
-NumberDictionary* JSObject::element_dictionary() {
-  DCHECK(HasDictionaryElements() || HasSlowStringWrapperElements());
-  return NumberDictionary::cast(elements());
-}
-
 // static
 Maybe<bool> Object::GreaterThan(Isolate* isolate, Handle<Object> x,
                                 Handle<Object> y) {
@@ -2729,9 +1694,9 @@ MaybeHandle<Object> Object::SetPropertyOrElement(Isolate* isolate,
                                                  Handle<Name> name,
                                                  Handle<Object> value,
                                                  LanguageMode language_mode,
-                                                 StoreFromKeyed store_mode) {
+                                                 StoreOrigin store_origin) {
   LookupIterator it = LookupIterator::PropertyOrElement(isolate, object, name);
-  MAYBE_RETURN_NULL(SetProperty(&it, value, language_mode, store_mode));
+  MAYBE_RETURN_NULL(SetProperty(&it, value, language_mode, store_origin));
   return value;
 }
 
@@ -2744,134 +1709,6 @@ MaybeHandle<Object> Object::GetPropertyOrElement(Handle<Object> receiver,
 }
 
 
-void JSReceiver::initialize_properties() {
-  Heap* heap = GetHeap();
-  ReadOnlyRoots roots(heap);
-  DCHECK(!Heap::InNewSpace(roots.empty_fixed_array()));
-  DCHECK(!Heap::InNewSpace(heap->empty_property_dictionary()));
-  if (map()->is_dictionary_map()) {
-    WRITE_FIELD(this, kPropertiesOrHashOffset,
-                heap->empty_property_dictionary());
-  } else {
-    WRITE_FIELD(this, kPropertiesOrHashOffset, roots.empty_fixed_array());
-  }
-}
-
-bool JSReceiver::HasFastProperties() const {
-  DCHECK(
-      raw_properties_or_hash()->IsSmi() ||
-      (raw_properties_or_hash()->IsDictionary() == map()->is_dictionary_map()));
-  return !map()->is_dictionary_map();
-}
-
-NameDictionary* JSReceiver::property_dictionary() const {
-  DCHECK(!IsJSGlobalObject());
-  DCHECK(!HasFastProperties());
-
-  Object* prop = raw_properties_or_hash();
-  if (prop->IsSmi()) {
-    return GetHeap()->empty_property_dictionary();
-  }
-
-  return NameDictionary::cast(prop);
-}
-
-// TODO(gsathya): Pass isolate directly to this function and access
-// the heap from this.
-PropertyArray* JSReceiver::property_array() const {
-  DCHECK(HasFastProperties());
-
-  Object* prop = raw_properties_or_hash();
-  if (prop->IsSmi() || prop == GetReadOnlyRoots().empty_fixed_array()) {
-    return GetReadOnlyRoots().empty_property_array();
-  }
-
-  return PropertyArray::cast(prop);
-}
-
-Maybe<bool> JSReceiver::HasProperty(Handle<JSReceiver> object,
-                                    Handle<Name> name) {
-  LookupIterator it = LookupIterator::PropertyOrElement(object->GetIsolate(),
-                                                        object, name, object);
-  return HasProperty(&it);
-}
-
-
-Maybe<bool> JSReceiver::HasOwnProperty(Handle<JSReceiver> object,
-                                       uint32_t index) {
-  if (object->IsJSModuleNamespace()) return Just(false);
-
-  if (object->IsJSObject()) {  // Shortcut.
-    LookupIterator it(object->GetIsolate(), object, index, object,
-                      LookupIterator::OWN);
-    return HasProperty(&it);
-  }
-
-  Maybe<PropertyAttributes> attributes =
-      JSReceiver::GetOwnPropertyAttributes(object, index);
-  MAYBE_RETURN(attributes, Nothing<bool>());
-  return Just(attributes.FromJust() != ABSENT);
-}
-
-Maybe<PropertyAttributes> JSReceiver::GetPropertyAttributes(
-    Handle<JSReceiver> object, Handle<Name> name) {
-  LookupIterator it = LookupIterator::PropertyOrElement(object->GetIsolate(),
-                                                        object, name, object);
-  return GetPropertyAttributes(&it);
-}
-
-
-Maybe<PropertyAttributes> JSReceiver::GetOwnPropertyAttributes(
-    Handle<JSReceiver> object, Handle<Name> name) {
-  LookupIterator it = LookupIterator::PropertyOrElement(
-      object->GetIsolate(), object, name, object, LookupIterator::OWN);
-  return GetPropertyAttributes(&it);
-}
-
-Maybe<PropertyAttributes> JSReceiver::GetOwnPropertyAttributes(
-    Handle<JSReceiver> object, uint32_t index) {
-  LookupIterator it(object->GetIsolate(), object, index, object,
-                    LookupIterator::OWN);
-  return GetPropertyAttributes(&it);
-}
-
-Maybe<bool> JSReceiver::HasElement(Handle<JSReceiver> object, uint32_t index) {
-  LookupIterator it(object->GetIsolate(), object, index, object);
-  return HasProperty(&it);
-}
-
-
-Maybe<PropertyAttributes> JSReceiver::GetElementAttributes(
-    Handle<JSReceiver> object, uint32_t index) {
-  Isolate* isolate = object->GetIsolate();
-  LookupIterator it(isolate, object, index, object);
-  return GetPropertyAttributes(&it);
-}
-
-
-Maybe<PropertyAttributes> JSReceiver::GetOwnElementAttributes(
-    Handle<JSReceiver> object, uint32_t index) {
-  Isolate* isolate = object->GetIsolate();
-  LookupIterator it(isolate, object, index, object, LookupIterator::OWN);
-  return GetPropertyAttributes(&it);
-}
-
-
-bool JSGlobalObject::IsDetached() {
-  return JSGlobalProxy::cast(global_proxy())->IsDetachedFrom(this);
-}
-
-
-bool JSGlobalProxy::IsDetachedFrom(JSGlobalObject* global) const {
-  const PrototypeIterator iter(this->GetIsolate(),
-                               const_cast<JSGlobalProxy*>(this));
-  return iter.GetCurrent() != global;
-}
-
-inline int JSGlobalProxy::SizeWithEmbedderFields(int embedder_field_count) {
-  DCHECK_GE(embedder_field_count, 0);
-  return kSize + embedder_field_count * kPointerSize;
-}
 
 Object* AccessorPair::get(AccessorComponent component) {
   return component == ACCESSOR_GETTER ? getter() : setter();
@@ -2936,14 +1773,14 @@ Object* GlobalDictionaryShape::Unwrap(Object* object) {
   return PropertyCell::cast(object)->name();
 }
 
-int GlobalDictionaryShape::GetMapRootIndex() {
-  return Heap::kGlobalDictionaryMapRootIndex;
+RootIndex GlobalDictionaryShape::GetMapRootIndex() {
+  return RootIndex::kGlobalDictionaryMap;
 }
 
 Name* NameDictionary::NameAt(int entry) { return Name::cast(KeyAt(entry)); }
 
-int NameDictionaryShape::GetMapRootIndex() {
-  return Heap::kNameDictionaryMapRootIndex;
+RootIndex NameDictionaryShape::GetMapRootIndex() {
+  return RootIndex::kNameDictionaryMap;
 }
 
 PropertyCell* GlobalDictionary::CellAt(int entry) {
@@ -2995,12 +1832,12 @@ Handle<Object> NumberDictionaryBaseShape::AsHandle(Isolate* isolate,
   return isolate->factory()->NewNumberFromUint(key);
 }
 
-int NumberDictionaryShape::GetMapRootIndex() {
-  return Heap::kNumberDictionaryMapRootIndex;
+RootIndex NumberDictionaryShape::GetMapRootIndex() {
+  return RootIndex::kNumberDictionaryMap;
 }
 
-int SimpleNumberDictionaryShape::GetMapRootIndex() {
-  return Heap::kSimpleNumberDictionaryMapRootIndex;
+RootIndex SimpleNumberDictionaryShape::GetMapRootIndex() {
+  return RootIndex::kSimpleNumberDictionaryMap;
 }
 
 bool NameDictionaryShape::IsMatch(Handle<Name> key, Object* other) {
@@ -3169,15 +2006,6 @@ static inline Handle<Object> MakeEntryPair(Isolate* isolate, Handle<Object> key,
                                                     PACKED_ELEMENTS, 2);
 }
 
-ACCESSORS(JSIteratorResult, value, Object, kValueOffset)
-ACCESSORS(JSIteratorResult, done, Object, kDoneOffset)
-
-ACCESSORS(JSAsyncFromSyncIterator, sync_iterator, JSReceiver,
-          kSyncIteratorOffset)
-ACCESSORS(JSAsyncFromSyncIterator, next, Object, kNextOffset)
-
-ACCESSORS(JSStringIterator, string, String, kStringOffset)
-SMI_ACCESSORS(JSStringIterator, index, kNextIndexOffset)
 
 bool ScopeInfo::IsAsmModule() const { return AsmModuleField::decode(Flags()); }
 
diff --git a/deps/v8/src/objects-printer.cc b/deps/v8/src/objects-printer.cc
index d76c036ba9..38dd9d1c52 100644
--- a/deps/v8/src/objects-printer.cc
+++ b/deps/v8/src/objects-printer.cc
@@ -14,30 +14,38 @@
 #include "src/interpreter/bytecodes.h"
 #include "src/objects-inl.h"
 #include "src/objects/arguments-inl.h"
-#ifdef V8_INTL_SUPPORT
-#include "src/objects/js-collator-inl.h"
-#endif  // V8_INTL_SUPPORT
 #include "src/objects/data-handler-inl.h"
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/js-array-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/js-break-iterator-inl.h"
+#include "src/objects/js-collator-inl.h"
+#endif  // V8_INTL_SUPPORT
 #include "src/objects/js-collection-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/js-date-time-format-inl.h"
+#endif  // V8_INTL_SUPPORT
 #include "src/objects/js-generator-inl.h"
 #ifdef V8_INTL_SUPPORT
 #include "src/objects/js-list-format-inl.h"
 #include "src/objects/js-locale-inl.h"
+#include "src/objects/js-number-format-inl.h"
+#include "src/objects/js-plural-rules-inl.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/js-regexp-string-iterator-inl.h"
 #ifdef V8_INTL_SUPPORT
-#include "src/objects/js-plural-rules-inl.h"
 #include "src/objects/js-relative-time-format-inl.h"
+#include "src/objects/js-segmenter-inl.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/microtask-inl.h"
+#include "src/objects/microtask-queue-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/ostreams.h"
 #include "src/regexp/jsregexp.h"
 #include "src/transitions-inl.h"
@@ -112,6 +120,7 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
       FixedDoubleArray::cast(this)->FixedDoubleArrayPrint(os);
       break;
     case FIXED_ARRAY_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
@@ -187,6 +196,7 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
     case JS_ARGUMENTS_TYPE:
     case JS_ERROR_TYPE:
     // TODO(titzer): debug printing for more wasm objects
+    case WASM_EXCEPTION_TYPE:
     case WASM_GLOBAL_TYPE:
     case WASM_MEMORY_TYPE:
     case WASM_TABLE_TYPE:
@@ -309,27 +319,39 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
       JSDataView::cast(this)->JSDataViewPrint(os);
       break;
 #ifdef V8_INTL_SUPPORT
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
+      JSV8BreakIterator::cast(this)->JSV8BreakIteratorPrint(os);
+      break;
     case JS_INTL_COLLATOR_TYPE:
       JSCollator::cast(this)->JSCollatorPrint(os);
       break;
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
+      JSDateTimeFormat::cast(this)->JSDateTimeFormatPrint(os);
+      break;
     case JS_INTL_LIST_FORMAT_TYPE:
       JSListFormat::cast(this)->JSListFormatPrint(os);
       break;
     case JS_INTL_LOCALE_TYPE:
       JSLocale::cast(this)->JSLocalePrint(os);
       break;
+    case JS_INTL_NUMBER_FORMAT_TYPE:
+      JSNumberFormat::cast(this)->JSNumberFormatPrint(os);
+      break;
     case JS_INTL_PLURAL_RULES_TYPE:
       JSPluralRules::cast(this)->JSPluralRulesPrint(os);
       break;
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
       JSRelativeTimeFormat::cast(this)->JSRelativeTimeFormatPrint(os);
       break;
+    case JS_INTL_SEGMENTER_TYPE:
+      JSSegmenter::cast(this)->JSSegmenterPrint(os);
+      break;
 #endif  // V8_INTL_SUPPORT
-#define MAKE_STRUCT_CASE(NAME, Name, name) \
-  case NAME##_TYPE:                        \
+#define MAKE_STRUCT_CASE(TYPE, Name, name) \
+  case TYPE:                               \
     Name::cast(this)->Name##Print(os);     \
     break;
-  STRUCT_LIST(MAKE_STRUCT_CASE)
+      STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
 
     case ALLOCATION_SITE_TYPE:
@@ -358,9 +380,9 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
     case ONE_BYTE_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
-    case SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE:
-    case SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
-    case SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
+    case UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE:
+    case UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE:
+    case UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
     case STRING_TYPE:
     case CONS_STRING_TYPE:
     case EXTERNAL_STRING_TYPE:
@@ -372,9 +394,9 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
     case SLICED_ONE_BYTE_STRING_TYPE:
     case THIN_ONE_BYTE_STRING_TYPE:
     case EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
-    case SHORT_EXTERNAL_STRING_TYPE:
-    case SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE:
-    case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
+    case UNCACHED_EXTERNAL_STRING_TYPE:
+    case UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE:
+    case UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
     case SMALL_ORDERED_HASH_MAP_TYPE:
     case SMALL_ORDERED_HASH_SET_TYPE:
     case JS_ASYNC_FROM_SYNC_ITERATOR_TYPE:
@@ -832,7 +854,7 @@ void Map::MapPrint(std::ostream& os) {  // NOLINT
       Smi* smi;
       if (raw_transitions()->ToSmi(&smi)) {
         os << Brief(smi);
-      } else if (raw_transitions()->ToStrongOrWeakHeapObject(&heap_object)) {
+      } else if (raw_transitions()->GetHeapObject(&heap_object)) {
         os << Brief(heap_object);
       }
       transitions.PrintTransitions(os);
@@ -1073,29 +1095,6 @@ void FeedbackVector::FeedbackSlotPrint(std::ostream& os,
   nexus.Print(os);
 }
 
-namespace {
-
-const char* ICState2String(InlineCacheState state) {
-  switch (state) {
-    case UNINITIALIZED:
-      return "UNINITIALIZED";
-    case PREMONOMORPHIC:
-      return "PREMONOMORPHIC";
-    case MONOMORPHIC:
-      return "MONOMORPHIC";
-    case RECOMPUTE_HANDLER:
-      return "RECOMPUTE_HANDLER";
-    case POLYMORPHIC:
-      return "POLYMORPHIC";
-    case MEGAMORPHIC:
-      return "MEGAMORPHIC";
-    case GENERIC:
-      return "GENERIC";
-  }
-  UNREACHABLE();
-}
-}  // anonymous namespace
-
 void FeedbackNexus::Print(std::ostream& os) {  // NOLINT
   switch (kind()) {
     case FeedbackSlotKind::kCall:
@@ -1114,7 +1113,7 @@ void FeedbackNexus::Print(std::ostream& os) {  // NOLINT
     case FeedbackSlotKind::kStoreKeyedStrict:
     case FeedbackSlotKind::kStoreInArrayLiteral:
     case FeedbackSlotKind::kCloneObject: {
-      os << ICState2String(StateFromFeedback());
+      os << InlineCacheState2String(StateFromFeedback());
       break;
     }
     case FeedbackSlotKind::kBinaryOp: {
@@ -1278,7 +1277,7 @@ void JSWeakSet::JSWeakSetPrint(std::ostream& os) {  // NOLINT
 void JSArrayBuffer::JSArrayBufferPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, this, "JSArrayBuffer");
   os << "\n - backing_store: " << backing_store();
-  os << "\n - byte_length: " << Brief(byte_length());
+  os << "\n - byte_length: " << byte_length();
   if (is_external()) os << "\n - external";
   if (is_neuterable()) os << "\n - neuterable";
   if (was_neutered()) os << "\n - neutered";
@@ -1291,8 +1290,8 @@ void JSArrayBuffer::JSArrayBufferPrint(std::ostream& os) {  // NOLINT
 void JSTypedArray::JSTypedArrayPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, this, "JSTypedArray");
   os << "\n - buffer: " << Brief(buffer());
-  os << "\n - byte_offset: " << Brief(byte_offset());
-  os << "\n - byte_length: " << Brief(byte_length());
+  os << "\n - byte_offset: " << byte_offset();
+  os << "\n - byte_length: " << byte_length();
   os << "\n - length: " << Brief(length());
   if (WasNeutered()) os << "\n - neutered";
   JSObjectPrintBody(os, this, !WasNeutered());
@@ -1309,8 +1308,8 @@ void JSArrayIterator::JSArrayIteratorPrint(std::ostream& os) {  // NOLING
 void JSDataView::JSDataViewPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, this, "JSDataView");
   os << "\n - buffer =" << Brief(buffer());
-  os << "\n - byte_offset: " << Brief(byte_offset());
-  os << "\n - byte_length: " << Brief(byte_length());
+  os << "\n - byte_offset: " << byte_offset();
+  os << "\n - byte_length: " << byte_length();
   if (WasNeutered()) os << "\n - neutered";
   JSObjectPrintBody(os, this, !WasNeutered());
 }
@@ -1953,20 +1952,41 @@ void Script::ScriptPrint(std::ostream& os) {  // NOLINT
 }
 
 #ifdef V8_INTL_SUPPORT
+void JSV8BreakIterator::JSV8BreakIteratorPrint(std::ostream& os) {  // NOLINT
+  JSObjectPrintHeader(os, this, "JSV8BreakIterator");
+  os << "\n - locale: " << Brief(locale());
+  os << "\n - type: " << TypeAsString();
+  os << "\n - break iterator: " << Brief(break_iterator());
+  os << "\n - unicode string: " << Brief(unicode_string());
+  os << "\n - bound adopt text: " << Brief(bound_adopt_text());
+  os << "\n - bound first: " << Brief(bound_first());
+  os << "\n - bound next: " << Brief(bound_next());
+  os << "\n - bound current: " << Brief(bound_current());
+  os << "\n - bound break type: " << Brief(bound_break_type());
+  os << "\n";
+}
+
 void JSCollator::JSCollatorPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, this, "JSCollator");
-  os << "\n - usage: " << JSCollator::UsageToString(usage());
   os << "\n - icu collator: " << Brief(icu_collator());
   os << "\n - bound compare: " << Brief(bound_compare());
   os << "\n";
 }
 
+void JSDateTimeFormat::JSDateTimeFormatPrint(std::ostream& os) {  // NOLINT
+  JSObjectPrintHeader(os, this, "JSDateTimeFormat");
+  os << "\n - icu locale: " << Brief(icu_locale());
+  os << "\n - icu simple date format: " << Brief(icu_simple_date_format());
+  os << "\n - bound format: " << Brief(bound_format());
+  os << "\n";
+}
+
 void JSListFormat::JSListFormatPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, this, "JSListFormat");
   os << "\n - locale: " << Brief(locale());
   os << "\n - style: " << StyleAsString();
   os << "\n - type: " << TypeAsString();
-  os << "\n - formatter: " << Brief(formatter());
+  os << "\n - icu formatter: " << Brief(icu_formatter());
   os << "\n";
 }
 
@@ -1978,14 +1998,24 @@ void JSLocale::JSLocalePrint(std::ostream& os) {  // NOLINT
   os << "\n - baseName: " << Brief(base_name());
   os << "\n - locale: " << Brief(locale());
   os << "\n - calendar: " << Brief(calendar());
-  os << "\n - caseFirst: " << Brief(case_first());
+  os << "\n - caseFirst: " << CaseFirstAsString();
   os << "\n - collation: " << Brief(collation());
-  os << "\n - hourCycle: " << Brief(hour_cycle());
-  os << "\n - numeric: " << Brief(numeric());
+  os << "\n - hourCycle: " << HourCycleAsString();
+  os << "\n - numeric: " << NumericAsString();
   os << "\n - numberingSystem: " << Brief(numbering_system());
   os << "\n";
 }
 
+void JSNumberFormat::JSNumberFormatPrint(std::ostream& os) {  // NOLINT
+  JSObjectPrintHeader(os, this, "JSNumberFormat");
+  os << "\n - locale: " << Brief(locale());
+  os << "\n - icu_number_format: " << Brief(icu_number_format());
+  os << "\n - bound_format: " << Brief(bound_format());
+  os << "\n - style: " << StyleAsString();
+  os << "\n - currency_display: " << CurrencyDisplayAsString();
+  os << "\n";
+}
+
 void JSPluralRules::JSPluralRulesPrint(std::ostream& os) {  // NOLINT
   HeapObject::PrintHeader(os, "JSPluralRules");
   JSObjectPrint(os);
@@ -2002,7 +2032,16 @@ void JSRelativeTimeFormat::JSRelativeTimeFormatPrint(
   os << "\n - locale: " << Brief(locale());
   os << "\n - style: " << StyleAsString();
   os << "\n - numeric: " << NumericAsString();
-  os << "\n - formatter: " << Brief(formatter());
+  os << "\n - icu formatter: " << Brief(icu_formatter());
+  os << "\n";
+}
+
+void JSSegmenter::JSSegmenterPrint(std::ostream& os) {  // NOLINT
+  JSObjectPrintHeader(os, this, "JSSegmenter");
+  os << "\n - locale: " << Brief(locale());
+  os << "\n - granularity: " << GranularityAsString();
+  os << "\n - lineBreakStyle: " << LineBreakStyleAsString();
+  os << "\n - icubreak iterator: " << Brief(icu_break_iterator());
   os << "\n";
 }
 #endif  // V8_INTL_SUPPORT
@@ -2173,6 +2212,13 @@ void UncompiledDataWithPreParsedScope::UncompiledDataWithPreParsedScopePrint(
   os << "\n";
 }
 
+void MicrotaskQueue::MicrotaskQueuePrint(std::ostream& os) {  // NOLINT
+  HeapObject::PrintHeader(os, "MicrotaskQueue");
+  os << "\n - pending_microtask_count: " << pending_microtask_count();
+  os << "\n - queue: " << Brief(queue());
+  os << "\n";
+}
+
 void InterpreterData::InterpreterDataPrint(std::ostream& os) {  // NOLINT
   HeapObject::PrintHeader(os, "InterpreterData");
   os << "\n - bytecode_array: " << Brief(bytecode_array());
@@ -2191,12 +2237,12 @@ void MaybeObject::Print(std::ostream& os) {
   HeapObject* heap_object;
   if (ToSmi(&smi)) {
     smi->SmiPrint(os);
-  } else if (IsClearedWeakHeapObject()) {
+  } else if (IsCleared()) {
     os << "[cleared]";
-  } else if (ToWeakHeapObject(&heap_object)) {
+  } else if (GetHeapObjectIfWeak(&heap_object)) {
     os << "[weak] ";
     heap_object->HeapObjectPrint(os);
-  } else if (ToStrongHeapObject(&heap_object)) {
+  } else if (GetHeapObjectIfStrong(&heap_object)) {
     heap_object->HeapObjectPrint(os);
   } else {
     UNREACHABLE();
@@ -2356,7 +2402,7 @@ void TransitionsAccessor::PrintTransitions(std::ostream& os) {  // NOLINT
     case kUninitialized:
       return;
     case kWeakRef: {
-      Map* target = Map::cast(raw_transitions_->ToWeakHeapObject());
+      Map* target = Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
       Name* key = GetSimpleTransitionKey(target);
       PrintOneTransition(os, key, target);
       break;
diff --git a/deps/v8/src/objects.cc b/deps/v8/src/objects.cc
index 811656ad9a..6ccdbf4e34 100644
--- a/deps/v8/src/objects.cc
+++ b/deps/v8/src/objects.cc
@@ -61,25 +61,33 @@
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-inl.h"
 #ifdef V8_INTL_SUPPORT
+#include "src/objects/js-break-iterator.h"
 #include "src/objects/js-collator.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/js-collection-inl.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/objects/js-date-time-format.h"
+#endif  // V8_INTL_SUPPORT
 #include "src/objects/js-generator-inl.h"
 #ifdef V8_INTL_SUPPORT
 #include "src/objects/js-list-format.h"
 #include "src/objects/js-locale.h"
+#include "src/objects/js-number-format.h"
+#include "src/objects/js-plural-rules.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/js-regexp-string-iterator.h"
 #ifdef V8_INTL_SUPPORT
-#include "src/objects/js-plural-rules.h"
 #include "src/objects/js-relative-time-format.h"
+#include "src/objects/js-segmenter.h"
 #endif  // V8_INTL_SUPPORT
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/map.h"
 #include "src/objects/microtask-inl.h"
+#include "src/objects/microtask-queue-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/parsing/preparsed-scope-data.h"
 #include "src/property-descriptor.h"
 #include "src/prototype.h"
@@ -364,8 +372,17 @@ Handle<String> Object::NoSideEffectsToString(Isolate* isolate,
                                              Handle<Object> input) {
   DisallowJavascriptExecution no_js(isolate);
 
-  if (input->IsString() || input->IsNumeric() || input->IsOddball()) {
+  if (input->IsString() || input->IsNumber() || input->IsOddball()) {
     return Object::ToString(isolate, input).ToHandleChecked();
+  } else if (input->IsBigInt()) {
+    MaybeHandle<String> maybe_string =
+        BigInt::ToString(isolate, Handle<BigInt>::cast(input), 10, kDontThrow);
+    Handle<String> result;
+    if (maybe_string.ToHandle(&result)) return result;
+    // BigInt-to-String conversion can fail on 32-bit platforms where
+    // String::kMaxLength is too small to fit this BigInt.
+    return isolate->factory()->NewStringFromStaticChars(
+        "<a very large BigInt>");
   } else if (input->IsFunction()) {
     // -- F u n c t i o n
     Handle<String> fun_str;
@@ -1444,16 +1461,24 @@ int JSObject::GetHeaderSize(InstanceType type,
     case JS_MODULE_NAMESPACE_TYPE:
       return JSModuleNamespace::kHeaderSize;
 #ifdef V8_INTL_SUPPORT
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
+      return JSV8BreakIterator::kSize;
     case JS_INTL_COLLATOR_TYPE:
       return JSCollator::kSize;
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
+      return JSDateTimeFormat::kSize;
     case JS_INTL_LIST_FORMAT_TYPE:
       return JSListFormat::kSize;
     case JS_INTL_LOCALE_TYPE:
       return JSLocale::kSize;
+    case JS_INTL_NUMBER_FORMAT_TYPE:
+      return JSNumberFormat::kSize;
     case JS_INTL_PLURAL_RULES_TYPE:
       return JSPluralRules::kSize;
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
       return JSRelativeTimeFormat::kSize;
+    case JS_INTL_SEGMENTER_TYPE:
+      return JSSegmenter::kSize;
 #endif  // V8_INTL_SUPPORT
     case WASM_GLOBAL_TYPE:
       return WasmGlobalObject::kSize;
@@ -2202,9 +2227,8 @@ V8_WARN_UNUSED_RESULT Maybe<bool> FastAssign(
 
     if (use_set) {
       LookupIterator it(target, next_key, target);
-      Maybe<bool> result =
-          Object::SetProperty(&it, prop_value, LanguageMode::kStrict,
-                              Object::CERTAINLY_NOT_STORE_FROM_KEYED);
+      Maybe<bool> result = Object::SetProperty(
+          &it, prop_value, LanguageMode::kStrict, StoreOrigin::kNamed);
       if (result.IsNothing()) return result;
       if (stable) stable = from->map() == *map;
     } else {
@@ -2267,7 +2291,8 @@ Maybe<bool> JSReceiver::SetOrCopyDataProperties(
         ASSIGN_RETURN_ON_EXCEPTION_VALUE(
             isolate, status,
             Runtime::SetObjectProperty(isolate, target, next_key, prop_value,
-                                       LanguageMode::kStrict),
+                                       LanguageMode::kStrict,
+                                       StoreOrigin::kMaybeKeyed),
             Nothing<bool>());
       } else {
         if (excluded_properties != nullptr &&
@@ -2536,12 +2561,12 @@ std::ostream& operator<<(std::ostream& os, const Brief& v) {
   HeapObject* heap_object;
   if (maybe_object->ToSmi(&smi)) {
     smi->SmiPrint(os);
-  } else if (maybe_object->IsClearedWeakHeapObject()) {
+  } else if (maybe_object->IsCleared()) {
     os << "[cleared]";
-  } else if (maybe_object->ToWeakHeapObject(&heap_object)) {
+  } else if (maybe_object->GetHeapObjectIfWeak(&heap_object)) {
     os << "[weak] ";
     heap_object->HeapObjectShortPrint(os);
-  } else if (maybe_object->ToStrongHeapObject(&heap_object)) {
+  } else if (maybe_object->GetHeapObjectIfStrong(&heap_object)) {
     heap_object->HeapObjectShortPrint(os);
   } else {
     UNREACHABLE();
@@ -2599,7 +2624,7 @@ bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
   // Externalizing twice leaks the external resource, so it's
   // prohibited by the API.
   DCHECK(this->SupportsExternalization());
-  DCHECK(!resource->IsCompressible());
+  DCHECK(resource->IsCacheable());
 #ifdef ENABLE_SLOW_DCHECKS
   if (FLAG_enable_slow_asserts) {
     // Assert that the resource and the string are equivalent.
@@ -2612,7 +2637,7 @@ bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
 #endif  // DEBUG
   int size = this->Size();  // Byte size of the original string.
   // Abort if size does not allow in-place conversion.
-  if (size < ExternalString::kShortSize) return false;
+  if (size < ExternalString::kUncachedSize) return false;
   Isolate* isolate;
   // Read-only strings cannot be made external, since that would mutate the
   // string.
@@ -2626,23 +2651,25 @@ bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
   }
   // Morph the string to an external string by replacing the map and
   // reinitializing the fields.  This won't work if the space the existing
-  // string occupies is too small for a regular  external string.
-  // Instead, we resort to a short external string instead, omitting
-  // the field caching the address of the backing store.  When we encounter
-  // short external strings in generated code, we need to bailout to runtime.
+  // string occupies is too small for a regular external string.  Instead, we
+  // resort to an uncached external string instead, omitting the field caching
+  // the address of the backing store.  When we encounter uncached external
+  // strings in generated code, we need to bailout to runtime.
   Map* new_map;
   ReadOnlyRoots roots(heap);
   if (size < ExternalString::kSize) {
     if (is_internalized) {
-      new_map =
-          is_one_byte
-              ? roots
-                    .short_external_internalized_string_with_one_byte_data_map()
-              : roots.short_external_internalized_string_map();
+      if (is_one_byte) {
+        new_map =
+            roots
+                .uncached_external_internalized_string_with_one_byte_data_map();
+      } else {
+        new_map = roots.uncached_external_internalized_string_map();
+      }
     } else {
       new_map = is_one_byte
-                    ? roots.short_external_string_with_one_byte_data_map()
-                    : roots.short_external_string_map();
+                    ? roots.uncached_external_string_with_one_byte_data_map()
+                    : roots.uncached_external_string_map();
     }
   } else {
     new_map =
@@ -2679,7 +2706,7 @@ bool String::MakeExternal(v8::String::ExternalOneByteStringResource* resource) {
   // Externalizing twice leaks the external resource, so it's
   // prohibited by the API.
   DCHECK(this->SupportsExternalization());
-  DCHECK(!resource->IsCompressible());
+  DCHECK(resource->IsCacheable());
 #ifdef ENABLE_SLOW_DCHECKS
   if (FLAG_enable_slow_asserts) {
     // Assert that the resource and the string are equivalent.
@@ -2697,7 +2724,7 @@ bool String::MakeExternal(v8::String::ExternalOneByteStringResource* resource) {
 #endif  // DEBUG
   int size = this->Size();  // Byte size of the original string.
   // Abort if size does not allow in-place conversion.
-  if (size < ExternalString::kShortSize) return false;
+  if (size < ExternalString::kUncachedSize) return false;
   Isolate* isolate;
   // Read-only strings cannot be made external, since that would mutate the
   // string.
@@ -2712,16 +2739,16 @@ bool String::MakeExternal(v8::String::ExternalOneByteStringResource* resource) {
 
   // Morph the string to an external string by replacing the map and
   // reinitializing the fields.  This won't work if the space the existing
-  // string occupies is too small for a regular  external string.
-  // Instead, we resort to a short external string instead, omitting
-  // the field caching the address of the backing store.  When we encounter
-  // short external strings in generated code, we need to bailout to runtime.
+  // string occupies is too small for a regular external string.  Instead, we
+  // resort to an uncached external string instead, omitting the field caching
+  // the address of the backing store.  When we encounter uncached external
+  // strings in generated code, we need to bailout to runtime.
   Map* new_map;
   ReadOnlyRoots roots(heap);
   if (size < ExternalString::kSize) {
     new_map = is_internalized
-                  ? roots.short_external_one_byte_internalized_string_map()
-                  : roots.short_external_one_byte_string_map();
+                  ? roots.uncached_external_one_byte_internalized_string_map()
+                  : roots.uncached_external_one_byte_string_map();
   } else {
     new_map = is_internalized
                   ? roots.external_one_byte_internalized_string_map()
@@ -3069,6 +3096,7 @@ VisitorId Map::GetVisitorId(Map* map) {
     case STRING_TABLE_TYPE:
     case SCOPE_INFO_TYPE:
     case SCRIPT_CONTEXT_TABLE_TYPE:
+    case AWAIT_CONTEXT_TYPE:
     case BLOCK_CONTEXT_TYPE:
     case CATCH_CONTEXT_TYPE:
     case DEBUG_EVALUATE_CONTEXT_TYPE:
@@ -3137,6 +3165,12 @@ VisitorId Map::GetVisitorId(Map* map) {
     case JS_ARRAY_BUFFER_TYPE:
       return kVisitJSArrayBuffer;
 
+    case JS_DATA_VIEW_TYPE:
+      return kVisitJSDataView;
+
+    case JS_TYPED_ARRAY_TYPE:
+      return kVisitJSTypedArray;
+
     case SMALL_ORDERED_HASH_MAP_TYPE:
       return kVisitSmallOrderedHashMap;
 
@@ -3170,11 +3204,10 @@ VisitorId Map::GetVisitorId(Map* map) {
     case JS_DATE_TYPE:
     case JS_ARRAY_ITERATOR_TYPE:
     case JS_ARRAY_TYPE:
+    case JS_FUNCTION_TYPE:
     case JS_GLOBAL_PROXY_TYPE:
     case JS_GLOBAL_OBJECT_TYPE:
     case JS_MESSAGE_OBJECT_TYPE:
-    case JS_TYPED_ARRAY_TYPE:
-    case JS_DATA_VIEW_TYPE:
     case JS_SET_TYPE:
     case JS_MAP_TYPE:
     case JS_SET_KEY_VALUE_ITERATOR_TYPE:
@@ -3187,12 +3220,17 @@ VisitorId Map::GetVisitorId(Map* map) {
     case JS_REGEXP_TYPE:
     case JS_REGEXP_STRING_ITERATOR_TYPE:
 #ifdef V8_INTL_SUPPORT
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
     case JS_INTL_COLLATOR_TYPE:
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
     case JS_INTL_LIST_FORMAT_TYPE:
     case JS_INTL_LOCALE_TYPE:
+    case JS_INTL_NUMBER_FORMAT_TYPE:
     case JS_INTL_PLURAL_RULES_TYPE:
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
+    case JS_INTL_SEGMENTER_TYPE:
 #endif  // V8_INTL_SUPPORT
+    case WASM_EXCEPTION_TYPE:
     case WASM_GLOBAL_TYPE:
     case WASM_MEMORY_TYPE:
     case WASM_MODULE_TYPE:
@@ -3203,9 +3241,6 @@ VisitorId Map::GetVisitorId(Map* map) {
     case JS_SPECIAL_API_OBJECT_TYPE:
       return kVisitJSApiObject;
 
-    case JS_FUNCTION_TYPE:
-      return kVisitJSFunction;
-
     case FILLER_TYPE:
     case FOREIGN_TYPE:
     case HEAP_NUMBER_TYPE:
@@ -3234,7 +3269,7 @@ VisitorId Map::GetVisitorId(Map* map) {
     case ALLOCATION_SITE_TYPE:
       return kVisitAllocationSite;
 
-#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE:
+#define MAKE_STRUCT_CASE(TYPE, Name, name) case TYPE:
       STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
       if (instance_type == PROTOTYPE_INFO_TYPE) {
@@ -3335,7 +3370,7 @@ bool JSObject::IsUnmodifiedApiObject(Object** o) {
   HeapObject* heap_object = HeapObject::cast(object);
   if (!object->IsJSObject()) return false;
   JSObject* js_object = JSObject::cast(object);
-  if (!js_object->IsApiWrapper()) return false;
+  if (!js_object->IsDroppableApiWrapper()) return false;
   Object* maybe_constructor = js_object->map()->GetConstructor();
   if (!maybe_constructor->IsJSFunction()) return false;
   JSFunction* constructor = JSFunction::cast(maybe_constructor);
@@ -3372,6 +3407,15 @@ void HeapObject::HeapObjectShortPrint(std::ostream& os) {  // NOLINT
       }
       os << ">";
     } break;
+    case AWAIT_CONTEXT_TYPE: {
+      os << "<AwaitContext generator= ";
+      HeapStringAllocator allocator;
+      StringStream accumulator(&allocator);
+      Context::cast(this)->extension()->ShortPrint(&accumulator);
+      os << accumulator.ToCString().get();
+      os << '>';
+      break;
+    }
     case BLOCK_CONTEXT_TYPE:
       os << "<BlockContext[" << FixedArray::cast(this)->length() << "]>";
       break;
@@ -3524,8 +3568,8 @@ void HeapObject::HeapObjectShortPrint(std::ostream& os) {  // NOLINT
     case JS_MESSAGE_OBJECT_TYPE:
       os << "<JSMessageObject>";
       break;
-#define MAKE_STRUCT_CASE(NAME, Name, name)   \
-  case NAME##_TYPE:                          \
+#define MAKE_STRUCT_CASE(TYPE, Name, name)   \
+  case TYPE:                                 \
     os << "<" #Name;                         \
     Name::cast(this)->BriefPrintDetails(os); \
     os << ">";                               \
@@ -3923,14 +3967,14 @@ MaybeObjectHandle Map::WrapFieldType(Isolate* isolate, Handle<FieldType> type) {
 
 // static
 FieldType* Map::UnwrapFieldType(MaybeObject* wrapped_type) {
-  if (wrapped_type->IsClearedWeakHeapObject()) {
+  if (wrapped_type->IsCleared()) {
     return FieldType::None();
   }
   HeapObject* heap_object;
-  if (wrapped_type->ToWeakHeapObject(&heap_object)) {
+  if (wrapped_type->GetHeapObjectIfWeak(&heap_object)) {
     return FieldType::cast(heap_object);
   }
-  return FieldType::cast(wrapped_type->ToObject());
+  return wrapped_type->cast<FieldType>();
 }
 
 MaybeHandle<Map> Map::CopyWithField(Isolate* isolate, Handle<Map> map,
@@ -4325,8 +4369,10 @@ void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map) {
         heap->ClearRecordedSlot(*object,
                                 HeapObject::RawField(*object, index.offset()));
       } else {
-        DCHECK(!heap->HasRecordedSlot(
-            *object, HeapObject::RawField(*object, index.offset())));
+#ifdef DEBUG
+        heap->VerifyClearedSlot(*object,
+                                HeapObject::RawField(*object, index.offset()));
+#endif
       }
     } else {
       object->RawFastPropertyAtPut(index, value);
@@ -4691,8 +4737,8 @@ Map* Map::FindFieldOwner(Isolate* isolate, int descriptor) const {
 void Map::UpdateFieldType(Isolate* isolate, int descriptor, Handle<Name> name,
                           PropertyConstness new_constness,
                           Representation new_representation,
-                          MaybeObjectHandle new_wrapped_type) {
-  DCHECK(new_wrapped_type->IsSmi() || new_wrapped_type->IsWeakHeapObject());
+                          const MaybeObjectHandle& new_wrapped_type) {
+  DCHECK(new_wrapped_type->IsSmi() || new_wrapped_type->IsWeak());
   // We store raw pointers in the queue, so no allocations are allowed.
   DisallowHeapAllocation no_allocation;
   PropertyDetails details = instance_descriptors()->GetDetails(descriptor);
@@ -4841,25 +4887,6 @@ Handle<Map> Map::ReconfigureElementsKind(Isolate* isolate, Handle<Map> map,
   return mu.ReconfigureElementsKind(new_elements_kind);
 }
 
-// Generalize all fields and update the transition tree.
-Handle<Map> Map::GeneralizeAllFields(Isolate* isolate, Handle<Map> map) {
-  Handle<FieldType> any_type = FieldType::Any(isolate);
-
-  Handle<DescriptorArray> descriptors(map->instance_descriptors(), isolate);
-  for (int i = 0; i < map->NumberOfOwnDescriptors(); ++i) {
-    PropertyDetails details = descriptors->GetDetails(i);
-    if (details.location() == kField) {
-      DCHECK_EQ(kData, details.kind());
-      MapUpdater mu(isolate, map);
-      map = mu.ReconfigureToDataField(i, details.attributes(),
-                                      PropertyConstness::kMutable,
-                                      Representation::Tagged(), any_type);
-    }
-  }
-  return map;
-}
-
-
 // static
 MaybeHandle<Map> Map::TryUpdate(Isolate* isolate, Handle<Map> old_map) {
   DisallowHeapAllocation no_allocation;
@@ -4988,18 +5015,16 @@ Maybe<bool> JSObject::SetPropertyWithInterceptor(LookupIterator* it,
 MaybeHandle<Object> Object::SetProperty(Isolate* isolate, Handle<Object> object,
                                         Handle<Name> name, Handle<Object> value,
                                         LanguageMode language_mode,
-                                        StoreFromKeyed store_mode) {
+                                        StoreOrigin store_origin) {
   LookupIterator it(isolate, object, name);
-  MAYBE_RETURN_NULL(SetProperty(&it, value, language_mode, store_mode));
+  MAYBE_RETURN_NULL(SetProperty(&it, value, language_mode, store_origin));
   return value;
 }
 
-
 Maybe<bool> Object::SetPropertyInternal(LookupIterator* it,
                                         Handle<Object> value,
                                         LanguageMode language_mode,
-                                        StoreFromKeyed store_mode,
-                                        bool* found) {
+                                        StoreOrigin store_origin, bool* found) {
   it->UpdateProtector();
   DCHECK(it->IsFound());
   ShouldThrow should_throw =
@@ -5104,14 +5129,13 @@ Maybe<bool> Object::SetPropertyInternal(LookupIterator* it,
   return Nothing<bool>();
 }
 
-
 Maybe<bool> Object::SetProperty(LookupIterator* it, Handle<Object> value,
                                 LanguageMode language_mode,
-                                StoreFromKeyed store_mode) {
+                                StoreOrigin store_origin) {
   if (it->IsFound()) {
     bool found = true;
     Maybe<bool> result =
-        SetPropertyInternal(it, value, language_mode, store_mode, &found);
+        SetPropertyInternal(it, value, language_mode, store_origin, &found);
     if (found) return result;
   }
 
@@ -5126,19 +5150,18 @@ Maybe<bool> Object::SetProperty(LookupIterator* it, Handle<Object> value,
 
   ShouldThrow should_throw =
       is_sloppy(language_mode) ? kDontThrow : kThrowOnError;
-  return AddDataProperty(it, value, NONE, should_throw, store_mode);
+  return AddDataProperty(it, value, NONE, should_throw, store_origin);
 }
 
-
 Maybe<bool> Object::SetSuperProperty(LookupIterator* it, Handle<Object> value,
                                      LanguageMode language_mode,
-                                     StoreFromKeyed store_mode) {
+                                     StoreOrigin store_origin) {
   Isolate* isolate = it->isolate();
 
   if (it->IsFound()) {
     bool found = true;
     Maybe<bool> result =
-        SetPropertyInternal(it, value, language_mode, store_mode, &found);
+        SetPropertyInternal(it, value, language_mode, store_origin, &found);
     if (found) return result;
   }
 
@@ -5217,7 +5240,7 @@ Maybe<bool> Object::SetSuperProperty(LookupIterator* it, Handle<Object> value,
     }
   }
 
-  return AddDataProperty(&own_lookup, value, NONE, should_throw, store_mode);
+  return AddDataProperty(&own_lookup, value, NONE, should_throw, store_origin);
 }
 
 Maybe<bool> Object::CannotCreateProperty(Isolate* isolate,
@@ -5314,11 +5337,10 @@ Maybe<bool> Object::SetDataProperty(LookupIterator* it, Handle<Object> value) {
   return Just(true);
 }
 
-
 Maybe<bool> Object::AddDataProperty(LookupIterator* it, Handle<Object> value,
                                     PropertyAttributes attributes,
                                     ShouldThrow should_throw,
-                                    StoreFromKeyed store_mode) {
+                                    StoreOrigin store_origin) {
   if (!it->GetReceiver()->IsJSReceiver()) {
     return CannotCreateProperty(it->isolate(), it->GetReceiver(), it->GetName(),
                                 value, should_throw);
@@ -5380,7 +5402,7 @@ Maybe<bool> Object::AddDataProperty(LookupIterator* it, Handle<Object> value,
     // Migrate to the most up-to-date map that will be able to store |value|
     // under it->name() with |attributes|.
     it->PrepareTransitionToDataProperty(receiver, value, attributes,
-                                        store_mode);
+                                        store_origin);
     DCHECK_EQ(LookupIterator::TRANSITION, it->state());
     it->ApplyTransitionToDataProperty(receiver);
 
@@ -5859,7 +5881,7 @@ Maybe<bool> JSProxy::SetProperty(Handle<JSProxy> proxy, Handle<Name> name,
     LookupIterator it =
         LookupIterator::PropertyOrElement(isolate, receiver, name, target);
     return Object::SetSuperProperty(&it, value, language_mode,
-                                    Object::MAY_BE_STORE_FROM_KEYED);
+                                    StoreOrigin::kMaybeKeyed);
   }
 
   Handle<Object> trap_result;
@@ -6225,7 +6247,7 @@ void JSObject::AddProperty(Isolate* isolate, Handle<JSObject> object,
   DCHECK(object->map()->is_extensible() || name->IsPrivate());
 #endif
   CHECK(AddDataProperty(&it, value, attributes, kThrowOnError,
-                        CERTAINLY_NOT_STORE_FROM_KEYED)
+                        StoreOrigin::kNamed)
             .IsJust());
 }
 
@@ -6328,7 +6350,7 @@ Maybe<bool> JSObject::DefineOwnPropertyIgnoreAttributes(
   }
 
   return AddDataProperty(it, value, attributes, should_throw,
-                         CERTAINLY_NOT_STORE_FROM_KEYED);
+                         StoreOrigin::kNamed);
 }
 
 MaybeHandle<Object> JSObject::SetOwnPropertyIgnoreAttributes(
@@ -6408,7 +6430,7 @@ MaybeHandle<Map> NormalizedMapCache::Get(Handle<Map> fast_map,
   DisallowHeapAllocation no_gc;
   MaybeObject* value = WeakFixedArray::Get(GetIndex(fast_map));
   HeapObject* heap_object;
-  if (!value->ToWeakHeapObject(&heap_object)) {
+  if (!value->GetHeapObjectIfWeak(&heap_object)) {
     return MaybeHandle<Map>();
   }
 
@@ -6698,6 +6720,11 @@ Object* SetHashAndUpdateProperties(Isolate* isolate, HeapObject* properties,
     return properties;
   }
 
+  if (properties->IsGlobalDictionary()) {
+    GlobalDictionary::cast(properties)->SetHash(hash);
+    return properties;
+  }
+
   DCHECK(properties->IsNameDictionary());
   NameDictionary::cast(properties)->SetHash(hash);
   return properties;
@@ -8096,144 +8123,6 @@ Maybe<bool> JSProxy::GetOwnPropertyDescriptor(Isolate* isolate,
 }
 
 
-bool JSObject::ReferencesObjectFromElements(FixedArray* elements,
-                                            ElementsKind kind,
-                                            Object* object) {
-  Isolate* isolate = GetIsolate();
-  if (IsObjectElementsKind(kind) || kind == FAST_STRING_WRAPPER_ELEMENTS) {
-    int length = IsJSArray() ? Smi::ToInt(JSArray::cast(this)->length())
-                             : elements->length();
-    for (int i = 0; i < length; ++i) {
-      Object* element = elements->get(i);
-      if (!element->IsTheHole(isolate) && element == object) return true;
-    }
-  } else {
-    DCHECK(kind == DICTIONARY_ELEMENTS || kind == SLOW_STRING_WRAPPER_ELEMENTS);
-    Object* key = NumberDictionary::cast(elements)->SlowReverseLookup(object);
-    if (!key->IsUndefined(isolate)) return true;
-  }
-  return false;
-}
-
-
-// Check whether this object references another object.
-bool JSObject::ReferencesObject(Object* obj) {
-  Map* map_of_this = map();
-  Heap* heap = GetHeap();
-  DisallowHeapAllocation no_allocation;
-
-  // Is the object the constructor for this object?
-  if (map_of_this->GetConstructor() == obj) {
-    return true;
-  }
-
-  // Is the object the prototype for this object?
-  if (map_of_this->prototype() == obj) {
-    return true;
-  }
-
-  // Check if the object is among the named properties.
-  Object* key = SlowReverseLookup(obj);
-  if (!key->IsUndefined(heap->isolate())) {
-    return true;
-  }
-
-  // Check if the object is among the indexed properties.
-  ElementsKind kind = GetElementsKind();
-  switch (kind) {
-    // Raw pixels and external arrays do not reference other
-    // objects.
-#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) \
-  case TYPE##_ELEMENTS:                           \
-    break;
-
-    TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-
-    case PACKED_DOUBLE_ELEMENTS:
-    case HOLEY_DOUBLE_ELEMENTS:
-      break;
-    case PACKED_SMI_ELEMENTS:
-    case HOLEY_SMI_ELEMENTS:
-      break;
-    case PACKED_ELEMENTS:
-    case HOLEY_ELEMENTS:
-    case DICTIONARY_ELEMENTS:
-    case FAST_STRING_WRAPPER_ELEMENTS:
-    case SLOW_STRING_WRAPPER_ELEMENTS: {
-      FixedArray* elements = FixedArray::cast(this->elements());
-      if (ReferencesObjectFromElements(elements, kind, obj)) return true;
-      break;
-    }
-    case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
-    case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: {
-      SloppyArgumentsElements* elements =
-          SloppyArgumentsElements::cast(this->elements());
-      // Check the mapped parameters.
-      for (uint32_t i = 0; i < elements->parameter_map_length(); ++i) {
-        Object* value = elements->get_mapped_entry(i);
-        if (!value->IsTheHole(heap->isolate()) && value == obj) return true;
-      }
-      // Check the arguments.
-      FixedArray* arguments = elements->arguments();
-      kind = arguments->IsNumberDictionary() ? DICTIONARY_ELEMENTS
-                                             : HOLEY_ELEMENTS;
-      if (ReferencesObjectFromElements(arguments, kind, obj)) return true;
-      break;
-    }
-    case NO_ELEMENTS:
-      break;
-  }
-
-  // For functions check the context.
-  if (IsJSFunction()) {
-    // Get the constructor function for arguments array.
-    Map* arguments_map =
-        heap->isolate()->context()->native_context()->sloppy_arguments_map();
-    JSFunction* arguments_function =
-        JSFunction::cast(arguments_map->GetConstructor());
-
-    // Get the context and don't check if it is the native context.
-    JSFunction* f = JSFunction::cast(this);
-    Context* context = f->context();
-    if (context->IsNativeContext()) {
-      return false;
-    }
-
-    // Check the non-special context slots.
-    for (int i = Context::MIN_CONTEXT_SLOTS; i < context->length(); i++) {
-      // Only check JS objects.
-      if (context->get(i)->IsJSObject()) {
-        JSObject* ctxobj = JSObject::cast(context->get(i));
-        // If it is an arguments array check the content.
-        if (ctxobj->map()->GetConstructor() == arguments_function) {
-          if (ctxobj->ReferencesObject(obj)) {
-            return true;
-          }
-        } else if (ctxobj == obj) {
-          return true;
-        }
-      }
-    }
-
-    // Check the context extension (if any) if it can have references.
-    if (context->has_extension() && !context->IsCatchContext() &&
-        !context->IsModuleContext()) {
-      // With harmony scoping, a JSFunction may have a script context.
-      // TODO(mvstanton): walk into the ScopeInfo.
-      if (context->IsScriptContext()) {
-        return false;
-      }
-
-      return context->extension_object()->ReferencesObject(obj);
-    }
-  }
-
-  // No references to object.
-  return false;
-}
-
-
 Maybe<bool> JSReceiver::SetIntegrityLevel(Handle<JSReceiver> receiver,
                                           IntegrityLevel level,
                                           ShouldThrow should_throw) {
@@ -8758,7 +8647,7 @@ Maybe<bool> JSObject::PreventExtensionsWithTransition(
   // typed array elements. Freeze works only if there are no actual elements.
   if (object->HasFixedTypedArrayElements()) {
     if (attrs == FROZEN &&
-        JSArrayBufferView::cast(*object)->byte_length()->Number() > 0) {
+        JSArrayBufferView::cast(*object)->byte_length() > 0) {
       isolate->Throw(*isolate->factory()->NewTypeError(
           MessageTemplate::kCannotFreezeArrayBufferView));
       return Nothing<bool>();
@@ -9937,7 +9826,7 @@ Handle<Map> Map::TransitionToDataProperty(Isolate* isolate, Handle<Map> map,
                                           Handle<Object> value,
                                           PropertyAttributes attributes,
                                           PropertyConstness constness,
-                                          StoreFromKeyed store_mode) {
+                                          StoreOrigin store_origin) {
   RuntimeCallTimerScope stats_scope(
       isolate, *map,
       map->is_prototype_map()
@@ -9966,7 +9855,7 @@ Handle<Map> Map::TransitionToDataProperty(Isolate* isolate, Handle<Map> map,
 
   TransitionFlag flag = INSERT_TRANSITION;
   MaybeHandle<Map> maybe_map;
-  if (!map->TooManyFastProperties(store_mode)) {
+  if (!map->TooManyFastProperties(store_origin)) {
     if (!FLAG_track_constant_fields && value->IsJSFunction()) {
       maybe_map =
           Map::CopyWithConstant(isolate, map, name, value, attributes, flag);
@@ -10142,7 +10031,7 @@ Handle<Map> Map::TransitionToAccessorProperty(Isolate* isolate, Handle<Map> map,
 
     pair = AccessorPair::Copy(isolate, Handle<AccessorPair>::cast(maybe_pair));
   } else if (map->NumberOfOwnDescriptors() >= kMaxNumberOfDescriptors ||
-             map->TooManyFastProperties(CERTAINLY_NOT_STORE_FROM_KEYED)) {
+             map->TooManyFastProperties(StoreOrigin::kNamed)) {
     return Map::Normalize(isolate, map, CLEAR_INOBJECT_PROPERTIES,
                           "TooManyAccessors");
   } else {
@@ -10229,7 +10118,7 @@ Handle<DescriptorArray> DescriptorArray::CopyUpToAddAttributes(
         // READ_ONLY is an invalid attribute for JS setters/getters.
         HeapObject* heap_object;
         if (details.kind() != kAccessor ||
-            !(value_or_field_type->ToStrongHeapObject(&heap_object) &&
+            !(value_or_field_type->GetHeapObjectIfStrong(&heap_object) &&
               heap_object->IsAccessorPair())) {
           mask |= READ_ONLY;
         }
@@ -10463,11 +10352,6 @@ Handle<FixedArray> ArrayList::Elements(Isolate* isolate,
   return result;
 }
 
-bool ArrayList::IsFull() {
-  int capacity = length();
-  return kFirstIndex + Length() == capacity;
-}
-
 namespace {
 
 Handle<FixedArray> EnsureSpaceInFixedArray(Isolate* isolate,
@@ -10501,7 +10385,7 @@ Handle<ArrayList> ArrayList::EnsureSpace(Isolate* isolate,
 // static
 Handle<WeakArrayList> WeakArrayList::AddToEnd(Isolate* isolate,
                                               Handle<WeakArrayList> array,
-                                              MaybeObjectHandle value) {
+                                              const MaybeObjectHandle& value) {
   int length = array->length();
   array = EnsureSpace(isolate, array, length + 1);
   // Reload length; GC might have removed elements from the array.
@@ -10532,14 +10416,14 @@ Handle<WeakArrayList> WeakArrayList::EnsureSpace(Isolate* isolate,
 int WeakArrayList::CountLiveWeakReferences() const {
   int live_weak_references = 0;
   for (int i = 0; i < length(); i++) {
-    if (Get(i)->IsWeakHeapObject()) {
+    if (Get(i)->IsWeak()) {
       ++live_weak_references;
     }
   }
   return live_weak_references;
 }
 
-bool WeakArrayList::RemoveOne(MaybeObjectHandle value) {
+bool WeakArrayList::RemoveOne(const MaybeObjectHandle& value) {
   if (length() == 0) return false;
   // Optimize for the most recently added element to be removed again.
   int last_index = length() - 1;
@@ -10585,7 +10469,7 @@ Handle<WeakArrayList> PrototypeUsers::Add(Isolate* isolate,
   if (empty_slot != kNoEmptySlotsMarker) {
     DCHECK_GE(empty_slot, kFirstIndex);
     CHECK_LT(empty_slot, array->length());
-    int next_empty_slot = Smi::ToInt(array->Get(empty_slot)->ToSmi());
+    int next_empty_slot = Smi::ToInt(array->Get(empty_slot)->cast<Smi>());
 
     array->Set(empty_slot, HeapObjectReference::Weak(*value));
     if (assigned_index != nullptr) *assigned_index = empty_slot;
@@ -10624,11 +10508,13 @@ WeakArrayList* PrototypeUsers::Compact(Handle<WeakArrayList> array, Heap* heap,
   int copy_to = kFirstIndex;
   for (int i = kFirstIndex; i < array->length(); i++) {
     MaybeObject* element = array->Get(i);
-    if (element->IsSmi()) continue;
-    if (element->IsClearedWeakHeapObject()) continue;
-    HeapObject* value = element->ToWeakHeapObject();
-    callback(value, i, copy_to);
-    new_array->Set(copy_to++, element);
+    HeapObject* value;
+    if (element->GetHeapObjectIfWeak(&value)) {
+      callback(value, i, copy_to);
+      new_array->Set(copy_to++, element);
+    } else {
+      DCHECK(element->IsCleared() || element->IsSmi());
+    }
   }
   new_array->set_length(copy_to);
   set_empty_slot_index(*new_array, kNoEmptySlotsMarker);
@@ -10707,7 +10593,7 @@ Handle<DescriptorArray> DescriptorArray::Allocate(Isolate* isolate,
   // Allocate the array of keys.
   Handle<WeakFixedArray> result =
       factory->NewWeakFixedArrayWithMap<DescriptorArray>(
-          Heap::kDescriptorArrayMapRootIndex, LengthFor(size), pretenure);
+          RootIndex::kDescriptorArrayMap, LengthFor(size), pretenure);
   result->Set(kDescriptorLengthIndex,
               MaybeObject::FromObject(Smi::FromInt(number_of_descriptors)));
   result->Set(kEnumCacheIndex, MaybeObject::FromObject(
@@ -11104,32 +10990,6 @@ std::unique_ptr<char[]> String::ToCString(AllowNullsFlag allow_nulls,
 }
 
 
-const uc16* String::GetTwoByteData(unsigned start) {
-  DCHECK(!IsOneByteRepresentationUnderneath());
-  switch (StringShape(this).representation_tag()) {
-    case kSeqStringTag:
-      return SeqTwoByteString::cast(this)->SeqTwoByteStringGetData(start);
-    case kExternalStringTag:
-      return ExternalTwoByteString::cast(this)->
-        ExternalTwoByteStringGetData(start);
-    case kSlicedStringTag: {
-      SlicedString* slice = SlicedString::cast(this);
-      return slice->parent()->GetTwoByteData(start + slice->offset());
-    }
-    case kConsStringTag:
-    case kThinStringTag:
-      UNREACHABLE();
-  }
-  UNREACHABLE();
-}
-
-
-const uc16* SeqTwoByteString::SeqTwoByteStringGetData(unsigned start) {
-  return reinterpret_cast<uc16*>(
-      reinterpret_cast<char*>(this) - kHeapObjectTag + kHeaderSize) + start;
-}
-
-
 void Relocatable::PostGarbageCollectionProcessing(Isolate* isolate) {
   Relocatable* current = isolate->relocatable_top();
   while (current != nullptr) {
@@ -11185,15 +11045,13 @@ FlatStringReader::FlatStringReader(Isolate* isolate, Handle<String> str)
   PostGarbageCollection();
 }
 
-
 FlatStringReader::FlatStringReader(Isolate* isolate, Vector<const char> input)
     : Relocatable(isolate),
-      str_(0),
+      str_(nullptr),
       is_one_byte_(true),
       length_(input.length()),
       start_(input.start()) {}
 
-
 void FlatStringReader::PostGarbageCollection() {
   if (str_ == nullptr) return;
   Handle<String> str(str_);
@@ -11638,7 +11496,7 @@ class StringComparator {
   };
 
  public:
-  inline StringComparator() {}
+  inline StringComparator() = default;
 
   template<typename Chars1, typename Chars2>
   static inline bool Equals(State* state_1, State* state_2, int to_check) {
@@ -12838,7 +12696,7 @@ void InvalidatePrototypeChainsInternal(Map* map) {
   for (int i = PrototypeUsers::kFirstIndex; i < prototype_users->length();
        ++i) {
     HeapObject* heap_object;
-    if (prototype_users->Get(i)->ToWeakHeapObject(&heap_object) &&
+    if (prototype_users->Get(i)->GetHeapObjectIfWeak(&heap_object) &&
         heap_object->IsMap()) {
       // Walk the prototype chain (backwards, towards leaf objects) if
       // necessary.
@@ -13135,9 +12993,14 @@ bool CanSubclassHaveInobjectProperties(InstanceType instance_type) {
     case JS_GENERATOR_OBJECT_TYPE:
 #ifdef V8_INTL_SUPPORT
     case JS_INTL_COLLATOR_TYPE:
+    case JS_INTL_DATE_TIME_FORMAT_TYPE:
     case JS_INTL_LIST_FORMAT_TYPE:
+    case JS_INTL_LOCALE_TYPE:
+    case JS_INTL_NUMBER_FORMAT_TYPE:
     case JS_INTL_PLURAL_RULES_TYPE:
     case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
+    case JS_INTL_SEGMENTER_TYPE:
+    case JS_INTL_V8_BREAK_ITERATOR_TYPE:
 #endif
     case JS_ASYNC_GENERATOR_OBJECT_TYPE:
     case JS_MAP_TYPE:
@@ -13198,7 +13061,7 @@ bool CanSubclassHaveInobjectProperties(InstanceType instance_type) {
   case FIXED_##TYPE##_ARRAY_TYPE:
 #undef TYPED_ARRAY_CASE
 
-#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE:
+#define MAKE_STRUCT_CASE(TYPE, Name, name) case TYPE:
       STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
       // We must not end up here for these instance types at all.
@@ -13268,6 +13131,8 @@ namespace {
 bool FastInitializeDerivedMap(Isolate* isolate, Handle<JSFunction> new_target,
                               Handle<JSFunction> constructor,
                               Handle<Map> constructor_initial_map) {
+  // Use the default intrinsic prototype instead.
+  if (!new_target->has_prototype_slot()) return false;
   // Check that |function|'s initial map still in sync with the |constructor|,
   // otherwise we must create a new initial map for |function|.
   if (new_target->has_initial_map() &&
@@ -13342,9 +13207,14 @@ MaybeHandle<Map> JSFunction::GetDerivedMap(Isolate* isolate,
   Handle<Object> prototype;
   if (new_target->IsJSFunction()) {
     Handle<JSFunction> function = Handle<JSFunction>::cast(new_target);
-    // Make sure the new.target.prototype is cached.
-    EnsureHasInitialMap(function);
-    prototype = handle(function->prototype(), isolate);
+    if (function->has_prototype_slot()) {
+      // Make sure the new.target.prototype is cached.
+      EnsureHasInitialMap(function);
+      prototype = handle(function->prototype(), isolate);
+    } else {
+      // No prototype property, use the intrinsict default proto further down.
+      prototype = isolate->factory()->undefined_value();
+    }
   } else {
     Handle<String> prototype_string = isolate->factory()->prototype_string();
     ASSIGN_RETURN_ON_EXCEPTION(
@@ -13384,8 +13254,8 @@ MaybeHandle<Map> JSFunction::GetDerivedMap(Isolate* isolate,
 }
 
 int JSFunction::ComputeInstanceSizeWithMinSlack(Isolate* isolate) {
-  if (has_prototype_slot() && has_initial_map() &&
-      initial_map()->IsInobjectSlackTrackingInProgress()) {
+  CHECK(has_initial_map());
+  if (initial_map()->IsInobjectSlackTrackingInProgress()) {
     int slack = initial_map()->ComputeMinObjectSlack(isolate);
     return initial_map()->InstanceSizeFromSlack(slack);
   }
@@ -13488,64 +13358,16 @@ Handle<String> JSFunction::ToString(Handle<JSFunction> function) {
     return NativeCodeFunctionSourceString(shared_info);
   }
 
-  if (FLAG_harmony_function_tostring) {
-    if (shared_info->function_token_position() == kNoSourcePosition) {
-      // If the function token position isn't valid, return [native code] to
-      // ensure calling eval on the returned source code throws rather than
-      // giving inconsistent call behaviour.
-      isolate->CountUsage(v8::Isolate::UseCounterFeature::
-                              kFunctionTokenOffsetTooLongForToString);
-      return NativeCodeFunctionSourceString(shared_info);
-    }
-    return Handle<String>::cast(
-        SharedFunctionInfo::GetSourceCodeHarmony(shared_info));
-  }
-
-  IncrementalStringBuilder builder(isolate);
-  FunctionKind kind = shared_info->kind();
-  if (!IsArrowFunction(kind)) {
-    if (IsConciseMethod(kind)) {
-      if (IsAsyncGeneratorFunction(kind)) {
-        builder.AppendCString("async *");
-      } else if (IsGeneratorFunction(kind)) {
-        builder.AppendCharacter('*');
-      } else if (IsAsyncFunction(kind)) {
-        builder.AppendCString("async ");
-      }
-    } else {
-      if (IsAsyncGeneratorFunction(kind)) {
-        builder.AppendCString("async function* ");
-      } else if (IsGeneratorFunction(kind)) {
-        builder.AppendCString("function* ");
-      } else if (IsAsyncFunction(kind)) {
-        builder.AppendCString("async function ");
-      } else {
-        builder.AppendCString("function ");
-      }
-    }
-    if (shared_info->name_should_print_as_anonymous()) {
-      builder.AppendCString("anonymous");
-    } else if (!shared_info->is_anonymous_expression()) {
-      builder.AppendString(handle(shared_info->Name(), isolate));
-    }
-  }
-  if (shared_info->is_wrapped()) {
-    builder.AppendCharacter('(');
-    Handle<FixedArray> args(
-        Script::cast(shared_info->script())->wrapped_arguments(), isolate);
-    int argc = args->length();
-    for (int i = 0; i < argc; i++) {
-      if (i > 0) builder.AppendCString(", ");
-      builder.AppendString(Handle<String>(String::cast(args->get(i)), isolate));
-    }
-    builder.AppendCString(") {\n");
-  }
-  builder.AppendString(
-      Handle<String>::cast(SharedFunctionInfo::GetSourceCode(shared_info)));
-  if (shared_info->is_wrapped()) {
-    builder.AppendCString("\n}");
+  if (shared_info->function_token_position() == kNoSourcePosition) {
+    // If the function token position isn't valid, return [native code] to
+    // ensure calling eval on the returned source code throws rather than
+    // giving inconsistent call behaviour.
+    isolate->CountUsage(
+        v8::Isolate::UseCounterFeature::kFunctionTokenOffsetTooLongForToString);
+    return NativeCodeFunctionSourceString(shared_info);
   }
-  return builder.Finish().ToHandleChecked();
+  return Handle<String>::cast(
+      SharedFunctionInfo::GetSourceCodeHarmony(shared_info));
 }
 
 void Oddball::Initialize(Isolate* isolate, Handle<Oddball> oddball,
@@ -13590,7 +13412,8 @@ int Script::GetEvalPosition() {
 void Script::InitLineEnds(Handle<Script> script) {
   Isolate* isolate = script->GetIsolate();
   if (!script->line_ends()->IsUndefined(isolate)) return;
-  DCHECK_NE(Script::TYPE_WASM, script->type());
+  DCHECK(script->type() != Script::TYPE_WASM ||
+         script->source_mapping_url()->IsString());
 
   Object* src_obj = script->source();
   if (!src_obj->IsString()) {
@@ -13775,7 +13598,7 @@ MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
   MaybeObject* shared =
       shared_function_infos()->Get(fun->function_literal_id());
   HeapObject* heap_object;
-  if (!shared->ToStrongOrWeakHeapObject(&heap_object) ||
+  if (!shared->GetHeapObject(&heap_object) ||
       heap_object->IsUndefined(isolate)) {
     return MaybeHandle<SharedFunctionInfo>();
   }
@@ -13855,7 +13678,7 @@ SharedFunctionInfo* SharedFunctionInfo::ScriptIterator::Next() {
   while (index_ < shared_function_infos_->length()) {
     MaybeObject* raw = shared_function_infos_->Get(index_++);
     HeapObject* heap_object;
-    if (!raw->ToStrongOrWeakHeapObject(&heap_object) ||
+    if (!raw->GetHeapObject(&heap_object) ||
         heap_object->IsUndefined(isolate_)) {
       continue;
     }
@@ -13911,7 +13734,7 @@ void SharedFunctionInfo::SetScript(Handle<SharedFunctionInfo> shared,
     DCHECK_LT(function_literal_id, list->length());
     MaybeObject* maybe_object = list->Get(function_literal_id);
     HeapObject* heap_object;
-    if (maybe_object->ToWeakHeapObject(&heap_object)) {
+    if (maybe_object->GetHeapObjectIfWeak(&heap_object)) {
       DCHECK_EQ(heap_object, *shared);
     }
 #endif
@@ -13951,7 +13774,7 @@ void SharedFunctionInfo::SetScript(Handle<SharedFunctionInfo> shared,
       MaybeObject* raw =
           old_script->shared_function_infos()->Get(function_literal_id);
       HeapObject* heap_object;
-      if (raw->ToWeakHeapObject(&heap_object) && heap_object == *shared) {
+      if (raw->GetHeapObjectIfWeak(&heap_object) && heap_object == *shared) {
         old_script->shared_function_infos()->Set(
             function_literal_id, HeapObjectReference::Strong(
                                      ReadOnlyRoots(isolate).undefined_value()));
@@ -14323,6 +14146,75 @@ void SharedFunctionInfo::SetFunctionTokenPosition(int function_token_position,
   set_raw_function_token_offset(offset);
 }
 
+int SharedFunctionInfo::StartPosition() const {
+  Object* maybe_scope_info = name_or_scope_info();
+  if (maybe_scope_info->IsScopeInfo()) {
+    ScopeInfo* info = ScopeInfo::cast(maybe_scope_info);
+    if (info->HasPositionInfo()) {
+      return info->StartPosition();
+    }
+  } else if (HasUncompiledData()) {
+    // Works with or without scope.
+    return uncompiled_data()->start_position();
+  } else if (IsApiFunction() || HasBuiltinId()) {
+    DCHECK_IMPLIES(HasBuiltinId(), builtin_id() != Builtins::kCompileLazy);
+    return 0;
+  }
+  return kNoSourcePosition;
+}
+
+int SharedFunctionInfo::EndPosition() const {
+  Object* maybe_scope_info = name_or_scope_info();
+  if (maybe_scope_info->IsScopeInfo()) {
+    ScopeInfo* info = ScopeInfo::cast(maybe_scope_info);
+    if (info->HasPositionInfo()) {
+      return info->EndPosition();
+    }
+  } else if (HasUncompiledData()) {
+    // Works with or without scope.
+    return uncompiled_data()->end_position();
+  } else if (IsApiFunction() || HasBuiltinId()) {
+    DCHECK_IMPLIES(HasBuiltinId(), builtin_id() != Builtins::kCompileLazy);
+    return 0;
+  }
+  return kNoSourcePosition;
+}
+
+int SharedFunctionInfo::FunctionLiteralId(Isolate* isolate) const {
+  // Fast path for the common case when the SFI is uncompiled and so the
+  // function literal id is already in the uncompiled data.
+  if (HasUncompiledData()) {
+    int id = uncompiled_data()->function_literal_id();
+    // Make sure the id is what we should have found with the slow path.
+    DCHECK_EQ(id, FindIndexInScript(isolate));
+    return id;
+  }
+
+  // Otherwise, search for the function in the SFI's script's function list,
+  // and return its index in that list.e
+  return FindIndexInScript(isolate);
+}
+
+void SharedFunctionInfo::SetPosition(int start_position, int end_position) {
+  Object* maybe_scope_info = name_or_scope_info();
+  if (maybe_scope_info->IsScopeInfo()) {
+    ScopeInfo* info = ScopeInfo::cast(maybe_scope_info);
+    if (info->HasPositionInfo()) {
+      info->SetPositionInfo(start_position, end_position);
+    }
+  } else if (HasUncompiledData()) {
+    if (HasUncompiledDataWithPreParsedScope()) {
+      // Clear out preparsed scope data, since the position setter invalidates
+      // any scope data.
+      ClearPreParsedScopeData();
+    }
+    uncompiled_data()->set_start_position(start_position);
+    uncompiled_data()->set_end_position(end_position);
+  } else {
+    UNREACHABLE();
+  }
+}
+
 void Map::StartInobjectSlackTracking() {
   DCHECK(!IsInobjectSlackTrackingInProgress());
   if (UnusedPropertyFields() == 0) return;
@@ -14374,11 +14266,6 @@ void Code::FlushICache() const {
   Assembler::FlushICache(raw_instruction_start(), raw_instruction_size());
 }
 
-void Code::CopyFrom(Heap* heap, const CodeDesc& desc) {
-  CopyFromNoFlush(heap, desc);
-  FlushICache();
-}
-
 void Code::CopyFromNoFlush(Heap* heap, const CodeDesc& desc) {
   // Copy code.
   CopyBytes(reinterpret_cast<byte*>(raw_instruction_start()), desc.buffer,
@@ -14589,7 +14476,7 @@ const char* Code::Kind2String(Kind kind) {
 // Identify kind of code.
 const char* AbstractCode::Kind2String(Kind kind) {
   if (kind < AbstractCode::INTERPRETED_FUNCTION)
-    return Code::Kind2String((Code::Kind)kind);
+    return Code::Kind2String(static_cast<Code::Kind>(kind));
   if (kind == AbstractCode::INTERPRETED_FUNCTION) return "INTERPRETED_FUNCTION";
   UNREACHABLE();
 }
@@ -14809,14 +14696,22 @@ void DeoptimizationData::DeoptimizationDataPrint(std::ostream& os) {  // NOLINT
 
         case Translation::INT32_REGISTER: {
           int reg_code = iterator.Next();
-          os << "{input=" << converter.NameOfCPURegister(reg_code) << "}";
+          os << "{input=" << converter.NameOfCPURegister(reg_code)
+             << " (int32)}";
+          break;
+        }
+
+        case Translation::INT64_REGISTER: {
+          int reg_code = iterator.Next();
+          os << "{input=" << converter.NameOfCPURegister(reg_code)
+             << " (int64)}";
           break;
         }
 
         case Translation::UINT32_REGISTER: {
           int reg_code = iterator.Next();
           os << "{input=" << converter.NameOfCPURegister(reg_code)
-             << " (unsigned)}";
+             << " (uint32)}";
           break;
         }
 
@@ -14852,13 +14747,19 @@ void DeoptimizationData::DeoptimizationDataPrint(std::ostream& os) {  // NOLINT
 
         case Translation::INT32_STACK_SLOT: {
           int input_slot_index = iterator.Next();
-          os << "{input=" << input_slot_index << "}";
+          os << "{input=" << input_slot_index << " (int32)}";
+          break;
+        }
+
+        case Translation::INT64_STACK_SLOT: {
+          int input_slot_index = iterator.Next();
+          os << "{input=" << input_slot_index << " (int64)}";
           break;
         }
 
         case Translation::UINT32_STACK_SLOT: {
           int input_slot_index = iterator.Next();
-          os << "{input=" << input_slot_index << " (unsigned)}";
+          os << "{input=" << input_slot_index << " (uint32)}";
           break;
         }
 
@@ -15223,7 +15124,8 @@ void DependentCode::SetDependentCode(Handle<HeapObject> object,
   }
 }
 
-void DependentCode::InstallDependency(Isolate* isolate, MaybeObjectHandle code,
+void DependentCode::InstallDependency(Isolate* isolate,
+                                      const MaybeObjectHandle& code,
                                       Handle<HeapObject> object,
                                       DependencyGroup group) {
   Handle<DependentCode> old_deps(DependentCode::GetDependentCode(object),
@@ -15237,7 +15139,7 @@ void DependentCode::InstallDependency(Isolate* isolate, MaybeObjectHandle code,
 
 Handle<DependentCode> DependentCode::InsertWeakCode(
     Isolate* isolate, Handle<DependentCode> entries, DependencyGroup group,
-    MaybeObjectHandle code) {
+    const MaybeObjectHandle& code) {
   if (entries->length() == 0 || entries->group() > group) {
     // There is no such group.
     return DependentCode::New(isolate, group, code, entries);
@@ -15270,7 +15172,7 @@ Handle<DependentCode> DependentCode::InsertWeakCode(
 
 Handle<DependentCode> DependentCode::New(Isolate* isolate,
                                          DependencyGroup group,
-                                         MaybeObjectHandle object,
+                                         const MaybeObjectHandle& object,
                                          Handle<DependentCode> next) {
   Handle<DependentCode> result = Handle<DependentCode>::cast(
       isolate->factory()->NewWeakFixedArray(kCodesStartIndex + 1, TENURED));
@@ -15295,7 +15197,7 @@ bool DependentCode::Compact() {
   int new_count = 0;
   for (int i = 0; i < old_count; i++) {
     MaybeObject* obj = object_at(i);
-    if (!obj->IsClearedWeakHeapObject()) {
+    if (!obj->IsCleared()) {
       if (i != new_count) {
         copy(i, new_count);
       }
@@ -15309,38 +15211,6 @@ bool DependentCode::Compact() {
   return new_count < old_count;
 }
 
-bool DependentCode::Contains(DependencyGroup group, MaybeObject* code) {
-  if (this->length() == 0 || this->group() > group) {
-    // There is no such group.
-    return false;
-  }
-  if (this->group() < group) {
-    // The group comes later in the list.
-    return next_link()->Contains(group, code);
-  }
-  DCHECK_EQ(group, this->group());
-  int count = this->count();
-  for (int i = 0; i < count; i++) {
-    if (object_at(i) == code) return true;
-  }
-  return false;
-}
-
-
-bool DependentCode::IsEmpty(DependencyGroup group) {
-  if (this->length() == 0 || this->group() > group) {
-    // There is no such group.
-    return true;
-  }
-  if (this->group() < group) {
-    // The group comes later in the list.
-    return next_link()->IsEmpty(group);
-  }
-  DCHECK_EQ(group, this->group());
-  return count() == 0;
-}
-
-
 bool DependentCode::MarkCodeForDeoptimization(
     Isolate* isolate,
     DependentCode::DependencyGroup group) {
@@ -15359,8 +15229,8 @@ bool DependentCode::MarkCodeForDeoptimization(
   int count = this->count();
   for (int i = 0; i < count; i++) {
     MaybeObject* obj = object_at(i);
-    if (obj->IsClearedWeakHeapObject()) continue;
-    Code* code = Code::cast(obj->ToWeakHeapObject());
+    if (obj->IsCleared()) continue;
+    Code* code = Code::cast(obj->GetHeapObjectAssumeWeak());
     if (!code->marked_for_deoptimization()) {
       code->SetMarkedForDeoptimization(DependencyGroupName(group));
       marked = true;
@@ -15974,19 +15844,6 @@ void JSObject::TransitionElementsKind(Handle<JSObject> object,
 }
 
 
-// static
-bool Map::IsValidElementsTransition(ElementsKind from_kind,
-                                    ElementsKind to_kind) {
-  // Transitions can't go backwards.
-  if (!IsMoreGeneralElementsKindTransition(from_kind, to_kind)) {
-    return false;
-  }
-
-  // Transitions from HOLEY -> PACKED are not allowed.
-  return !IsHoleyElementsKind(from_kind) || IsHoleyElementsKind(to_kind);
-}
-
-
 bool JSArray::HasReadOnlyLength(Handle<JSArray> array) {
   Map* map = array->map();
   // Fast path: "length" is the first fast property of arrays. Since it's not
@@ -16134,6 +15991,18 @@ bool FixedArrayBase::IsCowArray() const {
 }
 
 bool JSObject::IsApiWrapper() {
+  // These object types can carry information relevant for embedders. The
+  // *_API_* types are generated through templates which can have embedder
+  // fields. The other types have their embedder fields added at compile time.
+  auto instance_type = map()->instance_type();
+  return instance_type == JS_API_OBJECT_TYPE ||
+         instance_type == JS_ARRAY_BUFFER_TYPE ||
+         instance_type == JS_DATA_VIEW_TYPE ||
+         instance_type == JS_SPECIAL_API_OBJECT_TYPE ||
+         instance_type == JS_TYPED_ARRAY_TYPE;
+}
+
+bool JSObject::IsDroppableApiWrapper() {
   auto instance_type = map()->instance_type();
   return instance_type == JS_API_OBJECT_TYPE ||
          instance_type == JS_SPECIAL_API_OBJECT_TYPE;
@@ -16141,9 +16010,9 @@ bool JSObject::IsApiWrapper() {
 
 const char* Symbol::PrivateSymbolToName() const {
   ReadOnlyRoots roots = GetReadOnlyRoots();
-#define SYMBOL_CHECK_AND_PRINT(name) \
+#define SYMBOL_CHECK_AND_PRINT(_, name) \
   if (this == roots.name()) return #name;
-  PRIVATE_SYMBOL_LIST(SYMBOL_CHECK_AND_PRINT)
+  PRIVATE_SYMBOL_LIST_GENERATOR(SYMBOL_CHECK_AND_PRINT, /* not used */)
 #undef SYMBOL_CHECK_AND_PRINT
   return "UNKNOWN";
 }
@@ -16754,8 +16623,7 @@ Handle<Derived> HashTable<Derived, Shape>::NewInternal(
     Isolate* isolate, int capacity, PretenureFlag pretenure) {
   Factory* factory = isolate->factory();
   int length = EntryToIndex(capacity);
-  Heap::RootListIndex map_root_index =
-      static_cast<Heap::RootListIndex>(Shape::GetMapRootIndex());
+  RootIndex map_root_index = Shape::GetMapRootIndex();
   Handle<FixedArray> array =
       factory->NewFixedArrayWithMap(map_root_index, length, pretenure);
   Handle<Derived> table = Handle<Derived>::cast(array);
@@ -17264,7 +17132,7 @@ class StringTableNoAllocateKey : public StringTableKey {
     set_hash_field(string->hash_field());
   }
 
-  ~StringTableNoAllocateKey() {
+  ~StringTableNoAllocateKey() override {
     if (one_byte_) {
       if (one_byte_content_ != one_byte_buffer_) delete[] one_byte_content_;
     } else {
@@ -17436,18 +17304,6 @@ Handle<ObjectHashSet> ObjectHashSet::Add(Isolate* isolate,
   return set;
 }
 
-Handle<Object> CompilationCacheTable::Lookup(Handle<String> src,
-                                             Handle<SharedFunctionInfo> shared,
-                                             LanguageMode language_mode) {
-  Isolate* isolate = GetIsolate();
-  StringSharedKey key(src, shared, language_mode, kNoSourcePosition);
-  int entry = FindEntry(isolate, &key);
-  if (entry == kNotFound) return isolate->factory()->undefined_value();
-  int index = EntryToIndex(entry);
-  if (!get(index)->IsFixedArray()) return isolate->factory()->undefined_value();
-  return Handle<Object>(get(index + 1), isolate);
-}
-
 namespace {
 
 const int kLiteralEntryLength = 2;
@@ -17468,8 +17324,7 @@ int SearchLiteralsMapEntry(CompilationCacheTable* cache, int cache_entry,
     WeakFixedArray* literals_map = WeakFixedArray::cast(obj);
     int length = literals_map->length();
     for (int i = 0; i < length; i += kLiteralEntryLength) {
-      DCHECK(literals_map->Get(i + kLiteralContextOffset)
-                 ->IsWeakOrClearedHeapObject());
+      DCHECK(literals_map->Get(i + kLiteralContextOffset)->IsWeakOrCleared());
       if (literals_map->Get(i + kLiteralContextOffset) ==
           HeapObjectReference::Weak(native_context)) {
         return i;
@@ -17511,8 +17366,7 @@ void AddToFeedbackCellsMap(Handle<CompilationCacheTable> cache, int cache_entry,
     DCHECK_LT(entry, 0);
     int length = old_literals_map->length();
     for (int i = 0; i < length; i += kLiteralEntryLength) {
-      if (old_literals_map->Get(i + kLiteralContextOffset)
-              ->IsClearedWeakHeapObject()) {
+      if (old_literals_map->Get(i + kLiteralContextOffset)->IsCleared()) {
         new_literals_map = old_literals_map;
         entry = i;
         break;
@@ -17535,11 +17389,11 @@ void AddToFeedbackCellsMap(Handle<CompilationCacheTable> cache, int cache_entry,
 #ifdef DEBUG
   for (int i = 0; i < new_literals_map->length(); i += kLiteralEntryLength) {
     MaybeObject* object = new_literals_map->Get(i + kLiteralContextOffset);
-    DCHECK(object->IsClearedWeakHeapObject() ||
-           object->ToWeakHeapObject()->IsNativeContext());
+    DCHECK(object->IsCleared() ||
+           object->GetHeapObjectAssumeWeak()->IsNativeContext());
     object = new_literals_map->Get(i + kLiteralLiteralsOffset);
-    DCHECK(object->IsClearedWeakHeapObject() ||
-           object->ToWeakHeapObject()->IsFeedbackCell());
+    DCHECK(object->IsCleared() ||
+           object->GetHeapObjectAssumeWeak()->IsFeedbackCell());
   }
 #endif
 
@@ -17559,9 +17413,9 @@ FeedbackCell* SearchLiteralsMap(CompilationCacheTable* cache, int cache_entry,
     DCHECK_LE(entry + kLiteralEntryLength, literals_map->length());
     MaybeObject* object = literals_map->Get(entry + kLiteralLiteralsOffset);
 
-    result = object->IsClearedWeakHeapObject()
+    result = object->IsCleared()
                  ? nullptr
-                 : FeedbackCell::cast(object->ToWeakHeapObject());
+                 : FeedbackCell::cast(object->GetHeapObjectAssumeWeak());
   }
   DCHECK(result == nullptr || result->IsFeedbackCell());
   return result;
@@ -17618,21 +17472,6 @@ Handle<Object> CompilationCacheTable::LookupRegExp(Handle<String> src,
   return Handle<Object>(get(EntryToIndex(entry) + 1), isolate);
 }
 
-Handle<CompilationCacheTable> CompilationCacheTable::Put(
-    Handle<CompilationCacheTable> cache, Handle<String> src,
-    Handle<SharedFunctionInfo> shared, LanguageMode language_mode,
-    Handle<Object> value) {
-  Isolate* isolate = cache->GetIsolate();
-  StringSharedKey key(src, shared, language_mode, kNoSourcePosition);
-  Handle<Object> k = key.AsHandle(isolate);
-  cache = EnsureCapacity(isolate, cache, 1);
-  int entry = cache->FindInsertionEntry(key.Hash());
-  cache->set(EntryToIndex(entry), *k);
-  cache->set(EntryToIndex(entry) + 1, *value);
-  cache->ElementAdded();
-  return cache;
-}
-
 Handle<CompilationCacheTable> CompilationCacheTable::PutScript(
     Handle<CompilationCacheTable> cache, Handle<String> src,
     Handle<Context> native_context, LanguageMode language_mode,
@@ -18220,8 +18059,7 @@ Handle<Derived> ObjectHashTableBase<Derived, Shape>::Put(Isolate* isolate,
     if (capacity > ObjectHashTable::kMaxCapacity) {
       for (size_t i = 0; i < 2; ++i) {
         isolate->heap()->CollectAllGarbage(
-            Heap::kFinalizeIncrementalMarkingMask,
-            GarbageCollectionReason::kFullHashtable);
+            Heap::kNoGCFlags, GarbageCollectionReason::kFullHashtable);
       }
       table->Rehash(isolate);
     }
@@ -18390,8 +18228,10 @@ MaybeHandle<JSDate> JSDate::New(Handle<JSFunction> constructor,
                                 Handle<JSReceiver> new_target, double tv) {
   Isolate* const isolate = constructor->GetIsolate();
   Handle<JSObject> result;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, result,
-                             JSObject::New(constructor, new_target), JSDate);
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, result,
+      JSObject::New(constructor, new_target, Handle<AllocationSite>::null()),
+      JSDate);
   if (-DateCache::kMaxTimeInMs <= tv && tv <= DateCache::kMaxTimeInMs) {
     tv = DoubleToInteger(tv) + 0.0;
   } else {
@@ -18818,6 +18658,82 @@ MaybeHandle<Name> FunctionTemplateInfo::TryGetCachedPropertyName(
   return MaybeHandle<Name>();
 }
 
+Smi* Smi::LexicographicCompare(Isolate* isolate, Smi* x, Smi* y) {
+  DisallowHeapAllocation no_allocation;
+  DisallowJavascriptExecution no_js(isolate);
+
+  int x_value = Smi::ToInt(x);
+  int y_value = Smi::ToInt(y);
+
+  // If the integers are equal so are the string representations.
+  if (x_value == y_value) return Smi::FromInt(0);
+
+  // If one of the integers is zero the normal integer order is the
+  // same as the lexicographic order of the string representations.
+  if (x_value == 0 || y_value == 0)
+    return Smi::FromInt(x_value < y_value ? -1 : 1);
+
+  // If only one of the integers is negative the negative number is
+  // smallest because the char code of '-' is less than the char code
+  // of any digit.  Otherwise, we make both values positive.
+
+  // Use unsigned values otherwise the logic is incorrect for -MIN_INT on
+  // architectures using 32-bit Smis.
+  uint32_t x_scaled = x_value;
+  uint32_t y_scaled = y_value;
+  if (x_value < 0 || y_value < 0) {
+    if (y_value >= 0) return Smi::FromInt(-1);
+    if (x_value >= 0) return Smi::FromInt(1);
+    x_scaled = -x_value;
+    y_scaled = -y_value;
+  }
+
+  // clang-format off
+  static const uint32_t kPowersOf10[] = {
+      1,                 10,                100,         1000,
+      10 * 1000,         100 * 1000,        1000 * 1000, 10 * 1000 * 1000,
+      100 * 1000 * 1000, 1000 * 1000 * 1000};
+  // clang-format on
+
+  // If the integers have the same number of decimal digits they can be
+  // compared directly as the numeric order is the same as the
+  // lexicographic order.  If one integer has fewer digits, it is scaled
+  // by some power of 10 to have the same number of digits as the longer
+  // integer.  If the scaled integers are equal it means the shorter
+  // integer comes first in the lexicographic order.
+
+  // From http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog10
+  int x_log2 = 31 - base::bits::CountLeadingZeros(x_scaled);
+  int x_log10 = ((x_log2 + 1) * 1233) >> 12;
+  x_log10 -= x_scaled < kPowersOf10[x_log10];
+
+  int y_log2 = 31 - base::bits::CountLeadingZeros(y_scaled);
+  int y_log10 = ((y_log2 + 1) * 1233) >> 12;
+  y_log10 -= y_scaled < kPowersOf10[y_log10];
+
+  int tie = 0;
+
+  if (x_log10 < y_log10) {
+    // X has fewer digits.  We would like to simply scale up X but that
+    // might overflow, e.g when comparing 9 with 1_000_000_000, 9 would
+    // be scaled up to 9_000_000_000. So we scale up by the next
+    // smallest power and scale down Y to drop one digit. It is OK to
+    // drop one digit from the longer integer since the final digit is
+    // past the length of the shorter integer.
+    x_scaled *= kPowersOf10[y_log10 - x_log10 - 1];
+    y_scaled /= 10;
+    tie = -1;
+  } else if (y_log10 < x_log10) {
+    y_scaled *= kPowersOf10[x_log10 - y_log10 - 1];
+    x_scaled /= 10;
+    tie = 1;
+  }
+
+  if (x_scaled < y_scaled) return Smi::FromInt(-1);
+  if (x_scaled > y_scaled) return Smi::FromInt(1);
+  return Smi::FromInt(tie);
+}
+
 // Force instantiation of template instances class.
 // Please note this list is compiler dependent.
 // Keep this at the end of this file
diff --git a/deps/v8/src/objects.h b/deps/v8/src/objects.h
index c848e92af7..cd64199982 100644
--- a/deps/v8/src/objects.h
+++ b/deps/v8/src/objects.h
@@ -8,6 +8,7 @@
 #include <iosfwd>
 #include <memory>
 
+#include "include/v8-internal.h"
 #include "include/v8.h"
 #include "include/v8config.h"
 #include "src/assert-scope.h"
@@ -75,11 +76,16 @@
 //           - JSDate
 //         - JSMessageObject
 //         - JSModuleNamespace
+//         - JSV8BreakIterator     // If V8_INTL_SUPPORT enabled.
 //         - JSCollator            // If V8_INTL_SUPPORT enabled.
+//         - JSDateTimeFormat      // If V8_INTL_SUPPORT enabled.
 //         - JSListFormat          // If V8_INTL_SUPPORT enabled.
 //         - JSLocale              // If V8_INTL_SUPPORT enabled.
+//         - JSNumberFormat        // If V8_INTL_SUPPORT enabled.
 //         - JSPluralRules         // If V8_INTL_SUPPORT enabled.
 //         - JSRelativeTimeFormat  // If V8_INTL_SUPPORT enabled.
+//         - JSSegmenter           // If V8_INTL_SUPPORT enabled.
+//         - WasmExceptionObject
 //         - WasmGlobalObject
 //         - WasmInstanceObject
 //         - WasmMemoryObject
@@ -170,6 +176,7 @@
 //           - PromiseFulfillReactionJobTask
 //           - PromiseRejectReactionJobTask
 //         - PromiseResolveThenableJobTask
+//       - MicrotaskQueue
 //       - Module
 //       - ModuleInfoEntry
 //     - FeedbackCell
@@ -189,73 +196,6 @@ namespace internal {
 struct InliningPosition;
 class PropertyDescriptorObject;
 
-enum KeyedAccessLoadMode {
-  STANDARD_LOAD,
-  LOAD_IGNORE_OUT_OF_BOUNDS,
-};
-
-enum KeyedAccessStoreMode {
-  STANDARD_STORE,
-  STORE_TRANSITION_TO_OBJECT,
-  STORE_TRANSITION_TO_DOUBLE,
-  STORE_AND_GROW_NO_TRANSITION_HANDLE_COW,
-  STORE_AND_GROW_TRANSITION_TO_OBJECT,
-  STORE_AND_GROW_TRANSITION_TO_DOUBLE,
-  STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS,
-  STORE_NO_TRANSITION_HANDLE_COW
-};
-
-enum MutableMode {
-  MUTABLE,
-  IMMUTABLE
-};
-
-
-static inline bool IsTransitionStoreMode(KeyedAccessStoreMode store_mode) {
-  return store_mode == STORE_TRANSITION_TO_OBJECT ||
-         store_mode == STORE_TRANSITION_TO_DOUBLE ||
-         store_mode == STORE_AND_GROW_TRANSITION_TO_OBJECT ||
-         store_mode == STORE_AND_GROW_TRANSITION_TO_DOUBLE;
-}
-
-static inline bool IsCOWHandlingStoreMode(KeyedAccessStoreMode store_mode) {
-  return store_mode == STORE_NO_TRANSITION_HANDLE_COW ||
-         store_mode == STORE_AND_GROW_NO_TRANSITION_HANDLE_COW;
-}
-
-static inline KeyedAccessStoreMode GetNonTransitioningStoreMode(
-    KeyedAccessStoreMode store_mode, bool receiver_was_cow) {
-  switch (store_mode) {
-    case STORE_AND_GROW_NO_TRANSITION_HANDLE_COW:
-    case STORE_AND_GROW_TRANSITION_TO_OBJECT:
-    case STORE_AND_GROW_TRANSITION_TO_DOUBLE:
-      store_mode = STORE_AND_GROW_NO_TRANSITION_HANDLE_COW;
-      break;
-    case STANDARD_STORE:
-    case STORE_TRANSITION_TO_OBJECT:
-    case STORE_TRANSITION_TO_DOUBLE:
-      store_mode =
-          receiver_was_cow ? STORE_NO_TRANSITION_HANDLE_COW : STANDARD_STORE;
-      break;
-    case STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS:
-    case STORE_NO_TRANSITION_HANDLE_COW:
-      break;
-  }
-  DCHECK(!IsTransitionStoreMode(store_mode));
-  DCHECK_IMPLIES(receiver_was_cow, IsCOWHandlingStoreMode(store_mode));
-  return store_mode;
-}
-
-
-static inline bool IsGrowStoreMode(KeyedAccessStoreMode store_mode) {
-  return store_mode >= STORE_AND_GROW_NO_TRANSITION_HANDLE_COW &&
-         store_mode <= STORE_AND_GROW_TRANSITION_TO_DOUBLE;
-}
-
-
-enum IcCheckType { ELEMENT, PROPERTY };
-
-
 // SKIP_WRITE_BARRIER skips the write barrier.
 // UPDATE_WEAK_WRITE_BARRIER skips the marking part of the write barrier and
 // only performs the generational part.
@@ -351,8 +291,8 @@ const uint32_t kOneByteDataHintTag = 0x10;
 
 // If bit 7 is clear and string representation indicates an external string,
 // then bit 5 indicates whether the data pointer is cached.
-const uint32_t kShortExternalStringMask = 0x20;
-const uint32_t kShortExternalStringTag = 0x20;
+const uint32_t kUncachedExternalStringMask = 0x20;
+const uint32_t kUncachedExternalStringTag = 0x20;
 
 // A ConsString with an empty string as the right side is a candidate
 // for being shortcut by the garbage collector. We don't allocate any
@@ -383,15 +323,15 @@ enum InstanceType : uint16_t {
   EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
       EXTERNAL_INTERNALIZED_STRING_TYPE | kOneByteDataHintTag |
       kInternalizedTag,
-  SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE = EXTERNAL_INTERNALIZED_STRING_TYPE |
-                                            kShortExternalStringTag |
-                                            kInternalizedTag,
-  SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
-      EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kShortExternalStringTag |
+  UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE =
+      EXTERNAL_INTERNALIZED_STRING_TYPE | kUncachedExternalStringTag |
+      kInternalizedTag,
+  UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE =
+      EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kUncachedExternalStringTag |
       kInternalizedTag,
-  SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
+  UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE =
       EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
-      kShortExternalStringTag | kInternalizedTag,
+      kUncachedExternalStringTag | kInternalizedTag,
   STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
   ONE_BYTE_STRING_TYPE =
       ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
@@ -409,12 +349,12 @@ enum InstanceType : uint16_t {
   EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
       EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
       kNotInternalizedTag,
-  SHORT_EXTERNAL_STRING_TYPE =
-      SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
-  SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE =
-      SHORT_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
-  SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
-      SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
+  UNCACHED_EXTERNAL_STRING_TYPE =
+      UNCACHED_EXTERNAL_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
+  UNCACHED_EXTERNAL_ONE_BYTE_STRING_TYPE =
+      UNCACHED_EXTERNAL_ONE_BYTE_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
+  UNCACHED_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE =
+      UNCACHED_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE |
       kNotInternalizedTag,
   THIN_STRING_TYPE = kTwoByteStringTag | kThinStringTag | kNotInternalizedTag,
   THIN_ONE_BYTE_STRING_TYPE =
@@ -422,7 +362,7 @@ enum InstanceType : uint16_t {
 
   // Non-string names
   SYMBOL_TYPE =
-      1 + (kIsNotInternalizedMask | kShortExternalStringMask |
+      1 + (kIsNotInternalizedMask | kUncachedExternalStringMask |
            kOneByteDataHintMask | kStringEncodingMask |
            kStringRepresentationMask),  // FIRST_NONSTRING_TYPE, LAST_NAME_TYPE
 
@@ -488,6 +428,8 @@ enum InstanceType : uint16_t {
   PROMISE_REJECT_REACTION_JOB_TASK_TYPE,
   PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE,  // LAST_MICROTASK_TYPE
 
+  MICROTASK_QUEUE_TYPE,
+
   ALLOCATION_SITE_TYPE,
   // FixedArrays.
   FIXED_ARRAY_TYPE,  // FIRST_FIXED_ARRAY_TYPE
@@ -503,7 +445,8 @@ enum InstanceType : uint16_t {
   EPHEMERON_HASH_TABLE_TYPE,
   SCOPE_INFO_TYPE,
   SCRIPT_CONTEXT_TABLE_TYPE,
-  BLOCK_CONTEXT_TYPE,  // FIRST_CONTEXT_TYPE
+  AWAIT_CONTEXT_TYPE,  // FIRST_CONTEXT_TYPE
+  BLOCK_CONTEXT_TYPE,
   CATCH_CONTEXT_TYPE,
   DEBUG_EVALUATE_CONTEXT_TYPE,
   EVAL_CONTEXT_TYPE,
@@ -582,13 +525,18 @@ enum InstanceType : uint16_t {
   JS_DATA_VIEW_TYPE,
 
 #ifdef V8_INTL_SUPPORT
+  JS_INTL_V8_BREAK_ITERATOR_TYPE,
   JS_INTL_COLLATOR_TYPE,
+  JS_INTL_DATE_TIME_FORMAT_TYPE,
   JS_INTL_LIST_FORMAT_TYPE,
   JS_INTL_LOCALE_TYPE,
+  JS_INTL_NUMBER_FORMAT_TYPE,
   JS_INTL_PLURAL_RULES_TYPE,
   JS_INTL_RELATIVE_TIME_FORMAT_TYPE,
+  JS_INTL_SEGMENTER_TYPE,
 #endif  // V8_INTL_SUPPORT
 
+  WASM_EXCEPTION_TYPE,
   WASM_GLOBAL_TYPE,
   WASM_INSTANCE_TYPE,
   WASM_MEMORY_TYPE,
@@ -622,7 +570,7 @@ enum InstanceType : uint16_t {
   FIRST_WEAK_FIXED_ARRAY_TYPE = WEAK_FIXED_ARRAY_TYPE,
   LAST_WEAK_FIXED_ARRAY_TYPE = TRANSITION_ARRAY_TYPE,
   // Boundaries for testing if given HeapObject is a Context
-  FIRST_CONTEXT_TYPE = BLOCK_CONTEXT_TYPE,
+  FIRST_CONTEXT_TYPE = AWAIT_CONTEXT_TYPE,
   LAST_CONTEXT_TYPE = WITH_CONTEXT_TYPE,
   // Boundaries for testing if given HeapObject is a subclass of Microtask.
   FIRST_MICROTASK_TYPE = CALLABLE_TASK_TYPE,
@@ -695,22 +643,11 @@ class FixedArrayBase;
 class PropertyArray;
 class FunctionLiteral;
 class FunctionTemplateInfo;
-class JSGeneratorObject;
-class JSAsyncGeneratorObject;
-class JSGlobalObject;
-class JSGlobalProxy;
-#ifdef V8_INTL_SUPPORT
-class JSCollator;
-class JSListFormat;
-class JSLocale;
-class JSPluralRules;
-class JSRelativeTimeFormat;
-#endif  // V8_INTL_SUPPORT
-class JSPromise;
 class KeyAccumulator;
 class LayoutDescriptor;
 class LookupIterator;
 class FieldType;
+class MicrotaskQueue;
 class Module;
 class ModuleInfoEntry;
 class ObjectHashTable;
@@ -900,6 +837,7 @@ class ZoneForwardList;
   V(UncompiledDataWithoutPreParsedScope)       \
   V(Undetectable)                              \
   V(UniqueName)                                \
+  V(WasmExceptionObject)                       \
   V(WasmGlobalObject)                          \
   V(WasmInstanceObject)                        \
   V(WasmMemoryObject)                          \
@@ -911,11 +849,15 @@ class ZoneForwardList;
 #ifdef V8_INTL_SUPPORT
 #define HEAP_OBJECT_ORDINARY_TYPE_LIST(V) \
   HEAP_OBJECT_ORDINARY_TYPE_LIST_BASE(V)  \
+  V(JSV8BreakIterator)                    \
   V(JSCollator)                           \
+  V(JSDateTimeFormat)                     \
   V(JSListFormat)                         \
   V(JSLocale)                             \
+  V(JSNumberFormat)                       \
   V(JSPluralRules)                        \
-  V(JSRelativeTimeFormat)
+  V(JSRelativeTimeFormat)                 \
+  V(JSSegmenter)
 #else
 #define HEAP_OBJECT_ORDINARY_TYPE_LIST(V) HEAP_OBJECT_ORDINARY_TYPE_LIST_BASE(V)
 #endif  // V8_INTL_SUPPORT
@@ -983,6 +925,7 @@ class ZoneForwardList;
   V(JSMessageObject, JS_MESSAGE_OBJECT_TYPE)                           \
   V(JSModuleNamespace, JS_MODULE_NAMESPACE_TYPE)                       \
   V(JSPromise, JS_PROMISE_TYPE)                                        \
+  V(JSProxy, JS_PROXY_TYPE)                                            \
   V(JSRegExp, JS_REGEXP_TYPE)                                          \
   V(JSRegExpResult, JS_ARRAY_TYPE)                                     \
   V(JSRegExpStringIterator, JS_REGEXP_STRING_ITERATOR_TYPE)            \
@@ -1021,6 +964,7 @@ class ZoneForwardList;
     UNCOMPILED_DATA_WITHOUT_PRE_PARSED_SCOPE_TYPE)                     \
   V(UncompiledDataWithPreParsedScope,                                  \
     UNCOMPILED_DATA_WITH_PRE_PARSED_SCOPE_TYPE)                        \
+  V(WasmExceptionObject, WASM_EXCEPTION_TYPE)                          \
   V(WasmGlobalObject, WASM_GLOBAL_TYPE)                                \
   V(WasmInstanceObject, WASM_INSTANCE_TYPE)                            \
   V(WasmMemoryObject, WASM_MEMORY_TYPE)                                \
@@ -1029,13 +973,17 @@ class ZoneForwardList;
   V(WeakArrayList, WEAK_ARRAY_LIST_TYPE)
 #ifdef V8_INTL_SUPPORT
 
-#define INSTANCE_TYPE_CHECKERS_SINGLE(V)      \
-  INSTANCE_TYPE_CHECKERS_SINGLE_BASE(V)       \
-  V(JSCollator, JS_INTL_COLLATOR_TYPE)        \
-  V(JSListFormat, JS_INTL_LIST_FORMAT_TYPE)   \
-  V(JSLocale, JS_INTL_LOCALE_TYPE)            \
-  V(JSPluralRules, JS_INTL_PLURAL_RULES_TYPE) \
-  V(JSRelativeTimeFormat, JS_INTL_RELATIVE_TIME_FORMAT_TYPE)
+#define INSTANCE_TYPE_CHECKERS_SINGLE(V)                     \
+  INSTANCE_TYPE_CHECKERS_SINGLE_BASE(V)                      \
+  V(JSV8BreakIterator, JS_INTL_V8_BREAK_ITERATOR_TYPE)       \
+  V(JSCollator, JS_INTL_COLLATOR_TYPE)                       \
+  V(JSDateTimeFormat, JS_INTL_DATE_TIME_FORMAT_TYPE)         \
+  V(JSListFormat, JS_INTL_LIST_FORMAT_TYPE)                  \
+  V(JSLocale, JS_INTL_LOCALE_TYPE)                           \
+  V(JSNumberFormat, JS_INTL_NUMBER_FORMAT_TYPE)              \
+  V(JSPluralRules, JS_INTL_PLURAL_RULES_TYPE)                \
+  V(JSRelativeTimeFormat, JS_INTL_RELATIVE_TIME_FORMAT_TYPE) \
+  V(JSSegmenter, JS_INTL_SEGMENTER_TYPE)
 
 #else
 
@@ -1060,7 +1008,8 @@ class ZoneForwardList;
 #define INSTANCE_TYPE_CHECKERS_CUSTOM(V) \
   V(FixedArrayBase)                      \
   V(InternalizedString)                  \
-  V(JSObject)
+  V(JSObject)                            \
+  V(JSReceiver)
 
 #define INSTANCE_TYPE_CHECKERS(V)  \
   INSTANCE_TYPE_CHECKERS_SINGLE(V) \
@@ -1120,13 +1069,6 @@ class Object {
   V8_INLINE bool IsNullOrUndefined(ReadOnlyRoots roots) const;
   V8_INLINE bool IsNullOrUndefined() const;
 
-  // A non-keyed store is of the form a.x = foo or a["x"] = foo whereas
-  // a keyed store is of the form a[expression] = foo.
-  enum StoreFromKeyed {
-    MAY_BE_STORE_FROM_KEYED,
-    CERTAINLY_NOT_STORE_FROM_KEYED
-  };
-
   enum class Conversion { kToNumber, kToNumeric };
 
 #define RETURN_FAILURE(isolate, should_throw, call) \
@@ -1333,19 +1275,19 @@ class Object {
   // covered by it (eg., concerning API callbacks).
   V8_WARN_UNUSED_RESULT static Maybe<bool> SetProperty(
       LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
-      StoreFromKeyed store_mode);
+      StoreOrigin store_origin);
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> SetProperty(
       Isolate* isolate, Handle<Object> object, Handle<Name> name,
       Handle<Object> value, LanguageMode language_mode,
-      StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
+      StoreOrigin store_origin = StoreOrigin::kMaybeKeyed);
   V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> SetPropertyOrElement(
       Isolate* isolate, Handle<Object> object, Handle<Name> name,
       Handle<Object> value, LanguageMode language_mode,
-      StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
+      StoreOrigin store_origin = StoreOrigin::kMaybeKeyed);
 
   V8_WARN_UNUSED_RESULT static Maybe<bool> SetSuperProperty(
       LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
-      StoreFromKeyed store_mode);
+      StoreOrigin store_origin);
 
   V8_WARN_UNUSED_RESULT static Maybe<bool> CannotCreateProperty(
       Isolate* isolate, Handle<Object> receiver, Handle<Object> name,
@@ -1362,7 +1304,7 @@ class Object {
       LookupIterator* it, Handle<Object> value);
   V8_WARN_UNUSED_RESULT static Maybe<bool> AddDataProperty(
       LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
-      ShouldThrow should_throw, StoreFromKeyed store_mode);
+      ShouldThrow should_throw, StoreOrigin store_origin);
   V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
       Isolate* isolate, Handle<Object> object, Handle<Name> name);
   V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetPropertyOrElement(
@@ -1484,7 +1426,7 @@ class Object {
   // Return value is only meaningful if [found] is set to true on return.
   V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyInternal(
       LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
-      StoreFromKeyed store_mode, bool* found);
+      StoreOrigin store_origin, bool* found);
 
   V8_WARN_UNUSED_RESULT static MaybeHandle<Name> ConvertToName(
       Isolate* isolate, Handle<Object> input);
@@ -1569,6 +1511,13 @@ class Smi: public Object {
     return result;
   }
 
+  // Compare two Smis x, y as if they were converted to strings and then
+  // compared lexicographically. Returns:
+  // -1 if x < y.
+  //  0 if x == y.
+  //  1 if x > y.
+  static Smi* LexicographicCompare(Isolate* isolate, Smi* x, Smi* y);
+
   DECL_CAST(Smi)
 
   // Dispatched behavior.
@@ -1588,7 +1537,7 @@ class Smi: public Object {
 // during GC other data (e.g. mark bits, forwarding addresses) is sometimes
 // encoded in the first word.  The class MapWord is an abstraction of the
 // value in a heap object's first word.
-class MapWord BASE_EMBEDDED {
+class MapWord {
  public:
   // Normal state: the map word contains a map pointer.
 
@@ -1915,912 +1864,6 @@ enum class KeyCollectionMode {
       static_cast<int>(v8::KeyCollectionMode::kIncludePrototypes)
 };
 
-enum class AllocationSiteUpdateMode { kUpdate, kCheckOnly };
-
-class PropertyArray : public HeapObject {
- public:
-  // [length]: length of the array.
-  inline int length() const;
-
-  // Get the length using acquire loads.
-  inline int synchronized_length() const;
-
-  // This is only used on a newly allocated PropertyArray which
-  // doesn't have an existing hash.
-  inline void initialize_length(int length);
-
-  inline void SetHash(int hash);
-  inline int Hash() const;
-
-  inline Object* get(int index) const;
-
-  inline void set(int index, Object* value);
-  // Setter with explicit barrier mode.
-  inline void set(int index, Object* value, WriteBarrierMode mode);
-
-  // Gives access to raw memory which stores the array's data.
-  inline Object** data_start();
-
-  // Garbage collection support.
-  static constexpr int SizeFor(int length) {
-    return kHeaderSize + length * kPointerSize;
-  }
-
-  DECL_CAST(PropertyArray)
-  DECL_PRINTER(PropertyArray)
-  DECL_VERIFIER(PropertyArray)
-
-  // Layout description.
-  static const int kLengthAndHashOffset = HeapObject::kHeaderSize;
-  static const int kHeaderSize = kLengthAndHashOffset + kPointerSize;
-
-  // Garbage collection support.
-  typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
-
-  static const int kLengthFieldSize = 10;
-  class LengthField : public BitField<int, 0, kLengthFieldSize> {};
-  static const int kMaxLength = LengthField::kMax;
-  class HashField : public BitField<int, kLengthFieldSize,
-                                    kSmiValueSize - kLengthFieldSize - 1> {};
-
-  static const int kNoHashSentinel = 0;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyArray);
-};
-
-// JSReceiver includes types on which properties can be defined, i.e.,
-// JSObject and JSProxy.
-class JSReceiver : public HeapObject, public NeverReadOnlySpaceObject {
- public:
-  // Use the mixin methods over the HeapObject methods.
-  // TODO(v8:7786) Remove once the HeapObject methods are gone.
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
-  // Returns true if there is no slow (ie, dictionary) backing store.
-  inline bool HasFastProperties() const;
-
-  // Returns the properties array backing store if it
-  // exists. Otherwise, returns an empty_property_array when there's a
-  // Smi (hash code) or an empty_fixed_array for a fast properties
-  // map.
-  inline PropertyArray* property_array() const;
-
-  // Gets slow properties for non-global objects.
-  inline NameDictionary* property_dictionary() const;
-
-  // Sets the properties backing store and makes sure any existing hash is moved
-  // to the new properties store. To clear out the properties store, pass in the
-  // empty_fixed_array(), the hash will be maintained in this case as well.
-  void SetProperties(HeapObject* properties);
-
-  // There are five possible values for the properties offset.
-  // 1) EmptyFixedArray/EmptyPropertyDictionary - This is the standard
-  // placeholder.
-  //
-  // 2) Smi - This is the hash code of the object.
-  //
-  // 3) PropertyArray - This is similar to a FixedArray but stores
-  // the hash code of the object in its length field. This is a fast
-  // backing store.
-  //
-  // 4) NameDictionary - This is the dictionary-mode backing store.
-  //
-  // 4) GlobalDictionary - This is the backing store for the
-  // GlobalObject.
-  //
-  // This is used only in the deoptimizer and heap. Please use the
-  // above typed getters and setters to access the properties.
-  DECL_ACCESSORS(raw_properties_or_hash, Object)
-
-  inline void initialize_properties();
-
-  // Deletes an existing named property in a normalized object.
-  static void DeleteNormalizedProperty(Handle<JSReceiver> object, int entry);
-
-  DECL_CAST(JSReceiver)
-
-  // ES6 section 7.1.1 ToPrimitive
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ToPrimitive(
-      Handle<JSReceiver> receiver,
-      ToPrimitiveHint hint = ToPrimitiveHint::kDefault);
-
-  // ES6 section 7.1.1.1 OrdinaryToPrimitive
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> OrdinaryToPrimitive(
-      Handle<JSReceiver> receiver, OrdinaryToPrimitiveHint hint);
-
-  static MaybeHandle<Context> GetFunctionRealm(Handle<JSReceiver> receiver);
-
-  // Get the first non-hidden prototype.
-  static inline MaybeHandle<Object> GetPrototype(Isolate* isolate,
-                                                 Handle<JSReceiver> receiver);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> HasInPrototypeChain(
-      Isolate* isolate, Handle<JSReceiver> object, Handle<Object> proto);
-
-  // Reads all enumerable own properties of source and adds them to
-  // target, using either Set or CreateDataProperty depending on the
-  // use_set argument. This only copies values not present in the
-  // maybe_excluded_properties list.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> SetOrCopyDataProperties(
-      Isolate* isolate, Handle<JSReceiver> target, Handle<Object> source,
-      const ScopedVector<Handle<Object>>* excluded_properties = nullptr,
-      bool use_set = true);
-
-  // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> HasProperty(LookupIterator* it);
-  V8_WARN_UNUSED_RESULT static inline Maybe<bool> HasProperty(
-      Handle<JSReceiver> object, Handle<Name> name);
-  V8_WARN_UNUSED_RESULT static inline Maybe<bool> HasElement(
-      Handle<JSReceiver> object, uint32_t index);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> HasOwnProperty(
-      Handle<JSReceiver> object, Handle<Name> name);
-  V8_WARN_UNUSED_RESULT static inline Maybe<bool> HasOwnProperty(
-      Handle<JSReceiver> object, uint32_t index);
-
-  V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetProperty(
-      Isolate* isolate, Handle<JSReceiver> receiver, const char* key);
-  V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetProperty(
-      Isolate* isolate, Handle<JSReceiver> receiver, Handle<Name> name);
-  V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetElement(
-      Isolate* isolate, Handle<JSReceiver> receiver, uint32_t index);
-
-  // Implementation of ES6 [[Delete]]
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DeletePropertyOrElement(
-      Handle<JSReceiver> object, Handle<Name> name,
-      LanguageMode language_mode = LanguageMode::kSloppy);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DeleteProperty(
-      Handle<JSReceiver> object, Handle<Name> name,
-      LanguageMode language_mode = LanguageMode::kSloppy);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DeleteProperty(
-      LookupIterator* it, LanguageMode language_mode);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DeleteElement(
-      Handle<JSReceiver> object, uint32_t index,
-      LanguageMode language_mode = LanguageMode::kSloppy);
-
-  V8_WARN_UNUSED_RESULT static Object* DefineProperty(
-      Isolate* isolate, Handle<Object> object, Handle<Object> name,
-      Handle<Object> attributes);
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> DefineProperties(
-      Isolate* isolate, Handle<Object> object, Handle<Object> properties);
-
-  // "virtual" dispatcher to the correct [[DefineOwnProperty]] implementation.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DefineOwnProperty(
-      Isolate* isolate, Handle<JSReceiver> object, Handle<Object> key,
-      PropertyDescriptor* desc, ShouldThrow should_throw);
-
-  // ES6 7.3.4 (when passed kDontThrow)
-  V8_WARN_UNUSED_RESULT static Maybe<bool> CreateDataProperty(
-      Isolate* isolate, Handle<JSReceiver> object, Handle<Name> key,
-      Handle<Object> value, ShouldThrow should_throw);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> CreateDataProperty(
-      LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
-
-  // ES6 9.1.6.1
-  V8_WARN_UNUSED_RESULT static Maybe<bool> OrdinaryDefineOwnProperty(
-      Isolate* isolate, Handle<JSObject> object, Handle<Object> key,
-      PropertyDescriptor* desc, ShouldThrow should_throw);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> OrdinaryDefineOwnProperty(
-      LookupIterator* it, PropertyDescriptor* desc, ShouldThrow should_throw);
-  // ES6 9.1.6.2
-  V8_WARN_UNUSED_RESULT static Maybe<bool> IsCompatiblePropertyDescriptor(
-      Isolate* isolate, bool extensible, PropertyDescriptor* desc,
-      PropertyDescriptor* current, Handle<Name> property_name,
-      ShouldThrow should_throw);
-  // ES6 9.1.6.3
-  // |it| can be NULL in cases where the ES spec passes |undefined| as the
-  // receiver. Exactly one of |it| and |property_name| must be provided.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> ValidateAndApplyPropertyDescriptor(
-      Isolate* isolate, LookupIterator* it, bool extensible,
-      PropertyDescriptor* desc, PropertyDescriptor* current,
-      ShouldThrow should_throw, Handle<Name> property_name);
-
-  V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static Maybe<bool>
-  GetOwnPropertyDescriptor(Isolate* isolate, Handle<JSReceiver> object,
-                           Handle<Object> key, PropertyDescriptor* desc);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> GetOwnPropertyDescriptor(
-      LookupIterator* it, PropertyDescriptor* desc);
-
-  typedef PropertyAttributes IntegrityLevel;
-
-  // ES6 7.3.14 (when passed kDontThrow)
-  // 'level' must be SEALED or FROZEN.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> SetIntegrityLevel(
-      Handle<JSReceiver> object, IntegrityLevel lvl, ShouldThrow should_throw);
-
-  // ES6 7.3.15
-  // 'level' must be SEALED or FROZEN.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> TestIntegrityLevel(
-      Handle<JSReceiver> object, IntegrityLevel lvl);
-
-  // ES6 [[PreventExtensions]] (when passed kDontThrow)
-  V8_WARN_UNUSED_RESULT static Maybe<bool> PreventExtensions(
-      Handle<JSReceiver> object, ShouldThrow should_throw);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> IsExtensible(
-      Handle<JSReceiver> object);
-
-  // Returns the class name ([[Class]] property in the specification).
-  V8_EXPORT_PRIVATE String* class_name();
-
-  // Returns the constructor (the function that was used to instantiate the
-  // object).
-  static MaybeHandle<JSFunction> GetConstructor(Handle<JSReceiver> receiver);
-
-  // Returns the constructor name (the name (possibly, inferred name) of the
-  // function that was used to instantiate the object).
-  static Handle<String> GetConstructorName(Handle<JSReceiver> receiver);
-
-  Handle<Context> GetCreationContext();
-
-  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
-  GetPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
-  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
-  GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
-  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
-  GetOwnPropertyAttributes(Handle<JSReceiver> object, uint32_t index);
-
-  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
-  GetElementAttributes(Handle<JSReceiver> object, uint32_t index);
-  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
-  GetOwnElementAttributes(Handle<JSReceiver> object, uint32_t index);
-
-  V8_WARN_UNUSED_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
-      LookupIterator* it);
-
-  // Set the object's prototype (only JSReceiver and null are allowed values).
-  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPrototype(
-      Handle<JSReceiver> object, Handle<Object> value, bool from_javascript,
-      ShouldThrow should_throw);
-
-  inline static Handle<Object> GetDataProperty(Handle<JSReceiver> object,
-                                               Handle<Name> name);
-  static Handle<Object> GetDataProperty(LookupIterator* it);
-
-
-  // Retrieves a permanent object identity hash code. The undefined value might
-  // be returned in case no hash was created yet.
-  Object* GetIdentityHash(Isolate* isolate);
-
-  // Retrieves a permanent object identity hash code. May create and store a
-  // hash code if needed and none exists.
-  static Smi* CreateIdentityHash(Isolate* isolate, JSReceiver* key);
-  Smi* GetOrCreateIdentityHash(Isolate* isolate);
-
-  // Stores the hash code. The hash passed in must be masked with
-  // JSReceiver::kHashMask.
-  void SetIdentityHash(int masked_hash);
-
-  // ES6 [[OwnPropertyKeys]] (modulo return type)
-  V8_WARN_UNUSED_RESULT static inline MaybeHandle<FixedArray> OwnPropertyKeys(
-      Handle<JSReceiver> object);
-
-  V8_WARN_UNUSED_RESULT static MaybeHandle<FixedArray> GetOwnValues(
-      Handle<JSReceiver> object, PropertyFilter filter,
-      bool try_fast_path = true);
-
-  V8_WARN_UNUSED_RESULT static MaybeHandle<FixedArray> GetOwnEntries(
-      Handle<JSReceiver> object, PropertyFilter filter,
-      bool try_fast_path = true);
-
-  V8_WARN_UNUSED_RESULT static Handle<FixedArray> GetOwnElementIndices(
-      Isolate* isolate, Handle<JSReceiver> receiver, Handle<JSObject> object);
-
-  static const int kHashMask = PropertyArray::HashField::kMask;
-
-  // Layout description.
-  static const int kPropertiesOrHashOffset = HeapObject::kHeaderSize;
-  static const int kHeaderSize = HeapObject::kHeaderSize + kPointerSize;
-
-  bool HasProxyInPrototype(Isolate* isolate);
-
-  bool HasComplexElements();
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
-};
-
-
-// The JSObject describes real heap allocated JavaScript objects with
-// properties.
-// Note that the map of JSObject changes during execution to enable inline
-// caching.
-class JSObject: public JSReceiver {
- public:
-  static bool IsUnmodifiedApiObject(Object** o);
-
-  static V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> New(
-      Handle<JSFunction> constructor, Handle<JSReceiver> new_target,
-      Handle<AllocationSite> site = Handle<AllocationSite>::null());
-
-  static MaybeHandle<Context> GetFunctionRealm(Handle<JSObject> object);
-
-  // 9.1.12 ObjectCreate ( proto [ , internalSlotsList ] )
-  // Notice: This is NOT 19.1.2.2 Object.create ( O, Properties )
-  static V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> ObjectCreate(
-      Isolate* isolate, Handle<Object> prototype);
-
-  // [elements]: The elements (properties with names that are integers).
-  //
-  // Elements can be in two general modes: fast and slow. Each mode
-  // corresponds to a set of object representations of elements that
-  // have something in common.
-  //
-  // In the fast mode elements is a FixedArray and so each element can
-  // be quickly accessed. This fact is used in the generated code. The
-  // elements array can have one of three maps in this mode:
-  // fixed_array_map, sloppy_arguments_elements_map or
-  // fixed_cow_array_map (for copy-on-write arrays). In the latter case
-  // the elements array may be shared by a few objects and so before
-  // writing to any element the array must be copied. Use
-  // EnsureWritableFastElements in this case.
-  //
-  // In the slow mode the elements is either a NumberDictionary, a
-  // FixedArray parameter map for a (sloppy) arguments object.
-  DECL_ACCESSORS(elements, FixedArrayBase)
-  inline void initialize_elements();
-  static inline void SetMapAndElements(Handle<JSObject> object,
-                                       Handle<Map> map,
-                                       Handle<FixedArrayBase> elements);
-  inline ElementsKind GetElementsKind() const;
-  ElementsAccessor* GetElementsAccessor();
-  // Returns true if an object has elements of PACKED_SMI_ELEMENTS or
-  // HOLEY_SMI_ELEMENTS ElementsKind.
-  inline bool HasSmiElements();
-  // Returns true if an object has elements of PACKED_ELEMENTS or
-  // HOLEY_ELEMENTS ElementsKind.
-  inline bool HasObjectElements();
-  // Returns true if an object has elements of PACKED_SMI_ELEMENTS,
-  // HOLEY_SMI_ELEMENTS, PACKED_ELEMENTS, or HOLEY_ELEMENTS.
-  inline bool HasSmiOrObjectElements();
-  // Returns true if an object has any of the "fast" elements kinds.
-  inline bool HasFastElements();
-  // Returns true if an object has any of the PACKED elements kinds.
-  inline bool HasFastPackedElements();
-  // Returns true if an object has elements of PACKED_DOUBLE_ELEMENTS or
-  // HOLEY_DOUBLE_ELEMENTS ElementsKind.
-  inline bool HasDoubleElements();
-  // Returns true if an object has elements of HOLEY_SMI_ELEMENTS,
-  // HOLEY_DOUBLE_ELEMENTS, or HOLEY_ELEMENTS ElementsKind.
-  inline bool HasHoleyElements();
-  inline bool HasSloppyArgumentsElements();
-  inline bool HasStringWrapperElements();
-  inline bool HasDictionaryElements();
-
-  inline bool HasFixedTypedArrayElements();
-
-  inline bool HasFixedUint8ClampedElements();
-  inline bool HasFixedArrayElements();
-  inline bool HasFixedInt8Elements();
-  inline bool HasFixedUint8Elements();
-  inline bool HasFixedInt16Elements();
-  inline bool HasFixedUint16Elements();
-  inline bool HasFixedInt32Elements();
-  inline bool HasFixedUint32Elements();
-  inline bool HasFixedFloat32Elements();
-  inline bool HasFixedFloat64Elements();
-  inline bool HasFixedBigInt64Elements();
-  inline bool HasFixedBigUint64Elements();
-
-  inline bool HasFastArgumentsElements();
-  inline bool HasSlowArgumentsElements();
-  inline bool HasFastStringWrapperElements();
-  inline bool HasSlowStringWrapperElements();
-  bool HasEnumerableElements();
-
-  inline NumberDictionary* element_dictionary();  // Gets slow elements.
-
-  // Requires: HasFastElements().
-  static void EnsureWritableFastElements(Handle<JSObject> object);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyWithInterceptor(
-      LookupIterator* it, ShouldThrow should_throw, Handle<Object> value);
-
-  // The API currently still wants DefineOwnPropertyIgnoreAttributes to convert
-  // AccessorInfo objects to data fields. We allow FORCE_FIELD as an exception
-  // to the default behavior that calls the setter.
-  enum AccessorInfoHandling { FORCE_FIELD, DONT_FORCE_FIELD };
-
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
-  DefineOwnPropertyIgnoreAttributes(
-      LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
-      AccessorInfoHandling handling = DONT_FORCE_FIELD);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DefineOwnPropertyIgnoreAttributes(
-      LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
-      ShouldThrow should_throw,
-      AccessorInfoHandling handling = DONT_FORCE_FIELD);
-
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
-  SetOwnPropertyIgnoreAttributes(Handle<JSObject> object, Handle<Name> name,
-                                 Handle<Object> value,
-                                 PropertyAttributes attributes);
-
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
-  SetOwnElementIgnoreAttributes(Handle<JSObject> object, uint32_t index,
-                                Handle<Object> value,
-                                PropertyAttributes attributes);
-
-  // Equivalent to one of the above depending on whether |name| can be converted
-  // to an array index.
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
-  DefinePropertyOrElementIgnoreAttributes(Handle<JSObject> object,
-                                          Handle<Name> name,
-                                          Handle<Object> value,
-                                          PropertyAttributes attributes = NONE);
-
-  // Adds or reconfigures a property to attributes NONE. It will fail when it
-  // cannot.
-  V8_WARN_UNUSED_RESULT static Maybe<bool> CreateDataProperty(
-      LookupIterator* it, Handle<Object> value,
-      ShouldThrow should_throw = kDontThrow);
-
-  static void AddProperty(Isolate* isolate, Handle<JSObject> object,
-                          Handle<Name> name, Handle<Object> value,
-                          PropertyAttributes attributes);
-
-  static void AddDataElement(Handle<JSObject> receiver, uint32_t index,
-                             Handle<Object> value,
-                             PropertyAttributes attributes);
-
-  // Extend the receiver with a single fast property appeared first in the
-  // passed map. This also extends the property backing store if necessary.
-  static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
-
-  // Migrates the given object to a map whose field representations are the
-  // lowest upper bound of all known representations for that field.
-  static void MigrateInstance(Handle<JSObject> instance);
-
-  // Migrates the given object only if the target map is already available,
-  // or returns false if such a map is not yet available.
-  static bool TryMigrateInstance(Handle<JSObject> instance);
-
-  // Sets the property value in a normalized object given (key, value, details).
-  // Handles the special representation of JS global objects.
-  static void SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name,
-                                    Handle<Object> value,
-                                    PropertyDetails details);
-  static void SetDictionaryElement(Handle<JSObject> object, uint32_t index,
-                                   Handle<Object> value,
-                                   PropertyAttributes attributes);
-  static void SetDictionaryArgumentsElement(Handle<JSObject> object,
-                                            uint32_t index,
-                                            Handle<Object> value,
-                                            PropertyAttributes attributes);
-
-  static void OptimizeAsPrototype(Handle<JSObject> object,
-                                  bool enable_setup_mode = true);
-  static void ReoptimizeIfPrototype(Handle<JSObject> object);
-  static void MakePrototypesFast(Handle<Object> receiver,
-                                 WhereToStart where_to_start, Isolate* isolate);
-  static void LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate);
-  static void UpdatePrototypeUserRegistration(Handle<Map> old_map,
-                                              Handle<Map> new_map,
-                                              Isolate* isolate);
-  static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate);
-  static Map* InvalidatePrototypeChains(Map* map);
-  static void InvalidatePrototypeValidityCell(JSGlobalObject* global);
-
-  // Updates prototype chain tracking information when an object changes its
-  // map from |old_map| to |new_map|.
-  static void NotifyMapChange(Handle<Map> old_map, Handle<Map> new_map,
-                              Isolate* isolate);
-
-  // Utility used by many Array builtins and runtime functions
-  static inline bool PrototypeHasNoElements(Isolate* isolate, JSObject* object);
-
-  // To be passed to PrototypeUsers::Compact.
-  static void PrototypeRegistryCompactionCallback(HeapObject* value,
-                                                  int old_index, int new_index);
-
-  // Retrieve interceptors.
-  inline InterceptorInfo* GetNamedInterceptor();
-  inline InterceptorInfo* GetIndexedInterceptor();
-
-  // Used from JSReceiver.
-  V8_WARN_UNUSED_RESULT static Maybe<PropertyAttributes>
-  GetPropertyAttributesWithInterceptor(LookupIterator* it);
-  V8_WARN_UNUSED_RESULT static Maybe<PropertyAttributes>
-  GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
-
-  // Defines an AccessorPair property on the given object.
-  // TODO(mstarzinger): Rename to SetAccessor().
-  static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
-                                            Handle<Name> name,
-                                            Handle<Object> getter,
-                                            Handle<Object> setter,
-                                            PropertyAttributes attributes);
-  static MaybeHandle<Object> DefineAccessor(LookupIterator* it,
-                                            Handle<Object> getter,
-                                            Handle<Object> setter,
-                                            PropertyAttributes attributes);
-
-  // Defines an AccessorInfo property on the given object.
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> SetAccessor(
-      Handle<JSObject> object, Handle<Name> name, Handle<AccessorInfo> info,
-      PropertyAttributes attributes);
-
-  // The result must be checked first for exceptions. If there's no exception,
-  // the output parameter |done| indicates whether the interceptor has a result
-  // or not.
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
-      LookupIterator* it, bool* done);
-
-  static void ValidateElements(JSObject* object);
-
-  // Makes sure that this object can contain HeapObject as elements.
-  static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
-
-  // Makes sure that this object can contain the specified elements.
-  static inline void EnsureCanContainElements(
-      Handle<JSObject> object,
-      Object** elements,
-      uint32_t count,
-      EnsureElementsMode mode);
-  static inline void EnsureCanContainElements(
-      Handle<JSObject> object,
-      Handle<FixedArrayBase> elements,
-      uint32_t length,
-      EnsureElementsMode mode);
-  static void EnsureCanContainElements(
-      Handle<JSObject> object,
-      Arguments* arguments,
-      uint32_t first_arg,
-      uint32_t arg_count,
-      EnsureElementsMode mode);
-
-  // Would we convert a fast elements array to dictionary mode given
-  // an access at key?
-  bool WouldConvertToSlowElements(uint32_t index);
-
-  static const uint32_t kMinAddedElementsCapacity = 16;
-
-  // Computes the new capacity when expanding the elements of a JSObject.
-  static uint32_t NewElementsCapacity(uint32_t old_capacity) {
-    // (old_capacity + 50%) + kMinAddedElementsCapacity
-    return old_capacity + (old_capacity >> 1) + kMinAddedElementsCapacity;
-  }
-
-  // These methods do not perform access checks!
-  template <AllocationSiteUpdateMode update_or_check =
-                AllocationSiteUpdateMode::kUpdate>
-  static bool UpdateAllocationSite(Handle<JSObject> object,
-                                   ElementsKind to_kind);
-
-  // Lookup interceptors are used for handling properties controlled by host
-  // objects.
-  inline bool HasNamedInterceptor();
-  inline bool HasIndexedInterceptor();
-
-  // Support functions for v8 api (needed for correct interceptor behavior).
-  V8_WARN_UNUSED_RESULT static Maybe<bool> HasRealNamedProperty(
-      Handle<JSObject> object, Handle<Name> name);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> HasRealElementProperty(
-      Handle<JSObject> object, uint32_t index);
-  V8_WARN_UNUSED_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
-      Handle<JSObject> object, Handle<Name> name);
-
-  // Get the header size for a JSObject.  Used to compute the index of
-  // embedder fields as well as the number of embedder fields.
-  // The |function_has_prototype_slot| parameter is needed only for
-  // JSFunction objects.
-  static int GetHeaderSize(InstanceType instance_type,
-                           bool function_has_prototype_slot = false);
-  static inline int GetHeaderSize(const Map* map);
-  inline int GetHeaderSize() const;
-
-  static inline int GetEmbedderFieldCount(const Map* map);
-  inline int GetEmbedderFieldCount() const;
-  inline int GetEmbedderFieldOffset(int index);
-  inline Object* GetEmbedderField(int index);
-  inline void SetEmbedderField(int index, Object* value);
-  inline void SetEmbedderField(int index, Smi* value);
-
-  // Returns true when the object is potentially a wrapper that gets special
-  // garbage collection treatment.
-  // TODO(mlippautz): Make check exact and replace the pattern match in
-  // Heap::TracePossibleWrapper.
-  bool IsApiWrapper();
-
-  // Returns a new map with all transitions dropped from the object's current
-  // map and the ElementsKind set.
-  static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
-                                              ElementsKind to_kind);
-  static void TransitionElementsKind(Handle<JSObject> object,
-                                     ElementsKind to_kind);
-
-  // Always use this to migrate an object to a new map.
-  // |expected_additional_properties| is only used for fast-to-slow transitions
-  // and ignored otherwise.
-  static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map,
-                           int expected_additional_properties = 0);
-
-  // Forces a prototype without any of the checks that the regular SetPrototype
-  // would do.
-  static void ForceSetPrototype(Handle<JSObject> object, Handle<Object> proto);
-
-  // Convert the object to use the canonical dictionary
-  // representation. If the object is expected to have additional properties
-  // added this number can be indicated to have the backing store allocated to
-  // an initial capacity for holding these properties.
-  static void NormalizeProperties(Handle<JSObject> object,
-                                  PropertyNormalizationMode mode,
-                                  int expected_additional_properties,
-                                  const char* reason);
-
-  // Convert and update the elements backing store to be a
-  // NumberDictionary dictionary.  Returns the backing after conversion.
-  static Handle<NumberDictionary> NormalizeElements(Handle<JSObject> object);
-
-  void RequireSlowElements(NumberDictionary* dictionary);
-
-  // Transform slow named properties to fast variants.
-  static void MigrateSlowToFast(Handle<JSObject> object,
-                                int unused_property_fields, const char* reason);
-
-  inline bool IsUnboxedDoubleField(FieldIndex index);
-
-  // Access fast-case object properties at index.
-  static Handle<Object> FastPropertyAt(Handle<JSObject> object,
-                                       Representation representation,
-                                       FieldIndex index);
-  inline Object* RawFastPropertyAt(FieldIndex index);
-  inline double RawFastDoublePropertyAt(FieldIndex index);
-  inline uint64_t RawFastDoublePropertyAsBitsAt(FieldIndex index);
-
-  inline void FastPropertyAtPut(FieldIndex index, Object* value);
-  inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
-  inline void RawFastDoublePropertyAsBitsAtPut(FieldIndex index, uint64_t bits);
-  inline void WriteToField(int descriptor, PropertyDetails details,
-                           Object* value);
-
-  // Access to in object properties.
-  inline int GetInObjectPropertyOffset(int index);
-  inline Object* InObjectPropertyAt(int index);
-  inline Object* InObjectPropertyAtPut(int index,
-                                       Object* value,
-                                       WriteBarrierMode mode
-                                       = UPDATE_WRITE_BARRIER);
-
-  // Set the object's prototype (only JSReceiver and null are allowed values).
-  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPrototype(
-      Handle<JSObject> object, Handle<Object> value, bool from_javascript,
-      ShouldThrow should_throw);
-
-  // Makes the object prototype immutable
-  // Never called from JavaScript
-  static void SetImmutableProto(Handle<JSObject> object);
-
-  // Initializes the body starting at |start_offset|. It is responsibility of
-  // the caller to initialize object header. Fill the pre-allocated fields with
-  // pre_allocated_value and the rest with filler_value.
-  // Note: this call does not update write barrier, the caller is responsible
-  // to ensure that |filler_value| can be collected without WB here.
-  inline void InitializeBody(Map* map, int start_offset,
-                             Object* pre_allocated_value, Object* filler_value);
-
-  // Check whether this object references another object
-  bool ReferencesObject(Object* obj);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> TestIntegrityLevel(
-      Handle<JSObject> object, IntegrityLevel lvl);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> PreventExtensions(
-      Handle<JSObject> object, ShouldThrow should_throw);
-
-  static bool IsExtensible(Handle<JSObject> object);
-
-  DECL_CAST(JSObject)
-
-  // Dispatched behavior.
-  void JSObjectShortPrint(StringStream* accumulator);
-  DECL_PRINTER(JSObject)
-  DECL_VERIFIER(JSObject)
-#ifdef OBJECT_PRINT
-  bool PrintProperties(std::ostream& os);  // NOLINT
-  void PrintElements(std::ostream& os);    // NOLINT
-#endif
-#if defined(DEBUG) || defined(OBJECT_PRINT)
-  void PrintTransitions(std::ostream& os);  // NOLINT
-#endif
-
-  static void PrintElementsTransition(
-      FILE* file, Handle<JSObject> object,
-      ElementsKind from_kind, Handle<FixedArrayBase> from_elements,
-      ElementsKind to_kind, Handle<FixedArrayBase> to_elements);
-
-  void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
-
-#ifdef DEBUG
-  // Structure for collecting spill information about JSObjects.
-  class SpillInformation {
-   public:
-    void Clear();
-    void Print();
-    int number_of_objects_;
-    int number_of_objects_with_fast_properties_;
-    int number_of_objects_with_fast_elements_;
-    int number_of_fast_used_fields_;
-    int number_of_fast_unused_fields_;
-    int number_of_slow_used_properties_;
-    int number_of_slow_unused_properties_;
-    int number_of_fast_used_elements_;
-    int number_of_fast_unused_elements_;
-    int number_of_slow_used_elements_;
-    int number_of_slow_unused_elements_;
-  };
-
-  void IncrementSpillStatistics(Isolate* isolate, SpillInformation* info);
-#endif
-
-#ifdef VERIFY_HEAP
-  // If a GC was caused while constructing this object, the elements pointer
-  // may point to a one pointer filler map. The object won't be rooted, but
-  // our heap verification code could stumble across it.
-  bool ElementsAreSafeToExamine() const;
-#endif
-
-  Object* SlowReverseLookup(Object* value);
-
-  // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
-  // Also maximal value of JSArray's length property.
-  static const uint32_t kMaxElementCount = 0xffffffffu;
-
-  // Constants for heuristics controlling conversion of fast elements
-  // to slow elements.
-
-  // Maximal gap that can be introduced by adding an element beyond
-  // the current elements length.
-  static const uint32_t kMaxGap = 1024;
-
-  // Maximal length of fast elements array that won't be checked for
-  // being dense enough on expansion.
-  static const int kMaxUncheckedFastElementsLength = 5000;
-
-  // Same as above but for old arrays. This limit is more strict. We
-  // don't want to be wasteful with long lived objects.
-  static const int kMaxUncheckedOldFastElementsLength = 500;
-
-  // This constant applies only to the initial map of "global.Object" and
-  // not to arbitrary other JSObject maps.
-  static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
-
-  static const int kMaxInstanceSize = 255 * kPointerSize;
-
-  // When extending the backing storage for property values, we increase
-  // its size by more than the 1 entry necessary, so sequentially adding fields
-  // to the same object requires fewer allocations and copies.
-  static const int kFieldsAdded = 3;
-  STATIC_ASSERT(kMaxNumberOfDescriptors + kFieldsAdded <=
-                PropertyArray::kMaxLength);
-
-  // Layout description.
-  static const int kElementsOffset = JSReceiver::kHeaderSize;
-  static const int kHeaderSize = kElementsOffset + kPointerSize;
-
-  STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
-  static const int kMaxInObjectProperties =
-      (kMaxInstanceSize - kHeaderSize) >> kPointerSizeLog2;
-  STATIC_ASSERT(kMaxInObjectProperties <= kMaxNumberOfDescriptors);
-  // TODO(cbruni): Revisit calculation of the max supported embedder fields.
-  static const int kMaxEmbedderFields =
-      ((1 << kFirstInobjectPropertyOffsetBitCount) - 1 - kHeaderSize) >>
-      kPointerSizeLog2;
-  STATIC_ASSERT(kMaxEmbedderFields <= kMaxInObjectProperties);
-
-  class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
-
-  class FastBodyDescriptor;
-  // No weak fields.
-  typedef FastBodyDescriptor FastBodyDescriptorWeak;
-
-  // Gets the number of currently used elements.
-  int GetFastElementsUsage();
-
-  static bool AllCanRead(LookupIterator* it);
-  static bool AllCanWrite(LookupIterator* it);
-
- private:
-  friend class JSReceiver;
-  friend class Object;
-
-  // Used from Object::GetProperty().
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
-  GetPropertyWithFailedAccessCheck(LookupIterator* it);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyWithFailedAccessCheck(
-      LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
-
-  V8_WARN_UNUSED_RESULT static Maybe<bool> DeletePropertyWithInterceptor(
-      LookupIterator* it, ShouldThrow should_throw);
-
-  bool ReferencesObjectFromElements(FixedArray* elements,
-                                    ElementsKind kind,
-                                    Object* object);
-
-  // Helper for fast versions of preventExtensions, seal, and freeze.
-  // attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
-  template <PropertyAttributes attrs>
-  V8_WARN_UNUSED_RESULT static Maybe<bool> PreventExtensionsWithTransition(
-      Handle<JSObject> object, ShouldThrow should_throw);
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
-};
-
-
-// JSAccessorPropertyDescriptor is just a JSObject with a specific initial
-// map. This initial map adds in-object properties for "get", "set",
-// "enumerable" and "configurable" properties, as assigned by the
-// FromPropertyDescriptor function for regular accessor properties.
-class JSAccessorPropertyDescriptor: public JSObject {
- public:
-  // Offsets of object fields.
-  static const int kGetOffset = JSObject::kHeaderSize;
-  static const int kSetOffset = kGetOffset + kPointerSize;
-  static const int kEnumerableOffset = kSetOffset + kPointerSize;
-  static const int kConfigurableOffset = kEnumerableOffset + kPointerSize;
-  static const int kSize = kConfigurableOffset + kPointerSize;
-  // Indices of in-object properties.
-  static const int kGetIndex = 0;
-  static const int kSetIndex = 1;
-  static const int kEnumerableIndex = 2;
-  static const int kConfigurableIndex = 3;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSAccessorPropertyDescriptor);
-};
-
-
-// JSDataPropertyDescriptor is just a JSObject with a specific initial map.
-// This initial map adds in-object properties for "value", "writable",
-// "enumerable" and "configurable" properties, as assigned by the
-// FromPropertyDescriptor function for regular data properties.
-class JSDataPropertyDescriptor: public JSObject {
- public:
-  // Offsets of object fields.
-  static const int kValueOffset = JSObject::kHeaderSize;
-  static const int kWritableOffset = kValueOffset + kPointerSize;
-  static const int kEnumerableOffset = kWritableOffset + kPointerSize;
-  static const int kConfigurableOffset = kEnumerableOffset + kPointerSize;
-  static const int kSize = kConfigurableOffset + kPointerSize;
-  // Indices of in-object properties.
-  static const int kValueIndex = 0;
-  static const int kWritableIndex = 1;
-  static const int kEnumerableIndex = 2;
-  static const int kConfigurableIndex = 3;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataPropertyDescriptor);
-};
-
-
-// JSIteratorResult is just a JSObject with a specific initial map.
-// This initial map adds in-object properties for "done" and "value",
-// as specified by ES6 section 25.1.1.3 The IteratorResult Interface
-class JSIteratorResult: public JSObject {
- public:
-  DECL_ACCESSORS(value, Object)
-
-  DECL_ACCESSORS(done, Object)
-
-  // Offsets of object fields.
-  static const int kValueOffset = JSObject::kHeaderSize;
-  static const int kDoneOffset = kValueOffset + kPointerSize;
-  static const int kSize = kDoneOffset + kPointerSize;
-  // Indices of in-object properties.
-  static const int kValueIndex = 0;
-  static const int kDoneIndex = 1;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSIteratorResult);
-};
-
 // FreeSpace are fixed-size free memory blocks used by the heap and GC.
 // They look like heap objects (are heap object tagged and have a map) so that
 // the heap remains iterable.  They have a size and a next pointer.
@@ -2929,899 +1972,10 @@ class AsyncGeneratorRequest : public Struct {
   DISALLOW_IMPLICIT_CONSTRUCTORS(AsyncGeneratorRequest);
 };
 
-// List of builtin functions we want to identify to improve code
-// generation.
-//
-// Each entry has a name of a global object property holding an object
-// optionally followed by ".prototype", a name of a builtin function
-// on the object (the one the id is set for), and a label.
-//
-// Installation of ids for the selected builtin functions is handled
-// by the bootstrapper.
-#define FUNCTIONS_WITH_ID_LIST(V)                           \
-  V(Array, isArray, ArrayIsArray)                           \
-  V(Array.prototype, concat, ArrayConcat)                   \
-  V(Array.prototype, every, ArrayEvery)                     \
-  V(Array.prototype, fill, ArrayFill)                       \
-  V(Array.prototype, filter, ArrayFilter)                   \
-  V(Array.prototype, findIndex, ArrayFindIndex)             \
-  V(Array.prototype, forEach, ArrayForEach)                 \
-  V(Array.prototype, includes, ArrayIncludes)               \
-  V(Array.prototype, indexOf, ArrayIndexOf)                 \
-  V(Array.prototype, join, ArrayJoin)                       \
-  V(Array.prototype, lastIndexOf, ArrayLastIndexOf)         \
-  V(Array.prototype, map, ArrayMap)                         \
-  V(Array.prototype, pop, ArrayPop)                         \
-  V(Array.prototype, push, ArrayPush)                       \
-  V(Array.prototype, reverse, ArrayReverse)                 \
-  V(Array.prototype, shift, ArrayShift)                     \
-  V(Array.prototype, slice, ArraySlice)                     \
-  V(Array.prototype, some, ArraySome)                       \
-  V(Array.prototype, splice, ArraySplice)                   \
-  V(Array.prototype, unshift, ArrayUnshift)                 \
-  V(Date, now, DateNow)                                     \
-  V(Date.prototype, getDate, DateGetDate)                   \
-  V(Date.prototype, getDay, DateGetDay)                     \
-  V(Date.prototype, getFullYear, DateGetFullYear)           \
-  V(Date.prototype, getHours, DateGetHours)                 \
-  V(Date.prototype, getMilliseconds, DateGetMilliseconds)   \
-  V(Date.prototype, getMinutes, DateGetMinutes)             \
-  V(Date.prototype, getMonth, DateGetMonth)                 \
-  V(Date.prototype, getSeconds, DateGetSeconds)             \
-  V(Date.prototype, getTime, DateGetTime)                   \
-  V(Function.prototype, apply, FunctionApply)               \
-  V(Function.prototype, bind, FunctionBind)                 \
-  V(Function.prototype, call, FunctionCall)                 \
-  V(Object, assign, ObjectAssign)                           \
-  V(Object, create, ObjectCreate)                           \
-  V(Object, is, ObjectIs)                                   \
-  V(Object.prototype, hasOwnProperty, ObjectHasOwnProperty) \
-  V(Object.prototype, isPrototypeOf, ObjectIsPrototypeOf)   \
-  V(Object.prototype, toString, ObjectToString)             \
-  V(RegExp.prototype, compile, RegExpCompile)               \
-  V(RegExp.prototype, exec, RegExpExec)                     \
-  V(RegExp.prototype, test, RegExpTest)                     \
-  V(RegExp.prototype, toString, RegExpToString)             \
-  V(String.prototype, charCodeAt, StringCharCodeAt)         \
-  V(String.prototype, charAt, StringCharAt)                 \
-  V(String.prototype, codePointAt, StringCodePointAt)       \
-  V(String.prototype, concat, StringConcat)                 \
-  V(String.prototype, endsWith, StringEndsWith)             \
-  V(String.prototype, includes, StringIncludes)             \
-  V(String.prototype, indexOf, StringIndexOf)               \
-  V(String.prototype, lastIndexOf, StringLastIndexOf)       \
-  V(String.prototype, repeat, StringRepeat)                 \
-  V(String.prototype, slice, StringSlice)                   \
-  V(String.prototype, startsWith, StringStartsWith)         \
-  V(String.prototype, substr, StringSubstr)                 \
-  V(String.prototype, substring, StringSubstring)           \
-  V(String.prototype, toLowerCase, StringToLowerCase)       \
-  V(String.prototype, toString, StringToString)             \
-  V(String.prototype, toUpperCase, StringToUpperCase)       \
-  V(String.prototype, trim, StringTrim)                     \
-  V(String.prototype, trimLeft, StringTrimStart)            \
-  V(String.prototype, trimRight, StringTrimEnd)             \
-  V(String.prototype, valueOf, StringValueOf)               \
-  V(String, fromCharCode, StringFromCharCode)               \
-  V(String, fromCodePoint, StringFromCodePoint)             \
-  V(String, raw, StringRaw)                                 \
-  V(Math, random, MathRandom)                               \
-  V(Math, floor, MathFloor)                                 \
-  V(Math, round, MathRound)                                 \
-  V(Math, ceil, MathCeil)                                   \
-  V(Math, abs, MathAbs)                                     \
-  V(Math, log, MathLog)                                     \
-  V(Math, log1p, MathLog1p)                                 \
-  V(Math, log2, MathLog2)                                   \
-  V(Math, log10, MathLog10)                                 \
-  V(Math, cbrt, MathCbrt)                                   \
-  V(Math, exp, MathExp)                                     \
-  V(Math, expm1, MathExpm1)                                 \
-  V(Math, sqrt, MathSqrt)                                   \
-  V(Math, pow, MathPow)                                     \
-  V(Math, max, MathMax)                                     \
-  V(Math, min, MathMin)                                     \
-  V(Math, cos, MathCos)                                     \
-  V(Math, cosh, MathCosh)                                   \
-  V(Math, sign, MathSign)                                   \
-  V(Math, sin, MathSin)                                     \
-  V(Math, sinh, MathSinh)                                   \
-  V(Math, tan, MathTan)                                     \
-  V(Math, tanh, MathTanh)                                   \
-  V(Math, acos, MathAcos)                                   \
-  V(Math, acosh, MathAcosh)                                 \
-  V(Math, asin, MathAsin)                                   \
-  V(Math, asinh, MathAsinh)                                 \
-  V(Math, atan, MathAtan)                                   \
-  V(Math, atan2, MathAtan2)                                 \
-  V(Math, atanh, MathAtanh)                                 \
-  V(Math, imul, MathImul)                                   \
-  V(Math, clz32, MathClz32)                                 \
-  V(Math, fround, MathFround)                               \
-  V(Math, trunc, MathTrunc)                                 \
-  V(Number, isFinite, NumberIsFinite)                       \
-  V(Number, isInteger, NumberIsInteger)                     \
-  V(Number, isNaN, NumberIsNaN)                             \
-  V(Number, isSafeInteger, NumberIsSafeInteger)             \
-  V(Number, parseFloat, NumberParseFloat)                   \
-  V(Number, parseInt, NumberParseInt)                       \
-  V(Number.prototype, toString, NumberToString)             \
-  V(Map.prototype, clear, MapClear)                         \
-  V(Map.prototype, delete, MapDelete)                       \
-  V(Map.prototype, entries, MapEntries)                     \
-  V(Map.prototype, forEach, MapForEach)                     \
-  V(Map.prototype, has, MapHas)                             \
-  V(Map.prototype, keys, MapKeys)                           \
-  V(Map.prototype, get, MapGet)                             \
-  V(Map.prototype, set, MapSet)                             \
-  V(Map.prototype, values, MapValues)                       \
-  V(Set.prototype, add, SetAdd)                             \
-  V(Set.prototype, clear, SetClear)                         \
-  V(Set.prototype, delete, SetDelete)                       \
-  V(Set.prototype, entries, SetEntries)                     \
-  V(Set.prototype, forEach, SetForEach)                     \
-  V(Set.prototype, has, SetHas)                             \
-  V(Set.prototype, values, SetValues)                       \
-  V(WeakMap.prototype, delete, WeakMapDelete)               \
-  V(WeakMap.prototype, has, WeakMapHas)                     \
-  V(WeakMap.prototype, set, WeakMapSet)                     \
-  V(WeakSet.prototype, add, WeakSetAdd)                     \
-  V(WeakSet.prototype, delete, WeakSetDelete)               \
-  V(WeakSet.prototype, has, WeakSetHas)
-
-#define ATOMIC_FUNCTIONS_WITH_ID_LIST(V)              \
-  V(Atomics, load, AtomicsLoad)                       \
-  V(Atomics, store, AtomicsStore)                     \
-  V(Atomics, exchange, AtomicsExchange)               \
-  V(Atomics, compareExchange, AtomicsCompareExchange) \
-  V(Atomics, add, AtomicsAdd)                         \
-  V(Atomics, sub, AtomicsSub)                         \
-  V(Atomics, and, AtomicsAnd)                         \
-  V(Atomics, or, AtomicsOr)                           \
-  V(Atomics, xor, AtomicsXor)
-
-enum class BuiltinFunctionId : uint8_t {
-  kArrayConstructor,
-#define DECL_FUNCTION_ID(ignored1, ignore2, name) k##name,
-  FUNCTIONS_WITH_ID_LIST(DECL_FUNCTION_ID)
-      ATOMIC_FUNCTIONS_WITH_ID_LIST(DECL_FUNCTION_ID)
-#undef DECL_FUNCTION_ID
-  // These are manually assigned to special getters during bootstrapping.
-  kArrayBufferByteLength,
-  kArrayBufferIsView,
-  kArrayEntries,
-  kArrayKeys,
-  kArrayValues,
-  kArrayIteratorNext,
-  kBigIntConstructor,
-  kMapSize,
-  kSetSize,
-  kMapIteratorNext,
-  kSetIteratorNext,
-  kDataViewBuffer,
-  kDataViewByteLength,
-  kDataViewByteOffset,
-  kFunctionHasInstance,
-  kGlobalDecodeURI,
-  kGlobalDecodeURIComponent,
-  kGlobalEncodeURI,
-  kGlobalEncodeURIComponent,
-  kGlobalEscape,
-  kGlobalUnescape,
-  kGlobalIsFinite,
-  kGlobalIsNaN,
-  kNumberConstructor,
-  kSymbolConstructor,
-  kTypedArrayByteLength,
-  kTypedArrayByteOffset,
-  kTypedArrayEntries,
-  kTypedArrayKeys,
-  kTypedArrayLength,
-  kTypedArrayToStringTag,
-  kTypedArrayValues,
-  kSharedArrayBufferByteLength,
-  kStringConstructor,
-  kStringIterator,
-  kStringIteratorNext,
-  kStringToLowerCaseIntl,
-  kStringToUpperCaseIntl,
-  kInvalidBuiltinFunctionId = static_cast<uint8_t>(-1),
-};
-
-// JSBoundFunction describes a bound function exotic object.
-class JSBoundFunction : public JSObject {
- public:
-  // [bound_target_function]: The wrapped function object.
-  inline Object* raw_bound_target_function() const;
-  DECL_ACCESSORS(bound_target_function, JSReceiver)
-
-  // [bound_this]: The value that is always passed as the this value when
-  // calling the wrapped function.
-  DECL_ACCESSORS(bound_this, Object)
-
-  // [bound_arguments]: A list of values whose elements are used as the first
-  // arguments to any call to the wrapped function.
-  DECL_ACCESSORS(bound_arguments, FixedArray)
-
-  static MaybeHandle<String> GetName(Isolate* isolate,
-                                     Handle<JSBoundFunction> function);
-  static Maybe<int> GetLength(Isolate* isolate,
-                              Handle<JSBoundFunction> function);
-  static MaybeHandle<Context> GetFunctionRealm(
-      Handle<JSBoundFunction> function);
-
-  DECL_CAST(JSBoundFunction)
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSBoundFunction)
-  DECL_VERIFIER(JSBoundFunction)
-
-  // The bound function's string representation implemented according
-  // to ES6 section 19.2.3.5 Function.prototype.toString ( ).
-  static Handle<String> ToString(Handle<JSBoundFunction> function);
-
-  // Layout description.
-  static const int kBoundTargetFunctionOffset = JSObject::kHeaderSize;
-  static const int kBoundThisOffset = kBoundTargetFunctionOffset + kPointerSize;
-  static const int kBoundArgumentsOffset = kBoundThisOffset + kPointerSize;
-  static const int kSize = kBoundArgumentsOffset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSBoundFunction);
-};
-
-
-// JSFunction describes JavaScript functions.
-class JSFunction: public JSObject {
- public:
-  // [prototype_or_initial_map]:
-  DECL_ACCESSORS(prototype_or_initial_map, Object)
-
-  // [shared]: The information about the function that
-  // can be shared by instances.
-  DECL_ACCESSORS(shared, SharedFunctionInfo)
-
-  static const int kLengthDescriptorIndex = 0;
-  static const int kNameDescriptorIndex = 1;
-  // Home object descriptor index when function has a [[HomeObject]] slot.
-  static const int kMaybeHomeObjectDescriptorIndex = 2;
-
-  // [context]: The context for this function.
-  inline Context* context();
-  inline bool has_context() const;
-  inline void set_context(Object* context);
-  inline JSGlobalProxy* global_proxy();
-  inline Context* native_context();
-
-  static Handle<Object> GetName(Isolate* isolate, Handle<JSFunction> function);
-  static Maybe<int> GetLength(Isolate* isolate, Handle<JSFunction> function);
-  static Handle<Context> GetFunctionRealm(Handle<JSFunction> function);
-
-  // [code]: The generated code object for this function.  Executed
-  // when the function is invoked, e.g. foo() or new foo(). See
-  // [[Call]] and [[Construct]] description in ECMA-262, section
-  // 8.6.2, page 27.
-  inline Code* code();
-  inline void set_code(Code* code);
-  inline void set_code_no_write_barrier(Code* code);
-
-  // Get the abstract code associated with the function, which will either be
-  // a Code object or a BytecodeArray.
-  inline AbstractCode* abstract_code();
-
-  // Tells whether or not this function is interpreted.
-  //
-  // Note: function->IsInterpreted() does not necessarily return the same value
-  // as function->shared()->IsInterpreted() because the closure might have been
-  // optimized.
-  inline bool IsInterpreted();
-
-  // Tells whether or not this function checks its optimization marker in its
-  // feedback vector.
-  inline bool ChecksOptimizationMarker();
-
-  // Tells whether or not this function holds optimized code.
-  //
-  // Note: Returning false does not necessarily mean that this function hasn't
-  // been optimized, as it may have optimized code on its feedback vector.
-  inline bool IsOptimized();
-
-  // Tells whether or not this function has optimized code available to it,
-  // either because it is optimized or because it has optimized code in its
-  // feedback vector.
-  inline bool HasOptimizedCode();
-
-  // Tells whether or not this function has a (non-zero) optimization marker.
-  inline bool HasOptimizationMarker();
-
-  // Mark this function for lazy recompilation. The function will be recompiled
-  // the next time it is executed.
-  void MarkForOptimization(ConcurrencyMode mode);
-
-  // Tells whether or not the function is already marked for lazy recompilation.
-  inline bool IsMarkedForOptimization();
-  inline bool IsMarkedForConcurrentOptimization();
-
-  // Tells whether or not the function is on the concurrent recompilation queue.
-  inline bool IsInOptimizationQueue();
-
-  // Clears the optimized code slot in the function's feedback vector.
-  inline void ClearOptimizedCodeSlot(const char* reason);
-
-  // Sets the optimization marker in the function's feedback vector.
-  inline void SetOptimizationMarker(OptimizationMarker marker);
-
-  // Clears the optimization marker in the function's feedback vector.
-  inline void ClearOptimizationMarker();
-
-  // If slack tracking is active, it computes instance size of the initial map
-  // with minimum permissible object slack.  If it is not active, it simply
-  // returns the initial map's instance size.
-  int ComputeInstanceSizeWithMinSlack(Isolate* isolate);
-
-  // Completes inobject slack tracking on initial map if it is active.
-  inline void CompleteInobjectSlackTrackingIfActive();
-
-  // [feedback_cell]: The FeedbackCell used to hold the FeedbackVector
-  // eventually.
-  DECL_ACCESSORS(feedback_cell, FeedbackCell)
-
-  // feedback_vector() can be used once the function is compiled.
-  inline FeedbackVector* feedback_vector() const;
-  inline bool has_feedback_vector() const;
-  static void EnsureFeedbackVector(Handle<JSFunction> function);
-
-  // Unconditionally clear the type feedback vector.
-  void ClearTypeFeedbackInfo();
-
-  inline bool has_prototype_slot() const;
-
-  // The initial map for an object created by this constructor.
-  inline Map* initial_map();
-  static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
-                            Handle<Object> prototype);
-  inline bool has_initial_map();
-  static void EnsureHasInitialMap(Handle<JSFunction> function);
-
-  // Creates a map that matches the constructor's initial map, but with
-  // [[prototype]] being new.target.prototype. Because new.target can be a
-  // JSProxy, this can call back into JavaScript.
-  static V8_WARN_UNUSED_RESULT MaybeHandle<Map> GetDerivedMap(
-      Isolate* isolate, Handle<JSFunction> constructor,
-      Handle<JSReceiver> new_target);
-
-  // Get and set the prototype property on a JSFunction. If the
-  // function has an initial map the prototype is set on the initial
-  // map. Otherwise, the prototype is put in the initial map field
-  // until an initial map is needed.
-  inline bool has_prototype();
-  inline bool has_instance_prototype();
-  inline Object* prototype();
-  inline Object* instance_prototype();
-  inline bool has_prototype_property();
-  inline bool PrototypeRequiresRuntimeLookup();
-  static void SetPrototype(Handle<JSFunction> function,
-                           Handle<Object> value);
-
-  // Returns if this function has been compiled to native code yet.
-  inline bool is_compiled();
-
-  static int GetHeaderSize(bool function_has_prototype_slot) {
-    return function_has_prototype_slot ? JSFunction::kSizeWithPrototype
-                                       : JSFunction::kSizeWithoutPrototype;
-  }
-
-  // Prints the name of the function using PrintF.
-  void PrintName(FILE* out = stdout);
-
-  DECL_CAST(JSFunction)
-
-  // Calculate the instance size and in-object properties count.
-  static bool CalculateInstanceSizeForDerivedClass(
-      Handle<JSFunction> function, InstanceType instance_type,
-      int requested_embedder_fields, int* instance_size,
-      int* in_object_properties);
-  static void CalculateInstanceSizeHelper(InstanceType instance_type,
-                                          bool has_prototype_slot,
-                                          int requested_embedder_fields,
-                                          int requested_in_object_properties,
-                                          int* instance_size,
-                                          int* in_object_properties);
-
-  class BodyDescriptor;
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSFunction)
-  DECL_VERIFIER(JSFunction)
-
-  // The function's name if it is configured, otherwise shared function info
-  // debug name.
-  static Handle<String> GetName(Handle<JSFunction> function);
-
-  // ES6 section 9.2.11 SetFunctionName
-  // Because of the way this abstract operation is used in the spec,
-  // it should never fail, but in practice it will fail if the generated
-  // function name's length exceeds String::kMaxLength.
-  static V8_WARN_UNUSED_RESULT bool SetName(Handle<JSFunction> function,
-                                            Handle<Name> name,
-                                            Handle<String> prefix);
-
-  // The function's displayName if it is set, otherwise name if it is
-  // configured, otherwise shared function info
-  // debug name.
-  static Handle<String> GetDebugName(Handle<JSFunction> function);
-
-  // The function's string representation implemented according to
-  // ES6 section 19.2.3.5 Function.prototype.toString ( ).
-  static Handle<String> ToString(Handle<JSFunction> function);
-
-// Layout description.
-#define JS_FUNCTION_FIELDS(V)                              \
-  /* Pointer fields. */                                    \
-  V(kSharedFunctionInfoOffset, kPointerSize)               \
-  V(kContextOffset, kPointerSize)                          \
-  V(kFeedbackCellOffset, kPointerSize)                     \
-  V(kEndOfStrongFieldsOffset, 0)                           \
-  V(kCodeOffset, kPointerSize)                             \
-  /* Size of JSFunction object without prototype field. */ \
-  V(kSizeWithoutPrototype, 0)                              \
-  V(kPrototypeOrInitialMapOffset, kPointerSize)            \
-  /* Size of JSFunction object with prototype field. */    \
-  V(kSizeWithPrototype, 0)
-
-  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, JS_FUNCTION_FIELDS)
-#undef JS_FUNCTION_FIELDS
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
-};
-
-
-// JSGlobalProxy's prototype must be a JSGlobalObject or null,
-// and the prototype is hidden. JSGlobalProxy always delegates
-// property accesses to its prototype if the prototype is not null.
-//
-// A JSGlobalProxy can be reinitialized which will preserve its identity.
-//
-// Accessing a JSGlobalProxy requires security check.
-
-class JSGlobalProxy : public JSObject {
- public:
-  // [native_context]: the owner native context of this global proxy object.
-  // It is null value if this object is not used by any context.
-  DECL_ACCESSORS(native_context, Object)
-
-  DECL_CAST(JSGlobalProxy)
-
-  inline bool IsDetachedFrom(JSGlobalObject* global) const;
-
-  static int SizeWithEmbedderFields(int embedder_field_count);
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSGlobalProxy)
-  DECL_VERIFIER(JSGlobalProxy)
-
-  // Layout description.
-  static const int kNativeContextOffset = JSObject::kHeaderSize;
-  static const int kSize = kNativeContextOffset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
-};
-
-
-// JavaScript global object.
-class JSGlobalObject : public JSObject {
- public:
-  // [native context]: the natives corresponding to this global object.
-  DECL_ACCESSORS(native_context, Context)
-
-  // [global proxy]: the global proxy object of the context
-  DECL_ACCESSORS(global_proxy, JSObject)
-
-  // Gets global object properties.
-  inline GlobalDictionary* global_dictionary();
-  inline void set_global_dictionary(GlobalDictionary* dictionary);
-
-  static void InvalidatePropertyCell(Handle<JSGlobalObject> object,
-                                     Handle<Name> name);
-  // Ensure that the global object has a cell for the given property name.
-  static Handle<PropertyCell> EnsureEmptyPropertyCell(
-      Handle<JSGlobalObject> global, Handle<Name> name,
-      PropertyCellType cell_type, int* entry_out = nullptr);
-
-  DECL_CAST(JSGlobalObject)
-
-  inline bool IsDetached();
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSGlobalObject)
-  DECL_VERIFIER(JSGlobalObject)
-
-  // Layout description.
-  static const int kNativeContextOffset = JSObject::kHeaderSize;
-  static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
-  static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
-  static const int kSize = kHeaderSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
-};
-
-
-// Representation for JS Wrapper objects, String, Number, Boolean, etc.
-class JSValue: public JSObject {
- public:
-  // [value]: the object being wrapped.
-  DECL_ACCESSORS(value, Object)
-
-  DECL_CAST(JSValue)
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSValue)
-  DECL_VERIFIER(JSValue)
-
-  // Layout description.
-  static const int kValueOffset = JSObject::kHeaderSize;
-  static const int kSize = kValueOffset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
-};
-
-
-class DateCache;
-
-// Representation for JS date objects.
-class JSDate: public JSObject {
- public:
-  static V8_WARN_UNUSED_RESULT MaybeHandle<JSDate> New(
-      Handle<JSFunction> constructor, Handle<JSReceiver> new_target, double tv);
-
-  // If one component is NaN, all of them are, indicating a NaN time value.
-  // [value]: the time value.
-  DECL_ACCESSORS(value, Object)
-  // [year]: caches year. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(year, Object)
-  // [month]: caches month. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(month, Object)
-  // [day]: caches day. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(day, Object)
-  // [weekday]: caches day of week. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(weekday, Object)
-  // [hour]: caches hours. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(hour, Object)
-  // [min]: caches minutes. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(min, Object)
-  // [sec]: caches seconds. Either undefined, smi, or NaN.
-  DECL_ACCESSORS(sec, Object)
-  // [cache stamp]: sample of the date cache stamp at the
-  // moment when chached fields were cached.
-  DECL_ACCESSORS(cache_stamp, Object)
-
-  DECL_CAST(JSDate)
-
-  // Returns the time value (UTC) identifying the current time.
-  static double CurrentTimeValue(Isolate* isolate);
-
-  // Returns the date field with the specified index.
-  // See FieldIndex for the list of date fields.
-  static Object* GetField(Object* date, Smi* index);
-
-  static Handle<Object> SetValue(Handle<JSDate> date, double v);
-
-  void SetValue(Object* value, bool is_value_nan);
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSDate)
-  DECL_VERIFIER(JSDate)
-
-  // The order is important. It must be kept in sync with date macros
-  // in macros.py.
-  enum FieldIndex {
-    kDateValue,
-    kYear,
-    kMonth,
-    kDay,
-    kWeekday,
-    kHour,
-    kMinute,
-    kSecond,
-    kFirstUncachedField,
-    kMillisecond = kFirstUncachedField,
-    kDays,
-    kTimeInDay,
-    kFirstUTCField,
-    kYearUTC = kFirstUTCField,
-    kMonthUTC,
-    kDayUTC,
-    kWeekdayUTC,
-    kHourUTC,
-    kMinuteUTC,
-    kSecondUTC,
-    kMillisecondUTC,
-    kDaysUTC,
-    kTimeInDayUTC,
-    kTimezoneOffset
-  };
-
-  // Layout description.
-  static const int kValueOffset = JSObject::kHeaderSize;
-  static const int kYearOffset = kValueOffset + kPointerSize;
-  static const int kMonthOffset = kYearOffset + kPointerSize;
-  static const int kDayOffset = kMonthOffset + kPointerSize;
-  static const int kWeekdayOffset = kDayOffset + kPointerSize;
-  static const int kHourOffset = kWeekdayOffset  + kPointerSize;
-  static const int kMinOffset = kHourOffset + kPointerSize;
-  static const int kSecOffset = kMinOffset + kPointerSize;
-  static const int kCacheStampOffset = kSecOffset + kPointerSize;
-  static const int kSize = kCacheStampOffset + kPointerSize;
-
- private:
-  inline Object* DoGetField(FieldIndex index);
-
-  Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
-
-  // Computes and caches the cacheable fields of the date.
-  inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
-
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
-};
-
-
-// Representation of message objects used for error reporting through
-// the API. The messages are formatted in JavaScript so this object is
-// a real JavaScript object. The information used for formatting the
-// error messages are not directly accessible from JavaScript to
-// prevent leaking information to user code called during error
-// formatting.
-class JSMessageObject: public JSObject {
- public:
-  // [type]: the type of error message.
-  inline int type() const;
-  inline void set_type(int value);
-
-  // [arguments]: the arguments for formatting the error message.
-  DECL_ACCESSORS(argument, Object)
-
-  // [script]: the script from which the error message originated.
-  DECL_ACCESSORS(script, Script)
-
-  // [stack_frames]: an array of stack frames for this error object.
-  DECL_ACCESSORS(stack_frames, Object)
-
-  // [start_position]: the start position in the script for the error message.
-  inline int start_position() const;
-  inline void set_start_position(int value);
-
-  // [end_position]: the end position in the script for the error message.
-  inline int end_position() const;
-  inline void set_end_position(int value);
-
-  // Returns the line number for the error message (1-based), or
-  // Message::kNoLineNumberInfo if the line cannot be determined.
-  int GetLineNumber() const;
-
-  // Returns the offset of the given position within the containing line.
-  int GetColumnNumber() const;
-
-  // Returns the source code line containing the given source
-  // position, or the empty string if the position is invalid.
-  Handle<String> GetSourceLine() const;
-
-  inline int error_level() const;
-  inline void set_error_level(int level);
-
-  DECL_CAST(JSMessageObject)
-
-  // Dispatched behavior.
-  DECL_PRINTER(JSMessageObject)
-  DECL_VERIFIER(JSMessageObject)
-
-  // Layout description.
-  static const int kTypeOffset = JSObject::kHeaderSize;
-  static const int kArgumentsOffset = kTypeOffset + kPointerSize;
-  static const int kScriptOffset = kArgumentsOffset + kPointerSize;
-  static const int kStackFramesOffset = kScriptOffset + kPointerSize;
-  static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
-  static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
-  static const int kErrorLevelOffset = kEndPositionOffset + kPointerSize;
-  static const int kSize = kErrorLevelOffset + kPointerSize;
-
-  typedef FixedBodyDescriptor<HeapObject::kMapOffset,
-                              kStackFramesOffset + kPointerSize,
-                              kSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
-};
-
-class AllocationSite : public Struct, public NeverReadOnlySpaceObject {
- public:
-  static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
-  static const double kPretenureRatio;
-  static const int kPretenureMinimumCreated = 100;
-
-  // Values for pretenure decision field.
-  enum PretenureDecision {
-    kUndecided = 0,
-    kDontTenure = 1,
-    kMaybeTenure = 2,
-    kTenure = 3,
-    kZombie = 4,
-    kLastPretenureDecisionValue = kZombie
-  };
-
-  // Use the mixin methods over the HeapObject methods.
-  // TODO(v8:7786) Remove once the HeapObject methods are gone.
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
-  const char* PretenureDecisionName(PretenureDecision decision);
-
-  // Contains either a Smi-encoded bitfield or a boilerplate. If it's a Smi the
-  // AllocationSite is for a constructed Array.
-  DECL_ACCESSORS(transition_info_or_boilerplate, Object)
-  DECL_ACCESSORS(boilerplate, JSObject)
-  DECL_INT_ACCESSORS(transition_info)
-
-  // nested_site threads a list of sites that represent nested literals
-  // walked in a particular order. So [[1, 2], 1, 2] will have one
-  // nested_site, but [[1, 2], 3, [4]] will have a list of two.
-  DECL_ACCESSORS(nested_site, Object)
-
-  // Bitfield containing pretenuring information.
-  DECL_INT32_ACCESSORS(pretenure_data)
-
-  DECL_INT32_ACCESSORS(pretenure_create_count)
-  DECL_ACCESSORS(dependent_code, DependentCode)
-
-  // heap->allocation_site_list() points to the last AllocationSite which form
-  // a linked list through the weak_next property. The GC might remove elements
-  // from the list by updateing weak_next.
-  DECL_ACCESSORS(weak_next, Object)
-
-  inline void Initialize();
-
-  // Checks if the allocation site contain weak_next field;
-  inline bool HasWeakNext() const;
-
-  // This method is expensive, it should only be called for reporting.
-  bool IsNested();
-
-  // transition_info bitfields, for constructed array transition info.
-  class ElementsKindBits:       public BitField<ElementsKind, 0,  15> {};
-  class UnusedBits:             public BitField<int,          15, 14> {};
-  class DoNotInlineBit:         public BitField<bool,         29,  1> {};
-
-  // Bitfields for pretenure_data
-  class MementoFoundCountBits:  public BitField<int,               0, 26> {};
-  class PretenureDecisionBits:  public BitField<PretenureDecision, 26, 3> {};
-  class DeoptDependentCodeBit:  public BitField<bool,              29, 1> {};
-  STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
-
-  // Increments the mementos found counter and returns true when the first
-  // memento was found for a given allocation site.
-  inline bool IncrementMementoFoundCount(int increment = 1);
-
-  inline void IncrementMementoCreateCount();
-
-  PretenureFlag GetPretenureMode() const;
-
-  void ResetPretenureDecision();
-
-  inline PretenureDecision pretenure_decision() const;
-  inline void set_pretenure_decision(PretenureDecision decision);
-
-  inline bool deopt_dependent_code() const;
-  inline void set_deopt_dependent_code(bool deopt);
-
-  inline int memento_found_count() const;
-  inline void set_memento_found_count(int count);
-
-  inline int memento_create_count() const;
-  inline void set_memento_create_count(int count);
-
-  // The pretenuring decision is made during gc, and the zombie state allows
-  // us to recognize when an allocation site is just being kept alive because
-  // a later traversal of new space may discover AllocationMementos that point
-  // to this AllocationSite.
-  inline bool IsZombie() const;
-
-  inline bool IsMaybeTenure() const;
-
-  inline void MarkZombie();
-
-  inline bool MakePretenureDecision(PretenureDecision current_decision,
-                                    double ratio,
-                                    bool maximum_size_scavenge);
-
-  inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
-
-  inline ElementsKind GetElementsKind() const;
-  inline void SetElementsKind(ElementsKind kind);
-
-  inline bool CanInlineCall() const;
-  inline void SetDoNotInlineCall();
-
-  inline bool PointsToLiteral() const;
-
-  template <AllocationSiteUpdateMode update_or_check =
-                AllocationSiteUpdateMode::kUpdate>
-  static bool DigestTransitionFeedback(Handle<AllocationSite> site,
-                                       ElementsKind to_kind);
-
-  DECL_PRINTER(AllocationSite)
-  DECL_VERIFIER(AllocationSite)
-
-  DECL_CAST(AllocationSite)
-  static inline bool ShouldTrack(ElementsKind boilerplate_elements_kind);
-  static bool ShouldTrack(ElementsKind from, ElementsKind to);
-  static inline bool CanTrack(InstanceType type);
-
-// Layout description.
-// AllocationSite has to start with TransitionInfoOrboilerPlateOffset
-// and end with WeakNext field.
-#define ALLOCATION_SITE_FIELDS(V)                     \
-  V(kTransitionInfoOrBoilerplateOffset, kPointerSize) \
-  V(kNestedSiteOffset, kPointerSize)                  \
-  V(kDependentCodeOffset, kPointerSize)               \
-  V(kCommonPointerFieldEndOffset, 0)                  \
-  V(kPretenureDataOffset, kInt32Size)                 \
-  V(kPretenureCreateCountOffset, kInt32Size)          \
-  /* Size of AllocationSite without WeakNext field */ \
-  V(kSizeWithoutWeakNext, 0)                          \
-  V(kWeakNextOffset, kPointerSize)                    \
-  /* Size of AllocationSite with WeakNext field */    \
-  V(kSizeWithWeakNext, 0)
-
-  DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, ALLOCATION_SITE_FIELDS)
-
-  static const int kStartOffset = HeapObject::kHeaderSize;
-
-  template <bool includeWeakNext>
-  class BodyDescriptorImpl;
-
-  // BodyDescriptor is used to traverse all the pointer fields including
-  // weak_next
-  typedef BodyDescriptorImpl<true> BodyDescriptor;
-
-  // BodyDescriptorWeak is used to traverse all the pointer fields
-  // except for weak_next
-  typedef BodyDescriptorImpl<false> BodyDescriptorWeak;
-
- private:
-  inline bool PretenuringDecisionMade() const;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
-};
-
-
-class AllocationMemento: public Struct {
- public:
-  static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
-  static const int kSize = kAllocationSiteOffset + kPointerSize;
-
-  DECL_ACCESSORS(allocation_site, Object)
-
-  inline bool IsValid() const;
-  inline AllocationSite* GetAllocationSite() const;
-  inline Address GetAllocationSiteUnchecked() const;
-
-  DECL_PRINTER(AllocationMemento)
-  DECL_VERIFIER(AllocationMemento)
-
-  DECL_CAST(AllocationMemento)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
-};
-
-
 // Utility superclass for stack-allocated objects that must be updated
 // on gc.  It provides two ways for the gc to update instances, either
 // iterating or updating after gc.
-class Relocatable BASE_EMBEDDED {
+class Relocatable {
  public:
   explicit inline Relocatable(Isolate* isolate);
   inline virtual ~Relocatable();
@@ -3900,8 +2054,6 @@ class Oddball: public HeapObject {
 
   typedef FixedBodyDescriptor<kToStringOffset, kTypeOfOffset + kPointerSize,
                               kSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   STATIC_ASSERT(kToNumberRawOffset == HeapNumber::kValueOffset);
   STATIC_ASSERT(kKindOffset == Internals::kOddballKindOffset);
@@ -3940,8 +2092,6 @@ class Cell: public HeapObject {
   typedef FixedBodyDescriptor<kValueOffset,
                               kValueOffset + kPointerSize,
                               kSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
@@ -3968,8 +2118,6 @@ class FeedbackCell : public Struct {
 
   typedef FixedBodyDescriptor<kValueOffset, kValueOffset + kPointerSize, kSize>
       BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(FeedbackCell);
@@ -4026,67 +2174,11 @@ class PropertyCell : public HeapObject {
   static const int kSize = kDependentCodeOffset + kPointerSize;
 
   typedef FixedBodyDescriptor<kNameOffset, kSize, kSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyCell);
 };
 
-// The [Async-from-Sync Iterator] object
-// (proposal-async-iteration/#sec-async-from-sync-iterator-objects)
-// An object which wraps an ordinary Iterator and converts it to behave
-// according to the Async Iterator protocol.
-// (See https://tc39.github.io/proposal-async-iteration/#sec-iteration)
-class JSAsyncFromSyncIterator : public JSObject {
- public:
-  DECL_CAST(JSAsyncFromSyncIterator)
-  DECL_PRINTER(JSAsyncFromSyncIterator)
-  DECL_VERIFIER(JSAsyncFromSyncIterator)
-
-  // Async-from-Sync Iterator instances are ordinary objects that inherit
-  // properties from the %AsyncFromSyncIteratorPrototype% intrinsic object.
-  // Async-from-Sync Iterator instances are initially created with the internal
-  // slots listed in Table 4.
-  // (proposal-async-iteration/#table-async-from-sync-iterator-internal-slots)
-  DECL_ACCESSORS(sync_iterator, JSReceiver)
-
-  // The "next" method is loaded during GetIterator, and is not reloaded for
-  // subsequent "next" invocations.
-  DECL_ACCESSORS(next, Object)
-
-  // Offsets of object fields.
-  static const int kSyncIteratorOffset = JSObject::kHeaderSize;
-  static const int kNextOffset = kSyncIteratorOffset + kPointerSize;
-  static const int kSize = kNextOffset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSAsyncFromSyncIterator);
-};
-
-class JSStringIterator : public JSObject {
- public:
-  // Dispatched behavior.
-  DECL_PRINTER(JSStringIterator)
-  DECL_VERIFIER(JSStringIterator)
-
-  DECL_CAST(JSStringIterator)
-
-  // [string]: the [[IteratedString]] inobject property.
-  DECL_ACCESSORS(string, String)
-
-  // [index]: The [[StringIteratorNextIndex]] inobject property.
-  inline int index() const;
-  inline void set_index(int value);
-
-  static const int kStringOffset = JSObject::kHeaderSize;
-  static const int kNextIndexOffset = kStringOffset + kPointerSize;
-  static const int kSize = kNextIndexOffset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSStringIterator);
-};
-
 // Foreign describes objects pointing from JavaScript to C structures.
 class Foreign: public HeapObject {
  public:
@@ -4109,8 +2201,6 @@ class Foreign: public HeapObject {
   STATIC_ASSERT(kForeignAddressOffset == Internals::kForeignAddressOffset);
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   friend class Factory;
@@ -4172,66 +2262,6 @@ class AccessorPair: public Struct {
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
 };
 
-class StackFrameInfo : public Struct, public NeverReadOnlySpaceObject {
- public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
-  DECL_INT_ACCESSORS(line_number)
-  DECL_INT_ACCESSORS(column_number)
-  DECL_INT_ACCESSORS(script_id)
-  DECL_ACCESSORS(script_name, Object)
-  DECL_ACCESSORS(script_name_or_source_url, Object)
-  DECL_ACCESSORS(function_name, Object)
-  DECL_BOOLEAN_ACCESSORS(is_eval)
-  DECL_BOOLEAN_ACCESSORS(is_constructor)
-  DECL_BOOLEAN_ACCESSORS(is_wasm)
-  DECL_INT_ACCESSORS(flag)
-  DECL_INT_ACCESSORS(id)
-
-  DECL_CAST(StackFrameInfo)
-
-  // Dispatched behavior.
-  DECL_PRINTER(StackFrameInfo)
-  DECL_VERIFIER(StackFrameInfo)
-
-  static const int kLineNumberIndex = Struct::kHeaderSize;
-  static const int kColumnNumberIndex = kLineNumberIndex + kPointerSize;
-  static const int kScriptIdIndex = kColumnNumberIndex + kPointerSize;
-  static const int kScriptNameIndex = kScriptIdIndex + kPointerSize;
-  static const int kScriptNameOrSourceUrlIndex =
-      kScriptNameIndex + kPointerSize;
-  static const int kFunctionNameIndex =
-      kScriptNameOrSourceUrlIndex + kPointerSize;
-  static const int kFlagIndex = kFunctionNameIndex + kPointerSize;
-  static const int kIdIndex = kFlagIndex + kPointerSize;
-  static const int kSize = kIdIndex + kPointerSize;
-
- private:
-  // Bit position in the flag, from least significant bit position.
-  static const int kIsEvalBit = 0;
-  static const int kIsConstructorBit = 1;
-  static const int kIsWasmBit = 2;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(StackFrameInfo);
-};
-
-class SourcePositionTableWithFrameCache : public Tuple2 {
- public:
-  DECL_ACCESSORS(source_position_table, ByteArray)
-  DECL_ACCESSORS(stack_frame_cache, SimpleNumberDictionary)
-
-  DECL_CAST(SourcePositionTableWithFrameCache)
-
-  static const int kSourcePositionTableIndex = Struct::kHeaderSize;
-  static const int kStackFrameCacheIndex =
-      kSourcePositionTableIndex + kPointerSize;
-  static const int kSize = kStackFrameCacheIndex + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(SourcePositionTableWithFrameCache);
-};
-
 // BooleanBit is a helper class for setting and getting a bit in an integer.
 class BooleanBit : public AllStatic {
  public:
diff --git a/deps/v8/src/objects/allocation-site-inl.h b/deps/v8/src/objects/allocation-site-inl.h
new file mode 100644
index 0000000000..2ed280c054
--- /dev/null
+++ b/deps/v8/src/objects/allocation-site-inl.h
@@ -0,0 +1,197 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_ALLOCATION_SITE_INL_H_
+#define V8_OBJECTS_ALLOCATION_SITE_INL_H_
+
+#include "src/objects/allocation-site.h"
+
+#include "src/heap/heap-inl.h"
+#include "src/objects/js-objects-inl.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(AllocationMemento)
+CAST_ACCESSOR(AllocationSite)
+
+ACCESSORS(AllocationSite, transition_info_or_boilerplate, Object,
+          kTransitionInfoOrBoilerplateOffset)
+ACCESSORS(AllocationSite, nested_site, Object, kNestedSiteOffset)
+INT32_ACCESSORS(AllocationSite, pretenure_data, kPretenureDataOffset)
+INT32_ACCESSORS(AllocationSite, pretenure_create_count,
+                kPretenureCreateCountOffset)
+ACCESSORS(AllocationSite, dependent_code, DependentCode, kDependentCodeOffset)
+ACCESSORS_CHECKED(AllocationSite, weak_next, Object, kWeakNextOffset,
+                  HasWeakNext())
+ACCESSORS(AllocationMemento, allocation_site, Object, kAllocationSiteOffset)
+
+JSObject* AllocationSite::boilerplate() const {
+  DCHECK(PointsToLiteral());
+  return JSObject::cast(transition_info_or_boilerplate());
+}
+
+void AllocationSite::set_boilerplate(JSObject* object, WriteBarrierMode mode) {
+  set_transition_info_or_boilerplate(object, mode);
+}
+
+int AllocationSite::transition_info() const {
+  DCHECK(!PointsToLiteral());
+  return Smi::cast(transition_info_or_boilerplate())->value();
+}
+
+void AllocationSite::set_transition_info(int value) {
+  DCHECK(!PointsToLiteral());
+  set_transition_info_or_boilerplate(Smi::FromInt(value), SKIP_WRITE_BARRIER);
+}
+
+bool AllocationSite::HasWeakNext() const {
+  return map() == GetReadOnlyRoots().allocation_site_map();
+}
+
+void AllocationSite::Initialize() {
+  set_transition_info_or_boilerplate(Smi::kZero);
+  SetElementsKind(GetInitialFastElementsKind());
+  set_nested_site(Smi::kZero);
+  set_pretenure_data(0);
+  set_pretenure_create_count(0);
+  set_dependent_code(
+      DependentCode::cast(GetReadOnlyRoots().empty_weak_fixed_array()),
+      SKIP_WRITE_BARRIER);
+}
+
+bool AllocationSite::IsZombie() const {
+  return pretenure_decision() == kZombie;
+}
+
+bool AllocationSite::IsMaybeTenure() const {
+  return pretenure_decision() == kMaybeTenure;
+}
+
+bool AllocationSite::PretenuringDecisionMade() const {
+  return pretenure_decision() != kUndecided;
+}
+
+void AllocationSite::MarkZombie() {
+  DCHECK(!IsZombie());
+  Initialize();
+  set_pretenure_decision(kZombie);
+}
+
+ElementsKind AllocationSite::GetElementsKind() const {
+  return ElementsKindBits::decode(transition_info());
+}
+
+void AllocationSite::SetElementsKind(ElementsKind kind) {
+  set_transition_info(ElementsKindBits::update(transition_info(), kind));
+}
+
+bool AllocationSite::CanInlineCall() const {
+  return DoNotInlineBit::decode(transition_info()) == 0;
+}
+
+void AllocationSite::SetDoNotInlineCall() {
+  set_transition_info(DoNotInlineBit::update(transition_info(), true));
+}
+
+bool AllocationSite::PointsToLiteral() const {
+  Object* raw_value = transition_info_or_boilerplate();
+  DCHECK_EQ(!raw_value->IsSmi(),
+            raw_value->IsJSArray() || raw_value->IsJSObject());
+  return !raw_value->IsSmi();
+}
+
+// Heuristic: We only need to create allocation site info if the boilerplate
+// elements kind is the initial elements kind.
+bool AllocationSite::ShouldTrack(ElementsKind boilerplate_elements_kind) {
+  return IsSmiElementsKind(boilerplate_elements_kind);
+}
+
+inline bool AllocationSite::CanTrack(InstanceType type) {
+  if (FLAG_allocation_site_pretenuring) {
+    // TurboFan doesn't care at all about String pretenuring feedback,
+    // so don't bother even trying to track that.
+    return type == JS_ARRAY_TYPE || type == JS_OBJECT_TYPE;
+  }
+  return type == JS_ARRAY_TYPE;
+}
+
+AllocationSite::PretenureDecision AllocationSite::pretenure_decision() const {
+  return PretenureDecisionBits::decode(pretenure_data());
+}
+
+void AllocationSite::set_pretenure_decision(PretenureDecision decision) {
+  int32_t value = pretenure_data();
+  set_pretenure_data(PretenureDecisionBits::update(value, decision));
+}
+
+bool AllocationSite::deopt_dependent_code() const {
+  return DeoptDependentCodeBit::decode(pretenure_data());
+}
+
+void AllocationSite::set_deopt_dependent_code(bool deopt) {
+  int32_t value = pretenure_data();
+  set_pretenure_data(DeoptDependentCodeBit::update(value, deopt));
+}
+
+int AllocationSite::memento_found_count() const {
+  return MementoFoundCountBits::decode(pretenure_data());
+}
+
+inline void AllocationSite::set_memento_found_count(int count) {
+  int32_t value = pretenure_data();
+  // Verify that we can count more mementos than we can possibly find in one
+  // new space collection.
+  DCHECK((GetHeap()->MaxSemiSpaceSize() /
+          (Heap::kMinObjectSizeInWords * kPointerSize +
+           AllocationMemento::kSize)) < MementoFoundCountBits::kMax);
+  DCHECK_LT(count, MementoFoundCountBits::kMax);
+  set_pretenure_data(MementoFoundCountBits::update(value, count));
+}
+
+int AllocationSite::memento_create_count() const {
+  return pretenure_create_count();
+}
+
+void AllocationSite::set_memento_create_count(int count) {
+  set_pretenure_create_count(count);
+}
+
+bool AllocationSite::IncrementMementoFoundCount(int increment) {
+  if (IsZombie()) return false;
+
+  int value = memento_found_count();
+  set_memento_found_count(value + increment);
+  return memento_found_count() >= kPretenureMinimumCreated;
+}
+
+inline void AllocationSite::IncrementMementoCreateCount() {
+  DCHECK(FLAG_allocation_site_pretenuring);
+  int value = memento_create_count();
+  set_memento_create_count(value + 1);
+}
+
+bool AllocationMemento::IsValid() const {
+  return allocation_site()->IsAllocationSite() &&
+         !AllocationSite::cast(allocation_site())->IsZombie();
+}
+
+AllocationSite* AllocationMemento::GetAllocationSite() const {
+  DCHECK(IsValid());
+  return AllocationSite::cast(allocation_site());
+}
+
+Address AllocationMemento::GetAllocationSiteUnchecked() const {
+  return reinterpret_cast<Address>(allocation_site());
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_ALLOCATION_SITE_INL_H_
diff --git a/deps/v8/src/objects/allocation-site.h b/deps/v8/src/objects/allocation-site.h
new file mode 100644
index 0000000000..d923fd8f23
--- /dev/null
+++ b/deps/v8/src/objects/allocation-site.h
@@ -0,0 +1,186 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_ALLOCATION_SITE_H_
+#define V8_OBJECTS_ALLOCATION_SITE_H_
+
+#include "src/objects.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+class AllocationSite : public Struct, public NeverReadOnlySpaceObject {
+ public:
+  static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
+  static const double kPretenureRatio;
+  static const int kPretenureMinimumCreated = 100;
+
+  // Values for pretenure decision field.
+  enum PretenureDecision {
+    kUndecided = 0,
+    kDontTenure = 1,
+    kMaybeTenure = 2,
+    kTenure = 3,
+    kZombie = 4,
+    kLastPretenureDecisionValue = kZombie
+  };
+
+  const char* PretenureDecisionName(PretenureDecision decision);
+
+  // Contains either a Smi-encoded bitfield or a boilerplate. If it's a Smi the
+  // AllocationSite is for a constructed Array.
+  DECL_ACCESSORS(transition_info_or_boilerplate, Object)
+  DECL_ACCESSORS(boilerplate, JSObject)
+  DECL_INT_ACCESSORS(transition_info)
+
+  // nested_site threads a list of sites that represent nested literals
+  // walked in a particular order. So [[1, 2], 1, 2] will have one
+  // nested_site, but [[1, 2], 3, [4]] will have a list of two.
+  DECL_ACCESSORS(nested_site, Object)
+
+  // Bitfield containing pretenuring information.
+  DECL_INT32_ACCESSORS(pretenure_data)
+
+  DECL_INT32_ACCESSORS(pretenure_create_count)
+  DECL_ACCESSORS(dependent_code, DependentCode)
+
+  // heap->allocation_site_list() points to the last AllocationSite which form
+  // a linked list through the weak_next property. The GC might remove elements
+  // from the list by updateing weak_next.
+  DECL_ACCESSORS(weak_next, Object)
+
+  inline void Initialize();
+
+  // Checks if the allocation site contain weak_next field;
+  inline bool HasWeakNext() const;
+
+  // This method is expensive, it should only be called for reporting.
+  bool IsNested();
+
+  // transition_info bitfields, for constructed array transition info.
+  class ElementsKindBits : public BitField<ElementsKind, 0, 5> {};
+  class DoNotInlineBit : public BitField<bool, 5, 1> {};
+  // Unused bits 6-30.
+
+  // Bitfields for pretenure_data
+  class MementoFoundCountBits : public BitField<int, 0, 26> {};
+  class PretenureDecisionBits : public BitField<PretenureDecision, 26, 3> {};
+  class DeoptDependentCodeBit : public BitField<bool, 29, 1> {};
+  STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
+
+  // Increments the mementos found counter and returns true when the first
+  // memento was found for a given allocation site.
+  inline bool IncrementMementoFoundCount(int increment = 1);
+
+  inline void IncrementMementoCreateCount();
+
+  PretenureFlag GetPretenureMode() const;
+
+  void ResetPretenureDecision();
+
+  inline PretenureDecision pretenure_decision() const;
+  inline void set_pretenure_decision(PretenureDecision decision);
+
+  inline bool deopt_dependent_code() const;
+  inline void set_deopt_dependent_code(bool deopt);
+
+  inline int memento_found_count() const;
+  inline void set_memento_found_count(int count);
+
+  inline int memento_create_count() const;
+  inline void set_memento_create_count(int count);
+
+  // The pretenuring decision is made during gc, and the zombie state allows
+  // us to recognize when an allocation site is just being kept alive because
+  // a later traversal of new space may discover AllocationMementos that point
+  // to this AllocationSite.
+  inline bool IsZombie() const;
+
+  inline bool IsMaybeTenure() const;
+
+  inline void MarkZombie();
+
+  inline bool MakePretenureDecision(PretenureDecision current_decision,
+                                    double ratio, bool maximum_size_scavenge);
+
+  inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
+
+  inline ElementsKind GetElementsKind() const;
+  inline void SetElementsKind(ElementsKind kind);
+
+  inline bool CanInlineCall() const;
+  inline void SetDoNotInlineCall();
+
+  inline bool PointsToLiteral() const;
+
+  template <AllocationSiteUpdateMode update_or_check =
+                AllocationSiteUpdateMode::kUpdate>
+  static bool DigestTransitionFeedback(Handle<AllocationSite> site,
+                                       ElementsKind to_kind);
+
+  DECL_PRINTER(AllocationSite)
+  DECL_VERIFIER(AllocationSite)
+
+  DECL_CAST(AllocationSite)
+  static inline bool ShouldTrack(ElementsKind boilerplate_elements_kind);
+  static bool ShouldTrack(ElementsKind from, ElementsKind to);
+  static inline bool CanTrack(InstanceType type);
+
+// Layout description.
+// AllocationSite has to start with TransitionInfoOrboilerPlateOffset
+// and end with WeakNext field.
+#define ALLOCATION_SITE_FIELDS(V)                     \
+  V(kTransitionInfoOrBoilerplateOffset, kPointerSize) \
+  V(kNestedSiteOffset, kPointerSize)                  \
+  V(kDependentCodeOffset, kPointerSize)               \
+  V(kCommonPointerFieldEndOffset, 0)                  \
+  V(kPretenureDataOffset, kInt32Size)                 \
+  V(kPretenureCreateCountOffset, kInt32Size)          \
+  /* Size of AllocationSite without WeakNext field */ \
+  V(kSizeWithoutWeakNext, 0)                          \
+  V(kWeakNextOffset, kPointerSize)                    \
+  /* Size of AllocationSite with WeakNext field */    \
+  V(kSizeWithWeakNext, 0)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, ALLOCATION_SITE_FIELDS)
+
+  static const int kStartOffset = HeapObject::kHeaderSize;
+
+  class BodyDescriptor;
+
+ private:
+  inline bool PretenuringDecisionMade() const;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationSite);
+};
+
+class AllocationMemento : public Struct {
+ public:
+  static const int kAllocationSiteOffset = HeapObject::kHeaderSize;
+  static const int kSize = kAllocationSiteOffset + kPointerSize;
+
+  DECL_ACCESSORS(allocation_site, Object)
+
+  inline bool IsValid() const;
+  inline AllocationSite* GetAllocationSite() const;
+  inline Address GetAllocationSiteUnchecked() const;
+
+  DECL_PRINTER(AllocationMemento)
+  DECL_VERIFIER(AllocationMemento)
+
+  DECL_CAST(AllocationMemento)
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationMemento);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_ALLOCATION_SITE_H_
diff --git a/deps/v8/src/objects/api-callbacks-inl.h b/deps/v8/src/objects/api-callbacks-inl.h
index 4f7680d8ed..b8ca8bef20 100644
--- a/deps/v8/src/objects/api-callbacks-inl.h
+++ b/deps/v8/src/objects/api-callbacks-inl.h
@@ -59,8 +59,22 @@ BIT_FIELD_ACCESSORS(AccessorInfo, flags, is_special_data_property,
 BIT_FIELD_ACCESSORS(AccessorInfo, flags, replace_on_access,
                     AccessorInfo::ReplaceOnAccessBit)
 BIT_FIELD_ACCESSORS(AccessorInfo, flags, is_sloppy, AccessorInfo::IsSloppyBit)
-BIT_FIELD_ACCESSORS(AccessorInfo, flags, has_no_side_effect,
-                    AccessorInfo::HasNoSideEffectBit)
+BIT_FIELD_ACCESSORS(AccessorInfo, flags, getter_side_effect_type,
+                    AccessorInfo::GetterSideEffectTypeBits)
+
+SideEffectType AccessorInfo::setter_side_effect_type() const {
+  return SetterSideEffectTypeBits::decode(flags());
+}
+
+void AccessorInfo::set_setter_side_effect_type(SideEffectType value) {
+  // We do not support describing setters as having no side effect, since
+  // calling set accessors must go through a store bytecode. Store bytecodes
+  // support checking receivers for temporary objects, but still expect
+  // the receiver to be written to.
+  CHECK_NE(value, SideEffectType::kHasNoSideEffect);
+  set_flags(SetterSideEffectTypeBits::update(flags(), value));
+}
+
 BIT_FIELD_ACCESSORS(AccessorInfo, flags, initial_property_attributes,
                     AccessorInfo::InitialAttributesBits)
 
diff --git a/deps/v8/src/objects/api-callbacks.h b/deps/v8/src/objects/api-callbacks.h
index 6f3629a2c3..f7522da8a7 100644
--- a/deps/v8/src/objects/api-callbacks.h
+++ b/deps/v8/src/objects/api-callbacks.h
@@ -48,7 +48,12 @@ class AccessorInfo : public Struct {
   DECL_BOOLEAN_ACCESSORS(is_special_data_property)
   DECL_BOOLEAN_ACCESSORS(replace_on_access)
   DECL_BOOLEAN_ACCESSORS(is_sloppy)
-  DECL_BOOLEAN_ACCESSORS(has_no_side_effect)
+
+  inline SideEffectType getter_side_effect_type() const;
+  inline void set_getter_side_effect_type(SideEffectType type);
+
+  inline SideEffectType setter_side_effect_type() const;
+  inline void set_setter_side_effect_type(SideEffectType type);
 
   // The property attributes used when an API object template is instantiated
   // for the first time. Changing of this value afterwards does not affect
@@ -89,13 +94,15 @@ class AccessorInfo : public Struct {
   inline bool HasExpectedReceiverType();
 
 // Bit positions in |flags|.
-#define ACCESSOR_INFO_FLAGS_BIT_FIELDS(V, _) \
-  V(AllCanReadBit, bool, 1, _)               \
-  V(AllCanWriteBit, bool, 1, _)              \
-  V(IsSpecialDataPropertyBit, bool, 1, _)    \
-  V(IsSloppyBit, bool, 1, _)                 \
-  V(ReplaceOnAccessBit, bool, 1, _)          \
-  V(HasNoSideEffectBit, bool, 1, _)          \
+#define ACCESSOR_INFO_FLAGS_BIT_FIELDS(V, _)                           \
+  V(AllCanReadBit, bool, 1, _)                                         \
+  V(AllCanWriteBit, bool, 1, _)                                        \
+  V(IsSpecialDataPropertyBit, bool, 1, _)                              \
+  V(IsSloppyBit, bool, 1, _)                                           \
+  V(ReplaceOnAccessBit, bool, 1, _)                                    \
+  V(GetterSideEffectTypeBits, SideEffectType, 2, _)                    \
+  /* We could save a bit from setter side-effect type, if necessary */ \
+  V(SetterSideEffectTypeBits, SideEffectType, 2, _)                    \
   V(InitialAttributesBits, PropertyAttributes, 3, _)
 
   DEFINE_BIT_FIELDS(ACCESSOR_INFO_FLAGS_BIT_FIELDS)
diff --git a/deps/v8/src/objects/arguments-inl.h b/deps/v8/src/objects/arguments-inl.h
index 7d92ce0496..222ca7954e 100644
--- a/deps/v8/src/objects/arguments-inl.h
+++ b/deps/v8/src/objects/arguments-inl.h
@@ -63,7 +63,8 @@ bool JSSloppyArgumentsObject::GetSloppyArgumentsLength(Isolate* isolate,
     return false;
   }
   DCHECK(object->HasFastElements() || object->HasFastArgumentsElements());
-  Object* len_obj = object->InObjectPropertyAt(JSArgumentsObject::kLengthIndex);
+  Object* len_obj =
+      object->InObjectPropertyAt(JSArgumentsObjectWithLength::kLengthIndex);
   if (!len_obj->IsSmi()) return false;
   *out = Max(0, Smi::ToInt(len_obj));
 
diff --git a/deps/v8/src/objects/arguments.h b/deps/v8/src/objects/arguments.h
index 36c6204d1a..15f3d2a2f5 100644
--- a/deps/v8/src/objects/arguments.h
+++ b/deps/v8/src/objects/arguments.h
@@ -5,8 +5,8 @@
 #ifndef V8_OBJECTS_ARGUMENTS_H_
 #define V8_OBJECTS_ARGUMENTS_H_
 
-#include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -14,11 +14,21 @@
 namespace v8 {
 namespace internal {
 
+// Superclass for all objects with instance type {JS_ARGUMENTS_TYPE}
+class JSArgumentsObject : public JSObject {
+ public:
+  DECL_VERIFIER(JSArgumentsObject)
+  DECL_CAST(JSArgumentsObject)
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSArgumentsObject);
+};
+
 // Common superclass for JSSloppyArgumentsObject and JSStrictArgumentsObject.
 // Note that the instance type {JS_ARGUMENTS_TYPE} does _not_ guarantee the
 // below layout, the in-object properties might have transitioned to dictionary
 // mode already. Only use the below layout with the specific initial maps.
-class JSArgumentsObject : public JSObject {
+class JSArgumentsObjectWithLength : public JSArgumentsObject {
  public:
   // Offsets of object fields.
   static const int kLengthOffset = JSObject::kHeaderSize;
@@ -26,19 +36,19 @@ class JSArgumentsObject : public JSObject {
   // Indices of in-object properties.
   static const int kLengthIndex = 0;
 
-  DECL_VERIFIER(JSArgumentsObject)
-  DECL_CAST(JSArgumentsObject)
+  DECL_VERIFIER(JSArgumentsObjectWithLength)
+  DECL_CAST(JSArgumentsObjectWithLength)
 
  private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSArgumentsObject);
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSArgumentsObjectWithLength);
 };
 
 // JSSloppyArgumentsObject is just a JSObject with specific initial map.
 // This initial map adds in-object properties for "length" and "callee".
-class JSSloppyArgumentsObject : public JSArgumentsObject {
+class JSSloppyArgumentsObject : public JSArgumentsObjectWithLength {
  public:
   // Offsets of object fields.
-  static const int kCalleeOffset = JSArgumentsObject::kSize;
+  static const int kCalleeOffset = JSArgumentsObjectWithLength::kSize;
   static const int kSize = kCalleeOffset + kPointerSize;
   // Indices of in-object properties.
   static const int kCalleeIndex = kLengthIndex + 1;
@@ -53,10 +63,10 @@ class JSSloppyArgumentsObject : public JSArgumentsObject {
 
 // JSStrictArgumentsObject is just a JSObject with specific initial map.
 // This initial map adds an in-object property for "length".
-class JSStrictArgumentsObject : public JSArgumentsObject {
+class JSStrictArgumentsObject : public JSArgumentsObjectWithLength {
  public:
   // Offsets of object fields.
-  static const int kSize = JSArgumentsObject::kSize;
+  static const int kSize = JSArgumentsObjectWithLength::kSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSStrictArgumentsObject);
diff --git a/deps/v8/src/objects/bigint.cc b/deps/v8/src/objects/bigint.cc
index 458aa7c1eb..dcf99e2f29 100644
--- a/deps/v8/src/objects/bigint.cc
+++ b/deps/v8/src/objects/bigint.cc
@@ -36,9 +36,6 @@ namespace internal {
 class MutableBigInt : public FreshlyAllocatedBigInt,
                       public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   // Bottleneck for converting MutableBigInts to BigInts.
   static MaybeHandle<BigInt> MakeImmutable(MaybeHandle<MutableBigInt> maybe);
   static Handle<BigInt> MakeImmutable(Handle<MutableBigInt> result);
@@ -96,7 +93,8 @@ class MutableBigInt : public FreshlyAllocatedBigInt,
   static inline Handle<MutableBigInt> AbsoluteBitwiseOp(
       Isolate* isolate, Handle<BigIntBase> x, Handle<BigIntBase> y,
       MutableBigInt* result_storage, ExtraDigitsHandling extra_digits,
-      SymmetricOp symmetric, std::function<digit_t(digit_t, digit_t)> op);
+      SymmetricOp symmetric,
+      const std::function<digit_t(digit_t, digit_t)>& op);
   static Handle<MutableBigInt> AbsoluteAnd(
       Isolate* isolate, Handle<BigIntBase> x, Handle<BigIntBase> y,
       MutableBigInt* result_storage = nullptr);
@@ -155,9 +153,11 @@ class MutableBigInt : public FreshlyAllocatedBigInt,
 
   static MaybeHandle<String> ToStringBasePowerOfTwo(Isolate* isolate,
                                                     Handle<BigIntBase> x,
-                                                    int radix);
+                                                    int radix,
+                                                    ShouldThrow should_throw);
   static MaybeHandle<String> ToStringGeneric(Isolate* isolate,
-                                             Handle<BigIntBase> x, int radix);
+                                             Handle<BigIntBase> x, int radix,
+                                             ShouldThrow should_throw);
 
   static double ToDouble(Handle<BigIntBase> x);
   enum Rounding { kRoundDown, kTie, kRoundUp };
@@ -924,14 +924,15 @@ ComparisonResult BigInt::CompareToDouble(Handle<BigInt> x, double y) {
 }
 
 MaybeHandle<String> BigInt::ToString(Isolate* isolate, Handle<BigInt> bigint,
-                                     int radix) {
+                                     int radix, ShouldThrow should_throw) {
   if (bigint->is_zero()) {
     return isolate->factory()->NewStringFromStaticChars("0");
   }
   if (base::bits::IsPowerOfTwo(radix)) {
-    return MutableBigInt::ToStringBasePowerOfTwo(isolate, bigint, radix);
+    return MutableBigInt::ToStringBasePowerOfTwo(isolate, bigint, radix,
+                                                 should_throw);
   }
-  return MutableBigInt::ToStringGeneric(isolate, bigint, radix);
+  return MutableBigInt::ToStringGeneric(isolate, bigint, radix, should_throw);
 }
 
 MaybeHandle<BigInt> BigInt::FromNumber(Isolate* isolate,
@@ -1255,7 +1256,7 @@ MaybeHandle<MutableBigInt> MutableBigInt::AbsoluteSubOne(Isolate* isolate,
 inline Handle<MutableBigInt> MutableBigInt::AbsoluteBitwiseOp(
     Isolate* isolate, Handle<BigIntBase> x, Handle<BigIntBase> y,
     MutableBigInt* result_storage, ExtraDigitsHandling extra_digits,
-    SymmetricOp symmetric, std::function<digit_t(digit_t, digit_t)> op) {
+    SymmetricOp symmetric, const std::function<digit_t(digit_t, digit_t)>& op) {
   int x_length = x->length();
   int y_length = y->length();
   int num_pairs = y_length;
@@ -1924,9 +1925,9 @@ MaybeHandle<BigInt> BigInt::FromSerializedDigits(
 
 static const char kConversionChars[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 
-MaybeHandle<String> MutableBigInt::ToStringBasePowerOfTwo(Isolate* isolate,
-                                                          Handle<BigIntBase> x,
-                                                          int radix) {
+MaybeHandle<String> MutableBigInt::ToStringBasePowerOfTwo(
+    Isolate* isolate, Handle<BigIntBase> x, int radix,
+    ShouldThrow should_throw) {
   STATIC_ASSERT(base::bits::IsPowerOfTwo(kDigitBits));
   DCHECK(base::bits::IsPowerOfTwo(radix));
   DCHECK(radix >= 2 && radix <= 32);
@@ -1945,7 +1946,11 @@ MaybeHandle<String> MutableBigInt::ToStringBasePowerOfTwo(Isolate* isolate,
       (bit_length + bits_per_char - 1) / bits_per_char + sign;
 
   if (chars_required > String::kMaxLength) {
-    THROW_NEW_ERROR(isolate, NewInvalidStringLengthError(), String);
+    if (should_throw == kThrowOnError) {
+      THROW_NEW_ERROR(isolate, NewInvalidStringLengthError(), String);
+    } else {
+      return MaybeHandle<String>();
+    }
   }
 
   Handle<SeqOneByteString> result =
@@ -1988,7 +1993,8 @@ MaybeHandle<String> MutableBigInt::ToStringBasePowerOfTwo(Isolate* isolate,
 
 MaybeHandle<String> MutableBigInt::ToStringGeneric(Isolate* isolate,
                                                    Handle<BigIntBase> x,
-                                                   int radix) {
+                                                   int radix,
+                                                   ShouldThrow should_throw) {
   DCHECK(radix >= 2 && radix <= 36);
   DCHECK(!x->is_zero());
   Heap* heap = isolate->heap();
@@ -2014,7 +2020,11 @@ MaybeHandle<String> MutableBigInt::ToStringGeneric(Isolate* isolate,
   chars_required += sign;
 
   if (chars_required > String::kMaxLength) {
-    THROW_NEW_ERROR(isolate, NewInvalidStringLengthError(), String);
+    if (should_throw == kThrowOnError) {
+      THROW_NEW_ERROR(isolate, NewInvalidStringLengthError(), String);
+    } else {
+      return MaybeHandle<String>();
+    }
   }
   Handle<SeqOneByteString> result =
       isolate->factory()
diff --git a/deps/v8/src/objects/bigint.h b/deps/v8/src/objects/bigint.h
index a30a4779de..6081c5e3f8 100644
--- a/deps/v8/src/objects/bigint.h
+++ b/deps/v8/src/objects/bigint.h
@@ -173,7 +173,8 @@ class V8_EXPORT_PRIVATE BigInt : public BigIntBase {
   }
 
   static MaybeHandle<String> ToString(Isolate* isolate, Handle<BigInt> bigint,
-                                      int radix = 10);
+                                      int radix = 10,
+                                      ShouldThrow should_throw = kThrowOnError);
   // "The Number value for x", see:
   // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-number-type
   // Returns a Smi or HeapNumber.
diff --git a/deps/v8/src/objects/builtin-function-id.h b/deps/v8/src/objects/builtin-function-id.h
new file mode 100644
index 0000000000..ed54811a2b
--- /dev/null
+++ b/deps/v8/src/objects/builtin-function-id.h
@@ -0,0 +1,217 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_BUILTIN_FUNCTION_ID_H_
+#define V8_OBJECTS_BUILTIN_FUNCTION_ID_H_
+
+#include <stdint.h>
+
+namespace v8 {
+namespace internal {
+
+// List of builtin functions we want to identify to improve code
+// generation.
+//
+// Each entry has a name of a global object property holding an object
+// optionally followed by ".prototype", a name of a builtin function
+// on the object (the one the id is set for), and a label.
+//
+// Installation of ids for the selected builtin functions is handled
+// by the bootstrapper.
+#define FUNCTIONS_WITH_ID_LIST(V)                           \
+  V(Array, isArray, ArrayIsArray)                           \
+  V(Array.prototype, concat, ArrayConcat)                   \
+  V(Array.prototype, every, ArrayEvery)                     \
+  V(Array.prototype, fill, ArrayFill)                       \
+  V(Array.prototype, filter, ArrayFilter)                   \
+  V(Array.prototype, findIndex, ArrayFindIndex)             \
+  V(Array.prototype, forEach, ArrayForEach)                 \
+  V(Array.prototype, includes, ArrayIncludes)               \
+  V(Array.prototype, indexOf, ArrayIndexOf)                 \
+  V(Array.prototype, join, ArrayJoin)                       \
+  V(Array.prototype, lastIndexOf, ArrayLastIndexOf)         \
+  V(Array.prototype, map, ArrayMap)                         \
+  V(Array.prototype, pop, ArrayPop)                         \
+  V(Array.prototype, push, ArrayPush)                       \
+  V(Array.prototype, reverse, ArrayReverse)                 \
+  V(Array.prototype, shift, ArrayShift)                     \
+  V(Array.prototype, slice, ArraySlice)                     \
+  V(Array.prototype, some, ArraySome)                       \
+  V(Array.prototype, splice, ArraySplice)                   \
+  V(Array.prototype, unshift, ArrayUnshift)                 \
+  V(Date, now, DateNow)                                     \
+  V(Date.prototype, getDate, DateGetDate)                   \
+  V(Date.prototype, getDay, DateGetDay)                     \
+  V(Date.prototype, getFullYear, DateGetFullYear)           \
+  V(Date.prototype, getHours, DateGetHours)                 \
+  V(Date.prototype, getMilliseconds, DateGetMilliseconds)   \
+  V(Date.prototype, getMinutes, DateGetMinutes)             \
+  V(Date.prototype, getMonth, DateGetMonth)                 \
+  V(Date.prototype, getSeconds, DateGetSeconds)             \
+  V(Date.prototype, getTime, DateGetTime)                   \
+  V(Function.prototype, apply, FunctionApply)               \
+  V(Function.prototype, bind, FunctionBind)                 \
+  V(Function.prototype, call, FunctionCall)                 \
+  V(Object, assign, ObjectAssign)                           \
+  V(Object, create, ObjectCreate)                           \
+  V(Object, is, ObjectIs)                                   \
+  V(Object.prototype, hasOwnProperty, ObjectHasOwnProperty) \
+  V(Object.prototype, isPrototypeOf, ObjectIsPrototypeOf)   \
+  V(Object.prototype, toString, ObjectToString)             \
+  V(RegExp.prototype, compile, RegExpCompile)               \
+  V(RegExp.prototype, exec, RegExpExec)                     \
+  V(RegExp.prototype, test, RegExpTest)                     \
+  V(RegExp.prototype, toString, RegExpToString)             \
+  V(String.prototype, charCodeAt, StringCharCodeAt)         \
+  V(String.prototype, charAt, StringCharAt)                 \
+  V(String.prototype, codePointAt, StringCodePointAt)       \
+  V(String.prototype, concat, StringConcat)                 \
+  V(String.prototype, endsWith, StringEndsWith)             \
+  V(String.prototype, includes, StringIncludes)             \
+  V(String.prototype, indexOf, StringIndexOf)               \
+  V(String.prototype, lastIndexOf, StringLastIndexOf)       \
+  V(String.prototype, repeat, StringRepeat)                 \
+  V(String.prototype, slice, StringSlice)                   \
+  V(String.prototype, startsWith, StringStartsWith)         \
+  V(String.prototype, substr, StringSubstr)                 \
+  V(String.prototype, substring, StringSubstring)           \
+  V(String.prototype, toLowerCase, StringToLowerCase)       \
+  V(String.prototype, toString, StringToString)             \
+  V(String.prototype, toUpperCase, StringToUpperCase)       \
+  V(String.prototype, trim, StringTrim)                     \
+  V(String.prototype, trimLeft, StringTrimStart)            \
+  V(String.prototype, trimRight, StringTrimEnd)             \
+  V(String.prototype, valueOf, StringValueOf)               \
+  V(String, fromCharCode, StringFromCharCode)               \
+  V(String, fromCodePoint, StringFromCodePoint)             \
+  V(String, raw, StringRaw)                                 \
+  V(Math, random, MathRandom)                               \
+  V(Math, floor, MathFloor)                                 \
+  V(Math, round, MathRound)                                 \
+  V(Math, ceil, MathCeil)                                   \
+  V(Math, abs, MathAbs)                                     \
+  V(Math, log, MathLog)                                     \
+  V(Math, log1p, MathLog1p)                                 \
+  V(Math, log2, MathLog2)                                   \
+  V(Math, log10, MathLog10)                                 \
+  V(Math, cbrt, MathCbrt)                                   \
+  V(Math, exp, MathExp)                                     \
+  V(Math, expm1, MathExpm1)                                 \
+  V(Math, sqrt, MathSqrt)                                   \
+  V(Math, pow, MathPow)                                     \
+  V(Math, max, MathMax)                                     \
+  V(Math, min, MathMin)                                     \
+  V(Math, cos, MathCos)                                     \
+  V(Math, cosh, MathCosh)                                   \
+  V(Math, sign, MathSign)                                   \
+  V(Math, sin, MathSin)                                     \
+  V(Math, sinh, MathSinh)                                   \
+  V(Math, tan, MathTan)                                     \
+  V(Math, tanh, MathTanh)                                   \
+  V(Math, acos, MathAcos)                                   \
+  V(Math, acosh, MathAcosh)                                 \
+  V(Math, asin, MathAsin)                                   \
+  V(Math, asinh, MathAsinh)                                 \
+  V(Math, atan, MathAtan)                                   \
+  V(Math, atan2, MathAtan2)                                 \
+  V(Math, atanh, MathAtanh)                                 \
+  V(Math, imul, MathImul)                                   \
+  V(Math, clz32, MathClz32)                                 \
+  V(Math, fround, MathFround)                               \
+  V(Math, trunc, MathTrunc)                                 \
+  V(Number, isFinite, NumberIsFinite)                       \
+  V(Number, isInteger, NumberIsInteger)                     \
+  V(Number, isNaN, NumberIsNaN)                             \
+  V(Number, isSafeInteger, NumberIsSafeInteger)             \
+  V(Number, parseFloat, NumberParseFloat)                   \
+  V(Number, parseInt, NumberParseInt)                       \
+  V(Number.prototype, toString, NumberToString)             \
+  V(Map.prototype, clear, MapClear)                         \
+  V(Map.prototype, delete, MapDelete)                       \
+  V(Map.prototype, entries, MapEntries)                     \
+  V(Map.prototype, forEach, MapForEach)                     \
+  V(Map.prototype, has, MapHas)                             \
+  V(Map.prototype, keys, MapKeys)                           \
+  V(Map.prototype, get, MapGet)                             \
+  V(Map.prototype, set, MapSet)                             \
+  V(Map.prototype, values, MapValues)                       \
+  V(Set.prototype, add, SetAdd)                             \
+  V(Set.prototype, clear, SetClear)                         \
+  V(Set.prototype, delete, SetDelete)                       \
+  V(Set.prototype, entries, SetEntries)                     \
+  V(Set.prototype, forEach, SetForEach)                     \
+  V(Set.prototype, has, SetHas)                             \
+  V(Set.prototype, values, SetValues)                       \
+  V(WeakMap.prototype, delete, WeakMapDelete)               \
+  V(WeakMap.prototype, has, WeakMapHas)                     \
+  V(WeakMap.prototype, set, WeakMapSet)                     \
+  V(WeakSet.prototype, add, WeakSetAdd)                     \
+  V(WeakSet.prototype, delete, WeakSetDelete)               \
+  V(WeakSet.prototype, has, WeakSetHas)
+
+#define ATOMIC_FUNCTIONS_WITH_ID_LIST(V)              \
+  V(Atomics, load, AtomicsLoad)                       \
+  V(Atomics, store, AtomicsStore)                     \
+  V(Atomics, exchange, AtomicsExchange)               \
+  V(Atomics, compareExchange, AtomicsCompareExchange) \
+  V(Atomics, add, AtomicsAdd)                         \
+  V(Atomics, sub, AtomicsSub)                         \
+  V(Atomics, and, AtomicsAnd)                         \
+  V(Atomics, or, AtomicsOr)                           \
+  V(Atomics, xor, AtomicsXor)
+
+enum class BuiltinFunctionId : uint8_t {
+  kArrayConstructor,
+#define DECL_FUNCTION_ID(ignored1, ignore2, name) k##name,
+  FUNCTIONS_WITH_ID_LIST(DECL_FUNCTION_ID)
+      ATOMIC_FUNCTIONS_WITH_ID_LIST(DECL_FUNCTION_ID)
+#undef DECL_FUNCTION_ID
+  // These are manually assigned to special getters during bootstrapping.
+  kArrayBufferByteLength,
+  kArrayBufferIsView,
+  kArrayEntries,
+  kArrayKeys,
+  kArrayValues,
+  kArrayIteratorNext,
+  kBigIntConstructor,
+  kMapSize,
+  kSetSize,
+  kMapIteratorNext,
+  kSetIteratorNext,
+  kDataViewBuffer,
+  kDataViewByteLength,
+  kDataViewByteOffset,
+  kFunctionHasInstance,
+  kGlobalDecodeURI,
+  kGlobalDecodeURIComponent,
+  kGlobalEncodeURI,
+  kGlobalEncodeURIComponent,
+  kGlobalEscape,
+  kGlobalUnescape,
+  kGlobalIsFinite,
+  kGlobalIsNaN,
+  kNumberConstructor,
+  kSymbolConstructor,
+  kSymbolPrototypeToString,
+  kSymbolPrototypeValueOf,
+  kTypedArrayByteLength,
+  kTypedArrayByteOffset,
+  kTypedArrayEntries,
+  kTypedArrayKeys,
+  kTypedArrayLength,
+  kTypedArrayToStringTag,
+  kTypedArrayValues,
+  kSharedArrayBufferByteLength,
+  kStringConstructor,
+  kStringIterator,
+  kStringIteratorNext,
+  kStringToLowerCaseIntl,
+  kStringToUpperCaseIntl,
+  kInvalidBuiltinFunctionId = static_cast<uint8_t>(-1),
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_OBJECTS_BUILTIN_FUNCTION_ID_H_
diff --git a/deps/v8/src/objects/code-inl.h b/deps/v8/src/objects/code-inl.h
index 308e645c84..34c9f2fc28 100644
--- a/deps/v8/src/objects/code-inl.h
+++ b/deps/v8/src/objects/code-inl.h
@@ -26,6 +26,12 @@ CAST_ACCESSOR(Code)
 CAST_ACCESSOR(CodeDataContainer)
 CAST_ACCESSOR(DependentCode)
 CAST_ACCESSOR(DeoptimizationData)
+CAST_ACCESSOR(SourcePositionTableWithFrameCache)
+
+ACCESSORS(SourcePositionTableWithFrameCache, source_position_table, ByteArray,
+          kSourcePositionTableIndex)
+ACCESSORS(SourcePositionTableWithFrameCache, stack_frame_cache,
+          SimpleNumberDictionary, kStackFrameCacheIndex)
 
 int AbstractCode::raw_instruction_size() {
   if (IsCode()) {
@@ -133,14 +139,14 @@ BytecodeArray* AbstractCode::GetBytecodeArray() {
 }
 
 DependentCode* DependentCode::next_link() {
-  return DependentCode::cast(Get(kNextLinkIndex)->ToStrongHeapObject());
+  return DependentCode::cast(Get(kNextLinkIndex)->GetHeapObjectAssumeStrong());
 }
 
 void DependentCode::set_next_link(DependentCode* next) {
   Set(kNextLinkIndex, HeapObjectReference::Strong(next));
 }
 
-int DependentCode::flags() { return Smi::ToInt(Get(kFlagsIndex)->ToSmi()); }
+int DependentCode::flags() { return Smi::ToInt(Get(kFlagsIndex)->cast<Smi>()); }
 
 void DependentCode::set_flags(int flags) {
   Set(kFlagsIndex, MaybeObject::FromObject(Smi::FromInt(flags)));
diff --git a/deps/v8/src/objects/code.h b/deps/v8/src/objects/code.h
index f3c3c0b5b3..1f1d4b71d6 100644
--- a/deps/v8/src/objects/code.h
+++ b/deps/v8/src/objects/code.h
@@ -27,8 +27,6 @@ class Register;
 // Code describes objects with on-the-fly generated machine code.
 class Code : public HeapObject, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
   // Opaque data type for encapsulating code flags like kind, inline
   // cache state, and arguments count.
   typedef uint32_t Flags;
@@ -307,9 +305,6 @@ class Code : public HeapObject, public NeverReadOnlySpaceObject {
   // object has been moved by delta bytes.
   void Relocate(intptr_t delta);
 
-  // Migrate code described by desc.
-  void CopyFrom(Heap* heap, const CodeDesc& desc);
-
   // Migrate code from desc without flushing the instruction cache.
   void CopyFromNoFlush(Heap* heap, const CodeDesc& desc);
 
@@ -459,9 +454,6 @@ class Code : public HeapObject, public NeverReadOnlySpaceObject {
 // field {Code::code_data_container} itself is immutable.
 class CodeDataContainer : public HeapObject, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   DECL_ACCESSORS(next_code_link, Object)
   DECL_INT_ACCESSORS(kind_specific_flags)
 
@@ -485,15 +477,7 @@ class CodeDataContainer : public HeapObject, public NeverReadOnlySpaceObject {
   static const int kPointerFieldsStrongEndOffset = kNextCodeLinkOffset;
   static const int kPointerFieldsWeakEndOffset = kKindSpecificFlagsOffset;
 
-  // Ignores weakness.
-  typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
-                              kPointerFieldsWeakEndOffset, kSize>
-      BodyDescriptor;
-
-  // Respects weakness.
-  typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
-                              kPointerFieldsStrongEndOffset, kSize>
-      BodyDescriptorWeak;
+  class BodyDescriptor;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeDataContainer);
@@ -501,9 +485,6 @@ class CodeDataContainer : public HeapObject, public NeverReadOnlySpaceObject {
 
 class AbstractCode : public HeapObject, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   // All code kinds and INTERPRETED_FUNCTION.
   enum Kind {
 #define DEFINE_CODE_KIND_ENUM(name) name,
@@ -624,13 +605,10 @@ class DependentCode : public WeakFixedArray {
   };
 
   // Register a code dependency of {cell} on {object}.
-  static void InstallDependency(Isolate* isolate, MaybeObjectHandle code,
+  static void InstallDependency(Isolate* isolate, const MaybeObjectHandle& code,
                                 Handle<HeapObject> object,
                                 DependencyGroup group);
 
-  bool Contains(DependencyGroup group, MaybeObject* code);
-  bool IsEmpty(DependencyGroup group);
-
   void DeoptimizeDependentCodeGroup(Isolate* isolate, DependencyGroup group);
 
   bool MarkCodeForDeoptimization(Isolate* isolate, DependencyGroup group);
@@ -650,14 +628,14 @@ class DependentCode : public WeakFixedArray {
                                Handle<DependentCode> dep);
 
   static Handle<DependentCode> New(Isolate* isolate, DependencyGroup group,
-                                   MaybeObjectHandle object,
+                                   const MaybeObjectHandle& object,
                                    Handle<DependentCode> next);
   static Handle<DependentCode> EnsureSpace(Isolate* isolate,
                                            Handle<DependentCode> entries);
   static Handle<DependentCode> InsertWeakCode(Isolate* isolate,
                                               Handle<DependentCode> entries,
                                               DependencyGroup group,
-                                              MaybeObjectHandle code);
+                                              const MaybeObjectHandle& code);
 
   // Compact by removing cleared weak cells and return true if there was
   // any cleared weak cell.
@@ -811,8 +789,6 @@ class BytecodeArray : public FixedArrayBase {
   static const int kMaxLength = kMaxSize - kHeaderSize;
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(BytecodeArray);
@@ -903,6 +879,22 @@ class DeoptimizationData : public FixedArray {
   static int LengthFor(int entry_count) { return IndexForEntry(entry_count); }
 };
 
+class SourcePositionTableWithFrameCache : public Tuple2 {
+ public:
+  DECL_ACCESSORS(source_position_table, ByteArray)
+  DECL_ACCESSORS(stack_frame_cache, SimpleNumberDictionary)
+
+  DECL_CAST(SourcePositionTableWithFrameCache)
+
+  static const int kSourcePositionTableIndex = Struct::kHeaderSize;
+  static const int kStackFrameCacheIndex =
+      kSourcePositionTableIndex + kPointerSize;
+  static const int kSize = kStackFrameCacheIndex + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(SourcePositionTableWithFrameCache);
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/compilation-cache.h b/deps/v8/src/objects/compilation-cache.h
index 76deeb9684..8e118a0e60 100644
--- a/deps/v8/src/objects/compilation-cache.h
+++ b/deps/v8/src/objects/compilation-cache.h
@@ -69,12 +69,6 @@ class CompilationCacheTable
     : public HashTable<CompilationCacheTable, CompilationCacheShape>,
       public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
-  // Find cached value for a string key, otherwise return null.
-  Handle<Object> Lookup(Handle<String> src, Handle<SharedFunctionInfo> shared,
-                        LanguageMode language_mode);
   MaybeHandle<SharedFunctionInfo> LookupScript(Handle<String> src,
                                                Handle<Context> native_context,
                                                LanguageMode language_mode);
@@ -82,11 +76,6 @@ class CompilationCacheTable
                           Handle<Context> native_context,
                           LanguageMode language_mode, int position);
   Handle<Object> LookupRegExp(Handle<String> source, JSRegExp::Flags flags);
-  static Handle<CompilationCacheTable> Put(Handle<CompilationCacheTable> cache,
-                                           Handle<String> src,
-                                           Handle<SharedFunctionInfo> shared,
-                                           LanguageMode language_mode,
-                                           Handle<Object> value);
   static Handle<CompilationCacheTable> PutScript(
       Handle<CompilationCacheTable> cache, Handle<String> src,
       Handle<Context> native_context, LanguageMode language_mode,
diff --git a/deps/v8/src/objects/debug-objects.cc b/deps/v8/src/objects/debug-objects.cc
index b77b6e136e..43fcdb5aee 100644
--- a/deps/v8/src/objects/debug-objects.cc
+++ b/deps/v8/src/objects/debug-objects.cc
@@ -375,7 +375,7 @@ void CoverageInfo::Print(std::unique_ptr<char[]> function_name) {
 
   for (int i = 0; i < SlotCount(); i++) {
     os << "{" << StartSourcePosition(i) << "," << EndSourcePosition(i) << "}"
-       << std::endl;
+       << ": " << BlockCount(i) << std::endl;
   }
 }
 
diff --git a/deps/v8/src/objects/debug-objects.h b/deps/v8/src/objects/debug-objects.h
index 3b94a4e46e..84f244c758 100644
--- a/deps/v8/src/objects/debug-objects.h
+++ b/deps/v8/src/objects/debug-objects.h
@@ -21,9 +21,6 @@ class BytecodeArray;
 // debugged.
 class DebugInfo : public Struct, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   enum Flag {
     kNone = 0,
     kHasBreakInfo = 1 << 0,
diff --git a/deps/v8/src/objects/dictionary.h b/deps/v8/src/objects/dictionary.h
index eac358c1cd..6d7ee42eec 100644
--- a/deps/v8/src/objects/dictionary.h
+++ b/deps/v8/src/objects/dictionary.h
@@ -5,10 +5,10 @@
 #ifndef V8_OBJECTS_DICTIONARY_H_
 #define V8_OBJECTS_DICTIONARY_H_
 
-#include "src/objects/hash-table.h"
-
 #include "src/base/export-template.h"
 #include "src/globals.h"
+#include "src/objects/hash-table.h"
+#include "src/objects/property-array.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -113,7 +113,7 @@ class NameDictionaryShape : public BaseDictionaryShape<Handle<Name>> {
   static inline uint32_t Hash(Isolate* isolate, Handle<Name> key);
   static inline uint32_t HashForObject(Isolate* isolate, Object* object);
   static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
   static const int kPrefixSize = 2;
   static const int kEntrySize = 3;
   static const int kEntryValueIndex = 1;
@@ -216,7 +216,7 @@ class GlobalDictionaryShape : public NameDictionaryShape {
   static inline Object* Unwrap(Object* key);
   static inline bool IsKey(ReadOnlyRoots roots, Object* k);
   static inline bool IsLive(ReadOnlyRoots roots, Object* key);
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 };
 
 class GlobalDictionary
@@ -246,7 +246,7 @@ class NumberDictionaryShape : public NumberDictionaryBaseShape {
   static const int kPrefixSize = 1;
   static const int kEntrySize = 3;
 
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 };
 
 class SimpleNumberDictionaryShape : public NumberDictionaryBaseShape {
@@ -266,7 +266,7 @@ class SimpleNumberDictionaryShape : public NumberDictionaryBaseShape {
     UNREACHABLE();
   }
 
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 };
 
 extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
diff --git a/deps/v8/src/objects/fixed-array-inl.h b/deps/v8/src/objects/fixed-array-inl.h
index 29c4593cfd..8c24ee80be 100644
--- a/deps/v8/src/objects/fixed-array-inl.h
+++ b/deps/v8/src/objects/fixed-array-inl.h
@@ -288,8 +288,8 @@ HeapObject* WeakArrayList::Iterator::Next() {
   if (array_ != nullptr) {
     while (index_ < array_->length()) {
       MaybeObject* item = array_->Get(index_++);
-      DCHECK(item->IsWeakHeapObject() || item->IsClearedWeakHeapObject());
-      if (!item->IsClearedWeakHeapObject()) return item->ToWeakHeapObject();
+      DCHECK(item->IsWeakOrCleared());
+      if (!item->IsCleared()) return item->GetHeapObjectAssumeWeak();
     }
     array_ = nullptr;
   }
diff --git a/deps/v8/src/objects/fixed-array.h b/deps/v8/src/objects/fixed-array.h
index 287015ef7c..867d04e638 100644
--- a/deps/v8/src/objects/fixed-array.h
+++ b/deps/v8/src/objects/fixed-array.h
@@ -188,8 +188,6 @@ class FixedArray : public FixedArrayBase {
 #endif
 
   typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  protected:
   // Set operation on FixedArray without using write barriers. Can
@@ -256,8 +254,6 @@ class FixedDoubleArray : public FixedArrayBase {
   DECL_VERIFIER(FixedDoubleArray)
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray);
@@ -298,7 +294,6 @@ class WeakFixedArray : public HeapObject {
   DECL_VERIFIER(WeakFixedArray)
 
   typedef WeakArrayBodyDescriptor BodyDescriptor;
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   static const int kLengthOffset = HeapObject::kHeaderSize;
   static const int kHeaderSize = kLengthOffset + kPointerSize;
@@ -334,7 +329,7 @@ class WeakArrayList : public HeapObject {
 
   static Handle<WeakArrayList> AddToEnd(Isolate* isolate,
                                         Handle<WeakArrayList> array,
-                                        MaybeObjectHandle value);
+                                        const MaybeObjectHandle& value);
 
   inline MaybeObject* Get(int index) const;
 
@@ -361,7 +356,6 @@ class WeakArrayList : public HeapObject {
   inline void synchronized_set_capacity(int value);
 
   typedef WeakArrayBodyDescriptor BodyDescriptor;
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   static const int kCapacityOffset = HeapObject::kHeaderSize;
   static const int kLengthOffset = kCapacityOffset + kPointerSize;
@@ -381,7 +375,7 @@ class WeakArrayList : public HeapObject {
   // around in the array - this method can only be used in cases where the user
   // doesn't care about the indices! Users should make sure there are no
   // duplicates.
-  bool RemoveOne(MaybeObjectHandle value);
+  bool RemoveOne(const MaybeObjectHandle& value);
 
   class Iterator {
    public:
@@ -442,7 +436,6 @@ class ArrayList : public FixedArray {
   // Return a copy of the list of size Length() without the first entry. The
   // number returned by Length() is stored in the first entry.
   static Handle<FixedArray> Elements(Isolate* isolate, Handle<ArrayList> array);
-  bool IsFull();
   DECL_CAST(ArrayList)
 
  private:
@@ -521,8 +514,6 @@ class ByteArray : public FixedArrayBase {
                 "ByteArray maxLength not a Smi");
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray);
@@ -587,8 +578,6 @@ class FixedTypedArrayBase : public FixedArrayBase {
   static const size_t kMaxLength = Smi::kMaxValue;
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   inline int size() const;
 
diff --git a/deps/v8/src/objects/frame-array.h b/deps/v8/src/objects/frame-array.h
index 0ae22f9526..5bccfb5807 100644
--- a/deps/v8/src/objects/frame-array.h
+++ b/deps/v8/src/objects/frame-array.h
@@ -50,7 +50,8 @@ class FrameArray : public FixedArray {
     kIsAsmJsWasmFrame = 1 << 2,
     kIsStrict = 1 << 3,
     kIsConstructor = 1 << 4,
-    kAsmJsAtNumberConversion = 1 << 5
+    kAsmJsAtNumberConversion = 1 << 5,
+    kIsAsync = 1 << 6
   };
 
   static Handle<FrameArray> AppendJSFrame(Handle<FrameArray> in,
diff --git a/deps/v8/src/objects/hash-table-inl.h b/deps/v8/src/objects/hash-table-inl.h
index 1f2c09316d..bc391fede6 100644
--- a/deps/v8/src/objects/hash-table-inl.h
+++ b/deps/v8/src/objects/hash-table-inl.h
@@ -58,12 +58,12 @@ void HashTableBase::SetNumberOfDeletedElements(int nod) {
 }
 
 template <typename Key>
-int BaseShape<Key>::GetMapRootIndex() {
-  return Heap::kHashTableMapRootIndex;
+RootIndex BaseShape<Key>::GetMapRootIndex() {
+  return RootIndex::kHashTableMap;
 }
 
-int EphemeronHashTableShape::GetMapRootIndex() {
-  return Heap::kEphemeronHashTableMapRootIndex;
+RootIndex EphemeronHashTableShape::GetMapRootIndex() {
+  return RootIndex::kEphemeronHashTableMap;
 }
 
 template <typename Derived, typename Shape>
diff --git a/deps/v8/src/objects/hash-table.h b/deps/v8/src/objects/hash-table.h
index aa86865abf..66d3f6dfb2 100644
--- a/deps/v8/src/objects/hash-table.h
+++ b/deps/v8/src/objects/hash-table.h
@@ -55,7 +55,7 @@ template <typename KeyT>
 class BaseShape {
  public:
   typedef KeyT Key;
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
   static const bool kNeedsHoleCheck = true;
   static Object* Unwrap(Object* key) { return key; }
   static inline bool IsKey(ReadOnlyRoots roots, Object* key);
@@ -244,7 +244,7 @@ class HashTableKey {
   virtual bool IsMatch(Object* other) = 0;
   // Returns the hash value for this key.
   // Required.
-  virtual ~HashTableKey() {}
+  virtual ~HashTableKey() = default;
 
   uint32_t Hash() const { return hash_; }
 
@@ -321,7 +321,7 @@ class ObjectHashTable
 
 class EphemeronHashTableShape : public ObjectHashTableShape {
  public:
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 };
 
 // EphemeronHashTable is similar to ObjectHashTable but gets special treatment
diff --git a/deps/v8/src/objects/intl-objects.cc b/deps/v8/src/objects/intl-objects.cc
index b9ceecf9a1..dcacb4dd2f 100644
--- a/deps/v8/src/objects/intl-objects.cc
+++ b/deps/v8/src/objects/intl-objects.cc
@@ -21,543 +21,44 @@
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 #include "src/objects/js-collator-inl.h"
-#include "src/objects/managed.h"
+#include "src/objects/js-date-time-format-inl.h"
+#include "src/objects/js-number-format-inl.h"
 #include "src/objects/string.h"
 #include "src/property-descriptor.h"
 #include "unicode/brkiter.h"
-#include "unicode/bytestream.h"
-#include "unicode/calendar.h"
 #include "unicode/coll.h"
-#include "unicode/curramt.h"
-#include "unicode/dcfmtsym.h"
 #include "unicode/decimfmt.h"
-#include "unicode/dtfmtsym.h"
-#include "unicode/dtptngen.h"
-#include "unicode/gregocal.h"
 #include "unicode/locid.h"
 #include "unicode/numfmt.h"
 #include "unicode/numsys.h"
-#include "unicode/plurrule.h"
-#include "unicode/rbbi.h"
 #include "unicode/regex.h"
 #include "unicode/smpdtfmt.h"
 #include "unicode/timezone.h"
-#include "unicode/uchar.h"
 #include "unicode/ucol.h"
-#include "unicode/ucurr.h"
-#include "unicode/unum.h"
-#include "unicode/upluralrules.h"
 #include "unicode/ures.h"
 #include "unicode/uvernum.h"
 #include "unicode/uversion.h"
 
-#if U_ICU_VERSION_MAJOR_NUM >= 59
-#include "unicode/char16ptr.h"
-#endif
-
 namespace v8 {
 namespace internal {
 
-namespace {
-
-bool ExtractStringSetting(Isolate* isolate, Handle<JSObject> options,
-                          const char* key, icu::UnicodeString* setting) {
-  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
-  Handle<String> str = isolate->factory()->NewStringFromAsciiChecked(key);
-  Handle<Object> object =
-      JSReceiver::GetProperty(isolate, options, str).ToHandleChecked();
-  if (object->IsString()) {
-    v8::String::Utf8Value utf8_string(
-        v8_isolate, v8::Utils::ToLocal(Handle<String>::cast(object)));
-    *setting = icu::UnicodeString::fromUTF8(*utf8_string);
-    return true;
-  }
-  return false;
-}
-
-bool ExtractIntegerSetting(Isolate* isolate, Handle<JSObject> options,
-                           const char* key, int32_t* value) {
-  Handle<String> str = isolate->factory()->NewStringFromAsciiChecked(key);
-  Handle<Object> object =
-      JSReceiver::GetProperty(isolate, options, str).ToHandleChecked();
-  if (object->IsNumber()) {
-    return object->ToInt32(value);
-  }
-  return false;
-}
-
-bool ExtractBooleanSetting(Isolate* isolate, Handle<JSObject> options,
-                           const char* key, bool* value) {
-  Handle<String> str = isolate->factory()->NewStringFromAsciiChecked(key);
-  Handle<Object> object =
-      JSReceiver::GetProperty(isolate, options, str).ToHandleChecked();
-  if (object->IsBoolean()) {
-    *value = object->BooleanValue(isolate);
-    return true;
-  }
-  return false;
-}
-
-icu::SimpleDateFormat* CreateICUDateFormat(Isolate* isolate,
-                                           const icu::Locale& icu_locale,
-                                           Handle<JSObject> options) {
-  // Create time zone as specified by the user. We have to re-create time zone
-  // since calendar takes ownership.
-  icu::TimeZone* tz = nullptr;
-  icu::UnicodeString timezone;
-  if (ExtractStringSetting(isolate, options, "timeZone", &timezone)) {
-    tz = icu::TimeZone::createTimeZone(timezone);
-  } else {
-    tz = icu::TimeZone::createDefault();
-  }
-
-  // Create a calendar using locale, and apply time zone to it.
-  UErrorCode status = U_ZERO_ERROR;
-  icu::Calendar* calendar =
-      icu::Calendar::createInstance(tz, icu_locale, status);
-
-  if (calendar->getDynamicClassID() ==
-      icu::GregorianCalendar::getStaticClassID()) {
-    icu::GregorianCalendar* gc = (icu::GregorianCalendar*)calendar;
-    UErrorCode status = U_ZERO_ERROR;
-    // The beginning of ECMAScript time, namely -(2**53)
-    const double start_of_time = -9007199254740992;
-    gc->setGregorianChange(start_of_time, status);
-    DCHECK(U_SUCCESS(status));
-  }
-
-  // Make formatter from skeleton. Calendar and numbering system are added
-  // to the locale as Unicode extension (if they were specified at all).
-  icu::SimpleDateFormat* date_format = nullptr;
-  icu::UnicodeString skeleton;
-  if (ExtractStringSetting(isolate, options, "skeleton", &skeleton)) {
-    // See https://github.com/tc39/ecma402/issues/225 . The best pattern
-    // generation needs to be done in the base locale according to the
-    // current spec however odd it may be. See also crbug.com/826549 .
-    // This is a temporary work-around to get v8's external behavior to match
-    // the current spec, but does not follow the spec provisions mentioned
-    // in the above Ecma 402 issue.
-    // TODO(jshin): The spec may need to be revised because using the base
-    // locale for the pattern match is not quite right. Moreover, what to
-    // do with 'related year' part when 'chinese/dangi' calendar is specified
-    // has to be discussed. Revisit once the spec is clarified/revised.
-    icu::Locale no_extension_locale(icu_locale.getBaseName());
-    std::unique_ptr<icu::DateTimePatternGenerator> generator(
-        icu::DateTimePatternGenerator::createInstance(no_extension_locale,
-                                                      status));
-    icu::UnicodeString pattern;
-    if (U_SUCCESS(status))
-      pattern = generator->getBestPattern(skeleton, status);
-
-    date_format = new icu::SimpleDateFormat(pattern, icu_locale, status);
-    if (U_SUCCESS(status)) {
-      date_format->adoptCalendar(calendar);
-    }
-  }
-
-  if (U_FAILURE(status)) {
-    delete calendar;
-    delete date_format;
-    date_format = nullptr;
-  }
-
-  return date_format;
-}
-
-void SetResolvedDateSettings(Isolate* isolate, const icu::Locale& icu_locale,
-                             icu::SimpleDateFormat* date_format,
-                             Handle<JSObject> resolved) {
-  Factory* factory = isolate->factory();
-  UErrorCode status = U_ZERO_ERROR;
-  icu::UnicodeString pattern;
-  date_format->toPattern(pattern);
-  JSObject::SetProperty(
-      isolate, resolved, factory->intl_pattern_symbol(),
-      factory
-          ->NewStringFromTwoByte(Vector<const uint16_t>(
-              reinterpret_cast<const uint16_t*>(pattern.getBuffer()),
-              pattern.length()))
-          .ToHandleChecked(),
-      LanguageMode::kSloppy)
-      .Assert();
-
-  // Set time zone and calendar.
-  const icu::Calendar* calendar = date_format->getCalendar();
-  // getType() returns legacy calendar type name instead of LDML/BCP47 calendar
-  // key values. intl.js maps them to BCP47 values for key "ca".
-  // TODO(jshin): Consider doing it here, instead.
-  const char* calendar_name = calendar->getType();
-  JSObject::SetProperty(
-      isolate, resolved, factory->NewStringFromStaticChars("calendar"),
-      factory->NewStringFromAsciiChecked(calendar_name), LanguageMode::kSloppy)
-      .Assert();
-
-  const icu::TimeZone& tz = calendar->getTimeZone();
-  icu::UnicodeString time_zone;
-  tz.getID(time_zone);
-
-  icu::UnicodeString canonical_time_zone;
-  icu::TimeZone::getCanonicalID(time_zone, canonical_time_zone, status);
-  if (U_SUCCESS(status)) {
-    // In CLDR (http://unicode.org/cldr/trac/ticket/9943), Etc/UTC is made
-    // a separate timezone ID from Etc/GMT even though they're still the same
-    // timezone. We have Etc/UTC because 'UTC', 'Etc/Universal',
-    // 'Etc/Zulu' and others are turned to 'Etc/UTC' by ICU. Etc/GMT comes
-    // from Etc/GMT0, Etc/GMT+0, Etc/GMT-0, Etc/Greenwich.
-    // ecma402##sec-canonicalizetimezonename step 3
-    if (canonical_time_zone == UNICODE_STRING_SIMPLE("Etc/UTC") ||
-        canonical_time_zone == UNICODE_STRING_SIMPLE("Etc/GMT")) {
-      JSObject::SetProperty(
-          isolate, resolved, factory->NewStringFromStaticChars("timeZone"),
-          factory->NewStringFromStaticChars("UTC"), LanguageMode::kSloppy)
-          .Assert();
-    } else {
-      JSObject::SetProperty(isolate, resolved,
-                            factory->NewStringFromStaticChars("timeZone"),
-                            factory
-                                ->NewStringFromTwoByte(Vector<const uint16_t>(
-                                    reinterpret_cast<const uint16_t*>(
-                                        canonical_time_zone.getBuffer()),
-                                    canonical_time_zone.length()))
-                                .ToHandleChecked(),
-                            LanguageMode::kSloppy)
-          .Assert();
-    }
-  }
-
-  // Ugly hack. ICU doesn't expose numbering system in any way, so we have
-  // to assume that for given locale NumberingSystem constructor produces the
-  // same digits as NumberFormat/Calendar would.
-  status = U_ZERO_ERROR;
-  icu::NumberingSystem* numbering_system =
-      icu::NumberingSystem::createInstance(icu_locale, status);
-  if (U_SUCCESS(status)) {
-    const char* ns = numbering_system->getName();
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("numberingSystem"),
-        factory->NewStringFromAsciiChecked(ns), LanguageMode::kSloppy)
-        .Assert();
-  } else {
-    JSObject::SetProperty(isolate, resolved,
-                          factory->NewStringFromStaticChars("numberingSystem"),
-                          factory->undefined_value(), LanguageMode::kSloppy)
-        .Assert();
-  }
-  delete numbering_system;
-
-  // Set the locale
-  char result[ULOC_FULLNAME_CAPACITY];
-  status = U_ZERO_ERROR;
-  uloc_toLanguageTag(icu_locale.getName(), result, ULOC_FULLNAME_CAPACITY,
-                     FALSE, &status);
-  if (U_SUCCESS(status)) {
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("locale"),
-        factory->NewStringFromAsciiChecked(result), LanguageMode::kSloppy)
-        .Assert();
-  } else {
-    // This would never happen, since we got the locale from ICU.
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("locale"),
-        factory->NewStringFromStaticChars("und"), LanguageMode::kSloppy)
-        .Assert();
-  }
-}
-
-void SetNumericSettings(Isolate* isolate, icu::DecimalFormat* number_format,
-                        Handle<JSObject> options) {
-  int32_t digits;
-  if (ExtractIntegerSetting(isolate, options, "minimumIntegerDigits",
-                            &digits)) {
-    number_format->setMinimumIntegerDigits(digits);
-  }
-
-  if (ExtractIntegerSetting(isolate, options, "minimumFractionDigits",
-                            &digits)) {
-    number_format->setMinimumFractionDigits(digits);
-  }
-
-  if (ExtractIntegerSetting(isolate, options, "maximumFractionDigits",
-                            &digits)) {
-    number_format->setMaximumFractionDigits(digits);
-  }
-
-  bool significant_digits_used = false;
-  if (ExtractIntegerSetting(isolate, options, "minimumSignificantDigits",
-                            &digits)) {
-    number_format->setMinimumSignificantDigits(digits);
-    significant_digits_used = true;
-  }
-
-  if (ExtractIntegerSetting(isolate, options, "maximumSignificantDigits",
-                            &digits)) {
-    number_format->setMaximumSignificantDigits(digits);
-    significant_digits_used = true;
-  }
-
-  number_format->setSignificantDigitsUsed(significant_digits_used);
-
-  number_format->setRoundingMode(icu::DecimalFormat::kRoundHalfUp);
-}
-
-icu::DecimalFormat* CreateICUNumberFormat(Isolate* isolate,
-                                          const icu::Locale& icu_locale,
-                                          Handle<JSObject> options) {
-  // Make formatter from options. Numbering system is added
-  // to the locale as Unicode extension (if it was specified at all).
-  UErrorCode status = U_ZERO_ERROR;
-  icu::DecimalFormat* number_format = nullptr;
-  icu::UnicodeString style;
-  icu::UnicodeString currency;
-  if (ExtractStringSetting(isolate, options, "style", &style)) {
-    if (style == UNICODE_STRING_SIMPLE("currency")) {
-      icu::UnicodeString display;
-      ExtractStringSetting(isolate, options, "currency", &currency);
-      ExtractStringSetting(isolate, options, "currencyDisplay", &display);
-
-#if (U_ICU_VERSION_MAJOR_NUM == 4) && (U_ICU_VERSION_MINOR_NUM <= 6)
-      icu::NumberFormat::EStyles format_style;
-      if (display == UNICODE_STRING_SIMPLE("code")) {
-        format_style = icu::NumberFormat::kIsoCurrencyStyle;
-      } else if (display == UNICODE_STRING_SIMPLE("name")) {
-        format_style = icu::NumberFormat::kPluralCurrencyStyle;
-      } else {
-        format_style = icu::NumberFormat::kCurrencyStyle;
-      }
-#else  // ICU version is 4.8 or above (we ignore versions below 4.0).
-      UNumberFormatStyle format_style;
-      if (display == UNICODE_STRING_SIMPLE("code")) {
-        format_style = UNUM_CURRENCY_ISO;
-      } else if (display == UNICODE_STRING_SIMPLE("name")) {
-        format_style = UNUM_CURRENCY_PLURAL;
-      } else {
-        format_style = UNUM_CURRENCY;
-      }
-#endif
-
-      number_format = static_cast<icu::DecimalFormat*>(
-          icu::NumberFormat::createInstance(icu_locale, format_style, status));
-
-      if (U_FAILURE(status)) {
-        delete number_format;
-        return nullptr;
-      }
-    } else if (style == UNICODE_STRING_SIMPLE("percent")) {
-      number_format = static_cast<icu::DecimalFormat*>(
-          icu::NumberFormat::createPercentInstance(icu_locale, status));
-      if (U_FAILURE(status)) {
-        delete number_format;
-        return nullptr;
-      }
-      // Make sure 1.1% doesn't go into 2%.
-      number_format->setMinimumFractionDigits(1);
-    } else {
-      // Make a decimal instance by default.
-      number_format = static_cast<icu::DecimalFormat*>(
-          icu::NumberFormat::createInstance(icu_locale, status));
-    }
-  }
-
-  if (U_FAILURE(status)) {
-    delete number_format;
-    return nullptr;
-  }
-
-  // Set all options.
-  if (!currency.isEmpty()) {
-    number_format->setCurrency(currency.getBuffer(), status);
-  }
-
-  SetNumericSettings(isolate, number_format, options);
-
-  bool grouping;
-  if (ExtractBooleanSetting(isolate, options, "useGrouping", &grouping)) {
-    number_format->setGroupingUsed(grouping);
-  }
-
-  return number_format;
-}
-
-void SetResolvedNumericSettings(Isolate* isolate, const icu::Locale& icu_locale,
-                                icu::DecimalFormat* number_format,
-                                Handle<JSObject> resolved) {
-  Factory* factory = isolate->factory();
-
-  JSObject::SetProperty(
-      isolate, resolved,
-      factory->NewStringFromStaticChars("minimumIntegerDigits"),
-      factory->NewNumberFromInt(number_format->getMinimumIntegerDigits()),
-      LanguageMode::kSloppy)
-      .Assert();
-
-  JSObject::SetProperty(
-      isolate, resolved,
-      factory->NewStringFromStaticChars("minimumFractionDigits"),
-      factory->NewNumberFromInt(number_format->getMinimumFractionDigits()),
-      LanguageMode::kSloppy)
-      .Assert();
-
-  JSObject::SetProperty(
-      isolate, resolved,
-      factory->NewStringFromStaticChars("maximumFractionDigits"),
-      factory->NewNumberFromInt(number_format->getMaximumFractionDigits()),
-      LanguageMode::kSloppy)
-      .Assert();
-
-  Handle<String> key =
-      factory->NewStringFromStaticChars("minimumSignificantDigits");
-  Maybe<bool> maybe = JSReceiver::HasOwnProperty(resolved, key);
-  CHECK(maybe.IsJust());
-  if (maybe.FromJust()) {
-    JSObject::SetProperty(
-        isolate, resolved,
-        factory->NewStringFromStaticChars("minimumSignificantDigits"),
-        factory->NewNumberFromInt(number_format->getMinimumSignificantDigits()),
-        LanguageMode::kSloppy)
-        .Assert();
-  }
-
-  key = factory->NewStringFromStaticChars("maximumSignificantDigits");
-  maybe = JSReceiver::HasOwnProperty(resolved, key);
-  CHECK(maybe.IsJust());
-  if (maybe.FromJust()) {
-    JSObject::SetProperty(
-        isolate, resolved,
-        factory->NewStringFromStaticChars("maximumSignificantDigits"),
-        factory->NewNumberFromInt(number_format->getMaximumSignificantDigits()),
-        LanguageMode::kSloppy)
-        .Assert();
-  }
-
-  // Set the locale
-  char result[ULOC_FULLNAME_CAPACITY];
-  UErrorCode status = U_ZERO_ERROR;
-  uloc_toLanguageTag(icu_locale.getName(), result, ULOC_FULLNAME_CAPACITY,
-                     FALSE, &status);
-  if (U_SUCCESS(status)) {
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("locale"),
-        factory->NewStringFromAsciiChecked(result), LanguageMode::kSloppy)
-        .Assert();
-  } else {
-    // This would never happen, since we got the locale from ICU.
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("locale"),
-        factory->NewStringFromStaticChars("und"), LanguageMode::kSloppy)
-        .Assert();
-  }
-}
-
-void SetResolvedNumberSettings(Isolate* isolate, const icu::Locale& icu_locale,
-                               icu::DecimalFormat* number_format,
-                               Handle<JSObject> resolved) {
-  Factory* factory = isolate->factory();
-
-  // Set resolved currency code in options.currency if not empty.
-  icu::UnicodeString currency(number_format->getCurrency());
-  if (!currency.isEmpty()) {
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("currency"),
-        factory
-            ->NewStringFromTwoByte(Vector<const uint16_t>(
-                reinterpret_cast<const uint16_t*>(currency.getBuffer()),
-                currency.length()))
-            .ToHandleChecked(),
-        LanguageMode::kSloppy)
-        .Assert();
-  }
-
+std::string Intl::GetNumberingSystem(const icu::Locale& icu_locale) {
   // Ugly hack. ICU doesn't expose numbering system in any way, so we have
   // to assume that for given locale NumberingSystem constructor produces the
   // same digits as NumberFormat/Calendar would.
   UErrorCode status = U_ZERO_ERROR;
-  icu::NumberingSystem* numbering_system =
-      icu::NumberingSystem::createInstance(icu_locale, status);
-  if (U_SUCCESS(status)) {
-    const char* ns = numbering_system->getName();
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("numberingSystem"),
-        factory->NewStringFromAsciiChecked(ns), LanguageMode::kSloppy)
-        .Assert();
-  } else {
-    JSObject::SetProperty(isolate, resolved,
-                          factory->NewStringFromStaticChars("numberingSystem"),
-                          factory->undefined_value(), LanguageMode::kSloppy)
-        .Assert();
-  }
-  delete numbering_system;
-
-  JSObject::SetProperty(isolate, resolved,
-                        factory->NewStringFromStaticChars("useGrouping"),
-                        factory->ToBoolean(number_format->isGroupingUsed()),
-                        LanguageMode::kSloppy)
-      .Assert();
-
-  SetResolvedNumericSettings(isolate, icu_locale, number_format, resolved);
-}
-
-icu::BreakIterator* CreateICUBreakIterator(Isolate* isolate,
-                                           const icu::Locale& icu_locale,
-                                           Handle<JSObject> options) {
-  UErrorCode status = U_ZERO_ERROR;
-  icu::BreakIterator* break_iterator = nullptr;
-  icu::UnicodeString type;
-  if (!ExtractStringSetting(isolate, options, "type", &type)) return nullptr;
-
-  if (type == UNICODE_STRING_SIMPLE("character")) {
-    break_iterator =
-        icu::BreakIterator::createCharacterInstance(icu_locale, status);
-  } else if (type == UNICODE_STRING_SIMPLE("sentence")) {
-    break_iterator =
-        icu::BreakIterator::createSentenceInstance(icu_locale, status);
-  } else if (type == UNICODE_STRING_SIMPLE("line")) {
-    break_iterator = icu::BreakIterator::createLineInstance(icu_locale, status);
-  } else {
-    // Defualt is word iterator.
-    break_iterator = icu::BreakIterator::createWordInstance(icu_locale, status);
-  }
-
-  if (U_FAILURE(status)) {
-    delete break_iterator;
-    return nullptr;
-  }
-
-  isolate->CountUsage(v8::Isolate::UseCounterFeature::kBreakIterator);
-
-  return break_iterator;
-}
-
-void SetResolvedBreakIteratorSettings(Isolate* isolate,
-                                      const icu::Locale& icu_locale,
-                                      icu::BreakIterator* break_iterator,
-                                      Handle<JSObject> resolved) {
-  Factory* factory = isolate->factory();
-  UErrorCode status = U_ZERO_ERROR;
-
-  // Set the locale
-  char result[ULOC_FULLNAME_CAPACITY];
-  status = U_ZERO_ERROR;
-  uloc_toLanguageTag(icu_locale.getName(), result, ULOC_FULLNAME_CAPACITY,
-                     FALSE, &status);
+  std::unique_ptr<icu::NumberingSystem> numbering_system(
+      icu::NumberingSystem::createInstance(icu_locale, status));
+  std::string value;
   if (U_SUCCESS(status)) {
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("locale"),
-        factory->NewStringFromAsciiChecked(result), LanguageMode::kSloppy)
-        .Assert();
-  } else {
-    // This would never happen, since we got the locale from ICU.
-    JSObject::SetProperty(
-        isolate, resolved, factory->NewStringFromStaticChars("locale"),
-        factory->NewStringFromStaticChars("und"), LanguageMode::kSloppy)
-        .Assert();
+    value = numbering_system->getName();
   }
+  return value;
 }
 
-MaybeHandle<JSObject> CachedOrNewService(Isolate* isolate,
-                                         Handle<String> service,
-                                         Handle<Object> locales,
-                                         Handle<Object> options,
-                                         Handle<Object> internal_options) {
+MaybeHandle<JSObject> Intl::CachedOrNewService(
+    Isolate* isolate, Handle<String> service, Handle<Object> locales,
+    Handle<Object> options, Handle<Object> internal_options) {
   Handle<Object> result;
   Handle<Object> undefined_value(ReadOnlyRoots(isolate).undefined_value(),
                                  isolate);
@@ -569,7 +70,6 @@ MaybeHandle<JSObject> CachedOrNewService(Isolate* isolate,
       JSArray);
   return Handle<JSObject>::cast(result);
 }
-}  // namespace
 
 icu::Locale Intl::CreateICULocale(Isolate* isolate,
                                   Handle<String> bcp47_locale_str) {
@@ -583,14 +83,18 @@ icu::Locale Intl::CreateICULocale(Isolate* isolate,
   // Convert BCP47 into ICU locale format.
   UErrorCode status = U_ZERO_ERROR;
   char icu_result[ULOC_FULLNAME_CAPACITY];
-  int icu_length = 0;
+  int parsed_length = 0;
 
   // bcp47_locale_str should be a canonicalized language tag, which
   // means this shouldn't fail.
   uloc_forLanguageTag(*bcp47_locale, icu_result, ULOC_FULLNAME_CAPACITY,
-                      &icu_length, &status);
+                      &parsed_length, &status);
   CHECK(U_SUCCESS(status));
-  CHECK_LT(0, icu_length);
+
+  // bcp47_locale is already checked for its structural validity
+  // so that it should be parsed completely.
+  int bcp47length = bcp47_locale.length();
+  CHECK_EQ(bcp47length, parsed_length);
 
   icu::Locale icu_locale(icu_result);
   if (icu_locale.isBogus()) {
@@ -601,253 +105,6 @@ icu::Locale Intl::CreateICULocale(Isolate* isolate,
 }
 
 // static
-icu::SimpleDateFormat* DateFormat::InitializeDateTimeFormat(
-    Isolate* isolate, Handle<String> locale, Handle<JSObject> options,
-    Handle<JSObject> resolved) {
-  icu::Locale icu_locale = Intl::CreateICULocale(isolate, locale);
-  DCHECK(!icu_locale.isBogus());
-
-  icu::SimpleDateFormat* date_format =
-      CreateICUDateFormat(isolate, icu_locale, options);
-  if (!date_format) {
-    // Remove extensions and try again.
-    icu::Locale no_extension_locale(icu_locale.getBaseName());
-    date_format = CreateICUDateFormat(isolate, no_extension_locale, options);
-
-    if (!date_format) {
-      FATAL("Failed to create ICU date format, are ICU data files missing?");
-    }
-
-    // Set resolved settings (pattern, numbering system, calendar).
-    SetResolvedDateSettings(isolate, no_extension_locale, date_format,
-                            resolved);
-  } else {
-    SetResolvedDateSettings(isolate, icu_locale, date_format, resolved);
-  }
-
-  CHECK_NOT_NULL(date_format);
-  return date_format;
-}
-
-icu::SimpleDateFormat* DateFormat::UnpackDateFormat(Handle<JSObject> obj) {
-  return reinterpret_cast<icu::SimpleDateFormat*>(
-      obj->GetEmbedderField(DateFormat::kSimpleDateFormatIndex));
-}
-
-void DateFormat::DeleteDateFormat(const v8::WeakCallbackInfo<void>& data) {
-  delete reinterpret_cast<icu::SimpleDateFormat*>(data.GetInternalField(0));
-  GlobalHandles::Destroy(reinterpret_cast<Object**>(data.GetParameter()));
-}
-
-MaybeHandle<JSObject> DateFormat::Unwrap(Isolate* isolate,
-                                         Handle<JSReceiver> receiver,
-                                         const char* method_name) {
-  Handle<Context> native_context =
-      Handle<Context>(isolate->context()->native_context(), isolate);
-  Handle<JSFunction> constructor = Handle<JSFunction>(
-      JSFunction::cast(native_context->intl_date_time_format_function()),
-      isolate);
-  Handle<String> method_name_str =
-      isolate->factory()->NewStringFromAsciiChecked(method_name);
-
-  return Intl::UnwrapReceiver(isolate, receiver, constructor,
-                              Intl::Type::kDateTimeFormat, method_name_str,
-                              true);
-}
-
-// ecma402/#sec-formatdatetime
-// FormatDateTime( dateTimeFormat, x )
-MaybeHandle<String> DateFormat::FormatDateTime(
-    Isolate* isolate, Handle<JSObject> date_time_format_holder, double x) {
-  double date_value = DateCache::TimeClip(x);
-  if (std::isnan(date_value)) {
-    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kInvalidTimeValue),
-                    String);
-  }
-
-  CHECK(Intl::IsObjectOfType(isolate, date_time_format_holder,
-                             Intl::Type::kDateTimeFormat));
-  icu::SimpleDateFormat* date_format =
-      DateFormat::UnpackDateFormat(date_time_format_holder);
-  CHECK_NOT_NULL(date_format);
-
-  icu::UnicodeString result;
-  date_format->format(date_value, result);
-
-  return isolate->factory()->NewStringFromTwoByte(Vector<const uint16_t>(
-      reinterpret_cast<const uint16_t*>(result.getBuffer()), result.length()));
-}
-
-// ecma402/#sec-datetime-format-functions
-// DateTime Format Functions
-MaybeHandle<String> DateFormat::DateTimeFormat(
-    Isolate* isolate, Handle<JSObject> date_time_format_holder,
-    Handle<Object> date) {
-  // 2. Assert: Type(dtf) is Object and dtf has an [[InitializedDateTimeFormat]]
-  // internal slot.
-  DCHECK(Intl::IsObjectOfType(isolate, date_time_format_holder,
-                              Intl::Type::kDateTimeFormat));
-
-  // 3. If date is not provided or is undefined, then
-  double x;
-  if (date->IsUndefined()) {
-    // 3.a Let x be Call(%Date_now%, undefined).
-    x = JSDate::CurrentTimeValue(isolate);
-  } else {
-    // 4. Else,
-    //    a. Let x be ? ToNumber(date).
-    ASSIGN_RETURN_ON_EXCEPTION(isolate, date, Object::ToNumber(isolate, date),
-                               String);
-    CHECK(date->IsNumber());
-    x = date->Number();
-  }
-  // 5. Return FormatDateTime(dtf, x).
-  return DateFormat::FormatDateTime(isolate, date_time_format_holder, x);
-}
-
-MaybeHandle<String> DateFormat::ToLocaleDateTime(
-    Isolate* isolate, Handle<Object> date, Handle<Object> locales,
-    Handle<Object> options, const char* required, const char* defaults,
-    const char* service) {
-  Factory* factory = isolate->factory();
-  // 1. Let x be ? thisTimeValue(this value);
-  if (!date->IsJSDate()) {
-    THROW_NEW_ERROR(isolate,
-                    NewTypeError(MessageTemplate::kMethodInvokedOnWrongType,
-                                 factory->NewStringFromStaticChars("Date")),
-                    String);
-  }
-
-  double const x = Handle<JSDate>::cast(date)->value()->Number();
-  // 2. If x is NaN, return "Invalid Date"
-  if (std::isnan(x)) {
-    return factory->NewStringFromStaticChars("Invalid Date");
-  }
-
-  // 3. Let options be ? ToDateTimeOptions(options, required, defaults).
-  Handle<JSObject> internal_options;
-  ASSIGN_RETURN_ON_EXCEPTION(
-      isolate, internal_options,
-      DateFormat::ToDateTimeOptions(isolate, options, required, defaults),
-      String);
-
-  // 4. Let dateFormat be ? Construct(%DateTimeFormat%, « locales, options »).
-  Handle<JSObject> date_format;
-  ASSIGN_RETURN_ON_EXCEPTION(
-      isolate, date_format,
-      CachedOrNewService(isolate, factory->NewStringFromAsciiChecked(service),
-                         locales, options, internal_options),
-      String);
-
-  // 5. Return FormatDateTime(dateFormat, x).
-  return DateFormat::FormatDateTime(isolate, date_format, x);
-}
-
-icu::DecimalFormat* NumberFormat::InitializeNumberFormat(
-    Isolate* isolate, Handle<String> locale, Handle<JSObject> options,
-    Handle<JSObject> resolved) {
-  icu::Locale icu_locale = Intl::CreateICULocale(isolate, locale);
-  DCHECK(!icu_locale.isBogus());
-
-  icu::DecimalFormat* number_format =
-      CreateICUNumberFormat(isolate, icu_locale, options);
-  if (!number_format) {
-    // Remove extensions and try again.
-    icu::Locale no_extension_locale(icu_locale.getBaseName());
-    number_format =
-        CreateICUNumberFormat(isolate, no_extension_locale, options);
-
-    if (!number_format) {
-      FATAL("Failed to create ICU number format, are ICU data files missing?");
-    }
-
-    // Set resolved settings (pattern, numbering system).
-    SetResolvedNumberSettings(isolate, no_extension_locale, number_format,
-                              resolved);
-  } else {
-    SetResolvedNumberSettings(isolate, icu_locale, number_format, resolved);
-  }
-
-  CHECK_NOT_NULL(number_format);
-  return number_format;
-}
-
-icu::DecimalFormat* NumberFormat::UnpackNumberFormat(Handle<JSObject> obj) {
-  return reinterpret_cast<icu::DecimalFormat*>(
-      obj->GetEmbedderField(NumberFormat::kDecimalFormatIndex));
-}
-
-void NumberFormat::DeleteNumberFormat(const v8::WeakCallbackInfo<void>& data) {
-  delete reinterpret_cast<icu::DecimalFormat*>(data.GetInternalField(0));
-  GlobalHandles::Destroy(reinterpret_cast<Object**>(data.GetParameter()));
-}
-
-icu::BreakIterator* V8BreakIterator::InitializeBreakIterator(
-    Isolate* isolate, Handle<String> locale, Handle<JSObject> options,
-    Handle<JSObject> resolved) {
-  icu::Locale icu_locale = Intl::CreateICULocale(isolate, locale);
-  DCHECK(!icu_locale.isBogus());
-
-  icu::BreakIterator* break_iterator =
-      CreateICUBreakIterator(isolate, icu_locale, options);
-  if (!break_iterator) {
-    // Remove extensions and try again.
-    icu::Locale no_extension_locale(icu_locale.getBaseName());
-    break_iterator =
-        CreateICUBreakIterator(isolate, no_extension_locale, options);
-
-    if (!break_iterator) {
-      FATAL("Failed to create ICU break iterator, are ICU data files missing?");
-    }
-
-    // Set resolved settings (locale).
-    SetResolvedBreakIteratorSettings(isolate, no_extension_locale,
-                                     break_iterator, resolved);
-  } else {
-    SetResolvedBreakIteratorSettings(isolate, icu_locale, break_iterator,
-                                     resolved);
-  }
-
-  CHECK_NOT_NULL(break_iterator);
-  return break_iterator;
-}
-
-icu::BreakIterator* V8BreakIterator::UnpackBreakIterator(Handle<JSObject> obj) {
-  return reinterpret_cast<icu::BreakIterator*>(
-      obj->GetEmbedderField(V8BreakIterator::kBreakIteratorIndex));
-}
-
-void V8BreakIterator::DeleteBreakIterator(
-    const v8::WeakCallbackInfo<void>& data) {
-  delete reinterpret_cast<icu::BreakIterator*>(data.GetInternalField(0));
-  delete reinterpret_cast<icu::UnicodeString*>(data.GetInternalField(1));
-  GlobalHandles::Destroy(reinterpret_cast<Object**>(data.GetParameter()));
-}
-
-void V8BreakIterator::AdoptText(Isolate* isolate,
-                                Handle<JSObject> break_iterator_holder,
-                                Handle<String> text) {
-  icu::BreakIterator* break_iterator =
-      V8BreakIterator::UnpackBreakIterator(break_iterator_holder);
-  CHECK_NOT_NULL(break_iterator);
-
-  icu::UnicodeString* u_text = reinterpret_cast<icu::UnicodeString*>(
-      break_iterator_holder->GetEmbedderField(
-          V8BreakIterator::kUnicodeStringIndex));
-  delete u_text;
-
-  int length = text->length();
-  text = String::Flatten(isolate, text);
-  DisallowHeapAllocation no_gc;
-  String::FlatContent flat = text->GetFlatContent();
-  std::unique_ptr<uc16[]> sap;
-  const UChar* text_value = GetUCharBufferFromFlat(flat, &sap, length);
-  u_text = new icu::UnicodeString(text_value, length);
-  break_iterator_holder->SetEmbedderField(V8BreakIterator::kUnicodeStringIndex,
-                                          reinterpret_cast<Smi*>(u_text));
-
-  break_iterator->setText(*u_text);
-}
 
 MaybeHandle<String> Intl::ToString(Isolate* isolate,
                                    const icu::UnicodeString& string) {
@@ -902,12 +159,18 @@ void Intl::AddElement(Isolate* isolate, Handle<JSArray> array, int index,
   JSObject::AddProperty(isolate, element, additional_property_name,
                         additional_property_value, NONE);
 }
+
+namespace {
+
 // Build the shortened locale; eg, convert xx_Yyyy_ZZ  to xx_ZZ.
-bool Intl::RemoveLocaleScriptTag(const std::string& icu_locale,
-                                 std::string* locale_less_script) {
+//
+// If locale has a script tag then return true and the locale without the
+// script else return false and an empty string.
+bool RemoveLocaleScriptTag(const std::string& icu_locale,
+                           std::string* locale_less_script) {
   icu::Locale new_locale = icu::Locale::createCanonical(icu_locale.c_str());
   const char* icu_script = new_locale.getScript();
-  if (icu_script == NULL || strlen(icu_script) == 0) {
+  if (icu_script == nullptr || strlen(icu_script) == 0) {
     *locale_less_script = std::string();
     return false;
   }
@@ -915,134 +178,33 @@ bool Intl::RemoveLocaleScriptTag(const std::string& icu_locale,
   const char* icu_language = new_locale.getLanguage();
   const char* icu_country = new_locale.getCountry();
   icu::Locale short_locale = icu::Locale(icu_language, icu_country);
-  const char* icu_name = short_locale.getName();
-  *locale_less_script = std::string(icu_name);
+  *locale_less_script = short_locale.getName();
   return true;
 }
 
-namespace {
-
-Maybe<bool> IsPropertyUndefined(Isolate* isolate, Handle<JSObject> options,
-                                const char* property) {
-  Factory* factory = isolate->factory();
-  // i. Let prop be the property name.
-  // ii. Let value be ? Get(options, prop).
-  Handle<Object> value;
-  ASSIGN_RETURN_ON_EXCEPTION_VALUE(
-      isolate, value,
-      Object::GetPropertyOrElement(
-          isolate, options, factory->NewStringFromAsciiChecked(property)),
-      Nothing<bool>());
-  return Just(value->IsUndefined(isolate));
-}
-
 }  // namespace
 
-// ecma-402/#sec-todatetimeoptions
-MaybeHandle<JSObject> DateFormat::ToDateTimeOptions(
-    Isolate* isolate, Handle<Object> input_options, const char* required,
-    const char* defaults) {
-  Factory* factory = isolate->factory();
-  // 1. If options is undefined, let options be null; otherwise let options be ?
-  //    ToObject(options).
-  Handle<JSObject> options;
-  if (input_options->IsUndefined(isolate)) {
-    options = factory->NewJSObjectWithNullProto();
-  } else {
-    Handle<JSReceiver> options_obj;
-    ASSIGN_RETURN_ON_EXCEPTION(isolate, options_obj,
-                               Object::ToObject(isolate, input_options),
-                               JSObject);
-    // 2. Let options be ObjectCreate(options).
-    ASSIGN_RETURN_ON_EXCEPTION(isolate, options,
-                               JSObject::ObjectCreate(isolate, options_obj),
-                               JSObject);
-  }
-
-  // 3. Let needDefaults be true.
-  bool needs_default = true;
-
-  bool required_is_any = strcmp(required, "any") == 0;
-  // 4. If required is "date" or "any", then
-  if (required_is_any || (strcmp(required, "date") == 0)) {
-    // a. For each of the property names "weekday", "year", "month", "day", do
-    for (auto& prop : {"weekday", "year", "month", "day"}) {
-      //  i. Let prop be the property name.
-      // ii. Let value be ? Get(options, prop)
-      Maybe<bool> maybe_undefined = IsPropertyUndefined(isolate, options, prop);
-      MAYBE_RETURN(maybe_undefined, Handle<JSObject>());
-      // iii. If value is not undefined, let needDefaults be false.
-      if (!maybe_undefined.FromJust()) {
-        needs_default = false;
-      }
-    }
-  }
-
-  // 5. If required is "time" or "any", then
-  if (required_is_any || (strcmp(required, "time") == 0)) {
-    // a. For each of the property names "hour", "minute", "second", do
-    for (auto& prop : {"hour", "minute", "second"}) {
-      //  i. Let prop be the property name.
-      // ii. Let value be ? Get(options, prop)
-      Maybe<bool> maybe_undefined = IsPropertyUndefined(isolate, options, prop);
-      MAYBE_RETURN(maybe_undefined, Handle<JSObject>());
-      // iii. If value is not undefined, let needDefaults be false.
-      if (!maybe_undefined.FromJust()) {
-        needs_default = false;
-      }
-    }
-  }
-
-  // 6. If needDefaults is true and defaults is either "date" or "all", then
-  if (needs_default) {
-    bool default_is_all = strcmp(defaults, "all") == 0;
-    if (default_is_all || (strcmp(defaults, "date") == 0)) {
-      // a. For each of the property names "year", "month", "day", do
-      // i. Perform ? CreateDataPropertyOrThrow(options, prop, "numeric").
-      for (auto& prop : {"year", "month", "day"}) {
-        MAYBE_RETURN(
-            JSReceiver::CreateDataProperty(
-                isolate, options, factory->NewStringFromAsciiChecked(prop),
-                factory->numeric_string(), kThrowOnError),
-            Handle<JSObject>());
-      }
-    }
-    // 7. If needDefaults is true and defaults is either "time" or "all", then
-    if (default_is_all || (strcmp(defaults, "time") == 0)) {
-      // a. For each of the property names "hour", "minute", "second", do
-      // i. Perform ? CreateDataPropertyOrThrow(options, prop, "numeric").
-      for (auto& prop : {"hour", "minute", "second"}) {
-        MAYBE_RETURN(
-            JSReceiver::CreateDataProperty(
-                isolate, options, factory->NewStringFromAsciiChecked(prop),
-                factory->numeric_string(), kThrowOnError),
-            Handle<JSObject>());
-      }
-    }
-  }
-  // 8. Return options.
-  return options;
-}
-
-std::set<std::string> Intl::GetAvailableLocales(const IcuService& service) {
+std::set<std::string> Intl::GetAvailableLocales(const ICUService service) {
   const icu::Locale* icu_available_locales = nullptr;
   int32_t count = 0;
   std::set<std::string> locales;
 
   switch (service) {
-    case IcuService::kBreakIterator:
+    case ICUService::kBreakIterator:
+    case ICUService::kSegmenter:
       icu_available_locales = icu::BreakIterator::getAvailableLocales(count);
       break;
-    case IcuService::kCollator:
+    case ICUService::kCollator:
       icu_available_locales = icu::Collator::getAvailableLocales(count);
       break;
-    case IcuService::kDateFormat:
+    case ICUService::kRelativeDateTimeFormatter:
+    case ICUService::kDateFormat:
       icu_available_locales = icu::DateFormat::getAvailableLocales(count);
       break;
-    case IcuService::kNumberFormat:
+    case ICUService::kNumberFormat:
       icu_available_locales = icu::NumberFormat::getAvailableLocales(count);
       break;
-    case IcuService::kPluralRules:
+    case ICUService::kPluralRules:
       // TODO(littledan): For PluralRules, filter out locales that
       // don't support PluralRules.
       // PluralRules is missing an appropriate getAvailableLocales method,
@@ -1050,44 +212,7 @@ std::set<std::string> Intl::GetAvailableLocales(const IcuService& service) {
       // https://ssl.icu-project.org/trac/ticket/12756
       icu_available_locales = icu::Locale::getAvailableLocales(count);
       break;
-    case IcuService::kResourceBundle: {
-      UErrorCode status = U_ZERO_ERROR;
-      UEnumeration* en = ures_openAvailableLocales(nullptr, &status);
-      int32_t length = 0;
-      const char* locale_str = uenum_next(en, &length, &status);
-      while (U_SUCCESS(status) && (locale_str != nullptr)) {
-        std::string locale(locale_str, length);
-        std::replace(locale.begin(), locale.end(), '_', '-');
-        locales.insert(locale);
-        std::string shortened_locale;
-        if (Intl::RemoveLocaleScriptTag(locale_str, &shortened_locale)) {
-          std::replace(shortened_locale.begin(), shortened_locale.end(), '_',
-                       '-');
-          locales.insert(shortened_locale);
-        }
-        locale_str = uenum_next(en, &length, &status);
-      }
-      uenum_close(en);
-      return locales;
-    }
-    case IcuService::kRelativeDateTimeFormatter: {
-      // ICU RelativeDateTimeFormatter does not provide a getAvailableLocales()
-      // interface, because RelativeDateTimeFormatter depends on
-      // 1. NumberFormat and 2. ResourceBundle, return the
-      // intersection of these two set.
-      // ICU FR at https://unicode-org.atlassian.net/browse/ICU-20009
-      // TODO(ftang): change to call ICU's getAvailableLocales() after it is
-      // added.
-      std::set<std::string> number_format_set(
-          Intl::GetAvailableLocales(IcuService::kNumberFormat));
-      std::set<std::string> resource_bundle_set(
-          Intl::GetAvailableLocales(IcuService::kResourceBundle));
-      set_intersection(resource_bundle_set.begin(), resource_bundle_set.end(),
-                       number_format_set.begin(), number_format_set.end(),
-                       std::inserter(locales, locales.begin()));
-      return locales;
-    }
-    case IcuService::kListFormatter: {
+    case ICUService::kListFormatter: {
       // TODO(ftang): for now just use
       // icu::Locale::getAvailableLocales(count) until we migrate to
       // Intl::GetAvailableLocales().
@@ -1114,7 +239,7 @@ std::set<std::string> Intl::GetAvailableLocales(const IcuService& service) {
     locales.insert(locale);
 
     std::string shortened_locale;
-    if (Intl::RemoveLocaleScriptTag(icu_name, &shortened_locale)) {
+    if (RemoveLocaleScriptTag(icu_name, &shortened_locale)) {
       std::replace(shortened_locale.begin(), shortened_locale.end(), '_', '-');
       locales.insert(shortened_locale);
     }
@@ -1123,30 +248,60 @@ std::set<std::string> Intl::GetAvailableLocales(const IcuService& service) {
   return locales;
 }
 
-IcuService Intl::StringToIcuService(Handle<String> service) {
-  if (service->IsUtf8EqualTo(CStrVector("collator"))) {
-    return IcuService::kCollator;
-  } else if (service->IsUtf8EqualTo(CStrVector("numberformat"))) {
-    return IcuService::kNumberFormat;
-  } else if (service->IsUtf8EqualTo(CStrVector("dateformat"))) {
-    return IcuService::kDateFormat;
-  } else if (service->IsUtf8EqualTo(CStrVector("breakiterator"))) {
-    return IcuService::kBreakIterator;
-  } else if (service->IsUtf8EqualTo(CStrVector("pluralrules"))) {
-    return IcuService::kPluralRules;
-  } else if (service->IsUtf8EqualTo(CStrVector("relativetimeformat"))) {
-    return IcuService::kRelativeDateTimeFormatter;
-  } else if (service->IsUtf8EqualTo(CStrVector("listformat"))) {
-    return IcuService::kListFormatter;
+namespace {
+
+// TODO(gsathya): Remove this once we port ResolveLocale to C++.
+ICUService StringToICUService(Handle<String> service) {
+  std::unique_ptr<char[]> service_cstr = service->ToCString();
+  if (strcmp(service_cstr.get(), "collator") == 0) {
+    return ICUService::kCollator;
+  } else if (strcmp(service_cstr.get(), "numberformat") == 0) {
+    return ICUService::kNumberFormat;
+  } else if (strcmp(service_cstr.get(), "dateformat") == 0) {
+    return ICUService::kDateFormat;
+  } else if (strcmp(service_cstr.get(), "breakiterator") == 0) {
+    return ICUService::kBreakIterator;
+  } else if (strcmp(service_cstr.get(), "pluralrules") == 0) {
+    return ICUService::kPluralRules;
+  } else if (strcmp(service_cstr.get(), "relativetimeformat") == 0) {
+    return ICUService::kRelativeDateTimeFormatter;
+  } else if (strcmp(service_cstr.get(), "listformat") == 0) {
+    return ICUService::kListFormatter;
+  } else if (service->IsUtf8EqualTo(CStrVector("segmenter"))) {
+    return ICUService::kSegmenter;
+  }
+  UNREACHABLE();
+}
+
+const char* ICUServiceToString(ICUService service) {
+  switch (service) {
+    case ICUService::kCollator:
+      return "Intl.Collator";
+    case ICUService::kNumberFormat:
+      return "Intl.NumberFormat";
+    case ICUService::kDateFormat:
+      return "Intl.DateFormat";
+    case ICUService::kBreakIterator:
+      return "Intl.v8BreakIterator";
+    case ICUService::kPluralRules:
+      return "Intl.PluralRules";
+    case ICUService::kRelativeDateTimeFormatter:
+      return "Intl.RelativeTimeFormat";
+    case ICUService::kListFormatter:
+      return "Intl.kListFormat";
+    case ICUService::kSegmenter:
+      return "Intl.kSegmenter";
   }
   UNREACHABLE();
 }
 
+}  // namespace
+
 V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> Intl::AvailableLocalesOf(
     Isolate* isolate, Handle<String> service) {
   Factory* factory = isolate->factory();
   std::set<std::string> results =
-      Intl::GetAvailableLocales(StringToIcuService(service));
+      Intl::GetAvailableLocales(StringToICUService(service));
   Handle<JSObject> locales = factory->NewJSObjectWithNullProto();
 
   int32_t i = 0;
@@ -1196,24 +351,11 @@ bool Intl::IsObjectOfType(Isolate* isolate, Handle<Object> input,
   return type == expected_type;
 }
 
-namespace {
-
-// In ECMA 402 v1, Intl constructors supported a mode of operation
-// where calling them with an existing object as a receiver would
-// transform the receiver into the relevant Intl instance with all
-// internal slots. In ECMA 402 v2, this capability was removed, to
-// avoid adding internal slots on existing objects. In ECMA 402 v3,
-// the capability was re-added as "normative optional" in a mode
-// which chains the underlying Intl instance on any object, when the
-// constructor is called
-//
 // See ecma402/#legacy-constructor.
-MaybeHandle<Object> LegacyUnwrapReceiver(Isolate* isolate,
-                                         Handle<JSReceiver> receiver,
-                                         Handle<JSFunction> constructor,
-                                         Intl::Type type) {
-  bool has_initialized_slot = Intl::IsObjectOfType(isolate, receiver, type);
-
+MaybeHandle<Object> Intl::LegacyUnwrapReceiver(Isolate* isolate,
+                                               Handle<JSReceiver> receiver,
+                                               Handle<JSFunction> constructor,
+                                               bool has_initialized_slot) {
   Handle<Object> obj_is_instance_of;
   ASSIGN_RETURN_ON_EXCEPTION(isolate, obj_is_instance_of,
                              Object::InstanceOf(isolate, receiver, constructor),
@@ -1236,94 +378,9 @@ MaybeHandle<Object> LegacyUnwrapReceiver(Isolate* isolate,
   return receiver;
 }
 
-}  // namespace
-
-MaybeHandle<JSObject> Intl::UnwrapReceiver(Isolate* isolate,
-                                           Handle<JSReceiver> receiver,
-                                           Handle<JSFunction> constructor,
-                                           Intl::Type type,
-                                           Handle<String> method_name,
-                                           bool check_legacy_constructor) {
-  DCHECK(type == Intl::Type::kCollator || type == Intl::Type::kNumberFormat ||
-         type == Intl::Type::kDateTimeFormat ||
-         type == Intl::Type::kBreakIterator);
-  Handle<Object> new_receiver = receiver;
-  if (check_legacy_constructor) {
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, new_receiver,
-        LegacyUnwrapReceiver(isolate, receiver, constructor, type), JSObject);
-  }
-
-  // Collator has been ported to use regular instance types. We
-  // shouldn't be using Intl::IsObjectOfType anymore.
-  if (type == Intl::Type::kCollator) {
-    if (!receiver->IsJSCollator()) {
-      // 3. a. Throw a TypeError exception.
-      THROW_NEW_ERROR(isolate,
-                      NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                                   method_name, receiver),
-                      JSObject);
-    }
-    return Handle<JSCollator>::cast(receiver);
-  }
-
-  DCHECK_NE(type, Intl::Type::kCollator);
-  // 3. If Type(new_receiver) is not Object or nf does not have an
-  //    [[Initialized...]]  internal slot, then
-  if (!Intl::IsObjectOfType(isolate, new_receiver, type)) {
-    // 3. a. Throw a TypeError exception.
-    THROW_NEW_ERROR(isolate,
-                    NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                                 method_name, receiver),
-                    JSObject);
-  }
-
-  // The above IsObjectOfType returns true only for JSObjects, which
-  // makes this cast safe.
-  return Handle<JSObject>::cast(new_receiver);
-}
-
-MaybeHandle<JSObject> NumberFormat::Unwrap(Isolate* isolate,
-                                           Handle<JSReceiver> receiver,
-                                           const char* method_name) {
-  Handle<Context> native_context =
-      Handle<Context>(isolate->context()->native_context(), isolate);
-  Handle<JSFunction> constructor = Handle<JSFunction>(
-      JSFunction::cast(native_context->intl_number_format_function()), isolate);
-  Handle<String> method_name_str =
-      isolate->factory()->NewStringFromAsciiChecked(method_name);
-
-  return Intl::UnwrapReceiver(isolate, receiver, constructor,
-                              Intl::Type::kNumberFormat, method_name_str, true);
-}
-
-MaybeHandle<String> NumberFormat::FormatNumber(
-    Isolate* isolate, Handle<JSObject> number_format_holder, double value) {
-  icu::DecimalFormat* number_format =
-      NumberFormat::UnpackNumberFormat(number_format_holder);
-  CHECK_NOT_NULL(number_format);
-
-  icu::UnicodeString result;
-  number_format->format(value, result);
-
-  return isolate->factory()->NewStringFromTwoByte(Vector<const uint16_t>(
-      reinterpret_cast<const uint16_t*>(result.getBuffer()), result.length()));
-}
-
-void Intl::DefineWEProperty(Isolate* isolate, Handle<JSObject> target,
-                            Handle<Name> key, Handle<Object> value) {
-  PropertyDescriptor desc;
-  desc.set_writable(true);
-  desc.set_enumerable(true);
-  desc.set_value(value);
-  Maybe<bool> success =
-      JSReceiver::DefineOwnProperty(isolate, target, key, &desc, kDontThrow);
-  DCHECK(success.IsJust() && success.FromJust());
-  USE(success);
-}
-
 namespace {
 
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
 // Define general regexp macros.
 // Note "(?:" means the regexp group a non-capture group.
 #define REGEX_ALPHA "[a-z]"
@@ -1435,6 +492,7 @@ icu::RegexMatcher* GetLanguageVariantRegexMatcher(Isolate* isolate) {
   }
   return language_variant_regexp_matcher;
 }
+#endif  // USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
 
 }  // anonymous namespace
 
@@ -1560,6 +618,7 @@ char AsciiToLower(char c) {
   return c | (1 << 5);
 }
 
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
 /**
  * Check the structural Validity of the language tag per ECMA 402 6.2.2:
  *   - Well-formed per RFC 5646 2.1
@@ -1571,7 +630,7 @@ char AsciiToLower(char c) {
  * primary/extended language, script, region, variant are not checked
  * against the IANA language subtag registry.
  *
- * ICU is too permissible and lets invalid tags, like
+ * ICU 62 or earlier is too permissible and lets invalid tags, like
  * hant-cmn-cn, through.
  *
  * Returns false if the language tag is invalid.
@@ -1612,7 +671,7 @@ bool IsStructurallyValidLanguageTag(Isolate* isolate,
   // is not valid and would fail LANGUAGE_TAG_RE test.
   size_t pos = 0;
   std::vector<std::string> parts;
-  while ((pos = locale.find("-")) != std::string::npos) {
+  while ((pos = locale.find('-')) != std::string::npos) {
     std::string token = locale.substr(0, pos);
     parts.push_back(token);
     locale = locale.substr(pos + 1);
@@ -1662,6 +721,7 @@ bool IsStructurallyValidLanguageTag(Isolate* isolate,
 
   return true;
 }
+#endif  // USE_CHROMIUM_ICU == 0 || U_ICU_VERSION_MAJOR_NUM < 63
 
 bool IsLowerAscii(char c) { return c >= 'a' && c < 'z'; }
 
@@ -1713,6 +773,14 @@ Maybe<std::string> Intl::CanonicalizeLanguageTag(Isolate* isolate,
   }
   std::string locale(locale_str->ToCString().get());
 
+  if (locale.length() == 0 ||
+      !String::IsAscii(locale.data(), static_cast<int>(locale.length()))) {
+    THROW_NEW_ERROR_RETURN_VALUE(
+        isolate,
+        NewRangeError(MessageTemplate::kInvalidLanguageTag, locale_str),
+        Nothing<std::string>());
+  }
+
   // Optimize for the most common case: a 2-letter language code in the
   // canonical form/lowercase that is not one of the deprecated codes
   // (in, iw, ji, jw). Don't check for ~70 of 3-letter deprecated language
@@ -1726,12 +794,15 @@ Maybe<std::string> Intl::CanonicalizeLanguageTag(Isolate* isolate,
   // Because per BCP 47 2.1.1 language tags are case-insensitive, lowercase
   // the input before any more check.
   std::transform(locale.begin(), locale.end(), locale.begin(), AsciiToLower);
+
+#if USE_CHROMIUM_ICU == 0 && U_ICU_VERSION_MAJOR_NUM < 63
   if (!IsStructurallyValidLanguageTag(isolate, locale)) {
     THROW_NEW_ERROR_RETURN_VALUE(
         isolate,
         NewRangeError(MessageTemplate::kInvalidLanguageTag, locale_str),
         Nothing<std::string>());
   }
+#endif
 
   // ICU maps a few grandfathered tags to what looks like a regular language
   // tag even though IANA language tag registry does not have a preferred
@@ -1749,11 +820,18 @@ Maybe<std::string> Intl::CanonicalizeLanguageTag(Isolate* isolate,
   // https://unicode-org.atlassian.net/browse/ICU-13417
   UErrorCode error = U_ZERO_ERROR;
   char icu_result[ULOC_FULLNAME_CAPACITY];
+  // uloc_forLanguageTag checks the structrual validity. If the input BCP47
+  // language tag is parsed all the way to the end, it indicates that the input
+  // is structurally valid. Due to a couple of bugs, we can't use it
+  // without Chromium patches or ICU 62 or earlier.
+  int parsed_length;
   uloc_forLanguageTag(locale.c_str(), icu_result, ULOC_FULLNAME_CAPACITY,
-                      nullptr, &error);
-  if (U_FAILURE(error) || error == U_STRING_NOT_TERMINATED_WARNING) {
-    // TODO(jshin): This should not happen because the structural validity
-    // is already checked. If that's the case, remove this.
+                      &parsed_length, &error);
+  if (U_FAILURE(error) ||
+#if USE_CHROMIUM_ICU == 1 || U_ICU_VERSION_MAJOR_NUM >= 63
+      static_cast<size_t>(parsed_length) < locale.length() ||
+#endif
+      error == U_STRING_NOT_TERMINATED_WARNING) {
     THROW_NEW_ERROR_RETURN_VALUE(
         isolate,
         NewRangeError(MessageTemplate::kInvalidLanguageTag, locale_str),
@@ -1849,120 +927,6 @@ Maybe<std::vector<std::string>> Intl::CanonicalizeLocaleList(
   return Just(seen);
 }
 
-// ecma-402/#sec-currencydigits
-Handle<Smi> Intl::CurrencyDigits(Isolate* isolate, Handle<String> currency) {
-  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
-  v8::String::Value currency_string(v8_isolate, v8::Utils::ToLocal(currency));
-  CHECK_NOT_NULL(*currency_string);
-
-  DisallowHeapAllocation no_gc;
-  UErrorCode status = U_ZERO_ERROR;
-  uint32_t fraction_digits = ucurr_getDefaultFractionDigits(
-      reinterpret_cast<const UChar*>(*currency_string), &status);
-  // For missing currency codes, default to the most common, 2
-  if (U_FAILURE(status)) fraction_digits = 2;
-  return Handle<Smi>(Smi::FromInt(fraction_digits), isolate);
-}
-
-MaybeHandle<JSObject> Intl::CreateNumberFormat(Isolate* isolate,
-                                               Handle<String> locale,
-                                               Handle<JSObject> options,
-                                               Handle<JSObject> resolved) {
-  Handle<JSFunction> constructor(
-      isolate->native_context()->intl_number_format_function(), isolate);
-
-  Handle<JSObject> local_object;
-  ASSIGN_RETURN_ON_EXCEPTION(isolate, local_object,
-                             JSObject::New(constructor, constructor), JSObject);
-
-  // Set number formatter as embedder field of the resulting JS object.
-  icu::DecimalFormat* number_format =
-      NumberFormat::InitializeNumberFormat(isolate, locale, options, resolved);
-
-  CHECK_NOT_NULL(number_format);
-
-  local_object->SetEmbedderField(NumberFormat::kDecimalFormatIndex,
-                                 reinterpret_cast<Smi*>(number_format));
-
-  Handle<Object> wrapper = isolate->global_handles()->Create(*local_object);
-  GlobalHandles::MakeWeak(wrapper.location(), wrapper.location(),
-                          NumberFormat::DeleteNumberFormat,
-                          WeakCallbackType::kInternalFields);
-  return local_object;
-}
-
-/**
- * Parses Unicode extension into key - value map.
- * Returns empty object if the extension string is invalid.
- * We are not concerned with the validity of the values at this point.
- * 'attribute' in RFC 6047 is not supported. Keys without explicit
- * values are assigned UNDEFINED.
- * TODO(jshin): Fix the handling of 'attribute' (in RFC 6047, but none
- * has been defined so that it's not used) and boolean keys without
- * an explicit value.
- */
-void Intl::ParseExtension(Isolate* isolate, const std::string& extension,
-                          std::map<std::string, std::string>& out) {
-  if (extension.compare(0, 3, "-u-") != 0) return;
-
-  // Key is {2}alphanum, value is {3,8}alphanum.
-  // Some keys may not have explicit values (booleans).
-  std::string key;
-  std::string value;
-  // Skip the "-u-".
-  size_t start = 3;
-  size_t end;
-  do {
-    end = extension.find("-", start);
-    size_t length =
-        (end == std::string::npos) ? extension.length() - start : end - start;
-    std::string element = extension.substr(start, length);
-    // Key is {2}alphanum
-    if (length == 2) {
-      if (!key.empty()) {
-        out.insert(std::pair<std::string, std::string>(key, value));
-        value.clear();
-      }
-      key = element;
-      // value is {3,8}alphanum.
-    } else if (length >= 3 && length <= 8 && !key.empty()) {
-      value = value.empty() ? element : (value + "-" + element);
-    } else {
-      return;
-    }
-    start = end + 1;
-  } while (end != std::string::npos);
-  if (!key.empty()) out.insert(std::pair<std::string, std::string>(key, value));
-}
-
-namespace {
-
-bool IsAToZ(char ch) {
-  return IsInRange(AsciiAlphaToLower(ch), 'a', 'z');
-}
-
-}  // namespace
-
-// Verifies that the input is a well-formed ISO 4217 currency code.
-// ecma402/#sec-currency-codes
-bool Intl::IsWellFormedCurrencyCode(Isolate* isolate, Handle<String> currency) {
-  // 2. If the number of elements in normalized is not 3, return false.
-  if (currency->length() != 3) return false;
-
-  currency = String::Flatten(isolate, currency);
-  {
-    DisallowHeapAllocation no_gc;
-    String::FlatContent flat = currency->GetFlatContent();
-
-    // 1. Let normalized be the result of mapping currency to upper case as
-    // described in 6.1. 3. If normalized contains any character that is not in
-    // the range "A" to "Z" (U+0041 to U+005A), return false. 4. Return true.
-    // Don't uppercase to test. It could convert invalid code into a valid one.
-    // For example \u00DFP (Eszett+P) becomes SSP.
-    return (IsAToZ(flat.Get(0)) && IsAToZ(flat.Get(1)) && IsAToZ(flat.Get(2)));
-  }
-}
-
 // ecma402 #sup-string.prototype.tolocalelowercase
 // ecma402 #sup-string.prototype.tolocaleuppercase
 MaybeHandle<String> Intl::StringLocaleConvertCase(Isolate* isolate,
@@ -1976,7 +940,7 @@ MaybeHandle<String> Intl::StringLocaleConvertCase(Isolate* isolate,
   std::string requested_locale = requested_locales.size() == 0
                                      ? Intl::DefaultLocale(isolate)
                                      : requested_locales[0];
-  size_t dash = requested_locale.find("-");
+  size_t dash = requested_locale.find('-');
   if (dash != std::string::npos) {
     requested_locale = requested_locale.substr(0, dash);
   }
@@ -2069,22 +1033,26 @@ MaybeHandle<String> Intl::NumberToLocaleString(Isolate* isolate,
                          factory->NewStringFromStaticChars("numberformat"),
                          locales, options, factory->undefined_value()),
       String);
-  DCHECK(
-      Intl::IsObjectOfType(isolate, number_format_holder, Intl::kNumberFormat));
+  DCHECK(number_format_holder->IsJSNumberFormat());
+  Handle<JSNumberFormat> number_format = Handle<JSNumberFormat>(
+      JSNumberFormat::cast(*number_format_holder), isolate);
+
   Handle<Object> number_obj;
   ASSIGN_RETURN_ON_EXCEPTION(isolate, number_obj,
                              Object::ToNumber(isolate, num), String);
 
   // Spec treats -0 and +0 as 0.
   double number = number_obj->Number() + 0;
+
   // Return FormatNumber(numberFormat, x).
-  return NumberFormat::FormatNumber(isolate, number_format_holder, number);
+  return JSNumberFormat::FormatNumber(isolate, number_format, number);
 }
 
+namespace {
+
 // ecma402/#sec-defaultnumberoption
-Maybe<int> Intl::DefaultNumberOption(Isolate* isolate, Handle<Object> value,
-                                     int min, int max, int fallback,
-                                     Handle<String> property) {
+Maybe<int> DefaultNumberOption(Isolate* isolate, Handle<Object> value, int min,
+                               int max, int fallback, Handle<String> property) {
   // 2. Else, return fallback.
   if (value->IsUndefined()) return Just(fallback);
 
@@ -2114,9 +1082,9 @@ Maybe<int> Intl::DefaultNumberOption(Isolate* isolate, Handle<Object> value,
 }
 
 // ecma402/#sec-getnumberoption
-Maybe<int> Intl::GetNumberOption(Isolate* isolate, Handle<JSReceiver> options,
-                                 Handle<String> property, int min, int max,
-                                 int fallback) {
+Maybe<int> GetNumberOption(Isolate* isolate, Handle<JSReceiver> options,
+                           Handle<String> property, int min, int max,
+                           int fallback) {
   // 1. Let value be ? Get(options, property).
   Handle<Object> value;
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
@@ -2127,14 +1095,16 @@ Maybe<int> Intl::GetNumberOption(Isolate* isolate, Handle<JSReceiver> options,
   return DefaultNumberOption(isolate, value, min, max, fallback, property);
 }
 
-Maybe<int> Intl::GetNumberOption(Isolate* isolate, Handle<JSReceiver> options,
-                                 const char* property, int min, int max,
-                                 int fallback) {
+Maybe<int> GetNumberOption(Isolate* isolate, Handle<JSReceiver> options,
+                           const char* property, int min, int max,
+                           int fallback) {
   Handle<String> property_str =
       isolate->factory()->NewStringFromAsciiChecked(property);
   return GetNumberOption(isolate, options, property_str, min, max, fallback);
 }
 
+}  // namespace
+
 Maybe<bool> Intl::SetNumberFormatDigitOptions(Isolate* isolate,
                                               icu::DecimalFormat* number_format,
                                               Handle<JSReceiver> options,
@@ -2174,7 +1144,7 @@ Maybe<bool> Intl::SetNumberFormatDigitOptions(Isolate* isolate,
   // 9.  Let mnsd be ? Get(options, "minimumSignificantDigits").
   Handle<Object> mnsd_obj;
   Handle<String> mnsd_str =
-      isolate->factory()->NewStringFromStaticChars("minimumSignificantDigits");
+      isolate->factory()->minimumSignificantDigits_string();
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
       isolate, mnsd_obj, JSReceiver::GetProperty(isolate, options, mnsd_str),
       Nothing<bool>());
@@ -2182,7 +1152,7 @@ Maybe<bool> Intl::SetNumberFormatDigitOptions(Isolate* isolate,
   // 10. Let mxsd be ? Get(options, "maximumSignificantDigits").
   Handle<Object> mxsd_obj;
   Handle<String> mxsd_str =
-      isolate->factory()->NewStringFromStaticChars("maximumSignificantDigits");
+      isolate->factory()->maximumSignificantDigits_string();
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
       isolate, mxsd_obj, JSReceiver::GetProperty(isolate, options, mxsd_str),
       Nothing<bool>());
@@ -2228,96 +1198,108 @@ Maybe<bool> Intl::SetNumberFormatDigitOptions(Isolate* isolate,
 
 namespace {
 
-// ECMA 402 9.2.2 BestAvailableLocale(availableLocales, locale)
-// https://tc39.github.io/ecma402/#sec-bestavailablelocale
-std::string BestAvailableLocale(std::set<std::string> available_locales,
-                                std::string locale) {
-  const char separator = '-';
-
+// ecma402/#sec-bestavailablelocale
+std::string BestAvailableLocale(const std::set<std::string>& available_locales,
+                                const std::string& locale) {
   // 1. Let candidate be locale.
+  std::string candidate = locale;
+
   // 2. Repeat,
-  do {
+  while (true) {
     // 2.a. If availableLocales contains an element equal to candidate, return
     //      candidate.
-    if (available_locales.find(locale) != available_locales.end()) {
-      return locale;
+    if (available_locales.find(candidate) != available_locales.end()) {
+      return candidate;
     }
+
     // 2.b. Let pos be the character index of the last occurrence of "-"
     //      (U+002D) within candidate. If that character does not occur, return
     //      undefined.
-    size_t pos = locale.rfind(separator);
+    size_t pos = candidate.rfind('-');
     if (pos == std::string::npos) {
-      return "";
+      return std::string();
     }
+
     // 2.c. If pos ≥ 2 and the character "-" occurs at index pos-2 of candidate,
     //      decrease pos by 2.
-    if (pos >= 2 && locale[pos - 2] == separator) {
+    if (pos >= 2 && candidate[pos - 2] == '-') {
       pos -= 2;
     }
+
     // 2.d. Let candidate be the substring of candidate from position 0,
     //      inclusive, to position pos, exclusive.
-    locale = locale.substr(0, pos);
-  } while (true);
+    candidate = candidate.substr(0, pos);
+  }
 }
 
-#define ANY_EXTENSION_REGEXP "-[a-z0-9]{1}-.*"
+// Removes unicode extensions from a given bcp47 language tag.
+// For example, converts 'en-US-u-co-emoji' to 'en-US'.
+std::string RemoveUnicodeExtensions(const std::string& locale) {
+  size_t length = locale.length();
 
-std::unique_ptr<icu::RegexMatcher> GetAnyExtensionRegexpMatcher() {
-  UErrorCode status = U_ZERO_ERROR;
-  std::unique_ptr<icu::RegexMatcher> matcher(new icu::RegexMatcher(
-      icu::UnicodeString(ANY_EXTENSION_REGEXP, -1, US_INV), 0, status));
-  DCHECK(U_SUCCESS(status));
-  return matcher;
-}
+  // Privateuse or grandfathered locales have no extension sequences.
+  if ((length > 1) && (locale[1] == '-')) {
+    // Check to make sure that this really is a grandfathered or
+    // privateuse extension. ICU can sometimes mess up the
+    // canonicalization.
+    CHECK(locale[0] == 'x' || locale[0] == 'i');
+    return locale;
+  }
 
-#undef ANY_EXTENSION_REGEXP
+  size_t unicode_extension_start = locale.find("-u-");
 
-// ECMA 402 9.2.7 LookupSupportedLocales(availableLocales, requestedLocales)
-// https://tc39.github.io/ecma402/#sec-lookupsupportedlocales
-std::vector<std::string> LookupSupportedLocales(
-    std::set<std::string> available_locales,
-    std::vector<std::string> requested_locales) {
-  std::unique_ptr<icu::RegexMatcher> matcher = GetAnyExtensionRegexpMatcher();
+  // No unicode extensions found.
+  if (unicode_extension_start == std::string::npos) return locale;
+
+  size_t private_extension_start = locale.find("-x-");
+
+  // Unicode extensions found within privateuse subtags don't count.
+  if (private_extension_start != std::string::npos &&
+      private_extension_start < unicode_extension_start) {
+    return locale;
+  }
+
+  const std::string beginning = locale.substr(0, unicode_extension_start);
+  size_t unicode_extension_end = length;
+  DCHECK_GT(length, 2);
+
+  // Find the end of the extension production as per the bcp47 grammar
+  // by looking for '-' followed by 2 chars and then another '-'.
+  for (size_t i = unicode_extension_start + 1; i < length - 2; i++) {
+    if (locale[i] != '-') continue;
+
+    if (locale[i + 2] == '-') {
+      unicode_extension_end = i;
+      break;
+    }
+
+    i += 2;
+  }
 
+  const std::string end = locale.substr(unicode_extension_end);
+  return beginning + end;
+}
+
+// ecma402/#sec-lookupsupportedlocales
+std::vector<std::string> LookupSupportedLocales(
+    const std::set<std::string>& available_locales,
+    const std::vector<std::string>& requested_locales) {
   // 1. Let subset be a new empty List.
   std::vector<std::string> subset;
 
   // 2. For each element locale of requestedLocales in List order, do
-  for (auto locale : requested_locales) {
-    // 2.a. Let noExtensionsLocale be the String value that is locale with all
-    //      Unicode locale extension sequences removed.
-    icu::UnicodeString locale_uni(locale.c_str(), -1, US_INV);
-    // TODO(bstell): look at using uloc_forLanguageTag to convert the language
-    // tag to locale id
-    // TODO(bstell): look at using uloc_getBaseName to just get the name without
-    // all the keywords
-    matcher->reset(locale_uni);
-    UErrorCode status = U_ZERO_ERROR;
-    // TODO(bstell): need to determine if this is the correct behavior.
-    // This matches the JS implementation but might not match the spec.
-    // According to
-    // https://tc39.github.io/ecma402/#sec-unicode-locale-extension-sequences:
-    //
-    //     This standard uses the term "Unicode locale extension sequence" for
-    //     any substring of a language tag that is not part of a private use
-    //     subtag sequence, starts with a separator  "-" and the singleton "u",
-    //     and includes the maximum sequence of following non-singleton subtags
-    //     and their preceding "-" separators.
-    //
-    // According to the spec a locale "en-t-aaa-u-bbb-v-ccc-x-u-ddd", should
-    // remove only the "-u-bbb" part, and keep everything else, whereas this
-    // regexp matcher would leave only the "en".
-    icu::UnicodeString no_extensions_locale_uni =
-        matcher->replaceAll("", status);
-    DCHECK(U_SUCCESS(status));
-    std::string no_extensions_locale;
-    no_extensions_locale_uni.toUTF8String(no_extensions_locale);
-    // 2.b. Let availableLocale be BestAvailableLocale(availableLocales,
-    //      noExtensionsLocale).
+  for (const std::string& locale : requested_locales) {
+    // 2. a. Let noExtensionsLocale be the String value that is locale
+    //       with all Unicode locale extension sequences removed.
+    std::string no_extension_locale = RemoveUnicodeExtensions(locale);
+
+    // 2. b. Let availableLocale be
+    //       BestAvailableLocale(availableLocales, noExtensionsLocale).
     std::string available_locale =
-        BestAvailableLocale(available_locales, no_extensions_locale);
-    // 2.c. If availableLocale is not undefined, append locale to the end of
-    //      subset.
+        BestAvailableLocale(available_locales, no_extension_locale);
+
+    // 2. c. If availableLocale is not undefined, append locale to the
+    //       end of subset.
     if (!available_locale.empty()) {
       subset.push_back(locale);
     }
@@ -2330,8 +1312,8 @@ std::vector<std::string> LookupSupportedLocales(
 // ECMA 402 9.2.8 BestFitSupportedLocales(availableLocales, requestedLocales)
 // https://tc39.github.io/ecma402/#sec-bestfitsupportedlocales
 std::vector<std::string> BestFitSupportedLocales(
-    std::set<std::string> available_locales,
-    std::vector<std::string> requested_locales) {
+    const std::set<std::string>& available_locales,
+    const std::vector<std::string>& requested_locales) {
   return LookupSupportedLocales(available_locales, requested_locales);
 }
 
@@ -2378,26 +1360,28 @@ MaybeHandle<JSObject> CreateReadOnlyArray(Isolate* isolate,
 // ECMA 402 9.2.9 SupportedLocales(availableLocales, requestedLocales, options)
 // https://tc39.github.io/ecma402/#sec-supportedlocales
 MaybeHandle<JSObject> SupportedLocales(
-    Isolate* isolate, std::string service,
-    std::set<std::string> available_locales,
-    std::vector<std::string> requested_locales, Handle<Object> options) {
+    Isolate* isolate, ICUService service,
+    const std::set<std::string>& available_locales,
+    const std::vector<std::string>& requested_locales, Handle<Object> options) {
   std::vector<std::string> supported_locales;
 
-  // 1. If options is not undefined, then
-  //    a. Let options be ? ToObject(options).
-  //    b. Let matcher be ? GetOption(options, "localeMatcher", "string",
-  //       « "lookup", "best fit" », "best fit").
   // 2. Else, let matcher be "best fit".
   MatcherOption matcher = kBestFit;
+
+  // 1. If options is not undefined, then
   if (!options->IsUndefined(isolate)) {
+    // 1. a. Let options be ? ToObject(options).
     Handle<JSReceiver> options_obj;
     ASSIGN_RETURN_ON_EXCEPTION(isolate, options_obj,
                                Object::ToObject(isolate, options), JSObject);
+
+    // 1. b. Let matcher be ? GetOption(options, "localeMatcher", "string",
+    //       « "lookup", "best fit" », "best fit").
     std::unique_ptr<char[]> matcher_str = nullptr;
     std::vector<const char*> matcher_values = {"lookup", "best fit"};
-    Maybe<bool> maybe_found_matcher =
-        Intl::GetStringOption(isolate, options_obj, "localeMatcher",
-                              matcher_values, service.c_str(), &matcher_str);
+    Maybe<bool> maybe_found_matcher = Intl::GetStringOption(
+        isolate, options_obj, "localeMatcher", matcher_values,
+        ICUServiceToString(service), &matcher_str);
     MAYBE_RETURN(maybe_found_matcher, MaybeHandle<JSObject>());
     if (maybe_found_matcher.FromJust()) {
       DCHECK_NOT_NULL(matcher_str.get());
@@ -2440,28 +1424,69 @@ MaybeHandle<JSObject> SupportedLocales(
 }
 }  // namespace
 
-// ECMA 402 10.2.2 Intl.Collator.supportedLocalesOf
-// https://tc39.github.io/ecma402/#sec-intl.collator.supportedlocalesof
-// of Intl::SupportedLocalesOf thru JS
+// ECMA 402 Intl.*.supportedLocalesOf
 MaybeHandle<JSObject> Intl::SupportedLocalesOf(Isolate* isolate,
-                                               Handle<String> service,
-                                               Handle<Object> locales_in,
-                                               Handle<Object> options_in) {
+                                               ICUService service,
+                                               Handle<Object> locales,
+                                               Handle<Object> options) {
   // Let availableLocales be %Collator%.[[AvailableLocales]].
-  IcuService icu_service = Intl::StringToIcuService(service);
-  std::set<std::string> available_locales = GetAvailableLocales(icu_service);
-  std::vector<std::string> requested_locales;
+  std::set<std::string> available_locales = GetAvailableLocales(service);
+
   // Let requestedLocales be ? CanonicalizeLocaleList(locales).
-  bool got_requested_locales =
-      CanonicalizeLocaleList(isolate, locales_in, false).To(&requested_locales);
-  if (!got_requested_locales) {
-    return MaybeHandle<JSObject>();
-  }
+  Maybe<std::vector<std::string>> requested_locales =
+      CanonicalizeLocaleList(isolate, locales, false);
+  MAYBE_RETURN(requested_locales, MaybeHandle<JSObject>());
 
   // Return ? SupportedLocales(availableLocales, requestedLocales, options).
-  std::string service_str(service->ToCString().get());
-  return SupportedLocales(isolate, service_str, available_locales,
-                          requested_locales, options_in);
+  return SupportedLocales(isolate, service, available_locales,
+                          requested_locales.FromJust(), options);
+}
+
+std::map<std::string, std::string> Intl::LookupUnicodeExtensions(
+    const icu::Locale& icu_locale, const std::set<std::string>& relevant_keys) {
+  std::map<std::string, std::string> extensions;
+
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::StringEnumeration> keywords(
+      icu_locale.createKeywords(status));
+  if (U_FAILURE(status)) return extensions;
+
+  if (!keywords) return extensions;
+  char value[ULOC_FULLNAME_CAPACITY];
+
+  int32_t length;
+  status = U_ZERO_ERROR;
+  for (const char* keyword = keywords->next(&length, status);
+       keyword != nullptr; keyword = keywords->next(&length, status)) {
+    // Ignore failures in ICU and skip to the next keyword.
+    //
+    // This is fine.™
+    if (U_FAILURE(status)) {
+      status = U_ZERO_ERROR;
+      continue;
+    }
+
+    icu_locale.getKeywordValue(keyword, value, ULOC_FULLNAME_CAPACITY, status);
+
+    // Ignore failures in ICU and skip to the next keyword.
+    //
+    // This is fine.™
+    if (U_FAILURE(status)) {
+      status = U_ZERO_ERROR;
+      continue;
+    }
+
+    const char* bcp47_key = uloc_toUnicodeLocaleKey(keyword);
+
+    // Ignore keywords that we don't recognize - spec allows that.
+    if (bcp47_key && (relevant_keys.find(bcp47_key) != relevant_keys.end())) {
+      const char* bcp47_value = uloc_toUnicodeLocaleType(bcp47_key, value);
+      extensions.insert(
+          std::pair<std::string, std::string>(bcp47_key, bcp47_value));
+    }
+  }
+
+  return extensions;
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/intl-objects.h b/deps/v8/src/objects/intl-objects.h
index 38d11772a4..fd2842ebbb 100644
--- a/deps/v8/src/objects/intl-objects.h
+++ b/deps/v8/src/objects/intl-objects.h
@@ -20,10 +20,7 @@
 #include "unicode/uversion.h"
 
 namespace U_ICU_NAMESPACE {
-class BreakIterator;
-class Collator;
 class DecimalFormat;
-class PluralRules;
 class SimpleDateFormat;
 class UnicodeString;
 }
@@ -33,191 +30,7 @@ namespace internal {
 
 template <typename T>
 class Handle;
-
-class DateFormat {
- public:
-  // Create a formatter for the specificied locale and options. Returns the
-  // resolved settings for the locale / options.
-  static icu::SimpleDateFormat* InitializeDateTimeFormat(
-      Isolate* isolate, Handle<String> locale, Handle<JSObject> options,
-      Handle<JSObject> resolved);
-
-  // Unpacks date format object from corresponding JavaScript object.
-  static icu::SimpleDateFormat* UnpackDateFormat(Handle<JSObject> obj);
-
-  // Release memory we allocated for the DateFormat once the JS object that
-  // holds the pointer gets garbage collected.
-  static void DeleteDateFormat(const v8::WeakCallbackInfo<void>& data);
-
-  // ecma402/#sec-formatdatetime
-  // FormatDateTime( dateTimeFormat, x )
-  V8_WARN_UNUSED_RESULT static MaybeHandle<String> FormatDateTime(
-      Isolate* isolate, Handle<JSObject> date_time_format_holder, double x);
-
-  // ecma402/#sec-datetime-format-functions
-  // DateTime Format Functions
-  V8_WARN_UNUSED_RESULT static MaybeHandle<String> DateTimeFormat(
-      Isolate* isolate, Handle<JSObject> date_time_format_holder,
-      Handle<Object> date);
-
-  // The UnwrapDateTimeFormat abstract operation gets the underlying
-  // DateTimeFormat operation for various methods which implement ECMA-402 v1
-  // semantics for supporting initializing existing Intl objects.
-  //
-  // ecma402/#sec-unwrapdatetimeformat
-  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> Unwrap(
-      Isolate* isolate, Handle<JSReceiver> receiver, const char* method_name);
-
-  // ecma-402/#sec-todatetimeoptions
-  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> ToDateTimeOptions(
-      Isolate* isolate, Handle<Object> input_options, const char* required,
-      const char* defaults);
-
-  V8_WARN_UNUSED_RESULT static MaybeHandle<String> ToLocaleDateTime(
-      Isolate* isolate, Handle<Object> date, Handle<Object> locales,
-      Handle<Object> options, const char* required, const char* defaults,
-      const char* service);
-
-  // Layout description.
-#define DATE_FORMAT_FIELDS(V)        \
-  V(kSimpleDateFormat, kPointerSize) \
-  V(kBoundFormat, kPointerSize)      \
-  V(kSize, 0)
-
-  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, DATE_FORMAT_FIELDS)
-#undef DATE_FORMAT_FIELDS
-
-  // ContextSlot defines the context structure for the bound
-  // DateTimeFormat.prototype.format function
-  enum ContextSlot {
-    kDateFormat = Context::MIN_CONTEXT_SLOTS,
-
-    kLength
-  };
-
-  // TODO(ryzokuken): Remove this and use regular accessors once DateFormat is a
-  // subclass of JSObject
-  //
-  // This needs to be consistent with the above Layout Description
-  static const int kSimpleDateFormatIndex = 0;
-  static const int kBoundFormatIndex = 1;
-
- private:
-  DateFormat();
-};
-
-class NumberFormat {
- public:
-  // Create a formatter for the specificied locale and options. Returns the
-  // resolved settings for the locale / options.
-  static icu::DecimalFormat* InitializeNumberFormat(Isolate* isolate,
-                                                    Handle<String> locale,
-                                                    Handle<JSObject> options,
-                                                    Handle<JSObject> resolved);
-
-  // Unpacks number format object from corresponding JavaScript object.
-  static icu::DecimalFormat* UnpackNumberFormat(Handle<JSObject> obj);
-
-  // Release memory we allocated for the NumberFormat once the JS object that
-  // holds the pointer gets garbage collected.
-  static void DeleteNumberFormat(const v8::WeakCallbackInfo<void>& data);
-
-  // The UnwrapNumberFormat abstract operation gets the underlying
-  // NumberFormat operation for various methods which implement
-  // ECMA-402 v1 semantics for supporting initializing existing Intl
-  // objects.
-  //
-  // ecma402/#sec-unwrapnumberformat
-  static MaybeHandle<JSObject> Unwrap(Isolate* isolate,
-                                      Handle<JSReceiver> receiver,
-                                      const char* method_name);
-
-  // ecm402/#sec-formatnumber
-  static MaybeHandle<String> FormatNumber(Isolate* isolate,
-                                          Handle<JSObject> number_format_holder,
-                                          double value);
-
-  // Layout description.
-#define NUMBER_FORMAT_FIELDS(V)   \
-  /* Pointer fields. */           \
-  V(kDecimalFormat, kPointerSize) \
-  V(kBoundFormat, kPointerSize)   \
-  V(kSize, 0)
-
-  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, NUMBER_FORMAT_FIELDS)
-#undef NUMBER_FORMAT_FIELDS
-
-  // ContextSlot defines the context structure for the bound
-  // NumberFormat.prototype.format function.
-  enum ContextSlot {
-    // The number format instance that the function holding this
-    // context is bound to.
-    kNumberFormat = Context::MIN_CONTEXT_SLOTS,
-
-    kLength
-  };
-
-  // TODO(gsathya): Remove this and use regular accessors once
-  // NumberFormat is a sub class of JSObject.
-  //
-  // This needs to be consistent with the above LayoutDescription.
-  static const int kDecimalFormatIndex = 0;
-  static const int kBoundFormatIndex = 1;
-
- private:
-  NumberFormat();
-};
-
-class V8BreakIterator {
- public:
-  // Create a BreakIterator for the specificied locale and options. Returns the
-  // resolved settings for the locale / options.
-  static icu::BreakIterator* InitializeBreakIterator(Isolate* isolate,
-                                                     Handle<String> locale,
-                                                     Handle<JSObject> options,
-                                                     Handle<JSObject> resolved);
-
-  // Unpacks break iterator object from corresponding JavaScript object.
-  static icu::BreakIterator* UnpackBreakIterator(Handle<JSObject> obj);
-
-  // Release memory we allocated for the BreakIterator once the JS object that
-  // holds the pointer gets garbage collected.
-  static void DeleteBreakIterator(const v8::WeakCallbackInfo<void>& data);
-
-  static void AdoptText(Isolate* isolate,
-                        Handle<JSObject> break_iterator_holder,
-                        Handle<String> text);
-
-  // Layout description.
-#define BREAK_ITERATOR_FIELDS(V)   \
-  /* Pointer fields. */            \
-  V(kBreakIterator, kPointerSize)  \
-  V(kUnicodeString, kPointerSize)  \
-  V(kBoundAdoptText, kPointerSize) \
-  V(kSize, 0)
-
-  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, BREAK_ITERATOR_FIELDS)
-#undef BREAK_ITERATOR_FIELDS
-
-  // ContextSlot defines the context structure for the bound
-  // v8BreakIterator.prototype.adoptText function
-  enum class ContextSlot {
-    kV8BreakIterator = Context::MIN_CONTEXT_SLOTS,
-
-    kLength
-  };
-
-  // TODO(ryzokuken): Remove this and use regular accessors once v8BreakIterator
-  // is a subclass of JSObject
-  //
-  // This needs to be consistent with the above Layour Description
-  static const int kBreakIteratorIndex = 0;
-  static const int kUnicodeStringIndex = 1;
-  static const int kBoundAdoptTextIndex = 2;
-
- private:
-  V8BreakIterator();
-};
+class JSCollator;
 
 class Intl {
  public:
@@ -232,6 +45,11 @@ class Intl {
     kTypeCount
   };
 
+  enum class BoundFunctionContextSlot {
+    kBoundFunction = Context::MIN_CONTEXT_SLOTS,
+    kLength
+  };
+
   inline static Intl::Type TypeFromInt(int type);
   inline static Intl::Type TypeFromSmi(Smi* type);
 
@@ -243,41 +61,27 @@ class Intl {
   static bool IsObjectOfType(Isolate* isolate, Handle<Object> object,
                              Intl::Type expected_type);
 
-  static IcuService StringToIcuService(Handle<String> service);
-
   // Gets the ICU locales for a given service. If there is a locale with a
   // script tag then the locales also include a locale without the script; eg,
   // pa_Guru_IN (language=Panjabi, script=Gurmukhi, country-India) would include
   // pa_IN.
-  static std::set<std::string> GetAvailableLocales(const IcuService& service);
+  static std::set<std::string> GetAvailableLocales(ICUService service);
+
+  // Get the name of the numbering system from locale.
+  // ICU doesn't expose numbering system in any way, so we have to assume that
+  // for given locale NumberingSystem constructor produces the same digits as
+  // NumberFormat/Calendar would.
+  static std::string GetNumberingSystem(const icu::Locale& icu_locale);
 
   static V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> AvailableLocalesOf(
       Isolate* isolate, Handle<String> service);
 
-  static MaybeHandle<JSObject> SupportedLocalesOf(Isolate* isolate,
-                                                  Handle<String> service,
-                                                  Handle<Object> locales_in,
-                                                  Handle<Object> options_in);
+  static V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> SupportedLocalesOf(
+      Isolate* isolate, ICUService service, Handle<Object> locales_in,
+      Handle<Object> options_in);
 
   static std::string DefaultLocale(Isolate* isolate);
 
-  static void DefineWEProperty(Isolate* isolate, Handle<JSObject> target,
-                               Handle<Name> key, Handle<Object> value);
-
-  // If locale has a script tag then return true and the locale without the
-  // script else return false and an empty string
-  static bool RemoveLocaleScriptTag(const std::string& icu_locale,
-                                    std::string* locale_less_script);
-
-  // Returns the underlying Intl receiver for various methods which
-  // implement ECMA-402 v1 semantics for supporting initializing
-  // existing Intl objects.
-  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> UnwrapReceiver(
-      Isolate* isolate, Handle<JSReceiver> receiver,
-      Handle<JSFunction> constructor, Intl::Type type,
-      Handle<String> method_name /* TODO(gsathya): Make this char const* */,
-      bool check_legacy_constructor = false);
-
   // The ResolveLocale abstract operation compares a BCP 47 language
   // priority list requestedLocales against the locales in
   // availableLocales and determines the best available language to
@@ -355,22 +159,10 @@ class Intl {
       Isolate* isolate, Handle<Object> locales,
       bool only_return_one_result = false);
 
-  // ecma-402/#sec-currencydigits
-  // The currency is expected to an all upper case string value.
-  static Handle<Smi> CurrencyDigits(Isolate* isolate, Handle<String> currency);
-
-  // TODO(ftang): Remove this and use ICU to the conversion in the future
-  static void ParseExtension(Isolate* isolate, const std::string& extension,
-                             std::map<std::string, std::string>& out);
-
   V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> CreateNumberFormat(
       Isolate* isolate, Handle<String> locale, Handle<JSObject> options,
       Handle<JSObject> resolved);
 
-  // ecma402/#sec-iswellformedcurrencycode
-  static bool IsWellFormedCurrencyCode(Isolate* isolate,
-                                       Handle<String> currency);
-
   // For locale sensitive functions
   V8_WARN_UNUSED_RESULT static MaybeHandle<String> StringLocaleConvertCase(
       Isolate* isolate, Handle<String> s, bool is_upper,
@@ -389,19 +181,6 @@ class Intl {
       Isolate* isolate, Handle<Object> num, Handle<Object> locales,
       Handle<Object> options);
 
-  // ecma402/#sec-defaultnumberoption
-  V8_WARN_UNUSED_RESULT static Maybe<int> DefaultNumberOption(
-      Isolate* isolate, Handle<Object> value, int min, int max, int fallback,
-      Handle<String> property);
-
-  // ecma402/#sec-getnumberoption
-  V8_WARN_UNUSED_RESULT static Maybe<int> GetNumberOption(
-      Isolate* isolate, Handle<JSReceiver> options, Handle<String> property,
-      int min, int max, int fallback);
-  V8_WARN_UNUSED_RESULT static Maybe<int> GetNumberOption(
-      Isolate* isolate, Handle<JSReceiver> options, const char* property,
-      int min, int max, int fallback);
-
   // ecma402/#sec-setnfdigitoptions
   V8_WARN_UNUSED_RESULT static Maybe<bool> SetNumberFormatDigitOptions(
       Isolate* isolate, icu::DecimalFormat* number_format,
@@ -434,6 +213,29 @@ class Intl {
                          Handle<String> field_type_string, Handle<String> value,
                          Handle<String> additional_property_name,
                          Handle<String> additional_property_value);
+
+  // A helper function to help handle Unicode Extensions in locale.
+  static std::map<std::string, std::string> LookupUnicodeExtensions(
+    const icu::Locale& icu_locale, const std::set<std::string>& relevant_keys);
+
+  // In ECMA 402 v1, Intl constructors supported a mode of operation
+  // where calling them with an existing object as a receiver would
+  // transform the receiver into the relevant Intl instance with all
+  // internal slots. In ECMA 402 v2, this capability was removed, to
+  // avoid adding internal slots on existing objects. In ECMA 402 v3,
+  // the capability was re-added as "normative optional" in a mode
+  // which chains the underlying Intl instance on any object, when the
+  // constructor is called
+  //
+  // See ecma402/#legacy-constructor.
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> LegacyUnwrapReceiver(
+      Isolate* isolate, Handle<JSReceiver> receiver,
+      Handle<JSFunction> constructor, bool has_initialized_slot);
+
+  // A factory method to got cached objects.
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> CachedOrNewService(
+      Isolate* isolate, Handle<String> service, Handle<Object> locales,
+      Handle<Object> options, Handle<Object> internal_options);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/js-array-buffer-inl.h b/deps/v8/src/objects/js-array-buffer-inl.h
index 43bc294d04..7bc01a8b8a 100644
--- a/deps/v8/src/objects/js-array-buffer-inl.h
+++ b/deps/v8/src/objects/js-array-buffer-inl.h
@@ -20,6 +20,14 @@ CAST_ACCESSOR(JSArrayBuffer)
 CAST_ACCESSOR(JSArrayBufferView)
 CAST_ACCESSOR(JSTypedArray)
 
+size_t JSArrayBuffer::byte_length() const {
+  return READ_UINTPTR_FIELD(this, kByteLengthOffset);
+}
+
+void JSArrayBuffer::set_byte_length(size_t value) {
+  WRITE_UINTPTR_FIELD(this, kByteLengthOffset, value);
+}
+
 void* JSArrayBuffer::backing_store() const {
   intptr_t ptr = READ_INTPTR_FIELD(this, kBackingStoreOffset);
   return reinterpret_cast<void*>(ptr);
@@ -30,8 +38,6 @@ void JSArrayBuffer::set_backing_store(void* value, WriteBarrierMode mode) {
   WRITE_INTPTR_FIELD(this, kBackingStoreOffset, ptr);
 }
 
-ACCESSORS(JSArrayBuffer, byte_length, Object, kByteLengthOffset)
-
 size_t JSArrayBuffer::allocation_length() const {
   if (backing_store() == nullptr) {
     return 0;
@@ -44,7 +50,7 @@ size_t JSArrayBuffer::allocation_length() const {
     DCHECK_NOT_NULL(data);
     return data->allocation_length;
   }
-  return byte_length()->Number();
+  return byte_length();
 }
 
 void* JSArrayBuffer::allocation_base() const {
@@ -63,13 +69,17 @@ void* JSArrayBuffer::allocation_base() const {
 }
 
 bool JSArrayBuffer::is_wasm_memory() const {
-  bool const is_wasm_memory = IsWasmMemory::decode(bit_field());
+  bool const is_wasm_memory = IsWasmMemoryBit::decode(bit_field());
   DCHECK_EQ(is_wasm_memory,
             GetIsolate()->wasm_engine()->memory_tracker()->IsWasmMemory(
                 backing_store()));
   return is_wasm_memory;
 }
 
+void JSArrayBuffer::set_is_wasm_memory(bool is_wasm_memory) {
+  set_bit_field(IsWasmMemoryBit::update(bit_field(), is_wasm_memory));
+}
+
 void JSArrayBuffer::set_bit_field(uint32_t bits) {
   if (kInt32Size != kPointerSize) {
 #if V8_TARGET_LITTLE_ENDIAN
@@ -85,76 +95,46 @@ uint32_t JSArrayBuffer::bit_field() const {
   return READ_UINT32_FIELD(this, kBitFieldOffset);
 }
 
-bool JSArrayBuffer::is_external() { return IsExternal::decode(bit_field()); }
-
-void JSArrayBuffer::set_is_external(bool value) {
-  set_bit_field(IsExternal::update(bit_field(), value));
-}
-
-bool JSArrayBuffer::is_neuterable() {
-  return IsNeuterable::decode(bit_field());
-}
-
-void JSArrayBuffer::set_is_neuterable(bool value) {
-  set_bit_field(IsNeuterable::update(bit_field(), value));
-}
-
-bool JSArrayBuffer::was_neutered() { return WasNeutered::decode(bit_field()); }
-
-void JSArrayBuffer::set_was_neutered(bool value) {
-  set_bit_field(WasNeutered::update(bit_field(), value));
-}
-
-bool JSArrayBuffer::is_shared() { return IsShared::decode(bit_field()); }
-
-void JSArrayBuffer::set_is_shared(bool value) {
-  set_bit_field(IsShared::update(bit_field(), value));
-}
-
-bool JSArrayBuffer::is_growable() { return IsGrowable::decode(bit_field()); }
-
-void JSArrayBuffer::set_is_growable(bool value) {
-  set_bit_field(IsGrowable::update(bit_field(), value));
-}
+// |bit_field| fields.
+BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_external,
+                    JSArrayBuffer::IsExternalBit)
+BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_neuterable,
+                    JSArrayBuffer::IsNeuterableBit)
+BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, was_neutered,
+                    JSArrayBuffer::WasNeuteredBit)
+BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_shared,
+                    JSArrayBuffer::IsSharedBit)
+BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_growable,
+                    JSArrayBuffer::IsGrowableBit)
 
-Object* JSArrayBufferView::byte_offset() const {
-  if (WasNeutered()) return Smi::kZero;
-  return Object::cast(READ_FIELD(this, kByteOffsetOffset));
+size_t JSArrayBufferView::byte_offset() const {
+  return READ_UINTPTR_FIELD(this, kByteOffsetOffset);
 }
 
-void JSArrayBufferView::set_byte_offset(Object* value, WriteBarrierMode mode) {
-  WRITE_FIELD(this, kByteOffsetOffset, value);
-  CONDITIONAL_WRITE_BARRIER(this, kByteOffsetOffset, value, mode);
+void JSArrayBufferView::set_byte_offset(size_t value) {
+  WRITE_UINTPTR_FIELD(this, kByteOffsetOffset, value);
 }
 
-Object* JSArrayBufferView::byte_length() const {
-  if (WasNeutered()) return Smi::kZero;
-  return Object::cast(READ_FIELD(this, kByteLengthOffset));
+size_t JSArrayBufferView::byte_length() const {
+  return READ_UINTPTR_FIELD(this, kByteLengthOffset);
 }
 
-void JSArrayBufferView::set_byte_length(Object* value, WriteBarrierMode mode) {
-  WRITE_FIELD(this, kByteLengthOffset, value);
-  CONDITIONAL_WRITE_BARRIER(this, kByteLengthOffset, value, mode);
+void JSArrayBufferView::set_byte_length(size_t value) {
+  WRITE_UINTPTR_FIELD(this, kByteLengthOffset, value);
 }
 
 ACCESSORS(JSArrayBufferView, buffer, Object, kBufferOffset)
-#ifdef VERIFY_HEAP
-ACCESSORS(JSArrayBufferView, raw_byte_offset, Object, kByteOffsetOffset)
-ACCESSORS(JSArrayBufferView, raw_byte_length, Object, kByteLengthOffset)
-#endif
 
 bool JSArrayBufferView::WasNeutered() const {
   return JSArrayBuffer::cast(buffer())->was_neutered();
 }
 
 Object* JSTypedArray::length() const {
-  if (WasNeutered()) return Smi::kZero;
   return Object::cast(READ_FIELD(this, kLengthOffset));
 }
 
 size_t JSTypedArray::length_value() const {
-  if (WasNeutered()) return 0;
-  double val = Object::cast(READ_FIELD(this, kLengthOffset))->Number();
+  double val = length()->Number();
   DCHECK_LE(val, kMaxSafeInteger);   // 2^53-1
   DCHECK_GE(val, -kMaxSafeInteger);  // -2^53+1
   DCHECK_LE(val, std::numeric_limits<size_t>::max());
diff --git a/deps/v8/src/objects/js-array-buffer.cc b/deps/v8/src/objects/js-array-buffer.cc
index 5ff7828ead..36950f9de6 100644
--- a/deps/v8/src/objects/js-array-buffer.cc
+++ b/deps/v8/src/objects/js-array-buffer.cc
@@ -41,7 +41,7 @@ void JSArrayBuffer::Neuter() {
   CHECK(!was_neutered());
   CHECK(is_external());
   set_backing_store(nullptr);
-  set_byte_length(Smi::kZero);
+  set_byte_length(0);
   set_was_neutered(true);
   set_is_neuterable(false);
   // Invalidate the neutering protector.
@@ -51,13 +51,6 @@ void JSArrayBuffer::Neuter() {
   }
 }
 
-void JSArrayBuffer::StopTrackingWasmMemory(Isolate* isolate) {
-  DCHECK(is_wasm_memory());
-  isolate->wasm_engine()->memory_tracker()->ReleaseAllocation(isolate,
-                                                              backing_store());
-  set_is_wasm_memory(false);
-}
-
 void JSArrayBuffer::FreeBackingStoreFromMainThread() {
   if (allocation_base() == nullptr) {
     return;
@@ -76,7 +69,8 @@ void JSArrayBuffer::FreeBackingStore(Isolate* isolate, Allocation allocation) {
         isolate->wasm_engine()->memory_tracker();
     if (!memory_tracker->FreeMemoryIfIsWasmMemory(isolate,
                                                   allocation.backing_store)) {
-      CHECK(FreePages(allocation.allocation_base, allocation.length));
+      CHECK(FreePages(GetPlatformPageAllocator(), allocation.allocation_base,
+                      allocation.length));
     }
   } else {
     isolate->array_buffer_allocator()->Free(allocation.allocation_base,
@@ -84,28 +78,21 @@ void JSArrayBuffer::FreeBackingStore(Isolate* isolate, Allocation allocation) {
   }
 }
 
-void JSArrayBuffer::set_is_wasm_memory(bool is_wasm_memory) {
-  set_bit_field(IsWasmMemory::update(bit_field(), is_wasm_memory));
-}
-
 void JSArrayBuffer::Setup(Handle<JSArrayBuffer> array_buffer, Isolate* isolate,
                           bool is_external, void* data, size_t byte_length,
-                          SharedFlag shared, bool is_wasm_memory) {
+                          SharedFlag shared_flag, bool is_wasm_memory) {
   DCHECK_EQ(array_buffer->GetEmbedderFieldCount(),
             v8::ArrayBuffer::kEmbedderFieldCount);
+  DCHECK_LE(byte_length, JSArrayBuffer::kMaxByteLength);
   for (int i = 0; i < v8::ArrayBuffer::kEmbedderFieldCount; i++) {
     array_buffer->SetEmbedderField(i, Smi::kZero);
   }
+  array_buffer->set_byte_length(byte_length);
   array_buffer->set_bit_field(0);
   array_buffer->set_is_external(is_external);
-  array_buffer->set_is_neuterable(shared == SharedFlag::kNotShared);
-  array_buffer->set_is_shared(shared == SharedFlag::kShared);
+  array_buffer->set_is_neuterable(shared_flag == SharedFlag::kNotShared);
+  array_buffer->set_is_shared(shared_flag == SharedFlag::kShared);
   array_buffer->set_is_wasm_memory(is_wasm_memory);
-
-  Handle<Object> heap_byte_length =
-      isolate->factory()->NewNumberFromSize(byte_length);
-  CHECK(heap_byte_length->IsSmi() || heap_byte_length->IsHeapNumber());
-  array_buffer->set_byte_length(*heap_byte_length);
   // Initialize backing store at last to avoid handling of |JSArrayBuffers| that
   // are currently being constructed in the |ArrayBufferTracker|. The
   // registration method below handles the case of registering a buffer that has
@@ -120,14 +107,15 @@ void JSArrayBuffer::Setup(Handle<JSArrayBuffer> array_buffer, Isolate* isolate,
 bool JSArrayBuffer::SetupAllocatingData(Handle<JSArrayBuffer> array_buffer,
                                         Isolate* isolate,
                                         size_t allocated_length,
-                                        bool initialize, SharedFlag shared) {
+                                        bool initialize,
+                                        SharedFlag shared_flag) {
   void* data;
   CHECK_NOT_NULL(isolate->array_buffer_allocator());
   if (allocated_length != 0) {
     if (allocated_length >= MB)
       isolate->counters()->array_buffer_big_allocations()->AddSample(
           ConvertToMb(allocated_length));
-    if (shared == SharedFlag::kShared)
+    if (shared_flag == SharedFlag::kShared)
       isolate->counters()->shared_array_allocations()->AddSample(
           ConvertToMb(allocated_length));
     if (initialize) {
@@ -147,7 +135,7 @@ bool JSArrayBuffer::SetupAllocatingData(Handle<JSArrayBuffer> array_buffer,
 
   const bool is_external = false;
   JSArrayBuffer::Setup(array_buffer, isolate, is_external, data,
-                       allocated_length, shared);
+                       allocated_length, shared_flag);
   return true;
 }
 
@@ -175,9 +163,8 @@ Handle<JSArrayBuffer> JSTypedArray::MaterializeArrayBuffer(
         "JSTypedArray::MaterializeArrayBuffer");
   }
   buffer->set_is_external(false);
-  DCHECK(buffer->byte_length()->IsSmi() ||
-         buffer->byte_length()->IsHeapNumber());
-  DCHECK(NumberToInt32(buffer->byte_length()) == fixed_typed_array->DataSize());
+  DCHECK_EQ(buffer->byte_length(),
+            static_cast<uintptr_t>(fixed_typed_array->DataSize()));
   // Initialize backing store at last to avoid handling of |JSArrayBuffers| that
   // are currently being constructed in the |ArrayBufferTracker|. The
   // registration method below handles the case of registering a buffer that has
@@ -234,9 +221,9 @@ Maybe<bool> JSTypedArray::DefineOwnProperty(Isolate* isolate,
                        NewTypeError(MessageTemplate::kInvalidTypedArrayIndex));
       }
       // 3b iv. Let length be O.[[ArrayLength]].
-      uint32_t length = o->length()->Number();
+      size_t length = o->length_value();
       // 3b v. If numericIndex ≥ length, return false.
-      if (index >= length) {
+      if (o->WasNeutered() || index >= length) {
         RETURN_FAILURE(isolate, should_throw,
                        NewTypeError(MessageTemplate::kInvalidTypedArrayIndex));
       }
diff --git a/deps/v8/src/objects/js-array-buffer.h b/deps/v8/src/objects/js-array-buffer.h
index 109aacbc47..3f0dd064fa 100644
--- a/deps/v8/src/objects/js-array-buffer.h
+++ b/deps/v8/src/objects/js-array-buffer.h
@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_JS_ARRAY_BUFFER_H_
 #define V8_OBJECTS_JS_ARRAY_BUFFER_H_
 
-#include "src/objects.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -14,12 +14,22 @@ namespace v8 {
 namespace internal {
 
 // Whether a JSArrayBuffer is a SharedArrayBuffer or not.
-enum class SharedFlag { kNotShared, kShared };
+enum class SharedFlag : uint32_t { kNotShared, kShared };
 
 class JSArrayBuffer : public JSObject {
  public:
+// The maximum length for JSArrayBuffer's supported by V8.
+// On 32-bit architectures we limit this to 2GiB, so that
+// we can continue to use CheckBounds with the Unsigned31
+// restriction for the length.
+#if V8_HOST_ARCH_32_BIT
+  static constexpr size_t kMaxByteLength = kMaxInt;
+#else
+  static constexpr size_t kMaxByteLength = kMaxSafeInteger;
+#endif
+
   // [byte_length]: length in bytes
-  DECL_ACCESSORS(byte_length, Object)
+  DECL_PRIMITIVE_ACCESSORS(byte_length, size_t)
 
   // [backing_store]: backing memory for this array
   DECL_ACCESSORS(backing_store, void)
@@ -29,26 +39,39 @@ class JSArrayBuffer : public JSObject {
   inline size_t allocation_length() const;
   inline void* allocation_base() const;
 
-  inline uint32_t bit_field() const;
-  inline void set_bit_field(uint32_t bits);
+  // [bit_field]: boolean flags
+  DECL_PRIMITIVE_ACCESSORS(bit_field, uint32_t)
+
+// Bit positions for [bit_field].
+#define JS_ARRAY_BUFFER_BIT_FIELD_FIELDS(V, _) \
+  V(IsExternalBit, bool, 1, _)                 \
+  V(IsNeuterableBit, bool, 1, _)               \
+  V(WasNeuteredBit, bool, 1, _)                \
+  V(IsSharedBit, bool, 1, _)                   \
+  V(IsGrowableBit, bool, 1, _)                 \
+  V(IsWasmMemoryBit, bool, 1, _)
+  DEFINE_BIT_FIELDS(JS_ARRAY_BUFFER_BIT_FIELD_FIELDS)
+#undef JS_ARRAY_BUFFER_BIT_FIELD_FIELDS
 
   // [is_external]: true indicates that the embedder is in charge of freeing the
   // backing_store, while is_external == false means that v8 will free the
   // memory block once all ArrayBuffers referencing it are collected by the GC.
-  inline bool is_external();
-  inline void set_is_external(bool value);
+  DECL_BOOLEAN_ACCESSORS(is_external)
+
+  // [is_neuterable]: false indicates that this buffer cannot be detached.
+  DECL_BOOLEAN_ACCESSORS(is_neuterable)
 
-  inline bool is_neuterable();
-  inline void set_is_neuterable(bool value);
+  // [was_neutered]: true if the buffer was previously detached.
+  DECL_BOOLEAN_ACCESSORS(was_neutered)
 
-  inline bool was_neutered();
-  inline void set_was_neutered(bool value);
+  // [is_shared]: tells whether this is an ArrayBuffer or a SharedArrayBuffer.
+  DECL_BOOLEAN_ACCESSORS(is_shared)
 
-  inline bool is_shared();
-  inline void set_is_shared(bool value);
+  // [is_growable]: indicates whether it's possible to grow this buffer.
+  DECL_BOOLEAN_ACCESSORS(is_growable)
 
-  inline bool is_growable();
-  inline void set_is_growable(bool value);
+  // [is_wasm_memory]: whether the buffer is tracked by the WasmMemoryTracker.
+  DECL_BOOLEAN_ACCESSORS(is_wasm_memory)
 
   DECL_CAST(JSArrayBuffer)
 
@@ -68,39 +91,30 @@ class JSArrayBuffer : public JSObject {
     bool is_wasm_memory;
   };
 
-  // Returns whether the buffer is tracked by the WasmMemoryTracker.
-  inline bool is_wasm_memory() const;
-
-  // Sets whether the buffer is tracked by the WasmMemoryTracker.
-  void set_is_wasm_memory(bool is_wasm_memory);
-
-  // Removes the backing store from the WasmMemoryTracker and sets
-  // |is_wasm_memory| to false.
-  void StopTrackingWasmMemory(Isolate* isolate);
-
   void FreeBackingStoreFromMainThread();
   static void FreeBackingStore(Isolate* isolate, Allocation allocation);
 
   V8_EXPORT_PRIVATE static void Setup(
       Handle<JSArrayBuffer> array_buffer, Isolate* isolate, bool is_external,
       void* data, size_t allocated_length,
-      SharedFlag shared = SharedFlag::kNotShared, bool is_wasm_memory = false);
+      SharedFlag shared_flag = SharedFlag::kNotShared,
+      bool is_wasm_memory = false);
 
   // Returns false if array buffer contents could not be allocated.
   // In this case, |array_buffer| will not be set up.
   static bool SetupAllocatingData(
       Handle<JSArrayBuffer> array_buffer, Isolate* isolate,
       size_t allocated_length, bool initialize = true,
-      SharedFlag shared = SharedFlag::kNotShared) V8_WARN_UNUSED_RESULT;
+      SharedFlag shared_flag = SharedFlag::kNotShared) V8_WARN_UNUSED_RESULT;
 
   // Dispatched behavior.
   DECL_PRINTER(JSArrayBuffer)
   DECL_VERIFIER(JSArrayBuffer)
 
-  static const int kByteLengthOffset = JSObject::kHeaderSize;
-  // The rest of the fields are not JSObjects, so they are not iterated over in
+  // The fields are not pointers into our heap, so they are not iterated over in
   // objects-body-descriptors-inl.h.
-  static const int kBackingStoreOffset = kByteLengthOffset + kPointerSize;
+  static const int kByteLengthOffset = JSObject::kHeaderSize;
+  static const int kBackingStoreOffset = kByteLengthOffset + kUIntptrSize;
   static const int kBitFieldSlot = kBackingStoreOffset + kPointerSize;
 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
   static const int kBitFieldOffset = kBitFieldSlot;
@@ -115,15 +129,6 @@ class JSArrayBuffer : public JSObject {
   // Iterates all fields in the object including internal ones except
   // kBackingStoreOffset and kBitFieldSlot.
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
-
-  class IsExternal : public BitField<bool, 1, 1> {};
-  class IsNeuterable : public BitField<bool, 2, 1> {};
-  class WasNeutered : public BitField<bool, 3, 1> {};
-  class IsShared : public BitField<bool, 4, 1> {};
-  class IsGrowable : public BitField<bool, 5, 1> {};
-  class IsWasmMemory : public BitField<bool, 6, 1> {};
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
@@ -135,10 +140,10 @@ class JSArrayBufferView : public JSObject {
   DECL_ACCESSORS(buffer, Object)
 
   // [byte_offset]: offset of typed array in bytes.
-  DECL_ACCESSORS(byte_offset, Object)
+  DECL_PRIMITIVE_ACCESSORS(byte_offset, size_t)
 
   // [byte_length]: length of typed array in bytes.
-  DECL_ACCESSORS(byte_length, Object)
+  DECL_PRIMITIVE_ACCESSORS(byte_length, size_t)
 
   DECL_CAST(JSArrayBufferView)
 
@@ -148,15 +153,14 @@ class JSArrayBufferView : public JSObject {
 
   static const int kBufferOffset = JSObject::kHeaderSize;
   static const int kByteOffsetOffset = kBufferOffset + kPointerSize;
-  static const int kByteLengthOffset = kByteOffsetOffset + kPointerSize;
-  static const int kViewSize = kByteLengthOffset + kPointerSize;
+  static const int kByteLengthOffset = kByteOffsetOffset + kUIntptrSize;
+  static const int kHeaderSize = kByteLengthOffset + kUIntptrSize;
 
- private:
-#ifdef VERIFY_HEAP
-  DECL_ACCESSORS(raw_byte_offset, Object)
-  DECL_ACCESSORS(raw_byte_length, Object)
-#endif
+  // Iterates all fields in the object including internal ones except
+  // kByteOffset and kByteLengthOffset.
+  class BodyDescriptor;
 
+ private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBufferView);
 };
 
@@ -189,9 +193,8 @@ class JSTypedArray : public JSArrayBufferView {
   DECL_PRINTER(JSTypedArray)
   DECL_VERIFIER(JSTypedArray)
 
-  static const int kLengthOffset = kViewSize;
+  static const int kLengthOffset = JSArrayBufferView::kHeaderSize;
   static const int kSize = kLengthOffset + kPointerSize;
-
   static const int kSizeWithEmbedderFields =
       kSize + v8::ArrayBufferView::kEmbedderFieldCount * kPointerSize;
 
@@ -213,8 +216,7 @@ class JSDataView : public JSArrayBufferView {
   DECL_PRINTER(JSDataView)
   DECL_VERIFIER(JSDataView)
 
-  static const int kSize = kViewSize;
-
+  static const int kSize = JSArrayBufferView::kHeaderSize;
   static const int kSizeWithEmbedderFields =
       kSize + v8::ArrayBufferView::kEmbedderFieldCount * kPointerSize;
 
diff --git a/deps/v8/src/objects/js-array.h b/deps/v8/src/objects/js-array.h
index b212848ce7..3a9fe48d24 100644
--- a/deps/v8/src/objects/js-array.h
+++ b/deps/v8/src/objects/js-array.h
@@ -5,8 +5,9 @@
 #ifndef V8_OBJECTS_JS_ARRAY_H_
 #define V8_OBJECTS_JS_ARRAY_H_
 
-#include "src/objects.h"
+#include "src/objects/allocation-site.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
diff --git a/deps/v8/src/objects/js-break-iterator-inl.h b/deps/v8/src/objects/js-break-iterator-inl.h
new file mode 100644
index 0000000000..16f8111953
--- /dev/null
+++ b/deps/v8/src/objects/js-break-iterator-inl.h
@@ -0,0 +1,49 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_BREAK_ITERATOR_INL_H_
+#define V8_OBJECTS_JS_BREAK_ITERATOR_INL_H_
+
+#include "src/objects-inl.h"
+#include "src/objects/js-break-iterator.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+inline void JSV8BreakIterator::set_type(Type type) {
+  DCHECK_GT(JSV8BreakIterator::Type::COUNT, type);
+  WRITE_FIELD(this, kTypeOffset, Smi::FromInt(static_cast<int>(type)));
+}
+
+inline JSV8BreakIterator::Type JSV8BreakIterator::type() const {
+  Object* value = READ_FIELD(this, kTypeOffset);
+  return static_cast<JSV8BreakIterator::Type>(Smi::ToInt(value));
+}
+
+ACCESSORS(JSV8BreakIterator, locale, String, kLocaleOffset)
+ACCESSORS(JSV8BreakIterator, break_iterator, Managed<icu::BreakIterator>,
+          kBreakIteratorOffset)
+ACCESSORS(JSV8BreakIterator, unicode_string, Managed<icu::UnicodeString>,
+          kUnicodeStringOffset)
+ACCESSORS(JSV8BreakIterator, bound_adopt_text, Object, kBoundAdoptTextOffset)
+ACCESSORS(JSV8BreakIterator, bound_first, Object, kBoundFirstOffset)
+ACCESSORS(JSV8BreakIterator, bound_next, Object, kBoundNextOffset)
+ACCESSORS(JSV8BreakIterator, bound_current, Object, kBoundCurrentOffset)
+ACCESSORS(JSV8BreakIterator, bound_break_type, Object, kBoundBreakTypeOffset)
+
+CAST_ACCESSOR(JSV8BreakIterator)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_BREAK_ITERATOR_INL_H_
diff --git a/deps/v8/src/objects/js-break-iterator.cc b/deps/v8/src/objects/js-break-iterator.cc
new file mode 100644
index 0000000000..2031c2cc5b
--- /dev/null
+++ b/deps/v8/src/objects/js-break-iterator.cc
@@ -0,0 +1,170 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#include "src/objects/js-break-iterator.h"
+
+#include "src/objects/intl-objects-inl.h"
+#include "src/objects/intl-objects.h"
+#include "src/objects/js-break-iterator-inl.h"
+#include "unicode/brkiter.h"
+
+namespace v8 {
+namespace internal {
+
+JSV8BreakIterator::Type JSV8BreakIterator::getType(const char* str) {
+  if (strcmp(str, "character") == 0) return Type::CHARACTER;
+  if (strcmp(str, "word") == 0) return Type::WORD;
+  if (strcmp(str, "sentence") == 0) return Type::SENTENCE;
+  if (strcmp(str, "line") == 0) return Type::LINE;
+  UNREACHABLE();
+}
+
+MaybeHandle<JSV8BreakIterator> JSV8BreakIterator::Initialize(
+    Isolate* isolate, Handle<JSV8BreakIterator> break_iterator_holder,
+    Handle<Object> locales, Handle<Object> options_obj) {
+  Factory* factory = isolate->factory();
+
+  Handle<JSReceiver> options;
+  if (options_obj->IsUndefined(isolate)) {
+    options = factory->NewJSObjectWithNullProto();
+  } else {
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, options,
+        Object::ToObject(isolate, options_obj, "Intl.JSV8BreakIterator"),
+        JSV8BreakIterator);
+  }
+
+  // Extract locale string
+  Handle<JSObject> r;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, r,
+      Intl::ResolveLocale(isolate, "breakiterator", locales, options),
+      JSV8BreakIterator);
+  Handle<Object> locale_obj =
+      JSObject::GetDataProperty(r, factory->locale_string());
+  CHECK(locale_obj->IsString());
+  Handle<String> locale = Handle<String>::cast(locale_obj);
+
+  // Extract type from options
+  std::unique_ptr<char[]> type_str = nullptr;
+  std::vector<const char*> type_values = {"character", "word", "sentence",
+                                          "line"};
+  Maybe<bool> maybe_found_type = Intl::GetStringOption(
+      isolate, options, "type", type_values, "Intl.v8BreakIterator", &type_str);
+  Type type_enum = Type::WORD;
+  MAYBE_RETURN(maybe_found_type, MaybeHandle<JSV8BreakIterator>());
+  if (maybe_found_type.FromJust()) {
+    DCHECK_NOT_NULL(type_str.get());
+    type_enum = getType(type_str.get());
+  }
+
+  // Construct icu_locale using the locale string
+  icu::Locale icu_locale = Intl::CreateICULocale(isolate, locale);
+  DCHECK(!icu_locale.isBogus());
+
+  // Construct break_iterator using icu_locale and type
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::BreakIterator> break_iterator = nullptr;
+  switch (type_enum) {
+    case Type::CHARACTER:
+      break_iterator.reset(
+          icu::BreakIterator::createCharacterInstance(icu_locale, status));
+      break;
+    case Type::SENTENCE:
+      break_iterator.reset(
+          icu::BreakIterator::createSentenceInstance(icu_locale, status));
+      break;
+    case Type::LINE:
+      break_iterator.reset(
+          icu::BreakIterator::createLineInstance(icu_locale, status));
+      break;
+    default:
+      break_iterator.reset(
+          icu::BreakIterator::createWordInstance(icu_locale, status));
+      break;
+  }
+
+  // Error handling for break_iterator
+  if (U_FAILURE(status)) {
+    FATAL("Failed to create ICU break iterator, are ICU data files missing?");
+  }
+  CHECK_NOT_NULL(break_iterator.get());
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kBreakIterator);
+
+  // Construct managed objects from pointers
+  Handle<Managed<icu::BreakIterator>> managed_break_iterator =
+      Managed<icu::BreakIterator>::FromUniquePtr(isolate, 0,
+                                                 std::move(break_iterator));
+  Handle<Managed<icu::UnicodeString>> managed_unicode_string =
+      Managed<icu::UnicodeString>::FromRawPtr(isolate, 0, nullptr);
+
+  // Setting fields
+  break_iterator_holder->set_locale(*locale);
+  break_iterator_holder->set_type(type_enum);
+  break_iterator_holder->set_break_iterator(*managed_break_iterator);
+  break_iterator_holder->set_unicode_string(*managed_unicode_string);
+
+  // Return break_iterator_holder
+  return break_iterator_holder;
+}
+
+Handle<JSObject> JSV8BreakIterator::ResolvedOptions(
+    Isolate* isolate, Handle<JSV8BreakIterator> break_iterator) {
+  Factory* factory = isolate->factory();
+
+  Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
+  Handle<String> locale(break_iterator->locale(), isolate);
+
+  JSObject::AddProperty(isolate, result, factory->locale_string(), locale,
+                        NONE);
+  JSObject::AddProperty(isolate, result, factory->type_string(),
+                        break_iterator->TypeAsString(), NONE);
+  return result;
+}
+
+void JSV8BreakIterator::AdoptText(
+    Isolate* isolate, Handle<JSV8BreakIterator> break_iterator_holder,
+    Handle<String> text) {
+  icu::UnicodeString* u_text;
+  int length = text->length();
+  text = String::Flatten(isolate, text);
+  {
+    DisallowHeapAllocation no_gc;
+    String::FlatContent flat = text->GetFlatContent();
+    std::unique_ptr<uc16[]> sap;
+    const UChar* text_value = GetUCharBufferFromFlat(flat, &sap, length);
+    u_text = new icu::UnicodeString(text_value, length);
+  }
+
+  Handle<Managed<icu::UnicodeString>> new_u_text =
+      Managed<icu::UnicodeString>::FromRawPtr(isolate, 0, u_text);
+  break_iterator_holder->set_unicode_string(*new_u_text);
+
+  icu::BreakIterator* break_iterator =
+      break_iterator_holder->break_iterator()->raw();
+  CHECK_NOT_NULL(break_iterator);
+  break_iterator->setText(*u_text);
+}
+
+Handle<String> JSV8BreakIterator::TypeAsString() const {
+  switch (type()) {
+    case Type::CHARACTER:
+      return GetReadOnlyRoots().character_string_handle();
+    case Type::WORD:
+      return GetReadOnlyRoots().word_string_handle();
+    case Type::SENTENCE:
+      return GetReadOnlyRoots().sentence_string_handle();
+    case Type::LINE:
+      return GetReadOnlyRoots().line_string_handle();
+    case Type::COUNT:
+      UNREACHABLE();
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/objects/js-break-iterator.h b/deps/v8/src/objects/js-break-iterator.h
new file mode 100644
index 0000000000..d5847bdaf6
--- /dev/null
+++ b/deps/v8/src/objects/js-break-iterator.h
@@ -0,0 +1,87 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_BREAK_ITERATOR_H_
+#define V8_OBJECTS_JS_BREAK_ITERATOR_H_
+
+#include "src/objects.h"
+#include "src/objects/intl-objects.h"
+#include "src/objects/managed.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace U_ICU_NAMESPACE {
+class BreakIterator;
+}  // namespace U_ICU_NAMESPACE
+
+namespace v8 {
+namespace internal {
+
+class JSV8BreakIterator : public JSObject {
+ public:
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSV8BreakIterator> Initialize(
+      Isolate* isolate, Handle<JSV8BreakIterator> break_iterator_holder,
+      Handle<Object> input_locales, Handle<Object> input_options);
+
+  static Handle<JSObject> ResolvedOptions(
+      Isolate* isolate, Handle<JSV8BreakIterator> break_iterator);
+
+  static void AdoptText(Isolate* isolate,
+                        Handle<JSV8BreakIterator> break_iterator_holder,
+                        Handle<String> text);
+
+  enum class Type { CHARACTER, WORD, SENTENCE, LINE, COUNT };
+  inline void set_type(Type type);
+  inline Type type() const;
+
+  Handle<String> TypeAsString() const;
+
+  DECL_CAST(JSV8BreakIterator)
+  DECL_PRINTER(JSV8BreakIterator)
+  DECL_VERIFIER(JSV8BreakIterator)
+
+  DECL_ACCESSORS(locale, String)
+  DECL_ACCESSORS(break_iterator, Managed<icu::BreakIterator>)
+  DECL_ACCESSORS(unicode_string, Managed<icu::UnicodeString>)
+  DECL_ACCESSORS(bound_adopt_text, Object)
+  DECL_ACCESSORS(bound_first, Object)
+  DECL_ACCESSORS(bound_next, Object)
+  DECL_ACCESSORS(bound_current, Object)
+  DECL_ACCESSORS(bound_break_type, Object)
+
+// Layout description.
+#define BREAK_ITERATOR_FIELDS(V)         \
+  /* Pointer fields. */                  \
+  V(kLocaleOffset, kPointerSize)         \
+  V(kTypeOffset, kPointerSize)           \
+  V(kBreakIteratorOffset, kPointerSize)  \
+  V(kUnicodeStringOffset, kPointerSize)  \
+  V(kBoundAdoptTextOffset, kPointerSize) \
+  V(kBoundFirstOffset, kPointerSize)     \
+  V(kBoundNextOffset, kPointerSize)      \
+  V(kBoundCurrentOffset, kPointerSize)   \
+  V(kBoundBreakTypeOffset, kPointerSize) \
+  /* Total Size */                       \
+  V(kSize, 0)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, BREAK_ITERATOR_FIELDS)
+#undef BREAK_ITERATOR_FIELDS
+
+ private:
+  static Type getType(const char* str);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSV8BreakIterator)
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_BREAK_ITERATOR_H_
diff --git a/deps/v8/src/objects/js-collator-inl.h b/deps/v8/src/objects/js-collator-inl.h
index 279a8bfd49..1a94ac805c 100644
--- a/deps/v8/src/objects/js-collator-inl.h
+++ b/deps/v8/src/objects/js-collator-inl.h
@@ -20,18 +20,6 @@ namespace internal {
 
 ACCESSORS(JSCollator, icu_collator, Managed<icu::Collator>, kICUCollatorOffset)
 ACCESSORS(JSCollator, bound_compare, Object, kBoundCompareOffset);
-SMI_ACCESSORS(JSCollator, flags, kFlagsOffset)
-
-inline void JSCollator::set_usage(Usage usage) {
-  DCHECK_LT(usage, Usage::COUNT);
-  int hints = flags();
-  hints = UsageBits::update(hints, usage);
-  set_flags(hints);
-}
-
-inline JSCollator::Usage JSCollator::usage() const {
-  return UsageBits::decode(flags());
-}
 
 CAST_ACCESSOR(JSCollator);
 
diff --git a/deps/v8/src/objects/js-collator.cc b/deps/v8/src/objects/js-collator.cc
index c6cbecfb01..f62177b875 100644
--- a/deps/v8/src/objects/js-collator.cc
+++ b/deps/v8/src/objects/js-collator.cc
@@ -22,6 +22,11 @@ namespace internal {
 
 namespace {
 
+enum class Usage {
+  SORT,
+  SEARCH,
+};
+
 // TODO(gsathya): Consider internalizing the value strings.
 void CreateDataPropertyForOptions(Isolate* isolate, Handle<JSObject> options,
                                   Handle<String> key, const char* value) {
@@ -47,6 +52,13 @@ void CreateDataPropertyForOptions(Isolate* isolate, Handle<JSObject> options,
             .FromJust());
 }
 
+void toLanguageTag(const icu::Locale& locale, char* tag) {
+  UErrorCode status = U_ZERO_ERROR;
+  uloc_toLanguageTag(locale.getName(), tag, ULOC_FULLNAME_CAPACITY, FALSE,
+                     &status);
+  CHECK(U_SUCCESS(status));
+}
+
 }  // anonymous namespace
 
 // static
@@ -55,11 +67,6 @@ Handle<JSObject> JSCollator::ResolvedOptions(Isolate* isolate,
   Handle<JSObject> options =
       isolate->factory()->NewJSObject(isolate->object_function());
 
-  JSCollator::Usage usage = collator->usage();
-  CreateDataPropertyForOptions(isolate, options,
-                               isolate->factory()->usage_string(),
-                               JSCollator::UsageToString(usage));
-
   icu::Collator* icu_collator = collator->icu_collator()->raw();
   CHECK_NOT_NULL(icu_collator);
 
@@ -128,97 +135,71 @@ Handle<JSObject> JSCollator::ResolvedOptions(Isolate* isolate,
                                ignore_punctuation);
 
   status = U_ZERO_ERROR;
-  const char* collation;
-  std::unique_ptr<icu::StringEnumeration> collation_values(
-      icu_collator->getKeywordValues("co", status));
-  // Collation wasn't provided as a keyword to icu, use default.
-  if (status == U_ILLEGAL_ARGUMENT_ERROR) {
-    CreateDataPropertyForOptions(
-        isolate, options, isolate->factory()->collation_string(), "default");
-  } else {
-    CHECK(U_SUCCESS(status));
-    CHECK_NOT_NULL(collation_values.get());
-
-    int32_t length;
-    status = U_ZERO_ERROR;
-    collation = collation_values->next(&length, status);
-    CHECK(U_SUCCESS(status));
-
-    // There has to be at least one value.
-    CHECK_NOT_NULL(collation);
-    CreateDataPropertyForOptions(
-        isolate, options, isolate->factory()->collation_string(), collation);
-
-    status = U_ZERO_ERROR;
-    collation_values->reset(status);
-    CHECK(U_SUCCESS(status));
-  }
-
-  status = U_ZERO_ERROR;
-  icu::Locale icu_locale = icu_collator->getLocale(ULOC_VALID_LOCALE, status);
-  CHECK(U_SUCCESS(status));
 
-  char result[ULOC_FULLNAME_CAPACITY];
-  status = U_ZERO_ERROR;
-  uloc_toLanguageTag(icu_locale.getName(), result, ULOC_FULLNAME_CAPACITY,
-                     FALSE, &status);
+  icu::Locale icu_locale(icu_collator->getLocale(ULOC_VALID_LOCALE, status));
   CHECK(U_SUCCESS(status));
 
-  CreateDataPropertyForOptions(isolate, options,
-                               isolate->factory()->locale_string(), result);
-
-  return options;
-}
-
-namespace {
-
-std::map<std::string, std::string> LookupUnicodeExtensions(
-    const icu::Locale& icu_locale, const std::set<std::string>& relevant_keys) {
-  std::map<std::string, std::string> extensions;
-
-  UErrorCode status = U_ZERO_ERROR;
-  std::unique_ptr<icu::StringEnumeration> keywords(
-      icu_locale.createKeywords(status));
-  if (U_FAILURE(status)) return extensions;
+  const char* collation = "default";
+  const char* usage = "sort";
+  const char* collation_key = "co";
+  const char* legacy_collation_key = uloc_toLegacyKey(collation_key);
+  DCHECK_NOT_NULL(legacy_collation_key);
 
-  if (!keywords) return extensions;
-  char value[ULOC_FULLNAME_CAPACITY];
-
-  int32_t length;
+  char bcp47_locale_tag[ULOC_FULLNAME_CAPACITY];
+  char legacy_collation_value[ULOC_FULLNAME_CAPACITY];
   status = U_ZERO_ERROR;
-  for (const char* keyword = keywords->next(&length, status);
-       keyword != nullptr; keyword = keywords->next(&length, status)) {
-    // Ignore failures in ICU and skip to the next keyword.
-    //
-    // This is fine.™
-    if (U_FAILURE(status)) {
+  int32_t length =
+      icu_locale.getKeywordValue(legacy_collation_key, legacy_collation_value,
+                                 ULOC_FULLNAME_CAPACITY, status);
+
+  if (length > 0 && U_SUCCESS(status)) {
+    const char* collation_value =
+        uloc_toUnicodeLocaleType(collation_key, legacy_collation_value);
+    CHECK_NOT_NULL(collation_value);
+
+    if (strcmp(collation_value, "search") == 0) {
+      usage = "search";
+
+      // Search is disallowed as a collation value per spec. Let's
+      // use `default`, instead.
+      //
+      // https://tc39.github.io/ecma402/#sec-properties-of-intl-collator-instances
+      collation = "default";
+
+      // We clone the icu::Locale because we don't want the
+      // icu_collator to be affected when we remove the collation key
+      // below.
+      icu::Locale new_icu_locale = icu_locale;
+
+      // The spec forbids the search as a collation value in the
+      // locale tag, so let's filter it out.
       status = U_ZERO_ERROR;
-      continue;
-    }
-
-    icu_locale.getKeywordValue(keyword, value, ULOC_FULLNAME_CAPACITY, status);
+      new_icu_locale.setKeywordValue(legacy_collation_key, nullptr, status);
+      CHECK(U_SUCCESS(status));
 
-    // Ignore failures in ICU and skip to the next keyword.
-    //
-    // This is fine.™
-    if (U_FAILURE(status)) {
-      status = U_ZERO_ERROR;
-      continue;
+      toLanguageTag(new_icu_locale, bcp47_locale_tag);
+    } else {
+      collation = collation_value;
+      toLanguageTag(icu_locale, bcp47_locale_tag);
     }
+  } else {
+    toLanguageTag(icu_locale, bcp47_locale_tag);
+  }
 
-    const char* bcp47_key = uloc_toUnicodeLocaleKey(keyword);
+  CreateDataPropertyForOptions(
+      isolate, options, isolate->factory()->collation_string(), collation);
 
-    // Ignore keywords that we don't recognize - spec allows that.
-    if (bcp47_key && (relevant_keys.find(bcp47_key) != relevant_keys.end())) {
-      const char* bcp47_value = uloc_toUnicodeLocaleType(bcp47_key, value);
-      extensions.insert(
-          std::pair<std::string, std::string>(bcp47_key, bcp47_value));
-    }
-  }
+  CreateDataPropertyForOptions(isolate, options,
+                               isolate->factory()->usage_string(), usage);
+
+  CreateDataPropertyForOptions(
+      isolate, options, isolate->factory()->locale_string(), bcp47_locale_tag);
 
-  return extensions;
+  return options;
 }
 
+namespace {
+
 void SetCaseFirstOption(icu::Collator* icu_collator, const char* value) {
   CHECK_NOT_NULL(icu_collator);
   CHECK_NOT_NULL(value);
@@ -236,9 +217,10 @@ void SetCaseFirstOption(icu::Collator* icu_collator, const char* value) {
 }  // anonymous namespace
 
 // static
-MaybeHandle<JSCollator> JSCollator::InitializeCollator(
-    Isolate* isolate, Handle<JSCollator> collator, Handle<Object> locales,
-    Handle<Object> options_obj) {
+MaybeHandle<JSCollator> JSCollator::Initialize(Isolate* isolate,
+                                               Handle<JSCollator> collator,
+                                               Handle<Object> locales,
+                                               Handle<Object> options_obj) {
   // 1. Let requestedLocales be ? CanonicalizeLocaleList(locales).
   Handle<JSObject> requested_locales;
   ASSIGN_RETURN_ON_EXCEPTION(isolate, requested_locales,
@@ -264,7 +246,7 @@ MaybeHandle<JSCollator> JSCollator::InitializeCollator(
   // "search" », "sort").
   std::vector<const char*> values = {"sort", "search"};
   std::unique_ptr<char[]> usage_str = nullptr;
-  JSCollator::Usage usage = JSCollator::Usage::SORT;
+  Usage usage = Usage::SORT;
   Maybe<bool> found_usage = Intl::GetStringOption(
       isolate, options, "usage", values, "Intl.Collator", &usage_str);
   MAYBE_RETURN(found_usage, MaybeHandle<JSCollator>());
@@ -272,21 +254,10 @@ MaybeHandle<JSCollator> JSCollator::InitializeCollator(
   if (found_usage.FromJust()) {
     DCHECK_NOT_NULL(usage_str.get());
     if (strcmp(usage_str.get(), "search") == 0) {
-      usage = JSCollator::Usage::SEARCH;
+      usage = Usage::SEARCH;
     }
   }
 
-  // 5. Set collator.[[Usage]] to usage.
-  collator->set_usage(usage);
-
-  // 6. If usage is "sort", then
-  //    a. Let localeData be %Collator%.[[SortLocaleData]].
-  // 7. Else,
-  //    a. Let localeData be %Collator%.[[SearchLocaleData]].
-  //
-  // The above two spec operations aren't required, the Intl spec is
-  // crazy. See https://github.com/tc39/ecma402/issues/256
-
   // TODO(gsathya): This is currently done as part of the
   // Intl::ResolveLocale call below. Fix this once resolveLocale is
   // changed to not do the lookup.
@@ -368,7 +339,7 @@ MaybeHandle<JSCollator> JSCollator::InitializeCollator(
   DCHECK(!icu_locale.isBogus());
 
   std::map<std::string, std::string> extensions =
-      LookupUnicodeExtensions(icu_locale, relevant_extension_keys);
+      Intl::LookupUnicodeExtensions(icu_locale, relevant_extension_keys);
 
   // 19. Let collation be r.[[co]].
   //
@@ -386,11 +357,38 @@ MaybeHandle<JSCollator> JSCollator::InitializeCollator(
     const std::string& value = co_extension_it->second;
     if ((value == "search") || (value == "standard")) {
       UErrorCode status = U_ZERO_ERROR;
-      icu_locale.setKeywordValue("co", NULL, status);
+      const char* key = uloc_toLegacyKey("co");
+      icu_locale.setKeywordValue(key, nullptr, status);
       CHECK(U_SUCCESS(status));
     }
   }
 
+  // 5. Set collator.[[Usage]] to usage.
+  //
+  // 6. If usage is "sort", then
+  //    a. Let localeData be %Collator%.[[SortLocaleData]].
+  // 7. Else,
+  //    a. Let localeData be %Collator%.[[SearchLocaleData]].
+  //
+  // The Intl spec doesn't allow us to use "search" as an extension
+  // value for collation as per:
+  // https://tc39.github.io/ecma402/#sec-intl-collator-internal-slots
+  //
+  // But the only way to pass the value "search" for collation from
+  // the options object to ICU is to use the 'co' extension keyword.
+  //
+  // This will need to be filtered out when creating the
+  // resolvedOptions object.
+  if (usage == Usage::SEARCH) {
+    const char* key = uloc_toLegacyKey("co");
+    CHECK_NOT_NULL(key);
+    const char* value = uloc_toLegacyType(key, "search");
+    CHECK_NOT_NULL(value);
+    UErrorCode status = U_ZERO_ERROR;
+    icu_locale.setKeywordValue(key, value, status);
+    CHECK(U_SUCCESS(status));
+  }
+
   // 20. If collation is null, let collation be "default".
   // 21. Set collator.[[Collation]] to collation.
   //
@@ -525,17 +523,5 @@ MaybeHandle<JSCollator> JSCollator::InitializeCollator(
   return collator;
 }
 
-// static
-const char* JSCollator::UsageToString(Usage usage) {
-  switch (usage) {
-    case Usage::SORT:
-      return "sort";
-    case Usage::SEARCH:
-      return "search";
-    case Usage::COUNT:
-      UNREACHABLE();
-  }
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/objects/js-collator.h b/deps/v8/src/objects/js-collator.h
index b2751a446e..f857df95b1 100644
--- a/deps/v8/src/objects/js-collator.h
+++ b/deps/v8/src/objects/js-collator.h
@@ -18,13 +18,17 @@
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
 
+namespace U_ICU_NAMESPACE {
+class Collator;
+}  //  namespace U_ICU_NAMESPACE
+
 namespace v8 {
 namespace internal {
 
 class JSCollator : public JSObject {
  public:
   // ecma402/#sec-initializecollator
-  V8_WARN_UNUSED_RESULT static MaybeHandle<JSCollator> InitializeCollator(
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSCollator> Initialize(
       Isolate* isolate, Handle<JSCollator> collator, Handle<Object> locales,
       Handle<Object> options);
 
@@ -36,22 +40,9 @@ class JSCollator : public JSObject {
   DECL_PRINTER(JSCollator)
   DECL_VERIFIER(JSCollator)
 
-  // [[Usage]] is one of the values "sort" or "search", identifying
-  // the collator usage.
-  enum class Usage {
-    SORT,
-    SEARCH,
-
-    COUNT
-  };
-  inline void set_usage(Usage usage);
-  inline Usage usage() const;
-  static const char* UsageToString(Usage usage);
-
 // Layout description.
 #define JS_COLLATOR_FIELDS(V)          \
   V(kICUCollatorOffset, kPointerSize)  \
-  V(kFlagsOffset, kPointerSize)        \
   V(kBoundCompareOffset, kPointerSize) \
   /* Total size. */                    \
   V(kSize, 0)
@@ -59,26 +50,8 @@ class JSCollator : public JSObject {
   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, JS_COLLATOR_FIELDS)
 #undef JS_COLLATOR_FIELDS
 
-  // ContextSlot defines the context structure for the bound
-  // Collator.prototype.compare function.
-  enum ContextSlot {
-    // The collator instance that the function holding this context is bound to.
-    kCollator = Context::MIN_CONTEXT_SLOTS,
-    kLength
-  };
-
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _) V(UsageBits, Usage, 1, _)
-
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
-
-  STATIC_ASSERT(Usage::SORT <= UsageBits::kMax);
-  STATIC_ASSERT(Usage::SEARCH <= UsageBits::kMax);
-
   DECL_ACCESSORS(icu_collator, Managed<icu::Collator>)
   DECL_ACCESSORS(bound_compare, Object);
-  DECL_INT_ACCESSORS(flags)
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSCollator);
diff --git a/deps/v8/src/objects/js-collection.h b/deps/v8/src/objects/js-collection.h
index 47bb7a9c2a..7b5e38e7d8 100644
--- a/deps/v8/src/objects/js-collection.h
+++ b/deps/v8/src/objects/js-collection.h
@@ -113,9 +113,6 @@ class JSWeakCollection : public JSObject {
   // Visit the whole object.
   typedef BodyDescriptorImpl BodyDescriptor;
 
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
-
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCollection);
 };
diff --git a/deps/v8/src/objects/js-date-time-format-inl.h b/deps/v8/src/objects/js-date-time-format-inl.h
new file mode 100644
index 0000000000..0ad7f363c5
--- /dev/null
+++ b/deps/v8/src/objects/js-date-time-format-inl.h
@@ -0,0 +1,33 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_DATE_TIME_FORMAT_INL_H_
+#define V8_OBJECTS_JS_DATE_TIME_FORMAT_INL_H_
+
+#include "src/objects-inl.h"
+#include "src/objects/js-date-time-format.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+ACCESSORS(JSDateTimeFormat, icu_locale, Managed<icu::Locale>, kICULocaleOffset);
+ACCESSORS(JSDateTimeFormat, icu_simple_date_format,
+          Managed<icu::SimpleDateFormat>, kICUSimpleDateFormatOffset)
+ACCESSORS(JSDateTimeFormat, bound_format, Object, kBoundFormatOffset);
+
+CAST_ACCESSOR(JSDateTimeFormat);
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_DATE_TIME_FORMAT_INL_H_
diff --git a/deps/v8/src/objects/js-date-time-format.cc b/deps/v8/src/objects/js-date-time-format.cc
new file mode 100644
index 0000000000..6285b74b04
--- /dev/null
+++ b/deps/v8/src/objects/js-date-time-format.cc
@@ -0,0 +1,980 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#include "src/objects/js-date-time-format.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "src/heap/factory.h"
+#include "src/isolate.h"
+#include "src/objects/intl-objects.h"
+#include "src/objects/js-date-time-format-inl.h"
+
+#include "unicode/calendar.h"
+#include "unicode/dtptngen.h"
+#include "unicode/gregocal.h"
+#include "unicode/numsys.h"
+#include "unicode/smpdtfmt.h"
+#include "unicode/unistr.h"
+
+namespace v8 {
+namespace internal {
+
+namespace {
+
+class PatternMap {
+ public:
+  PatternMap(std::string pattern, std::string value)
+      : pattern(std::move(pattern)), value(std::move(value)) {}
+  virtual ~PatternMap() = default;
+  std::string pattern;
+  std::string value;
+};
+
+class PatternItem {
+ public:
+  PatternItem(const std::string property, std::vector<PatternMap> pairs,
+              std::vector<const char*> allowed_values)
+      : property(std::move(property)),
+        pairs(std::move(pairs)),
+        allowed_values(allowed_values) {}
+  virtual ~PatternItem() = default;
+
+  const std::string property;
+  // It is important for the pattern in the pairs from longer one to shorter one
+  // if the longer one contains substring of an shorter one.
+  std::vector<PatternMap> pairs;
+  std::vector<const char*> allowed_values;
+};
+
+const std::vector<PatternItem> GetPatternItems() {
+  const std::vector<const char*> kLongShort = {"long", "short"};
+  const std::vector<const char*> kNarrowLongShort = {"narrow", "long", "short"};
+  const std::vector<const char*> k2DigitNumeric = {"2-digit", "numeric"};
+  const std::vector<const char*> kNarrowLongShort2DigitNumeric = {
+      "narrow", "long", "short", "2-digit", "numeric"};
+  const std::vector<PatternItem> kPatternItems = {
+      PatternItem("weekday",
+                  {{"EEEEE", "narrow"}, {"EEEE", "long"}, {"EEE", "short"}},
+                  kNarrowLongShort),
+      PatternItem("era",
+                  {{"GGGGG", "narrow"}, {"GGGG", "long"}, {"GGG", "short"}},
+                  kNarrowLongShort),
+      PatternItem("year", {{"yy", "2-digit"}, {"y", "numeric"}},
+                  k2DigitNumeric),
+      // Sometimes we get L instead of M for month - standalone name.
+      PatternItem("month",
+                  {{"MMMMM", "narrow"},
+                   {"MMMM", "long"},
+                   {"MMM", "short"},
+                   {"MM", "2-digit"},
+                   {"M", "numeric"},
+                   {"LLLLL", "narrow"},
+                   {"LLLL", "long"},
+                   {"LLL", "short"},
+                   {"LL", "2-digit"},
+                   {"L", "numeric"}},
+                  kNarrowLongShort2DigitNumeric),
+      PatternItem("day", {{"dd", "2-digit"}, {"d", "numeric"}}, k2DigitNumeric),
+      PatternItem("hour",
+                  {{"HH", "2-digit"},
+                   {"H", "numeric"},
+                   {"hh", "2-digit"},
+                   {"h", "numeric"}},
+                  k2DigitNumeric),
+      PatternItem("minute", {{"mm", "2-digit"}, {"m", "numeric"}},
+                  k2DigitNumeric),
+      PatternItem("second", {{"ss", "2-digit"}, {"s", "numeric"}},
+                  k2DigitNumeric),
+      PatternItem("timeZoneName", {{"zzzz", "long"}, {"z", "short"}},
+                  kLongShort)};
+  return kPatternItems;
+}
+
+class PatternData {
+ public:
+  PatternData(const std::string property, std::vector<PatternMap> pairs,
+              std::vector<const char*> allowed_values)
+      : property(std::move(property)), allowed_values(allowed_values) {
+    for (const auto& pair : pairs) {
+      map.insert(std::make_pair(pair.value, pair.pattern));
+    }
+  }
+  virtual ~PatternData() = default;
+
+  const std::string property;
+  std::map<const std::string, const std::string> map;
+  std::vector<const char*> allowed_values;
+};
+
+enum HourOption {
+  H_UNKNOWN,
+  H_12,
+  H_24,
+};
+
+const std::vector<PatternData> CreateCommonData(const PatternData& hour_data) {
+  std::vector<PatternData> build;
+  for (const PatternItem& item : GetPatternItems()) {
+    if (item.property == "hour") {
+      build.push_back(hour_data);
+    } else {
+      build.push_back(
+          PatternData(item.property, item.pairs, item.allowed_values));
+    }
+  }
+  return build;
+}
+
+const std::vector<PatternData> CreateData(const char* digit2,
+                                          const char* numeric) {
+  static std::vector<const char*> k2DigitNumeric = {"2-digit", "numeric"};
+  return CreateCommonData(PatternData(
+      "hour", {{digit2, "2-digit"}, {numeric, "numeric"}}, k2DigitNumeric));
+}
+
+const std::vector<PatternData> GetPatternData(HourOption option) {
+  const std::vector<PatternData> data = CreateData("jj", "j");
+  const std::vector<PatternData> data_h12 = CreateData("hh", "h");
+  const std::vector<PatternData> data_h24 = CreateData("HH", "H");
+  switch (option) {
+    case HourOption::H_12:
+      return data_h12;
+    case HourOption::H_24:
+      return data_h24;
+    case HourOption::H_UNKNOWN:
+      return data;
+  }
+}
+
+void SetPropertyFromPattern(Isolate* isolate, const std::string& pattern,
+                            Handle<JSObject> options) {
+  Factory* factory = isolate->factory();
+  const std::vector<PatternItem> items = GetPatternItems();
+  for (const auto& item : items) {
+    for (const auto& pair : item.pairs) {
+      if (pattern.find(pair.pattern) != std::string::npos) {
+        // After we find the first pair in the item which matching the pattern,
+        // we set the property and look for the next item in kPatternItems.
+        CHECK(JSReceiver::CreateDataProperty(
+                  isolate, options,
+                  factory->NewStringFromAsciiChecked(item.property.c_str()),
+                  factory->NewStringFromAsciiChecked(pair.value.c_str()),
+                  kDontThrow)
+                  .FromJust());
+        break;
+      }
+    }
+  }
+  // hour12
+  // b. If p is "hour12", then
+  //  i. Let hc be dtf.[[HourCycle]].
+  //  ii. If hc is "h11" or "h12", let v be true.
+  //  iii. Else if, hc is "h23" or "h24", let v be false.
+  //  iv. Else, let v be undefined.
+  if (pattern.find('h') != std::string::npos) {
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->NewStringFromStaticChars("hour12"),
+              factory->true_value(), kDontThrow)
+              .FromJust());
+  } else if (pattern.find('H') != std::string::npos) {
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->NewStringFromStaticChars("hour12"),
+              factory->false_value(), kDontThrow)
+              .FromJust());
+  }
+}
+
+std::string GetGMTTzID(Isolate* isolate, const std::string& input) {
+  std::string ret = "Etc/GMT";
+  switch (input.length()) {
+    case 8:
+      if (input[7] == '0') return ret + '0';
+      break;
+    case 9:
+      if ((input[7] == '+' || input[7] == '-') &&
+          IsInRange(input[8], '0', '9')) {
+        return ret + input[7] + input[8];
+      }
+      break;
+    case 10:
+      if ((input[7] == '+' || input[7] == '-') && (input[8] == '1') &&
+          IsInRange(input[9], '0', '4')) {
+        return ret + input[7] + input[8] + input[9];
+      }
+      break;
+  }
+  return "";
+}
+
+// Locale independenty version of isalpha for ascii range. This will return
+// false if the ch is alpha but not in ascii range.
+bool IsAsciiAlpha(char ch) {
+  return IsInRange(ch, 'A', 'Z') || IsInRange(ch, 'a', 'z');
+}
+
+// Locale independent toupper for ascii range. This will not return İ (dotted I)
+// for i under Turkish locale while std::toupper may.
+char LocaleIndependentAsciiToUpper(char ch) {
+  return (IsInRange(ch, 'a', 'z')) ? (ch - 'a' + 'A') : ch;
+}
+
+// Locale independent tolower for ascii range.
+char LocaleIndependentAsciiToLower(char ch) {
+  return (IsInRange(ch, 'A', 'Z')) ? (ch - 'A' + 'a') : ch;
+}
+
+// Returns titlecased location, bueNos_airES -> Buenos_Aires
+// or ho_cHi_minH -> Ho_Chi_Minh. It is locale-agnostic and only
+// deals with ASCII only characters.
+// 'of', 'au' and 'es' are special-cased and lowercased.
+// ICU's timezone parsing is case sensitive, but ECMAScript is case insensitive
+std::string ToTitleCaseTimezoneLocation(Isolate* isolate,
+                                        const std::string& input) {
+  std::string title_cased;
+  int word_length = 0;
+  for (char ch : input) {
+    // Convert first char to upper case, the rest to lower case
+    if (IsAsciiAlpha(ch)) {
+      title_cased += word_length == 0 ? LocaleIndependentAsciiToUpper(ch)
+                                      : LocaleIndependentAsciiToLower(ch);
+      word_length++;
+    } else if (ch == '_' || ch == '-' || ch == '/') {
+      // Special case Au/Es/Of to be lower case.
+      if (word_length == 2) {
+        size_t pos = title_cased.length() - 2;
+        std::string substr = title_cased.substr(pos, 2);
+        if (substr == "Of" || substr == "Es" || substr == "Au") {
+          title_cased[pos] = LocaleIndependentAsciiToLower(title_cased[pos]);
+        }
+      }
+      title_cased += ch;
+      word_length = 0;
+    } else {
+      // Invalid input
+      return std::string();
+    }
+  }
+  return title_cased;
+}
+
+}  // namespace
+
+std::string JSDateTimeFormat::CanonicalizeTimeZoneID(Isolate* isolate,
+                                                     const std::string& input) {
+  std::string upper = input;
+  transform(upper.begin(), upper.end(), upper.begin(),
+            LocaleIndependentAsciiToUpper);
+  if (upper == "UTC" || upper == "GMT" || upper == "ETC/UTC" ||
+      upper == "ETC/GMT") {
+    return "UTC";
+  }
+  // We expect only _, '-' and / beside ASCII letters.
+  // All inputs should conform to Area/Location(/Location)*, or Etc/GMT* .
+  // TODO(jshin): 1. Support 'GB-Eire", 'EST5EDT", "ROK', 'US/*', 'NZ' and many
+  // other aliases/linked names when moving timezone validation code to C++.
+  // See crbug.com/364374 and crbug.com/v8/8007 .
+  // 2. Resolve the difference betwee CLDR/ICU and IANA time zone db.
+  // See http://unicode.org/cldr/trac/ticket/9892 and crbug.com/645807 .
+  if (strncmp(upper.c_str(), "ETC/GMT", 7) == 0) {
+    return GetGMTTzID(isolate, input);
+  }
+  return ToTitleCaseTimezoneLocation(isolate, input);
+}
+
+MaybeHandle<JSObject> JSDateTimeFormat::ResolvedOptions(
+    Isolate* isolate, Handle<JSDateTimeFormat> date_time_format) {
+  Factory* factory = isolate->factory();
+  // 4. Let options be ! ObjectCreate(%ObjectPrototype%).
+  Handle<JSObject> options = factory->NewJSObject(isolate->object_function());
+
+  // 5. For each row of Table 6, except the header row, in any order, do
+  // a. Let p be the Property value of the current row.
+  Handle<Object> resolved_obj;
+
+  // locale
+  UErrorCode status = U_ZERO_ERROR;
+  char language[ULOC_FULLNAME_CAPACITY];
+  uloc_toLanguageTag(date_time_format->icu_locale()->raw()->getName(), language,
+                     ULOC_FULLNAME_CAPACITY, FALSE, &status);
+  CHECK(U_SUCCESS(status));
+  Handle<String> locale = factory->NewStringFromAsciiChecked(language);
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, options, factory->locale_string(), locale, kDontThrow)
+            .FromJust());
+
+  icu::SimpleDateFormat* icu_simple_date_format =
+      date_time_format->icu_simple_date_format()->raw();
+  // calendar
+  const icu::Calendar* calendar = icu_simple_date_format->getCalendar();
+  // getType() returns legacy calendar type name instead of LDML/BCP47 calendar
+  // key values. intl.js maps them to BCP47 values for key "ca".
+  // TODO(jshin): Consider doing it here, instead.
+  std::string calendar_str = calendar->getType();
+
+  // Maps ICU calendar names to LDML/BCP47 types for key 'ca'.
+  // See typeMap section in third_party/icu/source/data/misc/keyTypeData.txt
+  // and
+  // http://www.unicode.org/repos/cldr/tags/latest/common/bcp47/calendar.xml
+  if (calendar_str == "gregorian") {
+    calendar_str = "gregory";
+  } else if (calendar_str == "ethiopic-amete-alem") {
+    calendar_str = "ethioaa";
+  }
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, options, factory->NewStringFromStaticChars("calendar"),
+            factory->NewStringFromAsciiChecked(calendar_str.c_str()),
+            kDontThrow)
+            .FromJust());
+
+  // Ugly hack. ICU doesn't expose numbering system in any way, so we have
+  // to assume that for given locale NumberingSystem constructor produces the
+  // same digits as NumberFormat/Calendar would.
+  // Tracked by https://unicode-org.atlassian.net/browse/ICU-13431
+  std::unique_ptr<icu::NumberingSystem> numbering_system(
+      icu::NumberingSystem::createInstance(
+          *(date_time_format->icu_locale()->raw()), status));
+  if (U_SUCCESS(status)) {
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->numberingSystem_string(),
+              factory->NewStringFromAsciiChecked(numbering_system->getName()),
+              kDontThrow)
+              .FromJust());
+  }
+
+  // timezone
+  const icu::TimeZone& tz = calendar->getTimeZone();
+  icu::UnicodeString time_zone;
+  tz.getID(time_zone);
+  status = U_ZERO_ERROR;
+  icu::UnicodeString canonical_time_zone;
+  icu::TimeZone::getCanonicalID(time_zone, canonical_time_zone, status);
+  if (U_SUCCESS(status)) {
+    Handle<String> timezone_value;
+    // In CLDR (http://unicode.org/cldr/trac/ticket/9943), Etc/UTC is made
+    // a separate timezone ID from Etc/GMT even though they're still the same
+    // timezone. We have Etc/UTC because 'UTC', 'Etc/Universal',
+    // 'Etc/Zulu' and others are turned to 'Etc/UTC' by ICU. Etc/GMT comes
+    // from Etc/GMT0, Etc/GMT+0, Etc/GMT-0, Etc/Greenwich.
+    // ecma402#sec-canonicalizetimezonename step 3
+    if (canonical_time_zone == UNICODE_STRING_SIMPLE("Etc/UTC") ||
+        canonical_time_zone == UNICODE_STRING_SIMPLE("Etc/GMT")) {
+      timezone_value = factory->NewStringFromStaticChars("UTC");
+    } else {
+      ASSIGN_RETURN_ON_EXCEPTION(isolate, timezone_value,
+                                 Intl::ToString(isolate, canonical_time_zone),
+                                 JSObject);
+    }
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->NewStringFromStaticChars("timeZone"),
+              timezone_value, kDontThrow)
+              .FromJust());
+  } else {
+    // Somehow on Windows we will reach here.
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->NewStringFromStaticChars("timeZone"),
+              factory->undefined_value(), kDontThrow)
+              .FromJust());
+  }
+
+  icu::UnicodeString pattern_unicode;
+  icu_simple_date_format->toPattern(pattern_unicode);
+  std::string pattern;
+  pattern_unicode.toUTF8String(pattern);
+  SetPropertyFromPattern(isolate, pattern, options);
+  return options;
+}
+
+namespace {
+
+// ecma402/#sec-formatdatetime
+// FormatDateTime( dateTimeFormat, x )
+MaybeHandle<String> FormatDateTime(Isolate* isolate,
+                                   Handle<JSDateTimeFormat> date_time_format,
+                                   double x) {
+  double date_value = DateCache::TimeClip(x);
+  if (std::isnan(date_value)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kInvalidTimeValue),
+                    String);
+  }
+
+  icu::SimpleDateFormat* date_format =
+      date_time_format->icu_simple_date_format()->raw();
+  CHECK_NOT_NULL(date_format);
+
+  icu::UnicodeString result;
+  date_format->format(date_value, result);
+
+  return Intl::ToString(isolate, result);
+}
+
+}  // namespace
+
+// ecma402/#sec-datetime-format-functions
+// DateTime Format Functions
+MaybeHandle<String> JSDateTimeFormat::DateTimeFormat(
+    Isolate* isolate, Handle<JSDateTimeFormat> date_time_format,
+    Handle<Object> date) {
+  // 2. Assert: Type(dtf) is Object and dtf has an [[InitializedDateTimeFormat]]
+  // internal slot.
+
+  // 3. If date is not provided or is undefined, then
+  double x;
+  if (date->IsUndefined()) {
+    // 3.a Let x be Call(%Date_now%, undefined).
+    x = JSDate::CurrentTimeValue(isolate);
+  } else {
+    // 4. Else,
+    //    a. Let x be ? ToNumber(date).
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, date, Object::ToNumber(isolate, date),
+                               String);
+    CHECK(date->IsNumber());
+    x = date->Number();
+  }
+  // 5. Return FormatDateTime(dtf, x).
+  return FormatDateTime(isolate, date_time_format, x);
+}
+
+MaybeHandle<String> JSDateTimeFormat::ToLocaleDateTime(
+    Isolate* isolate, Handle<Object> date, Handle<Object> locales,
+    Handle<Object> options, RequiredOption required, DefaultsOption defaults,
+    const char* service) {
+  Factory* factory = isolate->factory();
+  // 1. Let x be ? thisTimeValue(this value);
+  if (!date->IsJSDate()) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kMethodInvokedOnWrongType,
+                                 factory->NewStringFromStaticChars("Date")),
+                    String);
+  }
+
+  double const x = Handle<JSDate>::cast(date)->value()->Number();
+  // 2. If x is NaN, return "Invalid Date"
+  if (std::isnan(x)) {
+    return factory->NewStringFromStaticChars("Invalid Date");
+  }
+
+  // 3. Let options be ? ToDateTimeOptions(options, required, defaults).
+  Handle<JSObject> internal_options;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, internal_options,
+      ToDateTimeOptions(isolate, options, required, defaults), String);
+
+  // 4. Let dateFormat be ? Construct(%DateTimeFormat%, « locales, options »).
+  Handle<JSObject> object;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, object,
+      Intl::CachedOrNewService(isolate,
+                               factory->NewStringFromAsciiChecked(service),
+                               locales, options, internal_options),
+      String);
+
+  CHECK(object->IsJSDateTimeFormat());
+  Handle<JSDateTimeFormat> date_time_format =
+      Handle<JSDateTimeFormat>::cast(object);
+  // 5. Return FormatDateTime(dateFormat, x).
+  return FormatDateTime(isolate, date_time_format, x);
+}
+
+namespace {
+
+Maybe<bool> IsPropertyUndefined(Isolate* isolate, Handle<JSObject> options,
+                                const char* property) {
+  Factory* factory = isolate->factory();
+  // i. Let prop be the property name.
+  // ii. Let value be ? Get(options, prop).
+  Handle<Object> value;
+  ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+      isolate, value,
+      Object::GetPropertyOrElement(
+          isolate, options, factory->NewStringFromAsciiChecked(property)),
+      Nothing<bool>());
+  return Just(value->IsUndefined(isolate));
+}
+
+Maybe<bool> NeedsDefault(Isolate* isolate, Handle<JSObject> options,
+                         const std::vector<std::string>& props) {
+  bool needs_default = true;
+  for (const auto& prop : props) {
+    //  i. Let prop be the property name.
+    // ii. Let value be ? Get(options, prop)
+    Maybe<bool> maybe_undefined =
+        IsPropertyUndefined(isolate, options, prop.c_str());
+    MAYBE_RETURN(maybe_undefined, Nothing<bool>());
+    // iii. If value is not undefined, let needDefaults be false.
+    if (!maybe_undefined.FromJust()) {
+      needs_default = false;
+    }
+  }
+  return Just(needs_default);
+}
+
+Maybe<bool> CreateDefault(Isolate* isolate, Handle<JSObject> options,
+                          const std::vector<std::string>& props) {
+  Factory* factory = isolate->factory();
+  // i. Perform ? CreateDataPropertyOrThrow(options, prop, "numeric").
+  for (const auto& prop : props) {
+    MAYBE_RETURN(
+        JSReceiver::CreateDataProperty(
+            isolate, options, factory->NewStringFromAsciiChecked(prop.c_str()),
+            factory->numeric_string(), kThrowOnError),
+        Nothing<bool>());
+  }
+  return Just(true);
+}
+
+}  // namespace
+
+// ecma-402/#sec-todatetimeoptions
+MaybeHandle<JSObject> JSDateTimeFormat::ToDateTimeOptions(
+    Isolate* isolate, Handle<Object> input_options, RequiredOption required,
+    DefaultsOption defaults) {
+  Factory* factory = isolate->factory();
+  // 1. If options is undefined, let options be null; otherwise let options be ?
+  //    ToObject(options).
+  Handle<JSObject> options;
+  if (input_options->IsUndefined(isolate)) {
+    options = factory->NewJSObjectWithNullProto();
+  } else {
+    Handle<JSReceiver> options_obj;
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, options_obj,
+                               Object::ToObject(isolate, input_options),
+                               JSObject);
+    // 2. Let options be ObjectCreate(options).
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, options,
+                               JSObject::ObjectCreate(isolate, options_obj),
+                               JSObject);
+  }
+
+  // 3. Let needDefaults be true.
+  bool needs_default = true;
+
+  // 4. If required is "date" or "any", then
+  if (required == RequiredOption::kAny || required == RequiredOption::kDate) {
+    // a. For each of the property names "weekday", "year", "month", "day", do
+    const std::vector<std::string> list({"weekday", "year", "month", "day"});
+    Maybe<bool> maybe_needs_default = NeedsDefault(isolate, options, list);
+    MAYBE_RETURN(maybe_needs_default, Handle<JSObject>());
+    needs_default = maybe_needs_default.FromJust();
+  }
+
+  // 5. If required is "time" or "any", then
+  if (required == RequiredOption::kAny || required == RequiredOption::kTime) {
+    // a. For each of the property names "hour", "minute", "second", do
+    const std::vector<std::string> list({"hour", "minute", "second"});
+    Maybe<bool> maybe_needs_default = NeedsDefault(isolate, options, list);
+    MAYBE_RETURN(maybe_needs_default, Handle<JSObject>());
+    needs_default &= maybe_needs_default.FromJust();
+  }
+
+  // 6. If needDefaults is true and defaults is either "date" or "all", then
+  if (needs_default) {
+    if (defaults == DefaultsOption::kAll || defaults == DefaultsOption::kDate) {
+      // a. For each of the property names "year", "month", "day", do)
+      const std::vector<std::string> list({"year", "month", "day"});
+      MAYBE_RETURN(CreateDefault(isolate, options, list), Handle<JSObject>());
+    }
+    // 7. If needDefaults is true and defaults is either "time" or "all", then
+    if (defaults == DefaultsOption::kAll || defaults == DefaultsOption::kTime) {
+      // a. For each of the property names "hour", "minute", "second", do
+      const std::vector<std::string> list({"hour", "minute", "second"});
+      MAYBE_RETURN(CreateDefault(isolate, options, list), Handle<JSObject>());
+    }
+  }
+  // 8. Return options.
+  return options;
+}
+
+MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::UnwrapDateTimeFormat(
+    Isolate* isolate, Handle<JSReceiver> format_holder) {
+  Handle<Context> native_context =
+      Handle<Context>(isolate->context()->native_context(), isolate);
+  Handle<JSFunction> constructor = Handle<JSFunction>(
+      JSFunction::cast(native_context->intl_date_time_format_function()),
+      isolate);
+  Handle<Object> dtf;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, dtf,
+      Intl::LegacyUnwrapReceiver(isolate, format_holder, constructor,
+                                 format_holder->IsJSDateTimeFormat()),
+      JSDateTimeFormat);
+  // 2. If Type(dtf) is not Object or dtf does not have an
+  //    [[InitializedDateTimeFormat]] internal slot, then
+  if (!dtf->IsJSDateTimeFormat()) {
+    // a. Throw a TypeError exception.
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
+                                 isolate->factory()->NewStringFromAsciiChecked(
+                                     "UnwrapDateTimeFormat"),
+                                 format_holder),
+                    JSDateTimeFormat);
+  }
+  // 3. Return dtf.
+  return Handle<JSDateTimeFormat>::cast(dtf);
+}
+
+namespace {
+
+// ecma-402/#sec-isvalidtimezonename
+bool IsValidTimeZoneName(const icu::TimeZone& tz) {
+  UErrorCode status = U_ZERO_ERROR;
+  icu::UnicodeString id;
+  tz.getID(id);
+  icu::UnicodeString canonical;
+  icu::TimeZone::getCanonicalID(id, canonical, status);
+  return U_SUCCESS(status) &&
+         canonical != icu::UnicodeString("Etc/Unknown", -1, US_INV);
+}
+
+std::unique_ptr<icu::TimeZone> CreateTimeZone(Isolate* isolate,
+                                              const char* timezone) {
+  // Create time zone as specified by the user. We have to re-create time zone
+  // since calendar takes ownership.
+  if (timezone == nullptr) {
+    // 19.a. Else / Let timeZone be DefaultTimeZone().
+    return std::unique_ptr<icu::TimeZone>(icu::TimeZone::createDefault());
+  }
+  std::string canonicalized =
+      JSDateTimeFormat::CanonicalizeTimeZoneID(isolate, timezone);
+  if (canonicalized.empty()) return std::unique_ptr<icu::TimeZone>();
+  std::unique_ptr<icu::TimeZone> tz(
+      icu::TimeZone::createTimeZone(canonicalized.c_str()));
+  // 18.b If the result of IsValidTimeZoneName(timeZone) is false, then
+  // i. Throw a RangeError exception.
+  if (!IsValidTimeZoneName(*tz)) return std::unique_ptr<icu::TimeZone>();
+  return tz;
+}
+
+std::unique_ptr<icu::Calendar> CreateCalendar(Isolate* isolate,
+                                              const icu::Locale& icu_locale,
+                                              const char* timezone) {
+  std::unique_ptr<icu::TimeZone> tz = CreateTimeZone(isolate, timezone);
+  if (tz.get() == nullptr) return std::unique_ptr<icu::Calendar>();
+
+  // Create a calendar using locale, and apply time zone to it.
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::Calendar> calendar(
+      icu::Calendar::createInstance(tz.release(), icu_locale, status));
+  CHECK(U_SUCCESS(status));
+  CHECK_NOT_NULL(calendar.get());
+
+  if (calendar->getDynamicClassID() ==
+      icu::GregorianCalendar::getStaticClassID()) {
+    icu::GregorianCalendar* gc =
+        static_cast<icu::GregorianCalendar*>(calendar.get());
+    UErrorCode status = U_ZERO_ERROR;
+    // The beginning of ECMAScript time, namely -(2**53)
+    const double start_of_time = -9007199254740992;
+    gc->setGregorianChange(start_of_time, status);
+    DCHECK(U_SUCCESS(status));
+  }
+  return calendar;
+}
+
+std::unique_ptr<icu::SimpleDateFormat> CreateICUDateFormat(
+    Isolate* isolate, const icu::Locale& icu_locale,
+    const std::string& skeleton) {
+  // See https://github.com/tc39/ecma402/issues/225 . The best pattern
+  // generation needs to be done in the base locale according to the
+  // current spec however odd it may be. See also crbug.com/826549 .
+  // This is a temporary work-around to get v8's external behavior to match
+  // the current spec, but does not follow the spec provisions mentioned
+  // in the above Ecma 402 issue.
+  // TODO(jshin): The spec may need to be revised because using the base
+  // locale for the pattern match is not quite right. Moreover, what to
+  // do with 'related year' part when 'chinese/dangi' calendar is specified
+  // has to be discussed. Revisit once the spec is clarified/revised.
+  icu::Locale no_extension_locale(icu_locale.getBaseName());
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::DateTimePatternGenerator> generator(
+      icu::DateTimePatternGenerator::createInstance(no_extension_locale,
+                                                    status));
+  icu::UnicodeString pattern;
+  if (U_SUCCESS(status)) {
+    pattern =
+        generator->getBestPattern(icu::UnicodeString(skeleton.c_str()), status);
+  }
+
+  // Make formatter from skeleton. Calendar and numbering system are added
+  // to the locale as Unicode extension (if they were specified at all).
+  status = U_ZERO_ERROR;
+  std::unique_ptr<icu::SimpleDateFormat> date_format(
+      new icu::SimpleDateFormat(pattern, icu_locale, status));
+  if (U_FAILURE(status)) return std::unique_ptr<icu::SimpleDateFormat>();
+
+  CHECK_NOT_NULL(date_format.get());
+  return date_format;
+}
+
+}  // namespace
+
+enum FormatMatcherOption { kBestFit, kBasic };
+
+// ecma402/#sec-initializedatetimeformat
+MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::Initialize(
+    Isolate* isolate, Handle<JSDateTimeFormat> date_time_format,
+    Handle<Object> requested_locales, Handle<Object> input_options) {
+  // 2. Let options be ? ToDateTimeOptions(options, "any", "date").
+  Handle<JSObject> options;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, options,
+      JSDateTimeFormat::ToDateTimeOptions(
+          isolate, input_options, RequiredOption::kAny, DefaultsOption::kDate),
+      JSDateTimeFormat);
+
+  // ResolveLocale currently get option of localeMatcher so we have to call
+  // ResolveLocale before "hour12" and "hourCycle".
+  // TODO(ftang): fix this once ResolveLocale is ported to C++
+  // 11. Let r be ResolveLocale( %DateTimeFormat%.[[AvailableLocales]],
+  //     requestedLocales, opt, %DateTimeFormat%.[[RelevantExtensionKeys]],
+  //     localeData).
+  Handle<JSObject> r;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, r,
+      Intl::ResolveLocale(isolate, "dateformat", requested_locales, options),
+      JSDateTimeFormat);
+
+  // 6. Let hour12 be ? GetOption(options, "hour12", "boolean", undefined,
+  // undefined).
+  bool hour12;
+  Maybe<bool> maybe_get_hour12 = Intl::GetBoolOption(
+      isolate, options, "hour12", "Intl.DateTimeFormat", &hour12);
+  MAYBE_RETURN(maybe_get_hour12, Handle<JSDateTimeFormat>());
+  HourOption hour_option = HourOption::H_UNKNOWN;
+  if (maybe_get_hour12.FromJust()) {
+    hour_option = hour12 ? HourOption::H_12 : HourOption::H_24;
+  }
+
+  // 7. Let hourCycle be ? GetOption(options, "hourCycle", "string", « "h11",
+  // "h12", "h23", "h24" », undefined).
+  static std::vector<const char*> hour_cycle_values = {"h11", "h12", "h23",
+                                                       "h24"};
+  std::unique_ptr<char[]> hour_cycle = nullptr;
+  Maybe<bool> maybe_hour_cycle =
+      Intl::GetStringOption(isolate, options, "hourCycle", hour_cycle_values,
+                            "Intl.DateTimeFormat", &hour_cycle);
+  MAYBE_RETURN(maybe_hour_cycle, Handle<JSDateTimeFormat>());
+  // 8. If hour12 is not undefined, then
+  if (maybe_get_hour12.FromJust()) {
+    // a. Let hourCycle be null.
+    hour_cycle = nullptr;
+  }
+  // 9. Set opt.[[hc]] to hourCycle.
+  // TODO(ftang): change behavior based on hour_cycle.
+
+  Handle<String> locale_with_extension_str =
+      isolate->factory()->NewStringFromStaticChars("localeWithExtension");
+  Handle<Object> locale_with_extension_obj =
+      JSObject::GetDataProperty(r, locale_with_extension_str);
+
+  // The locale_with_extension has to be a string. Either a user
+  // provided canonicalized string or the default locale.
+  CHECK(locale_with_extension_obj->IsString());
+  Handle<String> locale_with_extension =
+      Handle<String>::cast(locale_with_extension_obj);
+
+  icu::Locale icu_locale =
+      Intl::CreateICULocale(isolate, locale_with_extension);
+  DCHECK(!icu_locale.isBogus());
+
+  // 17. Let timeZone be ? Get(options, "timeZone").
+  static std::vector<const char*> empty_values = {};
+  std::unique_ptr<char[]> timezone = nullptr;
+  Maybe<bool> maybe_timezone =
+      Intl::GetStringOption(isolate, options, "timeZone", empty_values,
+                            "Intl.DateTimeFormat", &timezone);
+  MAYBE_RETURN(maybe_timezone, Handle<JSDateTimeFormat>());
+
+  // 22. For each row of Table 5, except the header row, do
+  std::string skeleton;
+  for (const auto& item : GetPatternData(hour_option)) {
+    std::unique_ptr<char[]> input;
+    // a. Let prop be the name given in the Property column of the row.
+    // b. Let value be ? GetOption(options, prop, "string", « the strings given
+    // in the Values column of the row », undefined).
+    Maybe<bool> maybe_get_option = Intl::GetStringOption(
+        isolate, options, item.property.c_str(), item.allowed_values,
+        "Intl.DateTimeFormat", &input);
+    MAYBE_RETURN(maybe_get_option, Handle<JSDateTimeFormat>());
+    if (maybe_get_option.FromJust()) {
+      DCHECK_NOT_NULL(input.get());
+      // c. Set opt.[[<prop>]] to value.
+      skeleton += item.map.find(input.get())->second;
+    }
+  }
+
+  // We implement only best fit algorithm, but still need to check
+  // if the formatMatcher values are in range.
+  // 25. Let matcher be ? GetOption(options, "formatMatcher", "string",
+  //     «  "basic", "best fit" », "best fit").
+  Handle<JSReceiver> options_obj;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, options_obj,
+                             Object::ToObject(isolate, options),
+                             JSDateTimeFormat);
+  std::unique_ptr<char[]> matcher_str = nullptr;
+  std::vector<const char*> matcher_values = {"basic", "best fit"};
+  Maybe<bool> maybe_found_matcher = Intl::GetStringOption(
+      isolate, options_obj, "formatMatcher", matcher_values,
+      "Intl.DateTimeFormat", &matcher_str);
+  MAYBE_RETURN(maybe_found_matcher, Handle<JSDateTimeFormat>());
+
+  std::unique_ptr<icu::SimpleDateFormat> date_format(
+      CreateICUDateFormat(isolate, icu_locale, skeleton));
+  if (date_format.get() == nullptr) {
+    // Remove extensions and try again.
+    icu_locale = icu::Locale(icu_locale.getBaseName());
+    date_format = CreateICUDateFormat(isolate, icu_locale, skeleton);
+    if (date_format.get() == nullptr) {
+      FATAL("Failed to create ICU date format, are ICU data files missing?");
+    }
+  }
+
+  // Set the locale
+  // 12. Set dateTimeFormat.[[Locale]] to r.[[locale]].
+  icu::Locale* cloned_locale = icu_locale.clone();
+  CHECK_NOT_NULL(cloned_locale);
+  Handle<Managed<icu::Locale>> managed_locale =
+      Managed<icu::Locale>::FromRawPtr(isolate, 0, cloned_locale);
+  date_time_format->set_icu_locale(*managed_locale);
+
+  // 13. Set dateTimeFormat.[[Calendar]] to r.[[ca]].
+  std::unique_ptr<icu::Calendar> calendar(
+      CreateCalendar(isolate, icu_locale, timezone.get()));
+
+  // 18.b If the result of IsValidTimeZoneName(timeZone) is false, then
+  // i. Throw a RangeError exception.
+  if (calendar.get() == nullptr) {
+    THROW_NEW_ERROR(isolate,
+                    NewRangeError(MessageTemplate::kInvalidTimeZone,
+                                  isolate->factory()->NewStringFromAsciiChecked(
+                                      timezone.get())),
+                    JSDateTimeFormat);
+  }
+  date_format->adoptCalendar(calendar.release());
+
+  Handle<Managed<icu::SimpleDateFormat>> managed_format =
+      Managed<icu::SimpleDateFormat>::FromUniquePtr(isolate, 0,
+                                                    std::move(date_format));
+  date_time_format->set_icu_simple_date_format(*managed_format);
+  return date_time_format;
+}
+
+namespace {
+
+// The list comes from third_party/icu/source/i18n/unicode/udat.h.
+// They're mapped to DateTimeFormat components listed at
+// https://tc39.github.io/ecma402/#sec-datetimeformat-abstracts .
+Handle<String> IcuDateFieldIdToDateType(int32_t field_id, Isolate* isolate) {
+  switch (field_id) {
+    case -1:
+      return isolate->factory()->literal_string();
+    case UDAT_YEAR_FIELD:
+    case UDAT_EXTENDED_YEAR_FIELD:
+    case UDAT_YEAR_NAME_FIELD:
+      return isolate->factory()->year_string();
+    case UDAT_MONTH_FIELD:
+    case UDAT_STANDALONE_MONTH_FIELD:
+      return isolate->factory()->month_string();
+    case UDAT_DATE_FIELD:
+      return isolate->factory()->day_string();
+    case UDAT_HOUR_OF_DAY1_FIELD:
+    case UDAT_HOUR_OF_DAY0_FIELD:
+    case UDAT_HOUR1_FIELD:
+    case UDAT_HOUR0_FIELD:
+      return isolate->factory()->hour_string();
+    case UDAT_MINUTE_FIELD:
+      return isolate->factory()->minute_string();
+    case UDAT_SECOND_FIELD:
+      return isolate->factory()->second_string();
+    case UDAT_DAY_OF_WEEK_FIELD:
+    case UDAT_DOW_LOCAL_FIELD:
+    case UDAT_STANDALONE_DAY_FIELD:
+      return isolate->factory()->weekday_string();
+    case UDAT_AM_PM_FIELD:
+      return isolate->factory()->dayPeriod_string();
+    case UDAT_TIMEZONE_FIELD:
+    case UDAT_TIMEZONE_RFC_FIELD:
+    case UDAT_TIMEZONE_GENERIC_FIELD:
+    case UDAT_TIMEZONE_SPECIAL_FIELD:
+    case UDAT_TIMEZONE_LOCALIZED_GMT_OFFSET_FIELD:
+    case UDAT_TIMEZONE_ISO_FIELD:
+    case UDAT_TIMEZONE_ISO_LOCAL_FIELD:
+      return isolate->factory()->timeZoneName_string();
+    case UDAT_ERA_FIELD:
+      return isolate->factory()->era_string();
+    default:
+      // Other UDAT_*_FIELD's cannot show up because there is no way to specify
+      // them via options of Intl.DateTimeFormat.
+      UNREACHABLE();
+      // To prevent MSVC from issuing C4715 warning.
+      return Handle<String>();
+  }
+}
+
+}  // namespace
+
+MaybeHandle<Object> JSDateTimeFormat::FormatToParts(
+    Isolate* isolate, Handle<JSDateTimeFormat> date_time_format,
+    double date_value) {
+  Factory* factory = isolate->factory();
+  icu::SimpleDateFormat* format =
+      date_time_format->icu_simple_date_format()->raw();
+  CHECK_NOT_NULL(format);
+
+  icu::UnicodeString formatted;
+  icu::FieldPositionIterator fp_iter;
+  icu::FieldPosition fp;
+  UErrorCode status = U_ZERO_ERROR;
+  format->format(date_value, formatted, &fp_iter, status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), Object);
+  }
+
+  Handle<JSArray> result = factory->NewJSArray(0);
+  int32_t length = formatted.length();
+  if (length == 0) return result;
+
+  int index = 0;
+  int32_t previous_end_pos = 0;
+  Handle<String> substring;
+  while (fp_iter.next(fp)) {
+    int32_t begin_pos = fp.getBeginIndex();
+    int32_t end_pos = fp.getEndIndex();
+
+    if (previous_end_pos < begin_pos) {
+      ASSIGN_RETURN_ON_EXCEPTION(
+          isolate, substring,
+          Intl::ToString(isolate, formatted, previous_end_pos, begin_pos),
+          Object);
+      Intl::AddElement(isolate, result, index,
+                       IcuDateFieldIdToDateType(-1, isolate), substring);
+      ++index;
+    }
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, substring,
+        Intl::ToString(isolate, formatted, begin_pos, end_pos), Object);
+    Intl::AddElement(isolate, result, index,
+                     IcuDateFieldIdToDateType(fp.getField(), isolate),
+                     substring);
+    previous_end_pos = end_pos;
+    ++index;
+  }
+  if (previous_end_pos < length) {
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, substring,
+        Intl::ToString(isolate, formatted, previous_end_pos, length), Object);
+    Intl::AddElement(isolate, result, index,
+                     IcuDateFieldIdToDateType(-1, isolate), substring);
+  }
+  JSObject::ValidateElements(*result);
+  return result;
+}
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/objects/js-date-time-format.h b/deps/v8/src/objects/js-date-time-format.h
new file mode 100644
index 0000000000..ae2aa36a97
--- /dev/null
+++ b/deps/v8/src/objects/js-date-time-format.h
@@ -0,0 +1,100 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_DATE_TIME_FORMAT_H_
+#define V8_OBJECTS_JS_DATE_TIME_FORMAT_H_
+
+#include "src/isolate.h"
+#include "src/objects/managed.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace U_ICU_NAMESPACE {
+class Locale;
+class SimpleDateFormat;
+}
+
+namespace v8 {
+namespace internal {
+
+class JSDateTimeFormat : public JSObject {
+ public:
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSDateTimeFormat> Initialize(
+      Isolate* isolate, Handle<JSDateTimeFormat> date_time_format,
+      Handle<Object> locales, Handle<Object> options);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> ResolvedOptions(
+      Isolate* isolate, Handle<JSDateTimeFormat> date_time_format);
+
+  // ecma402/#sec-unwrapdatetimeformat
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSDateTimeFormat>
+  UnwrapDateTimeFormat(Isolate* isolate, Handle<JSReceiver> format_holder);
+
+  // Convert the options to ICU DateTimePatternGenerator skeleton.
+  static Maybe<std::string> OptionsToSkeleton(Isolate* isolate,
+                                              Handle<JSReceiver> options);
+
+  // Return the time zone id which match ICU's expectation of title casing
+  // return empty string when error.
+  static std::string CanonicalizeTimeZoneID(Isolate* isolate,
+                                            const std::string& input);
+
+  // ecma402/#sec-datetime-format-functions
+  // DateTime Format Functions
+  V8_WARN_UNUSED_RESULT static MaybeHandle<String> DateTimeFormat(
+      Isolate* isolate, Handle<JSDateTimeFormat> date_time_format,
+      Handle<Object> date);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> FormatToParts(
+      Isolate* isolate, Handle<JSDateTimeFormat> date_time_format,
+      double date_value);
+
+  // ecma-402/#sec-todatetimeoptions
+  enum class RequiredOption { kDate, kTime, kAny };
+  enum class DefaultsOption { kDate, kTime, kAll };
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> ToDateTimeOptions(
+      Isolate* isolate, Handle<Object> input_options, RequiredOption required,
+      DefaultsOption defaults);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<String> ToLocaleDateTime(
+      Isolate* isolate, Handle<Object> date, Handle<Object> locales,
+      Handle<Object> options, RequiredOption required, DefaultsOption defaults,
+      const char* service);
+
+  DECL_CAST(JSDateTimeFormat)
+
+// Layout description.
+#define JS_DATE_TIME_FORMAT_FIELDS(V)         \
+  V(kICULocaleOffset, kPointerSize)           \
+  V(kICUSimpleDateFormatOffset, kPointerSize) \
+  V(kBoundFormatOffset, kPointerSize)         \
+  /* Total size. */                           \
+  V(kSize, 0)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
+                                JS_DATE_TIME_FORMAT_FIELDS)
+#undef JS_DATE_TIME_FORMAT_FIELDS
+
+  DECL_ACCESSORS(icu_locale, Managed<icu::Locale>)
+  DECL_ACCESSORS(icu_simple_date_format, Managed<icu::SimpleDateFormat>)
+  DECL_ACCESSORS(bound_format, Object)
+
+  DECL_PRINTER(JSDateTimeFormat)
+  DECL_VERIFIER(JSDateTimeFormat)
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSDateTimeFormat);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_DATE_TIME_FORMAT_H_
diff --git a/deps/v8/src/objects/js-generator.h b/deps/v8/src/objects/js-generator.h
index 4d63d524ea..043b457cf0 100644
--- a/deps/v8/src/objects/js-generator.h
+++ b/deps/v8/src/objects/js-generator.h
@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_JS_GENERATOR_H_
 #define V8_OBJECTS_JS_GENERATOR_H_
 
-#include "src/objects.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
diff --git a/deps/v8/src/objects/js-list-format-inl.h b/deps/v8/src/objects/js-list-format-inl.h
index 554b3488b6..0f1395719e 100644
--- a/deps/v8/src/objects/js-list-format-inl.h
+++ b/deps/v8/src/objects/js-list-format-inl.h
@@ -20,7 +20,8 @@ namespace internal {
 
 // Base list format accessors.
 ACCESSORS(JSListFormat, locale, String, kLocaleOffset)
-ACCESSORS(JSListFormat, formatter, Foreign, kFormatterOffset)
+ACCESSORS(JSListFormat, icu_formatter, Managed<icu::ListFormatter>,
+          kICUFormatterOffset)
 SMI_ACCESSORS(JSListFormat, flags, kFlagsOffset)
 
 inline void JSListFormat::set_style(Style style) {
diff --git a/deps/v8/src/objects/js-list-format.cc b/deps/v8/src/objects/js-list-format.cc
index 66dbe0bfd9..d2713d489f 100644
--- a/deps/v8/src/objects/js-list-format.cc
+++ b/deps/v8/src/objects/js-list-format.cc
@@ -119,7 +119,7 @@ JSListFormat::Type get_type(const char* str) {
   UNREACHABLE();
 }
 
-MaybeHandle<JSListFormat> JSListFormat::InitializeListFormat(
+MaybeHandle<JSListFormat> JSListFormat::Initialize(
     Isolate* isolate, Handle<JSListFormat> list_format_holder,
     Handle<Object> input_locales, Handle<Object> input_options) {
   Factory* factory = isolate->factory();
@@ -199,7 +199,7 @@ MaybeHandle<JSListFormat> JSListFormat::InitializeListFormat(
   Handle<Managed<icu::ListFormatter>> managed_formatter =
       Managed<icu::ListFormatter>::FromRawPtr(isolate, 0, formatter);
 
-  list_format_holder->set_formatter(*managed_formatter);
+  list_format_holder->set_icu_formatter(*managed_formatter);
   return list_format_holder;
 }
 
@@ -217,11 +217,6 @@ Handle<JSObject> JSListFormat::ResolvedOptions(
   return result;
 }
 
-icu::ListFormatter* JSListFormat::UnpackFormatter(Isolate* isolate,
-                                                  Handle<JSListFormat> holder) {
-  return Managed<icu::ListFormatter>::cast(holder->formatter())->raw();
-}
-
 Handle<String> JSListFormat::StyleAsString() const {
   switch (style()) {
     case Style::LONG:
@@ -352,8 +347,7 @@ Maybe<bool> FormatListCommon(Isolate* isolate,
                              std::unique_ptr<icu::UnicodeString[]>& array) {
   DCHECK(!list->IsUndefined());
 
-  icu::ListFormatter* formatter =
-      JSListFormat::UnpackFormatter(isolate, format_holder);
+  icu::ListFormatter* formatter = format_holder->icu_formatter()->raw();
   CHECK_NOT_NULL(formatter);
 
   *length = list->GetElementsAccessor()->NumberOfElements(*list);
diff --git a/deps/v8/src/objects/js-list-format.h b/deps/v8/src/objects/js-list-format.h
index 22f8d20005..e9bfec7cc8 100644
--- a/deps/v8/src/objects/js-list-format.h
+++ b/deps/v8/src/objects/js-list-format.h
@@ -12,6 +12,7 @@
 #include "src/heap/factory.h"
 #include "src/isolate.h"
 #include "src/objects.h"
+#include "src/objects/managed.h"
 #include "unicode/uversion.h"
 
 // Has to be the last include (doesn't have include guards):
@@ -28,17 +29,13 @@ class JSListFormat : public JSObject {
  public:
   // Initializes relative time format object with properties derived from input
   // locales and options.
-  static MaybeHandle<JSListFormat> InitializeListFormat(
+  static MaybeHandle<JSListFormat> Initialize(
       Isolate* isolate, Handle<JSListFormat> list_format_holder,
       Handle<Object> locales, Handle<Object> options);
 
   static Handle<JSObject> ResolvedOptions(Isolate* isolate,
                                           Handle<JSListFormat> format_holder);
 
-  // Unpacks formatter object from corresponding JavaScript object.
-  static icu::ListFormatter* UnpackFormatter(
-      Isolate* isolate, Handle<JSListFormat> list_format_holder);
-
   // ecma402 #sec-formatlist
   V8_WARN_UNUSED_RESULT static MaybeHandle<String> FormatList(
       Isolate* isolate, Handle<JSListFormat> format_holder,
@@ -56,7 +53,7 @@ class JSListFormat : public JSObject {
 
   // ListFormat accessors.
   DECL_ACCESSORS(locale, String)
-  DECL_ACCESSORS(formatter, Foreign)
+  DECL_ACCESSORS(icu_formatter, Managed<icu::ListFormatter>)
 
   // Style: identifying the relative time format style used.
   //
@@ -105,8 +102,8 @@ class JSListFormat : public JSObject {
   // Layout description.
   static const int kJSListFormatOffset = JSObject::kHeaderSize;
   static const int kLocaleOffset = kJSListFormatOffset + kPointerSize;
-  static const int kFormatterOffset = kLocaleOffset + kPointerSize;
-  static const int kFlagsOffset = kFormatterOffset + kPointerSize;
+  static const int kICUFormatterOffset = kLocaleOffset + kPointerSize;
+  static const int kFlagsOffset = kICUFormatterOffset + kPointerSize;
   static const int kSize = kFlagsOffset + kPointerSize;
 
  private:
diff --git a/deps/v8/src/objects/js-locale-inl.h b/deps/v8/src/objects/js-locale-inl.h
index a70bef998e..ac0a7a914f 100644
--- a/deps/v8/src/objects/js-locale-inl.h
+++ b/deps/v8/src/objects/js-locale-inl.h
@@ -28,14 +28,45 @@ ACCESSORS(JSLocale, locale, String, kLocaleOffset);
 
 // Unicode extension accessors.
 ACCESSORS(JSLocale, calendar, Object, kCalendarOffset);
-ACCESSORS(JSLocale, case_first, Object, kCaseFirstOffset);
 ACCESSORS(JSLocale, collation, Object, kCollationOffset);
-ACCESSORS(JSLocale, hour_cycle, Object, kHourCycleOffset);
-ACCESSORS(JSLocale, numeric, Object, kNumericOffset);
 ACCESSORS(JSLocale, numbering_system, Object, kNumberingSystemOffset);
+SMI_ACCESSORS(JSLocale, flags, kFlagsOffset)
 
 CAST_ACCESSOR(JSLocale);
 
+inline void JSLocale::set_case_first(CaseFirst case_first) {
+  DCHECK_GT(CaseFirst::COUNT, case_first);
+  int hints = flags();
+  hints = CaseFirstBits::update(hints, case_first);
+  set_flags(hints);
+}
+
+inline JSLocale::CaseFirst JSLocale::case_first() const {
+  return CaseFirstBits::decode(flags());
+}
+
+inline void JSLocale::set_hour_cycle(HourCycle hour_cycle) {
+  DCHECK_GT(HourCycle::COUNT, hour_cycle);
+  int hints = flags();
+  hints = HourCycleBits::update(hints, hour_cycle);
+  set_flags(hints);
+}
+
+inline JSLocale::HourCycle JSLocale::hour_cycle() const {
+  return HourCycleBits::decode(flags());
+}
+
+inline void JSLocale::set_numeric(Numeric numeric) {
+  DCHECK_GT(Numeric::COUNT, numeric);
+  int hints = flags();
+  hints = NumericBits::update(hints, numeric);
+  set_flags(hints);
+}
+
+inline JSLocale::Numeric JSLocale::numeric() const {
+  return NumericBits::decode(flags());
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/js-locale.cc b/deps/v8/src/objects/js-locale.cc
index 8968aa58c9..78fb30fa41 100644
--- a/deps/v8/src/objects/js-locale.cc
+++ b/deps/v8/src/objects/js-locale.cc
@@ -35,6 +35,26 @@ namespace internal {
 
 namespace {
 
+JSLocale::CaseFirst GetCaseFirst(const char* str) {
+  if (strcmp(str, "upper") == 0) return JSLocale::CaseFirst::UPPER;
+  if (strcmp(str, "lower") == 0) return JSLocale::CaseFirst::LOWER;
+  if (strcmp(str, "false") == 0) return JSLocale::CaseFirst::FALSE_VALUE;
+  UNREACHABLE();
+}
+
+JSLocale::HourCycle GetHourCycle(const char* str) {
+  if (strcmp(str, "h11") == 0) return JSLocale::HourCycle::H11;
+  if (strcmp(str, "h12") == 0) return JSLocale::HourCycle::H12;
+  if (strcmp(str, "h23") == 0) return JSLocale::HourCycle::H23;
+  if (strcmp(str, "h24") == 0) return JSLocale::HourCycle::H24;
+  UNREACHABLE();
+}
+
+JSLocale::Numeric GetNumeric(const char* str) {
+  return strcmp(str, "true") == 0 ? JSLocale::Numeric::TRUE_VALUE
+                                  : JSLocale::Numeric::FALSE_VALUE;
+}
+
 struct OptionData {
   const char* name;
   const char* key;
@@ -49,12 +69,12 @@ Maybe<bool> InsertOptionsIntoLocale(Isolate* isolate,
   CHECK(isolate);
   CHECK(icu_locale);
 
-  static std::vector<const char*> hour_cycle_values = {"h11", "h12", "h23",
-                                                       "h24"};
-  static std::vector<const char*> case_first_values = {"upper", "lower",
-                                                       "false"};
-  static std::vector<const char*> empty_values = {};
-  static const std::array<OptionData, 6> kOptionToUnicodeTagMap = {
+  const std::vector<const char*> hour_cycle_values = {"h11", "h12", "h23",
+                                                      "h24"};
+  const std::vector<const char*> case_first_values = {"upper", "lower",
+                                                      "false"};
+  const std::vector<const char*> empty_values = {};
+  const std::array<OptionData, 6> kOptionToUnicodeTagMap = {
       {{"calendar", "ca", &empty_values, false},
        {"collation", "co", &empty_values, false},
        {"hourCycle", "hc", &hour_cycle_values, false},
@@ -75,7 +95,7 @@ Maybe<bool> InsertOptionsIntoLocale(Isolate* isolate,
             : Intl::GetStringOption(isolate, options, option_to_bcp47.name,
                                     *(option_to_bcp47.possible_values),
                                     "locale", &value_str);
-    if (maybe_found.IsNothing()) return maybe_found;
+    MAYBE_RETURN(maybe_found, Nothing<bool>());
 
     // TODO(cira): Use fallback value if value is not found to make
     // this spec compliant.
@@ -138,19 +158,23 @@ bool PopulateLocaleWithUnicodeTags(Isolate* isolate, const char* icu_locale,
     if (bcp47_key) {
       const char* bcp47_value = uloc_toUnicodeLocaleType(bcp47_key, value);
       if (bcp47_value) {
-          Handle<String> bcp47_handle =
-              factory->NewStringFromAsciiChecked(bcp47_value);
           if (strcmp(bcp47_key, "kn") == 0) {
-            locale_holder->set_numeric(*bcp47_handle);
+            locale_holder->set_numeric(GetNumeric(bcp47_value));
           } else if (strcmp(bcp47_key, "ca") == 0) {
+            Handle<String> bcp47_handle =
+                factory->NewStringFromAsciiChecked(bcp47_value);
             locale_holder->set_calendar(*bcp47_handle);
           } else if (strcmp(bcp47_key, "kf") == 0) {
-            locale_holder->set_case_first(*bcp47_handle);
+            locale_holder->set_case_first(GetCaseFirst(bcp47_value));
           } else if (strcmp(bcp47_key, "co") == 0) {
+            Handle<String> bcp47_handle =
+                factory->NewStringFromAsciiChecked(bcp47_value);
             locale_holder->set_collation(*bcp47_handle);
           } else if (strcmp(bcp47_key, "hc") == 0) {
-            locale_holder->set_hour_cycle(*bcp47_handle);
+            locale_holder->set_hour_cycle(GetHourCycle(bcp47_value));
           } else if (strcmp(bcp47_key, "nu") == 0) {
+            Handle<String> bcp47_handle =
+                factory->NewStringFromAsciiChecked(bcp47_value);
             locale_holder->set_numbering_system(*bcp47_handle);
           }
       }
@@ -163,17 +187,17 @@ bool PopulateLocaleWithUnicodeTags(Isolate* isolate, const char* icu_locale,
 }
 }  // namespace
 
-MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
-                                                 Handle<JSLocale> locale_holder,
-                                                 Handle<String> locale,
-                                                 Handle<JSReceiver> options) {
+MaybeHandle<JSLocale> JSLocale::Initialize(Isolate* isolate,
+                                           Handle<JSLocale> locale_holder,
+                                           Handle<String> locale,
+                                           Handle<JSReceiver> options) {
+  locale_holder->set_flags(0);
   static const char* const kMethod = "Intl.Locale";
   v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
   UErrorCode status = U_ZERO_ERROR;
 
   // Get ICU locale format, and canonicalize it.
   char icu_result[ULOC_FULLNAME_CAPACITY];
-  char icu_canonical[ULOC_FULLNAME_CAPACITY];
 
   if (locale->length() == 0) {
     THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kLocaleNotEmpty),
@@ -184,18 +208,20 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
   CHECK_LT(0, bcp47_locale.length());
   CHECK_NOT_NULL(*bcp47_locale);
 
-  int icu_length = uloc_forLanguageTag(
-      *bcp47_locale, icu_result, ULOC_FULLNAME_CAPACITY, nullptr, &status);
+  int parsed_length = 0;
+  int icu_length =
+      uloc_forLanguageTag(*bcp47_locale, icu_result, ULOC_FULLNAME_CAPACITY,
+                          &parsed_length, &status);
 
-  if (U_FAILURE(status) || status == U_STRING_NOT_TERMINATED_WARNING ||
-      icu_length == 0) {
+  if (U_FAILURE(status) ||
+      parsed_length < static_cast<int>(bcp47_locale.length()) ||
+      status == U_STRING_NOT_TERMINATED_WARNING || icu_length == 0) {
     THROW_NEW_ERROR(
         isolate,
         NewRangeError(MessageTemplate::kLocaleBadParameters,
                       isolate->factory()->NewStringFromAsciiChecked(kMethod),
                       locale_holder),
         JSLocale);
-    return MaybeHandle<JSLocale>();
   }
 
   Maybe<bool> error = InsertOptionsIntoLocale(isolate, options, icu_result);
@@ -207,40 +233,26 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
                       isolate->factory()->NewStringFromAsciiChecked(kMethod),
                       locale_holder),
         JSLocale);
-    return MaybeHandle<JSLocale>();
-  }
-  DCHECK(error.FromJust());
-
-  uloc_canonicalize(icu_result, icu_canonical, ULOC_FULLNAME_CAPACITY, &status);
-  if (U_FAILURE(status) || status == U_STRING_NOT_TERMINATED_WARNING) {
-    THROW_NEW_ERROR(
-        isolate,
-        NewRangeError(MessageTemplate::kLocaleBadParameters,
-                      isolate->factory()->NewStringFromAsciiChecked(kMethod),
-                      locale_holder),
-        JSLocale);
-    return MaybeHandle<JSLocale>();
   }
 
-  if (!PopulateLocaleWithUnicodeTags(isolate, icu_canonical, locale_holder)) {
+  if (!PopulateLocaleWithUnicodeTags(isolate, icu_result, locale_holder)) {
     THROW_NEW_ERROR(
         isolate,
         NewRangeError(MessageTemplate::kLocaleBadParameters,
                       isolate->factory()->NewStringFromAsciiChecked(kMethod),
                       locale_holder),
         JSLocale);
-    return MaybeHandle<JSLocale>();
   }
 
   // Extract language, script and region parts.
   char icu_language[ULOC_LANG_CAPACITY];
-  uloc_getLanguage(icu_canonical, icu_language, ULOC_LANG_CAPACITY, &status);
+  uloc_getLanguage(icu_result, icu_language, ULOC_LANG_CAPACITY, &status);
 
   char icu_script[ULOC_SCRIPT_CAPACITY];
-  uloc_getScript(icu_canonical, icu_script, ULOC_SCRIPT_CAPACITY, &status);
+  uloc_getScript(icu_result, icu_script, ULOC_SCRIPT_CAPACITY, &status);
 
   char icu_region[ULOC_COUNTRY_CAPACITY];
-  uloc_getCountry(icu_canonical, icu_region, ULOC_COUNTRY_CAPACITY, &status);
+  uloc_getCountry(icu_result, icu_region, ULOC_COUNTRY_CAPACITY, &status);
 
   if (U_FAILURE(status) || status == U_STRING_NOT_TERMINATED_WARNING) {
     THROW_NEW_ERROR(
@@ -249,7 +261,6 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
                       isolate->factory()->NewStringFromAsciiChecked(kMethod),
                       locale_holder),
         JSLocale);
-    return MaybeHandle<JSLocale>();
   }
 
   Factory* factory = isolate->factory();
@@ -271,8 +282,7 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
   }
 
   char icu_base_name[ULOC_FULLNAME_CAPACITY];
-  uloc_getBaseName(icu_canonical, icu_base_name, ULOC_FULLNAME_CAPACITY,
-                   &status);
+  uloc_getBaseName(icu_result, icu_base_name, ULOC_FULLNAME_CAPACITY, &status);
   // We need to convert it back to BCP47.
   char bcp47_result[ULOC_FULLNAME_CAPACITY];
   uloc_toLanguageTag(icu_base_name, bcp47_result, ULOC_FULLNAME_CAPACITY, true,
@@ -284,13 +294,12 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
                       isolate->factory()->NewStringFromAsciiChecked(kMethod),
                       locale_holder),
         JSLocale);
-    return MaybeHandle<JSLocale>();
   }
   Handle<String> base_name = factory->NewStringFromAsciiChecked(bcp47_result);
   locale_holder->set_base_name(*base_name);
 
   // Produce final representation of the locale string, for toString().
-  uloc_toLanguageTag(icu_canonical, bcp47_result, ULOC_FULLNAME_CAPACITY, true,
+  uloc_toLanguageTag(icu_result, bcp47_result, ULOC_FULLNAME_CAPACITY, true,
                      &status);
   if (U_FAILURE(status) || status == U_STRING_NOT_TERMINATED_WARNING) {
     THROW_NEW_ERROR(
@@ -299,7 +308,6 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
                       isolate->factory()->NewStringFromAsciiChecked(kMethod),
                       locale_holder),
         JSLocale);
-    return MaybeHandle<JSLocale>();
   }
   Handle<String> locale_handle =
       factory->NewStringFromAsciiChecked(bcp47_result);
@@ -310,20 +318,37 @@ MaybeHandle<JSLocale> JSLocale::InitializeLocale(Isolate* isolate,
 
 namespace {
 
-Handle<String> MorphLocale(Isolate* isolate, String* input,
+Handle<String> MorphLocale(Isolate* isolate, String* language_tag,
                            int32_t (*morph_func)(const char*, char*, int32_t,
                                                  UErrorCode*)) {
   Factory* factory = isolate->factory();
   char localeBuffer[ULOC_FULLNAME_CAPACITY];
+  char morphBuffer[ULOC_FULLNAME_CAPACITY];
+
   UErrorCode status = U_ZERO_ERROR;
+  // Convert from language id to locale.
+  int32_t parsed_length;
+  int32_t length =
+      uloc_forLanguageTag(language_tag->ToCString().get(), localeBuffer,
+                          ULOC_FULLNAME_CAPACITY, &parsed_length, &status);
+  CHECK(parsed_length == language_tag->length());
+  DCHECK(U_SUCCESS(status));
+  DCHECK_GT(length, 0);
   DCHECK_NOT_NULL(morph_func);
-  int32_t length = (*morph_func)(input->ToCString().get(), localeBuffer,
-                                 ULOC_FULLNAME_CAPACITY, &status);
+  // Add the likely subtags or Minimize the subtags on the locale id
+  length =
+      (*morph_func)(localeBuffer, morphBuffer, ULOC_FULLNAME_CAPACITY, &status);
+  DCHECK(U_SUCCESS(status));
+  DCHECK_GT(length, 0);
+  // Returns a well-formed language tag
+  length = uloc_toLanguageTag(morphBuffer, localeBuffer, ULOC_FULLNAME_CAPACITY,
+                              false, &status);
   DCHECK(U_SUCCESS(status));
   DCHECK_GT(length, 0);
-  std::string locale(localeBuffer, length);
-  std::replace(locale.begin(), locale.end(), '_', '-');
-  return factory->NewStringFromAsciiChecked(locale.c_str());
+  std::string lang(localeBuffer, length);
+  std::replace(lang.begin(), lang.end(), '_', '-');
+
+  return factory->NewStringFromAsciiChecked(lang.c_str());
 }
 
 }  // namespace
@@ -336,5 +361,46 @@ Handle<String> JSLocale::Minimize(Isolate* isolate, String* locale) {
   return MorphLocale(isolate, locale, uloc_minimizeSubtags);
 }
 
+Handle<String> JSLocale::CaseFirstAsString() const {
+  switch (case_first()) {
+    case CaseFirst::UPPER:
+      return GetReadOnlyRoots().upper_string_handle();
+    case CaseFirst::LOWER:
+      return GetReadOnlyRoots().lower_string_handle();
+    case CaseFirst::FALSE_VALUE:
+      return GetReadOnlyRoots().false_string_handle();
+    case CaseFirst::COUNT:
+      UNREACHABLE();
+  }
+}
+
+Handle<String> JSLocale::HourCycleAsString() const {
+  switch (hour_cycle()) {
+    case HourCycle::H11:
+      return GetReadOnlyRoots().h11_string_handle();
+    case HourCycle::H12:
+      return GetReadOnlyRoots().h12_string_handle();
+    case HourCycle::H23:
+      return GetReadOnlyRoots().h23_string_handle();
+    case HourCycle::H24:
+      return GetReadOnlyRoots().h24_string_handle();
+    case HourCycle::COUNT:
+      UNREACHABLE();
+  }
+}
+
+Handle<String> JSLocale::NumericAsString() const {
+  switch (numeric()) {
+    case Numeric::NOTSET:
+      return GetReadOnlyRoots().undefined_string_handle();
+    case Numeric::TRUE_VALUE:
+      return GetReadOnlyRoots().true_string_handle();
+    case Numeric::FALSE_VALUE:
+      return GetReadOnlyRoots().false_string_handle();
+    case Numeric::COUNT:
+      UNREACHABLE();
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/objects/js-locale.h b/deps/v8/src/objects/js-locale.h
index d111885d52..f42a4cdaee 100644
--- a/deps/v8/src/objects/js-locale.h
+++ b/deps/v8/src/objects/js-locale.h
@@ -25,13 +25,17 @@ class JSLocale : public JSObject {
  public:
   // Initializes locale object with properties derived from input locale string
   // and options.
-  static MaybeHandle<JSLocale> InitializeLocale(Isolate* isolate,
-                                                Handle<JSLocale> locale_holder,
-                                                Handle<String> locale,
-                                                Handle<JSReceiver> options);
+  static MaybeHandle<JSLocale> Initialize(Isolate* isolate,
+                                          Handle<JSLocale> locale_holder,
+                                          Handle<String> locale,
+                                          Handle<JSReceiver> options);
   static Handle<String> Maximize(Isolate* isolate, String* locale);
   static Handle<String> Minimize(Isolate* isolate, String* locale);
 
+  Handle<String> CaseFirstAsString() const;
+  Handle<String> NumericAsString() const;
+  Handle<String> HourCycleAsString() const;
+
   DECL_CAST(JSLocale)
 
   // Locale accessors.
@@ -43,12 +47,64 @@ class JSLocale : public JSObject {
 
   // Unicode extension accessors.
   DECL_ACCESSORS(calendar, Object)
-  DECL_ACCESSORS(case_first, Object)
   DECL_ACCESSORS(collation, Object)
-  DECL_ACCESSORS(hour_cycle, Object)
-  DECL_ACCESSORS(numeric, Object)
   DECL_ACCESSORS(numbering_system, Object)
 
+  // CaseFirst: "kf"
+  //
+  // ecma402 #sec-Intl.Locale.prototype.caseFirst
+  enum class CaseFirst {
+    UPPER,  // upper case sorts before lower case
+    LOWER,  // lower case sorts before upper case
+    // (compiler does not like FALSE so we have to name it FALSE_VALUE)
+    FALSE_VALUE,  // Turn the feature off
+    COUNT
+  };
+  inline void set_case_first(CaseFirst case_first);
+  inline CaseFirst case_first() const;
+
+  // Numeric: 'kn"
+  //
+  // ecma402 #sec-Intl.Locale.prototype.numeric
+  enum class Numeric { NOTSET, TRUE_VALUE, FALSE_VALUE, COUNT };
+  inline void set_numeric(Numeric numeric);
+  inline Numeric numeric() const;
+
+  // CaseFirst: "hc"
+  //
+  // ecma402 #sec-Intl.Locale.prototype.hourCycle
+  enum class HourCycle {
+    H11,  // 12-hour format start with hour 0 and go up to 11.
+    H12,  // 12-hour format start with hour 1 and go up to 12.
+    H23,  // 24-hour format start with hour 0 and go up to 23.
+    H24,  // 24-hour format start with hour 1 and go up to 24.
+    COUNT
+  };
+  inline void set_hour_cycle(HourCycle hour_cycle);
+  inline HourCycle hour_cycle() const;
+
+// Bit positions in |flags|.
+#define FLAGS_BIT_FIELDS(V, _)      \
+  V(CaseFirstBits, CaseFirst, 2, _) \
+  V(NumericBits, Numeric, 2, _)     \
+  V(HourCycleBits, HourCycle, 2, _)
+  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
+#undef FLAGS_BIT_FIELDS
+
+  STATIC_ASSERT(CaseFirst::UPPER <= CaseFirstBits::kMax);
+  STATIC_ASSERT(CaseFirst::LOWER <= CaseFirstBits::kMax);
+  STATIC_ASSERT(CaseFirst::FALSE_VALUE <= CaseFirstBits::kMax);
+  STATIC_ASSERT(Numeric::NOTSET <= NumericBits::kMax);
+  STATIC_ASSERT(Numeric::FALSE_VALUE <= NumericBits::kMax);
+  STATIC_ASSERT(Numeric::TRUE_VALUE <= NumericBits::kMax);
+  STATIC_ASSERT(HourCycle::H11 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::H12 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::H23 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::H24 <= HourCycleBits::kMax);
+
+  // [flags] Bit field containing various flags about the function.
+  DECL_INT_ACCESSORS(flags)
+
   DECL_PRINTER(JSLocale)
   DECL_VERIFIER(JSLocale)
 
@@ -61,12 +117,10 @@ class JSLocale : public JSObject {
   static const int kBaseNameOffset = kRegionOffset + kPointerSize;
   static const int kLocaleOffset = kBaseNameOffset + kPointerSize;
   // Unicode extension fields.
-  static const int kCalendarOffset = kLocaleOffset + kPointerSize;
-  static const int kCaseFirstOffset = kCalendarOffset + kPointerSize;
-  static const int kCollationOffset = kCaseFirstOffset + kPointerSize;
-  static const int kHourCycleOffset = kCollationOffset + kPointerSize;
-  static const int kNumericOffset = kHourCycleOffset + kPointerSize;
-  static const int kNumberingSystemOffset = kNumericOffset + kPointerSize;
+  static const int kFlagsOffset = kLocaleOffset + kPointerSize;
+  static const int kCalendarOffset = kFlagsOffset + kPointerSize;
+  static const int kCollationOffset = kCalendarOffset + kPointerSize;
+  static const int kNumberingSystemOffset = kCollationOffset + kPointerSize;
   // Final size.
   static const int kSize = kNumberingSystemOffset + kPointerSize;
 
diff --git a/deps/v8/src/objects/js-number-format-inl.h b/deps/v8/src/objects/js-number-format-inl.h
new file mode 100644
index 0000000000..880ef9344f
--- /dev/null
+++ b/deps/v8/src/objects/js-number-format-inl.h
@@ -0,0 +1,58 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_NUMBER_FORMAT_INL_H_
+#define V8_OBJECTS_JS_NUMBER_FORMAT_INL_H_
+
+#include "src/objects-inl.h"
+#include "src/objects/js-number-format.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+ACCESSORS(JSNumberFormat, locale, String, kLocaleOffset)
+ACCESSORS(JSNumberFormat, icu_number_format, Managed<icu::NumberFormat>,
+          kICUNumberFormatOffset)
+ACCESSORS(JSNumberFormat, bound_format, Object, kBoundFormatOffset)
+SMI_ACCESSORS(JSNumberFormat, flags, kFlagsOffset)
+
+inline void JSNumberFormat::set_style(Style style) {
+  DCHECK_LT(style, Style::COUNT);
+  int hints = flags();
+  hints = StyleBits::update(hints, style);
+  set_flags(hints);
+}
+
+inline JSNumberFormat::Style JSNumberFormat::style() const {
+  return StyleBits::decode(flags());
+}
+
+inline void JSNumberFormat::set_currency_display(
+    CurrencyDisplay currency_display) {
+  DCHECK_LT(currency_display, CurrencyDisplay::COUNT);
+  int hints = flags();
+  hints = CurrencyDisplayBits::update(hints, currency_display);
+  set_flags(hints);
+}
+
+inline JSNumberFormat::CurrencyDisplay JSNumberFormat::currency_display()
+    const {
+  return CurrencyDisplayBits::decode(flags());
+}
+
+CAST_ACCESSOR(JSNumberFormat);
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_NUMBER_FORMAT_INL_H_
diff --git a/deps/v8/src/objects/js-number-format.cc b/deps/v8/src/objects/js-number-format.cc
new file mode 100644
index 0000000000..9fe7c30a9d
--- /dev/null
+++ b/deps/v8/src/objects/js-number-format.cc
@@ -0,0 +1,709 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#include "src/objects/js-number-format.h"
+
+#include <set>
+#include <string>
+
+#include "src/isolate.h"
+#include "src/objects-inl.h"
+#include "src/objects/intl-objects.h"
+#include "src/objects/js-number-format-inl.h"
+#include "unicode/decimfmt.h"
+#include "unicode/locid.h"
+#include "unicode/numfmt.h"
+#include "unicode/strenum.h"
+#include "unicode/ucurr.h"
+#include "unicode/uloc.h"
+
+namespace v8 {
+namespace internal {
+
+namespace {
+
+// ecma-402/#sec-currencydigits
+// The currency is expected to an all upper case string value.
+int CurrencyDigits(const icu::UnicodeString& currency) {
+  UErrorCode status = U_ZERO_ERROR;
+  uint32_t fraction_digits = ucurr_getDefaultFractionDigits(
+      reinterpret_cast<const UChar*>(currency.getBuffer()), &status);
+  // For missing currency codes, default to the most common, 2
+  return U_SUCCESS(status) ? fraction_digits : 2;
+}
+
+bool IsAToZ(char ch) { return IsInRange(AsciiAlphaToLower(ch), 'a', 'z'); }
+
+// ecma402/#sec-iswellformedcurrencycode
+bool IsWellFormedCurrencyCode(const std::string& currency) {
+  // Verifies that the input is a well-formed ISO 4217 currency code.
+  // ecma402/#sec-currency-codes
+  // 2. If the number of elements in normalized is not 3, return false.
+  if (currency.length() != 3) return false;
+  // 1. Let normalized be the result of mapping currency to upper case as
+  //   described in 6.1.
+  //
+  // 3. If normalized contains any character that is not in
+  // the range "A" to "Z" (U+0041 to U+005A), return false.
+  //
+  // 4. Return true.
+  // Don't uppercase to test. It could convert invalid code into a valid one.
+  // For example \u00DFP (Eszett+P) becomes SSP.
+  return (IsAToZ(currency[0]) && IsAToZ(currency[1]) && IsAToZ(currency[2]));
+}
+
+}  // anonymous namespace
+
+// static
+Handle<JSObject> JSNumberFormat::ResolvedOptions(
+    Isolate* isolate, Handle<JSNumberFormat> number_format_holder) {
+  Factory* factory = isolate->factory();
+  Handle<JSObject> options = factory->NewJSObject(isolate->object_function());
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, options, factory->style_string(),
+            number_format_holder->StyleAsString(), kDontThrow)
+            .FromJust());
+
+  icu::NumberFormat* number_format =
+      number_format_holder->icu_number_format()->raw();
+  CHECK_NOT_NULL(number_format);
+  icu::DecimalFormat* decimal_format =
+      static_cast<icu::DecimalFormat*>(number_format);
+  CHECK_NOT_NULL(decimal_format);
+
+  Handle<String> locale =
+      Handle<String>(number_format_holder->locale(), isolate);
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, options, factory->locale_string(), locale, kDontThrow)
+            .FromJust());
+  UErrorCode error = U_ZERO_ERROR;
+  icu::Locale icu_locale = number_format->getLocale(ULOC_VALID_LOCALE, error);
+  DCHECK(U_SUCCESS(error));
+
+  std::string numbering_system = Intl::GetNumberingSystem(icu_locale);
+  if (!numbering_system.empty()) {
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->numberingSystem_string(),
+              factory->NewStringFromAsciiChecked(numbering_system.c_str()),
+              kDontThrow)
+              .FromJust());
+  }
+
+  if (number_format_holder->style() == Style::CURRENCY) {
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->currencyDisplay_string(),
+              number_format_holder->CurrencyDisplayAsString(), kDontThrow)
+              .FromJust());
+    icu::UnicodeString currency(number_format->getCurrency());
+    DCHECK(!currency.isEmpty());
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->currency_string(),
+              factory
+                  ->NewStringFromTwoByte(Vector<const uint16_t>(
+                      reinterpret_cast<const uint16_t*>(currency.getBuffer()),
+                      currency.length()))
+                  .ToHandleChecked(),
+              kDontThrow)
+              .FromJust());
+  }
+
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, options, factory->minimumIntegerDigits_string(),
+            factory->NewNumberFromInt(number_format->getMinimumIntegerDigits()),
+            kDontThrow)
+            .FromJust());
+  CHECK(
+      JSReceiver::CreateDataProperty(
+          isolate, options, factory->minimumFractionDigits_string(),
+          factory->NewNumberFromInt(number_format->getMinimumFractionDigits()),
+          kDontThrow)
+          .FromJust());
+  CHECK(
+      JSReceiver::CreateDataProperty(
+          isolate, options, factory->maximumFractionDigits_string(),
+          factory->NewNumberFromInt(number_format->getMaximumFractionDigits()),
+          kDontThrow)
+          .FromJust());
+  if (decimal_format->areSignificantDigitsUsed()) {
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->minimumSignificantDigits_string(),
+              factory->NewNumberFromInt(
+                  decimal_format->getMinimumSignificantDigits()),
+              kDontThrow)
+              .FromJust());
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->maximumSignificantDigits_string(),
+              factory->NewNumberFromInt(
+                  decimal_format->getMaximumSignificantDigits()),
+              kDontThrow)
+              .FromJust());
+  }
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, options, factory->useGrouping_string(),
+            factory->ToBoolean((number_format->isGroupingUsed() == TRUE)),
+            kDontThrow)
+            .FromJust());
+
+  return options;
+}
+
+// ecma402/#sec-unwrapnumberformat
+MaybeHandle<JSNumberFormat> JSNumberFormat::UnwrapNumberFormat(
+    Isolate* isolate, Handle<JSReceiver> format_holder) {
+  // old code copy from NumberFormat::Unwrap that has no spec comment and
+  // compiled but fail unit tests.
+  Handle<Context> native_context =
+      Handle<Context>(isolate->context()->native_context(), isolate);
+  Handle<JSFunction> constructor = Handle<JSFunction>(
+      JSFunction::cast(native_context->intl_number_format_function()), isolate);
+  Handle<Object> object;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, object,
+      Intl::LegacyUnwrapReceiver(isolate, format_holder, constructor,
+                                 format_holder->IsJSNumberFormat()),
+      JSNumberFormat);
+  // 4. If ... or nf does not have an [[InitializedNumberFormat]] internal slot,
+  // then
+  if (!object->IsJSNumberFormat()) {
+    // a. Throw a TypeError exception.
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
+                                 isolate->factory()->NewStringFromAsciiChecked(
+                                     "UnwrapNumberFormat")),
+                    JSNumberFormat);
+  }
+  // 5. Return nf.
+  return Handle<JSNumberFormat>::cast(object);
+}
+
+// static
+MaybeHandle<JSNumberFormat> JSNumberFormat::Initialize(
+    Isolate* isolate, Handle<JSNumberFormat> number_format,
+    Handle<Object> locales, Handle<Object> options_obj) {
+  // set the flags to 0 ASAP.
+  number_format->set_flags(0);
+  Factory* factory = isolate->factory();
+  // 1. Let requestedLocales be ? CanonicalizeLocaleList(locales).
+  Handle<JSObject> requested_locales;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, requested_locales,
+                             Intl::CanonicalizeLocaleListJS(isolate, locales),
+                             JSNumberFormat);
+
+  // 2. If options is undefined, then
+  if (options_obj->IsUndefined(isolate)) {
+    // 2. a. Let options be ObjectCreate(null).
+    options_obj = isolate->factory()->NewJSObjectWithNullProto();
+  } else {
+    // 3. Else
+    // 3. a. Let options be ? ToObject(options).
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, options_obj,
+        Object::ToObject(isolate, options_obj, "Intl.NumberFormat"),
+        JSNumberFormat);
+  }
+
+  // At this point, options_obj can either be a JSObject or a JSProxy only.
+  Handle<JSReceiver> options = Handle<JSReceiver>::cast(options_obj);
+
+  // 4. Let opt be a new Record.
+  //
+  // 5. Let matcher be ? GetOption(options, "localeMatcher", "string", «
+  // "lookup", "best fit" », "best fit").
+  //
+  // 6. Set opt.[[localeMatcher]] to matcher.
+  //
+  // 7. Let localeData be %NumberFormat%.[[LocaleData]].
+  //
+  // 8. Let r be ResolveLocale(%NumberFormat%.[[AvailableLocales]],
+  // requestedLocales, opt,  %NumberFormat%.[[RelevantExtensionKeys]],
+  // localeData).
+  //
+  // 9. Set numberFormat.[[Locale]] to r.[[locale]].
+
+  Handle<JSObject> r;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, r,
+      Intl::ResolveLocale(isolate, "numberformat", requested_locales, options),
+      JSNumberFormat);
+
+  Handle<String> locale_with_extension_str =
+      isolate->factory()->NewStringFromStaticChars("localeWithExtension");
+  Handle<Object> locale_with_extension_obj =
+      JSObject::GetDataProperty(r, locale_with_extension_str);
+
+  // The locale_with_extension has to be a string. Either a user
+  // provided canonicalized string or the default locale.
+  CHECK(locale_with_extension_obj->IsString());
+  Handle<String> locale_with_extension =
+      Handle<String>::cast(locale_with_extension_obj);
+
+  icu::Locale icu_locale =
+      Intl::CreateICULocale(isolate, locale_with_extension);
+  number_format->set_locale(*locale_with_extension);
+  DCHECK(!icu_locale.isBogus());
+
+  std::set<std::string> relevant_extension_keys{"nu"};
+  std::map<std::string, std::string> extensions =
+      Intl::LookupUnicodeExtensions(icu_locale, relevant_extension_keys);
+
+  // The list that is the value of the "nu" field of any locale field of
+  // [[LocaleData]] must not include the values "native",  "traditio", or
+  // "finance".
+  //
+  // See https://tc39.github.io/ecma402/#sec-intl.numberformat-internal-slots
+  if (extensions.find("nu") != extensions.end()) {
+    const std::string value = extensions.at("nu");
+    if (value == "native" || value == "traditio" || value == "finance") {
+      // 10. Set numberFormat.[[NumberingSystem]] to r.[[nu]].
+      UErrorCode status = U_ZERO_ERROR;
+      icu_locale.setKeywordValue("nu", nullptr, status);
+      CHECK(U_SUCCESS(status));
+    }
+  }
+
+  // 11. Let dataLocale be r.[[dataLocale]].
+  //
+  // 12. Let style be ? GetOption(options, "style", "string",  « "decimal",
+  // "percent", "currency" », "decimal").
+  const char* service = "Intl.NumberFormat";
+  std::unique_ptr<char[]> style_cstr;
+  const std::vector<const char*> style_values = {"decimal", "percent",
+                                                 "currency"};
+  Maybe<bool> found_style = Intl::GetStringOption(
+      isolate, options, "style", style_values, service, &style_cstr);
+  MAYBE_RETURN(found_style, MaybeHandle<JSNumberFormat>());
+  Style style = Style::DECIMAL;
+  if (found_style.FromJust()) {
+    DCHECK_NOT_NULL(style_cstr.get());
+    if (strcmp(style_cstr.get(), "percent") == 0) {
+      style = Style::PERCENT;
+    } else if (strcmp(style_cstr.get(), "currency") == 0) {
+      style = Style::CURRENCY;
+    }
+  }
+
+  // 13. Set numberFormat.[[Style]] to style.
+  number_format->set_style(style);
+
+  // 14. Let currency be ? GetOption(options, "currency", "string", undefined,
+  // undefined).
+  std::unique_ptr<char[]> currency_cstr;
+  const std::vector<const char*> empty_values = {};
+  Maybe<bool> found_currency = Intl::GetStringOption(
+      isolate, options, "currency", empty_values, service, &currency_cstr);
+  MAYBE_RETURN(found_currency, MaybeHandle<JSNumberFormat>());
+
+  std::string currency;
+  // 15. If currency is not undefined, then
+  if (found_currency.FromJust()) {
+    DCHECK_NOT_NULL(currency_cstr.get());
+    currency = currency_cstr.get();
+    // 15. a. If the result of IsWellFormedCurrencyCode(currency) is false,
+    // throw a RangeError exception.
+    if (!IsWellFormedCurrencyCode(currency)) {
+      THROW_NEW_ERROR(
+          isolate,
+          NewRangeError(MessageTemplate::kInvalidCurrencyCode,
+                        factory->NewStringFromAsciiChecked(currency.c_str())),
+          JSNumberFormat);
+    }
+  }
+
+  // 16. If style is "currency" and currency is undefined, throw a TypeError
+  // exception.
+  if (style == Style::CURRENCY && !found_currency.FromJust()) {
+    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kCurrencyCode),
+                    JSNumberFormat);
+  }
+  // 17. If style is "currency", then
+  int c_digits = 0;
+  icu::UnicodeString currency_ustr;
+  if (style == Style::CURRENCY) {
+    // a. Let currency be the result of converting currency to upper case as
+    //    specified in 6.1
+    std::transform(currency.begin(), currency.end(), currency.begin(), toupper);
+    // c. Let cDigits be CurrencyDigits(currency).
+    currency_ustr = currency.c_str();
+    c_digits = CurrencyDigits(currency_ustr);
+  }
+
+  // 18. Let currencyDisplay be ? GetOption(options, "currencyDisplay",
+  // "string", « "code",  "symbol", "name" », "symbol").
+  std::unique_ptr<char[]> currency_display_cstr;
+  const std::vector<const char*> currency_display_values = {"code", "name",
+                                                            "symbol"};
+  Maybe<bool> found_currency_display = Intl::GetStringOption(
+      isolate, options, "currencyDisplay", currency_display_values, service,
+      &currency_display_cstr);
+  MAYBE_RETURN(found_currency_display, MaybeHandle<JSNumberFormat>());
+  CurrencyDisplay currency_display = CurrencyDisplay::SYMBOL;
+  UNumberFormatStyle format_style = UNUM_CURRENCY;
+
+  if (found_currency_display.FromJust()) {
+    DCHECK_NOT_NULL(currency_display_cstr.get());
+    if (strcmp(currency_display_cstr.get(), "code") == 0) {
+      currency_display = CurrencyDisplay::CODE;
+      format_style = UNUM_CURRENCY_ISO;
+    } else if (strcmp(currency_display_cstr.get(), "name") == 0) {
+      currency_display = CurrencyDisplay::NAME;
+      format_style = UNUM_CURRENCY_PLURAL;
+    }
+  }
+
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::NumberFormat> icu_number_format;
+  if (style == Style::DECIMAL) {
+    icu_number_format.reset(
+        icu::NumberFormat::createInstance(icu_locale, status));
+  } else if (style == Style::PERCENT) {
+    icu_number_format.reset(
+        icu::NumberFormat::createPercentInstance(icu_locale, status));
+  } else {
+    DCHECK_EQ(style, Style::CURRENCY);
+    icu_number_format.reset(
+        icu::NumberFormat::createInstance(icu_locale, format_style, status));
+  }
+
+  if (U_FAILURE(status) || icu_number_format.get() == nullptr) {
+    status = U_ZERO_ERROR;
+    // Remove extensions and try again.
+    icu::Locale no_extension_locale(icu_locale.getBaseName());
+    icu_number_format.reset(
+        icu::NumberFormat::createInstance(no_extension_locale, status));
+
+    if (U_FAILURE(status) || icu_number_format.get() == nullptr) {
+      FATAL("Failed to create ICU number_format, are ICU data files missing?");
+    }
+  }
+  DCHECK(U_SUCCESS(status));
+  CHECK_NOT_NULL(icu_number_format.get());
+  if (style == Style::CURRENCY) {
+    // 19. If style is "currency", set  numberFormat.[[CurrencyDisplay]] to
+    // currencyDisplay.
+    number_format->set_currency_display(currency_display);
+
+    // 17.b. Set numberFormat.[[Currency]] to currency.
+    if (!currency_ustr.isEmpty()) {
+      status = U_ZERO_ERROR;
+      icu_number_format->setCurrency(currency_ustr.getBuffer(), status);
+      CHECK(U_SUCCESS(status));
+    }
+  }
+
+  // 20. If style is "currency", then
+  int mnfd_default, mxfd_default;
+  if (style == Style::CURRENCY) {
+    //  a. Let mnfdDefault be cDigits.
+    //  b. Let mxfdDefault be cDigits.
+    mnfd_default = c_digits;
+    mxfd_default = c_digits;
+  } else {
+    // 21. Else,
+    // a. Let mnfdDefault be 0.
+    mnfd_default = 0;
+    // b. If style is "percent", then
+    if (style == Style::PERCENT) {
+      // i. Let mxfdDefault be 0.
+      mxfd_default = 0;
+    } else {
+      // c. Else,
+      // i. Let mxfdDefault be 3.
+      mxfd_default = 3;
+    }
+  }
+  // 22. Perform ? SetNumberFormatDigitOptions(numberFormat, options,
+  // mnfdDefault, mxfdDefault).
+  icu::DecimalFormat* icu_decimal_format =
+      static_cast<icu::DecimalFormat*>(icu_number_format.get());
+  Maybe<bool> maybe_set_number_for_digit_options =
+      Intl::SetNumberFormatDigitOptions(isolate, icu_decimal_format, options,
+                                        mnfd_default, mxfd_default);
+  MAYBE_RETURN(maybe_set_number_for_digit_options, Handle<JSNumberFormat>());
+
+  // 23. Let useGrouping be ? GetOption(options, "useGrouping", "boolean",
+  // undefined, true).
+  bool use_grouping = true;
+  Maybe<bool> found_use_grouping = Intl::GetBoolOption(
+      isolate, options, "useGrouping", service, &use_grouping);
+  MAYBE_RETURN(found_use_grouping, MaybeHandle<JSNumberFormat>());
+  // 24. Set numberFormat.[[UseGrouping]] to useGrouping.
+  icu_number_format->setGroupingUsed(use_grouping ? TRUE : FALSE);
+
+  // 25. Let dataLocaleData be localeData.[[<dataLocale>]].
+  //
+  // 26. Let patterns be dataLocaleData.[[patterns]].
+  //
+  // 27. Assert: patterns is a record (see 11.3.3).
+  //
+  // 28. Let stylePatterns be patterns.[[<style>]].
+  //
+  // 29. Set numberFormat.[[PositivePattern]] to
+  // stylePatterns.[[positivePattern]].
+  //
+  // 30. Set numberFormat.[[NegativePattern]] to
+  // stylePatterns.[[negativePattern]].
+
+  Handle<Managed<icu::NumberFormat>> managed_number_format =
+      Managed<icu::NumberFormat>::FromUniquePtr(isolate, 0,
+                                                std::move(icu_number_format));
+  number_format->set_icu_number_format(*managed_number_format);
+  number_format->set_bound_format(*factory->undefined_value());
+
+  // 31. Return numberFormat.
+  return number_format;
+}
+
+Handle<String> JSNumberFormat::StyleAsString() const {
+  switch (style()) {
+    case Style::DECIMAL:
+      return GetReadOnlyRoots().decimal_string_handle();
+    case Style::PERCENT:
+      return GetReadOnlyRoots().percent_string_handle();
+    case Style::CURRENCY:
+      return GetReadOnlyRoots().currency_string_handle();
+    case Style::COUNT:
+      UNREACHABLE();
+  }
+}
+
+Handle<String> JSNumberFormat::CurrencyDisplayAsString() const {
+  switch (currency_display()) {
+    case CurrencyDisplay::CODE:
+      return GetReadOnlyRoots().code_string_handle();
+    case CurrencyDisplay::SYMBOL:
+      return GetReadOnlyRoots().symbol_string_handle();
+    case CurrencyDisplay::NAME:
+      return GetReadOnlyRoots().name_string_handle();
+    case CurrencyDisplay::COUNT:
+      UNREACHABLE();
+  }
+}
+
+MaybeHandle<String> JSNumberFormat::FormatNumber(
+    Isolate* isolate, Handle<JSNumberFormat> number_format_holder,
+    double number) {
+  icu::NumberFormat* number_format =
+      number_format_holder->icu_number_format()->raw();
+  CHECK_NOT_NULL(number_format);
+
+  icu::UnicodeString result;
+  number_format->format(number, result);
+
+  return isolate->factory()->NewStringFromTwoByte(Vector<const uint16_t>(
+      reinterpret_cast<const uint16_t*>(result.getBuffer()), result.length()));
+}
+
+namespace {
+
+bool cmp_NumberFormatSpan(const NumberFormatSpan& a,
+                          const NumberFormatSpan& b) {
+  // Regions that start earlier should be encountered earlier.
+  if (a.begin_pos < b.begin_pos) return true;
+  if (a.begin_pos > b.begin_pos) return false;
+  // For regions that start in the same place, regions that last longer should
+  // be encountered earlier.
+  if (a.end_pos < b.end_pos) return false;
+  if (a.end_pos > b.end_pos) return true;
+  // For regions that are exactly the same, one of them must be the "literal"
+  // backdrop we added, which has a field_id of -1, so consider higher field_ids
+  // to be later.
+  return a.field_id < b.field_id;
+}
+
+// The list comes from third_party/icu/source/i18n/unicode/unum.h.
+// They're mapped to NumberFormat part types mentioned throughout
+// https://tc39.github.io/ecma402/#sec-partitionnumberpattern .
+Handle<String> IcuNumberFieldIdToNumberType(int32_t field_id, double number,
+                                            Isolate* isolate) {
+  switch (static_cast<UNumberFormatFields>(field_id)) {
+    case UNUM_INTEGER_FIELD:
+      if (std::isfinite(number)) return isolate->factory()->integer_string();
+      if (std::isnan(number)) return isolate->factory()->nan_string();
+      return isolate->factory()->infinity_string();
+    case UNUM_FRACTION_FIELD:
+      return isolate->factory()->fraction_string();
+    case UNUM_DECIMAL_SEPARATOR_FIELD:
+      return isolate->factory()->decimal_string();
+    case UNUM_GROUPING_SEPARATOR_FIELD:
+      return isolate->factory()->group_string();
+    case UNUM_CURRENCY_FIELD:
+      return isolate->factory()->currency_string();
+    case UNUM_PERCENT_FIELD:
+      return isolate->factory()->percentSign_string();
+    case UNUM_SIGN_FIELD:
+      return number < 0 ? isolate->factory()->minusSign_string()
+                        : isolate->factory()->plusSign_string();
+
+    case UNUM_EXPONENT_SYMBOL_FIELD:
+    case UNUM_EXPONENT_SIGN_FIELD:
+    case UNUM_EXPONENT_FIELD:
+      // We should never get these because we're not using any scientific
+      // formatter.
+      UNREACHABLE();
+      return Handle<String>();
+
+    case UNUM_PERMILL_FIELD:
+      // We're not creating any permill formatter, and it's not even clear how
+      // that would be possible with the ICU API.
+      UNREACHABLE();
+      return Handle<String>();
+
+    default:
+      UNREACHABLE();
+      return Handle<String>();
+  }
+}
+}  // namespace
+
+// Flattens a list of possibly-overlapping "regions" to a list of
+// non-overlapping "parts". At least one of the input regions must span the
+// entire space of possible indexes. The regions parameter will sorted in-place
+// according to some criteria; this is done for performance to avoid copying the
+// input.
+std::vector<NumberFormatSpan> FlattenRegionsToParts(
+    std::vector<NumberFormatSpan>* regions) {
+  // The intention of this algorithm is that it's used to translate ICU "fields"
+  // to JavaScript "parts" of a formatted string. Each ICU field and JavaScript
+  // part has an integer field_id, which corresponds to something like "grouping
+  // separator", "fraction", or "percent sign", and has a begin and end
+  // position. Here's a diagram of:
+
+  // var nf = new Intl.NumberFormat(['de'], {style:'currency',currency:'EUR'});
+  // nf.formatToParts(123456.78);
+
+  //               :       6
+  //  input regions:    0000000211 7
+  // ('-' means -1):    ------------
+  // formatted string: "123.456,78 €"
+  // output parts:      0006000211-7
+
+  // To illustrate the requirements of this algorithm, here's a contrived and
+  // convoluted example of inputs and expected outputs:
+
+  //              :          4
+  //              :      22 33    3
+  //              :      11111   22
+  // input regions:     0000000  111
+  //              :     ------------
+  // formatted string: "abcdefghijkl"
+  // output parts:      0221340--231
+  // (The characters in the formatted string are irrelevant to this function.)
+
+  // We arrange the overlapping input regions like a mountain range where
+  // smaller regions are "on top" of larger regions, and we output a birds-eye
+  // view of the mountains, so that smaller regions take priority over larger
+  // regions.
+  std::sort(regions->begin(), regions->end(), cmp_NumberFormatSpan);
+  std::vector<size_t> overlapping_region_index_stack;
+  // At least one item in regions must be a region spanning the entire string.
+  // Due to the sorting above, the first item in the vector will be one of them.
+  overlapping_region_index_stack.push_back(0);
+  NumberFormatSpan top_region = regions->at(0);
+  size_t region_iterator = 1;
+  int32_t entire_size = top_region.end_pos;
+
+  std::vector<NumberFormatSpan> out_parts;
+
+  // The "climber" is a cursor that advances from left to right climbing "up"
+  // and "down" the mountains. Whenever the climber moves to the right, that
+  // represents an item of output.
+  int32_t climber = 0;
+  while (climber < entire_size) {
+    int32_t next_region_begin_pos;
+    if (region_iterator < regions->size()) {
+      next_region_begin_pos = regions->at(region_iterator).begin_pos;
+    } else {
+      // finish off the rest of the input by proceeding to the end.
+      next_region_begin_pos = entire_size;
+    }
+
+    if (climber < next_region_begin_pos) {
+      while (top_region.end_pos < next_region_begin_pos) {
+        if (climber < top_region.end_pos) {
+          // step down
+          out_parts.push_back(NumberFormatSpan(top_region.field_id, climber,
+                                               top_region.end_pos));
+          climber = top_region.end_pos;
+        } else {
+          // drop down
+        }
+        overlapping_region_index_stack.pop_back();
+        top_region = regions->at(overlapping_region_index_stack.back());
+      }
+      if (climber < next_region_begin_pos) {
+        // cross a plateau/mesa/valley
+        out_parts.push_back(NumberFormatSpan(top_region.field_id, climber,
+                                             next_region_begin_pos));
+        climber = next_region_begin_pos;
+      }
+    }
+    if (region_iterator < regions->size()) {
+      overlapping_region_index_stack.push_back(region_iterator++);
+      top_region = regions->at(overlapping_region_index_stack.back());
+    }
+  }
+  return out_parts;
+}
+
+MaybeHandle<JSArray> JSNumberFormat::FormatToParts(
+    Isolate* isolate, Handle<JSNumberFormat> number_format, double number) {
+  Factory* factory = isolate->factory();
+  icu::NumberFormat* fmt = number_format->icu_number_format()->raw();
+  CHECK_NOT_NULL(fmt);
+
+  icu::UnicodeString formatted;
+  icu::FieldPositionIterator fp_iter;
+  UErrorCode status = U_ZERO_ERROR;
+  fmt->format(number, formatted, &fp_iter, status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), JSArray);
+  }
+
+  Handle<JSArray> result = factory->NewJSArray(0);
+  int32_t length = formatted.length();
+  if (length == 0) return result;
+
+  std::vector<NumberFormatSpan> regions;
+  // Add a "literal" backdrop for the entire string. This will be used if no
+  // other region covers some part of the formatted string. It's possible
+  // there's another field with exactly the same begin and end as this backdrop,
+  // in which case the backdrop's field_id of -1 will give it lower priority.
+  regions.push_back(NumberFormatSpan(-1, 0, formatted.length()));
+
+  {
+    icu::FieldPosition fp;
+    while (fp_iter.next(fp)) {
+      regions.push_back(NumberFormatSpan(fp.getField(), fp.getBeginIndex(),
+                                         fp.getEndIndex()));
+    }
+  }
+
+  std::vector<NumberFormatSpan> parts = FlattenRegionsToParts(&regions);
+
+  int index = 0;
+  for (auto it = parts.begin(); it < parts.end(); it++) {
+    NumberFormatSpan part = *it;
+    Handle<String> field_type_string =
+        part.field_id == -1
+            ? isolate->factory()->literal_string()
+            : IcuNumberFieldIdToNumberType(part.field_id, number, isolate);
+    Handle<String> substring;
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, substring,
+        Intl::ToString(isolate, formatted, part.begin_pos, part.end_pos),
+        JSArray);
+    Intl::AddElement(isolate, result, index, field_type_string, substring);
+    ++index;
+  }
+  JSObject::ValidateElements(*result);
+
+  return result;
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/objects/js-number-format.h b/deps/v8/src/objects/js-number-format.h
new file mode 100644
index 0000000000..52443dc3d3
--- /dev/null
+++ b/deps/v8/src/objects/js-number-format.h
@@ -0,0 +1,135 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_NUMBER_FORMAT_H_
+#define V8_OBJECTS_JS_NUMBER_FORMAT_H_
+
+#include "src/heap/factory.h"
+#include "src/isolate.h"
+#include "src/objects.h"
+#include "src/objects/intl-objects.h"
+#include "src/objects/managed.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace U_ICU_NAMESPACE {
+class NumberFormat;
+}  //  namespace U_ICU_NAMESPACE
+
+namespace v8 {
+namespace internal {
+
+class JSNumberFormat : public JSObject {
+ public:
+  // ecma402/#sec-initializenumberformat
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSNumberFormat> Initialize(
+      Isolate* isolate, Handle<JSNumberFormat> number_format,
+      Handle<Object> locales, Handle<Object> options);
+
+  // ecma402/#sec-unwrapnumberformat
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSNumberFormat> UnwrapNumberFormat(
+      Isolate* isolate, Handle<JSReceiver> format_holder);
+
+  // ecma402/#sec-intl.numberformat.prototype.resolvedoptions
+  static Handle<JSObject> ResolvedOptions(Isolate* isolate,
+                                          Handle<JSNumberFormat> number_format);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSArray> FormatToParts(
+      Isolate* isolate, Handle<JSNumberFormat> number_format, double number);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<String> FormatNumber(
+      Isolate* isolate, Handle<JSNumberFormat> number_format, double number);
+
+  Handle<String> StyleAsString() const;
+  Handle<String> CurrencyDisplayAsString() const;
+
+  DECL_CAST(JSNumberFormat)
+  DECL_PRINTER(JSNumberFormat)
+  DECL_VERIFIER(JSNumberFormat)
+
+  // [[Style]] is one of the values "decimal", "percent" or "currency",
+  // identifying the style of the number format.
+  enum class Style {
+    DECIMAL,
+    PERCENT,
+    CURRENCY,
+
+    COUNT
+  };
+  inline void set_style(Style style);
+  inline Style style() const;
+
+  // [[CurrencyDisplay]] is one of the values "code", "symbol" or "name",
+  // identifying the display of the currency number format.
+  enum class CurrencyDisplay {
+    CODE,
+    SYMBOL,
+    NAME,
+
+    COUNT
+  };
+  inline void set_currency_display(CurrencyDisplay currency_display);
+  inline CurrencyDisplay currency_display() const;
+
+// Layout description.
+#define JS_NUMBER_FORMAT_FIELDS(V)        \
+  V(kLocaleOffset, kPointerSize)          \
+  V(kICUNumberFormatOffset, kPointerSize) \
+  V(kBoundFormatOffset, kPointerSize)     \
+  V(kFlagsOffset, kPointerSize)           \
+  /* Total size. */                       \
+  V(kSize, 0)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, JS_NUMBER_FORMAT_FIELDS)
+#undef JS_NUMBER_FORMAT_FIELDS
+
+// Bit positions in |flags|.
+#define FLAGS_BIT_FIELDS(V, _) \
+  V(StyleBits, Style, 2, _)    \
+  V(CurrencyDisplayBits, CurrencyDisplay, 2, _)
+
+  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
+#undef FLAGS_BIT_FIELDS
+
+  STATIC_ASSERT(Style::DECIMAL <= StyleBits::kMax);
+  STATIC_ASSERT(Style::PERCENT <= StyleBits::kMax);
+  STATIC_ASSERT(Style::CURRENCY <= StyleBits::kMax);
+
+  STATIC_ASSERT(CurrencyDisplay::CODE <= CurrencyDisplayBits::kMax);
+  STATIC_ASSERT(CurrencyDisplay::SYMBOL <= CurrencyDisplayBits::kMax);
+  STATIC_ASSERT(CurrencyDisplay::NAME <= CurrencyDisplayBits::kMax);
+
+  DECL_ACCESSORS(locale, String)
+  DECL_ACCESSORS(icu_number_format, Managed<icu::NumberFormat>)
+  DECL_ACCESSORS(bound_format, Object)
+  DECL_INT_ACCESSORS(flags)
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSNumberFormat);
+};
+
+struct NumberFormatSpan {
+  int32_t field_id;
+  int32_t begin_pos;
+  int32_t end_pos;
+
+  NumberFormatSpan() = default;
+  NumberFormatSpan(int32_t field_id, int32_t begin_pos, int32_t end_pos)
+      : field_id(field_id), begin_pos(begin_pos), end_pos(end_pos) {}
+};
+
+std::vector<NumberFormatSpan> FlattenRegionsToParts(
+    std::vector<NumberFormatSpan>* regions);
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_NUMBER_FORMAT_H_
diff --git a/deps/v8/src/objects/js-objects-inl.h b/deps/v8/src/objects/js-objects-inl.h
new file mode 100644
index 0000000000..53483136d8
--- /dev/null
+++ b/deps/v8/src/objects/js-objects-inl.h
@@ -0,0 +1,904 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_JS_OBJECTS_INL_H_
+#define V8_OBJECTS_JS_OBJECTS_INL_H_
+
+#include "src/objects/js-objects.h"
+
+#include "src/feedback-vector.h"
+#include "src/heap/heap-write-barrier.h"
+#include "src/keys.h"
+#include "src/lookup-inl.h"
+#include "src/objects/property-array-inl.h"
+#include "src/objects/shared-function-info.h"
+#include "src/prototype.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(JSAsyncFromSyncIterator)
+CAST_ACCESSOR(JSBoundFunction)
+CAST_ACCESSOR(JSDataView)
+CAST_ACCESSOR(JSDate)
+CAST_ACCESSOR(JSFunction)
+CAST_ACCESSOR(JSGlobalObject)
+CAST_ACCESSOR(JSGlobalProxy)
+CAST_ACCESSOR(JSMessageObject)
+CAST_ACCESSOR(JSObject)
+CAST_ACCESSOR(JSReceiver)
+CAST_ACCESSOR(JSStringIterator)
+CAST_ACCESSOR(JSValue)
+
+MaybeHandle<Object> JSReceiver::GetProperty(Isolate* isolate,
+                                            Handle<JSReceiver> receiver,
+                                            Handle<Name> name) {
+  LookupIterator it(isolate, receiver, name, receiver);
+  if (!it.IsFound()) return it.factory()->undefined_value();
+  return Object::GetProperty(&it);
+}
+
+MaybeHandle<Object> JSReceiver::GetElement(Isolate* isolate,
+                                           Handle<JSReceiver> receiver,
+                                           uint32_t index) {
+  LookupIterator it(isolate, receiver, index, receiver);
+  if (!it.IsFound()) return it.factory()->undefined_value();
+  return Object::GetProperty(&it);
+}
+
+Handle<Object> JSReceiver::GetDataProperty(Handle<JSReceiver> object,
+                                           Handle<Name> name) {
+  LookupIterator it(object, name, object,
+                    LookupIterator::PROTOTYPE_CHAIN_SKIP_INTERCEPTOR);
+  if (!it.IsFound()) return it.factory()->undefined_value();
+  return GetDataProperty(&it);
+}
+
+MaybeHandle<Object> JSReceiver::GetPrototype(Isolate* isolate,
+                                             Handle<JSReceiver> receiver) {
+  // We don't expect access checks to be needed on JSProxy objects.
+  DCHECK(!receiver->IsAccessCheckNeeded() || receiver->IsJSObject());
+  PrototypeIterator iter(isolate, receiver, kStartAtReceiver,
+                         PrototypeIterator::END_AT_NON_HIDDEN);
+  do {
+    if (!iter.AdvanceFollowingProxies()) return MaybeHandle<Object>();
+  } while (!iter.IsAtEnd());
+  return PrototypeIterator::GetCurrent(iter);
+}
+
+MaybeHandle<Object> JSReceiver::GetProperty(Isolate* isolate,
+                                            Handle<JSReceiver> receiver,
+                                            const char* name) {
+  Handle<String> str = isolate->factory()->InternalizeUtf8String(name);
+  return GetProperty(isolate, receiver, str);
+}
+
+// static
+V8_WARN_UNUSED_RESULT MaybeHandle<FixedArray> JSReceiver::OwnPropertyKeys(
+    Handle<JSReceiver> object) {
+  return KeyAccumulator::GetKeys(object, KeyCollectionMode::kOwnOnly,
+                                 ALL_PROPERTIES,
+                                 GetKeysConversion::kConvertToString);
+}
+
+bool JSObject::PrototypeHasNoElements(Isolate* isolate, JSObject* object) {
+  DisallowHeapAllocation no_gc;
+  HeapObject* prototype = HeapObject::cast(object->map()->prototype());
+  ReadOnlyRoots roots(isolate);
+  HeapObject* null = roots.null_value();
+  HeapObject* empty_fixed_array = roots.empty_fixed_array();
+  HeapObject* empty_slow_element_dictionary =
+      roots.empty_slow_element_dictionary();
+  while (prototype != null) {
+    Map* map = prototype->map();
+    if (map->IsCustomElementsReceiverMap()) return false;
+    HeapObject* elements = JSObject::cast(prototype)->elements();
+    if (elements != empty_fixed_array &&
+        elements != empty_slow_element_dictionary) {
+      return false;
+    }
+    prototype = HeapObject::cast(map->prototype());
+  }
+  return true;
+}
+
+ACCESSORS(JSReceiver, raw_properties_or_hash, Object, kPropertiesOrHashOffset)
+
+FixedArrayBase* JSObject::elements() const {
+  Object* array = READ_FIELD(this, kElementsOffset);
+  return static_cast<FixedArrayBase*>(array);
+}
+
+void JSObject::EnsureCanContainHeapObjectElements(Handle<JSObject> object) {
+  JSObject::ValidateElements(*object);
+  ElementsKind elements_kind = object->map()->elements_kind();
+  if (!IsObjectElementsKind(elements_kind)) {
+    if (IsHoleyElementsKind(elements_kind)) {
+      TransitionElementsKind(object, HOLEY_ELEMENTS);
+    } else {
+      TransitionElementsKind(object, PACKED_ELEMENTS);
+    }
+  }
+}
+
+void JSObject::EnsureCanContainElements(Handle<JSObject> object,
+                                        Object** objects, uint32_t count,
+                                        EnsureElementsMode mode) {
+  ElementsKind current_kind = object->GetElementsKind();
+  ElementsKind target_kind = current_kind;
+  {
+    DisallowHeapAllocation no_allocation;
+    DCHECK(mode != ALLOW_COPIED_DOUBLE_ELEMENTS);
+    bool is_holey = IsHoleyElementsKind(current_kind);
+    if (current_kind == HOLEY_ELEMENTS) return;
+    Object* the_hole = object->GetReadOnlyRoots().the_hole_value();
+    for (uint32_t i = 0; i < count; ++i) {
+      Object* current = *objects++;
+      if (current == the_hole) {
+        is_holey = true;
+        target_kind = GetHoleyElementsKind(target_kind);
+      } else if (!current->IsSmi()) {
+        if (mode == ALLOW_CONVERTED_DOUBLE_ELEMENTS && current->IsNumber()) {
+          if (IsSmiElementsKind(target_kind)) {
+            if (is_holey) {
+              target_kind = HOLEY_DOUBLE_ELEMENTS;
+            } else {
+              target_kind = PACKED_DOUBLE_ELEMENTS;
+            }
+          }
+        } else if (is_holey) {
+          target_kind = HOLEY_ELEMENTS;
+          break;
+        } else {
+          target_kind = PACKED_ELEMENTS;
+        }
+      }
+    }
+  }
+  if (target_kind != current_kind) {
+    TransitionElementsKind(object, target_kind);
+  }
+}
+
+void JSObject::EnsureCanContainElements(Handle<JSObject> object,
+                                        Handle<FixedArrayBase> elements,
+                                        uint32_t length,
+                                        EnsureElementsMode mode) {
+  ReadOnlyRoots roots = object->GetReadOnlyRoots();
+  if (elements->map() != roots.fixed_double_array_map()) {
+    DCHECK(elements->map() == roots.fixed_array_map() ||
+           elements->map() == roots.fixed_cow_array_map());
+    if (mode == ALLOW_COPIED_DOUBLE_ELEMENTS) {
+      mode = DONT_ALLOW_DOUBLE_ELEMENTS;
+    }
+    Object** objects =
+        Handle<FixedArray>::cast(elements)->GetFirstElementAddress();
+    EnsureCanContainElements(object, objects, length, mode);
+    return;
+  }
+
+  DCHECK(mode == ALLOW_COPIED_DOUBLE_ELEMENTS);
+  if (object->GetElementsKind() == HOLEY_SMI_ELEMENTS) {
+    TransitionElementsKind(object, HOLEY_DOUBLE_ELEMENTS);
+  } else if (object->GetElementsKind() == PACKED_SMI_ELEMENTS) {
+    Handle<FixedDoubleArray> double_array =
+        Handle<FixedDoubleArray>::cast(elements);
+    for (uint32_t i = 0; i < length; ++i) {
+      if (double_array->is_the_hole(i)) {
+        TransitionElementsKind(object, HOLEY_DOUBLE_ELEMENTS);
+        return;
+      }
+    }
+    TransitionElementsKind(object, PACKED_DOUBLE_ELEMENTS);
+  }
+}
+
+void JSObject::SetMapAndElements(Handle<JSObject> object, Handle<Map> new_map,
+                                 Handle<FixedArrayBase> value) {
+  JSObject::MigrateToMap(object, new_map);
+  DCHECK((object->map()->has_fast_smi_or_object_elements() ||
+          (*value == object->GetReadOnlyRoots().empty_fixed_array()) ||
+          object->map()->has_fast_string_wrapper_elements()) ==
+         (value->map() == object->GetReadOnlyRoots().fixed_array_map() ||
+          value->map() == object->GetReadOnlyRoots().fixed_cow_array_map()));
+  DCHECK((*value == object->GetReadOnlyRoots().empty_fixed_array()) ||
+         (object->map()->has_fast_double_elements() ==
+          value->IsFixedDoubleArray()));
+  object->set_elements(*value);
+}
+
+void JSObject::set_elements(FixedArrayBase* value, WriteBarrierMode mode) {
+  WRITE_FIELD(this, kElementsOffset, value);
+  CONDITIONAL_WRITE_BARRIER(this, kElementsOffset, value, mode);
+}
+
+void JSObject::initialize_elements() {
+  FixedArrayBase* elements = map()->GetInitialElements();
+  WRITE_FIELD(this, kElementsOffset, elements);
+}
+
+InterceptorInfo* JSObject::GetIndexedInterceptor() {
+  return map()->GetIndexedInterceptor();
+}
+
+InterceptorInfo* JSObject::GetNamedInterceptor() {
+  return map()->GetNamedInterceptor();
+}
+
+int JSObject::GetHeaderSize() const { return GetHeaderSize(map()); }
+
+int JSObject::GetHeaderSize(const Map* map) {
+  // Check for the most common kind of JavaScript object before
+  // falling into the generic switch. This speeds up the internal
+  // field operations considerably on average.
+  InstanceType instance_type = map->instance_type();
+  return instance_type == JS_OBJECT_TYPE
+             ? JSObject::kHeaderSize
+             : GetHeaderSize(instance_type, map->has_prototype_slot());
+}
+
+// static
+int JSObject::GetEmbedderFieldCount(const Map* map) {
+  int instance_size = map->instance_size();
+  if (instance_size == kVariableSizeSentinel) return 0;
+  return ((instance_size - GetHeaderSize(map)) >> kPointerSizeLog2) -
+         map->GetInObjectProperties();
+}
+
+int JSObject::GetEmbedderFieldCount() const {
+  return GetEmbedderFieldCount(map());
+}
+
+int JSObject::GetEmbedderFieldOffset(int index) {
+  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
+  return GetHeaderSize() + (kPointerSize * index);
+}
+
+Object* JSObject::GetEmbedderField(int index) {
+  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
+  // Internal objects do follow immediately after the header, whereas in-object
+  // properties are at the end of the object. Therefore there is no need
+  // to adjust the index here.
+  return READ_FIELD(this, GetHeaderSize() + (kPointerSize * index));
+}
+
+void JSObject::SetEmbedderField(int index, Object* value) {
+  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
+  // Internal objects do follow immediately after the header, whereas in-object
+  // properties are at the end of the object. Therefore there is no need
+  // to adjust the index here.
+  int offset = GetHeaderSize() + (kPointerSize * index);
+  WRITE_FIELD(this, offset, value);
+  WRITE_BARRIER(this, offset, value);
+}
+
+void JSObject::SetEmbedderField(int index, Smi* value) {
+  DCHECK(index < GetEmbedderFieldCount() && index >= 0);
+  // Internal objects do follow immediately after the header, whereas in-object
+  // properties are at the end of the object. Therefore there is no need
+  // to adjust the index here.
+  int offset = GetHeaderSize() + (kPointerSize * index);
+  WRITE_FIELD(this, offset, value);
+}
+
+bool JSObject::IsUnboxedDoubleField(FieldIndex index) {
+  if (!FLAG_unbox_double_fields) return false;
+  return map()->IsUnboxedDoubleField(index);
+}
+
+// Access fast-case object properties at index. The use of these routines
+// is needed to correctly distinguish between properties stored in-object and
+// properties stored in the properties array.
+Object* JSObject::RawFastPropertyAt(FieldIndex index) {
+  DCHECK(!IsUnboxedDoubleField(index));
+  if (index.is_inobject()) {
+    return READ_FIELD(this, index.offset());
+  } else {
+    return property_array()->get(index.outobject_array_index());
+  }
+}
+
+double JSObject::RawFastDoublePropertyAt(FieldIndex index) {
+  DCHECK(IsUnboxedDoubleField(index));
+  return READ_DOUBLE_FIELD(this, index.offset());
+}
+
+uint64_t JSObject::RawFastDoublePropertyAsBitsAt(FieldIndex index) {
+  DCHECK(IsUnboxedDoubleField(index));
+  return READ_UINT64_FIELD(this, index.offset());
+}
+
+void JSObject::RawFastPropertyAtPut(FieldIndex index, Object* value) {
+  if (index.is_inobject()) {
+    int offset = index.offset();
+    WRITE_FIELD(this, offset, value);
+    WRITE_BARRIER(this, offset, value);
+  } else {
+    property_array()->set(index.outobject_array_index(), value);
+  }
+}
+
+void JSObject::RawFastDoublePropertyAsBitsAtPut(FieldIndex index,
+                                                uint64_t bits) {
+  // Double unboxing is enabled only on 64-bit platforms.
+  DCHECK_EQ(kDoubleSize, kPointerSize);
+  Address field_addr = FIELD_ADDR(this, index.offset());
+  base::Relaxed_Store(reinterpret_cast<base::AtomicWord*>(field_addr),
+                      static_cast<base::AtomicWord>(bits));
+}
+
+void JSObject::FastPropertyAtPut(FieldIndex index, Object* value) {
+  if (IsUnboxedDoubleField(index)) {
+    DCHECK(value->IsMutableHeapNumber());
+    // Ensure that all bits of the double value are preserved.
+    RawFastDoublePropertyAsBitsAtPut(
+        index, MutableHeapNumber::cast(value)->value_as_bits());
+  } else {
+    RawFastPropertyAtPut(index, value);
+  }
+}
+
+void JSObject::WriteToField(int descriptor, PropertyDetails details,
+                            Object* value) {
+  DCHECK_EQ(kField, details.location());
+  DCHECK_EQ(kData, details.kind());
+  DisallowHeapAllocation no_gc;
+  FieldIndex index = FieldIndex::ForDescriptor(map(), descriptor);
+  if (details.representation().IsDouble()) {
+    // Nothing more to be done.
+    if (value->IsUninitialized()) {
+      return;
+    }
+    // Manipulating the signaling NaN used for the hole and uninitialized
+    // double field sentinel in C++, e.g. with bit_cast or value()/set_value(),
+    // will change its value on ia32 (the x87 stack is used to return values
+    // and stores to the stack silently clear the signalling bit).
+    uint64_t bits;
+    if (value->IsSmi()) {
+      bits = bit_cast<uint64_t>(static_cast<double>(Smi::ToInt(value)));
+    } else {
+      DCHECK(value->IsHeapNumber());
+      bits = HeapNumber::cast(value)->value_as_bits();
+    }
+    if (IsUnboxedDoubleField(index)) {
+      RawFastDoublePropertyAsBitsAtPut(index, bits);
+    } else {
+      auto box = MutableHeapNumber::cast(RawFastPropertyAt(index));
+      box->set_value_as_bits(bits);
+    }
+  } else {
+    RawFastPropertyAtPut(index, value);
+  }
+}
+
+int JSObject::GetInObjectPropertyOffset(int index) {
+  return map()->GetInObjectPropertyOffset(index);
+}
+
+Object* JSObject::InObjectPropertyAt(int index) {
+  int offset = GetInObjectPropertyOffset(index);
+  return READ_FIELD(this, offset);
+}
+
+Object* JSObject::InObjectPropertyAtPut(int index, Object* value,
+                                        WriteBarrierMode mode) {
+  // Adjust for the number of properties stored in the object.
+  int offset = GetInObjectPropertyOffset(index);
+  WRITE_FIELD(this, offset, value);
+  CONDITIONAL_WRITE_BARRIER(this, offset, value, mode);
+  return value;
+}
+
+void JSObject::InitializeBody(Map* map, int start_offset,
+                              Object* pre_allocated_value,
+                              Object* filler_value) {
+  DCHECK(!filler_value->IsHeapObject() || !Heap::InNewSpace(filler_value));
+  DCHECK(!pre_allocated_value->IsHeapObject() ||
+         !Heap::InNewSpace(pre_allocated_value));
+  int size = map->instance_size();
+  int offset = start_offset;
+  if (filler_value != pre_allocated_value) {
+    int end_of_pre_allocated_offset =
+        size - (map->UnusedPropertyFields() * kPointerSize);
+    DCHECK_LE(kHeaderSize, end_of_pre_allocated_offset);
+    while (offset < end_of_pre_allocated_offset) {
+      WRITE_FIELD(this, offset, pre_allocated_value);
+      offset += kPointerSize;
+    }
+  }
+  while (offset < size) {
+    WRITE_FIELD(this, offset, filler_value);
+    offset += kPointerSize;
+  }
+}
+
+Object* JSBoundFunction::raw_bound_target_function() const {
+  return READ_FIELD(this, kBoundTargetFunctionOffset);
+}
+
+ACCESSORS(JSBoundFunction, bound_target_function, JSReceiver,
+          kBoundTargetFunctionOffset)
+ACCESSORS(JSBoundFunction, bound_this, Object, kBoundThisOffset)
+ACCESSORS(JSBoundFunction, bound_arguments, FixedArray, kBoundArgumentsOffset)
+
+ACCESSORS(JSFunction, shared, SharedFunctionInfo, kSharedFunctionInfoOffset)
+ACCESSORS(JSFunction, feedback_cell, FeedbackCell, kFeedbackCellOffset)
+
+ACCESSORS(JSGlobalObject, native_context, Context, kNativeContextOffset)
+ACCESSORS(JSGlobalObject, global_proxy, JSObject, kGlobalProxyOffset)
+
+ACCESSORS(JSGlobalProxy, native_context, Object, kNativeContextOffset)
+
+FeedbackVector* JSFunction::feedback_vector() const {
+  DCHECK(has_feedback_vector());
+  return FeedbackVector::cast(feedback_cell()->value());
+}
+
+// Code objects that are marked for deoptimization are not considered to be
+// optimized. This is because the JSFunction might have been already
+// deoptimized but its code() still needs to be unlinked, which will happen on
+// its next activation.
+// TODO(jupvfranco): rename this function. Maybe RunOptimizedCode,
+// or IsValidOptimizedCode.
+bool JSFunction::IsOptimized() {
+  return code()->kind() == Code::OPTIMIZED_FUNCTION &&
+         !code()->marked_for_deoptimization();
+}
+
+bool JSFunction::HasOptimizedCode() {
+  return IsOptimized() ||
+         (has_feedback_vector() && feedback_vector()->has_optimized_code() &&
+          !feedback_vector()->optimized_code()->marked_for_deoptimization());
+}
+
+bool JSFunction::HasOptimizationMarker() {
+  return has_feedback_vector() && feedback_vector()->has_optimization_marker();
+}
+
+void JSFunction::ClearOptimizationMarker() {
+  DCHECK(has_feedback_vector());
+  feedback_vector()->ClearOptimizationMarker();
+}
+
+// Optimized code marked for deoptimization will tier back down to running
+// interpreted on its next activation, and already doesn't count as IsOptimized.
+bool JSFunction::IsInterpreted() {
+  return code()->is_interpreter_trampoline_builtin() ||
+         (code()->kind() == Code::OPTIMIZED_FUNCTION &&
+          code()->marked_for_deoptimization());
+}
+
+bool JSFunction::ChecksOptimizationMarker() {
+  return code()->checks_optimization_marker();
+}
+
+bool JSFunction::IsMarkedForOptimization() {
+  return has_feedback_vector() && feedback_vector()->optimization_marker() ==
+                                      OptimizationMarker::kCompileOptimized;
+}
+
+bool JSFunction::IsMarkedForConcurrentOptimization() {
+  return has_feedback_vector() &&
+         feedback_vector()->optimization_marker() ==
+             OptimizationMarker::kCompileOptimizedConcurrent;
+}
+
+bool JSFunction::IsInOptimizationQueue() {
+  return has_feedback_vector() && feedback_vector()->optimization_marker() ==
+                                      OptimizationMarker::kInOptimizationQueue;
+}
+
+void JSFunction::CompleteInobjectSlackTrackingIfActive() {
+  if (!has_prototype_slot()) return;
+  if (has_initial_map() && initial_map()->IsInobjectSlackTrackingInProgress()) {
+    initial_map()->CompleteInobjectSlackTracking(GetIsolate());
+  }
+}
+
+AbstractCode* JSFunction::abstract_code() {
+  if (IsInterpreted()) {
+    return AbstractCode::cast(shared()->GetBytecodeArray());
+  } else {
+    return AbstractCode::cast(code());
+  }
+}
+
+Code* JSFunction::code() { return Code::cast(READ_FIELD(this, kCodeOffset)); }
+
+void JSFunction::set_code(Code* value) {
+  DCHECK(!Heap::InNewSpace(value));
+  WRITE_FIELD(this, kCodeOffset, value);
+  MarkingBarrier(this, HeapObject::RawField(this, kCodeOffset), value);
+}
+
+void JSFunction::set_code_no_write_barrier(Code* value) {
+  DCHECK(!Heap::InNewSpace(value));
+  WRITE_FIELD(this, kCodeOffset, value);
+}
+
+void JSFunction::ClearOptimizedCodeSlot(const char* reason) {
+  if (has_feedback_vector() && feedback_vector()->has_optimized_code()) {
+    if (FLAG_trace_opt) {
+      PrintF("[evicting entry from optimizing code feedback slot (%s) for ",
+             reason);
+      ShortPrint();
+      PrintF("]\n");
+    }
+    feedback_vector()->ClearOptimizedCode();
+  }
+}
+
+void JSFunction::SetOptimizationMarker(OptimizationMarker marker) {
+  DCHECK(has_feedback_vector());
+  DCHECK(ChecksOptimizationMarker());
+  DCHECK(!HasOptimizedCode());
+
+  feedback_vector()->SetOptimizationMarker(marker);
+}
+
+bool JSFunction::has_feedback_vector() const {
+  return !feedback_cell()->value()->IsUndefined();
+}
+
+Context* JSFunction::context() {
+  return Context::cast(READ_FIELD(this, kContextOffset));
+}
+
+bool JSFunction::has_context() const {
+  return READ_FIELD(this, kContextOffset)->IsContext();
+}
+
+JSGlobalProxy* JSFunction::global_proxy() { return context()->global_proxy(); }
+
+Context* JSFunction::native_context() { return context()->native_context(); }
+
+void JSFunction::set_context(Object* value) {
+  DCHECK(value->IsUndefined() || value->IsContext());
+  WRITE_FIELD(this, kContextOffset, value);
+  WRITE_BARRIER(this, kContextOffset, value);
+}
+
+ACCESSORS_CHECKED(JSFunction, prototype_or_initial_map, Object,
+                  kPrototypeOrInitialMapOffset, map()->has_prototype_slot())
+
+bool JSFunction::has_prototype_slot() const {
+  return map()->has_prototype_slot();
+}
+
+Map* JSFunction::initial_map() { return Map::cast(prototype_or_initial_map()); }
+
+bool JSFunction::has_initial_map() {
+  DCHECK(has_prototype_slot());
+  return prototype_or_initial_map()->IsMap();
+}
+
+bool JSFunction::has_instance_prototype() {
+  DCHECK(has_prototype_slot());
+  return has_initial_map() || !prototype_or_initial_map()->IsTheHole();
+}
+
+bool JSFunction::has_prototype() {
+  DCHECK(has_prototype_slot());
+  return map()->has_non_instance_prototype() || has_instance_prototype();
+}
+
+bool JSFunction::has_prototype_property() {
+  return (has_prototype_slot() && IsConstructor()) ||
+         IsGeneratorFunction(shared()->kind());
+}
+
+bool JSFunction::PrototypeRequiresRuntimeLookup() {
+  return !has_prototype_property() || map()->has_non_instance_prototype();
+}
+
+Object* JSFunction::instance_prototype() {
+  DCHECK(has_instance_prototype());
+  if (has_initial_map()) return initial_map()->prototype();
+  // When there is no initial map and the prototype is a JSReceiver, the
+  // initial map field is used for the prototype field.
+  return prototype_or_initial_map();
+}
+
+Object* JSFunction::prototype() {
+  DCHECK(has_prototype());
+  // If the function's prototype property has been set to a non-JSReceiver
+  // value, that value is stored in the constructor field of the map.
+  if (map()->has_non_instance_prototype()) {
+    Object* prototype = map()->GetConstructor();
+    // The map must have a prototype in that field, not a back pointer.
+    DCHECK(!prototype->IsMap());
+    DCHECK(!prototype->IsFunctionTemplateInfo());
+    return prototype;
+  }
+  return instance_prototype();
+}
+
+bool JSFunction::is_compiled() {
+  return code()->builtin_index() != Builtins::kCompileLazy;
+}
+
+ACCESSORS(JSValue, value, Object, kValueOffset)
+
+ACCESSORS(JSDate, value, Object, kValueOffset)
+ACCESSORS(JSDate, cache_stamp, Object, kCacheStampOffset)
+ACCESSORS(JSDate, year, Object, kYearOffset)
+ACCESSORS(JSDate, month, Object, kMonthOffset)
+ACCESSORS(JSDate, day, Object, kDayOffset)
+ACCESSORS(JSDate, weekday, Object, kWeekdayOffset)
+ACCESSORS(JSDate, hour, Object, kHourOffset)
+ACCESSORS(JSDate, min, Object, kMinOffset)
+ACCESSORS(JSDate, sec, Object, kSecOffset)
+
+SMI_ACCESSORS(JSMessageObject, type, kTypeOffset)
+ACCESSORS(JSMessageObject, argument, Object, kArgumentsOffset)
+ACCESSORS(JSMessageObject, script, Script, kScriptOffset)
+ACCESSORS(JSMessageObject, stack_frames, Object, kStackFramesOffset)
+SMI_ACCESSORS(JSMessageObject, start_position, kStartPositionOffset)
+SMI_ACCESSORS(JSMessageObject, end_position, kEndPositionOffset)
+SMI_ACCESSORS(JSMessageObject, error_level, kErrorLevelOffset)
+
+ElementsKind JSObject::GetElementsKind() const {
+  ElementsKind kind = map()->elements_kind();
+#if VERIFY_HEAP && DEBUG
+  FixedArrayBase* fixed_array =
+      reinterpret_cast<FixedArrayBase*>(READ_FIELD(this, kElementsOffset));
+
+  // If a GC was caused while constructing this object, the elements
+  // pointer may point to a one pointer filler map.
+  if (ElementsAreSafeToExamine()) {
+    Map* map = fixed_array->map();
+    if (IsSmiOrObjectElementsKind(kind)) {
+      DCHECK(map == GetReadOnlyRoots().fixed_array_map() ||
+             map == GetReadOnlyRoots().fixed_cow_array_map());
+    } else if (IsDoubleElementsKind(kind)) {
+      DCHECK(fixed_array->IsFixedDoubleArray() ||
+             fixed_array == GetReadOnlyRoots().empty_fixed_array());
+    } else if (kind == DICTIONARY_ELEMENTS) {
+      DCHECK(fixed_array->IsFixedArray());
+      DCHECK(fixed_array->IsDictionary());
+    } else {
+      DCHECK(kind > DICTIONARY_ELEMENTS);
+    }
+    DCHECK(!IsSloppyArgumentsElementsKind(kind) ||
+           (elements()->IsFixedArray() && elements()->length() >= 2));
+  }
+#endif
+  return kind;
+}
+
+bool JSObject::HasObjectElements() {
+  return IsObjectElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasSmiElements() { return IsSmiElementsKind(GetElementsKind()); }
+
+bool JSObject::HasSmiOrObjectElements() {
+  return IsSmiOrObjectElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasDoubleElements() {
+  return IsDoubleElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasHoleyElements() {
+  return IsHoleyElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasFastElements() {
+  return IsFastElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasFastPackedElements() {
+  return IsFastPackedElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasDictionaryElements() {
+  return GetElementsKind() == DICTIONARY_ELEMENTS;
+}
+
+bool JSObject::HasFastArgumentsElements() {
+  return GetElementsKind() == FAST_SLOPPY_ARGUMENTS_ELEMENTS;
+}
+
+bool JSObject::HasSlowArgumentsElements() {
+  return GetElementsKind() == SLOW_SLOPPY_ARGUMENTS_ELEMENTS;
+}
+
+bool JSObject::HasSloppyArgumentsElements() {
+  return IsSloppyArgumentsElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasStringWrapperElements() {
+  return IsStringWrapperElementsKind(GetElementsKind());
+}
+
+bool JSObject::HasFastStringWrapperElements() {
+  return GetElementsKind() == FAST_STRING_WRAPPER_ELEMENTS;
+}
+
+bool JSObject::HasSlowStringWrapperElements() {
+  return GetElementsKind() == SLOW_STRING_WRAPPER_ELEMENTS;
+}
+
+bool JSObject::HasFixedTypedArrayElements() {
+  DCHECK_NOT_NULL(elements());
+  return map()->has_fixed_typed_array_elements();
+}
+
+#define FIXED_TYPED_ELEMENTS_CHECK(Type, type, TYPE, ctype)            \
+  bool JSObject::HasFixed##Type##Elements() {                          \
+    HeapObject* array = elements();                                    \
+    DCHECK_NOT_NULL(array);                                            \
+    if (!array->IsHeapObject()) return false;                          \
+    return array->map()->instance_type() == FIXED_##TYPE##_ARRAY_TYPE; \
+  }
+
+TYPED_ARRAYS(FIXED_TYPED_ELEMENTS_CHECK)
+
+#undef FIXED_TYPED_ELEMENTS_CHECK
+
+bool JSObject::HasNamedInterceptor() { return map()->has_named_interceptor(); }
+
+bool JSObject::HasIndexedInterceptor() {
+  return map()->has_indexed_interceptor();
+}
+
+void JSGlobalObject::set_global_dictionary(GlobalDictionary* dictionary) {
+  DCHECK(IsJSGlobalObject());
+  set_raw_properties_or_hash(dictionary);
+}
+
+GlobalDictionary* JSGlobalObject::global_dictionary() {
+  DCHECK(!HasFastProperties());
+  DCHECK(IsJSGlobalObject());
+  return GlobalDictionary::cast(raw_properties_or_hash());
+}
+
+NumberDictionary* JSObject::element_dictionary() {
+  DCHECK(HasDictionaryElements() || HasSlowStringWrapperElements());
+  return NumberDictionary::cast(elements());
+}
+
+void JSReceiver::initialize_properties() {
+  Heap* heap = GetHeap();
+  ReadOnlyRoots roots(heap);
+  DCHECK(!Heap::InNewSpace(roots.empty_fixed_array()));
+  DCHECK(!Heap::InNewSpace(heap->empty_property_dictionary()));
+  if (map()->is_dictionary_map()) {
+    WRITE_FIELD(this, kPropertiesOrHashOffset,
+                heap->empty_property_dictionary());
+  } else {
+    WRITE_FIELD(this, kPropertiesOrHashOffset, roots.empty_fixed_array());
+  }
+}
+
+bool JSReceiver::HasFastProperties() const {
+  DCHECK(
+      raw_properties_or_hash()->IsSmi() ||
+      (raw_properties_or_hash()->IsDictionary() == map()->is_dictionary_map()));
+  return !map()->is_dictionary_map();
+}
+
+NameDictionary* JSReceiver::property_dictionary() const {
+  DCHECK(!IsJSGlobalObject());
+  DCHECK(!HasFastProperties());
+
+  Object* prop = raw_properties_or_hash();
+  if (prop->IsSmi()) {
+    return GetHeap()->empty_property_dictionary();
+  }
+
+  return NameDictionary::cast(prop);
+}
+
+// TODO(gsathya): Pass isolate directly to this function and access
+// the heap from this.
+PropertyArray* JSReceiver::property_array() const {
+  DCHECK(HasFastProperties());
+
+  Object* prop = raw_properties_or_hash();
+  if (prop->IsSmi() || prop == GetReadOnlyRoots().empty_fixed_array()) {
+    return GetReadOnlyRoots().empty_property_array();
+  }
+
+  return PropertyArray::cast(prop);
+}
+
+Maybe<bool> JSReceiver::HasProperty(Handle<JSReceiver> object,
+                                    Handle<Name> name) {
+  LookupIterator it = LookupIterator::PropertyOrElement(object->GetIsolate(),
+                                                        object, name, object);
+  return HasProperty(&it);
+}
+
+Maybe<bool> JSReceiver::HasOwnProperty(Handle<JSReceiver> object,
+                                       uint32_t index) {
+  if (object->IsJSModuleNamespace()) return Just(false);
+
+  if (object->IsJSObject()) {  // Shortcut.
+    LookupIterator it(object->GetIsolate(), object, index, object,
+                      LookupIterator::OWN);
+    return HasProperty(&it);
+  }
+
+  Maybe<PropertyAttributes> attributes =
+      JSReceiver::GetOwnPropertyAttributes(object, index);
+  MAYBE_RETURN(attributes, Nothing<bool>());
+  return Just(attributes.FromJust() != ABSENT);
+}
+
+Maybe<PropertyAttributes> JSReceiver::GetPropertyAttributes(
+    Handle<JSReceiver> object, Handle<Name> name) {
+  LookupIterator it = LookupIterator::PropertyOrElement(object->GetIsolate(),
+                                                        object, name, object);
+  return GetPropertyAttributes(&it);
+}
+
+Maybe<PropertyAttributes> JSReceiver::GetOwnPropertyAttributes(
+    Handle<JSReceiver> object, Handle<Name> name) {
+  LookupIterator it = LookupIterator::PropertyOrElement(
+      object->GetIsolate(), object, name, object, LookupIterator::OWN);
+  return GetPropertyAttributes(&it);
+}
+
+Maybe<PropertyAttributes> JSReceiver::GetOwnPropertyAttributes(
+    Handle<JSReceiver> object, uint32_t index) {
+  LookupIterator it(object->GetIsolate(), object, index, object,
+                    LookupIterator::OWN);
+  return GetPropertyAttributes(&it);
+}
+
+Maybe<bool> JSReceiver::HasElement(Handle<JSReceiver> object, uint32_t index) {
+  LookupIterator it(object->GetIsolate(), object, index, object);
+  return HasProperty(&it);
+}
+
+Maybe<PropertyAttributes> JSReceiver::GetElementAttributes(
+    Handle<JSReceiver> object, uint32_t index) {
+  Isolate* isolate = object->GetIsolate();
+  LookupIterator it(isolate, object, index, object);
+  return GetPropertyAttributes(&it);
+}
+
+Maybe<PropertyAttributes> JSReceiver::GetOwnElementAttributes(
+    Handle<JSReceiver> object, uint32_t index) {
+  Isolate* isolate = object->GetIsolate();
+  LookupIterator it(isolate, object, index, object, LookupIterator::OWN);
+  return GetPropertyAttributes(&it);
+}
+
+bool JSGlobalObject::IsDetached() {
+  return JSGlobalProxy::cast(global_proxy())->IsDetachedFrom(this);
+}
+
+bool JSGlobalProxy::IsDetachedFrom(JSGlobalObject* global) const {
+  const PrototypeIterator iter(this->GetIsolate(),
+                               const_cast<JSGlobalProxy*>(this));
+  return iter.GetCurrent() != global;
+}
+
+inline int JSGlobalProxy::SizeWithEmbedderFields(int embedder_field_count) {
+  DCHECK_GE(embedder_field_count, 0);
+  return kSize + embedder_field_count * kPointerSize;
+}
+
+ACCESSORS(JSIteratorResult, value, Object, kValueOffset)
+ACCESSORS(JSIteratorResult, done, Object, kDoneOffset)
+
+ACCESSORS(JSAsyncFromSyncIterator, sync_iterator, JSReceiver,
+          kSyncIteratorOffset)
+ACCESSORS(JSAsyncFromSyncIterator, next, Object, kNextOffset)
+
+ACCESSORS(JSStringIterator, string, String, kStringOffset)
+SMI_ACCESSORS(JSStringIterator, index, kNextIndexOffset)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_OBJECTS_INL_H_
diff --git a/deps/v8/src/objects/js-objects.h b/deps/v8/src/objects/js-objects.h
new file mode 100644
index 0000000000..586fe757db
--- /dev/null
+++ b/deps/v8/src/objects/js-objects.h
@@ -0,0 +1,1408 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_JS_OBJECTS_H_
+#define V8_OBJECTS_JS_OBJECTS_H_
+
+#include "src/objects.h"
+#include "src/objects/property-array.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+class JSGlobalObject;
+class JSGlobalProxy;
+
+// JSReceiver includes types on which properties can be defined, i.e.,
+// JSObject and JSProxy.
+class JSReceiver : public HeapObject, public NeverReadOnlySpaceObject {
+ public:
+  // Returns true if there is no slow (ie, dictionary) backing store.
+  inline bool HasFastProperties() const;
+
+  // Returns the properties array backing store if it
+  // exists. Otherwise, returns an empty_property_array when there's a
+  // Smi (hash code) or an empty_fixed_array for a fast properties
+  // map.
+  inline PropertyArray* property_array() const;
+
+  // Gets slow properties for non-global objects.
+  inline NameDictionary* property_dictionary() const;
+
+  // Sets the properties backing store and makes sure any existing hash is moved
+  // to the new properties store. To clear out the properties store, pass in the
+  // empty_fixed_array(), the hash will be maintained in this case as well.
+  void SetProperties(HeapObject* properties);
+
+  // There are five possible values for the properties offset.
+  // 1) EmptyFixedArray/EmptyPropertyDictionary - This is the standard
+  // placeholder.
+  //
+  // 2) Smi - This is the hash code of the object.
+  //
+  // 3) PropertyArray - This is similar to a FixedArray but stores
+  // the hash code of the object in its length field. This is a fast
+  // backing store.
+  //
+  // 4) NameDictionary - This is the dictionary-mode backing store.
+  //
+  // 4) GlobalDictionary - This is the backing store for the
+  // GlobalObject.
+  //
+  // This is used only in the deoptimizer and heap. Please use the
+  // above typed getters and setters to access the properties.
+  DECL_ACCESSORS(raw_properties_or_hash, Object)
+
+  inline void initialize_properties();
+
+  // Deletes an existing named property in a normalized object.
+  static void DeleteNormalizedProperty(Handle<JSReceiver> object, int entry);
+
+  DECL_CAST(JSReceiver)
+
+  // ES6 section 7.1.1 ToPrimitive
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ToPrimitive(
+      Handle<JSReceiver> receiver,
+      ToPrimitiveHint hint = ToPrimitiveHint::kDefault);
+
+  // ES6 section 7.1.1.1 OrdinaryToPrimitive
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> OrdinaryToPrimitive(
+      Handle<JSReceiver> receiver, OrdinaryToPrimitiveHint hint);
+
+  static MaybeHandle<Context> GetFunctionRealm(Handle<JSReceiver> receiver);
+
+  // Get the first non-hidden prototype.
+  static inline MaybeHandle<Object> GetPrototype(Isolate* isolate,
+                                                 Handle<JSReceiver> receiver);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> HasInPrototypeChain(
+      Isolate* isolate, Handle<JSReceiver> object, Handle<Object> proto);
+
+  // Reads all enumerable own properties of source and adds them to
+  // target, using either Set or CreateDataProperty depending on the
+  // use_set argument. This only copies values not present in the
+  // maybe_excluded_properties list.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> SetOrCopyDataProperties(
+      Isolate* isolate, Handle<JSReceiver> target, Handle<Object> source,
+      const ScopedVector<Handle<Object>>* excluded_properties = nullptr,
+      bool use_set = true);
+
+  // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> HasProperty(LookupIterator* it);
+  V8_WARN_UNUSED_RESULT static inline Maybe<bool> HasProperty(
+      Handle<JSReceiver> object, Handle<Name> name);
+  V8_WARN_UNUSED_RESULT static inline Maybe<bool> HasElement(
+      Handle<JSReceiver> object, uint32_t index);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> HasOwnProperty(
+      Handle<JSReceiver> object, Handle<Name> name);
+  V8_WARN_UNUSED_RESULT static inline Maybe<bool> HasOwnProperty(
+      Handle<JSReceiver> object, uint32_t index);
+
+  V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetProperty(
+      Isolate* isolate, Handle<JSReceiver> receiver, const char* key);
+  V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetProperty(
+      Isolate* isolate, Handle<JSReceiver> receiver, Handle<Name> name);
+  V8_WARN_UNUSED_RESULT static inline MaybeHandle<Object> GetElement(
+      Isolate* isolate, Handle<JSReceiver> receiver, uint32_t index);
+
+  // Implementation of ES6 [[Delete]]
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DeletePropertyOrElement(
+      Handle<JSReceiver> object, Handle<Name> name,
+      LanguageMode language_mode = LanguageMode::kSloppy);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DeleteProperty(
+      Handle<JSReceiver> object, Handle<Name> name,
+      LanguageMode language_mode = LanguageMode::kSloppy);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DeleteProperty(
+      LookupIterator* it, LanguageMode language_mode);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DeleteElement(
+      Handle<JSReceiver> object, uint32_t index,
+      LanguageMode language_mode = LanguageMode::kSloppy);
+
+  V8_WARN_UNUSED_RESULT static Object* DefineProperty(
+      Isolate* isolate, Handle<Object> object, Handle<Object> name,
+      Handle<Object> attributes);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> DefineProperties(
+      Isolate* isolate, Handle<Object> object, Handle<Object> properties);
+
+  // "virtual" dispatcher to the correct [[DefineOwnProperty]] implementation.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DefineOwnProperty(
+      Isolate* isolate, Handle<JSReceiver> object, Handle<Object> key,
+      PropertyDescriptor* desc, ShouldThrow should_throw);
+
+  // ES6 7.3.4 (when passed kDontThrow)
+  V8_WARN_UNUSED_RESULT static Maybe<bool> CreateDataProperty(
+      Isolate* isolate, Handle<JSReceiver> object, Handle<Name> key,
+      Handle<Object> value, ShouldThrow should_throw);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> CreateDataProperty(
+      LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
+
+  // ES6 9.1.6.1
+  V8_WARN_UNUSED_RESULT static Maybe<bool> OrdinaryDefineOwnProperty(
+      Isolate* isolate, Handle<JSObject> object, Handle<Object> key,
+      PropertyDescriptor* desc, ShouldThrow should_throw);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> OrdinaryDefineOwnProperty(
+      LookupIterator* it, PropertyDescriptor* desc, ShouldThrow should_throw);
+  // ES6 9.1.6.2
+  V8_WARN_UNUSED_RESULT static Maybe<bool> IsCompatiblePropertyDescriptor(
+      Isolate* isolate, bool extensible, PropertyDescriptor* desc,
+      PropertyDescriptor* current, Handle<Name> property_name,
+      ShouldThrow should_throw);
+  // ES6 9.1.6.3
+  // |it| can be NULL in cases where the ES spec passes |undefined| as the
+  // receiver. Exactly one of |it| and |property_name| must be provided.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> ValidateAndApplyPropertyDescriptor(
+      Isolate* isolate, LookupIterator* it, bool extensible,
+      PropertyDescriptor* desc, PropertyDescriptor* current,
+      ShouldThrow should_throw, Handle<Name> property_name);
+
+  V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static Maybe<bool>
+  GetOwnPropertyDescriptor(Isolate* isolate, Handle<JSReceiver> object,
+                           Handle<Object> key, PropertyDescriptor* desc);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> GetOwnPropertyDescriptor(
+      LookupIterator* it, PropertyDescriptor* desc);
+
+  typedef PropertyAttributes IntegrityLevel;
+
+  // ES6 7.3.14 (when passed kDontThrow)
+  // 'level' must be SEALED or FROZEN.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> SetIntegrityLevel(
+      Handle<JSReceiver> object, IntegrityLevel lvl, ShouldThrow should_throw);
+
+  // ES6 7.3.15
+  // 'level' must be SEALED or FROZEN.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> TestIntegrityLevel(
+      Handle<JSReceiver> object, IntegrityLevel lvl);
+
+  // ES6 [[PreventExtensions]] (when passed kDontThrow)
+  V8_WARN_UNUSED_RESULT static Maybe<bool> PreventExtensions(
+      Handle<JSReceiver> object, ShouldThrow should_throw);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> IsExtensible(
+      Handle<JSReceiver> object);
+
+  // Returns the class name ([[Class]] property in the specification).
+  V8_EXPORT_PRIVATE String* class_name();
+
+  // Returns the constructor (the function that was used to instantiate the
+  // object).
+  static MaybeHandle<JSFunction> GetConstructor(Handle<JSReceiver> receiver);
+
+  // Returns the constructor name (the name (possibly, inferred name) of the
+  // function that was used to instantiate the object).
+  static Handle<String> GetConstructorName(Handle<JSReceiver> receiver);
+
+  Handle<Context> GetCreationContext();
+
+  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
+  GetPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
+  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
+  GetOwnPropertyAttributes(Handle<JSReceiver> object, Handle<Name> name);
+  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
+  GetOwnPropertyAttributes(Handle<JSReceiver> object, uint32_t index);
+
+  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
+  GetElementAttributes(Handle<JSReceiver> object, uint32_t index);
+  V8_WARN_UNUSED_RESULT static inline Maybe<PropertyAttributes>
+  GetOwnElementAttributes(Handle<JSReceiver> object, uint32_t index);
+
+  V8_WARN_UNUSED_RESULT static Maybe<PropertyAttributes> GetPropertyAttributes(
+      LookupIterator* it);
+
+  // Set the object's prototype (only JSReceiver and null are allowed values).
+  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPrototype(
+      Handle<JSReceiver> object, Handle<Object> value, bool from_javascript,
+      ShouldThrow should_throw);
+
+  inline static Handle<Object> GetDataProperty(Handle<JSReceiver> object,
+                                               Handle<Name> name);
+  static Handle<Object> GetDataProperty(LookupIterator* it);
+
+  // Retrieves a permanent object identity hash code. The undefined value might
+  // be returned in case no hash was created yet.
+  Object* GetIdentityHash(Isolate* isolate);
+
+  // Retrieves a permanent object identity hash code. May create and store a
+  // hash code if needed and none exists.
+  static Smi* CreateIdentityHash(Isolate* isolate, JSReceiver* key);
+  Smi* GetOrCreateIdentityHash(Isolate* isolate);
+
+  // Stores the hash code. The hash passed in must be masked with
+  // JSReceiver::kHashMask.
+  void SetIdentityHash(int masked_hash);
+
+  // ES6 [[OwnPropertyKeys]] (modulo return type)
+  V8_WARN_UNUSED_RESULT static inline MaybeHandle<FixedArray> OwnPropertyKeys(
+      Handle<JSReceiver> object);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<FixedArray> GetOwnValues(
+      Handle<JSReceiver> object, PropertyFilter filter,
+      bool try_fast_path = true);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<FixedArray> GetOwnEntries(
+      Handle<JSReceiver> object, PropertyFilter filter,
+      bool try_fast_path = true);
+
+  V8_WARN_UNUSED_RESULT static Handle<FixedArray> GetOwnElementIndices(
+      Isolate* isolate, Handle<JSReceiver> receiver, Handle<JSObject> object);
+
+  static const int kHashMask = PropertyArray::HashField::kMask;
+
+  // Layout description.
+  static const int kPropertiesOrHashOffset = HeapObject::kHeaderSize;
+  static const int kHeaderSize = HeapObject::kHeaderSize + kPointerSize;
+
+  bool HasProxyInPrototype(Isolate* isolate);
+
+  bool HasComplexElements();
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
+};
+
+// The JSObject describes real heap allocated JavaScript objects with
+// properties.
+// Note that the map of JSObject changes during execution to enable inline
+// caching.
+class JSObject : public JSReceiver {
+ public:
+  static bool IsUnmodifiedApiObject(Object** o);
+
+  static V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> New(
+      Handle<JSFunction> constructor, Handle<JSReceiver> new_target,
+      Handle<AllocationSite> site);
+
+  static MaybeHandle<Context> GetFunctionRealm(Handle<JSObject> object);
+
+  // 9.1.12 ObjectCreate ( proto [ , internalSlotsList ] )
+  // Notice: This is NOT 19.1.2.2 Object.create ( O, Properties )
+  static V8_WARN_UNUSED_RESULT MaybeHandle<JSObject> ObjectCreate(
+      Isolate* isolate, Handle<Object> prototype);
+
+  // [elements]: The elements (properties with names that are integers).
+  //
+  // Elements can be in two general modes: fast and slow. Each mode
+  // corresponds to a set of object representations of elements that
+  // have something in common.
+  //
+  // In the fast mode elements is a FixedArray and so each element can
+  // be quickly accessed. This fact is used in the generated code. The
+  // elements array can have one of three maps in this mode:
+  // fixed_array_map, sloppy_arguments_elements_map or
+  // fixed_cow_array_map (for copy-on-write arrays). In the latter case
+  // the elements array may be shared by a few objects and so before
+  // writing to any element the array must be copied. Use
+  // EnsureWritableFastElements in this case.
+  //
+  // In the slow mode the elements is either a NumberDictionary, a
+  // FixedArray parameter map for a (sloppy) arguments object.
+  DECL_ACCESSORS(elements, FixedArrayBase)
+  inline void initialize_elements();
+  static inline void SetMapAndElements(Handle<JSObject> object, Handle<Map> map,
+                                       Handle<FixedArrayBase> elements);
+  inline ElementsKind GetElementsKind() const;
+  ElementsAccessor* GetElementsAccessor();
+  // Returns true if an object has elements of PACKED_SMI_ELEMENTS or
+  // HOLEY_SMI_ELEMENTS ElementsKind.
+  inline bool HasSmiElements();
+  // Returns true if an object has elements of PACKED_ELEMENTS or
+  // HOLEY_ELEMENTS ElementsKind.
+  inline bool HasObjectElements();
+  // Returns true if an object has elements of PACKED_SMI_ELEMENTS,
+  // HOLEY_SMI_ELEMENTS, PACKED_ELEMENTS, or HOLEY_ELEMENTS.
+  inline bool HasSmiOrObjectElements();
+  // Returns true if an object has any of the "fast" elements kinds.
+  inline bool HasFastElements();
+  // Returns true if an object has any of the PACKED elements kinds.
+  inline bool HasFastPackedElements();
+  // Returns true if an object has elements of PACKED_DOUBLE_ELEMENTS or
+  // HOLEY_DOUBLE_ELEMENTS ElementsKind.
+  inline bool HasDoubleElements();
+  // Returns true if an object has elements of HOLEY_SMI_ELEMENTS,
+  // HOLEY_DOUBLE_ELEMENTS, or HOLEY_ELEMENTS ElementsKind.
+  inline bool HasHoleyElements();
+  inline bool HasSloppyArgumentsElements();
+  inline bool HasStringWrapperElements();
+  inline bool HasDictionaryElements();
+
+  inline bool HasFixedTypedArrayElements();
+
+  inline bool HasFixedUint8ClampedElements();
+  inline bool HasFixedArrayElements();
+  inline bool HasFixedInt8Elements();
+  inline bool HasFixedUint8Elements();
+  inline bool HasFixedInt16Elements();
+  inline bool HasFixedUint16Elements();
+  inline bool HasFixedInt32Elements();
+  inline bool HasFixedUint32Elements();
+  inline bool HasFixedFloat32Elements();
+  inline bool HasFixedFloat64Elements();
+  inline bool HasFixedBigInt64Elements();
+  inline bool HasFixedBigUint64Elements();
+
+  inline bool HasFastArgumentsElements();
+  inline bool HasSlowArgumentsElements();
+  inline bool HasFastStringWrapperElements();
+  inline bool HasSlowStringWrapperElements();
+  bool HasEnumerableElements();
+
+  inline NumberDictionary* element_dictionary();  // Gets slow elements.
+
+  // Requires: HasFastElements().
+  static void EnsureWritableFastElements(Handle<JSObject> object);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyWithInterceptor(
+      LookupIterator* it, ShouldThrow should_throw, Handle<Object> value);
+
+  // The API currently still wants DefineOwnPropertyIgnoreAttributes to convert
+  // AccessorInfo objects to data fields. We allow FORCE_FIELD as an exception
+  // to the default behavior that calls the setter.
+  enum AccessorInfoHandling { FORCE_FIELD, DONT_FORCE_FIELD };
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  DefineOwnPropertyIgnoreAttributes(
+      LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
+      AccessorInfoHandling handling = DONT_FORCE_FIELD);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DefineOwnPropertyIgnoreAttributes(
+      LookupIterator* it, Handle<Object> value, PropertyAttributes attributes,
+      ShouldThrow should_throw,
+      AccessorInfoHandling handling = DONT_FORCE_FIELD);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  SetOwnPropertyIgnoreAttributes(Handle<JSObject> object, Handle<Name> name,
+                                 Handle<Object> value,
+                                 PropertyAttributes attributes);
+
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  SetOwnElementIgnoreAttributes(Handle<JSObject> object, uint32_t index,
+                                Handle<Object> value,
+                                PropertyAttributes attributes);
+
+  // Equivalent to one of the above depending on whether |name| can be converted
+  // to an array index.
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  DefinePropertyOrElementIgnoreAttributes(Handle<JSObject> object,
+                                          Handle<Name> name,
+                                          Handle<Object> value,
+                                          PropertyAttributes attributes = NONE);
+
+  // Adds or reconfigures a property to attributes NONE. It will fail when it
+  // cannot.
+  V8_WARN_UNUSED_RESULT static Maybe<bool> CreateDataProperty(
+      LookupIterator* it, Handle<Object> value,
+      ShouldThrow should_throw = kDontThrow);
+
+  static void AddProperty(Isolate* isolate, Handle<JSObject> object,
+                          Handle<Name> name, Handle<Object> value,
+                          PropertyAttributes attributes);
+
+  static void AddDataElement(Handle<JSObject> receiver, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes);
+
+  // Extend the receiver with a single fast property appeared first in the
+  // passed map. This also extends the property backing store if necessary.
+  static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
+
+  // Migrates the given object to a map whose field representations are the
+  // lowest upper bound of all known representations for that field.
+  static void MigrateInstance(Handle<JSObject> instance);
+
+  // Migrates the given object only if the target map is already available,
+  // or returns false if such a map is not yet available.
+  static bool TryMigrateInstance(Handle<JSObject> instance);
+
+  // Sets the property value in a normalized object given (key, value, details).
+  // Handles the special representation of JS global objects.
+  static void SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name,
+                                    Handle<Object> value,
+                                    PropertyDetails details);
+  static void SetDictionaryElement(Handle<JSObject> object, uint32_t index,
+                                   Handle<Object> value,
+                                   PropertyAttributes attributes);
+  static void SetDictionaryArgumentsElement(Handle<JSObject> object,
+                                            uint32_t index,
+                                            Handle<Object> value,
+                                            PropertyAttributes attributes);
+
+  static void OptimizeAsPrototype(Handle<JSObject> object,
+                                  bool enable_setup_mode = true);
+  static void ReoptimizeIfPrototype(Handle<JSObject> object);
+  static void MakePrototypesFast(Handle<Object> receiver,
+                                 WhereToStart where_to_start, Isolate* isolate);
+  static void LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate);
+  static void UpdatePrototypeUserRegistration(Handle<Map> old_map,
+                                              Handle<Map> new_map,
+                                              Isolate* isolate);
+  static bool UnregisterPrototypeUser(Handle<Map> user, Isolate* isolate);
+  static Map* InvalidatePrototypeChains(Map* map);
+  static void InvalidatePrototypeValidityCell(JSGlobalObject* global);
+
+  // Updates prototype chain tracking information when an object changes its
+  // map from |old_map| to |new_map|.
+  static void NotifyMapChange(Handle<Map> old_map, Handle<Map> new_map,
+                              Isolate* isolate);
+
+  // Utility used by many Array builtins and runtime functions
+  static inline bool PrototypeHasNoElements(Isolate* isolate, JSObject* object);
+
+  // To be passed to PrototypeUsers::Compact.
+  static void PrototypeRegistryCompactionCallback(HeapObject* value,
+                                                  int old_index, int new_index);
+
+  // Retrieve interceptors.
+  inline InterceptorInfo* GetNamedInterceptor();
+  inline InterceptorInfo* GetIndexedInterceptor();
+
+  // Used from JSReceiver.
+  V8_WARN_UNUSED_RESULT static Maybe<PropertyAttributes>
+  GetPropertyAttributesWithInterceptor(LookupIterator* it);
+  V8_WARN_UNUSED_RESULT static Maybe<PropertyAttributes>
+  GetPropertyAttributesWithFailedAccessCheck(LookupIterator* it);
+
+  // Defines an AccessorPair property on the given object.
+  // TODO(mstarzinger): Rename to SetAccessor().
+  static MaybeHandle<Object> DefineAccessor(Handle<JSObject> object,
+                                            Handle<Name> name,
+                                            Handle<Object> getter,
+                                            Handle<Object> setter,
+                                            PropertyAttributes attributes);
+  static MaybeHandle<Object> DefineAccessor(LookupIterator* it,
+                                            Handle<Object> getter,
+                                            Handle<Object> setter,
+                                            PropertyAttributes attributes);
+
+  // Defines an AccessorInfo property on the given object.
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> SetAccessor(
+      Handle<JSObject> object, Handle<Name> name, Handle<AccessorInfo> info,
+      PropertyAttributes attributes);
+
+  // The result must be checked first for exceptions. If there's no exception,
+  // the output parameter |done| indicates whether the interceptor has a result
+  // or not.
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
+      LookupIterator* it, bool* done);
+
+  static void ValidateElements(JSObject* object);
+
+  // Makes sure that this object can contain HeapObject as elements.
+  static inline void EnsureCanContainHeapObjectElements(Handle<JSObject> obj);
+
+  // Makes sure that this object can contain the specified elements.
+  static inline void EnsureCanContainElements(Handle<JSObject> object,
+                                              Object** elements, uint32_t count,
+                                              EnsureElementsMode mode);
+  static inline void EnsureCanContainElements(Handle<JSObject> object,
+                                              Handle<FixedArrayBase> elements,
+                                              uint32_t length,
+                                              EnsureElementsMode mode);
+  static void EnsureCanContainElements(Handle<JSObject> object,
+                                       Arguments* arguments, uint32_t first_arg,
+                                       uint32_t arg_count,
+                                       EnsureElementsMode mode);
+
+  // Would we convert a fast elements array to dictionary mode given
+  // an access at key?
+  bool WouldConvertToSlowElements(uint32_t index);
+
+  static const uint32_t kMinAddedElementsCapacity = 16;
+
+  // Computes the new capacity when expanding the elements of a JSObject.
+  static uint32_t NewElementsCapacity(uint32_t old_capacity) {
+    // (old_capacity + 50%) + kMinAddedElementsCapacity
+    return old_capacity + (old_capacity >> 1) + kMinAddedElementsCapacity;
+  }
+
+  // These methods do not perform access checks!
+  template <AllocationSiteUpdateMode update_or_check =
+                AllocationSiteUpdateMode::kUpdate>
+  static bool UpdateAllocationSite(Handle<JSObject> object,
+                                   ElementsKind to_kind);
+
+  // Lookup interceptors are used for handling properties controlled by host
+  // objects.
+  inline bool HasNamedInterceptor();
+  inline bool HasIndexedInterceptor();
+
+  // Support functions for v8 api (needed for correct interceptor behavior).
+  V8_WARN_UNUSED_RESULT static Maybe<bool> HasRealNamedProperty(
+      Handle<JSObject> object, Handle<Name> name);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> HasRealElementProperty(
+      Handle<JSObject> object, uint32_t index);
+  V8_WARN_UNUSED_RESULT static Maybe<bool> HasRealNamedCallbackProperty(
+      Handle<JSObject> object, Handle<Name> name);
+
+  // Get the header size for a JSObject.  Used to compute the index of
+  // embedder fields as well as the number of embedder fields.
+  // The |function_has_prototype_slot| parameter is needed only for
+  // JSFunction objects.
+  static int GetHeaderSize(InstanceType instance_type,
+                           bool function_has_prototype_slot = false);
+  static inline int GetHeaderSize(const Map* map);
+  inline int GetHeaderSize() const;
+
+  static inline int GetEmbedderFieldCount(const Map* map);
+  inline int GetEmbedderFieldCount() const;
+  inline int GetEmbedderFieldOffset(int index);
+  inline Object* GetEmbedderField(int index);
+  inline void SetEmbedderField(int index, Object* value);
+  inline void SetEmbedderField(int index, Smi* value);
+
+  // Returns true when the object is potentially a wrapper that gets special
+  // garbage collection treatment.
+  // TODO(mlippautz): Make check exact and replace the pattern match in
+  // Heap::TracePossibleWrapper.
+  bool IsApiWrapper();
+
+  // Same as IsApiWrapper() but also allow dropping the wrapper on minor GCs.
+  bool IsDroppableApiWrapper();
+
+  // Returns a new map with all transitions dropped from the object's current
+  // map and the ElementsKind set.
+  static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object,
+                                              ElementsKind to_kind);
+  static void TransitionElementsKind(Handle<JSObject> object,
+                                     ElementsKind to_kind);
+
+  // Always use this to migrate an object to a new map.
+  // |expected_additional_properties| is only used for fast-to-slow transitions
+  // and ignored otherwise.
+  static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map,
+                           int expected_additional_properties = 0);
+
+  // Forces a prototype without any of the checks that the regular SetPrototype
+  // would do.
+  static void ForceSetPrototype(Handle<JSObject> object, Handle<Object> proto);
+
+  // Convert the object to use the canonical dictionary
+  // representation. If the object is expected to have additional properties
+  // added this number can be indicated to have the backing store allocated to
+  // an initial capacity for holding these properties.
+  static void NormalizeProperties(Handle<JSObject> object,
+                                  PropertyNormalizationMode mode,
+                                  int expected_additional_properties,
+                                  const char* reason);
+
+  // Convert and update the elements backing store to be a
+  // NumberDictionary dictionary.  Returns the backing after conversion.
+  static Handle<NumberDictionary> NormalizeElements(Handle<JSObject> object);
+
+  void RequireSlowElements(NumberDictionary* dictionary);
+
+  // Transform slow named properties to fast variants.
+  static void MigrateSlowToFast(Handle<JSObject> object,
+                                int unused_property_fields, const char* reason);
+
+  inline bool IsUnboxedDoubleField(FieldIndex index);
+
+  // Access fast-case object properties at index.
+  static Handle<Object> FastPropertyAt(Handle<JSObject> object,
+                                       Representation representation,
+                                       FieldIndex index);
+  inline Object* RawFastPropertyAt(FieldIndex index);
+  inline double RawFastDoublePropertyAt(FieldIndex index);
+  inline uint64_t RawFastDoublePropertyAsBitsAt(FieldIndex index);
+
+  inline void FastPropertyAtPut(FieldIndex index, Object* value);
+  inline void RawFastPropertyAtPut(FieldIndex index, Object* value);
+  inline void RawFastDoublePropertyAsBitsAtPut(FieldIndex index, uint64_t bits);
+  inline void WriteToField(int descriptor, PropertyDetails details,
+                           Object* value);
+
+  // Access to in object properties.
+  inline int GetInObjectPropertyOffset(int index);
+  inline Object* InObjectPropertyAt(int index);
+  inline Object* InObjectPropertyAtPut(
+      int index, Object* value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
+  // Set the object's prototype (only JSReceiver and null are allowed values).
+  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPrototype(
+      Handle<JSObject> object, Handle<Object> value, bool from_javascript,
+      ShouldThrow should_throw);
+
+  // Makes the object prototype immutable
+  // Never called from JavaScript
+  static void SetImmutableProto(Handle<JSObject> object);
+
+  // Initializes the body starting at |start_offset|. It is responsibility of
+  // the caller to initialize object header. Fill the pre-allocated fields with
+  // pre_allocated_value and the rest with filler_value.
+  // Note: this call does not update write barrier, the caller is responsible
+  // to ensure that |filler_value| can be collected without WB here.
+  inline void InitializeBody(Map* map, int start_offset,
+                             Object* pre_allocated_value, Object* filler_value);
+
+  // Check whether this object references another object
+  bool ReferencesObject(Object* obj);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> TestIntegrityLevel(
+      Handle<JSObject> object, IntegrityLevel lvl);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> PreventExtensions(
+      Handle<JSObject> object, ShouldThrow should_throw);
+
+  static bool IsExtensible(Handle<JSObject> object);
+
+  DECL_CAST(JSObject)
+
+  // Dispatched behavior.
+  void JSObjectShortPrint(StringStream* accumulator);
+  DECL_PRINTER(JSObject)
+  DECL_VERIFIER(JSObject)
+#ifdef OBJECT_PRINT
+  bool PrintProperties(std::ostream& os);  // NOLINT
+  void PrintElements(std::ostream& os);    // NOLINT
+#endif
+#if defined(DEBUG) || defined(OBJECT_PRINT)
+  void PrintTransitions(std::ostream& os);  // NOLINT
+#endif
+
+  static void PrintElementsTransition(FILE* file, Handle<JSObject> object,
+                                      ElementsKind from_kind,
+                                      Handle<FixedArrayBase> from_elements,
+                                      ElementsKind to_kind,
+                                      Handle<FixedArrayBase> to_elements);
+
+  void PrintInstanceMigration(FILE* file, Map* original_map, Map* new_map);
+
+#ifdef DEBUG
+  // Structure for collecting spill information about JSObjects.
+  class SpillInformation {
+   public:
+    void Clear();
+    void Print();
+    int number_of_objects_;
+    int number_of_objects_with_fast_properties_;
+    int number_of_objects_with_fast_elements_;
+    int number_of_fast_used_fields_;
+    int number_of_fast_unused_fields_;
+    int number_of_slow_used_properties_;
+    int number_of_slow_unused_properties_;
+    int number_of_fast_used_elements_;
+    int number_of_fast_unused_elements_;
+    int number_of_slow_used_elements_;
+    int number_of_slow_unused_elements_;
+  };
+
+  void IncrementSpillStatistics(Isolate* isolate, SpillInformation* info);
+#endif
+
+#ifdef VERIFY_HEAP
+  // If a GC was caused while constructing this object, the elements pointer
+  // may point to a one pointer filler map. The object won't be rooted, but
+  // our heap verification code could stumble across it.
+  bool ElementsAreSafeToExamine() const;
+#endif
+
+  Object* SlowReverseLookup(Object* value);
+
+  // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
+  // Also maximal value of JSArray's length property.
+  static const uint32_t kMaxElementCount = 0xffffffffu;
+
+  // Constants for heuristics controlling conversion of fast elements
+  // to slow elements.
+
+  // Maximal gap that can be introduced by adding an element beyond
+  // the current elements length.
+  static const uint32_t kMaxGap = 1024;
+
+  // Maximal length of fast elements array that won't be checked for
+  // being dense enough on expansion.
+  static const int kMaxUncheckedFastElementsLength = 5000;
+
+  // Same as above but for old arrays. This limit is more strict. We
+  // don't want to be wasteful with long lived objects.
+  static const int kMaxUncheckedOldFastElementsLength = 500;
+
+  // This constant applies only to the initial map of "global.Object" and
+  // not to arbitrary other JSObject maps.
+  static const int kInitialGlobalObjectUnusedPropertiesCount = 4;
+
+  static const int kMaxInstanceSize = 255 * kPointerSize;
+
+  // When extending the backing storage for property values, we increase
+  // its size by more than the 1 entry necessary, so sequentially adding fields
+  // to the same object requires fewer allocations and copies.
+  static const int kFieldsAdded = 3;
+  STATIC_ASSERT(kMaxNumberOfDescriptors + kFieldsAdded <=
+                PropertyArray::kMaxLength);
+
+  // Layout description.
+  static const int kElementsOffset = JSReceiver::kHeaderSize;
+  static const int kHeaderSize = kElementsOffset + kPointerSize;
+
+  STATIC_ASSERT(kHeaderSize == Internals::kJSObjectHeaderSize);
+  static const int kMaxInObjectProperties =
+      (kMaxInstanceSize - kHeaderSize) >> kPointerSizeLog2;
+  STATIC_ASSERT(kMaxInObjectProperties <= kMaxNumberOfDescriptors);
+  // TODO(cbruni): Revisit calculation of the max supported embedder fields.
+  static const int kMaxEmbedderFields =
+      ((1 << kFirstInobjectPropertyOffsetBitCount) - 1 - kHeaderSize) >>
+      kPointerSizeLog2;
+  STATIC_ASSERT(kMaxEmbedderFields <= kMaxInObjectProperties);
+
+  class BodyDescriptor;
+
+  class FastBodyDescriptor;
+
+  // Gets the number of currently used elements.
+  int GetFastElementsUsage();
+
+  static bool AllCanRead(LookupIterator* it);
+  static bool AllCanWrite(LookupIterator* it);
+
+ private:
+  friend class JSReceiver;
+  friend class Object;
+
+  // Used from Object::GetProperty().
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  GetPropertyWithFailedAccessCheck(LookupIterator* it);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> SetPropertyWithFailedAccessCheck(
+      LookupIterator* it, Handle<Object> value, ShouldThrow should_throw);
+
+  V8_WARN_UNUSED_RESULT static Maybe<bool> DeletePropertyWithInterceptor(
+      LookupIterator* it, ShouldThrow should_throw);
+
+  bool ReferencesObjectFromElements(FixedArray* elements, ElementsKind kind,
+                                    Object* object);
+
+  // Helper for fast versions of preventExtensions, seal, and freeze.
+  // attrs is one of NONE, SEALED, or FROZEN (depending on the operation).
+  template <PropertyAttributes attrs>
+  V8_WARN_UNUSED_RESULT static Maybe<bool> PreventExtensionsWithTransition(
+      Handle<JSObject> object, ShouldThrow should_throw);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
+};
+
+// JSAccessorPropertyDescriptor is just a JSObject with a specific initial
+// map. This initial map adds in-object properties for "get", "set",
+// "enumerable" and "configurable" properties, as assigned by the
+// FromPropertyDescriptor function for regular accessor properties.
+class JSAccessorPropertyDescriptor : public JSObject {
+ public:
+  // Offsets of object fields.
+  static const int kGetOffset = JSObject::kHeaderSize;
+  static const int kSetOffset = kGetOffset + kPointerSize;
+  static const int kEnumerableOffset = kSetOffset + kPointerSize;
+  static const int kConfigurableOffset = kEnumerableOffset + kPointerSize;
+  static const int kSize = kConfigurableOffset + kPointerSize;
+  // Indices of in-object properties.
+  static const int kGetIndex = 0;
+  static const int kSetIndex = 1;
+  static const int kEnumerableIndex = 2;
+  static const int kConfigurableIndex = 3;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSAccessorPropertyDescriptor);
+};
+
+// JSDataPropertyDescriptor is just a JSObject with a specific initial map.
+// This initial map adds in-object properties for "value", "writable",
+// "enumerable" and "configurable" properties, as assigned by the
+// FromPropertyDescriptor function for regular data properties.
+class JSDataPropertyDescriptor : public JSObject {
+ public:
+  // Offsets of object fields.
+  static const int kValueOffset = JSObject::kHeaderSize;
+  static const int kWritableOffset = kValueOffset + kPointerSize;
+  static const int kEnumerableOffset = kWritableOffset + kPointerSize;
+  static const int kConfigurableOffset = kEnumerableOffset + kPointerSize;
+  static const int kSize = kConfigurableOffset + kPointerSize;
+  // Indices of in-object properties.
+  static const int kValueIndex = 0;
+  static const int kWritableIndex = 1;
+  static const int kEnumerableIndex = 2;
+  static const int kConfigurableIndex = 3;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataPropertyDescriptor);
+};
+
+// JSIteratorResult is just a JSObject with a specific initial map.
+// This initial map adds in-object properties for "done" and "value",
+// as specified by ES6 section 25.1.1.3 The IteratorResult Interface
+class JSIteratorResult : public JSObject {
+ public:
+  DECL_ACCESSORS(value, Object)
+
+  DECL_ACCESSORS(done, Object)
+
+  // Offsets of object fields.
+  static const int kValueOffset = JSObject::kHeaderSize;
+  static const int kDoneOffset = kValueOffset + kPointerSize;
+  static const int kSize = kDoneOffset + kPointerSize;
+  // Indices of in-object properties.
+  static const int kValueIndex = 0;
+  static const int kDoneIndex = 1;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSIteratorResult);
+};
+
+// JSBoundFunction describes a bound function exotic object.
+class JSBoundFunction : public JSObject {
+ public:
+  // [bound_target_function]: The wrapped function object.
+  inline Object* raw_bound_target_function() const;
+  DECL_ACCESSORS(bound_target_function, JSReceiver)
+
+  // [bound_this]: The value that is always passed as the this value when
+  // calling the wrapped function.
+  DECL_ACCESSORS(bound_this, Object)
+
+  // [bound_arguments]: A list of values whose elements are used as the first
+  // arguments to any call to the wrapped function.
+  DECL_ACCESSORS(bound_arguments, FixedArray)
+
+  static MaybeHandle<String> GetName(Isolate* isolate,
+                                     Handle<JSBoundFunction> function);
+  static Maybe<int> GetLength(Isolate* isolate,
+                              Handle<JSBoundFunction> function);
+  static MaybeHandle<Context> GetFunctionRealm(
+      Handle<JSBoundFunction> function);
+
+  DECL_CAST(JSBoundFunction)
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSBoundFunction)
+  DECL_VERIFIER(JSBoundFunction)
+
+  // The bound function's string representation implemented according
+  // to ES6 section 19.2.3.5 Function.prototype.toString ( ).
+  static Handle<String> ToString(Handle<JSBoundFunction> function);
+
+  // Layout description.
+  static const int kBoundTargetFunctionOffset = JSObject::kHeaderSize;
+  static const int kBoundThisOffset = kBoundTargetFunctionOffset + kPointerSize;
+  static const int kBoundArgumentsOffset = kBoundThisOffset + kPointerSize;
+  static const int kSize = kBoundArgumentsOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSBoundFunction);
+};
+
+// JSFunction describes JavaScript functions.
+class JSFunction : public JSObject {
+ public:
+  // [prototype_or_initial_map]:
+  DECL_ACCESSORS(prototype_or_initial_map, Object)
+
+  // [shared]: The information about the function that
+  // can be shared by instances.
+  DECL_ACCESSORS(shared, SharedFunctionInfo)
+
+  static const int kLengthDescriptorIndex = 0;
+  static const int kNameDescriptorIndex = 1;
+  // Home object descriptor index when function has a [[HomeObject]] slot.
+  static const int kMaybeHomeObjectDescriptorIndex = 2;
+
+  // [context]: The context for this function.
+  inline Context* context();
+  inline bool has_context() const;
+  inline void set_context(Object* context);
+  inline JSGlobalProxy* global_proxy();
+  inline Context* native_context();
+
+  static Handle<Object> GetName(Isolate* isolate, Handle<JSFunction> function);
+  static Maybe<int> GetLength(Isolate* isolate, Handle<JSFunction> function);
+  static Handle<Context> GetFunctionRealm(Handle<JSFunction> function);
+
+  // [code]: The generated code object for this function.  Executed
+  // when the function is invoked, e.g. foo() or new foo(). See
+  // [[Call]] and [[Construct]] description in ECMA-262, section
+  // 8.6.2, page 27.
+  inline Code* code();
+  inline void set_code(Code* code);
+  inline void set_code_no_write_barrier(Code* code);
+
+  // Get the abstract code associated with the function, which will either be
+  // a Code object or a BytecodeArray.
+  inline AbstractCode* abstract_code();
+
+  // Tells whether or not this function is interpreted.
+  //
+  // Note: function->IsInterpreted() does not necessarily return the same value
+  // as function->shared()->IsInterpreted() because the closure might have been
+  // optimized.
+  inline bool IsInterpreted();
+
+  // Tells whether or not this function checks its optimization marker in its
+  // feedback vector.
+  inline bool ChecksOptimizationMarker();
+
+  // Tells whether or not this function holds optimized code.
+  //
+  // Note: Returning false does not necessarily mean that this function hasn't
+  // been optimized, as it may have optimized code on its feedback vector.
+  inline bool IsOptimized();
+
+  // Tells whether or not this function has optimized code available to it,
+  // either because it is optimized or because it has optimized code in its
+  // feedback vector.
+  inline bool HasOptimizedCode();
+
+  // Tells whether or not this function has a (non-zero) optimization marker.
+  inline bool HasOptimizationMarker();
+
+  // Mark this function for lazy recompilation. The function will be recompiled
+  // the next time it is executed.
+  void MarkForOptimization(ConcurrencyMode mode);
+
+  // Tells whether or not the function is already marked for lazy recompilation.
+  inline bool IsMarkedForOptimization();
+  inline bool IsMarkedForConcurrentOptimization();
+
+  // Tells whether or not the function is on the concurrent recompilation queue.
+  inline bool IsInOptimizationQueue();
+
+  // Clears the optimized code slot in the function's feedback vector.
+  inline void ClearOptimizedCodeSlot(const char* reason);
+
+  // Sets the optimization marker in the function's feedback vector.
+  inline void SetOptimizationMarker(OptimizationMarker marker);
+
+  // Clears the optimization marker in the function's feedback vector.
+  inline void ClearOptimizationMarker();
+
+  // If slack tracking is active, it computes instance size of the initial map
+  // with minimum permissible object slack.  If it is not active, it simply
+  // returns the initial map's instance size.
+  int ComputeInstanceSizeWithMinSlack(Isolate* isolate);
+
+  // Completes inobject slack tracking on initial map if it is active.
+  inline void CompleteInobjectSlackTrackingIfActive();
+
+  // [feedback_cell]: The FeedbackCell used to hold the FeedbackVector
+  // eventually.
+  DECL_ACCESSORS(feedback_cell, FeedbackCell)
+
+  // feedback_vector() can be used once the function is compiled.
+  inline FeedbackVector* feedback_vector() const;
+  inline bool has_feedback_vector() const;
+  static void EnsureFeedbackVector(Handle<JSFunction> function);
+
+  // Unconditionally clear the type feedback vector.
+  void ClearTypeFeedbackInfo();
+
+  inline bool has_prototype_slot() const;
+
+  // The initial map for an object created by this constructor.
+  inline Map* initial_map();
+  static void SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
+                            Handle<Object> prototype);
+  inline bool has_initial_map();
+  static void EnsureHasInitialMap(Handle<JSFunction> function);
+
+  // Creates a map that matches the constructor's initial map, but with
+  // [[prototype]] being new.target.prototype. Because new.target can be a
+  // JSProxy, this can call back into JavaScript.
+  static V8_WARN_UNUSED_RESULT MaybeHandle<Map> GetDerivedMap(
+      Isolate* isolate, Handle<JSFunction> constructor,
+      Handle<JSReceiver> new_target);
+
+  // Get and set the prototype property on a JSFunction. If the
+  // function has an initial map the prototype is set on the initial
+  // map. Otherwise, the prototype is put in the initial map field
+  // until an initial map is needed.
+  inline bool has_prototype();
+  inline bool has_instance_prototype();
+  inline Object* prototype();
+  inline Object* instance_prototype();
+  inline bool has_prototype_property();
+  inline bool PrototypeRequiresRuntimeLookup();
+  static void SetPrototype(Handle<JSFunction> function, Handle<Object> value);
+
+  // Returns if this function has been compiled to native code yet.
+  inline bool is_compiled();
+
+  static int GetHeaderSize(bool function_has_prototype_slot) {
+    return function_has_prototype_slot ? JSFunction::kSizeWithPrototype
+                                       : JSFunction::kSizeWithoutPrototype;
+  }
+
+  // Prints the name of the function using PrintF.
+  void PrintName(FILE* out = stdout);
+
+  DECL_CAST(JSFunction)
+
+  // Calculate the instance size and in-object properties count.
+  static bool CalculateInstanceSizeForDerivedClass(
+      Handle<JSFunction> function, InstanceType instance_type,
+      int requested_embedder_fields, int* instance_size,
+      int* in_object_properties);
+  static void CalculateInstanceSizeHelper(InstanceType instance_type,
+                                          bool has_prototype_slot,
+                                          int requested_embedder_fields,
+                                          int requested_in_object_properties,
+                                          int* instance_size,
+                                          int* in_object_properties);
+
+  class BodyDescriptor;
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSFunction)
+  DECL_VERIFIER(JSFunction)
+
+  // The function's name if it is configured, otherwise shared function info
+  // debug name.
+  static Handle<String> GetName(Handle<JSFunction> function);
+
+  // ES6 section 9.2.11 SetFunctionName
+  // Because of the way this abstract operation is used in the spec,
+  // it should never fail, but in practice it will fail if the generated
+  // function name's length exceeds String::kMaxLength.
+  static V8_WARN_UNUSED_RESULT bool SetName(Handle<JSFunction> function,
+                                            Handle<Name> name,
+                                            Handle<String> prefix);
+
+  // The function's displayName if it is set, otherwise name if it is
+  // configured, otherwise shared function info
+  // debug name.
+  static Handle<String> GetDebugName(Handle<JSFunction> function);
+
+  // The function's string representation implemented according to
+  // ES6 section 19.2.3.5 Function.prototype.toString ( ).
+  static Handle<String> ToString(Handle<JSFunction> function);
+
+// Layout description.
+#define JS_FUNCTION_FIELDS(V)                              \
+  /* Pointer fields. */                                    \
+  V(kSharedFunctionInfoOffset, kPointerSize)               \
+  V(kContextOffset, kPointerSize)                          \
+  V(kFeedbackCellOffset, kPointerSize)                     \
+  V(kEndOfStrongFieldsOffset, 0)                           \
+  V(kCodeOffset, kPointerSize)                             \
+  /* Size of JSFunction object without prototype field. */ \
+  V(kSizeWithoutPrototype, 0)                              \
+  V(kPrototypeOrInitialMapOffset, kPointerSize)            \
+  /* Size of JSFunction object with prototype field. */    \
+  V(kSizeWithPrototype, 0)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, JS_FUNCTION_FIELDS)
+#undef JS_FUNCTION_FIELDS
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction);
+};
+
+// JSGlobalProxy's prototype must be a JSGlobalObject or null,
+// and the prototype is hidden. JSGlobalProxy always delegates
+// property accesses to its prototype if the prototype is not null.
+//
+// A JSGlobalProxy can be reinitialized which will preserve its identity.
+//
+// Accessing a JSGlobalProxy requires security check.
+
+class JSGlobalProxy : public JSObject {
+ public:
+  // [native_context]: the owner native context of this global proxy object.
+  // It is null value if this object is not used by any context.
+  DECL_ACCESSORS(native_context, Object)
+
+  DECL_CAST(JSGlobalProxy)
+
+  inline bool IsDetachedFrom(JSGlobalObject* global) const;
+
+  static int SizeWithEmbedderFields(int embedder_field_count);
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSGlobalProxy)
+  DECL_VERIFIER(JSGlobalProxy)
+
+  // Layout description.
+  static const int kNativeContextOffset = JSObject::kHeaderSize;
+  static const int kSize = kNativeContextOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy);
+};
+
+// JavaScript global object.
+class JSGlobalObject : public JSObject {
+ public:
+  // [native context]: the natives corresponding to this global object.
+  DECL_ACCESSORS(native_context, Context)
+
+  // [global proxy]: the global proxy object of the context
+  DECL_ACCESSORS(global_proxy, JSObject)
+
+  // Gets global object properties.
+  inline GlobalDictionary* global_dictionary();
+  inline void set_global_dictionary(GlobalDictionary* dictionary);
+
+  static void InvalidatePropertyCell(Handle<JSGlobalObject> object,
+                                     Handle<Name> name);
+  // Ensure that the global object has a cell for the given property name.
+  static Handle<PropertyCell> EnsureEmptyPropertyCell(
+      Handle<JSGlobalObject> global, Handle<Name> name,
+      PropertyCellType cell_type, int* entry_out = nullptr);
+
+  DECL_CAST(JSGlobalObject)
+
+  inline bool IsDetached();
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSGlobalObject)
+  DECL_VERIFIER(JSGlobalObject)
+
+  // Layout description.
+  static const int kNativeContextOffset = JSObject::kHeaderSize;
+  static const int kGlobalProxyOffset = kNativeContextOffset + kPointerSize;
+  static const int kHeaderSize = kGlobalProxyOffset + kPointerSize;
+  static const int kSize = kHeaderSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject);
+};
+
+// Representation for JS Wrapper objects, String, Number, Boolean, etc.
+class JSValue : public JSObject {
+ public:
+  // [value]: the object being wrapped.
+  DECL_ACCESSORS(value, Object)
+
+  DECL_CAST(JSValue)
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSValue)
+  DECL_VERIFIER(JSValue)
+
+  // Layout description.
+  static const int kValueOffset = JSObject::kHeaderSize;
+  static const int kSize = kValueOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue);
+};
+
+class DateCache;
+
+// Representation for JS date objects.
+class JSDate : public JSObject {
+ public:
+  static V8_WARN_UNUSED_RESULT MaybeHandle<JSDate> New(
+      Handle<JSFunction> constructor, Handle<JSReceiver> new_target, double tv);
+
+  // If one component is NaN, all of them are, indicating a NaN time value.
+  // [value]: the time value.
+  DECL_ACCESSORS(value, Object)
+  // [year]: caches year. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(year, Object)
+  // [month]: caches month. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(month, Object)
+  // [day]: caches day. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(day, Object)
+  // [weekday]: caches day of week. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(weekday, Object)
+  // [hour]: caches hours. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(hour, Object)
+  // [min]: caches minutes. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(min, Object)
+  // [sec]: caches seconds. Either undefined, smi, or NaN.
+  DECL_ACCESSORS(sec, Object)
+  // [cache stamp]: sample of the date cache stamp at the
+  // moment when chached fields were cached.
+  DECL_ACCESSORS(cache_stamp, Object)
+
+  DECL_CAST(JSDate)
+
+  // Returns the time value (UTC) identifying the current time.
+  static double CurrentTimeValue(Isolate* isolate);
+
+  // Returns the date field with the specified index.
+  // See FieldIndex for the list of date fields.
+  static Object* GetField(Object* date, Smi* index);
+
+  static Handle<Object> SetValue(Handle<JSDate> date, double v);
+
+  void SetValue(Object* value, bool is_value_nan);
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSDate)
+  DECL_VERIFIER(JSDate)
+
+  // The order is important. It must be kept in sync with date macros
+  // in macros.py.
+  enum FieldIndex {
+    kDateValue,
+    kYear,
+    kMonth,
+    kDay,
+    kWeekday,
+    kHour,
+    kMinute,
+    kSecond,
+    kFirstUncachedField,
+    kMillisecond = kFirstUncachedField,
+    kDays,
+    kTimeInDay,
+    kFirstUTCField,
+    kYearUTC = kFirstUTCField,
+    kMonthUTC,
+    kDayUTC,
+    kWeekdayUTC,
+    kHourUTC,
+    kMinuteUTC,
+    kSecondUTC,
+    kMillisecondUTC,
+    kDaysUTC,
+    kTimeInDayUTC,
+    kTimezoneOffset
+  };
+
+  // Layout description.
+  static const int kValueOffset = JSObject::kHeaderSize;
+  static const int kYearOffset = kValueOffset + kPointerSize;
+  static const int kMonthOffset = kYearOffset + kPointerSize;
+  static const int kDayOffset = kMonthOffset + kPointerSize;
+  static const int kWeekdayOffset = kDayOffset + kPointerSize;
+  static const int kHourOffset = kWeekdayOffset + kPointerSize;
+  static const int kMinOffset = kHourOffset + kPointerSize;
+  static const int kSecOffset = kMinOffset + kPointerSize;
+  static const int kCacheStampOffset = kSecOffset + kPointerSize;
+  static const int kSize = kCacheStampOffset + kPointerSize;
+
+ private:
+  inline Object* DoGetField(FieldIndex index);
+
+  Object* GetUTCField(FieldIndex index, double value, DateCache* date_cache);
+
+  // Computes and caches the cacheable fields of the date.
+  inline void SetCachedFields(int64_t local_time_ms, DateCache* date_cache);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSDate);
+};
+
+// Representation of message objects used for error reporting through
+// the API. The messages are formatted in JavaScript so this object is
+// a real JavaScript object. The information used for formatting the
+// error messages are not directly accessible from JavaScript to
+// prevent leaking information to user code called during error
+// formatting.
+class JSMessageObject : public JSObject {
+ public:
+  // [type]: the type of error message.
+  inline int type() const;
+  inline void set_type(int value);
+
+  // [arguments]: the arguments for formatting the error message.
+  DECL_ACCESSORS(argument, Object)
+
+  // [script]: the script from which the error message originated.
+  DECL_ACCESSORS(script, Script)
+
+  // [stack_frames]: an array of stack frames for this error object.
+  DECL_ACCESSORS(stack_frames, Object)
+
+  // [start_position]: the start position in the script for the error message.
+  inline int start_position() const;
+  inline void set_start_position(int value);
+
+  // [end_position]: the end position in the script for the error message.
+  inline int end_position() const;
+  inline void set_end_position(int value);
+
+  // Returns the line number for the error message (1-based), or
+  // Message::kNoLineNumberInfo if the line cannot be determined.
+  int GetLineNumber() const;
+
+  // Returns the offset of the given position within the containing line.
+  int GetColumnNumber() const;
+
+  // Returns the source code line containing the given source
+  // position, or the empty string if the position is invalid.
+  Handle<String> GetSourceLine() const;
+
+  inline int error_level() const;
+  inline void set_error_level(int level);
+
+  DECL_CAST(JSMessageObject)
+
+  // Dispatched behavior.
+  DECL_PRINTER(JSMessageObject)
+  DECL_VERIFIER(JSMessageObject)
+
+  // Layout description.
+  static const int kTypeOffset = JSObject::kHeaderSize;
+  static const int kArgumentsOffset = kTypeOffset + kPointerSize;
+  static const int kScriptOffset = kArgumentsOffset + kPointerSize;
+  static const int kStackFramesOffset = kScriptOffset + kPointerSize;
+  static const int kStartPositionOffset = kStackFramesOffset + kPointerSize;
+  static const int kEndPositionOffset = kStartPositionOffset + kPointerSize;
+  static const int kErrorLevelOffset = kEndPositionOffset + kPointerSize;
+  static const int kSize = kErrorLevelOffset + kPointerSize;
+
+  typedef FixedBodyDescriptor<HeapObject::kMapOffset,
+                              kStackFramesOffset + kPointerSize, kSize>
+      BodyDescriptor;
+};
+
+// The [Async-from-Sync Iterator] object
+// (proposal-async-iteration/#sec-async-from-sync-iterator-objects)
+// An object which wraps an ordinary Iterator and converts it to behave
+// according to the Async Iterator protocol.
+// (See https://tc39.github.io/proposal-async-iteration/#sec-iteration)
+class JSAsyncFromSyncIterator : public JSObject {
+ public:
+  DECL_CAST(JSAsyncFromSyncIterator)
+  DECL_PRINTER(JSAsyncFromSyncIterator)
+  DECL_VERIFIER(JSAsyncFromSyncIterator)
+
+  // Async-from-Sync Iterator instances are ordinary objects that inherit
+  // properties from the %AsyncFromSyncIteratorPrototype% intrinsic object.
+  // Async-from-Sync Iterator instances are initially created with the internal
+  // slots listed in Table 4.
+  // (proposal-async-iteration/#table-async-from-sync-iterator-internal-slots)
+  DECL_ACCESSORS(sync_iterator, JSReceiver)
+
+  // The "next" method is loaded during GetIterator, and is not reloaded for
+  // subsequent "next" invocations.
+  DECL_ACCESSORS(next, Object)
+
+  // Offsets of object fields.
+  static const int kSyncIteratorOffset = JSObject::kHeaderSize;
+  static const int kNextOffset = kSyncIteratorOffset + kPointerSize;
+  static const int kSize = kNextOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSAsyncFromSyncIterator);
+};
+
+class JSStringIterator : public JSObject {
+ public:
+  // Dispatched behavior.
+  DECL_PRINTER(JSStringIterator)
+  DECL_VERIFIER(JSStringIterator)
+
+  DECL_CAST(JSStringIterator)
+
+  // [string]: the [[IteratedString]] inobject property.
+  DECL_ACCESSORS(string, String)
+
+  // [index]: The [[StringIteratorNextIndex]] inobject property.
+  inline int index() const;
+  inline void set_index(int value);
+
+  static const int kStringOffset = JSObject::kHeaderSize;
+  static const int kNextIndexOffset = kStringOffset + kPointerSize;
+  static const int kSize = kNextIndexOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSStringIterator);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_OBJECTS_H_
diff --git a/deps/v8/src/objects/js-plural-rules.cc b/deps/v8/src/objects/js-plural-rules.cc
index 07cc62a41e..f76692c501 100644
--- a/deps/v8/src/objects/js-plural-rules.cc
+++ b/deps/v8/src/objects/js-plural-rules.cc
@@ -85,7 +85,7 @@ void InitializeICUPluralRules(
 }  // namespace
 
 // static
-MaybeHandle<JSPluralRules> JSPluralRules::InitializePluralRules(
+MaybeHandle<JSPluralRules> JSPluralRules::Initialize(
     Isolate* isolate, Handle<JSPluralRules> plural_rules,
     Handle<Object> locales, Handle<Object> options_obj) {
   // 1. Let requestedLocales be ? CanonicalizeLocaleList(locales).
@@ -190,8 +190,7 @@ MaybeHandle<JSPluralRules> JSPluralRules::InitializePluralRules(
 }
 
 MaybeHandle<String> JSPluralRules::ResolvePlural(
-    Isolate* isolate, Handle<JSPluralRules> plural_rules,
-    Handle<Object> number) {
+    Isolate* isolate, Handle<JSPluralRules> plural_rules, double number) {
   icu::PluralRules* icu_plural_rules = plural_rules->icu_plural_rules()->raw();
   CHECK_NOT_NULL(icu_plural_rules);
 
@@ -207,7 +206,7 @@ MaybeHandle<String> JSPluralRules::ResolvePlural(
   // this step, then switch to that API. Bug thread:
   // http://bugs.icu-project.org/trac/ticket/12763
   icu::UnicodeString rounded_string;
-  icu_decimal_format->format(number->Number(), rounded_string);
+  icu_decimal_format->format(number, rounded_string);
 
   icu::Formattable formattable;
   UErrorCode status = U_ZERO_ERROR;
diff --git a/deps/v8/src/objects/js-plural-rules.h b/deps/v8/src/objects/js-plural-rules.h
index 9d5da795ab..f262457acb 100644
--- a/deps/v8/src/objects/js-plural-rules.h
+++ b/deps/v8/src/objects/js-plural-rules.h
@@ -18,12 +18,16 @@
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
 
+namespace U_ICU_NAMESPACE {
+class PluralRules;
+}  //  namespace U_ICU_NAMESPACE
+
 namespace v8 {
 namespace internal {
 
 class JSPluralRules : public JSObject {
  public:
-  V8_WARN_UNUSED_RESULT static MaybeHandle<JSPluralRules> InitializePluralRules(
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSPluralRules> Initialize(
       Isolate* isolate, Handle<JSPluralRules> plural_rules,
       Handle<Object> locales, Handle<Object> options);
 
@@ -31,8 +35,7 @@ class JSPluralRules : public JSObject {
                                           Handle<JSPluralRules> plural_rules);
 
   V8_WARN_UNUSED_RESULT static MaybeHandle<String> ResolvePlural(
-      Isolate* isolate, Handle<JSPluralRules> plural_rules,
-      Handle<Object> number);
+      Isolate* isolate, Handle<JSPluralRules> plural_rules, double number);
 
   DECL_CAST(JSPluralRules)
   DECL_PRINTER(JSPluralRules)
diff --git a/deps/v8/src/objects/js-promise.h b/deps/v8/src/objects/js-promise.h
index c52e19ce49..b395ac9b6d 100644
--- a/deps/v8/src/objects/js-promise.h
+++ b/deps/v8/src/objects/js-promise.h
@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_JS_PROMISE_H_
 #define V8_OBJECTS_JS_PROMISE_H_
 
-#include "src/objects.h"
+#include "src/objects/js-objects.h"
 #include "src/objects/promise.h"
 
 // Has to be the last include (doesn't have include guards):
diff --git a/deps/v8/src/objects/js-proxy.h b/deps/v8/src/objects/js-proxy.h
index 45e27473fe..2a7c518be4 100644
--- a/deps/v8/src/objects/js-proxy.h
+++ b/deps/v8/src/objects/js-proxy.h
@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_JS_PROXY_H_
 #define V8_OBJECTS_JS_PROXY_H_
 
-#include "src/objects.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -118,8 +118,6 @@ class JSProxy : public JSReceiver {
 
   typedef FixedBodyDescriptor<JSReceiver::kPropertiesOrHashOffset, kSize, kSize>
       BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   static Maybe<bool> SetPrivateSymbol(Isolate* isolate, Handle<JSProxy> proxy,
                                       Handle<Symbol> private_name,
diff --git a/deps/v8/src/objects/js-regexp-string-iterator.h b/deps/v8/src/objects/js-regexp-string-iterator.h
index 9821e33efb..9ad2851c7a 100644
--- a/deps/v8/src/objects/js-regexp-string-iterator.h
+++ b/deps/v8/src/objects/js-regexp-string-iterator.h
@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_JS_REGEXP_STRING_ITERATOR_H_
 #define V8_OBJECTS_JS_REGEXP_STRING_ITERATOR_H_
 
-#include "src/objects.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
diff --git a/deps/v8/src/objects/js-relative-time-format-inl.h b/deps/v8/src/objects/js-relative-time-format-inl.h
index 6dc984e252..a4ee3ee7f3 100644
--- a/deps/v8/src/objects/js-relative-time-format-inl.h
+++ b/deps/v8/src/objects/js-relative-time-format-inl.h
@@ -20,7 +20,8 @@ namespace internal {
 
 // Base relative time format accessors.
 ACCESSORS(JSRelativeTimeFormat, locale, String, kLocaleOffset)
-ACCESSORS(JSRelativeTimeFormat, formatter, Foreign, kFormatterOffset)
+ACCESSORS(JSRelativeTimeFormat, icu_formatter,
+          Managed<icu::RelativeDateTimeFormatter>, kICUFormatterOffset)
 SMI_ACCESSORS(JSRelativeTimeFormat, flags, kFlagsOffset)
 
 // TODO(ftang): Use bit field accessor for style and numeric later.
diff --git a/deps/v8/src/objects/js-relative-time-format.cc b/deps/v8/src/objects/js-relative-time-format.cc
index 56130f7311..b3aa996d64 100644
--- a/deps/v8/src/objects/js-relative-time-format.cc
+++ b/deps/v8/src/objects/js-relative-time-format.cc
@@ -17,9 +17,9 @@
 #include "src/objects-inl.h"
 #include "src/objects/intl-objects.h"
 #include "src/objects/js-relative-time-format-inl.h"
-#include "src/objects/managed.h"
 #include "unicode/numfmt.h"
 #include "unicode/reldatefmt.h"
+#include "unicode/uvernum.h"  // for U_ICU_VERSION_MAJOR_NUM
 
 namespace v8 {
 namespace internal {
@@ -54,8 +54,7 @@ JSRelativeTimeFormat::Numeric JSRelativeTimeFormat::getNumeric(
   UNREACHABLE();
 }
 
-MaybeHandle<JSRelativeTimeFormat>
-JSRelativeTimeFormat::InitializeRelativeTimeFormat(
+MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::Initialize(
     Isolate* isolate, Handle<JSRelativeTimeFormat> relative_time_format_holder,
     Handle<Object> input_locales, Handle<Object> input_options) {
   Factory* factory = isolate->factory();
@@ -161,7 +160,7 @@ JSRelativeTimeFormat::InitializeRelativeTimeFormat(
                                                           icu_formatter);
 
   // 30. Set relativeTimeFormat.[[InitializedRelativeTimeFormat]] to true.
-  relative_time_format_holder->set_formatter(*managed_formatter);
+  relative_time_format_holder->set_icu_formatter(*managed_formatter);
   // 31. Return relativeTimeFormat.
   return relative_time_format_holder;
 }
@@ -180,12 +179,6 @@ Handle<JSObject> JSRelativeTimeFormat::ResolvedOptions(
   return result;
 }
 
-icu::RelativeDateTimeFormatter* JSRelativeTimeFormat::UnpackFormatter(
-    Handle<JSRelativeTimeFormat> holder) {
-  return Managed<icu::RelativeDateTimeFormatter>::cast(holder->formatter())
-      ->raw();
-}
-
 Handle<String> JSRelativeTimeFormat::StyleAsString() const {
   switch (style()) {
     case Style::LONG:
@@ -210,5 +203,212 @@ Handle<String> JSRelativeTimeFormat::NumericAsString() const {
   }
 }
 
+namespace {
+
+Handle<String> UnitAsString(Isolate* isolate, URelativeDateTimeUnit unit_enum) {
+  Factory* factory = isolate->factory();
+  switch (unit_enum) {
+    case UDAT_REL_UNIT_SECOND:
+      return factory->second_string();
+    case UDAT_REL_UNIT_MINUTE:
+      return factory->minute_string();
+    case UDAT_REL_UNIT_HOUR:
+      return factory->hour_string();
+    case UDAT_REL_UNIT_DAY:
+      return factory->day_string();
+    case UDAT_REL_UNIT_WEEK:
+      return factory->week_string();
+    case UDAT_REL_UNIT_MONTH:
+      return factory->month_string();
+    case UDAT_REL_UNIT_QUARTER:
+      return factory->quarter_string();
+    case UDAT_REL_UNIT_YEAR:
+      return factory->year_string();
+    default:
+      UNREACHABLE();
+  }
+}
+
+MaybeHandle<JSArray> GenerateRelativeTimeFormatParts(
+    Isolate* isolate, const icu::UnicodeString& formatted,
+    const icu::UnicodeString& integer_part, URelativeDateTimeUnit unit_enum) {
+  Factory* factory = isolate->factory();
+  Handle<JSArray> array = factory->NewJSArray(0);
+  int32_t found = formatted.indexOf(integer_part);
+
+  Handle<String> substring;
+  if (found < 0) {
+    // Cannot find the integer_part in the formatted.
+    // Return [{'type': 'literal', 'value': formatted}]
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, substring,
+                               Intl::ToString(isolate, formatted), JSArray);
+    Intl::AddElement(isolate, array,
+                     0,                          // index
+                     factory->literal_string(),  // field_type_string
+                     substring);
+  } else {
+    // Found the formatted integer in the result.
+    int index = 0;
+
+    // array.push({
+    //     'type': 'literal',
+    //     'value': formatted.substring(0, found)})
+    if (found > 0) {
+      ASSIGN_RETURN_ON_EXCEPTION(isolate, substring,
+                                 Intl::ToString(isolate, formatted, 0, found),
+                                 JSArray);
+      Intl::AddElement(isolate, array, index++,
+                       factory->literal_string(),  // field_type_string
+                       substring);
+    }
+
+    // array.push({
+    //     'type': 'integer',
+    //     'value': formatted.substring(found, found + integer_part.length),
+    //     'unit': unit})
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, substring,
+                               Intl::ToString(isolate, formatted, found,
+                                              found + integer_part.length()),
+                               JSArray);
+    Handle<String> unit = UnitAsString(isolate, unit_enum);
+    Intl::AddElement(isolate, array, index++,
+                     factory->integer_string(),  // field_type_string
+                     substring, factory->unit_string(), unit);
+
+    // array.push({
+    //     'type': 'literal',
+    //     'value': formatted.substring(
+    //         found + integer_part.length, formatted.length)})
+    if (found + integer_part.length() < formatted.length()) {
+      ASSIGN_RETURN_ON_EXCEPTION(
+          isolate, substring,
+          Intl::ToString(isolate, formatted, found + integer_part.length(),
+                         formatted.length()),
+          JSArray);
+      Intl::AddElement(isolate, array, index,
+                       factory->literal_string(),  // field_type_string
+                       substring);
+    }
+  }
+  return array;
+}
+
+bool GetURelativeDateTimeUnit(Handle<String> unit,
+                              URelativeDateTimeUnit* unit_enum) {
+  std::unique_ptr<char[]> unit_str = unit->ToCString();
+  if ((strcmp("second", unit_str.get()) == 0) ||
+      (strcmp("seconds", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_SECOND;
+  } else if ((strcmp("minute", unit_str.get()) == 0) ||
+             (strcmp("minutes", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_MINUTE;
+  } else if ((strcmp("hour", unit_str.get()) == 0) ||
+             (strcmp("hours", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_HOUR;
+  } else if ((strcmp("day", unit_str.get()) == 0) ||
+             (strcmp("days", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_DAY;
+  } else if ((strcmp("week", unit_str.get()) == 0) ||
+             (strcmp("weeks", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_WEEK;
+  } else if ((strcmp("month", unit_str.get()) == 0) ||
+             (strcmp("months", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_MONTH;
+  } else if ((strcmp("quarter", unit_str.get()) == 0) ||
+             (strcmp("quarters", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_QUARTER;
+  } else if ((strcmp("year", unit_str.get()) == 0) ||
+             (strcmp("years", unit_str.get()) == 0)) {
+    *unit_enum = UDAT_REL_UNIT_YEAR;
+  } else {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace
+
+MaybeHandle<Object> JSRelativeTimeFormat::Format(
+    Isolate* isolate, Handle<Object> value_obj, Handle<Object> unit_obj,
+    Handle<JSRelativeTimeFormat> format_holder, const char* func_name,
+    bool to_parts) {
+  Factory* factory = isolate->factory();
+
+  // 3. Let value be ? ToNumber(value).
+  Handle<Object> value;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, value,
+                             Object::ToNumber(isolate, value_obj), Object);
+  double number = value->Number();
+  // 4. Let unit be ? ToString(unit).
+  Handle<String> unit;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, unit, Object::ToString(isolate, unit_obj),
+                             Object);
+
+  // 4. If isFinite(value) is false, then throw a RangeError exception.
+  if (!std::isfinite(number)) {
+    THROW_NEW_ERROR(
+        isolate,
+        NewRangeError(MessageTemplate::kNotFiniteNumber,
+                      isolate->factory()->NewStringFromAsciiChecked(func_name)),
+        Object);
+  }
+
+  icu::RelativeDateTimeFormatter* formatter =
+      format_holder->icu_formatter()->raw();
+  CHECK_NOT_NULL(formatter);
+
+  URelativeDateTimeUnit unit_enum;
+  if (!GetURelativeDateTimeUnit(unit, &unit_enum)) {
+    THROW_NEW_ERROR(
+        isolate,
+        NewRangeError(MessageTemplate::kInvalidUnit,
+                      isolate->factory()->NewStringFromAsciiChecked(func_name),
+                      unit),
+        Object);
+  }
+
+  UErrorCode status = U_ZERO_ERROR;
+  icu::UnicodeString formatted;
+
+#if USE_CHROMIUM_ICU != 1 && U_ICU_VERSION_MAJOR_NUM < 63
+  if (unit_enum != UDAT_REL_UNIT_QUARTER) {  // ICU did not implement
+                                             // UDAT_REL_UNIT_QUARTER < 63
+#endif  // USE_CHROMIUM_ICU != 1 && U_ICU_VERSION_MAJOR_NUM < 63
+    if (format_holder->numeric() == JSRelativeTimeFormat::Numeric::ALWAYS) {
+      formatter->formatNumeric(number, unit_enum, formatted, status);
+    } else {
+      DCHECK_EQ(JSRelativeTimeFormat::Numeric::AUTO, format_holder->numeric());
+      formatter->format(number, unit_enum, formatted, status);
+    }
+#if USE_CHROMIUM_ICU != 1 && U_ICU_VERSION_MAJOR_NUM < 63
+  }
+#endif  // USE_CHROMIUM_ICU != 1 && U_ICU_VERSION_MAJOR_NUM < 63
+
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), Object);
+  }
+
+  if (to_parts) {
+    icu::UnicodeString integer;
+    icu::FieldPosition pos;
+    formatter->getNumberFormat().format(std::abs(number), integer, pos, status);
+    if (U_FAILURE(status)) {
+      THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError),
+                      Object);
+    }
+
+    Handle<JSArray> elements;
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, elements,
+        GenerateRelativeTimeFormatParts(isolate, formatted, integer, unit_enum),
+        Object);
+    return elements;
+  }
+
+  return factory->NewStringFromTwoByte(Vector<const uint16_t>(
+      reinterpret_cast<const uint16_t*>(formatted.getBuffer()),
+      formatted.length()));
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/objects/js-relative-time-format.h b/deps/v8/src/objects/js-relative-time-format.h
index 397c6fe287..eaaeb0e05f 100644
--- a/deps/v8/src/objects/js-relative-time-format.h
+++ b/deps/v8/src/objects/js-relative-time-format.h
@@ -12,6 +12,7 @@
 #include "src/heap/factory.h"
 #include "src/isolate.h"
 #include "src/objects.h"
+#include "src/objects/managed.h"
 #include "unicode/uversion.h"
 
 // Has to be the last include (doesn't have include guards):
@@ -28,26 +29,30 @@ class JSRelativeTimeFormat : public JSObject {
  public:
   // Initializes relative time format object with properties derived from input
   // locales and options.
-  static MaybeHandle<JSRelativeTimeFormat> InitializeRelativeTimeFormat(
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSRelativeTimeFormat> Initialize(
       Isolate* isolate,
       Handle<JSRelativeTimeFormat> relative_time_format_holder,
       Handle<Object> locales, Handle<Object> options);
 
-  static Handle<JSObject> ResolvedOptions(
+  V8_WARN_UNUSED_RESULT static Handle<JSObject> ResolvedOptions(
       Isolate* isolate, Handle<JSRelativeTimeFormat> format_holder);
 
-  // Unpacks formatter object from corresponding JavaScript object.
-  static icu::RelativeDateTimeFormatter* UnpackFormatter(
-      Handle<JSRelativeTimeFormat> relative_time_format_holder);
   Handle<String> StyleAsString() const;
   Handle<String> NumericAsString() const;
 
+  // ecma402/#sec-Intl.RelativeTimeFormat.prototype.format
+  // ecma402/#sec-Intl.RelativeTimeFormat.prototype.formatToParts
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> Format(
+      Isolate* isolate, Handle<Object> value_obj, Handle<Object> unit_obj,
+      Handle<JSRelativeTimeFormat> format_holder, const char* func_name,
+      bool to_parts);
+
   DECL_CAST(JSRelativeTimeFormat)
 
   // RelativeTimeFormat accessors.
   DECL_ACCESSORS(locale, String)
 
-  DECL_ACCESSORS(formatter, Foreign)
+  DECL_ACCESSORS(icu_formatter, Managed<icu::RelativeDateTimeFormatter>)
 
   // Style: identifying the relative time format style used.
   //
@@ -98,8 +103,8 @@ class JSRelativeTimeFormat : public JSObject {
   // Layout description.
   static const int kJSRelativeTimeFormatOffset = JSObject::kHeaderSize;
   static const int kLocaleOffset = kJSRelativeTimeFormatOffset + kPointerSize;
-  static const int kFormatterOffset = kLocaleOffset + kPointerSize;
-  static const int kFlagsOffset = kFormatterOffset + kPointerSize;
+  static const int kICUFormatterOffset = kLocaleOffset + kPointerSize;
+  static const int kFlagsOffset = kICUFormatterOffset + kPointerSize;
   static const int kSize = kFlagsOffset + kPointerSize;
 
  private:
diff --git a/deps/v8/src/objects/js-segmenter-inl.h b/deps/v8/src/objects/js-segmenter-inl.h
new file mode 100644
index 0000000000..1aac2b1d63
--- /dev/null
+++ b/deps/v8/src/objects/js-segmenter-inl.h
@@ -0,0 +1,56 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_SEGMENTER_INL_H_
+#define V8_OBJECTS_JS_SEGMENTER_INL_H_
+
+#include "src/objects-inl.h"
+#include "src/objects/js-segmenter.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+// Base segmenter accessors.
+ACCESSORS(JSSegmenter, locale, String, kLocaleOffset)
+ACCESSORS(JSSegmenter, icu_break_iterator, Managed<icu::BreakIterator>,
+          kICUBreakIteratorOffset)
+SMI_ACCESSORS(JSSegmenter, flags, kFlagsOffset)
+
+inline void JSSegmenter::set_line_break_style(LineBreakStyle line_break_style) {
+  DCHECK_GT(LineBreakStyle::COUNT, line_break_style);
+  int hints = flags();
+  hints = LineBreakStyleBits::update(hints, line_break_style);
+  set_flags(hints);
+}
+
+inline JSSegmenter::LineBreakStyle JSSegmenter::line_break_style() const {
+  return LineBreakStyleBits::decode(flags());
+}
+
+inline void JSSegmenter::set_granularity(Granularity granularity) {
+  DCHECK_GT(Granularity::COUNT, granularity);
+  int hints = flags();
+  hints = GranularityBits::update(hints, granularity);
+  set_flags(hints);
+}
+
+inline JSSegmenter::Granularity JSSegmenter::granularity() const {
+  return GranularityBits::decode(flags());
+}
+
+CAST_ACCESSOR(JSSegmenter);
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_SEGMENTER_INL_H_
diff --git a/deps/v8/src/objects/js-segmenter.cc b/deps/v8/src/objects/js-segmenter.cc
new file mode 100644
index 0000000000..62d9bd508a
--- /dev/null
+++ b/deps/v8/src/objects/js-segmenter.cc
@@ -0,0 +1,214 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#include "src/objects/js-segmenter.h"
+
+#include <map>
+#include <memory>
+#include <string>
+
+#include "src/heap/factory.h"
+#include "src/isolate.h"
+#include "src/objects-inl.h"
+#include "src/objects/intl-objects.h"
+#include "src/objects/js-segmenter-inl.h"
+#include "src/objects/managed.h"
+#include "unicode/brkiter.h"
+
+namespace v8 {
+namespace internal {
+
+JSSegmenter::LineBreakStyle JSSegmenter::GetLineBreakStyle(const char* str) {
+  if (strcmp(str, "strict") == 0) return JSSegmenter::LineBreakStyle::STRICT;
+  if (strcmp(str, "normal") == 0) return JSSegmenter::LineBreakStyle::NORMAL;
+  if (strcmp(str, "loose") == 0) return JSSegmenter::LineBreakStyle::LOOSE;
+  UNREACHABLE();
+}
+
+JSSegmenter::Granularity JSSegmenter::GetGranularity(const char* str) {
+  if (strcmp(str, "grapheme") == 0) return JSSegmenter::Granularity::GRAPHEME;
+  if (strcmp(str, "word") == 0) return JSSegmenter::Granularity::WORD;
+  if (strcmp(str, "sentence") == 0) return JSSegmenter::Granularity::SENTENCE;
+  if (strcmp(str, "line") == 0) return JSSegmenter::Granularity::LINE;
+  UNREACHABLE();
+}
+
+MaybeHandle<JSSegmenter> JSSegmenter::Initialize(
+    Isolate* isolate, Handle<JSSegmenter> segmenter_holder,
+    Handle<Object> input_locales, Handle<Object> input_options) {
+  Factory* factory = isolate->factory();
+  segmenter_holder->set_flags(0);
+  // 3. Let requestedLocales be ? CanonicalizeLocaleList(locales).
+  Handle<JSObject> requested_locales;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, requested_locales,
+      Intl::CanonicalizeLocaleListJS(isolate, input_locales), JSSegmenter);
+
+  // 11. If options is undefined, then
+  Handle<JSReceiver> options;
+  if (input_options->IsUndefined(isolate)) {
+    // a. Let options be ObjectCreate(null).
+    options = isolate->factory()->NewJSObjectWithNullProto();
+    // 12. Else
+  } else {
+    // a. Let options be ? ToObject(options).
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, options,
+                               Object::ToObject(isolate, input_options),
+                               JSSegmenter);
+  }
+
+  // 8. Set opt.[[lb]] to lineBreakStyle.
+
+  // Because currently we access localeMatcher inside ResolveLocale, we have to
+  // move ResolveLocale before get lineBreakStyle
+  // 9. Let r be ResolveLocale(%Segmenter%.[[AvailableLocales]],
+  // requestedLocales, opt, %Segmenter%.[[RelevantExtensionKeys]]).
+  Handle<JSObject> r;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, r,
+      Intl::ResolveLocale(isolate, "segmenter", requested_locales, options),
+      JSSegmenter);
+  Handle<Object> locale_obj =
+      JSObject::GetDataProperty(r, factory->locale_string());
+  Handle<String> locale;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, locale, Object::ToString(isolate, locale_obj), JSSegmenter);
+
+  // 7. Let lineBreakStyle be ? GetOption(options, "lineBreakStyle", "string", «
+  // "strict", "normal", "loose" », "normal").
+  std::unique_ptr<char[]> line_break_style_str = nullptr;
+  const std::vector<const char*> line_break_style_values = {"strict", "normal",
+                                                            "loose"};
+  Maybe<bool> maybe_found_line_break_style = Intl::GetStringOption(
+      isolate, options, "lineBreakStyle", line_break_style_values,
+      "Intl.Segmenter", &line_break_style_str);
+  LineBreakStyle line_break_style_enum = LineBreakStyle::NORMAL;
+  MAYBE_RETURN(maybe_found_line_break_style, MaybeHandle<JSSegmenter>());
+  if (maybe_found_line_break_style.FromJust()) {
+    DCHECK_NOT_NULL(line_break_style_str.get());
+    line_break_style_enum = GetLineBreakStyle(line_break_style_str.get());
+  }
+
+  // 10. Set segmenter.[[Locale]] to the value of r.[[Locale]].
+  segmenter_holder->set_locale(*locale);
+
+  // 13. Let granularity be ? GetOption(options, "granularity", "string", «
+  // "grapheme", "word", "sentence", "line" », "grapheme").
+
+  std::unique_ptr<char[]> granularity_str = nullptr;
+  const std::vector<const char*> granularity_values = {"grapheme", "word",
+                                                       "sentence", "line"};
+  Maybe<bool> maybe_found_granularity =
+      Intl::GetStringOption(isolate, options, "granularity", granularity_values,
+                            "Intl.Segmenter", &granularity_str);
+  Granularity granularity_enum = Granularity::GRAPHEME;
+  MAYBE_RETURN(maybe_found_granularity, MaybeHandle<JSSegmenter>());
+  if (maybe_found_granularity.FromJust()) {
+    DCHECK_NOT_NULL(granularity_str.get());
+    granularity_enum = GetGranularity(granularity_str.get());
+  }
+
+  // 14. Set segmenter.[[SegmenterGranularity]] to granularity.
+  segmenter_holder->set_granularity(granularity_enum);
+
+  // 15. If granularity is "line",
+  if (granularity_enum == Granularity::LINE) {
+    // a. Set segmenter.[[SegmenterLineBreakStyle]] to r.[[lb]].
+    segmenter_holder->set_line_break_style(line_break_style_enum);
+  } else {
+    segmenter_holder->set_line_break_style(LineBreakStyle::NOTSET);
+  }
+
+  icu::Locale icu_locale = Intl::CreateICULocale(isolate, locale);
+  DCHECK(!icu_locale.isBogus());
+
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::BreakIterator> icu_break_iterator;
+
+  switch (granularity_enum) {
+    case Granularity::GRAPHEME:
+      icu_break_iterator.reset(
+          icu::BreakIterator::createCharacterInstance(icu_locale, status));
+      break;
+    case Granularity::WORD:
+      icu_break_iterator.reset(
+          icu::BreakIterator::createWordInstance(icu_locale, status));
+      break;
+    case Granularity::SENTENCE:
+      icu_break_iterator.reset(
+          icu::BreakIterator::createSentenceInstance(icu_locale, status));
+      break;
+    case Granularity::LINE:
+      icu_break_iterator.reset(
+          icu::BreakIterator::createLineInstance(icu_locale, status));
+      // 15. If granularity is "line",
+      // a. Set segmenter.[[SegmenterLineBreakStyle]] to r.[[lb]].
+      // TBW
+      break;
+    case Granularity::COUNT:
+      UNREACHABLE();
+  }
+
+  CHECK(U_SUCCESS(status));
+  CHECK_NOT_NULL(icu_break_iterator.get());
+
+  Handle<Managed<icu::BreakIterator>> managed_break_iterator =
+      Managed<icu::BreakIterator>::FromUniquePtr(isolate, 0,
+                                                 std::move(icu_break_iterator));
+
+  segmenter_holder->set_icu_break_iterator(*managed_break_iterator);
+  return segmenter_holder;
+}
+
+Handle<JSObject> JSSegmenter::ResolvedOptions(
+    Isolate* isolate, Handle<JSSegmenter> segmenter_holder) {
+  Factory* factory = isolate->factory();
+  Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
+  Handle<String> locale(segmenter_holder->locale(), isolate);
+  JSObject::AddProperty(isolate, result, factory->locale_string(), locale,
+                        NONE);
+  if (segmenter_holder->line_break_style() != LineBreakStyle::NOTSET) {
+    JSObject::AddProperty(isolate, result, factory->lineBreakStyle_string(),
+                          segmenter_holder->LineBreakStyleAsString(), NONE);
+  }
+  JSObject::AddProperty(isolate, result, factory->granularity_string(),
+                        segmenter_holder->GranularityAsString(), NONE);
+  return result;
+}
+
+Handle<String> JSSegmenter::LineBreakStyleAsString() const {
+  switch (line_break_style()) {
+    case LineBreakStyle::STRICT:
+      return GetReadOnlyRoots().strict_string_handle();
+    case LineBreakStyle::NORMAL:
+      return GetReadOnlyRoots().normal_string_handle();
+    case LineBreakStyle::LOOSE:
+      return GetReadOnlyRoots().loose_string_handle();
+    case LineBreakStyle::COUNT:
+    case LineBreakStyle::NOTSET:
+      UNREACHABLE();
+  }
+}
+
+Handle<String> JSSegmenter::GranularityAsString() const {
+  switch (granularity()) {
+    case Granularity::GRAPHEME:
+      return GetReadOnlyRoots().grapheme_string_handle();
+    case Granularity::WORD:
+      return GetReadOnlyRoots().word_string_handle();
+    case Granularity::SENTENCE:
+      return GetReadOnlyRoots().sentence_string_handle();
+    case Granularity::LINE:
+      return GetReadOnlyRoots().line_string_handle();
+    case Granularity::COUNT:
+      UNREACHABLE();
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/objects/js-segmenter.h b/deps/v8/src/objects/js-segmenter.h
new file mode 100644
index 0000000000..167d70c210
--- /dev/null
+++ b/deps/v8/src/objects/js-segmenter.h
@@ -0,0 +1,118 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_INTL_SUPPORT
+#error Internationalization is expected to be enabled.
+#endif  // V8_INTL_SUPPORT
+
+#ifndef V8_OBJECTS_JS_SEGMENTER_H_
+#define V8_OBJECTS_JS_SEGMENTER_H_
+
+#include "src/heap/factory.h"
+#include "src/isolate.h"
+#include "src/objects.h"
+#include "src/objects/managed.h"
+#include "unicode/uversion.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace U_ICU_NAMESPACE {
+class BreakIterator;
+}
+
+namespace v8 {
+namespace internal {
+
+class JSSegmenter : public JSObject {
+ public:
+  // Initializes segmenter object with properties derived from input
+  // locales and options.
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSSegmenter> Initialize(
+      Isolate* isolate, Handle<JSSegmenter> segmenter_holder,
+      Handle<Object> locales, Handle<Object> options);
+
+  V8_WARN_UNUSED_RESULT static Handle<JSObject> ResolvedOptions(
+      Isolate* isolate, Handle<JSSegmenter> segmenter_holder);
+
+  Handle<String> LineBreakStyleAsString() const;
+  Handle<String> GranularityAsString() const;
+
+  DECL_CAST(JSSegmenter)
+
+  // Segmenter accessors.
+  DECL_ACCESSORS(locale, String)
+
+  DECL_ACCESSORS(icu_break_iterator, Managed<icu::BreakIterator>)
+
+  // LineBreakStyle: identifying the style used for line break.
+  //
+  // ecma402 #sec-segmenter-internal-slots
+
+  enum class LineBreakStyle {
+    NOTSET,  // While the granularity is not LINE
+    STRICT,  // CSS level 3 line-break=strict, e.g. treat CJ as NS
+    NORMAL,  // CSS level 3 line-break=normal, e.g. treat CJ as ID, break before
+             // hyphens for ja,zh
+    LOOSE,   // CSS level 3 line-break=loose
+    COUNT
+  };
+  inline void set_line_break_style(LineBreakStyle line_break_style);
+  inline LineBreakStyle line_break_style() const;
+
+  // Granularity: identifying the segmenter used.
+  //
+  // ecma402 #sec-segmenter-internal-slots
+  enum class Granularity {
+    GRAPHEME,  // for character-breaks
+    WORD,      // for word-breaks
+    SENTENCE,  // for sentence-breaks
+    LINE,      // for line-breaks
+    COUNT
+  };
+  inline void set_granularity(Granularity granularity);
+  inline Granularity granularity() const;
+
+// Bit positions in |flags|.
+#define FLAGS_BIT_FIELDS(V, _)                \
+  V(LineBreakStyleBits, LineBreakStyle, 3, _) \
+  V(GranularityBits, Granularity, 3, _)
+  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
+#undef FLAGS_BIT_FIELDS
+
+  STATIC_ASSERT(LineBreakStyle::NOTSET <= LineBreakStyleBits::kMax);
+  STATIC_ASSERT(LineBreakStyle::STRICT <= LineBreakStyleBits::kMax);
+  STATIC_ASSERT(LineBreakStyle::NORMAL <= LineBreakStyleBits::kMax);
+  STATIC_ASSERT(LineBreakStyle::LOOSE <= LineBreakStyleBits::kMax);
+  STATIC_ASSERT(Granularity::GRAPHEME <= GranularityBits::kMax);
+  STATIC_ASSERT(Granularity::WORD <= GranularityBits::kMax);
+  STATIC_ASSERT(Granularity::SENTENCE <= GranularityBits::kMax);
+  STATIC_ASSERT(Granularity::LINE <= GranularityBits::kMax);
+
+  // [flags] Bit field containing various flags about the function.
+  DECL_INT_ACCESSORS(flags)
+
+  DECL_PRINTER(JSSegmenter)
+  DECL_VERIFIER(JSSegmenter)
+
+  // Layout description.
+  static const int kJSSegmenterOffset = JSObject::kHeaderSize;
+  static const int kLocaleOffset = kJSSegmenterOffset + kPointerSize;
+  static const int kICUBreakIteratorOffset = kLocaleOffset + kPointerSize;
+  static const int kFlagsOffset = kICUBreakIteratorOffset + kPointerSize;
+  static const int kSize = kFlagsOffset + kPointerSize;
+
+ private:
+  static LineBreakStyle GetLineBreakStyle(const char* str);
+  static Granularity GetGranularity(const char* str);
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSSegmenter);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_JS_SEGMENTER_H_
diff --git a/deps/v8/src/objects/map-inl.h b/deps/v8/src/objects/map-inl.h
index 59f061dc05..0ec4113d4d 100644
--- a/deps/v8/src/objects/map-inl.h
+++ b/deps/v8/src/objects/map-inl.h
@@ -136,10 +136,10 @@ bool Map::IsUnboxedDoubleField(FieldIndex index) const {
   return !layout_descriptor()->IsTagged(index.property_index());
 }
 
-bool Map::TooManyFastProperties(StoreFromKeyed store_mode) const {
+bool Map::TooManyFastProperties(StoreOrigin store_origin) const {
   if (UnusedPropertyFields() != 0) return false;
   if (is_prototype_map()) return false;
-  int minimum = store_mode == CERTAINLY_NOT_STORE_FROM_KEYED ? 128 : 12;
+  int minimum = store_origin == StoreOrigin::kNamed ? 128 : 12;
   int limit = Max(minimum, GetInObjectProperties());
   int external = NumberOfFields() - GetInObjectProperties();
   return external > limit;
@@ -511,57 +511,30 @@ void Map::NotifyLeafMapLayoutChange(Isolate* isolate) {
   }
 }
 
-bool Map::IsJSObject(InstanceType type) {
-  STATIC_ASSERT(LAST_TYPE == LAST_JS_OBJECT_TYPE);
-  return type >= FIRST_JS_OBJECT_TYPE;
-}
-
 bool Map::CanTransition() const {
   // Only JSObject and subtypes have map transitions and back pointers.
-  return IsJSObject(instance_type());
+  return InstanceTypeChecker::IsJSObject(instance_type());
 }
 
+#define DEF_TESTER(Type, ...)                              \
+  bool Map::Is##Type##Map() const {                        \
+    return InstanceTypeChecker::Is##Type(instance_type()); \
+  }
+INSTANCE_TYPE_CHECKERS(DEF_TESTER)
+#undef DEF_TESTER
+
 bool Map::IsBooleanMap() const {
   return this == GetReadOnlyRoots().boolean_map();
 }
 
-bool Map::IsNullMap() const { return this == GetReadOnlyRoots().null_map(); }
-
-bool Map::IsUndefinedMap() const {
-  return this == GetReadOnlyRoots().undefined_map();
-}
-
 bool Map::IsNullOrUndefinedMap() const {
-  return IsNullMap() || IsUndefinedMap();
+  return this == GetReadOnlyRoots().null_map() ||
+         this == GetReadOnlyRoots().undefined_map();
 }
 
 bool Map::IsPrimitiveMap() const {
   return instance_type() <= LAST_PRIMITIVE_TYPE;
 }
-bool Map::IsJSReceiverMap() const {
-  STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
-  return instance_type() >= FIRST_JS_RECEIVER_TYPE;
-}
-bool Map::IsJSObjectMap() const { return IsJSObject(instance_type()); }
-bool Map::IsJSPromiseMap() const { return instance_type() == JS_PROMISE_TYPE; }
-bool Map::IsJSArrayMap() const { return instance_type() == JS_ARRAY_TYPE; }
-bool Map::IsJSFunctionMap() const {
-  return instance_type() == JS_FUNCTION_TYPE;
-}
-bool Map::IsStringMap() const { return instance_type() < FIRST_NONSTRING_TYPE; }
-bool Map::IsJSProxyMap() const { return instance_type() == JS_PROXY_TYPE; }
-bool Map::IsJSGlobalProxyMap() const {
-  return instance_type() == JS_GLOBAL_PROXY_TYPE;
-}
-bool Map::IsJSGlobalObjectMap() const {
-  return instance_type() == JS_GLOBAL_OBJECT_TYPE;
-}
-bool Map::IsJSTypedArrayMap() const {
-  return instance_type() == JS_TYPED_ARRAY_TYPE;
-}
-bool Map::IsJSDataViewMap() const {
-  return instance_type() == JS_DATA_VIEW_TYPE;
-}
 
 Object* Map::prototype() const { return READ_FIELD(this, kPrototypeOffset); }
 
diff --git a/deps/v8/src/objects/map.h b/deps/v8/src/objects/map.h
index 397f874610..5f6b173cd3 100644
--- a/deps/v8/src/objects/map.h
+++ b/deps/v8/src/objects/map.h
@@ -37,9 +37,10 @@ namespace internal {
   V(FreeSpace)                           \
   V(JSApiObject)                         \
   V(JSArrayBuffer)                       \
-  V(JSFunction)                          \
+  V(JSDataView)                          \
   V(JSObject)                            \
   V(JSObjectFast)                        \
+  V(JSTypedArray)                        \
   V(JSWeakCollection)                    \
   V(Map)                                 \
   V(NativeContext)                       \
@@ -403,9 +404,6 @@ class Map : public HeapObject {
   inline bool has_fixed_typed_array_elements() const;
   inline bool has_dictionary_elements() const;
 
-  static bool IsValidElementsTransition(ElementsKind from_kind,
-                                        ElementsKind to_kind);
-
   // Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
   // map with DICTIONARY_ELEMENTS was found in the prototype chain.
   bool DictionaryElementsInPrototypeChainOnly(Isolate* isolate);
@@ -471,8 +469,6 @@ class Map : public HeapObject {
   bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
                               int target_inobject, int target_unused,
                               int* old_number_of_fields) const;
-  // TODO(ishell): moveit!
-  static Handle<Map> GeneralizeAllFields(Isolate* isolate, Handle<Map> map);
   V8_WARN_UNUSED_RESULT static Handle<FieldType> GeneralizeFieldType(
       Representation rep1, Handle<FieldType> type1, Representation rep2,
       Handle<FieldType> type2, Isolate* isolate);
@@ -693,13 +689,13 @@ class Map : public HeapObject {
   // Maximal number of fast properties. Used to restrict the number of map
   // transitions to avoid an explosion in the number of maps for objects used as
   // dictionaries.
-  inline bool TooManyFastProperties(StoreFromKeyed store_mode) const;
+  inline bool TooManyFastProperties(StoreOrigin store_origin) const;
   static Handle<Map> TransitionToDataProperty(Isolate* isolate, Handle<Map> map,
                                               Handle<Name> name,
                                               Handle<Object> value,
                                               PropertyAttributes attributes,
                                               PropertyConstness constness,
-                                              StoreFromKeyed store_mode);
+                                              StoreOrigin store_origin);
   static Handle<Map> TransitionToAccessorProperty(
       Isolate* isolate, Handle<Map> map, Handle<Name> name, int descriptor,
       Handle<Object> getter, Handle<Object> setter,
@@ -756,27 +752,14 @@ class Map : public HeapObject {
   Map* FindElementsKindTransitionedMap(Isolate* isolate,
                                        MapHandles const& candidates);
 
-  inline static bool IsJSObject(InstanceType type);
-
   inline bool CanTransition() const;
 
+#define DECL_TESTER(Type, ...) inline bool Is##Type##Map() const;
+  INSTANCE_TYPE_CHECKERS(DECL_TESTER)
+#undef DECL_TESTER
   inline bool IsBooleanMap() const;
-  inline bool IsNullMap() const;
-  inline bool IsUndefinedMap() const;
   inline bool IsNullOrUndefinedMap() const;
   inline bool IsPrimitiveMap() const;
-  inline bool IsJSReceiverMap() const;
-  inline bool IsJSObjectMap() const;
-  inline bool IsJSPromiseMap() const;
-  inline bool IsJSArrayMap() const;
-  inline bool IsJSFunctionMap() const;
-  inline bool IsStringMap() const;
-  inline bool IsJSProxyMap() const;
-  inline bool IsModuleMap() const;
-  inline bool IsJSGlobalProxyMap() const;
-  inline bool IsJSGlobalObjectMap() const;
-  inline bool IsJSTypedArrayMap() const;
-  inline bool IsJSDataViewMap() const;
   inline bool IsSpecialReceiverMap() const;
   inline bool IsCustomElementsReceiverMap() const;
 
@@ -945,7 +928,7 @@ class Map : public HeapObject {
   void UpdateFieldType(Isolate* isolate, int descriptor_number,
                        Handle<Name> name, PropertyConstness new_constness,
                        Representation new_representation,
-                       MaybeObjectHandle new_wrapped_type);
+                       const MaybeObjectHandle& new_wrapped_type);
 
   // TODO(ishell): Move to MapUpdater.
   void PrintReconfiguration(Isolate* isolate, FILE* file, int modify_index,
@@ -971,9 +954,6 @@ class Map : public HeapObject {
 class NormalizedMapCache : public WeakFixedArray,
                            public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   static Handle<NormalizedMapCache> New(Isolate* isolate);
 
   V8_WARN_UNUSED_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
diff --git a/deps/v8/src/objects/maybe-object-inl.h b/deps/v8/src/objects/maybe-object-inl.h
index fa3cd8c14f..6d2bc6a9ab 100644
--- a/deps/v8/src/objects/maybe-object-inl.h
+++ b/deps/v8/src/objects/maybe-object-inl.h
@@ -20,29 +20,24 @@ bool MaybeObject::ToSmi(Smi** value) {
   return false;
 }
 
-Smi* MaybeObject::ToSmi() {
-  DCHECK(HAS_SMI_TAG(this));
-  return Smi::cast(reinterpret_cast<Object*>(this));
-}
-
-bool MaybeObject::IsStrongOrWeakHeapObject() const {
-  if (IsSmi() || IsClearedWeakHeapObject()) {
+bool MaybeObject::IsStrongOrWeak() const {
+  if (IsSmi() || IsCleared()) {
     return false;
   }
   return true;
 }
 
-bool MaybeObject::ToStrongOrWeakHeapObject(HeapObject** result) {
-  if (IsSmi() || IsClearedWeakHeapObject()) {
+bool MaybeObject::GetHeapObject(HeapObject** result) {
+  if (IsSmi() || IsCleared()) {
     return false;
   }
   *result = GetHeapObject();
   return true;
 }
 
-bool MaybeObject::ToStrongOrWeakHeapObject(
-    HeapObject** result, HeapObjectReferenceType* reference_type) {
-  if (IsSmi() || IsClearedWeakHeapObject()) {
+bool MaybeObject::GetHeapObject(HeapObject** result,
+                                HeapObjectReferenceType* reference_type) {
+  if (IsSmi() || IsCleared()) {
     return false;
   }
   *reference_type = HasWeakHeapObjectTag(this)
@@ -52,11 +47,11 @@ bool MaybeObject::ToStrongOrWeakHeapObject(
   return true;
 }
 
-bool MaybeObject::IsStrongHeapObject() const {
+bool MaybeObject::IsStrong() const {
   return !HasWeakHeapObjectTag(this) && !IsSmi();
 }
 
-bool MaybeObject::ToStrongHeapObject(HeapObject** result) {
+bool MaybeObject::GetHeapObjectIfStrong(HeapObject** result) {
   if (!HasWeakHeapObjectTag(this) && !IsSmi()) {
     *result = reinterpret_cast<HeapObject*>(this);
     return true;
@@ -64,35 +59,33 @@ bool MaybeObject::ToStrongHeapObject(HeapObject** result) {
   return false;
 }
 
-HeapObject* MaybeObject::ToStrongHeapObject() {
-  DCHECK(IsStrongHeapObject());
+HeapObject* MaybeObject::GetHeapObjectAssumeStrong() {
+  DCHECK(IsStrong());
   return reinterpret_cast<HeapObject*>(this);
 }
 
-bool MaybeObject::IsWeakHeapObject() const {
-  return HasWeakHeapObjectTag(this) && !IsClearedWeakHeapObject();
+bool MaybeObject::IsWeak() const {
+  return HasWeakHeapObjectTag(this) && !IsCleared();
 }
 
-bool MaybeObject::IsWeakOrClearedHeapObject() const {
-  return HasWeakHeapObjectTag(this);
-}
+bool MaybeObject::IsWeakOrCleared() const { return HasWeakHeapObjectTag(this); }
 
-bool MaybeObject::ToWeakHeapObject(HeapObject** result) {
-  if (HasWeakHeapObjectTag(this) && !IsClearedWeakHeapObject()) {
+bool MaybeObject::GetHeapObjectIfWeak(HeapObject** result) {
+  if (IsWeak()) {
     *result = GetHeapObject();
     return true;
   }
   return false;
 }
 
-HeapObject* MaybeObject::ToWeakHeapObject() {
-  DCHECK(IsWeakHeapObject());
+HeapObject* MaybeObject::GetHeapObjectAssumeWeak() {
+  DCHECK(IsWeak());
   return GetHeapObject();
 }
 
 HeapObject* MaybeObject::GetHeapObject() {
   DCHECK(!IsSmi());
-  DCHECK(!IsClearedWeakHeapObject());
+  DCHECK(!IsCleared());
   return RemoveWeakHeapObjectMask(reinterpret_cast<HeapObjectReference*>(this));
 }
 
@@ -103,15 +96,10 @@ Object* MaybeObject::GetHeapObjectOrSmi() {
   return GetHeapObject();
 }
 
-bool MaybeObject::IsObject() const { return IsSmi() || IsStrongHeapObject(); }
-
-Object* MaybeObject::ToObject() {
-  DCHECK(!HasWeakHeapObjectTag(this));
-  return reinterpret_cast<Object*>(this);
-}
+bool MaybeObject::IsObject() const { return IsSmi() || IsStrong(); }
 
 MaybeObject* MaybeObject::MakeWeak(MaybeObject* object) {
-  DCHECK(object->IsStrongOrWeakHeapObject());
+  DCHECK(object->IsStrongOrWeak());
   return AddWeakHeapObjectMask(object);
 }
 
diff --git a/deps/v8/src/objects/maybe-object.h b/deps/v8/src/objects/maybe-object.h
index 84c8538224..0d55ff859c 100644
--- a/deps/v8/src/objects/maybe-object.h
+++ b/deps/v8/src/objects/maybe-object.h
@@ -5,6 +5,7 @@
 #ifndef V8_OBJECTS_MAYBE_OBJECT_H_
 #define V8_OBJECTS_MAYBE_OBJECT_H_
 
+#include "include/v8-internal.h"
 #include "include/v8.h"
 #include "src/globals.h"
 #include "src/objects.h"
@@ -23,30 +24,53 @@ class MaybeObject {
  public:
   bool IsSmi() const { return HAS_SMI_TAG(this); }
   inline bool ToSmi(Smi** value);
-  inline Smi* ToSmi();
 
-  bool IsClearedWeakHeapObject() const {
+  bool IsCleared() const {
     return ::v8::internal::IsClearedWeakHeapObject(this);
   }
 
-  inline bool IsStrongOrWeakHeapObject() const;
-  inline bool ToStrongOrWeakHeapObject(HeapObject** result);
-  inline bool ToStrongOrWeakHeapObject(HeapObject** result,
-                                       HeapObjectReferenceType* reference_type);
-  inline bool IsStrongHeapObject() const;
-  inline bool ToStrongHeapObject(HeapObject** result);
-  inline HeapObject* ToStrongHeapObject();
-  inline bool IsWeakHeapObject() const;
-  inline bool IsWeakOrClearedHeapObject() const;
-  inline bool ToWeakHeapObject(HeapObject** result);
-  inline HeapObject* ToWeakHeapObject();
-
-  // Returns the HeapObject pointed to (either strongly or weakly).
+  inline bool IsStrongOrWeak() const;
+  inline bool IsStrong() const;
+
+  // If this MaybeObject is a strong pointer to a HeapObject, returns true and
+  // sets *result. Otherwise returns false.
+  inline bool GetHeapObjectIfStrong(HeapObject** result);
+
+  // DCHECKs that this MaybeObject is a strong pointer to a HeapObject and
+  // returns the HeapObject.
+  inline HeapObject* GetHeapObjectAssumeStrong();
+
+  inline bool IsWeak() const;
+  inline bool IsWeakOrCleared() const;
+
+  // If this MaybeObject is a weak pointer to a HeapObject, returns true and
+  // sets *result. Otherwise returns false.
+  inline bool GetHeapObjectIfWeak(HeapObject** result);
+
+  // DCHECKs that this MaybeObject is a weak pointer to a HeapObject and
+  // returns the HeapObject.
+  inline HeapObject* GetHeapObjectAssumeWeak();
+
+  // If this MaybeObject is a strong or weak pointer to a HeapObject, returns
+  // true and sets *result. Otherwise returns false.
+  inline bool GetHeapObject(HeapObject** result);
+  inline bool GetHeapObject(HeapObject** result,
+                            HeapObjectReferenceType* reference_type);
+
+  // DCHECKs that this MaybeObject is a strong or a weak pointer to a HeapObject
+  // and returns the HeapObject.
   inline HeapObject* GetHeapObject();
+
+  // DCHECKs that this MaybeObject is a strong or a weak pointer to a HeapObject
+  // or a SMI and returns the HeapObject or SMI.
   inline Object* GetHeapObjectOrSmi();
 
   inline bool IsObject() const;
-  inline Object* ToObject();
+  template <typename T>
+  T* cast() {
+    DCHECK(!HasWeakHeapObjectTag(this));
+    return T::cast(reinterpret_cast<Object*>(this));
+  }
 
   static MaybeObject* FromSmi(Smi* smi) {
     DCHECK(HAS_SMI_TAG(smi));
diff --git a/deps/v8/src/objects/microtask-queue-inl.h b/deps/v8/src/objects/microtask-queue-inl.h
new file mode 100644
index 0000000000..8d93ee5226
--- /dev/null
+++ b/deps/v8/src/objects/microtask-queue-inl.h
@@ -0,0 +1,28 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_MICROTASK_QUEUE_INL_H_
+#define V8_OBJECTS_MICROTASK_QUEUE_INL_H_
+
+#include "src/objects/microtask-queue.h"
+
+#include "src/objects-inl.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(MicrotaskQueue)
+ACCESSORS(MicrotaskQueue, queue, FixedArray, kQueueOffset)
+SMI_ACCESSORS(MicrotaskQueue, pending_microtask_count,
+              kPendingMicrotaskCountOffset)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_MICROTASK_QUEUE_INL_H_
diff --git a/deps/v8/src/objects/microtask-queue.cc b/deps/v8/src/objects/microtask-queue.cc
new file mode 100644
index 0000000000..a8905acd36
--- /dev/null
+++ b/deps/v8/src/objects/microtask-queue.cc
@@ -0,0 +1,40 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/objects/microtask-queue.h"
+
+#include "src/objects/microtask-queue-inl.h"
+
+namespace v8 {
+namespace internal {
+
+// DCHECK requires this for taking the reference of it.
+constexpr int MicrotaskQueue::kMinimumQueueCapacity;
+
+// static
+void MicrotaskQueue::EnqueueMicrotask(Isolate* isolate,
+                                      Handle<MicrotaskQueue> microtask_queue,
+                                      Handle<Microtask> microtask) {
+  Handle<FixedArray> queue(microtask_queue->queue(), isolate);
+  int num_tasks = microtask_queue->pending_microtask_count();
+  DCHECK_LE(num_tasks, queue->length());
+  if (num_tasks == queue->length()) {
+    queue = isolate->factory()->CopyFixedArrayAndGrow(
+        queue, std::max(num_tasks, kMinimumQueueCapacity));
+    microtask_queue->set_queue(*queue);
+  }
+  DCHECK_LE(kMinimumQueueCapacity, queue->length());
+  DCHECK_LT(num_tasks, queue->length());
+  DCHECK(queue->get(num_tasks)->IsUndefined(isolate));
+  queue->set(num_tasks, *microtask);
+  microtask_queue->set_pending_microtask_count(num_tasks + 1);
+}
+
+// static
+void MicrotaskQueue::RunMicrotasks(Handle<MicrotaskQueue> microtask_queue) {
+  UNIMPLEMENTED();
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/objects/microtask-queue.h b/deps/v8/src/objects/microtask-queue.h
new file mode 100644
index 0000000000..bb14cfb498
--- /dev/null
+++ b/deps/v8/src/objects/microtask-queue.h
@@ -0,0 +1,55 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_MICROTASK_QUEUE_H_
+#define V8_OBJECTS_MICROTASK_QUEUE_H_
+
+#include "src/objects.h"
+#include "src/objects/microtask.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+class V8_EXPORT_PRIVATE MicrotaskQueue : public Struct {
+ public:
+  DECL_CAST(MicrotaskQueue)
+  DECL_VERIFIER(MicrotaskQueue)
+  DECL_PRINTER(MicrotaskQueue)
+
+  // A FixedArray that the queued microtasks are stored.
+  // The first |pending_microtask_count| slots contains Microtask instance
+  // for each, and followings are undefined_value if any.
+  DECL_ACCESSORS(queue, FixedArray)
+
+  // The number of microtasks queued in |queue|. This must be less or equal to
+  // the length of |queue|.
+  DECL_INT_ACCESSORS(pending_microtask_count)
+
+  // Enqueues |microtask| to |microtask_queue|.
+  static void EnqueueMicrotask(Isolate* isolate,
+                               Handle<MicrotaskQueue> microtask_queue,
+                               Handle<Microtask> microtask);
+
+  // Runs all enqueued microtasks.
+  static void RunMicrotasks(Handle<MicrotaskQueue> microtask_queue);
+
+  static constexpr int kMinimumQueueCapacity = 8;
+
+  static const int kQueueOffset = HeapObject::kHeaderSize;
+  static const int kPendingMicrotaskCountOffset = kQueueOffset + kPointerSize;
+  static const int kSize = kPendingMicrotaskCountOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(MicrotaskQueue);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_MICROTASK_QUEUE_H_
diff --git a/deps/v8/src/objects/module.cc b/deps/v8/src/objects/module.cc
index 02a94c446b..c4d2626e60 100644
--- a/deps/v8/src/objects/module.cc
+++ b/deps/v8/src/objects/module.cc
@@ -18,8 +18,6 @@
 namespace v8 {
 namespace internal {
 
-namespace {
-
 struct ModuleHandleHash {
   V8_INLINE size_t operator()(Handle<Module> module) const {
     return module->hash();
@@ -82,8 +80,6 @@ class UnorderedStringMap
                 zone)) {}
 };
 
-}  // anonymous namespace
-
 class Module::ResolveSet
     : public std::unordered_map<
           Handle<Module>, UnorderedStringSet*, ModuleHandleHash,
@@ -106,22 +102,18 @@ class Module::ResolveSet
   Zone* zone_;
 };
 
-namespace {
-
-int ExportIndex(int cell_index) {
+int Module::ExportIndex(int cell_index) {
   DCHECK_EQ(ModuleDescriptor::GetCellIndexKind(cell_index),
             ModuleDescriptor::kExport);
   return cell_index - 1;
 }
 
-int ImportIndex(int cell_index) {
+int Module::ImportIndex(int cell_index) {
   DCHECK_EQ(ModuleDescriptor::GetCellIndexKind(cell_index),
             ModuleDescriptor::kImport);
   return -cell_index - 1;
 }
 
-}  // anonymous namespace
-
 void Module::CreateIndirectExport(Isolate* isolate, Handle<Module> module,
                                   Handle<String> name,
                                   Handle<ModuleInfoEntry> entry) {
diff --git a/deps/v8/src/objects/module.h b/deps/v8/src/objects/module.h
index 4612d73c89..fd9f9ace80 100644
--- a/deps/v8/src/objects/module.h
+++ b/deps/v8/src/objects/module.h
@@ -7,6 +7,7 @@
 
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -27,9 +28,6 @@ class Zone;
 // The runtime representation of an ECMAScript module.
 class Module : public Struct, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   DECL_CAST(Module)
   DECL_VERIFIER(Module)
   DECL_PRINTER(Module)
@@ -111,6 +109,9 @@ class Module : public Struct, public NeverReadOnlySpaceObject {
   static void StoreVariable(Handle<Module> module, int cell_index,
                             Handle<Object> value);
 
+  static int ImportIndex(int cell_index);
+  static int ExportIndex(int cell_index);
+
   // Get the namespace object for [module_request] of [module].  If it doesn't
   // exist yet, it is created.
   static Handle<JSModuleNamespace> GetModuleNamespace(Isolate* isolate,
diff --git a/deps/v8/src/objects/name-inl.h b/deps/v8/src/objects/name-inl.h
index e768a40ec2..512e47875c 100644
--- a/deps/v8/src/objects/name-inl.h
+++ b/deps/v8/src/objects/name-inl.h
@@ -19,24 +19,25 @@ CAST_ACCESSOR(Name)
 CAST_ACCESSOR(Symbol)
 
 ACCESSORS(Symbol, name, Object, kNameOffset)
-SMI_ACCESSORS(Symbol, flags, kFlagsOffset)
-BOOL_ACCESSORS(Symbol, flags, is_private, kPrivateBit)
-BOOL_ACCESSORS(Symbol, flags, is_well_known_symbol, kWellKnownSymbolBit)
-BOOL_ACCESSORS(Symbol, flags, is_public, kPublicBit)
-BOOL_ACCESSORS(Symbol, flags, is_interesting_symbol, kInterestingSymbolBit)
+INT_ACCESSORS(Symbol, flags, kFlagsOffset)
+BIT_FIELD_ACCESSORS(Symbol, flags, is_private, Symbol::IsPrivateBit)
+BIT_FIELD_ACCESSORS(Symbol, flags, is_well_known_symbol,
+                    Symbol::IsWellKnownSymbolBit)
+BIT_FIELD_ACCESSORS(Symbol, flags, is_public, Symbol::IsPublicBit)
+BIT_FIELD_ACCESSORS(Symbol, flags, is_interesting_symbol,
+                    Symbol::IsInterestingSymbolBit)
 
 bool Symbol::is_private_field() const {
-  bool value = BooleanBit::get(flags(), kPrivateFieldBit);
+  bool value = Symbol::IsPrivateFieldBit::decode(flags());
   DCHECK_IMPLIES(value, is_private());
   return value;
 }
 
 void Symbol::set_is_private_field() {
-  int old_value = flags();
   // TODO(gsathya): Re-order the bits to have these next to each other
   // and just do the bit shifts once.
-  set_flags(BooleanBit::set(old_value, kPrivateBit, true) |
-            BooleanBit::set(old_value, kPrivateFieldBit, true));
+  set_flags(Symbol::IsPrivateBit::update(flags(), true));
+  set_flags(Symbol::IsPrivateFieldBit::update(flags(), true));
 }
 
 bool Name::IsUniqueName() const {
@@ -51,13 +52,6 @@ uint32_t Name::hash_field() {
 
 void Name::set_hash_field(uint32_t value) {
   WRITE_UINT32_FIELD(this, kHashFieldOffset, value);
-#if V8_HOST_ARCH_64_BIT
-#if V8_TARGET_LITTLE_ENDIAN
-  WRITE_UINT32_FIELD(this, kHashFieldSlot + kInt32Size, 0);
-#else
-  WRITE_UINT32_FIELD(this, kHashFieldSlot, 0);
-#endif
-#endif
 }
 
 bool Name::Equals(Name* other) {
diff --git a/deps/v8/src/objects/name.h b/deps/v8/src/objects/name.h
index 06e08deb82..bcc1f2c27d 100644
--- a/deps/v8/src/objects/name.h
+++ b/deps/v8/src/objects/name.h
@@ -67,13 +67,8 @@ class Name : public HeapObject {
   int NameShortPrint(Vector<char> str);
 
   // Layout description.
-  static const int kHashFieldSlot = HeapObject::kHeaderSize;
-#if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
-  static const int kHashFieldOffset = kHashFieldSlot;
-#else
-  static const int kHashFieldOffset = kHashFieldSlot + kInt32Size;
-#endif
-  static const int kSize = kHashFieldSlot + kPointerSize;
+  static const int kHashFieldOffset = HeapObject::kHeaderSize;
+  static const int kHeaderSize = kHashFieldOffset + kInt32Size;
 
   // Mask constant for checking if a name has a computed hash code
   // and if it is a string that is an array index.  The least significant bit
@@ -181,20 +176,22 @@ class Symbol : public Name {
   DECL_VERIFIER(Symbol)
 
   // Layout description.
-  static const int kNameOffset = Name::kSize;
-  static const int kFlagsOffset = kNameOffset + kPointerSize;
-  static const int kSize = kFlagsOffset + kPointerSize;
-
-  // Flags layout.
-  static const int kPrivateBit = 0;
-  static const int kWellKnownSymbolBit = 1;
-  static const int kPublicBit = 2;
-  static const int kInterestingSymbolBit = 3;
-  static const int kPrivateFieldBit = 4;
-
-  typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
+  static const int kFlagsOffset = Name::kHeaderSize;
+  static const int kNameOffset = kFlagsOffset + kInt32Size;
+  static const int kSize = kNameOffset + kPointerSize;
+
+// Flags layout.
+#define FLAGS_BIT_FIELDS(V, _)          \
+  V(IsPrivateBit, bool, 1, _)           \
+  V(IsWellKnownSymbolBit, bool, 1, _)   \
+  V(IsPublicBit, bool, 1, _)            \
+  V(IsInterestingSymbolBit, bool, 1, _) \
+  V(IsPrivateFieldBit, bool, 1, _)
+
+  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
+#undef FLAGS_BIT_FIELDS
+
+  typedef FixedBodyDescriptor<kNameOffset, kSize, kSize> BodyDescriptor;
 
   void SymbolShortPrint(std::ostream& os);
 
diff --git a/deps/v8/src/objects/object-macros-undef.h b/deps/v8/src/objects/object-macros-undef.h
index 8176bb0324..a0c19cab5c 100644
--- a/deps/v8/src/objects/object-macros-undef.h
+++ b/deps/v8/src/objects/object-macros-undef.h
@@ -46,6 +46,8 @@
 #undef WRITE_INTPTR_FIELD
 #undef RELAXED_READ_INTPTR_FIELD
 #undef RELAXED_WRITE_INTPTR_FIELD
+#undef READ_UINTPTR_FIELD
+#undef WRITE_UINTPTR_FIELD
 #undef READ_UINT8_FIELD
 #undef WRITE_UINT8_FIELD
 #undef READ_INT8_FIELD
diff --git a/deps/v8/src/objects/object-macros.h b/deps/v8/src/objects/object-macros.h
index 9ec24a62f7..c97f59f9c0 100644
--- a/deps/v8/src/objects/object-macros.h
+++ b/deps/v8/src/objects/object-macros.h
@@ -290,6 +290,12 @@
 #define WRITE_INTPTR_FIELD(p, offset, value) \
   (*reinterpret_cast<intptr_t*>(FIELD_ADDR(p, offset)) = value)
 
+#define READ_UINTPTR_FIELD(p, offset) \
+  (*reinterpret_cast<const uintptr_t*>(FIELD_ADDR(p, offset)))
+
+#define WRITE_UINTPTR_FIELD(p, offset, value) \
+  (*reinterpret_cast<uintptr_t*>(FIELD_ADDR(p, offset)) = value)
+
 #define READ_UINT8_FIELD(p, offset) \
   (*reinterpret_cast<const uint8_t*>(FIELD_ADDR(p, offset)))
 
diff --git a/deps/v8/src/objects/ordered-hash-table-inl.h b/deps/v8/src/objects/ordered-hash-table-inl.h
index 76b0692c46..76343c21ed 100644
--- a/deps/v8/src/objects/ordered-hash-table-inl.h
+++ b/deps/v8/src/objects/ordered-hash-table-inl.h
@@ -13,20 +13,20 @@
 namespace v8 {
 namespace internal {
 
-int OrderedHashSet::GetMapRootIndex() {
-  return Heap::kOrderedHashSetMapRootIndex;
+RootIndex OrderedHashSet::GetMapRootIndex() {
+  return RootIndex::kOrderedHashSetMap;
 }
 
-int OrderedHashMap::GetMapRootIndex() {
-  return Heap::kOrderedHashMapMapRootIndex;
+RootIndex OrderedHashMap::GetMapRootIndex() {
+  return RootIndex::kOrderedHashMapMap;
 }
 
-int SmallOrderedHashMap::GetMapRootIndex() {
-  return Heap::kSmallOrderedHashMapMapRootIndex;
+RootIndex SmallOrderedHashMap::GetMapRootIndex() {
+  return RootIndex::kSmallOrderedHashMapMap;
 }
 
-int SmallOrderedHashSet::GetMapRootIndex() {
-  return Heap::kSmallOrderedHashSetMapRootIndex;
+RootIndex SmallOrderedHashSet::GetMapRootIndex() {
+  return RootIndex::kSmallOrderedHashSetMap;
 }
 
 inline Object* OrderedHashMap::ValueAt(int entry) {
diff --git a/deps/v8/src/objects/ordered-hash-table.cc b/deps/v8/src/objects/ordered-hash-table.cc
index fdafce56ae..171e4dfae3 100644
--- a/deps/v8/src/objects/ordered-hash-table.cc
+++ b/deps/v8/src/objects/ordered-hash-table.cc
@@ -26,7 +26,7 @@ Handle<Derived> OrderedHashTable<Derived, entrysize>::Allocate(
   }
   int num_buckets = capacity / kLoadFactor;
   Handle<FixedArray> backing_store = isolate->factory()->NewFixedArrayWithMap(
-      static_cast<Heap::RootListIndex>(Derived::GetMapRootIndex()),
+      Derived::GetMapRootIndex(),
       kHashTableStartIndex + num_buckets + (capacity * kEntrySize), pretenure);
   Handle<Derived> table = Handle<Derived>::cast(backing_store);
   for (int i = 0; i < num_buckets; ++i) {
diff --git a/deps/v8/src/objects/ordered-hash-table.h b/deps/v8/src/objects/ordered-hash-table.h
index 0ee0f71c5c..6c606efc75 100644
--- a/deps/v8/src/objects/ordered-hash-table.h
+++ b/deps/v8/src/objects/ordered-hash-table.h
@@ -7,6 +7,7 @@
 
 #include "src/globals.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/js-objects.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -231,7 +232,7 @@ class OrderedHashSet : public OrderedHashTable<OrderedHashSet, 1> {
                                                Handle<OrderedHashSet> table,
                                                GetKeysConversion convert);
   static HeapObject* GetEmpty(ReadOnlyRoots ro_roots);
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
   static inline bool Is(Handle<HeapObject> table);
 };
 
@@ -249,7 +250,7 @@ class OrderedHashMap : public OrderedHashTable<OrderedHashMap, 2> {
   static Object* GetHash(Isolate* isolate, Object* key);
 
   static HeapObject* GetEmpty(ReadOnlyRoots ro_roots);
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
   static inline bool Is(Handle<HeapObject> table);
 
   static const int kValueOffset = 1;
@@ -326,9 +327,6 @@ class SmallOrderedHashTable : public HeapObject {
   // Iterates only fields in the DataTable.
   class BodyDescriptor;
 
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
-
   // Returns total size in bytes required for a table of given
   // capacity.
   static int SizeFor(int capacity) {
@@ -554,7 +552,7 @@ class SmallOrderedHashSet : public SmallOrderedHashTable<SmallOrderedHashSet> {
                                               Handle<SmallOrderedHashSet> table,
                                               Handle<Object> key);
   static inline bool Is(Handle<HeapObject> table);
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 };
 
 class SmallOrderedHashMap : public SmallOrderedHashTable<SmallOrderedHashMap> {
@@ -575,7 +573,7 @@ class SmallOrderedHashMap : public SmallOrderedHashTable<SmallOrderedHashMap> {
                                               Handle<Object> key,
                                               Handle<Object> value);
   static inline bool Is(Handle<HeapObject> table);
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 };
 
 // TODO(gsathya): Rename this to OrderedHashTable, after we rename
diff --git a/deps/v8/src/objects/promise.h b/deps/v8/src/objects/promise.h
index 5ff5dac6f3..0f7b4f23ce 100644
--- a/deps/v8/src/objects/promise.h
+++ b/deps/v8/src/objects/promise.h
@@ -13,6 +13,8 @@
 namespace v8 {
 namespace internal {
 
+class JSPromise;
+
 // Struct to hold state required for PromiseReactionJob. See the comment on the
 // PromiseReaction below for details on how this is being managed to reduce the
 // memory and allocation overhead. This is the base class for the concrete
diff --git a/deps/v8/src/objects/property-array-inl.h b/deps/v8/src/objects/property-array-inl.h
new file mode 100644
index 0000000000..cb157db5d6
--- /dev/null
+++ b/deps/v8/src/objects/property-array-inl.h
@@ -0,0 +1,83 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_PROPERTY_ARRAY_INL_H_
+#define V8_OBJECTS_PROPERTY_ARRAY_INL_H_
+
+#include "src/objects/property-array.h"
+
+#include "src/heap/heap-write-barrier-inl.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(PropertyArray)
+
+Object* PropertyArray::get(int index) const {
+  DCHECK_GE(index, 0);
+  DCHECK_LE(index, this->length());
+  return RELAXED_READ_FIELD(this, kHeaderSize + index * kPointerSize);
+}
+
+void PropertyArray::set(int index, Object* value) {
+  DCHECK(IsPropertyArray());
+  DCHECK_GE(index, 0);
+  DCHECK_LT(index, this->length());
+  int offset = kHeaderSize + index * kPointerSize;
+  RELAXED_WRITE_FIELD(this, offset, value);
+  WRITE_BARRIER(this, offset, value);
+}
+
+void PropertyArray::set(int index, Object* value, WriteBarrierMode mode) {
+  DCHECK_GE(index, 0);
+  DCHECK_LT(index, this->length());
+  int offset = kHeaderSize + index * kPointerSize;
+  RELAXED_WRITE_FIELD(this, offset, value);
+  CONDITIONAL_WRITE_BARRIER(this, offset, value, mode);
+}
+
+Object** PropertyArray::data_start() {
+  return HeapObject::RawField(this, kHeaderSize);
+}
+
+int PropertyArray::length() const {
+  Object* value_obj = READ_FIELD(this, kLengthAndHashOffset);
+  int value = Smi::ToInt(value_obj);
+  return LengthField::decode(value);
+}
+
+void PropertyArray::initialize_length(int len) {
+  SLOW_DCHECK(len >= 0);
+  SLOW_DCHECK(len < LengthField::kMax);
+  WRITE_FIELD(this, kLengthAndHashOffset, Smi::FromInt(len));
+}
+
+int PropertyArray::synchronized_length() const {
+  Object* value_obj = ACQUIRE_READ_FIELD(this, kLengthAndHashOffset);
+  int value = Smi::ToInt(value_obj);
+  return LengthField::decode(value);
+}
+
+int PropertyArray::Hash() const {
+  Object* value_obj = READ_FIELD(this, kLengthAndHashOffset);
+  int value = Smi::ToInt(value_obj);
+  return HashField::decode(value);
+}
+
+void PropertyArray::SetHash(int hash) {
+  Object* value_obj = READ_FIELD(this, kLengthAndHashOffset);
+  int value = Smi::ToInt(value_obj);
+  value = HashField::update(value, hash);
+  WRITE_FIELD(this, kLengthAndHashOffset, Smi::FromInt(value));
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_PROPERTY_ARRAY_INL_H_
diff --git a/deps/v8/src/objects/property-array.h b/deps/v8/src/objects/property-array.h
new file mode 100644
index 0000000000..70f535a8f0
--- /dev/null
+++ b/deps/v8/src/objects/property-array.h
@@ -0,0 +1,73 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_PROPERTY_ARRAY_H_
+#define V8_OBJECTS_PROPERTY_ARRAY_H_
+
+#include "src/objects.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+class PropertyArray : public HeapObject {
+ public:
+  // [length]: length of the array.
+  inline int length() const;
+
+  // Get the length using acquire loads.
+  inline int synchronized_length() const;
+
+  // This is only used on a newly allocated PropertyArray which
+  // doesn't have an existing hash.
+  inline void initialize_length(int length);
+
+  inline void SetHash(int hash);
+  inline int Hash() const;
+
+  inline Object* get(int index) const;
+
+  inline void set(int index, Object* value);
+  // Setter with explicit barrier mode.
+  inline void set(int index, Object* value, WriteBarrierMode mode);
+
+  // Gives access to raw memory which stores the array's data.
+  inline Object** data_start();
+
+  // Garbage collection support.
+  static constexpr int SizeFor(int length) {
+    return kHeaderSize + length * kPointerSize;
+  }
+
+  DECL_CAST(PropertyArray)
+  DECL_PRINTER(PropertyArray)
+  DECL_VERIFIER(PropertyArray)
+
+  // Layout description.
+  static const int kLengthAndHashOffset = HeapObject::kHeaderSize;
+  static const int kHeaderSize = kLengthAndHashOffset + kPointerSize;
+
+  // Garbage collection support.
+  typedef FlexibleBodyDescriptor<kHeaderSize> BodyDescriptor;
+
+  static const int kLengthFieldSize = 10;
+  class LengthField : public BitField<int, 0, kLengthFieldSize> {};
+  static const int kMaxLength = LengthField::kMax;
+  class HashField : public BitField<int, kLengthFieldSize,
+                                    kSmiValueSize - kLengthFieldSize - 1> {};
+
+  static const int kNoHashSentinel = 0;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PropertyArray);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_PROPERTY_ARRAY_H_
diff --git a/deps/v8/src/objects/prototype-info-inl.h b/deps/v8/src/objects/prototype-info-inl.h
index 298674eb10..24e219d46c 100644
--- a/deps/v8/src/objects/prototype-info-inl.h
+++ b/deps/v8/src/objects/prototype-info-inl.h
@@ -20,7 +20,7 @@ namespace internal {
 CAST_ACCESSOR(PrototypeInfo)
 
 Map* PrototypeInfo::ObjectCreateMap() {
-  return Map::cast(object_create_map()->ToWeakHeapObject());
+  return Map::cast(object_create_map()->GetHeapObjectAssumeWeak());
 }
 
 // static
@@ -31,7 +31,7 @@ void PrototypeInfo::SetObjectCreateMap(Handle<PrototypeInfo> info,
 
 bool PrototypeInfo::HasObjectCreateMap() {
   MaybeObject* cache = object_create_map();
-  return cache->IsWeakHeapObject();
+  return cache->IsWeak();
 }
 
 ACCESSORS(PrototypeInfo, module_namespace, Object, kJSModuleNamespaceOffset)
@@ -51,7 +51,7 @@ void PrototypeUsers::MarkSlotEmpty(WeakArrayList* array, int index) {
 }
 
 Smi* PrototypeUsers::empty_slot_index(WeakArrayList* array) {
-  return array->Get(kEmptySlotIndex)->ToSmi();
+  return array->Get(kEmptySlotIndex)->cast<Smi>();
 }
 
 void PrototypeUsers::set_empty_slot_index(WeakArrayList* array, int index) {
diff --git a/deps/v8/src/objects/scope-info.cc b/deps/v8/src/objects/scope-info.cc
index 9ec87dcb92..0fa5557e8c 100644
--- a/deps/v8/src/objects/scope-info.cc
+++ b/deps/v8/src/objects/scope-info.cc
@@ -369,7 +369,6 @@ Handle<ScopeInfo> ScopeInfo::CreateForEmptyFunction(Isolate* isolate) {
 // static
 Handle<ScopeInfo> ScopeInfo::CreateForBootstrapping(Isolate* isolate,
                                                     ScopeType type) {
-  DCHECK(isolate->bootstrapper()->IsActive());
   DCHECK(type == SCRIPT_SCOPE || type == FUNCTION_SCOPE);
 
   const int parameter_count = 0;
diff --git a/deps/v8/src/objects/scope-info.h b/deps/v8/src/objects/scope-info.h
index ac0664f7fb..622c51210b 100644
--- a/deps/v8/src/objects/scope-info.h
+++ b/deps/v8/src/objects/scope-info.h
@@ -177,7 +177,8 @@ class ScopeInfo : public FixedArray {
                                   MaybeHandle<ScopeInfo> outer_scope);
   static Handle<ScopeInfo> CreateForWithScope(
       Isolate* isolate, MaybeHandle<ScopeInfo> outer_scope);
-  static Handle<ScopeInfo> CreateForEmptyFunction(Isolate* isolate);
+  V8_EXPORT_PRIVATE static Handle<ScopeInfo> CreateForEmptyFunction(
+      Isolate* isolate);
   static Handle<ScopeInfo> CreateGlobalThisBinding(Isolate* isolate);
 
   // Serializes empty scope info.
diff --git a/deps/v8/src/objects/script.h b/deps/v8/src/objects/script.h
index 3420b71754..bd789ba2ff 100644
--- a/deps/v8/src/objects/script.h
+++ b/deps/v8/src/objects/script.h
@@ -17,9 +17,6 @@ namespace internal {
 // Script describes a script which has been added to the VM.
 class Script : public Struct, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   // Script types.
   enum Type {
     TYPE_NATIVE = 0,
diff --git a/deps/v8/src/objects/shared-function-info-inl.h b/deps/v8/src/objects/shared-function-info-inl.h
index 0b4a7effb9..cf057e9ca0 100644
--- a/deps/v8/src/objects/shared-function-info-inl.h
+++ b/deps/v8/src/objects/shared-function-info-inl.h
@@ -282,60 +282,6 @@ void SharedFunctionInfo::DontAdaptArguments() {
   set_internal_formal_parameter_count(kDontAdaptArgumentsSentinel);
 }
 
-int SharedFunctionInfo::StartPosition() const {
-  Object* maybe_scope_info = name_or_scope_info();
-  if (maybe_scope_info->IsScopeInfo()) {
-    ScopeInfo* info = ScopeInfo::cast(maybe_scope_info);
-    if (info->HasPositionInfo()) {
-      return info->StartPosition();
-    }
-  } else if (HasUncompiledData()) {
-    // Works with or without scope.
-    return uncompiled_data()->start_position();
-  } else if (IsApiFunction() || HasBuiltinId()) {
-    DCHECK_IMPLIES(HasBuiltinId(), builtin_id() != Builtins::kCompileLazy);
-    return 0;
-  }
-  return kNoSourcePosition;
-}
-
-int SharedFunctionInfo::EndPosition() const {
-  Object* maybe_scope_info = name_or_scope_info();
-  if (maybe_scope_info->IsScopeInfo()) {
-    ScopeInfo* info = ScopeInfo::cast(maybe_scope_info);
-    if (info->HasPositionInfo()) {
-      return info->EndPosition();
-    }
-  } else if (HasUncompiledData()) {
-    // Works with or without scope.
-    return uncompiled_data()->end_position();
-  } else if (IsApiFunction() || HasBuiltinId()) {
-    DCHECK_IMPLIES(HasBuiltinId(), builtin_id() != Builtins::kCompileLazy);
-    return 0;
-  }
-  return kNoSourcePosition;
-}
-
-void SharedFunctionInfo::SetPosition(int start_position, int end_position) {
-  Object* maybe_scope_info = name_or_scope_info();
-  if (maybe_scope_info->IsScopeInfo()) {
-    ScopeInfo* info = ScopeInfo::cast(maybe_scope_info);
-    if (info->HasPositionInfo()) {
-      info->SetPositionInfo(start_position, end_position);
-    }
-  } else if (HasUncompiledData()) {
-    if (HasUncompiledDataWithPreParsedScope()) {
-      // Clear out preparsed scope data, since the position setter invalidates
-      // any scope data.
-      ClearPreParsedScopeData();
-    }
-    uncompiled_data()->set_start_position(start_position);
-    uncompiled_data()->set_end_position(end_position);
-  } else {
-    UNREACHABLE();
-  }
-}
-
 bool SharedFunctionInfo::IsInterpreted() const { return HasBytecodeArray(); }
 
 ScopeInfo* SharedFunctionInfo::scope_info() const {
@@ -613,21 +559,6 @@ bool SharedFunctionInfo::HasWasmExportedFunctionData() const {
   return function_data()->IsWasmExportedFunctionData();
 }
 
-int SharedFunctionInfo::FunctionLiteralId(Isolate* isolate) const {
-  // Fast path for the common case when the SFI is uncompiled and so the
-  // function literal id is already in the uncompiled data.
-  if (HasUncompiledData()) {
-    int id = uncompiled_data()->function_literal_id();
-    // Make sure the id is what we should have found with the slow path.
-    DCHECK_EQ(id, FindIndexInScript(isolate));
-    return id;
-  }
-
-  // Otherwise, search for the function in the SFI's script's function list,
-  // and return its index in that list.e
-  return FindIndexInScript(isolate);
-}
-
 Object* SharedFunctionInfo::script() const {
   Object* maybe_script = script_or_debug_info();
   if (maybe_script->IsDebugInfo()) {
diff --git a/deps/v8/src/objects/shared-function-info.h b/deps/v8/src/objects/shared-function-info.h
index d5f65a91d1..f43fa61b2f 100644
--- a/deps/v8/src/objects/shared-function-info.h
+++ b/deps/v8/src/objects/shared-function-info.h
@@ -7,6 +7,7 @@
 
 #include "src/bailout-reason.h"
 #include "src/objects.h"
+#include "src/objects/builtin-function-id.h"
 #include "src/objects/script.h"
 
 // Has to be the last include (doesn't have include guards):
@@ -53,8 +54,6 @@ class PreParsedScopeData : public HeapObject {
       POINTER_SIZE_ALIGN(kUnalignedChildDataStartOffset);
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   static constexpr int SizeFor(int length) {
     return kChildDataStartOffset + length * kPointerSize;
@@ -114,8 +113,6 @@ class UncompiledDataWithoutPreParsedScope : public UncompiledData {
 
   // No extra fields compared to UncompiledData.
   typedef UncompiledData::BodyDescriptor BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(UncompiledDataWithoutPreParsedScope);
@@ -150,8 +147,6 @@ class UncompiledDataWithPreParsedScope : public UncompiledData {
       FixedBodyDescriptor<kStartOfPointerFieldsOffset,
                           kEndOfPointerFieldsOffset, kSize>>
       BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(UncompiledDataWithPreParsedScope);
@@ -179,9 +174,6 @@ class InterpreterData : public Struct {
 // shared by multiple instances of the function.
 class SharedFunctionInfo : public HeapObject, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   static constexpr Object* const kNoSharedNameSentinel = Smi::kZero;
 
   // [name]: Returns shared name if it exists or an empty string otherwise.
@@ -230,14 +222,14 @@ class SharedFunctionInfo : public HeapObject, public NeverReadOnlySpaceObject {
   DECL_ACCESSORS(scope_info, ScopeInfo)
 
   // End position of this function in the script source.
-  inline int EndPosition() const;
+  V8_EXPORT_PRIVATE int EndPosition() const;
 
   // Start position of this function in the script source.
-  inline int StartPosition() const;
+  V8_EXPORT_PRIVATE int StartPosition() const;
 
   // Set the start and end position of this function in the script source.
   // Updates the scope info if available.
-  inline void SetPosition(int start_position, int end_position);
+  V8_EXPORT_PRIVATE void SetPosition(int start_position, int end_position);
 
   // [outer scope info | feedback metadata] Shared storage for outer scope info
   // (on uncompiled functions) and feedback metadata (on compiled functions).
@@ -358,7 +350,7 @@ class SharedFunctionInfo : public HeapObject, public NeverReadOnlySpaceObject {
   inline String* inferred_name();
 
   // Get the function literal id associated with this function, for parsing.
-  inline int FunctionLiteralId(Isolate* isolate) const;
+  V8_EXPORT_PRIVATE int FunctionLiteralId(Isolate* isolate) const;
 
   // Break infos are contained in DebugInfo, this is a convenience method
   // to simplify access.
@@ -625,8 +617,6 @@ class SharedFunctionInfo : public HeapObject, public NeverReadOnlySpaceObject {
   typedef FixedBodyDescriptor<kStartOfPointerFieldsOffset,
                               kEndOfPointerFieldsOffset, kAlignedSize>
       BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
 // Bit positions in |flags|.
 #define FLAGS_BIT_FIELDS(V, _)                           \
diff --git a/deps/v8/src/objects/stack-frame-info-inl.h b/deps/v8/src/objects/stack-frame-info-inl.h
new file mode 100644
index 0000000000..8398c7cb5b
--- /dev/null
+++ b/deps/v8/src/objects/stack-frame-info-inl.h
@@ -0,0 +1,38 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_STACK_FRAME_INFO_INL_H_
+#define V8_OBJECTS_STACK_FRAME_INFO_INL_H_
+
+#include "src/objects/stack-frame-info.h"
+
+#include "src/heap/heap-write-barrier-inl.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(StackFrameInfo)
+
+SMI_ACCESSORS(StackFrameInfo, line_number, kLineNumberIndex)
+SMI_ACCESSORS(StackFrameInfo, column_number, kColumnNumberIndex)
+SMI_ACCESSORS(StackFrameInfo, script_id, kScriptIdIndex)
+ACCESSORS(StackFrameInfo, script_name, Object, kScriptNameIndex)
+ACCESSORS(StackFrameInfo, script_name_or_source_url, Object,
+          kScriptNameOrSourceUrlIndex)
+ACCESSORS(StackFrameInfo, function_name, Object, kFunctionNameIndex)
+SMI_ACCESSORS(StackFrameInfo, flag, kFlagIndex)
+BOOL_ACCESSORS(StackFrameInfo, flag, is_eval, kIsEvalBit)
+BOOL_ACCESSORS(StackFrameInfo, flag, is_constructor, kIsConstructorBit)
+BOOL_ACCESSORS(StackFrameInfo, flag, is_wasm, kIsWasmBit)
+SMI_ACCESSORS(StackFrameInfo, id, kIdIndex)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_STACK_FRAME_INFO_INL_H_
diff --git a/deps/v8/src/objects/stack-frame-info.h b/deps/v8/src/objects/stack-frame-info.h
new file mode 100644
index 0000000000..4adc37109e
--- /dev/null
+++ b/deps/v8/src/objects/stack-frame-info.h
@@ -0,0 +1,62 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_STACK_FRAME_INFO_H_
+#define V8_OBJECTS_STACK_FRAME_INFO_H_
+
+#include "src/objects.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+class StackFrameInfo : public Struct, public NeverReadOnlySpaceObject {
+ public:
+  DECL_INT_ACCESSORS(line_number)
+  DECL_INT_ACCESSORS(column_number)
+  DECL_INT_ACCESSORS(script_id)
+  DECL_ACCESSORS(script_name, Object)
+  DECL_ACCESSORS(script_name_or_source_url, Object)
+  DECL_ACCESSORS(function_name, Object)
+  DECL_BOOLEAN_ACCESSORS(is_eval)
+  DECL_BOOLEAN_ACCESSORS(is_constructor)
+  DECL_BOOLEAN_ACCESSORS(is_wasm)
+  DECL_INT_ACCESSORS(flag)
+  DECL_INT_ACCESSORS(id)
+
+  DECL_CAST(StackFrameInfo)
+
+  // Dispatched behavior.
+  DECL_PRINTER(StackFrameInfo)
+  DECL_VERIFIER(StackFrameInfo)
+
+  static const int kLineNumberIndex = Struct::kHeaderSize;
+  static const int kColumnNumberIndex = kLineNumberIndex + kPointerSize;
+  static const int kScriptIdIndex = kColumnNumberIndex + kPointerSize;
+  static const int kScriptNameIndex = kScriptIdIndex + kPointerSize;
+  static const int kScriptNameOrSourceUrlIndex =
+      kScriptNameIndex + kPointerSize;
+  static const int kFunctionNameIndex =
+      kScriptNameOrSourceUrlIndex + kPointerSize;
+  static const int kFlagIndex = kFunctionNameIndex + kPointerSize;
+  static const int kIdIndex = kFlagIndex + kPointerSize;
+  static const int kSize = kIdIndex + kPointerSize;
+
+ private:
+  // Bit position in the flag, from least significant bit position.
+  static const int kIsEvalBit = 0;
+  static const int kIsConstructorBit = 1;
+  static const int kIsWasmBit = 2;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(StackFrameInfo);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_STACK_FRAME_INFO_H_
diff --git a/deps/v8/src/objects/string-inl.h b/deps/v8/src/objects/string-inl.h
index 39f642063e..349fa31f9d 100644
--- a/deps/v8/src/objects/string-inl.h
+++ b/deps/v8/src/objects/string-inl.h
@@ -19,8 +19,17 @@
 namespace v8 {
 namespace internal {
 
-SMI_ACCESSORS(String, length, kLengthOffset)
-SYNCHRONIZED_SMI_ACCESSORS(String, length, kLengthOffset)
+INT32_ACCESSORS(String, length, kLengthOffset)
+
+int String::synchronized_length() const {
+  return base::AsAtomic32::Acquire_Load(
+      reinterpret_cast<const int32_t*>(FIELD_ADDR(this, kLengthOffset)));
+}
+
+void String::synchronized_set_length(int value) {
+  base::AsAtomic32::Release_Store(
+      reinterpret_cast<int32_t*>(FIELD_ADDR(this, kLengthOffset)), value);
+}
 
 CAST_ACCESSOR(ConsString)
 CAST_ACCESSOR(ExternalOneByteString)
@@ -536,9 +545,9 @@ HeapObject* ThinString::unchecked_actual() const {
   return reinterpret_cast<HeapObject*>(READ_FIELD(this, kActualOffset));
 }
 
-bool ExternalString::is_short() const {
+bool ExternalString::is_uncached() const {
   InstanceType type = map()->instance_type();
-  return (type & kShortExternalStringMask) == kShortExternalStringTag;
+  return (type & kUncachedExternalStringMask) == kUncachedExternalStringTag;
 }
 
 Address ExternalString::resource_as_address() {
@@ -562,7 +571,7 @@ uint32_t ExternalString::resource_as_uint32() {
 
 void ExternalString::set_uint32_as_resource(uint32_t value) {
   *reinterpret_cast<uintptr_t*>(FIELD_ADDR(this, kResourceOffset)) = value;
-  if (is_short()) return;
+  if (is_uncached()) return;
   const char** data_field =
       reinterpret_cast<const char**>(FIELD_ADDR(this, kResourceDataOffset));
   *data_field = nullptr;
@@ -573,7 +582,7 @@ const ExternalOneByteString::Resource* ExternalOneByteString::resource() {
 }
 
 void ExternalOneByteString::update_data_cache() {
-  if (is_short()) return;
+  if (is_uncached()) return;
   const char** data_field =
       reinterpret_cast<const char**>(FIELD_ADDR(this, kResourceDataOffset));
   *data_field = resource()->data();
@@ -609,7 +618,7 @@ const ExternalTwoByteString::Resource* ExternalTwoByteString::resource() {
 }
 
 void ExternalTwoByteString::update_data_cache() {
-  if (is_short()) return;
+  if (is_uncached()) return;
   const uint16_t** data_field =
       reinterpret_cast<const uint16_t**>(FIELD_ADDR(this, kResourceDataOffset));
   *data_field = resource()->data();
@@ -733,8 +742,7 @@ class String::SubStringRange::iterator final {
   typedef uc16* pointer;
   typedef uc16& reference;
 
-  iterator(const iterator& other)
-      : content_(other.content_), offset_(other.offset_) {}
+  iterator(const iterator& other) = default;
 
   uc16 operator*() { return content_.Get(offset_); }
   bool operator==(const iterator& other) const {
diff --git a/deps/v8/src/objects/string-table.h b/deps/v8/src/objects/string-table.h
index 8003bf1aac..b26e86a381 100644
--- a/deps/v8/src/objects/string-table.h
+++ b/deps/v8/src/objects/string-table.h
@@ -42,7 +42,7 @@ class StringTableShape : public BaseShape<StringTableKey*> {
 
   static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
 
-  static inline int GetMapRootIndex();
+  static inline RootIndex GetMapRootIndex();
 
   static const int kPrefixSize = 0;
   static const int kEntrySize = 1;
diff --git a/deps/v8/src/objects/string.h b/deps/v8/src/objects/string.h
index 4058c7cec3..206bed641c 100644
--- a/deps/v8/src/objects/string.h
+++ b/deps/v8/src/objects/string.h
@@ -31,7 +31,7 @@ enum RobustnessFlag { ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL };
 // shortcutting.  Keeping these restrictions in mind has proven to be error-
 // prone and so we no longer put StringShapes in variables unless there is a
 // concrete performance benefit at that particular point in the code.
-class StringShape BASE_EMBEDDED {
+class StringShape {
  public:
   inline explicit StringShape(const String* s);
   inline explicit StringShape(Map* s);
@@ -264,7 +264,7 @@ class String : public Name {
     virtual MaybeHandle<String> GetNamedCapture(Handle<String> name,
                                                 CaptureState* state) = 0;
 
-    virtual ~Match() {}
+    virtual ~Match() = default;
   };
 
   // ES#sec-getsubstitution
@@ -300,11 +300,11 @@ class String : public Name {
   // do any heap allocations.  This is useful when printing stack traces.
   std::unique_ptr<char[]> ToCString(AllowNullsFlag allow_nulls,
                                     RobustnessFlag robustness_flag, int offset,
-                                    int length, int* length_output = 0);
+                                    int length, int* length_output = nullptr);
   std::unique_ptr<char[]> ToCString(
       AllowNullsFlag allow_nulls = DISALLOW_NULLS,
       RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL,
-      int* length_output = 0);
+      int* length_output = nullptr);
 
   bool ComputeArrayIndex(uint32_t* index);
 
@@ -341,8 +341,8 @@ class String : public Name {
   inline bool IsFlat();
 
   // Layout description.
-  static const int kLengthOffset = Name::kSize;
-  static const int kSize = kLengthOffset + kPointerSize;
+  static const int kLengthOffset = Name::kHeaderSize;
+  static const int kHeaderSize = kLengthOffset + kInt32Size;
 
   // Max char codes.
   static const int32_t kMaxOneByteCharCode = unibrow::Latin1::kMaxChar;
@@ -360,7 +360,7 @@ class String : public Name {
 
   // See include/v8.h for the definition.
   static const int kMaxLength = v8::String::kMaxLength;
-  static_assert(kMaxLength <= (Smi::kMaxValue / 2 - kSize),
+  static_assert(kMaxLength <= (Smi::kMaxValue / 2 - kHeaderSize),
                 "Unexpected max String length");
 
   // Max length for computing hash. For strings longer than this limit the
@@ -370,9 +370,6 @@ class String : public Name {
   // Limit for truncation in short printing.
   static const int kMaxShortPrintLength = 1024;
 
-  // Support for regular expressions.
-  const uc16* GetTwoByteData(unsigned start);
-
   // Helper function for flattening strings.
   template <typename sinkchar>
   static void WriteToFlat(String* source, sinkchar* sink, int from, int to);
@@ -474,9 +471,6 @@ class SeqString : public String {
  public:
   DECL_CAST(SeqString)
 
-  // Layout description.
-  static const int kHeaderSize = String::kSize;
-
   // Truncate the string in-place if possible and return the result.
   // In case of new_length == 0, the empty string is returned without
   // truncating the original string.
@@ -533,8 +527,6 @@ class SeqOneByteString : public SeqString {
   STATIC_ASSERT((kMaxSize - kHeaderSize) >= String::kMaxLength);
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(SeqOneByteString);
@@ -559,9 +551,6 @@ class SeqTwoByteString : public SeqString {
   // is deterministic.
   void clear_padding();
 
-  // For regexp code.
-  const uint16_t* SeqTwoByteStringGetData(unsigned start);
-
   DECL_CAST(SeqTwoByteString)
 
   // Garbage collection support.  This method is called by the
@@ -581,8 +570,6 @@ class SeqTwoByteString : public SeqString {
                 String::kMaxLength);
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString);
@@ -620,7 +607,7 @@ class ConsString : public String {
   DECL_CAST(ConsString)
 
   // Layout description.
-  static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize);
+  static const int kFirstOffset = String::kHeaderSize;
   static const int kSecondOffset = kFirstOffset + kPointerSize;
   static const int kSize = kSecondOffset + kPointerSize;
 
@@ -629,8 +616,6 @@ class ConsString : public String {
 
   typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize>
       BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   DECL_VERIFIER(ConsString)
 
@@ -659,12 +644,10 @@ class ThinString : public String {
   DECL_VERIFIER(ThinString)
 
   // Layout description.
-  static const int kActualOffset = String::kSize;
+  static const int kActualOffset = String::kHeaderSize;
   static const int kSize = kActualOffset + kPointerSize;
 
   typedef FixedBodyDescriptor<kActualOffset, kSize, kSize> BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ThinString);
@@ -696,7 +679,7 @@ class SlicedString : public String {
   DECL_CAST(SlicedString)
 
   // Layout description.
-  static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize);
+  static const int kParentOffset = String::kHeaderSize;
   static const int kOffsetOffset = kParentOffset + kPointerSize;
   static const int kSize = kOffsetOffset + kPointerSize;
 
@@ -706,8 +689,6 @@ class SlicedString : public String {
   typedef FixedBodyDescriptor<kParentOffset, kOffsetOffset + kPointerSize,
                               kSize>
       BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
   DECL_VERIFIER(SlicedString)
 
@@ -729,13 +710,13 @@ class ExternalString : public String {
   DECL_CAST(ExternalString)
 
   // Layout description.
-  static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize);
-  static const int kShortSize = kResourceOffset + kPointerSize;
+  static const int kResourceOffset = String::kHeaderSize;
+  static const int kUncachedSize = kResourceOffset + kPointerSize;
   static const int kResourceDataOffset = kResourceOffset + kPointerSize;
   static const int kSize = kResourceDataOffset + kPointerSize;
 
-  // Return whether external string is short (data pointer is not cached).
-  inline bool is_short() const;
+  // Return whether the external string data pointer is not cached.
+  inline bool is_uncached() const;
   // Size in bytes of the external payload.
   int ExternalPayloadSize() const;
 
@@ -782,8 +763,6 @@ class ExternalOneByteString : public ExternalString {
   DECL_CAST(ExternalOneByteString)
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalOneByteString);
@@ -823,8 +802,6 @@ class ExternalTwoByteString : public ExternalString {
   DECL_CAST(ExternalTwoByteString)
 
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString);
@@ -837,7 +814,7 @@ class FlatStringReader : public Relocatable {
  public:
   FlatStringReader(Isolate* isolate, Handle<String> str);
   FlatStringReader(Isolate* isolate, Vector<const char> input);
-  void PostGarbageCollection();
+  void PostGarbageCollection() override;
   inline uc32 Get(int index);
   template <typename Char>
   inline Char Get(int index);
@@ -855,7 +832,7 @@ class FlatStringReader : public Relocatable {
 // traversal of the entire string
 class ConsStringIterator {
  public:
-  inline ConsStringIterator() {}
+  inline ConsStringIterator() = default;
   inline explicit ConsStringIterator(ConsString* cons_string, int offset = 0) {
     Reset(cons_string, offset);
   }
diff --git a/deps/v8/src/objects/templates.h b/deps/v8/src/objects/templates.h
index 6a229d847b..24cbd18bd2 100644
--- a/deps/v8/src/objects/templates.h
+++ b/deps/v8/src/objects/templates.h
@@ -15,9 +15,6 @@ namespace internal {
 
 class TemplateInfo : public Struct, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   DECL_ACCESSORS(tag, Object)
   DECL_ACCESSORS(serial_number, Object)
   DECL_INT_ACCESSORS(number_of_properties)
diff --git a/deps/v8/src/optimized-compilation-info.cc b/deps/v8/src/optimized-compilation-info.cc
index f14c3a6661..d6293c2228 100644
--- a/deps/v8/src/optimized-compilation-info.cc
+++ b/deps/v8/src/optimized-compilation-info.cc
@@ -17,22 +17,11 @@ namespace internal {
 OptimizedCompilationInfo::OptimizedCompilationInfo(
     Zone* zone, Isolate* isolate, Handle<SharedFunctionInfo> shared,
     Handle<JSFunction> closure)
-    : OptimizedCompilationInfo({}, AbstractCode::OPTIMIZED_FUNCTION, zone) {
+    : OptimizedCompilationInfo(Code::OPTIMIZED_FUNCTION, zone) {
   shared_info_ = shared;
   closure_ = closure;
   optimization_id_ = isolate->NextOptimizationId();
 
-  SetFlag(kCalledWithCodeStartRegister);
-  if (FLAG_function_context_specialization) MarkAsFunctionContextSpecializing();
-  if (FLAG_turbo_splitting) MarkAsSplittingEnabled();
-  SetFlag(kSwitchJumpTableEnabled);
-  if (FLAG_untrusted_code_mitigations) MarkAsPoisoningRegisterArguments();
-
-  // TODO(yangguo): Disable this in case of debugging for crbug.com/826613
-  if (FLAG_analyze_environment_liveness) {
-    MarkAsAnalyzeEnvironmentLiveness();
-  }
-
   // Collect source positions for optimized code when profiling or if debugger
   // is active, to be able to get more precise source positions at the price of
   // more memory consumption.
@@ -45,39 +34,54 @@ OptimizedCompilationInfo::OptimizedCompilationInfo(
 
 OptimizedCompilationInfo::OptimizedCompilationInfo(
     Vector<const char> debug_name, Zone* zone, Code::Kind code_kind)
-    : OptimizedCompilationInfo(
-          debug_name, static_cast<AbstractCode::Kind>(code_kind), zone) {
-  if (code_kind == Code::BYTECODE_HANDLER) {
-    SetFlag(OptimizedCompilationInfo::kCalledWithCodeStartRegister);
-  }
-#if ENABLE_GDB_JIT_INTERFACE
-#if DEBUG
-  if (code_kind == Code::BUILTIN || code_kind == Code::STUB) {
-    MarkAsSourcePositionsEnabled();
-  }
-#endif
-#endif
+    : OptimizedCompilationInfo(code_kind, zone) {
+  debug_name_ = debug_name;
+
   SetTracingFlags(
       PassesFilter(debug_name, CStrVector(FLAG_trace_turbo_filter)));
-  // Embedded builtins don't support embedded absolute code addresses, so we
-  // cannot use jump tables.
-  if (code_kind != Code::BUILTIN) {
-    SetFlag(kSwitchJumpTableEnabled);
-  }
 }
 
-OptimizedCompilationInfo::OptimizedCompilationInfo(
-    Vector<const char> debug_name, AbstractCode::Kind code_kind, Zone* zone)
-    : flags_(FLAG_untrusted_code_mitigations ? kUntrustedCodeMitigations : 0),
-      code_kind_(code_kind),
-      stub_key_(0),
-      builtin_index_(Builtins::kNoBuiltinId),
-      osr_offset_(BailoutId::None()),
-      zone_(zone),
-      deferred_handles_(nullptr),
-      bailout_reason_(BailoutReason::kNoReason),
-      optimization_id_(-1),
-      debug_name_(debug_name) {}
+OptimizedCompilationInfo::OptimizedCompilationInfo(Code::Kind code_kind,
+                                                   Zone* zone)
+    : code_kind_(code_kind), zone_(zone) {
+  ConfigureFlags();
+}
+
+void OptimizedCompilationInfo::ConfigureFlags() {
+  if (FLAG_untrusted_code_mitigations) SetFlag(kUntrustedCodeMitigations);
+
+  switch (code_kind_) {
+    case Code::OPTIMIZED_FUNCTION:
+      SetFlag(kCalledWithCodeStartRegister);
+      SetFlag(kSwitchJumpTableEnabled);
+      if (FLAG_function_context_specialization) {
+        MarkAsFunctionContextSpecializing();
+      }
+      if (FLAG_turbo_splitting) {
+        MarkAsSplittingEnabled();
+      }
+      if (FLAG_untrusted_code_mitigations) {
+        MarkAsPoisoningRegisterArguments();
+      }
+      if (FLAG_analyze_environment_liveness) {
+        // TODO(yangguo): Disable this in case of debugging for crbug.com/826613
+        MarkAsAnalyzeEnvironmentLiveness();
+      }
+      break;
+    case Code::BYTECODE_HANDLER:
+      SetFlag(kCalledWithCodeStartRegister);
+      break;
+    case Code::BUILTIN:
+    case Code::STUB:
+#if ENABLE_GDB_JIT_INTERFACE && DEBUG
+      MarkAsSourcePositionsEnabled();
+#endif  // ENABLE_GDB_JIT_INTERFACE && DEBUG
+      break;
+    default:
+      SetFlag(kSwitchJumpTableEnabled);
+      break;
+  }
+}
 
 OptimizedCompilationInfo::~OptimizedCompilationInfo() {
   if (GetFlag(kDisableFutureOptimization) && has_shared_info()) {
diff --git a/deps/v8/src/optimized-compilation-info.h b/deps/v8/src/optimized-compilation-info.h
index ecb883f49d..37232a2f06 100644
--- a/deps/v8/src/optimized-compilation-info.h
+++ b/deps/v8/src/optimized-compilation-info.h
@@ -27,6 +27,7 @@ class DeferredHandles;
 class FunctionLiteral;
 class Isolate;
 class JavaScriptFrame;
+class JSGlobalObject;
 class ParseInfo;
 class SourceRangeMap;
 class Zone;
@@ -79,11 +80,7 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   wasm::WasmCode* wasm_code() const {
     return const_cast<wasm::WasmCode*>(code_.as_wasm_code());
   }
-  AbstractCode::Kind abstract_code_kind() const { return code_kind_; }
-  Code::Kind code_kind() const {
-    DCHECK(code_kind_ < static_cast<AbstractCode::Kind>(Code::NUMBER_OF_KINDS));
-    return static_cast<Code::Kind>(code_kind_);
-  }
+  Code::Kind code_kind() const { return code_kind_; }
   uint32_t stub_key() const { return stub_key_; }
   void set_stub_key(uint32_t stub_key) { stub_key_ = stub_key; }
   int32_t builtin_index() const { return builtin_index_; }
@@ -200,15 +197,11 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   JSGlobalObject* global_object() const;
 
   // Accessors for the different compilation modes.
-  bool IsOptimizing() const {
-    return abstract_code_kind() == AbstractCode::OPTIMIZED_FUNCTION;
-  }
-  bool IsWasm() const {
-    return abstract_code_kind() == AbstractCode::WASM_FUNCTION;
-  }
+  bool IsOptimizing() const { return code_kind() == Code::OPTIMIZED_FUNCTION; }
+  bool IsWasm() const { return code_kind() == Code::WASM_FUNCTION; }
   bool IsStub() const {
-    return abstract_code_kind() != AbstractCode::OPTIMIZED_FUNCTION &&
-           abstract_code_kind() != AbstractCode::WASM_FUNCTION;
+    return code_kind() != Code::OPTIMIZED_FUNCTION &&
+           code_kind() != Code::WASM_FUNCTION;
   }
   void SetOptimizingForOsr(BailoutId osr_offset, JavaScriptFrame* osr_frame) {
     DCHECK(IsOptimizing());
@@ -281,8 +274,8 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   }
 
  private:
-  OptimizedCompilationInfo(Vector<const char> debug_name,
-                           AbstractCode::Kind code_kind, Zone* zone);
+  OptimizedCompilationInfo(Code::Kind code_kind, Zone* zone);
+  void ConfigureFlags();
 
   void SetFlag(Flag flag) { flags_ |= flag; }
   bool GetFlag(Flag flag) const { return (flags_ & flag) != 0; }
@@ -290,13 +283,13 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   void SetTracingFlags(bool passes_filter);
 
   // Compilation flags.
-  unsigned flags_;
+  unsigned flags_ = 0;
   PoisoningMitigationLevel poisoning_level_ =
       PoisoningMitigationLevel::kDontPoison;
 
-  AbstractCode::Kind code_kind_;
-  uint32_t stub_key_;
-  int32_t builtin_index_;
+  Code::Kind code_kind_;
+  uint32_t stub_key_ = 0;
+  int32_t builtin_index_ = -1;
 
   Handle<SharedFunctionInfo> shared_info_;
 
@@ -306,7 +299,7 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   CodeReference code_;
 
   // Entry point when compiling for OSR, {BailoutId::None} otherwise.
-  BailoutId osr_offset_;
+  BailoutId osr_offset_ = BailoutId::None();
 
   // The zone from which the compilation pipeline working on this
   // OptimizedCompilationInfo allocates.
@@ -314,11 +307,11 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
 
   std::shared_ptr<DeferredHandles> deferred_handles_;
 
-  BailoutReason bailout_reason_;
+  BailoutReason bailout_reason_ = BailoutReason::kNoReason;
 
   InlinedFunctionList inlined_functions_;
 
-  int optimization_id_;
+  int optimization_id_ = -1;
 
   // The current OSR frame for specialization or {nullptr}.
   JavaScriptFrame* osr_frame_ = nullptr;
diff --git a/deps/v8/src/ostreams.cc b/deps/v8/src/ostreams.cc
index 04486354cb..2dcd7892d8 100644
--- a/deps/v8/src/ostreams.cc
+++ b/deps/v8/src/ostreams.cc
@@ -22,10 +22,6 @@ namespace internal {
 
 OFStreamBase::OFStreamBase(FILE* f) : f_(f) {}
 
-
-OFStreamBase::~OFStreamBase() {}
-
-
 int OFStreamBase::sync() {
   std::fflush(f_);
   return 0;
@@ -47,9 +43,6 @@ OFStream::OFStream(FILE* f) : std::ostream(nullptr), buf_(f) {
   rdbuf(&buf_);
 }
 
-
-OFStream::~OFStream() {}
-
 #if defined(ANDROID) && !defined(V8_ANDROID_LOG_STDOUT)
 AndroidLogStream::~AndroidLogStream() {
   // If there is anything left in the line buffer, print it now, even though it
diff --git a/deps/v8/src/ostreams.h b/deps/v8/src/ostreams.h
index c6b64a1cd9..189f5384b9 100644
--- a/deps/v8/src/ostreams.h
+++ b/deps/v8/src/ostreams.h
@@ -18,10 +18,10 @@
 namespace v8 {
 namespace internal {
 
-class OFStreamBase : public std::streambuf {
+class V8_EXPORT_PRIVATE OFStreamBase : public std::streambuf {
  public:
   explicit OFStreamBase(FILE* f);
-  virtual ~OFStreamBase();
+  ~OFStreamBase() override = default;
 
  protected:
   FILE* const f_;
@@ -35,7 +35,7 @@ class OFStreamBase : public std::streambuf {
 class V8_EXPORT_PRIVATE OFStream : public std::ostream {
  public:
   explicit OFStream(FILE* f);
-  virtual ~OFStream();
+  ~OFStream() override = default;
 
  private:
   OFStreamBase buf_;
diff --git a/deps/v8/src/parsing/OWNERS b/deps/v8/src/parsing/OWNERS
index 24218df199..177f214415 100644
--- a/deps/v8/src/parsing/OWNERS
+++ b/deps/v8/src/parsing/OWNERS
@@ -2,6 +2,7 @@ set noparent
 
 adamk@chromium.org
 gsathya@chromium.org
+leszeks@chromium.org
 littledan@chromium.org
 marja@chromium.org
 neis@chromium.org
diff --git a/deps/v8/src/parsing/duplicate-finder.h b/deps/v8/src/parsing/duplicate-finder.h
index a4981c1872..65bcc4e00d 100644
--- a/deps/v8/src/parsing/duplicate-finder.h
+++ b/deps/v8/src/parsing/duplicate-finder.h
@@ -22,7 +22,7 @@ class Scanner;
 // Scanner::IsDuplicateSymbol.
 class DuplicateFinder {
  public:
-  DuplicateFinder() {}
+  DuplicateFinder() = default;
 
  private:
   friend class Scanner;
diff --git a/deps/v8/src/parsing/expression-classifier.h b/deps/v8/src/parsing/expression-classifier.h
index 7833dbc8d3..2eed75b939 100644
--- a/deps/v8/src/parsing/expression-classifier.h
+++ b/deps/v8/src/parsing/expression-classifier.h
@@ -5,9 +5,10 @@
 #ifndef V8_PARSING_EXPRESSION_CLASSIFIER_H_
 #define V8_PARSING_EXPRESSION_CLASSIFIER_H_
 
+#include <type_traits>
+
 #include "src/messages.h"
 #include "src/parsing/scanner.h"
-#include "src/zone/zone-containers.h"
 
 namespace v8 {
 namespace internal {
@@ -47,14 +48,38 @@ class DuplicateFinder;
 // by calling the method Discard.  Both actions result in removing the
 // classifier from the parser's stack.
 
+// Expression classifier is split into four parts. The base implementing the
+// general expression classifier logic. Two parts that implement the error
+// tracking interface, where one is the actual implementation and the other is
+// an empty class providing only the interface without logic. The expression
+// classifier class then combines the other parts and provides the full
+// expression classifier interface by inheriting conditionally, controlled by
+// Types::ExpressionClassifierReportErrors, either from the ErrorTracker or the
+// EmptyErrorTracker.
+//
+//                 Base
+//                  / \
+//                 /   \
+//                /     \
+//               /       \
+//      ErrorTracker    EmptyErrorTracker
+//               \       /
+//                \     /
+//                 \   /
+//                  \ /
+//           ExpressionClassifier
+
 template <typename Types>
-class ExpressionClassifier {
+class ExpressionClassifier;
+
+template <typename Types, typename ErrorTracker>
+class ExpressionClassifierBase {
  public:
   enum ErrorKind : unsigned {
 #define DEFINE_ERROR_KIND(NAME, CODE) k##NAME = CODE,
     ERROR_CODES(DEFINE_ERROR_KIND)
 #undef DEFINE_ERROR_KIND
-    kUnusedError = 15  // Larger than error codes; should fit in 4 bits
+        kUnusedError = 15  // Larger than error codes; should fit in 4 bits
   };
 
   struct Error {
@@ -86,23 +111,14 @@ class ExpressionClassifier {
   };
   // clang-format on
 
-  explicit ExpressionClassifier(typename Types::Base* base,
-                                DuplicateFinder* duplicate_finder = nullptr)
+  explicit ExpressionClassifierBase(typename Types::Base* base,
+                                    DuplicateFinder* duplicate_finder = nullptr)
       : base_(base),
-        previous_(base->classifier_),
-        zone_(base->impl()->zone()),
-        reported_errors_(base->impl()->GetReportedErrorList()),
         duplicate_finder_(duplicate_finder),
         invalid_productions_(0),
-        is_non_simple_parameter_list_(0) {
-    base->classifier_ = this;
-    reported_errors_begin_ = reported_errors_end_ = reported_errors_->size();
-  }
+        is_non_simple_parameter_list_(0) {}
 
-  V8_INLINE ~ExpressionClassifier() {
-    Discard();
-    if (base_->classifier_ == this) base_->classifier_ = previous_;
-  }
+  virtual ~ExpressionClassifierBase() = default;
 
   V8_INLINE bool is_valid(unsigned productions) const {
     return (invalid_productions_ & productions) == 0;
@@ -150,80 +166,338 @@ class ExpressionClassifier {
     return is_valid(AsyncArrowFormalParametersProduction);
   }
 
+  V8_INLINE bool is_simple_parameter_list() const {
+    return !is_non_simple_parameter_list_;
+  }
+
+  V8_INLINE void RecordNonSimpleParameter() {
+    is_non_simple_parameter_list_ = 1;
+  }
+
+  V8_INLINE void Accumulate(ExpressionClassifier<Types>* const inner,
+                            unsigned productions) {
+#ifdef DEBUG
+    static_cast<ErrorTracker*>(this)->CheckErrorPositions(inner);
+#endif
+    // Propagate errors from inner, but don't overwrite already recorded
+    // errors.
+    unsigned non_arrow_inner_invalid_productions =
+        inner->invalid_productions_ & ~ArrowFormalParametersProduction;
+    if (non_arrow_inner_invalid_productions) {
+      unsigned errors = non_arrow_inner_invalid_productions & productions &
+                        ~this->invalid_productions_;
+      // The result will continue to be a valid arrow formal parameters if the
+      // inner expression is a valid binding pattern.
+      bool copy_BP_to_AFP = false;
+      if (productions & ArrowFormalParametersProduction &&
+          this->is_valid_arrow_formal_parameters()) {
+        // Also whether we've seen any non-simple parameters
+        // if expecting an arrow function parameter.
+        this->is_non_simple_parameter_list_ |=
+            inner->is_non_simple_parameter_list_;
+        if (!inner->is_valid_binding_pattern()) {
+          copy_BP_to_AFP = true;
+          this->invalid_productions_ |= ArrowFormalParametersProduction;
+        }
+      }
+      if (errors != 0 || copy_BP_to_AFP) {
+        this->invalid_productions_ |= errors;
+        static_cast<ErrorTracker*>(this)->AccumulateErrorImpl(
+            inner, productions, errors, copy_BP_to_AFP);
+      }
+    }
+    static_cast<ErrorTracker*>(this)->RewindErrors(inner);
+  }
+
+ protected:
+  typename Types::Base* base_;
+  DuplicateFinder* duplicate_finder_;
+  unsigned invalid_productions_ : kUnusedError;
+  STATIC_ASSERT(kUnusedError <= 15);
+  unsigned is_non_simple_parameter_list_ : 1;
+};
+
+template <typename Types>
+class ExpressionClassifierErrorTracker
+    : public ExpressionClassifierBase<Types,
+                                      ExpressionClassifierErrorTracker<Types>> {
+ public:
+  using BaseClassType =
+      ExpressionClassifierBase<Types, ExpressionClassifierErrorTracker<Types>>;
+  using typename BaseClassType::Error;
+  using typename BaseClassType::ErrorKind;
+  using TP = typename BaseClassType::TargetProduction;
+
+  ExpressionClassifierErrorTracker(typename Types::Base* base,
+                                   DuplicateFinder* duplicate_finder)
+      : BaseClassType(base, duplicate_finder),
+        reported_errors_(base->impl()->GetReportedErrorList()) {
+    reported_errors_begin_ = reported_errors_end_ = reported_errors_->length();
+  }
+
+  ~ExpressionClassifierErrorTracker() override { Discard(); }
+
+  V8_INLINE void Discard() {
+    if (reported_errors_end_ == reported_errors_->length()) {
+      reported_errors_->Rewind(reported_errors_begin_);
+      reported_errors_end_ = reported_errors_begin_;
+    }
+    DCHECK_EQ(reported_errors_begin_, reported_errors_end_);
+  }
+
+ protected:
+  V8_INLINE const Error& reported_error(ErrorKind kind) const {
+    if (this->invalid_productions_ & (1 << kind)) {
+      for (int i = reported_errors_begin_; i < reported_errors_end_; i++) {
+        if (reported_errors_->at(i).kind == kind)
+          return reported_errors_->at(i);
+      }
+      UNREACHABLE();
+    }
+    // We should only be looking for an error when we know that one has
+    // been reported.  But we're not...  So this is to make sure we have
+    // the same behaviour.
+    UNREACHABLE();
+
+    // Make MSVC happy by returning an error from this inaccessible path.
+    static Error none;
+    return none;
+  }
+
+  // Adds e to the end of the list of reported errors for this classifier.
+  // It is expected that this classifier is the last one in the stack.
+  V8_INLINE void Add(const Error& e) {
+    DCHECK_EQ(reported_errors_end_, reported_errors_->length());
+    reported_errors_->Add(e, this->base_->impl()->zone());
+    reported_errors_end_++;
+  }
+
+  // Copies the error at position i of the list of reported errors, so that
+  // it becomes the last error reported for this classifier.  Position i
+  // could be either after the existing errors of this classifier (i.e.,
+  // in an inner classifier) or it could be an existing error (in case a
+  // copy is needed).
+  V8_INLINE void Copy(int i) {
+    DCHECK_LT(i, reported_errors_->length());
+    if (reported_errors_end_ != i)
+      reported_errors_->at(reported_errors_end_) = reported_errors_->at(i);
+    reported_errors_end_++;
+  }
+
+ private:
+#ifdef DEBUG
+  V8_INLINE void CheckErrorPositions(ExpressionClassifier<Types>* const inner) {
+    DCHECK_EQ(inner->reported_errors_, this->reported_errors_);
+    DCHECK_EQ(inner->reported_errors_begin_, this->reported_errors_end_);
+    DCHECK_EQ(inner->reported_errors_end_, this->reported_errors_->length());
+  }
+#endif
+
+  V8_INLINE void RewindErrors(ExpressionClassifier<Types>* const inner) {
+    this->reported_errors_->Rewind(this->reported_errors_end_);
+    inner->reported_errors_begin_ = inner->reported_errors_end_ =
+        this->reported_errors_end_;
+  }
+
+  void AccumulateErrorImpl(ExpressionClassifier<Types>* const inner,
+                           unsigned productions, unsigned errors,
+                           bool copy_BP_to_AFP) {
+    // Traverse the list of errors reported by the inner classifier
+    // to copy what's necessary.
+    int binding_pattern_index = inner->reported_errors_end_;
+    for (int i = inner->reported_errors_begin_; i < inner->reported_errors_end_;
+         i++) {
+      int k = this->reported_errors_->at(i).kind;
+      if (errors & (1 << k)) this->Copy(i);
+      // Check if it's a BP error that has to be copied to an AFP error.
+      if (k == ErrorKind::kBindingPatternProduction && copy_BP_to_AFP) {
+        if (this->reported_errors_end_ <= i) {
+          // If the BP error itself has not already been copied,
+          // copy it now and change it to an AFP error.
+          this->Copy(i);
+          this->reported_errors_->at(this->reported_errors_end_ - 1).kind =
+              ErrorKind::kArrowFormalParametersProduction;
+        } else {
+          // Otherwise, if the BP error was already copied, keep its
+          // position and wait until the end of the traversal.
+          DCHECK_EQ(this->reported_errors_end_, i + 1);
+          binding_pattern_index = i;
+        }
+      }
+    }
+    // Do we still have to copy the BP error to an AFP error?
+    if (binding_pattern_index < inner->reported_errors_end_) {
+      // If there's still unused space in the list of the inner
+      // classifier, copy it there, otherwise add it to the end
+      // of the list.
+      if (this->reported_errors_end_ < inner->reported_errors_end_)
+        this->Copy(binding_pattern_index);
+      else
+        Add(this->reported_errors_->at(binding_pattern_index));
+      this->reported_errors_->at(this->reported_errors_end_ - 1).kind =
+          ErrorKind::kArrowFormalParametersProduction;
+    }
+  }
+
+ private:
+  ZoneList<Error>* reported_errors_;
+  // The uint16_t for reported_errors_begin_ and reported_errors_end_ will
+  // not be enough in the case of a long series of expressions using nested
+  // classifiers, e.g., a long sequence of assignments, as in:
+  // literals with spreads, as in:
+  // var N=65536; eval("var x;" + "x=".repeat(N) + "42");
+  // This should not be a problem, as such things currently fail with a
+  // stack overflow while parsing.
+  uint16_t reported_errors_begin_;
+  uint16_t reported_errors_end_;
+
+  friend BaseClassType;
+};
+
+template <typename Types>
+class ExpressionClassifierEmptyErrorTracker
+    : public ExpressionClassifierBase<
+          Types, ExpressionClassifierEmptyErrorTracker<Types>> {
+ public:
+  using BaseClassType =
+      ExpressionClassifierBase<Types,
+                               ExpressionClassifierEmptyErrorTracker<Types>>;
+  using typename BaseClassType::Error;
+  using typename BaseClassType::ErrorKind;
+  using TP = typename BaseClassType::TargetProduction;
+
+  ExpressionClassifierEmptyErrorTracker(typename Types::Base* base,
+                                        DuplicateFinder* duplicate_finder)
+      : BaseClassType(base, duplicate_finder) {}
+
+  V8_INLINE void Discard() {}
+
+ protected:
+  V8_INLINE const Error& reported_error(ErrorKind kind) const {
+    static Error none;
+    return none;
+  }
+
+  V8_INLINE void Add(const Error& e) {}
+
+ private:
+#ifdef DEBUG
+  V8_INLINE void CheckErrorPositions(ExpressionClassifier<Types>* const inner) {
+  }
+#endif
+  V8_INLINE void RewindErrors(ExpressionClassifier<Types>* const inner) {}
+  V8_INLINE void AccumulateErrorImpl(ExpressionClassifier<Types>* const inner,
+                                     unsigned productions, unsigned errors,
+                                     bool copy_BP_to_AFP) {}
+
+  friend BaseClassType;
+};
+
+template <typename Types>
+class ExpressionClassifier
+    : public std::conditional<
+          Types::ExpressionClassifierReportErrors,
+          ExpressionClassifierErrorTracker<Types>,
+          ExpressionClassifierEmptyErrorTracker<Types>>::type {
+  static constexpr bool ReportErrors = Types::ExpressionClassifierReportErrors;
+
+ public:
+  using BaseClassType = typename std::conditional<
+      Types::ExpressionClassifierReportErrors,
+      typename ExpressionClassifierErrorTracker<Types>::BaseClassType,
+      typename ExpressionClassifierEmptyErrorTracker<Types>::BaseClassType>::
+      type;
+  using typename BaseClassType::Error;
+  using typename BaseClassType::ErrorKind;
+  using TP = typename BaseClassType::TargetProduction;
+
+  explicit ExpressionClassifier(typename Types::Base* base,
+                                DuplicateFinder* duplicate_finder = nullptr)
+      : std::conditional<Types::ExpressionClassifierReportErrors,
+                         ExpressionClassifierErrorTracker<Types>,
+                         ExpressionClassifierEmptyErrorTracker<Types>>::
+            type(base, duplicate_finder),
+        previous_(base->classifier_) {
+    base->classifier_ = this;
+  }
+
+  V8_INLINE ~ExpressionClassifier() override {
+    if (this->base_->classifier_ == this) this->base_->classifier_ = previous_;
+  }
+
   V8_INLINE const Error& expression_error() const {
-    return reported_error(kExpressionProduction);
+    return this->reported_error(ErrorKind::kExpressionProduction);
   }
 
   V8_INLINE const Error& formal_parameter_initializer_error() const {
-    return reported_error(kFormalParameterInitializerProduction);
+    return this->reported_error(
+        ErrorKind::kFormalParameterInitializerProduction);
   }
 
   V8_INLINE const Error& binding_pattern_error() const {
-    return reported_error(kBindingPatternProduction);
+    return this->reported_error(ErrorKind::kBindingPatternProduction);
   }
 
   V8_INLINE const Error& assignment_pattern_error() const {
-    return reported_error(kAssignmentPatternProduction);
+    return this->reported_error(ErrorKind::kAssignmentPatternProduction);
   }
 
   V8_INLINE const Error& arrow_formal_parameters_error() const {
-    return reported_error(kArrowFormalParametersProduction);
+    return this->reported_error(ErrorKind::kArrowFormalParametersProduction);
   }
 
   V8_INLINE const Error& duplicate_formal_parameter_error() const {
-    return reported_error(kDistinctFormalParametersProduction);
+    return this->reported_error(ErrorKind::kDistinctFormalParametersProduction);
   }
 
   V8_INLINE const Error& strict_mode_formal_parameter_error() const {
-    return reported_error(kStrictModeFormalParametersProduction);
+    return this->reported_error(
+        ErrorKind::kStrictModeFormalParametersProduction);
   }
 
   V8_INLINE const Error& let_pattern_error() const {
-    return reported_error(kLetPatternProduction);
+    return this->reported_error(ErrorKind::kLetPatternProduction);
   }
 
   V8_INLINE const Error& async_arrow_formal_parameters_error() const {
-    return reported_error(kAsyncArrowFormalParametersProduction);
-  }
-
-  V8_INLINE bool is_simple_parameter_list() const {
-    return !is_non_simple_parameter_list_;
+    return this->reported_error(
+        ErrorKind::kAsyncArrowFormalParametersProduction);
   }
 
-  V8_INLINE void RecordNonSimpleParameter() {
-    is_non_simple_parameter_list_ = 1;
-  }
+  V8_INLINE bool does_error_reporting() { return ReportErrors; }
 
   void RecordExpressionError(const Scanner::Location& loc,
                              MessageTemplate::Template message,
                              const char* arg = nullptr) {
-    if (!is_valid_expression()) return;
-    invalid_productions_ |= ExpressionProduction;
-    Add(Error(loc, message, kExpressionProduction, arg));
+    if (!this->is_valid_expression()) return;
+    this->invalid_productions_ |= TP::ExpressionProduction;
+    this->Add(Error(loc, message, ErrorKind::kExpressionProduction, arg));
   }
 
   void RecordFormalParameterInitializerError(const Scanner::Location& loc,
                                              MessageTemplate::Template message,
                                              const char* arg = nullptr) {
-    if (!is_valid_formal_parameter_initializer()) return;
-    invalid_productions_ |= FormalParameterInitializerProduction;
-    Add(Error(loc, message, kFormalParameterInitializerProduction, arg));
+    if (!this->is_valid_formal_parameter_initializer()) return;
+    this->invalid_productions_ |= TP::FormalParameterInitializerProduction;
+    this->Add(Error(loc, message,
+                    ErrorKind::kFormalParameterInitializerProduction, arg));
   }
 
   void RecordBindingPatternError(const Scanner::Location& loc,
                                  MessageTemplate::Template message,
                                  const char* arg = nullptr) {
-    if (!is_valid_binding_pattern()) return;
-    invalid_productions_ |= BindingPatternProduction;
-    Add(Error(loc, message, kBindingPatternProduction, arg));
+    if (!this->is_valid_binding_pattern()) return;
+    this->invalid_productions_ |= TP::BindingPatternProduction;
+    this->Add(Error(loc, message, ErrorKind::kBindingPatternProduction, arg));
   }
 
   void RecordAssignmentPatternError(const Scanner::Location& loc,
                                     MessageTemplate::Template message,
                                     const char* arg = nullptr) {
-    if (!is_valid_assignment_pattern()) return;
-    invalid_productions_ |= AssignmentPatternProduction;
-    Add(Error(loc, message, kAssignmentPatternProduction, arg));
+    if (!this->is_valid_assignment_pattern()) return;
+    this->invalid_productions_ |= TP::AssignmentPatternProduction;
+    this->Add(
+        Error(loc, message, ErrorKind::kAssignmentPatternProduction, arg));
   }
 
   void RecordPatternError(const Scanner::Location& loc,
@@ -236,24 +510,26 @@ class ExpressionClassifier {
   void RecordArrowFormalParametersError(const Scanner::Location& loc,
                                         MessageTemplate::Template message,
                                         const char* arg = nullptr) {
-    if (!is_valid_arrow_formal_parameters()) return;
-    invalid_productions_ |= ArrowFormalParametersProduction;
-    Add(Error(loc, message, kArrowFormalParametersProduction, arg));
+    if (!this->is_valid_arrow_formal_parameters()) return;
+    this->invalid_productions_ |= TP::ArrowFormalParametersProduction;
+    this->Add(
+        Error(loc, message, ErrorKind::kArrowFormalParametersProduction, arg));
   }
 
   void RecordAsyncArrowFormalParametersError(const Scanner::Location& loc,
                                              MessageTemplate::Template message,
                                              const char* arg = nullptr) {
-    if (!is_valid_async_arrow_formal_parameters()) return;
-    invalid_productions_ |= AsyncArrowFormalParametersProduction;
-    Add(Error(loc, message, kAsyncArrowFormalParametersProduction, arg));
+    if (!this->is_valid_async_arrow_formal_parameters()) return;
+    this->invalid_productions_ |= TP::AsyncArrowFormalParametersProduction;
+    this->Add(Error(loc, message,
+                    ErrorKind::kAsyncArrowFormalParametersProduction, arg));
   }
 
   void RecordDuplicateFormalParameterError(const Scanner::Location& loc) {
-    if (!is_valid_formal_parameter_list_without_duplicates()) return;
-    invalid_productions_ |= DistinctFormalParametersProduction;
-    Add(Error(loc, MessageTemplate::kParamDupe,
-              kDistinctFormalParametersProduction));
+    if (!this->is_valid_formal_parameter_list_without_duplicates()) return;
+    this->invalid_productions_ |= TP::DistinctFormalParametersProduction;
+    this->Add(Error(loc, MessageTemplate::kParamDupe,
+                    ErrorKind::kDistinctFormalParametersProduction));
   }
 
   // Record a binding that would be invalid in strict mode.  Confusingly this
@@ -262,160 +538,30 @@ class ExpressionClassifier {
   void RecordStrictModeFormalParameterError(const Scanner::Location& loc,
                                             MessageTemplate::Template message,
                                             const char* arg = nullptr) {
-    if (!is_valid_strict_mode_formal_parameters()) return;
-    invalid_productions_ |= StrictModeFormalParametersProduction;
-    Add(Error(loc, message, kStrictModeFormalParametersProduction, arg));
+    if (!this->is_valid_strict_mode_formal_parameters()) return;
+    this->invalid_productions_ |= TP::StrictModeFormalParametersProduction;
+    this->Add(Error(loc, message,
+                    ErrorKind::kStrictModeFormalParametersProduction, arg));
   }
 
   void RecordLetPatternError(const Scanner::Location& loc,
                              MessageTemplate::Template message,
                              const char* arg = nullptr) {
-    if (!is_valid_let_pattern()) return;
-    invalid_productions_ |= LetPatternProduction;
-    Add(Error(loc, message, kLetPatternProduction, arg));
-  }
-
-  void Accumulate(ExpressionClassifier* inner, unsigned productions) {
-    DCHECK_EQ(inner->reported_errors_, reported_errors_);
-    DCHECK_EQ(inner->reported_errors_begin_, reported_errors_end_);
-    DCHECK_EQ(inner->reported_errors_end_, reported_errors_->size());
-    // Propagate errors from inner, but don't overwrite already recorded
-    // errors.
-    unsigned non_arrow_inner_invalid_productions =
-        inner->invalid_productions_ & ~ArrowFormalParametersProduction;
-    if (non_arrow_inner_invalid_productions) {
-      unsigned errors = non_arrow_inner_invalid_productions & productions &
-                        ~invalid_productions_;
-      // The result will continue to be a valid arrow formal parameters if the
-      // inner expression is a valid binding pattern.
-      bool copy_BP_to_AFP = false;
-      if (productions & ArrowFormalParametersProduction &&
-          is_valid_arrow_formal_parameters()) {
-        // Also whether we've seen any non-simple parameters
-        // if expecting an arrow function parameter.
-        is_non_simple_parameter_list_ |= inner->is_non_simple_parameter_list_;
-        if (!inner->is_valid_binding_pattern()) {
-          copy_BP_to_AFP = true;
-          invalid_productions_ |= ArrowFormalParametersProduction;
-        }
-      }
-      // Traverse the list of errors reported by the inner classifier
-      // to copy what's necessary.
-      if (errors != 0 || copy_BP_to_AFP) {
-        invalid_productions_ |= errors;
-        int binding_pattern_index = inner->reported_errors_end_;
-        for (int i = inner->reported_errors_begin_;
-             i < inner->reported_errors_end_; i++) {
-          int k = reported_errors_->at(i).kind;
-          if (errors & (1 << k)) Copy(i);
-          // Check if it's a BP error that has to be copied to an AFP error.
-          if (k == kBindingPatternProduction && copy_BP_to_AFP) {
-            if (reported_errors_end_ <= i) {
-              // If the BP error itself has not already been copied,
-              // copy it now and change it to an AFP error.
-              Copy(i);
-              reported_errors_->at(reported_errors_end_-1).kind =
-                  kArrowFormalParametersProduction;
-            } else {
-              // Otherwise, if the BP error was already copied, keep its
-              // position and wait until the end of the traversal.
-              DCHECK_EQ(reported_errors_end_, i+1);
-              binding_pattern_index = i;
-            }
-          }
-        }
-        // Do we still have to copy the BP error to an AFP error?
-        if (binding_pattern_index < inner->reported_errors_end_) {
-          // If there's still unused space in the list of the inner
-          // classifier, copy it there, otherwise add it to the end
-          // of the list.
-          if (reported_errors_end_ < inner->reported_errors_end_)
-            Copy(binding_pattern_index);
-          else
-            Add(reported_errors_->at(binding_pattern_index));
-          reported_errors_->at(reported_errors_end_-1).kind =
-              kArrowFormalParametersProduction;
-        }
-      }
-    }
-    reported_errors_->resize(reported_errors_end_);
-    inner->reported_errors_begin_ = inner->reported_errors_end_ =
-        reported_errors_end_;
-  }
-
-  V8_INLINE void Discard() {
-    if (reported_errors_end_ == reported_errors_->size()) {
-      reported_errors_->resize(reported_errors_begin_);
-      reported_errors_end_ = reported_errors_begin_;
-    }
-    DCHECK_EQ(reported_errors_begin_, reported_errors_end_);
+    if (!this->is_valid_let_pattern()) return;
+    this->invalid_productions_ |= TP::LetPatternProduction;
+    this->Add(Error(loc, message, ErrorKind::kLetPatternProduction, arg));
   }
 
   ExpressionClassifier* previous() const { return previous_; }
 
  private:
-  V8_INLINE const Error& reported_error(ErrorKind kind) const {
-    if (invalid_productions_ & (1 << kind)) {
-      for (int i = reported_errors_begin_; i < reported_errors_end_; i++) {
-        if (reported_errors_->at(i).kind == kind)
-          return reported_errors_->at(i);
-      }
-      UNREACHABLE();
-    }
-    // We should only be looking for an error when we know that one has
-    // been reported.  But we're not...  So this is to make sure we have
-    // the same behaviour.
-    UNREACHABLE();
-
-    // Make MSVC happy by returning an error from this inaccessible path.
-    static Error none;
-    return none;
-  }
-
-  // Adds e to the end of the list of reported errors for this classifier.
-  // It is expected that this classifier is the last one in the stack.
-  V8_INLINE void Add(const Error& e) {
-    DCHECK_EQ(reported_errors_end_, reported_errors_->size());
-    reported_errors_->push_back(e);
-    reported_errors_end_++;
-  }
-
-  // Copies the error at position i of the list of reported errors, so that
-  // it becomes the last error reported for this classifier.  Position i
-  // could be either after the existing errors of this classifier (i.e.,
-  // in an inner classifier) or it could be an existing error (in case a
-  // copy is needed).
-  V8_INLINE void Copy(int i) {
-    DCHECK_LT(i, reported_errors_->size());
-    if (reported_errors_end_ != i)
-      reported_errors_->at(reported_errors_end_) = reported_errors_->at(i);
-    reported_errors_end_++;
-  }
-
-  typename Types::Base* base_;
   ExpressionClassifier* previous_;
-  Zone* zone_;
-  ZoneVector<Error>* reported_errors_;
-  DuplicateFinder* duplicate_finder_;
-  unsigned invalid_productions_ : 15;
-  unsigned is_non_simple_parameter_list_ : 1;
-  // The uint16_t for reported_errors_begin_ and reported_errors_end_ will
-  // not be enough in the case of a long series of expressions using nested
-  // classifiers, e.g., a long sequence of assignments, as in:
-  // literals with spreads, as in:
-  // var N=65536; eval("var x;" + "x=".repeat(N) + "42");
-  // This should not be a problem, as such things currently fail with a
-  // stack overflow while parsing.
-  uint16_t reported_errors_begin_;
-  uint16_t reported_errors_end_;
 
   DISALLOW_COPY_AND_ASSIGN(ExpressionClassifier);
 };
 
-
 #undef ERROR_CODES
 
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/parsing/func-name-inferrer.h b/deps/v8/src/parsing/func-name-inferrer.h
index 8f0f428a05..d46d7f2c2b 100644
--- a/deps/v8/src/parsing/func-name-inferrer.h
+++ b/deps/v8/src/parsing/func-name-inferrer.h
@@ -36,12 +36,8 @@ class FuncNameInferrer : public ZoneObject {
   // on the stack.
   class State {
    public:
-    explicit State(FuncNameInferrer* fni) : fni_(fni) {
-      if (fni_ != nullptr) fni_->Enter();
-    }
-    ~State() {
-      if (fni_ != nullptr) fni_->Leave();
-    }
+    explicit State(FuncNameInferrer* fni) : fni_(fni) { fni_->Enter(); }
+    ~State() { fni_->Leave(); }
 
    private:
     FuncNameInferrer* fni_;
diff --git a/deps/v8/src/parsing/parse-info.cc b/deps/v8/src/parsing/parse-info.cc
index 0a58c4f0bd..129b00a2c2 100644
--- a/deps/v8/src/parsing/parse-info.cc
+++ b/deps/v8/src/parsing/parse-info.cc
@@ -16,7 +16,7 @@
 namespace v8 {
 namespace internal {
 
-ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
+ParseInfo::ParseInfo(AccountingAllocator* zone_allocator)
     : zone_(base::make_unique<Zone>(zone_allocator, ZONE_NAME)),
       flags_(0),
       extension_(nullptr),
@@ -37,7 +37,10 @@ ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
       function_name_(nullptr),
       runtime_call_stats_(nullptr),
       source_range_map_(nullptr),
-      literal_(nullptr) {
+      literal_(nullptr) {}
+
+ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
+    : ParseInfo(zone_allocator) {
   set_hash_seed(isolate->heap()->HashSeed());
   set_stack_limit(isolate->stack_guard()->real_climit());
   set_unicode_cache(isolate->unicode_cache());
@@ -54,6 +57,18 @@ ParseInfo::ParseInfo(Isolate* isolate)
   LOG(isolate, ScriptEvent(Logger::ScriptEventType::kReserveId, script_id_));
 }
 
+template <typename T>
+void ParseInfo::SetFunctionInfo(T function) {
+  set_is_named_expression(function->is_named_expression());
+  set_language_mode(function->language_mode());
+  set_function_kind(function->kind());
+  set_declaration(function->is_declaration());
+  set_requires_instance_fields_initializer(
+      function->requires_instance_fields_initializer());
+  set_toplevel(function->is_toplevel());
+  set_wrapped_as_function(function->is_wrapped());
+}
+
 ParseInfo::ParseInfo(Isolate* isolate, Handle<SharedFunctionInfo> shared)
     : ParseInfo(isolate, isolate->allocator()) {
   // Do not support re-parsing top-level function of a wrapped script.
@@ -61,19 +76,13 @@ ParseInfo::ParseInfo(Isolate* isolate, Handle<SharedFunctionInfo> shared)
   //                wrapped script at all.
   DCHECK_IMPLIES(is_toplevel(), !Script::cast(shared->script())->is_wrapped());
 
-  set_toplevel(shared->is_toplevel());
-  set_wrapped_as_function(shared->is_wrapped());
   set_allow_lazy_parsing(FLAG_lazy_inner_functions);
-  set_is_named_expression(shared->is_named_expression());
+  set_asm_wasm_broken(shared->is_asm_wasm_broken());
+
   set_start_position(shared->StartPosition());
   set_end_position(shared->EndPosition());
   function_literal_id_ = shared->FunctionLiteralId(isolate);
-  set_language_mode(shared->language_mode());
-  set_function_kind(shared->kind());
-  set_declaration(shared->is_declaration());
-  set_requires_instance_fields_initializer(
-      shared->requires_instance_fields_initializer());
-  set_asm_wasm_broken(shared->is_asm_wasm_broken());
+  SetFunctionInfo(shared);
 
   Handle<Script> script(Script::cast(shared->script()), isolate);
   set_script(script);
@@ -99,37 +108,44 @@ ParseInfo::ParseInfo(Isolate* isolate, Handle<Script> script)
                            script->IsUserJavaScript());
 }
 
-ParseInfo::~ParseInfo() {}
-
-DeclarationScope* ParseInfo::scope() const { return literal()->scope(); }
-
-void ParseInfo::EmitBackgroundParseStatisticsOnBackgroundThread() {
-  // If runtime call stats was enabled by tracing, emit a trace event at the
-  // end of background parsing on the background thread.
-  if (runtime_call_stats_ &&
-      (FLAG_runtime_stats &
-       v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
-    auto value = v8::tracing::TracedValue::Create();
-    runtime_call_stats_->Dump(value.get());
-    TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("v8.runtime_stats"),
-                         "V8.RuntimeStats", TRACE_EVENT_SCOPE_THREAD,
-                         "runtime-call-stats", std::move(value));
-  }
+// static
+std::unique_ptr<ParseInfo> ParseInfo::FromParent(
+    const ParseInfo* outer_parse_info, AccountingAllocator* zone_allocator,
+    const FunctionLiteral* literal, const AstRawString* function_name) {
+  std::unique_ptr<ParseInfo> result =
+      base::make_unique<ParseInfo>(zone_allocator);
+
+  // Replicate shared state of the outer_parse_info.
+  result->flags_ = outer_parse_info->flags_;
+  result->script_id_ = outer_parse_info->script_id_;
+  result->set_logger(outer_parse_info->logger());
+  result->set_ast_string_constants(outer_parse_info->ast_string_constants());
+  result->set_hash_seed(outer_parse_info->hash_seed());
+
+  DCHECK_EQ(outer_parse_info->parameters_end_pos(), kNoSourcePosition);
+  DCHECK_NULL(outer_parse_info->extension());
+  DCHECK(outer_parse_info->maybe_outer_scope_info().is_null());
+
+  // Clone the function_name AstRawString into the ParseInfo's own
+  // AstValueFactory.
+  const AstRawString* cloned_function_name =
+      result->GetOrCreateAstValueFactory()->CloneFromOtherFactory(
+          function_name);
+
+  // Setup function specific details.
+  DCHECK(!literal->is_toplevel());
+  result->set_function_name(cloned_function_name);
+  result->set_start_position(literal->start_position());
+  result->set_end_position(literal->end_position());
+  result->set_function_literal_id(literal->function_literal_id());
+  result->SetFunctionInfo(literal);
+
+  return result;
 }
 
-void ParseInfo::UpdateBackgroundParseStatisticsOnMainThread(Isolate* isolate) {
-  // Copy over the counters from the background thread to the main counters on
-  // the isolate.
-  RuntimeCallStats* main_call_stats = isolate->counters()->runtime_call_stats();
-  if (FLAG_runtime_stats ==
-      v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE) {
-    DCHECK_NE(main_call_stats, runtime_call_stats());
-    DCHECK_NOT_NULL(main_call_stats);
-    DCHECK_NOT_NULL(runtime_call_stats());
-    main_call_stats->Add(runtime_call_stats());
-  }
-  set_runtime_call_stats(main_call_stats);
-}
+ParseInfo::~ParseInfo() = default;
+
+DeclarationScope* ParseInfo::scope() const { return literal()->scope(); }
 
 Handle<Script> ParseInfo::CreateScript(Isolate* isolate, Handle<String> source,
                                        ScriptOriginOptions origin_options,
diff --git a/deps/v8/src/parsing/parse-info.h b/deps/v8/src/parsing/parse-info.h
index 64a50806f5..ba3e3d2898 100644
--- a/deps/v8/src/parsing/parse-info.h
+++ b/deps/v8/src/parsing/parse-info.h
@@ -12,6 +12,7 @@
 #include "include/v8.h"
 #include "src/globals.h"
 #include "src/handles.h"
+#include "src/objects/script.h"
 #include "src/parsing/preparsed-scope-data.h"
 #include "src/pending-compilation-error-handler.h"
 
@@ -37,11 +38,18 @@ class Zone;
 // A container for the inputs, configuration options, and outputs of parsing.
 class V8_EXPORT_PRIVATE ParseInfo {
  public:
-  ParseInfo(Isolate*);
+  explicit ParseInfo(AccountingAllocator* zone_allocator);
+  explicit ParseInfo(Isolate*);
   ParseInfo(Isolate*, AccountingAllocator* zone_allocator);
   ParseInfo(Isolate* isolate, Handle<Script> script);
   ParseInfo(Isolate* isolate, Handle<SharedFunctionInfo> shared);
 
+  // Creates a new parse info based on parent top-level |outer_parse_info| for
+  // function |literal|.
+  static std::unique_ptr<ParseInfo> FromParent(
+      const ParseInfo* outer_parse_info, AccountingAllocator* zone_allocator,
+      const FunctionLiteral* literal, const AstRawString* function_name);
+
   ~ParseInfo();
 
   Handle<Script> CreateScript(Isolate* isolate, Handle<String> source,
@@ -105,9 +113,12 @@ class V8_EXPORT_PRIVATE ParseInfo {
   v8::Extension* extension() const { return extension_; }
   void set_extension(v8::Extension* extension) { extension_ = extension; }
 
-
+  void set_consumed_preparsed_scope_data(
+      std::unique_ptr<ConsumedPreParsedScopeData> data) {
+    consumed_preparsed_scope_data_.swap(data);
+  }
   ConsumedPreParsedScopeData* consumed_preparsed_scope_data() {
-    return &consumed_preparsed_scope_data_;
+    return consumed_preparsed_scope_data_.get();
   }
 
   DeclarationScope* script_scope() const { return script_scope_; }
@@ -198,6 +209,8 @@ class V8_EXPORT_PRIVATE ParseInfo {
   // TODO(titzer): these should not be part of ParseInfo.
   //--------------------------------------------------------------------------
   Handle<Script> script() const { return script_; }
+  void set_script(Handle<Script> script);
+
   MaybeHandle<ScopeInfo> maybe_outer_scope_info() const {
     return maybe_outer_scope_info_;
   }
@@ -216,12 +229,13 @@ class V8_EXPORT_PRIVATE ParseInfo {
     set_strict_mode(is_strict(language_mode));
   }
 
-  void EmitBackgroundParseStatisticsOnBackgroundThread();
-  void UpdateBackgroundParseStatisticsOnMainThread(Isolate* isolate);
-
  private:
   void SetScriptForToplevelCompile(Isolate* isolate, Handle<Script> script);
-  void set_script(Handle<Script> script);
+
+  // Set function info flags based on those in either FunctionLiteral or
+  // SharedFunctionInfo |function|
+  template <typename T>
+  void SetFunctionInfo(T function);
 
   // Various configuration flags for parsing.
   enum Flag {
@@ -268,7 +282,7 @@ class V8_EXPORT_PRIVATE ParseInfo {
 
   //----------- Inputs+Outputs of parsing and scope analysis -----------------
   std::unique_ptr<Utf16CharacterStream> character_stream_;
-  ConsumedPreParsedScopeData consumed_preparsed_scope_data_;
+  std::unique_ptr<ConsumedPreParsedScopeData> consumed_preparsed_scope_data_;
   std::unique_ptr<AstValueFactory> ast_value_factory_;
   const class AstStringConstants* ast_string_constants_;
   const AstRawString* function_name_;
diff --git a/deps/v8/src/parsing/parser-base.h b/deps/v8/src/parsing/parser-base.h
index 9d13724f06..d1ad0e9d13 100644
--- a/deps/v8/src/parsing/parser-base.h
+++ b/deps/v8/src/parsing/parser-base.h
@@ -5,12 +5,14 @@
 #ifndef V8_PARSING_PARSER_BASE_H_
 #define V8_PARSING_PARSER_BASE_H_
 
+#include <stdint.h>
 #include <vector>
 
 #include "src/ast/ast-source-ranges.h"
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
+#include "src/base/flags.h"
 #include "src/base/hashmap.h"
 #include "src/base/v8-fallthrough.h"
 #include "src/counters.h"
@@ -37,31 +39,13 @@ enum AllowLabelledFunctionStatement {
   kDisallowLabelledFunctionStatement,
 };
 
-enum class ParseFunctionFlags {
+enum class ParseFunctionFlag : uint8_t {
   kIsNormal = 0,
-  kIsGenerator = 1,
-  kIsAsync = 2,
-  kIsDefault = 4
+  kIsGenerator = 1 << 0,
+  kIsAsync = 1 << 1
 };
 
-static inline ParseFunctionFlags operator|(ParseFunctionFlags lhs,
-                                           ParseFunctionFlags rhs) {
-  typedef unsigned char T;
-  return static_cast<ParseFunctionFlags>(static_cast<T>(lhs) |
-                                         static_cast<T>(rhs));
-}
-
-static inline ParseFunctionFlags& operator|=(ParseFunctionFlags& lhs,
-                                             const ParseFunctionFlags& rhs) {
-  lhs = lhs | rhs;
-  return lhs;
-}
-
-static inline bool operator&(ParseFunctionFlags bitfield,
-                             ParseFunctionFlags mask) {
-  typedef unsigned char T;
-  return static_cast<T>(bitfield) & static_cast<T>(mask);
-}
+typedef base::Flags<ParseFunctionFlag> ParseFunctionFlags;
 
 struct FormalParametersBase {
   explicit FormalParametersBase(DeclarationScope* scope) : scope(scope) {}
@@ -228,6 +212,17 @@ class SourceRangeScope final {
 template <typename Impl>
 struct ParserTypes;
 
+enum class ParsePropertyKind : uint8_t {
+  kAccessorGetter,
+  kAccessorSetter,
+  kValue,
+  kShorthand,
+  kMethod,
+  kClassField,
+  kSpread,
+  kNotSet
+};
+
 template <typename Impl>
 class ParserBase {
  public:
@@ -248,6 +243,10 @@ class ParserBase {
   typedef typename Types::ForStatement ForStatementT;
   typedef typename v8::internal::ExpressionClassifier<Types>
       ExpressionClassifier;
+  typedef typename Types::FuncNameInferrer FuncNameInferrer;
+  typedef typename Types::FuncNameInferrer::State FuncNameInferrerState;
+  typedef typename Types::SourceRange SourceRange;
+  typedef typename Types::SourceRangeScope SourceRangeScope;
 
   // All implementation-specific methods must be called through this.
   Impl* impl() { return static_cast<Impl*>(this); }
@@ -262,7 +261,7 @@ class ParserBase {
         original_scope_(nullptr),
         function_state_(nullptr),
         extension_(extension),
-        fni_(nullptr),
+        fni_(ast_value_factory, zone),
         ast_value_factory_(ast_value_factory),
         ast_node_factory_(ast_value_factory, zone),
         runtime_call_stats_(runtime_call_stats),
@@ -300,12 +299,6 @@ class ParserBase {
 
 #undef ALLOW_ACCESSORS
 
-  bool allow_harmony_bigint() const {
-    return scanner()->allow_harmony_bigint();
-  }
-  void set_allow_harmony_bigint(bool allow) {
-    scanner()->set_allow_harmony_bigint(allow);
-  }
   bool allow_harmony_numeric_separator() const {
     return scanner()->allow_harmony_numeric_separator();
   }
@@ -370,7 +363,7 @@ class ParserBase {
   // The parser's current scope is in scope_. BlockState and FunctionState
   // constructors push on the scope stack and the destructors pop. They are also
   // used to hold the parser's per-funcion state.
-  class BlockState BASE_EMBEDDED {
+  class BlockState {
    public:
     BlockState(Scope** scope_stack, Scope* scope)
         : scope_stack_(scope_stack), outer_scope_(*scope_stack) {
@@ -433,7 +426,7 @@ class ParserBase {
       return destructuring_assignments_to_rewrite_;
     }
 
-    ZoneVector<typename ExpressionClassifier::Error>* GetReportedErrorList() {
+    ZoneList<typename ExpressionClassifier::Error>* GetReportedErrorList() {
       return &reported_errors_;
     }
 
@@ -490,8 +483,7 @@ class ParserBase {
 
     ZoneChunkList<RewritableExpressionT> destructuring_assignments_to_rewrite_;
 
-    // We use a ZoneVector here because we need to do a lot of random access.
-    ZoneVector<typename ExpressionClassifier::Error> reported_errors_;
+    ZoneList<typename ExpressionClassifier::Error> reported_errors_;
 
     // A reason, if any, why this function should not be optimized.
     BailoutReason dont_optimize_reason_;
@@ -652,11 +644,11 @@ class ParserBase {
   // scope itself is either allocated in zone() or in target_zone if one is
   // passed in.
   DeclarationScope* NewFunctionScope(FunctionKind kind,
-                                     Zone* target_zone = nullptr) const {
+                                     Zone* parse_zone = nullptr) const {
     DCHECK(ast_value_factory());
-    if (target_zone == nullptr) target_zone = zone();
-    DeclarationScope* result = new (target_zone)
-        DeclarationScope(zone(), scope(), FUNCTION_SCOPE, kind);
+    if (parse_zone == nullptr) parse_zone = zone();
+    DeclarationScope* result = new (zone())
+        DeclarationScope(parse_zone, scope(), FUNCTION_SCOPE, kind);
 
     // Record presence of an inner function scope
     function_state_->RecordFunctionOrEvalCall();
@@ -679,6 +671,8 @@ class ParserBase {
   AstValueFactory* ast_value_factory() const { return ast_value_factory_; }
   int position() const { return scanner_->location().beg_pos; }
   int peek_position() const { return scanner_->peek_location().beg_pos; }
+  int end_position() const { return scanner_->location().end_pos; }
+  int peek_end_position() const { return scanner_->peek_location().end_pos; }
   bool stack_overflow() const {
     return pending_error_handler()->stack_overflow();
   }
@@ -694,8 +688,7 @@ class ParserBase {
   // Returns the position past the following semicolon (if it exists), and the
   // position past the end of the current token otherwise.
   int PositionAfterSemicolon() {
-    return (peek() == Token::SEMICOLON) ? scanner_->peek_location().end_pos
-                                        : scanner_->location().end_pos;
+    return (peek() == Token::SEMICOLON) ? peek_end_position() : end_position();
   }
 
   V8_INLINE Token::Value PeekAhead() {
@@ -720,7 +713,7 @@ class ParserBase {
     Token::Value next = Next();
     USE(next);
     USE(token);
-    DCHECK(next == token);
+    DCHECK_EQ(next, token);
   }
 
   bool Check(Token::Value token) {
@@ -753,22 +746,14 @@ class ParserBase {
       return;
     }
 
-    Token::Value current = scanner()->current_token();
-    Scanner::Location current_location = scanner()->location();
-    Token::Value next = Next();
-
-    if (next == Token::SEMICOLON) {
-      return;
-    }
-
     *ok = false;
-    if (current == Token::AWAIT && !is_async_function()) {
-      ReportMessageAt(current_location,
+    if (scanner()->current_token() == Token::AWAIT && !is_async_function()) {
+      ReportMessageAt(scanner()->location(),
                       MessageTemplate::kAwaitNotInAsyncFunction, kSyntaxError);
       return;
     }
 
-    ReportUnexpectedToken(next);
+    ReportUnexpectedToken(Next());
   }
 
   // Dummy functions, just useful as arguments to CHECK_OK_CUSTOM.
@@ -778,14 +763,7 @@ class ParserBase {
     return result;
   }
 
-  bool is_any_identifier(Token::Value token) {
-    return token == Token::IDENTIFIER || token == Token::ENUM ||
-           token == Token::AWAIT || token == Token::ASYNC ||
-           token == Token::ESCAPED_STRICT_RESERVED_WORD ||
-           token == Token::FUTURE_STRICT_RESERVED_WORD || token == Token::LET ||
-           token == Token::STATIC || token == Token::YIELD;
-  }
-  bool peek_any_identifier() { return is_any_identifier(peek()); }
+  bool peek_any_identifier() { return Token::IsAnyIdentifier(peek()); }
 
   bool CheckContextualKeyword(Token::Value token) {
     if (PeekContextualKeyword(token)) {
@@ -961,7 +939,11 @@ class ParserBase {
 
   void ReportClassifierError(
       const typename ExpressionClassifier::Error& error) {
-    impl()->ReportMessageAt(error.location, error.message, error.arg);
+    if (classifier()->does_error_reporting()) {
+      impl()->ReportMessageAt(error.location, error.message, error.arg);
+    } else {
+      impl()->ReportUnidentifiableError();
+    }
   }
 
   void ValidateExpression(bool* ok) {
@@ -1006,7 +988,7 @@ class ParserBase {
   }
 
   bool IsValidArrowFormalParametersStart(Token::Value token) {
-    return is_any_identifier(token) || token == Token::LPAREN;
+    return Token::IsAnyIdentifier(token) || token == Token::LPAREN;
   }
 
   void ValidateArrowFormalParameters(ExpressionT expr,
@@ -1096,15 +1078,12 @@ class ParserBase {
 
   ExpressionT ParseRegExpLiteral(bool* ok);
 
+  ExpressionT ParseBindingPattern(bool* ok);
   ExpressionT ParsePrimaryExpression(bool* is_async, bool* ok);
-  ExpressionT ParsePrimaryExpression(bool* ok) {
-    bool is_async;
-    return ParsePrimaryExpression(&is_async, ok);
-  }
 
   // Use when parsing an expression that is known to not be a pattern or part
   // of a pattern.
-  V8_INLINE ExpressionT ParseExpression(bool accept_IN, bool* ok);
+  V8_INLINE ExpressionT ParseExpression(bool* ok);
 
   // This method does not wrap the parsing of the expression inside a
   // new expression classifier; it uses the top-level classifier instead.
@@ -1117,28 +1096,21 @@ class ParserBase {
 
   ExpressionT ParseArrayLiteral(bool* ok);
 
-  enum class PropertyKind {
-    kAccessorProperty,
-    kValueProperty,
-    kShorthandProperty,
-    kMethodProperty,
-    kClassField,
-    kSpreadProperty,
-    kNotSet
-  };
+  inline static bool IsAccessor(ParsePropertyKind kind) {
+    return IsInRange(kind, ParsePropertyKind::kAccessorGetter,
+                     ParsePropertyKind::kAccessorSetter);
+  }
 
-  bool SetPropertyKindFromToken(Token::Value token, PropertyKind* kind);
-  ExpressionT ParsePropertyName(IdentifierT* name, PropertyKind* kind,
-                                bool* is_generator, bool* is_get, bool* is_set,
-                                bool* is_async, bool* is_computed_name,
-                                bool* ok);
+  ExpressionT ParsePropertyName(IdentifierT* name, ParsePropertyKind* kind,
+                                ParseFunctionFlags* flags,
+                                bool* is_computed_name, bool* ok);
   ExpressionT ParseObjectLiteral(bool* ok);
   ClassLiteralPropertyT ParseClassPropertyDefinition(
       ClassLiteralChecker* checker, ClassInfo* class_info,
       IdentifierT* property_name, bool has_extends, bool* is_computed_name,
       ClassLiteralProperty::Kind* property_kind, bool* is_static, bool* ok);
-  ExpressionT ParseClassFieldInitializer(ClassInfo* class_info, bool is_static,
-                                         bool* ok);
+  ExpressionT ParseClassFieldInitializer(ClassInfo* class_info, int beg_pos,
+                                         bool is_static, bool* ok);
   ObjectLiteralPropertyT ParseObjectPropertyDefinition(
       ObjectLiteralChecker* checker, bool* is_computed_name,
       bool* is_rest_property, bool* ok);
@@ -1147,17 +1119,26 @@ class ParserBase {
                                  bool* is_simple_parameter_list, bool* ok);
   ExpressionListT ParseArguments(Scanner::Location* first_spread_pos,
                                  bool* ok) {
-    return ParseArguments(first_spread_pos, false, nullptr, ok);
+    bool is_simple = true;
+    return ParseArguments(first_spread_pos, false, &is_simple, ok);
   }
 
   ExpressionT ParseAssignmentExpression(bool accept_IN, bool* ok);
   ExpressionT ParseYieldExpression(bool accept_IN, bool* ok);
   V8_INLINE ExpressionT ParseConditionalExpression(bool accept_IN, bool* ok);
+  ExpressionT ParseConditionalContinuation(ExpressionT expression,
+                                           bool accept_IN, int pos, bool* ok);
   ExpressionT ParseBinaryExpression(int prec, bool accept_IN, bool* ok);
-  ExpressionT ParseUnaryExpression(bool* ok);
+  ExpressionT ParseUnaryOpExpression(bool* ok);
+  ExpressionT ParseAwaitExpression(bool* ok);
+  ExpressionT ParsePrefixExpression(bool* ok);
+  V8_INLINE ExpressionT ParseUnaryExpression(bool* ok);
   V8_INLINE ExpressionT ParsePostfixExpression(bool* ok);
   V8_INLINE ExpressionT ParseLeftHandSideExpression(bool* ok);
-  ExpressionT ParseMemberWithNewPrefixesExpression(bool* is_async, bool* ok);
+  ExpressionT ParseMemberWithPresentNewPrefixesExpression(bool* is_async,
+                                                          bool* ok);
+  V8_INLINE ExpressionT ParseMemberWithNewPrefixesExpression(bool* is_async,
+                                                             bool* ok);
   V8_INLINE ExpressionT ParseMemberExpression(bool* is_async, bool* ok);
   V8_INLINE ExpressionT ParseMemberExpressionContinuation(
       ExpressionT expression, bool* is_async, bool* ok);
@@ -1169,8 +1150,6 @@ class ParserBase {
   ExpressionT ParseArrowFunctionLiteral(bool accept_IN,
                                         const FormalParametersT& parameters,
                                         int rewritable_length, bool* ok);
-  void ParseSingleExpressionFunctionBody(StatementListT body, bool is_async,
-                                         bool accept_IN, bool* ok);
   void ParseAsyncFunctionBody(Scope* scope, StatementListT body, bool* ok);
   ExpressionT ParseAsyncFunctionLiteral(bool* ok);
   ExpressionT ParseClassLiteral(IdentifierT name,
@@ -1205,11 +1184,14 @@ class ParserBase {
                                    bool default_export, bool* ok);
   StatementT ParseNativeDeclaration(bool* ok);
 
+  // Whether we're parsing a single-expression arrow function or something else.
+  enum class FunctionBodyType { kExpression, kBlock };
   // Consumes the ending }.
   void ParseFunctionBody(StatementListT result, IdentifierT function_name,
                          int pos, const FormalParametersT& parameters,
                          FunctionKind kind,
-                         FunctionLiteral::FunctionType function_type, bool* ok);
+                         FunctionLiteral::FunctionType function_type,
+                         FunctionBodyType body_type, bool accept_IN, bool* ok);
 
   // Under some circumstances, we allow preparsing to abort if the preparsed
   // function is "long and trivial", and fully parse instead. Our current
@@ -1363,8 +1345,7 @@ class ParserBase {
       Scope* scope, Variable* var,
       typename DeclarationDescriptor::Kind declaration_kind);
 
-  FunctionKind FunctionKindForImpl(bool is_method, bool is_generator,
-                                   bool is_async) {
+  FunctionKind FunctionKindForImpl(bool is_method, ParseFunctionFlags flags) {
     static const FunctionKind kFunctionKinds[][2][2] = {
         {
             // is_method=false
@@ -1382,17 +1363,19 @@ class ParserBase {
              FunctionKind::kConciseGeneratorMethod,
              FunctionKind::kAsyncConciseGeneratorMethod},
         }};
-    return kFunctionKinds[is_method][is_generator][is_async];
+    return kFunctionKinds[is_method]
+                         [(flags & ParseFunctionFlag::kIsGenerator) != 0]
+                         [(flags & ParseFunctionFlag::kIsAsync) != 0];
   }
 
-  inline FunctionKind FunctionKindFor(bool is_generator, bool is_async) {
+  inline FunctionKind FunctionKindFor(ParseFunctionFlags flags) {
     const bool kIsMethod = false;
-    return FunctionKindForImpl(kIsMethod, is_generator, is_async);
+    return FunctionKindForImpl(kIsMethod, flags);
   }
 
-  inline FunctionKind MethodKindFor(bool is_generator, bool is_async) {
+  inline FunctionKind MethodKindFor(ParseFunctionFlags flags) {
     const bool kIsMethod = true;
-    return FunctionKindForImpl(kIsMethod, is_generator, is_async);
+    return FunctionKindForImpl(kIsMethod, flags);
   }
 
   // Keep track of eval() calls since they disable all local variable
@@ -1466,8 +1449,8 @@ class ParserBase {
     explicit ClassLiteralChecker(ParserBase* parser)
         : parser_(parser), has_seen_constructor_(false) {}
 
-    void CheckClassMethodName(Token::Value property, PropertyKind type,
-                              bool is_generator, bool is_async, bool is_static,
+    void CheckClassMethodName(Token::Value property, ParsePropertyKind type,
+                              ParseFunctionFlags flags, bool is_static,
                               bool* ok);
     void CheckClassFieldName(bool is_static, bool* ok);
 
@@ -1546,7 +1529,7 @@ class ParserBase {
   Scope* original_scope_;  // The top scope for the current parsing item.
   FunctionState* function_state_;  // Function state stack.
   v8::Extension* extension_;
-  FuncNameInferrer* fni_;
+  FuncNameInferrer fni_;
   AstValueFactory* ast_value_factory_;  // Not owned.
   typename Types::Factory ast_node_factory_;
   RuntimeCallStats* runtime_call_stats_;
@@ -1577,8 +1560,6 @@ class ParserBase {
   bool allow_harmony_import_meta_;
   bool allow_harmony_private_fields_;
   bool allow_eval_cache_;
-
-  friend class DiscardableZoneScope;
 };
 
 template <typename Impl>
@@ -1592,13 +1573,12 @@ ParserBase<Impl>::FunctionState::FunctionState(
       outer_function_state_(*function_state_stack),
       scope_(scope),
       destructuring_assignments_to_rewrite_(scope->zone()),
-      reported_errors_(scope_->zone()),
+      reported_errors_(16, scope->zone()),
       dont_optimize_reason_(BailoutReason::kNoReason),
       next_function_is_likely_called_(false),
       previous_function_was_likely_called_(false),
       contains_function_or_eval_(false) {
   *function_state_stack = this;
-  reported_errors_.reserve(16);
   if (outer_function_state_) {
     outer_function_state_->previous_function_was_likely_called_ =
         outer_function_state_->next_function_is_likely_called_;
@@ -1704,16 +1684,10 @@ template <typename Impl>
 typename ParserBase<Impl>::IdentifierT
 ParserBase<Impl>::ParseAndClassifyIdentifier(bool* ok) {
   Token::Value next = Next();
-  if (next == Token::IDENTIFIER || next == Token::ASYNC ||
-      (next == Token::AWAIT && !parsing_module_ && !is_async_function())) {
+  STATIC_ASSERT(Token::IDENTIFIER + 1 == Token::ASYNC);
+  if (IsInRange(next, Token::IDENTIFIER, Token::ASYNC)) {
     IdentifierT name = impl()->GetSymbol();
 
-    if (impl()->IsArguments(name) && scope()->ShouldBanArguments()) {
-      ReportMessage(MessageTemplate::kArgumentsDisallowedInInitializer);
-      *ok = false;
-      return impl()->NullIdentifier();
-    }
-
     // When this function is used to read a formal parameter, we don't always
     // know whether the function is going to be strict or sloppy.  Indeed for
     // arrow functions we don't always know that the identifier we are reading
@@ -1721,15 +1695,18 @@ ParserBase<Impl>::ParseAndClassifyIdentifier(bool* ok) {
     // must detect because we know we're in strict mode, we also record any
     // error that we might make in the future once we know the language mode.
     if (impl()->IsEvalOrArguments(name)) {
+      if (impl()->IsArguments(name) && scope()->ShouldBanArguments()) {
+        ReportMessage(MessageTemplate::kArgumentsDisallowedInInitializer);
+        *ok = false;
+        return impl()->NullIdentifier();
+      }
+
       classifier()->RecordStrictModeFormalParameterError(
           scanner()->location(), MessageTemplate::kStrictEvalArguments);
       if (is_strict(language_mode())) {
         classifier()->RecordBindingPatternError(
             scanner()->location(), MessageTemplate::kStrictEvalArguments);
       }
-    } else if (next == Token::AWAIT) {
-      classifier()->RecordAsyncArrowFormalParametersError(
-          scanner()->location(), MessageTemplate::kAwaitBindingIdentifier);
     }
 
     if (classifier()->duplicate_finder() != nullptr &&
@@ -1737,20 +1714,17 @@ ParserBase<Impl>::ParseAndClassifyIdentifier(bool* ok) {
                                      ast_value_factory())) {
       classifier()->RecordDuplicateFormalParameterError(scanner()->location());
     }
+
     return name;
+  } else if (next == Token::AWAIT && !parsing_module_ && !is_async_function()) {
+    classifier()->RecordAsyncArrowFormalParametersError(
+        scanner()->location(), MessageTemplate::kAwaitBindingIdentifier);
+    return impl()->GetSymbol();
   } else if (is_sloppy(language_mode()) &&
-             (next == Token::FUTURE_STRICT_RESERVED_WORD ||
-              next == Token::ESCAPED_STRICT_RESERVED_WORD ||
-              next == Token::LET || next == Token::STATIC ||
+             (Token::IsStrictReservedWord(next) ||
               (next == Token::YIELD && !is_generator()))) {
     classifier()->RecordStrictModeFormalParameterError(
         scanner()->location(), MessageTemplate::kUnexpectedStrictReserved);
-    if (next == Token::ESCAPED_STRICT_RESERVED_WORD &&
-        is_strict(language_mode())) {
-      ReportUnexpectedToken(next);
-      *ok = false;
-      return impl()->NullIdentifier();
-    }
     if (scanner()->IsLet()) {
       classifier()->RecordLetPatternError(
           scanner()->location(), MessageTemplate::kLetInLexicalBinding);
@@ -1774,9 +1748,7 @@ ParserBase<Impl>::ParseIdentifierOrStrictReservedWord(
       next == Token::ASYNC) {
     *is_strict_reserved = false;
     *is_await = next == Token::AWAIT;
-  } else if (next == Token::ESCAPED_STRICT_RESERVED_WORD ||
-             next == Token::FUTURE_STRICT_RESERVED_WORD || next == Token::LET ||
-             next == Token::STATIC ||
+  } else if (Token::IsStrictReservedWord(next) ||
              (next == Token::YIELD && !IsGeneratorFunction(function_kind))) {
     *is_strict_reserved = true;
   } else {
@@ -1792,12 +1764,8 @@ template <typename Impl>
 typename ParserBase<Impl>::IdentifierT ParserBase<Impl>::ParseIdentifierName(
     bool* ok) {
   Token::Value next = Next();
-  if (next != Token::IDENTIFIER && next != Token::ASYNC &&
-      next != Token::ENUM && next != Token::AWAIT && next != Token::LET &&
-      next != Token::STATIC && next != Token::YIELD &&
-      next != Token::FUTURE_STRICT_RESERVED_WORD &&
-      next != Token::ESCAPED_KEYWORD &&
-      next != Token::ESCAPED_STRICT_RESERVED_WORD && !Token::IsKeyword(next)) {
+  if (!Token::IsAnyIdentifier(next) && next != Token::ESCAPED_KEYWORD &&
+      !Token::IsKeyword(next)) {
     ReportUnexpectedToken(next);
     *ok = false;
     return impl()->NullIdentifier();
@@ -1852,6 +1820,39 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseRegExpLiteral(
 }
 
 template <typename Impl>
+typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseBindingPattern(
+    bool* ok) {
+  // Pattern ::
+  //   Identifier
+  //   ArrayLiteral
+  //   ObjectLiteral
+
+  int beg_pos = peek_position();
+  Token::Value token = peek();
+  ExpressionT result;
+
+  if (Token::IsAnyIdentifier(token)) {
+    IdentifierT name = ParseAndClassifyIdentifier(CHECK_OK);
+    result = impl()->ExpressionFromIdentifier(name, beg_pos);
+  } else {
+    classifier()->RecordNonSimpleParameter();
+
+    if (token == Token::LBRACK) {
+      result = ParseArrayLiteral(CHECK_OK);
+    } else if (token == Token::LBRACE) {
+      result = ParseObjectLiteral(CHECK_OK);
+    } else {
+      ReportUnexpectedToken(Next());
+      *ok = false;
+      return impl()->NullExpression();
+    }
+  }
+
+  ValidateBindingPattern(CHECK_OK);
+  return result;
+}
+
+template <typename Impl>
 typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
     bool* is_async, bool* ok) {
   // PrimaryExpression ::
@@ -1872,7 +1873,8 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
   //   AsyncFunctionLiteral
 
   int beg_pos = peek_position();
-  switch (peek()) {
+  Token::Value token = peek();
+  switch (token) {
     case Token::THIS: {
       BindingPatternUnexpectedToken();
       Consume(Token::THIS);
@@ -1884,16 +1886,25 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
     case Token::FALSE_LITERAL:
     case Token::SMI:
     case Token::NUMBER:
-    case Token::BIGINT:
+    case Token::BIGINT: {
+      // Ensure continuous enum range.
+      DCHECK(Token::IsLiteral(token));
       BindingPatternUnexpectedToken();
       return impl()->ExpressionFromLiteral(Next(), beg_pos);
+    }
+    case Token::STRING: {
+      DCHECK(Token::IsLiteral(token));
+      BindingPatternUnexpectedToken();
+      Consume(Token::STRING);
+      return impl()->ExpressionFromString(beg_pos);
+    }
 
     case Token::ASYNC:
       if (!scanner()->HasLineTerminatorAfterNext() &&
           PeekAhead() == Token::FUNCTION) {
         BindingPatternUnexpectedToken();
         Consume(Token::ASYNC);
-        return ParseAsyncFunctionLiteral(CHECK_OK);
+        return ParseAsyncFunctionLiteral(ok);
       }
       // CoverCallExpressionAndAsyncArrowHead
       *is_async = true;
@@ -1903,19 +1914,16 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
     case Token::STATIC:
     case Token::YIELD:
     case Token::AWAIT:
-    case Token::ESCAPED_STRICT_RESERVED_WORD:
-    case Token::FUTURE_STRICT_RESERVED_WORD: {
+    case Token::FUTURE_STRICT_RESERVED_WORD:
+    case Token::ESCAPED_STRICT_RESERVED_WORD: {
+      // Ensure continuous enum range.
+      DCHECK(IsInRange(token, Token::IDENTIFIER,
+                       Token::ESCAPED_STRICT_RESERVED_WORD));
       // Using eval or arguments in this context is OK even in strict mode.
       IdentifierT name = ParseAndClassifyIdentifier(CHECK_OK);
       return impl()->ExpressionFromIdentifier(name, beg_pos);
     }
 
-    case Token::STRING: {
-      BindingPatternUnexpectedToken();
-      Consume(Token::STRING);
-      return impl()->ExpressionFromString(beg_pos);
-    }
-
     case Token::ASSIGN_DIV:
     case Token::DIV:
       classifier()->RecordBindingPatternError(
@@ -1931,8 +1939,8 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
     case Token::LPAREN: {
       // Arrow function formal parameters are either a single identifier or a
       // list of BindingPattern productions enclosed in parentheses.
-      // Parentheses are not valid on the LHS of a BindingPattern, so we use the
-      // is_valid_binding_pattern() check to detect multiple levels of
+      // Parentheses are not valid on the LHS of a BindingPattern, so we use
+      // the is_valid_binding_pattern() check to detect multiple levels of
       // parenthesization.
       bool pattern_error = !classifier()->is_valid_binding_pattern();
       classifier()->RecordPatternError(scanner()->peek_location(),
@@ -1955,7 +1963,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
         function_state_->set_next_function_is_likely_called();
       }
       ExpressionT expr = ParseExpressionCoverGrammar(true, CHECK_OK);
-      Expect(Token::RPAREN, CHECK_OK);
+      Expect(Token::RPAREN, ok);
       return expr;
     }
 
@@ -2010,10 +2018,10 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrimaryExpression(
 
 template <typename Impl>
 typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseExpression(
-    bool accept_IN, bool* ok) {
+    bool* ok) {
   ExpressionClassifier classifier(this);
-  ExpressionT result = ParseExpressionCoverGrammar(accept_IN, CHECK_OK);
-  ValidateExpression(CHECK_OK);
+  ExpressionT result = ParseExpressionCoverGrammar(true, CHECK_OK);
+  ValidateExpression(ok);
   return result;
 }
 
@@ -2038,13 +2046,12 @@ ParserBase<Impl>::ParseExpressionCoverGrammar(bool accept_IN, bool* ok) {
                                           Token::String(Token::ELLIPSIS));
       int ellipsis_pos = position();
       int pattern_pos = peek_position();
-      ExpressionT pattern = ParsePrimaryExpression(CHECK_OK);
+      ExpressionT pattern = ParseBindingPattern(CHECK_OK);
       if (peek() == Token::ASSIGN) {
         ReportMessage(MessageTemplate::kRestDefaultInitializer);
         *ok = false;
         return result;
       }
-      ValidateBindingPattern(CHECK_OK);
       right = factory()->NewSpread(pattern, ellipsis_pos, pattern_pos);
     } else {
       right = ParseAssignmentExpression(accept_IN, CHECK_OK);
@@ -2097,14 +2104,13 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseArrayLiteral(
   int pos = peek_position();
   ExpressionListT values = impl()->NewExpressionList(4);
   int first_spread_index = -1;
-  Expect(Token::LBRACK, CHECK_OK);
-  while (peek() != Token::RBRACK) {
+  Consume(Token::LBRACK);
+  while (!Check(Token::RBRACK)) {
     ExpressionT elem;
     if (peek() == Token::COMMA) {
       elem = factory()->NewTheHoleLiteral();
-    } else if (peek() == Token::ELLIPSIS) {
-      int start_pos = peek_position();
-      Consume(Token::ELLIPSIS);
+    } else if (Check(Token::ELLIPSIS)) {
+      int start_pos = position();
       int expr_pos = peek_position();
       ExpressionT argument = ParseAssignmentExpression(true, CHECK_OK);
       elem = factory()->NewSpread(argument, start_pos, expr_pos);
@@ -2115,57 +2121,54 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseArrayLiteral(
 
       if (argument->IsAssignment()) {
         classifier()->RecordPatternError(
-            Scanner::Location(start_pos, scanner()->location().end_pos),
+            Scanner::Location(start_pos, end_position()),
             MessageTemplate::kInvalidDestructuringTarget);
       } else {
-        CheckDestructuringElement(argument, start_pos,
-                                  scanner()->location().end_pos);
+        CheckDestructuringElement(argument, start_pos, end_position());
       }
 
       if (peek() == Token::COMMA) {
         classifier()->RecordPatternError(
-            Scanner::Location(start_pos, scanner()->location().end_pos),
+            Scanner::Location(start_pos, end_position()),
             MessageTemplate::kElementAfterRest);
       }
     } else {
       int beg_pos = peek_position();
       elem = ParseAssignmentExpression(true, CHECK_OK);
-      CheckDestructuringElement(elem, beg_pos, scanner()->location().end_pos);
+      CheckDestructuringElement(elem, beg_pos, end_position());
     }
     values->Add(elem, zone_);
     if (peek() != Token::RBRACK) {
       Expect(Token::COMMA, CHECK_OK);
     }
   }
-  Expect(Token::RBRACK, CHECK_OK);
 
   return factory()->NewArrayLiteral(values, first_spread_index, pos);
 }
 
-template <class Impl>
-bool ParserBase<Impl>::SetPropertyKindFromToken(Token::Value token,
-                                                PropertyKind* kind) {
+inline bool ParsePropertyKindFromToken(Token::Value token,
+                                       ParsePropertyKind* kind) {
   // This returns true, setting the property kind, iff the given token is one
   // which must occur after a property name, indicating that the previous token
   // was in fact a name and not a modifier (like the "get" in "get x").
   switch (token) {
     case Token::COLON:
-      *kind = PropertyKind::kValueProperty;
+      *kind = ParsePropertyKind::kValue;
       return true;
     case Token::COMMA:
     case Token::RBRACE:
     case Token::ASSIGN:
-      *kind = PropertyKind::kShorthandProperty;
+      *kind = ParsePropertyKind::kShorthand;
       return true;
     case Token::LPAREN:
-      *kind = PropertyKind::kMethodProperty;
+      *kind = ParsePropertyKind::kMethod;
       return true;
     case Token::MUL:
     case Token::SEMICOLON:
-      *kind = PropertyKind::kClassField;
+      *kind = ParsePropertyKind::kClassField;
       return true;
     case Token::PRIVATE_NAME:
-      *kind = PropertyKind::kClassField;
+      *kind = ParsePropertyKind::kClassField;
       return true;
     default:
       break;
@@ -2173,57 +2176,55 @@ bool ParserBase<Impl>::SetPropertyKindFromToken(Token::Value token,
   return false;
 }
 
-template <class Impl>
-typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePropertyName(
-    IdentifierT* name, PropertyKind* kind, bool* is_generator, bool* is_get,
-    bool* is_set, bool* is_async, bool* is_computed_name, bool* ok) {
-  DCHECK_EQ(*kind, PropertyKind::kNotSet);
-  DCHECK(!*is_generator);
-  DCHECK(!*is_get);
-  DCHECK(!*is_set);
-  DCHECK(!*is_async);
-  DCHECK(!*is_computed_name);
+inline bool ParseAsAccessor(Token::Value token, Token::Value contextual_token,
+                            ParsePropertyKind* kind) {
+  if (ParsePropertyKindFromToken(token, kind)) return false;
 
-  *is_generator = Check(Token::MUL);
-  if (*is_generator) {
-    *kind = PropertyKind::kMethodProperty;
+  if (contextual_token == Token::GET) {
+    *kind = ParsePropertyKind::kAccessorGetter;
+  } else if (contextual_token == Token::SET) {
+    *kind = ParsePropertyKind::kAccessorSetter;
+  } else {
+    return false;
   }
 
-  Token::Value token = peek();
-  int pos = peek_position();
+  return true;
+}
 
-  if (!*is_generator && token == Token::ASYNC &&
-      !scanner()->HasLineTerminatorAfterNext()) {
-    Consume(Token::ASYNC);
-    token = peek();
-    if (token == Token::MUL && !scanner()->HasLineTerminatorBeforeNext()) {
-      Consume(Token::MUL);
-      token = peek();
-      *is_generator = true;
-    } else if (SetPropertyKindFromToken(token, kind)) {
-      *name = impl()->GetSymbol();  // TODO(bakkot) specialize on 'async'
-      impl()->PushLiteralName(*name);
-      return factory()->NewStringLiteral(*name, pos);
-    }
-    *kind = PropertyKind::kMethodProperty;
-    *is_async = true;
-    pos = peek_position();
-  }
+template <class Impl>
+typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePropertyName(
+    IdentifierT* name, ParsePropertyKind* kind, ParseFunctionFlags* flags,
+    bool* is_computed_name, bool* ok) {
+  DCHECK_EQ(ParsePropertyKind::kNotSet, *kind);
+  DCHECK_EQ(*flags, ParseFunctionFlag::kIsNormal);
+  DCHECK(!*is_computed_name);
 
-  if (token == Token::IDENTIFIER && !*is_generator && !*is_async) {
-    // This is checking for 'get' and 'set' in particular.
-    Consume(Token::IDENTIFIER);
-    token = peek();
-    if (SetPropertyKindFromToken(token, kind) ||
-        !scanner()->IsGetOrSet(is_get, is_set)) {
+  if (Check(Token::ASYNC)) {
+    Token::Value token = peek();
+    if ((token != Token::MUL && ParsePropertyKindFromToken(token, kind)) ||
+        scanner()->HasLineTerminatorBeforeNext()) {
       *name = impl()->GetSymbol();
       impl()->PushLiteralName(*name);
-      return factory()->NewStringLiteral(*name, pos);
+      return factory()->NewStringLiteral(*name, position());
     }
-    *kind = PropertyKind::kAccessorProperty;
-    pos = peek_position();
+    *flags = ParseFunctionFlag::kIsAsync;
+    *kind = ParsePropertyKind::kMethod;
+  }
+
+  if (Check(Token::MUL)) {
+    *flags |= ParseFunctionFlag::kIsGenerator;
+    *kind = ParsePropertyKind::kMethod;
   }
 
+  if (*kind == ParsePropertyKind::kNotSet && Check(Token::IDENTIFIER) &&
+      !ParseAsAccessor(peek(), scanner()->current_contextual_token(), kind)) {
+    *name = impl()->GetSymbol();
+    impl()->PushLiteralName(*name);
+    return factory()->NewStringLiteral(*name, position());
+  }
+
+  int pos = peek_position();
+
   // For non computed property names we normalize the name a bit:
   //
   //   "12" -> 12
@@ -2233,41 +2234,50 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePropertyName(
   //
   // This is important because we use the property name as a key in a hash
   // table when we compute constant properties.
-  ExpressionT expression = impl()->NullExpression();
-  switch (token) {
+  bool is_array_index;
+  uint32_t index;
+  switch (peek()) {
     case Token::STRING:
       Consume(Token::STRING);
       *name = impl()->GetSymbol();
+      is_array_index = impl()->IsArrayIndex(*name, &index);
       break;
 
     case Token::SMI:
       Consume(Token::SMI);
-      *name = impl()->GetNumberAsSymbol();
+      index = scanner()->smi_value();
+      is_array_index = true;
+      // Token::SMI were scanned from their canonical representation.
+      *name = impl()->GetSymbol();
       break;
 
-    case Token::NUMBER:
+    case Token::NUMBER: {
       Consume(Token::NUMBER);
       *name = impl()->GetNumberAsSymbol();
+      is_array_index = impl()->IsArrayIndex(*name, &index);
       break;
-
+    }
     case Token::LBRACK: {
       *name = impl()->NullIdentifier();
       *is_computed_name = true;
       Consume(Token::LBRACK);
       ExpressionClassifier computed_name_classifier(this);
-      expression = ParseAssignmentExpression(true, CHECK_OK);
+      ExpressionT expression = ParseAssignmentExpression(true, CHECK_OK);
       ValidateExpression(CHECK_OK);
       AccumulateFormalParameterContainmentErrors();
       Expect(Token::RBRACK, CHECK_OK);
-      break;
+      if (*kind == ParsePropertyKind::kNotSet) {
+        ParsePropertyKindFromToken(peek(), kind);
+      }
+      return expression;
     }
 
     case Token::ELLIPSIS:
-      if (!*is_generator && !*is_async && !*is_get && !*is_set) {
+      if (*kind == ParsePropertyKind::kNotSet) {
         *name = impl()->NullIdentifier();
         Consume(Token::ELLIPSIS);
-        expression = ParseAssignmentExpression(true, CHECK_OK);
-        *kind = PropertyKind::kSpreadProperty;
+        ExpressionT expression = ParseAssignmentExpression(true, CHECK_OK);
+        *kind = ParsePropertyKind::kSpread;
 
         if (!impl()->IsIdentifier(expression)) {
           classifier()->RecordBindingPatternError(
@@ -2291,23 +2301,16 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePropertyName(
 
     default:
       *name = ParseIdentifierName(CHECK_OK);
+      is_array_index = false;
       break;
   }
 
-  if (*kind == PropertyKind::kNotSet) {
-    SetPropertyKindFromToken(peek(), kind);
+  if (*kind == ParsePropertyKind::kNotSet) {
+    ParsePropertyKindFromToken(peek(), kind);
   }
-
-  if (*is_computed_name) {
-    return expression;
-  }
-
   impl()->PushLiteralName(*name);
-
-  uint32_t index;
-  return impl()->IsArrayIndex(*name, &index)
-             ? factory()->NewNumberLiteral(index, pos)
-             : factory()->NewStringLiteral(*name, pos);
+  return is_array_index ? factory()->NewNumberLiteral(index, pos)
+                        : factory()->NewStringLiteral(*name, pos);
 }
 
 template <typename Impl>
@@ -2317,26 +2320,24 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
     bool has_extends, bool* is_computed_name,
     ClassLiteralProperty::Kind* property_kind, bool* is_static, bool* ok) {
   DCHECK_NOT_NULL(class_info);
-  bool is_get = false;
-  bool is_set = false;
-  bool is_generator = false;
-  bool is_async = false;
+  ParseFunctionFlags function_flags = ParseFunctionFlag::kIsNormal;
   *is_static = false;
   *property_kind = ClassLiteralProperty::METHOD;
-  PropertyKind kind = PropertyKind::kNotSet;
+  ParsePropertyKind kind = ParsePropertyKind::kNotSet;
 
   Token::Value name_token = peek();
   DCHECK_IMPLIES(name_token == Token::PRIVATE_NAME,
                  allow_harmony_private_fields());
 
-  int name_token_position = scanner()->peek_location().beg_pos;
+  int property_beg_pos = scanner()->peek_location().beg_pos;
+  int name_token_position = property_beg_pos;
   *name = impl()->NullIdentifier();
   ExpressionT name_expression;
   if (name_token == Token::STATIC) {
     Consume(Token::STATIC);
     name_token_position = scanner()->peek_location().beg_pos;
     if (peek() == Token::LPAREN) {
-      kind = PropertyKind::kMethodProperty;
+      kind = ParsePropertyKind::kMethod;
       *name = impl()->GetSymbol();  // TODO(bakkot) specialize on 'static'
       name_expression = factory()->NewStringLiteral(*name, position());
     } else if (peek() == Token::ASSIGN || peek() == Token::SEMICOLON ||
@@ -2351,18 +2352,18 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
       return impl()->NullLiteralProperty();
     } else {
       *is_static = true;
-      name_expression = ParsePropertyName(name, &kind, &is_generator, &is_get,
-                                          &is_set, &is_async, is_computed_name,
-                                          CHECK_OK_CUSTOM(NullLiteralProperty));
+      name_expression =
+          ParsePropertyName(name, &kind, &function_flags, is_computed_name,
+                            CHECK_OK_CUSTOM(NullLiteralProperty));
     }
   } else if (name_token == Token::PRIVATE_NAME) {
     Consume(Token::PRIVATE_NAME);
     *name = impl()->GetSymbol();
     name_expression = factory()->NewStringLiteral(*name, position());
   } else {
-    name_expression = ParsePropertyName(name, &kind, &is_generator, &is_get,
-                                        &is_set, &is_async, is_computed_name,
-                                        CHECK_OK_CUSTOM(NullLiteralProperty));
+    name_expression =
+        ParsePropertyName(name, &kind, &function_flags, is_computed_name,
+                          CHECK_OK_CUSTOM(NullLiteralProperty));
   }
 
   if (!class_info->has_name_static_property && *is_static &&
@@ -2371,16 +2372,17 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
   }
 
   switch (kind) {
-    case PropertyKind::kClassField:
-    case PropertyKind::kNotSet:  // This case is a name followed by a name or
-                                 // other property. Here we have to assume
-                                 // that's an uninitialized field followed by a
-                                 // linebreak followed by a property, with ASI
-                                 // adding the semicolon. If not, there will be
-                                 // a syntax error after parsing the first name
-                                 // as an uninitialized field.
-    case PropertyKind::kShorthandProperty:
-    case PropertyKind::kValueProperty:
+    case ParsePropertyKind::kClassField:
+    case ParsePropertyKind::kNotSet:  // This case is a name followed by a name
+                                      // or other property. Here we have to
+                                      // assume that's an uninitialized field
+                                      // followed by a linebreak followed by a
+                                      // property, with ASI adding the
+                                      // semicolon. If not, there will be a
+                                      // syntax error after parsing the first
+                                      // name as an uninitialized field.
+    case ParsePropertyKind::kShorthand:
+    case ParsePropertyKind::kValue:
       if (allow_harmony_public_fields() || allow_harmony_private_fields()) {
         *property_kind = name_token == Token::PRIVATE_NAME
                              ? ClassLiteralProperty::PRIVATE_FIELD
@@ -2394,8 +2396,9 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
           checker->CheckClassFieldName(*is_static,
                                        CHECK_OK_CUSTOM(NullLiteralProperty));
         }
-        ExpressionT initializer = ParseClassFieldInitializer(
-            class_info, *is_static, CHECK_OK_CUSTOM(NullLiteralProperty));
+        ExpressionT initializer =
+            ParseClassFieldInitializer(class_info, property_beg_pos, *is_static,
+                                       CHECK_OK_CUSTOM(NullLiteralProperty));
         ExpectSemicolon(CHECK_OK_CUSTOM(NullLiteralProperty));
         ClassLiteralPropertyT result = factory()->NewClassLiteralProperty(
             name_expression, initializer, *property_kind, *is_static,
@@ -2409,9 +2412,7 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
         return impl()->NullLiteralProperty();
       }
 
-    case PropertyKind::kMethodProperty: {
-      DCHECK(!is_get && !is_set);
-
+    case ParsePropertyKind::kMethod: {
       // MethodDefinition
       //    PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
       //    '*' PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
@@ -2421,12 +2422,12 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
       //        '{' FunctionBody '}'
 
       if (!*is_computed_name) {
-        checker->CheckClassMethodName(name_token, PropertyKind::kMethodProperty,
-                                      is_generator, is_async, *is_static,
+        checker->CheckClassMethodName(name_token, ParsePropertyKind::kMethod,
+                                      function_flags, *is_static,
                                       CHECK_OK_CUSTOM(NullLiteralProperty));
       }
 
-      FunctionKind kind = MethodKindFor(is_generator, is_async);
+      FunctionKind kind = MethodKindFor(function_flags);
 
       if (!*is_static && impl()->IsConstructor(*name)) {
         class_info->has_seen_constructor = true;
@@ -2436,10 +2437,8 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
 
       ExpressionT value = impl()->ParseFunctionLiteral(
           *name, scanner()->location(), kSkipFunctionNameCheck, kind,
-          FLAG_harmony_function_tostring ? name_token_position
-                                         : kNoSourcePosition,
-          FunctionLiteral::kAccessorOrMethod, language_mode(), nullptr,
-          CHECK_OK_CUSTOM(NullLiteralProperty));
+          name_token_position, FunctionLiteral::kAccessorOrMethod,
+          language_mode(), nullptr, CHECK_OK_CUSTOM(NullLiteralProperty));
 
       *property_kind = ClassLiteralProperty::METHOD;
       ClassLiteralPropertyT result = factory()->NewClassLiteralProperty(
@@ -2449,13 +2448,15 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
       return result;
     }
 
-    case PropertyKind::kAccessorProperty: {
-      DCHECK((is_get || is_set) && !is_generator && !is_async);
+    case ParsePropertyKind::kAccessorGetter:
+    case ParsePropertyKind::kAccessorSetter: {
+      DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
+      bool is_get = kind == ParsePropertyKind::kAccessorGetter;
 
       if (!*is_computed_name) {
-        checker->CheckClassMethodName(
-            name_token, PropertyKind::kAccessorProperty, false, false,
-            *is_static, CHECK_OK_CUSTOM(NullLiteralProperty));
+        checker->CheckClassMethodName(name_token, kind,
+                                      ParseFunctionFlag::kIsNormal, *is_static,
+                                      CHECK_OK_CUSTOM(NullLiteralProperty));
         // Make sure the name expression is a string since we need a Name for
         // Runtime_DefineAccessorPropertyUnchecked and since we can determine
         // this statically we can skip the extra runtime check.
@@ -2468,10 +2469,8 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
 
       FunctionLiteralT value = impl()->ParseFunctionLiteral(
           *name, scanner()->location(), kSkipFunctionNameCheck, kind,
-          FLAG_harmony_function_tostring ? name_token_position
-                                         : kNoSourcePosition,
-          FunctionLiteral::kAccessorOrMethod, language_mode(), nullptr,
-          CHECK_OK_CUSTOM(NullLiteralProperty));
+          name_token_position, FunctionLiteral::kAccessorOrMethod,
+          language_mode(), nullptr, CHECK_OK_CUSTOM(NullLiteralProperty));
 
       *property_kind =
           is_get ? ClassLiteralProperty::GETTER : ClassLiteralProperty::SETTER;
@@ -2484,7 +2483,7 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
       impl()->SetFunctionNameFromPropertyName(result, *name, prefix);
       return result;
     }
-    case PropertyKind::kSpreadProperty:
+    case ParsePropertyKind::kSpread:
       ReportUnexpectedTokenAt(
           Scanner::Location(name_token_position, name_expression->position()),
           name_token);
@@ -2496,7 +2495,7 @@ ParserBase<Impl>::ParseClassPropertyDefinition(
 
 template <typename Impl>
 typename ParserBase<Impl>::ExpressionT
-ParserBase<Impl>::ParseClassFieldInitializer(ClassInfo* class_info,
+ParserBase<Impl>::ParseClassFieldInitializer(ClassInfo* class_info, int beg_pos,
                                              bool is_static, bool* ok) {
   DeclarationScope* initializer_scope = is_static
                                             ? class_info->static_fields_scope
@@ -2506,7 +2505,7 @@ ParserBase<Impl>::ParseClassFieldInitializer(ClassInfo* class_info,
     initializer_scope =
         NewFunctionScope(FunctionKind::kClassFieldsInitializerFunction);
     // TODO(gsathya): Make scopes be non contiguous.
-    initializer_scope->set_start_position(scanner()->location().end_pos);
+    initializer_scope->set_start_position(beg_pos);
     initializer_scope->SetLanguageMode(LanguageMode::kStrict);
   }
 
@@ -2523,7 +2522,7 @@ ParserBase<Impl>::ParseClassFieldInitializer(ClassInfo* class_info,
     initializer = factory()->NewUndefinedLiteral(kNoSourcePosition);
   }
 
-  initializer_scope->set_end_position(scanner()->location().end_pos);
+  initializer_scope->set_end_position(end_position());
   if (is_static) {
     class_info->static_fields_scope = initializer_scope;
     class_info->has_static_class_fields = true;
@@ -2541,26 +2540,23 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
                                                 bool* is_computed_name,
                                                 bool* is_rest_property,
                                                 bool* ok) {
-  bool is_get = false;
-  bool is_set = false;
-  bool is_generator = false;
-  bool is_async = false;
-  PropertyKind kind = PropertyKind::kNotSet;
+  ParseFunctionFlags function_flags = ParseFunctionFlag::kIsNormal;
+  ParsePropertyKind kind = ParsePropertyKind::kNotSet;
 
   IdentifierT name = impl()->NullIdentifier();
   Token::Value name_token = peek();
-  int next_beg_pos = scanner()->peek_location().beg_pos;
-  int next_end_pos = scanner()->peek_location().end_pos;
+  int next_beg_pos = peek_position();
+  int next_end_pos = peek_end_position();
 
-  ExpressionT name_expression = ParsePropertyName(
-      &name, &kind, &is_generator, &is_get, &is_set, &is_async,
-      is_computed_name, CHECK_OK_CUSTOM(NullLiteralProperty));
+  ExpressionT name_expression =
+      ParsePropertyName(&name, &kind, &function_flags, is_computed_name,
+                        CHECK_OK_CUSTOM(NullLiteralProperty));
 
   switch (kind) {
-    case PropertyKind::kSpreadProperty:
-      DCHECK(!is_get && !is_set && !is_generator && !is_async &&
-             !*is_computed_name);
-      DCHECK(name_token == Token::ELLIPSIS);
+    case ParsePropertyKind::kSpread:
+      DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
+      DCHECK(!*is_computed_name);
+      DCHECK_EQ(Token::ELLIPSIS, name_token);
 
       *is_computed_name = true;
       *is_rest_property = true;
@@ -2569,8 +2565,8 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
           factory()->NewTheHoleLiteral(), name_expression,
           ObjectLiteralProperty::SPREAD, true);
 
-    case PropertyKind::kValueProperty: {
-      DCHECK(!is_get && !is_set && !is_generator && !is_async);
+    case ParsePropertyKind::kValue: {
+      DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
 
       if (!*is_computed_name) {
         checker->CheckDuplicateProto(name_token);
@@ -2579,7 +2575,7 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
       int beg_pos = peek_position();
       ExpressionT value =
           ParseAssignmentExpression(true, CHECK_OK_CUSTOM(NullLiteralProperty));
-      CheckDestructuringElement(value, beg_pos, scanner()->location().end_pos);
+      CheckDestructuringElement(value, beg_pos, end_position());
 
       ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
           name_expression, value, *is_computed_name);
@@ -2587,14 +2583,14 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
       return result;
     }
 
-    case PropertyKind::kShorthandProperty: {
+    case ParsePropertyKind::kShorthand: {
       // PropertyDefinition
       //    IdentifierReference
       //    CoverInitializedName
       //
       // CoverInitializedName
       //    IdentifierReference Initializer?
-      DCHECK(!is_get && !is_set && !is_generator && !is_async);
+      DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
 
       if (!Token::IsIdentifier(name_token, language_mode(),
                                this->is_generator(),
@@ -2642,7 +2638,7 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
         value = factory()->NewAssignment(Token::ASSIGN, lhs, rhs,
                                          kNoSourcePosition);
         classifier()->RecordExpressionError(
-            Scanner::Location(next_beg_pos, scanner()->location().end_pos),
+            Scanner::Location(next_beg_pos, end_position()),
             MessageTemplate::kInvalidCoverInitializedName);
 
         impl()->SetFunctionNameFromIdentifierRef(rhs, lhs);
@@ -2656,24 +2652,21 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
       return result;
     }
 
-    case PropertyKind::kMethodProperty: {
-      DCHECK(!is_get && !is_set);
-
+    case ParsePropertyKind::kMethod: {
       // MethodDefinition
       //    PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
       //    '*' PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
 
       classifier()->RecordPatternError(
-          Scanner::Location(next_beg_pos, scanner()->location().end_pos),
+          Scanner::Location(next_beg_pos, end_position()),
           MessageTemplate::kInvalidDestructuringTarget);
 
-      FunctionKind kind = MethodKindFor(is_generator, is_async);
+      FunctionKind kind = MethodKindFor(function_flags);
 
       ExpressionT value = impl()->ParseFunctionLiteral(
           name, scanner()->location(), kSkipFunctionNameCheck, kind,
-          FLAG_harmony_function_tostring ? next_beg_pos : kNoSourcePosition,
-          FunctionLiteral::kAccessorOrMethod, language_mode(), nullptr,
-          CHECK_OK_CUSTOM(NullLiteralProperty));
+          next_beg_pos, FunctionLiteral::kAccessorOrMethod, language_mode(),
+          nullptr, CHECK_OK_CUSTOM(NullLiteralProperty));
 
       ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
           name_expression, value, ObjectLiteralProperty::COMPUTED,
@@ -2682,12 +2675,13 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
       return result;
     }
 
-    case PropertyKind::kAccessorProperty: {
-      DCHECK((is_get || is_set) && !(is_set && is_get) && !is_generator &&
-             !is_async);
+    case ParsePropertyKind::kAccessorGetter:
+    case ParsePropertyKind::kAccessorSetter: {
+      DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
+      bool is_get = kind == ParsePropertyKind::kAccessorGetter;
 
       classifier()->RecordPatternError(
-          Scanner::Location(next_beg_pos, scanner()->location().end_pos),
+          Scanner::Location(next_beg_pos, end_position()),
           MessageTemplate::kInvalidDestructuringTarget);
 
       if (!*is_computed_name) {
@@ -2703,9 +2697,8 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
 
       FunctionLiteralT value = impl()->ParseFunctionLiteral(
           name, scanner()->location(), kSkipFunctionNameCheck, kind,
-          FLAG_harmony_function_tostring ? next_beg_pos : kNoSourcePosition,
-          FunctionLiteral::kAccessorOrMethod, language_mode(), nullptr,
-          CHECK_OK_CUSTOM(NullLiteralProperty));
+          next_beg_pos, FunctionLiteral::kAccessorOrMethod, language_mode(),
+          nullptr, CHECK_OK_CUSTOM(NullLiteralProperty));
 
       ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
           name_expression, value,
@@ -2719,8 +2712,8 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
       return result;
     }
 
-    case PropertyKind::kClassField:
-    case PropertyKind::kNotSet:
+    case ParsePropertyKind::kClassField:
+    case ParsePropertyKind::kNotSet:
       ReportUnexpectedToken(Next());
       *ok = false;
       return impl()->NullLiteralProperty();
@@ -2743,10 +2736,10 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseObjectLiteral(
   bool has_rest_property = false;
   ObjectLiteralChecker checker(this);
 
-  Expect(Token::LBRACE, CHECK_OK);
+  Consume(Token::LBRACE);
 
-  while (peek() != Token::RBRACE) {
-    FuncNameInferrer::State fni_state(fni_);
+  while (!Check(Token::RBRACE)) {
+    FuncNameInferrerState fni_state(&fni_);
 
     bool is_computed_name = false;
     bool is_rest_property = false;
@@ -2774,9 +2767,8 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseObjectLiteral(
       Expect(Token::COMMA, CHECK_OK);
     }
 
-    if (fni_ != nullptr) fni_->Infer();
+    fni_.Infer();
   }
-  Expect(Token::RBRACE, CHECK_OK);
 
   // In pattern rewriter, we rewrite rest property to call out to a
   // runtime function passing all the other properties as arguments to
@@ -2802,25 +2794,20 @@ typename ParserBase<Impl>::ExpressionListT ParserBase<Impl>::ParseArguments(
   Scanner::Location spread_arg = Scanner::Location::invalid();
   ExpressionListT result = impl()->NewExpressionList(4);
   Expect(Token::LPAREN, CHECK_OK_CUSTOM(NullExpressionList));
-  bool done = (peek() == Token::RPAREN);
-  while (!done) {
+  while (peek() != Token::RPAREN) {
     int start_pos = peek_position();
     bool is_spread = Check(Token::ELLIPSIS);
     int expr_pos = peek_position();
 
     ExpressionT argument =
         ParseAssignmentExpression(true, CHECK_OK_CUSTOM(NullExpressionList));
-    if (!impl()->IsIdentifier(argument) &&
-        is_simple_parameter_list != nullptr) {
-      *is_simple_parameter_list = false;
-    }
+    if (!impl()->IsIdentifier(argument)) *is_simple_parameter_list = false;
+
     if (!maybe_arrow) {
       ValidateExpression(CHECK_OK_CUSTOM(NullExpressionList));
     }
     if (is_spread) {
-      if (is_simple_parameter_list != nullptr) {
-        *is_simple_parameter_list = false;
-      }
+      *is_simple_parameter_list = false;
       if (!spread_arg.IsValid()) {
         spread_arg.beg_pos = start_pos;
         spread_arg.end_pos = peek_position();
@@ -2833,24 +2820,22 @@ typename ParserBase<Impl>::ExpressionListT ParserBase<Impl>::ParseArguments(
     }
     result->Add(argument, zone_);
 
-    if (result->length() > Code::kMaxArguments) {
-      ReportMessage(MessageTemplate::kTooManyArguments);
-      *ok = false;
-      return impl()->NullExpressionList();
-    }
-    done = (peek() != Token::COMMA);
-    if (!done) {
-      Next();
-      if (argument->IsSpread()) {
-        classifier()->RecordAsyncArrowFormalParametersError(
-            scanner()->location(), MessageTemplate::kParamAfterRest);
-      }
-      if (peek() == Token::RPAREN) {
-        // allow trailing comma
-        done = true;
-      }
+    if (peek() != Token::COMMA) break;
+
+    Next();
+
+    if (argument->IsSpread()) {
+      classifier()->RecordAsyncArrowFormalParametersError(
+          scanner()->location(), MessageTemplate::kParamAfterRest);
     }
   }
+
+  if (result->length() > Code::kMaxArguments) {
+    ReportMessage(MessageTemplate::kTooManyArguments);
+    *ok = false;
+    return impl()->NullExpressionList();
+  }
+
   Scanner::Location location = scanner_->location();
   if (Token::RPAREN != Next()) {
     impl()->ReportMessageAt(location, MessageTemplate::kUnterminatedArgList);
@@ -2883,7 +2868,7 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN, bool* ok) {
     return ParseYieldExpression(accept_IN, ok);
   }
 
-  FuncNameInferrer::State fni_state(fni_);
+  FuncNameInferrerState fni_state(&fni_);
   ExpressionClassifier arrow_formals_classifier(
       this, classifier()->duplicate_finder());
 
@@ -2915,10 +2900,8 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN, bool* ok) {
     IdentifierT name = ParseAndClassifyIdentifier(CHECK_OK);
     expression =
         impl()->ExpressionFromIdentifier(name, position(), InferName::kNo);
-    if (fni_) {
-      // Remove `async` keyword from inferred name stack.
-      fni_->RemoveAsyncKeywordFromEnd();
-    }
+    // Remove `async` keyword from inferred name stack.
+    fni_.RemoveAsyncKeywordFromEnd();
   }
 
   if (peek() == Token::ARROW) {
@@ -2931,9 +2914,9 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN, bool* ok) {
     // in an arrow parameter list, this is correct.
     // TODO(adamk): Rename "FormalParameterInitializerError" to refer to
     // "YieldExpression", which is its only use.
-    ValidateFormalParameterInitializer(ok);
+    ValidateFormalParameterInitializer(CHECK_OK);
 
-    Scanner::Location loc(lhs_beg_pos, scanner()->location().end_pos);
+    Scanner::Location loc(lhs_beg_pos, end_position());
     DeclarationScope* scope =
         NewFunctionScope(is_async ? FunctionKind::kAsyncArrowFunction
                                   : FunctionKind::kArrowFunction);
@@ -2962,7 +2945,7 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN, bool* ok) {
                                      MessageTemplate::kUnexpectedToken,
                                      Token::String(Token::ARROW));
 
-    if (fni_ != nullptr) fni_->Infer();
+    fni_.Infer();
 
     return expression;
   }
@@ -2997,7 +2980,7 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN, bool* ok) {
     ValidateAssignmentPattern(CHECK_OK);
   } else {
     expression = CheckAndRewriteReferenceExpression(
-        expression, lhs_beg_pos, scanner()->location().end_pos,
+        expression, lhs_beg_pos, end_position(),
         MessageTemplate::kInvalidLhsInAssignment, CHECK_OK);
   }
 
@@ -3027,15 +3010,13 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN, bool* ok) {
 
   impl()->CheckAssigningFunctionLiteralToProperty(expression, right);
 
-  if (fni_ != nullptr) {
-    // Check if the right hand side is a call to avoid inferring a
-    // name if we're dealing with "a = function(){...}();"-like
-    // expression.
-    if (op == Token::ASSIGN && !right->IsCall() && !right->IsCallNew()) {
-      fni_->Infer();
-    } else {
-      fni_->RemoveLastFunction();
-    }
+  // Check if the right hand side is a call to avoid inferring a
+  // name if we're dealing with "a = function(){...}();"-like
+  // expression.
+  if (op == Token::ASSIGN && !right->IsCall() && !right->IsCallNew()) {
+    fni_.Infer();
+  } else {
+    fni_.RemoveLastFunction();
   }
 
   if (op == Token::ASSIGN) {
@@ -3124,11 +3105,20 @@ ParserBase<Impl>::ParseConditionalExpression(bool accept_IN,
   //   LogicalOrExpression
   //   LogicalOrExpression '?' AssignmentExpression ':' AssignmentExpression
 
-  SourceRange then_range, else_range;
   int pos = peek_position();
   // We start using the binary expression parser for prec >= 4 only!
   ExpressionT expression = ParseBinaryExpression(4, accept_IN, CHECK_OK);
-  if (peek() != Token::CONDITIONAL) return expression;
+  return peek() == Token::CONDITIONAL
+             ? ParseConditionalContinuation(expression, accept_IN, pos, ok)
+             : expression;
+}
+
+template <typename Impl>
+typename ParserBase<Impl>::ExpressionT
+ParserBase<Impl>::ParseConditionalContinuation(ExpressionT expression,
+                                               bool accept_IN, int pos,
+                                               bool* ok) {
+  SourceRange then_range, else_range;
   ValidateExpression(CHECK_OK);
   BindingPatternUnexpectedToken();
   ArrowFormalParametersUnexpectedToken();
@@ -3184,10 +3174,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseBinaryExpression(
       right_range_scope.Finalize();
       ValidateExpression(CHECK_OK);
 
-      if (impl()->ShortcutNumericLiteralBinaryExpression(&x, y, op, pos)) {
-        continue;
-      }
-
       // For now we distinguish between comparisons and other binary
       // operations.  (We could combine the two and get rid of this
       // code and AST node eventually.)
@@ -3204,9 +3190,9 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseBinaryExpression(
           // The comparison was negated - add a NOT.
           x = factory()->NewUnaryOperation(Token::NOT, x, pos);
         }
-      } else if (impl()->CollapseNaryExpression(&x, y, op, pos, right_range)) {
-        continue;
-      } else {
+      } else if (!impl()->ShortcutNumericLiteralBinaryExpression(&x, y, op,
+                                                                 pos) &&
+                 !impl()->CollapseNaryExpression(&x, y, op, pos, right_range)) {
         // We have a "normal" binary operation.
         x = factory()->NewBinaryOperation(op, x, y, pos);
         if (op == Token::OR || op == Token::AND) {
@@ -3219,97 +3205,109 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseBinaryExpression(
 }
 
 template <typename Impl>
-typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseUnaryExpression(
+typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseUnaryOpExpression(
     bool* ok) {
-  // UnaryExpression ::
-  //   PostfixExpression
-  //   'delete' UnaryExpression
-  //   'void' UnaryExpression
-  //   'typeof' UnaryExpression
-  //   '++' UnaryExpression
-  //   '--' UnaryExpression
-  //   '+' UnaryExpression
-  //   '-' UnaryExpression
-  //   '~' UnaryExpression
-  //   '!' UnaryExpression
-  //   [+Await] AwaitExpression[?Yield]
-
-  Token::Value op = peek();
-  if (Token::IsUnaryOp(op)) {
-    BindingPatternUnexpectedToken();
-    ArrowFormalParametersUnexpectedToken();
-
-    op = Next();
-    int pos = position();
+  BindingPatternUnexpectedToken();
+  ArrowFormalParametersUnexpectedToken();
 
-    // Assume "! function ..." indicates the function is likely to be called.
-    if (op == Token::NOT && peek() == Token::FUNCTION) {
-      function_state_->set_next_function_is_likely_called();
-    }
+  Token::Value op = Next();
+  int pos = position();
 
-    ExpressionT expression = ParseUnaryExpression(CHECK_OK);
-    ValidateExpression(CHECK_OK);
+  // Assume "! function ..." indicates the function is likely to be called.
+  if (op == Token::NOT && peek() == Token::FUNCTION) {
+    function_state_->set_next_function_is_likely_called();
+  }
 
-    if (op == Token::DELETE) {
-      if (impl()->IsIdentifier(expression) && is_strict(language_mode())) {
-        // "delete identifier" is a syntax error in strict mode.
-        ReportMessage(MessageTemplate::kStrictDelete);
-        *ok = false;
-        return impl()->NullExpression();
-      }
+  ExpressionT expression = ParseUnaryExpression(CHECK_OK);
+  ValidateExpression(CHECK_OK);
 
-      if (impl()->IsPropertyWithPrivateFieldKey(expression)) {
-        ReportMessage(MessageTemplate::kDeletePrivateField);
-        *ok = false;
-        return impl()->NullExpression();
-      }
+  if (op == Token::DELETE) {
+    if (impl()->IsIdentifier(expression) && is_strict(language_mode())) {
+      // "delete identifier" is a syntax error in strict mode.
+      ReportMessage(MessageTemplate::kStrictDelete);
+      *ok = false;
+      return impl()->NullExpression();
     }
 
-    if (peek() == Token::EXP) {
-      ReportUnexpectedToken(Next());
+    if (impl()->IsPropertyWithPrivateFieldKey(expression)) {
+      ReportMessage(MessageTemplate::kDeletePrivateField);
       *ok = false;
       return impl()->NullExpression();
     }
+  }
 
-    // Allow the parser's implementation to rewrite the expression.
-    return impl()->BuildUnaryExpression(expression, op, pos);
-  } else if (Token::IsCountOp(op)) {
-    BindingPatternUnexpectedToken();
-    ArrowFormalParametersUnexpectedToken();
-    op = Next();
-    int beg_pos = peek_position();
-    ExpressionT expression = ParseUnaryExpression(CHECK_OK);
-    expression = CheckAndRewriteReferenceExpression(
-        expression, beg_pos, scanner()->location().end_pos,
-        MessageTemplate::kInvalidLhsInPrefixOp, CHECK_OK);
-    impl()->MarkExpressionAsAssigned(expression);
-    ValidateExpression(CHECK_OK);
+  if (peek() == Token::EXP) {
+    ReportUnexpectedToken(Next());
+    *ok = false;
+    return impl()->NullExpression();
+  }
 
-    return factory()->NewCountOperation(op,
-                                        true /* prefix */,
-                                        expression,
-                                        position());
+  // Allow the parser's implementation to rewrite the expression.
+  return impl()->BuildUnaryExpression(expression, op, pos);
+}
 
-  } else if (is_async_function() && peek() == Token::AWAIT) {
-    classifier()->RecordFormalParameterInitializerError(
-        scanner()->peek_location(),
-        MessageTemplate::kAwaitExpressionFormalParameter);
-    int await_pos = peek_position();
-    Consume(Token::AWAIT);
+template <typename Impl>
+typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrefixExpression(
+    bool* ok) {
+  BindingPatternUnexpectedToken();
+  ArrowFormalParametersUnexpectedToken();
+  Token::Value op = Next();
+  int beg_pos = peek_position();
+  ExpressionT expression = ParseUnaryExpression(CHECK_OK);
+  expression = CheckAndRewriteReferenceExpression(
+      expression, beg_pos, end_position(),
+      MessageTemplate::kInvalidLhsInPrefixOp, CHECK_OK);
+  impl()->MarkExpressionAsAssigned(expression);
+  ValidateExpression(CHECK_OK);
 
-    ExpressionT value = ParseUnaryExpression(CHECK_OK);
+  return factory()->NewCountOperation(op, true /* prefix */, expression,
+                                      position());
+}
 
-    classifier()->RecordBindingPatternError(
-        Scanner::Location(await_pos, scanner()->location().end_pos),
-        MessageTemplate::kInvalidDestructuringTarget);
+template <typename Impl>
+typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseAwaitExpression(
+    bool* ok) {
+  classifier()->RecordFormalParameterInitializerError(
+      scanner()->peek_location(),
+      MessageTemplate::kAwaitExpressionFormalParameter);
+  int await_pos = peek_position();
+  Consume(Token::AWAIT);
 
-    ExpressionT expr = factory()->NewAwait(value, await_pos);
-    function_state_->AddSuspend();
-    impl()->RecordSuspendSourceRange(expr, PositionAfterSemicolon());
-    return expr;
-  } else {
-    return ParsePostfixExpression(ok);
+  ExpressionT value = ParseUnaryExpression(CHECK_OK);
+
+  classifier()->RecordBindingPatternError(
+      Scanner::Location(await_pos, end_position()),
+      MessageTemplate::kInvalidDestructuringTarget);
+
+  ExpressionT expr = factory()->NewAwait(value, await_pos);
+  function_state_->AddSuspend();
+  impl()->RecordSuspendSourceRange(expr, PositionAfterSemicolon());
+  return expr;
+}
+
+template <typename Impl>
+typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseUnaryExpression(
+    bool* ok) {
+  // UnaryExpression ::
+  //   PostfixExpression
+  //   'delete' UnaryExpression
+  //   'void' UnaryExpression
+  //   'typeof' UnaryExpression
+  //   '++' UnaryExpression
+  //   '--' UnaryExpression
+  //   '+' UnaryExpression
+  //   '-' UnaryExpression
+  //   '~' UnaryExpression
+  //   '!' UnaryExpression
+  //   [+Await] AwaitExpression[?Yield]
+
+  Token::Value op = peek();
+  if (Token::IsUnaryOp(op)) return ParseUnaryOpExpression(ok);
+  if (Token::IsCountOp(op)) return ParsePrefixExpression(ok);
+  if (is_async_function() && op == Token::AWAIT) {
+    return ParseAwaitExpression(ok);
   }
+  return ParsePostfixExpression(ok);
 }
 
 template <typename Impl>
@@ -3325,7 +3323,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePostfixExpression(
     ArrowFormalParametersUnexpectedToken();
 
     expression = CheckAndRewriteReferenceExpression(
-        expression, lhs_beg_pos, scanner()->location().end_pos,
+        expression, lhs_beg_pos, end_position(),
         MessageTemplate::kInvalidLhsInPostfixOp, CHECK_OK);
     impl()->MarkExpressionAsAssigned(expression);
     ValidateExpression(CHECK_OK);
@@ -3398,9 +3396,7 @@ ParserBase<Impl>::ParseLeftHandSideExpression(bool* ok) {
           args = ParseArguments(&spread_pos, true, &is_simple_parameter_list,
                                 CHECK_OK);
           if (peek() == Token::ARROW) {
-            if (fni_) {
-              fni_->RemoveAsyncKeywordFromEnd();
-            }
+            fni_.RemoveAsyncKeywordFromEnd();
             ValidateBindingPattern(CHECK_OK);
             ValidateFormalParameterInitializer(CHECK_OK);
             if (!classifier()->is_valid_async_arrow_formal_parameters()) {
@@ -3443,7 +3439,7 @@ ParserBase<Impl>::ParseLeftHandSideExpression(bool* ok) {
           result = factory()->NewCall(result, args, pos, is_possibly_eval);
         }
 
-        if (fni_ != nullptr) fni_->RemoveLastFunction();
+        fni_.RemoveLastFunction();
         break;
       }
 
@@ -3475,8 +3471,8 @@ ParserBase<Impl>::ParseLeftHandSideExpression(bool* ok) {
 
 template <typename Impl>
 typename ParserBase<Impl>::ExpressionT
-ParserBase<Impl>::ParseMemberWithNewPrefixesExpression(bool* is_async,
-                                                       bool* ok) {
+ParserBase<Impl>::ParseMemberWithPresentNewPrefixesExpression(bool* is_async,
+                                                              bool* ok) {
   // NewExpression ::
   //   ('new')+ MemberExpression
   //
@@ -3496,49 +3492,52 @@ ParserBase<Impl>::ParseMemberWithNewPrefixesExpression(bool* is_async,
   // new new foo means new (new foo)
   // new new foo() means new (new foo())
   // new new foo().bar().baz means (new (new foo()).bar()).baz
+  BindingPatternUnexpectedToken();
+  ArrowFormalParametersUnexpectedToken();
+  Consume(Token::NEW);
+  int new_pos = position();
+  ExpressionT result;
+  if (peek() == Token::SUPER) {
+    const bool is_new = true;
+    result = ParseSuperExpression(is_new, CHECK_OK);
+  } else if (allow_harmony_dynamic_import() && peek() == Token::IMPORT &&
+             (!allow_harmony_import_meta() || PeekAhead() == Token::LPAREN)) {
+    impl()->ReportMessageAt(scanner()->peek_location(),
+                            MessageTemplate::kImportCallNotNewExpression);
+    *ok = false;
+    return impl()->NullExpression();
+  } else if (peek() == Token::PERIOD) {
+    *is_async = false;
+    result = ParseNewTargetExpression(CHECK_OK);
+    return ParseMemberExpressionContinuation(result, is_async, ok);
+  } else {
+    result = ParseMemberWithNewPrefixesExpression(is_async, CHECK_OK);
+  }
+  ValidateExpression(CHECK_OK);
+  if (peek() == Token::LPAREN) {
+    // NewExpression with arguments.
+    Scanner::Location spread_pos;
+    ExpressionListT args = ParseArguments(&spread_pos, CHECK_OK);
 
-  if (peek() == Token::NEW) {
-    BindingPatternUnexpectedToken();
-    ArrowFormalParametersUnexpectedToken();
-    Consume(Token::NEW);
-    int new_pos = position();
-    ExpressionT result;
-    if (peek() == Token::SUPER) {
-      const bool is_new = true;
-      result = ParseSuperExpression(is_new, CHECK_OK);
-    } else if (allow_harmony_dynamic_import() && peek() == Token::IMPORT &&
-               (!allow_harmony_import_meta() || PeekAhead() == Token::LPAREN)) {
-      impl()->ReportMessageAt(scanner()->peek_location(),
-                              MessageTemplate::kImportCallNotNewExpression);
-      *ok = false;
-      return impl()->NullExpression();
-    } else if (peek() == Token::PERIOD) {
-      *is_async = false;
-      result = ParseNewTargetExpression(CHECK_OK);
-      return ParseMemberExpressionContinuation(result, is_async, CHECK_OK);
+    if (spread_pos.IsValid()) {
+      result = impl()->SpreadCallNew(result, args, new_pos);
     } else {
-      result = ParseMemberWithNewPrefixesExpression(is_async, CHECK_OK);
+      result = factory()->NewCallNew(result, args, new_pos);
     }
-    ValidateExpression(CHECK_OK);
-    if (peek() == Token::LPAREN) {
-      // NewExpression with arguments.
-      Scanner::Location spread_pos;
-      ExpressionListT args = ParseArguments(&spread_pos, CHECK_OK);
-
-      if (spread_pos.IsValid()) {
-        result = impl()->SpreadCallNew(result, args, new_pos);
-      } else {
-        result = factory()->NewCallNew(result, args, new_pos);
-      }
-      // The expression can still continue with . or [ after the arguments.
-      result = ParseMemberExpressionContinuation(result, is_async, CHECK_OK);
-      return result;
-    }
-    // NewExpression without arguments.
-    return factory()->NewCallNew(result, impl()->NewExpressionList(0), new_pos);
+    // The expression can still continue with . or [ after the arguments.
+    return ParseMemberExpressionContinuation(result, is_async, ok);
   }
-  // No 'new' or 'super' keyword.
-  return ParseMemberExpression(is_async, ok);
+  // NewExpression without arguments.
+  return factory()->NewCallNew(result, impl()->NewExpressionList(0), new_pos);
+}
+
+template <typename Impl>
+typename ParserBase<Impl>::ExpressionT
+ParserBase<Impl>::ParseMemberWithNewPrefixesExpression(bool* is_async,
+                                                       bool* ok) {
+  return peek() == Token::NEW
+             ? ParseMemberWithPresentNewPrefixesExpression(is_async, ok)
+             : ParseMemberExpression(is_async, ok);
 }
 
 template <typename Impl>
@@ -3604,8 +3603,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseMemberExpression(
     result = ParsePrimaryExpression(is_async, CHECK_OK);
   }
 
-  result = ParseMemberExpressionContinuation(result, is_async, CHECK_OK);
-  return result;
+  return ParseMemberExpressionContinuation(result, is_async, ok);
 }
 
 template <typename Impl>
@@ -3678,9 +3676,9 @@ void ParserBase<Impl>::ExpectMetaProperty(Token::Value property_name,
   Consume(Token::PERIOD);
   ExpectContextualKeyword(property_name, CHECK_OK_CUSTOM(Void));
   if (scanner()->literal_contains_escapes()) {
-    impl()->ReportMessageAt(
-        Scanner::Location(pos, scanner()->location().end_pos),
-        MessageTemplate::kInvalidEscapedMetaProperty, full_name);
+    impl()->ReportMessageAt(Scanner::Location(pos, end_position()),
+                            MessageTemplate::kInvalidEscapedMetaProperty,
+                            full_name);
     *ok = false;
   }
 }
@@ -3692,7 +3690,7 @@ ParserBase<Impl>::ParseNewTargetExpression(bool* ok) {
   ExpectMetaProperty(Token::TARGET, "new.target", pos, CHECK_OK);
 
   classifier()->RecordAssignmentPatternError(
-      Scanner::Location(pos, scanner()->location().end_pos),
+      Scanner::Location(pos, end_position()),
       MessageTemplate::kInvalidDestructuringTarget);
 
   if (!GetReceiverScope()->is_function_scope()) {
@@ -3780,14 +3778,11 @@ void ParserBase<Impl>::ParseFormalParameter(FormalParametersT* parameters,
   //   BindingElement[?Yield, ?GeneratorParameter]
   bool is_rest = parameters->has_rest;
 
-  FuncNameInferrer::State fni_state(fni_);
-  ExpressionT pattern = ParsePrimaryExpression(CHECK_OK_CUSTOM(Void));
-  ValidateBindingPattern(CHECK_OK_CUSTOM(Void));
-
+  FuncNameInferrerState fni_state(&fni_);
+  ExpressionT pattern = ParseBindingPattern(CHECK_OK_CUSTOM(Void));
   if (!impl()->IsIdentifier(pattern)) {
     parameters->is_simple = false;
     ValidateFormalParameterInitializer(CHECK_OK_CUSTOM(Void));
-    classifier()->RecordNonSimpleParameter();
   }
 
   ExpressionT initializer = impl()->NullExpression();
@@ -3808,8 +3803,8 @@ void ParserBase<Impl>::ParseFormalParameter(FormalParametersT* parameters,
     impl()->SetFunctionNameFromIdentifierRef(initializer, pattern);
   }
 
-  impl()->AddFormalParameter(parameters, pattern, initializer,
-                             scanner()->location().end_pos, is_rest);
+  impl()->AddFormalParameter(parameters, pattern, initializer, end_position(),
+                             is_rest);
 }
 
 template <typename Impl>
@@ -3908,23 +3903,21 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseVariableDeclarations(
   int bindings_start = peek_position();
   do {
     // Parse binding pattern.
-    FuncNameInferrer::State fni_state(fni_);
+    FuncNameInferrerState fni_state(&fni_);
 
     ExpressionT pattern = impl()->NullExpression();
     int decl_pos = peek_position();
     {
       ExpressionClassifier pattern_classifier(this);
-      pattern = ParsePrimaryExpression(CHECK_OK_CUSTOM(NullStatement));
+      pattern = ParseBindingPattern(CHECK_OK_CUSTOM(NullStatement));
 
-      ValidateBindingPattern(CHECK_OK_CUSTOM(NullStatement));
       if (IsLexicalVariableMode(parsing_result->descriptor.mode)) {
         ValidateLetPattern(CHECK_OK_CUSTOM(NullStatement));
       }
     }
-
     Scanner::Location variable_loc = scanner()->location();
-    bool single_name = impl()->IsIdentifier(pattern);
 
+    bool single_name = impl()->IsIdentifier(pattern);
     if (single_name) {
       impl()->PushVariableName(impl()->AsIdentifier(pattern));
     }
@@ -3939,32 +3932,32 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseVariableDeclarations(
       value = ParseAssignmentExpression(var_context != kForStatement,
                                         CHECK_OK_CUSTOM(NullStatement));
       ValidateExpression(CHECK_OK_CUSTOM(NullStatement));
-      variable_loc.end_pos = scanner()->location().end_pos;
+      variable_loc.end_pos = end_position();
 
       if (!parsing_result->first_initializer_loc.IsValid()) {
         parsing_result->first_initializer_loc = variable_loc;
       }
 
       // Don't infer if it is "a = function(){...}();"-like expression.
-      if (single_name && fni_ != nullptr) {
+      if (single_name) {
         if (!value->IsCall() && !value->IsCallNew()) {
-          fni_->Infer();
+          fni_.Infer();
         } else {
-          fni_->RemoveLastFunction();
+          fni_.RemoveLastFunction();
         }
       }
 
       impl()->SetFunctionNameFromIdentifierRef(value, pattern);
 
       // End position of the initializer is after the assignment expression.
-      initializer_position = scanner()->location().end_pos;
+      initializer_position = end_position();
     } else {
       if (var_context != kForStatement || !PeekInOrOf()) {
         // ES6 'const' and binding patterns require initializers.
         if (parsing_result->descriptor.mode == VariableMode::kConst ||
             !impl()->IsIdentifier(pattern)) {
           impl()->ReportMessageAt(
-              Scanner::Location(decl_pos, scanner()->location().end_pos),
+              Scanner::Location(decl_pos, end_position()),
               MessageTemplate::kDeclarationMissingInitializer,
               !impl()->IsIdentifier(pattern) ? "destructuring" : "const");
           *ok = false;
@@ -3998,7 +3991,7 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseVariableDeclarations(
   } while (Check(Token::COMMA));
 
   parsing_result->bindings_loc =
-      Scanner::Location(bindings_start, scanner()->location().end_pos);
+      Scanner::Location(bindings_start, end_position());
 
   DCHECK(*ok);
   return init_block;
@@ -4009,7 +4002,7 @@ typename ParserBase<Impl>::StatementT
 ParserBase<Impl>::ParseFunctionDeclaration(bool* ok) {
   Consume(Token::FUNCTION);
   int pos = position();
-  ParseFunctionFlags flags = ParseFunctionFlags::kIsNormal;
+  ParseFunctionFlags flags = ParseFunctionFlag::kIsNormal;
   if (Check(Token::MUL)) {
     impl()->ReportMessageAt(
         scanner()->location(),
@@ -4026,9 +4019,9 @@ ParserBase<Impl>::ParseHoistableDeclaration(
     ZonePtrList<const AstRawString>* names, bool default_export, bool* ok) {
   Expect(Token::FUNCTION, CHECK_OK_CUSTOM(NullStatement));
   int pos = position();
-  ParseFunctionFlags flags = ParseFunctionFlags::kIsNormal;
+  ParseFunctionFlags flags = ParseFunctionFlag::kIsNormal;
   if (Check(Token::MUL)) {
-    flags |= ParseFunctionFlags::kIsGenerator;
+    flags |= ParseFunctionFlag::kIsGenerator;
   }
   return ParseHoistableDeclaration(pos, flags, names, default_export, ok);
 }
@@ -4049,13 +4042,12 @@ ParserBase<Impl>::ParseHoistableDeclaration(
   //
   // 'function' and '*' (if present) have been consumed by the caller.
 
-  bool is_generator = flags & ParseFunctionFlags::kIsGenerator;
-  const bool is_async = flags & ParseFunctionFlags::kIsAsync;
-  DCHECK(!is_generator || !is_async);
+  DCHECK_IMPLIES((flags & ParseFunctionFlag::kIsAsync) != 0,
+                 (flags & ParseFunctionFlag::kIsGenerator) == 0);
 
-  if (is_async && Check(Token::MUL)) {
+  if ((flags & ParseFunctionFlag::kIsAsync) != 0 && Check(Token::MUL)) {
     // Async generator
-    is_generator = true;
+    flags |= ParseFunctionFlag::kIsGenerator;
   }
 
   IdentifierT name;
@@ -4074,10 +4066,10 @@ ParserBase<Impl>::ParseHoistableDeclaration(
     variable_name = name;
   }
 
-  FuncNameInferrer::State fni_state(fni_);
+  FuncNameInferrerState fni_state(&fni_);
   impl()->PushEnclosingName(name);
 
-  FunctionKind kind = FunctionKindFor(is_generator, is_async);
+  FunctionKind kind = FunctionKindFor(flags);
 
   FunctionLiteralT function = impl()->ParseFunctionLiteral(
       name, scanner()->location(), name_validity, kind, pos,
@@ -4097,7 +4089,7 @@ ParserBase<Impl>::ParseHoistableDeclaration(
   // a flag and UseCounting violations to assess web compatibility.
   bool is_sloppy_block_function = is_sloppy(language_mode()) &&
                                   !scope()->is_declaration_scope() &&
-                                  !is_async && !is_generator;
+                                  flags == ParseFunctionFlag::kIsNormal;
 
   return impl()->DeclareFunction(variable_name, function, mode, pos,
                                  is_sloppy_block_function, names, ok);
@@ -4187,7 +4179,7 @@ ParserBase<Impl>::ParseAsyncFunctionDeclaration(
     return impl()->NullStatement();
   }
   Expect(Token::FUNCTION, CHECK_OK_CUSTOM(NullStatement));
-  ParseFunctionFlags flags = ParseFunctionFlags::kIsAsync;
+  ParseFunctionFlags flags = ParseFunctionFlag::kIsAsync;
   return ParseHoistableDeclaration(pos, flags, names, default_export, ok);
 }
 
@@ -4195,7 +4187,8 @@ template <typename Impl>
 void ParserBase<Impl>::ParseFunctionBody(
     typename ParserBase<Impl>::StatementListT result, IdentifierT function_name,
     int pos, const FormalParametersT& parameters, FunctionKind kind,
-    FunctionLiteral::FunctionType function_type, bool* ok) {
+    FunctionLiteral::FunctionType function_type, FunctionBodyType body_type,
+    bool accept_IN, bool* ok) {
   DeclarationScope* function_scope = scope()->AsDeclarationScope();
   DeclarationScope* inner_scope = function_scope;
   BlockT inner_block = impl()->NullStatement();
@@ -4209,35 +4202,56 @@ void ParserBase<Impl>::ParseFunctionBody(
     body = inner_block->statements();
   }
 
-  // If we are parsing the source as if it is wrapped in a function, the source
-  // ends without a closing brace.
-  Token::Value closing_token =
-      function_type == FunctionLiteral::kWrapped ? Token::EOS : Token::RBRACE;
-
   {
     BlockState block_state(&scope_, inner_scope);
 
     if (IsResumableFunction(kind)) impl()->PrepareGeneratorVariables();
 
-    if (IsAsyncGeneratorFunction(kind)) {
-      impl()->ParseAndRewriteAsyncGeneratorFunctionBody(pos, kind, body, ok);
-    } else if (IsGeneratorFunction(kind)) {
-      impl()->ParseAndRewriteGeneratorFunctionBody(pos, kind, body, ok);
-    } else if (IsAsyncFunction(kind)) {
-      ParseAsyncFunctionBody(inner_scope, body, CHECK_OK_VOID);
+    if (body_type == FunctionBodyType::kExpression) {
+      ExpressionClassifier classifier(this);
+      ExpressionT expression =
+          ParseAssignmentExpression(accept_IN, CHECK_OK_VOID);
+      ValidateExpression(CHECK_OK_VOID);
+
+      if (IsAsyncFunction(kind)) {
+        BlockT block = factory()->NewBlock(1, true);
+        impl()->RewriteAsyncFunctionBody(body, block, expression,
+                                         CHECK_OK_VOID);
+      } else {
+        body->Add(BuildReturnStatement(expression, expression->position()),
+                  zone());
+      }
     } else {
-      ParseStatementList(body, closing_token, CHECK_OK_VOID);
-    }
+      DCHECK(accept_IN);
+      DCHECK_EQ(FunctionBodyType::kBlock, body_type);
+      // If we are parsing the source as if it is wrapped in a function, the
+      // source ends without a closing brace.
+      Token::Value closing_token = function_type == FunctionLiteral::kWrapped
+                                       ? Token::EOS
+                                       : Token::RBRACE;
+
+      if (IsAsyncGeneratorFunction(kind)) {
+        impl()->ParseAndRewriteAsyncGeneratorFunctionBody(pos, kind, body,
+                                                          CHECK_OK_VOID);
+      } else if (IsGeneratorFunction(kind)) {
+        impl()->ParseAndRewriteGeneratorFunctionBody(pos, kind, body,
+                                                     CHECK_OK_VOID);
+      } else if (IsAsyncFunction(kind)) {
+        ParseAsyncFunctionBody(inner_scope, body, CHECK_OK_VOID);
+      } else {
+        ParseStatementList(body, closing_token, CHECK_OK_VOID);
+      }
 
-    if (IsDerivedConstructor(kind)) {
-      body->Add(factory()->NewReturnStatement(impl()->ThisExpression(),
-                                              kNoSourcePosition),
-                zone());
+      if (IsDerivedConstructor(kind)) {
+        body->Add(factory()->NewReturnStatement(impl()->ThisExpression(),
+                                                kNoSourcePosition),
+                  zone());
+      }
+      Expect(closing_token, CHECK_OK_VOID);
     }
   }
 
-  Expect(closing_token, CHECK_OK_VOID);
-  scope()->set_end_position(scanner()->location().end_pos);
+  scope()->set_end_position(end_position());
 
   if (!parameters.is_simple) {
     DCHECK_NOT_NULL(inner_scope);
@@ -4256,7 +4270,7 @@ void ParserBase<Impl>::ParseFunctionBody(
       init_block = impl()->BuildRejectPromiseOnException(init_block);
     }
 
-    inner_scope->set_end_position(scanner()->location().end_pos);
+    inner_scope->set_end_position(end_position());
     if (inner_scope->FinalizeBlockScope() != nullptr) {
       impl()->CheckConflictingVarDeclarations(inner_scope, CHECK_OK_VOID);
       impl()->InsertShadowingVarBindingInitializers(inner_block);
@@ -4315,7 +4329,7 @@ void ParserBase<Impl>::CheckArityRestrictions(int param_count,
 
 template <typename Impl>
 bool ParserBase<Impl>::IsNextLetKeyword() {
-  DCHECK(peek() == Token::LET);
+  DCHECK_EQ(Token::LET, peek());
   Token::Value next_next = PeekAhead();
   switch (next_next) {
     case Token::LBRACE:
@@ -4340,17 +4354,13 @@ bool ParserBase<Impl>::IsNextLetKeyword() {
 
 template <typename Impl>
 bool ParserBase<Impl>::IsTrivialExpression() {
-  Token::Value peek_token = peek();
-  if (peek_token == Token::SMI || peek_token == Token::NUMBER ||
-      peek_token == Token::BIGINT || peek_token == Token::NULL_LITERAL ||
-      peek_token == Token::TRUE_LITERAL || peek_token == Token::FALSE_LITERAL ||
-      peek_token == Token::STRING || peek_token == Token::IDENTIFIER ||
-      peek_token == Token::THIS) {
-    // PeekAhead() is expensive & may not always be called, so we only call it
-    // after checking peek().
+  if (Token::IsTrivialExpressionToken(peek())) {
+    // PeekAhead() may not always be called, so we only call it after checking
+    // peek().
     Token::Value peek_ahead = PeekAhead();
     if (peek_ahead == Token::COMMA || peek_ahead == Token::RPAREN ||
-        peek_ahead == Token::SEMICOLON || peek_ahead == Token::RBRACK) {
+        peek_ahead == Token::SEMICOLON || peek_ahead == Token::RBRACK ||
+        Token::IsAssignmentOp(peek_ahead)) {
       return true;
     }
   }
@@ -4421,39 +4431,52 @@ ParserBase<Impl>::ParseArrowFunctionLiteral(
         // parameters.
         int dummy_num_parameters = -1;
         DCHECK_NE(kind & FunctionKind::kArrowFunction, 0);
-        LazyParsingResult result = impl()->SkipFunction(
+        FunctionLiteral::EagerCompileHint hint;
+        bool did_preparse_successfully = impl()->SkipFunction(
             nullptr, kind, FunctionLiteral::kAnonymousExpression,
             formal_parameters.scope, &dummy_num_parameters,
-            &produced_preparsed_scope_data, false, false, CHECK_OK);
-        DCHECK_NE(result, kLazyParsingAborted);
+            &produced_preparsed_scope_data, false, false, &hint, CHECK_OK);
+
         DCHECK_NULL(produced_preparsed_scope_data);
-        USE(result);
-        formal_parameters.scope->ResetAfterPreparsing(ast_value_factory_,
-                                                      false);
-        // Discard any queued destructuring assignments which appeared
-        // in this function's parameter list, and which were adopted
-        // into this function state, above.
-        function_state.RewindDestructuringAssignments(0);
+
+        if (did_preparse_successfully) {
+          // Discard any queued destructuring assignments which appeared
+          // in this function's parameter list, and which were adopted
+          // into this function state, above.
+          function_state.RewindDestructuringAssignments(0);
+        } else {
+          // In case we did not sucessfully preparse the function because of an
+          // unidentified error we do a full reparse to return the error.
+          Consume(Token::LBRACE);
+          body = impl()->NewStatementList(8);
+          ParseFunctionBody(body, impl()->NullIdentifier(), kNoSourcePosition,
+                            formal_parameters, kind,
+                            FunctionLiteral::kAnonymousExpression,
+                            FunctionBodyType::kBlock, true, ok);
+          CHECK(!*ok);
+          return impl()->NullExpression();
+        }
       } else {
         Consume(Token::LBRACE);
         body = impl()->NewStatementList(8);
         ParseFunctionBody(body, impl()->NullIdentifier(), kNoSourcePosition,
                           formal_parameters, kind,
-                          FunctionLiteral::kAnonymousExpression, CHECK_OK);
+                          FunctionLiteral::kAnonymousExpression,
+                          FunctionBodyType::kBlock, true, CHECK_OK);
         expected_property_count = function_state.expected_property_count();
       }
     } else {
       // Single-expression body
       has_braces = false;
-      const bool is_async = IsAsyncFunction(kind);
       body = impl()->NewStatementList(1);
-      impl()->AddParameterInitializationBlock(formal_parameters, body, is_async,
-                                              CHECK_OK);
-      ParseSingleExpressionFunctionBody(body, is_async, accept_IN, CHECK_OK);
+      ParseFunctionBody(body, impl()->NullIdentifier(), kNoSourcePosition,
+                        formal_parameters, kind,
+                        FunctionLiteral::kAnonymousExpression,
+                        FunctionBodyType::kExpression, accept_IN, CHECK_OK);
       expected_property_count = function_state.expected_property_count();
     }
 
-    formal_parameters.scope->set_end_position(scanner()->location().end_pos);
+    formal_parameters.scope->set_end_position(end_position());
 
     // Arrow function formal parameters are parsed as StrictFormalParameterList,
     // which is not the same as "parameters of a strict function"; it only means
@@ -4466,7 +4489,7 @@ ParserBase<Impl>::ParseArrowFunctionLiteral(
     // Validate strict mode.
     if (is_strict(language_mode())) {
       CheckStrictOctalLiteral(formal_parameters.scope->start_position(),
-                              scanner()->location().end_pos, CHECK_OK);
+                              end_position(), CHECK_OK);
     }
     impl()->CheckConflictingVarDeclarations(formal_parameters.scope, CHECK_OK);
 
@@ -4532,9 +4555,9 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
   class_info.is_anonymous = is_anonymous;
   impl()->DeclareClassVariable(name, &class_info, class_token_pos, CHECK_OK);
 
-  scope()->set_start_position(scanner()->location().end_pos);
+  scope()->set_start_position(end_position());
   if (Check(Token::EXTENDS)) {
-    FuncNameInferrer::State fni_state(fni_);
+    FuncNameInferrerState fni_state(&fni_);
     ExpressionClassifier extends_classifier(this);
     class_info.extends = ParseLeftHandSideExpression(CHECK_OK);
     ValidateExpression(CHECK_OK);
@@ -4548,7 +4571,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
   const bool has_extends = !impl()->IsNull(class_info.extends);
   while (peek() != Token::RBRACE) {
     if (Check(Token::SEMICOLON)) continue;
-    FuncNameInferrer::State fni_state(fni_);
+    FuncNameInferrerState fni_state(&fni_);
     bool is_computed_name = false;  // Classes do not care about computed
                                     // property names here.
     bool is_static;
@@ -4580,32 +4603,13 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
   }
 
   Expect(Token::RBRACE, CHECK_OK);
-  int end_pos = scanner()->location().end_pos;
+  int end_pos = end_position();
   block_scope->set_end_position(end_pos);
   return impl()->RewriteClassLiteral(block_scope, name, &class_info,
                                      class_token_pos, end_pos, ok);
 }
 
 template <typename Impl>
-void ParserBase<Impl>::ParseSingleExpressionFunctionBody(StatementListT body,
-                                                         bool is_async,
-                                                         bool accept_IN,
-                                                         bool* ok) {
-  if (is_async) impl()->PrepareGeneratorVariables();
-
-  ExpressionClassifier classifier(this);
-  ExpressionT expression = ParseAssignmentExpression(accept_IN, CHECK_OK_VOID);
-  ValidateExpression(CHECK_OK_VOID);
-
-  if (is_async) {
-    BlockT block = factory()->NewBlock(1, true);
-    impl()->RewriteAsyncFunctionBody(body, block, expression, CHECK_OK_VOID);
-  } else {
-    body->Add(BuildReturnStatement(expression, expression->position()), zone());
-  }
-}
-
-template <typename Impl>
 void ParserBase<Impl>::ParseAsyncFunctionBody(Scope* scope, StatementListT body,
                                               bool* ok) {
   BlockT block = factory()->NewBlock(8, true);
@@ -4614,7 +4618,7 @@ void ParserBase<Impl>::ParseAsyncFunctionBody(Scope* scope, StatementListT body,
   impl()->RewriteAsyncFunctionBody(
       body, block, factory()->NewUndefinedLiteral(kNoSourcePosition),
       CHECK_OK_VOID);
-  scope->set_end_position(scanner()->location().end_pos);
+  scope->set_end_position(end_position());
 }
 
 template <typename Impl>
@@ -4633,9 +4637,9 @@ ParserBase<Impl>::ParseAsyncFunctionLiteral(bool* ok) {
   IdentifierT name = impl()->NullIdentifier();
   FunctionLiteral::FunctionType type = FunctionLiteral::kAnonymousExpression;
 
-  bool is_generator = Check(Token::MUL);
-  const bool kIsAsync = true;
-  const FunctionKind kind = FunctionKindFor(is_generator, kIsAsync);
+  ParseFunctionFlags flags = ParseFunctionFlag::kIsAsync;
+  if (Check(Token::MUL)) flags |= ParseFunctionFlag::kIsGenerator;
+  const FunctionKind kind = FunctionKindFor(flags);
 
   if (impl()->ParsingDynamicFunctionDeclaration()) {
     // We don't want dynamic functions to actually declare their name
@@ -4659,7 +4663,7 @@ ParserBase<Impl>::ParseAsyncFunctionLiteral(bool* ok) {
       name, scanner()->location(),
       is_strict_reserved ? kFunctionNameIsStrictReserved
                          : kFunctionNameValidityUnknown,
-      kind, pos, type, language_mode(), nullptr, CHECK_OK);
+      kind, pos, type, language_mode(), nullptr, ok);
 }
 
 template <typename Impl>
@@ -5112,6 +5116,7 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
   Expect(Token::LBRACE, CHECK_OK_CUSTOM(NullStatement));
   {
     BlockState block_state(zone(), &scope_);
+    // Scope starts before opening brace.
     scope()->set_start_position(scanner()->location().beg_pos);
     typename Types::Target target(this, body);
 
@@ -5123,9 +5128,10 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
     }
 
     Expect(Token::RBRACE, CHECK_OK_CUSTOM(NullStatement));
-    int end_pos = scanner()->location().end_pos;
-    scope()->set_end_position(end_pos);
-    impl()->RecordBlockSourceRange(body, end_pos);
+    // Scope ends after closing brace.
+    scope()->set_end_position(scanner()->location().end_pos);
+    // Coverage range uses position before closing brace.
+    impl()->RecordBlockSourceRange(body, scanner()->location().beg_pos);
     body->set_scope(scope()->FinalizeBlockScope());
   }
   return body;
@@ -5144,7 +5150,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseScopedStatement(
     BlockT block = factory()->NewBlock(1, false);
     StatementT body = ParseFunctionDeclaration(CHECK_OK);
     block->statements()->Add(body, zone());
-    scope()->set_end_position(scanner()->location().end_pos);
+    scope()->set_end_position(end_position());
     block->set_scope(scope()->FinalizeBlockScope());
     return block;
   }
@@ -5172,7 +5178,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseVariableStatement(
   DeclarationParsingResult parsing_result;
   StatementT result =
       ParseVariableDeclarations(var_context, &parsing_result, names, CHECK_OK);
-  ExpectSemicolon(CHECK_OK);
+  ExpectSemicolon(ok);
   return result;
 }
 
@@ -5234,7 +5240,7 @@ ParserBase<Impl>::ParseExpressionOrLabelledStatement(
   }
 
   bool starts_with_identifier = peek_any_identifier();
-  ExpressionT expr = ParseExpression(true, CHECK_OK);
+  ExpressionT expr = ParseExpression(CHECK_OK);
   if (peek() == Token::COLON && starts_with_identifier &&
       impl()->IsIdentifier(expr)) {
     // The whole expression was a single identifier, and not, e.g.,
@@ -5273,7 +5279,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseIfStatement(
   int pos = peek_position();
   Expect(Token::IF, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
-  ExpressionT condition = ParseExpression(true, CHECK_OK);
+  ExpressionT condition = ParseExpression(CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   SourceRange then_range, else_range;
@@ -5285,9 +5291,8 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseIfStatement(
 
   StatementT else_statement = impl()->NullStatement();
   if (Check(Token::ELSE)) {
-    else_range = SourceRange::ContinuationOf(then_range);
     else_statement = ParseScopedStatement(labels, CHECK_OK);
-    else_range.end = scanner_->location().end_pos;
+    else_range = SourceRange::ContinuationOf(then_range, end_position());
   } else {
     else_statement = factory()->NewEmptyStatement(kNoSourcePosition);
   }
@@ -5330,7 +5335,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseContinueStatement(
   }
   ExpectSemicolon(CHECK_OK);
   StatementT stmt = factory()->NewContinueStatement(target, pos);
-  impl()->RecordJumpStatementSourceRange(stmt, scanner_->location().end_pos);
+  impl()->RecordJumpStatementSourceRange(stmt, end_position());
   return stmt;
 }
 
@@ -5369,7 +5374,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseBreakStatement(
   }
   ExpectSemicolon(CHECK_OK);
   StatementT stmt = factory()->NewBreakStatement(target, pos);
-  impl()->RecordJumpStatementSourceRange(stmt, scanner_->location().end_pos);
+  impl()->RecordJumpStatementSourceRange(stmt, end_position());
   return stmt;
 }
 
@@ -5404,14 +5409,14 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseReturnStatement(
       return_value = impl()->ThisExpression(loc.beg_pos);
     }
   } else {
-    return_value = ParseExpression(true, CHECK_OK);
+    return_value = ParseExpression(CHECK_OK);
   }
   ExpectSemicolon(CHECK_OK);
   return_value = impl()->RewriteReturn(return_value, loc.beg_pos);
-  int continuation_pos = scanner_->location().end_pos;
+  int continuation_pos = end_position();
   StatementT stmt =
       BuildReturnStatement(return_value, loc.beg_pos, continuation_pos);
-  impl()->RecordJumpStatementSourceRange(stmt, scanner_->location().end_pos);
+  impl()->RecordJumpStatementSourceRange(stmt, end_position());
   return stmt;
 }
 
@@ -5431,7 +5436,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseWithStatement(
   }
 
   Expect(Token::LPAREN, CHECK_OK);
-  ExpressionT expr = ParseExpression(true, CHECK_OK);
+  ExpressionT expr = ParseExpression(CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   Scope* with_scope = NewScope(WITH_SCOPE);
@@ -5440,7 +5445,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseWithStatement(
     BlockState block_state(&scope_, with_scope);
     with_scope->set_start_position(scanner()->peek_location().beg_pos);
     body = ParseStatement(labels, nullptr, CHECK_OK);
-    with_scope->set_end_position(scanner()->location().end_pos);
+    with_scope->set_end_position(end_position());
   }
   return factory()->NewWithStatement(with_scope, expr, body, pos);
 }
@@ -5467,7 +5472,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseDoWhileStatement(
   Expect(Token::WHILE, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
 
-  ExpressionT cond = ParseExpression(true, CHECK_OK);
+  ExpressionT cond = ParseExpression(CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   // Allow do-statements to be terminated with and without
@@ -5497,7 +5502,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseWhileStatement(
 
   Expect(Token::WHILE, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
-  ExpressionT cond = ParseExpression(true, CHECK_OK);
+  ExpressionT cond = ParseExpression(CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
   {
     SourceRangeScope range_scope(scanner(), &body_range);
@@ -5523,11 +5528,11 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseThrowStatement(
     *ok = false;
     return impl()->NullStatement();
   }
-  ExpressionT exception = ParseExpression(true, CHECK_OK);
+  ExpressionT exception = ParseExpression(CHECK_OK);
   ExpectSemicolon(CHECK_OK);
 
   StatementT stmt = impl()->NewThrowStatement(exception, pos);
-  impl()->RecordThrowSourceRange(stmt, scanner_->location().end_pos);
+  impl()->RecordThrowSourceRange(stmt, end_position());
 
   return stmt;
 }
@@ -5545,7 +5550,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseSwitchStatement(
 
   Expect(Token::SWITCH, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
-  ExpressionT tag = ParseExpression(true, CHECK_OK);
+  ExpressionT tag = ParseExpression(CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   auto switch_statement =
@@ -5565,7 +5570,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseSwitchStatement(
       SourceRange clause_range;
       SourceRangeScope range_scope(scanner(), &clause_range);
       if (Check(Token::CASE)) {
-        label = ParseExpression(true, CHECK_OK);
+        label = ParseExpression(CHECK_OK);
       } else {
         Expect(Token::DEFAULT, CHECK_OK);
         if (default_seen) {
@@ -5588,9 +5593,9 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseSwitchStatement(
     }
     Expect(Token::RBRACE, CHECK_OK);
 
-    int end_position = scanner()->location().end_pos;
-    scope()->set_end_position(end_position);
-    impl()->RecordSwitchStatementSourceRange(switch_statement, end_position);
+    int end_pos = end_position();
+    scope()->set_end_position(end_pos);
+    impl()->RecordSwitchStatementSourceRange(switch_statement, end_pos);
     Scope* switch_scope = scope()->FinalizeBlockScope();
     if (switch_scope != nullptr) {
       return impl()->RewriteSwitchStatement(switch_statement, switch_scope);
@@ -5659,8 +5664,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseTryStatement(
                   ParseIdentifier(kDontAllowRestrictedIdentifiers, CHECK_OK);
             } else {
               ExpressionClassifier pattern_classifier(this);
-              catch_info.pattern = ParsePrimaryExpression(CHECK_OK);
-              ValidateBindingPattern(CHECK_OK);
+              catch_info.pattern = ParseBindingPattern(CHECK_OK);
             }
 
             Expect(Token::RPAREN, CHECK_OK);
@@ -5672,12 +5676,12 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseTryStatement(
             catch_info.inner_block = ParseBlock(nullptr, CHECK_OK);
             catch_block->statements()->Add(catch_info.inner_block, zone());
             impl()->ValidateCatchBlock(catch_info, CHECK_OK);
-            scope()->set_end_position(scanner()->location().end_pos);
+            scope()->set_end_position(end_position());
             catch_block->set_scope(scope()->FinalizeBlockScope());
           }
         }
 
-        catch_info.scope->set_end_position(scanner()->location().end_pos);
+        catch_info.scope->set_end_position(end_position());
       } else {
         catch_block = ParseBlock(nullptr, CHECK_OK);
       }
@@ -5777,7 +5781,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForStatement(
     int lhs_beg_pos = peek_position();
     ExpressionClassifier classifier(this);
     ExpressionT expression = ParseExpressionCoverGrammar(false, CHECK_OK);
-    int lhs_end_pos = scanner()->location().end_pos;
+    int lhs_end_pos = end_position();
 
     bool is_for_each = CheckInOrOf(&for_info.mode);
     bool is_destructuring = is_for_each && (expression->IsArrayLiteral() ||
@@ -5853,7 +5857,7 @@ ParserBase<Impl>::ParseForEachStatementWithDeclarations(
     enumerable = ParseAssignmentExpression(true, CHECK_OK);
     ValidateExpression(CHECK_OK);
   } else {
-    enumerable = ParseExpression(true, CHECK_OK);
+    enumerable = ParseExpression(CHECK_OK);
   }
 
   Expect(Token::RPAREN, CHECK_OK);
@@ -5861,7 +5865,7 @@ ParserBase<Impl>::ParseForEachStatementWithDeclarations(
   Scope* for_scope = nullptr;
   if (inner_block_scope != nullptr) {
     for_scope = inner_block_scope->outer_scope();
-    DCHECK(for_scope == scope());
+    DCHECK_EQ(for_scope, scope());
     inner_block_scope->set_start_position(scanner()->location().beg_pos);
   }
 
@@ -5882,7 +5886,7 @@ ParserBase<Impl>::ParseForEachStatementWithDeclarations(
     body_block->statements()->Add(body, zone());
 
     if (inner_block_scope != nullptr) {
-      inner_block_scope->set_end_position(scanner()->location().end_pos);
+      inner_block_scope->set_end_position(end_position());
       body_block->set_scope(inner_block_scope->FinalizeBlockScope());
     }
   }
@@ -5890,10 +5894,11 @@ ParserBase<Impl>::ParseForEachStatementWithDeclarations(
   StatementT final_loop = impl()->InitializeForEachStatement(
       loop, each_variable, enumerable, body_block);
 
-  init_block = impl()->CreateForEachStatementTDZ(init_block, *for_info, ok);
+  init_block =
+      impl()->CreateForEachStatementTDZ(init_block, *for_info, CHECK_OK);
 
   if (for_scope != nullptr) {
-    for_scope->set_end_position(scanner()->location().end_pos);
+    for_scope->set_end_position(end_position());
     for_scope = for_scope->FinalizeBlockScope();
   }
 
@@ -5931,7 +5936,7 @@ ParserBase<Impl>::ParseForEachStatementWithoutDeclarations(
     enumerable = ParseAssignmentExpression(true, CHECK_OK);
     ValidateExpression(CHECK_OK);
   } else {
-    enumerable = ParseExpression(true, CHECK_OK);
+    enumerable = ParseExpression(CHECK_OK);
   }
 
   Expect(Token::RPAREN, CHECK_OK);
@@ -5965,10 +5970,10 @@ ParserBase<Impl>::ParseStandardForLoopWithLexicalDeclarations(
     scope()->set_start_position(scanner()->location().beg_pos);
     loop = ParseStandardForLoop(stmt_pos, labels, own_labels, &cond, &next,
                                 &body, CHECK_OK);
-    scope()->set_end_position(scanner()->location().end_pos);
+    scope()->set_end_position(end_position());
   }
 
-  scope()->set_end_position(scanner()->location().end_pos);
+  scope()->set_end_position(end_position());
   if (for_info->bound_names.length() > 0 &&
       function_state_->contains_function_or_eval()) {
     scope()->set_is_hidden();
@@ -6014,12 +6019,12 @@ typename ParserBase<Impl>::ForStatementT ParserBase<Impl>::ParseStandardForLoop(
   typename Types::Target target(this, loop);
 
   if (peek() != Token::SEMICOLON) {
-    *cond = ParseExpression(true, CHECK_OK);
+    *cond = ParseExpression(CHECK_OK);
   }
   Expect(Token::SEMICOLON, CHECK_OK);
 
   if (peek() != Token::RPAREN) {
-    ExpressionT exp = ParseExpression(true, CHECK_OK);
+    ExpressionT exp = ParseExpression(CHECK_OK);
     *next = factory()->NewExpressionStatement(exp, exp->position());
   }
   Expect(Token::RPAREN, CHECK_OK);
@@ -6114,7 +6119,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForAwaitStatement(
     BlockState inner_state(&scope_, inner_block_scope);
     ExpressionClassifier classifier(this);
     ExpressionT lhs = each_variable = ParseLeftHandSideExpression(CHECK_OK);
-    int lhs_end_pos = scanner()->location().end_pos;
+    int lhs_end_pos = end_position();
 
     if (lhs->IsArrayLiteral() || lhs->IsObjectLiteral()) {
       ValidateAssignmentPattern(CHECK_OK);
@@ -6149,7 +6154,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForAwaitStatement(
     SourceRangeScope range_scope(scanner(), &body_range);
 
     body = ParseStatement(nullptr, nullptr, CHECK_OK);
-    scope()->set_end_position(scanner()->location().end_pos);
+    scope()->set_end_position(end_position());
     impl()->RecordIterationStatementSourceRange(loop, range_scope.Finalize());
 
     if (has_declarations) {
@@ -6177,10 +6182,10 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForAwaitStatement(
     return final_loop;
   }
 
-  BlockT init_block =
-      impl()->CreateForEachStatementTDZ(impl()->NullStatement(), for_info, ok);
+  BlockT init_block = impl()->CreateForEachStatementTDZ(impl()->NullStatement(),
+                                                        for_info, CHECK_OK);
 
-  scope()->set_end_position(scanner()->location().end_pos);
+  scope()->set_end_position(end_position());
   Scope* for_scope = scope()->FinalizeBlockScope();
   // Parsed for-in loop w/ variable declarations.
   if (!impl()->IsNull(init_block)) {
@@ -6209,10 +6214,9 @@ void ParserBase<Impl>::ObjectLiteralChecker::CheckDuplicateProto(
 
 template <typename Impl>
 void ParserBase<Impl>::ClassLiteralChecker::CheckClassMethodName(
-    Token::Value property, PropertyKind type, bool is_generator, bool is_async,
+    Token::Value property, ParsePropertyKind type, ParseFunctionFlags flags,
     bool is_static, bool* ok) {
-  DCHECK(type == PropertyKind::kMethodProperty ||
-         type == PropertyKind::kAccessorProperty);
+  DCHECK(type == ParsePropertyKind::kMethod || IsAccessor(type));
 
   if (property == Token::SMI || property == Token::NUMBER) return;
 
@@ -6223,11 +6227,13 @@ void ParserBase<Impl>::ClassLiteralChecker::CheckClassMethodName(
       return;
     }
   } else if (IsConstructor()) {
-    if (is_generator || is_async || type == PropertyKind::kAccessorProperty) {
+    if (flags != ParseFunctionFlag::kIsNormal || IsAccessor(type)) {
       MessageTemplate::Template msg =
-          is_generator ? MessageTemplate::kConstructorIsGenerator
-                       : is_async ? MessageTemplate::kConstructorIsAsync
-                                  : MessageTemplate::kConstructorIsAccessor;
+          (flags & ParseFunctionFlag::kIsGenerator) != 0
+              ? MessageTemplate::kConstructorIsGenerator
+              : (flags & ParseFunctionFlag::kIsAsync) != 0
+                    ? MessageTemplate::kConstructorIsAsync
+                    : MessageTemplate::kConstructorIsAccessor;
       this->parser()->ReportMessage(msg);
       *ok = false;
       return;
diff --git a/deps/v8/src/parsing/parser.cc b/deps/v8/src/parsing/parser.cc
index 41ff551091..6d0d9fff21 100644
--- a/deps/v8/src/parsing/parser.cc
+++ b/deps/v8/src/parsing/parser.cc
@@ -29,56 +29,6 @@
 namespace v8 {
 namespace internal {
 
-
-
-// Helper for putting parts of the parse results into a temporary zone when
-// parsing inner function bodies.
-class DiscardableZoneScope {
- public:
-  DiscardableZoneScope(Parser* parser, Zone* temp_zone, bool use_temp_zone)
-      : fni_(parser->ast_value_factory_, temp_zone),
-        parser_(parser),
-        prev_fni_(parser->fni_),
-        prev_zone_(parser->zone_),
-        prev_allow_lazy_(parser->allow_lazy_),
-        prev_temp_zoned_(parser->temp_zoned_) {
-    if (use_temp_zone) {
-      DCHECK(!parser_->temp_zoned_);
-      parser_->allow_lazy_ = false;
-      parser_->temp_zoned_ = true;
-      parser_->fni_ = &fni_;
-      parser_->zone_ = temp_zone;
-      parser_->factory()->set_zone(temp_zone);
-      if (parser_->reusable_preparser_ != nullptr) {
-        parser_->reusable_preparser_->zone_ = temp_zone;
-        parser_->reusable_preparser_->factory()->set_zone(temp_zone);
-      }
-    }
-  }
-  void Reset() {
-    parser_->fni_ = prev_fni_;
-    parser_->zone_ = prev_zone_;
-    parser_->factory()->set_zone(prev_zone_);
-    parser_->allow_lazy_ = prev_allow_lazy_;
-    parser_->temp_zoned_ = prev_temp_zoned_;
-    if (parser_->reusable_preparser_ != nullptr) {
-      parser_->reusable_preparser_->zone_ = prev_zone_;
-      parser_->reusable_preparser_->factory()->set_zone(prev_zone_);
-    }
-  }
-  ~DiscardableZoneScope() { Reset(); }
-
- private:
-  FuncNameInferrer fni_;
-  Parser* parser_;
-  FuncNameInferrer* prev_fni_;
-  Zone* prev_zone_;
-  bool prev_allow_lazy_;
-  bool prev_temp_zoned_;
-
-  DISALLOW_COPY_AND_ASSIGN(DiscardableZoneScope);
-};
-
 FunctionLiteral* Parser::DefaultConstructor(const AstRawString* name,
                                             bool call_super, int pos,
                                             int end_pos) {
@@ -414,12 +364,12 @@ Parser::Parser(ParseInfo* info)
                          info->is_module(), true),
       scanner_(info->unicode_cache(), info->character_stream(),
                info->is_module()),
+      preparser_zone_(info->zone()->allocator(), ZONE_NAME),
       reusable_preparser_(nullptr),
       mode_(PARSE_EAGERLY),  // Lazy mode must be set explicitly.
       source_range_map_(info->source_range_map()),
       target_stack_(nullptr),
       total_preparse_skipped_(0),
-      temp_zoned_(false),
       consumed_preparsed_scope_data_(info->consumed_preparsed_scope_data()),
       parameters_end_pos_(info->parameters_end_pos()) {
   // Even though we were passed ParseInfo, we should not store it in
@@ -449,7 +399,6 @@ Parser::Parser(ParseInfo* info)
   set_allow_harmony_static_fields(FLAG_harmony_static_fields);
   set_allow_harmony_dynamic_import(FLAG_harmony_dynamic_import);
   set_allow_harmony_import_meta(FLAG_harmony_import_meta);
-  set_allow_harmony_bigint(FLAG_harmony_bigint);
   set_allow_harmony_numeric_separator(FLAG_harmony_numeric_separator);
   set_allow_harmony_private_fields(FLAG_harmony_private_fields);
   for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
@@ -458,22 +407,27 @@ Parser::Parser(ParseInfo* info)
   }
 }
 
-void Parser::DeserializeScopeChain(
-    Isolate* isolate, ParseInfo* info,
-    MaybeHandle<ScopeInfo> maybe_outer_scope_info) {
+void Parser::InitializeEmptyScopeChain(ParseInfo* info) {
+  DCHECK_NULL(original_scope_);
+  DCHECK_NULL(info->script_scope());
   // TODO(wingo): Add an outer SCRIPT_SCOPE corresponding to the native
   // context, which will have the "this" binding for script scopes.
   DeclarationScope* script_scope = NewScriptScope();
   info->set_script_scope(script_scope);
-  Scope* scope = script_scope;
+  original_scope_ = script_scope;
+}
+
+void Parser::DeserializeScopeChain(
+    Isolate* isolate, ParseInfo* info,
+    MaybeHandle<ScopeInfo> maybe_outer_scope_info) {
+  InitializeEmptyScopeChain(info);
   Handle<ScopeInfo> outer_scope_info;
   if (maybe_outer_scope_info.ToHandle(&outer_scope_info)) {
     DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
-    scope = Scope::DeserializeScopeChain(
-        isolate, zone(), *outer_scope_info, script_scope, ast_value_factory(),
-        Scope::DeserializationMode::kScopesOnly);
+    original_scope_ = Scope::DeserializeScopeChain(
+        isolate, zone(), *outer_scope_info, info->script_scope(),
+        ast_value_factory(), Scope::DeserializationMode::kScopesOnly);
   }
-  original_scope_ = scope;
 }
 
 namespace {
@@ -503,7 +457,6 @@ FunctionLiteral* Parser::ParseProgram(Isolate* isolate, ParseInfo* info) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.ParseProgram");
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
-  fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
 
   // Initialize parser state.
   DeserializeScopeChain(isolate, info, info->maybe_outer_scope_info());
@@ -749,8 +702,7 @@ FunctionLiteral* Parser::DoParseFunction(Isolate* isolate, ParseInfo* info,
   DCHECK_NULL(target_stack_);
 
   DCHECK(ast_value_factory());
-  fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
-  fni_->PushEnclosingName(raw_name);
+  fni_.PushEnclosingName(raw_name);
 
   ResetFunctionLiteralId();
   DCHECK_LT(0, info->function_literal_id());
@@ -2584,116 +2536,71 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
   int function_literal_id = GetNextFunctionLiteralId();
   ProducedPreParsedScopeData* produced_preparsed_scope_data = nullptr;
 
-  Zone* outer_zone = zone();
-  DeclarationScope* scope;
-
-  {
-    // Temporary zones can nest. When we migrate free variables (see below), we
-    // need to recreate them in the previous Zone.
-    AstNodeFactory previous_zone_ast_node_factory(ast_value_factory(), zone());
-
-    // Open a new zone scope, which sets our AstNodeFactory to allocate in the
-    // new temporary zone if the preconditions are satisfied, and ensures that
-    // the previous zone is always restored after parsing the body. To be able
-    // to do scope analysis correctly after full parsing, we migrate needed
-    // information when the function is parsed.
-    Zone temp_zone(zone()->allocator(), ZONE_NAME);
-    DiscardableZoneScope zone_scope(this, &temp_zone, should_preparse);
-
-    // This Scope lives in the main zone. We'll migrate data into that zone
-    // later.
-    scope = NewFunctionScope(kind, outer_zone);
-    SetLanguageMode(scope, language_mode);
+  // This Scope lives in the main zone. We'll migrate data into that zone later.
+  Zone* parse_zone = should_preparse ? &preparser_zone_ : zone();
+  DeclarationScope* scope = NewFunctionScope(kind, parse_zone);
+  SetLanguageMode(scope, language_mode);
 #ifdef DEBUG
-    scope->SetScopeName(function_name);
-    if (should_preparse) scope->set_needs_migration();
+  scope->SetScopeName(function_name);
 #endif
 
-    if (!is_wrapped) Expect(Token::LPAREN, CHECK_OK);
-    scope->set_start_position(scanner()->location().beg_pos);
-
-    // Eager or lazy parse? If is_lazy_top_level_function, we'll parse
-    // lazily. We'll call SkipFunction, which may decide to
-    // abort lazy parsing if it suspects that wasn't a good idea. If so (in
-    // which case the parser is expected to have backtracked), or if we didn't
-    // try to lazy parse in the first place, we'll have to parse eagerly.
-    if (should_preparse) {
-      DCHECK(parse_lazily());
-      DCHECK(is_lazy_top_level_function || is_lazy_inner_function);
-      DCHECK(!is_wrapped);
-      Scanner::BookmarkScope bookmark(scanner());
-      bookmark.Set();
-      LazyParsingResult result = SkipFunction(
-          function_name, kind, function_type, scope, &num_parameters,
-          &produced_preparsed_scope_data, is_lazy_inner_function,
-          is_lazy_top_level_function, CHECK_OK);
-
-      if (result == kLazyParsingAborted) {
-        DCHECK(is_lazy_top_level_function);
-        bookmark.Apply();
-        // This is probably an initialization function. Inform the compiler it
-        // should also eager-compile this function.
-        eager_compile_hint = FunctionLiteral::kShouldEagerCompile;
-        scope->ResetAfterPreparsing(ast_value_factory(), true);
-        zone_scope.Reset();
-        // Trigger eager (re-)parsing, just below this block.
-        should_preparse = false;
-      }
-    }
-
-    if (should_preparse) {
-      scope->AnalyzePartially(&previous_zone_ast_node_factory);
-    } else {
-      body = ParseFunction(
-          function_name, pos, kind, function_type, scope, &num_parameters,
-          &function_length, &has_duplicate_parameters, &expected_property_count,
-          &suspend_count, arguments_for_wrapped_function, CHECK_OK);
-    }
-
-    DCHECK_EQ(should_preparse, temp_zoned_);
-    if (V8_UNLIKELY(FLAG_log_function_events)) {
-      double ms = timer.Elapsed().InMillisecondsF();
-      const char* event_name = should_preparse
-                                   ? (is_top_level ? "preparse-no-resolution"
-                                                   : "preparse-resolution")
-                                   : "full-parse";
-      logger_->FunctionEvent(
-          event_name, script_id(), ms, scope->start_position(),
-          scope->end_position(),
-          reinterpret_cast<const char*>(function_name->raw_data()),
-          function_name->byte_length());
-    }
-    if (V8_UNLIKELY(FLAG_runtime_stats)) {
-      if (should_preparse) {
-        RuntimeCallCounterId counter_id =
-            parsing_on_main_thread_
-                ? RuntimeCallCounterId::kPreParseWithVariableResolution
-                : RuntimeCallCounterId::
-                      kPreParseBackgroundWithVariableResolution;
-        if (is_top_level) {
-          counter_id = parsing_on_main_thread_
-                           ? RuntimeCallCounterId::kPreParseNoVariableResolution
-                           : RuntimeCallCounterId::
-                                 kPreParseBackgroundNoVariableResolution;
-        }
-        if (runtime_call_stats_) {
-          runtime_call_stats_->CorrectCurrentCounterId(counter_id);
-        }
-      }
+  if (!is_wrapped) Expect(Token::LPAREN, CHECK_OK);
+  scope->set_start_position(position());
+
+  // Eager or lazy parse? If is_lazy_top_level_function, we'll parse
+  // lazily. We'll call SkipFunction, which may decide to
+  // abort lazy parsing if it suspects that wasn't a good idea. If so (in
+  // which case the parser is expected to have backtracked), or if we didn't
+  // try to lazy parse in the first place, we'll have to parse eagerly.
+  bool did_preparse_successfully =
+      should_preparse &&
+      SkipFunction(function_name, kind, function_type, scope, &num_parameters,
+                   &produced_preparsed_scope_data, is_lazy_inner_function,
+                   is_lazy_top_level_function, &eager_compile_hint, CHECK_OK);
+  if (!did_preparse_successfully) {
+    body = ParseFunction(
+        function_name, pos, kind, function_type, scope, &num_parameters,
+        &function_length, &has_duplicate_parameters, &expected_property_count,
+        &suspend_count, arguments_for_wrapped_function, CHECK_OK);
+  }
+
+  if (V8_UNLIKELY(FLAG_log_function_events)) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    const char* event_name =
+        should_preparse
+            ? (is_top_level ? "preparse-no-resolution" : "preparse-resolution")
+            : "full-parse";
+    logger_->FunctionEvent(
+        event_name, script_id(), ms, scope->start_position(),
+        scope->end_position(),
+        reinterpret_cast<const char*>(function_name->raw_data()),
+        function_name->byte_length());
+  }
+  if (V8_UNLIKELY(FLAG_runtime_stats) && did_preparse_successfully) {
+    const RuntimeCallCounterId counters[2][2] = {
+        {RuntimeCallCounterId::kPreParseBackgroundNoVariableResolution,
+         RuntimeCallCounterId::kPreParseNoVariableResolution},
+        {RuntimeCallCounterId::kPreParseBackgroundWithVariableResolution,
+         RuntimeCallCounterId::kPreParseWithVariableResolution}};
+    if (runtime_call_stats_) {
+      bool tracked_variables =
+          PreParser::ShouldTrackUnresolvedVariables(is_lazy_top_level_function);
+      runtime_call_stats_->CorrectCurrentCounterId(
+          counters[tracked_variables][parsing_on_main_thread_]);
     }
+  }
 
-    // Validate function name. We can do this only after parsing the function,
-    // since the function can declare itself strict.
-    language_mode = scope->language_mode();
-    CheckFunctionName(language_mode, function_name, function_name_validity,
-                      function_name_location, CHECK_OK);
+  // Validate function name. We can do this only after parsing the function,
+  // since the function can declare itself strict.
+  language_mode = scope->language_mode();
+  CheckFunctionName(language_mode, function_name, function_name_validity,
+                    function_name_location, CHECK_OK);
 
-    if (is_strict(language_mode)) {
-      CheckStrictOctalLiteral(scope->start_position(), scope->end_position(),
-                              CHECK_OK);
-    }
-    CheckConflictingVarDeclarations(scope, CHECK_OK);
-  }  // DiscardableZoneScope goes out of scope.
+  if (is_strict(language_mode)) {
+    CheckStrictOctalLiteral(scope->start_position(), scope->end_position(),
+                            CHECK_OK);
+  }
+  CheckConflictingVarDeclarations(scope, CHECK_OK);
 
   FunctionLiteral::ParameterFlag duplicate_parameters =
       has_duplicate_parameters ? FunctionLiteral::kHasDuplicateParameters
@@ -2708,19 +2615,20 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
   function_literal->set_suspend_count(suspend_count);
 
   if (should_infer_name) {
-    DCHECK_NOT_NULL(fni_);
-    fni_->AddFunction(function_literal);
+    fni_.AddFunction(function_literal);
   }
   return function_literal;
 }
 
-Parser::LazyParsingResult Parser::SkipFunction(
+bool Parser::SkipFunction(
     const AstRawString* function_name, FunctionKind kind,
     FunctionLiteral::FunctionType function_type,
     DeclarationScope* function_scope, int* num_parameters,
     ProducedPreParsedScopeData** produced_preparsed_scope_data,
-    bool is_inner_function, bool may_abort, bool* ok) {
+    bool is_inner_function, bool may_abort,
+    FunctionLiteral::EagerCompileHint* hint, bool* ok) {
   FunctionState function_state(&function_state_, &scope_, function_scope);
+  function_scope->set_zone(&preparser_zone_);
 
   DCHECK_NE(kNoSourcePosition, function_scope->start_position());
   DCHECK_EQ(kNoSourcePosition, parameters_end_pos_);
@@ -2729,8 +2637,7 @@ Parser::LazyParsingResult Parser::SkipFunction(
                  scanner()->current_token() == Token::ARROW);
 
   // FIXME(marja): There are 2 ways to skip functions now. Unify them.
-  DCHECK_NOT_NULL(consumed_preparsed_scope_data_);
-  if (consumed_preparsed_scope_data_->HasData()) {
+  if (consumed_preparsed_scope_data_) {
     DCHECK(FLAG_preparser_scope_analysis);
     int end_position;
     LanguageMode language_mode;
@@ -2752,9 +2659,13 @@ Parser::LazyParsingResult Parser::SkipFunction(
       function_scope->RecordSuperPropertyUsage();
     }
     SkipFunctionLiterals(num_inner_functions);
-    return kLazyParsingComplete;
+    function_scope->ResetAfterPreparsing(ast_value_factory_, false);
+    return true;
   }
 
+  Scanner::BookmarkScope bookmark(scanner());
+  bookmark.Set();
+
   // With no cached data, we partially parse the function, without building an
   // AST. This gathers the data needed to build a lazy function.
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.PreParse");
@@ -2768,28 +2679,41 @@ Parser::LazyParsingResult Parser::SkipFunction(
       may_abort, use_counts_, produced_preparsed_scope_data, this->script_id());
 
   // Return immediately if pre-parser decided to abort parsing.
-  if (result == PreParser::kPreParseAbort) return kLazyParsingAborted;
+  if (result == PreParser::kPreParseAbort) {
+    bookmark.Apply();
+    function_scope->ResetAfterPreparsing(ast_value_factory(), true);
+    *hint = FunctionLiteral::kShouldEagerCompile;
+    return false;
+  }
+
   if (result == PreParser::kPreParseStackOverflow) {
     // Propagate stack overflow.
     set_stack_overflow();
     *ok = false;
-    return kLazyParsingComplete;
-  }
-  if (pending_error_handler()->has_pending_error()) {
+  } else if (pending_error_handler()->ErrorUnidentifiableByPreParser()) {
+    // If we encounter an error that the preparser can not identify we reset to
+    // the state before preparsing. The caller may then fully parse the function
+    // to identify the actual error.
+    bookmark.Apply();
+    function_scope->ResetAfterPreparsing(ast_value_factory(), true);
+    pending_error_handler()->ResetUnidentifiableError();
+    return false;
+  } else if (pending_error_handler()->has_pending_error()) {
     *ok = false;
-    return kLazyParsingComplete;
-  }
+  } else {
+    set_allow_eval_cache(reusable_preparser()->allow_eval_cache());
 
-  set_allow_eval_cache(reusable_preparser()->allow_eval_cache());
+    PreParserLogger* logger = reusable_preparser()->logger();
+    function_scope->set_end_position(logger->end());
+    Expect(Token::RBRACE, CHECK_OK_VALUE(kLazyParsingComplete));
+    total_preparse_skipped_ +=
+        function_scope->end_position() - function_scope->start_position();
+    *num_parameters = logger->num_parameters();
+    SkipFunctionLiterals(logger->num_inner_functions());
+    function_scope->AnalyzePartially(factory());
+  }
 
-  PreParserLogger* logger = reusable_preparser()->logger();
-  function_scope->set_end_position(logger->end());
-  Expect(Token::RBRACE, CHECK_OK_VALUE(kLazyParsingComplete));
-  total_preparse_skipped_ +=
-      function_scope->end_position() - function_scope->start_position();
-  *num_parameters = logger->num_parameters();
-  SkipFunctionLiterals(logger->num_inner_functions());
-  return kLazyParsingComplete;
+  return true;
 }
 
 Statement* Parser::BuildAssertIsCoercible(Variable* var,
@@ -2863,7 +2787,7 @@ Block* Parser::BuildParameterInitializationBlock(
   DCHECK(!parameters.is_simple);
   DCHECK(scope()->is_function_scope());
   DCHECK_EQ(scope(), parameters.scope);
-  Block* init_block = factory()->NewBlock(1, true);
+  Block* init_block = factory()->NewBlock(parameters.num_parameters(), true);
   int index = 0;
   for (auto parameter : parameters.params) {
     DeclarationDescriptor descriptor;
@@ -3002,19 +2926,6 @@ Block* Parser::BuildRejectPromiseOnException(Block* inner_block) {
   return result;
 }
 
-Expression* Parser::BuildResolvePromise(Expression* value, int pos) {
-  // %ResolvePromise(.promise, value), .promise
-  ZonePtrList<Expression>* args =
-      new (zone()) ZonePtrList<Expression>(2, zone());
-  args->Add(factory()->NewVariableProxy(PromiseVariable()), zone());
-  args->Add(value, zone());
-  Expression* call_runtime =
-      factory()->NewCallRuntime(Runtime::kInlineResolvePromise, args, pos);
-  return factory()->NewBinaryOperation(
-      Token::COMMA, call_runtime,
-      factory()->NewVariableProxy(PromiseVariable()), pos);
-}
-
 Expression* Parser::BuildRejectPromise(Expression* value, int pos) {
   // %promise_internal_reject(.promise, value, false), .promise
   // Disables the additional debug event for the rejection since a debug event
@@ -3038,7 +2949,7 @@ Variable* Parser::PromiseVariable() {
   Variable* promise = function_state_->scope()->promise_var();
   if (promise == nullptr) {
     promise = function_state_->scope()->DeclarePromiseVar(
-        ast_value_factory()->empty_string());
+        ast_value_factory()->dot_promise_string());
   }
   return promise;
 }
@@ -3128,7 +3039,8 @@ ZonePtrList<Statement>* Parser::ParseFunction(
   *function_length = formals.function_length;
 
   ZonePtrList<Statement>* body = new (zone()) ZonePtrList<Statement>(8, zone());
-  ParseFunctionBody(body, function_name, pos, formals, kind, function_type, ok);
+  ParseFunctionBody(body, function_name, pos, formals, kind, function_type,
+                    FunctionBodyType::kBlock, true, ok);
 
   // Validate parameter names. We can do this only after parsing the function,
   // since the function can declare itself strict.
@@ -3238,7 +3150,8 @@ void Parser::DeclareClassProperty(const AstRawString* class_name,
 }
 
 FunctionLiteral* Parser::CreateInitializerFunction(
-    DeclarationScope* scope, ZonePtrList<ClassLiteral::Property>* fields) {
+    const char* name, DeclarationScope* scope,
+    ZonePtrList<ClassLiteral::Property>* fields) {
   DCHECK_EQ(scope->function_kind(),
             FunctionKind::kClassFieldsInitializerFunction);
   // function() { .. class fields initializer .. }
@@ -3247,10 +3160,10 @@ FunctionLiteral* Parser::CreateInitializerFunction(
       factory()->NewInitializeClassFieldsStatement(fields, kNoSourcePosition);
   statements->Add(static_fields, zone());
   return factory()->NewFunctionLiteral(
-      ast_value_factory()->empty_string(), scope, statements, 0, 0, 0,
+      ast_value_factory()->GetOneByteString(name), scope, statements, 0, 0, 0,
       FunctionLiteral::kNoDuplicateParameters,
       FunctionLiteral::kAnonymousExpression,
-      FunctionLiteral::kShouldEagerCompile, scope->start_position(), true,
+      FunctionLiteral::kShouldEagerCompile, scope->start_position(), false,
       GetNextFunctionLiteralId());
 }
 
@@ -3285,13 +3198,15 @@ Expression* Parser::RewriteClassLiteral(Scope* block_scope,
   FunctionLiteral* static_fields_initializer = nullptr;
   if (class_info->has_static_class_fields) {
     static_fields_initializer = CreateInitializerFunction(
-        class_info->static_fields_scope, class_info->static_fields);
+        "<static_fields_initializer>", class_info->static_fields_scope,
+        class_info->static_fields);
   }
 
   FunctionLiteral* instance_fields_initializer_function = nullptr;
   if (class_info->has_instance_class_fields) {
     instance_fields_initializer_function = CreateInitializerFunction(
-        class_info->instance_fields_scope, class_info->instance_fields);
+        "<instance_fields_initializer>", class_info->instance_fields_scope,
+        class_info->instance_fields);
     class_info->constructor->set_requires_instance_fields_initializer(true);
   }
 
@@ -3460,7 +3375,6 @@ void Parser::ParseOnBackground(ParseInfo* info) {
   // position set at the end of the script (the top scope and possible eval
   // scopes) and set their end position after we know the script length.
   if (info->is_toplevel()) {
-    fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
     result = DoParseProgram(/* isolate = */ nullptr, info);
   } else {
     result =
@@ -3647,10 +3561,9 @@ void Parser::RewriteAsyncFunctionBody(ZonePtrList<Statement>* body,
   //   })
   // }
 
-  return_value = BuildResolvePromise(return_value, return_value->position());
-  block->statements()->Add(
-      factory()->NewReturnStatement(return_value, return_value->position()),
-      zone());
+  block->statements()->Add(factory()->NewAsyncReturnStatement(
+                               return_value, return_value->position()),
+                           zone());
   block = BuildRejectPromiseOnException(block);
   body->Add(block, zone());
 }
diff --git a/deps/v8/src/parsing/parser.h b/deps/v8/src/parsing/parser.h
index 00e73f37a2..35de0656d3 100644
--- a/deps/v8/src/parsing/parser.h
+++ b/deps/v8/src/parsing/parser.h
@@ -11,11 +11,11 @@
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/base/compiler-specific.h"
+#include "src/base/threaded-list.h"
 #include "src/globals.h"
 #include "src/parsing/parser-base.h"
 #include "src/parsing/parsing.h"
 #include "src/parsing/preparser.h"
-#include "src/utils.h"
 #include "src/zone/zone-chunk-list.h"
 
 namespace v8 {
@@ -31,7 +31,7 @@ class ParserTargetScope;
 class PendingCompilationErrorHandler;
 class PreParsedScopeData;
 
-class FunctionEntry BASE_EMBEDDED {
+class FunctionEntry {
  public:
   enum {
     kStartPositionIndex,
@@ -109,7 +109,7 @@ struct ParserFormalParameters : FormalParametersBase {
 
   explicit ParserFormalParameters(DeclarationScope* scope)
       : FormalParametersBase(scope) {}
-  ThreadedList<Parameter> params;
+  base::ThreadedList<Parameter> params;
 };
 
 template <>
@@ -135,12 +135,17 @@ struct ParserTypes<Parser> {
   typedef v8::internal::BreakableStatement* BreakableStatement;
   typedef v8::internal::ForStatement* ForStatement;
   typedef v8::internal::IterationStatement* IterationStatement;
+  typedef v8::internal::FuncNameInferrer FuncNameInferrer;
+  typedef v8::internal::SourceRange SourceRange;
+  typedef v8::internal::SourceRangeScope SourceRangeScope;
 
   // For constructing objects returned by the traversing functions.
   typedef AstNodeFactory Factory;
 
   typedef ParserTarget Target;
   typedef ParserTargetScope TargetScope;
+
+  static constexpr bool ExpressionClassifierReportErrors = true;
 };
 
 class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
@@ -155,6 +160,10 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   void ParseOnBackground(ParseInfo* info);
 
+  // Initializes an empty scope chain for top-level scripts, or scopes which
+  // consist of only the native context.
+  void InitializeEmptyScopeChain(ParseInfo* info);
+
   // Deserialize the scope chain prior to parsing in which the script is going
   // to be executed. If the script is a top-level script, or the scope chain
   // consists of only a native context, maybe_outer_scope_info should be an
@@ -172,7 +181,8 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
  private:
   friend class ParserBase<Parser>;
-  friend class v8::internal::ExpressionClassifier<ParserTypes<Parser>>;
+  friend class v8::internal::ExpressionClassifierErrorTracker<
+      ParserTypes<Parser>>;
   friend bool v8::internal::parsing::ParseProgram(ParseInfo*, Isolate*);
   friend bool v8::internal::parsing::ParseFunction(
       ParseInfo*, Handle<SharedFunctionInfo> shared_info, Isolate*);
@@ -185,7 +195,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   bool parse_lazily() const { return mode_ == PARSE_LAZILY; }
   enum Mode { PARSE_LAZILY, PARSE_EAGERLY };
 
-  class ParsingModeScope BASE_EMBEDDED {
+  class ParsingModeScope {
    public:
     ParsingModeScope(Parser* parser, Mode mode)
         : parser_(parser), old_mode_(parser->mode_) {
@@ -233,14 +243,12 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
                                                            ParseInfo* info,
                                                            Zone* zone);
 
-  void StitchAst(ParseInfo* top_level_parse_info, Isolate* isolate);
-
   PreParser* reusable_preparser() {
     if (reusable_preparser_ == nullptr) {
-      reusable_preparser_ =
-          new PreParser(zone(), &scanner_, stack_limit_, ast_value_factory(),
-                        pending_error_handler(), runtime_call_stats_, logger_,
-                        -1, parsing_module_, parsing_on_main_thread_);
+      reusable_preparser_ = new PreParser(
+          &preparser_zone_, &scanner_, stack_limit_, ast_value_factory(),
+          pending_error_handler(), runtime_call_stats_, logger_, -1,
+          parsing_module_, parsing_on_main_thread_);
 #define SET_ALLOW(name) reusable_preparser_->set_allow_##name(allow_##name());
       SET_ALLOW(natives);
       SET_ALLOW(harmony_do_expressions);
@@ -248,7 +256,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
       SET_ALLOW(harmony_static_fields);
       SET_ALLOW(harmony_dynamic_import);
       SET_ALLOW(harmony_import_meta);
-      SET_ALLOW(harmony_bigint);
       SET_ALLOW(harmony_private_fields);
       SET_ALLOW(eval_cache);
 #undef SET_ALLOW
@@ -315,7 +322,8 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   Variable* CreateSyntheticContextVariable(const AstRawString* synthetic_name,
                                            bool* ok);
   FunctionLiteral* CreateInitializerFunction(
-      DeclarationScope* scope, ZonePtrList<ClassLiteral::Property>* fields);
+      const char* name, DeclarationScope* scope,
+      ZonePtrList<ClassLiteral::Property>* fields);
   V8_INLINE Statement* DeclareClass(const AstRawString* variable_name,
                                     Expression* value,
                                     ZonePtrList<const AstRawString>* names,
@@ -442,12 +450,19 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   // by parsing the function with PreParser. Consumes the ending }.
   // If may_abort == true, the (pre-)parser may decide to abort skipping
   // in order to force the function to be eagerly parsed, after all.
-  LazyParsingResult SkipFunction(
-      const AstRawString* function_name, FunctionKind kind,
-      FunctionLiteral::FunctionType function_type,
-      DeclarationScope* function_scope, int* num_parameters,
-      ProducedPreParsedScopeData** produced_preparsed_scope_data,
-      bool is_inner_function, bool may_abort, bool* ok);
+  // In case the preparser detects an error it cannot identify, it resets the
+  // scanner- and preparser state to the initial one, before PreParsing the
+  // function.
+  // SkipFunction returns true if it correctly parsed the function, including
+  // cases where we detect an error. It returns false, if we needed to stop
+  // parsing or could not identify an error correctly, meaning the caller needs
+  // to fully reparse. In this case it resets the scanner and preparser state.
+  bool SkipFunction(const AstRawString* function_name, FunctionKind kind,
+                    FunctionLiteral::FunctionType function_type,
+                    DeclarationScope* function_scope, int* num_parameters,
+                    ProducedPreParsedScopeData** produced_preparsed_scope_data,
+                    bool is_inner_function, bool may_abort,
+                    FunctionLiteral::EagerCompileHint* hint, bool* ok);
 
   Block* BuildParameterInitializationBlock(
       const ParserFormalParameters& parameters, bool* ok);
@@ -532,7 +547,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   Expression* BuildInitialYield(int pos, FunctionKind kind);
   Assignment* BuildCreateJSGeneratorObject(int pos, FunctionKind kind);
-  Expression* BuildResolvePromise(Expression* value, int pos);
   Expression* BuildRejectPromise(Expression* value, int pos);
   Variable* PromiseVariable();
   Variable* AsyncGeneratorAwaitVariable();
@@ -662,38 +676,30 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   // Functions for encapsulating the differences between parsing and preparsing;
   // operations interleaved with the recursive descent.
   V8_INLINE void PushLiteralName(const AstRawString* id) {
-    DCHECK_NOT_NULL(fni_);
-    fni_->PushLiteralName(id);
+    fni_.PushLiteralName(id);
   }
 
   V8_INLINE void PushVariableName(const AstRawString* id) {
-    DCHECK_NOT_NULL(fni_);
-    fni_->PushVariableName(id);
+    fni_.PushVariableName(id);
   }
 
   V8_INLINE void PushPropertyName(Expression* expression) {
-    DCHECK_NOT_NULL(fni_);
     if (expression->IsPropertyName()) {
-      fni_->PushLiteralName(expression->AsLiteral()->AsRawPropertyName());
+      fni_.PushLiteralName(expression->AsLiteral()->AsRawPropertyName());
     } else {
-      fni_->PushLiteralName(ast_value_factory()->anonymous_function_string());
+      fni_.PushLiteralName(ast_value_factory()->anonymous_function_string());
     }
   }
 
   V8_INLINE void PushEnclosingName(const AstRawString* name) {
-    DCHECK_NOT_NULL(fni_);
-    fni_->PushEnclosingName(name);
+    fni_.PushEnclosingName(name);
   }
 
   V8_INLINE void AddFunctionForNameInference(FunctionLiteral* func_to_infer) {
-    DCHECK_NOT_NULL(fni_);
-    fni_->AddFunction(func_to_infer);
+    fni_.AddFunction(func_to_infer);
   }
 
-  V8_INLINE void InferFunctionName() {
-    DCHECK_NOT_NULL(fni_);
-    fni_->Infer();
-  }
+  V8_INLINE void InferFunctionName() { fni_.Infer(); }
 
   // If we assign a function literal to a property we pretenure the
   // literal so it can be added as a constant function property.
@@ -784,6 +790,10 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
                                              arg, error_type);
   }
 
+  // Dummy implementation. The parser should never have a unidentifiable
+  // error.
+  V8_INLINE void ReportUnidentifiableError() { UNREACHABLE(); }
+
   void ReportMessageAt(Scanner::Location source_location,
                        MessageTemplate::Template message,
                        const AstRawString* arg,
@@ -856,14 +866,14 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
       const AstRawString* name, int start_position,
       InferName infer = InferName::kYes) {
     if (infer == InferName::kYes) {
-      fni_->PushVariableName(name);
+      fni_.PushVariableName(name);
     }
     return NewUnresolved(name, start_position);
   }
 
   V8_INLINE Expression* ExpressionFromString(int pos) {
     const AstRawString* symbol = GetSymbol();
-    fni_->PushLiteralName(symbol);
+    fni_.PushLiteralName(symbol);
     return factory()->NewStringLiteral(symbol, pos);
   }
 
@@ -891,18 +901,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
         factory()->NewThrow(exception, pos), pos);
   }
 
-  V8_INLINE void AddParameterInitializationBlock(
-      const ParserFormalParameters& parameters, ZonePtrList<Statement>* body,
-      bool is_async, bool* ok) {
-    if (parameters.is_simple) return;
-    auto* init_block = BuildParameterInitializationBlock(parameters, ok);
-    if (!*ok) return;
-    if (is_async) {
-      init_block = BuildRejectPromiseOnException(init_block);
-    }
-    body->Add(init_block, zone());
-  }
-
   V8_INLINE void AddFormalParameter(ParserFormalParameters* parameters,
                                     Expression* pattern,
                                     Expression* initializer,
@@ -923,7 +921,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   V8_INLINE void DeclareFormalParameters(
       DeclarationScope* scope,
-      const ThreadedList<ParserFormalParameters::Parameter>& parameters,
+      const base::ThreadedList<ParserFormalParameters::Parameter>& parameters,
       bool is_simple, bool* has_duplicate = nullptr) {
     if (!is_simple) scope->SetHasNonSimpleParameters();
     for (auto parameter : parameters) {
@@ -958,7 +956,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   void SetFunctionNameFromIdentifierRef(Expression* value,
                                         Expression* identifier);
 
-  V8_INLINE ZoneVector<typename ExpressionClassifier::Error>*
+  V8_INLINE ZoneList<typename ExpressionClassifier::Error>*
   GetReportedErrorList() const {
     return function_state_->GetReportedErrorList();
   }
@@ -1094,11 +1092,10 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   }
 
   // Parser's private field members.
-  friend class DiscardableZoneScope;  // Uses reusable_preparser_.
-  // FIXME(marja): Make reusable_preparser_ always use its own temp Zone (call
-  // DeleteAll after each function), so this won't be needed.
+  friend class PreParserZoneScope;  // Uses reusable_preparser().
 
   Scanner scanner_;
+  Zone preparser_zone_;
   PreParser* reusable_preparser_;
   Mode mode_;
 
@@ -1131,7 +1128,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 // 'continue' statement targets). Upon construction, a new target is
 // added; it is removed upon destruction.
 
-class ParserTarget BASE_EMBEDDED {
+class ParserTarget {
  public:
   ParserTarget(ParserBase<Parser>* parser, BreakableStatement* statement)
       : variable_(&parser->impl()->target_stack_),
@@ -1151,7 +1148,7 @@ class ParserTarget BASE_EMBEDDED {
   ParserTarget* previous_;
 };
 
-class ParserTargetScope BASE_EMBEDDED {
+class ParserTargetScope {
  public:
   explicit ParserTargetScope(ParserBase<Parser>* parser)
       : variable_(&parser->impl()->target_stack_),
diff --git a/deps/v8/src/parsing/pattern-rewriter.cc b/deps/v8/src/parsing/pattern-rewriter.cc
index ed3231c151..4465670a8f 100644
--- a/deps/v8/src/parsing/pattern-rewriter.cc
+++ b/deps/v8/src/parsing/pattern-rewriter.cc
@@ -31,38 +31,32 @@ class PatternRewriter final : public AstVisitor<PatternRewriter> {
       const Parser::DeclarationParsingResult::Declaration* declaration,
       ZonePtrList<const AstRawString>* names, bool* ok);
 
-  static void RewriteDestructuringAssignment(Parser* parser,
-                                             RewritableExpression* to_rewrite,
-                                             Scope* scope);
+  static Expression* RewriteDestructuringAssignment(Parser* parser,
+                                                    Assignment* to_rewrite,
+                                                    Scope* scope);
 
  private:
-  enum PatternContext { BINDING, ASSIGNMENT, ASSIGNMENT_ELEMENT };
-
-  class AssignmentElementScope {
-   public:
-    explicit AssignmentElementScope(PatternRewriter* rewriter)
-        : rewriter_(rewriter), context_(rewriter->context()) {
-      if (context_ == ASSIGNMENT) rewriter->context_ = ASSIGNMENT_ELEMENT;
-    }
-    ~AssignmentElementScope() { rewriter_->context_ = context_; }
-
-   private:
-    PatternRewriter* const rewriter_;
-    const PatternContext context_;
-  };
-
-  PatternRewriter(Scope* scope, Parser* parser, PatternContext context)
+  enum PatternContext : uint8_t { BINDING, ASSIGNMENT };
+
+  PatternRewriter(Scope* scope, Parser* parser, PatternContext context,
+                  const DeclarationDescriptor* descriptor = nullptr,
+                  ZonePtrList<const AstRawString>* names = nullptr,
+                  int initializer_position = kNoSourcePosition,
+                  int value_beg_position = kNoSourcePosition,
+                  bool declares_parameter_containing_sloppy_eval = false)
       : scope_(scope),
         parser_(parser),
-        context_(context),
-        initializer_position_(kNoSourcePosition),
-        value_beg_position_(kNoSourcePosition),
         block_(nullptr),
-        descriptor_(nullptr),
-        names_(nullptr),
+        descriptor_(descriptor),
+        names_(names),
         current_value_(nullptr),
-        recursion_level_(0),
-        ok_(nullptr) {}
+        ok_(nullptr),
+        initializer_position_(initializer_position),
+        value_beg_position_(value_beg_position),
+        context_(context),
+        declares_parameter_containing_sloppy_eval_(
+            declares_parameter_containing_sloppy_eval),
+        recursion_level_(0) {}
 
 #define DECLARE_VISIT(type) void Visit##type(v8::internal::type* node);
   // Visiting functions for AST nodes make this an AstVisitor.
@@ -80,16 +74,34 @@ class PatternRewriter final : public AstVisitor<PatternRewriter> {
     current_value_ = old_value;
   }
 
+  Expression* Rewrite(Assignment* assign) {
+    DCHECK_EQ(Token::ASSIGN, assign->op());
+
+    int pos = assign->position();
+    DCHECK_NULL(block_);
+    block_ = factory()->NewBlock(8, true);
+    Variable* temp = nullptr;
+    Expression* pattern = assign->target();
+    Expression* old_value = current_value_;
+    current_value_ = assign->value();
+    if (pattern->IsObjectLiteral()) {
+      VisitObjectLiteral(pattern->AsObjectLiteral(), &temp);
+    } else {
+      DCHECK(pattern->IsArrayLiteral());
+      VisitArrayLiteral(pattern->AsArrayLiteral(), &temp);
+    }
+    DCHECK_NOT_NULL(temp);
+    current_value_ = old_value;
+    return factory()->NewDoExpression(block_, temp, pos);
+  }
+
   void VisitObjectLiteral(ObjectLiteral* node, Variable** temp_var);
   void VisitArrayLiteral(ArrayLiteral* node, Variable** temp_var);
 
   bool IsBindingContext() const { return context_ == BINDING; }
-  bool IsAssignmentContext() const {
-    return context_ == ASSIGNMENT || context_ == ASSIGNMENT_ELEMENT;
-  }
+  bool IsAssignmentContext() const { return context_ == ASSIGNMENT; }
   bool IsSubPattern() const { return recursion_level_ > 1; }
 
-  bool DeclaresParameterContainingSloppyEval() const;
   void RewriteParameterScopes(Expression* expr);
 
   Variable* CreateTempVar(Expression* value = nullptr);
@@ -103,15 +115,16 @@ class PatternRewriter final : public AstVisitor<PatternRewriter> {
 
   Scope* const scope_;
   Parser* const parser_;
-  PatternContext context_;
-  int initializer_position_;
-  int value_beg_position_;
   Block* block_;
   const DeclarationDescriptor* descriptor_;
   ZonePtrList<const AstRawString>* names_;
   Expression* current_value_;
-  int recursion_level_;
   bool* ok_;
+  const int initializer_position_;
+  const int value_beg_position_;
+  PatternContext context_;
+  const bool declares_parameter_containing_sloppy_eval_ : 1;
+  int recursion_level_;
 
   DEFINE_AST_VISITOR_MEMBERS_WITHOUT_STACKOVERFLOW()
 };
@@ -125,15 +138,18 @@ void Parser::DeclareAndInitializeVariables(
 }
 
 void Parser::RewriteDestructuringAssignment(RewritableExpression* to_rewrite) {
-  PatternRewriter::RewriteDestructuringAssignment(this, to_rewrite, scope());
+  DCHECK(!to_rewrite->is_rewritten());
+  Assignment* assignment = to_rewrite->expression()->AsAssignment();
+  Expression* result = PatternRewriter::RewriteDestructuringAssignment(
+      this, assignment, scope());
+  to_rewrite->Rewrite(result);
 }
 
 Expression* Parser::RewriteDestructuringAssignment(Assignment* assignment) {
   DCHECK_NOT_NULL(assignment);
   DCHECK_EQ(Token::ASSIGN, assignment->op());
-  auto to_rewrite = factory()->NewRewritableExpression(assignment, scope());
-  RewriteDestructuringAssignment(to_rewrite);
-  return to_rewrite->expression();
+  return PatternRewriter::RewriteDestructuringAssignment(this, assignment,
+                                                         scope());
 }
 
 void PatternRewriter::DeclareAndInitializeVariables(
@@ -143,25 +159,26 @@ void PatternRewriter::DeclareAndInitializeVariables(
     ZonePtrList<const AstRawString>* names, bool* ok) {
   DCHECK(block->ignore_completion_value());
 
-  PatternRewriter rewriter(declaration_descriptor->scope, parser, BINDING);
-  rewriter.initializer_position_ = declaration->initializer_position;
-  rewriter.value_beg_position_ = declaration->value_beg_position;
+  Scope* scope = declaration_descriptor->scope;
+  PatternRewriter rewriter(scope, parser, BINDING, declaration_descriptor,
+                           names, declaration->initializer_position,
+                           declaration->value_beg_position,
+                           declaration_descriptor->declaration_kind ==
+                                   DeclarationDescriptor::PARAMETER &&
+                               scope->is_block_scope());
   rewriter.block_ = block;
-  rewriter.descriptor_ = declaration_descriptor;
-  rewriter.names_ = names;
   rewriter.ok_ = ok;
 
   rewriter.RecurseIntoSubpattern(declaration->pattern,
                                  declaration->initializer);
 }
 
-void PatternRewriter::RewriteDestructuringAssignment(
-    Parser* parser, RewritableExpression* to_rewrite, Scope* scope) {
+Expression* PatternRewriter::RewriteDestructuringAssignment(
+    Parser* parser, Assignment* to_rewrite, Scope* scope) {
   DCHECK(!scope->HasBeenRemoved());
-  DCHECK(!to_rewrite->is_rewritten());
 
   PatternRewriter rewriter(scope, parser, ASSIGNMENT);
-  rewriter.RecurseIntoSubpattern(to_rewrite, nullptr);
+  return rewriter.Rewrite(to_rewrite);
 }
 
 void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
@@ -181,7 +198,16 @@ void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   DCHECK_NOT_NULL(descriptor_);
   DCHECK_NOT_NULL(ok_);
 
-  descriptor_->scope->RemoveUnresolved(pattern);
+  Scope* outer_function_scope = nullptr;
+  bool success;
+  if (declares_parameter_containing_sloppy_eval_) {
+    outer_function_scope = scope()->outer_scope();
+    success = outer_function_scope->RemoveUnresolved(pattern);
+  } else {
+    success = scope()->RemoveUnresolved(pattern);
+  }
+  USE(success);
+  DCHECK(success);
 
   // Declare variable.
   // Note that we *always* must treat the initial value via a separate init
@@ -192,15 +218,13 @@ void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   // an initial value in the declaration (because they are initialized upon
   // entering the function).
   const AstRawString* name = pattern->raw_name();
-  VariableProxy* proxy =
-      factory()->NewVariableProxy(name, NORMAL_VARIABLE, pattern->position());
+  VariableProxy* proxy = pattern;
   Declaration* declaration;
   if (descriptor_->mode == VariableMode::kVar &&
-      !descriptor_->scope->is_declaration_scope()) {
-    DCHECK(descriptor_->scope->is_block_scope() ||
-           descriptor_->scope->is_with_scope());
+      !scope()->is_declaration_scope()) {
+    DCHECK(scope()->is_block_scope() || scope()->is_with_scope());
     declaration = factory()->NewNestedVariableDeclaration(
-        proxy, descriptor_->scope, descriptor_->declaration_pos);
+        proxy, scope(), descriptor_->declaration_pos);
   } else {
     declaration =
         factory()->NewVariableDeclaration(proxy, descriptor_->declaration_pos);
@@ -210,10 +234,6 @@ void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   // a sloppy eval in a default parameter or function body, the parameter
   // needs to be declared in the function's scope, not in the varblock
   // scope which will be used for the initializer expression.
-  Scope* outer_function_scope = nullptr;
-  if (DeclaresParameterContainingSloppyEval()) {
-    outer_function_scope = descriptor_->scope->outer_scope();
-  }
   Variable* var = parser_->Declare(
       declaration, descriptor_->declaration_kind, descriptor_->mode,
       Variable::DefaultInitializationFlag(descriptor_->mode), ok_,
@@ -224,12 +244,11 @@ void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   DCHECK_NE(initializer_position_, kNoSourcePosition);
   var->set_initializer_position(initializer_position_);
 
-  Scope* declaration_scope =
-      outer_function_scope != nullptr
-          ? outer_function_scope
-          : (IsLexicalVariableMode(descriptor_->mode)
-                 ? descriptor_->scope
-                 : descriptor_->scope->GetDeclarationScope());
+  Scope* declaration_scope = outer_function_scope != nullptr
+                                 ? outer_function_scope
+                                 : (IsLexicalVariableMode(descriptor_->mode)
+                                        ? scope()
+                                        : scope()->GetDeclarationScope());
   if (declaration_scope->num_var() > kMaxNumFunctionLocals) {
     parser_->ReportMessage(MessageTemplate::kTooManyVariables);
     *ok_ = false;
@@ -242,7 +261,7 @@ void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   // If there's no initializer, we're done.
   if (value == nullptr) return;
 
-  Scope* var_init_scope = descriptor_->scope;
+  Scope* var_init_scope = scope();
   Parser::MarkLoopVariableAsAssigned(var_init_scope, proxy->var(),
                                      descriptor_->declaration_kind);
 
@@ -254,15 +273,15 @@ void PatternRewriter::VisitVariableProxy(VariableProxy* pattern) {
   //
   //    var v; v = x;
   //
-  // In particular, we need to re-lookup 'v' as it may be a different
-  // 'v' than the 'v' in the declaration (e.g., if we are inside a
-  // 'with' statement or 'catch' block). Global var declarations
-  // also need special treatment.
-
-  // For 'let' and 'const' declared variables the initialization always
-  // assigns to the declared variable.
-  // But for var declarations we need to do a new lookup.
-  if (descriptor_->mode == VariableMode::kVar) {
+  // In particular, we need to re-lookup 'v' if it may be a different 'v' than
+  // the 'v' in the declaration (e.g., if we are inside a 'with' statement or
+  // 'catch' block).
+
+  // For 'let' and 'const' declared variables the initialization always assigns
+  // to the declared variable. But for var declarations that target a different
+  // scope we need to do a new lookup.
+  if (descriptor_->mode == VariableMode::kVar &&
+      var_init_scope != declaration_scope) {
     proxy = var_init_scope->NewUnresolved(factory(), name);
   } else {
     DCHECK_NOT_NULL(proxy);
@@ -294,64 +313,13 @@ Variable* PatternRewriter::CreateTempVar(Expression* value) {
 }
 
 void PatternRewriter::VisitRewritableExpression(RewritableExpression* node) {
-  if (!node->expression()->IsAssignment()) {
-    // RewritableExpressions are also used for desugaring Spread, which is
-    // orthogonal to PatternRewriter; just visit the underlying expression.
-    DCHECK_EQ(AstNode::kArrayLiteral, node->expression()->node_type());
-    return Visit(node->expression());
-  } else if (context() != ASSIGNMENT) {
-    // This is not a destructuring assignment. Mark the node as rewritten to
-    // prevent redundant rewriting and visit the underlying expression.
-    DCHECK(!node->is_rewritten());
-    node->set_rewritten();
-    return Visit(node->expression());
-  }
-
+  DCHECK(node->expression()->IsAssignment());
+  // This is not a top-level destructuring assignment. Mark the node as
+  // rewritten to prevent redundant rewriting and visit the underlying
+  // expression.
   DCHECK(!node->is_rewritten());
-  DCHECK_EQ(ASSIGNMENT, context());
-  Assignment* assign = node->expression()->AsAssignment();
-  DCHECK_NOT_NULL(assign);
-  DCHECK_EQ(Token::ASSIGN, assign->op());
-
-  int pos = assign->position();
-  Block* old_block = block_;
-  block_ = factory()->NewBlock(8, true);
-  Variable* temp = nullptr;
-  Expression* pattern = assign->target();
-  Expression* old_value = current_value_;
-  current_value_ = assign->value();
-  if (pattern->IsObjectLiteral()) {
-    VisitObjectLiteral(pattern->AsObjectLiteral(), &temp);
-  } else {
-    DCHECK(pattern->IsArrayLiteral());
-    VisitArrayLiteral(pattern->AsArrayLiteral(), &temp);
-  }
-  DCHECK_NOT_NULL(temp);
-  current_value_ = old_value;
-  Expression* expr = factory()->NewDoExpression(block_, temp, pos);
-  node->Rewrite(expr);
-  block_ = old_block;
-  if (block_) {
-    block_->statements()->Add(factory()->NewExpressionStatement(expr, pos),
-                              zone());
-  }
-}
-
-bool PatternRewriter::DeclaresParameterContainingSloppyEval() const {
-  // Need to check for a binding context to make sure we have a descriptor.
-  if (IsBindingContext() &&
-      // Only relevant for parameters.
-      descriptor_->declaration_kind == DeclarationDescriptor::PARAMETER &&
-      // And only when scope is a block scope;
-      // without eval, it is a function scope.
-      scope()->is_block_scope()) {
-    DCHECK(scope()->is_declaration_scope());
-    DCHECK(scope()->AsDeclarationScope()->calls_sloppy_eval());
-    DCHECK(scope()->outer_scope()->is_function_scope());
-    return true;
-  }
-
-  return false;
+  node->set_rewritten();
+  return Visit(node->expression());
 }
 
 // When an extra declaration scope needs to be inserted to account for
@@ -359,7 +327,7 @@ bool PatternRewriter::DeclaresParameterContainingSloppyEval() const {
 // needs to be in that new inner scope which was added after initial
 // parsing.
 void PatternRewriter::RewriteParameterScopes(Expression* expr) {
-  if (DeclaresParameterContainingSloppyEval()) {
+  if (declares_parameter_containing_sloppy_eval_) {
     ReparentExpressionScope(parser_->stack_limit(), expr, scope());
   }
 }
@@ -428,7 +396,6 @@ void PatternRewriter::VisitObjectLiteral(ObjectLiteral* pattern,
                                      kNoSourcePosition);
     }
 
-    AssignmentElementScope element_scope(this);
     RecurseIntoSubpattern(property->value(), value);
   }
 }
@@ -557,10 +524,7 @@ void PatternRewriter::VisitArrayLiteral(ArrayLiteral* node,
             factory()->NewExpressionStatement(assignment, nopos), zone());
       }
 
-      {
-        AssignmentElementScope element_scope(this);
-        RecurseIntoSubpattern(value, factory()->NewVariableProxy(v));
-      }
+      RecurseIntoSubpattern(value, factory()->NewVariableProxy(v));
 
       {
         // completion = kNormalCompletion;
@@ -709,10 +673,6 @@ void PatternRewriter::VisitAssignment(Assignment* node) {
   // <pattern> = temp === undefined ? <init> : temp;
   DCHECK_EQ(Token::ASSIGN, node->op());
 
-  // Rewriting of Assignment nodes for destructuring assignment
-  // is handled in VisitRewritableExpression().
-  DCHECK_NE(ASSIGNMENT, context());
-
   auto initializer = node->value();
   auto value = initializer;
   auto temp = CreateTempVar(current_value_);
diff --git a/deps/v8/src/parsing/preparsed-scope-data-impl.h b/deps/v8/src/parsing/preparsed-scope-data-impl.h
new file mode 100644
index 0000000000..e2d31c07d5
--- /dev/null
+++ b/deps/v8/src/parsing/preparsed-scope-data-impl.h
@@ -0,0 +1,259 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_PARSING_PREPARSED_SCOPE_DATA_IMPL_H_
+#define V8_PARSING_PREPARSED_SCOPE_DATA_IMPL_H_
+
+#include "src/parsing/preparsed-scope-data.h"
+
+#include "src/assert-scope.h"
+
+namespace v8 {
+namespace internal {
+
+// Classes which are internal to prepared-scope-data.cc, but are exposed in
+// a header for tests.
+
+struct PreParsedScopeByteDataConstants {
+#ifdef DEBUG
+  static constexpr int kMagicValue = 0xC0DE0DE;
+
+  static constexpr size_t kUint32Size = 5;
+  static constexpr size_t kUint8Size = 2;
+  static constexpr size_t kQuarterMarker = 0;
+  static constexpr size_t kPlaceholderSize = kUint32Size;
+#else
+  static constexpr size_t kUint32Size = 4;
+  static constexpr size_t kUint8Size = 1;
+  static constexpr size_t kPlaceholderSize = 0;
+#endif
+
+  static const size_t kSkippableFunctionDataSize =
+      4 * kUint32Size + 1 * kUint8Size;
+};
+
+class PreParsedScopeDataBuilder::ByteData
+    : public ZoneObject,
+      public PreParsedScopeByteDataConstants {
+ public:
+  explicit ByteData(Zone* zone)
+      : backing_store_(zone), free_quarters_in_last_byte_(0) {}
+
+  void WriteUint32(uint32_t data);
+  void WriteUint8(uint8_t data);
+  void WriteQuarter(uint8_t data);
+
+#ifdef DEBUG
+  // For overwriting previously written data at position 0.
+  void OverwriteFirstUint32(uint32_t data);
+#endif
+
+  Handle<PodArray<uint8_t>> Serialize(Isolate* isolate);
+
+  size_t size() const { return backing_store_.size(); }
+
+  ZoneChunkList<uint8_t>::iterator begin() { return backing_store_.begin(); }
+
+  ZoneChunkList<uint8_t>::iterator end() { return backing_store_.end(); }
+
+ private:
+  ZoneChunkList<uint8_t> backing_store_;
+  uint8_t free_quarters_in_last_byte_;
+};
+
+template <class Data>
+class BaseConsumedPreParsedScopeData : public ConsumedPreParsedScopeData {
+ public:
+  class ByteData : public PreParsedScopeByteDataConstants {
+   public:
+    ByteData()
+        : data_(nullptr), index_(0), stored_quarters_(0), stored_byte_(0) {}
+
+    // Reading from the ByteData is only allowed when a ReadingScope is on the
+    // stack. This ensures that we have a DisallowHeapAllocation in place
+    // whenever ByteData holds a raw pointer into the heap.
+    class ReadingScope {
+     public:
+      ReadingScope(ByteData* consumed_data, Data* data)
+          : consumed_data_(consumed_data) {
+        consumed_data->data_ = data;
+      }
+      explicit ReadingScope(BaseConsumedPreParsedScopeData<Data>* parent)
+          : ReadingScope(parent->scope_data_.get(), parent->GetScopeData()) {}
+      ~ReadingScope() { consumed_data_->data_ = nullptr; }
+
+     private:
+      ByteData* consumed_data_;
+      DisallowHeapAllocation no_gc;
+    };
+
+    void SetPosition(int position) { index_ = position; }
+
+    size_t RemainingBytes() const {
+      DCHECK_NOT_NULL(data_);
+      return data_->length() - index_;
+    }
+
+    int32_t ReadUint32() {
+      DCHECK_NOT_NULL(data_);
+      DCHECK_GE(RemainingBytes(), kUint32Size);
+#ifdef DEBUG
+      // Check that there indeed is an integer following.
+      DCHECK_EQ(data_->get(index_++), kUint32Size);
+#endif
+      int32_t result = 0;
+      byte* p = reinterpret_cast<byte*>(&result);
+      for (int i = 0; i < 4; ++i) {
+        *p++ = data_->get(index_++);
+      }
+      stored_quarters_ = 0;
+      return result;
+    }
+
+    uint8_t ReadUint8() {
+      DCHECK_NOT_NULL(data_);
+      DCHECK_GE(RemainingBytes(), kUint8Size);
+#ifdef DEBUG
+      // Check that there indeed is a byte following.
+      DCHECK_EQ(data_->get(index_++), kUint8Size);
+#endif
+      stored_quarters_ = 0;
+      return data_->get(index_++);
+    }
+
+    uint8_t ReadQuarter() {
+      DCHECK_NOT_NULL(data_);
+      if (stored_quarters_ == 0) {
+        DCHECK_GE(RemainingBytes(), kUint8Size);
+#ifdef DEBUG
+        // Check that there indeed are quarters following.
+        DCHECK_EQ(data_->get(index_++), kQuarterMarker);
+#endif
+        stored_byte_ = data_->get(index_++);
+        stored_quarters_ = 4;
+      }
+      // Read the first 2 bits from stored_byte_.
+      uint8_t result = (stored_byte_ >> 6) & 3;
+      DCHECK_LE(result, 3);
+      --stored_quarters_;
+      stored_byte_ <<= 2;
+      return result;
+    }
+
+   private:
+    Data* data_;
+    int index_;
+    uint8_t stored_quarters_;
+    uint8_t stored_byte_;
+  };
+
+  BaseConsumedPreParsedScopeData()
+      : scope_data_(new ByteData()), child_index_(0) {}
+
+  virtual Data* GetScopeData() = 0;
+
+  virtual ProducedPreParsedScopeData* GetChildData(Zone* zone,
+                                                   int child_index) = 0;
+
+  ProducedPreParsedScopeData* GetDataForSkippableFunction(
+      Zone* zone, int start_position, int* end_position, int* num_parameters,
+      int* num_inner_functions, bool* uses_super_property,
+      LanguageMode* language_mode) final;
+
+  void RestoreScopeAllocationData(DeclarationScope* scope) final;
+
+#ifdef DEBUG
+  void VerifyDataStart();
+#endif
+
+ private:
+  void RestoreData(Scope* scope);
+  void RestoreDataForVariable(Variable* var);
+  void RestoreDataForInnerScopes(Scope* scope);
+
+  std::unique_ptr<ByteData> scope_data_;
+  // When consuming the data, these indexes point to the data we're going to
+  // consume next.
+  int child_index_;
+
+  DISALLOW_COPY_AND_ASSIGN(BaseConsumedPreParsedScopeData);
+};
+
+// Implementation of ConsumedPreParsedScopeData for on-heap data.
+class OnHeapConsumedPreParsedScopeData final
+    : public BaseConsumedPreParsedScopeData<PodArray<uint8_t>> {
+ public:
+  OnHeapConsumedPreParsedScopeData(Isolate* isolate,
+                                   Handle<PreParsedScopeData> data);
+
+  PodArray<uint8_t>* GetScopeData() final;
+  ProducedPreParsedScopeData* GetChildData(Zone* zone, int child_index) final;
+
+ private:
+  Isolate* isolate_;
+  Handle<PreParsedScopeData> data_;
+};
+
+// Wraps a ZoneVector<uint8_t> to have with functions named the same as
+// PodArray<uint8_t>.
+class ZoneVectorWrapper {
+ public:
+  explicit ZoneVectorWrapper(ZoneVector<uint8_t>* data) : data_(data) {}
+
+  int length() const { return static_cast<int>(data_->size()); }
+
+  uint8_t get(int index) const { return data_->at(index); }
+
+ private:
+  ZoneVector<uint8_t>* data_;
+
+  DISALLOW_COPY_AND_ASSIGN(ZoneVectorWrapper);
+};
+
+// A serialized PreParsedScopeData in zone memory (as apposed to being on-heap).
+class ZonePreParsedScopeData : public ZoneObject {
+ public:
+  ZonePreParsedScopeData(Zone* zone,
+                         ZoneChunkList<uint8_t>::iterator byte_data_begin,
+                         ZoneChunkList<uint8_t>::iterator byte_data_end,
+                         int child_length);
+
+  Handle<PreParsedScopeData> Serialize(Isolate* isolate);
+
+  int child_length() const { return static_cast<int>(children_.size()); }
+
+  ZonePreParsedScopeData* get_child(int index) { return children_[index]; }
+
+  void set_child(int index, ZonePreParsedScopeData* child) {
+    children_[index] = child;
+  }
+
+  ZoneVector<uint8_t>* byte_data() { return &byte_data_; }
+
+ private:
+  ZoneVector<uint8_t> byte_data_;
+  ZoneVector<ZonePreParsedScopeData*> children_;
+
+  DISALLOW_COPY_AND_ASSIGN(ZonePreParsedScopeData);
+};
+
+// Implementation of ConsumedPreParsedScopeData for PreParsedScopeData
+// serialized into zone memory.
+class ZoneConsumedPreParsedScopeData final
+    : public BaseConsumedPreParsedScopeData<ZoneVectorWrapper> {
+ public:
+  ZoneConsumedPreParsedScopeData(Zone* zone, ZonePreParsedScopeData* data);
+
+  ZoneVectorWrapper* GetScopeData() final;
+  ProducedPreParsedScopeData* GetChildData(Zone* zone, int child_index) final;
+
+ private:
+  ZonePreParsedScopeData* data_;
+  ZoneVectorWrapper scope_data_wrapper_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_PARSING_PREPARSED_SCOPE_DATA_IMPL_H_
diff --git a/deps/v8/src/parsing/preparsed-scope-data.cc b/deps/v8/src/parsing/preparsed-scope-data.cc
index 90e8819e32..9d61740753 100644
--- a/deps/v8/src/parsing/preparsed-scope-data.cc
+++ b/deps/v8/src/parsing/preparsed-scope-data.cc
@@ -4,11 +4,14 @@
 
 #include "src/parsing/preparsed-scope-data.h"
 
+#include <vector>
+
 #include "src/ast/scopes.h"
 #include "src/ast/variables.h"
 #include "src/handles.h"
 #include "src/objects-inl.h"
 #include "src/objects/shared-function-info.h"
+#include "src/parsing/preparsed-scope-data-impl.h"
 #include "src/parsing/preparser.h"
 
 namespace v8 {
@@ -24,22 +27,6 @@ class VariableMaybeAssignedField : public BitField8<bool, 0, 1> {};
 class VariableContextAllocatedField
     : public BitField8<bool, VariableMaybeAssignedField::kNext, 1> {};
 
-
-#ifdef DEBUG
-const int kMagicValue = 0xC0DE0DE;
-
-const size_t kUint32Size = 5;
-const size_t kUint8Size = 2;
-const size_t kQuarterMarker = 0;
-const size_t kPlaceholderSize = kUint32Size;
-#else
-const size_t kUint32Size = 4;
-const size_t kUint8Size = 1;
-const size_t kPlaceholderSize = 0;
-#endif
-
-const size_t kSkippableFunctionDataSize = 4 * kUint32Size + 1 * kUint8Size;
-
 class LanguageField : public BitField8<LanguageMode, 0, 1> {};
 class UsesSuperField : public BitField8<bool, LanguageField::kNext, 1> {};
 STATIC_ASSERT(LanguageModeSize <= LanguageField::kNumValues);
@@ -48,7 +35,7 @@ STATIC_ASSERT(LanguageModeSize <= LanguageField::kNumValues);
 
 /*
 
-  Internal data format for the backing store of ProducedPreparsedScopeData and
+  Internal data format for the backing store of PreParsedScopeDataBuilder and
   PreParsedScopeData::scope_data (on the heap):
 
   (Skippable function data:)
@@ -91,7 +78,7 @@ STATIC_ASSERT(LanguageModeSize <= LanguageField::kNumValues);
 
  */
 
-void ProducedPreParsedScopeData::ByteData::WriteUint32(uint32_t data) {
+void PreParsedScopeDataBuilder::ByteData::WriteUint32(uint32_t data) {
 #ifdef DEBUG
   // Save expected item size in debug mode.
   backing_store_.push_back(kUint32Size);
@@ -104,7 +91,7 @@ void ProducedPreParsedScopeData::ByteData::WriteUint32(uint32_t data) {
 }
 
 #ifdef DEBUG
-void ProducedPreParsedScopeData::ByteData::OverwriteFirstUint32(uint32_t data) {
+void PreParsedScopeDataBuilder::ByteData::OverwriteFirstUint32(uint32_t data) {
   auto it = backing_store_.begin();
   // Check that that position already holds an item of the expected size.
   DCHECK_GE(backing_store_.size(), kUint32Size);
@@ -117,7 +104,7 @@ void ProducedPreParsedScopeData::ByteData::OverwriteFirstUint32(uint32_t data) {
 }
 #endif
 
-void ProducedPreParsedScopeData::ByteData::WriteUint8(uint8_t data) {
+void PreParsedScopeDataBuilder::ByteData::WriteUint8(uint8_t data) {
 #ifdef DEBUG
   // Save expected item size in debug mode.
   backing_store_.push_back(kUint8Size);
@@ -126,7 +113,7 @@ void ProducedPreParsedScopeData::ByteData::WriteUint8(uint8_t data) {
   free_quarters_in_last_byte_ = 0;
 }
 
-void ProducedPreParsedScopeData::ByteData::WriteQuarter(uint8_t data) {
+void PreParsedScopeDataBuilder::ByteData::WriteQuarter(uint8_t data) {
   DCHECK_LE(data, 3);
   if (free_quarters_in_last_byte_ == 0) {
 #ifdef DEBUG
@@ -144,7 +131,7 @@ void ProducedPreParsedScopeData::ByteData::WriteQuarter(uint8_t data) {
   backing_store_.back() |= (data << shift_amount);
 }
 
-Handle<PodArray<uint8_t>> ProducedPreParsedScopeData::ByteData::Serialize(
+Handle<PodArray<uint8_t>> PreParsedScopeDataBuilder::ByteData::Serialize(
     Isolate* isolate) {
   Handle<PodArray<uint8_t>> array = PodArray<uint8_t>::New(
       isolate, static_cast<int>(backing_store_.size()), TENURED);
@@ -159,12 +146,13 @@ Handle<PodArray<uint8_t>> ProducedPreParsedScopeData::ByteData::Serialize(
   return array;
 }
 
-ProducedPreParsedScopeData::ProducedPreParsedScopeData(
-    Zone* zone, ProducedPreParsedScopeData* parent)
+PreParsedScopeDataBuilder::PreParsedScopeDataBuilder(
+    Zone* zone, PreParsedScopeDataBuilder* parent)
     : parent_(parent),
       byte_data_(new (zone) ByteData(zone)),
       data_for_inner_functions_(zone),
       bailed_out_(false) {
+  DCHECK(FLAG_preparser_scope_analysis);
   if (parent != nullptr) {
     parent->data_for_inner_functions_.push_back(this);
   }
@@ -174,59 +162,43 @@ ProducedPreParsedScopeData::ProducedPreParsedScopeData(
 #endif
 }
 
-// Create a ProducedPreParsedScopeData which is just a proxy for a previous
-// produced PreParsedScopeData.
-ProducedPreParsedScopeData::ProducedPreParsedScopeData(
-    Handle<PreParsedScopeData> data, Zone* zone)
-    : parent_(nullptr),
-      byte_data_(nullptr),
-      data_for_inner_functions_(zone),
-      bailed_out_(false),
-      previously_produced_preparsed_scope_data_(data) {}
-
-ProducedPreParsedScopeData::DataGatheringScope::DataGatheringScope(
+PreParsedScopeDataBuilder::DataGatheringScope::DataGatheringScope(
     DeclarationScope* function_scope, PreParser* preparser)
     : function_scope_(function_scope),
       preparser_(preparser),
-      produced_preparsed_scope_data_(nullptr) {
+      builder_(nullptr) {
   if (FLAG_preparser_scope_analysis) {
-    ProducedPreParsedScopeData* parent =
-        preparser->produced_preparsed_scope_data();
+    PreParsedScopeDataBuilder* parent =
+        preparser->preparsed_scope_data_builder();
     Zone* main_zone = preparser->main_zone();
-    produced_preparsed_scope_data_ =
-        new (main_zone) ProducedPreParsedScopeData(main_zone, parent);
-    preparser->set_produced_preparsed_scope_data(
-        produced_preparsed_scope_data_);
-    function_scope->set_produced_preparsed_scope_data(
-        produced_preparsed_scope_data_);
+    builder_ = new (main_zone) PreParsedScopeDataBuilder(main_zone, parent);
+    preparser->set_preparsed_scope_data_builder(builder_);
+    function_scope->set_preparsed_scope_data_builder(builder_);
   }
 }
 
-ProducedPreParsedScopeData::DataGatheringScope::~DataGatheringScope() {
-  if (FLAG_preparser_scope_analysis) {
-    preparser_->set_produced_preparsed_scope_data(
-        produced_preparsed_scope_data_->parent_);
+PreParsedScopeDataBuilder::DataGatheringScope::~DataGatheringScope() {
+  if (builder_) {
+    preparser_->set_preparsed_scope_data_builder(builder_->parent_);
   }
 }
 
-void ProducedPreParsedScopeData::DataGatheringScope::MarkFunctionAsSkippable(
+void PreParsedScopeDataBuilder::DataGatheringScope::MarkFunctionAsSkippable(
     int end_position, int num_inner_functions) {
-  DCHECK(FLAG_preparser_scope_analysis);
-  DCHECK_NOT_NULL(produced_preparsed_scope_data_);
-  DCHECK_NOT_NULL(produced_preparsed_scope_data_->parent_);
-  produced_preparsed_scope_data_->parent_->AddSkippableFunction(
+  DCHECK_NOT_NULL(builder_);
+  DCHECK_NOT_NULL(builder_->parent_);
+  builder_->parent_->AddSkippableFunction(
       function_scope_->start_position(), end_position,
       function_scope_->num_parameters(), num_inner_functions,
       function_scope_->language_mode(), function_scope_->NeedsHomeObject());
 }
 
-void ProducedPreParsedScopeData::AddSkippableFunction(
-    int start_position, int end_position, int num_parameters,
-    int num_inner_functions, LanguageMode language_mode,
-    bool uses_super_property) {
-  DCHECK(FLAG_preparser_scope_analysis);
-  DCHECK(previously_produced_preparsed_scope_data_.is_null());
-
+void PreParsedScopeDataBuilder::AddSkippableFunction(int start_position,
+                                                     int end_position,
+                                                     int num_parameters,
+                                                     int num_inner_functions,
+                                                     LanguageMode language_mode,
+                                                     bool uses_super_property) {
   if (bailed_out_) {
     return;
   }
@@ -245,15 +217,14 @@ void ProducedPreParsedScopeData::AddSkippableFunction(
   byte_data_->WriteQuarter(language_and_super);
 }
 
-void ProducedPreParsedScopeData::SaveScopeAllocationData(
+void PreParsedScopeDataBuilder::SaveScopeAllocationData(
     DeclarationScope* scope) {
-  DCHECK(FLAG_preparser_scope_analysis);
-  DCHECK(previously_produced_preparsed_scope_data_.is_null());
   // The data contains a uint32 (reserved space for scope_data_start) and
   // function data items, kSkippableFunctionDataSize each.
-  DCHECK_GE(byte_data_->size(), kPlaceholderSize);
+  DCHECK_GE(byte_data_->size(), ByteData::kPlaceholderSize);
   DCHECK_LE(byte_data_->size(), std::numeric_limits<uint32_t>::max());
-  DCHECK_EQ(byte_data_->size() % kSkippableFunctionDataSize, kPlaceholderSize);
+  DCHECK_EQ(byte_data_->size() % ByteData::kSkippableFunctionDataSize,
+            ByteData::kPlaceholderSize);
 
   if (bailed_out_) {
     return;
@@ -262,7 +233,7 @@ void ProducedPreParsedScopeData::SaveScopeAllocationData(
   uint32_t scope_data_start = static_cast<uint32_t>(byte_data_->size());
 
   // If there are no skippable inner functions, we don't need to save anything.
-  if (scope_data_start == kPlaceholderSize) {
+  if (scope_data_start == ByteData::kPlaceholderSize) {
     return;
   }
 
@@ -271,7 +242,7 @@ void ProducedPreParsedScopeData::SaveScopeAllocationData(
 
   // For a data integrity check, write a value between data about skipped inner
   // funcs and data about variables.
-  byte_data_->WriteUint32(kMagicValue);
+  byte_data_->WriteUint32(ByteData::kMagicValue);
   byte_data_->WriteUint32(scope->start_position());
   byte_data_->WriteUint32(scope->end_position());
 #endif
@@ -279,24 +250,19 @@ void ProducedPreParsedScopeData::SaveScopeAllocationData(
   SaveDataForScope(scope);
 }
 
-bool ProducedPreParsedScopeData::ContainsInnerFunctions() const {
-  return byte_data_->size() > kPlaceholderSize;
+bool PreParsedScopeDataBuilder::ContainsInnerFunctions() const {
+  return byte_data_->size() > ByteData::kPlaceholderSize;
 }
 
-MaybeHandle<PreParsedScopeData> ProducedPreParsedScopeData::Serialize(
+MaybeHandle<PreParsedScopeData> PreParsedScopeDataBuilder::Serialize(
     Isolate* isolate) {
-  if (!previously_produced_preparsed_scope_data_.is_null()) {
-    DCHECK(!bailed_out_);
-    DCHECK_EQ(data_for_inner_functions_.size(), 0);
-    return previously_produced_preparsed_scope_data_;
-  }
   if (bailed_out_) {
     return MaybeHandle<PreParsedScopeData>();
   }
 
   DCHECK(!ThisOrParentBailedOut());
 
-  if (byte_data_->size() <= kPlaceholderSize) {
+  if (byte_data_->size() <= ByteData::kPlaceholderSize) {
     // The data contains only the placeholder.
     return MaybeHandle<PreParsedScopeData>();
   }
@@ -322,7 +288,33 @@ MaybeHandle<PreParsedScopeData> ProducedPreParsedScopeData::Serialize(
   return data;
 }
 
-bool ProducedPreParsedScopeData::ScopeNeedsData(Scope* scope) {
+ZonePreParsedScopeData* PreParsedScopeDataBuilder::Serialize(Zone* zone) {
+  if (bailed_out_) {
+    return nullptr;
+  }
+
+  DCHECK(!ThisOrParentBailedOut());
+
+  if (byte_data_->size() <= ByteData::kPlaceholderSize) {
+    // The data contains only the placeholder.
+    return nullptr;
+  }
+
+  int child_length = static_cast<int>(data_for_inner_functions_.size());
+  ZonePreParsedScopeData* result = new (zone) ZonePreParsedScopeData(
+      zone, byte_data_->begin(), byte_data_->end(), child_length);
+
+  int i = 0;
+  for (const auto& item : data_for_inner_functions_) {
+    ZonePreParsedScopeData* child = item->Serialize(zone);
+    result->set_child(i, child);
+    i++;
+  }
+
+  return result;
+}
+
+bool PreParsedScopeDataBuilder::ScopeNeedsData(Scope* scope) {
   if (scope->scope_type() == ScopeType::FUNCTION_SCOPE) {
     // Default constructors don't need data (they cannot contain inner functions
     // defined by the user). Other functions do.
@@ -344,9 +336,9 @@ bool ProducedPreParsedScopeData::ScopeNeedsData(Scope* scope) {
   return false;
 }
 
-bool ProducedPreParsedScopeData::ScopeIsSkippableFunctionScope(Scope* scope) {
+bool PreParsedScopeDataBuilder::ScopeIsSkippableFunctionScope(Scope* scope) {
   // Lazy non-arrow function scopes are skippable. Lazy functions are exactly
-  // those Scopes which have their own ProducedPreParsedScopeData object. This
+  // those Scopes which have their own PreParsedScopeDataBuilder object. This
   // logic ensures that the scope allocation data is consistent with the
   // skippable function data (both agree on where the lazy function boundaries
   // are).
@@ -355,10 +347,10 @@ bool ProducedPreParsedScopeData::ScopeIsSkippableFunctionScope(Scope* scope) {
   }
   DeclarationScope* declaration_scope = scope->AsDeclarationScope();
   return !declaration_scope->is_arrow_scope() &&
-         declaration_scope->produced_preparsed_scope_data() != nullptr;
+         declaration_scope->preparsed_scope_data_builder() != nullptr;
 }
 
-void ProducedPreParsedScopeData::SaveDataForScope(Scope* scope) {
+void PreParsedScopeDataBuilder::SaveDataForScope(Scope* scope) {
   DCHECK_NE(scope->end_position(), kNoSourcePosition);
 
   if (!ScopeNeedsData(scope)) {
@@ -392,7 +384,7 @@ void ProducedPreParsedScopeData::SaveDataForScope(Scope* scope) {
   SaveDataForInnerScopes(scope);
 }
 
-void ProducedPreParsedScopeData::SaveDataForVariable(Variable* var) {
+void PreParsedScopeDataBuilder::SaveDataForVariable(Variable* var) {
 #ifdef DEBUG
   // Store the variable name in debug mode; this way we can check that we
   // restore data to the correct variable.
@@ -410,7 +402,7 @@ void ProducedPreParsedScopeData::SaveDataForVariable(Variable* var) {
   byte_data_->WriteQuarter(variable_data);
 }
 
-void ProducedPreParsedScopeData::SaveDataForInnerScopes(Scope* scope) {
+void PreParsedScopeDataBuilder::SaveDataForInnerScopes(Scope* scope) {
   // Inner scopes are stored in the reverse order, but we'd like to write the
   // data in the logical order. There might be many inner scopes, so we don't
   // want to recurse here.
@@ -419,9 +411,9 @@ void ProducedPreParsedScopeData::SaveDataForInnerScopes(Scope* scope) {
        inner = inner->sibling()) {
     if (ScopeIsSkippableFunctionScope(inner)) {
       // Don't save data about function scopes, since they'll have their own
-      // ProducedPreParsedScopeData where their data is saved.
+      // PreParsedScopeDataBuilder where their data is saved.
       DCHECK_NOT_NULL(
-          inner->AsDeclarationScope()->produced_preparsed_scope_data());
+          inner->AsDeclarationScope()->preparsed_scope_data_builder());
       continue;
     }
     scopes.push_back(inner);
@@ -431,91 +423,83 @@ void ProducedPreParsedScopeData::SaveDataForInnerScopes(Scope* scope) {
   }
 }
 
-ConsumedPreParsedScopeData::ByteData::ReadingScope::ReadingScope(
-    ConsumedPreParsedScopeData* parent)
-    : ReadingScope(parent->scope_data_.get(), parent->data_->scope_data()) {}
+class BuilderProducedPreParsedScopeData final
+    : public ProducedPreParsedScopeData {
+ public:
+  explicit BuilderProducedPreParsedScopeData(PreParsedScopeDataBuilder* builder)
+      : builder_(builder) {}
 
-int32_t ConsumedPreParsedScopeData::ByteData::ReadUint32() {
-  DCHECK_NOT_NULL(data_);
-  DCHECK_GE(RemainingBytes(), kUint32Size);
-#ifdef DEBUG
-  // Check that there indeed is an integer following.
-  DCHECK_EQ(data_->get(index_++), kUint32Size);
-#endif
-  int32_t result = 0;
-  byte* p = reinterpret_cast<byte*>(&result);
-  for (int i = 0; i < 4; ++i) {
-    *p++ = data_->get(index_++);
+  MaybeHandle<PreParsedScopeData> Serialize(Isolate* isolate) final {
+    return builder_->Serialize(isolate);
   }
-  stored_quarters_ = 0;
-  return result;
-}
 
-uint8_t ConsumedPreParsedScopeData::ByteData::ReadUint8() {
-  DCHECK_NOT_NULL(data_);
-  DCHECK_GE(RemainingBytes(), kUint8Size);
-#ifdef DEBUG
-  // Check that there indeed is a byte following.
-  DCHECK_EQ(data_->get(index_++), kUint8Size);
-#endif
-  stored_quarters_ = 0;
-  return data_->get(index_++);
-}
+  ZonePreParsedScopeData* Serialize(Zone* zone) final {
+    return builder_->Serialize(zone);
+  };
 
-uint8_t ConsumedPreParsedScopeData::ByteData::ReadQuarter() {
-  DCHECK_NOT_NULL(data_);
-  if (stored_quarters_ == 0) {
-    DCHECK_GE(RemainingBytes(), kUint8Size);
-#ifdef DEBUG
-    // Check that there indeed are quarters following.
-    DCHECK_EQ(data_->get(index_++), kQuarterMarker);
-#endif
-    stored_byte_ = data_->get(index_++);
-    stored_quarters_ = 4;
-  }
-  // Read the first 2 bits from stored_byte_.
-  uint8_t result = (stored_byte_ >> 6) & 3;
-  DCHECK_LE(result, 3);
-  --stored_quarters_;
-  stored_byte_ <<= 2;
-  return result;
-}
+ private:
+  PreParsedScopeDataBuilder* builder_;
+};
 
-size_t ConsumedPreParsedScopeData::ByteData::RemainingBytes() const {
-  DCHECK_NOT_NULL(data_);
-  return data_->length() - index_;
-}
+class OnHeapProducedPreParsedScopeData final
+    : public ProducedPreParsedScopeData {
+ public:
+  explicit OnHeapProducedPreParsedScopeData(Handle<PreParsedScopeData> data)
+      : data_(data) {}
 
-ConsumedPreParsedScopeData::ConsumedPreParsedScopeData()
-    : isolate_(nullptr), scope_data_(new ByteData()), child_index_(0) {}
+  MaybeHandle<PreParsedScopeData> Serialize(Isolate* isolate) final {
+    return data_;
+  }
 
-ConsumedPreParsedScopeData::~ConsumedPreParsedScopeData() {}
+  ZonePreParsedScopeData* Serialize(Zone* zone) final {
+    // Not required.
+    UNREACHABLE();
+  };
 
-void ConsumedPreParsedScopeData::SetData(Isolate* isolate,
-                                         Handle<PreParsedScopeData> data) {
-  DCHECK_NOT_NULL(isolate);
-  DCHECK(data->IsPreParsedScopeData());
-  isolate_ = isolate;
-  data_ = data;
-#ifdef DEBUG
-  ByteData::ReadingScope reading_scope(this);
-  int scope_data_start = scope_data_->ReadUint32();
-  scope_data_->SetPosition(scope_data_start);
-  DCHECK_EQ(scope_data_->ReadUint32(), kMagicValue);
-  // The first data item is scope_data_start. Skip over it.
-  scope_data_->SetPosition(kPlaceholderSize);
-#endif
+ private:
+  Handle<PreParsedScopeData> data_;
+};
+
+class ZoneProducedPreParsedScopeData final : public ProducedPreParsedScopeData {
+ public:
+  explicit ZoneProducedPreParsedScopeData(ZonePreParsedScopeData* data)
+      : data_(data) {}
+
+  MaybeHandle<PreParsedScopeData> Serialize(Isolate* isolate) final {
+    return data_->Serialize(isolate);
+  }
+
+  ZonePreParsedScopeData* Serialize(Zone* zone) final { return data_; };
+
+ private:
+  ZonePreParsedScopeData* data_;
+};
+
+ProducedPreParsedScopeData* ProducedPreParsedScopeData::For(
+    PreParsedScopeDataBuilder* builder, Zone* zone) {
+  return new (zone) BuilderProducedPreParsedScopeData(builder);
+}
+
+ProducedPreParsedScopeData* ProducedPreParsedScopeData::For(
+    Handle<PreParsedScopeData> data, Zone* zone) {
+  return new (zone) OnHeapProducedPreParsedScopeData(data);
+}
+
+ProducedPreParsedScopeData* ProducedPreParsedScopeData::For(
+    ZonePreParsedScopeData* data, Zone* zone) {
+  return new (zone) ZoneProducedPreParsedScopeData(data);
 }
 
+template <class Data>
 ProducedPreParsedScopeData*
-ConsumedPreParsedScopeData::GetDataForSkippableFunction(
+BaseConsumedPreParsedScopeData<Data>::GetDataForSkippableFunction(
     Zone* zone, int start_position, int* end_position, int* num_parameters,
     int* num_inner_functions, bool* uses_super_property,
     LanguageMode* language_mode) {
   // The skippable function *must* be the next function in the data. Use the
   // start position as a sanity check.
-  ByteData::ReadingScope reading_scope(this);
-  CHECK_GE(scope_data_->RemainingBytes(), kSkippableFunctionDataSize);
+  typename ByteData::ReadingScope reading_scope(this);
+  CHECK_GE(scope_data_->RemainingBytes(), ByteData::kSkippableFunctionDataSize);
   int start_position_from_data = scope_data_->ReadUint32();
   CHECK_EQ(start_position, start_position_from_data);
 
@@ -531,28 +515,19 @@ ConsumedPreParsedScopeData::GetDataForSkippableFunction(
   // Retrieve the corresponding PreParsedScopeData and associate it to the
   // skipped function. If the skipped functions contains inner functions, those
   // can be skipped when the skipped function is eagerly parsed.
-  CHECK_GT(data_->length(), child_index_);
-  Object* child_data = data_->child_data(child_index_++);
-  if (!child_data->IsPreParsedScopeData()) {
-    return nullptr;
-  }
-  Handle<PreParsedScopeData> child_data_handle(
-      PreParsedScopeData::cast(child_data), isolate_);
-  return new (zone) ProducedPreParsedScopeData(child_data_handle, zone);
+  return GetChildData(zone, child_index_++);
 }
 
-void ConsumedPreParsedScopeData::RestoreScopeAllocationData(
+template <class Data>
+void BaseConsumedPreParsedScopeData<Data>::RestoreScopeAllocationData(
     DeclarationScope* scope) {
-  DCHECK(FLAG_preparser_scope_analysis);
   DCHECK_EQ(scope->scope_type(), ScopeType::FUNCTION_SCOPE);
-  DCHECK(!data_.is_null());
-
-  ByteData::ReadingScope reading_scope(this);
+  typename ByteData::ReadingScope reading_scope(this);
 
 #ifdef DEBUG
   int magic_value_from_data = scope_data_->ReadUint32();
   // Check that we've consumed all inner function data.
-  DCHECK_EQ(magic_value_from_data, kMagicValue);
+  DCHECK_EQ(magic_value_from_data, ByteData::kMagicValue);
 
   int start_position_from_data = scope_data_->ReadUint32();
   int end_position_from_data = scope_data_->ReadUint32();
@@ -566,7 +541,8 @@ void ConsumedPreParsedScopeData::RestoreScopeAllocationData(
   DCHECK_EQ(scope_data_->RemainingBytes(), 0);
 }
 
-void ConsumedPreParsedScopeData::RestoreData(Scope* scope) {
+template <typename Data>
+void BaseConsumedPreParsedScopeData<Data>::RestoreData(Scope* scope) {
   if (scope->is_declaration_scope() &&
       scope->AsDeclarationScope()->is_skipped_function()) {
     return;
@@ -575,18 +551,12 @@ void ConsumedPreParsedScopeData::RestoreData(Scope* scope) {
   // It's possible that scope is not present in the data at all (since PreParser
   // doesn't create the corresponding scope). In this case, the Scope won't
   // contain any variables for which we need the data.
-  if (!ProducedPreParsedScopeData::ScopeNeedsData(scope)) {
+  if (!PreParsedScopeDataBuilder::ScopeNeedsData(scope)) {
     return;
   }
 
-  if (scope_data_->RemainingBytes() < kUint8Size) {
-    // Temporary debugging code for detecting inconsistent data. Write debug
-    // information on the stack, then crash.
-    isolate_->PushStackTraceAndDie();
-  }
-
   // scope_type is stored only in debug mode.
-  CHECK_GE(scope_data_->RemainingBytes(), kUint8Size);
+  CHECK_GE(scope_data_->RemainingBytes(), ByteData::kUint8Size);
   DCHECK_EQ(scope_data_->ReadUint8(), scope->scope_type());
 
   uint32_t eval = scope_data_->ReadUint8();
@@ -613,7 +583,9 @@ void ConsumedPreParsedScopeData::RestoreData(Scope* scope) {
   RestoreDataForInnerScopes(scope);
 }
 
-void ConsumedPreParsedScopeData::RestoreDataForVariable(Variable* var) {
+template <typename Data>
+void BaseConsumedPreParsedScopeData<Data>::RestoreDataForVariable(
+    Variable* var) {
 #ifdef DEBUG
   const AstRawString* name = var->raw_name();
   bool data_one_byte = scope_data_->ReadUint8();
@@ -647,7 +619,9 @@ void ConsumedPreParsedScopeData::RestoreDataForVariable(Variable* var) {
   }
 }
 
-void ConsumedPreParsedScopeData::RestoreDataForInnerScopes(Scope* scope) {
+template <typename Data>
+void BaseConsumedPreParsedScopeData<Data>::RestoreDataForInnerScopes(
+    Scope* scope) {
   std::vector<Scope*> scopes;
   for (Scope* inner = scope->inner_scope(); inner != nullptr;
        inner = inner->sibling()) {
@@ -658,5 +632,106 @@ void ConsumedPreParsedScopeData::RestoreDataForInnerScopes(Scope* scope) {
   }
 }
 
+#ifdef DEBUG
+template <class Data>
+void BaseConsumedPreParsedScopeData<Data>::VerifyDataStart() {
+  typename ByteData::ReadingScope reading_scope(this);
+  int scope_data_start = scope_data_->ReadUint32();
+  scope_data_->SetPosition(scope_data_start);
+  DCHECK_EQ(scope_data_->ReadUint32(), ByteData::kMagicValue);
+  // The first data item is scope_data_start. Skip over it.
+  scope_data_->SetPosition(ByteData::kPlaceholderSize);
+}
+#endif
+
+PodArray<uint8_t>* OnHeapConsumedPreParsedScopeData::GetScopeData() {
+  return data_->scope_data();
+}
+
+ProducedPreParsedScopeData* OnHeapConsumedPreParsedScopeData::GetChildData(
+    Zone* zone, int child_index) {
+  CHECK_GT(data_->length(), child_index);
+  Object* child_data = data_->child_data(child_index);
+  if (!child_data->IsPreParsedScopeData()) {
+    return nullptr;
+  }
+  Handle<PreParsedScopeData> child_data_handle(
+      PreParsedScopeData::cast(child_data), isolate_);
+  return ProducedPreParsedScopeData::For(child_data_handle, zone);
+}
+
+OnHeapConsumedPreParsedScopeData::OnHeapConsumedPreParsedScopeData(
+    Isolate* isolate, Handle<PreParsedScopeData> data)
+    : BaseConsumedPreParsedScopeData<PodArray<uint8_t>>(),
+      isolate_(isolate),
+      data_(data) {
+  DCHECK_NOT_NULL(isolate);
+  DCHECK(data->IsPreParsedScopeData());
+#ifdef DEBUG
+  VerifyDataStart();
+#endif
+}
+
+ZonePreParsedScopeData::ZonePreParsedScopeData(
+    Zone* zone, ZoneChunkList<uint8_t>::iterator byte_data_begin,
+    ZoneChunkList<uint8_t>::iterator byte_data_end, int child_length)
+    : byte_data_(byte_data_begin, byte_data_end, zone),
+      children_(child_length, zone) {}
+
+Handle<PreParsedScopeData> ZonePreParsedScopeData::Serialize(Isolate* isolate) {
+  int child_data_length = child_length();
+  Handle<PreParsedScopeData> result =
+      isolate->factory()->NewPreParsedScopeData(child_data_length);
+
+  Handle<PodArray<uint8_t>> scope_data_array = PodArray<uint8_t>::New(
+      isolate, static_cast<int>(byte_data()->size()), TENURED);
+  scope_data_array->copy_in(0, byte_data()->data(),
+                            static_cast<int>(byte_data()->size()));
+  result->set_scope_data(*scope_data_array);
+
+  for (int i = 0; i < child_data_length; i++) {
+    ZonePreParsedScopeData* child = get_child(i);
+    if (child) {
+      Handle<PreParsedScopeData> child_data = child->Serialize(isolate);
+      result->set_child_data(i, *child_data);
+    }
+  }
+  return result;
+}
+
+ZoneConsumedPreParsedScopeData::ZoneConsumedPreParsedScopeData(
+    Zone* zone, ZonePreParsedScopeData* data)
+    : data_(data), scope_data_wrapper_(data_->byte_data()) {
+#ifdef DEBUG
+  VerifyDataStart();
+#endif
+}
+
+ZoneVectorWrapper* ZoneConsumedPreParsedScopeData::GetScopeData() {
+  return &scope_data_wrapper_;
+}
+
+ProducedPreParsedScopeData* ZoneConsumedPreParsedScopeData::GetChildData(
+    Zone* zone, int child_index) {
+  CHECK_GT(data_->child_length(), child_index);
+  ZonePreParsedScopeData* child_data = data_->get_child(child_index);
+  if (child_data == nullptr) {
+    return nullptr;
+  }
+  return ProducedPreParsedScopeData::For(child_data, zone);
+}
+
+std::unique_ptr<ConsumedPreParsedScopeData> ConsumedPreParsedScopeData::For(
+    Isolate* isolate, Handle<PreParsedScopeData> data) {
+  DCHECK(!data.is_null());
+  return base::make_unique<OnHeapConsumedPreParsedScopeData>(isolate, data);
+}
+
+std::unique_ptr<ConsumedPreParsedScopeData> ConsumedPreParsedScopeData::For(
+    Zone* zone, ZonePreParsedScopeData* data) {
+  if (data == nullptr) return {};
+  return base::make_unique<ZoneConsumedPreParsedScopeData>(zone, data);
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/parsing/preparsed-scope-data.h b/deps/v8/src/parsing/preparsed-scope-data.h
index 61d67291a4..25298c4331 100644
--- a/deps/v8/src/parsing/preparsed-scope-data.h
+++ b/deps/v8/src/parsing/preparsed-scope-data.h
@@ -5,23 +5,21 @@
 #ifndef V8_PARSING_PREPARSED_SCOPE_DATA_H_
 #define V8_PARSING_PREPARSED_SCOPE_DATA_H_
 
-#include <set>
-#include <unordered_map>
-#include <vector>
-
 #include "src/globals.h"
 #include "src/handles.h"
-#include "src/objects/shared-function-info.h"
+#include "src/maybe-handles.h"
 #include "src/zone/zone-chunk-list.h"
+#include "src/zone/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 
 template <typename T>
-class Handle;
+class PodArray;
 
 class PreParser;
 class PreParsedScopeData;
+class ZonePreParsedScopeData;
 
 /*
 
@@ -64,40 +62,15 @@ class PreParsedScopeData;
 
  */
 
-class ProducedPreParsedScopeData : public ZoneObject {
+class PreParsedScopeDataBuilder : public ZoneObject {
  public:
-  class ByteData : public ZoneObject {
-   public:
-    explicit ByteData(Zone* zone)
-        : backing_store_(zone), free_quarters_in_last_byte_(0) {}
-
-    void WriteUint32(uint32_t data);
-    void WriteUint8(uint8_t data);
-    void WriteQuarter(uint8_t data);
-
-#ifdef DEBUG
-    // For overwriting previously written data at position 0.
-    void OverwriteFirstUint32(uint32_t data);
-#endif
-
-    Handle<PodArray<uint8_t>> Serialize(Isolate* isolate);
-
-    size_t size() const { return backing_store_.size(); }
+  class ByteData;
 
-   private:
-    ZoneChunkList<uint8_t> backing_store_;
-    uint8_t free_quarters_in_last_byte_;
-  };
-
-  // Create a ProducedPreParsedScopeData object which will collect data as we
+  // Create a PreParsedScopeDataBuilder object which will collect data as we
   // parse.
-  ProducedPreParsedScopeData(Zone* zone, ProducedPreParsedScopeData* parent);
-
-  // Create a ProducedPreParsedScopeData which is just a proxy for a previous
-  // produced PreParsedScopeData.
-  ProducedPreParsedScopeData(Handle<PreParsedScopeData> data, Zone* zone);
+  PreParsedScopeDataBuilder(Zone* zone, PreParsedScopeDataBuilder* parent);
 
-  ProducedPreParsedScopeData* parent() const { return parent_; }
+  PreParsedScopeDataBuilder* parent() const { return parent_; }
 
   // For gathering the inner function data and splitting it up according to the
   // laziness boundaries. Each lazy function gets its own
@@ -112,7 +85,7 @@ class ProducedPreParsedScopeData : public ZoneObject {
    private:
     DeclarationScope* function_scope_;
     PreParser* preparser_;
-    ProducedPreParsedScopeData* produced_preparsed_scope_data_;
+    PreParsedScopeDataBuilder* builder_;
 
     DISALLOW_COPY_AND_ASSIGN(DataGatheringScope);
   };
@@ -148,15 +121,15 @@ class ProducedPreParsedScopeData : public ZoneObject {
 
   bool ContainsInnerFunctions() const;
 
-  // If there is data (if the Scope contains skippable inner functions), move
-  // the data into the heap and return a Handle to it; otherwise return a null
-  // MaybeHandle.
-  MaybeHandle<PreParsedScopeData> Serialize(Isolate* isolate);
-
   static bool ScopeNeedsData(Scope* scope);
   static bool ScopeIsSkippableFunctionScope(Scope* scope);
 
  private:
+  friend class BuilderProducedPreParsedScopeData;
+
+  virtual MaybeHandle<PreParsedScopeData> Serialize(Isolate* isolate);
+  virtual ZonePreParsedScopeData* Serialize(Zone* zone);
+
   void AddSkippableFunction(int start_position, int end_position,
                             int num_parameters, int num_inner_functions,
                             LanguageMode language_mode,
@@ -166,88 +139,72 @@ class ProducedPreParsedScopeData : public ZoneObject {
   void SaveDataForVariable(Variable* var);
   void SaveDataForInnerScopes(Scope* scope);
 
-  ProducedPreParsedScopeData* parent_;
+  PreParsedScopeDataBuilder* parent_;
 
   ByteData* byte_data_;
-  ZoneChunkList<ProducedPreParsedScopeData*> data_for_inner_functions_;
+  ZoneChunkList<PreParsedScopeDataBuilder*> data_for_inner_functions_;
 
   // Whether we've given up producing the data for this function.
   bool bailed_out_;
 
-  // ProducedPreParsedScopeData can also mask a Handle<PreParsedScopeData>
-  // which was produced already earlier. This happens for deeper lazy functions.
-  Handle<PreParsedScopeData> previously_produced_preparsed_scope_data_;
+  DISALLOW_COPY_AND_ASSIGN(PreParsedScopeDataBuilder);
+};
 
-  DISALLOW_COPY_AND_ASSIGN(ProducedPreParsedScopeData);
+class ProducedPreParsedScopeData : public ZoneObject {
+ public:
+  // If there is data (if the Scope contains skippable inner functions), move
+  // the data into the heap and return a Handle to it; otherwise return a null
+  // MaybeHandle.
+  virtual MaybeHandle<PreParsedScopeData> Serialize(Isolate* isolate) = 0;
+
+  // If there is data (if the Scope contains skippable inner functions), return
+  // an off-heap ZonePreParsedScopeData representing the data; otherwise
+  // return nullptr.
+  virtual ZonePreParsedScopeData* Serialize(Zone* zone) = 0;
+
+  // Create a ProducedPreParsedScopeData which is a proxy for a previous
+  // produced PreParsedScopeData in zone.
+  static ProducedPreParsedScopeData* For(PreParsedScopeDataBuilder* builder,
+                                         Zone* zone);
+
+  // Create a ProducedPreParsedScopeData which is a proxy for a previous
+  // produced PreParsedScopeData on the heap.
+  static ProducedPreParsedScopeData* For(Handle<PreParsedScopeData> data,
+                                         Zone* zone);
+
+  // Create a ProducedPreParsedScopeData which is a proxy for a previous
+  // produced PreParsedScopeData in zone.
+  static ProducedPreParsedScopeData* For(ZonePreParsedScopeData* data,
+                                         Zone* zone);
 };
 
 class ConsumedPreParsedScopeData {
  public:
-  class ByteData {
-   public:
-    ByteData()
-        : data_(nullptr), index_(0), stored_quarters_(0), stored_byte_(0) {}
-
-    // Reading from the ByteData is only allowed when a ReadingScope is on the
-    // stack. This ensures that we have a DisallowHeapAllocation in place
-    // whenever ByteData holds a raw pointer into the heap.
-    class ReadingScope {
-     public:
-      ReadingScope(ByteData* consumed_data, PodArray<uint8_t>* data)
-          : consumed_data_(consumed_data) {
-        consumed_data->data_ = data;
-      }
-      explicit ReadingScope(ConsumedPreParsedScopeData* parent);
-      ~ReadingScope() { consumed_data_->data_ = nullptr; }
-
-     private:
-      ByteData* consumed_data_;
-      DisallowHeapAllocation no_gc;
-    };
-
-    void SetPosition(int position) { index_ = position; }
-
-    int32_t ReadUint32();
-    uint8_t ReadUint8();
-    uint8_t ReadQuarter();
-
-    size_t RemainingBytes() const;
-
-    // private:
-    PodArray<uint8_t>* data_;
-    int index_;
-    uint8_t stored_quarters_;
-    uint8_t stored_byte_;
-  };
-
-  ConsumedPreParsedScopeData();
-  ~ConsumedPreParsedScopeData();
+  // Creates a ConsumedPreParsedScopeData representing the data of an on-heap
+  // PreParsedScopeData |data|.
+  static std::unique_ptr<ConsumedPreParsedScopeData> For(
+      Isolate* isolate, Handle<PreParsedScopeData> data);
 
-  void SetData(Isolate* isolate, Handle<PreParsedScopeData> data);
+  // Creates a ConsumedPreParsedScopeData representing the data of an off-heap
+  // ZonePreParsedScopeData |data|.
+  static std::unique_ptr<ConsumedPreParsedScopeData> For(
+      Zone* zone, ZonePreParsedScopeData* data);
 
-  bool HasData() const { return !data_.is_null(); }
+  virtual ~ConsumedPreParsedScopeData() = default;
 
-  ProducedPreParsedScopeData* GetDataForSkippableFunction(
+  virtual ProducedPreParsedScopeData* GetDataForSkippableFunction(
       Zone* zone, int start_position, int* end_position, int* num_parameters,
       int* num_inner_functions, bool* uses_super_property,
-      LanguageMode* language_mode);
+      LanguageMode* language_mode) = 0;
 
   // Restores the information needed for allocating the Scope's (and its
   // subscopes') variables.
-  void RestoreScopeAllocationData(DeclarationScope* scope);
+  virtual void RestoreScopeAllocationData(DeclarationScope* scope) = 0;
 
- private:
-  void RestoreData(Scope* scope);
-  void RestoreDataForVariable(Variable* var);
-  void RestoreDataForInnerScopes(Scope* scope);
-
-  Isolate* isolate_;
-  Handle<PreParsedScopeData> data_;
-  std::unique_ptr<ByteData> scope_data_;
-  // When consuming the data, these indexes point to the data we're going to
-  // consume next.
-  int child_index_;
+ protected:
+  ConsumedPreParsedScopeData() = default;
 
+ private:
   DISALLOW_COPY_AND_ASSIGN(ConsumedPreParsedScopeData);
 };
 
diff --git a/deps/v8/src/parsing/preparser.cc b/deps/v8/src/parsing/preparser.cc
index d449c8d76b..0e74014542 100644
--- a/deps/v8/src/parsing/preparser.cc
+++ b/deps/v8/src/parsing/preparser.cc
@@ -123,22 +123,23 @@ PreParser::PreParseResult PreParser::PreParseFunction(
     int script_id) {
   DCHECK_EQ(FUNCTION_SCOPE, function_scope->scope_type());
   use_counts_ = use_counts;
-  DCHECK(!track_unresolved_variables_);
-  track_unresolved_variables_ = is_inner_function;
   set_script_id(script_id);
 #ifdef DEBUG
   function_scope->set_is_being_lazily_parsed(true);
 #endif
 
+  track_unresolved_variables_ =
+      ShouldTrackUnresolvedVariables(is_inner_function);
+
   // Start collecting data for a new function which might contain skippable
   // functions.
-  std::unique_ptr<ProducedPreParsedScopeData::DataGatheringScope>
-      produced_preparsed_scope_data_scope;
+  std::unique_ptr<PreParsedScopeDataBuilder::DataGatheringScope>
+      preparsed_scope_data_builder_scope;
   if (FLAG_preparser_scope_analysis && !IsArrowFunction(kind)) {
-    track_unresolved_variables_ = true;
-    produced_preparsed_scope_data_scope.reset(
-        new ProducedPreParsedScopeData::DataGatheringScope(function_scope,
-                                                           this));
+    DCHECK(track_unresolved_variables_);
+    preparsed_scope_data_builder_scope.reset(
+        new PreParsedScopeDataBuilder::DataGatheringScope(function_scope,
+                                                          this));
   }
 
   // In the preparser, we use the function literal ids to count how many
@@ -166,7 +167,11 @@ PreParser::PreParseResult PreParser::PreParseFunction(
     formals_classifier.reset(new ExpressionClassifier(this, &duplicate_finder));
     // We return kPreParseSuccess in failure cases too - errors are retrieved
     // separately by Parser::SkipLazyFunctionBody.
-    ParseFormalParameterList(&formals, CHECK_OK_VALUE(kPreParseSuccess));
+    ParseFormalParameterList(
+        &formals,
+        CHECK_OK_VALUE(pending_error_handler()->ErrorUnidentifiableByPreParser()
+                           ? kPreParseNotIdentifiableError
+                           : kPreParseSuccess));
     Expect(Token::RPAREN, CHECK_OK_VALUE(kPreParseSuccess));
     int formals_end_position = scanner()->location().end_pos;
 
@@ -205,27 +210,22 @@ PreParser::PreParseResult PreParser::PreParseFunction(
     }
   }
 
-  if (!IsArrowFunction(kind) && track_unresolved_variables_ &&
-      result == kLazyParsingComplete) {
-    // Declare arguments after parsing the function since lexical 'arguments'
-    // masks the arguments object. Declare arguments before declaring the
-    // function var since the arguments object masks 'function arguments'.
-    function_scope->DeclareArguments(ast_value_factory());
-
-    DeclareFunctionNameVar(function_name, function_type, function_scope);
-  }
-
   use_counts_ = nullptr;
-  track_unresolved_variables_ = false;
 
   if (result == kLazyParsingAborted) {
+    DCHECK(!pending_error_handler()->ErrorUnidentifiableByPreParser());
     return kPreParseAbort;
   } else if (stack_overflow()) {
+    DCHECK(!pending_error_handler()->ErrorUnidentifiableByPreParser());
     return kPreParseStackOverflow;
+  } else if (pending_error_handler()->ErrorUnidentifiableByPreParser()) {
+    DCHECK(!*ok);
+    return kPreParseNotIdentifiableError;
   } else if (!*ok) {
     DCHECK(pending_error_handler()->has_pending_error());
   } else {
     DCHECK_EQ(Token::RBRACE, scanner()->peek());
+    DCHECK(result == kLazyParsingComplete);
 
     if (!IsArrowFunction(kind)) {
       // Validate parameter names. We can do this only after parsing the
@@ -234,17 +234,37 @@ PreParser::PreParseResult PreParser::PreParseFunction(
           is_sloppy(function_scope->language_mode()) && formals.is_simple &&
           !IsConciseMethod(kind);
       ValidateFormalParameters(function_scope->language_mode(),
-                               allow_duplicate_parameters,
-                               CHECK_OK_VALUE(kPreParseSuccess));
+                               allow_duplicate_parameters, ok);
+      if (!*ok) {
+        if (pending_error_handler()->ErrorUnidentifiableByPreParser()) {
+          return kPreParseNotIdentifiableError;
+        } else {
+          return kPreParseSuccess;
+        }
+      }
+
+      if (track_unresolved_variables_) {
+        // Declare arguments after parsing the function since lexical
+        // 'arguments' masks the arguments object. Declare arguments before
+        // declaring the function var since the arguments object masks 'function
+        // arguments'.
+        function_scope->DeclareArguments(ast_value_factory());
 
-      *produced_preparsed_scope_data = produced_preparsed_scope_data_;
+        DeclareFunctionNameVar(function_name, function_type, function_scope);
+      }
+
+      *produced_preparsed_scope_data = ProducedPreParsedScopeData::For(
+          preparsed_scope_data_builder_, main_zone());
     }
+    DCHECK(!pending_error_handler()->ErrorUnidentifiableByPreParser());
 
     if (is_strict(function_scope->language_mode())) {
       int end_pos = scanner()->location().end_pos;
       CheckStrictOctalLiteral(function_scope->start_position(), end_pos, ok);
     }
   }
+
+  DCHECK(!pending_error_handler()->ErrorUnidentifiableByPreParser());
   return kPreParseSuccess;
 }
 
@@ -290,15 +310,15 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
 
   // Start collecting data for a new function which might contain skippable
   // functions.
-  std::unique_ptr<ProducedPreParsedScopeData::DataGatheringScope>
-      produced_preparsed_scope_data_scope;
+  std::unique_ptr<PreParsedScopeDataBuilder::DataGatheringScope>
+      preparsed_scope_data_builder_scope;
   if (!function_state_->next_function_is_likely_called() &&
-      produced_preparsed_scope_data_ != nullptr) {
+      preparsed_scope_data_builder_ != nullptr) {
     DCHECK(FLAG_preparser_scope_analysis);
     DCHECK(track_unresolved_variables_);
-    produced_preparsed_scope_data_scope.reset(
-        new ProducedPreParsedScopeData::DataGatheringScope(function_scope,
-                                                           this));
+    preparsed_scope_data_builder_scope.reset(
+        new PreParsedScopeDataBuilder::DataGatheringScope(function_scope,
+                                                          this));
   }
 
   FunctionState function_state(&function_state_, &scope_, function_scope);
@@ -324,7 +344,7 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
   int pos = function_token_pos == kNoSourcePosition ? peek_position()
                                                     : function_token_pos;
   ParseFunctionBody(body, function_name, pos, formals, kind, function_type,
-                    CHECK_OK);
+                    FunctionBodyType::kBlock, true, CHECK_OK);
 
   // Parsing the body may change the language mode in our scope.
   language_mode = function_scope->language_mode();
@@ -346,8 +366,8 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
     CheckStrictOctalLiteral(start_position, end_position, CHECK_OK);
   }
 
-  if (produced_preparsed_scope_data_scope) {
-    produced_preparsed_scope_data_scope->MarkFunctionAsSkippable(
+  if (preparsed_scope_data_builder_scope) {
+    preparsed_scope_data_builder_scope->MarkFunctionAsSkippable(
         end_position, GetLastFunctionLiteralId() - func_id);
   }
   if (V8_UNLIKELY(FLAG_log_function_events)) {
@@ -394,19 +414,19 @@ PreParserStatement PreParser::BuildParameterInitializationBlock(
   DCHECK(scope()->is_function_scope());
   if (FLAG_preparser_scope_analysis &&
       scope()->AsDeclarationScope()->calls_sloppy_eval() &&
-      produced_preparsed_scope_data_ != nullptr) {
+      preparsed_scope_data_builder_ != nullptr) {
     // We cannot replicate the Scope structure constructed by the Parser,
     // because we've lost information whether each individual parameter was
     // simple or not. Give up trying to produce data to skip inner functions.
-    if (produced_preparsed_scope_data_->parent() != nullptr) {
+    if (preparsed_scope_data_builder_->parent() != nullptr) {
       // Lazy parsing started before the current function; the function which
       // cannot contain skippable functions is the parent function. (Its inner
       // functions cannot either; they are implicitly bailed out.)
-      produced_preparsed_scope_data_->parent()->Bailout();
+      preparsed_scope_data_builder_->parent()->Bailout();
     } else {
       // Lazy parsing started at the current function; it cannot contain
       // skippable functions.
-      produced_preparsed_scope_data_->Bailout();
+      preparsed_scope_data_builder_->Bailout();
     }
   }
 
diff --git a/deps/v8/src/parsing/preparser.h b/deps/v8/src/parsing/preparser.h
index 10c42fa940..65509a2029 100644
--- a/deps/v8/src/parsing/preparser.h
+++ b/deps/v8/src/parsing/preparser.h
@@ -10,7 +10,6 @@
 #include "src/parsing/parser-base.h"
 #include "src/parsing/preparser-logger.h"
 #include "src/pending-compilation-error-handler.h"
-#include "src/zone/zone-containers.h"
 
 namespace v8 {
 namespace internal {
@@ -23,7 +22,7 @@ namespace internal {
 // interface as AstNodeFactory, so ParserBase doesn't need to care which one is
 // used.
 
-class ProducedPreParsedScopeData;
+class PreParsedScopeDataBuilder;
 
 class PreParserIdentifier {
  public:
@@ -87,16 +86,18 @@ class PreParserIdentifier {
   friend class PreParserFactory;
 };
 
-
 class PreParserExpression {
  public:
+  using VariableZoneThreadedListType =
+      ZoneThreadedList<VariableProxy, VariableProxy::PreParserNext>;
+
   PreParserExpression()
       : code_(TypeField::encode(kNull)), variables_(nullptr) {}
 
   static PreParserExpression Null() { return PreParserExpression(); }
 
   static PreParserExpression Default(
-      ZonePtrList<VariableProxy>* variables = nullptr) {
+      VariableZoneThreadedListType* variables = nullptr) {
     return PreParserExpression(TypeField::encode(kExpression), variables);
   }
 
@@ -125,9 +126,7 @@ class PreParserExpression {
                                    right.variables_);
       }
       if (right.variables_ != nullptr) {
-        for (auto variable : *right.variables_) {
-          left.variables_->Add(variable, zone);
-        }
+        left.variables_->Append(std::move(*right.variables_));
       }
       return PreParserExpression(TypeField::encode(kExpression),
                                  left.variables_);
@@ -135,7 +134,8 @@ class PreParserExpression {
     return PreParserExpression(TypeField::encode(kExpression));
   }
 
-  static PreParserExpression Assignment(ZonePtrList<VariableProxy>* variables) {
+  static PreParserExpression Assignment(
+      VariableZoneThreadedListType* variables) {
     return PreParserExpression(TypeField::encode(kExpression) |
                                    ExpressionTypeField::encode(kAssignment),
                                variables);
@@ -146,13 +146,13 @@ class PreParserExpression {
   }
 
   static PreParserExpression ObjectLiteral(
-      ZonePtrList<VariableProxy>* variables) {
+      VariableZoneThreadedListType* variables) {
     return PreParserExpression(TypeField::encode(kObjectLiteralExpression),
                                variables);
   }
 
   static PreParserExpression ArrayLiteral(
-      ZonePtrList<VariableProxy>* variables) {
+      VariableZoneThreadedListType* variables) {
     return PreParserExpression(TypeField::encode(kArrayLiteralExpression),
                                variables);
   }
@@ -171,10 +171,9 @@ class PreParserExpression {
                                IsUseAsmField::encode(true));
   }
 
-  static PreParserExpression This(ZonePtrList<VariableProxy>* variables) {
+  static PreParserExpression This() {
     return PreParserExpression(TypeField::encode(kExpression) |
-                                   ExpressionTypeField::encode(kThisExpression),
-                               variables);
+                               ExpressionTypeField::encode(kThisExpression));
   }
 
   static PreParserExpression ThisPropertyWithPrivateFieldKey() {
@@ -336,7 +335,7 @@ class PreParserExpression {
     if (variables_ != nullptr) {
       DCHECK(IsIdentifier());
       DCHECK(AsIdentifier().IsPrivateName());
-      DCHECK_EQ(1, variables_->length());
+      DCHECK_EQ(1, variables_->LengthForTest());
       variables_->first()->set_is_private_field();
     }
   }
@@ -374,8 +373,9 @@ class PreParserExpression {
     kAssignment
   };
 
-  explicit PreParserExpression(uint32_t expression_code,
-                               ZonePtrList<VariableProxy>* variables = nullptr)
+  explicit PreParserExpression(
+      uint32_t expression_code,
+      VariableZoneThreadedListType* variables = nullptr)
       : code_(expression_code), variables_(variables) {}
 
   void AddVariable(VariableProxy* variable, Zone* zone) {
@@ -383,9 +383,9 @@ class PreParserExpression {
       return;
     }
     if (variables_ == nullptr) {
-      variables_ = new (zone) ZonePtrList<VariableProxy>(1, zone);
+      variables_ = new (zone) VariableZoneThreadedListType();
     }
-    variables_->Add(variable, zone);
+    variables_->Add(variable);
   }
 
   // The first three bits are for the Type.
@@ -410,64 +410,65 @@ class PreParserExpression {
   uint32_t code_;
   // If the PreParser is used in the variable tracking mode, PreParserExpression
   // accumulates variables in that expression.
-  ZonePtrList<VariableProxy>* variables_;
+  VariableZoneThreadedListType* variables_;
 
   friend class PreParser;
   friend class PreParserFactory;
-  template <typename T>
-  friend class PreParserList;
+  friend class PreParserExpressionList;
 };
 
 
 // The pre-parser doesn't need to build lists of expressions, identifiers, or
 // the like. If the PreParser is used in variable tracking mode, it needs to
 // build lists of variables though.
-template <typename T>
-class PreParserList {
+class PreParserExpressionList {
+  using VariableZoneThreadedListType =
+      ZoneThreadedList<VariableProxy, VariableProxy::PreParserNext>;
+
  public:
   // These functions make list->Add(some_expression) work (and do nothing).
-  PreParserList() : length_(0), variables_(nullptr) {}
-  PreParserList* operator->() { return this; }
-  void Add(const T& element, Zone* zone);
+  PreParserExpressionList() : PreParserExpressionList(0) {}
+  PreParserExpressionList* operator->() { return this; }
+  void Add(const PreParserExpression& expression, Zone* zone) {
+    if (expression.variables_ != nullptr) {
+      DCHECK(FLAG_lazy_inner_functions);
+      DCHECK_NOT_NULL(zone);
+      if (variables_ == nullptr) {
+        variables_ = new (zone) VariableZoneThreadedListType();
+      }
+      variables_->Append(std::move(*expression.variables_));
+    }
+    ++length_;
+  }
   int length() const { return length_; }
-  static PreParserList Null() { return PreParserList(-1); }
+  static PreParserExpressionList Null() { return PreParserExpressionList(-1); }
   bool IsNull() const { return length_ == -1; }
-  void Set(int index, const T& element) {}
+  void Set(int index, const PreParserExpression& element) {}
 
  private:
-  explicit PreParserList(int n) : length_(n), variables_(nullptr) {}
+  explicit PreParserExpressionList(int n) : length_(n), variables_(nullptr) {}
   int length_;
-  ZonePtrList<VariableProxy>* variables_;
+
+  VariableZoneThreadedListType* variables_;
 
   friend class PreParser;
   friend class PreParserFactory;
 };
 
-template <>
-inline void PreParserList<PreParserExpression>::Add(
-    const PreParserExpression& expression, Zone* zone) {
-  if (expression.variables_ != nullptr) {
-    DCHECK(FLAG_lazy_inner_functions);
-    DCHECK_NOT_NULL(zone);
-    if (variables_ == nullptr) {
-      variables_ = new (zone) ZonePtrList<VariableProxy>(1, zone);
-    }
-    for (auto identifier : (*expression.variables_)) {
-      variables_->Add(identifier, zone);
-    }
-  }
-  ++length_;
-}
-
-template <typename T>
-void PreParserList<T>::Add(const T& element, Zone* zone) {
-  ++length_;
-}
+class PreParserStatement;
 
-typedef PreParserList<PreParserExpression> PreParserExpressionList;
+class PreParserStatementList {
+ public:
+  PreParserStatementList() : PreParserStatementList(false) {}
+  PreParserStatementList* operator->() { return this; }
+  void Add(const PreParserStatement& element, Zone* zone) {}
+  static PreParserStatementList Null() { return PreParserStatementList(true); }
+  bool IsNull() const { return is_null_; }
 
-class PreParserStatement;
-typedef PreParserList<PreParserStatement> PreParserStatementList;
+ private:
+  explicit PreParserStatementList(bool is_null) : is_null_(is_null) {}
+  bool is_null_;
+};
 
 class PreParserStatement {
  public:
@@ -530,8 +531,6 @@ class PreParserStatement {
   // and PreParser.
   PreParserStatement* operator->() { return this; }
 
-  // TODO(adamk): These should return something even lighter-weight than
-  // PreParserStatementList.
   PreParserStatementList statements() { return PreParserStatementList(); }
   PreParserStatementList cases() { return PreParserStatementList(); }
 
@@ -563,11 +562,6 @@ class PreParserFactory {
   explicit PreParserFactory(AstValueFactory* ast_value_factory, Zone* zone)
       : ast_node_factory_(ast_value_factory, zone), zone_(zone) {}
 
-  void set_zone(Zone* zone) {
-    ast_node_factory_.set_zone(zone);
-    zone_ = zone;
-  }
-
   AstNodeFactory* ast_node_factory() { return &ast_node_factory_; }
 
   PreParserExpression NewStringLiteral(const PreParserIdentifier& identifier,
@@ -852,19 +846,22 @@ class PreParserFactory {
 
 struct PreParserFormalParameters : FormalParametersBase {
   struct Parameter : public ZoneObject {
-    Parameter(ZonePtrList<VariableProxy>* variables, bool is_rest)
+    using VariableZoneThreadedListType =
+        ZoneThreadedList<VariableProxy, VariableProxy::PreParserNext>;
+
+    Parameter(VariableZoneThreadedListType* variables, bool is_rest)
         : variables_(variables), is_rest(is_rest) {}
     Parameter** next() { return &next_parameter; }
     Parameter* const* next() const { return &next_parameter; }
 
-    ZonePtrList<VariableProxy>* variables_;
+    VariableZoneThreadedListType* variables_;
     Parameter* next_parameter = nullptr;
     bool is_rest : 1;
   };
   explicit PreParserFormalParameters(DeclarationScope* scope)
       : FormalParametersBase(scope) {}
 
-  ThreadedList<Parameter> params;
+  base::ThreadedList<Parameter> params;
 };
 
 
@@ -881,6 +878,48 @@ class PreParserTargetScope {
   explicit PreParserTargetScope(ParserBase<PreParser>* preparser) {}
 };
 
+class PreParserFuncNameInferrer {
+ public:
+  PreParserFuncNameInferrer(AstValueFactory* avf, Zone* zone) {}
+  void RemoveAsyncKeywordFromEnd() const {}
+  void Infer() const {}
+  void RemoveLastFunction() const {}
+
+  class State {
+   public:
+    explicit State(PreParserFuncNameInferrer* fni) {}
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(State);
+  };
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PreParserFuncNameInferrer);
+};
+
+class PreParserSourceRange {
+ public:
+  PreParserSourceRange() {}
+  PreParserSourceRange(int start, int end) {}
+  static PreParserSourceRange Empty() { return PreParserSourceRange(); }
+  static PreParserSourceRange OpenEnded(int32_t start) { return Empty(); }
+  static const PreParserSourceRange& ContinuationOf(
+      const PreParserSourceRange& that, int end) {
+    return that;
+  }
+};
+
+class PreParserSourceRangeScope {
+ public:
+  PreParserSourceRangeScope(Scanner* scanner, PreParserSourceRange* range) {}
+  const PreParserSourceRange& Finalize() const { return range_; }
+
+ private:
+  PreParserSourceRange range_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PreParserSourceRangeScope);
+};
+
 template <>
 struct ParserTypes<PreParser> {
   typedef ParserBase<PreParser> Base;
@@ -910,6 +949,10 @@ struct ParserTypes<PreParser> {
 
   typedef PreParserTarget Target;
   typedef PreParserTargetScope TargetScope;
+  typedef PreParserFuncNameInferrer FuncNameInferrer;
+  typedef PreParserSourceRange SourceRange;
+  typedef PreParserSourceRangeScope SourceRangeScope;
+  static constexpr bool ExpressionClassifierReportErrors = false;
 };
 
 
@@ -937,6 +980,7 @@ class PreParser : public ParserBase<PreParser> {
   enum PreParseResult {
     kPreParseStackOverflow,
     kPreParseAbort,
+    kPreParseNotIdentifiableError,
     kPreParseSuccess
   };
 
@@ -952,7 +996,7 @@ class PreParser : public ParserBase<PreParser> {
                               parsing_module, parsing_on_main_thread),
         use_counts_(nullptr),
         track_unresolved_variables_(false),
-        produced_preparsed_scope_data_(nullptr) {}
+        preparsed_scope_data_builder_(nullptr) {}
 
   static bool IsPreParser() { return true; }
 
@@ -980,13 +1024,17 @@ class PreParser : public ParserBase<PreParser> {
       ProducedPreParsedScopeData** produced_preparser_scope_data,
       int script_id);
 
-  ProducedPreParsedScopeData* produced_preparsed_scope_data() const {
-    return produced_preparsed_scope_data_;
+  V8_INLINE static bool ShouldTrackUnresolvedVariables(bool is_inner_function) {
+    return FLAG_preparser_scope_analysis || is_inner_function;
+  }
+
+  PreParsedScopeDataBuilder* preparsed_scope_data_builder() const {
+    return preparsed_scope_data_builder_;
   }
 
-  void set_produced_preparsed_scope_data(
-      ProducedPreParsedScopeData* produced_preparsed_scope_data) {
-    produced_preparsed_scope_data_ = produced_preparsed_scope_data;
+  void set_preparsed_scope_data_builder(
+      PreParsedScopeDataBuilder* preparsed_scope_data_builder) {
+    preparsed_scope_data_builder_ = preparsed_scope_data_builder;
   }
 
  private:
@@ -1009,12 +1057,13 @@ class PreParser : public ParserBase<PreParser> {
     return pending_error_handler_;
   }
 
-  V8_INLINE LazyParsingResult
-  SkipFunction(const AstRawString* name, FunctionKind kind,
-               FunctionLiteral::FunctionType function_type,
-               DeclarationScope* function_scope, int* num_parameters,
-               ProducedPreParsedScopeData** produced_preparsed_scope_data,
-               bool is_inner_function, bool may_abort, bool* ok) {
+  V8_INLINE bool SkipFunction(
+      const AstRawString* name, FunctionKind kind,
+      FunctionLiteral::FunctionType function_type,
+      DeclarationScope* function_scope, int* num_parameters,
+      ProducedPreParsedScopeData** produced_preparsed_scope_data,
+      bool is_inner_function, bool may_abort,
+      FunctionLiteral::EagerCompileHint* hint, bool* ok) {
     UNREACHABLE();
   }
 
@@ -1509,6 +1558,10 @@ class PreParser : public ParserBase<PreParser> {
                                              arg, error_type);
   }
 
+  V8_INLINE void ReportUnidentifiableError() {
+    pending_error_handler()->SetUnidentifiableError();
+  }
+
   V8_INLINE void ReportMessageAt(Scanner::Location source_location,
                                  MessageTemplate::Template message,
                                  const PreParserIdentifier& arg,
@@ -1558,16 +1611,12 @@ class PreParser : public ParserBase<PreParser> {
   }
 
   V8_INLINE PreParserExpression ThisExpression(int pos = kNoSourcePosition) {
-    ZonePtrList<VariableProxy>* variables = nullptr;
     if (track_unresolved_variables_) {
-      VariableProxy* proxy = scope()->NewUnresolved(
-          factory()->ast_node_factory(), ast_value_factory()->this_string(),
-          pos, THIS_VARIABLE);
-
-      variables = new (zone()) ZonePtrList<VariableProxy>(1, zone());
-      variables->Add(proxy, zone());
+      scope()->NewUnresolved(factory()->ast_node_factory(),
+                             ast_value_factory()->this_string(), pos,
+                             THIS_VARIABLE);
     }
-    return PreParserExpression::This(variables);
+    return PreParserExpression::This();
   }
 
   V8_INLINE PreParserExpression NewSuperPropertyReference(int pos) {
@@ -1648,14 +1697,6 @@ class PreParser : public ParserBase<PreParser> {
     return PreParserStatement::Jump();
   }
 
-  V8_INLINE void AddParameterInitializationBlock(
-      const PreParserFormalParameters& parameters, PreParserStatementList body,
-      bool is_async, bool* ok) {
-    if (!parameters.is_simple) {
-      BuildParameterInitializationBlock(parameters, ok);
-    }
-  }
-
   V8_INLINE void AddFormalParameter(PreParserFormalParameters* parameters,
                                     const PreParserExpression& pattern,
                                     const PreParserExpression& initializer,
@@ -1671,14 +1712,15 @@ class PreParser : public ParserBase<PreParser> {
 
   V8_INLINE void DeclareFormalParameters(
       DeclarationScope* scope,
-      const ThreadedList<PreParserFormalParameters::Parameter>& parameters,
+      const base::ThreadedList<PreParserFormalParameters::Parameter>&
+          parameters,
       bool is_simple) {
     if (!is_simple) scope->SetHasNonSimpleParameters();
     if (track_unresolved_variables_) {
       DCHECK(FLAG_lazy_inner_functions);
       for (auto parameter : parameters) {
         DCHECK_IMPLIES(is_simple, parameter->variables_ != nullptr);
-        DCHECK_IMPLIES(is_simple, parameter->variables_->length() == 1);
+        DCHECK_IMPLIES(is_simple, parameter->variables_->LengthForTest() == 1);
         // Make sure each parameter is added only once even if it's a
         // destructuring parameter which contains multiple names.
         bool add_parameter = true;
@@ -1733,7 +1775,7 @@ class PreParser : public ParserBase<PreParser> {
       const PreParserExpression& value, const PreParserExpression& identifier) {
   }
 
-  V8_INLINE ZoneVector<typename ExpressionClassifier::Error>*
+  V8_INLINE ZoneList<typename ExpressionClassifier::Error>*
   GetReportedErrorList() const {
     return function_state_->GetReportedErrorList();
   }
@@ -1758,7 +1800,7 @@ class PreParser : public ParserBase<PreParser> {
   bool track_unresolved_variables_;
   PreParserLogger log_;
 
-  ProducedPreParsedScopeData* produced_preparsed_scope_data_;
+  PreParsedScopeDataBuilder* preparsed_scope_data_builder_;
 };
 
 PreParserExpression PreParser::SpreadCall(const PreParserExpression& function,
diff --git a/deps/v8/src/parsing/scanner-character-streams.cc b/deps/v8/src/parsing/scanner-character-streams.cc
index d38fdd7c42..8472e9f4fc 100644
--- a/deps/v8/src/parsing/scanner-character-streams.cc
+++ b/deps/v8/src/parsing/scanner-character-streams.cc
@@ -4,6 +4,9 @@
 
 #include "src/parsing/scanner-character-streams.h"
 
+#include <memory>
+#include <vector>
+
 #include "include/v8.h"
 #include "src/counters.h"
 #include "src/globals.h"
@@ -15,21 +18,50 @@
 namespace v8 {
 namespace internal {
 
+class ScopedExternalStringLock {
+ public:
+  explicit ScopedExternalStringLock(ExternalString* string) {
+    DCHECK(string);
+    if (string->IsExternalOneByteString()) {
+      resource_ = ExternalOneByteString::cast(string)->resource();
+    } else {
+      DCHECK(string->IsExternalTwoByteString());
+      resource_ = ExternalTwoByteString::cast(string)->resource();
+    }
+    DCHECK(resource_);
+    resource_->Lock();
+  }
+
+  // Copying a lock increases the locking depth.
+  ScopedExternalStringLock(const ScopedExternalStringLock& other)
+      : resource_(other.resource_) {
+    resource_->Lock();
+  }
+
+  ~ScopedExternalStringLock() { resource_->Unlock(); }
+
+ private:
+  // Not nullptr.
+  const v8::String::ExternalStringResourceBase* resource_;
+};
+
 namespace {
 const unibrow::uchar kUtf8Bom = 0xFEFF;
 }  // namespace
 
 template <typename Char>
-struct HeapStringType;
+struct CharTraits;
 
 template <>
-struct HeapStringType<uint8_t> {
+struct CharTraits<uint8_t> {
   typedef SeqOneByteString String;
+  typedef ExternalOneByteString ExternalString;
 };
 
 template <>
-struct HeapStringType<uint16_t> {
+struct CharTraits<uint16_t> {
   typedef SeqTwoByteString String;
+  typedef ExternalTwoByteString ExternalString;
 };
 
 template <typename Char>
@@ -47,16 +79,21 @@ struct Range {
 template <typename Char>
 class OnHeapStream {
  public:
-  typedef typename HeapStringType<Char>::String String;
+  typedef typename CharTraits<Char>::String String;
 
   OnHeapStream(Handle<String> string, size_t start_offset, size_t end)
       : string_(string), start_offset_(start_offset), length_(end) {}
 
-  Range<Char> GetDataAt(size_t pos) {
+  OnHeapStream(const OnHeapStream& other) : start_offset_(0), length_(0) {
+    UNREACHABLE();
+  }
+
+  Range<Char> GetDataAt(size_t pos, RuntimeCallStats* stats) {
     return {&string_->GetChars()[start_offset_ + Min(length_, pos)],
             &string_->GetChars()[start_offset_ + length_]};
   }
 
+  static const bool kCanBeCloned = false;
   static const bool kCanAccessHeap = true;
 
  private:
@@ -69,14 +106,42 @@ class OnHeapStream {
 // ExternalTwoByteString.
 template <typename Char>
 class ExternalStringStream {
+  typedef typename CharTraits<Char>::ExternalString ExternalString;
+
  public:
-  ExternalStringStream(const Char* data, size_t end)
-      : data_(data), length_(end) {}
+  ExternalStringStream(ExternalString* string, size_t start_offset,
+                       size_t length)
+      : lock_(string),
+        data_(string->GetChars() + start_offset),
+        length_(length) {}
+
+  ExternalStringStream(const ExternalStringStream& other)
+      : lock_(other.lock_), data_(other.data_), length_(other.length_) {}
 
-  Range<Char> GetDataAt(size_t pos) {
+  Range<Char> GetDataAt(size_t pos, RuntimeCallStats* stats) {
     return {&data_[Min(length_, pos)], &data_[length_]};
   }
 
+  static const bool kCanBeCloned = true;
+  static const bool kCanAccessHeap = false;
+
+ private:
+  ScopedExternalStringLock lock_;
+  const Char* const data_;
+  const size_t length_;
+};
+
+// A Char stream backed by a C array. Testing only.
+template <typename Char>
+class TestingStream {
+ public:
+  TestingStream(const Char* data, size_t length)
+      : data_(data), length_(length) {}
+  Range<Char> GetDataAt(size_t pos, RuntimeCallStats* stats) {
+    return {&data_[Min(length_, pos)], &data_[length_]};
+  }
+
+  static const bool kCanBeCloned = true;
   static const bool kCanAccessHeap = false;
 
  private:
@@ -88,12 +153,16 @@ class ExternalStringStream {
 template <typename Char>
 class ChunkedStream {
  public:
-  ChunkedStream(ScriptCompiler::ExternalSourceStream* source,
-                RuntimeCallStats* stats)
-      : source_(source), stats_(stats) {}
+  explicit ChunkedStream(ScriptCompiler::ExternalSourceStream* source)
+      : source_(source) {}
+
+  ChunkedStream(const ChunkedStream& other) {
+    // TODO(rmcilroy): Implement cloning for chunked streams.
+    UNREACHABLE();
+  }
 
-  Range<Char> GetDataAt(size_t pos) {
-    Chunk chunk = FindChunk(pos);
+  Range<Char> GetDataAt(size_t pos, RuntimeCallStats* stats) {
+    Chunk chunk = FindChunk(pos, stats);
     size_t buffer_end = chunk.length;
     size_t buffer_pos = Min(buffer_end, pos - chunk.position);
     return {&chunk.data[buffer_pos], &chunk.data[buffer_end]};
@@ -103,6 +172,7 @@ class ChunkedStream {
     for (Chunk& chunk : chunks_) delete[] chunk.data;
   }
 
+  static const bool kCanBeCloned = false;
   static const bool kCanAccessHeap = false;
 
  private:
@@ -116,13 +186,13 @@ class ChunkedStream {
     size_t end_position() const { return position + length; }
   };
 
-  Chunk FindChunk(size_t position) {
-    while (V8_UNLIKELY(chunks_.empty())) FetchChunk(size_t{0});
+  Chunk FindChunk(size_t position, RuntimeCallStats* stats) {
+    while (V8_UNLIKELY(chunks_.empty())) FetchChunk(size_t{0}, stats);
 
     // Walk forwards while the position is in front of the current chunk.
     while (position >= chunks_.back().end_position() &&
            chunks_.back().length > 0) {
-      FetchChunk(chunks_.back().end_position());
+      FetchChunk(chunks_.back().end_position(), stats);
     }
 
     // Walk backwards.
@@ -142,11 +212,11 @@ class ChunkedStream {
                          length / sizeof(Char));
   }
 
-  void FetchChunk(size_t position) {
+  void FetchChunk(size_t position, RuntimeCallStats* stats) {
     const uint8_t* data = nullptr;
     size_t length;
     {
-      RuntimeCallTimerScope scope(stats_,
+      RuntimeCallTimerScope scope(stats,
                                   RuntimeCallCounterId::kGetMoreDataCallback);
       length = source_->GetMoreData(&data);
     }
@@ -154,102 +224,11 @@ class ChunkedStream {
   }
 
   ScriptCompiler::ExternalSourceStream* source_;
-  RuntimeCallStats* stats_;
 
  protected:
   std::vector<struct Chunk> chunks_;
 };
 
-template <typename Char>
-class Utf8ChunkedStream : public ChunkedStream<uint16_t> {
- public:
-  Utf8ChunkedStream(ScriptCompiler::ExternalSourceStream* source,
-                    RuntimeCallStats* stats)
-      : ChunkedStream<uint16_t>(source, stats) {}
-
-  STATIC_ASSERT(sizeof(Char) == sizeof(uint16_t));
-  void ProcessChunk(const uint8_t* data, size_t position, size_t length) final {
-    if (length == 0) {
-      unibrow::uchar t = unibrow::Utf8::ValueOfIncrementalFinish(&state_);
-      if (t != unibrow::Utf8::kBufferEmpty) {
-        DCHECK_EQ(t, unibrow::Utf8::kBadChar);
-        incomplete_char_ = 0;
-        uint16_t* result = new uint16_t[1];
-        result[0] = unibrow::Utf8::kBadChar;
-        chunks_.emplace_back(result, position, 1);
-        position++;
-      }
-      chunks_.emplace_back(nullptr, position, 0);
-      delete[] data;
-      return;
-    }
-
-    // First count the number of complete characters that can be produced.
-
-    unibrow::Utf8::State state = state_;
-    uint32_t incomplete_char = incomplete_char_;
-    bool seen_bom = seen_bom_;
-
-    size_t i = 0;
-    size_t chars = 0;
-    while (i < length) {
-      unibrow::uchar t = unibrow::Utf8::ValueOfIncremental(data[i], &i, &state,
-                                                           &incomplete_char);
-      if (!seen_bom && t == kUtf8Bom && position + chars == 0) {
-        seen_bom = true;
-        // BOM detected at beginning of the stream. Don't copy it.
-      } else if (t != unibrow::Utf8::kIncomplete) {
-        chars++;
-        if (t > unibrow::Utf16::kMaxNonSurrogateCharCode) chars++;
-      }
-    }
-
-    // Process the data.
-
-    // If there aren't any complete characters, update the state without
-    // producing a chunk.
-    if (chars == 0) {
-      state_ = state;
-      incomplete_char_ = incomplete_char;
-      seen_bom_ = seen_bom;
-      delete[] data;
-      return;
-    }
-
-    // Update the state and produce a chunk with complete characters.
-    uint16_t* result = new uint16_t[chars];
-    uint16_t* cursor = result;
-    i = 0;
-
-    while (i < length) {
-      unibrow::uchar t = unibrow::Utf8::ValueOfIncremental(data[i], &i, &state_,
-                                                           &incomplete_char_);
-      if (V8_LIKELY(t < kUtf8Bom)) {
-        *(cursor++) = static_cast<uc16>(t);  // The by most frequent case.
-      } else if (t == unibrow::Utf8::kIncomplete) {
-        continue;
-      } else if (!seen_bom_ && t == kUtf8Bom && position == 0 &&
-                 cursor == result) {
-        // BOM detected at beginning of the stream. Don't copy it.
-        seen_bom_ = true;
-      } else if (t <= unibrow::Utf16::kMaxNonSurrogateCharCode) {
-        *(cursor++) = static_cast<uc16>(t);
-      } else {
-        *(cursor++) = unibrow::Utf16::LeadSurrogate(t);
-        *(cursor++) = unibrow::Utf16::TrailSurrogate(t);
-      }
-    }
-
-    chunks_.emplace_back(result, position, chars);
-    delete[] data;
-  }
-
- private:
-  uint32_t incomplete_char_ = 0;
-  unibrow::Utf8::State state_ = unibrow::Utf8::State::kAccept;
-  bool seen_bom_ = false;
-};
-
 // Provides a buffered utf-16 view on the bytes from the underlying ByteStream.
 // Chars are buffered if either the underlying stream isn't utf-16 or the
 // underlying utf-16 stream might move (is on-heap).
@@ -261,6 +240,16 @@ class BufferedCharacterStream : public Utf16CharacterStream {
     buffer_pos_ = pos;
   }
 
+  bool can_be_cloned() const final {
+    return ByteStream<uint16_t>::kCanBeCloned;
+  }
+
+  std::unique_ptr<Utf16CharacterStream> Clone() const override {
+    CHECK(can_be_cloned());
+    return std::unique_ptr<Utf16CharacterStream>(
+        new BufferedCharacterStream<ByteStream>(*this));
+  }
+
  protected:
   bool ReadBlock() final {
     size_t position = pos();
@@ -268,7 +257,8 @@ class BufferedCharacterStream : public Utf16CharacterStream {
     buffer_start_ = &buffer_[0];
     buffer_cursor_ = buffer_start_;
 
-    Range<uint8_t> range = byte_stream_.GetDataAt(position);
+    Range<uint8_t> range =
+        byte_stream_.GetDataAt(position, runtime_call_stats());
     if (range.length() == 0) {
       buffer_end_ = buffer_start_;
       return false;
@@ -280,9 +270,14 @@ class BufferedCharacterStream : public Utf16CharacterStream {
     return true;
   }
 
-  bool can_access_heap() final { return ByteStream<uint8_t>::kCanAccessHeap; }
+  bool can_access_heap() const final {
+    return ByteStream<uint8_t>::kCanAccessHeap;
+  }
 
  private:
+  BufferedCharacterStream(const BufferedCharacterStream<ByteStream>& other)
+      : byte_stream_(other.byte_stream_) {}
+
   static const size_t kBufferSize = 512;
   uc16 buffer_[kBufferSize];
   ByteStream<uint8_t> byte_stream_;
@@ -298,11 +293,25 @@ class UnbufferedCharacterStream : public Utf16CharacterStream {
     buffer_pos_ = pos;
   }
 
+  bool can_access_heap() const final {
+    return ByteStream<uint16_t>::kCanAccessHeap;
+  }
+
+  bool can_be_cloned() const final {
+    return ByteStream<uint16_t>::kCanBeCloned;
+  }
+
+  std::unique_ptr<Utf16CharacterStream> Clone() const override {
+    return std::unique_ptr<Utf16CharacterStream>(
+        new UnbufferedCharacterStream<ByteStream>(*this));
+  }
+
  protected:
   bool ReadBlock() final {
     size_t position = pos();
     buffer_pos_ = position;
-    Range<uint16_t> range = byte_stream_.GetDataAt(position);
+    Range<uint16_t> range =
+        byte_stream_.GetDataAt(position, runtime_call_stats());
     buffer_start_ = range.start;
     buffer_end_ = range.end;
     buffer_cursor_ = buffer_start_;
@@ -313,7 +322,8 @@ class UnbufferedCharacterStream : public Utf16CharacterStream {
     return true;
   }
 
-  bool can_access_heap() final { return ByteStream<uint16_t>::kCanAccessHeap; }
+  UnbufferedCharacterStream(const UnbufferedCharacterStream<ByteStream>& other)
+      : byte_stream_(other.byte_stream_) {}
 
   ByteStream<uint16_t> byte_stream_;
 };
@@ -346,7 +356,7 @@ class RelocatingCharacterStream
   }
 
   void UpdateBufferPointers() {
-    Range<uint16_t> range = byte_stream_.GetDataAt(0);
+    Range<uint16_t> range = byte_stream_.GetDataAt(0, runtime_call_stats());
     if (range.start != buffer_start_) {
       buffer_cursor_ = (buffer_cursor_ - buffer_start_) + range.start;
       buffer_start_ = range.start;
@@ -412,16 +422,20 @@ bool BufferedUtf16CharacterStream::ReadBlock() {
 class Utf8ExternalStreamingStream : public BufferedUtf16CharacterStream {
  public:
   Utf8ExternalStreamingStream(
-      ScriptCompiler::ExternalSourceStream* source_stream,
-      RuntimeCallStats* stats)
+      ScriptCompiler::ExternalSourceStream* source_stream)
       : current_({0, {0, 0, 0, unibrow::Utf8::State::kAccept}}),
-        source_stream_(source_stream),
-        stats_(stats) {}
+        source_stream_(source_stream) {}
   ~Utf8ExternalStreamingStream() final {
     for (size_t i = 0; i < chunks_.size(); i++) delete[] chunks_[i].data;
   }
 
-  bool can_access_heap() final { return false; }
+  bool can_access_heap() const final { return false; }
+
+  bool can_be_cloned() const final { return false; }
+
+  std::unique_ptr<Utf16CharacterStream> Clone() const override {
+    UNREACHABLE();
+  }
 
  protected:
   size_t FillBuffer(size_t position) final;
@@ -468,7 +482,6 @@ class Utf8ExternalStreamingStream : public BufferedUtf16CharacterStream {
   std::vector<Chunk> chunks_;
   Position current_;
   ScriptCompiler::ExternalSourceStream* source_stream_;
-  RuntimeCallStats* stats_;
 };
 
 bool Utf8ExternalStreamingStream::SkipToPosition(size_t position) {
@@ -562,7 +575,7 @@ void Utf8ExternalStreamingStream::FillBufferFromCurrentChunk() {
 }
 
 bool Utf8ExternalStreamingStream::FetchChunk() {
-  RuntimeCallTimerScope scope(stats_,
+  RuntimeCallTimerScope scope(runtime_call_stats(),
                               RuntimeCallCounterId::kGetMoreDataCallback);
   DCHECK_EQ(current_.chunk_no, chunks_.size());
   DCHECK(chunks_.empty() || chunks_.back().length != 0);
@@ -704,14 +717,12 @@ Utf16CharacterStream* ScannerStream::For(Isolate* isolate, Handle<String> data,
   }
   if (data->IsExternalOneByteString()) {
     return new BufferedCharacterStream<ExternalStringStream>(
-        static_cast<size_t>(start_pos),
-        ExternalOneByteString::cast(*data)->GetChars() + start_offset,
-        static_cast<size_t>(end_pos));
+        static_cast<size_t>(start_pos), ExternalOneByteString::cast(*data),
+        start_offset, static_cast<size_t>(end_pos));
   } else if (data->IsExternalTwoByteString()) {
     return new UnbufferedCharacterStream<ExternalStringStream>(
-        static_cast<size_t>(start_pos),
-        ExternalTwoByteString::cast(*data)->GetChars() + start_offset,
-        static_cast<size_t>(end_pos));
+        static_cast<size_t>(start_pos), ExternalTwoByteString::cast(*data),
+        start_offset, static_cast<size_t>(end_pos));
   } else if (data->IsSeqOneByteString()) {
     return new BufferedCharacterStream<OnHeapStream>(
         static_cast<size_t>(start_pos), Handle<SeqOneByteString>::cast(data),
@@ -734,24 +745,23 @@ std::unique_ptr<Utf16CharacterStream> ScannerStream::ForTesting(
 std::unique_ptr<Utf16CharacterStream> ScannerStream::ForTesting(
     const char* data, size_t length) {
   return std::unique_ptr<Utf16CharacterStream>(
-      new BufferedCharacterStream<ExternalStringStream>(
+      new BufferedCharacterStream<TestingStream>(
           static_cast<size_t>(0), reinterpret_cast<const uint8_t*>(data),
           static_cast<size_t>(length)));
 }
 
 Utf16CharacterStream* ScannerStream::For(
     ScriptCompiler::ExternalSourceStream* source_stream,
-    v8::ScriptCompiler::StreamedSource::Encoding encoding,
-    RuntimeCallStats* stats) {
+    v8::ScriptCompiler::StreamedSource::Encoding encoding) {
   switch (encoding) {
     case v8::ScriptCompiler::StreamedSource::TWO_BYTE:
       return new UnbufferedCharacterStream<ChunkedStream>(
-          static_cast<size_t>(0), source_stream, stats);
+          static_cast<size_t>(0), source_stream);
     case v8::ScriptCompiler::StreamedSource::ONE_BYTE:
       return new BufferedCharacterStream<ChunkedStream>(static_cast<size_t>(0),
-                                                        source_stream, stats);
+                                                        source_stream);
     case v8::ScriptCompiler::StreamedSource::UTF8:
-      return new Utf8ExternalStreamingStream(source_stream, stats);
+      return new Utf8ExternalStreamingStream(source_stream);
   }
   UNREACHABLE();
 }
diff --git a/deps/v8/src/parsing/scanner-character-streams.h b/deps/v8/src/parsing/scanner-character-streams.h
index 091ef5b8ea..4c85f5383f 100644
--- a/deps/v8/src/parsing/scanner-character-streams.h
+++ b/deps/v8/src/parsing/scanner-character-streams.h
@@ -24,8 +24,7 @@ class V8_EXPORT_PRIVATE ScannerStream {
                                    int start_pos, int end_pos);
   static Utf16CharacterStream* For(
       ScriptCompiler::ExternalSourceStream* source_stream,
-      ScriptCompiler::StreamedSource::Encoding encoding,
-      RuntimeCallStats* stats);
+      ScriptCompiler::StreamedSource::Encoding encoding);
 
   static std::unique_ptr<Utf16CharacterStream> ForTesting(const char* data);
   static std::unique_ptr<Utf16CharacterStream> ForTesting(const char* data,
diff --git a/deps/v8/src/parsing/scanner-inl.h b/deps/v8/src/parsing/scanner-inl.h
index 809ef655a7..9647957062 100644
--- a/deps/v8/src/parsing/scanner-inl.h
+++ b/deps/v8/src/parsing/scanner-inl.h
@@ -5,25 +5,354 @@
 #ifndef V8_PARSING_SCANNER_INL_H_
 #define V8_PARSING_SCANNER_INL_H_
 
+#include "src/char-predicates-inl.h"
 #include "src/parsing/scanner.h"
 #include "src/unicode-cache-inl.h"
 
 namespace v8 {
 namespace internal {
 
+// Make sure tokens are stored as a single byte.
+STATIC_ASSERT(sizeof(Token::Value) == 1);
+
+// Table of one-character tokens, by character (0x00..0x7F only).
+// clang-format off
+static const Token::Value one_char_tokens[] = {
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::LPAREN,       // 0x28
+  Token::RPAREN,       // 0x29
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::COMMA,        // 0x2C
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::COLON,        // 0x3A
+  Token::SEMICOLON,    // 0x3B
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::CONDITIONAL,  // 0x3F
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::LBRACK,     // 0x5B
+  Token::ILLEGAL,
+  Token::RBRACK,     // 0x5D
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::ILLEGAL,
+  Token::LBRACE,       // 0x7B
+  Token::ILLEGAL,
+  Token::RBRACE,       // 0x7D
+  Token::BIT_NOT,      // 0x7E
+  Token::ILLEGAL
+};
+// clang-format on
+
+// ----------------------------------------------------------------------------
+// Keyword Matcher
+
+#define KEYWORDS(KEYWORD_GROUP, KEYWORD)                    \
+  KEYWORD_GROUP('a')                                        \
+  KEYWORD("arguments", Token::ARGUMENTS)                    \
+  KEYWORD("as", Token::AS)                                  \
+  KEYWORD("async", Token::ASYNC)                            \
+  KEYWORD("await", Token::AWAIT)                            \
+  KEYWORD("anonymous", Token::ANONYMOUS)                    \
+  KEYWORD_GROUP('b')                                        \
+  KEYWORD("break", Token::BREAK)                            \
+  KEYWORD_GROUP('c')                                        \
+  KEYWORD("case", Token::CASE)                              \
+  KEYWORD("catch", Token::CATCH)                            \
+  KEYWORD("class", Token::CLASS)                            \
+  KEYWORD("const", Token::CONST)                            \
+  KEYWORD("constructor", Token::CONSTRUCTOR)                \
+  KEYWORD("continue", Token::CONTINUE)                      \
+  KEYWORD_GROUP('d')                                        \
+  KEYWORD("debugger", Token::DEBUGGER)                      \
+  KEYWORD("default", Token::DEFAULT)                        \
+  KEYWORD("delete", Token::DELETE)                          \
+  KEYWORD("do", Token::DO)                                  \
+  KEYWORD_GROUP('e')                                        \
+  KEYWORD("else", Token::ELSE)                              \
+  KEYWORD("enum", Token::ENUM)                              \
+  KEYWORD("eval", Token::EVAL)                              \
+  KEYWORD("export", Token::EXPORT)                          \
+  KEYWORD("extends", Token::EXTENDS)                        \
+  KEYWORD_GROUP('f')                                        \
+  KEYWORD("false", Token::FALSE_LITERAL)                    \
+  KEYWORD("finally", Token::FINALLY)                        \
+  KEYWORD("for", Token::FOR)                                \
+  KEYWORD("from", Token::FROM)                              \
+  KEYWORD("function", Token::FUNCTION)                      \
+  KEYWORD_GROUP('g')                                        \
+  KEYWORD("get", Token::GET)                                \
+  KEYWORD_GROUP('i')                                        \
+  KEYWORD("if", Token::IF)                                  \
+  KEYWORD("implements", Token::FUTURE_STRICT_RESERVED_WORD) \
+  KEYWORD("import", Token::IMPORT)                          \
+  KEYWORD("in", Token::IN)                                  \
+  KEYWORD("instanceof", Token::INSTANCEOF)                  \
+  KEYWORD("interface", Token::FUTURE_STRICT_RESERVED_WORD)  \
+  KEYWORD_GROUP('l')                                        \
+  KEYWORD("let", Token::LET)                                \
+  KEYWORD_GROUP('m')                                        \
+  KEYWORD("meta", Token::META)                              \
+  KEYWORD_GROUP('n')                                        \
+  KEYWORD("name", Token::NAME)                              \
+  KEYWORD("new", Token::NEW)                                \
+  KEYWORD("null", Token::NULL_LITERAL)                      \
+  KEYWORD_GROUP('o')                                        \
+  KEYWORD("of", Token::OF)                                  \
+  KEYWORD_GROUP('p')                                        \
+  KEYWORD("package", Token::FUTURE_STRICT_RESERVED_WORD)    \
+  KEYWORD("private", Token::FUTURE_STRICT_RESERVED_WORD)    \
+  KEYWORD("protected", Token::FUTURE_STRICT_RESERVED_WORD)  \
+  KEYWORD("prototype", Token::PROTOTYPE)                    \
+  KEYWORD("public", Token::FUTURE_STRICT_RESERVED_WORD)     \
+  KEYWORD_GROUP('r')                                        \
+  KEYWORD("return", Token::RETURN)                          \
+  KEYWORD_GROUP('s')                                        \
+  KEYWORD("set", Token::SET)                                \
+  KEYWORD("static", Token::STATIC)                          \
+  KEYWORD("super", Token::SUPER)                            \
+  KEYWORD("switch", Token::SWITCH)                          \
+  KEYWORD_GROUP('t')                                        \
+  KEYWORD("target", Token::TARGET)                          \
+  KEYWORD("this", Token::THIS)                              \
+  KEYWORD("throw", Token::THROW)                            \
+  KEYWORD("true", Token::TRUE_LITERAL)                      \
+  KEYWORD("try", Token::TRY)                                \
+  KEYWORD("typeof", Token::TYPEOF)                          \
+  KEYWORD_GROUP('u')                                        \
+  KEYWORD("undefined", Token::UNDEFINED)                    \
+  KEYWORD_GROUP('v')                                        \
+  KEYWORD("var", Token::VAR)                                \
+  KEYWORD("void", Token::VOID)                              \
+  KEYWORD_GROUP('w')                                        \
+  KEYWORD("while", Token::WHILE)                            \
+  KEYWORD("with", Token::WITH)                              \
+  KEYWORD_GROUP('y')                                        \
+  KEYWORD("yield", Token::YIELD)                            \
+  KEYWORD_GROUP('_')                                        \
+  KEYWORD("__proto__", Token::PROTO_UNDERSCORED)            \
+  KEYWORD_GROUP('#')                                        \
+  KEYWORD("#constructor", Token::PRIVATE_CONSTRUCTOR)
+
+V8_INLINE Token::Value KeywordOrIdentifierToken(const uint8_t* input,
+                                                int input_length) {
+  DCHECK_GE(input_length, 1);
+  const int kMinLength = 2;
+  const int kMaxLength = 12;
+  if (input_length < kMinLength || input_length > kMaxLength) {
+    return Token::IDENTIFIER;
+  }
+  switch (input[0]) {
+    default:
+#define KEYWORD_GROUP_CASE(ch) \
+  break;                       \
+  case ch:
+#define KEYWORD(keyword, token)                                           \
+  {                                                                       \
+    /* 'keyword' is a char array, so sizeof(keyword) is */                \
+    /* strlen(keyword) plus 1 for the NUL char. */                        \
+    const int keyword_length = sizeof(keyword) - 1;                       \
+    STATIC_ASSERT(keyword_length >= kMinLength);                          \
+    STATIC_ASSERT(keyword_length <= kMaxLength);                          \
+    DCHECK_EQ(input[0], keyword[0]);                                      \
+    DCHECK(token == Token::FUTURE_STRICT_RESERVED_WORD ||                 \
+           0 == strncmp(keyword, Token::String(token), sizeof(keyword))); \
+    if (input_length == keyword_length && input[1] == keyword[1] &&       \
+        (keyword_length <= 2 || input[2] == keyword[2]) &&                \
+        (keyword_length <= 3 || input[3] == keyword[3]) &&                \
+        (keyword_length <= 4 || input[4] == keyword[4]) &&                \
+        (keyword_length <= 5 || input[5] == keyword[5]) &&                \
+        (keyword_length <= 6 || input[6] == keyword[6]) &&                \
+        (keyword_length <= 7 || input[7] == keyword[7]) &&                \
+        (keyword_length <= 8 || input[8] == keyword[8]) &&                \
+        (keyword_length <= 9 || input[9] == keyword[9]) &&                \
+        (keyword_length <= 10 || input[10] == keyword[10])) {             \
+      return token;                                                       \
+    }                                                                     \
+  }
+      KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD)
+  }
+  return Token::IDENTIFIER;
+#undef KEYWORDS
+#undef KEYWORD
+#undef KEYWORD_GROUP_CASE
+}
+
+V8_INLINE Token::Value Scanner::ScanIdentifierOrKeyword() {
+  LiteralScope literal(this);
+  return ScanIdentifierOrKeywordInner(&literal);
+}
+
+V8_INLINE Token::Value Scanner::ScanIdentifierOrKeywordInner(
+    LiteralScope* literal) {
+  DCHECK(unicode_cache_->IsIdentifierStart(c0_));
+  bool escaped = false;
+  if (IsInRange(c0_, 'a', 'z') || c0_ == '_') {
+    do {
+      AddLiteralChar(static_cast<char>(c0_));
+      Advance();
+    } while (IsInRange(c0_, 'a', 'z') || c0_ == '_');
+
+    if (IsDecimalDigit(c0_) || IsInRange(c0_, 'A', 'Z') || c0_ == '$') {
+      // Identifier starting with lowercase or _.
+      do {
+        AddLiteralChar(static_cast<char>(c0_));
+        Advance();
+      } while (IsAsciiIdentifier(c0_));
+
+      if (c0_ <= kMaxAscii && c0_ != '\\') {
+        literal->Complete();
+        return Token::IDENTIFIER;
+      }
+    } else if (c0_ <= kMaxAscii && c0_ != '\\') {
+      // Only a-z+ or _: could be a keyword or identifier.
+      Vector<const uint8_t> chars = next().literal_chars.one_byte_literal();
+      Token::Value token =
+          KeywordOrIdentifierToken(chars.start(), chars.length());
+      if (token == Token::IDENTIFIER ||
+          token == Token::FUTURE_STRICT_RESERVED_WORD ||
+          Token::IsContextualKeyword(token))
+        literal->Complete();
+      return token;
+    }
+  } else if (IsInRange(c0_, 'A', 'Z') || c0_ == '$') {
+    do {
+      AddLiteralChar(static_cast<char>(c0_));
+      Advance();
+    } while (IsAsciiIdentifier(c0_));
+
+    if (c0_ <= kMaxAscii && c0_ != '\\') {
+      literal->Complete();
+      return Token::IDENTIFIER;
+    }
+  } else if (c0_ == '\\') {
+    escaped = true;
+    uc32 c = ScanIdentifierUnicodeEscape();
+    DCHECK(!unicode_cache_->IsIdentifierStart(-1));
+    if (c == '\\' || !unicode_cache_->IsIdentifierStart(c)) {
+      return Token::ILLEGAL;
+    }
+    AddLiteralChar(c);
+  }
+
+  return ScanIdentifierOrKeywordInnerSlow(literal, escaped);
+}
+
 V8_INLINE Token::Value Scanner::SkipWhiteSpace() {
   int start_position = source_pos();
 
-  while (true) {
-    // We won't skip behind the end of input.
-    DCHECK(!unicode_cache_->IsWhiteSpace(kEndOfInput));
+  // We won't skip behind the end of input.
+  DCHECK(!unicode_cache_->IsWhiteSpaceOrLineTerminator(kEndOfInput));
 
-    // Advance as long as character is a WhiteSpace or LineTerminator.
-    // Remember if the latter is the case.
-    if (unibrow::IsLineTerminator(c0_)) {
+  // Advance as long as character is a WhiteSpace or LineTerminator.
+  while (unicode_cache_->IsWhiteSpaceOrLineTerminator(c0_)) {
+    if (!next().after_line_terminator && unibrow::IsLineTerminator(c0_)) {
       next().after_line_terminator = true;
-    } else if (!unicode_cache_->IsWhiteSpace(c0_)) {
-      break;
     }
     Advance();
   }
@@ -37,6 +366,191 @@ V8_INLINE Token::Value Scanner::SkipWhiteSpace() {
   return Token::WHITESPACE;
 }
 
+V8_INLINE Token::Value Scanner::ScanSingleToken() {
+  Token::Value token;
+  do {
+    next().location.beg_pos = source_pos();
+
+    if (static_cast<unsigned>(c0_) <= 0x7F) {
+      Token::Value token = one_char_tokens[c0_];
+      if (token != Token::ILLEGAL) {
+        Advance();
+        return token;
+      }
+    }
+
+    switch (c0_) {
+      case '"':
+      case '\'':
+        return ScanString();
+
+      case '<':
+        // < <= << <<= <!--
+        Advance();
+        if (c0_ == '=') return Select(Token::LTE);
+        if (c0_ == '<') return Select('=', Token::ASSIGN_SHL, Token::SHL);
+        if (c0_ == '!') {
+          token = ScanHtmlComment();
+          continue;
+        }
+        return Token::LT;
+
+      case '>':
+        // > >= >> >>= >>> >>>=
+        Advance();
+        if (c0_ == '=') return Select(Token::GTE);
+        if (c0_ == '>') {
+          // >> >>= >>> >>>=
+          Advance();
+          if (c0_ == '=') return Select(Token::ASSIGN_SAR);
+          if (c0_ == '>') return Select('=', Token::ASSIGN_SHR, Token::SHR);
+          return Token::SAR;
+        }
+        return Token::GT;
+
+      case '=':
+        // = == === =>
+        Advance();
+        if (c0_ == '=') return Select('=', Token::EQ_STRICT, Token::EQ);
+        if (c0_ == '>') return Select(Token::ARROW);
+        return Token::ASSIGN;
+
+      case '!':
+        // ! != !==
+        Advance();
+        if (c0_ == '=') return Select('=', Token::NE_STRICT, Token::NE);
+        return Token::NOT;
+
+      case '+':
+        // + ++ +=
+        Advance();
+        if (c0_ == '+') return Select(Token::INC);
+        if (c0_ == '=') return Select(Token::ASSIGN_ADD);
+        return Token::ADD;
+
+      case '-':
+        // - -- --> -=
+        Advance();
+        if (c0_ == '-') {
+          Advance();
+          if (c0_ == '>' && next().after_line_terminator) {
+            // For compatibility with SpiderMonkey, we skip lines that
+            // start with an HTML comment end '-->'.
+            token = SkipSingleHTMLComment();
+            continue;
+          }
+          return Token::DEC;
+        }
+        if (c0_ == '=') return Select(Token::ASSIGN_SUB);
+        return Token::SUB;
+
+      case '*':
+        // * *=
+        Advance();
+        if (c0_ == '*') return Select('=', Token::ASSIGN_EXP, Token::EXP);
+        if (c0_ == '=') return Select(Token::ASSIGN_MUL);
+        return Token::MUL;
+
+      case '%':
+        // % %=
+        return Select('=', Token::ASSIGN_MOD, Token::MOD);
+
+      case '/':
+        // /  // /* /=
+        Advance();
+        if (c0_ == '/') {
+          uc32 c = Peek();
+          if (c == '#' || c == '@') {
+            Advance();
+            Advance();
+            token = SkipSourceURLComment();
+            continue;
+          }
+          token = SkipSingleLineComment();
+          continue;
+        }
+        if (c0_ == '*') {
+          token = SkipMultiLineComment();
+          continue;
+        }
+        if (c0_ == '=') return Select(Token::ASSIGN_DIV);
+        return Token::DIV;
+
+      case '&':
+        // & && &=
+        Advance();
+        if (c0_ == '&') return Select(Token::AND);
+        if (c0_ == '=') return Select(Token::ASSIGN_BIT_AND);
+        return Token::BIT_AND;
+
+      case '|':
+        // | || |=
+        Advance();
+        if (c0_ == '|') return Select(Token::OR);
+        if (c0_ == '=') return Select(Token::ASSIGN_BIT_OR);
+        return Token::BIT_OR;
+
+      case '^':
+        // ^ ^=
+        return Select('=', Token::ASSIGN_BIT_XOR, Token::BIT_XOR);
+
+      case '.':
+        // . Number
+        Advance();
+        if (IsDecimalDigit(c0_)) return ScanNumber(true);
+        if (c0_ == '.') {
+          if (Peek() == '.') {
+            Advance();
+            Advance();
+            return Token::ELLIPSIS;
+          }
+        }
+        return Token::PERIOD;
+
+      case '`':
+        Advance();
+        return ScanTemplateSpan();
+
+      case '#':
+        return ScanPrivateName();
+
+      default:
+        if (unicode_cache_->IsIdentifierStart(c0_) ||
+            (CombineSurrogatePair() &&
+             unicode_cache_->IsIdentifierStart(c0_))) {
+          Token::Value token = ScanIdentifierOrKeyword();
+          if (!Token::IsContextualKeyword(token)) return token;
+
+          next().contextual_token = token;
+          return Token::IDENTIFIER;
+        }
+        if (IsDecimalDigit(c0_)) return ScanNumber(false);
+        if (c0_ == kEndOfInput) return Token::EOS;
+        token = SkipWhiteSpace();
+        continue;
+    }
+    // Continue scanning for tokens as long as we're just skipping whitespace.
+  } while (token == Token::WHITESPACE);
+
+  return token;
+}
+
+void Scanner::Scan() {
+  next().literal_chars.Drop();
+  next().raw_literal_chars.Drop();
+  next().contextual_token = Token::UNINITIALIZED;
+  next().invalid_template_escape_message = MessageTemplate::kNone;
+
+  next().token = ScanSingleToken();
+  next().location.end_pos = source_pos();
+
+#ifdef DEBUG
+  SanityCheckTokenDesc(current());
+  SanityCheckTokenDesc(next());
+  SanityCheckTokenDesc(next_next());
+#endif
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/parsing/scanner.cc b/deps/v8/src/parsing/scanner.cc
index 781832c2e6..525b1bc681 100644
--- a/deps/v8/src/parsing/scanner.cc
+++ b/deps/v8/src/parsing/scanner.cc
@@ -11,7 +11,6 @@
 #include <cmath>
 
 #include "src/ast/ast-value-factory.h"
-#include "src/char-predicates-inl.h"
 #include "src/conversions-inl.h"
 #include "src/objects/bigint.h"
 #include "src/parsing/duplicate-finder.h"  // For Scanner::FindSymbol
@@ -134,7 +133,6 @@ const size_t Scanner::BookmarkScope::kBookmarkWasApplied =
 
 void Scanner::BookmarkScope::Set() {
   DCHECK_EQ(bookmark_, kNoBookmark);
-  DCHECK_EQ(scanner_->next_next().token, Token::UNINITIALIZED);
 
   // The first token is a bit special, since current_ will still be
   // uninitialized. In this case, store kBookmarkAtFirstPos and special-case it
@@ -160,11 +158,11 @@ void Scanner::BookmarkScope::Apply() {
   bookmark_ = kBookmarkWasApplied;
 }
 
-bool Scanner::BookmarkScope::HasBeenSet() {
+bool Scanner::BookmarkScope::HasBeenSet() const {
   return bookmark_ != kNoBookmark && bookmark_ != kBookmarkWasApplied;
 }
 
-bool Scanner::BookmarkScope::HasBeenApplied() {
+bool Scanner::BookmarkScope::HasBeenApplied() const {
   return bookmark_ == kBookmarkWasApplied;
 }
 
@@ -175,12 +173,11 @@ Scanner::Scanner(UnicodeCache* unicode_cache, Utf16CharacterStream* source,
                  bool is_module)
     : unicode_cache_(unicode_cache),
       source_(source),
-      octal_pos_(Location::invalid()),
-      octal_message_(MessageTemplate::kNone),
       found_html_comment_(false),
-      allow_harmony_bigint_(false),
       allow_harmony_numeric_separator_(false),
-      is_module_(is_module) {
+      is_module_(is_module),
+      octal_pos_(Location::invalid()),
+      octal_message_(MessageTemplate::kNone) {
   DCHECK_NOT_NULL(source);
 }
 
@@ -234,146 +231,7 @@ uc32 Scanner::ScanUnlimitedLengthHexNumber(int max_value, int beg_pos) {
   return x;
 }
 
-
-// Ensure that tokens can be stored in a byte.
-STATIC_ASSERT(Token::NUM_TOKENS <= 0x100);
-
-// Table of one-character tokens, by character (0x00..0x7F only).
-// clang-format off
-static const byte one_char_tokens[] = {
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::LPAREN,       // 0x28
-  Token::RPAREN,       // 0x29
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::COMMA,        // 0x2C
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::COLON,        // 0x3A
-  Token::SEMICOLON,    // 0x3B
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::CONDITIONAL,  // 0x3F
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::LBRACK,     // 0x5B
-  Token::ILLEGAL,
-  Token::RBRACK,     // 0x5D
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::ILLEGAL,
-  Token::LBRACE,       // 0x7B
-  Token::ILLEGAL,
-  Token::RBRACE,       // 0x7D
-  Token::BIT_NOT,      // 0x7E
-  Token::ILLEGAL
-};
-// clang-format on
-
 Token::Value Scanner::Next() {
-  if (next().token == Token::EOS) next().location = current().location;
   // Rotate through tokens.
   TokenDesc* previous = current_;
   current_ = next_;
@@ -395,7 +253,6 @@ Token::Value Scanner::Next() {
   return current().token;
 }
 
-
 Token::Value Scanner::PeekAhead() {
   DCHECK(next().token != Token::DIV);
   DCHECK(next().token != Token::ASSIGN_DIV);
@@ -534,250 +391,6 @@ Token::Value Scanner::ScanHtmlComment() {
   return SkipSingleHTMLComment();
 }
 
-void Scanner::Scan() {
-  next().literal_chars.Drop();
-  next().raw_literal_chars.Drop();
-  next().invalid_template_escape_message = MessageTemplate::kNone;
-
-  Token::Value token;
-  do {
-    if (static_cast<unsigned>(c0_) <= 0x7F) {
-      Token::Value token = static_cast<Token::Value>(one_char_tokens[c0_]);
-      if (token != Token::ILLEGAL) {
-        int pos = source_pos();
-        next().token = token;
-        next().contextual_token = Token::UNINITIALIZED;
-        next().location.beg_pos = pos;
-        next().location.end_pos = pos + 1;
-        Advance();
-        return;
-      }
-    }
-
-    // Remember the position of the next token
-    next().location.beg_pos = source_pos();
-
-    switch (c0_) {
-      case '"':
-      case '\'':
-        token = ScanString();
-        break;
-
-      case '<':
-        // < <= << <<= <!--
-        Advance();
-        if (c0_ == '=') {
-          token = Select(Token::LTE);
-        } else if (c0_ == '<') {
-          token = Select('=', Token::ASSIGN_SHL, Token::SHL);
-        } else if (c0_ == '!') {
-          token = ScanHtmlComment();
-        } else {
-          token = Token::LT;
-        }
-        break;
-
-      case '>':
-        // > >= >> >>= >>> >>>=
-        Advance();
-        if (c0_ == '=') {
-          token = Select(Token::GTE);
-        } else if (c0_ == '>') {
-          // >> >>= >>> >>>=
-          Advance();
-          if (c0_ == '=') {
-            token = Select(Token::ASSIGN_SAR);
-          } else if (c0_ == '>') {
-            token = Select('=', Token::ASSIGN_SHR, Token::SHR);
-          } else {
-            token = Token::SAR;
-          }
-        } else {
-          token = Token::GT;
-        }
-        break;
-
-      case '=':
-        // = == === =>
-        Advance();
-        if (c0_ == '=') {
-          token = Select('=', Token::EQ_STRICT, Token::EQ);
-        } else if (c0_ == '>') {
-          token = Select(Token::ARROW);
-        } else {
-          token = Token::ASSIGN;
-        }
-        break;
-
-      case '!':
-        // ! != !==
-        Advance();
-        if (c0_ == '=') {
-          token = Select('=', Token::NE_STRICT, Token::NE);
-        } else {
-          token = Token::NOT;
-        }
-        break;
-
-      case '+':
-        // + ++ +=
-        Advance();
-        if (c0_ == '+') {
-          token = Select(Token::INC);
-        } else if (c0_ == '=') {
-          token = Select(Token::ASSIGN_ADD);
-        } else {
-          token = Token::ADD;
-        }
-        break;
-
-      case '-':
-        // - -- --> -=
-        Advance();
-        if (c0_ == '-') {
-          Advance();
-          if (c0_ == '>' && HasLineTerminatorBeforeNext()) {
-            // For compatibility with SpiderMonkey, we skip lines that
-            // start with an HTML comment end '-->'.
-            token = SkipSingleHTMLComment();
-          } else {
-            token = Token::DEC;
-          }
-        } else if (c0_ == '=') {
-          token = Select(Token::ASSIGN_SUB);
-        } else {
-          token = Token::SUB;
-        }
-        break;
-
-      case '*':
-        // * *=
-        Advance();
-        if (c0_ == '*') {
-          token = Select('=', Token::ASSIGN_EXP, Token::EXP);
-        } else if (c0_ == '=') {
-          token = Select(Token::ASSIGN_MUL);
-        } else {
-          token = Token::MUL;
-        }
-        break;
-
-      case '%':
-        // % %=
-        token = Select('=', Token::ASSIGN_MOD, Token::MOD);
-        break;
-
-      case '/':
-        // /  // /* /=
-        Advance();
-        if (c0_ == '/') {
-          uc32 c = Peek();
-          if (c == '#' || c == '@') {
-            Advance();
-            Advance();
-            token = SkipSourceURLComment();
-          } else {
-            token = SkipSingleLineComment();
-          }
-        } else if (c0_ == '*') {
-          token = SkipMultiLineComment();
-        } else if (c0_ == '=') {
-          token = Select(Token::ASSIGN_DIV);
-        } else {
-          token = Token::DIV;
-        }
-        break;
-
-      case '&':
-        // & && &=
-        Advance();
-        if (c0_ == '&') {
-          token = Select(Token::AND);
-        } else if (c0_ == '=') {
-          token = Select(Token::ASSIGN_BIT_AND);
-        } else {
-          token = Token::BIT_AND;
-        }
-        break;
-
-      case '|':
-        // | || |=
-        Advance();
-        if (c0_ == '|') {
-          token = Select(Token::OR);
-        } else if (c0_ == '=') {
-          token = Select(Token::ASSIGN_BIT_OR);
-        } else {
-          token = Token::BIT_OR;
-        }
-        break;
-
-      case '^':
-        // ^ ^=
-        token = Select('=', Token::ASSIGN_BIT_XOR, Token::BIT_XOR);
-        break;
-
-      case '.':
-        // . Number
-        Advance();
-        if (IsDecimalDigit(c0_)) {
-          token = ScanNumber(true);
-        } else {
-          token = Token::PERIOD;
-          if (c0_ == '.') {
-            if (Peek() == '.') {
-              Advance();
-              Advance();
-              token = Token::ELLIPSIS;
-            }
-          }
-        }
-        break;
-
-      case '`':
-        token = ScanTemplateStart();
-        break;
-
-      case '#':
-        token = ScanPrivateName();
-        break;
-
-      default:
-        if (unicode_cache_->IsIdentifierStart(c0_) ||
-            (CombineSurrogatePair() &&
-             unicode_cache_->IsIdentifierStart(c0_))) {
-          token = ScanIdentifierOrKeyword();
-        } else if (IsDecimalDigit(c0_)) {
-          token = ScanNumber(false);
-        } else if (c0_ == kEndOfInput) {
-          token = Token::EOS;
-        } else {
-          token = SkipWhiteSpace();
-          if (token == Token::ILLEGAL) Advance();
-        }
-        break;
-    }
-
-    // Continue scanning for tokens as long as we're just skipping
-    // whitespace.
-  } while (token == Token::WHITESPACE);
-
-  next().location.end_pos = source_pos();
-  if (Token::IsContextualKeyword(token)) {
-    next().token = Token::IDENTIFIER;
-    next().contextual_token = token;
-  } else {
-    next().token = token;
-    next().contextual_token = Token::UNINITIALIZED;
-  }
-
-#ifdef DEBUG
-  SanityCheckTokenDesc(current());
-  SanityCheckTokenDesc(next());
-  SanityCheckTokenDesc(next_next());
-#endif
-}
-
 #ifdef DEBUG
 void Scanner::SanityCheckTokenDesc(const TokenDesc& token) const {
   // Most tokens should not have literal_chars or even raw_literal chars.
@@ -916,7 +529,7 @@ uc32 Scanner::ScanOctalEscape(uc32 c, int length) {
   // can be reported later (in strict mode).
   // We don't report the error immediately, because the octal escape can
   // occur before the "use strict" directive.
-  if (c != '0' || i > 0 || c0_ == '8' || c0_ == '9') {
+  if (c != '0' || i > 0 || IsNonOctalDecimalDigit(c0_)) {
     octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1);
     octal_message_ = capture_raw ? MessageTemplate::kTemplateOctalLiteral
                                  : MessageTemplate::kStrictOctalEscape;
@@ -993,7 +606,7 @@ Token::Value Scanner::ScanTemplateSpan() {
 
   Token::Value result = Token::TEMPLATE_SPAN;
   LiteralScope literal(this);
-  StartRawLiteral();
+  next().raw_literal_chars.Start();
   const bool capture_raw = true;
   while (true) {
     uc32 c = c0_;
@@ -1053,14 +666,6 @@ Token::Value Scanner::ScanTemplateSpan() {
   return result;
 }
 
-Token::Value Scanner::ScanTemplateStart() {
-  DCHECK_EQ(next_next().token, Token::UNINITIALIZED);
-  DCHECK_EQ(c0_, '`');
-  next().location.beg_pos = source_pos();
-  Advance();  // Consume `
-  return ScanTemplateSpan();
-}
-
 Handle<String> Scanner::SourceUrl(Isolate* isolate) const {
   Handle<String> tmp;
   if (source_url_.length() > 0) {
@@ -1200,11 +805,11 @@ bool Scanner::ScanImplicitOctalDigits(int start_pos,
 
   while (true) {
     // (possible) octal number
-    if (c0_ == '8' || c0_ == '9') {
+    if (IsNonOctalDecimalDigit(c0_)) {
       *kind = DECIMAL_WITH_LEADING_ZERO;
       return true;
     }
-    if (c0_ < '0' || '7' < c0_) {
+    if (!IsOctalDigit(c0_)) {
       // Octal literal finished.
       octal_pos_ = Location(start_pos, source_pos());
       octal_message_ = MessageTemplate::kStrictOctalLiteral;
@@ -1272,7 +877,7 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
         AddLiteralCharAdvance();
         kind = BINARY;
         if (!ScanBinaryDigits()) return Token::ILLEGAL;
-      } else if ('0' <= c0_ && c0_ <= '7') {
+      } else if (IsOctalDigit(c0_)) {
         kind = IMPLICIT_OCTAL;
         if (!ScanImplicitOctalDigits(start_pos, &kind)) {
           return Token::ILLEGAL;
@@ -1280,7 +885,7 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
         if (kind == DECIMAL_WITH_LEADING_ZERO) {
           at_start = false;
         }
-      } else if (c0_ == '8' || c0_ == '9') {
+      } else if (IsNonOctalDecimalDigit(c0_)) {
         kind = DECIMAL_WITH_LEADING_ZERO;
       } else if (allow_harmony_numeric_separator() && c0_ == '_') {
         ReportScannerError(Location(source_pos(), source_pos() + 1),
@@ -1326,7 +931,7 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
   }
 
   bool is_bigint = false;
-  if (allow_harmony_bigint() && c0_ == 'n' && !seen_period &&
+  if (c0_ == 'n' && !seen_period &&
       (kind == DECIMAL || kind == HEX || kind == OCTAL || kind == BINARY)) {
     // Check that the literal is within our limits for BigInt length.
     // For simplicity, use 4 bits per character to calculate the maximum
@@ -1399,197 +1004,8 @@ uc32 Scanner::ScanUnicodeEscape() {
   return ScanHexNumber<capture_raw, unicode>(4);
 }
 
-
-// ----------------------------------------------------------------------------
-// Keyword Matcher
-
-#define KEYWORDS(KEYWORD_GROUP, KEYWORD)                    \
-  KEYWORD_GROUP('a')                                        \
-  KEYWORD("arguments", Token::ARGUMENTS)                    \
-  KEYWORD("as", Token::AS)                                  \
-  KEYWORD("async", Token::ASYNC)                            \
-  KEYWORD("await", Token::AWAIT)                            \
-  KEYWORD("anonymous", Token::ANONYMOUS)                    \
-  KEYWORD_GROUP('b')                                        \
-  KEYWORD("break", Token::BREAK)                            \
-  KEYWORD_GROUP('c')                                        \
-  KEYWORD("case", Token::CASE)                              \
-  KEYWORD("catch", Token::CATCH)                            \
-  KEYWORD("class", Token::CLASS)                            \
-  KEYWORD("const", Token::CONST)                            \
-  KEYWORD("constructor", Token::CONSTRUCTOR)                \
-  KEYWORD("continue", Token::CONTINUE)                      \
-  KEYWORD_GROUP('d')                                        \
-  KEYWORD("debugger", Token::DEBUGGER)                      \
-  KEYWORD("default", Token::DEFAULT)                        \
-  KEYWORD("delete", Token::DELETE)                          \
-  KEYWORD("do", Token::DO)                                  \
-  KEYWORD_GROUP('e')                                        \
-  KEYWORD("else", Token::ELSE)                              \
-  KEYWORD("enum", Token::ENUM)                              \
-  KEYWORD("eval", Token::EVAL)                              \
-  KEYWORD("export", Token::EXPORT)                          \
-  KEYWORD("extends", Token::EXTENDS)                        \
-  KEYWORD_GROUP('f')                                        \
-  KEYWORD("false", Token::FALSE_LITERAL)                    \
-  KEYWORD("finally", Token::FINALLY)                        \
-  KEYWORD("for", Token::FOR)                                \
-  KEYWORD("from", Token::FROM)                              \
-  KEYWORD("function", Token::FUNCTION)                      \
-  KEYWORD_GROUP('g')                                        \
-  KEYWORD("get", Token::GET)                                \
-  KEYWORD_GROUP('i')                                        \
-  KEYWORD("if", Token::IF)                                  \
-  KEYWORD("implements", Token::FUTURE_STRICT_RESERVED_WORD) \
-  KEYWORD("import", Token::IMPORT)                          \
-  KEYWORD("in", Token::IN)                                  \
-  KEYWORD("instanceof", Token::INSTANCEOF)                  \
-  KEYWORD("interface", Token::FUTURE_STRICT_RESERVED_WORD)  \
-  KEYWORD_GROUP('l')                                        \
-  KEYWORD("let", Token::LET)                                \
-  KEYWORD_GROUP('m')                                        \
-  KEYWORD("meta", Token::META)                              \
-  KEYWORD_GROUP('n')                                        \
-  KEYWORD("name", Token::NAME)                              \
-  KEYWORD("new", Token::NEW)                                \
-  KEYWORD("null", Token::NULL_LITERAL)                      \
-  KEYWORD_GROUP('o')                                        \
-  KEYWORD("of", Token::OF)                                  \
-  KEYWORD_GROUP('p')                                        \
-  KEYWORD("package", Token::FUTURE_STRICT_RESERVED_WORD)    \
-  KEYWORD("private", Token::FUTURE_STRICT_RESERVED_WORD)    \
-  KEYWORD("protected", Token::FUTURE_STRICT_RESERVED_WORD)  \
-  KEYWORD("prototype", Token::PROTOTYPE)                    \
-  KEYWORD("public", Token::FUTURE_STRICT_RESERVED_WORD)     \
-  KEYWORD_GROUP('r')                                        \
-  KEYWORD("return", Token::RETURN)                          \
-  KEYWORD_GROUP('s')                                        \
-  KEYWORD("set", Token::SET)                                \
-  KEYWORD("static", Token::STATIC)                          \
-  KEYWORD("super", Token::SUPER)                            \
-  KEYWORD("switch", Token::SWITCH)                          \
-  KEYWORD_GROUP('t')                                        \
-  KEYWORD("target", Token::TARGET)                          \
-  KEYWORD("this", Token::THIS)                              \
-  KEYWORD("throw", Token::THROW)                            \
-  KEYWORD("true", Token::TRUE_LITERAL)                      \
-  KEYWORD("try", Token::TRY)                                \
-  KEYWORD("typeof", Token::TYPEOF)                          \
-  KEYWORD_GROUP('u')                                        \
-  KEYWORD("undefined", Token::UNDEFINED)                    \
-  KEYWORD_GROUP('v')                                        \
-  KEYWORD("var", Token::VAR)                                \
-  KEYWORD("void", Token::VOID)                              \
-  KEYWORD_GROUP('w')                                        \
-  KEYWORD("while", Token::WHILE)                            \
-  KEYWORD("with", Token::WITH)                              \
-  KEYWORD_GROUP('y')                                        \
-  KEYWORD("yield", Token::YIELD)                            \
-  KEYWORD_GROUP('_')                                        \
-  KEYWORD("__proto__", Token::PROTO_UNDERSCORED)            \
-  KEYWORD_GROUP('#')                                        \
-  KEYWORD("#constructor", Token::PRIVATE_CONSTRUCTOR)
-
-static Token::Value KeywordOrIdentifierToken(const uint8_t* input,
-                                             int input_length) {
-  DCHECK_GE(input_length, 1);
-  const int kMinLength = 2;
-  const int kMaxLength = 12;
-  if (input_length < kMinLength || input_length > kMaxLength) {
-    return Token::IDENTIFIER;
-  }
-  switch (input[0]) {
-    default:
-#define KEYWORD_GROUP_CASE(ch)                                \
-      break;                                                  \
-    case ch:
-#define KEYWORD(keyword, token)                                           \
-  {                                                                       \
-    /* 'keyword' is a char array, so sizeof(keyword) is */                \
-    /* strlen(keyword) plus 1 for the NUL char. */                        \
-    const int keyword_length = sizeof(keyword) - 1;                       \
-    STATIC_ASSERT(keyword_length >= kMinLength);                          \
-    STATIC_ASSERT(keyword_length <= kMaxLength);                          \
-    DCHECK_EQ(input[0], keyword[0]);                                      \
-    DCHECK(token == Token::FUTURE_STRICT_RESERVED_WORD ||                 \
-           0 == strncmp(keyword, Token::String(token), sizeof(keyword))); \
-    if (input_length == keyword_length && input[1] == keyword[1] &&       \
-        (keyword_length <= 2 || input[2] == keyword[2]) &&                \
-        (keyword_length <= 3 || input[3] == keyword[3]) &&                \
-        (keyword_length <= 4 || input[4] == keyword[4]) &&                \
-        (keyword_length <= 5 || input[5] == keyword[5]) &&                \
-        (keyword_length <= 6 || input[6] == keyword[6]) &&                \
-        (keyword_length <= 7 || input[7] == keyword[7]) &&                \
-        (keyword_length <= 8 || input[8] == keyword[8]) &&                \
-        (keyword_length <= 9 || input[9] == keyword[9]) &&                \
-        (keyword_length <= 10 || input[10] == keyword[10])) {             \
-      return token;                                                       \
-    }                                                                     \
-  }
-      KEYWORDS(KEYWORD_GROUP_CASE, KEYWORD)
-  }
-  return Token::IDENTIFIER;
-#undef KEYWORDS
-#undef KEYWORD
-#undef KEYWORD_GROUP_CASE
-}
-
-Token::Value Scanner::ScanIdentifierOrKeyword() {
-  LiteralScope literal(this);
-  return ScanIdentifierOrKeywordInner(&literal);
-}
-
-Token::Value Scanner::ScanIdentifierOrKeywordInner(LiteralScope* literal) {
-  DCHECK(unicode_cache_->IsIdentifierStart(c0_));
-  bool escaped = false;
-  if (IsInRange(c0_, 'a', 'z') || c0_ == '_') {
-    do {
-      AddLiteralChar(static_cast<char>(c0_));
-      Advance();
-    } while (IsInRange(c0_, 'a', 'z') || c0_ == '_');
-
-    if (IsDecimalDigit(c0_) || IsInRange(c0_, 'A', 'Z') || c0_ == '$') {
-      // Identifier starting with lowercase or _.
-      do {
-        AddLiteralChar(static_cast<char>(c0_));
-        Advance();
-      } while (IsAsciiIdentifier(c0_));
-
-      if (c0_ <= kMaxAscii && c0_ != '\\') {
-        literal->Complete();
-        return Token::IDENTIFIER;
-      }
-    } else if (c0_ <= kMaxAscii && c0_ != '\\') {
-      // Only a-z+ or _: could be a keyword or identifier.
-      Vector<const uint8_t> chars = next().literal_chars.one_byte_literal();
-      Token::Value token =
-          KeywordOrIdentifierToken(chars.start(), chars.length());
-      if (token == Token::IDENTIFIER ||
-          token == Token::FUTURE_STRICT_RESERVED_WORD ||
-          Token::IsContextualKeyword(token))
-        literal->Complete();
-      return token;
-    }
-  } else if (IsInRange(c0_, 'A', 'Z') || c0_ == '$') {
-    do {
-      AddLiteralChar(static_cast<char>(c0_));
-      Advance();
-    } while (IsAsciiIdentifier(c0_));
-
-    if (c0_ <= kMaxAscii && c0_ != '\\') {
-      literal->Complete();
-      return Token::IDENTIFIER;
-    }
-  } else if (c0_ == '\\') {
-    escaped = true;
-    uc32 c = ScanIdentifierUnicodeEscape();
-    DCHECK(!unicode_cache_->IsIdentifierStart(-1));
-    if (c == '\\' || !unicode_cache_->IsIdentifierStart(c)) {
-      return Token::ILLEGAL;
-    }
-    AddLiteralChar(c);
-  }
-
+Token::Value Scanner::ScanIdentifierOrKeywordInnerSlow(LiteralScope* literal,
+                                                       bool escaped) {
   while (true) {
     if (c0_ == '\\') {
       escaped = true;
@@ -1645,18 +1061,12 @@ bool Scanner::ScanRegExpPattern() {
 
   // Scan: ('/' | '/=') RegularExpressionBody '/' RegularExpressionFlags
   bool in_character_class = false;
-  bool seen_equal = (next().token == Token::ASSIGN_DIV);
-
-  // Previous token is either '/' or '/=', in the second case, the
-  // pattern starts at =.
-  next().location.beg_pos = source_pos() - (seen_equal ? 2 : 1);
-  next().location.end_pos = source_pos() - (seen_equal ? 1 : 0);
 
   // Scan regular expression body: According to ECMA-262, 3rd, 7.8.5,
   // the scanner should pass uninterpreted bodies to the RegExp
   // constructor.
   LiteralScope literal(this);
-  if (seen_equal) {
+  if (next().token == Token::ASSIGN_DIV) {
     AddLiteralChar('=');
   }
 
diff --git a/deps/v8/src/parsing/scanner.h b/deps/v8/src/parsing/scanner.h
index e592debd8e..83002b53c8 100644
--- a/deps/v8/src/parsing/scanner.h
+++ b/deps/v8/src/parsing/scanner.h
@@ -21,13 +21,13 @@
 namespace v8 {
 namespace internal {
 
-
 class AstRawString;
 class AstValueFactory;
 class DuplicateFinder;
 class ExternalOneByteString;
 class ExternalTwoByteString;
 class ParserRecorder;
+class RuntimeCallStats;
 class UnicodeCache;
 
 // ---------------------------------------------------------------------
@@ -38,7 +38,7 @@ class Utf16CharacterStream {
  public:
   static const uc32 kEndOfInput = -1;
 
-  virtual ~Utf16CharacterStream() {}
+  virtual ~Utf16CharacterStream() = default;
 
   inline uc32 Peek() {
     if (V8_LIKELY(buffer_cursor_ < buffer_end_)) {
@@ -109,8 +109,21 @@ class Utf16CharacterStream {
     }
   }
 
+  // Returns true if the stream can be cloned with Clone.
+  // TODO(rmcilroy): Remove this once ChunkedStreams can be cloned.
+  virtual bool can_be_cloned() const = 0;
+
+  // Clones the character stream to enable another independent scanner to access
+  // the same underlying stream.
+  virtual std::unique_ptr<Utf16CharacterStream> Clone() const = 0;
+
   // Returns true if the stream could access the V8 heap after construction.
-  virtual bool can_access_heap() = 0;
+  virtual bool can_access_heap() const = 0;
+
+  RuntimeCallStats* runtime_call_stats() const { return runtime_call_stats_; }
+  void set_runtime_call_stats(RuntimeCallStats* runtime_call_stats) {
+    runtime_call_stats_ = runtime_call_stats;
+  }
 
  protected:
   Utf16CharacterStream(const uint16_t* buffer_start,
@@ -172,6 +185,7 @@ class Utf16CharacterStream {
   const uint16_t* buffer_cursor_;
   const uint16_t* buffer_end_;
   size_t buffer_pos_;
+  RuntimeCallStats* runtime_call_stats_;
 };
 
 // ----------------------------------------------------------------------------
@@ -186,12 +200,12 @@ class Scanner {
         : scanner_(scanner), bookmark_(kNoBookmark) {
       DCHECK_NOT_NULL(scanner_);
     }
-    ~BookmarkScope() {}
+    ~BookmarkScope() = default;
 
     void Set();
     void Apply();
-    bool HasBeenSet();
-    bool HasBeenApplied();
+    bool HasBeenSet() const;
+    bool HasBeenApplied() const;
 
    private:
     static const size_t kNoBookmark;
@@ -233,19 +247,21 @@ class Scanner {
   // Returns the token following peek()
   Token::Value PeekAhead();
   // Returns the current token again.
-  Token::Value current_token() { return current().token; }
+  Token::Value current_token() const { return current().token; }
 
-  Token::Value current_contextual_token() { return current().contextual_token; }
-  Token::Value next_contextual_token() { return next().contextual_token; }
+  Token::Value current_contextual_token() const {
+    return current().contextual_token;
+  }
+  Token::Value next_contextual_token() const { return next().contextual_token; }
 
   // Returns the location information for the current token
   // (the token last returned by Next()).
-  Location location() const { return current().location; }
+  const Location& location() const { return current().location; }
 
   // This error is specifically an invalid hex or unicode escape sequence.
   bool has_error() const { return scanner_error_ != MessageTemplate::kNone; }
   MessageTemplate::Template error() const { return scanner_error_; }
-  Location error_location() const { return scanner_error_location_; }
+  const Location& error_location() const { return scanner_error_location_; }
 
   bool has_invalid_template_escape() const {
     return current().invalid_template_escape_message != MessageTemplate::kNone;
@@ -264,13 +280,14 @@ class Scanner {
   // One token look-ahead (past the token returned by Next()).
   Token::Value peek() const { return next().token; }
 
-  Location peek_location() const { return next().location; }
+  const Location& peek_location() const { return next().location; }
 
   bool literal_contains_escapes() const {
     return LiteralContainsEscapes(current());
   }
 
   const AstRawString* CurrentSymbol(AstValueFactory* ast_value_factory) const;
+
   const AstRawString* NextSymbol(AstValueFactory* ast_value_factory) const;
   const AstRawString* CurrentRawSymbol(
       AstValueFactory* ast_value_factory) const;
@@ -286,7 +303,7 @@ class Scanner {
 
   inline bool CurrentMatchesContextual(Token::Value token) const {
     DCHECK(Token::IsContextualKeyword(token));
-    return current().contextual_token == token;
+    return current_contextual_token() == token;
   }
 
   // Match the token against the contextual keyword or literal buffer.
@@ -297,7 +314,7 @@ class Scanner {
     // (which was escape-processed already).
     // Conveniently, !current().literal_chars.is_used() for all proper
     // keywords, so this second condition should exit early in common cases.
-    return (current().contextual_token == token) ||
+    return (current_contextual_token() == token) ||
            (current().literal_chars.is_used() &&
             current().literal_chars.Equals(Vector<const char>(
                 Token::String(token), Token::StringLength(token))));
@@ -308,11 +325,11 @@ class Scanner {
            current().literal_chars.Equals(
                Vector<const char>("use strict", strlen("use strict")));
   }
-  bool IsGetOrSet(bool* is_get, bool* is_set) const {
-    *is_get = CurrentMatchesContextual(Token::GET);
-    *is_set = CurrentMatchesContextual(Token::SET);
-    return *is_get || *is_set;
-  }
+
+  bool IsGet() { return CurrentMatchesContextual(Token::GET); }
+
+  bool IsSet() { return CurrentMatchesContextual(Token::SET); }
+
   bool IsLet() const {
     return CurrentMatches(Token::LET) ||
            CurrentMatchesContextualEscaped(Token::LET);
@@ -324,7 +341,7 @@ class Scanner {
   bool IsDuplicateSymbol(DuplicateFinder* duplicate_finder,
                          AstValueFactory* ast_value_factory) const;
 
-  UnicodeCache* unicode_cache() { return unicode_cache_; }
+  UnicodeCache* unicode_cache() const { return unicode_cache_; }
 
   // Returns the location of the last seen octal literal.
   Location octal_position() const { return octal_pos_; }
@@ -362,10 +379,9 @@ class Scanner {
   Maybe<RegExp::Flags> ScanRegExpFlags();
 
   // Scans the input as a template literal
-  Token::Value ScanTemplateStart();
   Token::Value ScanTemplateContinuation() {
     DCHECK_EQ(next().token, Token::RBRACE);
-    next().location.beg_pos = source_pos() - 1;  // We already consumed }
+    DCHECK_EQ(source_pos() - 1, next().location.beg_pos);
     return ScanTemplateSpan();
   }
 
@@ -374,8 +390,6 @@ class Scanner {
 
   bool FoundHtmlComment() const { return found_html_comment_; }
 
-  bool allow_harmony_bigint() const { return allow_harmony_bigint_; }
-  void set_allow_harmony_bigint(bool allow) { allow_harmony_bigint_ = allow; }
   bool allow_harmony_private_fields() const {
     return allow_harmony_private_fields_;
   }
@@ -389,34 +403,19 @@ class Scanner {
     allow_harmony_numeric_separator_ = allow;
   }
 
+  const Utf16CharacterStream* stream() const { return source_; }
+
  private:
   // Scoped helper for saving & restoring scanner error state.
   // This is used for tagged template literals, in which normally forbidden
   // escape sequences are allowed.
   class ErrorState;
 
-  // Scoped helper for literal recording. Automatically drops the literal
-  // if aborting the scanning before it's complete.
-  class LiteralScope {
-   public:
-    explicit LiteralScope(Scanner* self) : scanner_(self), complete_(false) {
-      scanner_->StartLiteral();
-    }
-    ~LiteralScope() {
-      if (!complete_) scanner_->DropLiteral();
-    }
-    void Complete() { complete_ = true; }
-
-   private:
-    Scanner* scanner_;
-    bool complete_;
-  };
-
   // LiteralBuffer -  Collector of chars of literals.
   class LiteralBuffer {
    public:
     LiteralBuffer()
-        : position_(0), is_one_byte_(true), is_used_(false), backing_store_() {}
+        : backing_store_(), position_(0), is_one_byte_(true), is_used_(false) {}
 
     ~LiteralBuffer() { backing_store_.Dispose(); }
 
@@ -506,14 +505,32 @@ class Scanner {
     void ExpandBuffer();
     void ConvertToTwoByte();
 
+    Vector<byte> backing_store_;
     int position_;
     bool is_one_byte_;
     bool is_used_;
-    Vector<byte> backing_store_;
 
     DISALLOW_COPY_AND_ASSIGN(LiteralBuffer);
   };
 
+  // Scoped helper for literal recording. Automatically drops the literal
+  // if aborting the scanning before it's complete.
+  class LiteralScope {
+   public:
+    explicit LiteralScope(Scanner* scanner)
+        : buffer_(&scanner->next().literal_chars), complete_(false) {
+      buffer_->Start();
+    }
+    ~LiteralScope() {
+      if (!complete_) buffer_->Drop();
+    }
+    void Complete() { complete_ = true; }
+
+   private:
+    LiteralBuffer* buffer_;
+    bool complete_;
+  };
+
   // The current and look-ahead token.
   struct TokenDesc {
     Location location = {0, 0};
@@ -538,7 +555,7 @@ class Scanner {
   };
 
   static const int kCharacterLookaheadBufferSize = 1;
-  const int kMaxAscii = 127;
+  static const int kMaxAscii = 127;
 
   // Scans octal escape sequence. Also accepts "\0" decimal escape sequence.
   template <bool capture_raw>
@@ -574,11 +591,6 @@ class Scanner {
   // Seek to the next_ token at the given position.
   void SeekNext(size_t position);
 
-  // Literal buffer support
-  inline void StartLiteral() { next().literal_chars.Start(); }
-
-  inline void StartRawLiteral() { next().raw_literal_chars.Start(); }
-
   V8_INLINE void AddLiteralChar(uc32 c) { next().literal_chars.AddChar(c); }
 
   V8_INLINE void AddLiteralChar(char c) { next().literal_chars.AddChar(c); }
@@ -587,14 +599,7 @@ class Scanner {
     next().raw_literal_chars.AddChar(c);
   }
 
-  // Stops scanning of a literal and drop the collected characters,
-  // e.g., due to an encountered error.
-  inline void DropLiteral() {
-    next().literal_chars.Drop();
-    next().raw_literal_chars.Drop();
-  }
-
-  inline void AddLiteralCharAdvance() {
+  V8_INLINE void AddLiteralCharAdvance() {
     AddLiteralChar(c0_);
     Advance();
   }
@@ -714,7 +719,8 @@ class Scanner {
   uc32 ScanUnlimitedLengthHexNumber(int max_value, int beg_pos);
 
   // Scans a single JavaScript token.
-  void Scan();
+  V8_INLINE Token::Value ScanSingleToken();
+  V8_INLINE void Scan();
 
   V8_INLINE Token::Value SkipWhiteSpace();
   Token::Value SkipSingleHTMLComment();
@@ -738,8 +744,10 @@ class Scanner {
   bool ScanImplicitOctalDigits(int start_pos, NumberKind* kind);
 
   Token::Value ScanNumber(bool seen_period);
-  Token::Value ScanIdentifierOrKeyword();
-  Token::Value ScanIdentifierOrKeywordInner(LiteralScope* literal);
+  V8_INLINE Token::Value ScanIdentifierOrKeyword();
+  V8_INLINE Token::Value ScanIdentifierOrKeywordInner(LiteralScope* literal);
+  Token::Value ScanIdentifierOrKeywordInnerSlow(LiteralScope* literal,
+                                                bool escaped);
 
   Token::Value ScanString();
   Token::Value ScanPrivateName();
@@ -779,13 +787,7 @@ class Scanner {
   void SanityCheckTokenDesc(const TokenDesc&) const;
 #endif
 
-  UnicodeCache* unicode_cache_;
-
-  // Values parsed from magic comments.
-  LiteralBuffer source_url_;
-  LiteralBuffer source_mapping_url_;
-
-  TokenDesc token_storage_[3];
+  UnicodeCache* const unicode_cache_;
 
   TokenDesc& next() { return *next_; }
 
@@ -800,23 +802,28 @@ class Scanner {
   // Input stream. Must be initialized to an Utf16CharacterStream.
   Utf16CharacterStream* const source_;
 
-  // Last-seen positions of potentially problematic tokens.
-  Location octal_pos_;
-  MessageTemplate::Template octal_message_;
-
   // One Unicode character look-ahead; c0_ < 0 at the end of the input.
   uc32 c0_;
 
+  TokenDesc token_storage_[3];
+
   // Whether this scanner encountered an HTML comment.
   bool found_html_comment_;
 
   // Harmony flags to allow ESNext features.
-  bool allow_harmony_bigint_;
   bool allow_harmony_private_fields_;
   bool allow_harmony_numeric_separator_;
 
   const bool is_module_;
 
+  // Values parsed from magic comments.
+  LiteralBuffer source_url_;
+  LiteralBuffer source_mapping_url_;
+
+  // Last-seen positions of potentially problematic tokens.
+  Location octal_pos_;
+  MessageTemplate::Template octal_message_;
+
   MessageTemplate::Template scanner_error_;
   Location scanner_error_location_;
 };
diff --git a/deps/v8/src/parsing/token.cc b/deps/v8/src/parsing/token.cc
index 258c7b5d09..4cbf244a2b 100644
--- a/deps/v8/src/parsing/token.cc
+++ b/deps/v8/src/parsing/token.cc
@@ -29,7 +29,6 @@ const uint8_t Token::string_length_[NUM_TOKENS] = {TOKEN_LIST(T, T, T)};
 const int8_t Token::precedence_[NUM_TOKENS] = {TOKEN_LIST(T, T, T)};
 #undef T
 
-
 #define KT(a, b, c) 'T',
 #define KK(a, b, c) 'K',
 #define KC(a, b, c) 'C',
diff --git a/deps/v8/src/parsing/token.h b/deps/v8/src/parsing/token.h
index 660f24361c..e1c6239e36 100644
--- a/deps/v8/src/parsing/token.h
+++ b/deps/v8/src/parsing/token.h
@@ -7,6 +7,7 @@
 
 #include "src/base/logging.h"
 #include "src/globals.h"
+#include "src/utils.h"
 
 namespace v8 {
 namespace internal {
@@ -32,6 +33,27 @@ namespace internal {
 
 #define IGNORE_TOKEN(name, string, precedence)
 
+/* Binary operators sorted by precedence */
+#define BINARY_OP_TOKEN_LIST(T, E) \
+  E(T, BIT_OR, "|", 6)             \
+  E(T, BIT_XOR, "^", 7)            \
+  E(T, BIT_AND, "&", 8)            \
+  E(T, SHL, "<<", 11)              \
+  E(T, SAR, ">>", 11)              \
+  E(T, SHR, ">>>", 11)             \
+  E(T, ADD, "+", 12)               \
+  E(T, SUB, "-", 12)               \
+  E(T, MUL, "*", 13)               \
+  E(T, DIV, "/", 13)               \
+  E(T, MOD, "%", 13)               \
+  E(T, EXP, "**", 14)
+
+#define EXPAND_BINOP_ASSIGN_TOKEN(T, name, string, precedence) \
+  T(ASSIGN_##name, string "=", 2)
+
+#define EXPAND_BINOP_TOKEN(T, name, string, precedence) \
+  T(name, string, precedence)
+
 #define TOKEN_LIST(T, K, C)                                        \
   /* End of source indicator. */                                   \
   T(EOS, "EOS", 0)                                                 \
@@ -57,18 +79,7 @@ namespace internal {
   /* contiguous and sorted in the same order! */                   \
   T(INIT, "=init", 2) /* AST-use only. */                          \
   T(ASSIGN, "=", 2)                                                \
-  T(ASSIGN_BIT_OR, "|=", 2)                                        \
-  T(ASSIGN_BIT_XOR, "^=", 2)                                       \
-  T(ASSIGN_BIT_AND, "&=", 2)                                       \
-  T(ASSIGN_SHL, "<<=", 2)                                          \
-  T(ASSIGN_SAR, ">>=", 2)                                          \
-  T(ASSIGN_SHR, ">>>=", 2)                                         \
-  T(ASSIGN_ADD, "+=", 2)                                           \
-  T(ASSIGN_SUB, "-=", 2)                                           \
-  T(ASSIGN_MUL, "*=", 2)                                           \
-  T(ASSIGN_DIV, "/=", 2)                                           \
-  T(ASSIGN_MOD, "%=", 2)                                           \
-  T(ASSIGN_EXP, "**=", 2)                                          \
+  BINARY_OP_TOKEN_LIST(T, EXPAND_BINOP_ASSIGN_TOKEN)               \
                                                                    \
   /* Binary operators sorted by precedence. */                     \
   /* IsBinaryOp() relies on this block of enum values */           \
@@ -76,25 +87,14 @@ namespace internal {
   T(COMMA, ",", 1)                                                 \
   T(OR, "||", 4)                                                   \
   T(AND, "&&", 5)                                                  \
-  T(BIT_OR, "|", 6)                                                \
-  T(BIT_XOR, "^", 7)                                               \
-  T(BIT_AND, "&", 8)                                               \
-  T(SHL, "<<", 11)                                                 \
-  T(SAR, ">>", 11)                                                 \
-  T(SHR, ">>>", 11)                                                \
-  T(ADD, "+", 12)                                                  \
-  T(SUB, "-", 12)                                                  \
-  T(MUL, "*", 13)                                                  \
-  T(DIV, "/", 13)                                                  \
-  T(MOD, "%", 13)                                                  \
-  T(EXP, "**", 14)                                                 \
+  BINARY_OP_TOKEN_LIST(T, EXPAND_BINOP_TOKEN)                      \
                                                                    \
   /* Compare operators sorted by precedence. */                    \
   /* IsCompareOp() relies on this block of enum values */          \
   /* being contiguous and sorted in the same order! */             \
   T(EQ, "==", 9)                                                   \
-  T(NE, "!=", 9)                                                   \
   T(EQ_STRICT, "===", 9)                                           \
+  T(NE, "!=", 9)                                                   \
   T(NE_STRICT, "!==", 9)                                           \
   T(LT, "<", 10)                                                   \
   T(GT, ">", 10)                                                   \
@@ -131,7 +131,6 @@ namespace internal {
   K(NEW, "new", 0)                                                 \
   K(RETURN, "return", 0)                                           \
   K(SWITCH, "switch", 0)                                           \
-  K(THIS, "this", 0)                                               \
   K(THROW, "throw", 0)                                             \
   K(TRY, "try", 0)                                                 \
   /* TYPEOF */                                                     \
@@ -139,6 +138,7 @@ namespace internal {
   /* VOID */                                                       \
   K(WHILE, "while", 0)                                             \
   K(WITH, "with", 0)                                               \
+  K(THIS, "this", 0)                                               \
                                                                    \
   /* Literals (ECMA-262, section 7.8, page 16). */                 \
   K(NULL_LITERAL, "null", 0)                                       \
@@ -146,33 +146,34 @@ namespace internal {
   K(FALSE_LITERAL, "false", 0)                                     \
   T(NUMBER, nullptr, 0)                                            \
   T(SMI, nullptr, 0)                                               \
-  T(STRING, nullptr, 0)                                            \
   T(BIGINT, nullptr, 0)                                            \
+  T(STRING, nullptr, 0)                                            \
                                                                    \
+  /* BEGIN AnyIdentifier */                                        \
   /* Identifiers (not keywords or future reserved words). */       \
   T(IDENTIFIER, nullptr, 0)                                        \
-  T(PRIVATE_NAME, nullptr, 0)                                      \
-                                                                   \
-  /* Future reserved words (ECMA-262, section 7.6.1.2). */         \
-  T(FUTURE_STRICT_RESERVED_WORD, nullptr, 0)                       \
   K(ASYNC, "async", 0)                                             \
   /* `await` is a reserved word in module code only */             \
   K(AWAIT, "await", 0)                                             \
+  K(YIELD, "yield", 0)                                             \
+  K(LET, "let", 0)                                                 \
+  K(STATIC, "static", 0)                                           \
+  /* Future reserved words (ECMA-262, section 7.6.1.2). */         \
+  T(FUTURE_STRICT_RESERVED_WORD, nullptr, 0)                       \
+  T(ESCAPED_STRICT_RESERVED_WORD, nullptr, 0)                      \
+  K(ENUM, "enum", 0)                                               \
+  /* END AnyIdentifier */                                          \
   K(CLASS, "class", 0)                                             \
   K(CONST, "const", 0)                                             \
-  K(ENUM, "enum", 0)                                               \
   K(EXPORT, "export", 0)                                           \
   K(EXTENDS, "extends", 0)                                         \
   K(IMPORT, "import", 0)                                           \
-  K(LET, "let", 0)                                                 \
-  K(STATIC, "static", 0)                                           \
-  K(YIELD, "yield", 0)                                             \
   K(SUPER, "super", 0)                                             \
+  T(PRIVATE_NAME, nullptr, 0)                                      \
                                                                    \
   /* Illegal token - not able to scan. */                          \
   T(ILLEGAL, "ILLEGAL", 0)                                         \
   T(ESCAPED_KEYWORD, nullptr, 0)                                   \
-  T(ESCAPED_STRICT_RESERVED_WORD, nullptr, 0)                      \
                                                                    \
   /* Scanner-internal use only. */                                 \
   T(WHITESPACE, nullptr, 0)                                        \
@@ -205,127 +206,103 @@ class Token {
  public:
   // All token values.
 #define T(name, string, precedence) name,
-  enum Value { TOKEN_LIST(T, T, T) NUM_TOKENS };
+  enum Value : uint8_t { TOKEN_LIST(T, T, T) NUM_TOKENS };
 #undef T
 
   // Returns a string corresponding to the C++ token name
   // (e.g. "LT" for the token LT).
-  static const char* Name(Value tok) {
-    DCHECK(tok < NUM_TOKENS);  // tok is unsigned
-    return name_[tok];
+  static const char* Name(Value token) {
+    DCHECK_GT(NUM_TOKENS, token);  // token is unsigned
+    return name_[token];
   }
 
+  static char TypeForTesting(Value token) { return token_type[token]; }
+
   // Predicates
-  static bool IsKeyword(Value tok) {
-    return token_type[tok] == 'K';
+  static bool IsKeyword(Value token) { return token_type[token] == 'K'; }
+  static bool IsContextualKeyword(Value token) {
+    return IsInRange(token, GET, ANONYMOUS);
   }
-  static bool IsContextualKeyword(Value tok) { return token_type[tok] == 'C'; }
 
-  static bool IsIdentifier(Value tok, LanguageMode language_mode,
+  static bool IsIdentifier(Value token, LanguageMode language_mode,
                            bool is_generator, bool disallow_await) {
-    switch (tok) {
-      case IDENTIFIER:
-      case ASYNC:
-        return true;
-      case ESCAPED_STRICT_RESERVED_WORD:
-      case FUTURE_STRICT_RESERVED_WORD:
-      case LET:
-      case STATIC:
-        return is_sloppy(language_mode);
-      case YIELD:
-        return !is_generator && is_sloppy(language_mode);
-      case AWAIT:
-        return !disallow_await;
-      default:
-        return false;
+    if (IsInRange(token, IDENTIFIER, ASYNC)) return true;
+    if (IsInRange(token, LET, ESCAPED_STRICT_RESERVED_WORD)) {
+      return is_sloppy(language_mode);
     }
-    UNREACHABLE();
+    if (token == AWAIT) return !disallow_await;
+    if (token == YIELD) return !is_generator && is_sloppy(language_mode);
+    return false;
   }
 
-  static bool IsAssignmentOp(Value tok) {
-    return INIT <= tok && tok <= ASSIGN_EXP;
+  static bool IsAnyIdentifier(Value token) {
+    return IsInRange(token, IDENTIFIER, ENUM);
   }
 
-  static bool IsBinaryOp(Value op) { return COMMA <= op && op <= EXP; }
+  static bool IsStrictReservedWord(Value token) {
+    return IsInRange(token, LET, ESCAPED_STRICT_RESERVED_WORD);
+  }
 
-  static bool IsCompareOp(Value op) {
-    return EQ <= op && op <= IN;
+  static bool IsLiteral(Value token) {
+    return IsInRange(token, NULL_LITERAL, STRING);
   }
 
-  static bool IsOrderedRelationalCompareOp(Value op) {
-    return op == LT || op == LTE || op == GT || op == GTE;
+  static bool IsAssignmentOp(Value token) {
+    return IsInRange(token, INIT, ASSIGN_EXP);
   }
+  static bool IsGetOrSet(Value op) { return IsInRange(op, GET, SET); }
+
+  static bool IsBinaryOp(Value op) { return IsInRange(op, COMMA, EXP); }
 
-  static bool IsEqualityOp(Value op) {
-    return op == EQ || op == EQ_STRICT;
+  static bool IsCompareOp(Value op) { return IsInRange(op, EQ, IN); }
+
+  static bool IsOrderedRelationalCompareOp(Value op) {
+    return IsInRange(op, LT, GTE);
   }
 
+  static bool IsEqualityOp(Value op) { return IsInRange(op, EQ, EQ_STRICT); }
+
   static Value BinaryOpForAssignment(Value op) {
-    DCHECK(IsAssignmentOp(op));
-    switch (op) {
-      case Token::ASSIGN_BIT_OR:
-        return Token::BIT_OR;
-      case Token::ASSIGN_BIT_XOR:
-        return Token::BIT_XOR;
-      case Token::ASSIGN_BIT_AND:
-        return Token::BIT_AND;
-      case Token::ASSIGN_SHL:
-        return Token::SHL;
-      case Token::ASSIGN_SAR:
-        return Token::SAR;
-      case Token::ASSIGN_SHR:
-        return Token::SHR;
-      case Token::ASSIGN_ADD:
-        return Token::ADD;
-      case Token::ASSIGN_SUB:
-        return Token::SUB;
-      case Token::ASSIGN_MUL:
-        return Token::MUL;
-      case Token::ASSIGN_DIV:
-        return Token::DIV;
-      case Token::ASSIGN_MOD:
-        return Token::MOD;
-      case Token::ASSIGN_EXP:
-        return Token::EXP;
-      default:
-        UNREACHABLE();
-    }
+    DCHECK(IsInRange(op, ASSIGN_BIT_OR, ASSIGN_EXP));
+    Value result = static_cast<Value>(op - ASSIGN_BIT_OR + BIT_OR);
+    DCHECK(IsBinaryOp(result));
+    return result;
   }
 
   static bool IsBitOp(Value op) {
-    return (BIT_OR <= op && op <= SHR) || op == BIT_NOT;
+    return IsInRange(op, BIT_OR, SHR) || op == BIT_NOT;
   }
 
   static bool IsUnaryOp(Value op) {
-    return (NOT <= op && op <= VOID) || op == ADD || op == SUB;
+    return IsInRange(op, NOT, VOID) || IsInRange(op, ADD, SUB);
   }
 
-  static bool IsCountOp(Value op) {
-    return op == INC || op == DEC;
-  }
+  static bool IsCountOp(Value op) { return IsInRange(op, INC, DEC); }
+
+  static bool IsShiftOp(Value op) { return IsInRange(op, SHL, SHR); }
 
-  static bool IsShiftOp(Value op) {
-    return (SHL <= op) && (op <= SHR);
+  static bool IsTrivialExpressionToken(Value op) {
+    return IsInRange(op, THIS, IDENTIFIER);
   }
 
   // Returns a string corresponding to the JS token string
   // (.e., "<" for the token LT) or nullptr if the token doesn't
   // have a (unique) string (e.g. an IDENTIFIER).
-  static const char* String(Value tok) {
-    DCHECK(tok < NUM_TOKENS);  // tok is unsigned.
-    return string_[tok];
+  static const char* String(Value token) {
+    DCHECK_GT(NUM_TOKENS, token);  // token is unsigned
+    return string_[token];
   }
 
-  static uint8_t StringLength(Value tok) {
-    DCHECK(tok < NUM_TOKENS);
-    return string_length_[tok];
+  static uint8_t StringLength(Value token) {
+    DCHECK_GT(NUM_TOKENS, token);  // token is unsigned
+    return string_length_[token];
   }
 
   // Returns the precedence > 0 for binary and compare
   // operators; returns 0 otherwise.
-  static int Precedence(Value tok) {
-    DCHECK(tok < NUM_TOKENS);  // tok is unsigned.
-    return precedence_[tok];
+  static int Precedence(Value token) {
+    DCHECK_GT(NUM_TOKENS, token);  // token is unsigned
+    return precedence_[token];
   }
 
  private:
diff --git a/deps/v8/src/pending-compilation-error-handler.h b/deps/v8/src/pending-compilation-error-handler.h
index b828fff17c..f18a8369e4 100644
--- a/deps/v8/src/pending-compilation-error-handler.h
+++ b/deps/v8/src/pending-compilation-error-handler.h
@@ -62,6 +62,12 @@ class PendingCompilationErrorHandler {
 
   Handle<String> FormatErrorMessageForTest(Isolate* isolate) const;
 
+  bool SetUnidentifiableError() { return unidentifiable_error_ = true; }
+
+  bool ResetUnidentifiableError() { return unidentifiable_error_ = false; }
+
+  bool ErrorUnidentifiableByPreParser() { return unidentifiable_error_; }
+
  private:
   class MessageDetails {
    public:
@@ -97,6 +103,7 @@ class PendingCompilationErrorHandler {
 
   bool has_pending_error_;
   bool stack_overflow_;
+  bool unidentifiable_error_ = false;
 
   MessageDetails error_details_;
   ParseErrorType error_type_;
diff --git a/deps/v8/src/perf-jit.h b/deps/v8/src/perf-jit.h
index 3b11cf30c2..91f0dca10f 100644
--- a/deps/v8/src/perf-jit.h
+++ b/deps/v8/src/perf-jit.h
@@ -39,7 +39,7 @@ namespace internal {
 class PerfJitLogger : public CodeEventLogger {
  public:
   explicit PerfJitLogger(Isolate* isolate);
-  virtual ~PerfJitLogger();
+  ~PerfJitLogger() override;
 
   void CodeMoveEvent(AbstractCode* from, AbstractCode* to) override;
   void CodeDisableOptEvent(AbstractCode* code,
diff --git a/deps/v8/src/ppc/assembler-ppc.cc b/deps/v8/src/ppc/assembler-ppc.cc
index 24d9d2b8f3..5daa55604e 100644
--- a/deps/v8/src/ppc/assembler-ppc.cc
+++ b/deps/v8/src/ppc/assembler-ppc.cc
@@ -44,6 +44,7 @@
 #include "src/deoptimizer.h"
 #include "src/macro-assembler.h"
 #include "src/ppc/assembler-ppc-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -211,6 +212,13 @@ Operand Operand::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rn, int32_t offset)
     : ra_(rn), offset_(offset), rb_(no_reg) {}
 
@@ -218,22 +226,30 @@ MemOperand::MemOperand(Register ra, Register rb)
     : ra_(ra), offset_(0), rb_(rb) {}
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     switch (request.kind()) {
-      case HeapObjectRequest::kHeapNumber:
+      case HeapObjectRequest::kHeapNumber: {
         object =
             isolate->factory()->NewHeapNumber(request.heap_number(), TENURED);
         break;
-      case HeapObjectRequest::kCodeStub:
+      }
+      case HeapObjectRequest::kCodeStub: {
         request.code_stub()->set_isolate(isolate);
         object = request.code_stub()->GetCode();
         break;
+      }
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        object = str->AllocateStringConstant(isolate);
+        break;
+      }
     }
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     Address constant_pool = kNullAddress;
-    set_target_address_at(pc, constant_pool,
-                          reinterpret_cast<Address>(object.location()),
+    set_target_address_at(pc, constant_pool, object.address(),
                           SKIP_ICACHE_FLUSH);
   }
 }
@@ -2070,13 +2086,7 @@ void Assembler::dp(uintptr_t data) {
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
-  if (options().disable_reloc_info_for_patching) return;
-  if (RelocInfo::IsNone(rmode) ||
-      // Don't record external references unless the heap will be serialized.
-      (RelocInfo::IsOnlyForSerializer(rmode) &&
-       !options().record_reloc_info_for_serialization && !emit_debug_code())) {
-    return;
-  }
+  if (!ShouldRecordRelocInfo(rmode)) return;
   DeferredRelocInfo rinfo(pc_offset(), rmode, data);
   relocations_.push_back(rinfo);
 }
diff --git a/deps/v8/src/ppc/assembler-ppc.h b/deps/v8/src/ppc/assembler-ppc.h
index b737320cbb..9f3ff0dc7e 100644
--- a/deps/v8/src/ppc/assembler-ppc.h
+++ b/deps/v8/src/ppc/assembler-ppc.h
@@ -217,7 +217,7 @@ const int kNumSafepointRegisters = 32;
 // The following constants describe the stack frame linkage area as
 // defined by the ABI.  Note that kNumRequiredStackFrameSlots must
 // satisfy alignment requirements (rounding up if required).
-#if V8_TARGET_ARCH_PPC64 && V8_TARGET_LITTLE_ENDIAN
+#if V8_TARGET_ARCH_PPC64 && V8_TARGET_LITTLE_ENDIAN  // ppc64le linux
 // [0] back chain
 // [1] condition register save area
 // [2] link register save area
@@ -230,7 +230,7 @@ const int kNumSafepointRegisters = 32;
 const int kNumRequiredStackFrameSlots = 12;
 const int kStackFrameLRSlot = 2;
 const int kStackFrameExtraParamSlot = 12;
-#elif V8_OS_AIX || V8_TARGET_ARCH_PPC64
+#else  // AIX
 // [0] back chain
 // [1] condition register save area
 // [2] link register save area
@@ -242,21 +242,9 @@ const int kStackFrameExtraParamSlot = 12;
 // [13] Parameter8 save area
 // [14] Parameter9 slot (if necessary)
 // ...
-#if V8_TARGET_ARCH_PPC64
 const int kNumRequiredStackFrameSlots = 14;
-#else
-const int kNumRequiredStackFrameSlots = 16;
-#endif
 const int kStackFrameLRSlot = 2;
 const int kStackFrameExtraParamSlot = 14;
-#else
-// [0] back chain
-// [1] link register save area
-// [2] Parameter9 slot (if necessary)
-// ...
-const int kNumRequiredStackFrameSlots = 4;
-const int kStackFrameLRSlot = 1;
-const int kStackFrameExtraParamSlot = 2;
 #endif
 
 // Define the list of registers actually saved at safepoints.
@@ -373,7 +361,7 @@ C_REGISTERS(DECLARE_C_REGISTER)
 // Machine instruction Operands
 
 // Class Operand represents a shifter operand in data processing instructions
-class Operand BASE_EMBEDDED {
+class Operand {
  public:
   // immediate
   V8_INLINE explicit Operand(intptr_t immediate,
@@ -394,6 +382,7 @@ class Operand BASE_EMBEDDED {
   V8_INLINE explicit Operand(Register rm);
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
   static Operand EmbeddedCode(CodeStub* stub);
 
   // Return true if this is a register operand.
@@ -442,7 +431,7 @@ class Operand BASE_EMBEDDED {
 // Class MemOperand represents a memory operand in load and store instructions
 // On PowerPC we have base register + 16bit signed value
 // Alternatively we can have a 16bit signed value immediate
-class MemOperand BASE_EMBEDDED {
+class MemOperand {
  public:
   explicit MemOperand(Register rn, int32_t offset = 0);
 
@@ -1632,8 +1621,7 @@ class Assembler : public AssemblerBase {
   friend class EnsureSpace;
 };
 
-
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit EnsureSpace(Assembler* assembler) { assembler->CheckBuffer(); }
 };
diff --git a/deps/v8/src/ppc/code-stubs-ppc.cc b/deps/v8/src/ppc/code-stubs-ppc.cc
index cfa2709fd5..7e287b08b8 100644
--- a/deps/v8/src/ppc/code-stubs-ppc.cc
+++ b/deps/v8/src/ppc/code-stubs-ppc.cc
@@ -115,7 +115,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
                  IsolateAddressId::kPendingExceptionAddress, isolate())));
 
   __ StoreP(r3, MemOperand(ip));
-  __ LoadRoot(r3, Heap::kExceptionRootIndex);
+  __ LoadRoot(r3, RootIndex::kException);
   __ b(&exit);
 
   // Invoke: Link this frame into the handler chain.
@@ -439,7 +439,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ LeaveExitFrame(false, r14, stack_space_operand != nullptr);
 
   // Check if the function scheduled an exception.
-  __ LoadRoot(r14, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(r14, RootIndex::kTheHoleValue);
   __ Move(r15, ExternalReference::scheduled_exception_address(isolate));
   __ LoadP(r15, MemOperand(r15));
   __ cmp(r14, r15);
@@ -490,13 +490,13 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data
   __ push(call_data);
 
   Register scratch = call_data;
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   // return value
   __ push(scratch);
   // return value default
@@ -577,7 +577,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // Push data from AccessorInfo.
   __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
   __ push(scratch);
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   __ Push(scratch, scratch);
   __ Move(scratch, ExternalReference::isolate_address(isolate()));
   __ Push(scratch, holder);
diff --git a/deps/v8/src/ppc/codegen-ppc.cc b/deps/v8/src/ppc/codegen-ppc.cc
index 65963b9af6..b27890d1f5 100644
--- a/deps/v8/src/ppc/codegen-ppc.cc
+++ b/deps/v8/src/ppc/codegen-ppc.cc
@@ -7,7 +7,6 @@
 #include <memory>
 
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 #include "src/ppc/simulator-ppc.h"
 
@@ -16,16 +15,17 @@ namespace internal {
 
 #define __ masm.
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
 #if defined(USE_SIMULATOR)
   return nullptr;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   // Called from C
   __ function_descriptor();
@@ -36,13 +36,14 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(ABI_USES_FUNCTION_DESCRIPTORS ||
          !RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 #endif
 }
 
diff --git a/deps/v8/src/ppc/constants-ppc.h b/deps/v8/src/ppc/constants-ppc.h
index 0f2679008c..a6cecf7dc2 100644
--- a/deps/v8/src/ppc/constants-ppc.h
+++ b/deps/v8/src/ppc/constants-ppc.h
@@ -1201,13 +1201,15 @@ typedef uint32_t Instr;
   /* Compare Logical */             \
   V(cmpl, CMPL, 0x7C000040)
 
-#define PPC_X_OPCODE_EH_S_FORM_LIST(V)              \
-  /* Store Byte Conditional Indexed */              \
-  V(stbcx, STBCX, 0x7C00056D)                       \
-  /* Store Halfword Conditional Indexed Xform */    \
-  V(sthcx, STHCX, 0x7C0005AD)                       \
-  /* Store Word Conditional Indexed & record CR0 */ \
-  V(stwcx, STWCX, 0x7C00012D)
+#define PPC_X_OPCODE_EH_S_FORM_LIST(V)                    \
+  /* Store Byte Conditional Indexed */                    \
+  V(stbcx, STBCX, 0x7C00056D)                             \
+  /* Store Halfword Conditional Indexed Xform */          \
+  V(sthcx, STHCX, 0x7C0005AD)                             \
+  /* Store Word Conditional Indexed & record CR0 */       \
+  V(stwcx, STWCX, 0x7C00012D)                             \
+  /* Store Doubleword Conditional Indexed & record CR0 */ \
+  V(stdcx, STDCX, 0x7C0001AD)
 
 #define PPC_X_OPCODE_EH_L_FORM_LIST(V)          \
   /* Load Byte And Reserve Indexed */           \
@@ -1215,15 +1217,15 @@ typedef uint32_t Instr;
   /* Load Halfword And Reserve Indexed Xform */ \
   V(lharx, LHARX, 0x7C0000E8)                   \
   /* Load Word and Reserve Indexed */           \
-  V(lwarx, LWARX, 0x7C000028)
+  V(lwarx, LWARX, 0x7C000028)                   \
+  /* Load Doubleword And Reserve Indexed */     \
+  V(ldarx, LDARX, 0x7C0000A8)
 
 #define PPC_X_OPCODE_UNUSED_LIST(V)                                            \
   /* Bit Permute Doubleword */                                                 \
   V(bpermd, BPERMD, 0x7C0001F8)                                                \
   /* Extend Sign Word */                                                       \
   V(extsw, EXTSW, 0x7C0007B4)                                                  \
-  /* Load Doubleword And Reserve Indexed */                                    \
-  V(ldarx, LDARX, 0x7C0000A8)                                                  \
   /* Load Word Algebraic with Update Indexed */                                \
   V(lwaux, LWAUX, 0x7C0002EA)                                                  \
   /* Load Word Algebraic Indexed */                                            \
@@ -1232,8 +1234,6 @@ typedef uint32_t Instr;
   V(prtyd, PRTYD, 0x7C000174)                                                  \
   /* Store Doubleword Byte-Reverse Indexed */                                  \
   V(stdbrx, STDBRX, 0x7C000528)                                                \
-  /* Store Doubleword Conditional Indexed & record CR0 */                      \
-  V(stdcx, STDCX, 0x7C0001AD)                                                  \
   /* Trap Doubleword */                                                        \
   V(td, TD, 0x7C000088)                                                        \
   /* Branch Conditional to Branch Target Address Register */                   \
diff --git a/deps/v8/src/ppc/disasm-ppc.cc b/deps/v8/src/ppc/disasm-ppc.cc
index 1b8a1139a3..ae56f3616d 100644
--- a/deps/v8/src/ppc/disasm-ppc.cc
+++ b/deps/v8/src/ppc/disasm-ppc.cc
@@ -665,6 +665,10 @@ void Decoder::DecodeExt2(Instruction* instr) {
       Format(instr, "stwcx   'rs, 'ra, 'rb");
       return;
     }
+    case STDCX: {
+      Format(instr, "stdcx   'rs, 'ra, 'rb");
+      return;
+    }
   }
 
   // ?? are all of these xo_form?
@@ -898,6 +902,10 @@ void Decoder::DecodeExt2(Instruction* instr) {
       Format(instr, "ldux    'rt, 'ra, 'rb");
       return;
     }
+    case LDARX: {
+      Format(instr, "ldarx   'rt, 'ra, 'rb");
+      return;
+    }
     case STDX: {
       Format(instr, "stdx    'rt, 'ra, 'rb");
       return;
diff --git a/deps/v8/src/ppc/interface-descriptors-ppc.cc b/deps/v8/src/ppc/interface-descriptors-ppc.cc
index 857ab7a883..505aaef93d 100644
--- a/deps/v8/src/ppc/interface-descriptors-ppc.cc
+++ b/deps/v8/src/ppc/interface-descriptors-ppc.cc
@@ -88,9 +88,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // r3 : number of arguments (on the stack, not including receiver)
   // r4 : the target to call
-  // r5 : arguments list (FixedArray)
   // r7 : arguments list length (untagged)
-  Register registers[] = {r4, r3, r5, r7};
+  // r5 : arguments list (FixedArray)
+  Register registers[] = {r4, r3, r7, r5};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -125,9 +125,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // r3 : number of arguments (on the stack, not including receiver)
   // r4 : the target to call
   // r6 : the new target
-  // r5 : arguments list (FixedArray)
   // r7 : arguments list length (untagged)
-  Register registers[] = {r4, r6, r3, r5, r7};
+  // r5 : arguments list (FixedArray)
+  Register registers[] = {r4, r6, r3, r7, r5};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -194,7 +194,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r4,  // JSFunction
@@ -238,10 +238,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r3,  // argument count (not including receiver)
-      r6,  // new target
+      r7,  // address of the first argument
       r4,  // constructor to call
+      r6,  // new target
       r5,  // allocation site feedback if available, undefined otherwise
-      r7   // address of the first argument
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/ppc/macro-assembler-ppc.cc b/deps/v8/src/ppc/macro-assembler-ppc.cc
index 9ae1e7139a..9565d04a4d 100644
--- a/deps/v8/src/ppc/macro-assembler-ppc.cc
+++ b/deps/v8/src/ppc/macro-assembler-ppc.cc
@@ -128,14 +128,14 @@ void TurboAssembler::Jump(Register target) {
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
+      RootIndex::kBuiltinsConstantsTable));
 
   const uint32_t offset =
       FixedArray::kHeaderSize + constant_index * kPointerSize - kHeapObjectTag;
 
   CHECK(is_uint19(offset));
   DCHECK_NE(destination, r0);
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   LoadP(destination, MemOperand(destination, offset), r0);
 }
 
@@ -395,7 +395,7 @@ void TurboAssembler::MultiPopDoubles(RegList dregs, Register location) {
   addi(location, location, Operand(stack_offset));
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index,
+void TurboAssembler::LoadRoot(Register destination, RootIndex index,
                               Condition cond) {
   DCHECK(cond == al);
   LoadP(destination, MemOperand(kRootRegister, RootRegisterOffset(index)), r0);
@@ -483,8 +483,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -496,7 +494,6 @@ void TurboAssembler::CallRecordWriteStub(
   pop(slot_parameter);
   pop(object_parameter);
 
-  Move(isolate_parameter, ExternalReference::isolate_address(isolate()));
   Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -1322,7 +1319,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(r6, Heap::kUndefinedValueRootIndex);
+    LoadRoot(r6, RootIndex::kUndefinedValue);
   }
 
   Label done;
@@ -1446,8 +1443,7 @@ void MacroAssembler::CompareInstanceType(Register map, Register type_reg,
   cmpi(type_reg, Operand(type));
 }
 
-
-void MacroAssembler::CompareRoot(Register obj, Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(Register obj, RootIndex index) {
   DCHECK(obj != r0);
   LoadRoot(r0, index);
   cmp(obj, r0);
@@ -1894,7 +1890,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
   if (emit_debug_code()) {
     Label done_checking;
     AssertNotSmi(object);
-    CompareRoot(object, Heap::kUndefinedValueRootIndex);
+    CompareRoot(object, RootIndex::kUndefinedValue);
     beq(&done_checking);
     LoadP(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
     CompareInstanceType(scratch, scratch, ALLOCATION_SITE_TYPE);
diff --git a/deps/v8/src/ppc/macro-assembler-ppc.h b/deps/v8/src/ppc/macro-assembler-ppc.h
index 364b60d037..897ac5553e 100644
--- a/deps/v8/src/ppc/macro-assembler-ppc.h
+++ b/deps/v8/src/ppc/macro-assembler-ppc.h
@@ -90,6 +90,9 @@ Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -321,11 +324,10 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                      Register exclusion3 = no_reg);
 
   // Load an object from the root table.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override {
+  void LoadRoot(Register destination, RootIndex index) override {
     LoadRoot(destination, index, al);
   }
-  void LoadRoot(Register destination, Heap::RootListIndex index,
-                Condition cond);
+  void LoadRoot(Register destination, RootIndex index, Condition cond);
 
   void SwapP(Register src, Register dst, Register scratch);
   void SwapP(Register src, MemOperand dst, Register scratch);
@@ -662,10 +664,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used acros.
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -846,21 +852,20 @@ class MacroAssembler : public TurboAssembler {
 
   // Compare the object in a register to a value from the root list.
   // Uses the ip register as scratch.
-  void CompareRoot(Register obj, Heap::RootListIndex index);
-  void PushRoot(Heap::RootListIndex index) {
+  void CompareRoot(Register obj, RootIndex index);
+  void PushRoot(RootIndex index) {
     LoadRoot(r0, index);
     Push(r0);
   }
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal) {
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal) {
     CompareRoot(with, index);
     beq(if_equal);
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal) {
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal) {
     CompareRoot(with, index);
     bne(if_not_equal);
   }
diff --git a/deps/v8/src/ppc/simulator-ppc.cc b/deps/v8/src/ppc/simulator-ppc.cc
index 0fd03df30c..900e03f6bb 100644
--- a/deps/v8/src/ppc/simulator-ppc.cc
+++ b/deps/v8/src/ppc/simulator-ppc.cc
@@ -870,6 +870,27 @@ void Simulator::TrashCallerSaveRegisters() {
 #endif
 }
 
+int Simulator::WriteExDW(intptr_t addr, uint64_t value, Instruction* instr) {
+  base::LockGuard<base::Mutex> lock_guard(&global_monitor_.Pointer()->mutex);
+  if (local_monitor_.NotifyStoreExcl(addr, TransactionSize::Word) &&
+      global_monitor_.Pointer()->NotifyStoreExcl_Locked(
+          addr, &global_monitor_processor_)) {
+    uint64_t* ptr = reinterpret_cast<uint64_t*>(addr);
+    *ptr = value;
+    return 0;
+  } else {
+    return 1;
+  }
+}
+
+uint64_t Simulator::ReadExDWU(intptr_t addr, Instruction* instr) {
+  base::LockGuard<base::Mutex> lock_guard(&global_monitor_.Pointer()->mutex);
+  local_monitor_.NotifyLoadExcl(addr, TransactionSize::Word);
+  global_monitor_.Pointer()->NotifyLoadExcl_Locked(addr,
+                                                   &global_monitor_processor_);
+  uint64_t* ptr = reinterpret_cast<uint64_t*>(addr);
+  return *ptr;
+}
 
 uint32_t Simulator::ReadWU(intptr_t addr, Instruction* instr) {
   // All supported PPC targets allow unaligned accesses, so we don't need to
@@ -2320,6 +2341,16 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       SetCR0(WriteExW(ra_val + rb_val, rs_val, instr));
       break;
     }
+    case STDCX: {
+      int rs = instr->RSValue();
+      int ra = instr->RAValue();
+      int rb = instr->RBValue();
+      intptr_t ra_val = ra == 0 ? 0 : get_register(ra);
+      int64_t rs_val = get_register(rs);
+      intptr_t rb_val = get_register(rb);
+      SetCR0(WriteExDW(ra_val + rb_val, rs_val, instr));
+      break;
+    }
     case TW: {
       // used for call redirection in simulation mode
       SoftwareInterrupt(instr);
@@ -3087,6 +3118,15 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       set_register(rt, ReadExWU(ra_val + rb_val, instr));
       break;
     }
+    case LDARX: {
+      int rt = instr->RTValue();
+      int ra = instr->RAValue();
+      int rb = instr->RBValue();
+      intptr_t ra_val = ra == 0 ? 0 : get_register(ra);
+      intptr_t rb_val = get_register(rb);
+      set_register(rt, ReadExDWU(ra_val + rb_val, instr));
+      break;
+    }
     case DCBF: {
       // todo - simulate dcbf
       break;
@@ -3305,11 +3345,11 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       return;
     }
     case FSQRT: {
-      lazily_initialize_fast_sqrt(isolate_);
+      lazily_initialize_fast_sqrt();
       int frt = instr->RTValue();
       int frb = instr->RBValue();
       double frb_val = get_double_from_d_register(frb);
-      double frt_val = fast_sqrt(frb_val, isolate_);
+      double frt_val = fast_sqrt(frb_val);
       set_d_register_from_double(frt, frt_val);
       return;
     }
diff --git a/deps/v8/src/ppc/simulator-ppc.h b/deps/v8/src/ppc/simulator-ppc.h
index 22f34015a6..7b26906c29 100644
--- a/deps/v8/src/ppc/simulator-ppc.h
+++ b/deps/v8/src/ppc/simulator-ppc.h
@@ -265,6 +265,8 @@ class Simulator : public SimulatorBase {
 
   intptr_t* ReadDW(intptr_t addr);
   void WriteDW(intptr_t addr, int64_t value);
+  inline int WriteExDW(intptr_t addr, uint64_t value, Instruction* instr);
+  inline uint64_t ReadExDWU(intptr_t addr, Instruction* instr);
 
   void Trace(Instruction* instr);
   void SetCR0(intptr_t result, bool setSO = false);
diff --git a/deps/v8/src/profiler/allocation-tracker.cc b/deps/v8/src/profiler/allocation-tracker.cc
index e5b3139785..51cb0eb47f 100644
--- a/deps/v8/src/profiler/allocation-tracker.cc
+++ b/deps/v8/src/profiler/allocation-tracker.cc
@@ -75,11 +75,6 @@ AllocationTraceTree::AllocationTraceTree()
       root_(this, 0) {
 }
 
-
-AllocationTraceTree::~AllocationTraceTree() {
-}
-
-
 AllocationTraceNode* AllocationTraceTree::AddPathFromEnd(
     const Vector<unsigned>& path) {
   AllocationTraceNode* node = root();
diff --git a/deps/v8/src/profiler/allocation-tracker.h b/deps/v8/src/profiler/allocation-tracker.h
index cd9e120db2..bff9a62750 100644
--- a/deps/v8/src/profiler/allocation-tracker.h
+++ b/deps/v8/src/profiler/allocation-tracker.h
@@ -57,7 +57,7 @@ class AllocationTraceNode {
 class AllocationTraceTree {
  public:
   AllocationTraceTree();
-  ~AllocationTraceTree();
+  ~AllocationTraceTree() = default;
   AllocationTraceNode* AddPathFromEnd(const Vector<unsigned>& path);
   AllocationTraceNode* root() { return &root_; }
   unsigned next_node_id() { return next_node_id_++; }
diff --git a/deps/v8/src/profiler/circular-queue-inl.h b/deps/v8/src/profiler/circular-queue-inl.h
index 413b236d37..855e217805 100644
--- a/deps/v8/src/profiler/circular-queue-inl.h
+++ b/deps/v8/src/profiler/circular-queue-inl.h
@@ -16,11 +16,8 @@ SamplingCircularQueue<T, L>::SamplingCircularQueue()
       dequeue_pos_(buffer_) {
 }
 
-
-template<typename T, unsigned L>
-SamplingCircularQueue<T, L>::~SamplingCircularQueue() {
-}
-
+template <typename T, unsigned L>
+SamplingCircularQueue<T, L>::~SamplingCircularQueue() = default;
 
 template<typename T, unsigned L>
 T* SamplingCircularQueue<T, L>::Peek() {
diff --git a/deps/v8/src/profiler/cpu-profiler.h b/deps/v8/src/profiler/cpu-profiler.h
index 78bb3b4a25..6e2acdfde7 100644
--- a/deps/v8/src/profiler/cpu-profiler.h
+++ b/deps/v8/src/profiler/cpu-profiler.h
@@ -106,7 +106,7 @@ class TickSampleEventRecord {
  public:
   // The parameterless constructor is used when we dequeue data from
   // the ticks buffer.
-  TickSampleEventRecord() { }
+  TickSampleEventRecord() = default;
   explicit TickSampleEventRecord(unsigned order) : order(order) { }
 
   unsigned order;
@@ -135,10 +135,10 @@ class ProfilerEventsProcessor : public base::Thread {
  public:
   ProfilerEventsProcessor(Isolate* isolate, ProfileGenerator* generator,
                           base::TimeDelta period);
-  virtual ~ProfilerEventsProcessor();
+  ~ProfilerEventsProcessor() override;
 
   // Thread control.
-  virtual void Run();
+  void Run() override;
   void StopSynchronously();
   V8_INLINE bool running() { return !!base::Relaxed_Load(&running_); }
   void Enqueue(const CodeEventsContainer& event);
diff --git a/deps/v8/src/profiler/heap-profiler.cc b/deps/v8/src/profiler/heap-profiler.cc
index 3a1df29bd4..0978e76cff 100644
--- a/deps/v8/src/profiler/heap-profiler.cc
+++ b/deps/v8/src/profiler/heap-profiler.cc
@@ -23,14 +23,9 @@ HeapProfiler::~HeapProfiler() = default;
 
 void HeapProfiler::DeleteAllSnapshots() {
   snapshots_.clear();
-  MaybeClearStringsStorage();
+  names_.reset(new StringsStorage());
 }
 
-void HeapProfiler::MaybeClearStringsStorage() {
-  if (snapshots_.empty() && !sampling_heap_profiler_ && !allocation_tracker_) {
-    names_.reset(new StringsStorage());
-  }
-}
 
 void HeapProfiler::RemoveSnapshot(HeapSnapshot* snapshot) {
   snapshots_.erase(
@@ -131,7 +126,6 @@ bool HeapProfiler::StartSamplingHeapProfiler(
 
 void HeapProfiler::StopSamplingHeapProfiler() {
   sampling_heap_profiler_.reset();
-  MaybeClearStringsStorage();
 }
 
 
@@ -165,7 +159,6 @@ void HeapProfiler::StopHeapObjectsTracking() {
   ids_->StopHeapObjectsTracking();
   if (allocation_tracker_) {
     allocation_tracker_.reset();
-    MaybeClearStringsStorage();
     heap()->RemoveHeapObjectAllocationTracker(this);
   }
 }
@@ -236,10 +229,7 @@ void HeapProfiler::QueryObjects(Handle<Context> context,
                                 PersistentValueVector<v8::Object>* objects) {
   // We should return accurate information about live objects, so we need to
   // collect all garbage first.
-  heap()->CollectAllAvailableGarbage(
-      GarbageCollectionReason::kLowMemoryNotification);
-  heap()->CollectAllGarbage(Heap::kMakeHeapIterableMask,
-                            GarbageCollectionReason::kHeapProfiler);
+  heap()->CollectAllAvailableGarbage(GarbageCollectionReason::kHeapProfiler);
   HeapIterator heap_iterator(heap());
   HeapObject* heap_obj;
   while ((heap_obj = heap_iterator.next()) != nullptr) {
diff --git a/deps/v8/src/profiler/heap-profiler.h b/deps/v8/src/profiler/heap-profiler.h
index 099c0e24fa..acbdc6aa7a 100644
--- a/deps/v8/src/profiler/heap-profiler.h
+++ b/deps/v8/src/profiler/heap-profiler.h
@@ -27,7 +27,7 @@ class StringsStorage;
 class HeapProfiler : public HeapObjectAllocationTracker {
  public:
   explicit HeapProfiler(Heap* heap);
-  ~HeapProfiler();
+  ~HeapProfiler() override;
 
   HeapSnapshot* TakeSnapshot(
       v8::ActivityControl* control,
@@ -92,8 +92,6 @@ class HeapProfiler : public HeapObjectAllocationTracker {
                     v8::PersistentValueVector<v8::Object>* objects);
 
  private:
-  void MaybeClearStringsStorage();
-
   Heap* heap() const;
 
   // Mapping from HeapObject addresses to objects' uids.
diff --git a/deps/v8/src/profiler/heap-snapshot-generator-inl.h b/deps/v8/src/profiler/heap-snapshot-generator-inl.h
index edf6559706..6ddb6d4658 100644
--- a/deps/v8/src/profiler/heap-snapshot-generator-inl.h
+++ b/deps/v8/src/profiler/heap-snapshot-generator-inl.h
@@ -13,51 +13,41 @@
 namespace v8 {
 namespace internal {
 
-
 HeapEntry* HeapGraphEdge::from() const {
   return &snapshot()->entries()[from_index()];
 }
 
-
-Isolate* HeapGraphEdge::isolate() const {
-  return snapshot()->profiler()->isolate();
-}
-
+Isolate* HeapGraphEdge::isolate() const { return to_entry_->isolate(); }
 
 HeapSnapshot* HeapGraphEdge::snapshot() const {
   return to_entry_->snapshot();
 }
 
-
-int HeapEntry::index() const {
-  return static_cast<int>(this - &snapshot_->entries().front());
-}
-
-
 int HeapEntry::set_children_index(int index) {
-  children_index_ = index;
+  // Note: children_count_ and children_end_index_ are parts of a union.
   int next_index = index + children_count_;
-  children_count_ = 0;
+  children_end_index_ = index;
   return next_index;
 }
 
 void HeapEntry::add_child(HeapGraphEdge* edge) {
-  *(children_begin() + children_count_++) = edge;
+  snapshot_->children()[children_end_index_++] = edge;
 }
 
-HeapGraphEdge* HeapEntry::child(int i) { return *(children_begin() + i); }
+HeapGraphEdge* HeapEntry::child(int i) { return children_begin()[i]; }
+
+std::vector<HeapGraphEdge*>::iterator HeapEntry::children_begin() const {
+  return index_ == 0 ? snapshot_->children().begin()
+                     : snapshot_->entries()[index_ - 1].children_end();
+}
 
-std::deque<HeapGraphEdge*>::iterator HeapEntry::children_begin() {
-  DCHECK_GE(children_index_, 0);
-  SLOW_DCHECK(
-      children_index_ < static_cast<int>(snapshot_->children().size()) ||
-      (children_index_ == static_cast<int>(snapshot_->children().size()) &&
-       children_count_ == 0));
-  return snapshot_->children().begin() + children_index_;
+std::vector<HeapGraphEdge*>::iterator HeapEntry::children_end() const {
+  DCHECK_GE(children_end_index_, 0);
+  return snapshot_->children().begin() + children_end_index_;
 }
 
-std::deque<HeapGraphEdge*>::iterator HeapEntry::children_end() {
-  return children_begin() + children_count_;
+int HeapEntry::children_count() const {
+  return static_cast<int>(children_end() - children_begin());
 }
 
 Isolate* HeapEntry::isolate() const { return snapshot_->profiler()->isolate(); }
diff --git a/deps/v8/src/profiler/heap-snapshot-generator.cc b/deps/v8/src/profiler/heap-snapshot-generator.cc
index 5d98a98b8e..57f620f4ec 100644
--- a/deps/v8/src/profiler/heap-snapshot-generator.cc
+++ b/deps/v8/src/profiler/heap-snapshot-generator.cc
@@ -33,10 +33,11 @@
 namespace v8 {
 namespace internal {
 
-
-HeapGraphEdge::HeapGraphEdge(Type type, const char* name, int from, int to)
-    : bit_field_(TypeField::encode(type) | FromIndexField::encode(from)),
-      to_index_(to),
+HeapGraphEdge::HeapGraphEdge(Type type, const char* name, HeapEntry* from,
+                             HeapEntry* to)
+    : bit_field_(TypeField::encode(type) |
+                 FromIndexField::encode(from->index())),
+      to_entry_(to),
       name_(name) {
   DCHECK(type == kContextVariable
       || type == kProperty
@@ -45,55 +46,53 @@ HeapGraphEdge::HeapGraphEdge(Type type, const char* name, int from, int to)
       || type == kWeak);
 }
 
-
-HeapGraphEdge::HeapGraphEdge(Type type, int index, int from, int to)
-    : bit_field_(TypeField::encode(type) | FromIndexField::encode(from)),
-      to_index_(to),
+HeapGraphEdge::HeapGraphEdge(Type type, int index, HeapEntry* from,
+                             HeapEntry* to)
+    : bit_field_(TypeField::encode(type) |
+                 FromIndexField::encode(from->index())),
+      to_entry_(to),
       index_(index) {
   DCHECK(type == kElement || type == kHidden);
 }
 
-
-void HeapGraphEdge::ReplaceToIndexWithEntry(HeapSnapshot* snapshot) {
-  to_entry_ = &snapshot->entries()[to_index_];
-}
-
-
-const int HeapEntry::kNoEntry = -1;
-
-HeapEntry::HeapEntry(HeapSnapshot* snapshot,
-                     Type type,
-                     const char* name,
-                     SnapshotObjectId id,
-                     size_t self_size,
+HeapEntry::HeapEntry(HeapSnapshot* snapshot, int index, Type type,
+                     const char* name, SnapshotObjectId id, size_t self_size,
                      unsigned trace_node_id)
     : type_(type),
+      index_(index),
       children_count_(0),
-      children_index_(-1),
       self_size_(self_size),
       snapshot_(snapshot),
       name_(name),
       id_(id),
-      trace_node_id_(trace_node_id) { }
-
+      trace_node_id_(trace_node_id) {
+  DCHECK_GE(index, 0);
+}
 
 void HeapEntry::SetNamedReference(HeapGraphEdge::Type type,
                                   const char* name,
                                   HeapEntry* entry) {
-  HeapGraphEdge edge(type, name, this->index(), entry->index());
-  snapshot_->edges().push_back(edge);
   ++children_count_;
+  snapshot_->edges().emplace_back(type, name, this, entry);
 }
 
-
 void HeapEntry::SetIndexedReference(HeapGraphEdge::Type type,
                                     int index,
                                     HeapEntry* entry) {
-  HeapGraphEdge edge(type, index, this->index(), entry->index());
-  snapshot_->edges().push_back(edge);
   ++children_count_;
+  snapshot_->edges().emplace_back(type, index, this, entry);
 }
 
+void HeapEntry::SetNamedAutoIndexReference(HeapGraphEdge::Type type,
+                                           const char* description,
+                                           HeapEntry* child,
+                                           StringsStorage* names) {
+  int index = children_count_ + 1;
+  const char* name = description
+                         ? names->GetFormatted("%d / %s", index, description)
+                         : names->GetName(index);
+  SetNamedReference(type, name, child);
+}
 
 void HeapEntry::Print(
     const char* prefix, const char* edge_name, int max_depth, int indent) {
@@ -154,7 +153,6 @@ void HeapEntry::Print(
   }
 }
 
-
 const char* HeapEntry::TypeAsString() {
   switch (type()) {
     case kHidden: return "/hidden/";
@@ -176,34 +174,24 @@ const char* HeapEntry::TypeAsString() {
   }
 }
 
-
-HeapSnapshot::HeapSnapshot(HeapProfiler* profiler)
-    : profiler_(profiler),
-      root_index_(HeapEntry::kNoEntry),
-      gc_roots_index_(HeapEntry::kNoEntry),
-      max_snapshot_js_object_id_(0) {
+HeapSnapshot::HeapSnapshot(HeapProfiler* profiler) : profiler_(profiler) {
   // It is very important to keep objects that form a heap snapshot
   // as small as possible. Check assumptions about data structure sizes.
-  STATIC_ASSERT(((kPointerSize == 4) && (sizeof(HeapGraphEdge) == 12)) ||
-                ((kPointerSize == 8) && (sizeof(HeapGraphEdge) == 24)));
-  STATIC_ASSERT(((kPointerSize == 4) && (sizeof(HeapEntry) == 28)) ||
-                ((kPointerSize == 8) && (sizeof(HeapEntry) == 40)));
-  for (int i = 0; i < static_cast<int>(Root::kNumberOfRoots); ++i) {
-    gc_subroot_indexes_[i] = HeapEntry::kNoEntry;
-  }
+  STATIC_ASSERT((kPointerSize == 4 && sizeof(HeapGraphEdge) == 12) ||
+                (kPointerSize == 8 && sizeof(HeapGraphEdge) == 24));
+  STATIC_ASSERT((kPointerSize == 4 && sizeof(HeapEntry) == 28) ||
+                (kPointerSize == 8 && sizeof(HeapEntry) == 40));
+  memset(&gc_subroot_entries_, 0, sizeof(gc_subroot_entries_));
 }
 
-
 void HeapSnapshot::Delete() {
   profiler_->RemoveSnapshot(this);
 }
 
-
 void HeapSnapshot::RememberLastJSObjectId() {
   max_snapshot_js_object_id_ = profiler_->heap_object_map()->last_assigned_id();
 }
 
-
 void HeapSnapshot::AddSyntheticRootEntries() {
   AddRootEntry();
   AddGcRootsEntry();
@@ -215,42 +203,30 @@ void HeapSnapshot::AddSyntheticRootEntries() {
   DCHECK_EQ(HeapObjectsMap::kFirstAvailableObjectId, id);
 }
 
-
-HeapEntry* HeapSnapshot::AddRootEntry() {
-  DCHECK_EQ(root_index_, HeapEntry::kNoEntry);
+void HeapSnapshot::AddRootEntry() {
+  DCHECK_NULL(root_entry_);
   DCHECK(entries_.empty());  // Root entry must be the first one.
-  HeapEntry* entry = AddEntry(HeapEntry::kSynthetic,
-                              "",
-                              HeapObjectsMap::kInternalRootObjectId,
-                              0,
-                              0);
-  root_index_ = entry->index();
-  DCHECK_EQ(root_index_, 0);
-  return entry;
-}
-
-
-HeapEntry* HeapSnapshot::AddGcRootsEntry() {
-  DCHECK_EQ(gc_roots_index_, HeapEntry::kNoEntry);
-  HeapEntry* entry = AddEntry(HeapEntry::kSynthetic,
-                              "(GC roots)",
-                              HeapObjectsMap::kGcRootsObjectId,
-                              0,
-                              0);
-  gc_roots_index_ = entry->index();
-  return entry;
-}
-
-HeapEntry* HeapSnapshot::AddGcSubrootEntry(Root root, SnapshotObjectId id) {
-  DCHECK_EQ(gc_subroot_indexes_[static_cast<int>(root)], HeapEntry::kNoEntry);
-  HeapEntry* entry =
+  root_entry_ = AddEntry(HeapEntry::kSynthetic, "",
+                         HeapObjectsMap::kInternalRootObjectId, 0, 0);
+  DCHECK_EQ(1u, entries_.size());
+  DCHECK_EQ(root_entry_, &entries_.front());
+}
+
+void HeapSnapshot::AddGcRootsEntry() {
+  DCHECK_NULL(gc_roots_entry_);
+  gc_roots_entry_ = AddEntry(HeapEntry::kSynthetic, "(GC roots)",
+                             HeapObjectsMap::kGcRootsObjectId, 0, 0);
+}
+
+void HeapSnapshot::AddGcSubrootEntry(Root root, SnapshotObjectId id) {
+  DCHECK_NULL(gc_subroot_entries_[static_cast<int>(root)]);
+  gc_subroot_entries_[static_cast<int>(root)] =
       AddEntry(HeapEntry::kSynthetic, RootVisitor::RootName(root), id, 0, 0);
-  gc_subroot_indexes_[static_cast<int>(root)] = entry->index();
-  return entry;
 }
 
-void HeapSnapshot::AddLocation(int entry, int scriptId, int line, int col) {
-  locations_.emplace_back(entry, scriptId, line, col);
+void HeapSnapshot::AddLocation(HeapEntry* entry, int scriptId, int line,
+                               int col) {
+  locations_.emplace_back(entry->index(), scriptId, line, col);
 }
 
 HeapEntry* HeapSnapshot::AddEntry(HeapEntry::Type type,
@@ -258,52 +234,35 @@ HeapEntry* HeapSnapshot::AddEntry(HeapEntry::Type type,
                                   SnapshotObjectId id,
                                   size_t size,
                                   unsigned trace_node_id) {
-  DCHECK(sorted_entries_.empty());
-  entries_.emplace_back(this, type, name, id, size, trace_node_id);
+  DCHECK(!is_complete());
+  entries_.emplace_back(this, static_cast<int>(entries_.size()), type, name, id,
+                        size, trace_node_id);
   return &entries_.back();
 }
 
-
 void HeapSnapshot::FillChildren() {
   DCHECK(children().empty());
-  children().resize(edges().size());
   int children_index = 0;
   for (HeapEntry& entry : entries()) {
     children_index = entry.set_children_index(children_index);
   }
   DCHECK_EQ(edges().size(), static_cast<size_t>(children_index));
+  children().resize(edges().size());
   for (HeapGraphEdge& edge : edges()) {
-    edge.ReplaceToIndexWithEntry(this);
     edge.from()->add_child(&edge);
   }
 }
 
 HeapEntry* HeapSnapshot::GetEntryById(SnapshotObjectId id) {
-  std::vector<HeapEntry*>* entries_by_id = GetSortedEntriesList();
-
-  auto it = std::lower_bound(
-      entries_by_id->begin(), entries_by_id->end(), id,
-      [](HeapEntry* first, SnapshotObjectId val) { return first->id() < val; });
-
-  if (it == entries_by_id->end() || (*it)->id() != id) return nullptr;
-  return *it;
-}
-
-struct SortByIds {
-  bool operator()(const HeapEntry* entry1_ptr, const HeapEntry* entry2_ptr) {
-    return entry1_ptr->id() < entry2_ptr->id();
-  }
-};
-
-std::vector<HeapEntry*>* HeapSnapshot::GetSortedEntriesList() {
-  if (sorted_entries_.empty()) {
-    sorted_entries_.reserve(entries_.size());
+  if (entries_by_id_cache_.empty()) {
+    CHECK(is_complete());
+    entries_by_id_cache_.reserve(entries_.size());
     for (HeapEntry& entry : entries_) {
-      sorted_entries_.push_back(&entry);
+      entries_by_id_cache_.emplace(entry.id(), &entry);
     }
-    std::sort(sorted_entries_.begin(), sorted_entries_.end(), SortByIds());
   }
-  return &sorted_entries_;
+  auto it = entries_by_id_cache_.find(id);
+  return it != entries_by_id_cache_.end() ? it->second : nullptr;
 }
 
 void HeapSnapshot::Print(int max_depth) {
@@ -427,8 +386,8 @@ void HeapObjectsMap::UpdateHeapObjectsMap() {
     PrintF("Begin HeapObjectsMap::UpdateHeapObjectsMap. map has %d entries.\n",
            entries_map_.occupancy());
   }
-  heap_->CollectAllGarbage(Heap::kMakeHeapIterableMask,
-                           GarbageCollectionReason::kHeapProfiler);
+  heap_->PreciseCollectAllGarbage(Heap::kNoGCFlags,
+                                  GarbageCollectionReason::kHeapProfiler);
   HeapIterator iterator(heap_);
   for (HeapObject* obj = iterator.next(); obj != nullptr;
        obj = iterator.next()) {
@@ -540,61 +499,6 @@ SnapshotObjectId HeapObjectsMap::GenerateId(v8::RetainedObjectInfo* info) {
   return id << 1;
 }
 
-HeapEntriesMap::HeapEntriesMap() : entries_() {}
-
-int HeapEntriesMap::Map(HeapThing thing) {
-  base::HashMap::Entry* cache_entry = entries_.Lookup(thing, Hash(thing));
-  if (cache_entry == nullptr) return HeapEntry::kNoEntry;
-  return static_cast<int>(reinterpret_cast<intptr_t>(cache_entry->value));
-}
-
-
-void HeapEntriesMap::Pair(HeapThing thing, int entry) {
-  base::HashMap::Entry* cache_entry =
-      entries_.LookupOrInsert(thing, Hash(thing));
-  DCHECK_NULL(cache_entry->value);
-  cache_entry->value = reinterpret_cast<void*>(static_cast<intptr_t>(entry));
-}
-
-HeapObjectsSet::HeapObjectsSet() : entries_() {}
-
-void HeapObjectsSet::Clear() {
-  entries_.Clear();
-}
-
-
-bool HeapObjectsSet::Contains(Object* obj) {
-  if (!obj->IsHeapObject()) return false;
-  HeapObject* object = HeapObject::cast(obj);
-  return entries_.Lookup(object, HeapEntriesMap::Hash(object)) != nullptr;
-}
-
-
-void HeapObjectsSet::Insert(Object* obj) {
-  if (!obj->IsHeapObject()) return;
-  HeapObject* object = HeapObject::cast(obj);
-  entries_.LookupOrInsert(object, HeapEntriesMap::Hash(object));
-}
-
-
-const char* HeapObjectsSet::GetTag(Object* obj) {
-  HeapObject* object = HeapObject::cast(obj);
-  base::HashMap::Entry* cache_entry =
-      entries_.Lookup(object, HeapEntriesMap::Hash(object));
-  return cache_entry != nullptr
-             ? reinterpret_cast<const char*>(cache_entry->value)
-             : nullptr;
-}
-
-
-V8_NOINLINE void HeapObjectsSet::SetTag(Object* obj, const char* tag) {
-  if (!obj->IsHeapObject()) return;
-  HeapObject* object = HeapObject::cast(obj);
-  base::HashMap::Entry* cache_entry =
-      entries_.LookupOrInsert(object, HeapEntriesMap::Hash(object));
-  cache_entry->value = const_cast<char*>(tag);
-}
-
 V8HeapExplorer::V8HeapExplorer(HeapSnapshot* snapshot,
                                SnapshottingProgressReportingInterface* progress,
                                v8::HeapProfiler::ObjectNameResolver* resolver)
@@ -603,18 +507,14 @@ V8HeapExplorer::V8HeapExplorer(HeapSnapshot* snapshot,
       names_(snapshot_->profiler()->names()),
       heap_object_map_(snapshot_->profiler()->heap_object_map()),
       progress_(progress),
-      filler_(nullptr),
+      generator_(nullptr),
       global_object_name_resolver_(resolver) {}
 
-V8HeapExplorer::~V8HeapExplorer() {
-}
-
-
 HeapEntry* V8HeapExplorer::AllocateEntry(HeapThing ptr) {
   return AddEntry(reinterpret_cast<HeapObject*>(ptr));
 }
 
-void V8HeapExplorer::ExtractLocation(int entry, HeapObject* object) {
+void V8HeapExplorer::ExtractLocation(HeapEntry* entry, HeapObject* object) {
   if (object->IsJSFunction()) {
     JSFunction* func = JSFunction::cast(object);
     ExtractLocationForJSFunction(entry, func);
@@ -632,7 +532,8 @@ void V8HeapExplorer::ExtractLocation(int entry, HeapObject* object) {
   }
 }
 
-void V8HeapExplorer::ExtractLocationForJSFunction(int entry, JSFunction* func) {
+void V8HeapExplorer::ExtractLocationForJSFunction(HeapEntry* entry,
+                                                  JSFunction* func) {
   if (!func->shared()->script()->IsScript()) return;
   Script* script = Script::cast(func->shared()->script());
   int scriptId = script->id();
@@ -659,25 +560,22 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object) {
     const char* name = names_->GetName(
         GetConstructorName(JSObject::cast(object)));
     if (object->IsJSGlobalObject()) {
-      const char* tag = objects_tags_.GetTag(object);
-      if (tag != nullptr) {
-        name = names_->GetFormatted("%s / %s", name, tag);
+      auto it = objects_tags_.find(JSGlobalObject::cast(object));
+      if (it != objects_tags_.end()) {
+        name = names_->GetFormatted("%s / %s", name, it->second);
       }
     }
     return AddEntry(object, HeapEntry::kObject, name);
   } else if (object->IsString()) {
     String* string = String::cast(object);
-    if (string->IsConsString())
-      return AddEntry(object,
-                      HeapEntry::kConsString,
-                      "(concatenated string)");
-    if (string->IsSlicedString())
-      return AddEntry(object,
-                      HeapEntry::kSlicedString,
-                      "(sliced string)");
-    return AddEntry(object,
-                    HeapEntry::kString,
-                    names_->GetName(String::cast(object)));
+    if (string->IsConsString()) {
+      return AddEntry(object, HeapEntry::kConsString, "(concatenated string)");
+    } else if (string->IsSlicedString()) {
+      return AddEntry(object, HeapEntry::kSlicedString, "(sliced string)");
+    } else {
+      return AddEntry(object, HeapEntry::kString,
+                      names_->GetName(String::cast(object)));
+    }
   } else if (object->IsSymbol()) {
     if (Symbol::cast(object)->is_private())
       return AddEntry(object, HeapEntry::kHidden, "private symbol");
@@ -689,16 +587,12 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object) {
     return AddEntry(object, HeapEntry::kCode, "");
   } else if (object->IsSharedFunctionInfo()) {
     String* name = SharedFunctionInfo::cast(object)->Name();
-    return AddEntry(object,
-                    HeapEntry::kCode,
-                    names_->GetName(name));
+    return AddEntry(object, HeapEntry::kCode, names_->GetName(name));
   } else if (object->IsScript()) {
     Object* name = Script::cast(object)->name();
-    return AddEntry(object,
-                    HeapEntry::kCode,
-                    name->IsString()
-                        ? names_->GetName(String::cast(name))
-                        : "");
+    return AddEntry(
+        object, HeapEntry::kCode,
+        name->IsString() ? names_->GetName(String::cast(name)) : "");
   } else if (object->IsNativeContext()) {
     return AddEntry(object, HeapEntry::kHidden, "system / NativeContext");
   } else if (object->IsContext()) {
@@ -712,14 +606,12 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object) {
   return AddEntry(object, HeapEntry::kHidden, GetSystemEntryName(object));
 }
 
-
 HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object,
                                     HeapEntry::Type type,
                                     const char* name) {
   return AddEntry(object->address(), type, name, object->Size());
 }
 
-
 HeapEntry* V8HeapExplorer::AddEntry(Address address,
                                     HeapEntry::Type type,
                                     const char* name,
@@ -735,66 +627,6 @@ HeapEntry* V8HeapExplorer::AddEntry(Address address,
   return snapshot_->AddEntry(type, name, object_id, size, trace_node_id);
 }
 
-
-class SnapshotFiller {
- public:
-  explicit SnapshotFiller(HeapSnapshot* snapshot, HeapEntriesMap* entries)
-      : snapshot_(snapshot),
-        names_(snapshot->profiler()->names()),
-        entries_(entries) { }
-  HeapEntry* AddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
-    HeapEntry* entry = allocator->AllocateEntry(ptr);
-    entries_->Pair(ptr, entry->index());
-    return entry;
-  }
-  HeapEntry* FindEntry(HeapThing ptr) {
-    int index = entries_->Map(ptr);
-    return index != HeapEntry::kNoEntry ? &snapshot_->entries()[index]
-                                        : nullptr;
-  }
-  HeapEntry* FindOrAddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
-    HeapEntry* entry = FindEntry(ptr);
-    return entry != nullptr ? entry : AddEntry(ptr, allocator);
-  }
-  void SetIndexedReference(HeapGraphEdge::Type type,
-                           int parent,
-                           int index,
-                           HeapEntry* child_entry) {
-    HeapEntry* parent_entry = &snapshot_->entries()[parent];
-    parent_entry->SetIndexedReference(type, index, child_entry);
-  }
-  void SetIndexedAutoIndexReference(HeapGraphEdge::Type type,
-                                    int parent,
-                                    HeapEntry* child_entry) {
-    HeapEntry* parent_entry = &snapshot_->entries()[parent];
-    int index = parent_entry->children_count() + 1;
-    parent_entry->SetIndexedReference(type, index, child_entry);
-  }
-  void SetNamedReference(HeapGraphEdge::Type type,
-                         int parent,
-                         const char* reference_name,
-                         HeapEntry* child_entry) {
-    HeapEntry* parent_entry = &snapshot_->entries()[parent];
-    parent_entry->SetNamedReference(type, reference_name, child_entry);
-  }
-  void SetNamedAutoIndexReference(HeapGraphEdge::Type type, int parent,
-                                  const char* description,
-                                  HeapEntry* child_entry) {
-    HeapEntry* parent_entry = &snapshot_->entries()[parent];
-    int index = parent_entry->children_count() + 1;
-    const char* name = description
-                           ? names_->GetFormatted("%d / %s", index, description)
-                           : names_->GetName(index);
-    parent_entry->SetNamedReference(type, name, child_entry);
-  }
-
- private:
-  HeapSnapshot* snapshot_;
-  StringsStorage* names_;
-  HeapEntriesMap* entries_;
-};
-
-
 const char* V8HeapExplorer::GetSystemEntryName(HeapObject* object) {
   switch (object->map()->instance_type()) {
     case MAP_TYPE:
@@ -811,9 +643,10 @@ const char* V8HeapExplorer::GetSystemEntryName(HeapObject* object) {
     case ODDBALL_TYPE: return "system / Oddball";
     case ALLOCATION_SITE_TYPE:
       return "system / AllocationSite";
-#define MAKE_STRUCT_CASE(NAME, Name, name) \
-    case NAME##_TYPE: return "system / "#Name;
-  STRUCT_LIST(MAKE_STRUCT_CASE)
+#define MAKE_STRUCT_CASE(TYPE, Name, name) \
+  case TYPE:                               \
+    return "system / " #Name;
+      STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
     default: return "system";
   }
@@ -829,7 +662,7 @@ int V8HeapExplorer::EstimateObjectsCount() {
 class IndexedReferencesExtractor : public ObjectVisitor {
  public:
   IndexedReferencesExtractor(V8HeapExplorer* generator, HeapObject* parent_obj,
-                             int parent)
+                             HeapEntry* parent)
       : generator_(generator),
         parent_obj_(parent_obj),
         parent_start_(HeapObject::RawField(parent_obj_, 0)),
@@ -855,8 +688,8 @@ class IndexedReferencesExtractor : public ObjectVisitor {
         continue;
       }
       HeapObject* heap_object;
-      if ((*p)->ToWeakHeapObject(&heap_object) ||
-          (*p)->ToStrongHeapObject(&heap_object)) {
+      if ((*p)->GetHeapObjectIfWeak(&heap_object) ||
+          (*p)->GetHeapObjectIfStrong(&heap_object)) {
         generator_->SetHiddenReference(parent_obj_, parent_, next_index,
                                        heap_object, index * kPointerSize);
       }
@@ -868,10 +701,10 @@ class IndexedReferencesExtractor : public ObjectVisitor {
   HeapObject* parent_obj_;
   Object** parent_start_;
   Object** parent_end_;
-  int parent_;
+  HeapEntry* parent_;
 };
 
-void V8HeapExplorer::ExtractReferences(int entry, HeapObject* obj) {
+void V8HeapExplorer::ExtractReferences(HeapEntry* entry, HeapObject* obj) {
   if (obj->IsJSGlobalProxy()) {
     ExtractJSGlobalProxyReferences(entry, JSGlobalProxy::cast(obj));
   } else if (obj->IsJSArrayBuffer()) {
@@ -935,38 +768,35 @@ void V8HeapExplorer::ExtractReferences(int entry, HeapObject* obj) {
   }
 }
 
-
-void V8HeapExplorer::ExtractJSGlobalProxyReferences(
-    int entry, JSGlobalProxy* proxy) {
-  SetInternalReference(proxy, entry,
-                       "native_context", proxy->native_context(),
+void V8HeapExplorer::ExtractJSGlobalProxyReferences(HeapEntry* entry,
+                                                    JSGlobalProxy* proxy) {
+  SetInternalReference(entry, "native_context", proxy->native_context(),
                        JSGlobalProxy::kNativeContextOffset);
 }
 
-
-void V8HeapExplorer::ExtractJSObjectReferences(
-    int entry, JSObject* js_obj) {
+void V8HeapExplorer::ExtractJSObjectReferences(HeapEntry* entry,
+                                               JSObject* js_obj) {
   HeapObject* obj = js_obj;
   ExtractPropertyReferences(js_obj, entry);
   ExtractElementReferences(js_obj, entry);
   ExtractInternalReferences(js_obj, entry);
   PrototypeIterator iter(heap_->isolate(), js_obj);
   ReadOnlyRoots roots(heap_);
-  SetPropertyReference(obj, entry, roots.proto_string(), iter.GetCurrent());
+  SetPropertyReference(entry, roots.proto_string(), iter.GetCurrent());
   if (obj->IsJSBoundFunction()) {
     JSBoundFunction* js_fun = JSBoundFunction::cast(obj);
     TagObject(js_fun->bound_arguments(), "(bound arguments)");
-    SetInternalReference(js_fun, entry, "bindings", js_fun->bound_arguments(),
+    SetInternalReference(entry, "bindings", js_fun->bound_arguments(),
                          JSBoundFunction::kBoundArgumentsOffset);
-    SetInternalReference(js_obj, entry, "bound_this", js_fun->bound_this(),
+    SetInternalReference(entry, "bound_this", js_fun->bound_this(),
                          JSBoundFunction::kBoundThisOffset);
-    SetInternalReference(js_obj, entry, "bound_function",
+    SetInternalReference(entry, "bound_function",
                          js_fun->bound_target_function(),
                          JSBoundFunction::kBoundTargetFunctionOffset);
     FixedArray* bindings = js_fun->bound_arguments();
     for (int i = 0; i < bindings->length(); i++) {
       const char* reference_name = names_->GetFormatted("bound_argument_%d", i);
-      SetNativeBindReference(js_obj, entry, reference_name, bindings->get(i));
+      SetNativeBindReference(entry, reference_name, bindings->get(i));
     }
   } else if (obj->IsJSFunction()) {
     JSFunction* js_fun = JSFunction::cast(js_obj);
@@ -974,124 +804,123 @@ void V8HeapExplorer::ExtractJSObjectReferences(
       Object* proto_or_map = js_fun->prototype_or_initial_map();
       if (!proto_or_map->IsTheHole(heap_->isolate())) {
         if (!proto_or_map->IsMap()) {
-          SetPropertyReference(obj, entry, roots.prototype_string(),
-                               proto_or_map, nullptr,
+          SetPropertyReference(entry, roots.prototype_string(), proto_or_map,
+                               nullptr,
                                JSFunction::kPrototypeOrInitialMapOffset);
         } else {
-          SetPropertyReference(obj, entry, roots.prototype_string(),
+          SetPropertyReference(entry, roots.prototype_string(),
                                js_fun->prototype());
-          SetInternalReference(obj, entry, "initial_map", proto_or_map,
+          SetInternalReference(entry, "initial_map", proto_or_map,
                                JSFunction::kPrototypeOrInitialMapOffset);
         }
       }
     }
     SharedFunctionInfo* shared_info = js_fun->shared();
     TagObject(js_fun->feedback_cell(), "(function feedback cell)");
-    SetInternalReference(js_fun, entry, "feedback_cell",
-                         js_fun->feedback_cell(),
+    SetInternalReference(entry, "feedback_cell", js_fun->feedback_cell(),
                          JSFunction::kFeedbackCellOffset);
     TagObject(shared_info, "(shared function info)");
-    SetInternalReference(js_fun, entry,
-                         "shared", shared_info,
+    SetInternalReference(entry, "shared", shared_info,
                          JSFunction::kSharedFunctionInfoOffset);
     TagObject(js_fun->context(), "(context)");
-    SetInternalReference(js_fun, entry,
-                         "context", js_fun->context(),
+    SetInternalReference(entry, "context", js_fun->context(),
                          JSFunction::kContextOffset);
     TagCodeObject(js_fun->code());
-    SetInternalReference(js_fun, entry, "code", js_fun->code(),
+    SetInternalReference(entry, "code", js_fun->code(),
                          JSFunction::kCodeOffset);
   } else if (obj->IsJSGlobalObject()) {
     JSGlobalObject* global_obj = JSGlobalObject::cast(obj);
-    SetInternalReference(global_obj, entry, "native_context",
-                         global_obj->native_context(),
+    SetInternalReference(entry, "native_context", global_obj->native_context(),
                          JSGlobalObject::kNativeContextOffset);
-    SetInternalReference(global_obj, entry, "global_proxy",
-                         global_obj->global_proxy(),
+    SetInternalReference(entry, "global_proxy", global_obj->global_proxy(),
                          JSGlobalObject::kGlobalProxyOffset);
     STATIC_ASSERT(JSGlobalObject::kSize - JSObject::kHeaderSize ==
                   2 * kPointerSize);
   } else if (obj->IsJSArrayBufferView()) {
     JSArrayBufferView* view = JSArrayBufferView::cast(obj);
-    SetInternalReference(view, entry, "buffer", view->buffer(),
+    SetInternalReference(entry, "buffer", view->buffer(),
                          JSArrayBufferView::kBufferOffset);
   }
 
   TagObject(js_obj->raw_properties_or_hash(), "(object properties)");
-  SetInternalReference(obj, entry, "properties",
-                       js_obj->raw_properties_or_hash(),
+  SetInternalReference(entry, "properties", js_obj->raw_properties_or_hash(),
                        JSObject::kPropertiesOrHashOffset);
 
   TagObject(js_obj->elements(), "(object elements)");
-  SetInternalReference(obj, entry,
-                       "elements", js_obj->elements(),
+  SetInternalReference(entry, "elements", js_obj->elements(),
                        JSObject::kElementsOffset);
 }
 
-
-void V8HeapExplorer::ExtractStringReferences(int entry, String* string) {
+void V8HeapExplorer::ExtractStringReferences(HeapEntry* entry, String* string) {
   if (string->IsConsString()) {
     ConsString* cs = ConsString::cast(string);
-    SetInternalReference(cs, entry, "first", cs->first(),
-                         ConsString::kFirstOffset);
-    SetInternalReference(cs, entry, "second", cs->second(),
+    SetInternalReference(entry, "first", cs->first(), ConsString::kFirstOffset);
+    SetInternalReference(entry, "second", cs->second(),
                          ConsString::kSecondOffset);
   } else if (string->IsSlicedString()) {
     SlicedString* ss = SlicedString::cast(string);
-    SetInternalReference(ss, entry, "parent", ss->parent(),
+    SetInternalReference(entry, "parent", ss->parent(),
                          SlicedString::kParentOffset);
   } else if (string->IsThinString()) {
     ThinString* ts = ThinString::cast(string);
-    SetInternalReference(ts, entry, "actual", ts->actual(),
+    SetInternalReference(entry, "actual", ts->actual(),
                          ThinString::kActualOffset);
   }
 }
 
-
-void V8HeapExplorer::ExtractSymbolReferences(int entry, Symbol* symbol) {
-  SetInternalReference(symbol, entry,
-                       "name", symbol->name(),
-                       Symbol::kNameOffset);
+void V8HeapExplorer::ExtractSymbolReferences(HeapEntry* entry, Symbol* symbol) {
+  SetInternalReference(entry, "name", symbol->name(), Symbol::kNameOffset);
 }
 
-
-void V8HeapExplorer::ExtractJSCollectionReferences(int entry,
+void V8HeapExplorer::ExtractJSCollectionReferences(HeapEntry* entry,
                                                    JSCollection* collection) {
-  SetInternalReference(collection, entry, "table", collection->table(),
+  SetInternalReference(entry, "table", collection->table(),
                        JSCollection::kTableOffset);
 }
 
-void V8HeapExplorer::ExtractJSWeakCollectionReferences(int entry,
+void V8HeapExplorer::ExtractJSWeakCollectionReferences(HeapEntry* entry,
                                                        JSWeakCollection* obj) {
-  SetInternalReference(obj, entry, "table", obj->table(),
+  SetInternalReference(entry, "table", obj->table(),
                        JSWeakCollection::kTableOffset);
 }
 
 void V8HeapExplorer::ExtractEphemeronHashTableReferences(
-    int entry, EphemeronHashTable* table) {
+    HeapEntry* entry, EphemeronHashTable* table) {
   for (int i = 0, capacity = table->Capacity(); i < capacity; ++i) {
     int key_index = EphemeronHashTable::EntryToIndex(i) +
                     EphemeronHashTable::kEntryKeyIndex;
     int value_index = EphemeronHashTable::EntryToValueIndex(i);
     Object* key = table->get(key_index);
     Object* value = table->get(value_index);
-    SetWeakReference(table, entry, key_index, key,
+    SetWeakReference(entry, key_index, key,
                      table->OffsetOfElementAt(key_index));
-    SetInternalReference(table, entry, value_index, value,
-                         table->OffsetOfElementAt(value_index));
+    SetWeakReference(entry, value_index, value,
+                     table->OffsetOfElementAt(value_index));
     HeapEntry* key_entry = GetEntry(key);
-    int key_entry_index = key_entry->index();
     HeapEntry* value_entry = GetEntry(value);
     if (key_entry && value_entry) {
       const char* edge_name =
           names_->GetFormatted("key %s in WeakMap", key_entry->name());
-      filler_->SetNamedAutoIndexReference(
-          HeapGraphEdge::kInternal, key_entry_index, edge_name, value_entry);
+      key_entry->SetNamedAutoIndexReference(HeapGraphEdge::kInternal, edge_name,
+                                            value_entry, names_);
     }
   }
 }
 
-void V8HeapExplorer::ExtractContextReferences(int entry, Context* context) {
+// These static arrays are used to prevent excessive code-size in
+// ExtractContextReferences below, which would happen if we called
+// SetInternalReference for every native context field in a macro.
+static const struct {
+  int index;
+  const char* name;
+} native_context_names[] = {
+#define CONTEXT_FIELD_INDEX_NAME(index, _, name) {Context::index, #name},
+    NATIVE_CONTEXT_FIELDS(CONTEXT_FIELD_INDEX_NAME)
+#undef CONTEXT_FIELD_INDEX
+};
+
+void V8HeapExplorer::ExtractContextReferences(HeapEntry* entry,
+                                              Context* context) {
   if (!context->IsNativeContext() && context->is_declaration_context()) {
     ScopeInfo* scope_info = context->scope_info();
     // Add context allocated locals.
@@ -1099,39 +928,49 @@ void V8HeapExplorer::ExtractContextReferences(int entry, Context* context) {
     for (int i = 0; i < context_locals; ++i) {
       String* local_name = scope_info->ContextLocalName(i);
       int idx = Context::MIN_CONTEXT_SLOTS + i;
-      SetContextReference(context, entry, local_name, context->get(idx),
+      SetContextReference(entry, local_name, context->get(idx),
                           Context::OffsetOfElementAt(idx));
     }
     if (scope_info->HasFunctionName()) {
       String* name = String::cast(scope_info->FunctionName());
       int idx = scope_info->FunctionContextSlotIndex(name);
       if (idx >= 0) {
-        SetContextReference(context, entry, name, context->get(idx),
+        SetContextReference(entry, name, context->get(idx),
                             Context::OffsetOfElementAt(idx));
       }
     }
   }
 
-#define EXTRACT_CONTEXT_FIELD(index, type, name) \
-  if (Context::index < Context::FIRST_WEAK_SLOT || \
-      Context::index == Context::MAP_CACHE_INDEX) { \
-    SetInternalReference(context, entry, #name, context->get(Context::index), \
-        FixedArray::OffsetOfElementAt(Context::index)); \
-  } else { \
-    SetWeakReference(context, entry, #name, context->get(Context::index), \
-        FixedArray::OffsetOfElementAt(Context::index)); \
-  }
-  EXTRACT_CONTEXT_FIELD(SCOPE_INFO_INDEX, ScopeInfo, scope_info);
-  EXTRACT_CONTEXT_FIELD(PREVIOUS_INDEX, Context, previous);
-  EXTRACT_CONTEXT_FIELD(EXTENSION_INDEX, HeapObject, extension);
-  EXTRACT_CONTEXT_FIELD(NATIVE_CONTEXT_INDEX, Context, native_context);
+  SetInternalReference(
+      entry, "scope_info", context->get(Context::SCOPE_INFO_INDEX),
+      FixedArray::OffsetOfElementAt(Context::SCOPE_INFO_INDEX));
+  SetInternalReference(entry, "previous", context->get(Context::PREVIOUS_INDEX),
+                       FixedArray::OffsetOfElementAt(Context::PREVIOUS_INDEX));
+  SetInternalReference(entry, "extension",
+                       context->get(Context::EXTENSION_INDEX),
+                       FixedArray::OffsetOfElementAt(Context::EXTENSION_INDEX));
+  SetInternalReference(
+      entry, "native_context", context->get(Context::NATIVE_CONTEXT_INDEX),
+      FixedArray::OffsetOfElementAt(Context::NATIVE_CONTEXT_INDEX));
+
   if (context->IsNativeContext()) {
     TagObject(context->normalized_map_cache(), "(context norm. map cache)");
     TagObject(context->embedder_data(), "(context data)");
-    NATIVE_CONTEXT_FIELDS(EXTRACT_CONTEXT_FIELD)
-    EXTRACT_CONTEXT_FIELD(OPTIMIZED_CODE_LIST, unused, optimized_code_list);
-    EXTRACT_CONTEXT_FIELD(DEOPTIMIZED_CODE_LIST, unused, deoptimized_code_list);
-#undef EXTRACT_CONTEXT_FIELD
+    for (size_t i = 0; i < arraysize(native_context_names); i++) {
+      int index = native_context_names[i].index;
+      const char* name = native_context_names[i].name;
+      SetInternalReference(entry, name, context->get(index),
+                           FixedArray::OffsetOfElementAt(index));
+    }
+
+    SetWeakReference(
+        entry, "optimized_code_list",
+        context->get(Context::OPTIMIZED_CODE_LIST),
+        FixedArray::OffsetOfElementAt(Context::OPTIMIZED_CODE_LIST));
+    SetWeakReference(
+        entry, "deoptimized_code_list",
+        context->get(Context::DEOPTIMIZED_CODE_LIST),
+        FixedArray::OffsetOfElementAt(Context::DEOPTIMIZED_CODE_LIST));
     STATIC_ASSERT(Context::OPTIMIZED_CODE_LIST == Context::FIRST_WEAK_SLOT);
     STATIC_ASSERT(Context::NEXT_CONTEXT_LINK + 1 ==
                   Context::NATIVE_CONTEXT_SLOTS);
@@ -1140,17 +979,15 @@ void V8HeapExplorer::ExtractContextReferences(int entry, Context* context) {
   }
 }
 
-
-void V8HeapExplorer::ExtractMapReferences(int entry, Map* map) {
+void V8HeapExplorer::ExtractMapReferences(HeapEntry* entry, Map* map) {
   MaybeObject* maybe_raw_transitions_or_prototype_info = map->raw_transitions();
   HeapObject* raw_transitions_or_prototype_info;
-  if (maybe_raw_transitions_or_prototype_info->ToWeakHeapObject(
+  if (maybe_raw_transitions_or_prototype_info->GetHeapObjectIfWeak(
           &raw_transitions_or_prototype_info)) {
     DCHECK(raw_transitions_or_prototype_info->IsMap());
-    SetWeakReference(map, entry, "transition",
-                     raw_transitions_or_prototype_info,
+    SetWeakReference(entry, "transition", raw_transitions_or_prototype_info,
                      Map::kTransitionsOrPrototypeInfoOffset);
-  } else if (maybe_raw_transitions_or_prototype_info->ToStrongHeapObject(
+  } else if (maybe_raw_transitions_or_prototype_info->GetHeapObjectIfStrong(
                  &raw_transitions_or_prototype_info)) {
     if (raw_transitions_or_prototype_info->IsTransitionArray()) {
       TransitionArray* transitions =
@@ -1160,55 +997,52 @@ void V8HeapExplorer::ExtractMapReferences(int entry, Map* map) {
                   "(prototype transitions)");
       }
       TagObject(transitions, "(transition array)");
-      SetInternalReference(map, entry, "transitions", transitions,
+      SetInternalReference(entry, "transitions", transitions,
                            Map::kTransitionsOrPrototypeInfoOffset);
     } else if (raw_transitions_or_prototype_info->IsTuple3() ||
                raw_transitions_or_prototype_info->IsFixedArray()) {
       TagObject(raw_transitions_or_prototype_info, "(transition)");
-      SetInternalReference(map, entry, "transition",
+      SetInternalReference(entry, "transition",
                            raw_transitions_or_prototype_info,
                            Map::kTransitionsOrPrototypeInfoOffset);
     } else if (map->is_prototype_map()) {
       TagObject(raw_transitions_or_prototype_info, "prototype_info");
-      SetInternalReference(map, entry, "prototype_info",
+      SetInternalReference(entry, "prototype_info",
                            raw_transitions_or_prototype_info,
                            Map::kTransitionsOrPrototypeInfoOffset);
     }
   }
   DescriptorArray* descriptors = map->instance_descriptors();
   TagObject(descriptors, "(map descriptors)");
-  SetInternalReference(map, entry, "descriptors", descriptors,
+  SetInternalReference(entry, "descriptors", descriptors,
                        Map::kDescriptorsOffset);
-  SetInternalReference(map, entry, "prototype", map->prototype(),
+  SetInternalReference(entry, "prototype", map->prototype(),
                        Map::kPrototypeOffset);
   if (FLAG_unbox_double_fields) {
-    SetInternalReference(map, entry, "layout_descriptor",
-                         map->layout_descriptor(),
+    SetInternalReference(entry, "layout_descriptor", map->layout_descriptor(),
                          Map::kLayoutDescriptorOffset);
   }
   Object* constructor_or_backpointer = map->constructor_or_backpointer();
   if (constructor_or_backpointer->IsMap()) {
     TagObject(constructor_or_backpointer, "(back pointer)");
-    SetInternalReference(map, entry, "back_pointer", constructor_or_backpointer,
+    SetInternalReference(entry, "back_pointer", constructor_or_backpointer,
                          Map::kConstructorOrBackPointerOffset);
   } else if (constructor_or_backpointer->IsFunctionTemplateInfo()) {
     TagObject(constructor_or_backpointer, "(constructor function data)");
-    SetInternalReference(map, entry, "constructor_function_data",
+    SetInternalReference(entry, "constructor_function_data",
                          constructor_or_backpointer,
                          Map::kConstructorOrBackPointerOffset);
   } else {
-    SetInternalReference(map, entry, "constructor", constructor_or_backpointer,
+    SetInternalReference(entry, "constructor", constructor_or_backpointer,
                          Map::kConstructorOrBackPointerOffset);
   }
   TagObject(map->dependent_code(), "(dependent code)");
-  SetInternalReference(map, entry, "dependent_code", map->dependent_code(),
+  SetInternalReference(entry, "dependent_code", map->dependent_code(),
                        Map::kDependentCodeOffset);
 }
 
-
 void V8HeapExplorer::ExtractSharedFunctionInfoReferences(
-    int entry, SharedFunctionInfo* shared) {
-  HeapObject* obj = shared;
+    HeapEntry* entry, SharedFunctionInfo* shared) {
   String* shared_name = shared->DebugName();
   const char* name = nullptr;
   if (shared_name != ReadOnlyRoots(heap_).empty_string()) {
@@ -1223,59 +1057,51 @@ void V8HeapExplorer::ExtractSharedFunctionInfoReferences(
   if (shared->name_or_scope_info()->IsScopeInfo()) {
     TagObject(shared->name_or_scope_info(), "(function scope info)");
   }
-  SetInternalReference(obj, entry, "name_or_scope_info",
+  SetInternalReference(entry, "name_or_scope_info",
                        shared->name_or_scope_info(),
                        SharedFunctionInfo::kNameOrScopeInfoOffset);
-  SetInternalReference(obj, entry, "script_or_debug_info",
+  SetInternalReference(entry, "script_or_debug_info",
                        shared->script_or_debug_info(),
                        SharedFunctionInfo::kScriptOrDebugInfoOffset);
-  SetInternalReference(obj, entry,
-                       "function_data", shared->function_data(),
+  SetInternalReference(entry, "function_data", shared->function_data(),
                        SharedFunctionInfo::kFunctionDataOffset);
   SetInternalReference(
-      obj, entry, "raw_outer_scope_info_or_feedback_metadata",
+      entry, "raw_outer_scope_info_or_feedback_metadata",
       shared->raw_outer_scope_info_or_feedback_metadata(),
       SharedFunctionInfo::kOuterScopeInfoOrFeedbackMetadataOffset);
 }
 
-void V8HeapExplorer::ExtractScriptReferences(int entry, Script* script) {
-  HeapObject* obj = script;
-  SetInternalReference(obj, entry,
-                       "source", script->source(),
+void V8HeapExplorer::ExtractScriptReferences(HeapEntry* entry, Script* script) {
+  SetInternalReference(entry, "source", script->source(),
                        Script::kSourceOffset);
-  SetInternalReference(obj, entry,
-                       "name", script->name(),
-                       Script::kNameOffset);
-  SetInternalReference(obj, entry,
-                       "context_data", script->context_data(),
+  SetInternalReference(entry, "name", script->name(), Script::kNameOffset);
+  SetInternalReference(entry, "context_data", script->context_data(),
                        Script::kContextOffset);
   TagObject(script->line_ends(), "(script line ends)");
-  SetInternalReference(obj, entry,
-                       "line_ends", script->line_ends(),
+  SetInternalReference(entry, "line_ends", script->line_ends(),
                        Script::kLineEndsOffset);
 }
 
-
 void V8HeapExplorer::ExtractAccessorInfoReferences(
-    int entry, AccessorInfo* accessor_info) {
-  SetInternalReference(accessor_info, entry, "name", accessor_info->name(),
+    HeapEntry* entry, AccessorInfo* accessor_info) {
+  SetInternalReference(entry, "name", accessor_info->name(),
                        AccessorInfo::kNameOffset);
-  SetInternalReference(accessor_info, entry, "expected_receiver_type",
+  SetInternalReference(entry, "expected_receiver_type",
                        accessor_info->expected_receiver_type(),
                        AccessorInfo::kExpectedReceiverTypeOffset);
-  SetInternalReference(accessor_info, entry, "getter", accessor_info->getter(),
+  SetInternalReference(entry, "getter", accessor_info->getter(),
                        AccessorInfo::kGetterOffset);
-  SetInternalReference(accessor_info, entry, "setter", accessor_info->setter(),
+  SetInternalReference(entry, "setter", accessor_info->setter(),
                        AccessorInfo::kSetterOffset);
-  SetInternalReference(accessor_info, entry, "data", accessor_info->data(),
+  SetInternalReference(entry, "data", accessor_info->data(),
                        AccessorInfo::kDataOffset);
 }
 
-void V8HeapExplorer::ExtractAccessorPairReferences(
-    int entry, AccessorPair* accessors) {
-  SetInternalReference(accessors, entry, "getter", accessors->getter(),
+void V8HeapExplorer::ExtractAccessorPairReferences(HeapEntry* entry,
+                                                   AccessorPair* accessors) {
+  SetInternalReference(entry, "getter", accessors->getter(),
                        AccessorPair::kGetterOffset);
-  SetInternalReference(accessors, entry, "setter", accessors->setter(),
+  SetInternalReference(entry, "setter", accessors->setter(),
                        AccessorPair::kSetterOffset);
 }
 
@@ -1291,58 +1117,56 @@ void V8HeapExplorer::TagCodeObject(Code* code) {
   }
 }
 
-void V8HeapExplorer::ExtractCodeReferences(int entry, Code* code) {
+void V8HeapExplorer::ExtractCodeReferences(HeapEntry* entry, Code* code) {
   TagCodeObject(code);
   TagObject(code->relocation_info(), "(code relocation info)");
-  SetInternalReference(code, entry,
-                       "relocation_info", code->relocation_info(),
+  SetInternalReference(entry, "relocation_info", code->relocation_info(),
                        Code::kRelocationInfoOffset);
   TagObject(code->deoptimization_data(), "(code deopt data)");
-  SetInternalReference(code, entry,
-                       "deoptimization_data", code->deoptimization_data(),
+  SetInternalReference(entry, "deoptimization_data",
+                       code->deoptimization_data(),
                        Code::kDeoptimizationDataOffset);
   TagObject(code->source_position_table(), "(source position table)");
-  SetInternalReference(code, entry, "source_position_table",
+  SetInternalReference(entry, "source_position_table",
                        code->source_position_table(),
                        Code::kSourcePositionTableOffset);
 }
 
-void V8HeapExplorer::ExtractCellReferences(int entry, Cell* cell) {
-  SetInternalReference(cell, entry, "value", cell->value(), Cell::kValueOffset);
+void V8HeapExplorer::ExtractCellReferences(HeapEntry* entry, Cell* cell) {
+  SetInternalReference(entry, "value", cell->value(), Cell::kValueOffset);
 }
 
 void V8HeapExplorer::ExtractFeedbackCellReferences(
-    int entry, FeedbackCell* feedback_cell) {
+    HeapEntry* entry, FeedbackCell* feedback_cell) {
   TagObject(feedback_cell, "(feedback cell)");
-  SetInternalReference(feedback_cell, entry, "value", feedback_cell->value(),
+  SetInternalReference(entry, "value", feedback_cell->value(),
                        FeedbackCell::kValueOffset);
 }
 
-void V8HeapExplorer::ExtractPropertyCellReferences(int entry,
+void V8HeapExplorer::ExtractPropertyCellReferences(HeapEntry* entry,
                                                    PropertyCell* cell) {
-  SetInternalReference(cell, entry, "value", cell->value(),
+  SetInternalReference(entry, "value", cell->value(),
                        PropertyCell::kValueOffset);
   TagObject(cell->dependent_code(), "(dependent code)");
-  SetInternalReference(cell, entry, "dependent_code", cell->dependent_code(),
+  SetInternalReference(entry, "dependent_code", cell->dependent_code(),
                        PropertyCell::kDependentCodeOffset);
 }
 
-void V8HeapExplorer::ExtractAllocationSiteReferences(int entry,
+void V8HeapExplorer::ExtractAllocationSiteReferences(HeapEntry* entry,
                                                      AllocationSite* site) {
-  SetInternalReference(site, entry, "transition_info",
+  SetInternalReference(entry, "transition_info",
                        site->transition_info_or_boilerplate(),
                        AllocationSite::kTransitionInfoOrBoilerplateOffset);
-  SetInternalReference(site, entry, "nested_site", site->nested_site(),
+  SetInternalReference(entry, "nested_site", site->nested_site(),
                        AllocationSite::kNestedSiteOffset);
   TagObject(site->dependent_code(), "(dependent code)");
-  SetInternalReference(site, entry, "dependent_code", site->dependent_code(),
+  SetInternalReference(entry, "dependent_code", site->dependent_code(),
                        AllocationSite::kDependentCodeOffset);
 }
 
 void V8HeapExplorer::ExtractArrayBoilerplateDescriptionReferences(
-    int entry, ArrayBoilerplateDescription* value) {
-  SetInternalReference(value, entry, "constant_elements",
-                       value->constant_elements(),
+    HeapEntry* entry, ArrayBoilerplateDescription* value) {
+  SetInternalReference(entry, "constant_elements", value->constant_elements(),
                        ArrayBoilerplateDescription::kConstantElementsOffset);
 }
 
@@ -1352,7 +1176,7 @@ class JSArrayBufferDataEntryAllocator : public HeapEntriesAllocator {
       : size_(size)
       , explorer_(explorer) {
   }
-  virtual HeapEntry* AllocateEntry(HeapThing ptr) {
+  HeapEntry* AllocateEntry(HeapThing ptr) override {
     return explorer_->AddEntry(reinterpret_cast<Address>(ptr),
                                HeapEntry::kNative, "system / JSArrayBufferData",
                                size_);
@@ -1362,73 +1186,74 @@ class JSArrayBufferDataEntryAllocator : public HeapEntriesAllocator {
   V8HeapExplorer* explorer_;
 };
 
-void V8HeapExplorer::ExtractJSArrayBufferReferences(
-    int entry, JSArrayBuffer* buffer) {
+void V8HeapExplorer::ExtractJSArrayBufferReferences(HeapEntry* entry,
+                                                    JSArrayBuffer* buffer) {
   // Setup a reference to a native memory backing_store object.
   if (!buffer->backing_store())
     return;
-  size_t data_size = NumberToSize(buffer->byte_length());
+  size_t data_size = buffer->byte_length();
   JSArrayBufferDataEntryAllocator allocator(data_size, this);
   HeapEntry* data_entry =
-      filler_->FindOrAddEntry(buffer->backing_store(), &allocator);
-  filler_->SetNamedReference(HeapGraphEdge::kInternal,
-                             entry, "backing_store", data_entry);
+      generator_->FindOrAddEntry(buffer->backing_store(), &allocator);
+  entry->SetNamedReference(HeapGraphEdge::kInternal, "backing_store",
+                           data_entry);
 }
 
-void V8HeapExplorer::ExtractJSPromiseReferences(int entry, JSPromise* promise) {
-  SetInternalReference(promise, entry, "reactions_or_result",
+void V8HeapExplorer::ExtractJSPromiseReferences(HeapEntry* entry,
+                                                JSPromise* promise) {
+  SetInternalReference(entry, "reactions_or_result",
                        promise->reactions_or_result(),
                        JSPromise::kReactionsOrResultOffset);
 }
 
 void V8HeapExplorer::ExtractJSGeneratorObjectReferences(
-    int entry, JSGeneratorObject* generator) {
-  SetInternalReference(generator, entry, "function", generator->function(),
+    HeapEntry* entry, JSGeneratorObject* generator) {
+  SetInternalReference(entry, "function", generator->function(),
                        JSGeneratorObject::kFunctionOffset);
-  SetInternalReference(generator, entry, "context", generator->context(),
+  SetInternalReference(entry, "context", generator->context(),
                        JSGeneratorObject::kContextOffset);
-  SetInternalReference(generator, entry, "receiver", generator->receiver(),
+  SetInternalReference(entry, "receiver", generator->receiver(),
                        JSGeneratorObject::kReceiverOffset);
-  SetInternalReference(generator, entry, "parameters_and_registers",
+  SetInternalReference(entry, "parameters_and_registers",
                        generator->parameters_and_registers(),
                        JSGeneratorObject::kParametersAndRegistersOffset);
 }
 
-void V8HeapExplorer::ExtractFixedArrayReferences(int entry, FixedArray* array) {
+void V8HeapExplorer::ExtractFixedArrayReferences(HeapEntry* entry,
+                                                 FixedArray* array) {
   for (int i = 0, l = array->length(); i < l; ++i) {
     DCHECK(!HasWeakHeapObjectTag(array->get(i)));
-    SetInternalReference(array, entry, i, array->get(i),
-                         array->OffsetOfElementAt(i));
+    SetInternalReference(entry, i, array->get(i), array->OffsetOfElementAt(i));
   }
 }
 
 void V8HeapExplorer::ExtractFeedbackVectorReferences(
-    int entry, FeedbackVector* feedback_vector) {
+    HeapEntry* entry, FeedbackVector* feedback_vector) {
   MaybeObject* code = feedback_vector->optimized_code_weak_or_smi();
   HeapObject* code_heap_object;
-  if (code->ToWeakHeapObject(&code_heap_object)) {
-    SetWeakReference(feedback_vector, entry, "optimized code", code_heap_object,
+  if (code->GetHeapObjectIfWeak(&code_heap_object)) {
+    SetWeakReference(entry, "optimized code", code_heap_object,
                      FeedbackVector::kOptimizedCodeOffset);
   }
 }
 
 template <typename T>
-void V8HeapExplorer::ExtractWeakArrayReferences(int header_size, int entry,
-                                                T* array) {
+void V8HeapExplorer::ExtractWeakArrayReferences(int header_size,
+                                                HeapEntry* entry, T* array) {
   for (int i = 0; i < array->length(); ++i) {
     MaybeObject* object = array->Get(i);
     HeapObject* heap_object;
-    if (object->ToWeakHeapObject(&heap_object)) {
-      SetWeakReference(array, entry, i, heap_object,
-                       header_size + i * kPointerSize);
-    } else if (object->ToStrongHeapObject(&heap_object)) {
-      SetInternalReference(array, entry, i, heap_object,
+    if (object->GetHeapObjectIfWeak(&heap_object)) {
+      SetWeakReference(entry, i, heap_object, header_size + i * kPointerSize);
+    } else if (object->GetHeapObjectIfStrong(&heap_object)) {
+      SetInternalReference(entry, i, heap_object,
                            header_size + i * kPointerSize);
     }
   }
 }
 
-void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj, int entry) {
+void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj,
+                                               HeapEntry* entry) {
   Isolate* isolate = js_obj->GetIsolate();
   if (js_obj->HasFastProperties()) {
     DescriptorArray* descs = js_obj->map()->instance_descriptors();
@@ -1446,12 +1271,12 @@ void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj, int entry) {
           int field_offset =
               field_index.is_inobject() ? field_index.offset() : -1;
 
-          SetDataOrAccessorPropertyReference(details.kind(), js_obj, entry, k,
-                                             value, nullptr, field_offset);
+          SetDataOrAccessorPropertyReference(details.kind(), entry, k, value,
+                                             nullptr, field_offset);
           break;
         }
         case kDescriptor:
-          SetDataOrAccessorPropertyReference(details.kind(), js_obj, entry,
+          SetDataOrAccessorPropertyReference(details.kind(), entry,
                                              descs->GetKey(i),
                                              descs->GetStrongValue(i));
           break;
@@ -1464,14 +1289,12 @@ void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj, int entry) {
     int length = dictionary->Capacity();
     ReadOnlyRoots roots(isolate);
     for (int i = 0; i < length; ++i) {
-      if (dictionary->IsKey(roots, dictionary->KeyAt(i))) {
-        PropertyCell* cell = dictionary->CellAt(i);
-        Name* name = cell->name();
-        Object* value = cell->value();
-        PropertyDetails details = cell->property_details();
-        SetDataOrAccessorPropertyReference(details.kind(), js_obj, entry, name,
-                                           value);
-      }
+      if (!dictionary->IsKey(roots, dictionary->KeyAt(i))) continue;
+      PropertyCell* cell = dictionary->CellAt(i);
+      Name* name = cell->name();
+      Object* value = cell->value();
+      PropertyDetails details = cell->property_details();
+      SetDataOrAccessorPropertyReference(details.kind(), entry, name, value);
     }
   } else {
     NameDictionary* dictionary = js_obj->property_dictionary();
@@ -1479,36 +1302,33 @@ void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj, int entry) {
     ReadOnlyRoots roots(isolate);
     for (int i = 0; i < length; ++i) {
       Object* k = dictionary->KeyAt(i);
-      if (dictionary->IsKey(roots, k)) {
-        Object* value = dictionary->ValueAt(i);
-        PropertyDetails details = dictionary->DetailsAt(i);
-        SetDataOrAccessorPropertyReference(details.kind(), js_obj, entry,
-                                           Name::cast(k), value);
-      }
+      if (!dictionary->IsKey(roots, k)) continue;
+      Object* value = dictionary->ValueAt(i);
+      PropertyDetails details = dictionary->DetailsAt(i);
+      SetDataOrAccessorPropertyReference(details.kind(), entry, Name::cast(k),
+                                         value);
     }
   }
 }
 
-
-void V8HeapExplorer::ExtractAccessorPairProperty(JSObject* js_obj, int entry,
-                                                 Name* key,
+void V8HeapExplorer::ExtractAccessorPairProperty(HeapEntry* entry, Name* key,
                                                  Object* callback_obj,
                                                  int field_offset) {
   if (!callback_obj->IsAccessorPair()) return;
   AccessorPair* accessors = AccessorPair::cast(callback_obj);
-  SetPropertyReference(js_obj, entry, key, accessors, nullptr, field_offset);
+  SetPropertyReference(entry, key, accessors, nullptr, field_offset);
   Object* getter = accessors->getter();
   if (!getter->IsOddball()) {
-    SetPropertyReference(js_obj, entry, key, getter, "get %s");
+    SetPropertyReference(entry, key, getter, "get %s");
   }
   Object* setter = accessors->setter();
   if (!setter->IsOddball()) {
-    SetPropertyReference(js_obj, entry, key, setter, "set %s");
+    SetPropertyReference(entry, key, setter, "set %s");
   }
 }
 
-
-void V8HeapExplorer::ExtractElementReferences(JSObject* js_obj, int entry) {
+void V8HeapExplorer::ExtractElementReferences(JSObject* js_obj,
+                                              HeapEntry* entry) {
   ReadOnlyRoots roots = js_obj->GetReadOnlyRoots();
   if (js_obj->HasObjectElements()) {
     FixedArray* elements = FixedArray::cast(js_obj->elements());
@@ -1517,7 +1337,7 @@ void V8HeapExplorer::ExtractElementReferences(JSObject* js_obj, int entry) {
                      : elements->length();
     for (int i = 0; i < length; ++i) {
       if (!elements->get(i)->IsTheHole(roots)) {
-        SetElementReference(js_obj, entry, i, elements->get(i));
+        SetElementReference(entry, i, elements->get(i));
       }
     }
   } else if (js_obj->HasDictionaryElements()) {
@@ -1525,22 +1345,20 @@ void V8HeapExplorer::ExtractElementReferences(JSObject* js_obj, int entry) {
     int length = dictionary->Capacity();
     for (int i = 0; i < length; ++i) {
       Object* k = dictionary->KeyAt(i);
-      if (dictionary->IsKey(roots, k)) {
-        DCHECK(k->IsNumber());
-        uint32_t index = static_cast<uint32_t>(k->Number());
-        SetElementReference(js_obj, entry, index, dictionary->ValueAt(i));
-      }
+      if (!dictionary->IsKey(roots, k)) continue;
+      DCHECK(k->IsNumber());
+      uint32_t index = static_cast<uint32_t>(k->Number());
+      SetElementReference(entry, index, dictionary->ValueAt(i));
     }
   }
 }
 
-
-void V8HeapExplorer::ExtractInternalReferences(JSObject* js_obj, int entry) {
+void V8HeapExplorer::ExtractInternalReferences(JSObject* js_obj,
+                                               HeapEntry* entry) {
   int length = js_obj->GetEmbedderFieldCount();
   for (int i = 0; i < length; ++i) {
     Object* o = js_obj->GetEmbedderField(i);
-    SetInternalReference(js_obj, entry, i, o,
-                         js_obj->GetEmbedderFieldOffset(i));
+    SetInternalReference(entry, i, o, js_obj->GetEmbedderFieldOffset(i));
   }
 }
 
@@ -1564,10 +1382,8 @@ String* V8HeapExplorer::GetConstructorName(JSObject* object) {
   return *JSReceiver::GetConstructorName(handle(object, isolate));
 }
 
-
 HeapEntry* V8HeapExplorer::GetEntry(Object* obj) {
-  if (!obj->IsHeapObject()) return nullptr;
-  return filler_->FindOrAddEntry(obj, this);
+  return obj->IsHeapObject() ? generator_->FindOrAddEntry(obj, this) : nullptr;
 }
 
 class RootsReferencesExtractor : public RootVisitor {
@@ -1597,8 +1413,9 @@ class RootsReferencesExtractor : public RootVisitor {
   bool visiting_weak_roots_;
 };
 
-bool V8HeapExplorer::IterateAndExtractReferences(SnapshotFiller* filler) {
-  filler_ = filler;
+bool V8HeapExplorer::IterateAndExtractReferences(
+    HeapSnapshotGenerator* generator) {
+  generator_ = generator;
 
   // Create references to the synthetic roots.
   SetRootGcRootsReference();
@@ -1610,7 +1427,7 @@ bool V8HeapExplorer::IterateAndExtractReferences(SnapshotFiller* filler) {
   // first. Otherwise a particular JSFunction object could set
   // its custom name to a generic builtin.
   RootsReferencesExtractor extractor(this);
-  heap_->IterateRoots(&extractor, VISIT_ONLY_STRONG);
+  heap_->IterateRoots(&extractor, VISIT_ONLY_STRONG_FOR_SERIALIZATION);
   extractor.SetVisitingWeakRoots();
   heap_->IterateWeakGlobalHandles(&extractor);
 
@@ -1630,10 +1447,9 @@ bool V8HeapExplorer::IterateAndExtractReferences(SnapshotFiller* filler) {
       visited_fields_.resize(max_pointer, false);
     }
 
-    HeapEntry* heap_entry = GetEntry(obj);
-    int entry = heap_entry->index();
+    HeapEntry* entry = GetEntry(obj);
     ExtractReferences(entry, obj);
-    SetInternalReference(obj, entry, "map", obj->map(), HeapObject::kMapOffset);
+    SetInternalReference(entry, "map", obj->map(), HeapObject::kMapOffset);
     // Extract unvisited fields as hidden references and restore tags
     // of visited fields.
     IndexedReferencesExtractor refs_extractor(this, obj, entry);
@@ -1650,7 +1466,7 @@ bool V8HeapExplorer::IterateAndExtractReferences(SnapshotFiller* filler) {
     if (!progress_->ProgressReport(false)) interrupted = true;
   }
 
-  filler_ = nullptr;
+  generator_ = nullptr;
   return interrupted ? false : progress_->ProgressReport(true);
 }
 
@@ -1684,16 +1500,13 @@ bool V8HeapExplorer::IsEssentialHiddenReference(Object* parent,
   return true;
 }
 
-void V8HeapExplorer::SetContextReference(HeapObject* parent_obj,
-                                         int parent_entry,
+void V8HeapExplorer::SetContextReference(HeapEntry* parent_entry,
                                          String* reference_name,
-                                         Object* child_obj,
-                                         int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
+                                         Object* child_obj, int field_offset) {
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
-  filler_->SetNamedReference(HeapGraphEdge::kContextVariable, parent_entry,
-                             names_->GetName(reference_name), child_entry);
+  parent_entry->SetNamedReference(HeapGraphEdge::kContextVariable,
+                                  names_->GetName(reference_name), child_entry);
   MarkVisitedField(field_offset);
 }
 
@@ -1704,135 +1517,98 @@ void V8HeapExplorer::MarkVisitedField(int offset) {
   visited_fields_[index] = true;
 }
 
-
-void V8HeapExplorer::SetNativeBindReference(HeapObject* parent_obj,
-                                            int parent_entry,
+void V8HeapExplorer::SetNativeBindReference(HeapEntry* parent_entry,
                                             const char* reference_name,
                                             Object* child_obj) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
-  filler_->SetNamedReference(HeapGraphEdge::kShortcut, parent_entry,
-                             reference_name, child_entry);
+  parent_entry->SetNamedReference(HeapGraphEdge::kShortcut, reference_name,
+                                  child_entry);
 }
 
-
-void V8HeapExplorer::SetElementReference(HeapObject* parent_obj,
-                                         int parent_entry,
-                                         int index,
+void V8HeapExplorer::SetElementReference(HeapEntry* parent_entry, int index,
                                          Object* child_obj) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
-  filler_->SetIndexedReference(HeapGraphEdge::kElement, parent_entry, index,
-                               child_entry);
+  parent_entry->SetIndexedReference(HeapGraphEdge::kElement, index,
+                                    child_entry);
 }
 
-
-void V8HeapExplorer::SetInternalReference(HeapObject* parent_obj,
-                                          int parent_entry,
+void V8HeapExplorer::SetInternalReference(HeapEntry* parent_entry,
                                           const char* reference_name,
-                                          Object* child_obj,
-                                          int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
+                                          Object* child_obj, int field_offset) {
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
   if (IsEssentialObject(child_obj)) {
-    filler_->SetNamedReference(HeapGraphEdge::kInternal,
-                               parent_entry,
-                               reference_name,
-                               child_entry);
+    parent_entry->SetNamedReference(HeapGraphEdge::kInternal, reference_name,
+                                    child_entry);
   }
   MarkVisitedField(field_offset);
 }
 
-
-void V8HeapExplorer::SetInternalReference(HeapObject* parent_obj,
-                                          int parent_entry,
-                                          int index,
-                                          Object* child_obj,
-                                          int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
+void V8HeapExplorer::SetInternalReference(HeapEntry* parent_entry, int index,
+                                          Object* child_obj, int field_offset) {
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
   if (IsEssentialObject(child_obj)) {
-    filler_->SetNamedReference(HeapGraphEdge::kInternal,
-                               parent_entry,
-                               names_->GetName(index),
-                               child_entry);
+    parent_entry->SetNamedReference(HeapGraphEdge::kInternal,
+                                    names_->GetName(index), child_entry);
   }
   MarkVisitedField(field_offset);
 }
 
 void V8HeapExplorer::SetHiddenReference(HeapObject* parent_obj,
-                                        int parent_entry, int index,
+                                        HeapEntry* parent_entry, int index,
                                         Object* child_obj, int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
+  DCHECK_EQ(parent_entry, GetEntry(parent_obj));
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry != nullptr && IsEssentialObject(child_obj) &&
       IsEssentialHiddenReference(parent_obj, field_offset)) {
-    filler_->SetIndexedReference(HeapGraphEdge::kHidden, parent_entry, index,
-                                 child_entry);
+    parent_entry->SetIndexedReference(HeapGraphEdge::kHidden, index,
+                                      child_entry);
   }
 }
 
-
-void V8HeapExplorer::SetWeakReference(HeapObject* parent_obj,
-                                      int parent_entry,
+void V8HeapExplorer::SetWeakReference(HeapEntry* parent_entry,
                                       const char* reference_name,
-                                      Object* child_obj,
-                                      int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
+                                      Object* child_obj, int field_offset) {
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
   if (IsEssentialObject(child_obj)) {
-    filler_->SetNamedReference(HeapGraphEdge::kWeak,
-                               parent_entry,
-                               reference_name,
-                               child_entry);
+    parent_entry->SetNamedReference(HeapGraphEdge::kWeak, reference_name,
+                                    child_entry);
   }
   MarkVisitedField(field_offset);
 }
 
-
-void V8HeapExplorer::SetWeakReference(HeapObject* parent_obj,
-                                      int parent_entry,
-                                      int index,
-                                      Object* child_obj,
-                                      int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
+void V8HeapExplorer::SetWeakReference(HeapEntry* parent_entry, int index,
+                                      Object* child_obj, int field_offset) {
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
   if (IsEssentialObject(child_obj)) {
-    filler_->SetNamedReference(HeapGraphEdge::kWeak,
-                               parent_entry,
-                               names_->GetFormatted("%d", index),
-                               child_entry);
+    parent_entry->SetNamedReference(
+        HeapGraphEdge::kWeak, names_->GetFormatted("%d", index), child_entry);
   }
   MarkVisitedField(field_offset);
 }
 
 void V8HeapExplorer::SetDataOrAccessorPropertyReference(
-    PropertyKind kind, JSObject* parent_obj, int parent_entry,
-    Name* reference_name, Object* child_obj, const char* name_format_string,
-    int field_offset) {
+    PropertyKind kind, HeapEntry* parent_entry, Name* reference_name,
+    Object* child_obj, const char* name_format_string, int field_offset) {
   if (kind == kAccessor) {
-    ExtractAccessorPairProperty(parent_obj, parent_entry, reference_name,
-                                child_obj, field_offset);
+    ExtractAccessorPairProperty(parent_entry, reference_name, child_obj,
+                                field_offset);
   } else {
-    SetPropertyReference(parent_obj, parent_entry, reference_name, child_obj,
+    SetPropertyReference(parent_entry, reference_name, child_obj,
                          name_format_string, field_offset);
   }
 }
 
-
-void V8HeapExplorer::SetPropertyReference(HeapObject* parent_obj,
-                                          int parent_entry,
+void V8HeapExplorer::SetPropertyReference(HeapEntry* parent_entry,
                                           Name* reference_name,
                                           Object* child_obj,
                                           const char* name_format_string,
                                           int field_offset) {
-  DCHECK(parent_entry == GetEntry(parent_obj)->index());
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
   HeapGraphEdge::Type type =
@@ -1848,29 +1624,25 @@ void V8HeapExplorer::SetPropertyReference(HeapObject* parent_obj,
                     .get())
           : names_->GetName(reference_name);
 
-  filler_->SetNamedReference(type, parent_entry, name, child_entry);
+  parent_entry->SetNamedReference(type, name, child_entry);
   MarkVisitedField(field_offset);
 }
 
 void V8HeapExplorer::SetRootGcRootsReference() {
-  filler_->SetIndexedAutoIndexReference(
-      HeapGraphEdge::kElement,
-      snapshot_->root()->index(),
-      snapshot_->gc_roots());
+  snapshot_->root()->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
+                                                  snapshot_->gc_roots());
 }
 
 void V8HeapExplorer::SetUserGlobalReference(Object* child_obj) {
   HeapEntry* child_entry = GetEntry(child_obj);
   DCHECK_NOT_NULL(child_entry);
-  filler_->SetNamedAutoIndexReference(HeapGraphEdge::kShortcut,
-                                      snapshot_->root()->index(), nullptr,
-                                      child_entry);
+  snapshot_->root()->SetNamedAutoIndexReference(HeapGraphEdge::kShortcut,
+                                                nullptr, child_entry, names_);
 }
 
 void V8HeapExplorer::SetGcRootsReference(Root root) {
-  filler_->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
-                                        snapshot_->gc_roots()->index(),
-                                        snapshot_->gc_subroot(root));
+  snapshot_->gc_roots()->SetIndexedAutoIndexReference(
+      HeapGraphEdge::kElement, snapshot_->gc_subroot(root));
 }
 
 void V8HeapExplorer::SetGcSubrootReference(Root root, const char* description,
@@ -1881,12 +1653,11 @@ void V8HeapExplorer::SetGcSubrootReference(Root root, const char* description,
   HeapGraphEdge::Type edge_type =
       is_weak ? HeapGraphEdge::kWeak : HeapGraphEdge::kInternal;
   if (name != nullptr) {
-    filler_->SetNamedReference(edge_type, snapshot_->gc_subroot(root)->index(),
-                               name, child_entry);
+    snapshot_->gc_subroot(root)->SetNamedReference(edge_type, name,
+                                                   child_entry);
   } else {
-    filler_->SetNamedAutoIndexReference(edge_type,
-                                        snapshot_->gc_subroot(root)->index(),
-                                        description, child_entry);
+    snapshot_->gc_subroot(root)->SetNamedAutoIndexReference(
+        edge_type, description, child_entry, names_);
   }
 
   // Add a shortcut to JS global object reference at snapshot root.
@@ -1897,53 +1668,34 @@ void V8HeapExplorer::SetGcSubrootReference(Root root, const char* description,
   JSGlobalObject* global = Context::cast(child_obj)->global_object();
   if (!global->IsJSGlobalObject()) return;
 
-  if (user_roots_.Contains(global)) return;
+  if (!user_roots_.insert(global).second) return;
 
-  user_roots_.Insert(global);
   SetUserGlobalReference(global);
 }
 
-const char* V8HeapExplorer::GetStrongGcSubrootName(Object* object) {
-  ReadOnlyRoots roots(heap_);
-  if (strong_gc_subroot_names_.is_empty()) {
-#define NAME_ENTRY(name) strong_gc_subroot_names_.SetTag(heap_->name(), #name);
-#define RO_NAME_ENTRY(name) \
-  strong_gc_subroot_names_.SetTag(roots.name(), #name);
-#define ROOT_NAME(type, name, camel_name) NAME_ENTRY(name)
-    STRONG_MUTABLE_ROOT_LIST(ROOT_NAME)
+// This static array is used to prevent excessive code-size in
+// GetStrongGcSubrootName below, which would happen if we called emplace() for
+// every root in a macro.
+static const char* root_names[] = {
+#define ROOT_NAME(type, name, CamelName) #name,
+    READ_ONLY_ROOT_LIST(ROOT_NAME) MUTABLE_ROOT_LIST(ROOT_NAME)
 #undef ROOT_NAME
-#define ROOT_NAME(type, name, camel_name) RO_NAME_ENTRY(name)
-    STRONG_READ_ONLY_ROOT_LIST(ROOT_NAME)
-#undef ROOT_NAME
-#define STRUCT_MAP_NAME(NAME, Name, name) RO_NAME_ENTRY(name##_map)
-    STRUCT_LIST(STRUCT_MAP_NAME)
-#undef STRUCT_MAP_NAME
-#define ALLOCATION_SITE_MAP_NAME(NAME, Name, Size, name) \
-  RO_NAME_ENTRY(name##_map)
-    ALLOCATION_SITE_LIST(ALLOCATION_SITE_MAP_NAME)
-#undef ALLOCATION_SITE_MAP_NAME
-#define DATA_HANDLER_MAP_NAME(NAME, Name, Size, name) NAME_ENTRY(name##_map)
-    DATA_HANDLER_LIST(DATA_HANDLER_MAP_NAME)
-#undef DATA_HANDLER_MAP_NAME
-#define STRING_NAME(name, str) RO_NAME_ENTRY(name)
-    INTERNALIZED_STRING_LIST(STRING_NAME)
-#undef STRING_NAME
-#define SYMBOL_NAME(name) RO_NAME_ENTRY(name)
-    PRIVATE_SYMBOL_LIST(SYMBOL_NAME)
-#undef SYMBOL_NAME
-#define SYMBOL_NAME(name, description) RO_NAME_ENTRY(name)
-    PUBLIC_SYMBOL_LIST(SYMBOL_NAME)
-    WELL_KNOWN_SYMBOL_LIST(SYMBOL_NAME)
-#undef SYMBOL_NAME
-#define ACCESSOR_NAME(accessor_name, AccessorName) \
-  NAME_ENTRY(accessor_name##_accessor)
-    ACCESSOR_INFO_LIST(ACCESSOR_NAME)
-#undef ACCESSOR_NAME
-#undef NAME_ENTRY
-#undef RO_NAME_ENTRY
-    CHECK(!strong_gc_subroot_names_.is_empty());
-  }
-  return strong_gc_subroot_names_.GetTag(object);
+};
+STATIC_ASSERT(static_cast<uint16_t>(RootIndex::kRootListLength) ==
+              arraysize(root_names));
+
+const char* V8HeapExplorer::GetStrongGcSubrootName(Object* object) {
+  if (strong_gc_subroot_names_.empty()) {
+    for (uint16_t i = 0; i < static_cast<uint16_t>(RootIndex::kRootListLength);
+         i++) {
+      const char* name = root_names[i];
+      RootIndex index = static_cast<RootIndex>(i);
+      strong_gc_subroot_names_.emplace(heap_->root(index), name);
+    }
+    CHECK(!strong_gc_subroot_names_.empty());
+  }
+  auto it = strong_gc_subroot_names_.find(object);
+  return it != strong_gc_subroot_names_.end() ? it->second : nullptr;
 }
 
 void V8HeapExplorer::TagObject(Object* obj, const char* tag) {
@@ -1993,7 +1745,7 @@ void V8HeapExplorer::TagGlobalObjects() {
 
   DisallowHeapAllocation no_allocation;
   for (int i = 0, l = enumerator.count(); i < l; ++i) {
-    objects_tags_.SetTag(*enumerator.at(i), urls[i]);
+    if (urls[i]) objects_tags_.emplace(*enumerator.at(i), urls[i]);
   }
 }
 
@@ -2055,7 +1807,7 @@ class GlobalHandlesExtractor : public PersistentHandleVisitor {
  public:
   explicit GlobalHandlesExtractor(NativeObjectsExplorer* explorer)
       : explorer_(explorer) {}
-  ~GlobalHandlesExtractor() override {}
+  ~GlobalHandlesExtractor() override = default;
   void VisitPersistentHandle(Persistent<Value>* value,
                              uint16_t class_id) override {
     Handle<Object> object = Utils::OpenPersistent(value);
@@ -2077,7 +1829,7 @@ class BasicHeapEntriesAllocator : public HeapEntriesAllocator {
       heap_object_map_(snapshot_->profiler()->heap_object_map()),
       entries_type_(entries_type) {
   }
-  virtual HeapEntry* AllocateEntry(HeapThing ptr);
+  HeapEntry* AllocateEntry(HeapThing ptr) override;
  private:
   HeapSnapshot* snapshot_;
   StringsStorage* names_;
@@ -2108,7 +1860,7 @@ class EmbedderGraphEntriesAllocator : public HeapEntriesAllocator {
       : snapshot_(snapshot),
         names_(snapshot_->profiler()->names()),
         heap_object_map_(snapshot_->profiler()->heap_object_map()) {}
-  virtual HeapEntry* AllocateEntry(HeapThing ptr);
+  HeapEntry* AllocateEntry(HeapThing ptr) override;
 
  private:
   HeapSnapshot* snapshot_;
@@ -2135,12 +1887,9 @@ HeapEntry::Type EmbedderGraphNodeType(EmbedderGraphImpl::Node* node) {
 // Otherwise, the result is the embedder node name.
 const char* MergeNames(StringsStorage* names, const char* embedder_name,
                        const char* wrapper_name) {
-  for (const char* suffix = wrapper_name; *suffix; suffix++) {
-    if (*suffix == '/') {
-      return names->GetFormatted("%s %s", embedder_name, suffix);
-    }
-  }
-  return embedder_name;
+  const char* suffix = strchr(wrapper_name, '/');
+  return suffix ? names->GetFormatted("%s %s", embedder_name, suffix)
+                : embedder_name;
 }
 
 }  // anonymous namespace
@@ -2163,17 +1912,17 @@ class NativeGroupRetainedObjectInfo : public v8::RetainedObjectInfo {
         hash_(reinterpret_cast<intptr_t>(label)),
         label_(label) {}
 
-  virtual ~NativeGroupRetainedObjectInfo() {}
-  virtual void Dispose() {
+  ~NativeGroupRetainedObjectInfo() override = default;
+  void Dispose() override {
     CHECK(!disposed_);
     disposed_ = true;
     delete this;
   }
-  virtual bool IsEquivalent(RetainedObjectInfo* other) {
+  bool IsEquivalent(RetainedObjectInfo* other) override {
     return hash_ == other->GetHash() && !strcmp(label_, other->GetLabel());
   }
-  virtual intptr_t GetHash() { return hash_; }
-  virtual const char* GetLabel() { return label_; }
+  intptr_t GetHash() override { return hash_; }
+  const char* GetLabel() override { return label_; }
 
  private:
   bool disposed_;
@@ -2193,8 +1942,7 @@ NativeObjectsExplorer::NativeObjectsExplorer(
       native_entries_allocator_(
           new BasicHeapEntriesAllocator(snapshot, HeapEntry::kNative)),
       embedder_graph_entries_allocator_(
-          new EmbedderGraphEntriesAllocator(snapshot)),
-      filler_(nullptr) {}
+          new EmbedderGraphEntriesAllocator(snapshot)) {}
 
 NativeObjectsExplorer::~NativeObjectsExplorer() {
   for (auto map_entry : objects_by_info_) {
@@ -2231,7 +1979,7 @@ void NativeObjectsExplorer::FillRetainedObjects() {
       DCHECK(!object.is_null());
       HeapObject* heap_object = HeapObject::cast(*object);
       info->push_back(heap_object);
-      in_groups_.Insert(heap_object);
+      in_groups_.insert(heap_object);
     }
   }
 
@@ -2252,25 +2000,23 @@ void NativeObjectsExplorer::FillEdges() {
     Handle<Object> parent_object = v8::Utils::OpenHandle(
         *pair.first->Get(reinterpret_cast<v8::Isolate*>(isolate_)));
     HeapObject* parent = HeapObject::cast(*parent_object);
-    int parent_entry =
-        filler_->FindOrAddEntry(parent, native_entries_allocator_.get())
-            ->index();
-    DCHECK_NE(parent_entry, HeapEntry::kNoEntry);
+    HeapEntry* parent_entry =
+        generator_->FindOrAddEntry(parent, native_entries_allocator_.get());
+    DCHECK_NOT_NULL(parent_entry);
     Handle<Object> child_object = v8::Utils::OpenHandle(
         *pair.second->Get(reinterpret_cast<v8::Isolate*>(isolate_)));
     HeapObject* child = HeapObject::cast(*child_object);
     HeapEntry* child_entry =
-        filler_->FindOrAddEntry(child, native_entries_allocator_.get());
-    filler_->SetNamedReference(HeapGraphEdge::kInternal, parent_entry, "native",
-                               child_entry);
+        generator_->FindOrAddEntry(child, native_entries_allocator_.get());
+    parent_entry->SetNamedReference(HeapGraphEdge::kInternal, "native",
+                                    child_entry);
   }
   edges_.clear();
 }
 
 std::vector<HeapObject*>* NativeObjectsExplorer::GetVectorMaybeDisposeInfo(
     v8::RetainedObjectInfo* info) {
-  auto map_entry = objects_by_info_.find(info);
-  if (map_entry != objects_by_info_.end()) {
+  if (objects_by_info_.count(info)) {
     info->Dispose();
   } else {
     objects_by_info_[info] = new std::vector<HeapObject*>();
@@ -2285,21 +2031,20 @@ HeapEntry* NativeObjectsExplorer::EntryForEmbedderGraphNode(
     node = wrapper;
   }
   if (node->IsEmbedderNode()) {
-    return filler_->FindOrAddEntry(node,
-                                   embedder_graph_entries_allocator_.get());
+    return generator_->FindOrAddEntry(node,
+                                      embedder_graph_entries_allocator_.get());
   } else {
     EmbedderGraphImpl::V8NodeImpl* v8_node =
         static_cast<EmbedderGraphImpl::V8NodeImpl*>(node);
     Object* object = v8_node->GetObject();
     if (object->IsSmi()) return nullptr;
-    HeapEntry* entry = filler_->FindEntry(HeapObject::cast(object));
-    return entry;
+    return generator_->FindEntry(HeapObject::cast(object));
   }
 }
 
 bool NativeObjectsExplorer::IterateAndExtractReferences(
-    SnapshotFiller* filler) {
-  filler_ = filler;
+    HeapSnapshotGenerator* generator) {
+  generator_ = generator;
 
   if (FLAG_heap_profiler_use_embedder_graph &&
       snapshot_->profiler()->HasBuildEmbedderGraphCallback()) {
@@ -2309,9 +2054,8 @@ bool NativeObjectsExplorer::IterateAndExtractReferences(
     snapshot_->profiler()->BuildEmbedderGraph(isolate_, &graph);
     for (const auto& node : graph.nodes()) {
       if (node->IsRootNode()) {
-        filler_->SetIndexedAutoIndexReference(
-            HeapGraphEdge::kElement, snapshot_->root()->index(),
-            EntryForEmbedderGraphNode(node.get()));
+        snapshot_->root()->SetIndexedAutoIndexReference(
+            HeapGraphEdge::kElement, EntryForEmbedderGraphNode(node.get()));
       }
       // Adjust the name and the type of the V8 wrapper node.
       auto wrapper = node->WrapperNode();
@@ -2326,21 +2070,15 @@ bool NativeObjectsExplorer::IterateAndExtractReferences(
     // Fill edges of the graph.
     for (const auto& edge : graph.edges()) {
       HeapEntry* from = EntryForEmbedderGraphNode(edge.from);
-      // The |from| and |to| can nullptr if the corrsponding node is a V8 node
+      // |from| and |to| can be nullptr if the corresponding node is a V8 node
       // pointing to a Smi.
       if (!from) continue;
-      // Adding an entry for |edge.to| can invalidate the |from| entry because
-      // it is an address in std::vector. Use index instead of pointer.
-      int from_index = from->index();
       HeapEntry* to = EntryForEmbedderGraphNode(edge.to);
-      if (to) {
-        if (edge.name == nullptr) {
-          filler_->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
-                                                from_index, to);
-        } else {
-          filler_->SetNamedReference(HeapGraphEdge::kInternal, from_index,
-                                     edge.name, to);
-        }
+      if (!to) continue;
+      if (edge.name == nullptr) {
+        from->SetIndexedAutoIndexReference(HeapGraphEdge::kElement, to);
+      } else {
+        from->SetNamedReference(HeapGraphEdge::kInternal, edge.name, to);
       }
     }
   } else {
@@ -2358,15 +2096,14 @@ bool NativeObjectsExplorer::IterateAndExtractReferences(
       SetRootNativeRootsReference();
     }
   }
-  filler_ = nullptr;
+  generator_ = nullptr;
   return true;
 }
 
 NativeGroupRetainedObjectInfo* NativeObjectsExplorer::FindOrAddGroupInfo(
     const char* label) {
   const char* label_copy = names_->GetCopy(label);
-  auto map_entry = native_groups_.find(label_copy);
-  if (map_entry == native_groups_.end()) {
+  if (!native_groups_.count(label_copy)) {
     native_groups_[label_copy] = new NativeGroupRetainedObjectInfo(label);
   }
   return native_groups_[label_copy];
@@ -2375,61 +2112,48 @@ NativeGroupRetainedObjectInfo* NativeObjectsExplorer::FindOrAddGroupInfo(
 void NativeObjectsExplorer::SetNativeRootReference(
     v8::RetainedObjectInfo* info) {
   HeapEntry* child_entry =
-      filler_->FindOrAddEntry(info, native_entries_allocator_.get());
+      generator_->FindOrAddEntry(info, native_entries_allocator_.get());
   DCHECK_NOT_NULL(child_entry);
   NativeGroupRetainedObjectInfo* group_info =
       FindOrAddGroupInfo(info->GetGroupLabel());
-  HeapEntry* group_entry =
-      filler_->FindOrAddEntry(group_info, synthetic_entries_allocator_.get());
-  // |FindOrAddEntry| can move and resize the entries backing store. Reload
-  // potentially-stale pointer.
-  child_entry = filler_->FindEntry(info);
-  filler_->SetNamedAutoIndexReference(
-      HeapGraphEdge::kInternal, group_entry->index(), nullptr, child_entry);
+  HeapEntry* group_entry = generator_->FindOrAddEntry(
+      group_info, synthetic_entries_allocator_.get());
+  group_entry->SetNamedAutoIndexReference(HeapGraphEdge::kInternal, nullptr,
+                                          child_entry, names_);
 }
 
-
 void NativeObjectsExplorer::SetWrapperNativeReferences(
     HeapObject* wrapper, v8::RetainedObjectInfo* info) {
-  HeapEntry* wrapper_entry = filler_->FindEntry(wrapper);
+  HeapEntry* wrapper_entry = generator_->FindEntry(wrapper);
   DCHECK_NOT_NULL(wrapper_entry);
   HeapEntry* info_entry =
-      filler_->FindOrAddEntry(info, native_entries_allocator_.get());
+      generator_->FindOrAddEntry(info, native_entries_allocator_.get());
   DCHECK_NOT_NULL(info_entry);
-  filler_->SetNamedReference(HeapGraphEdge::kInternal,
-                             wrapper_entry->index(),
-                             "native",
-                             info_entry);
-  filler_->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
-                                        info_entry->index(),
-                                        wrapper_entry);
+  wrapper_entry->SetNamedReference(HeapGraphEdge::kInternal, "native",
+                                   info_entry);
+  info_entry->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
+                                           wrapper_entry);
 }
 
-
 void NativeObjectsExplorer::SetRootNativeRootsReference() {
   for (auto map_entry : native_groups_) {
     NativeGroupRetainedObjectInfo* group_info = map_entry.second;
     HeapEntry* group_entry =
-        filler_->FindOrAddEntry(group_info, native_entries_allocator_.get());
+        generator_->FindOrAddEntry(group_info, native_entries_allocator_.get());
     DCHECK_NOT_NULL(group_entry);
-    filler_->SetIndexedAutoIndexReference(
-        HeapGraphEdge::kElement,
-        snapshot_->root()->index(),
-        group_entry);
+    snapshot_->root()->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
+                                                    group_entry);
   }
 }
 
-
 void NativeObjectsExplorer::VisitSubtreeWrapper(Object** p, uint16_t class_id) {
-  if (in_groups_.Contains(*p)) return;
-  Isolate* isolate = isolate_;
+  if (in_groups_.count(*p)) return;
   v8::RetainedObjectInfo* info =
-      isolate->heap_profiler()->ExecuteWrapperClassCallback(class_id, p);
+      isolate_->heap_profiler()->ExecuteWrapperClassCallback(class_id, p);
   if (info == nullptr) return;
   GetVectorMaybeDisposeInfo(info)->push_back(HeapObject::cast(*p));
 }
 
-
 HeapSnapshotGenerator::HeapSnapshotGenerator(
     HeapSnapshot* snapshot,
     v8::ActivityControl* control,
@@ -2464,10 +2188,10 @@ bool HeapSnapshotGenerator::GenerateSnapshot() {
   // full GC is reachable from the root when computing dominators.
   // This is not true for weakly reachable objects.
   // As a temporary solution we call GC twice.
-  heap_->CollectAllGarbage(Heap::kMakeHeapIterableMask,
-                           GarbageCollectionReason::kHeapProfiler);
-  heap_->CollectAllGarbage(Heap::kMakeHeapIterableMask,
-                           GarbageCollectionReason::kHeapProfiler);
+  heap_->PreciseCollectAllGarbage(Heap::kNoGCFlags,
+                                  GarbageCollectionReason::kHeapProfiler);
+  heap_->PreciseCollectAllGarbage(Heap::kNoGCFlags,
+                                  GarbageCollectionReason::kHeapProfiler);
 
   NullContextScope null_context_scope(heap_->isolate());
 
@@ -2525,12 +2249,10 @@ void HeapSnapshotGenerator::InitProgressCounter() {
 }
 
 bool HeapSnapshotGenerator::FillReferences() {
-  SnapshotFiller filler(snapshot_, &entries_);
-  return v8_heap_explorer_.IterateAndExtractReferences(&filler) &&
-         dom_explorer_.IterateAndExtractReferences(&filler);
+  return v8_heap_explorer_.IterateAndExtractReferences(this) &&
+         dom_explorer_.IterateAndExtractReferences(this);
 }
 
-
 template<int bytes> struct MaxDecimalDigitsIn;
 template<> struct MaxDecimalDigitsIn<4> {
   static const int kSigned = 11;
@@ -2541,7 +2263,6 @@ template<> struct MaxDecimalDigitsIn<8> {
   static const int kUnsigned = 20;
 };
 
-
 class OutputStreamWriter {
  public:
   explicit OutputStreamWriter(v8::OutputStream* stream)
@@ -2765,9 +2486,8 @@ void HeapSnapshotJSONSerializer::SerializeEdge(HeapGraphEdge* edge,
   writer_->AddString(buffer.start());
 }
 
-
 void HeapSnapshotJSONSerializer::SerializeEdges() {
-  std::deque<HeapGraphEdge*>& edges = snapshot_->children();
+  std::vector<HeapGraphEdge*>& edges = snapshot_->children();
   for (size_t i = 0; i < edges.size(); ++i) {
     DCHECK(i == 0 ||
            edges[i - 1]->from()->index() <= edges[i]->from()->index());
@@ -2803,16 +2523,14 @@ void HeapSnapshotJSONSerializer::SerializeNode(const HeapEntry* entry) {
   writer_->AddString(buffer.start());
 }
 
-
 void HeapSnapshotJSONSerializer::SerializeNodes() {
-  std::vector<HeapEntry>& entries = snapshot_->entries();
+  const std::deque<HeapEntry>& entries = snapshot_->entries();
   for (const HeapEntry& entry : entries) {
     SerializeNode(&entry);
     if (writer_->aborted()) return;
   }
 }
 
-
 void HeapSnapshotJSONSerializer::SerializeSnapshot() {
   writer_->AddString("\"meta\":");
   // The object describing node serialization layout.
diff --git a/deps/v8/src/profiler/heap-snapshot-generator.h b/deps/v8/src/profiler/heap-snapshot-generator.h
index f25bee9f46..1f8f364912 100644
--- a/deps/v8/src/profiler/heap-snapshot-generator.h
+++ b/deps/v8/src/profiler/heap-snapshot-generator.h
@@ -7,6 +7,7 @@
 
 #include <deque>
 #include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 #include "include/v8-profiler.h"
@@ -28,10 +29,14 @@ class HeapEntry;
 class HeapIterator;
 class HeapProfiler;
 class HeapSnapshot;
+class HeapSnapshotGenerator;
 class JSArrayBuffer;
 class JSCollection;
+class JSGeneratorObject;
+class JSGlobalObject;
+class JSGlobalProxy;
+class JSPromise;
 class JSWeakCollection;
-class SnapshotFiller;
 
 struct SourceLocation {
   SourceLocation(int entry_index, int scriptId, int line, int col)
@@ -43,7 +48,7 @@ struct SourceLocation {
   const int col;
 };
 
-class HeapGraphEdge BASE_EMBEDDED {
+class HeapGraphEdge {
  public:
   enum Type {
     kContextVariable = v8::HeapGraphEdge::kContextVariable,
@@ -55,9 +60,8 @@ class HeapGraphEdge BASE_EMBEDDED {
     kWeak = v8::HeapGraphEdge::kWeak
   };
 
-  HeapGraphEdge(Type type, const char* name, int from, int to);
-  HeapGraphEdge(Type type, int index, int from, int to);
-  void ReplaceToIndexWithEntry(HeapSnapshot* snapshot);
+  HeapGraphEdge(Type type, const char* name, HeapEntry* from, HeapEntry* to);
+  HeapGraphEdge(Type type, int index, HeapEntry* from, HeapEntry* to);
 
   Type type() const { return TypeField::decode(bit_field_); }
   int index() const {
@@ -81,12 +85,7 @@ class HeapGraphEdge BASE_EMBEDDED {
   class TypeField : public BitField<Type, 0, 3> {};
   class FromIndexField : public BitField<int, 3, 29> {};
   uint32_t bit_field_;
-  union {
-    // During entries population |to_index_| is used for storing the index,
-    // afterwards it is replaced with a pointer to the entry.
-    int to_index_;
-    HeapEntry* to_entry_;
-  };
+  HeapEntry* to_entry_;
   union {
     int index_;
     const char* name_;
@@ -96,7 +95,7 @@ class HeapGraphEdge BASE_EMBEDDED {
 
 // HeapEntry instances represent an entity from the heap (or a special
 // virtual node, e.g. root).
-class HeapEntry BASE_EMBEDDED {
+class HeapEntry {
  public:
   enum Type {
     kHidden = v8::HeapGraphNode::kHidden,
@@ -114,15 +113,9 @@ class HeapEntry BASE_EMBEDDED {
     kSymbol = v8::HeapGraphNode::kSymbol,
     kBigInt = v8::HeapGraphNode::kBigInt
   };
-  static const int kNoEntry;
 
-  HeapEntry() { }
-  HeapEntry(HeapSnapshot* snapshot,
-            Type type,
-            const char* name,
-            SnapshotObjectId id,
-            size_t self_size,
-            unsigned trace_node_id);
+  HeapEntry(HeapSnapshot* snapshot, int index, Type type, const char* name,
+            SnapshotObjectId id, size_t self_size, unsigned trace_node_id);
 
   HeapSnapshot* snapshot() { return snapshot_; }
   Type type() const { return static_cast<Type>(type_); }
@@ -132,8 +125,8 @@ class HeapEntry BASE_EMBEDDED {
   SnapshotObjectId id() const { return id_; }
   size_t self_size() const { return self_size_; }
   unsigned trace_node_id() const { return trace_node_id_; }
-  V8_INLINE int index() const;
-  int children_count() const { return children_count_; }
+  int index() const { return index_; }
+  V8_INLINE int children_count() const;
   V8_INLINE int set_children_index(int index);
   V8_INLINE void add_child(HeapGraphEdge* edge);
   V8_INLINE HeapGraphEdge* child(int i);
@@ -143,18 +136,30 @@ class HeapEntry BASE_EMBEDDED {
       HeapGraphEdge::Type type, int index, HeapEntry* entry);
   void SetNamedReference(
       HeapGraphEdge::Type type, const char* name, HeapEntry* entry);
+  void SetIndexedAutoIndexReference(HeapGraphEdge::Type type,
+                                    HeapEntry* child) {
+    SetIndexedReference(type, children_count_ + 1, child);
+  }
+  void SetNamedAutoIndexReference(HeapGraphEdge::Type type,
+                                  const char* description, HeapEntry* child,
+                                  StringsStorage* strings);
 
   void Print(
       const char* prefix, const char* edge_name, int max_depth, int indent);
 
  private:
-  V8_INLINE std::deque<HeapGraphEdge*>::iterator children_begin();
-  V8_INLINE std::deque<HeapGraphEdge*>::iterator children_end();
+  V8_INLINE std::vector<HeapGraphEdge*>::iterator children_begin() const;
+  V8_INLINE std::vector<HeapGraphEdge*>::iterator children_end() const;
   const char* TypeAsString();
 
   unsigned type_: 4;
-  int children_count_: 28;
-  int children_index_;
+  unsigned index_ : 28;  // Supports up to ~250M objects.
+  union {
+    // The count is used during the snapshot build phase,
+    // then it gets converted into the index by the |FillChildren| function.
+    unsigned children_count_;
+    unsigned children_end_index_;
+  };
   size_t self_size_;
   HeapSnapshot* snapshot_;
   const char* name_;
@@ -163,7 +168,6 @@ class HeapEntry BASE_EMBEDDED {
   unsigned trace_node_id_;
 };
 
-
 // HeapSnapshot represents a single heap snapshot. It is stored in
 // HeapProfiler, which is also a factory for
 // HeapSnapshots. All HeapSnapshots share strings copied from JS heap
@@ -174,22 +178,23 @@ class HeapSnapshot {
   explicit HeapSnapshot(HeapProfiler* profiler);
   void Delete();
 
-  HeapProfiler* profiler() { return profiler_; }
-  HeapEntry* root() { return &entries_[root_index_]; }
-  HeapEntry* gc_roots() { return &entries_[gc_roots_index_]; }
-  HeapEntry* gc_subroot(Root root) {
-    return &entries_[gc_subroot_indexes_[static_cast<int>(root)]];
+  HeapProfiler* profiler() const { return profiler_; }
+  HeapEntry* root() const { return root_entry_; }
+  HeapEntry* gc_roots() const { return gc_roots_entry_; }
+  HeapEntry* gc_subroot(Root root) const {
+    return gc_subroot_entries_[static_cast<int>(root)];
   }
-  std::vector<HeapEntry>& entries() { return entries_; }
+  std::deque<HeapEntry>& entries() { return entries_; }
   std::deque<HeapGraphEdge>& edges() { return edges_; }
-  std::deque<HeapGraphEdge*>& children() { return children_; }
+  std::vector<HeapGraphEdge*>& children() { return children_; }
   const std::vector<SourceLocation>& locations() const { return locations_; }
   void RememberLastJSObjectId();
   SnapshotObjectId max_snapshot_js_object_id() const {
     return max_snapshot_js_object_id_;
   }
+  bool is_complete() const { return !children_.empty(); }
 
-  void AddLocation(int entry, int scriptId, int line, int col);
+  void AddLocation(HeapEntry* entry, int scriptId, int line, int col);
   HeapEntry* AddEntry(HeapEntry::Type type,
                       const char* name,
                       SnapshotObjectId id,
@@ -197,28 +202,28 @@ class HeapSnapshot {
                       unsigned trace_node_id);
   void AddSyntheticRootEntries();
   HeapEntry* GetEntryById(SnapshotObjectId id);
-  std::vector<HeapEntry*>* GetSortedEntriesList();
   void FillChildren();
 
   void Print(int max_depth);
 
  private:
-  HeapEntry* AddRootEntry();
-  HeapEntry* AddGcRootsEntry();
-  HeapEntry* AddGcSubrootEntry(Root root, SnapshotObjectId id);
+  void AddRootEntry();
+  void AddGcRootsEntry();
+  void AddGcSubrootEntry(Root root, SnapshotObjectId id);
 
   HeapProfiler* profiler_;
-  int root_index_;
-  int gc_roots_index_;
-  int gc_subroot_indexes_[static_cast<int>(Root::kNumberOfRoots)];
-  std::vector<HeapEntry> entries_;
+  HeapEntry* root_entry_ = nullptr;
+  HeapEntry* gc_roots_entry_ = nullptr;
+  HeapEntry* gc_subroot_entries_[static_cast<int>(Root::kNumberOfRoots)];
+  // For |entries_| we rely on the deque property, that it never reallocates
+  // backing storage, thus all entry pointers remain valid for the duration
+  // of snapshotting.
+  std::deque<HeapEntry> entries_;
   std::deque<HeapGraphEdge> edges_;
-  std::deque<HeapGraphEdge*> children_;
-  std::vector<HeapEntry*> sorted_entries_;
+  std::vector<HeapGraphEdge*> children_;
+  std::unordered_map<SnapshotObjectId, HeapEntry*> entries_by_id_cache_;
   std::vector<SourceLocation> locations_;
-  SnapshotObjectId max_snapshot_js_object_id_;
-
-  friend class HeapSnapshotTester;
+  SnapshotObjectId max_snapshot_js_object_id_ = -1;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshot);
 };
@@ -294,68 +299,28 @@ typedef void* HeapThing;
 // An interface that creates HeapEntries by HeapThings.
 class HeapEntriesAllocator {
  public:
-  virtual ~HeapEntriesAllocator() { }
+  virtual ~HeapEntriesAllocator() = default;
   virtual HeapEntry* AllocateEntry(HeapThing ptr) = 0;
 };
 
-// The HeapEntriesMap instance is used to track a mapping between
-// real heap objects and their representations in heap snapshots.
-class HeapEntriesMap {
- public:
-  HeapEntriesMap();
-
-  int Map(HeapThing thing);
-  void Pair(HeapThing thing, int entry);
-
- private:
-  static uint32_t Hash(HeapThing thing) {
-    return ComputeUnseededHash(
-        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(thing)));
-  }
-
-  base::HashMap entries_;
-
-  friend class HeapObjectsSet;
-
-  DISALLOW_COPY_AND_ASSIGN(HeapEntriesMap);
-};
-
-
-class HeapObjectsSet {
- public:
-  HeapObjectsSet();
-  void Clear();
-  bool Contains(Object* object);
-  void Insert(Object* obj);
-  const char* GetTag(Object* obj);
-  void SetTag(Object* obj, const char* tag);
-  bool is_empty() const { return entries_.occupancy() == 0; }
-
- private:
-  base::HashMap entries_;
-
-  DISALLOW_COPY_AND_ASSIGN(HeapObjectsSet);
-};
-
-
 class SnapshottingProgressReportingInterface {
  public:
-  virtual ~SnapshottingProgressReportingInterface() { }
+  virtual ~SnapshottingProgressReportingInterface() = default;
   virtual void ProgressStep() = 0;
   virtual bool ProgressReport(bool force) = 0;
 };
 
-
 // An implementation of V8 heap graph extractor.
 class V8HeapExplorer : public HeapEntriesAllocator {
  public:
   V8HeapExplorer(HeapSnapshot* snapshot,
                  SnapshottingProgressReportingInterface* progress,
                  v8::HeapProfiler::ObjectNameResolver* resolver);
-  virtual ~V8HeapExplorer();
-  virtual HeapEntry* AllocateEntry(HeapThing ptr);
+  ~V8HeapExplorer() override = default;
+
+  HeapEntry* AllocateEntry(HeapThing ptr) override;
   int EstimateObjectsCount();
-  bool IterateAndExtractReferences(SnapshotFiller* filler);
+  bool IterateAndExtractReferences(HeapSnapshotGenerator* generator);
   void TagGlobalObjects();
   void TagCodeObject(Code* code);
   void TagBuiltinCodeObject(Code* code, const char* name);
@@ -377,91 +342,74 @@ class V8HeapExplorer : public HeapEntriesAllocator {
 
   const char* GetSystemEntryName(HeapObject* object);
 
-  void ExtractLocation(int entry, HeapObject* object);
-  void ExtractLocationForJSFunction(int entry, JSFunction* func);
-  void ExtractReferences(int entry, HeapObject* obj);
-  void ExtractJSGlobalProxyReferences(int entry, JSGlobalProxy* proxy);
-  void ExtractJSObjectReferences(int entry, JSObject* js_obj);
-  void ExtractStringReferences(int entry, String* obj);
-  void ExtractSymbolReferences(int entry, Symbol* symbol);
-  void ExtractJSCollectionReferences(int entry, JSCollection* collection);
-  void ExtractJSWeakCollectionReferences(int entry,
+  void ExtractLocation(HeapEntry* entry, HeapObject* object);
+  void ExtractLocationForJSFunction(HeapEntry* entry, JSFunction* func);
+  void ExtractReferences(HeapEntry* entry, HeapObject* obj);
+  void ExtractJSGlobalProxyReferences(HeapEntry* entry, JSGlobalProxy* proxy);
+  void ExtractJSObjectReferences(HeapEntry* entry, JSObject* js_obj);
+  void ExtractStringReferences(HeapEntry* entry, String* obj);
+  void ExtractSymbolReferences(HeapEntry* entry, Symbol* symbol);
+  void ExtractJSCollectionReferences(HeapEntry* entry,
+                                     JSCollection* collection);
+  void ExtractJSWeakCollectionReferences(HeapEntry* entry,
                                          JSWeakCollection* collection);
-  void ExtractEphemeronHashTableReferences(int entry,
+  void ExtractEphemeronHashTableReferences(HeapEntry* entry,
                                            EphemeronHashTable* table);
-  void ExtractContextReferences(int entry, Context* context);
-  void ExtractMapReferences(int entry, Map* map);
-  void ExtractSharedFunctionInfoReferences(int entry,
+  void ExtractContextReferences(HeapEntry* entry, Context* context);
+  void ExtractMapReferences(HeapEntry* entry, Map* map);
+  void ExtractSharedFunctionInfoReferences(HeapEntry* entry,
                                            SharedFunctionInfo* shared);
-  void ExtractScriptReferences(int entry, Script* script);
-  void ExtractAccessorInfoReferences(int entry, AccessorInfo* accessor_info);
-  void ExtractAccessorPairReferences(int entry, AccessorPair* accessors);
-  void ExtractCodeReferences(int entry, Code* code);
-  void ExtractCellReferences(int entry, Cell* cell);
-  void ExtractFeedbackCellReferences(int entry, FeedbackCell* feedback_cell);
-  void ExtractPropertyCellReferences(int entry, PropertyCell* cell);
-  void ExtractAllocationSiteReferences(int entry, AllocationSite* site);
+  void ExtractScriptReferences(HeapEntry* entry, Script* script);
+  void ExtractAccessorInfoReferences(HeapEntry* entry,
+                                     AccessorInfo* accessor_info);
+  void ExtractAccessorPairReferences(HeapEntry* entry, AccessorPair* accessors);
+  void ExtractCodeReferences(HeapEntry* entry, Code* code);
+  void ExtractCellReferences(HeapEntry* entry, Cell* cell);
+  void ExtractFeedbackCellReferences(HeapEntry* entry,
+                                     FeedbackCell* feedback_cell);
+  void ExtractPropertyCellReferences(HeapEntry* entry, PropertyCell* cell);
+  void ExtractAllocationSiteReferences(HeapEntry* entry, AllocationSite* site);
   void ExtractArrayBoilerplateDescriptionReferences(
-      int entry, ArrayBoilerplateDescription* value);
-  void ExtractJSArrayBufferReferences(int entry, JSArrayBuffer* buffer);
-  void ExtractJSPromiseReferences(int entry, JSPromise* promise);
-  void ExtractJSGeneratorObjectReferences(int entry,
+      HeapEntry* entry, ArrayBoilerplateDescription* value);
+  void ExtractJSArrayBufferReferences(HeapEntry* entry, JSArrayBuffer* buffer);
+  void ExtractJSPromiseReferences(HeapEntry* entry, JSPromise* promise);
+  void ExtractJSGeneratorObjectReferences(HeapEntry* entry,
                                           JSGeneratorObject* generator);
-  void ExtractFixedArrayReferences(int entry, FixedArray* array);
-  void ExtractFeedbackVectorReferences(int entry,
+  void ExtractFixedArrayReferences(HeapEntry* entry, FixedArray* array);
+  void ExtractFeedbackVectorReferences(HeapEntry* entry,
                                        FeedbackVector* feedback_vector);
   template <typename T>
-  void ExtractWeakArrayReferences(int header_size, int entry, T* array);
-  void ExtractPropertyReferences(JSObject* js_obj, int entry);
-  void ExtractAccessorPairProperty(JSObject* js_obj, int entry, Name* key,
+  void ExtractWeakArrayReferences(int header_size, HeapEntry* entry, T* array);
+  void ExtractPropertyReferences(JSObject* js_obj, HeapEntry* entry);
+  void ExtractAccessorPairProperty(HeapEntry* entry, Name* key,
                                    Object* callback_obj, int field_offset = -1);
-  void ExtractElementReferences(JSObject* js_obj, int entry);
-  void ExtractInternalReferences(JSObject* js_obj, int entry);
+  void ExtractElementReferences(JSObject* js_obj, HeapEntry* entry);
+  void ExtractInternalReferences(JSObject* js_obj, HeapEntry* entry);
 
   bool IsEssentialObject(Object* object);
   bool IsEssentialHiddenReference(Object* parent, int field_offset);
 
-  void SetContextReference(HeapObject* parent_obj,
-                           int parent,
-                           String* reference_name,
-                           Object* child,
-                           int field_offset);
-  void SetNativeBindReference(HeapObject* parent_obj,
-                              int parent,
-                              const char* reference_name,
-                              Object* child);
-  void SetElementReference(HeapObject* parent_obj,
-                           int parent,
-                           int index,
-                           Object* child);
-  void SetInternalReference(HeapObject* parent_obj,
-                            int parent,
-                            const char* reference_name,
-                            Object* child,
-                            int field_offset = -1);
-  void SetInternalReference(HeapObject* parent_obj,
-                            int parent,
-                            int index,
-                            Object* child,
+  void SetContextReference(HeapEntry* parent_entry, String* reference_name,
+                           Object* child, int field_offset);
+  void SetNativeBindReference(HeapEntry* parent_entry,
+                              const char* reference_name, Object* child);
+  void SetElementReference(HeapEntry* parent_entry, int index, Object* child);
+  void SetInternalReference(HeapEntry* parent_entry, const char* reference_name,
+                            Object* child, int field_offset = -1);
+  void SetInternalReference(HeapEntry* parent_entry, int index, Object* child,
                             int field_offset = -1);
-  void SetHiddenReference(HeapObject* parent_obj, int parent, int index,
-                          Object* child, int field_offset);
-  void SetWeakReference(HeapObject* parent_obj,
-                        int parent,
-                        const char* reference_name,
-                        Object* child_obj,
+  void SetHiddenReference(HeapObject* parent_obj, HeapEntry* parent_entry,
+                          int index, Object* child, int field_offset);
+  void SetWeakReference(HeapEntry* parent_entry, const char* reference_name,
+                        Object* child_obj, int field_offset);
+  void SetWeakReference(HeapEntry* parent_entry, int index, Object* child_obj,
                         int field_offset);
-  void SetWeakReference(HeapObject* parent_obj,
-                        int parent,
-                        int index,
-                        Object* child_obj,
-                        int field_offset);
-  void SetPropertyReference(HeapObject* parent_obj, int parent,
-                            Name* reference_name, Object* child,
+  void SetPropertyReference(HeapEntry* parent_entry, Name* reference_name,
+                            Object* child,
                             const char* name_format_string = nullptr,
                             int field_offset = -1);
   void SetDataOrAccessorPropertyReference(
-      PropertyKind kind, JSObject* parent_obj, int parent, Name* reference_name,
+      PropertyKind kind, HeapEntry* parent_entry, Name* reference_name,
       Object* child, const char* name_format_string = nullptr,
       int field_offset = -1);
 
@@ -480,10 +428,10 @@ class V8HeapExplorer : public HeapEntriesAllocator {
   StringsStorage* names_;
   HeapObjectsMap* heap_object_map_;
   SnapshottingProgressReportingInterface* progress_;
-  SnapshotFiller* filler_;
-  HeapObjectsSet objects_tags_;
-  HeapObjectsSet strong_gc_subroot_names_;
-  HeapObjectsSet user_roots_;
+  HeapSnapshotGenerator* generator_ = nullptr;
+  std::unordered_map<JSGlobalObject*, const char*> objects_tags_;
+  std::unordered_map<Object*, const char*> strong_gc_subroot_names_;
+  std::unordered_set<JSGlobalObject*> user_roots_;
   v8::HeapProfiler::ObjectNameResolver* global_object_name_resolver_;
 
   std::vector<bool> visited_fields_;
@@ -505,7 +453,7 @@ class NativeObjectsExplorer {
                         SnapshottingProgressReportingInterface* progress);
   virtual ~NativeObjectsExplorer();
   int EstimateObjectsCount();
-  bool IterateAndExtractReferences(SnapshotFiller* filler);
+  bool IterateAndExtractReferences(HeapSnapshotGenerator* generator);
 
  private:
   void FillRetainedObjects();
@@ -538,7 +486,7 @@ class NativeObjectsExplorer {
   HeapSnapshot* snapshot_;
   StringsStorage* names_;
   bool embedder_queried_;
-  HeapObjectsSet in_groups_;
+  std::unordered_set<Object*> in_groups_;
   std::unordered_map<v8::RetainedObjectInfo*, std::vector<HeapObject*>*,
                      RetainedInfoHasher, RetainedInfoEquals>
       objects_by_info_;
@@ -549,7 +497,7 @@ class NativeObjectsExplorer {
   std::unique_ptr<HeapEntriesAllocator> native_entries_allocator_;
   std::unique_ptr<HeapEntriesAllocator> embedder_graph_entries_allocator_;
   // Used during references extraction.
-  SnapshotFiller* filler_;
+  HeapSnapshotGenerator* generator_ = nullptr;
   v8::HeapProfiler::RetainerEdges edges_;
 
   static HeapThing const kNativesRootObject;
@@ -559,27 +507,45 @@ class NativeObjectsExplorer {
   DISALLOW_COPY_AND_ASSIGN(NativeObjectsExplorer);
 };
 
-
 class HeapSnapshotGenerator : public SnapshottingProgressReportingInterface {
  public:
+  // The HeapEntriesMap instance is used to track a mapping between
+  // real heap objects and their representations in heap snapshots.
+  using HeapEntriesMap = std::unordered_map<HeapThing, HeapEntry*>;
+
   HeapSnapshotGenerator(HeapSnapshot* snapshot,
                         v8::ActivityControl* control,
                         v8::HeapProfiler::ObjectNameResolver* resolver,
                         Heap* heap);
   bool GenerateSnapshot();
 
+  HeapEntry* FindEntry(HeapThing ptr) {
+    auto it = entries_map_.find(ptr);
+    return it != entries_map_.end() ? it->second : nullptr;
+  }
+
+  HeapEntry* AddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
+    return entries_map_.emplace(ptr, allocator->AllocateEntry(ptr))
+        .first->second;
+  }
+
+  HeapEntry* FindOrAddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
+    HeapEntry* entry = FindEntry(ptr);
+    return entry != nullptr ? entry : AddEntry(ptr, allocator);
+  }
+
  private:
   bool FillReferences();
-  void ProgressStep();
-  bool ProgressReport(bool force = false);
+  void ProgressStep() override;
+  bool ProgressReport(bool force = false) override;
   void InitProgressCounter();
 
   HeapSnapshot* snapshot_;
   v8::ActivityControl* control_;
   V8HeapExplorer v8_heap_explorer_;
   NativeObjectsExplorer dom_explorer_;
-  // Mapping from HeapThing pointers to HeapEntry* pointers.
-  HeapEntriesMap entries_;
+  // Mapping from HeapThing pointers to HeapEntry indices.
+  HeapEntriesMap entries_map_;
   // Used during snapshot generation.
   int progress_counter_;
   int progress_total_;
diff --git a/deps/v8/src/profiler/sampling-heap-profiler.cc b/deps/v8/src/profiler/sampling-heap-profiler.cc
index 48c3f73958..2e07135d85 100644
--- a/deps/v8/src/profiler/sampling-heap-profiler.cc
+++ b/deps/v8/src/profiler/sampling-heap-profiler.cc
@@ -6,8 +6,10 @@
 
 #include <stdint.h>
 #include <memory>
+
 #include "src/api-inl.h"
 #include "src/base/ieee754.h"
+#include "src/base/template-utils.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/frames-inl.h"
 #include "src/heap/heap.h"
@@ -61,7 +63,6 @@ SamplingHeapProfiler::SamplingHeapProfiler(
           heap->isolate()->random_number_generator())),
       names_(names),
       profile_root_(nullptr, "(root)", v8::UnboundScript::kNoScriptId, 0),
-      samples_(),
       stack_depth_(stack_depth),
       rate_(rate),
       flags_(flags) {
@@ -75,8 +76,6 @@ SamplingHeapProfiler::SamplingHeapProfiler(
 SamplingHeapProfiler::~SamplingHeapProfiler() {
   heap_->RemoveAllocationObserversFromAllSpaces(other_spaces_observer_.get(),
                                                 new_space_observer_.get());
-
-  samples_.clear();
 }
 
 
@@ -96,9 +95,9 @@ void SamplingHeapProfiler::SampleObject(Address soon_object, size_t size) {
 
   AllocationNode* node = AddStack();
   node->allocations_[size]++;
-  Sample* sample = new Sample(size, node, loc, this);
-  samples_.emplace(sample);
-  sample->global.SetWeak(sample, OnWeakCallback, WeakCallbackType::kParameter);
+  auto sample = base::make_unique<Sample>(size, node, loc, this);
+  sample->global.SetWeak(sample.get(), OnWeakCallback,
+                         WeakCallbackType::kParameter);
 #if __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated"
@@ -109,6 +108,7 @@ void SamplingHeapProfiler::SampleObject(Address soon_object, size_t size) {
 #if __clang__
 #pragma clang diagnostic pop
 #endif
+  samples_.emplace(sample.get(), std::move(sample));
 }
 
 void SamplingHeapProfiler::OnWeakCallback(
@@ -125,17 +125,10 @@ void SamplingHeapProfiler::OnWeakCallback(
       AllocationNode::FunctionId id = AllocationNode::function_id(
           node->script_id_, node->script_position_, node->name_);
       parent->children_.erase(id);
-      delete node;
       node = parent;
     }
   }
-  auto it = std::find_if(sample->profiler->samples_.begin(),
-                         sample->profiler->samples_.end(),
-                         [&sample](const std::unique_ptr<Sample>& s) {
-                           return s.get() == sample;
-                         });
-
-  sample->profiler->samples_.erase(it);
+  sample->profiler->samples_.erase(sample);
   // sample is deleted because its unique ptr was erased from samples_.
 }
 
@@ -147,11 +140,11 @@ SamplingHeapProfiler::AllocationNode::FindOrAddChildNode(const char* name,
   auto it = children_.find(id);
   if (it != children_.end()) {
     DCHECK_EQ(strcmp(it->second->name_, name), 0);
-    return it->second;
+    return it->second.get();
   }
-  auto child = new AllocationNode(this, name, script_id, start_position);
-  children_.insert(std::make_pair(id, child));
-  return child;
+  auto child =
+      base::make_unique<AllocationNode>(this, name, script_id, start_position);
+  return children_.emplace(id, std::move(child)).first->second.get();
 }
 
 SamplingHeapProfiler::AllocationNode* SamplingHeapProfiler::AddStack() {
@@ -262,19 +255,19 @@ v8::AllocationProfile::Node* SamplingHeapProfiler::TranslateAllocationNode(
     allocations.push_back(ScaleSample(alloc.first, alloc.second));
   }
 
-  profile->nodes().push_back(v8::AllocationProfile::Node(
-      {ToApiHandle<v8::String>(
-           isolate_->factory()->InternalizeUtf8String(node->name_)),
-       script_name, node->script_id_, node->script_position_, line, column,
-       std::vector<v8::AllocationProfile::Node*>(), allocations}));
+  profile->nodes().push_back(v8::AllocationProfile::Node{
+      ToApiHandle<v8::String>(
+          isolate_->factory()->InternalizeUtf8String(node->name_)),
+      script_name, node->script_id_, node->script_position_, line, column,
+      std::vector<v8::AllocationProfile::Node*>(), allocations});
   v8::AllocationProfile::Node* current = &profile->nodes().back();
-  // The children map may have nodes inserted into it during translation
+  // The |children_| map may have nodes inserted into it during translation
   // because the translation may allocate strings on the JS heap that have
   // the potential to be sampled. That's ok since map iterators are not
   // invalidated upon std::map insertion.
-  for (auto it : node->children_) {
+  for (const auto& it : node->children_) {
     current->children.push_back(
-        TranslateAllocationNode(profile, it.second, scripts));
+        TranslateAllocationNode(profile, it.second.get(), scripts));
   }
   node->pinned_ = false;
   return current;
@@ -299,6 +292,5 @@ v8::AllocationProfile* SamplingHeapProfiler::GetAllocationProfile() {
   return profile;
 }
 
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/profiler/sampling-heap-profiler.h b/deps/v8/src/profiler/sampling-heap-profiler.h
index 46fa405279..072c5eb677 100644
--- a/deps/v8/src/profiler/sampling-heap-profiler.h
+++ b/deps/v8/src/profiler/sampling-heap-profiler.h
@@ -8,7 +8,7 @@
 #include <deque>
 #include <map>
 #include <memory>
-#include <set>
+#include <unordered_map>
 #include "include/v8-profiler.h"
 #include "src/heap/heap.h"
 #include "src/profiler/strings-storage.h"
@@ -77,13 +77,7 @@ class SamplingHeapProfiler {
         : parent_(parent),
           script_id_(script_id),
           script_position_(start_position),
-          name_(name),
-          pinned_(false) {}
-    ~AllocationNode() {
-      for (auto child : children_) {
-        delete child.second;
-      }
-    }
+          name_(name) {}
 
    private:
     typedef uint64_t FunctionId;
@@ -107,12 +101,12 @@ class SamplingHeapProfiler {
     // TODO(alph): make use of unordered_map's here. Pay attention to
     // iterator invalidation during TranslateAllocationNode.
     std::map<size_t, unsigned int> allocations_;
-    std::map<FunctionId, AllocationNode*> children_;
+    std::map<FunctionId, std::unique_ptr<AllocationNode>> children_;
     AllocationNode* const parent_;
     const int script_id_;
     const int script_position_;
     const char* const name_;
-    bool pinned_;
+    bool pinned_ = false;
 
     friend class SamplingHeapProfiler;
 
@@ -146,7 +140,7 @@ class SamplingHeapProfiler {
   std::unique_ptr<SamplingAllocationObserver> other_spaces_observer_;
   StringsStorage* const names_;
   AllocationNode profile_root_;
-  std::set<std::unique_ptr<Sample>> samples_;
+  std::unordered_map<Sample*, std::unique_ptr<Sample>> samples_;
   const int stack_depth_;
   const uint64_t rate_;
   v8::HeapProfiler::SamplingFlags flags_;
@@ -166,7 +160,7 @@ class SamplingAllocationObserver : public AllocationObserver {
         heap_(heap),
         random_(random),
         rate_(rate) {}
-  virtual ~SamplingAllocationObserver() {}
+  ~SamplingAllocationObserver() override = default;
 
  protected:
   void Step(int bytes_allocated, Address soon_object, size_t size) override {
diff --git a/deps/v8/src/profiler/tick-sample.cc b/deps/v8/src/profiler/tick-sample.cc
index e3bd1d9c69..69a6bbf778 100644
--- a/deps/v8/src/profiler/tick-sample.cc
+++ b/deps/v8/src/profiler/tick-sample.cc
@@ -206,7 +206,7 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
   // Check whether we interrupted setup/teardown of a stack frame in JS code.
   // Avoid this check for C++ code, as that would trigger false positives.
   if (regs->pc &&
-      isolate->heap()->memory_allocator()->code_range()->contains(
+      isolate->heap()->memory_allocator()->code_range().contains(
           reinterpret_cast<i::Address>(regs->pc)) &&
       IsNoFrameRegion(reinterpret_cast<i::Address>(regs->pc))) {
     // The frame is not setup, so it'd be hard to iterate the stack. Bailout.
diff --git a/deps/v8/src/profiler/tracing-cpu-profiler.h b/deps/v8/src/profiler/tracing-cpu-profiler.h
index d7da209e2e..d5888f54a3 100644
--- a/deps/v8/src/profiler/tracing-cpu-profiler.h
+++ b/deps/v8/src/profiler/tracing-cpu-profiler.h
@@ -20,7 +20,7 @@ class TracingCpuProfilerImpl final
     : private v8::TracingController::TraceStateObserver {
  public:
   explicit TracingCpuProfilerImpl(Isolate*);
-  ~TracingCpuProfilerImpl();
+  ~TracingCpuProfilerImpl() override;
 
   // v8::TracingController::TraceStateObserver
   void OnTraceEnabled() final;
diff --git a/deps/v8/src/profiler/unbound-queue.h b/deps/v8/src/profiler/unbound-queue.h
index 0efe95abdf..547ac191b3 100644
--- a/deps/v8/src/profiler/unbound-queue.h
+++ b/deps/v8/src/profiler/unbound-queue.h
@@ -18,8 +18,8 @@ namespace internal {
 // elements, so producer never blocks.  Implemented after Herb
 // Sutter's article:
 // http://www.ddj.com/high-performance-computing/210604448
-template<typename Record>
-class UnboundQueue BASE_EMBEDDED {
+template <typename Record>
+class UnboundQueue {
  public:
   inline UnboundQueue();
   inline ~UnboundQueue();
diff --git a/deps/v8/src/property-details.h b/deps/v8/src/property-details.h
index 4968258860..1e953001eb 100644
--- a/deps/v8/src/property-details.h
+++ b/deps/v8/src/property-details.h
@@ -230,7 +230,7 @@ enum class PropertyCellConstantType {
 
 // PropertyDetails captures type and attributes for a property.
 // They are used both in property dictionaries and instance descriptors.
-class PropertyDetails BASE_EMBEDDED {
+class PropertyDetails {
  public:
   // Property details for dictionary mode properties/elements.
   PropertyDetails(PropertyKind kind, PropertyAttributes attributes,
diff --git a/deps/v8/src/property.cc b/deps/v8/src/property.cc
index 8e56dcf47e..5f41948cfd 100644
--- a/deps/v8/src/property.cc
+++ b/deps/v8/src/property.cc
@@ -25,7 +25,7 @@ std::ostream& operator<<(std::ostream& os,
 
 Descriptor::Descriptor() : details_(Smi::kZero) {}
 
-Descriptor::Descriptor(Handle<Name> key, MaybeObjectHandle value,
+Descriptor::Descriptor(Handle<Name> key, const MaybeObjectHandle& value,
                        PropertyKind kind, PropertyAttributes attributes,
                        PropertyLocation location, PropertyConstness constness,
                        Representation representation, int field_index)
@@ -37,7 +37,7 @@ Descriptor::Descriptor(Handle<Name> key, MaybeObjectHandle value,
   DCHECK_IMPLIES(key->IsPrivate(), !details_.IsEnumerable());
 }
 
-Descriptor::Descriptor(Handle<Name> key, MaybeObjectHandle value,
+Descriptor::Descriptor(Handle<Name> key, const MaybeObjectHandle& value,
                        PropertyDetails details)
     : key_(key), value_(value), details_(details) {
   DCHECK(key->IsUniqueName());
@@ -55,8 +55,8 @@ Descriptor Descriptor::DataField(Handle<Name> key, int field_index,
                                  PropertyAttributes attributes,
                                  PropertyConstness constness,
                                  Representation representation,
-                                 MaybeObjectHandle wrapped_field_type) {
-  DCHECK(wrapped_field_type->IsSmi() || wrapped_field_type->IsWeakHeapObject());
+                                 const MaybeObjectHandle& wrapped_field_type) {
+  DCHECK(wrapped_field_type->IsSmi() || wrapped_field_type->IsWeak());
   PropertyDetails details(kData, attributes, kField, constness, representation,
                           field_index);
   return Descriptor(key, wrapped_field_type, details);
diff --git a/deps/v8/src/property.h b/deps/v8/src/property.h
index 7a7d485bc3..276a5fd46a 100644
--- a/deps/v8/src/property.h
+++ b/deps/v8/src/property.h
@@ -22,7 +22,7 @@ namespace internal {
 // Each descriptor has a key, property attributes, property type,
 // property index (in the actual instance-descriptor array) and
 // optionally a piece of data.
-class Descriptor final BASE_EMBEDDED {
+class Descriptor final {
  public:
   Descriptor();
 
@@ -40,7 +40,7 @@ class Descriptor final BASE_EMBEDDED {
                               PropertyAttributes attributes,
                               PropertyConstness constness,
                               Representation representation,
-                              MaybeObjectHandle wrapped_field_type);
+                              const MaybeObjectHandle& wrapped_field_type);
 
   static Descriptor DataConstant(Handle<Name> key, Handle<Object> value,
                                  PropertyAttributes attributes);
@@ -58,13 +58,13 @@ class Descriptor final BASE_EMBEDDED {
   PropertyDetails details_;
 
  protected:
-  Descriptor(Handle<Name> key, MaybeObjectHandle value,
+  Descriptor(Handle<Name> key, const MaybeObjectHandle& value,
              PropertyDetails details);
 
-  Descriptor(Handle<Name> key, MaybeObjectHandle value, PropertyKind kind,
-             PropertyAttributes attributes, PropertyLocation location,
-             PropertyConstness constness, Representation representation,
-             int field_index);
+  Descriptor(Handle<Name> key, const MaybeObjectHandle& value,
+             PropertyKind kind, PropertyAttributes attributes,
+             PropertyLocation location, PropertyConstness constness,
+             Representation representation, int field_index);
 
   friend class MapUpdater;
 };
diff --git a/deps/v8/src/prototype.h b/deps/v8/src/prototype.h
index d09a6c82a6..e8fe06ac44 100644
--- a/deps/v8/src/prototype.h
+++ b/deps/v8/src/prototype.h
@@ -41,7 +41,7 @@ class PrototypeIterator {
   inline explicit PrototypeIterator(Isolate* isolate, Handle<Map> receiver_map,
                                     WhereToEnd where_to_end = END_AT_NULL);
 
-  ~PrototypeIterator() {}
+  ~PrototypeIterator() = default;
 
   inline bool HasAccess() const;
 
diff --git a/deps/v8/src/regexp/jsregexp.cc b/deps/v8/src/regexp/jsregexp.cc
index 3fdc3d98f5..64028d3927 100644
--- a/deps/v8/src/regexp/jsregexp.cc
+++ b/deps/v8/src/regexp/jsregexp.cc
@@ -2168,10 +2168,7 @@ static void EmitCharClass(RegExpMacroAssembler* macro_assembler,
   macro_assembler->Bind(&fall_through);
 }
 
-
-RegExpNode::~RegExpNode() {
-}
-
+RegExpNode::~RegExpNode() = default;
 
 RegExpNode::LimitResult RegExpNode::LimitVersions(RegExpCompiler* compiler,
                                                   Trace* trace) {
diff --git a/deps/v8/src/regexp/jsregexp.h b/deps/v8/src/regexp/jsregexp.h
index fd2a90521d..ee9d167aa2 100644
--- a/deps/v8/src/regexp/jsregexp.h
+++ b/deps/v8/src/regexp/jsregexp.h
@@ -592,9 +592,9 @@ class SeqRegExpNode: public RegExpNode {
       : RegExpNode(on_success->zone()), on_success_(on_success) { }
   RegExpNode* on_success() { return on_success_; }
   void set_on_success(RegExpNode* node) { on_success_ = node; }
-  virtual RegExpNode* FilterOneByte(int depth);
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start) {
+  RegExpNode* FilterOneByte(int depth) override;
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override {
     on_success_->FillInBMInfo(isolate, offset, budget - 1, bm, not_at_start);
     if (offset == 0) set_bm_info(not_at_start, bm);
   }
@@ -636,21 +636,22 @@ class ActionNode: public SeqRegExpNode {
                                      int repetition_register,
                                      int repetition_limit,
                                      RegExpNode* on_success);
-  virtual void Accept(NodeVisitor* visitor);
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int filled_in,
-                                    bool not_at_start) {
+  void Accept(NodeVisitor* visitor) override;
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int filled_in,
+                            bool not_at_start) override {
     return on_success()->GetQuickCheckDetails(
         details, compiler, filled_in, not_at_start);
   }
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start);
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override;
   ActionType action_type() { return action_type_; }
   // TODO(erikcorry): We should allow some action nodes in greedy loops.
-  virtual int GreedyLoopTextLength() { return kNodeIsTooComplexForGreedyLoops; }
+  int GreedyLoopTextLength() override {
+    return kNodeIsTooComplexForGreedyLoops;
+  }
 
  private:
   union {
@@ -714,23 +715,22 @@ class TextNode: public SeqRegExpNode {
                                           bool read_backward,
                                           RegExpNode* on_success,
                                           JSRegExp::Flags flags);
-  virtual void Accept(NodeVisitor* visitor);
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int characters_filled_in,
-                                    bool not_at_start);
+  void Accept(NodeVisitor* visitor) override;
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int characters_filled_in,
+                            bool not_at_start) override;
   ZoneList<TextElement>* elements() { return elms_; }
   bool read_backward() { return read_backward_; }
   void MakeCaseIndependent(Isolate* isolate, bool is_one_byte);
-  virtual int GreedyLoopTextLength();
-  virtual RegExpNode* GetSuccessorOfOmnivorousTextNode(
-      RegExpCompiler* compiler);
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start);
+  int GreedyLoopTextLength() override;
+  RegExpNode* GetSuccessorOfOmnivorousTextNode(
+      RegExpCompiler* compiler) override;
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override;
   void CalculateOffsets();
-  virtual RegExpNode* FilterOneByte(int depth);
+  RegExpNode* FilterOneByte(int depth) override;
 
  private:
   enum TextEmitPassType {
@@ -779,15 +779,14 @@ class AssertionNode: public SeqRegExpNode {
   static AssertionNode* AfterNewline(RegExpNode* on_success) {
     return new(on_success->zone()) AssertionNode(AFTER_NEWLINE, on_success);
   }
-  virtual void Accept(NodeVisitor* visitor);
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int filled_in,
-                                    bool not_at_start);
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start);
+  void Accept(NodeVisitor* visitor) override;
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int filled_in,
+                            bool not_at_start) override;
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override;
   AssertionType assertion_type() { return assertion_type_; }
 
  private:
@@ -811,22 +810,20 @@ class BackReferenceNode: public SeqRegExpNode {
         end_reg_(end_reg),
         flags_(flags),
         read_backward_(read_backward) {}
-  virtual void Accept(NodeVisitor* visitor);
+  void Accept(NodeVisitor* visitor) override;
   int start_register() { return start_reg_; }
   int end_register() { return end_reg_; }
   bool read_backward() { return read_backward_; }
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find,
-                          int recursion_depth,
-                          bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int characters_filled_in,
-                                    bool not_at_start) {
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int recursion_depth,
+                  bool not_at_start) override;
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int characters_filled_in,
+                            bool not_at_start) override {
     return;
   }
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start);
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override;
 
  private:
   int start_reg_;
@@ -840,20 +837,20 @@ class EndNode: public RegExpNode {
  public:
   enum Action { ACCEPT, BACKTRACK, NEGATIVE_SUBMATCH_SUCCESS };
   EndNode(Action action, Zone* zone) : RegExpNode(zone), action_(action) {}
-  virtual void Accept(NodeVisitor* visitor);
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find,
-                          int recursion_depth,
-                          bool not_at_start) { return 0; }
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int characters_filled_in,
-                                    bool not_at_start) {
+  void Accept(NodeVisitor* visitor) override;
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int recursion_depth,
+                  bool not_at_start) override {
+    return 0;
+  }
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int characters_filled_in,
+                            bool not_at_start) override {
     // Returning 0 from EatsAtLeast should ensure we never get here.
     UNREACHABLE();
   }
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start) {
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override {
     // Returning 0 from EatsAtLeast should ensure we never get here.
     UNREACHABLE();
   }
@@ -875,7 +872,7 @@ class NegativeSubmatchSuccess: public EndNode {
         current_position_register_(position_reg),
         clear_capture_count_(clear_capture_count),
         clear_capture_start_(clear_capture_start) { }
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
 
  private:
   int stack_pointer_register_;
@@ -930,24 +927,23 @@ class ChoiceNode: public RegExpNode {
         table_(nullptr),
         not_at_start_(false),
         being_calculated_(false) {}
-  virtual void Accept(NodeVisitor* visitor);
+  void Accept(NodeVisitor* visitor) override;
   void AddAlternative(GuardedAlternative node) {
     alternatives()->Add(node, zone());
   }
   ZoneList<GuardedAlternative>* alternatives() { return alternatives_; }
   DispatchTable* GetTable(bool ignore_case);
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
   int EatsAtLeastHelper(int still_to_find,
                         int budget,
                         RegExpNode* ignore_this_node,
                         bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int characters_filled_in,
-                                    bool not_at_start);
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start);
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int characters_filled_in,
+                            bool not_at_start) override;
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override;
 
   bool being_calculated() { return being_calculated_; }
   bool not_at_start() { return not_at_start_; }
@@ -956,7 +952,7 @@ class ChoiceNode: public RegExpNode {
   virtual bool try_to_emit_quick_check_for_alternative(bool is_first) {
     return true;
   }
-  virtual RegExpNode* FilterOneByte(int depth);
+  RegExpNode* FilterOneByte(int depth) override;
   virtual bool read_backward() { return false; }
 
  protected:
@@ -1009,13 +1005,12 @@ class NegativeLookaroundChoiceNode : public ChoiceNode {
     AddAlternative(this_must_fail);
     AddAlternative(then_do_this);
   }
-  virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int characters_filled_in,
-                                    bool not_at_start);
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start) {
+  int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int characters_filled_in,
+                            bool not_at_start) override;
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override {
     alternatives_->at(1).node()->FillInBMInfo(isolate, offset, budget - 1, bm,
                                               not_at_start);
     if (offset == 0) set_bm_info(not_at_start, bm);
@@ -1025,10 +1020,10 @@ class NegativeLookaroundChoiceNode : public ChoiceNode {
   // starts by loading enough characters for the alternative that takes fewest
   // characters, but on a negative lookahead the negative branch did not take
   // part in that calculation (EatsAtLeast) so the assumptions don't hold.
-  virtual bool try_to_emit_quick_check_for_alternative(bool is_first) {
+  bool try_to_emit_quick_check_for_alternative(bool is_first) override {
     return !is_first;
   }
-  virtual RegExpNode* FilterOneByte(int depth);
+  RegExpNode* FilterOneByte(int depth) override;
 };
 
 
@@ -1042,20 +1037,19 @@ class LoopChoiceNode: public ChoiceNode {
         read_backward_(read_backward) {}
   void AddLoopAlternative(GuardedAlternative alt);
   void AddContinueAlternative(GuardedAlternative alt);
-  virtual void Emit(RegExpCompiler* compiler, Trace* trace);
-  virtual int EatsAtLeast(int still_to_find,  int budget, bool not_at_start);
-  virtual void GetQuickCheckDetails(QuickCheckDetails* details,
-                                    RegExpCompiler* compiler,
-                                    int characters_filled_in,
-                                    bool not_at_start);
-  virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
-                            BoyerMooreLookahead* bm, bool not_at_start);
+  void Emit(RegExpCompiler* compiler, Trace* trace) override;
+  int EatsAtLeast(int still_to_find, int budget, bool not_at_start) override;
+  void GetQuickCheckDetails(QuickCheckDetails* details,
+                            RegExpCompiler* compiler, int characters_filled_in,
+                            bool not_at_start) override;
+  void FillInBMInfo(Isolate* isolate, int offset, int budget,
+                    BoyerMooreLookahead* bm, bool not_at_start) override;
   RegExpNode* loop_node() { return loop_node_; }
   RegExpNode* continue_node() { return continue_node_; }
   bool body_can_be_zero_length() { return body_can_be_zero_length_; }
-  virtual bool read_backward() { return read_backward_; }
-  virtual void Accept(NodeVisitor* visitor);
-  virtual RegExpNode* FilterOneByte(int depth);
+  bool read_backward() override { return read_backward_; }
+  void Accept(NodeVisitor* visitor) override;
+  RegExpNode* FilterOneByte(int depth) override;
 
  private:
   // AddAlternative is made private for loop nodes because alternatives
@@ -1404,7 +1398,7 @@ struct PreloadState {
 
 class NodeVisitor {
  public:
-  virtual ~NodeVisitor() { }
+  virtual ~NodeVisitor() = default;
 #define DECLARE_VISIT(Type)                                          \
   virtual void Visit##Type(Type##Node* that) = 0;
 FOR_EACH_NODE_TYPE(DECLARE_VISIT)
@@ -1466,11 +1460,10 @@ class Analysis: public NodeVisitor {
       : isolate_(isolate), is_one_byte_(is_one_byte), error_message_(nullptr) {}
   void EnsureAnalyzed(RegExpNode* node);
 
-#define DECLARE_VISIT(Type)                                          \
-  virtual void Visit##Type(Type##Node* that);
-FOR_EACH_NODE_TYPE(DECLARE_VISIT)
+#define DECLARE_VISIT(Type) void Visit##Type(Type##Node* that) override;
+  FOR_EACH_NODE_TYPE(DECLARE_VISIT)
 #undef DECLARE_VISIT
-  virtual void VisitLoopChoice(LoopChoiceNode* that);
+  void VisitLoopChoice(LoopChoiceNode* that) override;
 
   bool has_failed() { return error_message_ != nullptr; }
   const char* error_message() {
diff --git a/deps/v8/src/regexp/property-sequences.cc b/deps/v8/src/regexp/property-sequences.cc
new file mode 100644
index 0000000000..08194f1e70
--- /dev/null
+++ b/deps/v8/src/regexp/property-sequences.cc
@@ -0,0 +1,1115 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifdef V8_INTL_SUPPORT
+
+#include "src/regexp/property-sequences.h"
+
+namespace v8 {
+namespace internal {
+
+/*
+Generated from following Node.js source:
+
+package.json
+
+```
+{
+  "private": true,
+  "dependencies": {
+    "unicode-11.0.0": "^0.7.8"
+  }
+}
+```
+
+generate-unicode-sequence-property-data.js
+```
+const toHex = (symbol) => {
+  return '0x' + symbol.codePointAt(0).toString(16)
+                      .toUpperCase().padStart(6, '0');
+};
+
+```
+const generateData = (property) => {
+  const sequences =
+      require(`unicode-11.0.0/Sequence_Property/${ property }/index.js`);
+  const id = property.replace(/_/g, '') + 's';
+  const buffer = [];
+  for (const sequence of sequences) {
+    const symbols = [...sequence];
+    const codePoints = symbols.map(symbol => toHex(symbol));
+    buffer.push('    ' + codePoints.join(', ') + ', 0,');
+  }
+  const output =
+      `const uc32 UnicodePropertySequences::k${ id }[] = {\n` +
+      `${ buffer.join('\n') }\n0  // null-terminating the list\n};\n`;
+  return output;
+};
+
+const properties = [
+  'Emoji_Flag_Sequence',
+  'Emoji_Tag_Sequence',
+  'Emoji_ZWJ_Sequence',
+];
+
+for (const property of properties) {
+  console.log(generateData(property));
+}
+```
+*/
+
+const uc32 UnicodePropertySequences::kEmojiFlagSequences[] = {
+    0x01F1E6, 0x01F1E8, 0,
+    0x01F1FF, 0x01F1FC, 0,
+    0x01F1E6, 0x01F1EA, 0,
+    0x01F1E6, 0x01F1EB, 0,
+    0x01F1E6, 0x01F1EC, 0,
+    0x01F1E6, 0x01F1EE, 0,
+    0x01F1E6, 0x01F1F1, 0,
+    0x01F1E6, 0x01F1F2, 0,
+    0x01F1E6, 0x01F1F4, 0,
+    0x01F1E6, 0x01F1F6, 0,
+    0x01F1E6, 0x01F1F7, 0,
+    0x01F1E6, 0x01F1F8, 0,
+    0x01F1E6, 0x01F1F9, 0,
+    0x01F1E6, 0x01F1FA, 0,
+    0x01F1E6, 0x01F1FC, 0,
+    0x01F1E6, 0x01F1FD, 0,
+    0x01F1E6, 0x01F1FF, 0,
+    0x01F1E7, 0x01F1E6, 0,
+    0x01F1E7, 0x01F1E7, 0,
+    0x01F1E7, 0x01F1E9, 0,
+    0x01F1E7, 0x01F1EA, 0,
+    0x01F1E7, 0x01F1EB, 0,
+    0x01F1E7, 0x01F1EC, 0,
+    0x01F1E7, 0x01F1ED, 0,
+    0x01F1E7, 0x01F1EE, 0,
+    0x01F1E7, 0x01F1EF, 0,
+    0x01F1E7, 0x01F1F1, 0,
+    0x01F1E7, 0x01F1F2, 0,
+    0x01F1E7, 0x01F1F3, 0,
+    0x01F1E7, 0x01F1F4, 0,
+    0x01F1E7, 0x01F1F6, 0,
+    0x01F1E7, 0x01F1F7, 0,
+    0x01F1E7, 0x01F1F8, 0,
+    0x01F1E7, 0x01F1F9, 0,
+    0x01F1E7, 0x01F1FB, 0,
+    0x01F1E7, 0x01F1FC, 0,
+    0x01F1E7, 0x01F1FE, 0,
+    0x01F1E7, 0x01F1FF, 0,
+    0x01F1E8, 0x01F1E6, 0,
+    0x01F1E8, 0x01F1E8, 0,
+    0x01F1E8, 0x01F1E9, 0,
+    0x01F1E8, 0x01F1EB, 0,
+    0x01F1E8, 0x01F1EC, 0,
+    0x01F1E8, 0x01F1ED, 0,
+    0x01F1E8, 0x01F1EE, 0,
+    0x01F1E8, 0x01F1F0, 0,
+    0x01F1E8, 0x01F1F1, 0,
+    0x01F1E8, 0x01F1F2, 0,
+    0x01F1E8, 0x01F1F3, 0,
+    0x01F1E8, 0x01F1F4, 0,
+    0x01F1E8, 0x01F1F5, 0,
+    0x01F1E8, 0x01F1F7, 0,
+    0x01F1E8, 0x01F1FA, 0,
+    0x01F1E8, 0x01F1FB, 0,
+    0x01F1E8, 0x01F1FC, 0,
+    0x01F1E8, 0x01F1FD, 0,
+    0x01F1E8, 0x01F1FE, 0,
+    0x01F1E8, 0x01F1FF, 0,
+    0x01F1E9, 0x01F1EA, 0,
+    0x01F1E9, 0x01F1EC, 0,
+    0x01F1E9, 0x01F1EF, 0,
+    0x01F1E9, 0x01F1F0, 0,
+    0x01F1E9, 0x01F1F2, 0,
+    0x01F1E9, 0x01F1F4, 0,
+    0x01F1E9, 0x01F1FF, 0,
+    0x01F1EA, 0x01F1E6, 0,
+    0x01F1EA, 0x01F1E8, 0,
+    0x01F1EA, 0x01F1EA, 0,
+    0x01F1EA, 0x01F1EC, 0,
+    0x01F1EA, 0x01F1ED, 0,
+    0x01F1EA, 0x01F1F7, 0,
+    0x01F1EA, 0x01F1F8, 0,
+    0x01F1EA, 0x01F1F9, 0,
+    0x01F1EA, 0x01F1FA, 0,
+    0x01F1EB, 0x01F1EE, 0,
+    0x01F1EB, 0x01F1EF, 0,
+    0x01F1EB, 0x01F1F0, 0,
+    0x01F1EB, 0x01F1F2, 0,
+    0x01F1EB, 0x01F1F4, 0,
+    0x01F1EB, 0x01F1F7, 0,
+    0x01F1EC, 0x01F1E6, 0,
+    0x01F1EC, 0x01F1E7, 0,
+    0x01F1EC, 0x01F1E9, 0,
+    0x01F1EC, 0x01F1EA, 0,
+    0x01F1EC, 0x01F1EB, 0,
+    0x01F1EC, 0x01F1EC, 0,
+    0x01F1EC, 0x01F1ED, 0,
+    0x01F1EC, 0x01F1EE, 0,
+    0x01F1EC, 0x01F1F1, 0,
+    0x01F1EC, 0x01F1F2, 0,
+    0x01F1EC, 0x01F1F3, 0,
+    0x01F1EC, 0x01F1F5, 0,
+    0x01F1EC, 0x01F1F6, 0,
+    0x01F1EC, 0x01F1F7, 0,
+    0x01F1EC, 0x01F1F8, 0,
+    0x01F1EC, 0x01F1F9, 0,
+    0x01F1EC, 0x01F1FA, 0,
+    0x01F1EC, 0x01F1FC, 0,
+    0x01F1EC, 0x01F1FE, 0,
+    0x01F1ED, 0x01F1F0, 0,
+    0x01F1ED, 0x01F1F2, 0,
+    0x01F1ED, 0x01F1F3, 0,
+    0x01F1ED, 0x01F1F7, 0,
+    0x01F1ED, 0x01F1F9, 0,
+    0x01F1ED, 0x01F1FA, 0,
+    0x01F1EE, 0x01F1E8, 0,
+    0x01F1EE, 0x01F1E9, 0,
+    0x01F1EE, 0x01F1EA, 0,
+    0x01F1EE, 0x01F1F1, 0,
+    0x01F1EE, 0x01F1F2, 0,
+    0x01F1EE, 0x01F1F3, 0,
+    0x01F1EE, 0x01F1F4, 0,
+    0x01F1EE, 0x01F1F6, 0,
+    0x01F1EE, 0x01F1F7, 0,
+    0x01F1EE, 0x01F1F8, 0,
+    0x01F1EE, 0x01F1F9, 0,
+    0x01F1EF, 0x01F1EA, 0,
+    0x01F1EF, 0x01F1F2, 0,
+    0x01F1EF, 0x01F1F4, 0,
+    0x01F1EF, 0x01F1F5, 0,
+    0x01F1F0, 0x01F1EA, 0,
+    0x01F1F0, 0x01F1EC, 0,
+    0x01F1F0, 0x01F1ED, 0,
+    0x01F1F0, 0x01F1EE, 0,
+    0x01F1F0, 0x01F1F2, 0,
+    0x01F1F0, 0x01F1F3, 0,
+    0x01F1F0, 0x01F1F5, 0,
+    0x01F1F0, 0x01F1F7, 0,
+    0x01F1F0, 0x01F1FC, 0,
+    0x01F1E6, 0x01F1E9, 0,
+    0x01F1F0, 0x01F1FF, 0,
+    0x01F1F1, 0x01F1E6, 0,
+    0x01F1F1, 0x01F1E7, 0,
+    0x01F1F1, 0x01F1E8, 0,
+    0x01F1F1, 0x01F1EE, 0,
+    0x01F1F1, 0x01F1F0, 0,
+    0x01F1F1, 0x01F1F7, 0,
+    0x01F1F1, 0x01F1F8, 0,
+    0x01F1F1, 0x01F1F9, 0,
+    0x01F1F1, 0x01F1FA, 0,
+    0x01F1F1, 0x01F1FB, 0,
+    0x01F1F1, 0x01F1FE, 0,
+    0x01F1F2, 0x01F1E6, 0,
+    0x01F1F2, 0x01F1E8, 0,
+    0x01F1F2, 0x01F1E9, 0,
+    0x01F1F2, 0x01F1EA, 0,
+    0x01F1F2, 0x01F1EB, 0,
+    0x01F1F2, 0x01F1EC, 0,
+    0x01F1F2, 0x01F1ED, 0,
+    0x01F1F2, 0x01F1F0, 0,
+    0x01F1F2, 0x01F1F1, 0,
+    0x01F1F2, 0x01F1F2, 0,
+    0x01F1F2, 0x01F1F3, 0,
+    0x01F1F2, 0x01F1F4, 0,
+    0x01F1F2, 0x01F1F5, 0,
+    0x01F1F2, 0x01F1F6, 0,
+    0x01F1F2, 0x01F1F7, 0,
+    0x01F1F2, 0x01F1F8, 0,
+    0x01F1F2, 0x01F1F9, 0,
+    0x01F1F2, 0x01F1FA, 0,
+    0x01F1F2, 0x01F1FB, 0,
+    0x01F1F2, 0x01F1FC, 0,
+    0x01F1F2, 0x01F1FD, 0,
+    0x01F1F2, 0x01F1FE, 0,
+    0x01F1F2, 0x01F1FF, 0,
+    0x01F1F3, 0x01F1E6, 0,
+    0x01F1F3, 0x01F1E8, 0,
+    0x01F1F3, 0x01F1EA, 0,
+    0x01F1F3, 0x01F1EB, 0,
+    0x01F1F3, 0x01F1EC, 0,
+    0x01F1F3, 0x01F1EE, 0,
+    0x01F1F3, 0x01F1F1, 0,
+    0x01F1F3, 0x01F1F4, 0,
+    0x01F1F3, 0x01F1F5, 0,
+    0x01F1F3, 0x01F1F7, 0,
+    0x01F1F3, 0x01F1FA, 0,
+    0x01F1F3, 0x01F1FF, 0,
+    0x01F1F4, 0x01F1F2, 0,
+    0x01F1F5, 0x01F1E6, 0,
+    0x01F1F5, 0x01F1EA, 0,
+    0x01F1F5, 0x01F1EB, 0,
+    0x01F1F5, 0x01F1EC, 0,
+    0x01F1F5, 0x01F1ED, 0,
+    0x01F1F5, 0x01F1F0, 0,
+    0x01F1F5, 0x01F1F1, 0,
+    0x01F1F5, 0x01F1F2, 0,
+    0x01F1F5, 0x01F1F3, 0,
+    0x01F1F5, 0x01F1F7, 0,
+    0x01F1F5, 0x01F1F8, 0,
+    0x01F1F5, 0x01F1F9, 0,
+    0x01F1F5, 0x01F1FC, 0,
+    0x01F1F5, 0x01F1FE, 0,
+    0x01F1F6, 0x01F1E6, 0,
+    0x01F1F7, 0x01F1EA, 0,
+    0x01F1F7, 0x01F1F4, 0,
+    0x01F1F7, 0x01F1F8, 0,
+    0x01F1F7, 0x01F1FA, 0,
+    0x01F1F7, 0x01F1FC, 0,
+    0x01F1F8, 0x01F1E6, 0,
+    0x01F1F8, 0x01F1E7, 0,
+    0x01F1F8, 0x01F1E8, 0,
+    0x01F1F8, 0x01F1E9, 0,
+    0x01F1F8, 0x01F1EA, 0,
+    0x01F1F8, 0x01F1EC, 0,
+    0x01F1F8, 0x01F1ED, 0,
+    0x01F1F8, 0x01F1EE, 0,
+    0x01F1F8, 0x01F1EF, 0,
+    0x01F1F8, 0x01F1F0, 0,
+    0x01F1F8, 0x01F1F1, 0,
+    0x01F1F8, 0x01F1F2, 0,
+    0x01F1F8, 0x01F1F3, 0,
+    0x01F1F8, 0x01F1F4, 0,
+    0x01F1F8, 0x01F1F7, 0,
+    0x01F1F8, 0x01F1F8, 0,
+    0x01F1F8, 0x01F1F9, 0,
+    0x01F1F8, 0x01F1FB, 0,
+    0x01F1F8, 0x01F1FD, 0,
+    0x01F1F8, 0x01F1FE, 0,
+    0x01F1F8, 0x01F1FF, 0,
+    0x01F1F9, 0x01F1E6, 0,
+    0x01F1F9, 0x01F1E8, 0,
+    0x01F1F9, 0x01F1E9, 0,
+    0x01F1F9, 0x01F1EB, 0,
+    0x01F1F9, 0x01F1EC, 0,
+    0x01F1F9, 0x01F1ED, 0,
+    0x01F1F9, 0x01F1EF, 0,
+    0x01F1F9, 0x01F1F0, 0,
+    0x01F1F9, 0x01F1F1, 0,
+    0x01F1F9, 0x01F1F2, 0,
+    0x01F1F9, 0x01F1F3, 0,
+    0x01F1F9, 0x01F1F4, 0,
+    0x01F1F9, 0x01F1F7, 0,
+    0x01F1F9, 0x01F1F9, 0,
+    0x01F1F9, 0x01F1FB, 0,
+    0x01F1F9, 0x01F1FC, 0,
+    0x01F1F9, 0x01F1FF, 0,
+    0x01F1FA, 0x01F1E6, 0,
+    0x01F1FA, 0x01F1EC, 0,
+    0x01F1FA, 0x01F1F2, 0,
+    0x01F1FA, 0x01F1F3, 0,
+    0x01F1FA, 0x01F1F8, 0,
+    0x01F1FA, 0x01F1FE, 0,
+    0x01F1FA, 0x01F1FF, 0,
+    0x01F1FB, 0x01F1E6, 0,
+    0x01F1FB, 0x01F1E8, 0,
+    0x01F1FB, 0x01F1EA, 0,
+    0x01F1FB, 0x01F1EC, 0,
+    0x01F1FB, 0x01F1EE, 0,
+    0x01F1FB, 0x01F1F3, 0,
+    0x01F1FB, 0x01F1FA, 0,
+    0x01F1FC, 0x01F1EB, 0,
+    0x01F1FC, 0x01F1F8, 0,
+    0x01F1FD, 0x01F1F0, 0,
+    0x01F1FE, 0x01F1EA, 0,
+    0x01F1FE, 0x01F1F9, 0,
+    0x01F1FF, 0x01F1E6, 0,
+    0x01F1FF, 0x01F1F2, 0,
+    0x01F1F0, 0x01F1FE, 0,
+    0  // null-terminating the list
+};
+
+const uc32 UnicodePropertySequences::kEmojiTagSequences[] = {
+    0x01F3F4, 0x0E0067, 0x0E0062, 0x0E0065, 0x0E006E, 0x0E0067, 0x0E007F, 0,
+    0x01F3F4, 0x0E0067, 0x0E0062, 0x0E0073, 0x0E0063, 0x0E0074, 0x0E007F, 0,
+    0x01F3F4, 0x0E0067, 0x0E0062, 0x0E0077, 0x0E006C, 0x0E0073, 0x0E007F, 0,
+    0  // null-terminating the list
+};
+
+const uc32 UnicodePropertySequences::kEmojiZWJSequences[] = {
+    0x0026F9, 0x00FE0F, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x0026F9, 0x00FE0F, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x0026F9, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C3, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C3, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C3, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C4, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C4, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3C4, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CA, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CA, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CA, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CB, 0x00FE0F, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CB, 0x00FE0F, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CB, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CC, 0x00FE0F, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CC, 0x00FE0F, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F3CC, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F3F3, 0x00FE0F, 0x00200D, 0x01F308, 0,
+    0x01F3F4, 0x00200D, 0x002620, 0x00FE0F, 0,
+    0x01F441, 0x00FE0F, 0x00200D, 0x01F5E8, 0x00FE0F, 0,
+    0x01F468, 0x00200D, 0x002695, 0x00FE0F, 0,
+    0x01F468, 0x00200D, 0x002696, 0x00FE0F, 0,
+    0x01F468, 0x00200D, 0x002708, 0x00FE0F, 0,
+    0x01F468, 0x00200D, 0x002764, 0x00FE0F, 0x00200D, 0x01F468, 0,
+    0x01F468, 0x00200D, 0x002764, 0x00FE0F, 0x00200D, 0x01F48B, 0x00200D,
+        0x01F468, 0,
+    0x01F468, 0x00200D, 0x01F33E, 0,
+    0x01F468, 0x00200D, 0x01F373, 0,
+    0x01F468, 0x00200D, 0x01F393, 0,
+    0x01F468, 0x00200D, 0x01F3A4, 0,
+    0x01F468, 0x00200D, 0x01F3A8, 0,
+    0x01F468, 0x00200D, 0x01F3EB, 0,
+    0x01F468, 0x00200D, 0x01F3ED, 0,
+    0x01F468, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F466, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F467, 0,
+    0x01F468, 0x00200D, 0x01F467, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F467, 0x00200D, 0x01F467, 0,
+    0x01F468, 0x00200D, 0x01F468, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F468, 0x00200D, 0x01F466, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F468, 0x00200D, 0x01F467, 0,
+    0x01F468, 0x00200D, 0x01F468, 0x00200D, 0x01F467, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F468, 0x00200D, 0x01F467, 0x00200D, 0x01F467, 0,
+    0x01F468, 0x00200D, 0x01F469, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F469, 0x00200D, 0x01F466, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F469, 0x00200D, 0x01F467, 0,
+    0x01F468, 0x00200D, 0x01F469, 0x00200D, 0x01F467, 0x00200D, 0x01F466, 0,
+    0x01F468, 0x00200D, 0x01F469, 0x00200D, 0x01F467, 0x00200D, 0x01F467, 0,
+    0x01F468, 0x00200D, 0x01F4BB, 0,
+    0x01F468, 0x00200D, 0x01F4BC, 0,
+    0x01F468, 0x00200D, 0x01F527, 0,
+    0x01F468, 0x00200D, 0x01F52C, 0,
+    0x01F468, 0x00200D, 0x01F680, 0,
+    0x01F468, 0x00200D, 0x01F692, 0,
+    0x01F468, 0x00200D, 0x01F9B0, 0,
+    0x01F468, 0x00200D, 0x01F9B1, 0,
+    0x01F468, 0x00200D, 0x01F9B2, 0,
+    0x01F468, 0x00200D, 0x01F9B3, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x002695, 0x00FE0F, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x002696, 0x00FE0F, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x002708, 0x00FE0F, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F33E, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F373, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F393, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F3A4, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F3A8, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F3EB, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F3ED, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F4BB, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F4BC, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F527, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F52C, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F680, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F692, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F9B0, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F9B1, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F9B2, 0,
+    0x01F468, 0x01F3FB, 0x00200D, 0x01F9B3, 0,
+    0x01F468, 0x01F3FC, 0x00200D, 0x002695, 0x00FE0F, 0,
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+    0x01F937, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F938, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F938, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F938, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F938, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F938, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F938, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F938, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F938, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F938, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F938, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F938, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F938, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F939, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F939, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F939, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F939, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F939, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F939, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F939, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F939, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F939, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F939, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F939, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F939, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93C, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93C, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93D, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93D, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93D, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93E, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93E, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F93E, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B8, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B8, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B8, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B9, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B9, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9B9, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D6, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D6, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D6, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D7, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D7, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D7, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D8, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D8, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D8, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D9, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D9, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9D9, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DA, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DA, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DA, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DB, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DC, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FB, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FB, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FC, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FC, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FD, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FD, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DD, 0x01F3FF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DE, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DE, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0x01F9DF, 0x00200D, 0x002640, 0x00FE0F, 0,
+    0x01F9DF, 0x00200D, 0x002642, 0x00FE0F, 0,
+    0  // null-terminating the list
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTL_SUPPORT
diff --git a/deps/v8/src/regexp/property-sequences.h b/deps/v8/src/regexp/property-sequences.h
new file mode 100644
index 0000000000..52d8a855c5
--- /dev/null
+++ b/deps/v8/src/regexp/property-sequences.h
@@ -0,0 +1,28 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_REGEXP_PROPERTY_SEQUENCES_H_
+#define V8_REGEXP_PROPERTY_SEQUENCES_H_
+
+#ifdef V8_INTL_SUPPORT
+
+#include "src/globals.h"
+
+namespace v8 {
+namespace internal {
+
+class UnicodePropertySequences : public AllStatic {
+ public:
+  static const uc32 kEmojiFlagSequences[];
+
+  static const uc32 kEmojiTagSequences[];
+  static const uc32 kEmojiZWJSequences[];
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTL_SUPPORT
+
+#endif  // V8_REGEXP_PROPERTY_SEQUENCES_H_
diff --git a/deps/v8/src/regexp/regexp-ast.h b/deps/v8/src/regexp/regexp-ast.h
index 1a94832f71..9c39dda64e 100644
--- a/deps/v8/src/regexp/regexp-ast.h
+++ b/deps/v8/src/regexp/regexp-ast.h
@@ -37,10 +37,9 @@ class RegExpCompiler;
 class RegExpNode;
 class RegExpTree;
 
-
-class RegExpVisitor BASE_EMBEDDED {
+class RegExpVisitor {
  public:
-  virtual ~RegExpVisitor() {}
+  virtual ~RegExpVisitor() = default;
 #define MAKE_CASE(Name) \
   virtual void* Visit##Name(RegExp##Name*, void* data) = 0;
   FOR_EACH_REG_EXP_TREE_TYPE(MAKE_CASE)
@@ -137,8 +136,7 @@ class CharacterRange {
   uc32 to_;
 };
 
-
-class CharacterSet final BASE_EMBEDDED {
+class CharacterSet final {
  public:
   explicit CharacterSet(uc16 standard_set_type)
       : ranges_(nullptr), standard_set_type_(standard_set_type) {}
@@ -159,8 +157,7 @@ class CharacterSet final BASE_EMBEDDED {
   uc16 standard_set_type_;
 };
 
-
-class TextElement final BASE_EMBEDDED {
+class TextElement final {
  public:
   enum TextType { ATOM, CHAR_CLASS };
 
@@ -198,7 +195,7 @@ class TextElement final BASE_EMBEDDED {
 class RegExpTree : public ZoneObject {
  public:
   static const int kInfinity = kMaxInt;
-  virtual ~RegExpTree() {}
+  virtual ~RegExpTree() = default;
   virtual void* Accept(RegExpVisitor* visitor, void* data) = 0;
   virtual RegExpNode* ToNode(RegExpCompiler* compiler,
                              RegExpNode* on_success) = 0;
@@ -580,7 +577,7 @@ class RegExpBackReference final : public RegExpTree {
 
 class RegExpEmpty final : public RegExpTree {
  public:
-  RegExpEmpty() {}
+  RegExpEmpty() = default;
   void* Accept(RegExpVisitor* visitor, void* data) override;
   RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
   RegExpEmpty* AsEmpty() override;
diff --git a/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc b/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc
index d311a09e41..945c6927b5 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc
+++ b/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc
@@ -20,10 +20,7 @@ RegExpMacroAssemblerTracer::RegExpMacroAssemblerTracer(
   PrintF("RegExpMacroAssembler%s();\n", impl_names[type]);
 }
 
-
-RegExpMacroAssemblerTracer::~RegExpMacroAssemblerTracer() {
-}
-
+RegExpMacroAssemblerTracer::~RegExpMacroAssemblerTracer() = default;
 
 void RegExpMacroAssemblerTracer::AbortedCodeGeneration() {
   PrintF(" AbortedCodeGeneration\n");
diff --git a/deps/v8/src/regexp/regexp-macro-assembler-tracer.h b/deps/v8/src/regexp/regexp-macro-assembler-tracer.h
index 8a9ebe3683..d0b68bd59d 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler-tracer.h
+++ b/deps/v8/src/regexp/regexp-macro-assembler-tracer.h
@@ -14,71 +14,62 @@ namespace internal {
 class RegExpMacroAssemblerTracer: public RegExpMacroAssembler {
  public:
   RegExpMacroAssemblerTracer(Isolate* isolate, RegExpMacroAssembler* assembler);
-  virtual ~RegExpMacroAssemblerTracer();
-  virtual void AbortedCodeGeneration();
-  virtual int stack_limit_slack() { return assembler_->stack_limit_slack(); }
-  virtual bool CanReadUnaligned() { return assembler_->CanReadUnaligned(); }
-  virtual void AdvanceCurrentPosition(int by);  // Signed cp change.
-  virtual void AdvanceRegister(int reg, int by);  // r[reg] += by.
-  virtual void Backtrack();
-  virtual void Bind(Label* label);
-  virtual void CheckAtStart(Label* on_at_start);
-  virtual void CheckCharacter(unsigned c, Label* on_equal);
-  virtual void CheckCharacterAfterAnd(unsigned c,
-                                      unsigned and_with,
-                                      Label* on_equal);
-  virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
-  virtual void CheckCharacterLT(uc16 limit, Label* on_less);
-  virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
-  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
-  virtual void CheckNotBackReference(int start_reg, bool read_backward,
-                                     Label* on_no_match);
-  virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
-                                               Label* on_no_match);
-  virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
-  virtual void CheckNotCharacterAfterAnd(unsigned c,
-                                         unsigned and_with,
-                                         Label* on_not_equal);
-  virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
-                                              uc16 minus,
-                                              uc16 and_with,
-                                              Label* on_not_equal);
-  virtual void CheckCharacterInRange(uc16 from,
-                                     uc16 to,
-                                     Label* on_in_range);
-  virtual void CheckCharacterNotInRange(uc16 from,
-                                        uc16 to,
-                                        Label* on_not_in_range);
-  virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
-  virtual void CheckPosition(int cp_offset, Label* on_outside_input);
-  virtual bool CheckSpecialCharacterClass(uc16 type,
-                                          Label* on_no_match);
-  virtual void Fail();
-  virtual Handle<HeapObject> GetCode(Handle<String> source);
-  virtual void GoTo(Label* label);
-  virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
-  virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
-  virtual void IfRegisterEqPos(int reg, Label* if_eq);
-  virtual IrregexpImplementation Implementation();
-  virtual void LoadCurrentCharacter(int cp_offset,
-                                    Label* on_end_of_input,
-                                    bool check_bounds = true,
-                                    int characters = 1);
-  virtual void PopCurrentPosition();
-  virtual void PopRegister(int register_index);
-  virtual void PushBacktrack(Label* label);
-  virtual void PushCurrentPosition();
-  virtual void PushRegister(int register_index,
-                            StackCheckFlag check_stack_limit);
-  virtual void ReadCurrentPositionFromRegister(int reg);
-  virtual void ReadStackPointerFromRegister(int reg);
-  virtual void SetCurrentPositionFromEnd(int by);
-  virtual void SetRegister(int register_index, int to);
-  virtual bool Succeed();
-  virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
-  virtual void ClearRegisters(int reg_from, int reg_to);
-  virtual void WriteStackPointerToRegister(int reg);
+  ~RegExpMacroAssemblerTracer() override;
+  void AbortedCodeGeneration() override;
+  int stack_limit_slack() override { return assembler_->stack_limit_slack(); }
+  bool CanReadUnaligned() override { return assembler_->CanReadUnaligned(); }
+  void AdvanceCurrentPosition(int by) override;    // Signed cp change.
+  void AdvanceRegister(int reg, int by) override;  // r[reg] += by.
+  void Backtrack() override;
+  void Bind(Label* label) override;
+  void CheckAtStart(Label* on_at_start) override;
+  void CheckCharacter(unsigned c, Label* on_equal) override;
+  void CheckCharacterAfterAnd(unsigned c, unsigned and_with,
+                              Label* on_equal) override;
+  void CheckCharacterGT(uc16 limit, Label* on_greater) override;
+  void CheckCharacterLT(uc16 limit, Label* on_less) override;
+  void CheckGreedyLoop(Label* on_tos_equals_current_position) override;
+  void CheckNotAtStart(int cp_offset, Label* on_not_at_start) override;
+  void CheckNotBackReference(int start_reg, bool read_backward,
+                             Label* on_no_match) override;
+  void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
+                                       bool unicode,
+                                       Label* on_no_match) override;
+  void CheckNotCharacter(unsigned c, Label* on_not_equal) override;
+  void CheckNotCharacterAfterAnd(unsigned c, unsigned and_with,
+                                 Label* on_not_equal) override;
+  void CheckNotCharacterAfterMinusAnd(uc16 c, uc16 minus, uc16 and_with,
+                                      Label* on_not_equal) override;
+  void CheckCharacterInRange(uc16 from, uc16 to, Label* on_in_range) override;
+  void CheckCharacterNotInRange(uc16 from, uc16 to,
+                                Label* on_not_in_range) override;
+  void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) override;
+  void CheckPosition(int cp_offset, Label* on_outside_input) override;
+  bool CheckSpecialCharacterClass(uc16 type, Label* on_no_match) override;
+  void Fail() override;
+  Handle<HeapObject> GetCode(Handle<String> source) override;
+  void GoTo(Label* label) override;
+  void IfRegisterGE(int reg, int comparand, Label* if_ge) override;
+  void IfRegisterLT(int reg, int comparand, Label* if_lt) override;
+  void IfRegisterEqPos(int reg, Label* if_eq) override;
+  IrregexpImplementation Implementation() override;
+  void LoadCurrentCharacter(int cp_offset, Label* on_end_of_input,
+                            bool check_bounds = true,
+                            int characters = 1) override;
+  void PopCurrentPosition() override;
+  void PopRegister(int register_index) override;
+  void PushBacktrack(Label* label) override;
+  void PushCurrentPosition() override;
+  void PushRegister(int register_index,
+                    StackCheckFlag check_stack_limit) override;
+  void ReadCurrentPositionFromRegister(int reg) override;
+  void ReadStackPointerFromRegister(int reg) override;
+  void SetCurrentPositionFromEnd(int by) override;
+  void SetRegister(int register_index, int to) override;
+  bool Succeed() override;
+  void WriteCurrentPositionToRegister(int reg, int cp_offset) override;
+  void ClearRegisters(int reg_from, int reg_to) override;
+  void WriteStackPointerToRegister(int reg) override;
 
  private:
   RegExpMacroAssembler* assembler_;
diff --git a/deps/v8/src/regexp/regexp-macro-assembler.cc b/deps/v8/src/regexp/regexp-macro-assembler.cc
index 77e8847d68..24bd10c616 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler.cc
+++ b/deps/v8/src/regexp/regexp-macro-assembler.cc
@@ -23,10 +23,7 @@ RegExpMacroAssembler::RegExpMacroAssembler(Isolate* isolate, Zone* zone)
       isolate_(isolate),
       zone_(zone) {}
 
-
-RegExpMacroAssembler::~RegExpMacroAssembler() {
-}
-
+RegExpMacroAssembler::~RegExpMacroAssembler() = default;
 
 int RegExpMacroAssembler::CaseInsensitiveCompareUC16(Address byte_offset1,
                                                      Address byte_offset2,
@@ -117,10 +114,7 @@ NativeRegExpMacroAssembler::NativeRegExpMacroAssembler(Isolate* isolate,
                                                        Zone* zone)
     : RegExpMacroAssembler(isolate, zone) {}
 
-
-NativeRegExpMacroAssembler::~NativeRegExpMacroAssembler() {
-}
-
+NativeRegExpMacroAssembler::~NativeRegExpMacroAssembler() = default;
 
 bool NativeRegExpMacroAssembler::CanReadUnaligned() {
   return FLAG_enable_regexp_unaligned_accesses && !slow_safe();
diff --git a/deps/v8/src/regexp/regexp-macro-assembler.h b/deps/v8/src/regexp/regexp-macro-assembler.h
index 65da431568..e6bdd842c6 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler.h
+++ b/deps/v8/src/regexp/regexp-macro-assembler.h
@@ -212,8 +212,8 @@ class NativeRegExpMacroAssembler: public RegExpMacroAssembler {
   enum Result { RETRY = -2, EXCEPTION = -1, FAILURE = 0, SUCCESS = 1 };
 
   NativeRegExpMacroAssembler(Isolate* isolate, Zone* zone);
-  virtual ~NativeRegExpMacroAssembler();
-  virtual bool CanReadUnaligned();
+  ~NativeRegExpMacroAssembler() override;
+  bool CanReadUnaligned() override;
 
   static Result Match(Handle<Code> regexp,
                       Handle<String> subject,
diff --git a/deps/v8/src/regexp/regexp-parser.cc b/deps/v8/src/regexp/regexp-parser.cc
index c1d2c7d5cd..797424baf8 100644
--- a/deps/v8/src/regexp/regexp-parser.cc
+++ b/deps/v8/src/regexp/regexp-parser.cc
@@ -12,6 +12,7 @@
 #include "src/objects-inl.h"
 #include "src/ostreams.h"
 #include "src/regexp/jsregexp.h"
+#include "src/regexp/property-sequences.h"
 #include "src/utils.h"
 
 #ifdef V8_INTL_SUPPORT
@@ -344,13 +345,23 @@ RegExpTree* RegExpParser::ParseDisjunction() {
             if (unicode()) {
               ZoneList<CharacterRange>* ranges =
                   new (zone()) ZoneList<CharacterRange>(2, zone());
-              if (!ParsePropertyClass(ranges, p == 'P')) {
-                return ReportError(CStrVector("Invalid property name"));
+              std::vector<char> name_1, name_2;
+              if (ParsePropertyClassName(&name_1, &name_2)) {
+                if (AddPropertyClassRange(ranges, p == 'P', name_1, name_2)) {
+                  RegExpCharacterClass* cc = new (zone())
+                      RegExpCharacterClass(zone(), ranges, builder->flags());
+                  builder->AddCharacterClass(cc);
+                  break;
+                }
+                if (p == 'p' && name_2.empty()) {
+                  RegExpTree* sequence = GetPropertySequence(name_1);
+                  if (sequence != nullptr) {
+                    builder->AddAtom(sequence);
+                    break;
+                  }
+                }
               }
-              RegExpCharacterClass* cc = new (zone())
-                  RegExpCharacterClass(zone(), ranges, builder->flags());
-              builder->AddCharacterClass(cc);
-
+              return ReportError(CStrVector("Invalid property name"));
             } else {
               builder->AddCharacter(p);
             }
@@ -1346,8 +1357,10 @@ bool IsUnicodePropertyValueCharacter(char c) {
 
 }  // anonymous namespace
 
-bool RegExpParser::ParsePropertyClass(ZoneList<CharacterRange>* result,
-                                      bool negate) {
+bool RegExpParser::ParsePropertyClassName(std::vector<char>* name_1,
+                                          std::vector<char>* name_2) {
+  DCHECK(name_1->empty());
+  DCHECK(name_2->empty());
   // Parse the property class as follows:
   // - In \p{name}, 'name' is interpreted
   //   - either as a general category property value name.
@@ -1356,55 +1369,58 @@ bool RegExpParser::ParsePropertyClass(ZoneList<CharacterRange>* result,
   //   and 'value' is interpreted as one of the available property value names.
   // - Aliases in PropertyAlias.txt and PropertyValueAlias.txt can be used.
   // - Loose matching is not applied.
-  std::vector<char> first_part;
-  std::vector<char> second_part;
   if (current() == '{') {
     // Parse \p{[PropertyName=]PropertyNameValue}
     for (Advance(); current() != '}' && current() != '='; Advance()) {
       if (!IsUnicodePropertyValueCharacter(current())) return false;
       if (!has_next()) return false;
-      first_part.push_back(static_cast<char>(current()));
+      name_1->push_back(static_cast<char>(current()));
     }
     if (current() == '=') {
       for (Advance(); current() != '}'; Advance()) {
         if (!IsUnicodePropertyValueCharacter(current())) return false;
         if (!has_next()) return false;
-        second_part.push_back(static_cast<char>(current()));
+        name_2->push_back(static_cast<char>(current()));
       }
-      second_part.push_back(0);  // null-terminate string.
+      name_2->push_back(0);  // null-terminate string.
     }
   } else {
     return false;
   }
   Advance();
-  first_part.push_back(0);  // null-terminate string.
+  name_1->push_back(0);  // null-terminate string.
 
-  DCHECK(first_part.size() - 1 == std::strlen(first_part.data()));
-  DCHECK(second_part.empty() ||
-         second_part.size() - 1 == std::strlen(second_part.data()));
+  DCHECK(name_1->size() - 1 == std::strlen(name_1->data()));
+  DCHECK(name_2->empty() || name_2->size() - 1 == std::strlen(name_2->data()));
+  return true;
+}
 
-  if (second_part.empty()) {
+bool RegExpParser::AddPropertyClassRange(ZoneList<CharacterRange>* add_to,
+                                         bool negate,
+                                         const std::vector<char>& name_1,
+                                         const std::vector<char>& name_2) {
+  if (name_2.empty()) {
     // First attempt to interpret as general category property value name.
-    const char* name = first_part.data();
+    const char* name = name_1.data();
     if (LookupPropertyValueName(UCHAR_GENERAL_CATEGORY_MASK, name, negate,
-                                result, zone())) {
+                                add_to, zone())) {
       return true;
     }
     // Interpret "Any", "ASCII", and "Assigned".
-    if (LookupSpecialPropertyValueName(name, result, negate, zone())) {
+    if (LookupSpecialPropertyValueName(name, add_to, negate, zone())) {
       return true;
     }
     // Then attempt to interpret as binary property name with value name 'Y'.
     UProperty property = u_getPropertyEnum(name);
     if (!IsSupportedBinaryProperty(property)) return false;
     if (!IsExactPropertyAlias(name, property)) return false;
-    return LookupPropertyValueName(property, negate ? "N" : "Y", false, result,
+    return LookupPropertyValueName(property, negate ? "N" : "Y", false, add_to,
                                    zone());
   } else {
     // Both property name and value name are specified. Attempt to interpret
     // the property name as enumerated property.
-    const char* property_name = first_part.data();
-    const char* value_name = second_part.data();
+    const char* property_name = name_1.data();
+    const char* value_name = name_2.data();
     UProperty property = u_getPropertyEnum(property_name);
     if (!IsExactPropertyAlias(property_name, property)) return false;
     if (property == UCHAR_GENERAL_CATEGORY) {
@@ -1414,18 +1430,93 @@ bool RegExpParser::ParsePropertyClass(ZoneList<CharacterRange>* result,
                property != UCHAR_SCRIPT_EXTENSIONS) {
       return false;
     }
-    return LookupPropertyValueName(property, value_name, negate, result,
+    return LookupPropertyValueName(property, value_name, negate, add_to,
                                    zone());
   }
 }
 
+RegExpTree* RegExpParser::GetPropertySequence(const std::vector<char>& name_1) {
+  if (!FLAG_harmony_regexp_sequence) return nullptr;
+  const char* name = name_1.data();
+  const uc32* sequence_list = nullptr;
+  JSRegExp::Flags flags = JSRegExp::kUnicode;
+  if (NameEquals(name, "Emoji_Flag_Sequence")) {
+    sequence_list = UnicodePropertySequences::kEmojiFlagSequences;
+  } else if (NameEquals(name, "Emoji_Tag_Sequence")) {
+    sequence_list = UnicodePropertySequences::kEmojiTagSequences;
+  } else if (NameEquals(name, "Emoji_ZWJ_Sequence")) {
+    sequence_list = UnicodePropertySequences::kEmojiZWJSequences;
+  }
+  if (sequence_list != nullptr) {
+    // TODO(yangguo): this creates huge regexp code. Alternative to this is
+    // to create a new operator that checks for these sequences at runtime.
+    RegExpBuilder builder(zone(), flags);
+    while (true) {                   // Iterate through list of sequences.
+      while (*sequence_list != 0) {  // Iterate through sequence.
+        builder.AddUnicodeCharacter(*sequence_list);
+        sequence_list++;
+      }
+      sequence_list++;
+      if (*sequence_list == 0) break;
+      builder.NewAlternative();
+    }
+    return builder.ToRegExp();
+  }
+
+  if (NameEquals(name, "Emoji_Keycap_Sequence")) {
+    // https://unicode.org/reports/tr51/#def_emoji_keycap_sequence
+    // emoji_keycap_sequence := [0-9#*] \x{FE0F 20E3}
+    RegExpBuilder builder(zone(), flags);
+    ZoneList<CharacterRange>* prefix_ranges =
+        new (zone()) ZoneList<CharacterRange>(2, zone());
+    prefix_ranges->Add(CharacterRange::Range('0', '9'), zone());
+    prefix_ranges->Add(CharacterRange::Singleton('#'), zone());
+    prefix_ranges->Add(CharacterRange::Singleton('*'), zone());
+    builder.AddCharacterClass(
+        new (zone()) RegExpCharacterClass(zone(), prefix_ranges, flags));
+    builder.AddCharacter(0xFE0F);
+    builder.AddCharacter(0x20E3);
+    return builder.ToRegExp();
+  } else if (NameEquals(name, "Emoji_Modifier_Sequence")) {
+    // https://unicode.org/reports/tr51/#def_emoji_modifier_sequence
+    // emoji_modifier_sequence := emoji_modifier_base emoji_modifier
+    RegExpBuilder builder(zone(), flags);
+    ZoneList<CharacterRange>* modifier_base_ranges =
+        new (zone()) ZoneList<CharacterRange>(2, zone());
+    LookupPropertyValueName(UCHAR_EMOJI_MODIFIER_BASE, "Y", false,
+                            modifier_base_ranges, zone());
+    builder.AddCharacterClass(
+        new (zone()) RegExpCharacterClass(zone(), modifier_base_ranges, flags));
+    ZoneList<CharacterRange>* modifier_ranges =
+        new (zone()) ZoneList<CharacterRange>(2, zone());
+    LookupPropertyValueName(UCHAR_EMOJI_MODIFIER, "Y", false, modifier_ranges,
+                            zone());
+    builder.AddCharacterClass(
+        new (zone()) RegExpCharacterClass(zone(), modifier_ranges, flags));
+    return builder.ToRegExp();
+  }
+
+  return nullptr;
+}
+
 #else  // V8_INTL_SUPPORT
 
-bool RegExpParser::ParsePropertyClass(ZoneList<CharacterRange>* result,
-                                      bool negate) {
+bool RegExpParser::ParsePropertyClassName(std::vector<char>* name_1,
+                                          std::vector<char>* name_2) {
+  return false;
+}
+
+bool RegExpParser::AddPropertyClassRange(ZoneList<CharacterRange>* add_to,
+                                         bool negate,
+                                         const std::vector<char>& name_1,
+                                         const std::vector<char>& name_2) {
   return false;
 }
 
+RegExpTree* RegExpParser::GetPropertySequence(const std::vector<char>& name) {
+  return nullptr;
+}
+
 #endif  // V8_INTL_SUPPORT
 
 bool RegExpParser::ParseUnlimitedLengthHexNumber(int max_value, uc32* value) {
@@ -1591,7 +1682,9 @@ void RegExpParser::ParseClassEscape(ZoneList<CharacterRange>* ranges,
         if (unicode()) {
           bool negate = Next() == 'P';
           Advance(2);
-          if (!ParsePropertyClass(ranges, negate)) {
+          std::vector<char> name_1, name_2;
+          if (!ParsePropertyClassName(&name_1, &name_2) ||
+              !AddPropertyClassRange(ranges, negate, name_1, name_2)) {
             ReportError(CStrVector("Invalid property name in character class"));
           }
           *is_class_escape = true;
diff --git a/deps/v8/src/regexp/regexp-parser.h b/deps/v8/src/regexp/regexp-parser.h
index 56d4ac8599..799017bb1c 100644
--- a/deps/v8/src/regexp/regexp-parser.h
+++ b/deps/v8/src/regexp/regexp-parser.h
@@ -151,8 +151,7 @@ class RegExpBuilder : public ZoneObject {
 #endif
 };
 
-
-class RegExpParser BASE_EMBEDDED {
+class RegExpParser {
  public:
   RegExpParser(FlatStringReader* in, Handle<String>* error,
                JSRegExp::Flags flags, Isolate* isolate, Zone* zone);
@@ -177,7 +176,14 @@ class RegExpParser BASE_EMBEDDED {
   bool ParseHexEscape(int length, uc32* value);
   bool ParseUnicodeEscape(uc32* value);
   bool ParseUnlimitedLengthHexNumber(int max_value, uc32* value);
-  bool ParsePropertyClass(ZoneList<CharacterRange>* result, bool negate);
+
+  bool ParsePropertyClassName(std::vector<char>* name_1,
+                              std::vector<char>* name_2);
+  bool AddPropertyClassRange(ZoneList<CharacterRange>* add_to, bool negate,
+                             const std::vector<char>& name_1,
+                             const std::vector<char>& name_2);
+
+  RegExpTree* GetPropertySequence(const std::vector<char>& name_1);
   RegExpTree* ParseCharacterClass(const RegExpBuilder* state);
 
   uc32 ParseOctalLiteral();
diff --git a/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h b/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h
index 1cf2f73ac3..59d4b43397 100644
--- a/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h
+++ b/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h
@@ -19,74 +19,65 @@ class RegExpMacroAssemblerX64: public NativeRegExpMacroAssembler {
  public:
   RegExpMacroAssemblerX64(Isolate* isolate, Zone* zone, Mode mode,
                           int registers_to_save);
-  virtual ~RegExpMacroAssemblerX64();
-  virtual int stack_limit_slack();
-  virtual void AdvanceCurrentPosition(int by);
-  virtual void AdvanceRegister(int reg, int by);
-  virtual void Backtrack();
-  virtual void Bind(Label* label);
-  virtual void CheckAtStart(Label* on_at_start);
-  virtual void CheckCharacter(uint32_t c, Label* on_equal);
-  virtual void CheckCharacterAfterAnd(uint32_t c,
-                                      uint32_t mask,
-                                      Label* on_equal);
-  virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
-  virtual void CheckCharacterLT(uc16 limit, Label* on_less);
+  ~RegExpMacroAssemblerX64() override;
+  int stack_limit_slack() override;
+  void AdvanceCurrentPosition(int by) override;
+  void AdvanceRegister(int reg, int by) override;
+  void Backtrack() override;
+  void Bind(Label* label) override;
+  void CheckAtStart(Label* on_at_start) override;
+  void CheckCharacter(uint32_t c, Label* on_equal) override;
+  void CheckCharacterAfterAnd(uint32_t c, uint32_t mask,
+                              Label* on_equal) override;
+  void CheckCharacterGT(uc16 limit, Label* on_greater) override;
+  void CheckCharacterLT(uc16 limit, Label* on_less) override;
   // A "greedy loop" is a loop that is both greedy and with a simple
   // body. It has a particularly simple implementation.
-  virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
-  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
-  virtual void CheckNotBackReference(int start_reg, bool read_backward,
-                                     Label* on_no_match);
-  virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
-                                               Label* on_no_match);
-  virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
-  virtual void CheckNotCharacterAfterAnd(uint32_t c,
-                                         uint32_t mask,
-                                         Label* on_not_equal);
-  virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
-                                              uc16 minus,
-                                              uc16 mask,
-                                              Label* on_not_equal);
-  virtual void CheckCharacterInRange(uc16 from,
-                                     uc16 to,
-                                     Label* on_in_range);
-  virtual void CheckCharacterNotInRange(uc16 from,
-                                        uc16 to,
-                                        Label* on_not_in_range);
-  virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
+  void CheckGreedyLoop(Label* on_tos_equals_current_position) override;
+  void CheckNotAtStart(int cp_offset, Label* on_not_at_start) override;
+  void CheckNotBackReference(int start_reg, bool read_backward,
+                             Label* on_no_match) override;
+  void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
+                                       bool unicode,
+                                       Label* on_no_match) override;
+  void CheckNotCharacter(uint32_t c, Label* on_not_equal) override;
+  void CheckNotCharacterAfterAnd(uint32_t c, uint32_t mask,
+                                 Label* on_not_equal) override;
+  void CheckNotCharacterAfterMinusAnd(uc16 c, uc16 minus, uc16 mask,
+                                      Label* on_not_equal) override;
+  void CheckCharacterInRange(uc16 from, uc16 to, Label* on_in_range) override;
+  void CheckCharacterNotInRange(uc16 from, uc16 to,
+                                Label* on_not_in_range) override;
+  void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) override;
 
   // Checks whether the given offset from the current position is before
   // the end of the string.
-  virtual void CheckPosition(int cp_offset, Label* on_outside_input);
-  virtual bool CheckSpecialCharacterClass(uc16 type,
-                                          Label* on_no_match);
-  virtual void Fail();
-  virtual Handle<HeapObject> GetCode(Handle<String> source);
-  virtual void GoTo(Label* label);
-  virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
-  virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
-  virtual void IfRegisterEqPos(int reg, Label* if_eq);
-  virtual IrregexpImplementation Implementation();
-  virtual void LoadCurrentCharacter(int cp_offset,
-                                    Label* on_end_of_input,
-                                    bool check_bounds = true,
-                                    int characters = 1);
-  virtual void PopCurrentPosition();
-  virtual void PopRegister(int register_index);
-  virtual void PushBacktrack(Label* label);
-  virtual void PushCurrentPosition();
-  virtual void PushRegister(int register_index,
-                            StackCheckFlag check_stack_limit);
-  virtual void ReadCurrentPositionFromRegister(int reg);
-  virtual void ReadStackPointerFromRegister(int reg);
-  virtual void SetCurrentPositionFromEnd(int by);
-  virtual void SetRegister(int register_index, int to);
-  virtual bool Succeed();
-  virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
-  virtual void ClearRegisters(int reg_from, int reg_to);
-  virtual void WriteStackPointerToRegister(int reg);
+  void CheckPosition(int cp_offset, Label* on_outside_input) override;
+  bool CheckSpecialCharacterClass(uc16 type, Label* on_no_match) override;
+  void Fail() override;
+  Handle<HeapObject> GetCode(Handle<String> source) override;
+  void GoTo(Label* label) override;
+  void IfRegisterGE(int reg, int comparand, Label* if_ge) override;
+  void IfRegisterLT(int reg, int comparand, Label* if_lt) override;
+  void IfRegisterEqPos(int reg, Label* if_eq) override;
+  IrregexpImplementation Implementation() override;
+  void LoadCurrentCharacter(int cp_offset, Label* on_end_of_input,
+                            bool check_bounds = true,
+                            int characters = 1) override;
+  void PopCurrentPosition() override;
+  void PopRegister(int register_index) override;
+  void PushBacktrack(Label* label) override;
+  void PushCurrentPosition() override;
+  void PushRegister(int register_index,
+                    StackCheckFlag check_stack_limit) override;
+  void ReadCurrentPositionFromRegister(int reg) override;
+  void ReadStackPointerFromRegister(int reg) override;
+  void SetCurrentPositionFromEnd(int by) override;
+  void SetRegister(int register_index, int to) override;
+  bool Succeed() override;
+  void WriteCurrentPositionToRegister(int reg, int cp_offset) override;
+  void ClearRegisters(int reg_from, int reg_to) override;
+  void WriteStackPointerToRegister(int reg) override;
 
   static Result Match(Handle<Code> regexp,
                       Handle<String> subject,
diff --git a/deps/v8/src/register-configuration.h b/deps/v8/src/register-configuration.h
index 538c3331ec..46e2df79e9 100644
--- a/deps/v8/src/register-configuration.h
+++ b/deps/v8/src/register-configuration.h
@@ -144,7 +144,7 @@ class V8_EXPORT_PRIVATE RegisterConfiguration {
   bool AreAliases(MachineRepresentation rep, int index,
                   MachineRepresentation other_rep, int other_index) const;
 
-  virtual ~RegisterConfiguration() {}
+  virtual ~RegisterConfiguration() = default;
 
  private:
   const int num_general_registers_;
diff --git a/deps/v8/src/reloc-info.h b/deps/v8/src/reloc-info.h
index 53d52830a0..5f7071f845 100644
--- a/deps/v8/src/reloc-info.h
+++ b/deps/v8/src/reloc-info.h
@@ -341,7 +341,7 @@ class RelocInfo {
 
 // RelocInfoWriter serializes a stream of relocation info. It writes towards
 // lower addresses.
-class RelocInfoWriter BASE_EMBEDDED {
+class RelocInfoWriter {
  public:
   RelocInfoWriter() : pos_(nullptr), last_pc_(nullptr) {}
 
@@ -402,7 +402,6 @@ class RelocIterator : public Malloced {
                          Vector<const byte> reloc_info, Address const_pool,
                          int mode_mask = -1);
   RelocIterator(RelocIterator&&) = default;
-  RelocIterator& operator=(RelocIterator&&) = default;
 
   // Iteration
   bool done() const { return done_; }
diff --git a/deps/v8/src/roots-inl.h b/deps/v8/src/roots-inl.h
index 4caa9d8f0a..fc6f86c8be 100644
--- a/deps/v8/src/roots-inl.h
+++ b/deps/v8/src/roots-inl.h
@@ -8,89 +8,74 @@
 #include "src/roots.h"
 
 #include "src/heap/heap-inl.h"
-#include "src/objects/api-callbacks.h"
 
 namespace v8 {
-
 namespace internal {
 
-ReadOnlyRoots::ReadOnlyRoots(Isolate* isolate) : heap_(isolate->heap()) {}
+V8_INLINE bool operator<(RootIndex lhs, RootIndex rhs) {
+  typedef typename std::underlying_type<RootIndex>::type type;
+  return static_cast<type>(lhs) < static_cast<type>(rhs);
+}
+
+V8_INLINE RootIndex operator++(RootIndex& index) {
+  typedef typename std::underlying_type<RootIndex>::type type;
+  index = static_cast<RootIndex>(static_cast<type>(index) + 1);
+  return index;
+}
+
+ReadOnlyRoots::ReadOnlyRoots(Heap* heap) : roots_table_(heap->roots_table()) {}
 
-#define ROOT_ACCESSOR(type, name, camel_name)                              \
-  type* ReadOnlyRoots::name() {                                            \
-    return type::cast(heap_->roots_[Heap::k##camel_name##RootIndex]);      \
-  }                                                                        \
-  Handle<type> ReadOnlyRoots::name##_handle() {                            \
-    return Handle<type>(                                                   \
-        bit_cast<type**>(&heap_->roots_[Heap::k##camel_name##RootIndex])); \
+ReadOnlyRoots::ReadOnlyRoots(Isolate* isolate)
+    : roots_table_(isolate->heap()->roots_table()) {}
+
+#define ROOT_ACCESSOR(type, name, CamelName)                       \
+  type* ReadOnlyRoots::name() {                                    \
+    return type::cast(roots_table_[RootIndex::k##CamelName]);      \
+  }                                                                \
+  Handle<type> ReadOnlyRoots::name##_handle() {                    \
+    return Handle<type>(                                           \
+        bit_cast<type**>(&roots_table_[RootIndex::k##CamelName])); \
   }
-STRONG_READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
+
+READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
-#define STRING_ACCESSOR(name, str)                                     \
-  String* ReadOnlyRoots::name() {                                      \
-    return String::cast(heap_->roots_[Heap::k##name##RootIndex]);      \
-  }                                                                    \
-  Handle<String> ReadOnlyRoots::name##_handle() {                      \
-    return Handle<String>(                                             \
-        bit_cast<String**>(&heap_->roots_[Heap::k##name##RootIndex])); \
-  }
-INTERNALIZED_STRING_LIST(STRING_ACCESSOR)
-#undef STRING_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name)                                          \
-  Symbol* ReadOnlyRoots::name() {                                      \
-    return Symbol::cast(heap_->roots_[Heap::k##name##RootIndex]);      \
-  }                                                                    \
-  Handle<Symbol> ReadOnlyRoots::name##_handle() {                      \
-    return Handle<Symbol>(                                             \
-        bit_cast<Symbol**>(&heap_->roots_[Heap::k##name##RootIndex])); \
-  }
-PRIVATE_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name, description)                             \
-  Symbol* ReadOnlyRoots::name() {                                      \
-    return Symbol::cast(heap_->roots_[Heap::k##name##RootIndex]);      \
-  }                                                                    \
-  Handle<Symbol> ReadOnlyRoots::name##_handle() {                      \
-    return Handle<Symbol>(                                             \
-        bit_cast<Symbol**>(&heap_->roots_[Heap::k##name##RootIndex])); \
-  }
-PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR)
-WELL_KNOWN_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define STRUCT_MAP_ACCESSOR(NAME, Name, name)                          \
-  Map* ReadOnlyRoots::name##_map() {                                   \
-    return Map::cast(heap_->roots_[Heap::k##Name##MapRootIndex]);      \
-  }                                                                    \
-  Handle<Map> ReadOnlyRoots::name##_map_handle() {                     \
-    return Handle<Map>(                                                \
-        bit_cast<Map**>(&heap_->roots_[Heap::k##Name##MapRootIndex])); \
-  }
-STRUCT_LIST(STRUCT_MAP_ACCESSOR)
-#undef STRUCT_MAP_ACCESSOR
-
-#define ALLOCATION_SITE_MAP_ACCESSOR(NAME, Name, Size, name)                 \
-  Map* ReadOnlyRoots::name##_map() {                                         \
-    return Map::cast(heap_->roots_[Heap::k##Name##Size##MapRootIndex]);      \
-  }                                                                          \
-  Handle<Map> ReadOnlyRoots::name##_map_handle() {                           \
-    return Handle<Map>(                                                      \
-        bit_cast<Map**>(&heap_->roots_[Heap::k##Name##Size##MapRootIndex])); \
-  }
-ALLOCATION_SITE_LIST(ALLOCATION_SITE_MAP_ACCESSOR)
-#undef ALLOCATION_SITE_MAP_ACCESSOR
+Map* ReadOnlyRoots::MapForFixedTypedArray(ExternalArrayType array_type) {
+  RootIndex root_index = RootsTable::RootIndexForFixedTypedArray(array_type);
+  return Map::cast(roots_table_[root_index]);
+}
+
+Map* ReadOnlyRoots::MapForFixedTypedArray(ElementsKind elements_kind) {
+  RootIndex root_index = RootsTable::RootIndexForFixedTypedArray(elements_kind);
+  return Map::cast(roots_table_[root_index]);
+}
 
 FixedTypedArrayBase* ReadOnlyRoots::EmptyFixedTypedArrayForMap(const Map* map) {
-  // TODO(delphick): All of these empty fixed type arrays are in RO_SPACE so
-  // this the method below can be moved into ReadOnlyRoots.
-  return heap_->EmptyFixedTypedArrayForMap(map);
+  RootIndex root_index =
+      RootsTable::RootIndexForEmptyFixedTypedArray(map->elements_kind());
+  return FixedTypedArrayBase::cast(roots_table_[root_index]);
 }
 
-}  // namespace internal
+Object** RootsTable::read_only_roots_end() {
+// Enumerate the read-only roots into an expression of the form:
+// (root_1, root_2, root_3, ..., root_n)
+// This evaluates to root_n, but Clang warns that the other values in the list
+// are unused so suppress that warning.
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-value"
+#endif
+#define ROOT(type, name, CamelName) , RootIndex::k##CamelName
+  constexpr RootIndex kLastReadOnlyRoot =
+      (RootIndex::kFirstRoot READ_ONLY_ROOT_LIST(ROOT));
+#undef ROOT
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
+  return &roots_[static_cast<size_t>(kLastReadOnlyRoot) + 1];
+}
 
+}  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ROOTS_INL_H_
diff --git a/deps/v8/src/roots.cc b/deps/v8/src/roots.cc
new file mode 100644
index 0000000000..529d2ec472
--- /dev/null
+++ b/deps/v8/src/roots.cc
@@ -0,0 +1,54 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/roots.h"
+#include "src/elements-kind.h"
+
+namespace v8 {
+namespace internal {
+
+// static
+RootIndex RootsTable::RootIndexForFixedTypedArray(
+    ExternalArrayType array_type) {
+  switch (array_type) {
+#define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype) \
+  case kExternal##Type##Array:                            \
+    return RootIndex::kFixed##Type##ArrayMap;
+
+    TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX)
+#undef ARRAY_TYPE_TO_ROOT_INDEX
+  }
+  UNREACHABLE();
+}
+
+// static
+RootIndex RootsTable::RootIndexForFixedTypedArray(ElementsKind elements_kind) {
+  switch (elements_kind) {
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) \
+  case TYPE##_ELEMENTS:                           \
+    return RootIndex::kFixed##Type##ArrayMap;
+    TYPED_ARRAYS(TYPED_ARRAY_CASE)
+    default:
+      UNREACHABLE();
+#undef TYPED_ARRAY_CASE
+  }
+}
+
+// static
+RootIndex RootsTable::RootIndexForEmptyFixedTypedArray(
+    ElementsKind elements_kind) {
+  switch (elements_kind) {
+#define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype) \
+  case TYPE##_ELEMENTS:                                     \
+    return RootIndex::kEmptyFixed##Type##Array;
+
+    TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX)
+#undef ELEMENT_KIND_TO_ROOT_INDEX
+    default:
+      UNREACHABLE();
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/roots.h b/deps/v8/src/roots.h
index a15cdcea2a..fc2b155604 100644
--- a/deps/v8/src/roots.h
+++ b/deps/v8/src/roots.h
@@ -5,14 +5,24 @@
 #ifndef V8_ROOTS_H_
 #define V8_ROOTS_H_
 
+#include "src/accessors.h"
+#include "src/globals.h"
 #include "src/handles.h"
 #include "src/heap-symbols.h"
 #include "src/objects-definitions.h"
 
 namespace v8 {
-
 namespace internal {
 
+// Forward declarations.
+enum ElementsKind : uint8_t;
+class FixedTypedArrayBase;
+class Heap;
+class Isolate;
+class Map;
+class String;
+class Symbol;
+
 // Defines all the read-only roots in Heap.
 #define STRONG_READ_ONLY_ROOT_LIST(V)                                          \
   /* Cluster the most popular ones in a few cache lines here at the top.    */ \
@@ -64,6 +74,7 @@ namespace internal {
   V(Map, module_context_map, ModuleContextMap)                                 \
   V(Map, eval_context_map, EvalContextMap)                                     \
   V(Map, script_context_map, ScriptContextMap)                                 \
+  V(Map, await_context_map, AwaitContextMap)                                   \
   V(Map, block_context_map, BlockContextMap)                                   \
   V(Map, catch_context_map, CatchContextMap)                                   \
   V(Map, with_context_map, WithContextMap)                                     \
@@ -120,22 +131,23 @@ namespace internal {
   V(Map, external_string_with_one_byte_data_map,                               \
     ExternalStringWithOneByteDataMap)                                          \
   V(Map, external_one_byte_string_map, ExternalOneByteStringMap)               \
-  V(Map, short_external_string_map, ShortExternalStringMap)                    \
-  V(Map, short_external_string_with_one_byte_data_map,                         \
-    ShortExternalStringWithOneByteDataMap)                                     \
+  V(Map, uncached_external_string_map, UncachedExternalStringMap)              \
+  V(Map, uncached_external_string_with_one_byte_data_map,                      \
+    UncachedExternalStringWithOneByteDataMap)                                  \
   V(Map, internalized_string_map, InternalizedStringMap)                       \
   V(Map, external_internalized_string_map, ExternalInternalizedStringMap)      \
   V(Map, external_internalized_string_with_one_byte_data_map,                  \
     ExternalInternalizedStringWithOneByteDataMap)                              \
   V(Map, external_one_byte_internalized_string_map,                            \
     ExternalOneByteInternalizedStringMap)                                      \
-  V(Map, short_external_internalized_string_map,                               \
-    ShortExternalInternalizedStringMap)                                        \
-  V(Map, short_external_internalized_string_with_one_byte_data_map,            \
-    ShortExternalInternalizedStringWithOneByteDataMap)                         \
-  V(Map, short_external_one_byte_internalized_string_map,                      \
-    ShortExternalOneByteInternalizedStringMap)                                 \
-  V(Map, short_external_one_byte_string_map, ShortExternalOneByteStringMap)    \
+  V(Map, uncached_external_internalized_string_map,                            \
+    UncachedExternalInternalizedStringMap)                                     \
+  V(Map, uncached_external_internalized_string_with_one_byte_data_map,         \
+    UncachedExternalInternalizedStringWithOneByteDataMap)                      \
+  V(Map, uncached_external_one_byte_internalized_string_map,                   \
+    UncachedExternalOneByteInternalizedStringMap)                              \
+  V(Map, uncached_external_one_byte_string_map,                                \
+    UncachedExternalOneByteStringMap)                                          \
   /* Array element maps */                                                     \
   V(Map, fixed_uint8_array_map, FixedUint8ArrayMap)                            \
   V(Map, fixed_int8_array_map, FixedInt8ArrayMap)                              \
@@ -222,6 +234,7 @@ namespace internal {
   V(PropertyCell, promise_hook_protector, PromiseHookProtector)              \
   V(Cell, promise_resolve_protector, PromiseResolveProtector)                \
   V(PropertyCell, promise_then_protector, PromiseThenProtector)              \
+  V(PropertyCell, string_iterator_protector, StringIteratorProtector)        \
   /* Caches */                                                               \
   V(FixedArray, number_string_cache, NumberStringCache)                      \
   V(FixedArray, single_character_string_cache, SingleCharacterStringCache)   \
@@ -235,7 +248,7 @@ namespace internal {
   V(WeakArrayList, script_list, ScriptList)                                  \
   V(SimpleNumberDictionary, code_stubs, CodeStubs)                           \
   V(FixedArray, materialized_objects, MaterializedObjects)                   \
-  V(FixedArray, microtask_queue, MicrotaskQueue)                             \
+  V(MicrotaskQueue, default_microtask_queue, DefaultMicrotaskQueue)          \
   V(WeakArrayList, detached_contexts, DetachedContexts)                      \
   V(WeakArrayList, retaining_path_targets, RetainingPathTargets)             \
   V(WeakArrayList, retained_maps, RetainedMaps)                              \
@@ -249,11 +262,6 @@ namespace internal {
   V(FixedArray, serialized_objects, SerializedObjects)                       \
   V(FixedArray, serialized_global_proxy_sizes, SerializedGlobalProxySizes)   \
   V(TemplateList, message_listeners, MessageListeners)                       \
-  /* DeserializeLazy handlers for lazy bytecode deserialization */           \
-  V(Object, deserialize_lazy_handler, DeserializeLazyHandler)                \
-  V(Object, deserialize_lazy_handler_wide, DeserializeLazyHandlerWide)       \
-  V(Object, deserialize_lazy_handler_extra_wide,                             \
-    DeserializeLazyHandlerExtraWide)                                         \
   /* Hash seed */                                                            \
   V(ByteArray, hash_seed, HashSeed)                                          \
   /* JS Entries */                                                           \
@@ -261,10 +269,6 @@ namespace internal {
   V(Code, js_construct_entry_code, JsConstructEntryCode)                     \
   V(Code, js_run_microtasks_entry_code, JsRunMicrotasksEntryCode)
 
-#define STRONG_ROOT_LIST(V)     \
-  STRONG_READ_ONLY_ROOT_LIST(V) \
-  STRONG_MUTABLE_ROOT_LIST(V)
-
 // Entries in this list are limited to Smis and are not visited during GC.
 #define SMI_ROOT_LIST(V)                                                       \
   V(Smi, stack_limit, StackLimit)                                              \
@@ -281,69 +285,158 @@ namespace internal {
     ConstructStubInvokeDeoptPCOffset)                                          \
   V(Smi, interpreter_entry_return_pc_offset, InterpreterEntryReturnPCOffset)
 
-#define MUTABLE_ROOT_LIST(V)  \
-  STRONG_MUTABLE_ROOT_LIST(V) \
-  SMI_ROOT_LIST(V)            \
-  V(StringTable, string_table, StringTable)
+// Adapts one INTERNALIZED_STRING_LIST_GENERATOR entry to
+// the ROOT_LIST-compatible entry
+#define INTERNALIZED_STRING_LIST_ADAPTER(V, name, ...) V(String, name, name)
 
-#define ROOT_LIST(V)   \
-  MUTABLE_ROOT_LIST(V) \
-  STRONG_READ_ONLY_ROOT_LIST(V)
+// Produces (String, name, CamelCase) entries
+#define INTERNALIZED_STRING_ROOT_LIST(V) \
+  INTERNALIZED_STRING_LIST_GENERATOR(INTERNALIZED_STRING_LIST_ADAPTER, V)
 
-class FixedTypedArrayBase;
-class Heap;
-class Isolate;
-class Map;
-class String;
-class Symbol;
+// Adapts one XXX_SYMBOL_LIST_GENERATOR entry to the ROOT_LIST-compatible entry
+#define SYMBOL_ROOT_LIST_ADAPTER(V, name, ...) V(Symbol, name, name)
+
+// Produces (Symbol, name, CamelCase) entries
+#define PRIVATE_SYMBOL_ROOT_LIST(V) \
+  PRIVATE_SYMBOL_LIST_GENERATOR(SYMBOL_ROOT_LIST_ADAPTER, V)
+#define PUBLIC_SYMBOL_ROOT_LIST(V) \
+  PUBLIC_SYMBOL_LIST_GENERATOR(SYMBOL_ROOT_LIST_ADAPTER, V)
+#define WELL_KNOWN_SYMBOL_ROOT_LIST(V) \
+  WELL_KNOWN_SYMBOL_LIST_GENERATOR(SYMBOL_ROOT_LIST_ADAPTER, V)
+
+// Adapts one ACCESSOR_INFO_LIST_GENERATOR entry to the ROOT_LIST-compatible
+// entry
+#define ACCESSOR_INFO_ROOT_LIST_ADAPTER(V, name, CamelName, ...) \
+  V(AccessorInfo, name##_accessor, CamelName##Accessor)
+
+// Produces (AccessorInfo, name, CamelCase) entries
+#define ACCESSOR_INFO_ROOT_LIST(V) \
+  ACCESSOR_INFO_LIST_GENERATOR(ACCESSOR_INFO_ROOT_LIST_ADAPTER, V)
+
+#define READ_ONLY_ROOT_LIST(V)     \
+  STRONG_READ_ONLY_ROOT_LIST(V)    \
+  INTERNALIZED_STRING_ROOT_LIST(V) \
+  PRIVATE_SYMBOL_ROOT_LIST(V)      \
+  PUBLIC_SYMBOL_ROOT_LIST(V)       \
+  WELL_KNOWN_SYMBOL_ROOT_LIST(V)   \
+  STRUCT_MAPS_LIST(V)              \
+  ALLOCATION_SITE_MAPS_LIST(V)     \
+  DATA_HANDLER_MAPS_LIST(V)
+
+#define MUTABLE_ROOT_LIST(V)                \
+  STRONG_MUTABLE_ROOT_LIST(V)               \
+  ACCESSOR_INFO_ROOT_LIST(V)                \
+  V(StringTable, string_table, StringTable) \
+  SMI_ROOT_LIST(V)
+
+#define ROOT_LIST(V)     \
+  READ_ONLY_ROOT_LIST(V) \
+  MUTABLE_ROOT_LIST(V)
+
+// Declare all the root indices.  This defines the root list order.
+// clang-format off
+enum class RootIndex : uint16_t {
+#define DECL(type, name, CamelName) k##CamelName,
+  ROOT_LIST(DECL)
+#undef DECL
+
+  kRootListLength,
+
+  // Helper aliases for inclusive regions of root indices.
+  kFirstRoot = 0,
+  kLastRoot = kRootListLength - 1,
+
+  // kStringTable is not a strong root.
+  kFirstStrongRoot = kFirstRoot,
+  kLastStrongRoot = kStringTable - 1,
+
+  kFirstSmiRoot = kStringTable + 1,
+  kLastSmiRoot = kLastRoot
+};
+// clang-format on
+
+// Represents a storage of V8 heap roots.
+class RootsTable {
+ public:
+  static constexpr size_t kEntriesCount =
+      static_cast<size_t>(RootIndex::kRootListLength);
+
+  RootsTable() : roots_{} {}
+
+  bool IsRootHandleLocation(Object** handle_location, RootIndex* index) const {
+    if (handle_location >= &roots_[kEntriesCount]) return false;
+    if (handle_location < &roots_[0]) return false;
+    *index = static_cast<RootIndex>(handle_location - &roots_[0]);
+    return true;
+  }
+
+  template <typename T>
+  bool IsRootHandle(Handle<T> handle, RootIndex* index) const {
+    Object** handle_location = bit_cast<Object**>(handle.address());
+    return IsRootHandleLocation(handle_location, index);
+  }
+
+  Object* const& operator[](RootIndex root_index) const {
+    size_t index = static_cast<size_t>(root_index);
+    DCHECK_LT(index, kEntriesCount);
+    return roots_[index];
+  }
+
+  static RootIndex RootIndexForFixedTypedArray(ExternalArrayType array_type);
+  static RootIndex RootIndexForFixedTypedArray(ElementsKind elements_kind);
+  static RootIndex RootIndexForEmptyFixedTypedArray(ElementsKind elements_kind);
+
+ private:
+  Object** read_only_roots_begin() {
+    return &roots_[static_cast<size_t>(RootIndex::kFirstStrongRoot)];
+  }
+  inline Object** read_only_roots_end();
+
+  Object** strong_roots_begin() {
+    return &roots_[static_cast<size_t>(RootIndex::kFirstStrongRoot)];
+  }
+  Object** strong_roots_end() {
+    return &roots_[static_cast<size_t>(RootIndex::kLastStrongRoot) + 1];
+  }
+
+  Object** smi_roots_begin() {
+    return &roots_[static_cast<size_t>(RootIndex::kFirstSmiRoot)];
+  }
+  Object** smi_roots_end() {
+    return &roots_[static_cast<size_t>(RootIndex::kLastSmiRoot) + 1];
+  }
+
+  Object*& operator[](RootIndex root_index) {
+    size_t index = static_cast<size_t>(root_index);
+    DCHECK_LT(index, kEntriesCount);
+    return roots_[index];
+  }
+
+  Object* roots_[kEntriesCount];
+
+  friend class Heap;
+  friend class Factory;
+  friend class ReadOnlyRoots;
+};
 
 class ReadOnlyRoots {
  public:
-  explicit ReadOnlyRoots(Heap* heap) : heap_(heap) {}
-  inline explicit ReadOnlyRoots(Isolate* isolate);
+  V8_INLINE explicit ReadOnlyRoots(Heap* heap);
+  V8_INLINE explicit ReadOnlyRoots(Isolate* isolate);
+
+#define ROOT_ACCESSOR(type, name, CamelName) \
+  V8_INLINE class type* name();              \
+  V8_INLINE Handle<type> name##_handle();
 
-#define ROOT_ACCESSOR(type, name, camel_name) \
-  inline class type* name();                  \
-  inline Handle<type> name##_handle();
-  STRONG_READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
+  READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
-#define STRING_ACCESSOR(name, str) \
-  inline String* name();           \
-  inline Handle<String> name##_handle();
-  INTERNALIZED_STRING_LIST(STRING_ACCESSOR)
-#undef STRING_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name) \
-  inline Symbol* name();      \
-  inline Handle<Symbol> name##_handle();
-  PRIVATE_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-#define SYMBOL_ACCESSOR(name, description) \
-  inline Symbol* name();                   \
-  inline Handle<Symbol> name##_handle();
-  PUBLIC_SYMBOL_LIST(SYMBOL_ACCESSOR)
-  WELL_KNOWN_SYMBOL_LIST(SYMBOL_ACCESSOR)
-#undef SYMBOL_ACCESSOR
-
-// Utility type maps.
-#define STRUCT_MAP_ACCESSOR(NAME, Name, name) \
-  inline Map* name##_map();                   \
-  inline class Handle<Map> name##_map_handle();
-  STRUCT_LIST(STRUCT_MAP_ACCESSOR)
-#undef STRUCT_MAP_ACCESSOR
-
-#define ALLOCATION_SITE_MAP_ACCESSOR(NAME, Name, Size, name) \
-  inline Map* name##_map();                                  \
-  inline class Handle<Map> name##_map_handle();
-  ALLOCATION_SITE_LIST(ALLOCATION_SITE_MAP_ACCESSOR)
-#undef ALLOCATION_SITE_MAP_ACCESSOR
-
-  inline FixedTypedArrayBase* EmptyFixedTypedArrayForMap(const Map* map);
+  V8_INLINE Map* MapForFixedTypedArray(ExternalArrayType array_type);
+  V8_INLINE Map* MapForFixedTypedArray(ElementsKind elements_kind);
+  V8_INLINE FixedTypedArrayBase* EmptyFixedTypedArrayForMap(const Map* map);
 
  private:
-  Heap* heap_;
+  const RootsTable& roots_table_;
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/runtime/runtime-array.cc b/deps/v8/src/runtime/runtime-array.cc
index d72159b0ac..abe3883097 100644
--- a/deps/v8/src/runtime/runtime-array.cc
+++ b/deps/v8/src/runtime/runtime-array.cc
@@ -30,6 +30,16 @@ RUNTIME_FUNCTION(Runtime_TransitionElementsKind) {
   return *object;
 }
 
+RUNTIME_FUNCTION(Runtime_TransitionElementsKindWithKind) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Smi, elements_kind_smi, 1);
+  ElementsKind to_kind = static_cast<ElementsKind>(elements_kind_smi->value());
+  JSObject::TransitionElementsKind(object, to_kind);
+  return *object;
+}
+
 namespace {
 // Find the next free position. undefined and holes are both considered
 // free spots. Returns "Nothing" if an exception occurred.
@@ -313,7 +323,7 @@ Maybe<bool> ConditionalCopy(Isolate* isolate, Handle<JSReceiver> source,
 
   Handle<Object> source_element;
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
-      isolate, source_element, JSReceiver::GetElement(isolate, source, index),
+      isolate, source_element, JSReceiver::GetElement(isolate, target, index),
       Nothing<bool>());
 
   Handle<Object> set_result;
diff --git a/deps/v8/src/runtime/runtime-atomics.cc b/deps/v8/src/runtime/runtime-atomics.cc
index 972e48bae6..3fd07af255 100644
--- a/deps/v8/src/runtime/runtime-atomics.cc
+++ b/deps/v8/src/runtime/runtime-atomics.cc
@@ -17,10 +17,32 @@
 namespace v8 {
 namespace internal {
 
+// Other platforms have CSA support, see builtins-sharedarraybuffer-gen.h.
+#if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64 || \
+    V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
+
 namespace {
 
 #if V8_CC_GNU
 
+// GCC/Clang helpfully warn us that using 64-bit atomics on 32-bit platforms
+// can be slow. Good to know, but we don't have a choice.
+#ifdef V8_TARGET_ARCH_32_BIT
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Watomic-alignment"
+#endif  // V8_TARGET_ARCH_32_BIT
+
+template <typename T>
+inline T LoadSeqCst(T* p) {
+  return __atomic_load_n(p, __ATOMIC_SEQ_CST);
+}
+
+template <typename T>
+inline void StoreSeqCst(T* p, T value) {
+  __atomic_store_n(p, value, __ATOMIC_SEQ_CST);
+}
+
 template <typename T>
 inline T ExchangeSeqCst(T* p, T value) {
   return __atomic_exchange_n(p, value, __ATOMIC_SEQ_CST);
@@ -58,6 +80,10 @@ inline T XorSeqCst(T* p, T value) {
   return __atomic_fetch_xor(p, value, __ATOMIC_SEQ_CST);
 }
 
+#ifdef V8_TARGET_ARCH_32_BIT
+#pragma GCC diagnostic pop
+#endif  // V8_TARGET_ARCH_32_BIT
+
 #elif V8_CC_MSVC
 
 #define InterlockedExchange32 _InterlockedExchange
@@ -67,6 +93,7 @@ inline T XorSeqCst(T* p, T value) {
 #define InterlockedExchangeAdd16 _InterlockedExchangeAdd16
 #define InterlockedExchangeAdd8 _InterlockedExchangeAdd8
 #define InterlockedAnd32 _InterlockedAnd
+#define InterlockedOr64 _InterlockedOr64
 #define InterlockedOr32 _InterlockedOr
 #define InterlockedXor32 _InterlockedXor
 
@@ -107,6 +134,18 @@ ATOMIC_OPS(int16_t, 16, short)  /* NOLINT(runtime/int) */
 ATOMIC_OPS(uint16_t, 16, short) /* NOLINT(runtime/int) */
 ATOMIC_OPS(int32_t, 32, long)   /* NOLINT(runtime/int) */
 ATOMIC_OPS(uint32_t, 32, long)  /* NOLINT(runtime/int) */
+ATOMIC_OPS(int64_t, 64, __int64)
+ATOMIC_OPS(uint64_t, 64, __int64)
+
+template <typename T>
+inline T LoadSeqCst(T* p) {
+  UNREACHABLE();
+}
+
+template <typename T>
+inline void StoreSeqCst(T* p, T value) {
+  UNREACHABLE();
+}
 
 #undef ATOMIC_OPS
 
@@ -117,6 +156,7 @@ ATOMIC_OPS(uint32_t, 32, long)  /* NOLINT(runtime/int) */
 #undef InterlockedExchangeAdd16
 #undef InterlockedExchangeAdd8
 #undef InterlockedAnd32
+#undef InterlockedOr64
 #undef InterlockedOr32
 #undef InterlockedXor32
 
@@ -159,6 +199,15 @@ inline int32_t FromObject<int32_t>(Handle<Object> number) {
   return NumberToInt32(*number);
 }
 
+template <>
+inline uint64_t FromObject<uint64_t>(Handle<Object> bigint) {
+  return Handle<BigInt>::cast(bigint)->AsUint64();
+}
+
+template <>
+inline int64_t FromObject<int64_t>(Handle<Object> bigint) {
+  return Handle<BigInt>::cast(bigint)->AsInt64();
+}
 
 inline Object* ToObject(Isolate* isolate, int8_t t) { return Smi::FromInt(t); }
 
@@ -178,15 +227,42 @@ inline Object* ToObject(Isolate* isolate, uint32_t t) {
   return *isolate->factory()->NewNumber(t);
 }
 
-template <typename T>
-inline Object* DoExchange(Isolate* isolate, void* buffer, size_t index,
-                          Handle<Object> obj) {
-  T value = FromObject<T>(obj);
-  T result = ExchangeSeqCst(static_cast<T*>(buffer) + index, value);
-  return ToObject(isolate, result);
+inline Object* ToObject(Isolate* isolate, int64_t t) {
+  return *BigInt::FromInt64(isolate, t);
+}
+
+inline Object* ToObject(Isolate* isolate, uint64_t t) {
+  return *BigInt::FromUint64(isolate, t);
 }
 
 template <typename T>
+struct Load {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index) {
+    T result = LoadSeqCst(static_cast<T*>(buffer) + index);
+    return ToObject(isolate, result);
+  }
+};
+
+template <typename T>
+struct Store {
+  static inline void Do(Isolate* isolate, void* buffer, size_t index,
+                        Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    StoreSeqCst(static_cast<T*>(buffer) + index, value);
+  }
+};
+
+template <typename T>
+struct Exchange {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index,
+                           Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    T result = ExchangeSeqCst(static_cast<T*>(buffer) + index, value);
+    return ToObject(isolate, result);
+  }
+};
+
+template <typename T>
 inline Object* DoCompareExchange(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> oldobj, Handle<Object> newobj) {
   T oldval = FromObject<T>(oldobj);
@@ -197,44 +273,54 @@ inline Object* DoCompareExchange(Isolate* isolate, void* buffer, size_t index,
 }
 
 template <typename T>
-inline Object* DoAdd(Isolate* isolate, void* buffer, size_t index,
-                     Handle<Object> obj) {
-  T value = FromObject<T>(obj);
-  T result = AddSeqCst(static_cast<T*>(buffer) + index, value);
-  return ToObject(isolate, result);
-}
+struct Add {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index,
+                           Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    T result = AddSeqCst(static_cast<T*>(buffer) + index, value);
+    return ToObject(isolate, result);
+  }
+};
 
 template <typename T>
-inline Object* DoSub(Isolate* isolate, void* buffer, size_t index,
-                     Handle<Object> obj) {
-  T value = FromObject<T>(obj);
-  T result = SubSeqCst(static_cast<T*>(buffer) + index, value);
-  return ToObject(isolate, result);
-}
+struct Sub {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index,
+                           Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    T result = SubSeqCst(static_cast<T*>(buffer) + index, value);
+    return ToObject(isolate, result);
+  }
+};
 
 template <typename T>
-inline Object* DoAnd(Isolate* isolate, void* buffer, size_t index,
-                     Handle<Object> obj) {
-  T value = FromObject<T>(obj);
-  T result = AndSeqCst(static_cast<T*>(buffer) + index, value);
-  return ToObject(isolate, result);
-}
+struct And {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index,
+                           Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    T result = AndSeqCst(static_cast<T*>(buffer) + index, value);
+    return ToObject(isolate, result);
+  }
+};
 
 template <typename T>
-inline Object* DoOr(Isolate* isolate, void* buffer, size_t index,
-                    Handle<Object> obj) {
-  T value = FromObject<T>(obj);
-  T result = OrSeqCst(static_cast<T*>(buffer) + index, value);
-  return ToObject(isolate, result);
-}
+struct Or {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index,
+                           Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    T result = OrSeqCst(static_cast<T*>(buffer) + index, value);
+    return ToObject(isolate, result);
+  }
+};
 
 template <typename T>
-inline Object* DoXor(Isolate* isolate, void* buffer, size_t index,
-                     Handle<Object> obj) {
-  T value = FromObject<T>(obj);
-  T result = XorSeqCst(static_cast<T*>(buffer) + index, value);
-  return ToObject(isolate, result);
-}
+struct Xor {
+  static inline Object* Do(Isolate* isolate, void* buffer, size_t index,
+                           Handle<Object> obj) {
+    T value = FromObject<T>(obj);
+    T result = XorSeqCst(static_cast<T*>(buffer) + index, value);
+    return ToObject(isolate, result);
+  }
+};
 
 }  // anonymous namespace
 
@@ -248,22 +334,44 @@ inline Object* DoXor(Isolate* isolate, void* buffer, size_t index,
   V(Uint32, uint32, UINT32, uint32_t) \
   V(Int32, int32, INT32, int32_t)
 
-RUNTIME_FUNCTION(Runtime_AtomicsExchange) {
+// This is https://tc39.github.io/ecma262/#sec-getmodifysetvalueinbuffer
+// but also includes the ToInteger/ToBigInt conversion that's part of
+// https://tc39.github.io/ecma262/#sec-atomicreadmodifywrite
+template <template <typename> class Op>
+Object* GetModifySetValueInBuffer(Arguments args, Isolate* isolate) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
   CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value_obj, 2);
   CHECK(sta->GetBuffer()->is_shared());
-  CHECK_LT(index, NumberToSize(sta->length()));
 
   uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
+                    sta->byte_offset();
+
+  if (sta->type() >= kExternalBigInt64Array) {
+    Handle<BigInt> bigint;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, bigint,
+                                       BigInt::FromObject(isolate, value_obj));
+    // SharedArrayBuffers are not neuterable.
+    CHECK_LT(index, NumberToSize(sta->length()));
+    if (sta->type() == kExternalBigInt64Array) {
+      return Op<int64_t>::Do(isolate, source, index, bigint);
+    }
+    DCHECK(sta->type() == kExternalBigUint64Array);
+    return Op<uint64_t>::Do(isolate, source, index, bigint);
+  }
+
+  Handle<Object> value;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, value,
+                                     Object::ToInteger(isolate, value_obj));
+  // SharedArrayBuffers are not neuterable.
+  CHECK_LT(index, NumberToSize(sta->length()));
 
   switch (sta->type()) {
 #define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
   case kExternal##Type##Array:                        \
-    return DoExchange<ctype>(isolate, source, index, value);
+    return Op<ctype>::Do(isolate, source, index, value);
 
     INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
@@ -275,81 +383,104 @@ RUNTIME_FUNCTION(Runtime_AtomicsExchange) {
   UNREACHABLE();
 }
 
-RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange) {
+RUNTIME_FUNCTION(Runtime_AtomicsLoad64) {
   HandleScope scope(isolate);
-  DCHECK_EQ(4, args.length());
+  DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
   CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(oldobj, 2);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(newobj, 3);
   CHECK(sta->GetBuffer()->is_shared());
-  CHECK_LT(index, NumberToSize(sta->length()));
 
   uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
+                    sta->byte_offset();
 
-  switch (sta->type()) {
-#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
-  case kExternal##Type##Array:                        \
-    return DoCompareExchange<ctype>(isolate, source, index, oldobj, newobj);
-
-    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-
-    default:
-      break;
+  DCHECK(sta->type() == kExternalBigInt64Array ||
+         sta->type() == kExternalBigUint64Array);
+  // SharedArrayBuffers are not neuterable.
+  CHECK_LT(index, NumberToSize(sta->length()));
+  if (sta->type() == kExternalBigInt64Array) {
+    return Load<int64_t>::Do(isolate, source, index);
   }
-
-  UNREACHABLE();
+  DCHECK(sta->type() == kExternalBigUint64Array);
+  return Load<uint64_t>::Do(isolate, source, index);
 }
 
-// ES #sec-atomics.add
-// Atomics.add( typedArray, index, value )
-RUNTIME_FUNCTION(Runtime_AtomicsAdd) {
+RUNTIME_FUNCTION(Runtime_AtomicsStore64) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
   CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value_obj, 2);
   CHECK(sta->GetBuffer()->is_shared());
-  CHECK_LT(index, NumberToSize(sta->length()));
 
   uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
+                    sta->byte_offset();
 
-  switch (sta->type()) {
-#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
-  case kExternal##Type##Array:                        \
-    return DoAdd<ctype>(isolate, source, index, value);
+  Handle<BigInt> bigint;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, bigint,
+                                     BigInt::FromObject(isolate, value_obj));
 
-    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-
-    default:
-      break;
+  DCHECK(sta->type() == kExternalBigInt64Array ||
+         sta->type() == kExternalBigUint64Array);
+  // SharedArrayBuffers are not neuterable.
+  CHECK_LT(index, NumberToSize(sta->length()));
+  if (sta->type() == kExternalBigInt64Array) {
+    Store<int64_t>::Do(isolate, source, index, bigint);
+    return *bigint;
   }
+  DCHECK(sta->type() == kExternalBigUint64Array);
+  Store<uint64_t>::Do(isolate, source, index, bigint);
+  return *bigint;
+}
 
-  UNREACHABLE();
+RUNTIME_FUNCTION(Runtime_AtomicsExchange) {
+  return GetModifySetValueInBuffer<Exchange>(args, isolate);
 }
 
-// ES #sec-atomics.sub
-// Atomics.sub( typedArray, index, value )
-RUNTIME_FUNCTION(Runtime_AtomicsSub) {
+RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange) {
   HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
+  DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
   CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, old_value_obj, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, new_value_obj, 3);
   CHECK(sta->GetBuffer()->is_shared());
   CHECK_LT(index, NumberToSize(sta->length()));
 
   uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
+                    sta->byte_offset();
+
+  if (sta->type() >= kExternalBigInt64Array) {
+    Handle<BigInt> old_bigint;
+    Handle<BigInt> new_bigint;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, old_bigint, BigInt::FromObject(isolate, old_value_obj));
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, new_bigint, BigInt::FromObject(isolate, new_value_obj));
+    // SharedArrayBuffers are not neuterable.
+    CHECK_LT(index, NumberToSize(sta->length()));
+    if (sta->type() == kExternalBigInt64Array) {
+      return DoCompareExchange<int64_t>(isolate, source, index, old_bigint,
+                                        new_bigint);
+    }
+    DCHECK(sta->type() == kExternalBigUint64Array);
+    return DoCompareExchange<uint64_t>(isolate, source, index, old_bigint,
+                                       new_bigint);
+  }
+
+  Handle<Object> old_value;
+  Handle<Object> new_value;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, old_value,
+                                     Object::ToInteger(isolate, old_value_obj));
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, new_value,
+                                     Object::ToInteger(isolate, new_value_obj));
+  // SharedArrayBuffers are not neuterable.
+  CHECK_LT(index, NumberToSize(sta->length()));
 
   switch (sta->type()) {
-#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
-  case kExternal##Type##Array:                        \
-    return DoSub<ctype>(isolate, source, index, value);
+#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype)                  \
+  case kExternal##Type##Array:                                         \
+    return DoCompareExchange<ctype>(isolate, source, index, old_value, \
+                                    new_value);
 
     INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
@@ -361,94 +492,60 @@ RUNTIME_FUNCTION(Runtime_AtomicsSub) {
   UNREACHABLE();
 }
 
+// ES #sec-atomics.add
+// Atomics.add( typedArray, index, value )
+RUNTIME_FUNCTION(Runtime_AtomicsAdd) {
+  return GetModifySetValueInBuffer<Add>(args, isolate);
+}
+
+// ES #sec-atomics.sub
+// Atomics.sub( typedArray, index, value )
+RUNTIME_FUNCTION(Runtime_AtomicsSub) {
+  return GetModifySetValueInBuffer<Sub>(args, isolate);
+}
+
 // ES #sec-atomics.and
 // Atomics.and( typedArray, index, value )
 RUNTIME_FUNCTION(Runtime_AtomicsAnd) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
-  CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
-  CHECK(sta->GetBuffer()->is_shared());
-  CHECK_LT(index, NumberToSize(sta->length()));
-
-  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
-
-  switch (sta->type()) {
-#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
-  case kExternal##Type##Array:                        \
-    return DoAnd<ctype>(isolate, source, index, value);
-
-    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-
-    default:
-      break;
-  }
-
-  UNREACHABLE();
+  return GetModifySetValueInBuffer<And>(args, isolate);
 }
 
 // ES #sec-atomics.or
 // Atomics.or( typedArray, index, value )
 RUNTIME_FUNCTION(Runtime_AtomicsOr) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
-  CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
-  CHECK(sta->GetBuffer()->is_shared());
-  CHECK_LT(index, NumberToSize(sta->length()));
+  return GetModifySetValueInBuffer<Or>(args, isolate);
+}
 
-  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
+// ES #sec-atomics.xor
+// Atomics.xor( typedArray, index, value )
+RUNTIME_FUNCTION(Runtime_AtomicsXor) {
+  return GetModifySetValueInBuffer<Xor>(args, isolate);
+}
 
-  switch (sta->type()) {
-#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
-  case kExternal##Type##Array:                        \
-    return DoOr<ctype>(isolate, source, index, value);
+#undef INTEGER_TYPED_ARRAYS
 
-    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
+#else
 
-    default:
-      break;
-  }
+RUNTIME_FUNCTION(Runtime_AtomicsLoad64) { UNREACHABLE(); }
 
-  UNREACHABLE();
-}
+RUNTIME_FUNCTION(Runtime_AtomicsStore64) { UNREACHABLE(); }
 
-// ES #sec-atomics.xor
-// Atomics.xor( typedArray, index, value )
-RUNTIME_FUNCTION(Runtime_AtomicsXor) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
-  CONVERT_SIZE_ARG_CHECKED(index, 1);
-  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
-  CHECK(sta->GetBuffer()->is_shared());
-  CHECK_LT(index, NumberToSize(sta->length()));
+RUNTIME_FUNCTION(Runtime_AtomicsExchange) { UNREACHABLE(); }
 
-  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
-                    NumberToSize(sta->byte_offset());
+RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange) { UNREACHABLE(); }
 
-  switch (sta->type()) {
-#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
-  case kExternal##Type##Array:                        \
-    return DoXor<ctype>(isolate, source, index, value);
+RUNTIME_FUNCTION(Runtime_AtomicsAdd) { UNREACHABLE(); }
 
-    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
+RUNTIME_FUNCTION(Runtime_AtomicsSub) { UNREACHABLE(); }
 
-    default:
-      break;
-  }
+RUNTIME_FUNCTION(Runtime_AtomicsAnd) { UNREACHABLE(); }
 
-  UNREACHABLE();
-}
+RUNTIME_FUNCTION(Runtime_AtomicsOr) { UNREACHABLE(); }
 
-#undef INTEGER_TYPED_ARRAYS
+RUNTIME_FUNCTION(Runtime_AtomicsXor) { UNREACHABLE(); }
+
+#endif  // V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64
+        // || V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/runtime/runtime-classes.cc b/deps/v8/src/runtime/runtime-classes.cc
index d4fb0df3c3..0aea983f41 100644
--- a/deps/v8/src/runtime/runtime-classes.cc
+++ b/deps/v8/src/runtime/runtime-classes.cc
@@ -731,9 +731,9 @@ MaybeHandle<Object> StoreToSuper(Isolate* isolate, Handle<JSObject> home_object,
                                             SuperMode::kStore, name, 0),
                              Object);
   LookupIterator it(receiver, name, holder);
-  MAYBE_RETURN(Object::SetSuperProperty(&it, value, language_mode,
-                                        Object::CERTAINLY_NOT_STORE_FROM_KEYED),
-               MaybeHandle<Object>());
+  MAYBE_RETURN(
+      Object::SetSuperProperty(&it, value, language_mode, StoreOrigin::kNamed),
+      MaybeHandle<Object>());
   return value;
 }
 
@@ -750,7 +750,7 @@ MaybeHandle<Object> StoreElementToSuper(Isolate* isolate,
       Object);
   LookupIterator it(isolate, receiver, index, holder);
   MAYBE_RETURN(Object::SetSuperProperty(&it, value, language_mode,
-                                        Object::MAY_BE_STORE_FROM_KEYED),
+                                        StoreOrigin::kMaybeKeyed),
                MaybeHandle<Object>());
   return value;
 }
diff --git a/deps/v8/src/runtime/runtime-collections.cc b/deps/v8/src/runtime/runtime-collections.cc
index 6c64802963..03a24139f3 100644
--- a/deps/v8/src/runtime/runtime-collections.cc
+++ b/deps/v8/src/runtime/runtime-collections.cc
@@ -39,16 +39,6 @@ RUNTIME_FUNCTION(Runtime_SetShrink) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-RUNTIME_FUNCTION(Runtime_SetIteratorClone) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSSetIterator, holder, 0);
-  return *isolate->factory()->NewJSSetIterator(
-      handle(holder->map(), isolate),
-      handle(OrderedHashSet::cast(holder->table()), isolate),
-      Smi::ToInt(holder->index()));
-}
-
 RUNTIME_FUNCTION(Runtime_MapShrink) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -69,25 +59,6 @@ RUNTIME_FUNCTION(Runtime_MapGrow) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-RUNTIME_FUNCTION(Runtime_MapIteratorClone) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSMapIterator, holder, 0);
-  return *isolate->factory()->NewJSMapIterator(
-      handle(holder->map(), isolate),
-      handle(OrderedHashMap::cast(holder->table()), isolate),
-      Smi::ToInt(holder->index()));
-}
-
-RUNTIME_FUNCTION(Runtime_GetWeakMapEntries) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSWeakCollection, holder, 0);
-  CONVERT_NUMBER_CHECKED(int, max_entries, Int32, args[1]);
-  CHECK_GE(max_entries, 0);
-  return *JSWeakCollection::GetEntries(holder, max_entries);
-}
-
 RUNTIME_FUNCTION(Runtime_WeakCollectionDelete) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());
@@ -110,15 +81,6 @@ RUNTIME_FUNCTION(Runtime_WeakCollectionDelete) {
   return isolate->heap()->ToBoolean(was_present);
 }
 
-RUNTIME_FUNCTION(Runtime_GetWeakSetValues) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSWeakCollection, holder, 0);
-  CONVERT_NUMBER_CHECKED(int, max_values, Int32, args[1]);
-  CHECK_GE(max_values, 0);
-  return *JSWeakCollection::GetEntries(holder, max_values);
-}
-
 RUNTIME_FUNCTION(Runtime_WeakCollectionSet) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
diff --git a/deps/v8/src/runtime/runtime-date.cc b/deps/v8/src/runtime/runtime-date.cc
index e459da4da3..102f89ac14 100644
--- a/deps/v8/src/runtime/runtime-date.cc
+++ b/deps/v8/src/runtime/runtime-date.cc
@@ -14,13 +14,6 @@
 namespace v8 {
 namespace internal {
 
-RUNTIME_FUNCTION(Runtime_IsDate) {
-  SealHandleScope shs(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_CHECKED(Object, obj, 0);
-  return isolate->heap()->ToBoolean(obj->IsJSDate());
-}
-
 RUNTIME_FUNCTION(Runtime_DateCurrentTime) {
   HandleScope scope(isolate);
   DCHECK_EQ(0, args.length());
diff --git a/deps/v8/src/runtime/runtime-debug.cc b/deps/v8/src/runtime/runtime-debug.cc
index c1dc4ec9df..4381fa6dcf 100644
--- a/deps/v8/src/runtime/runtime-debug.cc
+++ b/deps/v8/src/runtime/runtime-debug.cc
@@ -450,8 +450,8 @@ RUNTIME_FUNCTION(Runtime_FunctionGetInferredName) {
 RUNTIME_FUNCTION(Runtime_CollectGarbage) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
-  isolate->heap()->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask,
-                                     GarbageCollectionReason::kRuntime);
+  isolate->heap()->PreciseCollectAllGarbage(Heap::kNoGCFlags,
+                                            GarbageCollectionReason::kRuntime);
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
@@ -641,11 +641,6 @@ RUNTIME_FUNCTION(Runtime_DebugPopPromise) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-RUNTIME_FUNCTION(Runtime_DebugIsActive) {
-  SealHandleScope shs(isolate);
-  return Smi::FromInt(isolate->debug()->is_active());
-}
-
 namespace {
 Handle<JSObject> MakeRangeObject(Isolate* isolate, const CoverageBlock& range) {
   Factory* factory = isolate->factory();
@@ -810,5 +805,19 @@ RUNTIME_FUNCTION(Runtime_LiveEditPatchScript) {
   }
   return ReadOnlyRoots(isolate).undefined_value();
 }
+
+RUNTIME_FUNCTION(Runtime_PerformSideEffectCheckForObject) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, object, 0);
+
+  DCHECK_EQ(isolate->debug_execution_mode(), DebugInfo::kSideEffects);
+  if (!isolate->debug()->PerformSideEffectCheckForObject(object)) {
+    DCHECK(isolate->has_pending_exception());
+    return ReadOnlyRoots(isolate).exception();
+  }
+  return ReadOnlyRoots(isolate).undefined_value();
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/runtime/runtime-function.cc b/deps/v8/src/runtime/runtime-function.cc
index 22f4a4fb48..769ccc528b 100644
--- a/deps/v8/src/runtime/runtime-function.cc
+++ b/deps/v8/src/runtime/runtime-function.cc
@@ -12,20 +12,6 @@
 namespace v8 {
 namespace internal {
 
-RUNTIME_FUNCTION(Runtime_FunctionGetName) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, function, 0);
-  if (function->IsJSBoundFunction()) {
-    RETURN_RESULT_OR_FAILURE(
-        isolate, JSBoundFunction::GetName(
-                     isolate, Handle<JSBoundFunction>::cast(function)));
-  } else {
-    return *JSFunction::GetName(isolate, Handle<JSFunction>::cast(function));
-  }
-}
-
 // TODO(5530): Remove once uses in debug.js are gone.
 RUNTIME_FUNCTION(Runtime_FunctionGetScriptSource) {
   HandleScope scope(isolate);
@@ -87,64 +73,6 @@ RUNTIME_FUNCTION(Runtime_FunctionIsAPIFunction) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_SetCode) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, target, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, source, 1);
-
-  Handle<SharedFunctionInfo> target_shared(target->shared(), isolate);
-  Handle<SharedFunctionInfo> source_shared(source->shared(), isolate);
-
-  if (!source->is_compiled() &&
-      !Compiler::Compile(source, Compiler::KEEP_EXCEPTION)) {
-    return ReadOnlyRoots(isolate).exception();
-  }
-
-  // Set the function data, scope info, formal parameter count, and the length
-  // of the target shared function info.
-  target_shared->set_function_data(source_shared->function_data());
-  target_shared->set_length(source_shared->GetLength());
-  target_shared->set_raw_outer_scope_info_or_feedback_metadata(
-      source_shared->raw_outer_scope_info_or_feedback_metadata());
-  target_shared->set_internal_formal_parameter_count(
-      source_shared->internal_formal_parameter_count());
-  bool was_native = target_shared->native();
-  target_shared->set_flags(source_shared->flags());
-  target_shared->set_native(was_native);
-  target_shared->set_scope_info(source_shared->scope_info());
-
-  Handle<Object> source_script(source_shared->script(), isolate);
-  int function_literal_id = source_shared->FunctionLiteralId(isolate);
-  if (source_script->IsScript()) {
-    SharedFunctionInfo::SetScript(source_shared,
-                                  isolate->factory()->undefined_value(),
-                                  function_literal_id);
-  }
-  SharedFunctionInfo::SetScript(target_shared, source_script,
-                                function_literal_id);
-
-  // Set the code of the target function.
-  target->set_code(source_shared->GetCode());
-  Handle<Context> context(source->context(), isolate);
-  target->set_context(*context);
-
-  // Make sure we get a fresh copy of the feedback vector to avoid cross
-  // context contamination, and that the feedback vector makes it's way into
-  // the target_shared optimized code map.
-  JSFunction::EnsureFeedbackVector(target);
-
-  if (isolate->logger()->is_listening_to_code_events() ||
-      isolate->is_profiling()) {
-    isolate->logger()->LogExistingFunction(
-        source_shared, handle(source_shared->abstract_code(), isolate));
-  }
-
-  return *target;
-}
-
-
 // Set the native flag on the function.
 // This is used to decide if we should transform null and undefined
 // into the global object when doing call and apply.
@@ -162,14 +90,6 @@ RUNTIME_FUNCTION(Runtime_SetNativeFlag) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_IsConstructor) {
-  SealHandleScope shs(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_CHECKED(Object, object, 0);
-  return isolate->heap()->ToBoolean(object->IsConstructor());
-}
-
-
 RUNTIME_FUNCTION(Runtime_Call) {
   HandleScope scope(isolate);
   DCHECK_LE(2, args.length());
diff --git a/deps/v8/src/runtime/runtime-futex.cc b/deps/v8/src/runtime/runtime-futex.cc
index 3c9a90fbbd..c891b6582c 100644
--- a/deps/v8/src/runtime/runtime-futex.cc
+++ b/deps/v8/src/runtime/runtime-futex.cc
@@ -23,12 +23,13 @@ RUNTIME_FUNCTION(Runtime_AtomicsNumWaitersForTesting) {
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
   CONVERT_SIZE_ARG_CHECKED(index, 1);
+  CHECK(!sta->WasNeutered());
   CHECK(sta->GetBuffer()->is_shared());
   CHECK_LT(index, NumberToSize(sta->length()));
   CHECK_EQ(sta->type(), kExternalInt32Array);
 
   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
-  size_t addr = (index << 2) + NumberToSize(sta->byte_offset());
+  size_t addr = (index << 2) + sta->byte_offset();
 
   return FutexEmulation::NumWaitersForTesting(array_buffer, addr);
 }
diff --git a/deps/v8/src/runtime/runtime-generator.cc b/deps/v8/src/runtime/runtime-generator.cc
index 636aa63879..9d652599c1 100644
--- a/deps/v8/src/runtime/runtime-generator.cc
+++ b/deps/v8/src/runtime/runtime-generator.cc
@@ -53,12 +53,6 @@ RUNTIME_FUNCTION(Runtime_GeneratorGetFunction) {
   return generator->function();
 }
 
-RUNTIME_FUNCTION(Runtime_GeneratorGetInputOrDebugPos) {
-  // Runtime call is implemented in InterpreterIntrinsics and lowered in
-  // JSIntrinsicLowering
-  UNREACHABLE();
-}
-
 RUNTIME_FUNCTION(Runtime_AsyncGeneratorResolve) {
   // Runtime call is implemented in InterpreterIntrinsics and lowered in
   // JSIntrinsicLowering
diff --git a/deps/v8/src/runtime/runtime-internal.cc b/deps/v8/src/runtime/runtime-internal.cc
index c98b27da27..8c227a1703 100644
--- a/deps/v8/src/runtime/runtime-internal.cc
+++ b/deps/v8/src/runtime/runtime-internal.cc
@@ -19,6 +19,7 @@
 #include "src/parsing/parsing.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/snapshot/snapshot.h"
+#include "src/string-builder-inl.h"
 
 namespace v8 {
 namespace internal {
@@ -343,6 +344,31 @@ bool ComputeLocation(Isolate* isolate, MessageLocation* target) {
   return false;
 }
 
+Handle<String> BuildDefaultCallSite(Isolate* isolate, Handle<Object> object) {
+  IncrementalStringBuilder builder(isolate);
+
+  builder.AppendString(Object::TypeOf(isolate, object));
+  if (object->IsString()) {
+    builder.AppendCString(" \"");
+    builder.AppendString(Handle<String>::cast(object));
+    builder.AppendCString("\"");
+  } else if (object->IsNull(isolate)) {
+    builder.AppendCString(" ");
+    builder.AppendString(isolate->factory()->null_string());
+  } else if (object->IsTrue(isolate)) {
+    builder.AppendCString(" ");
+    builder.AppendString(isolate->factory()->true_string());
+  } else if (object->IsFalse(isolate)) {
+    builder.AppendCString(" ");
+    builder.AppendString(isolate->factory()->false_string());
+  } else if (object->IsNumber()) {
+    builder.AppendCString(" ");
+    builder.AppendString(isolate->factory()->NumberToString(object));
+  }
+
+  return builder.Finish().ToHandleChecked();
+}
+
 Handle<String> RenderCallSite(Isolate* isolate, Handle<Object> object,
                               CallPrinter::ErrorHint* hint) {
   MessageLocation location;
@@ -358,7 +384,7 @@ Handle<String> RenderCallSite(Isolate* isolate, Handle<Object> object,
       isolate->clear_pending_exception();
     }
   }
-  return Object::TypeOf(isolate, object);
+  return BuildDefaultCallSite(isolate, object);
 }
 
 MessageTemplate::Template UpdateErrorTemplate(
@@ -388,11 +414,11 @@ MaybeHandle<Object> Runtime::ThrowIteratorError(Isolate* isolate,
                                                 Handle<Object> object) {
   CallPrinter::ErrorHint hint = CallPrinter::kNone;
   Handle<String> callsite = RenderCallSite(isolate, object, &hint);
-  MessageTemplate::Template id = MessageTemplate::kNonObjectPropertyLoad;
+  MessageTemplate::Template id = MessageTemplate::kNotIterableNoSymbolLoad;
 
   if (hint == CallPrinter::kNone) {
     Handle<Symbol> iterator_symbol = isolate->factory()->iterator_symbol();
-    THROW_NEW_ERROR(isolate, NewTypeError(id, iterator_symbol, callsite),
+    THROW_NEW_ERROR(isolate, NewTypeError(id, callsite, iterator_symbol),
                     Object);
   }
 
@@ -400,6 +426,14 @@ MaybeHandle<Object> Runtime::ThrowIteratorError(Isolate* isolate,
   THROW_NEW_ERROR(isolate, NewTypeError(id, callsite), Object);
 }
 
+RUNTIME_FUNCTION(Runtime_ThrowIteratorError) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  RETURN_RESULT_OR_FAILURE(isolate,
+                           Runtime::ThrowIteratorError(isolate, object));
+}
+
 RUNTIME_FUNCTION(Runtime_ThrowCalledNonCallable) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -476,6 +510,12 @@ RUNTIME_FUNCTION(Runtime_IncrementUseCounter) {
 
 RUNTIME_FUNCTION(Runtime_GetAndResetRuntimeCallStats) {
   HandleScope scope(isolate);
+
+  // Append any worker thread runtime call stats to the main table before
+  // printing.
+  isolate->counters()->worker_thread_runtime_call_stats()->AddToMainTable(
+      isolate->counters()->runtime_call_stats());
+
   if (args.length() == 0) {
     // Without arguments, the result is returned as a string.
     DCHECK_EQ(0, args.length());
@@ -591,5 +631,14 @@ RUNTIME_FUNCTION(Runtime_ReportMessage) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_GetInitializerFunction) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, constructor, 0);
+  Handle<Symbol> key = isolate->factory()->class_fields_symbol();
+  Handle<Object> initializer = JSReceiver::GetDataProperty(constructor, key);
+  return *initializer;
+}
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/runtime/runtime-interpreter.cc b/deps/v8/src/runtime/runtime-interpreter.cc
index 7f07d084a1..e87feac361 100644
--- a/deps/v8/src/runtime/runtime-interpreter.cc
+++ b/deps/v8/src/runtime/runtime-interpreter.cc
@@ -23,7 +23,6 @@ namespace internal {
 RUNTIME_FUNCTION(Runtime_InterpreterDeserializeLazy) {
   HandleScope scope(isolate);
 
-  DCHECK(FLAG_lazy_handler_deserialization);
   DCHECK(FLAG_lazy_deserialization);
   DCHECK_EQ(2, args.length());
   CONVERT_SMI_ARG_CHECKED(bytecode_int, 0);
diff --git a/deps/v8/src/runtime/runtime-intl.cc b/deps/v8/src/runtime/runtime-intl.cc
index ad75952824..32e7a46b6e 100644
--- a/deps/v8/src/runtime/runtime-intl.cc
+++ b/deps/v8/src/runtime/runtime-intl.cc
@@ -22,8 +22,10 @@
 #include "src/objects/intl-objects.h"
 #include "src/objects/js-array-inl.h"
 #include "src/objects/js-collator-inl.h"
+#include "src/objects/js-date-time-format-inl.h"
 #include "src/objects/js-list-format-inl.h"
 #include "src/objects/js-list-format.h"
+#include "src/objects/js-number-format-inl.h"
 #include "src/objects/js-plural-rules-inl.h"
 #include "src/objects/managed.h"
 #include "src/runtime/runtime-utils.h"
@@ -42,7 +44,6 @@
 #include "unicode/numfmt.h"
 #include "unicode/numsys.h"
 #include "unicode/plurrule.h"
-#include "unicode/rbbi.h"
 #include "unicode/smpdtfmt.h"
 #include "unicode/timezone.h"
 #include "unicode/uchar.h"
@@ -77,40 +78,6 @@ RUNTIME_FUNCTION(Runtime_FormatListToParts) {
       isolate, JSListFormat::FormatListToParts(isolate, list_format, list));
 }
 
-RUNTIME_FUNCTION(Runtime_GetNumberOption) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(5, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, options, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, property, 1);
-  CONVERT_SMI_ARG_CHECKED(min, 2);
-  CONVERT_SMI_ARG_CHECKED(max, 3);
-  CONVERT_SMI_ARG_CHECKED(fallback, 4);
-
-  Maybe<int> num =
-      Intl::GetNumberOption(isolate, options, property, min, max, fallback);
-  if (num.IsNothing()) {
-    return ReadOnlyRoots(isolate).exception();
-  }
-  return Smi::FromInt(num.FromJust());
-}
-
-RUNTIME_FUNCTION(Runtime_DefaultNumberOption) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(5, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, value, 0);
-  CONVERT_SMI_ARG_CHECKED(min, 1);
-  CONVERT_SMI_ARG_CHECKED(max, 2);
-  CONVERT_SMI_ARG_CHECKED(fallback, 3);
-  CONVERT_ARG_HANDLE_CHECKED(String, property, 4);
-
-  Maybe<int> num =
-      Intl::DefaultNumberOption(isolate, value, min, max, fallback, property);
-  if (num.IsNothing()) {
-    return ReadOnlyRoots(isolate).exception();
-  }
-  return Smi::FromInt(num.FromJust());
-}
-
 // ECMA 402 6.2.3
 RUNTIME_FUNCTION(Runtime_CanonicalizeLanguageTag) {
   HandleScope scope(isolate);
@@ -143,340 +110,6 @@ RUNTIME_FUNCTION(Runtime_GetDefaultICULocale) {
       Intl::DefaultLocale(isolate).c_str());
 }
 
-RUNTIME_FUNCTION(Runtime_IsWellFormedCurrencyCode) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(String, currency, 0);
-  return *(isolate->factory()->ToBoolean(
-      Intl::IsWellFormedCurrencyCode(isolate, currency)));
-}
-
-RUNTIME_FUNCTION(Runtime_DefineWEProperty) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(3, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, target, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
-  Intl::DefineWEProperty(isolate, target, key, value);
-  return ReadOnlyRoots(isolate).undefined_value();
-}
-
-RUNTIME_FUNCTION(Runtime_IsInitializedIntlObjectOfType) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(2, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
-  CONVERT_SMI_ARG_CHECKED(expected_type_int, 1);
-
-  Intl::Type expected_type = Intl::TypeFromInt(expected_type_int);
-
-  return isolate->heap()->ToBoolean(
-      Intl::IsObjectOfType(isolate, input, expected_type));
-}
-
-RUNTIME_FUNCTION(Runtime_MarkAsInitializedIntlObjectOfType) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(2, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, input, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Smi, type, 1);
-
-#ifdef DEBUG
-  // TypeFromSmi does correctness checks.
-  Intl::Type type_intl = Intl::TypeFromSmi(*type);
-  USE(type_intl);
-#endif
-
-  Handle<Symbol> marker = isolate->factory()->intl_initialized_marker_symbol();
-  JSObject::SetProperty(isolate, input, marker, type, LanguageMode::kStrict)
-      .Assert();
-
-  return ReadOnlyRoots(isolate).undefined_value();
-}
-
-RUNTIME_FUNCTION(Runtime_CreateDateTimeFormat) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(3, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(String, locale, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, options, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, resolved, 2);
-
-  Handle<JSFunction> constructor(
-      isolate->native_context()->intl_date_time_format_function(), isolate);
-
-  Handle<JSObject> local_object;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, local_object,
-                                     JSObject::New(constructor, constructor));
-
-  // Set date time formatter as embedder field of the resulting JS object.
-  icu::SimpleDateFormat* date_format =
-      DateFormat::InitializeDateTimeFormat(isolate, locale, options, resolved);
-  CHECK_NOT_NULL(date_format);
-
-  local_object->SetEmbedderField(DateFormat::kSimpleDateFormatIndex,
-                                 reinterpret_cast<Smi*>(date_format));
-
-  // Make object handle weak so we can delete the data format once GC kicks in.
-  Handle<Object> wrapper = isolate->global_handles()->Create(*local_object);
-  GlobalHandles::MakeWeak(wrapper.location(), wrapper.location(),
-                          DateFormat::DeleteDateFormat,
-                          WeakCallbackType::kInternalFields);
-  return *local_object;
-}
-
-RUNTIME_FUNCTION(Runtime_CreateNumberFormat) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(3, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(String, locale, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, options, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, resolved, 2);
-  RETURN_RESULT_OR_FAILURE(
-      isolate, Intl::CreateNumberFormat(isolate, locale, options, resolved));
-}
-
-RUNTIME_FUNCTION(Runtime_CurrencyDigits) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(String, currency, 0);
-  return *Intl::CurrencyDigits(isolate, currency);
-}
-
-RUNTIME_FUNCTION(Runtime_CollatorResolvedOptions) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, collator_obj, 0);
-
-  // 3. If pr does not have an [[InitializedCollator]] internal
-  // slot, throw a TypeError exception.
-  if (!collator_obj->IsJSCollator()) {
-    Handle<String> method_str = isolate->factory()->NewStringFromStaticChars(
-        "Intl.Collator.prototype.resolvedOptions");
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                              method_str, collator_obj));
-  }
-
-  Handle<JSCollator> collator = Handle<JSCollator>::cast(collator_obj);
-
-  return *JSCollator::ResolvedOptions(isolate, collator);
-}
-
-RUNTIME_FUNCTION(Runtime_PluralRulesResolvedOptions) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, plural_rules_obj, 0);
-
-  // 3. If pr does not have an [[InitializedPluralRules]] internal
-  // slot, throw a TypeError exception.
-  if (!plural_rules_obj->IsJSPluralRules()) {
-    Handle<String> method_str = isolate->factory()->NewStringFromStaticChars(
-        "Intl.PluralRules.prototype.resolvedOptions");
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                              method_str, plural_rules_obj));
-  }
-
-  Handle<JSPluralRules> plural_rules =
-      Handle<JSPluralRules>::cast(plural_rules_obj);
-
-  return *JSPluralRules::ResolvedOptions(isolate, plural_rules);
-}
-
-RUNTIME_FUNCTION(Runtime_ParseExtension) {
-  Factory* factory = isolate->factory();
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(String, extension, 0);
-  std::map<std::string, std::string> map;
-  Intl::ParseExtension(isolate, std::string(extension->ToCString().get()), map);
-  Handle<JSObject> extension_map =
-      isolate->factory()->NewJSObjectWithNullProto();
-  for (std::map<std::string, std::string>::iterator it = map.begin();
-       it != map.end(); it++) {
-    JSObject::AddProperty(
-        isolate, extension_map,
-        factory->NewStringFromAsciiChecked(it->first.c_str()),
-        factory->NewStringFromAsciiChecked(it->second.c_str()), NONE);
-  }
-  return *extension_map;
-}
-
-RUNTIME_FUNCTION(Runtime_PluralRulesSelect) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, plural_rules_obj, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, number, 1);
-
-  // 3. If pr does not have an [[InitializedPluralRules]] internal
-  // slot, throw a TypeError exception.
-  if (!plural_rules_obj->IsJSPluralRules()) {
-    Handle<String> method_str = isolate->factory()->NewStringFromStaticChars(
-        "Intl.PluralRules.prototype.select");
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
-                              method_str, plural_rules_obj));
-  }
-
-  Handle<JSPluralRules> plural_rules =
-      Handle<JSPluralRules>::cast(plural_rules_obj);
-
-  // 4. Return ? ResolvePlural(pr, n).
-
-  RETURN_RESULT_OR_FAILURE(
-      isolate, JSPluralRules::ResolvePlural(isolate, plural_rules, number));
-}
-
-RUNTIME_FUNCTION(Runtime_CreateBreakIterator) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(3, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(String, locale, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, options, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, resolved, 2);
-
-  Handle<JSFunction> constructor(
-      isolate->native_context()->intl_v8_break_iterator_function(), isolate);
-
-  Handle<JSObject> local_object;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, local_object,
-                                     JSObject::New(constructor, constructor));
-
-  // Set break iterator as embedder field of the resulting JS object.
-  icu::BreakIterator* break_iterator = V8BreakIterator::InitializeBreakIterator(
-      isolate, locale, options, resolved);
-  CHECK_NOT_NULL(break_iterator);
-
-  if (!break_iterator) return isolate->ThrowIllegalOperation();
-
-  local_object->SetEmbedderField(V8BreakIterator::kBreakIteratorIndex,
-                                 reinterpret_cast<Smi*>(break_iterator));
-  // Make sure that the pointer to adopted text is nullptr.
-  local_object->SetEmbedderField(V8BreakIterator::kUnicodeStringIndex,
-                                 static_cast<Smi*>(nullptr));
-
-  // Make object handle weak so we can delete the break iterator once GC kicks
-  // in.
-  Handle<Object> wrapper = isolate->global_handles()->Create(*local_object);
-  GlobalHandles::MakeWeak(wrapper.location(), wrapper.location(),
-                          V8BreakIterator::DeleteBreakIterator,
-                          WeakCallbackType::kInternalFields);
-  return *local_object;
-}
-
-RUNTIME_FUNCTION(Runtime_BreakIteratorFirst) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(1, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, break_iterator_holder, 0);
-
-  icu::BreakIterator* break_iterator =
-      V8BreakIterator::UnpackBreakIterator(break_iterator_holder);
-  CHECK_NOT_NULL(break_iterator);
-
-  return *isolate->factory()->NewNumberFromInt(break_iterator->first());
-}
-
-RUNTIME_FUNCTION(Runtime_BreakIteratorNext) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(1, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, break_iterator_holder, 0);
-
-  icu::BreakIterator* break_iterator =
-      V8BreakIterator::UnpackBreakIterator(break_iterator_holder);
-  CHECK_NOT_NULL(break_iterator);
-
-  return *isolate->factory()->NewNumberFromInt(break_iterator->next());
-}
-
-RUNTIME_FUNCTION(Runtime_BreakIteratorCurrent) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(1, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, break_iterator_holder, 0);
-
-  icu::BreakIterator* break_iterator =
-      V8BreakIterator::UnpackBreakIterator(break_iterator_holder);
-  CHECK_NOT_NULL(break_iterator);
-
-  return *isolate->factory()->NewNumberFromInt(break_iterator->current());
-}
-
-RUNTIME_FUNCTION(Runtime_BreakIteratorBreakType) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(1, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, break_iterator_holder, 0);
-
-  icu::BreakIterator* break_iterator =
-      V8BreakIterator::UnpackBreakIterator(break_iterator_holder);
-  CHECK_NOT_NULL(break_iterator);
-
-  // TODO(cira): Remove cast once ICU fixes base BreakIterator class.
-  icu::RuleBasedBreakIterator* rule_based_iterator =
-      static_cast<icu::RuleBasedBreakIterator*>(break_iterator);
-  int32_t status = rule_based_iterator->getRuleStatus();
-  // Keep return values in sync with JavaScript BreakType enum.
-  if (status >= UBRK_WORD_NONE && status < UBRK_WORD_NONE_LIMIT) {
-    return *isolate->factory()->NewStringFromStaticChars("none");
-  } else if (status >= UBRK_WORD_NUMBER && status < UBRK_WORD_NUMBER_LIMIT) {
-    return ReadOnlyRoots(isolate).number_string();
-  } else if (status >= UBRK_WORD_LETTER && status < UBRK_WORD_LETTER_LIMIT) {
-    return *isolate->factory()->NewStringFromStaticChars("letter");
-  } else if (status >= UBRK_WORD_KANA && status < UBRK_WORD_KANA_LIMIT) {
-    return *isolate->factory()->NewStringFromStaticChars("kana");
-  } else if (status >= UBRK_WORD_IDEO && status < UBRK_WORD_IDEO_LIMIT) {
-    return *isolate->factory()->NewStringFromStaticChars("ideo");
-  } else {
-    return *isolate->factory()->NewStringFromStaticChars("unknown");
-  }
-}
-
-RUNTIME_FUNCTION(Runtime_ToLocaleDateTime) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(6, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(Object, date, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, locales, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, options, 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, required, 3);
-  CONVERT_ARG_HANDLE_CHECKED(String, defaults, 4);
-  CONVERT_ARG_HANDLE_CHECKED(String, service, 5);
-
-  RETURN_RESULT_OR_FAILURE(
-      isolate, DateFormat::ToLocaleDateTime(
-                   isolate, date, locales, options, required->ToCString().get(),
-                   defaults->ToCString().get(), service->ToCString().get()));
-}
-
-RUNTIME_FUNCTION(Runtime_ToDateTimeOptions) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(args.length(), 3);
-  CONVERT_ARG_HANDLE_CHECKED(Object, options, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, required, 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, defaults, 2);
-  RETURN_RESULT_OR_FAILURE(
-      isolate, DateFormat::ToDateTimeOptions(isolate, options,
-                                             required->ToCString().get(),
-                                             defaults->ToCString().get()));
-}
-
 RUNTIME_FUNCTION(Runtime_StringToLowerCaseIntl) {
   HandleScope scope(isolate);
   DCHECK_EQ(args.length(), 1);
@@ -511,33 +144,5 @@ RUNTIME_FUNCTION(Runtime_DateCacheVersion) {
   return date_cache_version->get(0);
 }
 
-RUNTIME_FUNCTION(Runtime_IntlUnwrapReceiver) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(5, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0);
-  CONVERT_SMI_ARG_CHECKED(type_int, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, method, 3);
-  CONVERT_BOOLEAN_ARG_CHECKED(check_legacy_constructor, 4);
-
-  RETURN_RESULT_OR_FAILURE(
-      isolate, Intl::UnwrapReceiver(isolate, receiver, constructor,
-                                    Intl::TypeFromInt(type_int), method,
-                                    check_legacy_constructor));
-}
-
-RUNTIME_FUNCTION(Runtime_SupportedLocalesOf) {
-  HandleScope scope(isolate);
-
-  DCHECK_EQ(args.length(), 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, service, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, locales, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, options, 2);
-
-  RETURN_RESULT_OR_FAILURE(
-      isolate, Intl::SupportedLocalesOf(isolate, service, locales, options));
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/runtime/runtime-literals.cc b/deps/v8/src/runtime/runtime-literals.cc
index d5111f7efa..8632388388 100644
--- a/deps/v8/src/runtime/runtime-literals.cc
+++ b/deps/v8/src/runtime/runtime-literals.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "src/allocation-site-scopes.h"
+#include "src/allocation-site-scopes-inl.h"
 #include "src/arguments-inl.h"
 #include "src/ast/ast.h"
 #include "src/isolate-inl.h"
@@ -497,7 +497,8 @@ MaybeHandle<JSObject> CreateLiteral(Isolate* isolate,
                                     Handle<HeapObject> description, int flags) {
   FeedbackSlot literals_slot(FeedbackVector::ToSlot(literals_index));
   CHECK(literals_slot.ToInt() < vector->length());
-  Handle<Object> literal_site(vector->Get(literals_slot)->ToObject(), isolate);
+  Handle<Object> literal_site(vector->Get(literals_slot)->cast<Object>(),
+                              isolate);
   DeepCopyHints copy_hints = DecodeCopyHints(flags);
 
   Handle<AllocationSite> site;
@@ -597,7 +598,8 @@ RUNTIME_FUNCTION(Runtime_CreateRegExpLiteral) {
   FeedbackSlot literal_slot(FeedbackVector::ToSlot(index));
 
   // Check if boilerplate exists. If not, create it first.
-  Handle<Object> literal_site(vector->Get(literal_slot)->ToObject(), isolate);
+  Handle<Object> literal_site(vector->Get(literal_slot)->cast<Object>(),
+                              isolate);
   Handle<Object> boilerplate;
   if (!HasBoilerplate(literal_site)) {
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
diff --git a/deps/v8/src/runtime/runtime-maths.cc b/deps/v8/src/runtime/runtime-maths.cc
deleted file mode 100644
index 7695c14657..0000000000
--- a/deps/v8/src/runtime/runtime-maths.cc
+++ /dev/null
@@ -1,72 +0,0 @@
-// Copyright 2014 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/runtime/runtime-utils.h"
-
-#include "src/arguments.h"
-#include "src/base/utils/random-number-generator.h"
-#include "src/bootstrapper.h"
-#include "src/counters.h"
-#include "src/double.h"
-#include "src/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-
-RUNTIME_FUNCTION(Runtime_GenerateRandomNumbers) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(0, args.length());
-
-  Handle<Context> native_context = isolate->native_context();
-  DCHECK_EQ(0, native_context->math_random_index()->value());
-
-  static const int kCacheSize = 64;
-  static const int kState0Offset = kCacheSize - 1;
-  static const int kState1Offset = kState0Offset - 1;
-  // The index is decremented before used to access the cache.
-  static const int kInitialIndex = kState1Offset;
-
-  Handle<FixedDoubleArray> cache;
-  uint64_t state0 = 0;
-  uint64_t state1 = 0;
-  if (native_context->math_random_cache()->IsFixedDoubleArray()) {
-    cache = Handle<FixedDoubleArray>(
-        FixedDoubleArray::cast(native_context->math_random_cache()), isolate);
-    state0 = double_to_uint64(cache->get_scalar(kState0Offset));
-    state1 = double_to_uint64(cache->get_scalar(kState1Offset));
-  } else {
-    cache = Handle<FixedDoubleArray>::cast(
-        isolate->factory()->NewFixedDoubleArray(kCacheSize, TENURED));
-    native_context->set_math_random_cache(*cache);
-    // Initialize state if not yet initialized. If a fixed random seed was
-    // requested, use it to reset our state the first time a script asks for
-    // random numbers in this context. This ensures the script sees a consistent
-    // sequence.
-    if (FLAG_random_seed != 0) {
-      state0 = FLAG_random_seed;
-      state1 = FLAG_random_seed;
-    } else {
-      while (state0 == 0 || state1 == 0) {
-        isolate->random_number_generator()->NextBytes(&state0, sizeof(state0));
-        isolate->random_number_generator()->NextBytes(&state1, sizeof(state1));
-      }
-    }
-  }
-
-  DisallowHeapAllocation no_gc;
-  FixedDoubleArray* raw_cache = *cache;
-  // Create random numbers.
-  for (int i = 0; i < kInitialIndex; i++) {
-    // Generate random numbers using xorshift128+.
-    base::RandomNumberGenerator::XorShift128(&state0, &state1);
-    raw_cache->set(i, base::RandomNumberGenerator::ToDouble(state0, state1));
-  }
-
-  // Persist current state.
-  raw_cache->set(kState0Offset, uint64_to_double(state0));
-  raw_cache->set(kState1Offset, uint64_to_double(state1));
-  return Smi::FromInt(kInitialIndex);
-}
-}  // namespace internal
-}  // namespace v8
diff --git a/deps/v8/src/runtime/runtime-numbers.cc b/deps/v8/src/runtime/runtime-numbers.cc
index 14b91c8f1b..a8f62099a4 100644
--- a/deps/v8/src/runtime/runtime-numbers.cc
+++ b/deps/v8/src/runtime/runtime-numbers.cc
@@ -82,80 +82,16 @@ RUNTIME_FUNCTION(Runtime_NumberToString) {
 // -1 if x < y
 //  0 if x == y
 //  1 if x > y
+// TODO(szuend): Remove once the call-site in src/js/array.js is gone.
 RUNTIME_FUNCTION(Runtime_SmiLexicographicCompare) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(2, args.length());
-  CONVERT_SMI_ARG_CHECKED(x_value, 0);
-  CONVERT_SMI_ARG_CHECKED(y_value, 1);
-
-  // If the integers are equal so are the string representations.
-  if (x_value == y_value) return Smi::FromInt(0);
-
-  // If one of the integers is zero the normal integer order is the
-  // same as the lexicographic order of the string representations.
-  if (x_value == 0 || y_value == 0)
-    return Smi::FromInt(x_value < y_value ? -1 : 1);
-
-  // If only one of the integers is negative the negative number is
-  // smallest because the char code of '-' is less than the char code
-  // of any digit.  Otherwise, we make both values positive.
-
-  // Use unsigned values otherwise the logic is incorrect for -MIN_INT on
-  // architectures using 32-bit Smis.
-  uint32_t x_scaled = x_value;
-  uint32_t y_scaled = y_value;
-  if (x_value < 0 || y_value < 0) {
-    if (y_value >= 0) return Smi::FromInt(-1);
-    if (x_value >= 0) return Smi::FromInt(1);
-    x_scaled = -x_value;
-    y_scaled = -y_value;
-  }
-
-  static const uint32_t kPowersOf10[] = {
-      1,                 10,                100,         1000,
-      10 * 1000,         100 * 1000,        1000 * 1000, 10 * 1000 * 1000,
-      100 * 1000 * 1000, 1000 * 1000 * 1000};
-
-  // If the integers have the same number of decimal digits they can be
-  // compared directly as the numeric order is the same as the
-  // lexicographic order.  If one integer has fewer digits, it is scaled
-  // by some power of 10 to have the same number of digits as the longer
-  // integer.  If the scaled integers are equal it means the shorter
-  // integer comes first in the lexicographic order.
-
-  // From http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog10
-  int x_log2 = 31 - base::bits::CountLeadingZeros(x_scaled);
-  int x_log10 = ((x_log2 + 1) * 1233) >> 12;
-  x_log10 -= x_scaled < kPowersOf10[x_log10];
-
-  int y_log2 = 31 - base::bits::CountLeadingZeros(y_scaled);
-  int y_log10 = ((y_log2 + 1) * 1233) >> 12;
-  y_log10 -= y_scaled < kPowersOf10[y_log10];
-
-  int tie = 0;
-
-  if (x_log10 < y_log10) {
-    // X has fewer digits.  We would like to simply scale up X but that
-    // might overflow, e.g when comparing 9 with 1_000_000_000, 9 would
-    // be scaled up to 9_000_000_000. So we scale up by the next
-    // smallest power and scale down Y to drop one digit. It is OK to
-    // drop one digit from the longer integer since the final digit is
-    // past the length of the shorter integer.
-    x_scaled *= kPowersOf10[y_log10 - x_log10 - 1];
-    y_scaled /= 10;
-    tie = -1;
-  } else if (y_log10 < x_log10) {
-    y_scaled *= kPowersOf10[x_log10 - y_log10 - 1];
-    x_scaled /= 10;
-    tie = 1;
-  }
+  CONVERT_ARG_CHECKED(Smi, x_value, 0);
+  CONVERT_ARG_CHECKED(Smi, y_value, 1);
 
-  if (x_scaled < y_scaled) return Smi::FromInt(-1);
-  if (x_scaled > y_scaled) return Smi::FromInt(1);
-  return Smi::FromInt(tie);
+  return Smi::LexicographicCompare(isolate, x_value, y_value);
 }
 
-
 RUNTIME_FUNCTION(Runtime_MaxSmi) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(0, args.length());
@@ -184,6 +120,5 @@ RUNTIME_FUNCTION(Runtime_GetHoleNaNLower) {
   return *isolate->factory()->NewNumberFromUint(kHoleNanLower32);
 }
 
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/runtime/runtime-object.cc b/deps/v8/src/runtime/runtime-object.cc
index 81478b0e1b..3778e0576c 100644
--- a/deps/v8/src/runtime/runtime-object.cc
+++ b/deps/v8/src/runtime/runtime-object.cc
@@ -49,95 +49,6 @@ MaybeHandle<Object> Runtime::GetObjectProperty(Isolate* isolate,
   return result;
 }
 
-static MaybeHandle<Object> KeyedGetObjectProperty(Isolate* isolate,
-                                                  Handle<Object> receiver_obj,
-                                                  Handle<Object> key_obj) {
-  // Fast cases for getting named properties of the receiver JSObject
-  // itself.
-  //
-  // The global proxy objects has to be excluded since LookupOwn on
-  // the global proxy object can return a valid result even though the
-  // global proxy object never has properties.  This is the case
-  // because the global proxy object forwards everything to its hidden
-  // prototype including own lookups.
-  //
-  // Additionally, we need to make sure that we do not cache results
-  // for objects that require access checks.
-
-  // Convert string-index keys to their number variant to avoid internalization
-  // below; and speed up subsequent conversion to index.
-  uint32_t index;
-  if (key_obj->IsString() && String::cast(*key_obj)->AsArrayIndex(&index)) {
-    key_obj = isolate->factory()->NewNumberFromUint(index);
-  }
-  if (receiver_obj->IsJSObject()) {
-    if (!receiver_obj->IsJSGlobalProxy() &&
-        !receiver_obj->IsAccessCheckNeeded() && key_obj->IsName()) {
-      Handle<JSObject> receiver = Handle<JSObject>::cast(receiver_obj);
-      Handle<Name> key = Handle<Name>::cast(key_obj);
-      key_obj = key = isolate->factory()->InternalizeName(key);
-
-      DisallowHeapAllocation no_allocation;
-      if (receiver->IsJSGlobalObject()) {
-        // Attempt dictionary lookup.
-        GlobalDictionary* dictionary =
-            JSGlobalObject::cast(*receiver)->global_dictionary();
-        int entry = dictionary->FindEntry(isolate, key);
-        if (entry != GlobalDictionary::kNotFound) {
-          PropertyCell* cell = dictionary->CellAt(entry);
-          if (cell->property_details().kind() == kData) {
-            Object* value = cell->value();
-            if (!value->IsTheHole(isolate)) {
-              return Handle<Object>(value, isolate);
-            }
-            // If value is the hole (meaning, absent) do the general lookup.
-          }
-        }
-      } else if (!receiver->HasFastProperties()) {
-        // Attempt dictionary lookup.
-        NameDictionary* dictionary = receiver->property_dictionary();
-        int entry = dictionary->FindEntry(isolate, key);
-        if ((entry != NameDictionary::kNotFound) &&
-            (dictionary->DetailsAt(entry).kind() == kData)) {
-          Object* value = dictionary->ValueAt(entry);
-          return Handle<Object>(value, isolate);
-        }
-      }
-    } else if (key_obj->IsSmi()) {
-      // JSObject without a name key. If the key is a Smi, check for a
-      // definite out-of-bounds access to elements, which is a strong indicator
-      // that subsequent accesses will also call the runtime. Proactively
-      // transition elements to FAST_*_ELEMENTS to avoid excessive boxing of
-      // doubles for those future calls in the case that the elements would
-      // become PACKED_DOUBLE_ELEMENTS.
-      Handle<JSObject> js_object = Handle<JSObject>::cast(receiver_obj);
-      ElementsKind elements_kind = js_object->GetElementsKind();
-      if (IsDoubleElementsKind(elements_kind)) {
-        if (Smi::ToInt(*key_obj) >= js_object->elements()->length()) {
-          elements_kind = IsHoleyElementsKind(elements_kind) ? HOLEY_ELEMENTS
-                                                             : PACKED_ELEMENTS;
-          JSObject::TransitionElementsKind(js_object, elements_kind);
-        }
-      } else {
-        DCHECK(IsSmiOrObjectElementsKind(elements_kind) ||
-               !IsFastElementsKind(elements_kind));
-      }
-    }
-  } else if (receiver_obj->IsString() && key_obj->IsSmi()) {
-    // Fast case for string indexing using [] with a smi index.
-    Handle<String> str = Handle<String>::cast(receiver_obj);
-    int index = Handle<Smi>::cast(key_obj)->value();
-    if (index >= 0 && index < str->length()) {
-      Factory* factory = isolate->factory();
-      return factory->LookupSingleCharacterStringFromCode(
-          String::Flatten(isolate, str)->Get(index));
-    }
-  }
-
-  // Fall back to GetObjectProperty.
-  return Runtime::GetObjectProperty(isolate, receiver_obj, key_obj);
-}
-
 namespace {
 
 bool DeleteObjectPropertyFast(Isolate* isolate, Handle<JSReceiver> receiver,
@@ -431,7 +342,8 @@ MaybeHandle<Object> Runtime::SetObjectProperty(Isolate* isolate,
                                                Handle<Object> object,
                                                Handle<Object> key,
                                                Handle<Object> value,
-                                               LanguageMode language_mode) {
+                                               LanguageMode language_mode,
+                                               StoreOrigin store_origin) {
   if (object->IsNullOrUndefined(isolate)) {
     THROW_NEW_ERROR(
         isolate,
@@ -453,17 +365,10 @@ MaybeHandle<Object> Runtime::SetObjectProperty(Isolate* isolate,
         Object);
   }
 
-  MAYBE_RETURN_NULL(Object::SetProperty(&it, value, language_mode,
-                                        Object::MAY_BE_STORE_FROM_KEYED));
-  return value;
-}
-
+  MAYBE_RETURN_NULL(
+      Object::SetProperty(&it, value, language_mode, store_origin));
 
-RUNTIME_FUNCTION(Runtime_GetPrototype) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, obj, 0);
-  RETURN_RESULT_OR_FAILURE(isolate, JSReceiver::GetPrototype(isolate, obj));
+  return value;
 }
 
 
@@ -561,24 +466,91 @@ RUNTIME_FUNCTION(Runtime_ObjectEntriesSkipFastPath) {
 RUNTIME_FUNCTION(Runtime_GetProperty) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, receiver_obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key_obj, 1);
 
-  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
-
-  RETURN_RESULT_OR_FAILURE(isolate,
-                           Runtime::GetObjectProperty(isolate, object, key));
-}
+  // Fast cases for getting named properties of the receiver JSObject
+  // itself.
+  //
+  // The global proxy objects has to be excluded since LookupOwn on
+  // the global proxy object can return a valid result even though the
+  // global proxy object never has properties.  This is the case
+  // because the global proxy object forwards everything to its hidden
+  // prototype including own lookups.
+  //
+  // Additionally, we need to make sure that we do not cache results
+  // for objects that require access checks.
 
-// KeyedGetProperty is called from KeyedLoadIC::GenerateGeneric.
-RUNTIME_FUNCTION(Runtime_KeyedGetProperty) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
+  // Convert string-index keys to their number variant to avoid internalization
+  // below; and speed up subsequent conversion to index.
+  uint32_t index;
+  if (key_obj->IsString() && String::cast(*key_obj)->AsArrayIndex(&index)) {
+    key_obj = isolate->factory()->NewNumberFromUint(index);
+  }
+  if (receiver_obj->IsJSObject()) {
+    if (!receiver_obj->IsJSGlobalProxy() &&
+        !receiver_obj->IsAccessCheckNeeded() && key_obj->IsName()) {
+      Handle<JSObject> receiver = Handle<JSObject>::cast(receiver_obj);
+      Handle<Name> key = Handle<Name>::cast(key_obj);
+      key_obj = key = isolate->factory()->InternalizeName(key);
 
-  CONVERT_ARG_HANDLE_CHECKED(Object, receiver_obj, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, key_obj, 1);
+      DisallowHeapAllocation no_allocation;
+      if (receiver->IsJSGlobalObject()) {
+        // Attempt dictionary lookup.
+        GlobalDictionary* dictionary =
+            JSGlobalObject::cast(*receiver)->global_dictionary();
+        int entry = dictionary->FindEntry(isolate, key);
+        if (entry != GlobalDictionary::kNotFound) {
+          PropertyCell* cell = dictionary->CellAt(entry);
+          if (cell->property_details().kind() == kData) {
+            Object* value = cell->value();
+            if (!value->IsTheHole(isolate)) return value;
+            // If value is the hole (meaning, absent) do the general lookup.
+          }
+        }
+      } else if (!receiver->HasFastProperties()) {
+        // Attempt dictionary lookup.
+        NameDictionary* dictionary = receiver->property_dictionary();
+        int entry = dictionary->FindEntry(isolate, key);
+        if ((entry != NameDictionary::kNotFound) &&
+            (dictionary->DetailsAt(entry).kind() == kData)) {
+          return dictionary->ValueAt(entry);
+        }
+      }
+    } else if (key_obj->IsSmi()) {
+      // JSObject without a name key. If the key is a Smi, check for a
+      // definite out-of-bounds access to elements, which is a strong indicator
+      // that subsequent accesses will also call the runtime. Proactively
+      // transition elements to FAST_*_ELEMENTS to avoid excessive boxing of
+      // doubles for those future calls in the case that the elements would
+      // become PACKED_DOUBLE_ELEMENTS.
+      Handle<JSObject> js_object = Handle<JSObject>::cast(receiver_obj);
+      ElementsKind elements_kind = js_object->GetElementsKind();
+      if (IsDoubleElementsKind(elements_kind)) {
+        if (Smi::ToInt(*key_obj) >= js_object->elements()->length()) {
+          elements_kind = IsHoleyElementsKind(elements_kind) ? HOLEY_ELEMENTS
+                                                             : PACKED_ELEMENTS;
+          JSObject::TransitionElementsKind(js_object, elements_kind);
+        }
+      } else {
+        DCHECK(IsSmiOrObjectElementsKind(elements_kind) ||
+               !IsFastElementsKind(elements_kind));
+      }
+    }
+  } else if (receiver_obj->IsString() && key_obj->IsSmi()) {
+    // Fast case for string indexing using [] with a smi index.
+    Handle<String> str = Handle<String>::cast(receiver_obj);
+    int index = Handle<Smi>::cast(key_obj)->value();
+    if (index >= 0 && index < str->length()) {
+      Factory* factory = isolate->factory();
+      return *factory->LookupSingleCharacterStringFromCode(
+          String::Flatten(isolate, str)->Get(index));
+    }
+  }
 
+  // Fall back to GetObjectProperty.
   RETURN_RESULT_OR_FAILURE(
-      isolate, KeyedGetObjectProperty(isolate, receiver_obj, key_obj));
+      isolate, Runtime::GetObjectProperty(isolate, receiver_obj, key_obj));
 }
 
 RUNTIME_FUNCTION(Runtime_AddNamedProperty) {
@@ -634,8 +606,7 @@ RUNTIME_FUNCTION(Runtime_AddElement) {
                                         object, index, value, NONE));
 }
 
-
-RUNTIME_FUNCTION(Runtime_SetProperty) {
+RUNTIME_FUNCTION(Runtime_SetKeyedProperty) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
 
@@ -646,9 +617,48 @@ RUNTIME_FUNCTION(Runtime_SetProperty) {
 
   RETURN_RESULT_OR_FAILURE(
       isolate,
-      Runtime::SetObjectProperty(isolate, object, key, value, language_mode));
+      Runtime::SetObjectProperty(isolate, object, key, value, language_mode,
+                                 StoreOrigin::kMaybeKeyed));
+}
+
+RUNTIME_FUNCTION(Runtime_SetNamedProperty) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(4, args.length());
+
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
+  CONVERT_LANGUAGE_MODE_ARG_CHECKED(language_mode, 3);
+
+  RETURN_RESULT_OR_FAILURE(
+      isolate, Runtime::SetObjectProperty(isolate, object, key, value,
+                                          language_mode, StoreOrigin::kNamed));
 }
 
+// Similar to DefineDataPropertyInLiteral, but does not update feedback, and
+// and does not have a flags parameter for performing SetFunctionName().
+//
+// Currently, this is used for ObjectLiteral spread properties.
+RUNTIME_FUNCTION(Runtime_StoreDataPropertyInLiteral) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(3, args.length());
+
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, key, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
+
+  bool success;
+  LookupIterator it = LookupIterator::PropertyOrElement(
+      isolate, object, key, &success, LookupIterator::OWN);
+
+  Maybe<bool> result =
+      JSObject::DefineOwnPropertyIgnoreAttributes(&it, value, NONE, kDontThrow);
+  RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
+  DCHECK(result.IsJust());
+  USE(result);
+
+  return *value;
+}
 
 namespace {
 
@@ -755,7 +765,9 @@ RUNTIME_FUNCTION(Runtime_NewObject) {
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, target, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, new_target, 1);
-  RETURN_RESULT_OR_FAILURE(isolate, JSObject::New(target, new_target));
+  RETURN_RESULT_OR_FAILURE(
+      isolate,
+      JSObject::New(target, new_target, Handle<AllocationSite>::null()));
 }
 
 RUNTIME_FUNCTION(Runtime_CompleteInobjectSlackTrackingForMap) {
@@ -905,15 +917,6 @@ RUNTIME_FUNCTION(Runtime_HasFastPackedElements) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_ValueOf) {
-  SealHandleScope shs(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_CHECKED(Object, obj, 0);
-  if (!obj->IsJSValue()) return obj;
-  return JSValue::cast(obj)->value();
-}
-
-
 RUNTIME_FUNCTION(Runtime_IsJSReceiver) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
@@ -1114,22 +1117,6 @@ RUNTIME_FUNCTION(Runtime_ToObject) {
   UNREACHABLE();
 }
 
-RUNTIME_FUNCTION(Runtime_ToPrimitive) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
-  RETURN_RESULT_OR_FAILURE(isolate, Object::ToPrimitive(input));
-}
-
-
-RUNTIME_FUNCTION(Runtime_ToPrimitive_Number) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
-  RETURN_RESULT_OR_FAILURE(
-      isolate, Object::ToPrimitive(input, ToPrimitiveHint::kNumber));
-}
-
 RUNTIME_FUNCTION(Runtime_ToNumber) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -1144,13 +1131,6 @@ RUNTIME_FUNCTION(Runtime_ToNumeric) {
   RETURN_RESULT_OR_FAILURE(isolate, Object::ToNumeric(isolate, input));
 }
 
-RUNTIME_FUNCTION(Runtime_ToInteger) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
-  RETURN_RESULT_OR_FAILURE(isolate, Object::ToInteger(isolate, input));
-}
-
 
 RUNTIME_FUNCTION(Runtime_ToLength) {
   HandleScope scope(isolate);
@@ -1175,24 +1155,6 @@ RUNTIME_FUNCTION(Runtime_ToName) {
   RETURN_RESULT_OR_FAILURE(isolate, Object::ToName(isolate, input));
 }
 
-
-RUNTIME_FUNCTION(Runtime_SameValue) {
-  SealHandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_CHECKED(Object, x, 0);
-  CONVERT_ARG_CHECKED(Object, y, 1);
-  return isolate->heap()->ToBoolean(x->SameValue(y));
-}
-
-
-RUNTIME_FUNCTION(Runtime_SameValueZero) {
-  SealHandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_CHECKED(Object, x, 0);
-  CONVERT_ARG_CHECKED(Object, y, 1);
-  return isolate->heap()->ToBoolean(x->SameValueZero(y));
-}
-
 RUNTIME_FUNCTION(Runtime_HasInPrototypeChain) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
@@ -1264,7 +1226,7 @@ RUNTIME_FUNCTION(Runtime_AddPrivateField) {
   }
 
   CHECK(Object::AddDataProperty(&it, value, NONE, kDontThrow,
-                                Object::MAY_BE_STORE_FROM_KEYED)
+                                StoreOrigin::kMaybeKeyed)
             .FromJust());
   return ReadOnlyRoots(isolate).undefined_value();
 }
diff --git a/deps/v8/src/runtime/runtime-proxy.cc b/deps/v8/src/runtime/runtime-proxy.cc
index 7eeee631be..69b7c9795c 100644
--- a/deps/v8/src/runtime/runtime-proxy.cc
+++ b/deps/v8/src/runtime/runtime-proxy.cc
@@ -77,8 +77,8 @@ RUNTIME_FUNCTION(Runtime_SetPropertyWithReceiver) {
     DCHECK(isolate->has_pending_exception());
     return ReadOnlyRoots(isolate).exception();
   }
-  Maybe<bool> result = Object::SetSuperProperty(
-      &it, value, language_mode, Object::MAY_BE_STORE_FROM_KEYED);
+  Maybe<bool> result = Object::SetSuperProperty(&it, value, language_mode,
+                                                StoreOrigin::kMaybeKeyed);
   MAYBE_RETURN(result, ReadOnlyRoots(isolate).exception());
   return *isolate->factory()->ToBoolean(result.FromJust());
 }
diff --git a/deps/v8/src/runtime/runtime-regexp.cc b/deps/v8/src/runtime/runtime-regexp.cc
index 3e77bf1f3b..e66319bfb5 100644
--- a/deps/v8/src/runtime/runtime-regexp.cc
+++ b/deps/v8/src/runtime/runtime-regexp.cc
@@ -38,7 +38,7 @@ uint32_t GetArgcForReplaceCallable(uint32_t num_captures,
 
 // Looks up the capture of the given name. Returns the (1-based) numbered
 // capture index or -1 on failure.
-int LookupNamedCapture(std::function<bool(String*)> name_matches,
+int LookupNamedCapture(const std::function<bool(String*)>& name_matches,
                        FixedArray* capture_name_map) {
   // TODO(jgruber): Sort capture_name_map and do binary search via
   // internalized strings.
@@ -1097,7 +1097,7 @@ class VectorBackedMatch : public String::Match {
 // RegExpBuiltinsAssembler::ConstructNewResultFromMatchInfo).
 Handle<JSObject> ConstructNamedCaptureGroupsObject(
     Isolate* isolate, Handle<FixedArray> capture_map,
-    std::function<Object*(int)> f_get_capture) {
+    const std::function<Object*(int)>& f_get_capture) {
   Handle<JSObject> groups = isolate->factory()->NewJSObjectWithNullProto();
 
   const int capture_count = capture_map->length() >> 1;
diff --git a/deps/v8/src/runtime/runtime-scopes.cc b/deps/v8/src/runtime/runtime-scopes.cc
index 4772f400b3..7a24b066c1 100644
--- a/deps/v8/src/runtime/runtime-scopes.cc
+++ b/deps/v8/src/runtime/runtime-scopes.cc
@@ -158,8 +158,8 @@ Object* DeclareGlobals(Isolate* isolate, Handle<FixedArray> declarations,
       FeedbackSlot feedback_cells_slot(
           Smi::ToInt(*possibly_feedback_cell_slot));
       Handle<FeedbackCell> feedback_cell(
-          FeedbackCell::cast(
-              feedback_vector->Get(feedback_cells_slot)->ToStrongHeapObject()),
+          FeedbackCell::cast(feedback_vector->Get(feedback_cells_slot)
+                                 ->GetHeapObjectAssumeStrong()),
           isolate);
       Handle<JSFunction> function =
           isolate->factory()->NewFunctionFromSharedFunctionInfo(
@@ -461,8 +461,7 @@ Handle<JSObject> NewSloppyArguments(Isolate* isolate, Handle<JSFunction> callee,
   return result;
 }
 
-
-class HandleArguments BASE_EMBEDDED {
+class HandleArguments {
  public:
   explicit HandleArguments(Handle<Object>* array) : array_(array) {}
   Object* operator[](int index) { return *array_[index]; }
@@ -471,8 +470,7 @@ class HandleArguments BASE_EMBEDDED {
   Handle<Object>* array_;
 };
 
-
-class ParameterArguments BASE_EMBEDDED {
+class ParameterArguments {
  public:
   explicit ParameterArguments(Object** parameters) : parameters_(parameters) {}
   Object*& operator[](int index) { return *(parameters_ - index - 1); }
@@ -803,6 +801,8 @@ MaybeHandle<Object> LoadLookupSlot(Isolate* isolate, Handle<String> name,
   if (isolate->has_pending_exception()) return MaybeHandle<Object>();
 
   if (!holder.is_null() && holder->IsModule()) {
+    Handle<Object> receiver = isolate->factory()->undefined_value();
+    if (receiver_return) *receiver_return = receiver;
     return Module::LoadVariable(isolate, Handle<Module>::cast(holder), index);
   }
   if (index != Context::kNotFound) {
diff --git a/deps/v8/src/runtime/runtime-strings.cc b/deps/v8/src/runtime/runtime-strings.cc
index f6537fd073..d57959687c 100644
--- a/deps/v8/src/runtime/runtime-strings.cc
+++ b/deps/v8/src/runtime/runtime-strings.cc
@@ -581,7 +581,8 @@ static int CopyCachedOneByteCharsToArray(Heap* heap, const uint8_t* chars,
     elements->set(i, value, mode);
   }
   if (i < length) {
-    static_assert(Smi::kZero == 0, "Can use memset since Smi::kZero is 0");
+    static_assert(Smi::kZero == nullptr,
+                  "Can use memset since Smi::kZero is 0");
     memset(elements->data_start() + i, 0, kPointerSize * (length - i));
   }
 #ifdef DEBUG
@@ -693,14 +694,6 @@ RUNTIME_FUNCTION(Runtime_StringEqual) {
   return isolate->heap()->ToBoolean(String::Equals(isolate, x, y));
 }
 
-RUNTIME_FUNCTION(Runtime_StringNotEqual) {
-  HandleScope handle_scope(isolate);
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
-  return isolate->heap()->ToBoolean(!String::Equals(isolate, x, y));
-}
-
 RUNTIME_FUNCTION(Runtime_FlattenString) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -708,17 +701,6 @@ RUNTIME_FUNCTION(Runtime_FlattenString) {
   return *String::Flatten(isolate, str);
 }
 
-RUNTIME_FUNCTION(Runtime_StringCharFromCode) {
-  HandleScope handlescope(isolate);
-  DCHECK_EQ(1, args.length());
-  if (args[0]->IsNumber()) {
-    CONVERT_NUMBER_CHECKED(uint32_t, code, Uint32, args[0]);
-    code &= 0xFFFF;
-    return *isolate->factory()->LookupSingleCharacterStringFromCode(code);
-  }
-  return ReadOnlyRoots(isolate).empty_string();
-}
-
 RUNTIME_FUNCTION(Runtime_StringMaxLength) {
   SealHandleScope shs(isolate);
   return Smi::FromInt(String::kMaxLength);
diff --git a/deps/v8/src/runtime/runtime-test.cc b/deps/v8/src/runtime/runtime-test.cc
index 94376e1364..bcc36e9d87 100644
--- a/deps/v8/src/runtime/runtime-test.cc
+++ b/deps/v8/src/runtime/runtime-test.cc
@@ -10,6 +10,7 @@
 #include "src/api-inl.h"
 #include "src/arguments-inl.h"
 #include "src/assembler-inl.h"
+#include "src/base/platform/mutex.h"
 #include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
 #include "src/compiler.h"
 #include "src/deoptimizer.h"
@@ -25,6 +26,9 @@
 #include "src/wasm/wasm-objects-inl.h"
 #include "src/wasm/wasm-serialization.h"
 
+namespace v8 {
+namespace internal {
+
 namespace {
 struct WasmCompileControls {
   uint32_t MaxWasmBufferSize = std::numeric_limits<uint32_t>::max();
@@ -32,14 +36,16 @@ struct WasmCompileControls {
 };
 
 // We need per-isolate controls, because we sometimes run tests in multiple
-// isolates
-// concurrently.
+// isolates concurrently. Methods need to hold the accompanying mutex on access.
 // To avoid upsetting the static initializer count, we lazy initialize this.
-v8::base::LazyInstance<std::map<v8::Isolate*, WasmCompileControls>>::type
+base::LazyInstance<std::map<v8::Isolate*, WasmCompileControls>>::type
     g_PerIsolateWasmControls = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<base::Mutex>::type g_PerIsolateWasmControlsMutex =
+    LAZY_INSTANCE_INITIALIZER;
 
 bool IsWasmCompileAllowed(v8::Isolate* isolate, v8::Local<v8::Value> value,
                           bool is_async) {
+  base::LockGuard<base::Mutex> guard(g_PerIsolateWasmControlsMutex.Pointer());
   DCHECK_GT(g_PerIsolateWasmControls.Get().count(isolate), 0);
   const WasmCompileControls& ctrls = g_PerIsolateWasmControls.Get().at(isolate);
   return (is_async && ctrls.AllowAnySizeForAsync) ||
@@ -52,6 +58,7 @@ bool IsWasmCompileAllowed(v8::Isolate* isolate, v8::Local<v8::Value> value,
 bool IsWasmInstantiateAllowed(v8::Isolate* isolate,
                               v8::Local<v8::Value> module_or_bytes,
                               bool is_async) {
+  base::LockGuard<base::Mutex> guard(g_PerIsolateWasmControlsMutex.Pointer());
   DCHECK_GT(g_PerIsolateWasmControls.Get().count(isolate), 0);
   const WasmCompileControls& ctrls = g_PerIsolateWasmControls.Get().at(isolate);
   if (is_async && ctrls.AllowAnySizeForAsync) return true;
@@ -91,9 +98,6 @@ bool WasmInstanceOverride(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 }  // namespace
 
-namespace v8 {
-namespace internal {
-
 RUNTIME_FUNCTION(Runtime_ConstructDouble) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
@@ -477,6 +481,7 @@ RUNTIME_FUNCTION(Runtime_SetWasmCompileControls) {
   CHECK_EQ(args.length(), 2);
   CONVERT_ARG_HANDLE_CHECKED(Smi, block_size, 0);
   CONVERT_BOOLEAN_ARG_CHECKED(allow_async, 1);
+  base::LockGuard<base::Mutex> guard(g_PerIsolateWasmControlsMutex.Pointer());
   WasmCompileControls& ctrl = (*g_PerIsolateWasmControls.Pointer())[v8_isolate];
   ctrl.AllowAnySizeForAsync = allow_async;
   ctrl.MaxWasmBufferSize = static_cast<uint32_t>(block_size->value());
@@ -533,17 +538,18 @@ RUNTIME_FUNCTION(Runtime_DebugPrint) {
   MaybeObject* maybe_object = reinterpret_cast<MaybeObject*>(args[0]);
 
   StdoutStream os;
-  if (maybe_object->IsClearedWeakHeapObject()) {
+  if (maybe_object->IsCleared()) {
     os << "[weak cleared]";
   } else {
     Object* object;
+    HeapObject* heap_object;
     bool weak = false;
-    if (maybe_object->IsWeakHeapObject()) {
+    if (maybe_object->GetHeapObjectIfWeak(&heap_object)) {
       weak = true;
-      object = maybe_object->ToWeakHeapObject();
+      object = heap_object;
     } else {
       // Strong reference or SMI.
-      object = maybe_object->ToObject();
+      object = maybe_object->cast<Object>();
     }
 
 #ifdef DEBUG
@@ -830,12 +836,39 @@ RUNTIME_FUNCTION(Runtime_IsWasmTrapHandlerEnabled) {
 }
 
 RUNTIME_FUNCTION(Runtime_GetWasmRecoveredTrapCount) {
-  HandleScope shs(isolate);
+  HandleScope scope(isolate);
   DCHECK_EQ(0, args.length());
   size_t trap_count = trap_handler::GetRecoveredTrapCount();
   return *isolate->factory()->NewNumberFromSize(trap_count);
 }
 
+RUNTIME_FUNCTION(Runtime_GetWasmExceptionId) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, exception, 0);
+  CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 1);
+  Handle<Object> tag;
+  if (JSReceiver::GetProperty(isolate, exception,
+                              isolate->factory()->wasm_exception_tag_symbol())
+          .ToHandle(&tag)) {
+    Handle<FixedArray> exceptions_table(instance->exceptions_table(), isolate);
+    for (int index = 0; index < exceptions_table->length(); ++index) {
+      if (exceptions_table->get(index) == *tag) return Smi::FromInt(index);
+    }
+  }
+  return ReadOnlyRoots(isolate).undefined_value();
+}
+
+RUNTIME_FUNCTION(Runtime_GetWasmExceptionValues) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, exception, 0);
+  RETURN_RESULT_OR_FAILURE(
+      isolate, JSReceiver::GetProperty(
+                   isolate, exception,
+                   isolate->factory()->wasm_exception_values_symbol()));
+}
+
 namespace {
 bool EnableWasmThreads(v8::Local<v8::Context> context) { return true; }
 
@@ -902,6 +935,13 @@ RUNTIME_FUNCTION(Runtime_PromiseSpeciesProtector) {
       isolate->IsPromiseSpeciesLookupChainIntact());
 }
 
+RUNTIME_FUNCTION(Runtime_StringIteratorProtector) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(0, args.length());
+  return isolate->heap()->ToBoolean(
+      isolate->IsStringIteratorLookupChainIntact());
+}
+
 // Take a compiled wasm module and serialize it into an array buffer, which is
 // then returned.
 RUNTIME_FUNCTION(Runtime_SerializeWasmModule) {
@@ -937,9 +977,9 @@ RUNTIME_FUNCTION(Runtime_DeserializeWasmModule) {
       wasm::DeserializeNativeModule(
           isolate,
           {reinterpret_cast<uint8_t*>(buffer->backing_store()),
-           static_cast<size_t>(buffer->byte_length()->Number())},
+           buffer->byte_length()},
           {reinterpret_cast<uint8_t*>(wire_bytes->backing_store()),
-           static_cast<size_t>(wire_bytes->byte_length()->Number())});
+           wire_bytes->byte_length()});
   Handle<WasmModuleObject> module_object;
   if (!maybe_module_object.ToHandle(&module_object)) {
     return ReadOnlyRoots(isolate).undefined_value();
@@ -971,7 +1011,7 @@ RUNTIME_FUNCTION(Runtime_WasmGetNumberOfInstances) {
   int instance_count = 0;
   WeakArrayList* weak_instance_list = module_obj->weak_instance_list();
   for (int i = 0; i < weak_instance_list->length(); ++i) {
-    if (weak_instance_list->Get(i)->IsWeakHeapObject()) instance_count++;
+    if (weak_instance_list->Get(i)->IsWeak()) instance_count++;
   }
   return Smi::FromInt(instance_count);
 }
@@ -980,7 +1020,7 @@ RUNTIME_FUNCTION(Runtime_WasmNumInterpretedCalls) {
   DCHECK_EQ(1, args.length());
   HandleScope scope(isolate);
   CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
-  if (!instance->has_debug_info()) return 0;
+  if (!instance->has_debug_info()) return nullptr;
   uint64_t num = instance->debug_info()->NumInterpretedCalls();
   return *isolate->factory()->NewNumberFromSize(static_cast<size_t>(num));
 }
diff --git a/deps/v8/src/runtime/runtime-typedarray.cc b/deps/v8/src/runtime/runtime-typedarray.cc
index c101219d2c..8a9d6fe366 100644
--- a/deps/v8/src/runtime/runtime-typedarray.cc
+++ b/deps/v8/src/runtime/runtime-typedarray.cc
@@ -30,14 +30,14 @@ RUNTIME_FUNCTION(Runtime_ArrayBufferNeuter) {
     return ReadOnlyRoots(isolate).undefined_value();
   }
   if (array_buffer->backing_store() == nullptr) {
-    CHECK_EQ(Smi::kZero, array_buffer->byte_length());
+    CHECK_EQ(0, array_buffer->byte_length());
     return ReadOnlyRoots(isolate).undefined_value();
   }
   // Shared array buffers should never be neutered.
   CHECK(!array_buffer->is_shared());
   DCHECK(!array_buffer->is_external());
   void* backing_store = array_buffer->backing_store();
-  size_t byte_length = NumberToSize(array_buffer->byte_length());
+  size_t byte_length = array_buffer->byte_length();
   array_buffer->set_is_external(true);
   isolate->heap()->UnregisterArrayBuffer(*array_buffer);
   array_buffer->Neuter();
diff --git a/deps/v8/src/runtime/runtime-wasm.cc b/deps/v8/src/runtime/runtime-wasm.cc
index 5a6c782292..f852df0d85 100644
--- a/deps/v8/src/runtime/runtime-wasm.cc
+++ b/deps/v8/src/runtime/runtime-wasm.cc
@@ -24,41 +24,28 @@ namespace internal {
 
 namespace {
 
-WasmInstanceObject* GetWasmInstanceOnStackTop(Isolate* isolate) {
+Context* GetNativeContextFromWasmInstanceOnStackTop(Isolate* isolate) {
   StackFrameIterator it(isolate, isolate->thread_local_top());
   // On top: C entry stub.
   DCHECK_EQ(StackFrame::EXIT, it.frame()->type());
   it.Advance();
-  // Next: the wasm (compiled or interpreted) frame.
-  WasmInstanceObject* result = nullptr;
-  if (it.frame()->is_wasm_compiled()) {
-    result = WasmCompiledFrame::cast(it.frame())->wasm_instance();
-  } else {
-    DCHECK(it.frame()->is_wasm_interpreter_entry());
-    result = WasmInterpreterEntryFrame::cast(it.frame())->wasm_instance();
-  }
-  return result;
-}
-
-Context* GetNativeContextFromWasmInstanceOnStackTop(Isolate* isolate) {
-  return GetWasmInstanceOnStackTop(isolate)->native_context();
+  // Next: the wasm compiled frame.
+  DCHECK(it.frame()->is_wasm_compiled());
+  WasmCompiledFrame* frame = WasmCompiledFrame::cast(it.frame());
+  return frame->wasm_instance()->native_context();
 }
 
 class ClearThreadInWasmScope {
  public:
-  explicit ClearThreadInWasmScope(bool coming_from_wasm)
-      : coming_from_wasm_(coming_from_wasm) {
-    DCHECK_EQ(trap_handler::IsTrapHandlerEnabled() && coming_from_wasm,
+  ClearThreadInWasmScope() {
+    DCHECK_EQ(trap_handler::IsTrapHandlerEnabled(),
               trap_handler::IsThreadInWasm());
-    if (coming_from_wasm) trap_handler::ClearThreadInWasm();
+    trap_handler::ClearThreadInWasm();
   }
   ~ClearThreadInWasmScope() {
     DCHECK(!trap_handler::IsThreadInWasm());
-    if (coming_from_wasm_) trap_handler::SetThreadInWasm();
+    trap_handler::SetThreadInWasm();
   }
-
- private:
-  const bool coming_from_wasm_;
 };
 
 }  // namespace
@@ -72,11 +59,7 @@ RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
   CONVERT_UINT32_ARG_CHECKED(delta_pages, 1);
 
   // This runtime function is always being called from wasm code.
-  ClearThreadInWasmScope flag_scope(true);
-
-  // Set the current isolate's context.
-  DCHECK_NULL(isolate->context());
-  isolate->set_context(instance->native_context());
+  ClearThreadInWasmScope flag_scope;
 
   int ret = WasmMemoryObject::Grow(
       isolate, handle(instance->memory_object(), isolate), delta_pages);
@@ -88,11 +71,9 @@ RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
 RUNTIME_FUNCTION(Runtime_ThrowWasmError) {
   DCHECK_EQ(1, args.length());
   CONVERT_SMI_ARG_CHECKED(message_id, 0);
-  ClearThreadInWasmScope clear_wasm_flag(isolate->context() == nullptr);
+  ClearThreadInWasmScope clear_wasm_flag;
 
   HandleScope scope(isolate);
-  DCHECK_NULL(isolate->context());
-  isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
   Handle<Object> error_obj = isolate->factory()->NewWasmRuntimeError(
       static_cast<MessageTemplate::Template>(message_id));
   return isolate->Throw(*error_obj);
@@ -116,81 +97,73 @@ RUNTIME_FUNCTION(Runtime_WasmThrowTypeError) {
 RUNTIME_FUNCTION(Runtime_WasmThrowCreate) {
   // TODO(kschimpf): Can this be replaced with equivalent TurboFan code/calls.
   HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
   DCHECK_NULL(isolate->context());
   isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
-  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_CHECKED(HeapObject, tag_raw, 0);
+  CONVERT_SMI_ARG_CHECKED(size, 1);
+  // TODO(mstarzinger): Manually box because parameters are not visited yet.
+  Handle<Object> tag(tag_raw, isolate);
   Handle<Object> exception = isolate->factory()->NewWasmRuntimeError(
       static_cast<MessageTemplate::Template>(
           MessageTemplate::kWasmExceptionError));
-  isolate->set_wasm_caught_exception(*exception);
-  CONVERT_ARG_HANDLE_CHECKED(Smi, id, 0);
-  CHECK(!JSReceiver::SetProperty(isolate, exception,
-                                 isolate->factory()->InternalizeUtf8String(
-                                     wasm::WasmException::kRuntimeIdStr),
-                                 id, LanguageMode::kStrict)
-             .is_null());
-  CONVERT_SMI_ARG_CHECKED(size, 1);
+  CHECK(
+      !JSReceiver::SetProperty(isolate, exception,
+                               isolate->factory()->wasm_exception_tag_symbol(),
+                               tag, LanguageMode::kStrict)
+           .is_null());
   Handle<JSTypedArray> values =
       isolate->factory()->NewJSTypedArray(ElementsKind::UINT16_ELEMENTS, size);
-  CHECK(!JSReceiver::SetProperty(isolate, exception,
-                                 isolate->factory()->InternalizeUtf8String(
-                                     wasm::WasmException::kRuntimeValuesStr),
-                                 values, LanguageMode::kStrict)
+  CHECK(!JSReceiver::SetProperty(
+             isolate, exception,
+             isolate->factory()->wasm_exception_values_symbol(), values,
+             LanguageMode::kStrict)
              .is_null());
-  return ReadOnlyRoots(isolate).undefined_value();
+  return *exception;
 }
 
-RUNTIME_FUNCTION(Runtime_WasmThrow) {
-  // TODO(kschimpf): Can this be replaced with equivalent TurboFan code/calls.
-  HandleScope scope(isolate);
-  DCHECK_NULL(isolate->context());
-  isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
-  DCHECK_EQ(0, args.length());
-  Handle<Object> exception(isolate->get_wasm_caught_exception(), isolate);
-  CHECK(!exception.is_null());
-  isolate->clear_wasm_caught_exception();
-  return isolate->Throw(*exception);
-}
-
-RUNTIME_FUNCTION(Runtime_WasmGetExceptionRuntimeId) {
+RUNTIME_FUNCTION(Runtime_WasmExceptionGetTag) {
   // TODO(kschimpf): Can this be replaced with equivalent TurboFan code/calls.
   HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
   DCHECK_NULL(isolate->context());
   isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
-  Handle<Object> except_obj(isolate->get_wasm_caught_exception(), isolate);
+  CONVERT_ARG_CHECKED(Object, except_obj_raw, 0);
+  // TODO(mstarzinger): Manually box because parameters are not visited yet.
+  Handle<Object> except_obj(except_obj_raw, isolate);
   if (!except_obj.is_null() && except_obj->IsJSReceiver()) {
     Handle<JSReceiver> exception(JSReceiver::cast(*except_obj), isolate);
     Handle<Object> tag;
     if (JSReceiver::GetProperty(isolate, exception,
-                                isolate->factory()->InternalizeUtf8String(
-                                    wasm::WasmException::kRuntimeIdStr))
+                                isolate->factory()->wasm_exception_tag_symbol())
             .ToHandle(&tag)) {
-      if (tag->IsSmi()) {
-        return *tag;
-      }
+      return *tag;
     }
   }
-  return Smi::FromInt(wasm::kInvalidExceptionTag);
+  return ReadOnlyRoots(isolate).undefined_value();
 }
 
 RUNTIME_FUNCTION(Runtime_WasmExceptionGetElement) {
   // TODO(kschimpf): Can this be replaced with equivalent TurboFan code/calls.
   HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
   DCHECK_NULL(isolate->context());
   isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
-  DCHECK_EQ(1, args.length());
-  Handle<Object> except_obj(isolate->get_wasm_caught_exception(), isolate);
+  CONVERT_ARG_CHECKED(Object, except_obj_raw, 0);
+  // TODO(mstarzinger): Manually box because parameters are not visited yet.
+  Handle<Object> except_obj(except_obj_raw, isolate);
   if (!except_obj.is_null() && except_obj->IsJSReceiver()) {
     Handle<JSReceiver> exception(JSReceiver::cast(*except_obj), isolate);
     Handle<Object> values_obj;
-    if (JSReceiver::GetProperty(isolate, exception,
-                                isolate->factory()->InternalizeUtf8String(
-                                    wasm::WasmException::kRuntimeValuesStr))
+    if (JSReceiver::GetProperty(
+            isolate, exception,
+            isolate->factory()->wasm_exception_values_symbol())
             .ToHandle(&values_obj)) {
       if (values_obj->IsJSTypedArray()) {
         Handle<JSTypedArray> values = Handle<JSTypedArray>::cast(values_obj);
         CHECK_EQ(values->type(), kExternalUint16Array);
-        CONVERT_SMI_ARG_CHECKED(index, 0);
+        CONVERT_SMI_ARG_CHECKED(index, 1);
+        CHECK(!values->WasNeutered());
         CHECK_LT(index, Smi::ToInt(values->length()));
         auto* vals =
             reinterpret_cast<uint16_t*>(values->GetBuffer()->backing_store());
@@ -204,23 +177,26 @@ RUNTIME_FUNCTION(Runtime_WasmExceptionGetElement) {
 RUNTIME_FUNCTION(Runtime_WasmExceptionSetElement) {
   // TODO(kschimpf): Can this be replaced with equivalent TurboFan code/calls.
   HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
+  DCHECK_EQ(3, args.length());
   DCHECK_NULL(isolate->context());
   isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
-  Handle<Object> except_obj(isolate->get_wasm_caught_exception(), isolate);
+  CONVERT_ARG_CHECKED(Object, except_obj_raw, 0);
+  // TODO(mstarzinger): Manually box because parameters are not visited yet.
+  Handle<Object> except_obj(except_obj_raw, isolate);
   if (!except_obj.is_null() && except_obj->IsJSReceiver()) {
     Handle<JSReceiver> exception(JSReceiver::cast(*except_obj), isolate);
     Handle<Object> values_obj;
-    if (JSReceiver::GetProperty(isolate, exception,
-                                isolate->factory()->InternalizeUtf8String(
-                                    wasm::WasmException::kRuntimeValuesStr))
+    if (JSReceiver::GetProperty(
+            isolate, exception,
+            isolate->factory()->wasm_exception_values_symbol())
             .ToHandle(&values_obj)) {
       if (values_obj->IsJSTypedArray()) {
         Handle<JSTypedArray> values = Handle<JSTypedArray>::cast(values_obj);
         CHECK_EQ(values->type(), kExternalUint16Array);
-        CONVERT_SMI_ARG_CHECKED(index, 0);
+        CONVERT_SMI_ARG_CHECKED(index, 1);
+        CHECK(!values->WasNeutered());
         CHECK_LT(index, Smi::ToInt(values->length()));
-        CONVERT_SMI_ARG_CHECKED(value, 1);
+        CONVERT_SMI_ARG_CHECKED(value, 2);
         auto* vals =
             reinterpret_cast<uint16_t*>(values->GetBuffer()->backing_store());
         vals[index] = static_cast<uint16_t>(value);
@@ -235,8 +211,6 @@ RUNTIME_FUNCTION(Runtime_WasmRunInterpreter) {
   HandleScope scope(isolate);
   CONVERT_NUMBER_CHECKED(int32_t, func_index, Int32, args[0]);
   CONVERT_ARG_HANDLE_CHECKED(Object, arg_buffer_obj, 1);
-  Handle<WasmInstanceObject> instance(GetWasmInstanceOnStackTop(isolate),
-                                      isolate);
 
   // The arg buffer is the raw pointer to the caller's stack. It looks like a
   // Smi (lowest bit not set, as checked by IsSmi), but is no valid Smi. We just
@@ -245,13 +219,10 @@ RUNTIME_FUNCTION(Runtime_WasmRunInterpreter) {
   CHECK(arg_buffer_obj->IsSmi());
   Address arg_buffer = reinterpret_cast<Address>(*arg_buffer_obj);
 
-  ClearThreadInWasmScope wasm_flag(true);
-
-  // Set the current isolate's context.
-  DCHECK_NULL(isolate->context());
-  isolate->set_context(instance->native_context());
+  ClearThreadInWasmScope wasm_flag;
 
-  // Find the frame pointer of the interpreter entry.
+  // Find the frame pointer and instance of the interpreter frame on the stack.
+  Handle<WasmInstanceObject> instance;
   Address frame_pointer = 0;
   {
     StackFrameIterator it(isolate, isolate->thread_local_top());
@@ -260,9 +231,15 @@ RUNTIME_FUNCTION(Runtime_WasmRunInterpreter) {
     it.Advance();
     // Next: the wasm interpreter entry.
     DCHECK_EQ(StackFrame::WASM_INTERPRETER_ENTRY, it.frame()->type());
+    instance = handle(
+        WasmInterpreterEntryFrame::cast(it.frame())->wasm_instance(), isolate);
     frame_pointer = it.frame()->fp();
   }
 
+  // Set the current isolate's context.
+  DCHECK_NULL(isolate->context());
+  isolate->set_context(instance->native_context());
+
   // Run the function in the interpreter. Note that neither the {WasmDebugInfo}
   // nor the {InterpreterHandle} have to exist, because interpretation might
   // have been triggered by another Isolate sharing the same WasmEngine.
@@ -284,11 +261,7 @@ RUNTIME_FUNCTION(Runtime_WasmStackGuard) {
   DCHECK(!trap_handler::IsTrapHandlerEnabled() ||
          trap_handler::IsThreadInWasm());
 
-  ClearThreadInWasmScope wasm_flag(true);
-
-  // Set the current isolate's context.
-  DCHECK_NULL(isolate->context());
-  isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
+  ClearThreadInWasmScope wasm_flag;
 
   // Check if this is a real stack overflow.
   StackLimitCheck check(isolate);
@@ -303,7 +276,7 @@ RUNTIME_FUNCTION(Runtime_WasmCompileLazy) {
   CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
   CONVERT_SMI_ARG_CHECKED(func_index, 1);
 
-  ClearThreadInWasmScope wasm_flag(true);
+  ClearThreadInWasmScope wasm_flag;
 
 #ifdef DEBUG
   StackFrameIterator it(isolate, isolate->thread_local_top());
diff --git a/deps/v8/src/runtime/runtime.cc b/deps/v8/src/runtime/runtime.cc
index ec35131c90..d9d7d85664 100644
--- a/deps/v8/src/runtime/runtime.cc
+++ b/deps/v8/src/runtime/runtime.cc
@@ -45,9 +45,7 @@ FOR_EACH_INTRINSIC_RETURN_PAIR(P)
   ,
 
 static const Runtime::Function kIntrinsicFunctions[] = {
-  FOR_EACH_INTRINSIC(F)
-  FOR_EACH_INTRINSIC(I)
-};
+    FOR_EACH_INTRINSIC(F) FOR_EACH_INLINE_INTRINSIC(I)};
 
 #undef I
 #undef F
@@ -98,6 +96,44 @@ void InitializeIntrinsicFunctionNames() {
 
 }  // namespace
 
+bool Runtime::NeedsExactContext(FunctionId id) {
+  switch (id) {
+    case Runtime::kAddPrivateField:
+    case Runtime::kCopyDataProperties:
+    case Runtime::kCreateDataProperty:
+    case Runtime::kCreatePrivateFieldSymbol:
+    case Runtime::kReThrow:
+    case Runtime::kThrow:
+    case Runtime::kThrowApplyNonFunction:
+    case Runtime::kThrowCalledNonCallable:
+    case Runtime::kThrowConstAssignError:
+    case Runtime::kThrowConstructorNonCallableError:
+    case Runtime::kThrowConstructedNonConstructable:
+    case Runtime::kThrowConstructorReturnedNonObject:
+    case Runtime::kThrowInvalidStringLength:
+    case Runtime::kThrowInvalidTypedArrayAlignment:
+    case Runtime::kThrowIteratorError:
+    case Runtime::kThrowIteratorResultNotAnObject:
+    case Runtime::kThrowNotConstructor:
+    case Runtime::kThrowRangeError:
+    case Runtime::kThrowReferenceError:
+    case Runtime::kThrowStackOverflow:
+    case Runtime::kThrowStaticPrototypeError:
+    case Runtime::kThrowSuperAlreadyCalledError:
+    case Runtime::kThrowSuperNotCalled:
+    case Runtime::kThrowSymbolAsyncIteratorInvalid:
+    case Runtime::kThrowSymbolIteratorInvalid:
+    case Runtime::kThrowThrowMethodMissing:
+    case Runtime::kThrowTypeError:
+    case Runtime::kThrowUnsupportedSuperError:
+    case Runtime::kThrowWasmError:
+    case Runtime::kThrowWasmStackOverflow:
+      return false;
+    default:
+      return true;
+  }
+}
+
 bool Runtime::IsNonReturning(FunctionId id) {
   switch (id) {
     case Runtime::kThrowUnsupportedSuperError:
@@ -113,6 +149,7 @@ bool Runtime::IsNonReturning(FunctionId id) {
     case Runtime::kThrowConstructorReturnedNonObject:
     case Runtime::kThrowInvalidStringLength:
     case Runtime::kThrowInvalidTypedArrayAlignment:
+    case Runtime::kThrowIteratorError:
     case Runtime::kThrowIteratorResultNotAnObject:
     case Runtime::kThrowThrowMethodMissing:
     case Runtime::kThrowSymbolIteratorInvalid:
diff --git a/deps/v8/src/runtime/runtime.h b/deps/v8/src/runtime/runtime.h
index 5a6364f644..f091d99092 100644
--- a/deps/v8/src/runtime/runtime.h
+++ b/deps/v8/src/runtime/runtime.h
@@ -17,10 +17,10 @@
 namespace v8 {
 namespace internal {
 
-// * Each intrinsic is consistently exposed in JavaScript via 2 names:
+// * Each intrinsic is exposed in JavaScript via:
 //    * %#name, which is always a runtime call.
-//    * %_#name, which can be inlined or just a runtime call, the compiler in
-//      question decides.
+//    * (optionally) %_#name, which can be inlined or just a runtime call, the
+//      compiler in question decides.
 //
 // * IntrinsicTypes are Runtime::RUNTIME and Runtime::INLINE, respectively.
 //
@@ -31,53 +31,57 @@ namespace internal {
 // * Each compiler has an explicit list of intrisics it supports, falling back
 //   to a simple runtime call if necessary.
 
-
 // Entries have the form F(name, number of arguments, number of values):
 // A variable number of arguments is specified by a -1, additional restrictions
-// are specified by inline comments
-
-#define FOR_EACH_INTRINSIC_ARRAY(F) \
-  F(ArrayIncludes_Slow, 3, 1)       \
-  F(ArrayIndexOf, 3, 1)             \
-  F(ArrayIsArray, 1, 1)             \
-  F(ArraySpeciesConstructor, 1, 1)  \
-  F(EstimateNumberOfElements, 1, 1) \
-  F(GetArrayKeys, 2, 1)             \
-  F(GrowArrayElements, 2, 1)        \
-  F(HasComplexElements, 1, 1)       \
-  F(IsArray, 1, 1)                  \
-  F(MoveArrayContents, 2, 1)        \
-  F(NewArray, -1 /* >= 3 */, 1)     \
-  F(NormalizeElements, 1, 1)        \
-  F(PrepareElementsForSort, 2, 1)   \
-  F(TransitionElementsKind, 2, 1)   \
+// are specified by inline comments. To declare only the runtime version (no
+// inline), use the F macro below. To declare the runtime version and the inline
+// version simultaneously, use the I macro below.
+
+#define FOR_EACH_INTRINSIC_ARRAY(F, I)    \
+  F(ArrayIncludes_Slow, 3, 1)             \
+  F(ArrayIndexOf, 3, 1)                   \
+  F(ArrayIsArray, 1, 1)                   \
+  F(ArraySpeciesConstructor, 1, 1)        \
+  F(EstimateNumberOfElements, 1, 1)       \
+  F(GetArrayKeys, 2, 1)                   \
+  F(GrowArrayElements, 2, 1)              \
+  F(HasComplexElements, 1, 1)             \
+  I(IsArray, 1, 1)                        \
+  F(MoveArrayContents, 2, 1)              \
+  F(NewArray, -1 /* >= 3 */, 1)           \
+  F(NormalizeElements, 1, 1)              \
+  F(PrepareElementsForSort, 2, 1)         \
+  F(TransitionElementsKind, 2, 1)         \
+  F(TransitionElementsKindWithKind, 2, 1) \
   F(TrySliceSimpleNonFastElements, 3, 1)
 
-#define FOR_EACH_INTRINSIC_ATOMICS(F)  \
-  F(AtomicsAdd, 3, 1)                  \
-  F(AtomicsAnd, 3, 1)                  \
-  F(AtomicsCompareExchange, 4, 1)      \
-  F(AtomicsExchange, 3, 1)             \
-  F(AtomicsNumWaitersForTesting, 2, 1) \
-  F(AtomicsOr, 3, 1)                   \
-  F(AtomicsSub, 3, 1)                  \
-  F(AtomicsXor, 3, 1)                  \
+#define FOR_EACH_INTRINSIC_ATOMICS(F, I) \
+  F(AtomicsLoad64, 2, 1)                 \
+  F(AtomicsStore64, 3, 1)                \
+  F(AtomicsAdd, 3, 1)                    \
+  F(AtomicsAnd, 3, 1)                    \
+  F(AtomicsCompareExchange, 4, 1)        \
+  F(AtomicsExchange, 3, 1)               \
+  F(AtomicsNumWaitersForTesting, 2, 1)   \
+  F(AtomicsOr, 3, 1)                     \
+  F(AtomicsSub, 3, 1)                    \
+  F(AtomicsXor, 3, 1)                    \
   F(SetAllowAtomicsWait, 1, 1)
 
-#define FOR_EACH_INTRINSIC_BIGINT(F) \
-  F(BigIntBinaryOp, 3, 1)            \
-  F(BigIntCompareToBigInt, 3, 1)     \
-  F(BigIntCompareToNumber, 3, 1)     \
-  F(BigIntCompareToString, 3, 1)     \
-  F(BigIntEqualToBigInt, 2, 1)       \
-  F(BigIntEqualToNumber, 2, 1)       \
-  F(BigIntEqualToString, 2, 1)       \
-  F(BigIntToBoolean, 1, 1)           \
-  F(BigIntToNumber, 1, 1)            \
-  F(BigIntUnaryOp, 2, 1)             \
+#define FOR_EACH_INTRINSIC_BIGINT(F, I) \
+  F(BigIntBinaryOp, 3, 1)               \
+  F(BigIntCompareToBigInt, 3, 1)        \
+  F(BigIntCompareToNumber, 3, 1)        \
+  F(BigIntCompareToString, 3, 1)        \
+  F(BigIntEqualToBigInt, 2, 1)          \
+  F(BigIntEqualToNumber, 2, 1)          \
+  F(BigIntEqualToString, 2, 1)          \
+  F(BigIntToBoolean, 1, 1)              \
+  F(BigIntToNumber, 1, 1)               \
+  F(BigIntUnaryOp, 2, 1)                \
   F(ToBigInt, 1, 1)
 
-#define FOR_EACH_INTRINSIC_CLASSES(F)       \
+#define FOR_EACH_INTRINSIC_CLASSES(F, I)    \
   F(DefineClass, -1 /* >= 3 */, 1)          \
   F(HomeObjectSymbol, 0, 1)                 \
   F(LoadFromSuper, 3, 1)                    \
@@ -93,20 +97,16 @@ namespace internal {
   F(ThrowSuperNotCalled, 0, 1)              \
   F(ThrowUnsupportedSuperError, 0, 1)
 
-#define FOR_EACH_INTRINSIC_COLLECTIONS(F) \
-  F(GetWeakMapEntries, 2, 1)              \
-  F(GetWeakSetValues, 2, 1)               \
-  F(MapGrow, 1, 1)                        \
-  F(MapIteratorClone, 1, 1)               \
-  F(MapShrink, 1, 1)                      \
-  F(SetGrow, 1, 1)                        \
-  F(SetIteratorClone, 1, 1)               \
-  F(SetShrink, 1, 1)                      \
-  F(TheHole, 0, 1)                        \
-  F(WeakCollectionDelete, 3, 1)           \
+#define FOR_EACH_INTRINSIC_COLLECTIONS(F, I) \
+  F(MapGrow, 1, 1)                           \
+  F(MapShrink, 1, 1)                         \
+  F(SetGrow, 1, 1)                           \
+  F(SetShrink, 1, 1)                         \
+  F(TheHole, 0, 1)                           \
+  F(WeakCollectionDelete, 3, 1)              \
   F(WeakCollectionSet, 4, 1)
 
-#define FOR_EACH_INTRINSIC_COMPILER(F)    \
+#define FOR_EACH_INTRINSIC_COMPILER(F, I) \
   F(CompileForOnStackReplacement, 1, 1)   \
   F(CompileLazy, 1, 1)                    \
   F(CompileOptimized_Concurrent, 1, 1)    \
@@ -117,17 +117,14 @@ namespace internal {
   F(NotifyDeoptimized, 0, 1)              \
   F(ResolvePossiblyDirectEval, 6, 1)
 
-#define FOR_EACH_INTRINSIC_DATE(F) \
-  F(DateCurrentTime, 0, 1)         \
-  F(IsDate, 1, 1)
+#define FOR_EACH_INTRINSIC_DATE(F, I) F(DateCurrentTime, 0, 1)
 
-#define FOR_EACH_INTRINSIC_DEBUG(F)             \
+#define FOR_EACH_INTRINSIC_DEBUG(F, I)          \
   F(ClearStepping, 0, 1)                        \
   F(CollectGarbage, 1, 1)                       \
   F(DebugBreakAtEntry, 1, 1)                    \
   F(DebugCollectCoverage, 0, 1)                 \
   F(DebugGetLoadedScriptIds, 0, 1)              \
-  F(DebugIsActive, 0, 1)                        \
   F(DebugOnFunctionCall, 2, 1)                  \
   F(DebugPopPromise, 0, 1)                      \
   F(DebugPrepareStepInSuspendedGenerator, 0, 1) \
@@ -149,164 +146,136 @@ namespace internal {
   F(SetGeneratorScopeVariableValue, 4, 1)       \
   F(LiveEditPatchScript, 2, 1)
 
-#define FOR_EACH_INTRINSIC_FORIN(F) \
-  F(ForInEnumerate, 1, 1)           \
+#define FOR_EACH_INTRINSIC_FORIN(F, I) \
+  F(ForInEnumerate, 1, 1)              \
   F(ForInHasProperty, 2, 1)
 
 #ifdef V8_TRACE_IGNITION
-#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE(F) \
-  F(InterpreterTraceBytecodeEntry, 3, 1)        \
+#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE(F, I) \
+  F(InterpreterTraceBytecodeEntry, 3, 1)           \
   F(InterpreterTraceBytecodeExit, 3, 1)
 #else
-#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE(F)
+#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE(F, I)
 #endif
 
 #ifdef V8_TRACE_FEEDBACK_UPDATES
-#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE_FEEDBACK(F) \
+#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE_FEEDBACK(F, I) \
   F(InterpreterTraceUpdateFeedback, 3, 1)
 #else
-#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE_FEEDBACK(F)
+#define FOR_EACH_INTRINSIC_INTERPRETER_TRACE_FEEDBACK(F, I)
 #endif
 
-#define FOR_EACH_INTRINSIC_INTERPRETER(F)          \
-  FOR_EACH_INTRINSIC_INTERPRETER_TRACE(F)          \
-  FOR_EACH_INTRINSIC_INTERPRETER_TRACE_FEEDBACK(F) \
+#define FOR_EACH_INTRINSIC_INTERPRETER(F, I)          \
+  FOR_EACH_INTRINSIC_INTERPRETER_TRACE(F, I)          \
+  FOR_EACH_INTRINSIC_INTERPRETER_TRACE_FEEDBACK(F, I) \
   F(InterpreterDeserializeLazy, 2, 1)
 
-#define FOR_EACH_INTRINSIC_FUNCTION(F)     \
-  F(Call, -1 /* >= 2 */, 1)                \
-  F(FunctionGetName, 1, 1)                 \
+#define FOR_EACH_INTRINSIC_FUNCTION(F, I)  \
+  I(Call, -1 /* >= 2 */, 1)                \
   F(FunctionGetScriptSource, 1, 1)         \
   F(FunctionGetScriptId, 1, 1)             \
   F(FunctionGetScriptSourcePosition, 1, 1) \
   F(FunctionGetSourceCode, 1, 1)           \
   F(FunctionIsAPIFunction, 1, 1)           \
-  F(IsConstructor, 1, 1)                   \
   F(IsFunction, 1, 1)                      \
-  F(SetCode, 2, 1)                         \
   F(SetNativeFlag, 1, 1)
 
-#define FOR_EACH_INTRINSIC_GENERATOR(F)       \
+#define FOR_EACH_INTRINSIC_GENERATOR(F, I)    \
   F(AsyncGeneratorHasCatchHandlerForPC, 1, 1) \
-  F(AsyncGeneratorReject, 2, 1)               \
-  F(AsyncGeneratorResolve, 3, 1)              \
-  F(AsyncGeneratorYield, 3, 1)                \
-  F(CreateJSGeneratorObject, 2, 1)            \
-  F(GeneratorClose, 1, 1)                     \
+  I(AsyncGeneratorReject, 2, 1)               \
+  I(AsyncGeneratorResolve, 3, 1)              \
+  I(AsyncGeneratorYield, 3, 1)                \
+  I(CreateJSGeneratorObject, 2, 1)            \
+  I(GeneratorClose, 1, 1)                     \
   F(GeneratorGetFunction, 1, 1)               \
-  F(GeneratorGetInputOrDebugPos, 1, 1)        \
-  F(GeneratorGetResumeMode, 1, 1)
+  I(GeneratorGetResumeMode, 1, 1)
 
 #ifdef V8_INTL_SUPPORT
-#define FOR_EACH_INTRINSIC_INTL(F)           \
-  F(AvailableLocalesOf, 1, 1)                \
-  F(BreakIteratorBreakType, 1, 1)            \
-  F(BreakIteratorCurrent, 1, 1)              \
-  F(BreakIteratorFirst, 1, 1)                \
-  F(BreakIteratorNext, 1, 1)                 \
-  F(CanonicalizeLanguageTag, 1, 1)           \
-  F(CollatorResolvedOptions, 1, 1)           \
-  F(CreateBreakIterator, 3, 1)               \
-  F(CreateDateTimeFormat, 3, 1)              \
-  F(CreateNumberFormat, 3, 1)                \
-  F(CurrencyDigits, 1, 1)                    \
-  F(DateCacheVersion, 0, 1)                  \
-  F(DefaultNumberOption, 5, 1)               \
-  F(DefineWEProperty, 3, 1)                  \
-  F(FormatList, 2, 1)                        \
-  F(FormatListToParts, 2, 1)                 \
-  F(GetDefaultICULocale, 0, 1)               \
-  F(GetNumberOption, 5, 1)                   \
-  F(IntlUnwrapReceiver, 5, 1)                \
-  F(IsInitializedIntlObjectOfType, 2, 1)     \
-  F(IsWellFormedCurrencyCode, 1, 1)          \
-  F(MarkAsInitializedIntlObjectOfType, 2, 1) \
-  F(ParseExtension, 1, 1)                    \
-  F(PluralRulesResolvedOptions, 1, 1)        \
-  F(PluralRulesSelect, 2, 1)                 \
-  F(ToDateTimeOptions, 3, 1)                 \
-  F(ToLocaleDateTime, 6, 1)                  \
-  F(StringToLowerCaseIntl, 1, 1)             \
-  F(StringToUpperCaseIntl, 1, 1)             \
-  F(SupportedLocalesOf, 3, 1)                \
-// End of macro.
+#define FOR_EACH_INTRINSIC_INTL(F, I) \
+  F(AvailableLocalesOf, 1, 1)         \
+  F(CanonicalizeLanguageTag, 1, 1)    \
+  F(DateCacheVersion, 0, 1)           \
+  F(FormatList, 2, 1)                 \
+  F(FormatListToParts, 2, 1)          \
+  F(GetDefaultICULocale, 0, 1)        \
+  F(StringToLowerCaseIntl, 1, 1)      \
+  F(StringToUpperCaseIntl, 1, 1)  // End of macro.
 #else
-#define FOR_EACH_INTRINSIC_INTL(F)
+#define FOR_EACH_INTRINSIC_INTL(F, I)
 #endif  // V8_INTL_SUPPORT
 
-#define FOR_EACH_INTRINSIC_INTERNAL(F)                               \
-  F(AllocateInNewSpace, 1, 1)                                        \
-  F(AllocateInTargetSpace, 2, 1)                                     \
-  F(AllocateSeqOneByteString, 1, 1)                                  \
-  F(AllocateSeqTwoByteString, 1, 1)                                  \
-  F(AllowDynamicFunction, 1, 1)                                      \
-  F(CheckIsBootstrapping, 0, 1)                                      \
-  F(CreateAsyncFromSyncIterator, 1, 1)                               \
-  F(CreateListFromArrayLike, 1, 1)                                   \
-  F(CreateTemplateObject, 1, 1)                                      \
-  F(DeserializeLazy, 1, 1)                                           \
-  F(ExportFromRuntime, 1, 1)                                         \
-  F(GetAndResetRuntimeCallStats, -1 /* <= 2 */, 1)                   \
-  F(IncrementUseCounter, 1, 1)                                       \
-  F(InstallToContext, 1, 1)                                          \
-  F(Interrupt, 0, 1)                                                 \
-  F(IS_VAR, 1, 1)                                                    \
-  F(NewReferenceError, 2, 1)                                         \
-  F(NewSyntaxError, 2, 1)                                            \
-  F(NewTypeError, 2, 1)                                              \
-  F(OrdinaryHasInstance, 2, 1)                                       \
-  F(PromoteScheduledException, 0, 1)                                 \
-  F(ReportMessage, 1, 1)                                             \
-  F(ReThrow, 1, 1)                                                   \
-  F(RunMicrotaskCallback, 2, 1)                                      \
-  F(RunMicrotasks, 0, 1)                                             \
-  F(StackGuard, 0, 1)                                                \
-  F(Throw, 1, 1)                                                     \
-  F(ThrowApplyNonFunction, 1, 1)                                     \
-  F(ThrowCalledNonCallable, 1, 1)                                    \
-  F(ThrowConstructedNonConstructable, 1, 1)                          \
-  F(ThrowConstructorReturnedNonObject, 0, 1)                         \
-  F(ThrowInvalidStringLength, 0, 1)                                  \
-  F(ThrowInvalidTypedArrayAlignment, 2, 1)                           \
-  F(ThrowIteratorResultNotAnObject, 1, 1)                            \
-  F(ThrowNotConstructor, 1, 1)                                       \
-  F(ThrowRangeError, -1 /* >= 1 */, 1)                               \
-  F(ThrowReferenceError, 1, 1)                                       \
-  F(ThrowStackOverflow, 0, 1)                                        \
-  F(ThrowSymbolAsyncIteratorInvalid, 0, 1)                           \
-  F(ThrowSymbolIteratorInvalid, 0, 1)                                \
-  F(ThrowThrowMethodMissing, 0, 1)                                   \
-  F(ThrowTypeError, -1 /* >= 1 */, 1)                                \
-  F(Typeof, 1, 1)                                                    \
+#define FOR_EACH_INTRINSIC_INTERNAL(F, I)          \
+  F(AllocateInNewSpace, 1, 1)                      \
+  F(AllocateInTargetSpace, 2, 1)                   \
+  F(AllocateSeqOneByteString, 1, 1)                \
+  F(AllocateSeqTwoByteString, 1, 1)                \
+  F(AllowDynamicFunction, 1, 1)                    \
+  F(CheckIsBootstrapping, 0, 1)                    \
+  I(CreateAsyncFromSyncIterator, 1, 1)             \
+  F(CreateListFromArrayLike, 1, 1)                 \
+  F(CreateTemplateObject, 1, 1)                    \
+  F(DeserializeLazy, 1, 1)                         \
+  F(ExportFromRuntime, 1, 1)                       \
+  F(GetAndResetRuntimeCallStats, -1 /* <= 2 */, 1) \
+  F(IncrementUseCounter, 1, 1)                     \
+  F(InstallToContext, 1, 1)                        \
+  F(Interrupt, 0, 1)                               \
+  F(IS_VAR, 1, 1)                                  \
+  F(NewReferenceError, 2, 1)                       \
+  F(NewSyntaxError, 2, 1)                          \
+  F(NewTypeError, 2, 1)                            \
+  F(OrdinaryHasInstance, 2, 1)                     \
+  F(PromoteScheduledException, 0, 1)               \
+  F(ReportMessage, 1, 1)                           \
+  F(ReThrow, 1, 1)                                 \
+  F(RunMicrotaskCallback, 2, 1)                    \
+  F(RunMicrotasks, 0, 1)                           \
+  F(StackGuard, 0, 1)                              \
+  F(Throw, 1, 1)                                   \
+  F(ThrowApplyNonFunction, 1, 1)                   \
+  F(ThrowCalledNonCallable, 1, 1)                  \
+  F(ThrowConstructedNonConstructable, 1, 1)        \
+  F(ThrowConstructorReturnedNonObject, 0, 1)       \
+  F(ThrowInvalidStringLength, 0, 1)                \
+  F(ThrowInvalidTypedArrayAlignment, 2, 1)         \
+  F(ThrowIteratorError, 1, 1)                      \
+  F(ThrowIteratorResultNotAnObject, 1, 1)          \
+  F(ThrowNotConstructor, 1, 1)                     \
+  F(ThrowRangeError, -1 /* >= 1 */, 1)             \
+  F(ThrowReferenceError, 1, 1)                     \
+  F(ThrowStackOverflow, 0, 1)                      \
+  F(ThrowSymbolAsyncIteratorInvalid, 0, 1)         \
+  F(ThrowSymbolIteratorInvalid, 0, 1)              \
+  F(ThrowThrowMethodMissing, 0, 1)                 \
+  F(ThrowTypeError, -1 /* >= 1 */, 1)              \
+  F(Typeof, 1, 1)                                  \
   F(UnwindAndFindExceptionHandler, 0, 1)
 
-#define FOR_EACH_INTRINSIC_LITERALS(F)              \
+#define FOR_EACH_INTRINSIC_LITERALS(F, I)           \
   F(CreateArrayLiteral, 4, 1)                       \
   F(CreateArrayLiteralWithoutAllocationSite, 2, 1)  \
   F(CreateObjectLiteral, 4, 1)                      \
   F(CreateObjectLiteralWithoutAllocationSite, 2, 1) \
   F(CreateRegExpLiteral, 4, 1)
 
-#define FOR_EACH_INTRINSIC_MATHS(F) F(GenerateRandomNumbers, 0, 1)
-
-#define FOR_EACH_INTRINSIC_MODULE(F) \
-  F(DynamicImportCall, 2, 1)         \
-  F(GetImportMetaObject, 0, 1)       \
+#define FOR_EACH_INTRINSIC_MODULE(F, I) \
+  F(DynamicImportCall, 2, 1)            \
+  I(GetImportMetaObject, 0, 1)          \
   F(GetModuleNamespace, 1, 1)
 
-#define FOR_EACH_INTRINSIC_NUMBERS(F) \
-  F(GetHoleNaNLower, 0, 1)            \
-  F(GetHoleNaNUpper, 0, 1)            \
-  F(IsSmi, 1, 1)                      \
-  F(IsValidSmi, 1, 1)                 \
-  F(MaxSmi, 0, 1)                     \
-  F(NumberToString, 1, 1)             \
-  F(SmiLexicographicCompare, 2, 1)    \
-  F(StringParseFloat, 1, 1)           \
-  F(StringParseInt, 2, 1)             \
+#define FOR_EACH_INTRINSIC_NUMBERS(F, I) \
+  F(GetHoleNaNLower, 0, 1)               \
+  F(GetHoleNaNUpper, 0, 1)               \
+  I(IsSmi, 1, 1)                         \
+  F(IsValidSmi, 1, 1)                    \
+  F(MaxSmi, 0, 1)                        \
+  F(NumberToString, 1, 1)                \
+  F(SmiLexicographicCompare, 2, 1)       \
+  F(StringParseFloat, 1, 1)              \
+  F(StringParseInt, 2, 1)                \
   F(StringToNumber, 1, 1)
 
-#define FOR_EACH_INTRINSIC_OBJECT(F)                            \
+#define FOR_EACH_INTRINSIC_OBJECT(F, I)                         \
   F(AddDictionaryProperty, 3, 1)                                \
   F(AddElement, 3, 1)                                           \
   F(AddNamedProperty, 4, 1)                                     \
@@ -317,8 +286,8 @@ namespace internal {
   F(CompleteInobjectSlackTrackingForMap, 1, 1)                  \
   F(CopyDataProperties, 2, 1)                                   \
   F(CopyDataPropertiesWithExcludedProperties, -1 /* >= 1 */, 1) \
-  F(CreateDataProperty, 3, 1)                                   \
-  F(CreateIterResultObject, 2, 1)                               \
+  I(CreateDataProperty, 3, 1)                                   \
+  I(CreateIterResultObject, 2, 1)                               \
   F(DefineAccessorPropertyUnchecked, 5, 1)                      \
   F(DefineDataPropertyInLiteral, 6, 1)                          \
   F(DefineGetterPropertyUnchecked, 4, 1)                        \
@@ -329,13 +298,11 @@ namespace internal {
   F(GetOwnPropertyDescriptor, 2, 1)                             \
   F(GetOwnPropertyKeys, 2, 1)                                   \
   F(GetProperty, 2, 1)                                          \
-  F(GetPrototype, 1, 1)                                         \
   F(HasFastPackedElements, 1, 1)                                \
   F(HasInPrototypeChain, 2, 1)                                  \
-  F(HasProperty, 2, 1)                                          \
+  I(HasProperty, 2, 1)                                          \
   F(InternalSetPrototype, 2, 1)                                 \
-  F(IsJSReceiver, 1, 1)                                         \
-  F(KeyedGetProperty, 2, 1)                                     \
+  I(IsJSReceiver, 1, 1)                                         \
   F(NewObject, 2, 1)                                            \
   F(ObjectCreate, 2, 1)                                         \
   F(ObjectEntries, 1, 1)                                        \
@@ -347,62 +314,59 @@ namespace internal {
   F(ObjectValues, 1, 1)                                         \
   F(ObjectValuesSkipFastPath, 1, 1)                             \
   F(OptimizeObjectForAddingMultipleProperties, 2, 1)            \
-  F(SameValue, 2, 1)                                            \
-  F(SameValueZero, 2, 1)                                        \
+  F(PerformSideEffectCheckForObject, 1, 1)                      \
   F(SetDataProperties, 2, 1)                                    \
-  F(SetProperty, 4, 1)                                          \
+  F(SetKeyedProperty, 4, 1)                                     \
+  F(SetNamedProperty, 4, 1)                                     \
+  F(StoreDataPropertyInLiteral, 3, 1)                           \
   F(ShrinkPropertyDictionary, 1, 1)                             \
   F(ToFastProperties, 1, 1)                                     \
-  F(ToInteger, 1, 1)                                            \
-  F(ToLength, 1, 1)                                             \
+  I(ToLength, 1, 1)                                             \
   F(ToName, 1, 1)                                               \
-  F(ToNumber, 1, 1)                                             \
+  I(ToNumber, 1, 1)                                             \
   F(ToNumeric, 1, 1)                                            \
-  F(ToObject, 1, 1)                                             \
-  F(ToPrimitive, 1, 1)                                          \
-  F(ToPrimitive_Number, 1, 1)                                   \
-  F(ToString, 1, 1)                                             \
-  F(TryMigrateInstance, 1, 1)                                   \
-  F(ValueOf, 1, 1)
-
-#define FOR_EACH_INTRINSIC_OPERATORS(F) \
-  F(Add, 2, 1)                          \
-  F(Equal, 2, 1)                        \
-  F(GreaterThan, 2, 1)                  \
-  F(GreaterThanOrEqual, 2, 1)           \
-  F(LessThan, 2, 1)                     \
-  F(LessThanOrEqual, 2, 1)              \
-  F(NotEqual, 2, 1)                     \
-  F(StrictEqual, 2, 1)                  \
+  I(ToObject, 1, 1)                                             \
+  I(ToString, 1, 1)                                             \
+  F(TryMigrateInstance, 1, 1)
+
+#define FOR_EACH_INTRINSIC_OPERATORS(F, I) \
+  F(Add, 2, 1)                             \
+  F(Equal, 2, 1)                           \
+  F(GreaterThan, 2, 1)                     \
+  F(GreaterThanOrEqual, 2, 1)              \
+  F(LessThan, 2, 1)                        \
+  F(LessThanOrEqual, 2, 1)                 \
+  F(NotEqual, 2, 1)                        \
+  F(StrictEqual, 2, 1)                     \
   F(StrictNotEqual, 2, 1)
 
-#define FOR_EACH_INTRINSIC_PROMISE(F)  \
-  F(EnqueueMicrotask, 1, 1)            \
-  F(PromiseHookAfter, 1, 1)            \
-  F(PromiseHookBefore, 1, 1)           \
-  F(PromiseHookInit, 2, 1)             \
-  F(AwaitPromisesInit, 3, 1)           \
-  F(PromiseMarkAsHandled, 1, 1)        \
-  F(PromiseRejectEventFromStack, 2, 1) \
-  F(PromiseResult, 1, 1)               \
-  F(PromiseRevokeReject, 1, 1)         \
-  F(PromiseStatus, 1, 1)               \
-  F(RejectPromise, 3, 1)               \
-  F(ResolvePromise, 2, 1)              \
-  F(PromiseRejectAfterResolved, 2, 1)  \
+#define FOR_EACH_INTRINSIC_PROMISE(F, I) \
+  F(EnqueueMicrotask, 1, 1)              \
+  F(PromiseHookAfter, 1, 1)              \
+  F(PromiseHookBefore, 1, 1)             \
+  F(PromiseHookInit, 2, 1)               \
+  F(AwaitPromisesInit, 3, 1)             \
+  F(PromiseMarkAsHandled, 1, 1)          \
+  F(PromiseRejectEventFromStack, 2, 1)   \
+  F(PromiseResult, 1, 1)                 \
+  F(PromiseRevokeReject, 1, 1)           \
+  F(PromiseStatus, 1, 1)                 \
+  I(RejectPromise, 3, 1)                 \
+  I(ResolvePromise, 2, 1)                \
+  F(PromiseRejectAfterResolved, 2, 1)    \
   F(PromiseResolveAfterResolved, 2, 1)
 
-#define FOR_EACH_INTRINSIC_PROXY(F)   \
-  F(CheckProxyGetSetTrapResult, 2, 1) \
-  F(CheckProxyHasTrap, 2, 1)          \
-  F(GetPropertyWithReceiver, 3, 1)    \
-  F(IsJSProxy, 1, 1)                  \
-  F(JSProxyGetHandler, 1, 1)          \
-  F(JSProxyGetTarget, 1, 1)           \
+#define FOR_EACH_INTRINSIC_PROXY(F, I) \
+  F(CheckProxyGetSetTrapResult, 2, 1)  \
+  F(CheckProxyHasTrap, 2, 1)           \
+  F(GetPropertyWithReceiver, 3, 1)     \
+  F(IsJSProxy, 1, 1)                   \
+  F(JSProxyGetHandler, 1, 1)           \
+  F(JSProxyGetTarget, 1, 1)            \
   F(SetPropertyWithReceiver, 5, 1)
 
-#define FOR_EACH_INTRINSIC_REGEXP(F)                \
-  F(IsRegExp, 1, 1)                                 \
+#define FOR_EACH_INTRINSIC_REGEXP(F, I)             \
+  I(IsRegExp, 1, 1)                                 \
   F(RegExpExec, 4, 1)                               \
   F(RegExpExecMultiple, 4, 1)                       \
   F(RegExpInitializeAndCompile, 3, 1)               \
@@ -412,7 +376,7 @@ namespace internal {
   F(StringReplaceNonGlobalRegExpWithFunction, 3, 1) \
   F(StringSplit, 3, 1)
 
-#define FOR_EACH_INTRINSIC_SCOPES(F)      \
+#define FOR_EACH_INTRINSIC_SCOPES(F, I)   \
   F(DeclareEvalFunction, 2, 1)            \
   F(DeclareEvalVar, 1, 1)                 \
   F(DeclareGlobals, 3, 1)                 \
@@ -438,7 +402,7 @@ namespace internal {
   F(StoreLookupSlot_Strict, 2, 1)         \
   F(ThrowConstAssignError, 0, 1)
 
-#define FOR_EACH_INTRINSIC_STRINGS(F)     \
+#define FOR_EACH_INTRINSIC_STRINGS(F, I)  \
   F(FlattenString, 1, 1)                  \
   F(GetSubstitution, 5, 1)                \
   F(InternalizeString, 1, 1)              \
@@ -447,7 +411,6 @@ namespace internal {
   F(StringBuilderConcat, 3, 1)            \
   F(StringBuilderJoin, 3, 1)              \
   F(StringCharCodeAt, 2, 1)               \
-  F(StringCharFromCode, 1, 1)             \
   F(StringEqual, 2, 1)                    \
   F(StringGreaterThan, 2, 1)              \
   F(StringGreaterThanOrEqual, 2, 1)       \
@@ -458,19 +421,18 @@ namespace internal {
   F(StringLessThan, 2, 1)                 \
   F(StringLessThanOrEqual, 2, 1)          \
   F(StringMaxLength, 0, 1)                \
-  F(StringNotEqual, 2, 1)                 \
   F(StringReplaceOneCharWithString, 3, 1) \
   F(StringSubstring, 3, 1)                \
   F(StringToArray, 2, 1)                  \
   F(StringTrim, 2, 1)
 
-#define FOR_EACH_INTRINSIC_SYMBOL(F)       \
+#define FOR_EACH_INTRINSIC_SYMBOL(F, I)    \
   F(CreatePrivateFieldSymbol, 0, 1)        \
   F(CreatePrivateSymbol, -1 /* <= 1 */, 1) \
   F(SymbolDescriptiveString, 1, 1)         \
   F(SymbolIsPrivate, 1, 1)
 
-#define FOR_EACH_INTRINSIC_TEST(F)            \
+#define FOR_EACH_INTRINSIC_TEST(F, I)         \
   F(Abort, 1, 1)                              \
   F(AbortJS, 1, 1)                            \
   F(ClearFunctionFeedback, 1, 1)              \
@@ -482,7 +444,7 @@ namespace internal {
   F(DebugTrace, 0, 1)                         \
   F(DebugTrackRetainingPath, -1, 1)           \
   F(DeoptimizeFunction, 1, 1)                 \
-  F(DeoptimizeNow, 0, 1)                      \
+  I(DeoptimizeNow, 0, 1)                      \
   F(DeserializeWasmModule, 2, 1)              \
   F(DisallowCodegenFromStrings, 1, 1)         \
   F(DisallowWasmCodegen, 1, 1)                \
@@ -490,8 +452,11 @@ namespace internal {
   F(FreezeWasmLazyCompilation, 1, 1)          \
   F(GetCallable, 0, 1)                        \
   F(GetDeoptCount, 1, 1)                      \
+  F(GetInitializerFunction, 1, 1)             \
   F(GetOptimizationStatus, -1, 1)             \
   F(GetUndetectable, 0, 1)                    \
+  F(GetWasmExceptionId, 2, 1)                 \
+  F(GetWasmExceptionValues, 1, 1)             \
   F(GetWasmRecoveredTrapCount, 0, 1)          \
   F(GlobalPrint, 1, 1)                        \
   F(HasDictionaryElements, 1, 1)              \
@@ -538,6 +503,7 @@ namespace internal {
   F(ArraySpeciesProtector, 0, 1)              \
   F(TypedArraySpeciesProtector, 0, 1)         \
   F(PromiseSpeciesProtector, 0, 1)            \
+  F(StringIteratorProtector, 0, 1)            \
   F(SystemBreak, 0, 1)                        \
   F(TraceEnter, 0, 1)                         \
   F(TraceExit, 1, 1)                          \
@@ -548,37 +514,36 @@ namespace internal {
   F(WasmMemoryHasFullGuardRegion, 1, 1)       \
   F(SetWasmThreadsEnabled, 1, 1)
 
-#define FOR_EACH_INTRINSIC_TYPEDARRAY(F) \
-  F(ArrayBufferNeuter, 1, 1)             \
-  F(ArrayBufferViewWasNeutered, 1, 1)    \
-  F(IsTypedArray, 1, 1)                  \
-  F(TypedArrayCopyElements, 3, 1)        \
-  F(TypedArrayGetBuffer, 1, 1)           \
-  F(TypedArrayGetLength, 1, 1)           \
-  F(TypedArraySet, 2, 1)                 \
+#define FOR_EACH_INTRINSIC_TYPEDARRAY(F, I) \
+  F(ArrayBufferNeuter, 1, 1)                \
+  F(ArrayBufferViewWasNeutered, 1, 1)       \
+  I(IsTypedArray, 1, 1)                     \
+  F(TypedArrayCopyElements, 3, 1)           \
+  F(TypedArrayGetBuffer, 1, 1)              \
+  F(TypedArrayGetLength, 1, 1)              \
+  F(TypedArraySet, 2, 1)                    \
   F(TypedArraySortFast, 1, 1)
 
-#define FOR_EACH_INTRINSIC_WASM(F)   \
-  F(ThrowWasmError, 1, 1)            \
-  F(ThrowWasmStackOverflow, 0, 1)    \
-  F(WasmExceptionGetElement, 1, 1)   \
-  F(WasmExceptionSetElement, 2, 1)   \
-  F(WasmGetExceptionRuntimeId, 0, 1) \
-  F(WasmGrowMemory, 2, 1)            \
-  F(WasmRunInterpreter, 2, 1)        \
-  F(WasmStackGuard, 0, 1)            \
-  F(WasmThrow, 0, 1)                 \
-  F(WasmThrowCreate, 2, 1)           \
-  F(WasmThrowTypeError, 0, 1)        \
+#define FOR_EACH_INTRINSIC_WASM(F, I) \
+  F(ThrowWasmError, 1, 1)             \
+  F(ThrowWasmStackOverflow, 0, 1)     \
+  F(WasmExceptionGetElement, 2, 1)    \
+  F(WasmExceptionSetElement, 3, 1)    \
+  F(WasmExceptionGetTag, 1, 1)        \
+  F(WasmGrowMemory, 2, 1)             \
+  F(WasmRunInterpreter, 2, 1)         \
+  F(WasmStackGuard, 0, 1)             \
+  F(WasmThrowCreate, 2, 1)            \
+  F(WasmThrowTypeError, 0, 1)         \
   F(WasmCompileLazy, 2, 1)
 
-#define FOR_EACH_INTRINSIC_RETURN_PAIR(F) \
-  F(DebugBreakOnBytecode, 1, 2)           \
+#define FOR_EACH_INTRINSIC_RETURN_PAIR_IMPL(F, I) \
+  F(DebugBreakOnBytecode, 1, 2)                   \
   F(LoadLookupSlotForCall, 1, 2)
 
 // Most intrinsics are implemented in the runtime/ directory, but ICs are
 // implemented in ic.cc for now.
-#define FOR_EACH_INTRINSIC_IC(F)             \
+#define FOR_EACH_INTRINSIC_IC(F, I)          \
   F(ElementsTransitionAndStoreIC_Miss, 6, 1) \
   F(KeyedLoadIC_Miss, 4, 1)                  \
   F(KeyedStoreIC_Miss, 5, 1)                 \
@@ -599,44 +564,55 @@ namespace internal {
   F(CloneObjectIC_Miss, 4, 1)                \
   F(CloneObjectIC_Slow, 2, 1)
 
+#define FOR_EACH_INTRINSIC_RETURN_OBJECT_IMPL(F, I) \
+  FOR_EACH_INTRINSIC_ARRAY(F, I)                    \
+  FOR_EACH_INTRINSIC_ATOMICS(F, I)                  \
+  FOR_EACH_INTRINSIC_BIGINT(F, I)                   \
+  FOR_EACH_INTRINSIC_CLASSES(F, I)                  \
+  FOR_EACH_INTRINSIC_COLLECTIONS(F, I)              \
+  FOR_EACH_INTRINSIC_COMPILER(F, I)                 \
+  FOR_EACH_INTRINSIC_DATE(F, I)                     \
+  FOR_EACH_INTRINSIC_DEBUG(F, I)                    \
+  FOR_EACH_INTRINSIC_FORIN(F, I)                    \
+  FOR_EACH_INTRINSIC_FUNCTION(F, I)                 \
+  FOR_EACH_INTRINSIC_GENERATOR(F, I)                \
+  FOR_EACH_INTRINSIC_IC(F, I)                       \
+  FOR_EACH_INTRINSIC_INTERNAL(F, I)                 \
+  FOR_EACH_INTRINSIC_INTERPRETER(F, I)              \
+  FOR_EACH_INTRINSIC_INTL(F, I)                     \
+  FOR_EACH_INTRINSIC_LITERALS(F, I)                 \
+  FOR_EACH_INTRINSIC_MODULE(F, I)                   \
+  FOR_EACH_INTRINSIC_NUMBERS(F, I)                  \
+  FOR_EACH_INTRINSIC_OBJECT(F, I)                   \
+  FOR_EACH_INTRINSIC_OPERATORS(F, I)                \
+  FOR_EACH_INTRINSIC_PROMISE(F, I)                  \
+  FOR_EACH_INTRINSIC_PROXY(F, I)                    \
+  FOR_EACH_INTRINSIC_REGEXP(F, I)                   \
+  FOR_EACH_INTRINSIC_SCOPES(F, I)                   \
+  FOR_EACH_INTRINSIC_STRINGS(F, I)                  \
+  FOR_EACH_INTRINSIC_SYMBOL(F, I)                   \
+  FOR_EACH_INTRINSIC_TEST(F, I)                     \
+  FOR_EACH_INTRINSIC_TYPEDARRAY(F, I)               \
+  FOR_EACH_INTRINSIC_WASM(F, I)
+
+// Defines the list of all intrinsics, coming in 2 flavors, either returning an
+// object or a pair.
+#define FOR_EACH_INTRINSIC_IMPL(F, I)       \
+  FOR_EACH_INTRINSIC_RETURN_PAIR_IMPL(F, I) \
+  FOR_EACH_INTRINSIC_RETURN_OBJECT_IMPL(F, I)
+
 #define FOR_EACH_INTRINSIC_RETURN_OBJECT(F) \
-  FOR_EACH_INTRINSIC_ARRAY(F)               \
-  FOR_EACH_INTRINSIC_ATOMICS(F)             \
-  FOR_EACH_INTRINSIC_BIGINT(F)              \
-  FOR_EACH_INTRINSIC_CLASSES(F)             \
-  FOR_EACH_INTRINSIC_COLLECTIONS(F)         \
-  FOR_EACH_INTRINSIC_COMPILER(F)            \
-  FOR_EACH_INTRINSIC_DATE(F)                \
-  FOR_EACH_INTRINSIC_DEBUG(F)               \
-  FOR_EACH_INTRINSIC_FORIN(F)               \
-  FOR_EACH_INTRINSIC_FUNCTION(F)            \
-  FOR_EACH_INTRINSIC_GENERATOR(F)           \
-  FOR_EACH_INTRINSIC_IC(F)                  \
-  FOR_EACH_INTRINSIC_INTERNAL(F)            \
-  FOR_EACH_INTRINSIC_INTERPRETER(F)         \
-  FOR_EACH_INTRINSIC_INTL(F)                \
-  FOR_EACH_INTRINSIC_LITERALS(F)            \
-  FOR_EACH_INTRINSIC_MATHS(F)               \
-  FOR_EACH_INTRINSIC_MODULE(F)              \
-  FOR_EACH_INTRINSIC_NUMBERS(F)             \
-  FOR_EACH_INTRINSIC_OBJECT(F)              \
-  FOR_EACH_INTRINSIC_OPERATORS(F)           \
-  FOR_EACH_INTRINSIC_PROMISE(F)             \
-  FOR_EACH_INTRINSIC_PROXY(F)               \
-  FOR_EACH_INTRINSIC_REGEXP(F)              \
-  FOR_EACH_INTRINSIC_SCOPES(F)              \
-  FOR_EACH_INTRINSIC_STRINGS(F)             \
-  FOR_EACH_INTRINSIC_SYMBOL(F)              \
-  FOR_EACH_INTRINSIC_TEST(F)                \
-  FOR_EACH_INTRINSIC_TYPEDARRAY(F)          \
-  FOR_EACH_INTRINSIC_WASM(F)
-
-// FOR_EACH_INTRINSIC defines the list of all intrinsics, coming in 2 flavors,
-// either returning an object or a pair.
-#define FOR_EACH_INTRINSIC(F)         \
-  FOR_EACH_INTRINSIC_RETURN_PAIR(F)   \
-  FOR_EACH_INTRINSIC_RETURN_OBJECT(F)
+  FOR_EACH_INTRINSIC_RETURN_OBJECT_IMPL(F, F)
+
+#define FOR_EACH_INTRINSIC_RETURN_PAIR(F) \
+  FOR_EACH_INTRINSIC_RETURN_PAIR_IMPL(F, F)
+
+// The list of all intrinsics, including those that have inline versions, but
+// not the inline versions themselves.
+#define FOR_EACH_INTRINSIC(F) FOR_EACH_INTRINSIC_IMPL(F, F)
 
+// The list of all inline intrinsics only.
+#define FOR_EACH_INLINE_INTRINSIC(I) FOR_EACH_INTRINSIC_IMPL(NOTHING, I)
 
 #define F(name, nargs, ressize)                                 \
   Object* Runtime_##name(int args_length, Object** args_object, \
@@ -652,12 +628,17 @@ class Runtime : public AllStatic {
   enum FunctionId : int32_t {
 #define F(name, nargs, ressize) k##name,
 #define I(name, nargs, ressize) kInline##name,
-    FOR_EACH_INTRINSIC(F) FOR_EACH_INTRINSIC(I)
+    FOR_EACH_INTRINSIC(F) FOR_EACH_INLINE_INTRINSIC(I)
 #undef I
 #undef F
         kNumFunctions,
   };
 
+  static constexpr int kNumInlineFunctions =
+#define COUNT(...) +1
+      FOR_EACH_INLINE_INTRINSIC(COUNT);
+#undef COUNT
+
   enum IntrinsicType { RUNTIME, INLINE };
 
   // Intrinsic function descriptor.
@@ -680,6 +661,11 @@ class Runtime : public AllStatic {
 
   static const int kNotFound = -1;
 
+  // Checks whether the runtime function with the given {id} depends on the
+  // "current context", i.e. because it does scoped lookups, or whether it's
+  // fine to just pass any context within the same "native context".
+  static bool NeedsExactContext(FunctionId id);
+
   // Checks whether the runtime function with the given {id} never returns
   // to it's caller normally, i.e. whether it'll always raise an exception.
   // More specifically: The C++ implementation returns the Heap::exception
@@ -704,7 +690,8 @@ class Runtime : public AllStatic {
 
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> SetObjectProperty(
       Isolate* isolate, Handle<Object> object, Handle<Object> key,
-      Handle<Object> value, LanguageMode language_mode);
+      Handle<Object> value, LanguageMode language_mode,
+      StoreOrigin store_origin);
 
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> GetObjectProperty(
       Isolate* isolate, Handle<Object> object, Handle<Object> key,
@@ -739,7 +726,7 @@ class RuntimeState {
   }
 
  private:
-  RuntimeState() {}
+  RuntimeState() = default;
 #ifndef V8_INTL_SUPPORT
   unibrow::Mapping<unibrow::ToUppercase, 128> to_upper_mapping_;
   unibrow::Mapping<unibrow::ToLowercase, 128> to_lower_mapping_;
@@ -781,6 +768,8 @@ enum class OptimizationStatus {
   kTopmostFrameIsTurboFanned = 1 << 11,
 };
 
+Smi* SmiLexicographicCompare(Smi* x_value, Smi* y_value);
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/s390/assembler-s390.cc b/deps/v8/src/s390/assembler-s390.cc
index 6f1cbcd2f9..f25d79ab5a 100644
--- a/deps/v8/src/s390/assembler-s390.cc
+++ b/deps/v8/src/s390/assembler-s390.cc
@@ -51,6 +51,7 @@
 #include "src/deoptimizer.h"
 #include "src/macro-assembler.h"
 #include "src/s390/assembler-s390-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -180,13 +181,14 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
     //   Bit 45 - Distinct Operands for instructions like ARK, SRK, etc.
     // As such, we require only 1 double word
     int64_t facilities[3] = {0L};
+    int16_t reg0;
     // LHI sets up GPR0
     // STFLE is specified as .insn, as opcode is not recognized.
     // We register the instructions kill r0 (LHI) and the CC (STFLE).
     asm volatile(
-        "lhi   0,2\n"
+        "lhi   %%r0,2\n"
         ".insn s,0xb2b00000,%0\n"
-        : "=Q"(facilities)
+        : "=Q"(facilities), "=r"(reg0)
         :
         : "cc", "r0");
 
@@ -315,6 +317,13 @@ Operand Operand::EmbeddedNumber(double value) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rn, int32_t offset)
     : baseRegister(rn), indexRegister(r0), offset_(offset) {}
 
@@ -322,24 +331,33 @@ MemOperand::MemOperand(Register rx, Register rb, int32_t offset)
     : baseRegister(rb), indexRegister(rx), offset_(offset) {}
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     Address pc = reinterpret_cast<Address>(buffer_ + request.offset());
     switch (request.kind()) {
-      case HeapObjectRequest::kHeapNumber:
+      case HeapObjectRequest::kHeapNumber: {
         object =
             isolate->factory()->NewHeapNumber(request.heap_number(), TENURED);
-        set_target_address_at(pc, kNullAddress,
-                              reinterpret_cast<Address>(object.location()),
+        set_target_address_at(pc, kNullAddress, object.address(),
                               SKIP_ICACHE_FLUSH);
         break;
-      case HeapObjectRequest::kCodeStub:
+      }
+      case HeapObjectRequest::kCodeStub: {
         request.code_stub()->set_isolate(isolate);
         SixByteInstr instr =
             Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));
         int index = instr & 0xFFFFFFFF;
         UpdateCodeTarget(index, request.code_stub()->GetCode());
         break;
+      }
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        set_target_address_at(pc, kNullAddress,
+                              str->AllocateStringConstant(isolate).address());
+        break;
+      }
     }
   }
 }
@@ -794,13 +812,7 @@ void Assembler::dp(uintptr_t data) {
 }
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
-  if (options().disable_reloc_info_for_patching) return;
-  if (RelocInfo::IsNone(rmode) ||
-      // Don't record external references unless the heap will be serialized.
-      (RelocInfo::IsOnlyForSerializer(rmode) &&
-       !options().record_reloc_info_for_serialization && !emit_debug_code())) {
-    return;
-  }
+  if (!ShouldRecordRelocInfo(rmode)) return;
   DeferredRelocInfo rinfo(pc_offset(), rmode, data);
   relocations_.push_back(rinfo);
 }
diff --git a/deps/v8/src/s390/assembler-s390.h b/deps/v8/src/s390/assembler-s390.h
index 9e0a9ab32f..8e494543f8 100644
--- a/deps/v8/src/s390/assembler-s390.h
+++ b/deps/v8/src/s390/assembler-s390.h
@@ -346,7 +346,7 @@ C_REGISTERS(DECLARE_C_REGISTER)
 
 // Class Operand represents a shifter operand in data processing instructions
 // defining immediate numbers and masks
-class Operand BASE_EMBEDDED {
+class Operand {
  public:
   // immediate
   V8_INLINE explicit Operand(intptr_t immediate,
@@ -368,6 +368,7 @@ class Operand BASE_EMBEDDED {
   V8_INLINE explicit Operand(Register rm);
 
   static Operand EmbeddedNumber(double value);  // Smi or HeapNumber
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Return true if this is a register operand.
   V8_INLINE bool is_reg() const { return rm_.is_valid(); }
@@ -424,7 +425,7 @@ typedef int32_t Disp;
 //   1) a base register + 16 bit unsigned displacement
 //   2) a base register + index register + 16 bit unsigned displacement
 //   3) a base register + index register + 20 bit signed displacement
-class MemOperand BASE_EMBEDDED {
+class MemOperand {
  public:
   explicit MemOperand(Register rx, Disp offset = 0);
   explicit MemOperand(Register rx, Register rb, Disp offset = 0);
@@ -1663,7 +1664,7 @@ inline void ss_a_format(Opcode op, int f1, int f2, int f3, int f4, int f5) {
   friend class EnsureSpace;
 };
 
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit EnsureSpace(Assembler* assembler) { assembler->CheckBuffer(); }
 };
diff --git a/deps/v8/src/s390/code-stubs-s390.cc b/deps/v8/src/s390/code-stubs-s390.cc
index c06a3f636a..9a8111ffcf 100644
--- a/deps/v8/src/s390/code-stubs-s390.cc
+++ b/deps/v8/src/s390/code-stubs-s390.cc
@@ -134,7 +134,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
                  IsolateAddressId::kPendingExceptionAddress, isolate())));
 
   __ StoreP(r2, MemOperand(ip));
-  __ LoadRoot(r2, Heap::kExceptionRootIndex);
+  __ LoadRoot(r2, RootIndex::kException);
   __ b(&exit, Label::kNear);
 
   // Invoke: Link this frame into the handler chain.
@@ -475,7 +475,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   // Check if the function scheduled an exception.
   __ Move(r7, ExternalReference::scheduled_exception_address(isolate));
   __ LoadP(r7, MemOperand(r7));
-  __ CompareRoot(r7, Heap::kTheHoleValueRootIndex);
+  __ CompareRoot(r7, RootIndex::kTheHoleValue);
   __ bne(&promote_scheduled_exception, Label::kNear);
 
   __ b(r14);
@@ -523,13 +523,13 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   STATIC_ASSERT(FCA::kHolderIndex == 0);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data
   __ push(call_data);
 
   Register scratch = call_data;
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   // return value
   __ push(scratch);
   // return value default
@@ -609,7 +609,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   // Push data from AccessorInfo.
   __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
   __ push(scratch);
-  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   __ Push(scratch, scratch);
   __ Move(scratch, ExternalReference::isolate_address(isolate()));
   __ Push(scratch, holder);
diff --git a/deps/v8/src/s390/codegen-s390.cc b/deps/v8/src/s390/codegen-s390.cc
index cae0cf60e6..00342955e6 100644
--- a/deps/v8/src/s390/codegen-s390.cc
+++ b/deps/v8/src/s390/codegen-s390.cc
@@ -7,7 +7,6 @@
 #include <memory>
 
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 #include "src/s390/simulator-s390.h"
 
@@ -16,16 +15,17 @@ namespace internal {
 
 #define __ masm.
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
 #if defined(USE_SIMULATOR)
   return nullptr;
 #else
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   __ MovFromFloatParameter(d0);
   __ sqdbr(d0, d0);
@@ -33,13 +33,14 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(ABI_USES_FUNCTION_DESCRIPTORS ||
          !RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 #endif
 }
 
diff --git a/deps/v8/src/s390/interface-descriptors-s390.cc b/deps/v8/src/s390/interface-descriptors-s390.cc
index 4b30bc0547..dee5452ea2 100644
--- a/deps/v8/src/s390/interface-descriptors-s390.cc
+++ b/deps/v8/src/s390/interface-descriptors-s390.cc
@@ -87,9 +87,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // r2 : number of arguments (on the stack, not including receiver)
   // r3 : the target to call
-  // r4 : arguments list (FixedArray)
   // r6 : arguments list length (untagged)
-  Register registers[] = {r3, r2, r4, r6};
+  // r4 : arguments list (FixedArray)
+  Register registers[] = {r3, r2, r6, r4};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -124,9 +124,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // r2 : number of arguments (on the stack, not including receiver)
   // r3 : the target to call
   // r5 : the new target
-  // r4 : arguments list (FixedArray)
   // r6 : arguments list length (untagged)
-  Register registers[] = {r3, r5, r2, r4, r6};
+  // r4 : arguments list (FixedArray)
+  Register registers[] = {r3, r5, r2, r6, r4};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -192,7 +192,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r3,  // JSFunction
@@ -236,10 +236,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r2,  // argument count (not including receiver)
-      r5,  // new target
+      r6,  // address of the first argument
       r3,  // constructor to call
+      r5,  // new target
       r4,  // allocation site feedback if available, undefined otherwise
-      r6   // address of the first argument
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/s390/macro-assembler-s390.cc b/deps/v8/src/s390/macro-assembler-s390.cc
index 3ddcd9fd9b..1a047e3eba 100644
--- a/deps/v8/src/s390/macro-assembler-s390.cc
+++ b/deps/v8/src/s390/macro-assembler-s390.cc
@@ -123,14 +123,14 @@ int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
+      RootIndex::kBuiltinsConstantsTable));
 
   const uint32_t offset =
       FixedArray::kHeaderSize + constant_index * kPointerSize - kHeapObjectTag;
 
   CHECK(is_uint19(offset));
   DCHECK_NE(destination, r0);
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   LoadP(destination, MemOperand(destination, offset), r1);
 }
 
@@ -429,7 +429,7 @@ void TurboAssembler::MultiPopDoubles(RegList dregs, Register location) {
   AddP(location, location, Operand(stack_offset));
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index,
+void TurboAssembler::LoadRoot(Register destination, RootIndex index,
                               Condition) {
   LoadP(destination, MemOperand(kRootRegister, RootRegisterOffset(index)), r0);
 }
@@ -514,8 +514,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -527,7 +525,6 @@ void TurboAssembler::CallRecordWriteStub(
   Pop(slot_parameter);
   Pop(object_parameter);
 
-  Move(isolate_parameter, ExternalReference::isolate_address(isolate()));
   Move(remembered_set_parameter, Smi::FromEnum(remembered_set_action));
   Move(fp_mode_parameter, Smi::FromEnum(fp_mode));
   Call(callable.code(), RelocInfo::CODE_TARGET);
@@ -1388,7 +1385,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(r5, Heap::kUndefinedValueRootIndex);
+    LoadRoot(r5, RootIndex::kUndefinedValue);
   }
 
   Label done;
@@ -1515,7 +1512,7 @@ void MacroAssembler::CompareInstanceType(Register map, Register type_reg,
   CmpP(type_reg, Operand(type));
 }
 
-void MacroAssembler::CompareRoot(Register obj, Heap::RootListIndex index) {
+void MacroAssembler::CompareRoot(Register obj, RootIndex index) {
   CmpP(obj, MemOperand(kRootRegister, RootRegisterOffset(index)));
 }
 
@@ -1839,7 +1836,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
   if (emit_debug_code()) {
     Label done_checking;
     AssertNotSmi(object);
-    CompareRoot(object, Heap::kUndefinedValueRootIndex);
+    CompareRoot(object, RootIndex::kUndefinedValue);
     beq(&done_checking, Label::kNear);
     LoadP(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
     CompareInstanceType(scratch, scratch, ALLOCATION_SITE_TYPE);
@@ -2882,6 +2879,12 @@ void TurboAssembler::LoadAndSub32(Register dst, Register src,
   laa(dst, dst, opnd);
 }
 
+void TurboAssembler::LoadAndSub64(Register dst, Register src,
+                                  const MemOperand& opnd) {
+  lcgr(dst, src);
+  laag(dst, dst, opnd);
+}
+
 //----------------------------------------------------------------------------
 //  Subtract Logical Instructions
 //----------------------------------------------------------------------------
@@ -3372,6 +3375,12 @@ void TurboAssembler::CmpAndSwap(Register old_val, Register new_val,
   }
 }
 
+void TurboAssembler::CmpAndSwap64(Register old_val, Register new_val,
+                                  const MemOperand& opnd) {
+  DCHECK(is_int20(opnd.offset()));
+  csg(old_val, new_val, opnd);
+}
+
 //-----------------------------------------------------------------------------
 // Compare Logical Helpers
 //-----------------------------------------------------------------------------
diff --git a/deps/v8/src/s390/macro-assembler-s390.h b/deps/v8/src/s390/macro-assembler-s390.h
index 54aecf5896..98f8bb6e03 100644
--- a/deps/v8/src/s390/macro-assembler-s390.h
+++ b/deps/v8/src/s390/macro-assembler-s390.h
@@ -52,11 +52,6 @@ inline MemOperand FieldMemOperand(Register object, Register index, int offset) {
   return MemOperand(object, index, offset - kHeapObjectTag);
 }
 
-// Generate a MemOperand for loading a field from Root register
-inline MemOperand RootMemOperand(Heap::RootListIndex index) {
-  return MemOperand(kRootRegister, index << kPointerSizeLog2);
-}
-
 enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
 enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
@@ -153,6 +148,9 @@ Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -255,11 +253,10 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                      Register exclusion3 = no_reg);
 
   // Load an object from the root table.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override {
+  void LoadRoot(Register destination, RootIndex index) override {
     LoadRoot(destination, index, al);
   }
-  void LoadRoot(Register destination, Heap::RootListIndex index,
-                Condition cond);
+  void LoadRoot(Register destination, RootIndex index, Condition cond);
   //--------------------------------------------------------------------------
   // S390 Macro Assemblers for Instructions
   //--------------------------------------------------------------------------
@@ -328,6 +325,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void SubP(Register dst, const MemOperand& opnd);
   void SubP_ExtendSrc(Register dst, const MemOperand& opnd);
   void LoadAndSub32(Register dst, Register src, const MemOperand& opnd);
+  void LoadAndSub64(Register dst, Register src, const MemOperand& opnd);
 
   // Subtract Logical (Register - Mem)
   void SubLogical(Register dst, const MemOperand& opnd);
@@ -395,6 +393,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Cmp32(Register dst, const MemOperand& opnd);
   void CmpP(Register dst, const MemOperand& opnd);
   void CmpAndSwap(Register old_val, Register new_val, const MemOperand& opnd);
+  void CmpAndSwap64(Register old_val, Register new_val, const MemOperand& opnd);
 
   // Compare Logical
   void CmpLogical32(Register src1, Register src2);
@@ -1027,10 +1026,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler : public TurboAssembler {
  public:
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -1082,8 +1085,8 @@ class MacroAssembler : public TurboAssembler {
 
   // Compare the object in a register to a value from the root list.
   // Uses the ip register as scratch.
-  void CompareRoot(Register obj, Heap::RootListIndex index);
-  void PushRoot(Heap::RootListIndex index) {
+  void CompareRoot(Register obj, RootIndex index);
+  void PushRoot(RootIndex index) {
     LoadRoot(r0, index);
     Push(r0);
   }
@@ -1096,14 +1099,13 @@ class MacroAssembler : public TurboAssembler {
   void JumpToInstructionStream(Address entry);
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal) {
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal) {
     CompareRoot(with, index);
     beq(if_equal);
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal) {
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal) {
     CompareRoot(with, index);
     bne(if_not_equal);
   }
diff --git a/deps/v8/src/s390/simulator-s390.cc b/deps/v8/src/s390/simulator-s390.cc
index 0fec28b69e..e6761ca610 100644
--- a/deps/v8/src/s390/simulator-s390.cc
+++ b/deps/v8/src/s390/simulator-s390.cc
@@ -1369,6 +1369,7 @@ void Simulator::EvalTableInit() {
   EvalTable[SRLG] = &Simulator::Evaluate_SRLG;
   EvalTable[SLLG] = &Simulator::Evaluate_SLLG;
   EvalTable[CSY] = &Simulator::Evaluate_CSY;
+  EvalTable[CSG] = &Simulator::Evaluate_CSG;
   EvalTable[RLLG] = &Simulator::Evaluate_RLLG;
   EvalTable[RLL] = &Simulator::Evaluate_RLL;
   EvalTable[STMG] = &Simulator::Evaluate_STMG;
@@ -8778,9 +8779,26 @@ EVALUATE(CSY) {
 }
 
 EVALUATE(CSG) {
-  UNIMPLEMENTED();
-  USE(instr);
-  return 0;
+  DCHECK_OPCODE(CSG);
+  DECODE_RSY_A_INSTRUCTION(r1, r3, b2, d2);
+  int32_t offset = d2;
+  int64_t b2_val = (b2 == 0) ? 0 : get_register(b2);
+  intptr_t target_addr = static_cast<intptr_t>(b2_val) + offset;
+
+  int64_t r1_val = get_register(r1);
+  int64_t r3_val = get_register(r3);
+
+  DCHECK_EQ(target_addr & 0x3, 0);
+  bool is_success = __atomic_compare_exchange_n(
+      reinterpret_cast<int64_t*>(target_addr), &r1_val, r3_val, true,
+      __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
+  if (!is_success) {
+    set_register(r1, r1_val);
+    condition_reg_ = 0x4;
+  } else {
+    condition_reg_ = 0x8;
+  }
+  return length;
 }
 
 EVALUATE(RLLG) {
@@ -9153,28 +9171,38 @@ EVALUATE(STOCG) {
   return 0;
 }
 
+#define ATOMIC_LOAD_AND_UPDATE_WORD64(op)                             \
+  DECODE_RSY_A_INSTRUCTION(r1, r3, b2, d2);                           \
+  int64_t b2_val = (b2 == 0) ? 0 : get_register(b2);                  \
+  intptr_t addr = static_cast<intptr_t>(b2_val) + d2;                 \
+  int64_t r3_val = get_register(r3);                                  \
+  DCHECK_EQ(addr & 0x3, 0);                                           \
+  int64_t r1_val =                                                    \
+      op(reinterpret_cast<int64_t*>(addr), r3_val, __ATOMIC_SEQ_CST); \
+  set_register(r1, r1_val);
+
 EVALUATE(LANG) {
-  UNIMPLEMENTED();
-  USE(instr);
-  return 0;
+  DCHECK_OPCODE(LANG);
+  ATOMIC_LOAD_AND_UPDATE_WORD64(__atomic_fetch_and);
+  return length;
 }
 
 EVALUATE(LAOG) {
-  UNIMPLEMENTED();
-  USE(instr);
-  return 0;
+  DCHECK_OPCODE(LAOG);
+  ATOMIC_LOAD_AND_UPDATE_WORD64(__atomic_fetch_or);
+  return length;
 }
 
 EVALUATE(LAXG) {
-  UNIMPLEMENTED();
-  USE(instr);
-  return 0;
+  DCHECK_OPCODE(LAXG);
+  ATOMIC_LOAD_AND_UPDATE_WORD64(__atomic_fetch_xor);
+  return length;
 }
 
 EVALUATE(LAAG) {
-  UNIMPLEMENTED();
-  USE(instr);
-  return 0;
+  DCHECK_OPCODE(LAAG);
+  ATOMIC_LOAD_AND_UPDATE_WORD64(__atomic_fetch_add);
+  return length;
 }
 
 EVALUATE(LAALG) {
@@ -9183,6 +9211,8 @@ EVALUATE(LAALG) {
   return 0;
 }
 
+#undef ATOMIC_LOAD_AND_UPDATE_WORD64
+
 EVALUATE(LOC) {
   UNIMPLEMENTED();
   USE(instr);
diff --git a/deps/v8/src/safepoint-table.h b/deps/v8/src/safepoint-table.h
index e85a27fcb3..475b4a80b1 100644
--- a/deps/v8/src/safepoint-table.h
+++ b/deps/v8/src/safepoint-table.h
@@ -17,7 +17,7 @@ namespace internal {
 
 class Register;
 
-class SafepointEntry BASE_EMBEDDED {
+class SafepointEntry {
  public:
   SafepointEntry() : info_(0), bits_(nullptr), trampoline_pc_(-1) {}
 
@@ -87,8 +87,7 @@ class SafepointEntry BASE_EMBEDDED {
   int trampoline_pc_;
 };
 
-
-class SafepointTable BASE_EMBEDDED {
+class SafepointTable {
  public:
   explicit SafepointTable(Code* code);
   explicit SafepointTable(Address instruction_start,
@@ -171,8 +170,7 @@ class SafepointTable BASE_EMBEDDED {
   DISALLOW_COPY_AND_ASSIGN(SafepointTable);
 };
 
-
-class Safepoint BASE_EMBEDDED {
+class Safepoint {
  public:
   typedef enum {
     kSimple = 0,
@@ -201,8 +199,7 @@ class Safepoint BASE_EMBEDDED {
   friend class SafepointTableBuilder;
 };
 
-
-class SafepointTableBuilder BASE_EMBEDDED {
+class SafepointTableBuilder {
  public:
   explicit SafepointTableBuilder(Zone* zone)
       : deoptimization_info_(zone),
diff --git a/deps/v8/src/setup-isolate-deserialize.cc b/deps/v8/src/setup-isolate-deserialize.cc
index a99d735af6..fdfaa7e188 100644
--- a/deps/v8/src/setup-isolate-deserialize.cc
+++ b/deps/v8/src/setup-isolate-deserialize.cc
@@ -17,19 +17,6 @@ void SetupIsolateDelegate::SetupBuiltins(Isolate* isolate) {
   // No actual work to be done; builtins will be deserialized from the snapshot.
 }
 
-void SetupIsolateDelegate::SetupInterpreter(
-    interpreter::Interpreter* interpreter) {
-#if defined(V8_USE_SNAPSHOT) && !defined(V8_USE_SNAPSHOT_WITH_UNWINDING_INFO)
-  if (FLAG_perf_prof_unwinding_info) {
-    StdoutStream{}
-        << "Warning: The --perf-prof-unwinding-info flag can be passed at "
-           "mksnapshot time to get better results."
-        << std::endl;
-  }
-#endif
-  CHECK(interpreter->IsDispatchTableInitialized());
-}
-
 bool SetupIsolateDelegate::SetupHeap(Heap* heap) {
   CHECK(!create_heap_objects_);
   // No actual work to be done; heap will be deserialized from the snapshot.
diff --git a/deps/v8/src/setup-isolate-full.cc b/deps/v8/src/setup-isolate-full.cc
index c3a367986c..c902f06b30 100644
--- a/deps/v8/src/setup-isolate-full.cc
+++ b/deps/v8/src/setup-isolate-full.cc
@@ -7,7 +7,6 @@
 #include "src/base/logging.h"
 #include "src/heap/heap-inl.h"
 #include "src/interpreter/interpreter.h"
-#include "src/interpreter/setup-interpreter.h"
 #include "src/isolate.h"
 
 namespace v8 {
@@ -21,15 +20,6 @@ void SetupIsolateDelegate::SetupBuiltins(Isolate* isolate) {
   }
 }
 
-void SetupIsolateDelegate::SetupInterpreter(
-    interpreter::Interpreter* interpreter) {
-  if (create_heap_objects_) {
-    interpreter::SetupInterpreter::InstallBytecodeHandlers(interpreter);
-  } else {
-    CHECK(interpreter->IsDispatchTableInitialized());
-  }
-}
-
 bool SetupIsolateDelegate::SetupHeap(Heap* heap) {
   if (create_heap_objects_) {
     return SetupHeapInternal(heap);
diff --git a/deps/v8/src/setup-isolate.h b/deps/v8/src/setup-isolate.h
index 2003caeac9..61dedd6fe8 100644
--- a/deps/v8/src/setup-isolate.h
+++ b/deps/v8/src/setup-isolate.h
@@ -34,12 +34,10 @@ class SetupIsolateDelegate {
  public:
   explicit SetupIsolateDelegate(bool create_heap_objects)
       : create_heap_objects_(create_heap_objects) {}
-  virtual ~SetupIsolateDelegate() {}
+  virtual ~SetupIsolateDelegate() = default;
 
   virtual void SetupBuiltins(Isolate* isolate);
 
-  virtual void SetupInterpreter(interpreter::Interpreter* interpreter);
-
   virtual bool SetupHeap(Heap* heap);
 
  protected:
diff --git a/deps/v8/src/snapshot/builtin-deserializer-allocator.cc b/deps/v8/src/snapshot/builtin-deserializer-allocator.cc
index 4e3d546fa0..80300c9f1d 100644
--- a/deps/v8/src/snapshot/builtin-deserializer-allocator.cc
+++ b/deps/v8/src/snapshot/builtin-deserializer-allocator.cc
@@ -19,16 +19,6 @@ BuiltinDeserializerAllocator::BuiltinDeserializerAllocator(
     Deserializer<BuiltinDeserializerAllocator>* deserializer)
     : deserializer_(deserializer) {}
 
-BuiltinDeserializerAllocator::~BuiltinDeserializerAllocator() {
-  delete handler_allocations_;
-}
-
-namespace {
-int HandlerAllocationIndex(int code_object_id) {
-  return code_object_id - BuiltinSnapshotUtils::kFirstHandlerIndex;
-}
-}  // namespace
-
 Address BuiltinDeserializerAllocator::Allocate(AllocationSpace space,
                                                int size) {
   const int code_object_id = deserializer()->CurrentCodeObjectId();
@@ -39,30 +29,14 @@ Address BuiltinDeserializerAllocator::Allocate(AllocationSpace space,
   RegisterCodeObjectAllocation(code_object_id);
 #endif
 
-  if (BSU::IsBuiltinIndex(code_object_id)) {
-    Object* obj = isolate()->builtins()->builtin(code_object_id);
-    DCHECK(Internals::HasHeapObjectTag(obj));
-    return HeapObject::cast(obj)->address();
-  } else if (BSU::IsHandlerIndex(code_object_id)) {
-    if (handler_allocation_ != kNullAddress) {
-      // Lazy deserialization.
-      DCHECK_NULL(handler_allocations_);
-      return handler_allocation_;
-    } else {
-      // Eager deserialization.
-      DCHECK_EQ(kNullAddress, handler_allocation_);
-      DCHECK_NOT_NULL(handler_allocations_);
-      int index = HandlerAllocationIndex(code_object_id);
-      DCHECK_NE(kNullAddress, handler_allocations_->at(index));
-      return handler_allocations_->at(index);
-    }
-  }
-
-  UNREACHABLE();
+  DCHECK(Builtins::IsBuiltinId(code_object_id));
+  Object* obj = isolate()->builtins()->builtin(code_object_id);
+  DCHECK(Internals::HasHeapObjectTag(obj));
+  return HeapObject::cast(obj)->address();
 }
 
 Heap::Reservation
-BuiltinDeserializerAllocator::CreateReservationsForEagerBuiltinsAndHandlers() {
+BuiltinDeserializerAllocator::CreateReservationsForEagerBuiltins() {
   Heap::Reservation result;
 
   // Reservations for builtins.
@@ -77,7 +51,7 @@ BuiltinDeserializerAllocator::CreateReservationsForEagerBuiltinsAndHandlers() {
     result.push_back({builtin_size, kNullAddress, kNullAddress});
   }
 
-  for (int i = 0; i < BSU::kNumberOfBuiltins; i++) {
+  for (int i = 0; i < Builtins::builtin_count; i++) {
     if (i == Builtins::kDeserializeLazy) continue;
 
     // Skip lazy builtins. These will be replaced by the DeserializeLazy code
@@ -91,28 +65,6 @@ BuiltinDeserializerAllocator::CreateReservationsForEagerBuiltinsAndHandlers() {
     result.push_back({builtin_size, kNullAddress, kNullAddress});
   }
 
-  // Reservations for bytecode handlers.
-
-  BSU::ForEachBytecode(
-      [=, &result](Bytecode bytecode, OperandScale operand_scale) {
-        if (!Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) {
-          // Bytecodes without a handler don't require a reservation.
-          return;
-        } else if (FLAG_lazy_handler_deserialization &&
-                   deserializer()->IsLazyDeserializationEnabled() &&
-                   Bytecodes::IsLazy(bytecode)) {
-          // Skip lazy handlers. These will be replaced by the DeserializeLazy
-          // code object in InitializeFromReservations and thus require no
-          // reserved space.
-          return;
-        }
-
-        const int index = BSU::BytecodeToIndex(bytecode, operand_scale);
-        uint32_t handler_size = deserializer()->ExtractCodeObjectSize(index);
-        DCHECK_LE(handler_size, MemoryAllocator::PageAreaSize(CODE_SPACE));
-        result.push_back({handler_size, kNullAddress, kNullAddress});
-      });
-
   return result;
 }
 
@@ -130,26 +82,6 @@ void BuiltinDeserializerAllocator::InitializeBuiltinFromReservation(
 #endif
 }
 
-void BuiltinDeserializerAllocator::InitializeHandlerFromReservation(
-    const Heap::Chunk& chunk, interpreter::Bytecode bytecode,
-    interpreter::OperandScale operand_scale) {
-  DCHECK_EQ(deserializer()->ExtractCodeObjectSize(
-                BSU::BytecodeToIndex(bytecode, operand_scale)),
-            chunk.size);
-  DCHECK_EQ(chunk.size, chunk.end - chunk.start);
-
-  SkipList::Update(chunk.start, chunk.size);
-
-  DCHECK_NOT_NULL(handler_allocations_);
-  const int index =
-      HandlerAllocationIndex(BSU::BytecodeToIndex(bytecode, operand_scale));
-  handler_allocations_->at(index) = chunk.start;
-
-#ifdef DEBUG
-  RegisterCodeObjectReservation(BSU::BytecodeToIndex(bytecode, operand_scale));
-#endif
-}
-
 void BuiltinDeserializerAllocator::InitializeFromReservations(
     const Heap::Reservation& reservation) {
   DCHECK(!AllowHeapAllocation::IsAllowed());
@@ -168,41 +100,18 @@ void BuiltinDeserializerAllocator::InitializeFromReservations(
     reservation_index++;
   }
 
-  Code* deserialize_lazy = builtins->builtin(Builtins::kDeserializeLazy);
-
-  for (int i = 0; i < BSU::kNumberOfBuiltins; i++) {
+  for (int i = 0; i < Builtins::builtin_count; i++) {
     if (i == Builtins::kDeserializeLazy) continue;
 
     if (deserializer()->IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) {
-      builtins->set_builtin(i, deserialize_lazy);
+      builtins->set_builtin(
+          i, builtins->builtin(builtins->LazyDeserializerForBuiltin(i)));
     } else {
       InitializeBuiltinFromReservation(reservation[reservation_index], i);
       reservation_index++;
     }
   }
 
-  // Initialize interpreter bytecode handler reservations.
-
-  DCHECK_NULL(handler_allocations_);
-  handler_allocations_ = new std::vector<Address>(BSU::kNumberOfHandlers);
-
-  BSU::ForEachBytecode(
-      [=, &reservation_index](Bytecode bytecode, OperandScale operand_scale) {
-        if (!Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) {
-          // Bytecodes without a handler don't have a reservation.
-          return;
-        } else if (FLAG_lazy_handler_deserialization &&
-                   deserializer()->IsLazyDeserializationEnabled() &&
-                   Bytecodes::IsLazy(bytecode)) {
-          // Likewise, bytecodes with lazy handlers don't either.
-          return;
-        }
-
-        InitializeHandlerFromReservation(reservation[reservation_index],
-                                         bytecode, operand_scale);
-        reservation_index++;
-      });
-
   DCHECK_EQ(reservation.size(), reservation_index);
 }
 
@@ -211,9 +120,9 @@ void BuiltinDeserializerAllocator::ReserveAndInitializeBuiltinsTableForBuiltin(
   DCHECK(AllowHeapAllocation::IsAllowed());
   DCHECK(isolate()->builtins()->is_initialized());
   DCHECK(Builtins::IsBuiltinId(builtin_id));
-  DCHECK_NE(Builtins::kDeserializeLazy, builtin_id);
-  DCHECK_EQ(Builtins::kDeserializeLazy,
-            isolate()->builtins()->builtin(builtin_id)->builtin_index());
+  DCHECK(!Builtins::IsLazyDeserializer(builtin_id));
+  DCHECK(Builtins::IsLazyDeserializer(
+      isolate()->builtins()->builtin(builtin_id)->builtin_index()));
 
   const uint32_t builtin_size =
       deserializer()->ExtractCodeObjectSize(builtin_id);
@@ -236,28 +145,6 @@ void BuiltinDeserializerAllocator::ReserveAndInitializeBuiltinsTableForBuiltin(
 #endif
 }
 
-void BuiltinDeserializerAllocator::ReserveForHandler(
-    Bytecode bytecode, OperandScale operand_scale) {
-  DCHECK(AllowHeapAllocation::IsAllowed());
-  DCHECK(isolate()->interpreter()->IsDispatchTableInitialized());
-
-  const int code_object_id = BSU::BytecodeToIndex(bytecode, operand_scale);
-  const uint32_t handler_size =
-      deserializer()->ExtractCodeObjectSize(code_object_id);
-  DCHECK_LE(handler_size, MemoryAllocator::PageAreaSize(CODE_SPACE));
-
-  handler_allocation_ =
-      isolate()->factory()->NewCodeForDeserialization(handler_size)->address();
-
-// Note: After this point and until deserialization finishes, heap allocation
-// is disallowed. We currently can't safely assert this since we'd need to
-// pass the DisallowHeapAllocation scope out of this function.
-
-#ifdef DEBUG
-  RegisterCodeObjectReservation(code_object_id);
-#endif
-}
-
 #ifdef DEBUG
 void BuiltinDeserializerAllocator::RegisterCodeObjectReservation(
     int code_object_id) {
diff --git a/deps/v8/src/snapshot/builtin-deserializer-allocator.h b/deps/v8/src/snapshot/builtin-deserializer-allocator.h
index 65c5872d7a..b606eb2749 100644
--- a/deps/v8/src/snapshot/builtin-deserializer-allocator.h
+++ b/deps/v8/src/snapshot/builtin-deserializer-allocator.h
@@ -30,8 +30,6 @@ class BuiltinDeserializerAllocator final {
   BuiltinDeserializerAllocator(
       Deserializer<BuiltinDeserializerAllocator>* deserializer);
 
-  ~BuiltinDeserializerAllocator();
-
   // ------- Allocation Methods -------
   // Methods related to memory allocation during deserialization.
 
@@ -42,13 +40,10 @@ class BuiltinDeserializerAllocator final {
   // deserialization) in order to avoid having to patch builtin references
   // later on. See also the kBuiltin case in deserializer.cc.
   //
-  // There are three ways that we use to reserve / allocate space. In all
-  // cases, required objects are requested from the GC prior to
-  // deserialization. 1. pre-allocated builtin code objects are written into
-  // the builtins table (this is to make deserialization of builtin references
-  // easier). Pre-allocated handler code objects are 2. stored in the
-  // {handler_allocations_} vector (at eager-deserialization time) and 3.
-  // stored in {handler_allocation_} (at lazy-deserialization time).
+  // There is one way that we use to reserve / allocate space. Required objects
+  // are requested from the GC prior to deserialization. Pre-allocated builtin
+  // code objects are written into the builtins table (this is to make
+  // deserialization of builtin references easier).
   //
   // Allocate simply returns the pre-allocated object prepared by
   // InitializeFromReservations.
@@ -83,23 +78,19 @@ class BuiltinDeserializerAllocator final {
 
   // Builtin deserialization does not bake reservations into the snapshot, hence
   // this is a nop.
-  void DecodeReservation(std::vector<SerializedData::Reservation> res) {}
+  void DecodeReservation(const std::vector<SerializedData::Reservation>& res) {}
 
   // These methods are used to pre-allocate builtin objects prior to
   // deserialization.
   // TODO(jgruber): Refactor reservation/allocation logic in deserializers to
   // make this less messy.
-  Heap::Reservation CreateReservationsForEagerBuiltinsAndHandlers();
+  Heap::Reservation CreateReservationsForEagerBuiltins();
   void InitializeFromReservations(const Heap::Reservation& reservation);
 
   // Creates reservations and initializes the builtins table in preparation for
   // lazily deserializing a single builtin.
   void ReserveAndInitializeBuiltinsTableForBuiltin(int builtin_id);
 
-  // Pre-allocates a code object preparation for lazily deserializing a single
-  // handler.
-  void ReserveForHandler(Bytecode bytecode, OperandScale operand_scale);
-
 #ifdef DEBUG
   bool ReservationsAreFullyUsed() const;
 #endif
@@ -113,11 +104,6 @@ class BuiltinDeserializerAllocator final {
   void InitializeBuiltinFromReservation(const Heap::Chunk& chunk,
                                         int builtin_id);
 
-  // As above, but for interpreter bytecode handlers.
-  void InitializeHandlerFromReservation(
-      const Heap::Chunk& chunk, interpreter::Bytecode bytecode,
-      interpreter::OperandScale operand_scale);
-
 #ifdef DEBUG
   void RegisterCodeObjectReservation(int code_object_id);
   void RegisterCodeObjectAllocation(int code_object_id);
@@ -130,13 +116,6 @@ class BuiltinDeserializerAllocator final {
   // construction since that makes vtable-based checks fail.
   Deserializer<BuiltinDeserializerAllocator>* const deserializer_;
 
-  // Stores allocated space for bytecode handlers during eager deserialization.
-  std::vector<Address>* handler_allocations_ = nullptr;
-
-  // Stores the allocated space for a single handler during lazy
-  // deserialization.
-  Address handler_allocation_ = kNullAddress;
-
   bool next_reference_is_weak_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(BuiltinDeserializerAllocator)
diff --git a/deps/v8/src/snapshot/builtin-deserializer.cc b/deps/v8/src/snapshot/builtin-deserializer.cc
index 0e32844ba0..136b74b26e 100644
--- a/deps/v8/src/snapshot/builtin-deserializer.cc
+++ b/deps/v8/src/snapshot/builtin-deserializer.cc
@@ -42,24 +42,24 @@ BuiltinDeserializer::BuiltinDeserializer(Isolate* isolate,
                                          const BuiltinSnapshotData* data)
     : Deserializer(data, false) {
   code_offsets_ = data->BuiltinOffsets();
-  DCHECK_EQ(BSU::kNumberOfCodeObjects, code_offsets_.length());
+  DCHECK_EQ(Builtins::builtin_count, code_offsets_.length());
   DCHECK(std::is_sorted(code_offsets_.begin(), code_offsets_.end()));
 
   Initialize(isolate);
 }
 
-void BuiltinDeserializer::DeserializeEagerBuiltinsAndHandlers() {
+void BuiltinDeserializer::DeserializeEagerBuiltins() {
   DCHECK(!AllowHeapAllocation::IsAllowed());
   DCHECK_EQ(0, source()->position());
 
   // Deserialize builtins.
 
   Builtins* builtins = isolate()->builtins();
-  for (int i = 0; i < BSU::kNumberOfBuiltins; i++) {
+  for (int i = 0; i < Builtins::builtin_count; i++) {
     if (IsLazyDeserializationEnabled() && Builtins::IsLazy(i)) {
       // Do nothing. These builtins have been replaced by DeserializeLazy in
       // InitializeFromReservations.
-      DCHECK_EQ(builtins->builtin(Builtins::kDeserializeLazy),
+      DCHECK_EQ(builtins->builtin(builtins->LazyDeserializerForBuiltin(i)),
                 builtins->builtin(i));
     } else {
       builtins->set_builtin(i, DeserializeBuiltinRaw(i));
@@ -67,7 +67,7 @@ void BuiltinDeserializer::DeserializeEagerBuiltinsAndHandlers() {
   }
 
 #ifdef DEBUG
-  for (int i = 0; i < BSU::kNumberOfBuiltins; i++) {
+  for (int i = 0; i < Builtins::builtin_count; i++) {
     Object* o = builtins->builtin(i);
     DCHECK(o->IsCode() && Code::cast(o)->is_builtin());
   }
@@ -77,7 +77,7 @@ void BuiltinDeserializer::DeserializeEagerBuiltinsAndHandlers() {
   if (FLAG_print_builtin_code) {
     // We can't print builtins during deserialization because they may refer
     // to not yet deserialized builtins.
-    for (int i = 0; i < BSU::kNumberOfBuiltins; i++) {
+    for (int i = 0; i < Builtins::builtin_count; i++) {
       if (!IsLazyDeserializationEnabled() || !Builtins::IsLazy(i)) {
         Code* code = builtins->builtin(i);
         const char* name = Builtins::name(i);
@@ -86,38 +86,6 @@ void BuiltinDeserializer::DeserializeEagerBuiltinsAndHandlers() {
     }
   }
 #endif
-
-  // Deserialize bytecode handlers.
-
-  Interpreter* interpreter = isolate()->interpreter();
-  DCHECK(!isolate()->interpreter()->IsDispatchTableInitialized());
-
-  BSU::ForEachBytecode([=](Bytecode bytecode, OperandScale operand_scale) {
-    // Bytecodes without a dedicated handler are patched up in a second pass.
-    if (!Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) return;
-
-    // If lazy-deserialization is enabled and the current bytecode is lazy,
-    // we write the generic LazyDeserialization handler into the dispatch table
-    // and deserialize later upon first use.
-    Code* code = (FLAG_lazy_handler_deserialization &&
-                  IsLazyDeserializationEnabled() && Bytecodes::IsLazy(bytecode))
-                     ? GetDeserializeLazyHandler(operand_scale)
-                     : DeserializeHandlerRaw(bytecode, operand_scale);
-
-    interpreter->SetBytecodeHandler(bytecode, operand_scale, code);
-  });
-
-  // Patch up holes in the dispatch table.
-
-  Code* illegal_handler = interpreter->GetBytecodeHandler(
-      Bytecode::kIllegal, OperandScale::kSingle);
-
-  BSU::ForEachBytecode([=](Bytecode bytecode, OperandScale operand_scale) {
-    if (Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) return;
-    interpreter->SetBytecodeHandler(bytecode, operand_scale, illegal_handler);
-  });
-
-  DCHECK(isolate()->interpreter()->IsDispatchTableInitialized());
 }
 
 Code* BuiltinDeserializer::DeserializeBuiltin(int builtin_id) {
@@ -135,13 +103,6 @@ Code* BuiltinDeserializer::DeserializeBuiltin(int builtin_id) {
   return code;
 }
 
-Code* BuiltinDeserializer::DeserializeHandler(Bytecode bytecode,
-                                              OperandScale operand_scale) {
-  allocator()->ReserveForHandler(bytecode, operand_scale);
-  DisallowHeapAllocation no_gc;
-  return DeserializeHandlerRaw(bytecode, operand_scale);
-}
-
 Code* BuiltinDeserializer::DeserializeBuiltinRaw(int builtin_id) {
   DCHECK(!AllowHeapAllocation::IsAllowed());
   DCHECK(Builtins::IsBuiltinId(builtin_id));
@@ -162,8 +123,19 @@ Code* BuiltinDeserializer::DeserializeBuiltinRaw(int builtin_id) {
   Assembler::FlushICache(code->raw_instruction_start(),
                          code->raw_instruction_size());
 
-  PROFILE(isolate(), CodeCreateEvent(CodeEventListener::BUILTIN_TAG,
-                                     AbstractCode::cast(code),
+  CodeEventListener::LogEventsAndTags code_tag;
+  switch (code->kind()) {
+    case AbstractCode::BUILTIN:
+      code_tag = CodeEventListener::BUILTIN_TAG;
+      break;
+    case AbstractCode::BYTECODE_HANDLER:
+      code_tag = CodeEventListener::BYTECODE_HANDLER_TAG;
+      break;
+    default:
+      UNREACHABLE();
+  }
+
+  PROFILE(isolate(), CodeCreateEvent(code_tag, AbstractCode::cast(code),
                                      Builtins::name(builtin_id)));
   LOG_CODE_EVENT(isolate(),
                  CodeLinePosInfoRecordEvent(
@@ -172,42 +144,8 @@ Code* BuiltinDeserializer::DeserializeBuiltinRaw(int builtin_id) {
   return code;
 }
 
-Code* BuiltinDeserializer::DeserializeHandlerRaw(Bytecode bytecode,
-                                                 OperandScale operand_scale) {
-  DCHECK(!AllowHeapAllocation::IsAllowed());
-  DCHECK(Bytecodes::BytecodeHasHandler(bytecode, operand_scale));
-
-  const int code_object_id = BSU::BytecodeToIndex(bytecode, operand_scale);
-  DeserializingCodeObjectScope scope(this, code_object_id);
-
-  const int initial_position = source()->position();
-  source()->set_position(code_offsets_[code_object_id]);
-
-  Object* o = ReadDataSingle();
-  DCHECK(o->IsCode() && Code::cast(o)->kind() == Code::BYTECODE_HANDLER);
-
-  // Rewind.
-  source()->set_position(initial_position);
-
-  // Flush the instruction cache.
-  Code* code = Code::cast(o);
-  Assembler::FlushICache(code->raw_instruction_start(),
-                         code->raw_instruction_size());
-
-  std::string name = Bytecodes::ToString(bytecode, operand_scale);
-  PROFILE(isolate(), CodeCreateEvent(CodeEventListener::HANDLER_TAG,
-                                     AbstractCode::cast(code), name.c_str()));
-#ifdef ENABLE_DISASSEMBLER
-  if (FLAG_print_builtin_code) {
-    code->PrintBuiltinCode(isolate(), name.c_str());
-  }
-#endif  // ENABLE_DISASSEMBLER
-
-  return code;
-}
-
 uint32_t BuiltinDeserializer::ExtractCodeObjectSize(int code_object_id) {
-  DCHECK_LT(code_object_id, BSU::kNumberOfCodeObjects);
+  DCHECK_LT(code_object_id, Builtins::builtin_count);
 
   const int initial_position = source()->position();
 
@@ -225,20 +163,5 @@ uint32_t BuiltinDeserializer::ExtractCodeObjectSize(int code_object_id) {
   return result;
 }
 
-Code* BuiltinDeserializer::GetDeserializeLazyHandler(
-    interpreter::OperandScale operand_scale) const {
-  STATIC_ASSERT(interpreter::BytecodeOperands::kOperandScaleCount == 3);
-  switch (operand_scale) {
-    case OperandScale::kSingle:
-      return Code::cast(isolate()->heap()->deserialize_lazy_handler());
-    case OperandScale::kDouble:
-      return Code::cast(isolate()->heap()->deserialize_lazy_handler_wide());
-    case OperandScale::kQuadruple:
-      return Code::cast(
-          isolate()->heap()->deserialize_lazy_handler_extra_wide());
-  }
-  UNREACHABLE();
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/snapshot/builtin-deserializer.h b/deps/v8/src/snapshot/builtin-deserializer.h
index 1ae49686b8..e77598db68 100644
--- a/deps/v8/src/snapshot/builtin-deserializer.h
+++ b/deps/v8/src/snapshot/builtin-deserializer.h
@@ -7,7 +7,6 @@
 
 #include "src/interpreter/interpreter.h"
 #include "src/snapshot/builtin-deserializer-allocator.h"
-#include "src/snapshot/builtin-snapshot-utils.h"
 #include "src/snapshot/deserializer.h"
 
 namespace v8 {
@@ -32,25 +31,17 @@ class BuiltinDeserializer final
   //
   // After this, the instruction cache must be flushed by the caller (we don't
   // do it ourselves since the startup serializer batch-flushes all code pages).
-  void DeserializeEagerBuiltinsAndHandlers();
+  void DeserializeEagerBuiltins();
 
   // Deserializes the single given builtin. This is used whenever a builtin is
   // lazily deserialized at runtime.
   Code* DeserializeBuiltin(int builtin_id);
 
-  // Deserializes the single given handler. This is used whenever a handler is
-  // lazily deserialized at runtime.
-  Code* DeserializeHandler(Bytecode bytecode, OperandScale operand_scale);
-
  private:
   // Deserializes the single given builtin. Assumes that reservations have
   // already been allocated.
   Code* DeserializeBuiltinRaw(int builtin_id);
 
-  // Deserializes the single given bytecode handler. Assumes that reservations
-  // have already been allocated.
-  Code* DeserializeHandlerRaw(Bytecode bytecode, OperandScale operand_scale);
-
   // Extracts the size builtin Code objects (baked into the snapshot).
   uint32_t ExtractCodeObjectSize(int builtin_id);
 
diff --git a/deps/v8/src/snapshot/builtin-serializer.cc b/deps/v8/src/snapshot/builtin-serializer.cc
index 0109a85b6b..6c71606b2e 100644
--- a/deps/v8/src/snapshot/builtin-serializer.cc
+++ b/deps/v8/src/snapshot/builtin-serializer.cc
@@ -26,42 +26,24 @@ BuiltinSerializer::~BuiltinSerializer() {
 void BuiltinSerializer::SerializeBuiltinsAndHandlers() {
   // Serialize builtins.
 
-  STATIC_ASSERT(0 == BSU::kFirstBuiltinIndex);
-
-  for (int i = 0; i < BSU::kNumberOfBuiltins; i++) {
+  for (int i = 0; i < Builtins::builtin_count; i++) {
+    Code* code = isolate()->builtins()->builtin(i);
+    DCHECK_IMPLIES(Builtins::IsLazyDeserializer(code),
+                   Builtins::IsLazyDeserializer(i));
     SetBuiltinOffset(i, sink_.Position());
-    SerializeBuiltin(isolate()->builtins()->builtin(i));
+    SerializeBuiltin(code);
   }
 
-  // Serialize bytecode handlers.
-
-  STATIC_ASSERT(BSU::kNumberOfBuiltins == BSU::kFirstHandlerIndex);
-
-  BSU::ForEachBytecode([=](Bytecode bytecode, OperandScale operand_scale) {
-    SetHandlerOffset(bytecode, operand_scale, sink_.Position());
-    if (!Bytecodes::BytecodeHasHandler(bytecode, operand_scale)) return;
-
-    SerializeHandler(
-        isolate()->interpreter()->GetBytecodeHandler(bytecode, operand_scale));
-  });
-
-  STATIC_ASSERT(BSU::kFirstHandlerIndex + BSU::kNumberOfHandlers ==
-                BSU::kNumberOfCodeObjects);
-
-  // The DeserializeLazy handlers are serialized by the StartupSerializer
-  // during strong root iteration.
-
-  DCHECK(isolate()->heap()->deserialize_lazy_handler()->IsCode());
-  DCHECK(isolate()->heap()->deserialize_lazy_handler_wide()->IsCode());
-  DCHECK(isolate()->heap()->deserialize_lazy_handler_extra_wide()->IsCode());
+  // Append the offset table. During deserialization, the offset table is
+  // extracted by BuiltinSnapshotData.
+  const byte* data = reinterpret_cast<const byte*>(&code_offsets_[0]);
+  int data_length = static_cast<int>(sizeof(code_offsets_));
 
   // Pad with kNop since GetInt() might read too far.
-  Pad();
+  Pad(data_length);
 
   // Append the offset table. During deserialization, the offset table is
   // extracted by BuiltinSnapshotData.
-  const byte* data = reinterpret_cast<const byte*>(&code_offsets_[0]);
-  int data_length = static_cast<int>(sizeof(code_offsets_));
   sink_.PutRaw(data, data_length, "BuiltinOffsets");
 }
 
@@ -83,20 +65,13 @@ void BuiltinSerializer::SerializeBuiltin(Code* code) {
   object_serializer.Serialize();
 }
 
-void BuiltinSerializer::SerializeHandler(Code* code) {
-  DCHECK(ObjectIsBytecodeHandler(code));
-  ObjectSerializer object_serializer(this, code, &sink_, kPlain,
-                                     kStartOfObject);
-  object_serializer.Serialize();
-}
-
 void BuiltinSerializer::SerializeObject(HeapObject* o, HowToCode how_to_code,
                                         WhereToPoint where_to_point, int skip) {
   DCHECK(!o->IsSmi());
 
   // Roots can simply be serialized as root references.
-  int root_index = root_index_map()->Lookup(o);
-  if (root_index != RootIndexMap::kInvalidRootIndex) {
+  RootIndex root_index;
+  if (root_index_map()->Lookup(o, &root_index)) {
     DCHECK(startup_serializer_->root_has_been_serialized(root_index));
     PutRoot(root_index, o, how_to_code, where_to_point, skip);
     return;
@@ -115,8 +90,8 @@ void BuiltinSerializer::SerializeObject(HeapObject* o, HowToCode how_to_code,
   // * Strings: CSA_ASSERTs in debug builds, various other string constants.
   // * HeapNumbers: Embedded constants.
   // TODO(6624): Jump targets should never trigger content serialization, it
-  // should always result in a reference instead. Reloc infos and handler
-  // tables should not end up in the partial snapshot cache.
+  // should always result in a reference instead. Reloc infos and handler tables
+  // should not end up in the partial snapshot cache.
 
   FlushSkip(skip);
 
@@ -128,17 +103,8 @@ void BuiltinSerializer::SerializeObject(HeapObject* o, HowToCode how_to_code,
 
 void BuiltinSerializer::SetBuiltinOffset(int builtin_id, uint32_t offset) {
   DCHECK(Builtins::IsBuiltinId(builtin_id));
-  DCHECK(BSU::IsBuiltinIndex(builtin_id));
   code_offsets_[builtin_id] = offset;
 }
 
-void BuiltinSerializer::SetHandlerOffset(Bytecode bytecode,
-                                         OperandScale operand_scale,
-                                         uint32_t offset) {
-  const int index = BSU::BytecodeToIndex(bytecode, operand_scale);
-  DCHECK(BSU::IsHandlerIndex(index));
-  code_offsets_[index] = offset;
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/snapshot/builtin-serializer.h b/deps/v8/src/snapshot/builtin-serializer.h
index abc8be74e5..132aa0894b 100644
--- a/deps/v8/src/snapshot/builtin-serializer.h
+++ b/deps/v8/src/snapshot/builtin-serializer.h
@@ -5,9 +5,9 @@
 #ifndef V8_SNAPSHOT_BUILTIN_SERIALIZER_H_
 #define V8_SNAPSHOT_BUILTIN_SERIALIZER_H_
 
+#include "src/builtins/builtins.h"
 #include "src/interpreter/interpreter.h"
 #include "src/snapshot/builtin-serializer-allocator.h"
-#include "src/snapshot/builtin-snapshot-utils.h"
 #include "src/snapshot/serializer.h"
 
 namespace v8 {
@@ -15,12 +15,10 @@ namespace internal {
 
 class StartupSerializer;
 
-// Responsible for serializing builtin and bytecode handler objects during
-// startup snapshot creation into a dedicated area of the snapshot.
+// Responsible for serializing builtin objects during startup snapshot creation
+// into a dedicated area of the snapshot.
 // See snapshot.h for documentation of the snapshot layout.
 class BuiltinSerializer : public Serializer<BuiltinSerializerAllocator> {
-  using BSU = BuiltinSnapshotUtils;
-
  public:
   BuiltinSerializer(Isolate* isolate, StartupSerializer* startup_serializer);
   ~BuiltinSerializer() override;
@@ -32,7 +30,6 @@ class BuiltinSerializer : public Serializer<BuiltinSerializerAllocator> {
                          Object** end) override;
 
   void SerializeBuiltin(Code* code);
-  void SerializeHandler(Code* code);
   void SerializeObject(HeapObject* o, HowToCode how_to_code,
                        WhereToPoint where_to_point, int skip) override;
 
@@ -47,14 +44,11 @@ class BuiltinSerializer : public Serializer<BuiltinSerializerAllocator> {
 
   // Stores the starting offset, within the serialized data, of each code
   // object. This is later packed into the builtin snapshot, and used by the
-  // builtin deserializer to deserialize individual builtins and bytecode
-  // handlers.
+  // builtin deserializer to deserialize individual builtins.
   //
   // Indices [kFirstBuiltinIndex, kFirstBuiltinIndex + kNumberOfBuiltins[:
   //     Builtin offsets.
-  // Indices [kFirstHandlerIndex, kFirstHandlerIndex + kNumberOfHandlers[:
-  //     Bytecode handler offsets.
-  uint32_t code_offsets_[BuiltinSnapshotUtils::kNumberOfCodeObjects];
+  uint32_t code_offsets_[Builtins::builtin_count];
 
   DISALLOW_COPY_AND_ASSIGN(BuiltinSerializer);
 };
diff --git a/deps/v8/src/snapshot/builtin-snapshot-utils.cc b/deps/v8/src/snapshot/builtin-snapshot-utils.cc
deleted file mode 100644
index e32a857c0b..0000000000
--- a/deps/v8/src/snapshot/builtin-snapshot-utils.cc
+++ /dev/null
@@ -1,67 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/snapshot/builtin-snapshot-utils.h"
-
-namespace v8 {
-namespace internal {
-
-// static
-bool BuiltinSnapshotUtils::IsBuiltinIndex(int maybe_index) {
-  return (kFirstBuiltinIndex <= maybe_index &&
-          maybe_index < kFirstBuiltinIndex + kNumberOfBuiltins);
-}
-
-// static
-bool BuiltinSnapshotUtils::IsHandlerIndex(int maybe_index) {
-  return (kFirstHandlerIndex <= maybe_index &&
-          maybe_index < kFirstHandlerIndex + kNumberOfHandlers);
-}
-
-// static
-int BuiltinSnapshotUtils::BytecodeToIndex(Bytecode bytecode,
-                                          OperandScale operand_scale) {
-  int index =
-      BuiltinSnapshotUtils::kNumberOfBuiltins + static_cast<int>(bytecode);
-  switch (operand_scale) {  // clang-format off
-    case OperandScale::kSingle: return index;
-    case OperandScale::kDouble: return index + Bytecodes::kBytecodeCount;
-    case OperandScale::kQuadruple: return index + 2 * Bytecodes::kBytecodeCount;
-  }  // clang-format on
-  UNREACHABLE();
-}
-
-// static
-std::pair<interpreter::Bytecode, interpreter::OperandScale>
-BuiltinSnapshotUtils::BytecodeFromIndex(int index) {
-  DCHECK(IsHandlerIndex(index));
-
-  const int x = index - BuiltinSnapshotUtils::kNumberOfBuiltins;
-  Bytecode bytecode = Bytecodes::FromByte(x % Bytecodes::kBytecodeCount);
-  switch (x / Bytecodes::kBytecodeCount) {  // clang-format off
-    case 0: return {bytecode, OperandScale::kSingle};
-    case 1: return {bytecode, OperandScale::kDouble};
-    case 2: return {bytecode, OperandScale::kQuadruple};
-    default: UNREACHABLE();
-  }  // clang-format on
-}
-
-// static
-void BuiltinSnapshotUtils::ForEachBytecode(
-    std::function<void(Bytecode, OperandScale)> f) {
-  static const OperandScale kOperandScales[] = {
-#define VALUE(Name, _) OperandScale::k##Name,
-      OPERAND_SCALE_LIST(VALUE)
-#undef VALUE
-  };
-
-  for (OperandScale operand_scale : kOperandScales) {
-    for (int i = 0; i < Bytecodes::kBytecodeCount; i++) {
-      f(Bytecodes::FromByte(i), operand_scale);
-    }
-  }
-}
-
-}  // namespace internal
-}  // namespace v8
diff --git a/deps/v8/src/snapshot/builtin-snapshot-utils.h b/deps/v8/src/snapshot/builtin-snapshot-utils.h
deleted file mode 100644
index 587b4a35b0..0000000000
--- a/deps/v8/src/snapshot/builtin-snapshot-utils.h
+++ /dev/null
@@ -1,56 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_SNAPSHOT_BUILTIN_SNAPSHOT_UTILS_H_
-#define V8_SNAPSHOT_BUILTIN_SNAPSHOT_UTILS_H_
-
-#include <functional>
-
-#include "src/interpreter/interpreter.h"
-
-namespace v8 {
-namespace internal {
-
-// Constants and utility methods used by builtin and bytecode handler
-// (de)serialization.
-class BuiltinSnapshotUtils : public AllStatic {
-  using Bytecode = interpreter::Bytecode;
-  using BytecodeOperands = interpreter::BytecodeOperands;
-  using Bytecodes = interpreter::Bytecodes;
-  using Interpreter = interpreter::Interpreter;
-  using OperandScale = interpreter::OperandScale;
-
- public:
-  static const int kFirstBuiltinIndex = 0;
-  static const int kNumberOfBuiltins = Builtins::builtin_count;
-
-  static const int kFirstHandlerIndex = kFirstBuiltinIndex + kNumberOfBuiltins;
-  static const int kNumberOfHandlers =
-      Bytecodes::kBytecodeCount * BytecodeOperands::kOperandScaleCount;
-
-  // The number of code objects in the builtin snapshot.
-  // TODO(jgruber): This could be reduced by a bit since not every
-  // {bytecode, operand_scale} combination has an associated handler
-  // (see Bytecodes::BytecodeHasHandler).
-  static const int kNumberOfCodeObjects = kNumberOfBuiltins + kNumberOfHandlers;
-
-  // Indexes into the offsets vector contained in snapshot.
-  // See e.g. BuiltinSerializer::code_offsets_.
-  static bool IsBuiltinIndex(int maybe_index);
-  static bool IsHandlerIndex(int maybe_index);
-  static int BytecodeToIndex(Bytecode bytecode, OperandScale operand_scale);
-
-  // Converts an index back into the {bytecode,operand_scale} tuple. This is the
-  // inverse operation of BytecodeToIndex().
-  static std::pair<Bytecode, OperandScale> BytecodeFromIndex(int index);
-
-  // Iteration over all {bytecode,operand_scale} pairs. Implemented here since
-  // (de)serialization depends on the iteration order.
-  static void ForEachBytecode(std::function<void(Bytecode, OperandScale)> f);
-};
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_SNAPSHOT_BUILTIN_SNAPSHOT_UTILS_H_
diff --git a/deps/v8/src/snapshot/code-serializer.cc b/deps/v8/src/snapshot/code-serializer.cc
index 5db7cae94b..b463ca2047 100644
--- a/deps/v8/src/snapshot/code-serializer.cc
+++ b/deps/v8/src/snapshot/code-serializer.cc
@@ -4,8 +4,6 @@
 
 #include "src/snapshot/code-serializer.h"
 
-#include <memory>
-
 #include "src/code-stubs.h"
 #include "src/counters.h"
 #include "src/debug/debug.h"
@@ -126,8 +124,8 @@ void CodeSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
                                      WhereToPoint where_to_point, int skip) {
   if (SerializeHotObject(obj, how_to_code, where_to_point, skip)) return;
 
-  int root_index = root_index_map()->Lookup(obj);
-  if (root_index != RootIndexMap::kInvalidRootIndex) {
+  RootIndex root_index;
+  if (root_index_map()->Lookup(obj, &root_index)) {
     PutRoot(root_index, obj, how_to_code, where_to_point, skip);
     return;
   }
@@ -336,44 +334,6 @@ MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
   return scope.CloseAndEscape(result);
 }
 
-class Checksum {
- public:
-  explicit Checksum(Vector<const byte> payload) {
-#ifdef MEMORY_SANITIZER
-    // Computing the checksum includes padding bytes for objects like strings.
-    // Mark every object as initialized in the code serializer.
-    MSAN_MEMORY_IS_INITIALIZED(payload.start(), payload.length());
-#endif  // MEMORY_SANITIZER
-    // Fletcher's checksum. Modified to reduce 64-bit sums to 32-bit.
-    uintptr_t a = 1;
-    uintptr_t b = 0;
-    const uintptr_t* cur = reinterpret_cast<const uintptr_t*>(payload.start());
-    DCHECK(IsAligned(payload.length(), kIntptrSize));
-    const uintptr_t* end = cur + payload.length() / kIntptrSize;
-    while (cur < end) {
-      // Unsigned overflow expected and intended.
-      a += *cur++;
-      b += a;
-    }
-#if V8_HOST_ARCH_64_BIT
-    a ^= a >> 32;
-    b ^= b >> 32;
-#endif  // V8_HOST_ARCH_64_BIT
-    a_ = static_cast<uint32_t>(a);
-    b_ = static_cast<uint32_t>(b);
-  }
-
-  bool Check(uint32_t a, uint32_t b) const { return a == a_ && b == b_; }
-
-  uint32_t a() const { return a_; }
-  uint32_t b() const { return b_; }
-
- private:
-  uint32_t a_;
-  uint32_t b_;
-
-  DISALLOW_COPY_AND_ASSIGN(Checksum);
-};
 
 SerializedCodeData::SerializedCodeData(const std::vector<byte>* payload,
                                        const CodeSerializer* cs) {
@@ -390,10 +350,14 @@ SerializedCodeData::SerializedCodeData(const std::vector<byte>* payload,
   uint32_t padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
   uint32_t size =
       padded_payload_offset + static_cast<uint32_t>(payload->size());
+  DCHECK(IsAligned(size, kPointerAlignment));
 
   // Allocate backing store and create result data.
   AllocateData(size);
 
+  // Zero out pre-payload data. Part of that is only used for padding.
+  memset(data_, 0, padded_payload_offset);
+
   // Set header values.
   SetMagicNumber(cs->isolate());
   SetHeaderValue(kVersionHashOffset, Version::Hash());
@@ -418,16 +382,13 @@ SerializedCodeData::SerializedCodeData(const std::vector<byte>* payload,
   CopyBytes(data_ + kHeaderSize + reservation_size,
             reinterpret_cast<const byte*>(stub_keys->data()), stub_keys_size);
 
-  // Zero out any padding before the payload.
-  memset(data_ + payload_offset, 0, padded_payload_offset - payload_offset);
-
   // Copy serialized data.
   CopyBytes(data_ + padded_payload_offset, payload->data(),
             static_cast<size_t>(payload->size()));
 
-  Checksum checksum(DataWithoutHeader());
-  SetHeaderValue(kChecksum1Offset, checksum.a());
-  SetHeaderValue(kChecksum2Offset, checksum.b());
+  Checksum checksum(ChecksummedContent());
+  SetHeaderValue(kChecksumPartAOffset, checksum.a());
+  SetHeaderValue(kChecksumPartBOffset, checksum.b());
 }
 
 SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck(
@@ -440,8 +401,8 @@ SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck(
   uint32_t cpu_features = GetHeaderValue(kCpuFeaturesOffset);
   uint32_t flags_hash = GetHeaderValue(kFlagHashOffset);
   uint32_t payload_length = GetHeaderValue(kPayloadLengthOffset);
-  uint32_t c1 = GetHeaderValue(kChecksum1Offset);
-  uint32_t c2 = GetHeaderValue(kChecksum2Offset);
+  uint32_t c1 = GetHeaderValue(kChecksumPartAOffset);
+  uint32_t c2 = GetHeaderValue(kChecksumPartBOffset);
   if (version_hash != Version::Hash()) return VERSION_MISMATCH;
   if (source_hash != expected_source_hash) return SOURCE_MISMATCH;
   if (cpu_features != static_cast<uint32_t>(CpuFeatures::SupportedFeatures())) {
@@ -454,7 +415,7 @@ SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck(
                          GetHeaderValue(kNumReservationsOffset) * kInt32Size +
                          GetHeaderValue(kNumCodeStubKeysOffset) * kInt32Size);
   if (payload_length > max_payload_length) return LENGTH_MISMATCH;
-  if (!Checksum(DataWithoutHeader()).Check(c1, c2)) return CHECKSUM_MISMATCH;
+  if (!Checksum(ChecksummedContent()).Check(c1, c2)) return CHECKSUM_MISMATCH;
   return CHECK_SUCCESS;
 }
 
diff --git a/deps/v8/src/snapshot/code-serializer.h b/deps/v8/src/snapshot/code-serializer.h
index d1f19ef081..d9b4be9a34 100644
--- a/deps/v8/src/snapshot/code-serializer.h
+++ b/deps/v8/src/snapshot/code-serializer.h
@@ -110,8 +110,8 @@ class SerializedCodeData : public SerializedData {
   // [6] number of code stub keys
   // [7] number of reservation size entries
   // [8] payload length
-  // [9] payload checksum part 1
-  // [10] payload checksum part 2
+  // [9] payload checksum part A
+  // [10] payload checksum part B
   // ...  reservations
   // ...  code stub keys
   // ...  serialized payload
@@ -124,9 +124,12 @@ class SerializedCodeData : public SerializedData {
       kNumReservationsOffset + kUInt32Size;
   static const uint32_t kPayloadLengthOffset =
       kNumCodeStubKeysOffset + kUInt32Size;
-  static const uint32_t kChecksum1Offset = kPayloadLengthOffset + kUInt32Size;
-  static const uint32_t kChecksum2Offset = kChecksum1Offset + kUInt32Size;
-  static const uint32_t kUnalignedHeaderSize = kChecksum2Offset + kUInt32Size;
+  static const uint32_t kChecksumPartAOffset =
+      kPayloadLengthOffset + kUInt32Size;
+  static const uint32_t kChecksumPartBOffset =
+      kChecksumPartAOffset + kUInt32Size;
+  static const uint32_t kUnalignedHeaderSize =
+      kChecksumPartBOffset + kUInt32Size;
   static const uint32_t kHeaderSize = POINTER_SIZE_ALIGN(kUnalignedHeaderSize);
 
   // Used when consuming.
@@ -155,7 +158,7 @@ class SerializedCodeData : public SerializedData {
   SerializedCodeData(const byte* data, int size)
       : SerializedData(const_cast<byte*>(data), size) {}
 
-  Vector<const byte> DataWithoutHeader() const {
+  Vector<const byte> ChecksummedContent() const {
     return Vector<const byte>(data_ + kHeaderSize, size_ - kHeaderSize);
   }
 
diff --git a/deps/v8/src/snapshot/default-deserializer-allocator.cc b/deps/v8/src/snapshot/default-deserializer-allocator.cc
index 610b87c771..f3afc4d498 100644
--- a/deps/v8/src/snapshot/default-deserializer-allocator.cc
+++ b/deps/v8/src/snapshot/default-deserializer-allocator.cc
@@ -121,7 +121,7 @@ HeapObject* DefaultDeserializerAllocator::GetObject(AllocationSpace space,
 }
 
 void DefaultDeserializerAllocator::DecodeReservation(
-    std::vector<SerializedData::Reservation> res) {
+    const std::vector<SerializedData::Reservation>& res) {
   DCHECK_EQ(0, reservations_[FIRST_SPACE].size());
   int current_space = FIRST_SPACE;
   for (auto& r : res) {
@@ -167,8 +167,7 @@ bool DefaultDeserializerAllocator::ReserveSpace(
   }
 
   Heap::Reservation builtin_reservations =
-      builtin_deserializer->allocator()
-          ->CreateReservationsForEagerBuiltinsAndHandlers();
+      builtin_deserializer->allocator()->CreateReservationsForEagerBuiltins();
   DCHECK(!builtin_reservations.empty());
 
   for (const auto& c : builtin_reservations) {
diff --git a/deps/v8/src/snapshot/default-deserializer-allocator.h b/deps/v8/src/snapshot/default-deserializer-allocator.h
index e6a5ba3fdc..4a5758cc5a 100644
--- a/deps/v8/src/snapshot/default-deserializer-allocator.h
+++ b/deps/v8/src/snapshot/default-deserializer-allocator.h
@@ -58,7 +58,7 @@ class DefaultDeserializerAllocator final {
   // ------- Reservation Methods -------
   // Methods related to memory reservations (prior to deserialization).
 
-  void DecodeReservation(std::vector<SerializedData::Reservation> res);
+  void DecodeReservation(const std::vector<SerializedData::Reservation>& res);
   bool ReserveSpace();
 
   // Atomically reserves space for the two given deserializers. Guarantees
diff --git a/deps/v8/src/snapshot/deserializer.cc b/deps/v8/src/snapshot/deserializer.cc
index 3ed360e14a..bc5805fb52 100644
--- a/deps/v8/src/snapshot/deserializer.cc
+++ b/deps/v8/src/snapshot/deserializer.cc
@@ -69,8 +69,7 @@ template <class AllocatorT>
 void Deserializer<AllocatorT>::VisitRootPointers(Root root,
                                                  const char* description,
                                                  Object** start, Object** end) {
-  // Builtins and bytecode handlers are deserialized in a separate pass by the
-  // BuiltinDeserializer.
+  // Builtins are deserialized in a separate pass by the BuiltinDeserializer.
   if (root == Root::kBuiltins || root == Root::kDispatchTable) return;
 
   // The space must be new space.  Any other space would cause ReadChunk to try
@@ -179,18 +178,11 @@ HeapObject* Deserializer<AllocatorT>::PostProcessNewObject(HeapObject* obj,
   }
 
   if (obj->IsAllocationSite()) {
-    // Allocation sites are present in the snapshot, and must be linked into
-    // a list at deserialization time.
-    AllocationSite* site = AllocationSite::cast(obj);
-    // TODO(mvstanton): consider treating the heap()->allocation_sites_list()
-    // as a (weak) root. If this root is relocated correctly, this becomes
-    // unnecessary.
-    if (isolate_->heap()->allocation_sites_list() == Smi::kZero) {
-      site->set_weak_next(ReadOnlyRoots(isolate_).undefined_value());
-    } else {
-      site->set_weak_next(isolate_->heap()->allocation_sites_list());
-    }
-    isolate_->heap()->set_allocation_sites_list(site);
+    // We should link new allocation sites, but we can't do this immediately
+    // because |AllocationSite::HasWeakNext()| internally accesses
+    // |Heap::roots_| that may not have been initialized yet. So defer this to
+    // |ObjectDeserializer::CommitPostProcessedObjects()|.
+    new_allocation_sites_.push_back(AllocationSite::cast(obj));
   } else if (obj->IsCode()) {
     // We flush all code pages after deserializing the startup snapshot. In that
     // case, we only need to remember code objects in the large object space.
@@ -209,7 +201,7 @@ HeapObject* Deserializer<AllocatorT>::PostProcessNewObject(HeapObject* obj,
   } else if (obj->IsExternalString()) {
     if (obj->map() == ReadOnlyRoots(isolate_).native_source_string_map()) {
       ExternalOneByteString* string = ExternalOneByteString::cast(obj);
-      DCHECK(string->is_short());
+      DCHECK(string->is_uncached());
       string->SetResource(
           isolate_, NativesExternalStringResource::DecodeForDeserialization(
                         string->resource()));
@@ -225,8 +217,8 @@ HeapObject* Deserializer<AllocatorT>::PostProcessNewObject(HeapObject* obj,
     isolate_->heap()->RegisterExternalString(String::cast(obj));
   } else if (obj->IsJSTypedArray()) {
     JSTypedArray* typed_array = JSTypedArray::cast(obj);
-    CHECK(typed_array->byte_offset()->IsSmi());
-    int32_t byte_offset = NumberToInt32(typed_array->byte_offset());
+    CHECK_LE(typed_array->byte_offset(), Smi::kMaxValue);
+    int32_t byte_offset = static_cast<int32_t>(typed_array->byte_offset());
     if (byte_offset > 0) {
       FixedTypedArrayBase* elements =
           FixedTypedArrayBase::cast(typed_array->elements());
@@ -370,11 +362,7 @@ Object* Deserializer<AllocatorT>::ReadDataSingle() {
   Address current_object = kNullAddress;
 
   CHECK(ReadData(start, end, source_space, current_object));
-  HeapObject* heap_object;
-  bool success = o->ToStrongHeapObject(&heap_object);
-  DCHECK(success);
-  USE(success);
-  return heap_object;
+  return o->GetHeapObjectAssumeStrong();
 }
 
 static void NoExternalReferencesCallback() {
@@ -684,7 +672,7 @@ bool Deserializer<AllocatorT>::ReadData(MaybeObject** current,
       SIXTEEN_CASES(kRootArrayConstants)
       SIXTEEN_CASES(kRootArrayConstants + 16) {
         int id = data & kRootArrayConstantsMask;
-        Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(id);
+        RootIndex root_index = static_cast<RootIndex>(id);
         MaybeObject* object =
             MaybeObject::FromObject(isolate->heap()->root(root_index));
         DCHECK(!Heap::InNewSpace(object));
@@ -818,7 +806,7 @@ MaybeObject** Deserializer<AllocatorT>::ReadDataCase(
       new_object = GetBackReferencedObject(data & kSpaceMask);
     } else if (where == kRootArray) {
       int id = source_.GetInt();
-      Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(id);
+      RootIndex root_index = static_cast<RootIndex>(id);
       new_object = isolate->heap()->root(root_index);
       emit_write_barrier = Heap::InNewSpace(new_object);
       hot_objects_.Add(HeapObject::cast(new_object));
diff --git a/deps/v8/src/snapshot/deserializer.h b/deps/v8/src/snapshot/deserializer.h
index f13bc03fd4..8340a93538 100644
--- a/deps/v8/src/snapshot/deserializer.h
+++ b/deps/v8/src/snapshot/deserializer.h
@@ -15,6 +15,7 @@
 namespace v8 {
 namespace internal {
 
+class AllocationSite;
 class HeapObject;
 class Object;
 
@@ -71,6 +72,9 @@ class Deserializer : public SerializerDeserializer {
 
   Isolate* isolate() const { return isolate_; }
   SnapshotByteSource* source() { return &source_; }
+  const std::vector<AllocationSite*>& new_allocation_sites() const {
+    return new_allocation_sites_;
+  }
   const std::vector<Code*>& new_code_objects() const {
     return new_code_objects_;
   }
@@ -148,6 +152,7 @@ class Deserializer : public SerializerDeserializer {
 
   ExternalReferenceTable* external_reference_table_;
 
+  std::vector<AllocationSite*> new_allocation_sites_;
   std::vector<Code*> new_code_objects_;
   std::vector<AccessorInfo*> accessor_infos_;
   std::vector<CallHandlerInfo*> call_handler_infos_;
diff --git a/deps/v8/src/snapshot/mksnapshot.cc b/deps/v8/src/snapshot/mksnapshot.cc
index a2303613d6..09db077694 100644
--- a/deps/v8/src/snapshot/mksnapshot.cc
+++ b/deps/v8/src/snapshot/mksnapshot.cc
@@ -165,10 +165,10 @@ class SnapshotWriter {
     // present in the binary.
     // For now, the straight-forward solution seems to be to just emit a pure
     // .byte stream on OSX.
-    WriteBinaryContentsAsByteDirective(fp, blob->data(), blob->size());
+    WriteBinaryContentsAsInlineAssembly(fp, blob->data(), blob->size());
 #else
-    WriteBinaryContentsAsByteDirective(fp, blob->data(),
-                                       i::EmbeddedData::RawDataOffset());
+    WriteBinaryContentsAsInlineAssembly(fp, blob->data(),
+                                        i::EmbeddedData::RawDataOffset());
     WriteBuiltins(fp, blob, embedded_variant);
 #endif
     fprintf(fp, "extern \"C\" const uint8_t v8_%s_embedded_blob_[];\n",
@@ -197,7 +197,7 @@ class SnapshotWriter {
                 embedded_variant, i::Builtins::name(i));
       }
 
-      WriteBinaryContentsAsByteDirective(
+      WriteBinaryContentsAsInlineAssembly(
           fp,
           reinterpret_cast<const uint8_t*>(blob->InstructionStartOfBuiltin(i)),
           blob->PaddedInstructionSizeOfBuiltin(i));
@@ -205,34 +205,77 @@ class SnapshotWriter {
     fprintf(fp, "\n");
   }
 
-  static void WriteBinaryContentsAsByteDirective(FILE* fp, const uint8_t* data,
-                                                 uint32_t size) {
-    static const int kTextWidth = 80;
-    int current_line_length = 0;
-    int printed_chars;
+  static int WriteOcta(FILE* fp, int current_line_length, const uint8_t* data) {
+    const uint64_t* quad_ptr1 = reinterpret_cast<const uint64_t*>(data);
+    const uint64_t* quad_ptr2 = reinterpret_cast<const uint64_t*>(data + 8);
 
-    fprintf(fp, "__asm__(\n");
-    for (uint32_t i = 0; i < size; i++) {
-      if (current_line_length == 0) {
-        printed_chars = fprintf(fp, "%s", "  \".byte ");
-        DCHECK_LT(0, printed_chars);
-        current_line_length += printed_chars;
-      } else {
-        printed_chars = fprintf(fp, ",");
-        DCHECK_EQ(1, printed_chars);
-        current_line_length += printed_chars;
-      }
+#ifdef V8_TARGET_BIG_ENDIAN
+    uint64_t part1 = *quad_ptr1;
+    uint64_t part2 = *quad_ptr2;
+#else
+    uint64_t part1 = *quad_ptr2;
+    uint64_t part2 = *quad_ptr1;
+#endif  // V8_TARGET_BIG_ENDIAN
+
+    if (part1 != 0) {
+      current_line_length +=
+          fprintf(fp, "0x%" PRIx64 "%016" PRIx64, part1, part2);
+    } else {
+      current_line_length += fprintf(fp, "0x%" PRIx64, part2);
+    }
+    return current_line_length;
+  }
 
-      printed_chars = fprintf(fp, "0x%02x", data[i]);
+  static int WriteDirectiveOrSeparator(FILE* fp, int current_line_length,
+                                       const char* directive) {
+    int printed_chars;
+    if (current_line_length == 0) {
+      printed_chars = fprintf(fp, "  \"%s ", directive);
       DCHECK_LT(0, printed_chars);
-      current_line_length += printed_chars;
+    } else {
+      printed_chars = fprintf(fp, ",");
+      DCHECK_EQ(1, printed_chars);
+    }
+    return current_line_length + printed_chars;
+  }
 
-      if (current_line_length + strlen(",0xFF\\n\"") > kTextWidth) {
-        fprintf(fp, "\\n\"\n");
-        current_line_length = 0;
-      }
+  static int WriteLineEndIfNeeded(FILE* fp, int current_line_length,
+                                  int write_size) {
+    static const int kTextWidth = 80;
+    // Check if adding ',0xFF...FF\n"' would force a line wrap. This doesn't use
+    // the actual size of the string to be written to determine this so it's
+    // more conservative than strictly needed.
+    if (current_line_length + strlen(",0x\\n\"") + write_size * 2 >
+        kTextWidth) {
+      fprintf(fp, "\\n\"\n");
+      return 0;
+    } else {
+      return current_line_length;
     }
+  }
+
+  static void WriteBinaryContentsAsInlineAssembly(FILE* fp, const uint8_t* data,
+                                                  uint32_t size) {
+    int current_line_length = 0;
 
+    fprintf(fp, "__asm__(\n");
+    uint32_t i = 0;
+    const uint32_t size_of_octa = 16;
+    for (; i <= size - size_of_octa; i += size_of_octa) {
+      current_line_length =
+          WriteDirectiveOrSeparator(fp, current_line_length, ".octa");
+      current_line_length = WriteOcta(fp, current_line_length, data + i);
+      current_line_length =
+          WriteLineEndIfNeeded(fp, current_line_length, size_of_octa);
+    }
+    if (current_line_length != 0) fprintf(fp, "\\n\"\n");
+    current_line_length = 0;
+    for (; i < size; i++) {
+      current_line_length =
+          WriteDirectiveOrSeparator(fp, current_line_length, ".byte");
+      current_line_length += fprintf(fp, "0x%x", data[i]);
+      current_line_length = WriteLineEndIfNeeded(fp, current_line_length, 1);
+    }
     if (current_line_length != 0) fprintf(fp, "\\n\"\n");
     fprintf(fp, ");\n");
   }
@@ -307,7 +350,7 @@ bool RunExtraCode(v8::Isolate* isolate, v8::Local<v8::Context> context,
 }
 
 v8::StartupData CreateSnapshotDataBlob(v8::SnapshotCreator* snapshot_creator,
-                                       const char* script_source = NULL) {
+                                       const char* script_source = nullptr) {
   // Create a new isolate and a new context from scratch, optionally run
   // a script to embed, and serialize to create a snapshot blob.
   v8::StartupData result = {nullptr, 0};
diff --git a/deps/v8/src/snapshot/object-deserializer.cc b/deps/v8/src/snapshot/object-deserializer.cc
index aabc5bf1e0..8935c0ef89 100644
--- a/deps/v8/src/snapshot/object-deserializer.cc
+++ b/deps/v8/src/snapshot/object-deserializer.cc
@@ -90,6 +90,21 @@ void ObjectDeserializer::CommitPostProcessedObjects() {
                                    MaybeObjectHandle::Weak(script));
     heap->SetRootScriptList(*list);
   }
+
+  // Allocation sites are present in the snapshot, and must be linked into
+  // a list at deserialization time.
+  for (AllocationSite* site : new_allocation_sites()) {
+    if (!site->HasWeakNext()) continue;
+    // TODO(mvstanton): consider treating the heap()->allocation_sites_list()
+    // as a (weak) root. If this root is relocated correctly, this becomes
+    // unnecessary.
+    if (heap->allocation_sites_list() == Smi::kZero) {
+      site->set_weak_next(ReadOnlyRoots(heap).undefined_value());
+    } else {
+      site->set_weak_next(heap->allocation_sites_list());
+    }
+    heap->set_allocation_sites_list(site);
+  }
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/snapshot/partial-serializer.cc b/deps/v8/src/snapshot/partial-serializer.cc
index d127aa5f0a..1f3cbc5521 100644
--- a/deps/v8/src/snapshot/partial-serializer.cc
+++ b/deps/v8/src/snapshot/partial-serializer.cc
@@ -6,6 +6,7 @@
 #include "src/snapshot/startup-serializer.h"
 
 #include "src/api-inl.h"
+#include "src/math-random.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
@@ -40,8 +41,7 @@ void PartialSerializer::Serialize(Context** o, bool include_global_proxy) {
                 ReadOnlyRoots(isolate()).undefined_value());
   DCHECK(!context_->global_object()->IsUndefined());
   // Reset math random cache to get fresh random numbers.
-  context_->set_math_random_index(Smi::kZero);
-  context_->set_math_random_cache(ReadOnlyRoots(isolate()).undefined_value());
+  MathRandom::ResetContext(context_);
 
   VisitRootPointer(Root::kPartialSnapshotCache, nullptr,
                    reinterpret_cast<Object**>(o));
@@ -59,8 +59,8 @@ void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
   }
   if (SerializeHotObject(obj, how_to_code, where_to_point, skip)) return;
 
-  int root_index = root_index_map()->Lookup(obj);
-  if (root_index != RootIndexMap::kInvalidRootIndex) {
+  RootIndex root_index;
+  if (root_index_map()->Lookup(obj, &root_index)) {
     PutRoot(root_index, obj, how_to_code, where_to_point, skip);
     return;
   }
diff --git a/deps/v8/src/snapshot/serializer-common.h b/deps/v8/src/snapshot/serializer-common.h
index 34a6b64676..8f547243d6 100644
--- a/deps/v8/src/snapshot/serializer-common.h
+++ b/deps/v8/src/snapshot/serializer-common.h
@@ -9,6 +9,7 @@
 #include "src/base/bits.h"
 #include "src/external-reference-table.h"
 #include "src/globals.h"
+#include "src/msan.h"
 #include "src/snapshot/references.h"
 #include "src/v8memory.h"
 #include "src/visitors.h"
@@ -39,7 +40,7 @@ class ExternalReferenceEncoder {
   };
 
   explicit ExternalReferenceEncoder(Isolate* isolate);
-  ~ExternalReferenceEncoder();
+  ~ExternalReferenceEncoder();  // NOLINT (modernize-use-equals-default)
 
   Value Encode(Address key);
   Maybe<Value> TryEncode(Address key);
@@ -350,6 +351,45 @@ class SerializedData {
   DISALLOW_COPY_AND_ASSIGN(SerializedData);
 };
 
+class Checksum {
+ public:
+  explicit Checksum(Vector<const byte> payload) {
+#ifdef MEMORY_SANITIZER
+    // Computing the checksum includes padding bytes for objects like strings.
+    // Mark every object as initialized in the code serializer.
+    MSAN_MEMORY_IS_INITIALIZED(payload.start(), payload.length());
+#endif  // MEMORY_SANITIZER
+    // Fletcher's checksum. Modified to reduce 64-bit sums to 32-bit.
+    uintptr_t a = 1;
+    uintptr_t b = 0;
+    const uintptr_t* cur = reinterpret_cast<const uintptr_t*>(payload.start());
+    DCHECK(IsAligned(payload.length(), kIntptrSize));
+    const uintptr_t* end = cur + payload.length() / kIntptrSize;
+    while (cur < end) {
+      // Unsigned overflow expected and intended.
+      a += *cur++;
+      b += a;
+    }
+#if V8_HOST_ARCH_64_BIT
+    a ^= a >> 32;
+    b ^= b >> 32;
+#endif  // V8_HOST_ARCH_64_BIT
+    a_ = static_cast<uint32_t>(a);
+    b_ = static_cast<uint32_t>(b);
+  }
+
+  bool Check(uint32_t a, uint32_t b) const { return a == a_ && b == b_; }
+
+  uint32_t a() const { return a_; }
+  uint32_t b() const { return b_; }
+
+ private:
+  uint32_t a_;
+  uint32_t b_;
+
+  DISALLOW_COPY_AND_ASSIGN(Checksum);
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/snapshot/serializer.cc b/deps/v8/src/snapshot/serializer.cc
index 56d87b8916..a8b911a191 100644
--- a/deps/v8/src/snapshot/serializer.cc
+++ b/deps/v8/src/snapshot/serializer.cc
@@ -111,8 +111,7 @@ template <class AllocatorT>
 void Serializer<AllocatorT>::VisitRootPointers(Root root,
                                                const char* description,
                                                Object** start, Object** end) {
-  // Builtins and bytecode handlers are serialized in a separate pass by the
-  // BuiltinSerializer.
+  // Builtins are serialized in a separate pass by the BuiltinSerializer.
   if (root == Root::kBuiltins || root == Root::kDispatchTable) return;
 
   for (Object** current = start; current < end; current++) {
@@ -233,16 +232,15 @@ bool Serializer<AllocatorT>::SerializeBuiltinReference(
 template <class AllocatorT>
 bool Serializer<AllocatorT>::ObjectIsBytecodeHandler(HeapObject* obj) const {
   if (!obj->IsCode()) return false;
-  Code* code = Code::cast(obj);
-  if (isolate()->heap()->IsDeserializeLazyHandler(code)) return false;
-  return (code->kind() == Code::BYTECODE_HANDLER);
+  return (Code::cast(obj)->kind() == Code::BYTECODE_HANDLER);
 }
 
 template <class AllocatorT>
 void Serializer<AllocatorT>::PutRoot(
-    int root_index, HeapObject* object,
+    RootIndex root, HeapObject* object,
     SerializerDeserializer::HowToCode how_to_code,
     SerializerDeserializer::WhereToPoint where_to_point, int skip) {
+  int root_index = static_cast<int>(root);
   if (FLAG_trace_serializer) {
     PrintF(" Encoding root %d:", root_index);
     object->ShortPrint();
@@ -251,7 +249,7 @@ void Serializer<AllocatorT>::PutRoot(
 
   // Assert that the first 32 root array items are a conscious choice. They are
   // chosen so that the most common ones can be encoded more efficiently.
-  STATIC_ASSERT(Heap::kArgumentsMarkerRootIndex ==
+  STATIC_ASSERT(static_cast<int>(RootIndex::kArgumentsMarker) ==
                 kNumberOfRootArrayConstants - 1);
 
   if (how_to_code == kPlain && where_to_point == kStartOfObject &&
@@ -330,14 +328,14 @@ void Serializer<AllocatorT>::PutNextChunk(int space) {
 }
 
 template <class AllocatorT>
-void Serializer<AllocatorT>::Pad() {
+void Serializer<AllocatorT>::Pad(int padding_offset) {
   // The non-branching GetInt will read up to 3 bytes too far, so we need
   // to pad the snapshot to make sure we don't read over the end.
   for (unsigned i = 0; i < sizeof(int32_t) - 1; i++) {
     sink_.Put(kNop, "Padding");
   }
   // Pad up to pointer size for checksum.
-  while (!IsAligned(sink_.Position(), kPointerAlignment)) {
+  while (!IsAligned(sink_.Position() + padding_offset, kPointerAlignment)) {
     sink_.Put(kNop, "Padding");
   }
 }
@@ -436,10 +434,10 @@ void Serializer<AllocatorT>::ObjectSerializer::SerializeJSTypedArray() {
     if (!typed_array->is_on_heap()) {
       // Explicitly serialize the backing store now.
       JSArrayBuffer* buffer = JSArrayBuffer::cast(typed_array->buffer());
-      CHECK(buffer->byte_length()->IsSmi());
-      CHECK(typed_array->byte_offset()->IsSmi());
-      int32_t byte_length = NumberToInt32(buffer->byte_length());
-      int32_t byte_offset = NumberToInt32(typed_array->byte_offset());
+      CHECK_LE(buffer->byte_length(), Smi::kMaxValue);
+      CHECK_LE(typed_array->byte_offset(), Smi::kMaxValue);
+      int32_t byte_length = static_cast<int32_t>(buffer->byte_length());
+      int32_t byte_offset = static_cast<int32_t>(typed_array->byte_offset());
 
       // We need to calculate the backing store from the external pointer
       // because the ArrayBuffer may already have been serialized.
@@ -469,9 +467,8 @@ void Serializer<AllocatorT>::ObjectSerializer::SerializeJSArrayBuffer() {
   JSArrayBuffer* buffer = JSArrayBuffer::cast(object_);
   void* backing_store = buffer->backing_store();
   // We cannot store byte_length larger than Smi range in the snapshot.
-  // Attempt to make sure that NumberToInt32 produces something sensible.
-  CHECK(buffer->byte_length()->IsSmi());
-  int32_t byte_length = NumberToInt32(buffer->byte_length());
+  CHECK_LE(buffer->byte_length(), Smi::kMaxValue);
+  int32_t byte_length = static_cast<int32_t>(buffer->byte_length());
 
   // The embedder-allocated backing store only exists for the off-heap case.
   if (backing_store != nullptr) {
@@ -505,7 +502,7 @@ void Serializer<AllocatorT>::ObjectSerializer::SerializeExternalString() {
     }
   } else {
     ExternalOneByteString* string = ExternalOneByteString::cast(object_);
-    DCHECK(string->is_short());
+    DCHECK(string->is_uncached());
     const NativesExternalStringResource* resource =
         reinterpret_cast<const NativesExternalStringResource*>(
             string->resource());
@@ -581,7 +578,8 @@ class UnlinkWeakNextScope {
  public:
   explicit UnlinkWeakNextScope(Heap* heap, HeapObject* object)
       : object_(nullptr) {
-    if (object->IsAllocationSite()) {
+    if (object->IsAllocationSite() &&
+        AllocationSite::cast(object)->HasWeakNext()) {
       object_ = object;
       next_ = AllocationSite::cast(object)->weak_next();
       AllocationSite::cast(object)->set_weak_next(
@@ -729,8 +727,7 @@ void Serializer<AllocatorT>::ObjectSerializer::VisitPointers(
     HeapObject* host, MaybeObject** start, MaybeObject** end) {
   MaybeObject** current = start;
   while (current < end) {
-    while (current < end &&
-           ((*current)->IsSmi() || (*current)->IsClearedWeakHeapObject())) {
+    while (current < end && ((*current)->IsSmi() || (*current)->IsCleared())) {
       current++;
     }
     if (current < end) {
@@ -738,12 +735,14 @@ void Serializer<AllocatorT>::ObjectSerializer::VisitPointers(
     }
     HeapObject* current_contents;
     HeapObjectReferenceType reference_type;
-    while (current < end && (*current)->ToStrongOrWeakHeapObject(
-                                &current_contents, &reference_type)) {
-      int root_index = serializer_->root_index_map()->Lookup(current_contents);
+    while (current < end &&
+           (*current)->GetHeapObject(&current_contents, &reference_type)) {
+      RootIndex root_index;
       // Repeats are not subject to the write barrier so we can only use
       // immortal immovable root members. They are never in new space.
-      if (current != start && root_index != RootIndexMap::kInvalidRootIndex &&
+      if (current != start &&
+          serializer_->root_index_map()->Lookup(current_contents,
+                                                &root_index) &&
           Heap::RootIsImmortalImmovable(root_index) &&
           *current == current[-1]) {
         DCHECK_EQ(reference_type, HeapObjectReferenceType::STRONG);
diff --git a/deps/v8/src/snapshot/serializer.h b/deps/v8/src/snapshot/serializer.h
index 9427cb6c78..5a08e4299e 100644
--- a/deps/v8/src/snapshot/serializer.h
+++ b/deps/v8/src/snapshot/serializer.h
@@ -172,8 +172,8 @@ class Serializer : public SerializerDeserializer {
                          Object** end) override;
   void SerializeRootObject(Object* object);
 
-  void PutRoot(int index, HeapObject* object, HowToCode how, WhereToPoint where,
-               int skip);
+  void PutRoot(RootIndex root_index, HeapObject* object, HowToCode how,
+               WhereToPoint where, int skip);
   void PutSmi(Smi* smi);
   void PutBackReference(HeapObject* object, SerializerReference reference);
   void PutAttachedReference(SerializerReference reference,
@@ -210,7 +210,8 @@ class Serializer : public SerializerDeserializer {
   }
 
   // GetInt reads 4 bytes at once, requiring padding at the end.
-  void Pad();
+  // Use padding_offset to specify the space you want to use after padding.
+  void Pad(int padding_offset = 0);
 
   // We may not need the code address map for logging for every instance
   // of the serializer.  Initialize it on demand.
@@ -284,6 +285,7 @@ class Serializer<AllocatorT>::ObjectSerializer : public ObjectVisitor {
     serializer_->PushStack(obj);
 #endif  // DEBUG
   }
+  // NOLINTNEXTLINE (modernize-use-equals-default)
   ~ObjectSerializer() override {
 #ifdef DEBUG
     serializer_->PopStack();
diff --git a/deps/v8/src/snapshot/snapshot-common.cc b/deps/v8/src/snapshot/snapshot-common.cc
index 31f378792b..95baef0cc0 100644
--- a/deps/v8/src/snapshot/snapshot-common.cc
+++ b/deps/v8/src/snapshot/snapshot-common.cc
@@ -44,6 +44,7 @@ bool Snapshot::Initialize(Isolate* isolate) {
 
   const v8::StartupData* blob = isolate->snapshot_blob();
   CheckVersion(blob);
+  CHECK(VerifyChecksum(blob));
   Vector<const byte> startup_data = ExtractStartupData(blob);
   SnapshotData startup_snapshot_data(startup_data);
   Vector<const byte> builtin_data = ExtractBuiltinData(blob);
@@ -136,13 +137,17 @@ void Snapshot::EnsureAllBuiltinsAreDeserialized(Isolate* isolate) {
 
     DCHECK_NE(Builtins::kDeserializeLazy, i);
     Code* code = builtins->builtin(i);
-    if (code->builtin_index() == Builtins::kDeserializeLazy) {
+    if (code->builtin_index() == Builtins::LazyDeserializerForBuiltin(i)) {
       code = Snapshot::DeserializeBuiltin(isolate, i);
     }
 
     DCHECK_EQ(i, code->builtin_index());
     DCHECK_EQ(code, builtins->builtin(i));
   }
+
+  // Re-initialize the dispatch table now that any bytecodes have been
+  // deserialized.
+  isolate->interpreter()->InitializeDispatchTable();
 }
 
 // static
@@ -168,42 +173,6 @@ Code* Snapshot::EnsureBuiltinIsDeserialized(Isolate* isolate,
   return code;
 }
 
-// static
-Code* Snapshot::DeserializeHandler(Isolate* isolate,
-                                   interpreter::Bytecode bytecode,
-                                   interpreter::OperandScale operand_scale) {
-  if (FLAG_trace_lazy_deserialization) {
-    PrintF("Lazy-deserializing handler %s\n",
-           interpreter::Bytecodes::ToString(bytecode, operand_scale).c_str());
-  }
-
-  base::ElapsedTimer timer;
-  if (FLAG_profile_deserialization) timer.Start();
-
-  const v8::StartupData* blob = isolate->snapshot_blob();
-  Vector<const byte> builtin_data = Snapshot::ExtractBuiltinData(blob);
-  BuiltinSnapshotData builtin_snapshot_data(builtin_data);
-
-  CodeSpaceMemoryModificationScope code_allocation(isolate->heap());
-  BuiltinDeserializer builtin_deserializer(isolate, &builtin_snapshot_data);
-  Code* code = builtin_deserializer.DeserializeHandler(bytecode, operand_scale);
-
-  if (FLAG_profile_deserialization) {
-    double ms = timer.Elapsed().InMillisecondsF();
-    int bytes = code->Size();
-    PrintF("[Deserializing handler %s (%d bytes) took %0.3f ms]\n",
-           interpreter::Bytecodes::ToString(bytecode, operand_scale).c_str(),
-           bytes, ms);
-  }
-
-  if (isolate->logger()->is_listening_to_code_events() ||
-      isolate->is_profiling()) {
-    isolate->logger()->LogBytecodeHandler(bytecode, operand_scale, code);
-  }
-
-  return code;
-}
-
 void ProfileDeserialization(
     const SnapshotData* startup_snapshot, const SnapshotData* builtin_snapshot,
     const std::vector<SnapshotData*>& context_snapshots) {
@@ -234,15 +203,22 @@ v8::StartupData Snapshot::CreateSnapshotBlob(
   uint32_t num_contexts = static_cast<uint32_t>(context_snapshots.size());
   uint32_t startup_snapshot_offset = StartupSnapshotOffset(num_contexts);
   uint32_t total_length = startup_snapshot_offset;
+  DCHECK(IsAligned(total_length, kPointerAlignment));
   total_length += static_cast<uint32_t>(startup_snapshot->RawData().length());
+  DCHECK(IsAligned(total_length, kPointerAlignment));
   total_length += static_cast<uint32_t>(builtin_snapshot->RawData().length());
+  DCHECK(IsAligned(total_length, kPointerAlignment));
   for (const auto context_snapshot : context_snapshots) {
     total_length += static_cast<uint32_t>(context_snapshot->RawData().length());
+    DCHECK(IsAligned(total_length, kPointerAlignment));
   }
 
   ProfileDeserialization(startup_snapshot, builtin_snapshot, context_snapshots);
 
   char* data = new char[total_length];
+  // Zero out pre-payload data. Part of that is only used for padding.
+  memset(data, 0, StartupSnapshotOffset(num_contexts));
+
   SetHeaderValue(data, kNumberOfContextsOffset, num_contexts);
   SetHeaderValue(data, kRehashabilityOffset, can_be_rehashed ? 1 : 0);
 
@@ -292,8 +268,13 @@ v8::StartupData Snapshot::CreateSnapshotBlob(
     payload_offset += payload_length;
   }
 
-  v8::StartupData result = {data, static_cast<int>(total_length)};
   DCHECK_EQ(total_length, payload_offset);
+  v8::StartupData result = {data, static_cast<int>(total_length)};
+
+  Checksum checksum(ChecksummedContent(&result));
+  SetHeaderValue(data, kChecksumPartAOffset, checksum.a());
+  SetHeaderValue(data, kChecksumPartBOffset, checksum.b());
+
   return result;
 }
 
@@ -308,9 +289,11 @@ bool BuiltinAliasesOffHeapTrampolineRegister(Isolate* isolate, Code* code) {
     case Builtins::TFS:
       break;
 
-    // Bytecode handlers will only ever be used by the interpreter and so there
-    // will never be a need to use trampolines with them.
+    // Bytecode handlers (and their lazy deserializers) will only ever be used
+    // by the interpreter and so there will never be a need to use trampolines
+    // with them.
     case Builtins::BCH:
+    case Builtins::DLH:
     case Builtins::API:
     case Builtins::ASM:
       // TODO(jgruber): Extend checks to remaining kinds.
@@ -511,6 +494,19 @@ uint32_t Snapshot::ExtractNumContexts(const v8::StartupData* data) {
   return num_contexts;
 }
 
+bool Snapshot::VerifyChecksum(const v8::StartupData* data) {
+  base::ElapsedTimer timer;
+  if (FLAG_profile_deserialization) timer.Start();
+  uint32_t expected_a = GetHeaderValue(data, kChecksumPartAOffset);
+  uint32_t expected_b = GetHeaderValue(data, kChecksumPartBOffset);
+  Checksum checksum(ChecksummedContent(data));
+  if (FLAG_profile_deserialization) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    PrintF("[Verifying snapshot checksum took %0.3f ms]\n", ms);
+  }
+  return checksum.Check(expected_a, expected_b);
+}
+
 void EmbeddedData::PrintStatistics() const {
   DCHECK(FLAG_serialization_statistics);
 
@@ -644,12 +640,18 @@ SnapshotData::SnapshotData(const Serializer<AllocatorT>* serializer) {
   // Calculate sizes.
   uint32_t reservation_size =
       static_cast<uint32_t>(reservations.size()) * kUInt32Size;
+  uint32_t payload_offset = kHeaderSize + reservation_size;
+  uint32_t padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
   uint32_t size =
-      kHeaderSize + reservation_size + static_cast<uint32_t>(payload->size());
+      padded_payload_offset + static_cast<uint32_t>(payload->size());
+  DCHECK(IsAligned(size, kPointerAlignment));
 
   // Allocate backing store and create result data.
   AllocateData(size);
 
+  // Zero out pre-payload data. Part of that is only used for padding.
+  memset(data_, 0, padded_payload_offset);
+
   // Set header values.
   SetMagicNumber(serializer->isolate());
   SetHeaderValue(kNumReservationsOffset, static_cast<int>(reservations.size()));
@@ -660,7 +662,7 @@ SnapshotData::SnapshotData(const Serializer<AllocatorT>* serializer) {
             reservation_size);
 
   // Copy serialized data.
-  CopyBytes(data_ + kHeaderSize + reservation_size, payload->data(),
+  CopyBytes(data_ + padded_payload_offset, payload->data(),
             static_cast<size_t>(payload->size()));
 }
 
@@ -679,7 +681,9 @@ std::vector<SerializedData::Reservation> SnapshotData::Reservations() const {
 Vector<const byte> SnapshotData::Payload() const {
   uint32_t reservations_size =
       GetHeaderValue(kNumReservationsOffset) * kUInt32Size;
-  const byte* payload = data_ + kHeaderSize + reservations_size;
+  uint32_t padded_payload_offset =
+      POINTER_SIZE_ALIGN(kHeaderSize + reservations_size);
+  const byte* payload = data_ + padded_payload_offset;
   uint32_t length = GetHeaderValue(kPayloadLengthOffset);
   DCHECK_EQ(data_ + size_, payload + length);
   return Vector<const byte>(payload, length);
@@ -689,30 +693,22 @@ BuiltinSnapshotData::BuiltinSnapshotData(const BuiltinSerializer* serializer)
     : SnapshotData(serializer) {}
 
 Vector<const byte> BuiltinSnapshotData::Payload() const {
-  uint32_t reservations_size =
-      GetHeaderValue(kNumReservationsOffset) * kUInt32Size;
-  const byte* payload = data_ + kHeaderSize + reservations_size;
-  const int builtin_offsets_size =
-      BuiltinSnapshotUtils::kNumberOfCodeObjects * kUInt32Size;
-  uint32_t payload_length = GetHeaderValue(kPayloadLengthOffset);
-  DCHECK_EQ(data_ + size_, payload + payload_length);
-  DCHECK_GT(payload_length, builtin_offsets_size);
-  return Vector<const byte>(payload, payload_length - builtin_offsets_size);
+  Vector<const byte> payload = SnapshotData::Payload();
+  const int builtin_offsets_size = Builtins::builtin_count * kUInt32Size;
+  DCHECK_EQ(data_ + size_, payload.start() + payload.size());
+  DCHECK_GT(payload.size(), builtin_offsets_size);
+  return Vector<const byte>(payload.start(),
+                            payload.size() - builtin_offsets_size);
 }
 
 Vector<const uint32_t> BuiltinSnapshotData::BuiltinOffsets() const {
-  uint32_t reservations_size =
-      GetHeaderValue(kNumReservationsOffset) * kUInt32Size;
-  const byte* payload = data_ + kHeaderSize + reservations_size;
-  const int builtin_offsets_size =
-      BuiltinSnapshotUtils::kNumberOfCodeObjects * kUInt32Size;
-  uint32_t payload_length = GetHeaderValue(kPayloadLengthOffset);
-  DCHECK_EQ(data_ + size_, payload + payload_length);
-  DCHECK_GT(payload_length, builtin_offsets_size);
+  Vector<const byte> payload = SnapshotData::Payload();
+  const int builtin_offsets_size = Builtins::builtin_count * kUInt32Size;
+  DCHECK_EQ(data_ + size_, payload.start() + payload.size());
+  DCHECK_GT(payload.size(), builtin_offsets_size);
   const uint32_t* data = reinterpret_cast<const uint32_t*>(
-      payload + payload_length - builtin_offsets_size);
-  return Vector<const uint32_t>(data,
-                                BuiltinSnapshotUtils::kNumberOfCodeObjects);
+      payload.start() + payload.size() - builtin_offsets_size);
+  return Vector<const uint32_t>(data, Builtins::builtin_count);
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/snapshot/snapshot-source-sink.h b/deps/v8/src/snapshot/snapshot-source-sink.h
index 584f86a760..8cf86526a3 100644
--- a/deps/v8/src/snapshot/snapshot-source-sink.h
+++ b/deps/v8/src/snapshot/snapshot-source-sink.h
@@ -27,7 +27,7 @@ class SnapshotByteSource final {
   explicit SnapshotByteSource(Vector<const byte> payload)
       : data_(payload.start()), length_(payload.length()), position_(0) {}
 
-  ~SnapshotByteSource() {}
+  ~SnapshotByteSource() = default;
 
   bool HasMore() { return position_ < length_; }
 
@@ -82,10 +82,10 @@ class SnapshotByteSource final {
  */
 class SnapshotByteSink {
  public:
-  SnapshotByteSink() {}
+  SnapshotByteSink() = default;
   explicit SnapshotByteSink(int initial_size) : data_(initial_size) {}
 
-  ~SnapshotByteSink() {}
+  ~SnapshotByteSink() = default;
 
   void Put(byte b, const char* description) { data_.push_back(b); }
 
diff --git a/deps/v8/src/snapshot/snapshot.h b/deps/v8/src/snapshot/snapshot.h
index b973ebb356..9edc12c1ce 100644
--- a/deps/v8/src/snapshot/snapshot.h
+++ b/deps/v8/src/snapshot/snapshot.h
@@ -175,12 +175,6 @@ class Snapshot : public AllStatic {
   static Code* EnsureBuiltinIsDeserialized(Isolate* isolate,
                                            Handle<SharedFunctionInfo> shared);
 
-  // Deserializes a single given handler code object. Intended to be called at
-  // runtime after the isolate has been fully initialized.
-  static Code* DeserializeHandler(Isolate* isolate,
-                                  interpreter::Bytecode bytecode,
-                                  interpreter::OperandScale operand_scale);
-
   // ---------------- Helper methods ----------------
 
   static bool HasContextSnapshot(Isolate* isolate, size_t index);
@@ -189,6 +183,8 @@ class Snapshot : public AllStatic {
   // To be implemented by the snapshot source.
   static const v8::StartupData* DefaultSnapshotBlob();
 
+  static bool VerifyChecksum(const v8::StartupData* data);
+
   // ---------------- Serialization ----------------
 
   static v8::StartupData CreateSnapshotBlob(
@@ -224,10 +220,12 @@ class Snapshot : public AllStatic {
   // Snapshot blob layout:
   // [0] number of contexts N
   // [1] rehashability
-  // [2] (128 bytes) version string
-  // [3] offset to builtins
-  // [4] offset to context 0
-  // [5] offset to context 1
+  // [2] checksum part A
+  // [3] checksum part B
+  // [4] (128 bytes) version string
+  // [5] offset to builtins
+  // [6] offset to context 0
+  // [7] offset to context 1
   // ...
   // ... offset to context N - 1
   // ... startup snapshot data
@@ -239,16 +237,28 @@ class Snapshot : public AllStatic {
   // TODO(yangguo): generalize rehashing, and remove this flag.
   static const uint32_t kRehashabilityOffset =
       kNumberOfContextsOffset + kUInt32Size;
-  static const uint32_t kVersionStringOffset =
+  static const uint32_t kChecksumPartAOffset =
       kRehashabilityOffset + kUInt32Size;
+  static const uint32_t kChecksumPartBOffset =
+      kChecksumPartAOffset + kUInt32Size;
+  static const uint32_t kVersionStringOffset =
+      kChecksumPartBOffset + kUInt32Size;
   static const uint32_t kVersionStringLength = 64;
   static const uint32_t kBuiltinOffsetOffset =
       kVersionStringOffset + kVersionStringLength;
   static const uint32_t kFirstContextOffsetOffset =
       kBuiltinOffsetOffset + kUInt32Size;
 
+  static Vector<const byte> ChecksummedContent(const v8::StartupData* data) {
+    const uint32_t kChecksumStart = kVersionStringOffset;
+    return Vector<const byte>(
+        reinterpret_cast<const byte*>(data->data + kChecksumStart),
+        data->raw_size - kChecksumStart);
+  }
+
   static uint32_t StartupSnapshotOffset(int num_contexts) {
-    return kFirstContextOffsetOffset + num_contexts * kInt32Size;
+    return POINTER_SIZE_ALIGN(kFirstContextOffsetOffset +
+                              num_contexts * kInt32Size);
   }
 
   static uint32_t ContextSnapshotOffsetOffset(int index) {
diff --git a/deps/v8/src/snapshot/startup-deserializer.cc b/deps/v8/src/snapshot/startup-deserializer.cc
index 8fbb073703..e9c23bb907 100644
--- a/deps/v8/src/snapshot/startup-deserializer.cc
+++ b/deps/v8/src/snapshot/startup-deserializer.cc
@@ -37,7 +37,8 @@ void StartupDeserializer::DeserializeInto(Isolate* isolate) {
   {
     DisallowHeapAllocation no_gc;
     isolate->heap()->IterateSmiRoots(this);
-    isolate->heap()->IterateStrongRoots(this, VISIT_ONLY_STRONG);
+    isolate->heap()->IterateStrongRoots(this,
+                                        VISIT_ONLY_STRONG_FOR_SERIALIZATION);
     isolate->heap()->RepairFreeListsAfterDeserialization();
     isolate->heap()->IterateWeakRoots(this, VISIT_FOR_SERIALIZATION);
     DeserializeDeferredObjects();
@@ -46,7 +47,7 @@ void StartupDeserializer::DeserializeInto(Isolate* isolate) {
 
     // Deserialize eager builtins from the builtin snapshot. Note that deferred
     // objects must have been deserialized prior to this.
-    builtin_deserializer.DeserializeEagerBuiltinsAndHandlers();
+    builtin_deserializer.DeserializeEagerBuiltins();
 
     // Flush the instruction cache for the entire code-space. Must happen after
     // builtins deserialization.
@@ -64,7 +65,6 @@ void StartupDeserializer::DeserializeInto(Isolate* isolate) {
 
   // Issue code events for newly deserialized code objects.
   LOG_CODE_EVENT(isolate, LogCodeObjects());
-  LOG_CODE_EVENT(isolate, LogBytecodeHandlers());
   LOG_CODE_EVENT(isolate, LogCompiledFunctions());
 
   isolate->builtins()->MarkInitialized();
diff --git a/deps/v8/src/snapshot/startup-serializer.cc b/deps/v8/src/snapshot/startup-serializer.cc
index 9ad6cda5d1..146d413de8 100644
--- a/deps/v8/src/snapshot/startup-serializer.cc
+++ b/deps/v8/src/snapshot/startup-serializer.cc
@@ -34,10 +34,10 @@ void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
   }
   if (SerializeHotObject(obj, how_to_code, where_to_point, skip)) return;
 
-  int root_index = root_index_map()->Lookup(obj);
+  RootIndex root_index;
   // We can only encode roots as such if it has already been serialized.
   // That applies to root indices below the wave front.
-  if (root_index != RootIndexMap::kInvalidRootIndex) {
+  if (root_index_map()->Lookup(obj, &root_index)) {
     if (root_has_been_serialized(root_index)) {
       PutRoot(root_index, obj, how_to_code, where_to_point, skip);
       return;
@@ -136,7 +136,7 @@ void StartupSerializer::VisitRootPointers(Root root, const char* description,
     //   referenced using kRootArray bytecodes.
     for (Object** current = start; current < end; current++) {
       SerializeRootObject(*current);
-      int root_index = static_cast<int>(current - start);
+      size_t root_index = static_cast<size_t>(current - start);
       root_has_been_serialized_.set(root_index);
     }
   } else {
@@ -152,9 +152,9 @@ void StartupSerializer::CheckRehashability(HeapObject* obj) {
 }
 
 bool StartupSerializer::MustBeDeferred(HeapObject* object) {
-  if (root_has_been_serialized_.test(Heap::kFreeSpaceMapRootIndex) &&
-      root_has_been_serialized_.test(Heap::kOnePointerFillerMapRootIndex) &&
-      root_has_been_serialized_.test(Heap::kTwoPointerFillerMapRootIndex)) {
+  if (root_has_been_serialized(RootIndex::kFreeSpaceMap) &&
+      root_has_been_serialized(RootIndex::kOnePointerFillerMap) &&
+      root_has_been_serialized(RootIndex::kTwoPointerFillerMap)) {
     // All required root objects are serialized, so any aligned objects can
     // be saved without problems.
     return false;
diff --git a/deps/v8/src/snapshot/startup-serializer.h b/deps/v8/src/snapshot/startup-serializer.h
index cf334d10b2..0b2065c3d0 100644
--- a/deps/v8/src/snapshot/startup-serializer.h
+++ b/deps/v8/src/snapshot/startup-serializer.h
@@ -28,8 +28,8 @@ class StartupSerializer : public Serializer<> {
   int PartialSnapshotCacheIndex(HeapObject* o);
 
   bool can_be_rehashed() const { return can_be_rehashed_; }
-  bool root_has_been_serialized(int root_index) const {
-    return root_has_been_serialized_.test(root_index);
+  bool root_has_been_serialized(RootIndex root_index) const {
+    return root_has_been_serialized_.test(static_cast<size_t>(root_index));
   }
 
  private:
@@ -69,7 +69,7 @@ class StartupSerializer : public Serializer<> {
 
   void CheckRehashability(HeapObject* obj);
 
-  std::bitset<Heap::kStrongRootListLength> root_has_been_serialized_;
+  std::bitset<RootsTable::kEntriesCount> root_has_been_serialized_;
   PartialCacheIndexMap partial_cache_index_map_;
   std::vector<AccessorInfo*> accessor_infos_;
   std::vector<CallHandlerInfo*> call_handler_infos_;
@@ -83,8 +83,8 @@ class StartupSerializer : public Serializer<> {
 class SerializedHandleChecker : public RootVisitor {
  public:
   SerializedHandleChecker(Isolate* isolate, std::vector<Context*>* contexts);
-  virtual void VisitRootPointers(Root root, const char* description,
-                                 Object** start, Object** end);
+  void VisitRootPointers(Root root, const char* description, Object** start,
+                         Object** end) override;
   bool CheckGlobalAndEternalHandles();
 
  private:
diff --git a/deps/v8/src/splay-tree.h b/deps/v8/src/splay-tree.h
index e16575419f..454b409fbb 100644
--- a/deps/v8/src/splay-tree.h
+++ b/deps/v8/src/splay-tree.h
@@ -128,7 +128,7 @@ class SplayTree {
 
   // A locator provides access to a node in the tree without actually
   // exposing the node.
-  class Locator BASE_EMBEDDED {
+  class Locator {
    public:
     explicit Locator(Node* node) : node_(node) { }
     Locator() : node_(nullptr) {}
@@ -159,8 +159,8 @@ class SplayTree {
   // Removes root_ node.
   void RemoveRootNode(const Key& key);
 
-  template<class Callback>
-  class NodeToPairAdaptor BASE_EMBEDDED {
+  template <class Callback>
+  class NodeToPairAdaptor {
    public:
     explicit NodeToPairAdaptor(Callback* callback)
         : callback_(callback) { }
@@ -174,9 +174,9 @@ class SplayTree {
     DISALLOW_COPY_AND_ASSIGN(NodeToPairAdaptor);
   };
 
-  class NodeDeleter BASE_EMBEDDED {
+  class NodeDeleter {
    public:
-    NodeDeleter() { }
+    NodeDeleter() = default;
     void Call(Node* node) { AllocationPolicy::Delete(node); }
 
    private:
diff --git a/deps/v8/src/string-constants.cc b/deps/v8/src/string-constants.cc
new file mode 100644
index 0000000000..26a5d2045f
--- /dev/null
+++ b/deps/v8/src/string-constants.cc
@@ -0,0 +1,186 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/string-constants.h"
+
+#include "src/base/functional.h"
+#include "src/dtoa.h"
+#include "src/objects.h"
+#include "src/objects/string-inl.h"
+
+namespace v8 {
+namespace internal {
+
+Handle<String> StringConstantBase::AllocateStringConstant(
+    Isolate* isolate) const {
+  if (!flattened_.is_null()) {
+    return flattened_;
+  }
+
+  Handle<String> result;
+  switch (kind()) {
+    case StringConstantKind::kStringLiteral: {
+      result = static_cast<const StringLiteral*>(this)->str();
+      break;
+    }
+    case StringConstantKind::kNumberToStringConstant: {
+      auto num_constant = static_cast<const NumberToStringConstant*>(this);
+      Handle<Object> num_obj =
+          isolate->factory()->NewNumber(num_constant->num());
+      result = isolate->factory()->NumberToString(num_obj);
+      break;
+    }
+    case StringConstantKind::kStringCons: {
+      Handle<String> lhs =
+          static_cast<const StringCons*>(this)->lhs()->AllocateStringConstant(
+              isolate);
+      Handle<String> rhs =
+          static_cast<const StringCons*>(this)->rhs()->AllocateStringConstant(
+              isolate);
+      result = isolate->factory()->NewConsString(lhs, rhs).ToHandleChecked();
+      break;
+    }
+  }
+
+  // TODO(mslekova): Normally we'd want to flatten the string here
+  // but that results in OOM for too long strings.
+  Memoize(result);
+  return flattened_;
+}
+
+bool StringConstantBase::operator==(const StringConstantBase& other) const {
+  if (kind() != other.kind()) return false;
+
+  switch (kind()) {
+    case StringConstantKind::kStringLiteral: {
+      return static_cast<const StringLiteral*>(this) ==
+             static_cast<const StringLiteral*>(&other);
+    }
+    case StringConstantKind::kNumberToStringConstant: {
+      return static_cast<const NumberToStringConstant*>(this) ==
+             static_cast<const NumberToStringConstant*>(&other);
+    }
+    case StringConstantKind::kStringCons: {
+      return static_cast<const StringCons*>(this) ==
+             static_cast<const StringCons*>(&other);
+    }
+  }
+  UNREACHABLE();
+}
+
+size_t hash_value(StringConstantBase const& base) {
+  switch (base.kind()) {
+    case StringConstantKind::kStringLiteral: {
+      return hash_value(*static_cast<const StringLiteral*>(&base));
+    }
+    case StringConstantKind::kNumberToStringConstant: {
+      return hash_value(*static_cast<const NumberToStringConstant*>(&base));
+    }
+    case StringConstantKind::kStringCons: {
+      return hash_value(*static_cast<const StringCons*>(&base));
+    }
+  }
+  UNREACHABLE();
+}
+
+bool operator==(StringLiteral const& lhs, StringLiteral const& rhs) {
+  return lhs.str().address() == rhs.str().address();
+}
+
+bool operator!=(StringLiteral const& lhs, StringLiteral const& rhs) {
+  return !(lhs == rhs);
+}
+
+size_t hash_value(StringLiteral const& p) {
+  return base::hash_combine(p.str().address());
+}
+
+std::ostream& operator<<(std::ostream& os, StringLiteral const& p) {
+  return os << Brief(*p.str());
+}
+
+bool operator==(NumberToStringConstant const& lhs,
+                NumberToStringConstant const& rhs) {
+  return lhs.num() == rhs.num();
+}
+
+bool operator!=(NumberToStringConstant const& lhs,
+                NumberToStringConstant const& rhs) {
+  return !(lhs == rhs);
+}
+
+size_t hash_value(NumberToStringConstant const& p) {
+  return base::hash_combine(p.num());
+}
+
+std::ostream& operator<<(std::ostream& os, NumberToStringConstant const& p) {
+  return os << p.num();
+}
+
+bool operator==(StringCons const& lhs, StringCons const& rhs) {
+  // TODO(mslekova): Think if we can express this in a more readable manner
+  return *(lhs.lhs()) == *(rhs.lhs()) && *(lhs.rhs()) == *(rhs.rhs());
+}
+
+bool operator!=(StringCons const& lhs, StringCons const& rhs) {
+  return !(lhs == rhs);
+}
+
+size_t hash_value(StringCons const& p) {
+  return base::hash_combine(*(p.lhs()), *(p.rhs()));
+}
+
+std::ostream& operator<<(std::ostream& os, const StringConstantBase* base) {
+  os << "DelayedStringConstant: ";
+  switch (base->kind()) {
+    case StringConstantKind::kStringLiteral: {
+      os << *static_cast<const StringLiteral*>(base);
+      break;
+    }
+    case StringConstantKind::kNumberToStringConstant: {
+      os << *static_cast<const NumberToStringConstant*>(base);
+      break;
+    }
+    case StringConstantKind::kStringCons: {
+      os << *static_cast<const StringCons*>(base);
+      break;
+    }
+  }
+  return os;
+}
+
+std::ostream& operator<<(std::ostream& os, StringCons const& p) {
+  return os << p.lhs() << ", " << p.rhs();
+}
+
+size_t StringConstantBase::GetMaxStringConstantLength() const {
+  switch (kind()) {
+    case StringConstantKind::kStringLiteral: {
+      return static_cast<const StringLiteral*>(this)
+          ->GetMaxStringConstantLength();
+    }
+    case StringConstantKind::kNumberToStringConstant: {
+      return static_cast<const NumberToStringConstant*>(this)
+          ->GetMaxStringConstantLength();
+    }
+    case StringConstantKind::kStringCons: {
+      return static_cast<const StringCons*>(this)->GetMaxStringConstantLength();
+    }
+  }
+  UNREACHABLE();
+}
+
+size_t StringLiteral::GetMaxStringConstantLength() const { return length_; }
+
+size_t NumberToStringConstant::GetMaxStringConstantLength() const {
+  return kBase10MaximalLength + 1;
+}
+
+size_t StringCons::GetMaxStringConstantLength() const {
+  return lhs()->GetMaxStringConstantLength() +
+         rhs()->GetMaxStringConstantLength();
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/string-constants.h b/deps/v8/src/string-constants.h
new file mode 100644
index 0000000000..b7134849db
--- /dev/null
+++ b/deps/v8/src/string-constants.h
@@ -0,0 +1,115 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_STRING_CONSTANTS_H_
+#define V8_STRING_CONSTANTS_H_
+
+#include "src/objects/string.h"
+#include "src/zone/zone.h"
+
+namespace v8 {
+namespace internal {
+
+enum class StringConstantKind {
+  kStringLiteral,
+  kNumberToStringConstant,
+  kStringCons
+};
+
+class StringConstantBase : public ZoneObject {
+ public:
+  explicit StringConstantBase(StringConstantKind kind) : kind_(kind) {}
+
+  StringConstantKind kind() const { return kind_; }
+  Handle<String> AllocateStringConstant(Isolate* isolate) const;
+
+  size_t GetMaxStringConstantLength() const;
+
+  bool operator==(const StringConstantBase& other) const;
+
+ private:
+  void Memoize(Handle<String> flattened) const { flattened_ = flattened; }
+
+  StringConstantKind kind_;
+  mutable Handle<String> flattened_ = Handle<String>::null();
+};
+
+size_t hash_value(StringConstantBase const& base);
+
+class StringLiteral final : public StringConstantBase {
+ public:
+  explicit StringLiteral(Handle<String> str, size_t length)
+      : StringConstantBase(StringConstantKind::kStringLiteral),
+        str_(str),
+        length_(length) {}
+
+  Handle<String> str() const { return str_; }
+
+  size_t GetMaxStringConstantLength() const;
+
+ private:
+  Handle<String> str_;
+  size_t length_;  // We store this separately to avoid accessing the heap.
+};
+
+bool operator==(StringLiteral const& lhs, StringLiteral const& rhs);
+bool operator!=(StringLiteral const& lhs, StringLiteral const& rhs);
+
+size_t hash_value(StringLiteral const& parameters);
+
+std::ostream& operator<<(std::ostream& os, StringLiteral const& parameters);
+
+class NumberToStringConstant final : public StringConstantBase {
+ public:
+  explicit NumberToStringConstant(double num)
+      : StringConstantBase(StringConstantKind::kNumberToStringConstant),
+        num_(num) {}
+
+  double num() const { return num_; }
+
+  size_t GetMaxStringConstantLength() const;
+
+ private:
+  double num_;
+};
+
+bool operator==(NumberToStringConstant const& lhs,
+                NumberToStringConstant const& rhs);
+bool operator!=(NumberToStringConstant const& lhs,
+                NumberToStringConstant const& rhs);
+
+size_t hash_value(NumberToStringConstant const& parameters);
+
+std::ostream& operator<<(std::ostream& os,
+                         NumberToStringConstant const& parameters);
+
+class StringCons final : public StringConstantBase {
+ public:
+  explicit StringCons(const StringConstantBase* lhs,
+                      const StringConstantBase* rhs)
+      : StringConstantBase(StringConstantKind::kStringCons),
+        lhs_(lhs),
+        rhs_(rhs) {}
+
+  const StringConstantBase* lhs() const { return lhs_; }
+  const StringConstantBase* rhs() const { return rhs_; }
+
+  size_t GetMaxStringConstantLength() const;
+
+ private:
+  const StringConstantBase* lhs_;
+  const StringConstantBase* rhs_;
+};
+
+bool operator==(StringCons const& lhs, StringCons const& rhs);
+bool operator!=(StringCons const& lhs, StringCons const& rhs);
+
+size_t hash_value(StringCons const& parameters);
+
+std::ostream& operator<<(std::ostream& os, StringCons const& parameters);
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_STRING_CONSTANTS_H_
diff --git a/deps/v8/src/string-stream.h b/deps/v8/src/string-stream.h
index aa4edffab4..6c4da47508 100644
--- a/deps/v8/src/string-stream.h
+++ b/deps/v8/src/string-stream.h
@@ -17,7 +17,7 @@ class ByteArray;
 
 class StringAllocator {
  public:
-  virtual ~StringAllocator() { }
+  virtual ~StringAllocator() = default;
   // Allocate a number of bytes.
   virtual char* allocate(unsigned bytes) = 0;
   // Allocate a larger number of bytes and copy the old buffer to the new one.
@@ -31,7 +31,7 @@ class StringAllocator {
 // Normal allocator uses new[] and delete[].
 class HeapStringAllocator final : public StringAllocator {
  public:
-  ~HeapStringAllocator() { DeleteArray(space_); }
+  ~HeapStringAllocator() override { DeleteArray(space_); }
   char* allocate(unsigned bytes) override;
   char* grow(unsigned* bytes) override;
 
@@ -44,7 +44,8 @@ class FixedStringAllocator final : public StringAllocator {
  public:
   FixedStringAllocator(char* buffer, unsigned length)
       : buffer_(buffer), length_(length) {}
-  ~FixedStringAllocator() override{};
+  ~FixedStringAllocator() override = default;
+
   char* allocate(unsigned bytes) override;
   char* grow(unsigned* bytes) override;
 
diff --git a/deps/v8/src/torque-assembler.h b/deps/v8/src/torque-assembler.h
new file mode 100644
index 0000000000..3d7cf361c4
--- /dev/null
+++ b/deps/v8/src/torque-assembler.h
@@ -0,0 +1,58 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TORQUE_ASSEMBLER_H_
+#define V8_TORQUE_ASSEMBLER_H_
+
+#include <deque>
+#include <vector>
+
+#include "src/code-stub-assembler.h"
+
+#include "src/base/optional.h"
+
+namespace v8 {
+namespace internal {
+
+class TorqueAssembler : public CodeStubAssembler {
+ public:
+  using CodeStubAssembler::CodeStubAssembler;
+
+ protected:
+  template <class... Ts>
+  using PLabel = compiler::CodeAssemblerParameterizedLabel<Ts...>;
+
+  template <class T>
+  TNode<T> Uninitialized() {
+    return {};
+  }
+
+  template <class... T, class... Args>
+  void Goto(PLabel<T...>* label, Args... args) {
+    label->AddInputs(args...);
+    CodeStubAssembler::Goto(label->plain_label());
+  }
+  using CodeStubAssembler::Goto;
+  template <class... T>
+  void Bind(PLabel<T...>* label, TNode<T>*... phis) {
+    Bind(label->plain_label());
+    label->CreatePhis(phis...);
+  }
+  void Bind(Label* label) { CodeAssembler::Bind(label); }
+  using CodeStubAssembler::Bind;
+  template <class... T, class... Args>
+  void Branch(TNode<BoolT> condition, PLabel<T...>* if_true,
+              PLabel<T...>* if_false, Args... args) {
+    if_true->AddInputs(args...);
+    if_false->AddInputs(args...);
+    CodeStubAssembler::Branch(condition, if_true->plain_label(),
+                              if_false->plain_label());
+  }
+  using CodeStubAssembler::Branch;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TORQUE_ASSEMBLER_H_
diff --git a/deps/v8/src/torque/ast.h b/deps/v8/src/torque/ast.h
index d9bb71a663..6bd4d79096 100644
--- a/deps/v8/src/torque/ast.h
+++ b/deps/v8/src/torque/ast.h
@@ -30,7 +30,9 @@ namespace torque {
   V(ElementAccessExpression)             \
   V(AssignmentExpression)                \
   V(IncrementDecrementExpression)        \
-  V(AssumeTypeImpossibleExpression)
+  V(AssumeTypeImpossibleExpression)      \
+  V(StatementExpression)                 \
+  V(TryLabelExpression)
 
 #define AST_TYPE_EXPRESSION_NODE_KIND_LIST(V) \
   V(BasicTypeExpression)                      \
@@ -52,7 +54,6 @@ namespace torque {
   V(TailCallStatement)                  \
   V(VarDeclarationStatement)            \
   V(GotoStatement)                      \
-  V(TryLabelStatement)
 
 #define AST_DECLARATION_NODE_KIND_LIST(V) \
   V(TypeDeclaration)                      \
@@ -90,7 +91,7 @@ struct AstNode {
   };
 
   AstNode(Kind kind, SourcePosition pos) : kind(kind), pos(pos) {}
-  virtual ~AstNode() {}
+  virtual ~AstNode() = default;
 
   const Kind kind;
   SourcePosition pos;
@@ -171,7 +172,7 @@ struct DefaultModuleDeclaration : ModuleDeclaration {
   DEFINE_AST_NODE_LEAF_BOILERPLATE(DefaultModuleDeclaration)
   DefaultModuleDeclaration(SourcePosition pos,
                            std::vector<Declaration*> declarations)
-      : ModuleDeclaration(kKind, pos, declarations) {}
+      : ModuleDeclaration(kKind, pos, std::move(declarations)) {}
   bool IsDefault() const override { return true; }
 };
 
@@ -179,7 +180,8 @@ struct ExplicitModuleDeclaration : ModuleDeclaration {
   DEFINE_AST_NODE_LEAF_BOILERPLATE(ExplicitModuleDeclaration)
   ExplicitModuleDeclaration(SourcePosition pos, std::string name,
                             std::vector<Declaration*> declarations)
-      : ModuleDeclaration(kKind, pos, declarations), name(std::move(name)) {}
+      : ModuleDeclaration(kKind, pos, std::move(declarations)),
+        name(std::move(name)) {}
   bool IsDefault() const override { return false; }
   std::string name;
 };
@@ -228,7 +230,7 @@ struct CallExpression : Expression {
         callee(pos, std::move(callee), std::move(generic_arguments)),
         is_operator(is_operator),
         arguments(std::move(arguments)),
-        labels(labels) {}
+        labels(std::move(labels)) {}
   IdentifierExpression callee;
   bool is_operator;
   std::vector<Expression*> arguments;
@@ -240,7 +242,7 @@ struct StructExpression : Expression {
   StructExpression(SourcePosition pos, std::string name,
                    std::vector<Expression*> expressions)
       : Expression(kKind, pos),
-        name(name),
+        name(std::move(name)),
         expressions(std::move(expressions)) {}
   std::string name;
   std::vector<Expression*> expressions;
@@ -362,7 +364,9 @@ struct ParameterList {
 struct BasicTypeExpression : TypeExpression {
   DEFINE_AST_NODE_LEAF_BOILERPLATE(BasicTypeExpression)
   BasicTypeExpression(SourcePosition pos, bool is_constexpr, std::string name)
-      : TypeExpression(kKind, pos), is_constexpr(is_constexpr), name(name) {}
+      : TypeExpression(kKind, pos),
+        is_constexpr(is_constexpr),
+        name(std::move(name)) {}
   bool is_constexpr;
   std::string name;
 };
@@ -373,7 +377,7 @@ struct FunctionTypeExpression : TypeExpression {
                          std::vector<TypeExpression*> parameters,
                          TypeExpression* return_type)
       : TypeExpression(kKind, pos),
-        parameters(parameters),
+        parameters(std::move(parameters)),
         return_type(return_type) {}
   std::vector<TypeExpression*> parameters;
   TypeExpression* return_type;
@@ -550,15 +554,22 @@ struct LabelBlock : AstNode {
   Statement* body;
 };
 
-struct TryLabelStatement : Statement {
-  DEFINE_AST_NODE_LEAF_BOILERPLATE(TryLabelStatement)
-  TryLabelStatement(SourcePosition pos, Statement* try_block,
-                    std::vector<LabelBlock*> label_blocks)
-      : Statement(kKind, pos),
-        try_block(try_block),
-        label_blocks(std::move(label_blocks)) {}
-  Statement* try_block;
-  std::vector<LabelBlock*> label_blocks;
+struct StatementExpression : Expression {
+  DEFINE_AST_NODE_LEAF_BOILERPLATE(StatementExpression)
+  StatementExpression(SourcePosition pos, Statement* statement)
+      : Expression(kKind, pos), statement(statement) {}
+  Statement* statement;
+};
+
+struct TryLabelExpression : Expression {
+  DEFINE_AST_NODE_LEAF_BOILERPLATE(TryLabelExpression)
+  TryLabelExpression(SourcePosition pos, Expression* try_expression,
+                     LabelBlock* label_block)
+      : Expression(kKind, pos),
+        try_expression(try_expression),
+        label_block(label_block) {}
+  Expression* try_expression;
+  LabelBlock* label_block;
 };
 
 struct BlockStatement : Statement {
@@ -634,7 +645,8 @@ struct MacroDeclaration : CallableNode {
                    base::Optional<std::string> op, ParameterList parameters,
                    TypeExpression* return_type,
                    const LabelAndTypesVector& labels)
-      : CallableNode(kind, pos, name, parameters, return_type, labels),
+      : CallableNode(kind, pos, std::move(name), std::move(parameters),
+                     return_type, labels),
         op(std::move(op)) {}
   base::Optional<std::string> op;
 };
@@ -646,8 +658,8 @@ struct ExternalMacroDeclaration : MacroDeclaration {
                            ParameterList parameters,
                            TypeExpression* return_type,
                            const LabelAndTypesVector& labels)
-      : MacroDeclaration(kKind, pos, name, op, parameters, return_type,
-                         labels) {}
+      : MacroDeclaration(kKind, pos, std::move(name), std::move(op),
+                         std::move(parameters), return_type, labels) {}
 };
 
 struct TorqueMacroDeclaration : MacroDeclaration {
@@ -656,15 +668,16 @@ struct TorqueMacroDeclaration : MacroDeclaration {
                          base::Optional<std::string> op,
                          ParameterList parameters, TypeExpression* return_type,
                          const LabelAndTypesVector& labels)
-      : MacroDeclaration(kKind, pos, name, op, parameters, return_type,
-                         labels) {}
+      : MacroDeclaration(kKind, pos, std::move(name), std::move(op),
+                         std::move(parameters), return_type, labels) {}
 };
 
 struct BuiltinDeclaration : CallableNode {
   BuiltinDeclaration(AstNode::Kind kind, SourcePosition pos,
                      bool javascript_linkage, std::string name,
                      ParameterList parameters, TypeExpression* return_type)
-      : CallableNode(kind, pos, name, parameters, return_type, {}),
+      : CallableNode(kind, pos, std::move(name), std::move(parameters),
+                     return_type, {}),
         javascript_linkage(javascript_linkage) {}
   bool javascript_linkage;
 };
@@ -674,8 +687,8 @@ struct ExternalBuiltinDeclaration : BuiltinDeclaration {
   ExternalBuiltinDeclaration(SourcePosition pos, bool javascript_linkage,
                              std::string name, ParameterList parameters,
                              TypeExpression* return_type)
-      : BuiltinDeclaration(kKind, pos, javascript_linkage, name, parameters,
-                           return_type) {}
+      : BuiltinDeclaration(kKind, pos, javascript_linkage, std::move(name),
+                           std::move(parameters), return_type) {}
 };
 
 struct TorqueBuiltinDeclaration : BuiltinDeclaration {
@@ -683,8 +696,8 @@ struct TorqueBuiltinDeclaration : BuiltinDeclaration {
   TorqueBuiltinDeclaration(SourcePosition pos, bool javascript_linkage,
                            std::string name, ParameterList parameters,
                            TypeExpression* return_type)
-      : BuiltinDeclaration(kKind, pos, javascript_linkage, name, parameters,
-                           return_type) {}
+      : BuiltinDeclaration(kKind, pos, javascript_linkage, std::move(name),
+                           std::move(parameters), return_type) {}
 };
 
 struct ExternalRuntimeDeclaration : CallableNode {
@@ -741,8 +754,9 @@ struct SpecializationDeclaration : Declaration {
       : Declaration(kKind, pos),
         name(std::move(name)),
         external(false),
-        generic_parameters(generic_parameters),
-        signature(new CallableNodeSignature{parameters, return_type, labels}),
+        generic_parameters(std::move(generic_parameters)),
+        signature(new CallableNodeSignature{std::move(parameters), return_type,
+                                            std::move(labels)}),
         body(b) {}
   std::string name;
   bool external;
diff --git a/deps/v8/src/torque/cfg.cc b/deps/v8/src/torque/cfg.cc
new file mode 100644
index 0000000000..1489d9f6af
--- /dev/null
+++ b/deps/v8/src/torque/cfg.cc
@@ -0,0 +1,134 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/torque/cfg.h"
+
+#include "src/torque/type-oracle.h"
+
+namespace v8 {
+namespace internal {
+namespace torque {
+
+void Block::SetInputTypes(const Stack<const Type*>& input_types) {
+  if (!input_types_) {
+    input_types_ = input_types;
+  } else if (*input_types_ != input_types) {
+    std::stringstream error;
+    error << "incompatible types at branch:\n";
+    for (intptr_t i = std::max(input_types_->Size(), input_types.Size()) - 1;
+         i >= 0; --i) {
+      base::Optional<const Type*> left;
+      base::Optional<const Type*> right;
+      if (static_cast<size_t>(i) < input_types.Size()) {
+        left = input_types.Peek(BottomOffset{static_cast<size_t>(i)});
+      }
+      if (static_cast<size_t>(i) < input_types_->Size()) {
+        right = input_types_->Peek(BottomOffset{static_cast<size_t>(i)});
+      }
+      if (left && right && *left == *right) {
+        error << **left << "\n";
+      } else {
+        if (left) {
+          error << **left;
+        } else {
+          error << "/*missing*/";
+        }
+        error << "   =>   ";
+        if (right) {
+          error << **right;
+        } else {
+          error << "/*missing*/";
+        }
+        error << "\n";
+      }
+    }
+    ReportError(error.str());
+  }
+}
+
+void CfgAssembler::Bind(Block* block) {
+  DCHECK(current_block_->IsComplete());
+  DCHECK(block->instructions().empty());
+  DCHECK(block->HasInputTypes());
+  current_block_ = block;
+  current_stack_ = block->InputTypes();
+  cfg_.PlaceBlock(block);
+}
+
+void CfgAssembler::Goto(Block* block) {
+  if (block->HasInputTypes()) {
+    DropTo(block->InputTypes().AboveTop());
+  }
+  Emit(GotoInstruction{block});
+}
+
+StackRange CfgAssembler::Goto(Block* block, size_t preserved_slots) {
+  DCHECK(block->HasInputTypes());
+  DCHECK_GE(CurrentStack().Size(), block->InputTypes().Size());
+  Emit(DeleteRangeInstruction{
+      StackRange{block->InputTypes().AboveTop() - preserved_slots,
+                 CurrentStack().AboveTop() - preserved_slots}});
+  StackRange preserved_slot_range = TopRange(preserved_slots);
+  Emit(GotoInstruction{block});
+  return preserved_slot_range;
+}
+
+void CfgAssembler::Branch(Block* if_true, Block* if_false) {
+  Emit(BranchInstruction{if_true, if_false});
+}
+
+// Delete the specified range of slots, moving upper slots to fill the gap.
+void CfgAssembler::DeleteRange(StackRange range) {
+  DCHECK_LE(range.end(), current_stack_.AboveTop());
+  if (range.Size() == 0) return;
+  Emit(DeleteRangeInstruction{range});
+}
+
+void CfgAssembler::DropTo(BottomOffset new_level) {
+  DeleteRange(StackRange{new_level, CurrentStack().AboveTop()});
+}
+
+StackRange CfgAssembler::Peek(StackRange range,
+                              base::Optional<const Type*> type) {
+  std::vector<const Type*> lowered_types;
+  if (type) {
+    lowered_types = LowerType(*type);
+    DCHECK_EQ(lowered_types.size(), range.Size());
+  }
+  for (size_t i = 0; i < range.Size(); ++i) {
+    Emit(PeekInstruction{
+        range.begin() + i,
+        type ? lowered_types[i] : base::Optional<const Type*>{}});
+  }
+  return TopRange(range.Size());
+}
+
+void CfgAssembler::Poke(StackRange destination, StackRange origin,
+                        base::Optional<const Type*> type) {
+  DCHECK_EQ(destination.Size(), origin.Size());
+  DCHECK_LE(destination.end(), origin.begin());
+  DCHECK_EQ(origin.end(), CurrentStack().AboveTop());
+  std::vector<const Type*> lowered_types;
+  if (type) {
+    lowered_types = LowerType(*type);
+    DCHECK_EQ(lowered_types.size(), origin.Size());
+  }
+  for (intptr_t i = origin.Size() - 1; i >= 0; --i) {
+    Emit(PokeInstruction{
+        destination.begin() + i,
+        type ? lowered_types[i] : base::Optional<const Type*>{}});
+  }
+}
+
+void CfgAssembler::Print(std::string s) {
+  Emit(PrintConstantStringInstruction{std::move(s)});
+}
+
+void CfgAssembler::Unreachable() { Emit(DebugBreakInstruction{true}); }
+
+void CfgAssembler::DebugBreak() { Emit(DebugBreakInstruction{false}); }
+
+}  // namespace torque
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/torque/cfg.h b/deps/v8/src/torque/cfg.h
new file mode 100644
index 0000000000..6fca593505
--- /dev/null
+++ b/deps/v8/src/torque/cfg.h
@@ -0,0 +1,149 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TORQUE_CFG_H_
+#define V8_TORQUE_CFG_H_
+
+#include <list>
+#include <memory>
+#include <unordered_map>
+#include <vector>
+
+#include "src/torque/ast.h"
+#include "src/torque/instructions.h"
+#include "src/torque/source-positions.h"
+#include "src/torque/types.h"
+
+namespace v8 {
+namespace internal {
+namespace torque {
+
+class Block {
+ public:
+  explicit Block(size_t id, base::Optional<Stack<const Type*>> input_types,
+                 bool is_deferred)
+      : input_types_(std::move(input_types)),
+        id_(id),
+        is_deferred_(is_deferred) {}
+  void Add(Instruction instruction) {
+    DCHECK(!IsComplete());
+    instructions_.push_back(std::move(instruction));
+  }
+
+  bool HasInputTypes() const { return input_types_ != base::nullopt; }
+  const Stack<const Type*>& InputTypes() const { return *input_types_; }
+  void SetInputTypes(const Stack<const Type*>& input_types);
+
+  const std::vector<Instruction>& instructions() const { return instructions_; }
+  bool IsComplete() const {
+    return !instructions_.empty() && instructions_.back()->IsBlockTerminator();
+  }
+  size_t id() const { return id_; }
+  bool IsDeferred() const { return is_deferred_; }
+
+ private:
+  std::vector<Instruction> instructions_;
+  base::Optional<Stack<const Type*>> input_types_;
+  const size_t id_;
+  bool is_deferred_;
+};
+
+class ControlFlowGraph {
+ public:
+  explicit ControlFlowGraph(Stack<const Type*> input_types) {
+    start_ = NewBlock(std::move(input_types), false);
+    PlaceBlock(start_);
+  }
+
+  Block* NewBlock(base::Optional<Stack<const Type*>> input_types,
+                  bool is_deferred) {
+    blocks_.emplace_back(next_block_id_++, std::move(input_types), is_deferred);
+    return &blocks_.back();
+  }
+  void PlaceBlock(Block* block) { placed_blocks_.push_back(block); }
+  Block* start() const { return start_; }
+  base::Optional<Block*> end() const { return end_; }
+  void set_end(Block* end) { end_ = end; }
+  void SetReturnType(const Type* t) {
+    if (!return_type_) {
+      return_type_ = t;
+      return;
+    }
+    if (t != *return_type_) {
+      ReportError("expected return type ", **return_type_, " instead of ", *t);
+    }
+  }
+  const std::vector<Block*>& blocks() const { return placed_blocks_; }
+
+ private:
+  std::list<Block> blocks_;
+  Block* start_;
+  std::vector<Block*> placed_blocks_;
+  base::Optional<Block*> end_;
+  base::Optional<const Type*> return_type_;
+  size_t next_block_id_ = 0;
+};
+
+class CfgAssembler {
+ public:
+  explicit CfgAssembler(Stack<const Type*> input_types)
+      : current_stack_(std::move(input_types)), cfg_(current_stack_) {}
+
+  const ControlFlowGraph& Result() {
+    if (!CurrentBlockIsComplete()) {
+      cfg_.set_end(current_block_);
+    }
+    return cfg_;
+  }
+
+  Block* NewBlock(
+      base::Optional<Stack<const Type*>> input_types = base::nullopt,
+      bool is_deferred = false) {
+    return cfg_.NewBlock(std::move(input_types), is_deferred);
+  }
+
+  bool CurrentBlockIsComplete() const { return current_block_->IsComplete(); }
+
+  void Emit(Instruction instruction) {
+    instruction.TypeInstruction(&current_stack_, &cfg_);
+    current_block_->Add(std::move(instruction));
+  }
+
+  const Stack<const Type*>& CurrentStack() const { return current_stack_; }
+
+  StackRange TopRange(size_t slot_count) const {
+    return CurrentStack().TopRange(slot_count);
+  }
+
+  void Bind(Block* block);
+  void Goto(Block* block);
+  // Goto block while keeping {preserved_slots} many slots on the top and
+  // deleting additional the slots below these to match the input type of the
+  // target block.
+  // Returns the StackRange of the preserved slots in the target block.
+  StackRange Goto(Block* block, size_t preserved_slots);
+  // The condition must be of type bool and on the top of stack. It is removed
+  // from the stack before branching.
+  void Branch(Block* if_true, Block* if_false);
+  // Delete the specified range of slots, moving upper slots to fill the gap.
+  void DeleteRange(StackRange range);
+  void DropTo(BottomOffset new_level);
+  StackRange Peek(StackRange range, base::Optional<const Type*> type);
+  void Poke(StackRange destination, StackRange origin,
+            base::Optional<const Type*> type);
+  void Print(std::string s);
+  void Unreachable();
+  void DebugBreak();
+
+ private:
+  Stack<const Type*> current_stack_;
+  ControlFlowGraph cfg_;
+  Block* current_block_ = cfg_.start();
+};
+
+}  // namespace torque
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TORQUE_CFG_H_
diff --git a/deps/v8/src/torque/csa-generator.cc b/deps/v8/src/torque/csa-generator.cc
new file mode 100644
index 0000000000..902b1b7f4a
--- /dev/null
+++ b/deps/v8/src/torque/csa-generator.cc
@@ -0,0 +1,487 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/torque/csa-generator.h"
+
+#include "src/torque/type-oracle.h"
+#include "src/torque/utils.h"
+
+namespace v8 {
+namespace internal {
+namespace torque {
+
+base::Optional<Stack<std::string>> CSAGenerator::EmitGraph(
+    Stack<std::string> parameters) {
+  for (Block* block : cfg_.blocks()) {
+    out_ << "  PLabel<";
+    PrintCommaSeparatedList(out_, block->InputTypes(), [](const Type* t) {
+      return t->GetGeneratedTNodeTypeName();
+    });
+    out_ << "> " << BlockName(block) << "(this, compiler::CodeAssemblerLabel::"
+         << (block->IsDeferred() ? "kDeferred" : "kNonDeferred") << ");\n";
+  }
+
+  EmitInstruction(GotoInstruction{cfg_.start()}, &parameters);
+  for (Block* block : cfg_.blocks()) {
+    if (cfg_.end() && *cfg_.end() == block) continue;
+    out_ << "\n  if (" << BlockName(block) << ".is_used()) {\n";
+    EmitBlock(block);
+    out_ << "  }\n";
+  }
+  if (cfg_.end()) {
+    out_ << "\n";
+    return EmitBlock(*cfg_.end());
+  }
+  return base::nullopt;
+}
+
+Stack<std::string> CSAGenerator::EmitBlock(const Block* block) {
+  Stack<std::string> stack;
+  for (const Type* t : block->InputTypes()) {
+    stack.Push(FreshNodeName());
+    out_ << "    TNode<" << t->GetGeneratedTNodeTypeName() << "> "
+         << stack.Top() << ";\n";
+  }
+  out_ << "    Bind(&" << BlockName(block);
+  for (const std::string& name : stack) {
+    out_ << ", &" << name;
+  }
+  out_ << ");\n";
+  for (const Instruction& instruction : block->instructions()) {
+    EmitInstruction(instruction, &stack);
+  }
+  return stack;
+}
+
+void CSAGenerator::EmitInstruction(const Instruction& instruction,
+                                   Stack<std::string>* stack) {
+  switch (instruction.kind()) {
+#define ENUM_ITEM(T)          \
+  case InstructionKind::k##T: \
+    return EmitInstruction(instruction.Cast<T>(), stack);
+    TORQUE_INSTRUCTION_LIST(ENUM_ITEM)
+#undef ENUM_ITEM
+  }
+}
+
+void CSAGenerator::EmitInstruction(const PeekInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  stack->Push(stack->Peek(instruction.slot));
+}
+
+void CSAGenerator::EmitInstruction(const PokeInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  stack->Poke(instruction.slot, stack->Top());
+  stack->Pop();
+}
+
+void CSAGenerator::EmitInstruction(const DeleteRangeInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  stack->DeleteRange(instruction.range);
+}
+
+void CSAGenerator::EmitInstruction(
+    const PushUninitializedInstruction& instruction,
+    Stack<std::string>* stack) {
+  // TODO(tebbi): This can trigger an error in CSA if it is used. Instead, we
+  // should prevent usage of uninitialized in the type system. This
+  // requires "if constexpr" being evaluated at Torque time.
+  stack->Push("Uninitialized<" + instruction.type->GetGeneratedTNodeTypeName() +
+              ">()");
+}
+
+void CSAGenerator::EmitInstruction(
+    const PushCodePointerInstruction& instruction, Stack<std::string>* stack) {
+  stack->Push(
+      "UncheckedCast<Code>(HeapConstant(Builtins::CallableFor(isolate(), "
+      "Builtins::k" +
+      instruction.external_name + ").code()))");
+}
+
+void CSAGenerator::EmitInstruction(const ModuleConstantInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  const Type* type = instruction.constant->type();
+  std::vector<std::string> results;
+  for (const Type* lowered : LowerType(type)) {
+    results.push_back(FreshNodeName());
+    stack->Push(results.back());
+    out_ << "    TNode<" << lowered->GetGeneratedTNodeTypeName() << "> "
+         << stack->Top() << ";\n";
+    out_ << "    USE(" << stack->Top() << ");\n";
+  }
+  out_ << "    ";
+  if (type->IsStructType()) {
+    out_ << "std::tie(";
+    PrintCommaSeparatedList(out_, results);
+    out_ << ") = ";
+  } else if (results.size() == 1) {
+    out_ << results[0] << " = ";
+  }
+  out_ << instruction.constant->constant_name() << "()";
+  if (type->IsStructType()) {
+    out_ << ".Flatten();\n";
+  } else {
+    out_ << ";\n";
+  }
+}
+
+void CSAGenerator::EmitInstruction(const CallCsaMacroInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  std::vector<std::string> constexpr_arguments =
+      instruction.constexpr_arguments;
+  std::vector<std::string> args;
+  TypeVector parameter_types =
+      instruction.macro->signature().parameter_types.types;
+  for (auto it = parameter_types.rbegin(); it != parameter_types.rend(); ++it) {
+    const Type* type = *it;
+    VisitResult arg;
+    if (type->IsConstexpr()) {
+      args.push_back(std::move(constexpr_arguments.back()));
+      constexpr_arguments.pop_back();
+    } else {
+      std::stringstream s;
+      size_t slot_count = LoweredSlotCount(type);
+      VisitResult arg = VisitResult(type, stack->TopRange(slot_count));
+      EmitCSAValue(arg, *stack, s);
+      args.push_back(s.str());
+      stack->PopMany(slot_count);
+    }
+  }
+  std::reverse(args.begin(), args.end());
+
+  const Type* return_type = instruction.macro->signature().return_type;
+  std::vector<std::string> results;
+  for (const Type* type : LowerType(return_type)) {
+    results.push_back(FreshNodeName());
+    stack->Push(results.back());
+    out_ << "    TNode<" << type->GetGeneratedTNodeTypeName() << "> "
+         << stack->Top() << ";\n";
+    out_ << "    USE(" << stack->Top() << ");\n";
+  }
+  out_ << "    ";
+  if (return_type->IsStructType()) {
+    out_ << "std::tie(";
+    PrintCommaSeparatedList(out_, results);
+    out_ << ") = ";
+  } else {
+    if (results.size() == 1) {
+      out_ << results[0] << " = UncheckedCast<"
+           << return_type->GetGeneratedTNodeTypeName() << ">(";
+    }
+  }
+  out_ << instruction.macro->name() << "(";
+  PrintCommaSeparatedList(out_, args);
+  if (return_type->IsStructType()) {
+    out_ << ").Flatten();\n";
+  } else {
+    if (results.size() == 1) out_ << ")";
+    out_ << ");\n";
+  }
+}
+
+void CSAGenerator::EmitInstruction(
+    const CallCsaMacroAndBranchInstruction& instruction,
+    Stack<std::string>* stack) {
+  std::vector<std::string> constexpr_arguments =
+      instruction.constexpr_arguments;
+  std::vector<std::string> args;
+  TypeVector parameter_types =
+      instruction.macro->signature().parameter_types.types;
+  for (auto it = parameter_types.rbegin(); it != parameter_types.rend(); ++it) {
+    const Type* type = *it;
+    VisitResult arg;
+    if (type->IsConstexpr()) {
+      args.push_back(std::move(constexpr_arguments.back()));
+      constexpr_arguments.pop_back();
+    } else {
+      std::stringstream s;
+      size_t slot_count = LoweredSlotCount(type);
+      VisitResult arg = VisitResult(type, stack->TopRange(slot_count));
+      EmitCSAValue(arg, *stack, s);
+      args.push_back(s.str());
+      stack->PopMany(slot_count);
+    }
+  }
+  std::reverse(args.begin(), args.end());
+
+  std::vector<std::string> results;
+  const Type* return_type = instruction.macro->signature().return_type;
+  if (return_type != TypeOracle::GetNeverType()) {
+    for (const Type* type :
+         LowerType(instruction.macro->signature().return_type)) {
+      results.push_back(FreshNodeName());
+      out_ << "    TNode<" << type->GetGeneratedTNodeTypeName() << "> "
+           << results.back() << ";\n";
+      out_ << "    USE(" << results.back() << ");\n";
+    }
+  }
+
+  std::vector<std::string> label_names;
+  std::vector<std::vector<std::string>> var_names;
+  const LabelDeclarationVector& labels = instruction.macro->signature().labels;
+  DCHECK_EQ(labels.size(), instruction.label_blocks.size());
+  for (size_t i = 0; i < labels.size(); ++i) {
+    TypeVector label_parameters = labels[i].types;
+    label_names.push_back("label" + std::to_string(i));
+    var_names.push_back({});
+    for (size_t j = 0; j < label_parameters.size(); ++j) {
+      var_names[i].push_back("result_" + std::to_string(i) + "_" +
+                             std::to_string(j));
+      out_ << "    TVariable<"
+           << label_parameters[j]->GetGeneratedTNodeTypeName() << "> "
+           << var_names[i][j] << "(this);\n";
+    }
+    out_ << "    Label " << label_names[i] << "(this);\n";
+  }
+
+  out_ << "    ";
+  if (results.size() == 1) {
+    out_ << results[0] << " = ";
+  } else if (results.size() > 1) {
+    out_ << "std::tie(";
+    PrintCommaSeparatedList(out_, results);
+    out_ << ") = ";
+  }
+  out_ << instruction.macro->name() << "(";
+  PrintCommaSeparatedList(out_, args);
+  bool first = args.empty();
+  for (size_t i = 0; i < label_names.size(); ++i) {
+    if (!first) out_ << ", ";
+    out_ << "&" << label_names[i];
+    first = false;
+    for (size_t j = 0; j < var_names[i].size(); ++j) {
+      out_ << ", &" << var_names[i][j];
+    }
+  }
+  out_ << ");\n";
+  if (instruction.return_continuation) {
+    out_ << "    Goto(&" << BlockName(*instruction.return_continuation);
+    for (const std::string& value : *stack) {
+      out_ << ", " << value;
+    }
+    for (const std::string& result : results) {
+      out_ << ", " << result;
+    }
+    out_ << ");\n";
+  }
+  for (size_t i = 0; i < label_names.size(); ++i) {
+    out_ << "    if (" << label_names[i] << ".is_used()) {\n";
+    out_ << "      Bind(&" << label_names[i] << ");\n";
+    out_ << "      Goto(&" << BlockName(instruction.label_blocks[i]);
+    for (const std::string& value : *stack) {
+      out_ << ", " << value;
+    }
+    for (const std::string& var : var_names[i]) {
+      out_ << ", " << var << ".value()";
+    }
+    out_ << ");\n";
+
+    out_ << "    }\n";
+  }
+}
+
+void CSAGenerator::EmitInstruction(const CallBuiltinInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  std::vector<std::string> arguments = stack->PopMany(instruction.argc);
+  std::vector<const Type*> result_types =
+      LowerType(instruction.builtin->signature().return_type);
+  if (instruction.is_tailcall) {
+    out_ << "   TailCallBuiltin(Builtins::k" << instruction.builtin->name()
+         << ", ";
+    PrintCommaSeparatedList(out_, arguments);
+    out_ << ");\n";
+  } else {
+    if (result_types.size() == 1) {
+      std::string generated_type = result_types[0]->GetGeneratedTNodeTypeName();
+      stack->Push(FreshNodeName());
+      out_ << "    TNode<" << generated_type << "> " << stack->Top() << " = ";
+      if (generated_type != "Object") out_ << "CAST(";
+      out_ << "CallBuiltin(Builtins::k" << instruction.builtin->name() << ", ";
+      PrintCommaSeparatedList(out_, arguments);
+      if (generated_type != "Object") out_ << ")";
+      out_ << ");\n";
+      out_ << "    USE(" << stack->Top() << ");\n";
+    } else {
+      DCHECK_EQ(0, result_types.size());
+      // TODO(tebbi): Actually, builtins have to return a value, so we should
+      // not have to handle this case.
+      out_ << "    CallBuiltin(Builtins::k" << instruction.builtin->name()
+           << ", ";
+      PrintCommaSeparatedList(out_, arguments);
+      out_ << ");\n";
+    }
+  }
+}
+
+void CSAGenerator::EmitInstruction(
+    const CallBuiltinPointerInstruction& instruction,
+    Stack<std::string>* stack) {
+  std::vector<std::string> function_and_arguments =
+      stack->PopMany(1 + instruction.argc);
+  std::vector<const Type*> result_types =
+      LowerType(instruction.example_builtin->signature().return_type);
+  if (result_types.size() != 1) {
+    ReportError("builtins must have exactly one result");
+  }
+  if (instruction.is_tailcall) {
+    out_ << "    Tail (Builtins::CallableFor(isolate(), Builtins::k"
+         << instruction.example_builtin->name() << ").descriptor(), ";
+    PrintCommaSeparatedList(out_, function_and_arguments);
+    out_ << ");\n";
+  } else {
+    stack->Push(FreshNodeName());
+    std::string generated_type = result_types[0]->GetGeneratedTNodeTypeName();
+    out_ << "    TNode<" << generated_type << "> " << stack->Top() << " = ";
+    if (generated_type != "Object") out_ << "CAST(";
+    out_ << "CallStub(Builtins::CallableFor(isolate(), Builtins::k"
+         << instruction.example_builtin->name() << ").descriptor(), ";
+    PrintCommaSeparatedList(out_, function_and_arguments);
+    out_ << ")";
+    if (generated_type != "Object") out_ << ")";
+    out_ << "; \n";
+    out_ << "    USE(" << stack->Top() << ");\n";
+  }
+}
+
+void CSAGenerator::EmitInstruction(const CallRuntimeInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  std::vector<std::string> arguments = stack->PopMany(instruction.argc);
+  std::vector<const Type*> result_types =
+      LowerType(instruction.runtime_function->signature().return_type);
+  if (result_types.size() > 1) {
+    ReportError("runtime function must have at most one result");
+  }
+  if (instruction.is_tailcall) {
+    out_ << "    TailCallRuntime(Runtime::k"
+         << instruction.runtime_function->name() << ", ";
+    PrintCommaSeparatedList(out_, arguments);
+    out_ << ");\n";
+  } else {
+    if (result_types.size() == 1) {
+      stack->Push(FreshNodeName());
+      out_ << "    TNode<" << result_types[0]->GetGeneratedTNodeTypeName()
+           << "> " << stack->Top() << " = CAST(CallRuntime(Runtime::k"
+           << instruction.runtime_function->name() << ", ";
+      PrintCommaSeparatedList(out_, arguments);
+      out_ << "));\n";
+      out_ << "    USE(" << stack->Top() << ");\n";
+    } else {
+      DCHECK_EQ(0, result_types.size());
+      // TODO(tebbi): Actually, runtime functions have to return a value, so we
+      // should not have to handle this case.
+      out_ << "    CallRuntime(Runtime::k"
+           << instruction.runtime_function->name() << ", ";
+      PrintCommaSeparatedList(out_, arguments);
+      out_ << ");\n";
+    }
+  }
+}
+
+void CSAGenerator::EmitInstruction(const BranchInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  out_ << "    Branch(" << stack->Pop() << ", &"
+       << BlockName(instruction.if_true) << ", &"
+       << BlockName(instruction.if_false);
+  for (const std::string& value : *stack) {
+    out_ << ", " << value;
+  }
+  out_ << ");\n";
+}
+
+void CSAGenerator::EmitInstruction(
+    const ConstexprBranchInstruction& instruction, Stack<std::string>* stack) {
+  out_ << "    if (" << instruction.condition << ") {\n";
+  out_ << "      Goto(&" << BlockName(instruction.if_true);
+  for (const std::string& value : *stack) {
+    out_ << ", " << value;
+  }
+  out_ << ");\n";
+  out_ << "    } else {\n";
+  out_ << "      Goto(&" << BlockName(instruction.if_false);
+  for (const std::string& value : *stack) {
+    out_ << ", " << value;
+  }
+  out_ << ");\n";
+
+  out_ << "    }\n";
+}
+
+void CSAGenerator::EmitInstruction(const GotoInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  out_ << "    Goto(&" << BlockName(instruction.destination);
+  for (const std::string& value : *stack) {
+    out_ << ", " << value;
+  }
+  out_ << ");\n";
+}
+
+void CSAGenerator::EmitInstruction(const GotoExternalInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  for (auto it = instruction.variable_names.rbegin();
+       it != instruction.variable_names.rend(); ++it) {
+    out_ << "    *" << *it << " = " << stack->Pop() << ";\n";
+  }
+  out_ << "    Goto(" << instruction.destination << ");\n";
+}
+
+void CSAGenerator::EmitInstruction(const ReturnInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  if (*linkage_ == Builtin::kVarArgsJavaScript) {
+    out_ << "    " << ARGUMENTS_VARIABLE_STRING << "->PopAndReturn(";
+  } else {
+    out_ << "    Return(";
+  }
+  out_ << stack->Pop() << ");\n";
+}
+
+void CSAGenerator::EmitInstruction(
+    const PrintConstantStringInstruction& instruction,
+    Stack<std::string>* stack) {
+  out_ << "    Print(" << StringLiteralQuote(instruction.message) << ");\n";
+}
+
+void CSAGenerator::EmitInstruction(const DebugBreakInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  if (instruction.never_continues) {
+    out_ << "    Unreachable();\n";
+  } else {
+    out_ << "    DebugBreak();\n";
+  }
+}
+
+void CSAGenerator::EmitInstruction(const UnsafeCastInstruction& instruction,
+                                   Stack<std::string>* stack) {
+  stack->Poke(stack->AboveTop() - 1,
+              "UncheckedCast<" +
+                  instruction.destination_type->GetGeneratedTNodeTypeName() +
+                  ">(" + stack->Top() + ")");
+}
+
+// static
+void CSAGenerator::EmitCSAValue(VisitResult result,
+                                const Stack<std::string>& values,
+                                std::ostream& out) {
+  if (!result.IsOnStack()) {
+    out << result.constexpr_value();
+  } else if (auto* struct_type = StructType::DynamicCast(result.type())) {
+    out << struct_type->name() << "{";
+    bool first = true;
+    for (auto& field : struct_type->fields()) {
+      if (!first) {
+        out << ", ";
+      }
+      first = false;
+      EmitCSAValue(ProjectStructField(result, field.name), values, out);
+    }
+    out << "}";
+  } else {
+    DCHECK_EQ(1, result.stack_range().Size());
+    out << "TNode<" << result.type()->GetGeneratedTNodeTypeName() << ">{"
+        << values.Peek(result.stack_range().begin()) << "}";
+  }
+}
+
+}  // namespace torque
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/torque/csa-generator.h b/deps/v8/src/torque/csa-generator.h
new file mode 100644
index 0000000000..78fccebd6d
--- /dev/null
+++ b/deps/v8/src/torque/csa-generator.h
@@ -0,0 +1,53 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TORQUE_CSA_GENERATOR_H_
+#define V8_TORQUE_CSA_GENERATOR_H_
+
+#include <iostream>
+
+#include "src/torque/cfg.h"
+#include "src/torque/declarable.h"
+
+namespace v8 {
+namespace internal {
+namespace torque {
+
+class CSAGenerator {
+ public:
+  CSAGenerator(const ControlFlowGraph& cfg, std::ostream& out,
+               base::Optional<Builtin::Kind> linkage = base::nullopt)
+      : cfg_(cfg), out_(out), linkage_(linkage) {}
+  base::Optional<Stack<std::string>> EmitGraph(Stack<std::string> parameters);
+
+  static constexpr const char* ARGUMENTS_VARIABLE_STRING = "arguments";
+
+  static void EmitCSAValue(VisitResult result, const Stack<std::string>& values,
+                           std::ostream& out);
+
+ private:
+  const ControlFlowGraph& cfg_;
+  std::ostream& out_;
+  size_t fresh_id_ = 0;
+  base::Optional<Builtin::Kind> linkage_;
+
+  std::string FreshNodeName() { return "tmp" + std::to_string(fresh_id_++); }
+  std::string BlockName(const Block* block) {
+    return "block" + std::to_string(block->id());
+  }
+
+  Stack<std::string> EmitBlock(const Block* block);
+  void EmitInstruction(const Instruction& instruction,
+                       Stack<std::string>* stack);
+#define EMIT_INSTRUCTION_DECLARATION(T) \
+  void EmitInstruction(const T& instruction, Stack<std::string>* stack);
+  TORQUE_INSTRUCTION_LIST(EMIT_INSTRUCTION_DECLARATION)
+#undef EMIT_INSTRUCTION_DECLARATION
+};
+
+}  // namespace torque
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TORQUE_CSA_GENERATOR_H_
diff --git a/deps/v8/src/torque/declarable.cc b/deps/v8/src/torque/declarable.cc
index bf0b9a9d7a..6768da5474 100644
--- a/deps/v8/src/torque/declarable.cc
+++ b/deps/v8/src/torque/declarable.cc
@@ -34,18 +34,6 @@ std::ostream& operator<<(std::ostream& os, const RuntimeFunction& b) {
   return os;
 }
 
-std::string Variable::RValue() const {
-  if (!IsDefined()) {
-    ReportError("Reading uninitialized variable.");
-  }
-  if (type()->IsStructType()) {
-    return value();
-  }
-  std::string result = "(*" + value() + ")";
-  if (!IsConst()) result += ".value()";
-  return result;
-}
-
 void PrintLabel(std::ostream& os, const Label& l, bool with_names) {
   os << l.name();
   if (l.GetParameterCount() != 0) {
diff --git a/deps/v8/src/torque/declarable.h b/deps/v8/src/torque/declarable.h
index 315ff8f636..1d173062bd 100644
--- a/deps/v8/src/torque/declarable.h
+++ b/deps/v8/src/torque/declarable.h
@@ -18,13 +18,14 @@ namespace v8 {
 namespace internal {
 namespace torque {
 
+class Block;
+class Generic;
 class Scope;
 class ScopeChain;
-class Generic;
 
 class Declarable {
  public:
-  virtual ~Declarable() {}
+  virtual ~Declarable() = default;
   enum Kind {
     kVariable,
     kParameter,
@@ -88,13 +89,17 @@ class Declarable {
 
 class Value : public Declarable {
  public:
+  DECLARE_DECLARABLE_BOILERPLATE(Value, value);
   const std::string& name() const { return name_; }
   virtual bool IsConst() const { return true; }
-  virtual std::string value() const = 0;
-  virtual std::string RValue() const { return value(); }
-  DECLARE_DECLARABLE_BOILERPLATE(Value, value);
+  VisitResult value() const { return *value_; }
   const Type* type() const { return type_; }
 
+  void set_value(VisitResult value) {
+    DCHECK(!value_);
+    value_ = value;
+  }
+
  protected:
   Value(Kind kind, const Type* type, const std::string& name)
       : Declarable(kind), type_(type), name_(name) {}
@@ -102,40 +107,44 @@ class Value : public Declarable {
  private:
   const Type* type_;
   std::string name_;
+  base::Optional<VisitResult> value_;
 };
 
 class Parameter : public Value {
  public:
   DECLARE_DECLARABLE_BOILERPLATE(Parameter, parameter);
-  std::string value() const override { return var_name_; }
+
+  const std::string& external_name() const { return external_name_; }
 
  private:
   friend class Declarations;
-  Parameter(const std::string& name, const Type* type,
-            const std::string& var_name)
-      : Value(Declarable::kParameter, type, name), var_name_(var_name) {}
+  Parameter(const std::string& name, std::string external_name,
+            const Type* type)
+      : Value(Declarable::kParameter, type, name),
+        external_name_(external_name) {}
 
-  std::string var_name_;
+  std::string external_name_;
 };
 
 class ModuleConstant : public Value {
  public:
   DECLARE_DECLARABLE_BOILERPLATE(ModuleConstant, constant);
-  std::string value() const override { UNREACHABLE(); }
-  std::string RValue() const override { return name() + "()"; }
+
+  const std::string& constant_name() const { return constant_name_; }
 
  private:
   friend class Declarations;
-  explicit ModuleConstant(const std::string& name, const Type* type)
-      : Value(Declarable::kModuleConstant, type, name) {}
+  explicit ModuleConstant(std::string constant_name, const Type* type)
+      : Value(Declarable::kModuleConstant, type, constant_name),
+        constant_name_(std::move(constant_name)) {}
+
+  std::string constant_name_;
 };
 
 class Variable : public Value {
  public:
   DECLARE_DECLARABLE_BOILERPLATE(Variable, variable);
   bool IsConst() const override { return const_; }
-  std::string value() const override { return value_; }
-  std::string RValue() const override;
   void Define() {
     if (defined_ && IsConst()) {
       ReportError("Cannot re-define a const-bound variable.");
@@ -146,10 +155,8 @@ class Variable : public Value {
 
  private:
   friend class Declarations;
-  Variable(const std::string& name, const std::string& value, const Type* type,
-           bool is_const)
+  Variable(std::string name, const Type* type, bool is_const)
       : Value(Declarable::kVariable, type, name),
-        value_(value),
         defined_(false),
         const_(is_const) {
     DCHECK_IMPLIES(type->IsConstexpr(), IsConst());
@@ -163,8 +170,20 @@ class Variable : public Value {
 class Label : public Declarable {
  public:
   void AddVariable(Variable* var) { parameters_.push_back(var); }
-  std::string name() const { return name_; }
-  std::string generated() const { return generated_; }
+  Block* block() const { return *block_; }
+  void set_block(Block* block) {
+    DCHECK(!block_);
+    block_ = block;
+  }
+  const std::string& external_label_name() const {
+    return *external_label_name_;
+  }
+  const std::string& name() const { return name_; }
+  void set_external_label_name(std::string external_label_name) {
+    DCHECK(!block_);
+    DCHECK(!external_label_name_);
+    external_label_name_ = std::move(external_label_name);
+  }
   Variable* GetParameter(size_t i) const { return parameters_[i]; }
   size_t GetParameterCount() const { return parameters_.size(); }
   const std::vector<Variable*>& GetParameters() const { return parameters_; }
@@ -172,34 +191,35 @@ class Label : public Declarable {
   DECLARE_DECLARABLE_BOILERPLATE(Label, label);
   void MarkUsed() { used_ = true; }
   bool IsUsed() const { return used_; }
+  bool IsDeferred() const { return deferred_; }
 
  private:
   friend class Declarations;
-  explicit Label(const std::string& name)
+  explicit Label(std::string name, bool deferred = false)
       : Declarable(Declarable::kLabel),
-        name_(name),
-        generated_("label_" + name + "_" + std::to_string(next_id_++)),
-        used_(false) {}
+        name_(std::move(name)),
+        used_(false),
+        deferred_(deferred) {}
 
   std::string name_;
-  std::string generated_;
+  base::Optional<Block*> block_;
+  base::Optional<std::string> external_label_name_;
   std::vector<Variable*> parameters_;
   static size_t next_id_;
   bool used_;
+  bool deferred_;
 };
 
 class ExternConstant : public Value {
  public:
   DECLARE_DECLARABLE_BOILERPLATE(ExternConstant, constant);
-  std::string value() const override { return value_; }
 
  private:
   friend class Declarations;
-  explicit ExternConstant(const std::string& name, const Type* type,
-                          const std::string& value)
-      : Value(Declarable::kExternConstant, type, name), value_(value) {}
-
-  std::string value_;
+  explicit ExternConstant(std::string name, const Type* type, std::string value)
+      : Value(Declarable::kExternConstant, type, std::move(name)) {
+    set_value(VisitResult(type, std::move(value)));
+  }
 };
 
 class Callable : public Declarable {
diff --git a/deps/v8/src/torque/declaration-visitor.cc b/deps/v8/src/torque/declaration-visitor.cc
index 2f3a1fa869..abc207c049 100644
--- a/deps/v8/src/torque/declaration-visitor.cc
+++ b/deps/v8/src/torque/declaration-visitor.cc
@@ -174,22 +174,10 @@ void DeclarationVisitor::Visit(TorqueMacroDeclaration* decl,
   CurrentCallableActivator activator(global_context_, macro, decl);
 
   DeclareSignature(signature);
-  Variable* return_variable = nullptr;
-  if (!signature.return_type->IsVoidOrNever()) {
-    return_variable =
-        DeclareVariable(kReturnValueVariable, signature.return_type,
-                        signature.return_type->IsConstexpr());
-  }
 
-  PushControlSplit();
   if (body != nullptr) {
     Visit(body);
   }
-  auto changed_vars = PopControlSplit();
-  if (return_variable) changed_vars.insert(return_variable);
-  global_context_.AddControlSplitChangedVariables(
-      decl, declarations()->GetCurrentSpecializationTypeNamesVector(),
-      changed_vars);
 }
 
 void DeclarationVisitor::Visit(ConstDeclaration* decl) {
@@ -273,28 +261,13 @@ void DeclarationVisitor::Visit(ReturnStatement* stmt) {
 Variable* DeclarationVisitor::DeclareVariable(const std::string& name,
                                               const Type* type, bool is_const) {
   Variable* result = declarations()->DeclareVariable(name, type, is_const);
-  if (type->IsStructType()) {
-    const StructType* struct_type = StructType::cast(type);
-    for (auto& field : struct_type->fields()) {
-      std::string field_var_name = name + "." + field.name;
-      DeclareVariable(field_var_name, field.type, is_const);
-    }
-  }
   return result;
 }
 
 Parameter* DeclarationVisitor::DeclareParameter(const std::string& name,
                                                 const Type* type) {
-  Parameter* result = declarations()->DeclareParameter(
+  return declarations()->DeclareParameter(
       name, GetParameterVariableFromName(name), type);
-  if (type->IsStructType()) {
-    const StructType* struct_type = StructType::cast(type);
-    for (auto& field : struct_type->fields()) {
-      std::string field_var_name = name + "." + field.name;
-      DeclareParameter(field_var_name, field.type);
-    }
-  }
-  return result;
 }
 
 void DeclarationVisitor::Visit(VarDeclarationStatement* stmt) {
@@ -372,7 +345,9 @@ void DeclarationVisitor::Visit(LogicalAndExpression* expr) {
   Visit(expr->right);
 }
 
-void DeclarationVisitor::DeclareExpressionForBranch(Expression* node) {
+void DeclarationVisitor::DeclareExpressionForBranch(
+    Expression* node, base::Optional<Statement*> true_statement,
+    base::Optional<Statement*> false_statement) {
   Declarations::NodeScopeActivator scope(declarations(), node);
   // Conditional expressions can either explicitly return a bit
   // type, or they can be backed by macros that don't return but
@@ -380,46 +355,27 @@ void DeclarationVisitor::DeclareExpressionForBranch(Expression* node) {
   // visiting the conditional expression, those label-based
   // macro conditionals will be able to find them through normal
   // label lookups.
-  declarations()->DeclareLabel(kTrueLabelName);
-  declarations()->DeclareLabel(kFalseLabelName);
+  declarations()->DeclareLabel(kTrueLabelName, true_statement);
+  declarations()->DeclareLabel(kFalseLabelName, false_statement);
   Visit(node);
 }
 
 void DeclarationVisitor::Visit(ConditionalExpression* expr) {
   DeclareExpressionForBranch(expr->condition);
-  PushControlSplit();
   Visit(expr->if_true);
   Visit(expr->if_false);
-  auto changed_vars = PopControlSplit();
-  global_context_.AddControlSplitChangedVariables(
-      expr, declarations()->GetCurrentSpecializationTypeNamesVector(),
-      changed_vars);
 }
 
 void DeclarationVisitor::Visit(IfStatement* stmt) {
-  if (!stmt->is_constexpr) {
-    PushControlSplit();
-  }
-  DeclareExpressionForBranch(stmt->condition);
+  DeclareExpressionForBranch(stmt->condition, stmt->if_true, stmt->if_false);
   Visit(stmt->if_true);
   if (stmt->if_false) Visit(*stmt->if_false);
-  if (!stmt->is_constexpr) {
-    auto changed_vars = PopControlSplit();
-    global_context_.AddControlSplitChangedVariables(
-        stmt, declarations()->GetCurrentSpecializationTypeNamesVector(),
-        changed_vars);
-  }
 }
 
 void DeclarationVisitor::Visit(WhileStatement* stmt) {
   Declarations::NodeScopeActivator scope(declarations(), stmt);
   DeclareExpressionForBranch(stmt->condition);
-  PushControlSplit();
   Visit(stmt->body);
-  auto changed_vars = PopControlSplit();
-  global_context_.AddControlSplitChangedVariables(
-      stmt, declarations()->GetCurrentSpecializationTypeNamesVector(),
-      changed_vars);
 }
 
 void DeclarationVisitor::Visit(ForOfLoopStatement* stmt) {
@@ -429,18 +385,12 @@ void DeclarationVisitor::Visit(ForOfLoopStatement* stmt) {
   Visit(stmt->iterable);
   if (stmt->begin) Visit(*stmt->begin);
   if (stmt->end) Visit(*stmt->end);
-  PushControlSplit();
   Visit(stmt->body);
-  auto changed_vars = PopControlSplit();
-  global_context_.AddControlSplitChangedVariables(
-      stmt, declarations()->GetCurrentSpecializationTypeNamesVector(),
-      changed_vars);
 }
 
 void DeclarationVisitor::Visit(ForLoopStatement* stmt) {
   Declarations::NodeScopeActivator scope(declarations(), stmt);
   if (stmt->var_declaration) Visit(*stmt->var_declaration);
-  PushControlSplit();
 
   // Same as DeclareExpressionForBranch, but without the extra scope.
   // If no test expression is present we can not use it for the scope.
@@ -450,22 +400,20 @@ void DeclarationVisitor::Visit(ForLoopStatement* stmt) {
 
   Visit(stmt->body);
   if (stmt->action) Visit(*stmt->action);
-  auto changed_vars = PopControlSplit();
-  global_context_.AddControlSplitChangedVariables(
-      stmt, declarations()->GetCurrentSpecializationTypeNamesVector(),
-      changed_vars);
 }
 
-void DeclarationVisitor::Visit(TryLabelStatement* stmt) {
-  // Activate a new scope to declare handler labels, they should not be
-  // visible outside the label block.
+void DeclarationVisitor::Visit(TryLabelExpression* stmt) {
+  // Activate a new scope to declare the handler's label parameters, they should
+  // not be visible outside the label block.
   {
     Declarations::NodeScopeActivator scope(declarations(), stmt);
 
-    // Declare labels
-    for (LabelBlock* block : stmt->label_blocks) {
+    // Declare label
+    {
+      LabelBlock* block = stmt->label_block;
       CurrentSourcePosition::Scope scope(block->pos);
-      Label* shared_label = declarations()->DeclareLabel(block->label);
+      Label* shared_label =
+          declarations()->DeclareLabel(block->label, block->body);
       {
         Declarations::NodeScopeActivator scope(declarations(), block->body);
         if (block->parameters.has_varargs) {
@@ -475,7 +423,7 @@ void DeclarationVisitor::Visit(TryLabelStatement* stmt) {
         }
 
         size_t i = 0;
-        for (auto p : block->parameters.names) {
+        for (const auto& p : block->parameters.names) {
           const Type* type =
               declarations()->GetType(block->parameters.types[i]);
           if (type->IsConstexpr()) {
@@ -485,18 +433,16 @@ void DeclarationVisitor::Visit(TryLabelStatement* stmt) {
           shared_label->AddVariable(DeclareVariable(p, type, false));
           ++i;
         }
-      }
-      if (global_context_.verbose()) {
-        std::cout << " declaring label " << block->label << "\n";
+        if (global_context_.verbose()) {
+          std::cout << " declaring label " << block->label << "\n";
+        }
       }
     }
 
-    Visit(stmt->try_block);
+    Visit(stmt->try_expression);
   }
 
-  for (LabelBlock* block : stmt->label_blocks) {
-    Visit(block->body);
-  }
+  Visit(stmt->label_block->body);
 }
 
 void DeclarationVisitor::GenerateHeader(std::string& file_name) {
@@ -531,7 +477,7 @@ void DeclarationVisitor::GenerateHeader(std::string& file_name) {
     }
     if (declareParameters) {
       int index = 0;
-      for (auto parameter : builtin->parameter_names()) {
+      for (const auto& parameter : builtin->parameter_names()) {
         if (index >= firstParameterIndex) {
           new_contents_stream << ", k" << CamelifyString(parameter);
         }
@@ -569,6 +515,10 @@ void DeclarationVisitor::Visit(IdentifierExpression* expr) {
   }
 }
 
+void DeclarationVisitor::Visit(StatementExpression* expr) {
+  Visit(expr->statement);
+}
+
 void DeclarationVisitor::Visit(CallExpression* expr) {
   Visit(&expr->callee);
   for (Expression* arg : expr->arguments) Visit(arg);
@@ -589,37 +539,9 @@ void DeclarationVisitor::Visit(TypeDeclaration* decl) {
   }
 }
 
-void DeclarationVisitor::MarkLocationModified(Expression* location) {
-  if (IdentifierExpression* id = IdentifierExpression::cast(location)) {
-    const Value* value = declarations()->LookupValue(id->name);
-    if (value->IsVariable()) {
-      const Variable* variable = Variable::cast(value);
-      bool was_live = MarkVariableModified(variable);
-      if (was_live && global_context_.verbose()) {
-        std::cout << *variable << " was modified in control split at "
-                  << PositionAsString(id->pos) << "\n";
-      }
-    }
-  }
-}
-
-bool DeclarationVisitor::MarkVariableModified(const Variable* variable) {
-  auto e = live_and_changed_variables_.rend();
-  auto c = live_and_changed_variables_.rbegin();
-  bool was_live_in_preceeding_split = false;
-  while (c != e) {
-    if (c->live.find(variable) != c->live.end()) {
-      c->changed.insert(variable);
-      was_live_in_preceeding_split = true;
-    }
-    c++;
-  }
-  return was_live_in_preceeding_split;
-}
-
 void DeclarationVisitor::DeclareSignature(const Signature& signature) {
   auto type_iterator = signature.parameter_types.types.begin();
-  for (auto name : signature.parameter_names) {
+  for (const auto& name : signature.parameter_names) {
     const Type* t(*type_iterator++);
     if (name.size() != 0) {
       DeclareParameter(name, t);
@@ -628,6 +550,7 @@ void DeclarationVisitor::DeclareSignature(const Signature& signature) {
   for (auto& label : signature.labels) {
     auto label_params = label.types;
     Label* new_label = declarations()->DeclareLabel(label.name);
+    new_label->set_external_label_name("label_" + label.name);
     size_t i = 0;
     for (auto var_type : label_params) {
       if (var_type->IsConstexpr()) {
@@ -635,7 +558,8 @@ void DeclarationVisitor::DeclareSignature(const Signature& signature) {
       }
 
       std::string var_name = label.name + std::to_string(i++);
-      new_label->AddVariable(DeclareVariable(var_name, var_type, false));
+      new_label->AddVariable(
+          declarations()->CreateVariable(var_name, var_type, false));
     }
   }
 }
diff --git a/deps/v8/src/torque/declaration-visitor.h b/deps/v8/src/torque/declaration-visitor.h
index e1d5439018..d8a9698c6f 100644
--- a/deps/v8/src/torque/declaration-visitor.h
+++ b/deps/v8/src/torque/declaration-visitor.h
@@ -114,7 +114,9 @@ class DeclarationVisitor : public FileVisitor {
 
   void Visit(LogicalOrExpression* expr);
   void Visit(LogicalAndExpression* expr);
-  void DeclareExpressionForBranch(Expression* node);
+  void DeclareExpressionForBranch(
+      Expression* node, base::Optional<Statement*> true_statement = {},
+      base::Optional<Statement*> false_statement = {});
 
   void Visit(ConditionalExpression* expr);
   void Visit(IfStatement* stmt);
@@ -122,7 +124,6 @@ class DeclarationVisitor : public FileVisitor {
   void Visit(ForOfLoopStatement* stmt);
 
   void Visit(AssignmentExpression* expr) {
-    MarkLocationModified(expr->location);
     Visit(expr->location);
     Visit(expr->value);
   }
@@ -133,39 +134,20 @@ class DeclarationVisitor : public FileVisitor {
   void Visit(ForLoopStatement* stmt);
 
   void Visit(IncrementDecrementExpression* expr) {
-    MarkLocationModified(expr->location);
     Visit(expr->location);
   }
 
   void Visit(AssumeTypeImpossibleExpression* expr) { Visit(expr->expression); }
 
-  void Visit(TryLabelStatement* stmt);
+  void Visit(TryLabelExpression* stmt);
+  void Visit(StatementExpression* stmt);
   void GenerateHeader(std::string& file_name);
 
  private:
-  struct LiveAndChanged {
-    std::set<const Variable*> live;
-    std::set<const Variable*> changed;
-  };
-
-  void PushControlSplit() {
-    LiveAndChanged live_and_changed;
-    live_and_changed.live = declarations()->GetLiveVariables();
-    live_and_changed_variables_.push_back(live_and_changed);
-  }
-
   Variable* DeclareVariable(const std::string& name, const Type* type,
                             bool is_const);
   Parameter* DeclareParameter(const std::string& name, const Type* type);
 
-  std::set<const Variable*> PopControlSplit() {
-    auto result = live_and_changed_variables_.back().changed;
-    live_and_changed_variables_.pop_back();
-    return result;
-  }
-
-  void MarkLocationModified(Expression* location);
-  bool MarkVariableModified(const Variable* variable);
   void DeclareSignature(const Signature& signature);
   void DeclareSpecializedTypes(const SpecializationKey& key);
 
@@ -175,7 +157,6 @@ class DeclarationVisitor : public FileVisitor {
 
   Declarations::ModuleScopeActivator scope_;
   std::vector<Builtin*> torque_builtins_;
-  std::vector<LiveAndChanged> live_and_changed_variables_;
 };
 
 }  // namespace torque
diff --git a/deps/v8/src/torque/declarations.cc b/deps/v8/src/torque/declarations.cc
index 9b2964d210..f001b98355 100644
--- a/deps/v8/src/torque/declarations.cc
+++ b/deps/v8/src/torque/declarations.cc
@@ -233,9 +233,15 @@ void Declarations::DeclareStruct(Module* module, const std::string& name,
   DeclareType(name, new_type);
 }
 
-Label* Declarations::DeclareLabel(const std::string& name) {
+Label* Declarations::DeclareLabel(const std::string& name,
+                                  base::Optional<Statement*> statement) {
   CheckAlreadyDeclared(name, "label");
-  Label* result = new Label(name);
+  bool deferred = false;
+  if (statement) {
+    BlockStatement* block = BlockStatement::DynamicCast(*statement);
+    deferred = block && block->deferred;
+  }
+  Label* result = new Label(name, deferred);
   Declare(name, std::unique_ptr<Declarable>(result));
   return result;
 }
@@ -298,38 +304,31 @@ RuntimeFunction* Declarations::DeclareRuntimeFunction(
   return result;
 }
 
+Variable* Declarations::CreateVariable(const std::string& var, const Type* type,
+                                       bool is_const) {
+  return RegisterDeclarable(
+      std::unique_ptr<Variable>(new Variable(var, type, is_const)));
+}
+
 Variable* Declarations::DeclareVariable(const std::string& var,
                                         const Type* type, bool is_const) {
-  std::string name(var + "_" +
-                   std::to_string(GetNextUniqueDeclarationNumber()));
-  std::replace(name.begin(), name.end(), '.', '_');
   CheckAlreadyDeclared(var, "variable");
-  Variable* result = new Variable(var, name, type, is_const);
+  Variable* result = new Variable(var, type, is_const);
   Declare(var, std::unique_ptr<Declarable>(result));
   return result;
 }
 
 Parameter* Declarations::DeclareParameter(const std::string& name,
-                                          const std::string& var_name,
+                                          std::string external_name,
                                           const Type* type) {
   CheckAlreadyDeclared(name, "parameter");
-  Parameter* result = new Parameter(name, type, var_name);
-  Declare(name, std::unique_ptr<Declarable>(result));
-  return result;
-}
-
-Label* Declarations::DeclarePrivateLabel(const std::string& raw_name) {
-  std::string name =
-      raw_name + "_" + std::to_string(GetNextUniqueDeclarationNumber());
-  CheckAlreadyDeclared(name, "label");
-  Label* result = new Label(name);
+  Parameter* result = new Parameter(name, std::move(external_name), type);
   Declare(name, std::unique_ptr<Declarable>(result));
   return result;
 }
 
 void Declarations::DeclareExternConstant(const std::string& name,
-                                         const Type* type,
-                                         const std::string& value) {
+                                         const Type* type, std::string value) {
   CheckAlreadyDeclared(name, "constant, parameter or arguments");
   ExternConstant* result = new ExternConstant(name, type, value);
   Declare(name, std::unique_ptr<Declarable>(result));
diff --git a/deps/v8/src/torque/declarations.h b/deps/v8/src/torque/declarations.h
index 880b3e75a6..5a45e5dbda 100644
--- a/deps/v8/src/torque/declarations.h
+++ b/deps/v8/src/torque/declarations.h
@@ -15,7 +15,7 @@ namespace v8 {
 namespace internal {
 namespace torque {
 
-static constexpr const char* const kFromConstexprMacroName = "from_constexpr";
+static constexpr const char* const kFromConstexprMacroName = "FromConstexpr";
 static constexpr const char* kTrueLabelName = "_True";
 static constexpr const char* kFalseLabelName = "_False";
 
@@ -79,7 +79,8 @@ class Declarations {
   void DeclareStruct(Module* module, const std::string& name,
                      const std::vector<NameAndType>& fields);
 
-  Label* DeclareLabel(const std::string& name);
+  Label* DeclareLabel(const std::string& name,
+                      base::Optional<Statement*> statement = {});
 
   Macro* DeclareMacro(const std::string& name, const Signature& signature,
                       base::Optional<std::string> op = {});
@@ -90,17 +91,16 @@ class Declarations {
   RuntimeFunction* DeclareRuntimeFunction(const std::string& name,
                                           const Signature& signature);
 
+  Variable* CreateVariable(const std::string& var, const Type* type,
+                           bool is_const);
   Variable* DeclareVariable(const std::string& var, const Type* type,
                             bool is_const);
 
   Parameter* DeclareParameter(const std::string& name,
-                              const std::string& mangled_name,
-                              const Type* type);
-
-  Label* DeclarePrivateLabel(const std::string& name);
+                              std::string external_name, const Type* type);
 
   void DeclareExternConstant(const std::string& name, const Type* type,
-                             const std::string& value);
+                             std::string value);
   ModuleConstant* DeclareModuleConstant(const std::string& name,
                                         const Type* type);
 
@@ -219,7 +219,7 @@ class Declarations::ScopedGenericScopeChainSnapshot {
   ScopedGenericScopeChainSnapshot(Declarations* declarations,
                                   const SpecializationKey& key)
       : restorer_(declarations->generic_declaration_scopes_[key.first]) {}
-  ~ScopedGenericScopeChainSnapshot() {}
+  ~ScopedGenericScopeChainSnapshot() = default;
 
  private:
   ScopeChain::ScopedSnapshotRestorer restorer_;
diff --git a/deps/v8/src/torque/file-visitor.cc b/deps/v8/src/torque/file-visitor.cc
index c2e5aa7924..865b7b456d 100644
--- a/deps/v8/src/torque/file-visitor.cc
+++ b/deps/v8/src/torque/file-visitor.cc
@@ -13,7 +13,7 @@ namespace torque {
 
 Signature FileVisitor::MakeSignature(const CallableNodeSignature* signature) {
   LabelDeclarationVector definition_vector;
-  for (auto label : signature->labels) {
+  for (const auto& label : signature->labels) {
     LabelDeclaration def = {label.name, GetTypeVector(label.types)};
     definition_vector.push_back(def);
   }
diff --git a/deps/v8/src/torque/file-visitor.h b/deps/v8/src/torque/file-visitor.h
index d306392446..7d79e9acba 100644
--- a/deps/v8/src/torque/file-visitor.h
+++ b/deps/v8/src/torque/file-visitor.h
@@ -51,10 +51,6 @@ class FileVisitor {
   };
 
  protected:
-  static constexpr const char* kReturnValueVariable = "_return";
-  static constexpr const char* kDoneLabelName = "_done";
-  static constexpr const char* kForIndexValueVariable = "_for_index";
-
   Module* CurrentModule() const { return module_; }
 
   friend class ScopedModuleActivator;
diff --git a/deps/v8/src/torque/global-context.h b/deps/v8/src/torque/global-context.h
index 33573f7175..cd20c332f3 100644
--- a/deps/v8/src/torque/global-context.h
+++ b/deps/v8/src/torque/global-context.h
@@ -65,34 +65,12 @@ class GlobalContext {
   void SetVerbose() { verbose_ = true; }
   bool verbose() const { return verbose_; }
 
-  void AddControlSplitChangedVariables(const AstNode* node,
-                                       const TypeVector& specialization_types,
-                                       const std::set<const Variable*>& vars) {
-    auto key = std::make_pair(node, specialization_types);
-    control_split_changed_variables_[key] = vars;
-  }
-
-  const std::set<const Variable*>& GetControlSplitChangedVariables(
-      const AstNode* node, const TypeVector& specialization_types) {
-    auto key = std::make_pair(node, specialization_types);
-    assert(control_split_changed_variables_.find(key) !=
-           control_split_changed_variables_.end());
-    return control_split_changed_variables_.find(key)->second;
-  }
-
-  void MarkVariableChanged(const AstNode* node,
-                           const TypeVector& specialization_types,
-                           Variable* var) {
-    auto key = std::make_pair(node, specialization_types);
-    control_split_changed_variables_[key].insert(var);
-  }
-
   friend class CurrentCallableActivator;
   friend class BreakContinueActivator;
 
   Callable* GetCurrentCallable() const { return current_callable_; }
-  Label* GetCurrentBreak() const { return break_continue_stack_.back().first; }
-  Label* GetCurrentContinue() const {
+  Block* GetCurrentBreak() const { return break_continue_stack_.back().first; }
+  Block* GetCurrentContinue() const {
     return break_continue_stack_.back().second;
   }
 
@@ -104,11 +82,9 @@ class GlobalContext {
   int next_label_number_;
   Declarations declarations_;
   Callable* current_callable_;
-  std::vector<std::pair<Label*, Label*>> break_continue_stack_;
+  std::vector<std::pair<Block*, Block*>> break_continue_stack_;
   std::map<std::string, std::unique_ptr<Module>> modules_;
   Module* default_module_;
-  std::map<std::pair<const AstNode*, TypeVector>, std::set<const Variable*>>
-      control_split_changed_variables_;
   Ast ast_;
 };
 
@@ -132,10 +108,10 @@ class CurrentCallableActivator {
 
 class BreakContinueActivator {
  public:
-  BreakContinueActivator(GlobalContext& context, Label* break_label,
-                         Label* continue_label)
+  BreakContinueActivator(GlobalContext& context, Block* break_block,
+                         Block* continue_block)
       : context_(context) {
-    context_.break_continue_stack_.push_back({break_label, continue_label});
+    context_.break_continue_stack_.push_back({break_block, continue_block});
   }
   ~BreakContinueActivator() { context_.break_continue_stack_.pop_back(); }
 
diff --git a/deps/v8/src/torque/implementation-visitor.cc b/deps/v8/src/torque/implementation-visitor.cc
index 5044d914db..89c0c70416 100644
--- a/deps/v8/src/torque/implementation-visitor.cc
+++ b/deps/v8/src/torque/implementation-visitor.cc
@@ -4,6 +4,7 @@
 
 #include <algorithm>
 
+#include "src/torque/csa-generator.h"
 #include "src/torque/implementation-visitor.h"
 #include "src/torque/parameter-difference.h"
 
@@ -26,19 +27,20 @@ VisitResult ImplementationVisitor::Visit(Expression* expr) {
 
 const Type* ImplementationVisitor::Visit(Statement* stmt) {
   CurrentSourcePosition::Scope scope(stmt->pos);
-  GenerateIndent();
-  source_out() << "// " << CurrentPositionAsString() << "\n";
+  const Type* result;
   switch (stmt->kind) {
-#define ENUM_ITEM(name)        \
-  case AstNode::Kind::k##name: \
-    return Visit(name::cast(stmt));
+#define ENUM_ITEM(name)               \
+  case AstNode::Kind::k##name:        \
+    result = Visit(name::cast(stmt)); \
+    break;
     AST_STATEMENT_NODE_KIND_LIST(ENUM_ITEM)
 #undef ENUM_ITEM
     default:
-      UNIMPLEMENTED();
+      UNREACHABLE();
   }
-  UNREACHABLE();
-  return nullptr;
+  DCHECK_EQ(result == TypeOracle::GetNeverType(),
+            assembler().CurrentBlockIsComplete());
+  return result;
 }
 
 void ImplementationVisitor::Visit(Declaration* decl) {
@@ -72,12 +74,13 @@ void ImplementationVisitor::BeginModuleFile(Module* module) {
   std::ostream& header = module->header_stream();
 
   if (module->IsDefault()) {
-    source << "#include \"src/code-stub-assembler.h\"";
+    source << "#include \"src/torque-assembler.h\"";
   } else {
     source << "#include \"src/builtins/builtins-" +
                   DashifyString(module->name()) + "-gen.h\"";
   }
   source << "\n";
+  source << "#include \"src/objects/arguments.h\"\n";
   source << "#include \"src/builtins/builtins-utils-gen.h\"\n";
   source << "#include \"src/builtins/builtins.h\"\n";
   source << "#include \"src/code-factory.h\"\n";
@@ -103,7 +106,7 @@ void ImplementationVisitor::BeginModuleFile(Module* module) {
   header << "#ifndef " << headerDefine << "\n";
   header << "#define " << headerDefine << "\n\n";
   if (module->IsDefault()) {
-    header << "#include \"src/code-stub-assembler.h\"";
+    header << "#include \"src/torque-assembler.h\"";
   } else {
     header << "#include \"src/builtins/builtins-" +
                   DashifyString(module->name()) + "-gen.h\"\n";
@@ -176,12 +179,20 @@ void ImplementationVisitor::Visit(ConstDeclaration* decl) {
 
   DCHECK(!signature.return_type->IsVoidOrNever());
 
+  assembler_ = CfgAssembler(Stack<const Type*>{});
+
   VisitResult expression_result = Visit(decl->expression);
   VisitResult return_result =
       GenerateImplicitConvert(signature.return_type, expression_result);
 
-  GenerateIndent();
-  source_out() << "return " << return_result.RValue() << ";\n";
+  CSAGenerator csa_generator{assembler().Result(), source_out()};
+  Stack<std::string> values = *csa_generator.EmitGraph(Stack<std::string>{});
+
+  assembler_ = base::nullopt;
+
+  source_out() << "return ";
+  CSAGenerator::EmitCSAValue(return_result, values, source_out());
+  source_out() << ";\n";
   source_out() << "}\n\n";
 }
 
@@ -193,13 +204,41 @@ void ImplementationVisitor::Visit(StructDeclaration* decl) {
     header_out() << "    " << field.type->GetGeneratedTypeName();
     header_out() << " " << field.name << ";\n";
   }
-  header_out() << "  } "
-               << ";\n";
+  header_out() << "\n    std::tuple<";
+  bool first = true;
+  for (const Type* type : LowerType(struct_type)) {
+    if (!first) {
+      header_out() << ", ";
+    }
+    first = false;
+    header_out() << type->GetGeneratedTypeName();
+  }
+  header_out() << "> Flatten() const {\n"
+               << "      return std::tuple_cat(";
+  first = true;
+  for (auto& field : struct_type->fields()) {
+    if (!first) {
+      header_out() << ", ";
+    }
+    first = false;
+    if (field.type->IsStructType()) {
+      header_out() << field.name << ".Flatten()";
+    } else {
+      header_out() << "std::make_tuple(" << field.name << ")";
+    }
+  }
+  header_out() << ");\n";
+  header_out() << "    }\n";
+  header_out() << "  };\n";
 }
 
 void ImplementationVisitor::Visit(TorqueMacroDeclaration* decl,
                                   const Signature& sig, Statement* body) {
   Signature signature = MakeSignature(decl->signature.get());
+  const Type* return_type = signature.return_type;
+  bool can_return = return_type != TypeOracle::GetNeverType();
+  bool has_return_value =
+      can_return && return_type != TypeOracle::GetVoidType();
   std::string name = GetGeneratedCallableName(
       decl->name, declarations()->GetCurrentSpecializationTypeNamesVector());
   const TypeVector& list = signature.types();
@@ -216,15 +255,43 @@ void ImplementationVisitor::Visit(TorqueMacroDeclaration* decl,
         source_out(), GetDSLAssemblerName(CurrentModule()) + "::", macro);
     source_out() << " {\n";
 
-    const Variable* result_var = nullptr;
-    if (macro->HasReturnValue()) {
-      result_var =
-          GeneratePredeclaredVariableDeclaration(kReturnValueVariable, {});
+    Stack<std::string> lowered_parameters;
+    Stack<const Type*> lowered_parameter_types;
+
+    for (const std::string& name : macro->parameter_names()) {
+      Parameter* parameter = Parameter::cast(declarations()->LookupValue(name));
+      const Type* type = parameter->type();
+      if (type->IsConstexpr()) {
+        parameter->set_value(
+            VisitResult(parameter->type(), parameter->external_name()));
+      } else {
+        LowerParameter(type, parameter->external_name(), &lowered_parameters);
+        StackRange range = lowered_parameter_types.PushMany(LowerType(type));
+        parameter->set_value(VisitResult(type, range));
+      }
+    }
+
+    DCHECK_EQ(lowered_parameters.Size(), lowered_parameter_types.Size());
+    assembler_ = CfgAssembler(lowered_parameter_types);
+
+    for (const LabelDeclaration& label_info : sig.labels) {
+      Label* label = declarations()->LookupLabel(label_info.name);
+      Stack<const Type*> label_input_stack;
+      for (Variable* v : label->GetParameters()) {
+        label_input_stack.PushMany(LowerType(v->type()));
+      }
+      CreateBlockForLabel(label, label_input_stack);
     }
+
     Label* macro_end = declarations()->DeclareLabel("macro_end");
-    GenerateLabelDefinition(macro_end, decl);
+    if (can_return) {
+      Stack<const Type*> result_stack;
+      CreateBlockForLabel(macro_end,
+                          Stack<const Type*>{LowerType(signature.return_type)});
+    }
 
     const Type* result = Visit(body);
+
     if (result->IsNever()) {
       if (!macro->signature().return_type->IsNever() && !macro->HasReturns()) {
         std::stringstream s;
@@ -246,23 +313,54 @@ void ImplementationVisitor::Visit(TorqueMacroDeclaration* decl,
         ReportError(s.str());
       }
     }
-    if (macro->HasReturns()) {
-      if (!result->IsNever()) {
-        GenerateLabelGoto(macro_end);
+    if (!result->IsNever()) {
+      GenerateLabelGoto(macro_end);
+    }
+
+    for (const LabelDeclaration& label_info : sig.labels) {
+      Label* label = declarations()->LookupLabel(label_info.name);
+      GenerateLabelBind(label);
+      std::vector<std::string> label_parameter_variables;
+      for (size_t i = 0; i < label->GetParameterCount(); ++i) {
+        label_parameter_variables.push_back(
+            ExternalLabelParameterName(label, i));
       }
+      assembler().Emit(GotoExternalInstruction{label->external_label_name(),
+                                               label_parameter_variables});
+    }
+
+    if (macro->HasReturns() || !result->IsNever()) {
       GenerateLabelBind(macro_end);
     }
-    if (result_var != nullptr) {
-      GenerateIndent();
-      source_out() << "return "
-                   << RValueFlattenStructs(
-                          VisitResult(result_var->type(), result_var))
-                   << ";\n";
+
+    CSAGenerator csa_generator{assembler().Result(), source_out()};
+    base::Optional<Stack<std::string>> values =
+        csa_generator.EmitGraph(lowered_parameters);
+
+    assembler_ = base::nullopt;
+
+    if (has_return_value) {
+      source_out() << "  return ";
+      CSAGenerator::EmitCSAValue(GetAndClearReturnValue(), *values,
+                                 source_out());
+      source_out() << ";\n";
     }
     source_out() << "}\n\n";
   }
 }
 
+namespace {
+std::string AddParameter(Value* parameter, size_t i,
+                         Stack<std::string>* parameters,
+                         Stack<const Type*>* parameter_types) {
+  std::string name = "parameter" + std::to_string(i);
+  parameters->Push(name);
+  StackRange range = parameter_types->PushMany(LowerType(parameter->type()));
+  parameter->set_value(VisitResult(parameter->type(), range));
+  return name;
+}
+}  // namespace
+
 void ImplementationVisitor::Visit(TorqueBuiltinDeclaration* decl,
                                   const Signature& signature, Statement* body) {
   std::string name = GetGeneratedCallableName(
@@ -272,15 +370,17 @@ void ImplementationVisitor::Visit(TorqueBuiltinDeclaration* decl,
   Builtin* builtin = declarations()->LookupBuiltin(name);
   CurrentCallableActivator activator(global_context_, builtin, decl);
 
+  Stack<const Type*> parameter_types;
+  Stack<std::string> parameters;
+
   // Context
-  const Value* val =
+  Value* val =
       declarations()->LookupValue(decl->signature->parameters.names[0]);
-  GenerateIndent();
-  source_out() << "TNode<Context> " << val->value()
+  std::string parameter0 = AddParameter(val, 0, &parameters, &parameter_types);
+  source_out() << "  TNode<Context> " << parameter0
                << " = UncheckedCast<Context>(Parameter("
                << "Descriptor::kContext));\n";
-  GenerateIndent();
-  source_out() << "USE(" << val->value() << ");\n";
+  source_out() << "  USE(" << parameter0 << ");\n";
 
   size_t first = 1;
   if (builtin->IsVarArgsJavaScript()) {
@@ -288,41 +388,82 @@ void ImplementationVisitor::Visit(TorqueBuiltinDeclaration* decl,
     ExternConstant* arguments =
         ExternConstant::cast(declarations()->LookupValue(
             decl->signature->parameters.arguments_variable));
-    std::string arguments_name = arguments->value();
-    GenerateIndent();
+    std::string arguments_name = arguments->value().constexpr_value();
     source_out()
-        << "Node* argc = Parameter(Descriptor::kJSActualArgumentsCount);\n";
-    GenerateIndent();
-    source_out() << "CodeStubArguments arguments_impl(this, "
+        << "  Node* argc = Parameter(Descriptor::kJSActualArgumentsCount);\n";
+    source_out() << "  CodeStubArguments arguments_impl(this, "
                     "ChangeInt32ToIntPtr(argc));\n";
-    const Value* receiver =
+    Value* receiver =
         declarations()->LookupValue(decl->signature->parameters.names[1]);
-    GenerateIndent();
-    source_out() << "TNode<Object> " << receiver->value()
+    std::string parameter1 =
+        AddParameter(receiver, 1, &parameters, &parameter_types);
+
+    source_out() << "  TNode<Object> " << parameter1
                  << " = arguments_impl.GetReceiver();\n";
-    GenerateIndent();
-    source_out() << "auto arguments = &arguments_impl;\n";
-    GenerateIndent();
+    source_out() << "auto " << CSAGenerator::ARGUMENTS_VARIABLE_STRING
+                 << " = &arguments_impl;\n";
     source_out() << "USE(arguments);\n";
-    GenerateIndent();
-    source_out() << "USE(" << receiver->value() << ");\n";
+    source_out() << "USE(" << parameter1 << ");\n";
     first = 2;
   }
 
-  GenerateParameterList(decl->signature->parameters.names, first);
-  Visit(body);
+  for (size_t i = 0; i < decl->signature->parameters.names.size(); ++i) {
+    if (i < first) continue;
+    const std::string& parameter_name = decl->signature->parameters.names[i];
+    Value* parameter = declarations()->LookupValue(parameter_name);
+    std::string var = AddParameter(parameter, i, &parameters, &parameter_types);
+    source_out() << "  " << parameter->type()->GetGeneratedTypeName() << " "
+                 << var << " = "
+                 << "UncheckedCast<"
+                 << parameter->type()->GetGeneratedTNodeTypeName()
+                 << ">(Parameter(Descriptor::k"
+                 << CamelifyString(parameter_name) << "));\n";
+    source_out() << "  USE(" << var << ");\n";
+  }
+
+  assembler_ = CfgAssembler(parameter_types);
+  const Type* body_result = Visit(body);
+  if (body_result != TypeOracle::GetNeverType()) {
+    ReportError("control reaches end of builtin, expected return of a value");
+  }
+  CSAGenerator csa_generator{assembler().Result(), source_out(),
+                             builtin->kind()};
+  csa_generator.EmitGraph(parameters);
+  assembler_ = base::nullopt;
   source_out() << "}\n\n";
 }
 
 const Type* ImplementationVisitor::Visit(VarDeclarationStatement* stmt) {
+  base::Optional<const Type*> type;
+  if (stmt->type) type = declarations()->GetType(*stmt->type);
   base::Optional<VisitResult> init_result;
   if (stmt->initializer) {
+    StackScope scope(this);
     init_result = Visit(*stmt->initializer);
+    if (type) {
+      init_result = GenerateImplicitConvert(*type, *init_result);
+    }
+    init_result = scope.Yield(*init_result);
+  } else {
+    DCHECK(type.has_value());
+    if ((*type)->IsConstexpr()) {
+      ReportError("constexpr variables need an initializer");
+    }
+    TypeVector lowered_types = LowerType(*type);
+    for (const Type* type : lowered_types) {
+      assembler().Emit(PushUninitializedInstruction{type});
+    }
+    init_result =
+        VisitResult(*type, assembler().TopRange(lowered_types.size()));
   }
-  base::Optional<const Type*> type;
-  if (stmt->type) type = declarations()->GetType(*stmt->type);
-  GenerateVariableDeclaration(stmt, stmt->name, stmt->const_qualified, type,
-                              init_result);
+  Variable* var;
+  if (stmt->const_qualified) {
+    var = declarations()->DeclareVariable(stmt->name, init_result->type(),
+                                          stmt->const_qualified);
+  } else {
+    var = Variable::cast(declarations()->LookupValue(stmt->name));
+  }
+  var->set_value(*init_result);
   return TypeOracle::GetVoidType();
 }
 
@@ -331,72 +472,61 @@ const Type* ImplementationVisitor::Visit(TailCallStatement* stmt) {
 }
 
 VisitResult ImplementationVisitor::Visit(ConditionalExpression* expr) {
-  std::string f1 = NewTempVariable();
-  std::string f2 = NewTempVariable();
-
-  // The code for both paths of the conditional need to be generated first in
-  // lambdas before evaluating the conditional expression because the common
-  // type of the result of both the true and false of the condition needs to be
-  // known when declaring the variable to hold the result of the conditional.
-  VisitResult left, right;
-  GenerateIndent();
-  source_out() << "auto " << f1 << " = [=]() ";
-  {
-    ScopedIndent indent(this, false);
-    source_out() << "\n";
-    left = Visit(expr->if_true);
-    GenerateIndent();
-    source_out() << "return " << RValueFlattenStructs(left) << ";\n";
-  }
-  source_out() << ";\n";
-  GenerateIndent();
-  source_out() << "auto " << f2 << " = [=]() ";
+  Label* true_label;
+  Label* false_label;
+  Block* done_block = assembler().NewBlock();
+  Block* true_conversion_block = assembler().NewBlock();
   {
-    ScopedIndent indent(this, false);
-    source_out() << "\n";
-    right = Visit(expr->if_false);
-    GenerateIndent();
-    source_out() << "return " << RValueFlattenStructs(right) << ";\n";
+    Declarations::NodeScopeActivator scope(declarations(), expr->condition);
+
+    true_label = declarations()->LookupLabel(kTrueLabelName);
+    CreateBlockForLabel(true_label, assembler().CurrentStack());
+    false_label = declarations()->LookupLabel(kFalseLabelName);
+    CreateBlockForLabel(false_label, assembler().CurrentStack());
+    done_block = assembler().NewBlock();
+
+    {
+      StackScope condition_scope(this);
+      VisitResult condition_result = Visit(expr->condition);
+      if (!condition_result.type()->IsNever()) {
+        condition_result = condition_scope.Yield(GenerateImplicitConvert(
+            TypeOracle::GetBoolType(), condition_result));
+        assembler().Branch(true_label->block(), false_label->block());
+      }
+    }
   }
-  source_out() << ";\n";
 
-  const Type* common_type = GetCommonType(left.type(), right.type());
-  std::string result_var = NewTempVariable();
-  Variable* result =
-      GenerateVariableDeclaration(expr, result_var, false, common_type);
+  VisitResult left;
+  VisitResult right;
 
   {
-    ScopedIndent indent(this);
-    Declarations::NodeScopeActivator scope(declarations(), expr->condition);
-
-    Label* true_label = declarations()->LookupLabel(kTrueLabelName);
-    GenerateLabelDefinition(true_label);
-    Label* false_label = declarations()->LookupLabel(kFalseLabelName);
-    GenerateLabelDefinition(false_label);
-    Label* done_label = declarations()->DeclarePrivateLabel(kDoneLabelName);
-    GenerateLabelDefinition(done_label, expr);
+    // The code for both paths of the conditional need to be generated first
+    // before evaluating the conditional expression because the common type of
+    // the result of both the true and false of the condition needs to be known
+    // to convert both branches to a common type.
+    assembler().Bind(true_label->block());
+    StackScope left_scope(this);
+    left = Visit(expr->if_true);
+    assembler().Goto(true_conversion_block);
 
-    VisitResult condition_result = Visit(expr->condition);
-    if (!condition_result.type()->IsNever()) {
-      condition_result =
-          GenerateImplicitConvert(TypeOracle::GetBoolType(), condition_result);
-      GenerateBranch(condition_result, true_label, false_label);
+    const Type* common_type;
+    {
+      assembler().Bind(false_label->block());
+      StackScope right_scope(this);
+      right = Visit(expr->if_false);
+      common_type = GetCommonType(left.type(), right.type());
+      right = right_scope.Yield(GenerateImplicitConvert(common_type, right));
+      assembler().Goto(done_block);
     }
-    GenerateLabelBind(true_label);
-    GenerateIndent();
-    VisitResult left_result = {right.type(), f1 + "()"};
-    GenerateAssignToVariable(result, left_result);
-    GenerateLabelGoto(done_label);
 
-    GenerateLabelBind(false_label);
-    GenerateIndent();
-    VisitResult right_result = {right.type(), f2 + "()"};
-    GenerateAssignToVariable(result, right_result);
-    GenerateLabelGoto(done_label);
-
-    GenerateLabelBind(done_label);
+    assembler().Bind(true_conversion_block);
+    left = left_scope.Yield(GenerateImplicitConvert(common_type, left));
+    assembler().Goto(done_block);
   }
-  return VisitResult(common_type, result);
+
+  assembler().Bind(done_block);
+  CHECK_EQ(left, right);
+  return left;
 }
 
 VisitResult ImplementationVisitor::Visit(LogicalOrExpression* expr) {
@@ -404,32 +534,44 @@ VisitResult ImplementationVisitor::Visit(LogicalOrExpression* expr) {
   {
     Declarations::NodeScopeActivator scope(declarations(), expr->left);
     Label* false_label = declarations()->LookupLabel(kFalseLabelName);
-    GenerateLabelDefinition(false_label);
+    CreateBlockForLabel(false_label, assembler().CurrentStack());
     left_result = Visit(expr->left);
     if (left_result.type()->IsBool()) {
       Label* true_label = declarations()->LookupLabel(kTrueLabelName);
-      GenerateIndent();
-      source_out() << "GotoIf(" << RValueFlattenStructs(left_result) << ", "
-                   << true_label->generated() << ");\n";
+      assembler().Branch(true_label->block(), false_label->block());
+      assembler().Bind(false_label->block());
+    } else if (left_result.type()->IsNever()) {
+      assembler().Bind(false_label->block());
     } else if (!left_result.type()->IsConstexprBool()) {
-      GenerateLabelBind(false_label);
+      ReportError(
+          "expected type bool, constexpr bool, or never on left-hand side of "
+          "operator ||");
     }
   }
-  VisitResult right_result = Visit(expr->right);
-  if (right_result.type() != left_result.type()) {
-    std::stringstream stream;
-    stream << "types of left and right expression of logical OR don't match (\""
-           << *left_result.type() << "\" vs. \"" << *right_result.type()
-           << "\")";
-    ReportError(stream.str());
-  }
+
   if (left_result.type()->IsConstexprBool()) {
-    return VisitResult(left_result.type(),
-                       std::string("(") + RValueFlattenStructs(left_result) +
-                           " || " + RValueFlattenStructs(right_result) + ")");
-  } else {
-    return right_result;
+    VisitResult right_result = Visit(expr->right);
+    if (!right_result.type()->IsConstexprBool()) {
+      ReportError(
+          "expected type constexpr bool on right-hand side of operator "
+          "||");
+    }
+    return VisitResult(TypeOracle::GetConstexprBoolType(),
+                       std::string("(") + left_result.constexpr_value() +
+                           " || " + right_result.constexpr_value() + ")");
   }
+
+  VisitResult right_result = Visit(expr->right);
+  if (right_result.type()->IsBool()) {
+    Label* true_label = declarations()->LookupLabel(kTrueLabelName);
+    Label* false_label = declarations()->LookupLabel(kFalseLabelName);
+    assembler().Branch(true_label->block(), false_label->block());
+    return VisitResult::NeverResult();
+  } else if (!right_result.type()->IsNever()) {
+    ReportError(
+        "expected type bool or never on right-hand side of operator ||");
+  }
+  return right_result;
 }
 
 VisitResult ImplementationVisitor::Visit(LogicalAndExpression* expr) {
@@ -437,67 +579,75 @@ VisitResult ImplementationVisitor::Visit(LogicalAndExpression* expr) {
   {
     Declarations::NodeScopeActivator scope(declarations(), expr->left);
     Label* true_label = declarations()->LookupLabel(kTrueLabelName);
-    GenerateLabelDefinition(true_label);
+    CreateBlockForLabel(true_label, assembler().CurrentStack());
     left_result = Visit(expr->left);
     if (left_result.type()->IsBool()) {
       Label* false_label = declarations()->LookupLabel(kFalseLabelName);
-      GenerateIndent();
-      source_out() << "GotoIfNot(" << RValueFlattenStructs(left_result) << ", "
-                   << false_label->generated() << ");\n";
+      assembler().Branch(true_label->block(), false_label->block());
+      assembler().Bind(true_label->block());
+    } else if (left_result.type()->IsNever()) {
+      assembler().Bind(true_label->block());
     } else if (!left_result.type()->IsConstexprBool()) {
-      GenerateLabelBind(true_label);
+      ReportError(
+          "expected type bool, constexpr bool, or never on left-hand side of "
+          "operator &&");
     }
   }
-  VisitResult right_result = Visit(expr->right);
-  if (right_result.type() != left_result.type()) {
-    std::stringstream stream;
-    stream
-        << "types of left and right expression of logical AND don't match (\""
-        << *left_result.type() << "\" vs. \"" << *right_result.type() << "\")";
-    ReportError(stream.str());
-  }
+
   if (left_result.type()->IsConstexprBool()) {
-    return VisitResult(left_result.type(),
-                       std::string("(") + RValueFlattenStructs(left_result) +
-                           " && " + RValueFlattenStructs(right_result) + ")");
-  } else {
-    return right_result;
+    VisitResult right_result = Visit(expr->right);
+    if (!right_result.type()->IsConstexprBool()) {
+      ReportError(
+          "expected type constexpr bool on right-hand side of operator "
+          "&&");
+    }
+    return VisitResult(TypeOracle::GetConstexprBoolType(),
+                       std::string("(") + left_result.constexpr_value() +
+                           " && " + right_result.constexpr_value() + ")");
+  }
+
+  VisitResult right_result = Visit(expr->right);
+  if (right_result.type()->IsBool()) {
+    Label* true_label = declarations()->LookupLabel(kTrueLabelName);
+    Label* false_label = declarations()->LookupLabel(kFalseLabelName);
+    assembler().Branch(true_label->block(), false_label->block());
+    return VisitResult::NeverResult();
+  } else if (!right_result.type()->IsNever()) {
+    ReportError(
+        "expected type bool or never on right-hand side of operator &&");
   }
+  return right_result;
 }
 
 VisitResult ImplementationVisitor::Visit(IncrementDecrementExpression* expr) {
-  VisitResult value_copy;
-  auto location_ref = GetLocationReference(expr->location);
-  VisitResult current_value =
-      GenerateFetchFromLocation(expr->location, location_ref);
-  if (expr->postfix) {
-    value_copy = GenerateCopy(current_value);
-  }
+  StackScope scope(this);
+  LocationReference location_ref = GetLocationReference(expr->location);
+  VisitResult current_value = GenerateFetchFromLocation(location_ref);
   VisitResult one = {TypeOracle::GetConstInt31Type(), "1"};
   Arguments args;
   args.parameters = {current_value, one};
   VisitResult assignment_value = GenerateCall(
       expr->op == IncrementDecrementOperator::kIncrement ? "+" : "-", args);
-  GenerateAssignToLocation(expr->location, location_ref, assignment_value);
-  return expr->postfix ? value_copy : assignment_value;
+  GenerateAssignToLocation(location_ref, assignment_value);
+  return scope.Yield(expr->postfix ? current_value : assignment_value);
 }
 
 VisitResult ImplementationVisitor::Visit(AssignmentExpression* expr) {
+  StackScope scope(this);
   LocationReference location_ref = GetLocationReference(expr->location);
   VisitResult assignment_value;
   if (expr->op) {
-    VisitResult location_value =
-        GenerateFetchFromLocation(expr->location, location_ref);
+    VisitResult location_value = GenerateFetchFromLocation(location_ref);
     assignment_value = Visit(expr->value);
     Arguments args;
     args.parameters = {location_value, assignment_value};
     assignment_value = GenerateCall(*expr->op, args);
-    GenerateAssignToLocation(expr->location, location_ref, assignment_value);
+    GenerateAssignToLocation(location_ref, assignment_value);
   } else {
     assignment_value = Visit(expr->value);
-    GenerateAssignToLocation(expr->location, location_ref, assignment_value);
+    GenerateAssignToLocation(location_ref, assignment_value);
   }
-  return assignment_value;
+  return scope.Yield(assignment_value);
 }
 
 VisitResult ImplementationVisitor::Visit(NumberLiteralExpression* expr) {
@@ -513,9 +663,7 @@ VisitResult ImplementationVisitor::Visit(NumberLiteralExpression* expr) {
       result_type = declarations()->LookupType(CONST_INT32_TYPE_STRING);
     }
   }
-  std::string temp = GenerateNewTempVariable(result_type);
-  source_out() << expr->number << ";\n";
-  return VisitResult{result_type, temp};
+  return VisitResult{result_type, expr->number};
 }
 
 VisitResult ImplementationVisitor::Visit(AssumeTypeImpossibleExpression* expr) {
@@ -525,16 +673,16 @@ VisitResult ImplementationVisitor::Visit(AssumeTypeImpossibleExpression* expr) {
   if (result_type->IsNever()) {
     ReportError("unreachable code");
   }
-  return VisitResult{result_type, "UncheckedCast<" +
-                                      result_type->GetGeneratedTNodeTypeName() +
-                                      ">(" + result.RValue() + ")"};
+  CHECK_EQ(LowerType(result_type), TypeVector{result_type});
+  assembler().Emit(UnsafeCastInstruction{result_type});
+  result.SetType(result_type);
+  return result;
 }
 
 VisitResult ImplementationVisitor::Visit(StringLiteralExpression* expr) {
-  std::string temp = GenerateNewTempVariable(TypeOracle::GetConstStringType());
-  source_out() << "\"" << expr->literal.substr(1, expr->literal.size() - 2)
-               << "\";\n";
-  return VisitResult{TypeOracle::GetConstStringType(), temp};
+  return VisitResult{
+      TypeOracle::GetConstStringType(),
+      "\"" + expr->literal.substr(1, expr->literal.size() - 2) + "\""};
 }
 
 VisitResult ImplementationVisitor::GetBuiltinCode(Builtin* builtin) {
@@ -546,13 +694,12 @@ VisitResult ImplementationVisitor::GetBuiltinCode(Builtin* builtin) {
   const Type* type = TypeOracle::GetFunctionPointerType(
       builtin->signature().parameter_types.types,
       builtin->signature().return_type);
-  std::string code =
-      "HeapConstant(Builtins::CallableFor(isolate(), Builtins::k" +
-      builtin->name() + ").code())";
-  return VisitResult(type, code);
+  assembler().Emit(PushCodePointerInstruction{builtin->name(), type});
+  return VisitResult(type, assembler().TopRange(1));
 }
 
 VisitResult ImplementationVisitor::Visit(IdentifierExpression* expr) {
+  StackScope scope(this);
   std::string name = expr->name;
   if (expr->generic_arguments.size() != 0) {
     GenericList* generic_list = declarations()->LookupGeneric(expr->name);
@@ -567,10 +714,10 @@ VisitResult ImplementationVisitor::Visit(IdentifierExpression* expr) {
   }
 
   if (Builtin* builtin = Builtin::DynamicCast(declarations()->Lookup(name))) {
-    return GetBuiltinCode(builtin);
+    return scope.Yield(GetBuiltinCode(builtin));
   }
 
-  return GenerateFetchFromLocation(expr, GetLocationReference(expr));
+  return scope.Yield(GenerateFetchFromLocation(GetLocationReference(expr)));
 }
 
 const Type* ImplementationVisitor::Visit(GotoStatement* stmt) {
@@ -585,20 +732,21 @@ const Type* ImplementationVisitor::Visit(GotoStatement* stmt) {
   }
 
   size_t i = 0;
+  StackRange arguments = assembler().TopRange(0);
   for (Expression* e : stmt->arguments) {
+    StackScope scope(this);
     VisitResult result = Visit(e);
     Variable* var = label->GetParameter(i++);
-    GenerateAssignToVariable(var, result);
+    result = GenerateImplicitConvert(var->type(), result);
+    arguments.Extend(scope.Yield(result).stack_range());
   }
 
-  GenerateLabelGoto(label);
+  GenerateLabelGoto(label, arguments);
   label->MarkUsed();
   return TypeOracle::GetNeverType();
 }
 
 const Type* ImplementationVisitor::Visit(IfStatement* stmt) {
-  ScopedIndent indent(this);
-
   bool has_else = stmt->if_false.has_value();
 
   if (stmt->is_constexpr) {
@@ -611,23 +759,33 @@ const Type* ImplementationVisitor::Visit(IfStatement* stmt) {
       ReportError(stream.str());
     }
 
+    Block* true_block = assembler().NewBlock();
+    Block* false_block = assembler().NewBlock();
+    Block* done_block = assembler().NewBlock();
+
+    assembler().Emit(ConstexprBranchInstruction{
+        expression_result.constexpr_value(), true_block, false_block});
+
+    assembler().Bind(true_block);
     const Type* left_result;
-    const Type* right_result = TypeOracle::GetVoidType();
     {
-      GenerateIndent();
-      source_out() << "if ((" << RValueFlattenStructs(expression_result)
-                   << ")) ";
-      ScopedIndent indent(this, false);
-      source_out() << "\n";
+      StackScope stack_scope(this);
       left_result = Visit(stmt->if_true);
     }
+    if (left_result == TypeOracle::GetVoidType()) {
+      assembler().Goto(done_block);
+    }
 
+    assembler().Bind(false_block);
+    const Type* right_result = TypeOracle::GetVoidType();
     if (has_else) {
-      source_out() << " else ";
-      ScopedIndent indent(this, false);
-      source_out() << "\n";
+      StackScope stack_scope(this);
       right_result = Visit(*stmt->if_false);
     }
+    if (right_result == TypeOracle::GetVoidType()) {
+      assembler().Goto(done_block);
+    }
+
     if (left_result->IsNever() != right_result->IsNever()) {
       std::stringstream stream;
       stream << "either both or neither branches in a constexpr if statement "
@@ -636,8 +794,9 @@ const Type* ImplementationVisitor::Visit(IfStatement* stmt) {
       ReportError(stream.str());
     }
 
-    source_out() << "\n";
-
+    if (left_result != TypeOracle::GetNeverType()) {
+      assembler().Bind(done_block);
+    }
     return left_result;
   } else {
     Label* true_label = nullptr;
@@ -645,56 +804,54 @@ const Type* ImplementationVisitor::Visit(IfStatement* stmt) {
     {
       Declarations::NodeScopeActivator scope(declarations(), &*stmt->condition);
       true_label = declarations()->LookupLabel(kTrueLabelName);
-      GenerateLabelDefinition(true_label);
+      CreateBlockForLabel(true_label, assembler().CurrentStack());
       false_label = declarations()->LookupLabel(kFalseLabelName);
-      GenerateLabelDefinition(false_label, !has_else ? stmt : nullptr);
+      CreateBlockForLabel(false_label, assembler().CurrentStack());
     }
 
-    Label* done_label = nullptr;
+    Block* done_block;
     bool live = false;
     if (has_else) {
-      done_label = declarations()->DeclarePrivateLabel("if_done_label");
-      GenerateLabelDefinition(done_label, stmt);
+      done_block = assembler().NewBlock();
     } else {
-      done_label = false_label;
+      done_block = false_label->block();
       live = true;
     }
     std::vector<Statement*> blocks = {stmt->if_true};
     std::vector<Label*> labels = {true_label, false_label};
     if (has_else) blocks.push_back(*stmt->if_false);
-    if (GenerateExpressionBranch(stmt->condition, labels, blocks, done_label)) {
+    if (GenerateExpressionBranch(stmt->condition, labels, blocks, done_block)) {
       live = true;
     }
     if (live) {
-      GenerateLabelBind(done_label);
+      assembler().Bind(done_block);
     }
     return live ? TypeOracle::GetVoidType() : TypeOracle::GetNeverType();
   }
 }
 
 const Type* ImplementationVisitor::Visit(WhileStatement* stmt) {
-  ScopedIndent indent(this);
-
   Label* body_label = nullptr;
   Label* exit_label = nullptr;
   {
     Declarations::NodeScopeActivator scope(declarations(), stmt->condition);
     body_label = declarations()->LookupLabel(kTrueLabelName);
-    GenerateLabelDefinition(body_label);
+    CreateBlockForLabel(body_label, assembler().CurrentStack());
     exit_label = declarations()->LookupLabel(kFalseLabelName);
-    GenerateLabelDefinition(exit_label);
+    CreateBlockForLabel(exit_label, assembler().CurrentStack());
   }
 
-  Label* header_label = declarations()->DeclarePrivateLabel("header");
-  GenerateLabelDefinition(header_label, stmt);
-  GenerateLabelGoto(header_label);
-  GenerateLabelBind(header_label);
+  Block* header_block = assembler().NewBlock();
+  assembler().Goto(header_block);
+
+  assembler().Bind(header_block);
 
   Declarations::NodeScopeActivator scope(declarations(), stmt->body);
-  BreakContinueActivator activator(global_context_, exit_label, header_label);
+  BreakContinueActivator activator(global_context_, exit_label->block(),
+                                   header_block);
 
   GenerateExpressionBranch(stmt->condition, {body_label, exit_label},
-                           {stmt->body}, header_label);
+                           {stmt->body}, header_block);
 
   GenerateLabelBind(exit_label);
   return TypeOracle::GetVoidType();
@@ -702,7 +859,6 @@ const Type* ImplementationVisitor::Visit(WhileStatement* stmt) {
 
 const Type* ImplementationVisitor::Visit(BlockStatement* block) {
   Declarations::NodeScopeActivator scope(declarations(), block);
-  ScopedIndent indent(this);
   const Type* type = TypeOracle::GetVoidType();
   for (Statement* s : block->statements) {
     if (type->IsNever()) {
@@ -717,17 +873,14 @@ const Type* ImplementationVisitor::Visit(BlockStatement* block) {
 
 const Type* ImplementationVisitor::Visit(DebugStatement* stmt) {
 #if defined(DEBUG)
-  GenerateIndent();
-  source_out() << "Print(\""
-               << "halting because of '" << stmt->reason << "' at "
-               << PositionAsString(stmt->pos) << "\");\n";
+  assembler().Emit(PrintConstantStringInstruction{"halting because of '" +
+                                                  stmt->reason + "' at " +
+                                                  PositionAsString(stmt->pos)});
 #endif
-  GenerateIndent();
+  assembler().Emit(DebugBreakInstruction{stmt->never_continues});
   if (stmt->never_continues) {
-    source_out() << "Unreachable();\n";
     return TypeOracle::GetNeverType();
   } else {
-    source_out() << "DebugBreak();\n";
     return TypeOracle::GetVoidType();
   }
 }
@@ -769,9 +922,9 @@ const Type* ImplementationVisitor::Visit(AssertStatement* stmt) {
     Label* false_label = nullptr;
     Declarations::NodeScopeActivator scope(declarations(), stmt->expression);
     true_label = declarations()->LookupLabel(kTrueLabelName);
-    GenerateLabelDefinition(true_label);
+    CreateBlockForLabel(true_label, assembler().CurrentStack());
     false_label = declarations()->LookupLabel(kFalseLabelName);
-    GenerateLabelDefinition(false_label);
+    CreateBlockForLabel(false_label, assembler().CurrentStack());
 
     VisitResult expression_result = Visit(stmt->expression);
     if (expression_result.type() == TypeOracle::GetBoolType()) {
@@ -786,12 +939,10 @@ const Type* ImplementationVisitor::Visit(AssertStatement* stmt) {
     }
 
     GenerateLabelBind(false_label);
-    GenerateIndent();
-    source_out() << "Print(\""
-                 << "assert '" << FormatAssertSource(stmt->source)
-                 << "' failed at " << PositionAsString(stmt->pos) << "\");\n";
-    GenerateIndent();
-    source_out() << "Unreachable();\n";
+    assembler().Emit(PrintConstantStringInstruction{
+        "assert '" + FormatAssertSource(stmt->source) + "' failed at " +
+        PositionAsString(stmt->pos)});
+    assembler().Emit(DebugBreakInstruction{true});
 
     GenerateLabelBind(true_label);
   }
@@ -824,20 +975,16 @@ const Type* ImplementationVisitor::Visit(ReturnStatement* stmt) {
     VisitResult return_result = GenerateImplicitConvert(
         current_callable->signature().return_type, expression_result);
     if (current_callable->IsMacro()) {
-      Variable* var =
-          Variable::cast(declarations()->LookupValue(kReturnValueVariable));
-      GenerateAssignToVariable(var, return_result);
-      GenerateLabelGoto(end);
-    } else if (current_callable->IsBuiltin()) {
-      if (Builtin::cast(current_callable)->IsVarArgsJavaScript()) {
-        GenerateIndent();
-        source_out() << "arguments->PopAndReturn("
-                     << RValueFlattenStructs(return_result) << ");\n";
+      if (return_result.IsOnStack()) {
+        StackRange return_value_range =
+            GenerateLabelGoto(end, return_result.stack_range());
+        SetReturnValue(VisitResult(return_result.type(), return_value_range));
       } else {
-        GenerateIndent();
-        source_out() << "Return(" << RValueFlattenStructs(return_result)
-                     << ");\n";
+        GenerateLabelGoto(end);
+        SetReturnValue(return_result);
       }
+    } else if (current_callable->IsBuiltin()) {
+      assembler().Emit(ReturnInstruction{});
     } else {
       UNREACHABLE();
     }
@@ -856,6 +1003,7 @@ const Type* ImplementationVisitor::Visit(ReturnStatement* stmt) {
 
 const Type* ImplementationVisitor::Visit(ForOfLoopStatement* stmt) {
   Declarations::NodeScopeActivator scope(declarations(), stmt);
+  StackScope stack_scope(this);
 
   VisitResult expression_result = Visit(stmt->iterable);
   VisitResult begin = stmt->begin
@@ -866,194 +1014,207 @@ const Type* ImplementationVisitor::Visit(ForOfLoopStatement* stmt) {
                         ? Visit(*stmt->end)
                         : GenerateCall(".length", {{expression_result}, {}});
 
-  Label* body_label = declarations()->DeclarePrivateLabel("body");
-  GenerateLabelDefinition(body_label);
-  Label* increment_label = declarations()->DeclarePrivateLabel("increment");
-  GenerateLabelDefinition(increment_label);
-  Label* exit_label = declarations()->DeclarePrivateLabel("exit");
-  GenerateLabelDefinition(exit_label);
-
   const Type* common_type = GetCommonType(begin.type(), end.type());
-  Variable* index_var = GenerateVariableDeclaration(
-      stmt, std::string(kForIndexValueVariable) + "_" + NewTempVariable(),
-      false, common_type, begin);
+  VisitResult index = GenerateImplicitConvert(common_type, begin);
 
-  VisitResult index_for_read = {index_var->type(), index_var};
+  Block* body_block = assembler().NewBlock();
+  Block* increment_block = assembler().NewBlock(assembler().CurrentStack());
+  Block* exit_block = assembler().NewBlock(assembler().CurrentStack());
 
-  Label* header_label = declarations()->DeclarePrivateLabel("header");
-  GenerateLabelDefinition(header_label, stmt);
+  Block* header_block = assembler().NewBlock();
 
-  GenerateLabelGoto(header_label);
+  assembler().Goto(header_block);
 
-  GenerateLabelBind(header_label);
+  assembler().Bind(header_block);
 
-  BreakContinueActivator activator(global_context_, exit_label,
-                                   increment_label);
+  BreakContinueActivator activator(global_context_, exit_block,
+                                   increment_block);
 
-  VisitResult result = GenerateCall("<", {{index_for_read, end}, {}});
-  GenerateBranch(result, body_label, exit_label);
+  {
+    StackScope comparison_scope(this);
+    VisitResult result = GenerateCall("<", {{index, end}, {}});
+    if (result.type() != TypeOracle::GetBoolType()) {
+      ReportError("operator < with arguments(", *index.type(), ", ",
+                  *end.type(),
+                  ")  used in for-of loop has to return type bool, but "
+                  "returned type ",
+                  *result.type());
+    }
+    comparison_scope.Yield(result);
+  }
+  assembler().Branch(body_block, exit_block);
 
-  GenerateLabelBind(body_label);
-  VisitResult element_result =
-      GenerateCall("[]", {{expression_result, index_for_read}, {}});
-  base::Optional<const Type*> declared_type;
-  if (stmt->var_declaration->type)
-    declared_type = declarations()->GetType(*stmt->var_declaration->type);
-  GenerateVariableDeclaration(
-      stmt->var_declaration, stmt->var_declaration->name,
-      stmt->var_declaration->const_qualified, declared_type, element_result);
-  Visit(stmt->body);
-  GenerateLabelGoto(increment_label);
+  assembler().Bind(body_block);
+  {
+    StackScope body_scope(this);
 
-  GenerateLabelBind(increment_label);
-  Arguments increment_args;
-  increment_args.parameters = {index_for_read,
-                               {TypeOracle::GetConstInt31Type(), "1"}};
-  VisitResult increment_result = GenerateCall("+", increment_args);
+    VisitResult element_result;
+    {
+      StackScope element_scope(this);
+      VisitResult result = GenerateCall("[]", {{expression_result, index}, {}});
+      if (stmt->var_declaration->type) {
+        const Type* declared_type =
+            declarations()->GetType(*stmt->var_declaration->type);
+        result = GenerateImplicitConvert(declared_type, result);
+      }
+      element_result = element_scope.Yield(result);
+    }
+    Variable* element_var = Variable::cast(
+        declarations()->LookupValue(stmt->var_declaration->name));
+    element_var->set_value(element_result);
+    Visit(stmt->body);
+  }
+  assembler().Goto(increment_block);
+
+  assembler().Bind(increment_block);
+  {
+    Arguments increment_args;
+    increment_args.parameters = {index, {TypeOracle::GetConstInt31Type(), "1"}};
+    VisitResult increment_result = GenerateCall("+", increment_args);
 
-  GenerateAssignToVariable(index_var, increment_result);
+    GenerateAssignToLocation(LocationReference::VariableAccess(index),
+                             increment_result);
+  }
 
-  GenerateLabelGoto(header_label);
+  assembler().Goto(header_block);
 
-  GenerateLabelBind(exit_label);
+  assembler().Bind(exit_block);
   return TypeOracle::GetVoidType();
 }
 
-const Type* ImplementationVisitor::Visit(TryLabelStatement* stmt) {
-  ScopedIndent indent(this);
-  Label* try_done = declarations()->DeclarePrivateLabel("try_done");
-  GenerateLabelDefinition(try_done);
-  const Type* try_result = TypeOracle::GetNeverType();
-  std::vector<Label*> labels;
+VisitResult ImplementationVisitor::Visit(TryLabelExpression* expr) {
+  Block* done_block = assembler().NewBlock();
+  VisitResult try_result;
+  Label* label = nullptr;
 
   // Output labels for the goto handlers and for the merge after the try.
   {
     // Activate a new scope to see handler labels
-    Declarations::NodeScopeActivator scope(declarations(), stmt);
-    for (LabelBlock* block : stmt->label_blocks) {
-      CurrentSourcePosition::Scope scope(block->pos);
-      Label* label = declarations()->LookupLabel(block->label);
-      labels.push_back(label);
-      GenerateLabelDefinition(label);
-    }
-
-    size_t i = 0;
-    for (auto label : labels) {
-      Declarations::NodeScopeActivator scope(declarations(),
-                                             stmt->label_blocks[i]->body);
-      for (auto& v : label->GetParameters()) {
-        GenerateVariableDeclaration(stmt, v->name(), false, v->type());
+    Declarations::NodeScopeActivator scope(declarations(), expr);
+    {
+      LabelBlock* block = expr->label_block;
+      CurrentSourcePosition::Scope source_position(block->pos);
+      label = declarations()->LookupLabel(block->label);
+
+      Declarations::NodeScopeActivator scope(declarations(), block->body);
+      Stack<const Type*> label_input_stack = assembler().CurrentStack();
+      for (Variable* v : label->GetParameters()) {
+        StackRange range = label_input_stack.PushMany(LowerType(v->type()));
+        v->set_value(VisitResult(v->type(), range));
         v->Define();
       }
-      ++i;
+      CreateBlockForLabel(label, label_input_stack);
     }
 
-    Label* try_begin_label = declarations()->DeclarePrivateLabel("try_begin");
-    GenerateLabelDefinition(try_begin_label);
-    GenerateLabelGoto(try_begin_label);
-
     // Visit try
-    if (GenerateLabeledStatementBlocks({stmt->try_block},
-                                       std::vector<Label*>({try_begin_label}),
-                                       try_done)) {
-      try_result = TypeOracle::GetVoidType();
+    {
+      StackScope stack_scope(this);
+      try_result = Visit(expr->try_expression);
+      if (try_result.type() != TypeOracle::GetNeverType()) {
+        try_result = stack_scope.Yield(try_result);
+        assembler().Goto(done_block);
+      }
     }
   }
 
-  // Make sure that each label clause is actually used. It's not just a friendly
-  // thing to do, it will cause problems downstream in the compiler if there are
-  // bound labels that are never jumped to.
-  auto label_iterator = stmt->label_blocks.begin();
-  for (auto label : labels) {
-    CurrentSourcePosition::Scope scope((*label_iterator)->pos);
-    if (!label->IsUsed()) {
-      std::stringstream s;
-      s << "label ";
-      s << (*label_iterator)->label;
-      s << " has a handler block but is never referred to in try block";
-      ReportError(s.str());
+  if (label->IsUsed()) {
+    // Visit and output the code for the label block. If the label block falls
+    // through, then the try must not return a value. Also, if the try doesn't
+    // fall through, but the label does, then overall the try-label block
+    // returns type void.
+    GenerateLabelBind(label);
+    const Type* label_result;
+    {
+      StackScope stack_scope(this);
+      label_result = Visit(expr->label_block->body);
+    }
+    if (!try_result.type()->IsVoidOrNever() && label_result->IsVoid()) {
+      ReportError(
+          "otherwise clauses cannot fall through in a non-void expression");
+    }
+    if (label_result != TypeOracle::GetNeverType()) {
+      assembler().Goto(done_block);
+    }
+    if (label_result->IsVoid() && try_result.type()->IsNever()) {
+      try_result =
+          VisitResult(TypeOracle::GetVoidType(), try_result.stack_range());
     }
-    label_iterator++;
-  }
-
-  // Visit and output the code for each catch block, one-by-one.
-  std::vector<Statement*> bodies;
-  for (LabelBlock* block : stmt->label_blocks) bodies.push_back(block->body);
-  if (GenerateLabeledStatementBlocks(bodies, labels, try_done)) {
-    try_result = TypeOracle::GetVoidType();
   }
 
-  if (!try_result->IsNever()) {
-    GenerateLabelBind(try_done);
+  if (!try_result.type()->IsNever()) {
+    assembler().Bind(done_block);
   }
   return try_result;
 }
 
+VisitResult ImplementationVisitor::Visit(StatementExpression* expr) {
+  return VisitResult{Visit(expr->statement), assembler().TopRange(0)};
+}
+
 const Type* ImplementationVisitor::Visit(BreakStatement* stmt) {
-  Label* break_label = global_context_.GetCurrentBreak();
-  if (break_label == nullptr) {
+  Block* break_block = global_context_.GetCurrentBreak();
+  if (break_block == nullptr) {
     ReportError("break used outside of loop");
   }
-  GenerateLabelGoto(break_label);
+  assembler().Goto(break_block);
   return TypeOracle::GetNeverType();
 }
 
 const Type* ImplementationVisitor::Visit(ContinueStatement* stmt) {
-  Label* continue_label = global_context_.GetCurrentContinue();
-  if (continue_label == nullptr) {
+  Block* continue_block = global_context_.GetCurrentContinue();
+  if (continue_block == nullptr) {
     ReportError("continue used outside of loop");
   }
-  GenerateLabelGoto(continue_label);
+  assembler().Goto(continue_block);
   return TypeOracle::GetNeverType();
 }
 
 const Type* ImplementationVisitor::Visit(ForLoopStatement* stmt) {
   Declarations::NodeScopeActivator scope(declarations(), stmt);
+  StackScope stack_scope(this);
 
   if (stmt->var_declaration) Visit(*stmt->var_declaration);
 
   Label* body_label = declarations()->LookupLabel(kTrueLabelName);
-  GenerateLabelDefinition(body_label);
+  CreateBlockForLabel(body_label, assembler().CurrentStack());
   Label* exit_label = declarations()->LookupLabel(kFalseLabelName);
-  GenerateLabelDefinition(exit_label);
+  CreateBlockForLabel(exit_label, assembler().CurrentStack());
 
-  Label* header_label = declarations()->DeclarePrivateLabel("header");
-  GenerateLabelDefinition(header_label, stmt);
-  GenerateLabelGoto(header_label);
-  GenerateLabelBind(header_label);
+  Block* header_block = assembler().NewBlock();
+  assembler().Goto(header_block);
+  assembler().Bind(header_block);
 
   // The continue label is where "continue" statements jump to. If no action
   // expression is provided, we jump directly to the header.
-  Label* continue_label = header_label;
+  Block* continue_block = header_block;
 
   // The action label is only needed when an action expression was provided.
-  Label* action_label = nullptr;
+  Block* action_block = nullptr;
   if (stmt->action) {
-    action_label = declarations()->DeclarePrivateLabel("action");
-    GenerateLabelDefinition(action_label);
+    action_block = assembler().NewBlock();
 
     // The action expression needs to be executed on a continue.
-    continue_label = action_label;
+    continue_block = action_block;
   }
 
-  BreakContinueActivator activator(global_context_, exit_label, continue_label);
+  BreakContinueActivator activator(global_context_, exit_label->block(),
+                                   continue_block);
 
   std::vector<Label*> labels = {body_label, exit_label};
   bool generate_action = true;
   if (stmt->test) {
     generate_action = GenerateExpressionBranch(*stmt->test, labels,
-                                               {stmt->body}, continue_label);
+                                               {stmt->body}, continue_block);
   } else {
     GenerateLabelGoto(body_label);
     generate_action =
-        GenerateLabeledStatementBlocks({stmt->body}, labels, continue_label);
+        GenerateLabeledStatementBlocks({stmt->body}, labels, continue_block);
   }
 
   if (generate_action && stmt->action) {
-    ScopedIndent indent(this);
-    GenerateLabelBind(action_label);
+    assembler().Bind(action_block);
     Visit(*stmt->action);
-    GenerateLabelGoto(header_label);
+    assembler().Goto(header_block);
   }
 
   GenerateLabelBind(exit_label);
@@ -1075,7 +1236,7 @@ void ImplementationVisitor::GenerateImplementation(const std::string& dir,
 
 std::string ImplementationVisitor::GetBaseAssemblerName(Module* module) {
   if (module == global_context_.GetDefaultModule()) {
-    return "CodeStubAssembler";
+    return "TorqueAssembler";
   } else {
     std::string assembler_name(CamelifyString(module->name()) +
                                "BuiltinsAssembler");
@@ -1089,12 +1250,6 @@ std::string ImplementationVisitor::GetDSLAssemblerName(Module* module) {
   return assembler_name;
 }
 
-void ImplementationVisitor::GenerateIndent() {
-  for (size_t i = 0; i <= indent_; ++i) {
-    source_out() << "  ";
-  }
-}
-
 void ImplementationVisitor::GenerateMacroFunctionDeclaration(
     std::ostream& o, const std::string& macro_prefix, Macro* macro) {
   GenerateFunctionDeclaration(o, macro_prefix, macro->name(),
@@ -1128,11 +1283,12 @@ void ImplementationVisitor::GenerateFunctionDeclaration(
     if (!first) {
       o << ", ";
     }
-    const Value* parameter = declarations()->LookupValue(name);
+    const Parameter* parameter =
+        Parameter::cast(declarations()->LookupValue(name));
     const Type* parameter_type = *type_iterator;
     const std::string& generated_type_name =
         parameter_type->GetGeneratedTypeName();
-    o << generated_type_name << " " << parameter->value();
+    o << generated_type_name << " " << parameter->external_name();
     type_iterator++;
     first = false;
   }
@@ -1142,13 +1298,15 @@ void ImplementationVisitor::GenerateFunctionDeclaration(
     if (!first) {
       o << ", ";
     }
-    o << "Label* " << label->generated();
+    o << "Label* " << label->external_label_name();
+    size_t i = 0;
     for (Variable* var : label->GetParameters()) {
       std::string generated_type_name("TVariable<");
       generated_type_name += var->type()->GetGeneratedTNodeTypeName();
       generated_type_name += ">*";
       o << ", ";
-      o << generated_type_name << " " << var->value();
+      o << generated_type_name << " " << ExternalLabelParameterName(label, i);
+      ++i;
     }
   }
 
@@ -1280,43 +1438,6 @@ Callable* ImplementationVisitor::LookupCall(
   return result;
 }
 
-void ImplementationVisitor::GetFlattenedStructsVars(
-    const Variable* base, std::set<const Variable*>* vars) {
-  const Type* type = base->type();
-  if (base->IsConst()) return;
-  if (type->IsStructType()) {
-    const StructType* struct_type = StructType::cast(type);
-    for (auto& field : struct_type->fields()) {
-      std::string field_var_name = base->name() + "." + field.name;
-      GetFlattenedStructsVars(
-          Variable::cast(declarations()->LookupValue(field_var_name)), vars);
-    }
-  } else {
-    vars->insert(base);
-  }
-}
-
-void ImplementationVisitor::GenerateChangedVarsFromControlSplit(AstNode* node) {
-  const std::set<const Variable*>& changed_vars =
-      global_context_.GetControlSplitChangedVariables(
-          node, declarations()->GetCurrentSpecializationTypeNamesVector());
-  std::set<const Variable*> flattened_vars;
-  for (auto v : changed_vars) {
-    GetFlattenedStructsVars(v, &flattened_vars);
-  }
-  std::vector<const Variable*> flattened_vars_sorted(flattened_vars.begin(),
-                                                     flattened_vars.end());
-  auto compare_variables = [](const Variable* a, const Variable* b) {
-    return a->value() < b->value();
-  };
-  std::sort(flattened_vars_sorted.begin(), flattened_vars_sorted.end(),
-            compare_variables);
-  source_out() << "{";
-  PrintCommaSeparatedList(source_out(), flattened_vars_sorted,
-                          [](const Variable* v) { return v->value(); });
-  source_out() << "}";
-}
-
 const Type* ImplementationVisitor::GetCommonType(const Type* left,
                                                  const Type* right) {
   const Type* common_type;
@@ -1332,11 +1453,11 @@ const Type* ImplementationVisitor::GetCommonType(const Type* left,
 }
 
 VisitResult ImplementationVisitor::GenerateCopy(const VisitResult& to_copy) {
-  std::string temp = GenerateNewTempVariable(to_copy.type());
-  source_out() << RValueFlattenStructs(to_copy) << ";\n";
-  GenerateIndent();
-  source_out() << "USE(" << temp << ");\n";
-  return VisitResult(to_copy.type(), temp);
+  if (to_copy.IsOnStack()) {
+    return VisitResult(to_copy.type(),
+                       assembler().Peek(to_copy.stack_range(), to_copy.type()));
+  }
+  return to_copy;
 }
 
 VisitResult ImplementationVisitor::Visit(StructExpression* decl) {
@@ -1354,23 +1475,19 @@ VisitResult ImplementationVisitor::Visit(StructExpression* decl) {
       << ")";
     ReportError(s.str());
   }
-  std::vector<VisitResult> expression_results;
-  for (auto& field : struct_type->fields()) {
-    VisitResult value = Visit(decl->expressions[expression_results.size()]);
+  StackRange stack_range = assembler().TopRange(0);
+  for (size_t i = 0; i < struct_type->fields().size(); ++i) {
+    const NameAndType& field = struct_type->fields()[i];
+    StackScope scope(this);
+    VisitResult value = Visit(decl->expressions[i]);
     value = GenerateImplicitConvert(field.type, value);
-    expression_results.push_back(value);
+    stack_range.Extend(scope.Yield(value).stack_range());
   }
-  std::string result_var_name = GenerateNewTempVariable(struct_type);
-  source_out() << "{";
-  PrintCommaSeparatedList(
-      source_out(), expression_results,
-      [&](const VisitResult& result) { return RValueFlattenStructs(result); });
-  source_out() << "};\n";
-  return VisitResult(struct_type, result_var_name);
+  return VisitResult(struct_type, stack_range);
 }
 
 LocationReference ImplementationVisitor::GetLocationReference(
-    LocationExpression* location) {
+    Expression* location) {
   switch (location->kind) {
     case AstNode::Kind::kIdentifierExpression:
       return GetLocationReference(static_cast<IdentifierExpression*>(location));
@@ -1381,231 +1498,92 @@ LocationReference ImplementationVisitor::GetLocationReference(
       return GetLocationReference(
           static_cast<ElementAccessExpression*>(location));
     default:
-      UNREACHABLE();
+      return LocationReference::Temporary(Visit(location), "expression");
   }
 }
 
 LocationReference ImplementationVisitor::GetLocationReference(
     FieldAccessExpression* expr) {
-  VisitResult result = Visit(expr->object);
-  if (result.type()->IsStructType()) {
-    if (result.declarable()) {
-      return LocationReference(
-          declarations()->LookupValue((*result.declarable())->name() + "." +
-                                      expr->field),
-          {}, {});
-    }
+  LocationReference reference = GetLocationReference(expr->object);
+  if (reference.IsVariableAccess() &&
+      reference.variable().type()->IsStructType()) {
+    return LocationReference::VariableAccess(
+        ProjectStructField(reference.variable(), expr->field));
   }
-  return LocationReference(nullptr, result, {});
-}
-
-std::string ImplementationVisitor::RValueFlattenStructs(VisitResult result) {
-  if (result.declarable()) {
-    const Value* value = *result.declarable();
-    const Type* type = value->type();
-    if (const StructType* struct_type = StructType::DynamicCast(type)) {
-      std::stringstream s;
-      s << struct_type->name() << "{";
-      PrintCommaSeparatedList(
-          s, struct_type->fields(), [&](const NameAndType& field) {
-            std::string field_declaration = value->name() + "." + field.name;
-            Variable* field_variable =
-                Variable::cast(declarations()->LookupValue(field_declaration));
-            return RValueFlattenStructs(
-                VisitResult(field_variable->type(), field_variable));
-          });
-      s << "}";
-      return s.str();
-    }
+  if (reference.IsTemporary() && reference.temporary().type()->IsStructType()) {
+    return LocationReference::Temporary(
+        ProjectStructField(reference.temporary(), expr->field),
+        reference.temporary_description());
   }
-  return result.RValue();
+  return LocationReference::FieldAccess(GenerateFetchFromLocation(reference),
+                                        expr->field);
 }
 
-VisitResult ImplementationVisitor::GenerateFetchFromLocation(
-    LocationExpression* location, LocationReference reference) {
-  switch (location->kind) {
-    case AstNode::Kind::kIdentifierExpression:
-      return GenerateFetchFromLocation(
-          static_cast<IdentifierExpression*>(location), reference);
-    case AstNode::Kind::kFieldAccessExpression:
-      return GenerateFetchFromLocation(
-          static_cast<FieldAccessExpression*>(location), reference);
-    case AstNode::Kind::kElementAccessExpression:
-      return GenerateFetchFromLocation(
-          static_cast<ElementAccessExpression*>(location), reference);
-    default:
-      UNREACHABLE();
-  }
-}
-
-VisitResult ImplementationVisitor::GenerateFetchFromLocation(
-    FieldAccessExpression* expr, LocationReference reference) {
-  if (reference.value != nullptr) {
-    return GenerateFetchFromLocation(reference);
-  }
-  const Type* type = reference.base.type();
-  if (const StructType* struct_type = StructType::DynamicCast(type)) {
-    return VisitResult(struct_type->GetFieldType(expr->field),
-                       reference.base.RValue() + "." + expr->field);
-  } else {
-    Arguments arguments;
-    arguments.parameters = {reference.base};
-    return GenerateCall(std::string(".") + expr->field, arguments);
-  }
+LocationReference ImplementationVisitor::GetLocationReference(
+    ElementAccessExpression* expr) {
+  VisitResult array = Visit(expr->array);
+  VisitResult index = Visit(expr->index);
+  return LocationReference::ArrayAccess(array, index);
 }
 
-void ImplementationVisitor::GenerateAssignToVariable(Variable* var,
-                                                     VisitResult value) {
-  if (var->type()->IsStructType()) {
-    if (value.type() != var->type()) {
-      std::stringstream s;
-      s << "incompatable assignment from type " << *value.type() << " to "
-        << *var->type();
-      ReportError(s.str());
-    }
-    const StructType* struct_type = StructType::cast(var->type());
-    for (auto& field : struct_type->fields()) {
-      std::string field_declaration = var->name() + "." + field.name;
-      Variable* field_variable =
-          Variable::cast(declarations()->LookupValue(field_declaration));
-      if (value.declarable() && (*value.declarable())->IsVariable()) {
-        Variable* source_field = Variable::cast(declarations()->LookupValue(
-            Variable::cast((*value.declarable()))->name() + "." + field.name));
-        GenerateAssignToVariable(
-            field_variable, VisitResult{source_field->type(), source_field});
-      } else {
-        GenerateAssignToVariable(
-            field_variable, VisitResult{field_variable->type(),
-                                        value.RValue() + "." + field.name});
-      }
+LocationReference ImplementationVisitor::GetLocationReference(
+    IdentifierExpression* expr) {
+  Value* value = declarations()->LookupValue(expr->name);
+  if (auto* constant = ModuleConstant::DynamicCast(value)) {
+    if (constant->type()->IsConstexpr()) {
+      return LocationReference::Temporary(
+          VisitResult(constant->type(), constant->constant_name() + "()"),
+          "module constant " + expr->name);
     }
-  } else {
-    VisitResult casted_value = GenerateImplicitConvert(var->type(), value);
-    GenerateIndent();
-    VisitResult var_value = {var->type(), var};
-    source_out() << var_value.LValue() << " = "
-                 << RValueFlattenStructs(casted_value) << ";\n";
+    assembler().Emit(ModuleConstantInstruction{constant});
+    StackRange stack_range =
+        assembler().TopRange(LoweredSlotCount(constant->type()));
+    return LocationReference::Temporary(
+        VisitResult(constant->type(), stack_range),
+        "module constant " + expr->name);
   }
-  var->Define();
-}
-
-void ImplementationVisitor::GenerateAssignToLocation(
-    LocationExpression* location, const LocationReference& reference,
-    VisitResult assignment_value) {
-  if (reference.value != nullptr) {
-    Value* value = reference.value;
-    Variable* var = Variable::cast(value);
-    if (var->IsConst()) {
-      std::stringstream s;
-      s << "\"" << var->name()
-        << "\" is declared const (maybe implicitly) and cannot be assigned to";
-      ReportError(s.str());
-    }
-    GenerateAssignToVariable(var, assignment_value);
-  } else if (auto access = FieldAccessExpression::DynamicCast(location)) {
-    GenerateCall(std::string(".") + access->field + "=",
-                 {{reference.base, assignment_value}, {}});
-  } else {
-    DCHECK_NOT_NULL(ElementAccessExpression::cast(location));
-    GenerateCall("[]=",
-                 {{reference.base, reference.index, assignment_value}, {}});
+  if (value->IsConst()) {
+    return LocationReference::Temporary(value->value(),
+                                        "constant value " + expr->name);
   }
+  DCHECK(value->IsVariable());
+  return LocationReference::VariableAccess(value->value());
 }
 
-void ImplementationVisitor::GenerateVariableDeclaration(const Variable* var) {
-  const Type* var_type = var->type();
-  if (var_type->IsStructType()) {
-    const StructType* struct_type = StructType::cast(var_type);
-    for (auto& field : struct_type->fields()) {
-      GenerateVariableDeclaration(Variable::cast(
-          declarations()->LookupValue(var->name() + "." + field.name)));
-    }
+VisitResult ImplementationVisitor::GenerateFetchFromLocation(
+    const LocationReference& reference) {
+  if (reference.IsTemporary()) {
+    return GenerateCopy(reference.temporary());
+  } else if (reference.IsVariableAccess()) {
+    return GenerateCopy(reference.variable());
   } else {
-    std::string value = var->value();
-    GenerateIndent();
-    if (var_type->IsConstexpr()) {
-      source_out() << var_type->GetGeneratedTypeName();
-      source_out() << " " << value << "_impl;\n";
-    } else if (var->IsConst()) {
-      source_out() << "TNode<" << var->type()->GetGeneratedTNodeTypeName();
-      source_out() << "> " << var->value() << "_impl;\n";
-    } else {
-      source_out() << "TVARIABLE(";
-      source_out() << var_type->GetGeneratedTNodeTypeName();
-      source_out() << ", " << value << "_impl);\n";
-    }
-    GenerateIndent();
-    source_out() << "auto " << value << " = &" << value << "_impl;\n";
-    GenerateIndent();
-    source_out() << "USE(" << value << ");\n";
-  }
-}
-
-Variable* ImplementationVisitor::GeneratePredeclaredVariableDeclaration(
-    const std::string& name,
-    const base::Optional<VisitResult>& initialization) {
-  Variable* variable = Variable::cast(declarations()->LookupValue(name));
-  GenerateVariableDeclaration(variable);
-  if (initialization) {
-    GenerateAssignToVariable(variable, *initialization);
+    DCHECK(reference.IsCallAccess());
+    return GenerateCall(reference.eval_function(),
+                        Arguments{reference.call_arguments(), {}});
   }
-  return variable;
 }
 
-Variable* ImplementationVisitor::GenerateVariableDeclaration(
-    AstNode* node, const std::string& name, bool is_const,
-    const base::Optional<const Type*>& type,
-    const base::Optional<VisitResult>& initialization) {
-  Variable* variable = nullptr;
-  if (declarations()->IsDeclaredInCurrentScope(name)) {
-    variable = Variable::cast(declarations()->LookupValue(name));
+void ImplementationVisitor::GenerateAssignToLocation(
+    const LocationReference& reference, const VisitResult& assignment_value) {
+  if (reference.IsCallAccess()) {
+    Arguments arguments{reference.call_arguments(), {}};
+    arguments.parameters.push_back(assignment_value);
+    GenerateCall(reference.assign_function(), arguments);
+  } else if (reference.IsVariableAccess()) {
+    VisitResult variable = reference.variable();
+    VisitResult converted_value =
+        GenerateImplicitConvert(variable.type(), assignment_value);
+    assembler().Poke(variable.stack_range(), converted_value.stack_range(),
+                     variable.type());
   } else {
-    variable = declarations()->DeclareVariable(
-        name, type ? *type : initialization->type(), is_const);
-    if (!is_const) {
-      // Because the variable is being defined during code generation, it must
-      // be assumed that it changes along all control split paths because it's
-      // no longer possible to run the control-flow anlaysis in the declaration
-      // pass over the variable.
-      global_context_.MarkVariableChanged(
-          node, declarations()->GetCurrentSpecializationTypeNamesVector(),
-          variable);
-    }
-  }
-  GenerateVariableDeclaration(variable);
-  if (initialization) {
-    GenerateAssignToVariable(variable, *initialization);
-  }
-  return variable;
-}
-
-void ImplementationVisitor::GenerateParameter(
-    const std::string& parameter_name) {
-  const Value* val = declarations()->LookupValue(parameter_name);
-  std::string var = val->value();
-  GenerateIndent();
-  source_out() << val->type()->GetGeneratedTypeName() << " " << var << " = ";
-
-  source_out() << "UncheckedCast<" << val->type()->GetGeneratedTNodeTypeName()
-               << ">(Parameter(Descriptor::k" << CamelifyString(parameter_name)
-               << "));\n";
-  GenerateIndent();
-  source_out() << "USE(" << var << ");\n";
-}
-
-void ImplementationVisitor::GenerateParameterList(const NameVector& list,
-                                                  size_t first) {
-  for (auto p : list) {
-    if (first == 0) {
-      GenerateParameter(p);
-    } else {
-      first--;
-    }
+    DCHECK(reference.IsTemporary());
+    ReportError("cannot assign to ", reference.temporary_description());
   }
 }
 
 VisitResult ImplementationVisitor::GeneratePointerCall(
     Expression* callee, const Arguments& arguments, bool is_tailcall) {
+  StackScope scope(this);
   TypeVector parameter_types(arguments.parameters.GetTypeVector());
   VisitResult callee_result = Visit(callee);
   if (!callee_result.type()->IsFunctionPointerType()) {
@@ -1637,28 +1615,13 @@ VisitResult ImplementationVisitor::GeneratePointerCall(
     ReportError(stream.str());
   }
 
-  std::vector<std::string> variables;
+  callee_result = GenerateCopy(callee_result);
+  StackRange arg_range = assembler().TopRange(0);
   for (size_t current = 0; current < arguments.parameters.size(); ++current) {
     const Type* to_type = type->parameter_types()[current];
-    VisitResult result =
-        GenerateImplicitConvert(to_type, arguments.parameters[current]);
-    variables.push_back(RValueFlattenStructs(result));
-  }
-
-  std::string result_variable_name;
-  bool no_result = type->return_type()->IsVoidOrNever() || is_tailcall;
-  if (no_result) {
-    GenerateIndent();
-  } else {
-    const Type* return_type = type->return_type();
-    result_variable_name = GenerateNewTempVariable(return_type);
-    if (return_type->IsStructType()) {
-      source_out() << "(";
-    } else {
-      source_out() << "UncheckedCast<";
-      source_out() << type->return_type()->GetGeneratedTNodeTypeName();
-      source_out() << ">(";
-    }
+    arg_range.Extend(
+        GenerateImplicitConvert(to_type, arguments.parameters[current])
+            .stack_range());
   }
 
   Builtin* example_builtin =
@@ -1669,27 +1632,14 @@ VisitResult ImplementationVisitor::GeneratePointerCall(
     ReportError(stream.str());
   }
 
-  if (is_tailcall) {
-    source_out() << "TailCallStub(";
-  } else {
-    source_out() << "CallStub(";
-  }
-  source_out() << "Builtins::CallableFor(isolate(), Builtins::k"
-               << example_builtin->name() << ").descriptor(), "
-               << RValueFlattenStructs(callee_result) << ", ";
+  assembler().Emit(CallBuiltinPointerInstruction{is_tailcall, example_builtin,
+                                                 arg_range.Size()});
 
-  size_t total_parameters = 0;
-  for (size_t i = 0; i < arguments.parameters.size(); ++i) {
-    if (total_parameters++ != 0) {
-      source_out() << ", ";
-    }
-    source_out() << variables[i];
-  }
-  if (!no_result) {
-    source_out() << ")";
+  if (is_tailcall) {
+    return VisitResult::NeverResult();
   }
-  source_out() << ");\n";
-  return VisitResult(type->return_type(), result_variable_name);
+  DCHECK_EQ(1, LoweredSlotCount(type->return_type()));
+  return scope.Yield(VisitResult(type->return_type(), assembler().TopRange(1)));
 }
 
 VisitResult ImplementationVisitor::GenerateCall(
@@ -1708,67 +1658,29 @@ VisitResult ImplementationVisitor::GenerateCall(
     arguments.labels.push_back(false_label);
   }
 
-  const Type* result_type = callable->signature().return_type;
+  const Type* return_type = callable->signature().return_type;
 
-  std::vector<std::string> variables;
+  std::vector<VisitResult> converted_arguments;
+  StackRange argument_range = assembler().TopRange(0);
+  std::vector<std::string> constexpr_arguments;
   for (size_t current = 0; current < arguments.parameters.size(); ++current) {
     const Type* to_type = (current >= callable->signature().types().size())
                               ? TypeOracle::GetObjectType()
                               : callable->signature().types()[current];
-    VisitResult result =
+    VisitResult converted =
         GenerateImplicitConvert(to_type, arguments.parameters[current]);
-    variables.push_back(RValueFlattenStructs(result));
-  }
-
-  std::string result_variable_name;
-  if (result_type->IsVoidOrNever() || is_tailcall) {
-    GenerateIndent();
-  } else {
-    result_variable_name = GenerateNewTempVariable(result_type);
-    if (!result_type->IsConstexpr()) {
-      if (result_type->IsStructType()) {
-        source_out() << "(";
-      } else {
-        source_out() << "UncheckedCast<";
-        source_out() << result_type->GetGeneratedTNodeTypeName();
-        source_out() << ">(";
-      }
-    }
-  }
-  if (callable->IsBuiltin()) {
-    if (is_tailcall) {
-      source_out() << "TailCallBuiltin(Builtins::k" << callable->name() << ", ";
+    converted_arguments.push_back(converted);
+    if (converted.IsOnStack()) {
+      argument_range.Extend(converted.stack_range());
     } else {
-      source_out() << "CallBuiltin(Builtins::k" << callable->name() << ", ";
+      constexpr_arguments.push_back(converted.constexpr_value());
     }
-  } else if (callable->IsMacro()) {
-    if (is_tailcall) {
-      std::stringstream stream;
-      stream << "can't tail call a macro";
-      ReportError(stream.str());
-    }
-    source_out() << callable->name() << "(";
-  } else if (callable->IsRuntimeFunction()) {
-    if (is_tailcall) {
-      source_out() << "TailCallRuntime(Runtime::k" << callable->name() << ", ";
-    } else {
-      source_out() << "CallRuntime(Runtime::k" << callable->name() << ", ";
-    }
-  } else {
-    UNREACHABLE();
   }
+
   if (global_context_.verbose()) {
     std::cout << "generating code for call to " << callable_name << "\n";
   }
 
-  size_t total_parameters = 0;
-  for (size_t i = 0; i < arguments.parameters.size(); ++i) {
-    if (total_parameters++ != 0) {
-      source_out() << ", ";
-    }
-    source_out() << variables[i];
-  }
-
   size_t label_count = callable->signature().labels.size();
   if (label_count != arguments.labels.size()) {
     std::stringstream s;
@@ -1777,49 +1689,114 @@ VisitResult ImplementationVisitor::GenerateCall(
       << std::to_string(arguments.labels.size()) << ")";
     ReportError(s.str());
   }
-  for (size_t i = 0; i < label_count; ++i) {
-    if (total_parameters++ != 0) {
-      source_out() << ", ";
+
+  if (auto* builtin = Builtin::DynamicCast(callable)) {
+    assembler().Emit(
+        CallBuiltinInstruction{is_tailcall, builtin, argument_range.Size()});
+    if (is_tailcall) {
+      return VisitResult::NeverResult();
+    } else {
+      size_t slot_count = LoweredSlotCount(return_type);
+      DCHECK_LE(slot_count, 1);
+      // TODO(tebbi): Actually, builtins have to return a value, so we should
+      // assert slot_count == 1 here.
+      return VisitResult(return_type, assembler().TopRange(slot_count));
     }
-    Label* label = arguments.labels[i];
-    size_t callee_label_parameters =
-        callable->signature().labels[i].types.size();
-    if (label->GetParameterCount() != callee_label_parameters) {
-      std::stringstream s;
-      s << "label " << label->name()
-        << " doesn't have the right number of parameters (found "
-        << std::to_string(label->GetParameterCount()) << " expected "
-        << std::to_string(callee_label_parameters) << ")";
-      ReportError(s.str());
+  } else if (auto* macro = Macro::DynamicCast(callable)) {
+    if (is_tailcall) {
+      ReportError("can't tail call a macro");
     }
-    source_out() << label->generated();
-    size_t j = 0;
-    for (auto t : callable->signature().labels[i].types) {
-      source_out() << ", ";
-      Variable* variable = label->GetParameter(j);
-      if (!(variable->type() == t)) {
-        std::stringstream s;
-        s << "mismatch of label parameters (expected " << *t << " got "
-          << *label->GetParameter(j)->type() << " for parameter "
-          << std::to_string(i + 1) << ")";
-        ReportError(s.str());
+    if (return_type->IsConstexpr()) {
+      DCHECK_EQ(0, arguments.labels.size());
+      std::stringstream result;
+      result << "(" << macro->name() << "(";
+      bool first = true;
+      for (VisitResult arg : arguments.parameters) {
+        DCHECK(!arg.IsOnStack());
+        if (!first) {
+          result << ", ";
+        }
+        first = false;
+        result << arg.constexpr_value();
+      }
+      result << "))";
+      return VisitResult(return_type, result.str());
+    } else if (arguments.labels.empty() &&
+               return_type != TypeOracle::GetNeverType()) {
+      assembler().Emit(CallCsaMacroInstruction{macro, constexpr_arguments});
+      size_t return_slot_count = LoweredSlotCount(return_type);
+      return VisitResult(return_type, assembler().TopRange(return_slot_count));
+    } else {
+      base::Optional<Block*> return_continuation;
+      if (return_type != TypeOracle::GetNeverType()) {
+        return_continuation = assembler().NewBlock();
       }
-      j++;
-      source_out() << variable->value();
-    }
-    label->MarkUsed();
-  }
 
-  if (global_context_.verbose()) {
-    std::cout << "finished generating code for call to " << callable_name
-              << "\n";
-  }
-  if (!result_type->IsVoidOrNever() && !is_tailcall &&
-      !result_type->IsConstexpr()) {
-    source_out() << ")";
+      std::vector<Block*> label_blocks;
+
+      for (size_t i = 0; i < label_count; ++i) {
+        label_blocks.push_back(assembler().NewBlock());
+      }
+
+      assembler().Emit(CallCsaMacroAndBranchInstruction{
+          macro, constexpr_arguments, return_continuation, label_blocks});
+
+      for (size_t i = 0; i < label_count; ++i) {
+        Label* label = arguments.labels[i];
+        size_t callee_label_parameters =
+            callable->signature().labels[i].types.size();
+        if (label->GetParameterCount() != callee_label_parameters) {
+          std::stringstream s;
+          s << "label " << label->name()
+            << " doesn't have the right number of parameters (found "
+            << std::to_string(label->GetParameterCount()) << " expected "
+            << std::to_string(callee_label_parameters) << ")";
+          ReportError(s.str());
+        }
+        assembler().Bind(label_blocks[i]);
+        assembler().Goto(
+            label->block(),
+            LowerParameterTypes(callable->signature().labels[i].types).size());
+
+        size_t j = 0;
+        for (auto t : callable->signature().labels[i].types) {
+          Variable* variable = label->GetParameter(j);
+          if (!(variable->type() == t)) {
+            std::stringstream s;
+            s << "mismatch of label parameters (expected " << *t << " got "
+              << *label->GetParameter(j)->type() << " for parameter "
+              << std::to_string(i + 1) << ")";
+            ReportError(s.str());
+          }
+          j++;
+        }
+        label->MarkUsed();
+      }
+
+      if (return_continuation) {
+        assembler().Bind(*return_continuation);
+        size_t return_slot_count = LoweredSlotCount(return_type);
+        return VisitResult(return_type,
+                           assembler().TopRange(return_slot_count));
+      } else {
+        return VisitResult::NeverResult();
+      }
+    }
+  } else if (auto* runtime_function = RuntimeFunction::DynamicCast(callable)) {
+    assembler().Emit(CallRuntimeInstruction{is_tailcall, runtime_function,
+                                            argument_range.Size()});
+    if (is_tailcall) {
+      return VisitResult::NeverResult();
+    } else {
+      size_t slot_count = LoweredSlotCount(return_type);
+      DCHECK_LE(slot_count, 1);
+      // TODO(tebbi): Actually, runtime functions have to return a value, so
+      // we should assert slot_count == 1 here.
+      return VisitResult(return_type, assembler().TopRange(slot_count));
+    }
+  } else {
+    UNREACHABLE();
   }
-  source_out() << ");\n";
-  return VisitResult(result_type, result_variable_name);
 }
 
 void ImplementationVisitor::Visit(StandardDeclaration* decl) {
@@ -1856,45 +1833,40 @@ void ImplementationVisitor::Visit(SpecializationDeclaration* decl) {
 
 VisitResult ImplementationVisitor::Visit(CallExpression* expr,
                                          bool is_tailcall) {
+  StackScope scope(this);
   Arguments arguments;
   std::string name = expr->callee.name;
-    TypeVector specialization_types =
-        GetTypeVector(expr->callee.generic_arguments);
-    bool has_template_arguments = !specialization_types.empty();
-    for (Expression* arg : expr->arguments)
-      arguments.parameters.push_back(Visit(arg));
-    arguments.labels = LabelsFromIdentifiers(expr->labels);
-    VisitResult result;
-    if (!has_template_arguments &&
-        declarations()->Lookup(expr->callee.name)->IsValue()) {
-      result = GeneratePointerCall(&expr->callee, arguments, is_tailcall);
+  TypeVector specialization_types =
+      GetTypeVector(expr->callee.generic_arguments);
+  bool has_template_arguments = !specialization_types.empty();
+  for (Expression* arg : expr->arguments)
+    arguments.parameters.push_back(Visit(arg));
+  arguments.labels = LabelsFromIdentifiers(expr->labels);
+  VisitResult result;
+  if (!has_template_arguments &&
+      declarations()->Lookup(expr->callee.name)->IsValue()) {
+    return scope.Yield(
+        GeneratePointerCall(&expr->callee, arguments, is_tailcall));
   } else {
-    result = GenerateCall(name, arguments, specialization_types, is_tailcall);
-  }
-  if (!result.type()->IsVoidOrNever()) {
-    GenerateIndent();
-    source_out() << "USE(" << RValueFlattenStructs(result) << ");\n";
-  }
-  if (is_tailcall) {
-    result = {TypeOracle::GetNeverType(), ""};
+    return scope.Yield(
+        GenerateCall(name, arguments, specialization_types, is_tailcall));
   }
-  return result;
 }
 
 bool ImplementationVisitor::GenerateLabeledStatementBlocks(
     const std::vector<Statement*>& blocks,
-    const std::vector<Label*>& statement_labels, Label* merge_label) {
+    const std::vector<Label*>& statement_labels, Block* merge_block) {
   bool live = false;
   auto label_iterator = statement_labels.begin();
   for (Statement* block : blocks) {
-    GenerateIndent();
-    source_out() << "if (" << (*label_iterator)->generated()
-                 << "->is_used())\n";
-    ScopedIndent indent(this);
-
     GenerateLabelBind(*label_iterator++);
-    if (!Visit(block)->IsNever()) {
-      GenerateLabelGoto(merge_label);
+    const Type* stmt_result;
+    {
+      StackScope stack_scope(this);
+      stmt_result = Visit(block);
+    }
+    if (stmt_result != TypeOracle::GetNeverType()) {
+      assembler().Goto(merge_block);
       live = true;
     }
   }
@@ -1904,15 +1876,14 @@ bool ImplementationVisitor::GenerateLabeledStatementBlocks(
 void ImplementationVisitor::GenerateBranch(const VisitResult& condition,
                                            Label* true_label,
                                            Label* false_label) {
-  GenerateIndent();
-  source_out() << "Branch(" << RValueFlattenStructs(condition) << ", "
-               << true_label->generated() << ", " << false_label->generated()
-               << ");\n";
+  DCHECK_EQ(condition,
+            VisitResult(TypeOracle::GetBoolType(), assembler().TopRange(1)));
+  assembler().Branch(true_label->block(), false_label->block());
 }
 
 bool ImplementationVisitor::GenerateExpressionBranch(
     Expression* expression, const std::vector<Label*>& statement_labels,
-    const std::vector<Statement*>& statement_blocks, Label* merge_label) {
+    const std::vector<Statement*>& statement_blocks, Block* merge_block) {
   // Activate a new scope to define True/False catch labels
   Declarations::NodeScopeActivator scope(declarations(), expression);
 
@@ -1929,23 +1900,28 @@ bool ImplementationVisitor::GenerateExpressionBranch(
   }
 
   return GenerateLabeledStatementBlocks(statement_blocks, statement_labels,
-                                        merge_label);
+                                        merge_block);
 }
 
 VisitResult ImplementationVisitor::GenerateImplicitConvert(
     const Type* destination_type, VisitResult source) {
+  StackScope scope(this);
+  if (source.type() == TypeOracle::GetNeverType()) {
+    ReportError("it is not allowed to use a value of type never");
+  }
+
   if (destination_type == source.type()) {
-    return source;
+    return scope.Yield(GenerateCopy(source));
   }
 
   if (TypeOracle::IsImplicitlyConvertableFrom(destination_type,
                                               source.type())) {
     std::string name =
         GetGeneratedCallableName(kFromConstexprMacroName, {destination_type});
-    return GenerateCall(name, {{source}, {}}, {}, false);
+    return scope.Yield(GenerateCall(name, {{source}, {}}, {}, false));
   } else if (IsAssignableFrom(destination_type, source.type())) {
     source.SetType(destination_type);
-    return source;
+    return scope.Yield(GenerateCopy(source));
   } else {
     std::stringstream s;
     s << "cannot use expression of type " << *source.type()
@@ -1954,56 +1930,53 @@ VisitResult ImplementationVisitor::GenerateImplicitConvert(
   }
 }
 
-std::string ImplementationVisitor::NewTempVariable() {
-  std::string name("t");
-  name += std::to_string(next_temp_++);
-  return name;
-}
-
-std::string ImplementationVisitor::GenerateNewTempVariable(const Type* type) {
-  std::string temp = NewTempVariable();
-  GenerateIndent();
-  source_out() << type->GetGeneratedTypeName() << " " << temp << " = ";
-  return temp;
-}
-
-void ImplementationVisitor::GenerateLabelDefinition(Label* label,
-                                                    AstNode* node) {
-  std::string label_string = label->generated();
-  std::string label_string_impl = label_string + "_impl";
-  GenerateIndent();
-  source_out() << "Label " + label_string_impl + "(this";
-  if (node != nullptr) {
-    source_out() << ", ";
-    GenerateChangedVarsFromControlSplit(node);
-  }
-  source_out() << ");\n";
-  GenerateIndent();
-  source_out() << "Label* " + label_string + " = &" << label_string_impl
-               << ";\n";
-  GenerateIndent();
-  source_out() << "USE(" << label_string << ");\n";
+void ImplementationVisitor::CreateBlockForLabel(Label* label,
+                                                Stack<const Type*> stack) {
+  label->set_block(assembler().NewBlock(std::move(stack), label->IsDeferred()));
 }
 
 void ImplementationVisitor::GenerateLabelBind(Label* label) {
-  GenerateIndent();
-  source_out() << "BIND(" << label->generated() << ");\n";
+  assembler().Bind(label->block());
 }
 
-void ImplementationVisitor::GenerateLabelGoto(Label* label) {
-  GenerateIndent();
-  source_out() << "Goto(" << label->generated() << ");\n";
+StackRange ImplementationVisitor::GenerateLabelGoto(
+    Label* label, base::Optional<StackRange> arguments) {
+  return assembler().Goto(label->block(), arguments ? arguments->Size() : 0);
 }
 
 std::vector<Label*> ImplementationVisitor::LabelsFromIdentifiers(
     const std::vector<std::string>& names) {
   std::vector<Label*> result;
-  for (auto name : names) {
+  result.reserve(names.size());
+  for (const auto& name : names) {
     result.push_back(declarations()->LookupLabel(name));
   }
   return result;
 }
 
+StackRange ImplementationVisitor::LowerParameter(
+    const Type* type, const std::string& parameter_name,
+    Stack<std::string>* lowered_parameters) {
+  if (type->IsStructType()) {
+    const StructType* struct_type = StructType::cast(type);
+    StackRange range = lowered_parameters->TopRange(0);
+    for (auto& field : struct_type->fields()) {
+      StackRange parameter_range = LowerParameter(
+          field.type, parameter_name + "." + field.name, lowered_parameters);
+      range.Extend(parameter_range);
+    }
+    return range;
+  } else {
+    lowered_parameters->Push(parameter_name);
+    return lowered_parameters->TopRange(1);
+  }
+}
+
+std::string ImplementationVisitor::ExternalLabelParameterName(Label* label,
+                                                              size_t i) {
+  return label->external_label_name() + "_parameter_" + std::to_string(i);
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/torque/implementation-visitor.h b/deps/v8/src/torque/implementation-visitor.h
index 43520239da..a7440251d7 100644
--- a/deps/v8/src/torque/implementation-visitor.h
+++ b/deps/v8/src/torque/implementation-visitor.h
@@ -9,6 +9,7 @@
 
 #include "src/base/macros.h"
 #include "src/torque/ast.h"
+#include "src/torque/cfg.h"
 #include "src/torque/file-visitor.h"
 #include "src/torque/global-context.h"
 #include "src/torque/types.h"
@@ -18,18 +19,95 @@ namespace v8 {
 namespace internal {
 namespace torque {
 
-struct LocationReference {
-  LocationReference(Value* value, VisitResult base, VisitResult index)
-      : value(value), base(base), index(index) {}
-  Value* value;
-  VisitResult base;
-  VisitResult index;
+// LocationReference is the representation of an l-value, so a value that might
+// allow for assignment. For uniformity, this class can also represent
+// unassignable temporaries. Assignable values fall in two categories:
+//   - stack ranges that represent mutable variables, including structs.
+//   - field or element access expressions that generate operator calls.
+class LocationReference {
+ public:
+  // An assignable stack range.
+  static LocationReference VariableAccess(VisitResult variable) {
+    DCHECK(variable.IsOnStack());
+    LocationReference result;
+    result.variable_ = std::move(variable);
+    return result;
+  }
+  // An unassignable value. {description} is only used for error messages.
+  static LocationReference Temporary(VisitResult temporary,
+                                     std::string description) {
+    LocationReference result;
+    result.temporary_ = std::move(temporary);
+    result.temporary_description_ = std::move(description);
+    return result;
+  }
+  static LocationReference ArrayAccess(VisitResult base, VisitResult offset) {
+    LocationReference result;
+    result.eval_function_ = std::string{"[]"};
+    result.assign_function_ = std::string{"[]="};
+    result.call_arguments_ = {base, offset};
+    return result;
+  }
+  static LocationReference FieldAccess(VisitResult object,
+                                       std::string fieldname) {
+    LocationReference result;
+    result.eval_function_ = "." + fieldname;
+    result.assign_function_ = "." + fieldname + "=";
+    result.call_arguments_ = {object};
+    return result;
+  }
+
+  bool IsConst() const { return temporary_.has_value(); }
+
+  bool IsVariableAccess() const { return variable_.has_value(); }
+  const VisitResult& variable() const {
+    DCHECK(IsVariableAccess());
+    return *variable_;
+  }
+  bool IsTemporary() const { return temporary_.has_value(); }
+  const VisitResult& temporary() const {
+    DCHECK(IsTemporary());
+    return *temporary_;
+  }
+  // For error reporting.
+  const std::string& temporary_description() const {
+    DCHECK(IsTemporary());
+    return *temporary_description_;
+  }
+
+  bool IsCallAccess() const {
+    bool is_call_access = eval_function_.has_value();
+    DCHECK_EQ(is_call_access, assign_function_.has_value());
+    return is_call_access;
+  }
+  const VisitResultVector& call_arguments() const {
+    DCHECK(IsCallAccess());
+    return call_arguments_;
+  }
+  const std::string& eval_function() const {
+    DCHECK(IsCallAccess());
+    return *eval_function_;
+  }
+  const std::string& assign_function() const {
+    DCHECK(IsCallAccess());
+    return *assign_function_;
+  }
+
+ private:
+  base::Optional<VisitResult> variable_;
+  base::Optional<VisitResult> temporary_;
+  base::Optional<std::string> temporary_description_;
+  base::Optional<std::string> eval_function_;
+  base::Optional<std::string> assign_function_;
+  VisitResultVector call_arguments_;
+
+  LocationReference() = default;
 };
 
 class ImplementationVisitor : public FileVisitor {
  public:
   explicit ImplementationVisitor(GlobalContext& global_context)
-      : FileVisitor(global_context), indent_(0), next_temp_(0) {}
+      : FileVisitor(global_context) {}
 
   void Visit(Ast* ast) { Visit(ast->default_module()); }
 
@@ -39,44 +117,23 @@ class ImplementationVisitor : public FileVisitor {
 
   VisitResult Visit(StructExpression* decl);
 
-  LocationReference GetLocationReference(LocationExpression* location);
-  LocationReference GetLocationReference(IdentifierExpression* expr) {
-    return LocationReference(declarations()->LookupValue(expr->name), {}, {});
-  }
+  LocationReference GetLocationReference(Expression* location);
+  LocationReference GetLocationReference(IdentifierExpression* expr);
   LocationReference GetLocationReference(FieldAccessExpression* expr);
-  LocationReference GetLocationReference(ElementAccessExpression* expr) {
-    return LocationReference({}, Visit(expr->array), Visit(expr->index));
-  }
-
-  std::string RValueFlattenStructs(VisitResult result);
+  LocationReference GetLocationReference(ElementAccessExpression* expr);
 
-  VisitResult GenerateFetchFromLocation(LocationReference reference) {
-    const Value* value = reference.value;
-    return VisitResult(value->type(), value);
-  }
-  VisitResult GenerateFetchFromLocation(LocationExpression* location,
-                                        LocationReference reference);
-  VisitResult GenerateFetchFromLocation(IdentifierExpression* expr,
-                                        LocationReference reference) {
-    return GenerateFetchFromLocation(reference);
-  }
-  VisitResult GenerateFetchFromLocation(FieldAccessExpression* expr,
-                                        LocationReference reference);
-  VisitResult GenerateFetchFromLocation(ElementAccessExpression* expr,
-                                        LocationReference reference) {
-    Arguments arguments;
-    arguments.parameters = {reference.base, reference.index};
-    return GenerateCall("[]", arguments);
-  }
+  VisitResult GenerateFetchFromLocation(const LocationReference& reference);
 
   VisitResult GetBuiltinCode(Builtin* builtin);
 
   VisitResult Visit(IdentifierExpression* expr);
   VisitResult Visit(FieldAccessExpression* expr) {
-    return GenerateFetchFromLocation(expr, GetLocationReference(expr));
+    StackScope scope(this);
+    return scope.Yield(GenerateFetchFromLocation(GetLocationReference(expr)));
   }
   VisitResult Visit(ElementAccessExpression* expr) {
-    return GenerateFetchFromLocation(expr, GetLocationReference(expr));
+    StackScope scope(this);
+    return scope.Yield(GenerateFetchFromLocation(GetLocationReference(expr)));
   }
 
   void Visit(ModuleDeclaration* decl);
@@ -120,8 +177,9 @@ class ImplementationVisitor : public FileVisitor {
   VisitResult Visit(StringLiteralExpression* expr);
   VisitResult Visit(NumberLiteralExpression* expr);
   VisitResult Visit(AssumeTypeImpossibleExpression* expr);
+  VisitResult Visit(TryLabelExpression* expr);
+  VisitResult Visit(StatementExpression* expr);
 
-  const Type* Visit(TryLabelStatement* stmt);
   const Type* Visit(ReturnStatement* stmt);
   const Type* Visit(GotoStatement* stmt);
   const Type* Visit(IfStatement* stmt);
@@ -146,63 +204,70 @@ class ImplementationVisitor : public FileVisitor {
 
   std::string GetDSLAssemblerName(Module* module);
 
-  void GenerateIndent();
-
-  class ScopedIndent {
+  // {StackScope} records the stack height at creation time and reconstructs it
+  // when being destructed by emitting a {DeleteRangeInstruction}, except for
+  // the slots protected by {StackScope::Yield}. Calling {Yield(v)} deletes all
+  // slots above the initial stack height except for the slots of {v}, which are
+  // moved to form the only slots above the initial height and marks them to
+  // survive destruction of the {StackScope}. A typical pattern is the
+  // following:
+  //
+  // VisitResult result;
+  // {
+  //   StackScope stack_scope(this);
+  //   // ... create temporary slots ...
+  //   result = stack_scope.Yield(surviving_slots);
+  // }
+  class StackScope {
    public:
-    explicit ScopedIndent(ImplementationVisitor* visitor, bool new_lines = true)
-        : new_lines_(new_lines), visitor_(visitor) {
-      if (new_lines) visitor->GenerateIndent();
-      visitor->source_out() << "{";
-      if (new_lines) visitor->source_out() << "\n";
-      visitor->indent_++;
+    explicit StackScope(ImplementationVisitor* visitor) : visitor_(visitor) {
+      base_ = visitor_->assembler().CurrentStack().AboveTop();
+    }
+    VisitResult Yield(VisitResult result) {
+      DCHECK(!yield_called_);
+      yield_called_ = true;
+      if (!result.IsOnStack()) {
+        if (!visitor_->assembler().CurrentBlockIsComplete()) {
+          visitor_->assembler().DropTo(base_);
+        }
+        return result;
+      }
+      DCHECK_LE(base_, result.stack_range().begin());
+      DCHECK_LE(result.stack_range().end(),
+                visitor_->assembler().CurrentStack().AboveTop());
+      visitor_->assembler().DropTo(result.stack_range().end());
+      visitor_->assembler().DeleteRange(
+          StackRange{base_, result.stack_range().begin()});
+      base_ = visitor_->assembler().CurrentStack().AboveTop();
+      return VisitResult(result.type(), visitor_->assembler().TopRange(
+                                            result.stack_range().Size()));
     }
-    ~ScopedIndent() {
-      visitor_->indent_--;
-      visitor_->GenerateIndent();
-      visitor_->source_out() << "}";
-      if (new_lines_) visitor_->source_out() << "\n";
+
+    ~StackScope() {
+      if (yield_called_) {
+        DCHECK_IMPLIES(
+            !visitor_->assembler().CurrentBlockIsComplete(),
+            base_ == visitor_->assembler().CurrentStack().AboveTop());
+      } else if (!visitor_->assembler().CurrentBlockIsComplete()) {
+        visitor_->assembler().DropTo(base_);
+      }
     }
 
    private:
-    bool new_lines_;
     ImplementationVisitor* visitor_;
+    BottomOffset base_;
+    bool yield_called_ = false;
   };
 
   Callable* LookupCall(const std::string& name, const Arguments& arguments,
                        const TypeVector& specialization_types);
 
-  bool GenerateChangedVarFromControlSplit(const Variable* v, bool first = true);
-
-  void GetFlattenedStructsVars(const Variable* base,
-                               std::set<const Variable*>* vars);
-
-  void GenerateChangedVarsFromControlSplit(AstNode* node);
-
   const Type* GetCommonType(const Type* left, const Type* right);
 
   VisitResult GenerateCopy(const VisitResult& to_copy);
 
-  void GenerateAssignToVariable(Variable* var, VisitResult value);
-
-  void GenerateAssignToLocation(LocationExpression* location,
-                                const LocationReference& reference,
-                                VisitResult assignment_value);
-
-  void GenerateVariableDeclaration(const Variable* var);
-
-  Variable* GeneratePredeclaredVariableDeclaration(
-      const std::string& name,
-      const base::Optional<VisitResult>& initialization);
-
-  Variable* GenerateVariableDeclaration(
-      AstNode* node, const std::string& name, bool is_const,
-      const base::Optional<const Type*>& type,
-      const base::Optional<VisitResult>& initialization = {});
-
-  void GenerateParameter(const std::string& parameter_name);
-
-  void GenerateParameterList(const NameVector& list, size_t first = 0);
+  void GenerateAssignToLocation(const LocationReference& reference,
+                                const VisitResult& assignment_value);
 
   VisitResult GenerateCall(const std::string& callable_name,
                            Arguments parameters,
@@ -213,7 +278,7 @@ class ImplementationVisitor : public FileVisitor {
 
   bool GenerateLabeledStatementBlocks(
       const std::vector<Statement*>& blocks,
-      const std::vector<Label*>& statement_labels, Label* merge_label);
+      const std::vector<Label*>& statement_labels, Block* merge_block);
 
   void GenerateBranch(const VisitResult& condition, Label* true_label,
                       Label* false_label);
@@ -221,7 +286,7 @@ class ImplementationVisitor : public FileVisitor {
   bool GenerateExpressionBranch(Expression* expression,
                                 const std::vector<Label*>& statement_labels,
                                 const std::vector<Statement*>& statement_blocks,
-                                Label* merge_label);
+                                Block* merge_block);
 
   void GenerateMacroFunctionDeclaration(std::ostream& o,
                                         const std::string& macro_prefix,
@@ -242,25 +307,40 @@ class ImplementationVisitor : public FileVisitor {
     Visit(callable, MakeSignature(signature), body);
   }
 
-  std::string NewTempVariable();
-
-  std::string GenerateNewTempVariable(const Type* type);
-
-  void GenerateLabelDefinition(Label* label, AstNode* node = nullptr);
+  void CreateBlockForLabel(Label* label, Stack<const Type*> stack);
 
   void GenerateLabelBind(Label* label);
 
-  void GenerateLabelGoto(Label* label);
+  StackRange GenerateLabelGoto(Label* label,
+                               base::Optional<StackRange> arguments = {});
 
   std::vector<Label*> LabelsFromIdentifiers(
       const std::vector<std::string>& names);
 
+  StackRange LowerParameter(const Type* type, const std::string& parameter_name,
+                            Stack<std::string>* lowered_parameters);
+
+  std::string ExternalLabelParameterName(Label* label, size_t i);
+
   std::ostream& source_out() { return module_->source_stream(); }
 
   std::ostream& header_out() { return module_->header_stream(); }
 
-  size_t indent_;
-  int32_t next_temp_;
+  CfgAssembler& assembler() { return *assembler_; }
+
+  void SetReturnValue(VisitResult return_value) {
+    DCHECK_IMPLIES(return_value_, *return_value_ == return_value);
+    return_value_ = std::move(return_value);
+  }
+
+  VisitResult GetAndClearReturnValue() {
+    VisitResult return_value = *return_value_;
+    return_value_ = base::nullopt;
+    return return_value;
+  }
+
+  base::Optional<CfgAssembler> assembler_;
+  base::Optional<VisitResult> return_value_;
 };
 
 }  // namespace torque
diff --git a/deps/v8/src/torque/instructions.cc b/deps/v8/src/torque/instructions.cc
new file mode 100644
index 0000000000..13dbd75a2e
--- /dev/null
+++ b/deps/v8/src/torque/instructions.cc
@@ -0,0 +1,204 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/torque/instructions.h"
+#include "src/torque/cfg.h"
+#include "src/torque/type-oracle.h"
+
+namespace v8 {
+namespace internal {
+namespace torque {
+
+#define TORQUE_INSTRUCTION_BOILERPLATE_DEFINITIONS(Name)        \
+  const InstructionKind Name::kKind = InstructionKind::k##Name; \
+  std::unique_ptr<InstructionBase> Name::Clone() const {        \
+    return std::unique_ptr<InstructionBase>(new Name(*this));   \
+  }                                                             \
+  void Name::Assign(const InstructionBase& other) {             \
+    *this = static_cast<const Name&>(other);                    \
+  }
+TORQUE_INSTRUCTION_LIST(TORQUE_INSTRUCTION_BOILERPLATE_DEFINITIONS)
+#undef TORQUE_INSTRUCTION_BOILERPLATE_DEFINITIONS
+
+void PeekInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                      ControlFlowGraph* cfg) const {
+  const Type* type = stack->Peek(slot);
+  if (widened_type) {
+    if (!type->IsSubtypeOf(*widened_type)) {
+      ReportError("type ", type, " is not a subtype of ", *widened_type);
+    }
+    type = *widened_type;
+  }
+  stack->Push(type);
+}
+
+void PokeInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                      ControlFlowGraph* cfg) const {
+  const Type* type = stack->Top();
+  if (widened_type) {
+    if (!type->IsSubtypeOf(*widened_type)) {
+      ReportError("type ", type, " is not a subtype of ", *widened_type);
+    }
+    type = *widened_type;
+  }
+  stack->Poke(slot, type);
+  stack->Pop();
+}
+
+void DeleteRangeInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                             ControlFlowGraph* cfg) const {
+  stack->DeleteRange(range);
+}
+
+void PushUninitializedInstruction::TypeInstruction(
+    Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
+  stack->Push(type);
+}
+
+void PushCodePointerInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                                 ControlFlowGraph* cfg) const {
+  stack->Push(type);
+}
+
+void ModuleConstantInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                                ControlFlowGraph* cfg) const {
+  stack->PushMany(LowerType(constant->type()));
+}
+
+void CallCsaMacroInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                              ControlFlowGraph* cfg) const {
+  std::vector<const Type*> parameter_types =
+      LowerParameterTypes(macro->signature().parameter_types);
+  for (intptr_t i = parameter_types.size() - 1; i >= 0; --i) {
+    const Type* arg_type = stack->Pop();
+    const Type* parameter_type = parameter_types.back();
+    parameter_types.pop_back();
+    if (arg_type != parameter_type) {
+      ReportError("parameter ", i, ": expected type ", *parameter_type,
+                  " but found type ", *arg_type);
+    }
+  }
+  if (!parameter_types.empty()) ReportError("missing arguments");
+
+  stack->PushMany(LowerType(macro->signature().return_type));
+}
+
+void CallCsaMacroAndBranchInstruction::TypeInstruction(
+    Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
+  std::vector<const Type*> parameter_types =
+      LowerParameterTypes(macro->signature().parameter_types);
+  for (intptr_t i = parameter_types.size() - 1; i >= 0; --i) {
+    const Type* arg_type = stack->Pop();
+    const Type* parameter_type = parameter_types.back();
+    parameter_types.pop_back();
+    if (arg_type != parameter_type) {
+      ReportError("parameter ", i, ": expected type ", *parameter_type,
+                  " but found type ", *arg_type);
+    }
+  }
+  if (!parameter_types.empty()) ReportError("missing arguments");
+
+  if (label_blocks.size() != macro->signature().labels.size()) {
+    ReportError("wrong number of labels");
+  }
+  for (size_t i = 0; i < label_blocks.size(); ++i) {
+    Stack<const Type*> continuation_stack = *stack;
+    continuation_stack.PushMany(
+        LowerParameterTypes(macro->signature().labels[i].types));
+    label_blocks[i]->SetInputTypes(std::move(continuation_stack));
+  }
+
+  if (macro->signature().return_type != TypeOracle::GetNeverType()) {
+    Stack<const Type*> return_stack = *stack;
+    return_stack.PushMany(LowerType(macro->signature().return_type));
+    if (return_continuation == base::nullopt) {
+      ReportError("missing return continuation.");
+    }
+    (*return_continuation)->SetInputTypes(return_stack);
+  } else {
+    if (return_continuation != base::nullopt) {
+      ReportError("unreachable return continuation.");
+    }
+  }
+}
+
+void CallBuiltinInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                             ControlFlowGraph* cfg) const {
+  std::vector<const Type*> argument_types = stack->PopMany(argc);
+  if (argument_types !=
+      LowerParameterTypes(builtin->signature().parameter_types)) {
+    ReportError("wrong argument types");
+  }
+  stack->PushMany(LowerType(builtin->signature().return_type));
+}
+
+void CallBuiltinPointerInstruction::TypeInstruction(
+    Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
+  std::vector<const Type*> argument_types = stack->PopMany(argc);
+  const FunctionPointerType* f = FunctionPointerType::DynamicCast(stack->Pop());
+  if (!f) ReportError("expected function pointer type");
+  if (argument_types != LowerParameterTypes(f->parameter_types())) {
+    ReportError("wrong argument types");
+  }
+  stack->PushMany(LowerType(f->return_type()));
+}
+
+void CallRuntimeInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                             ControlFlowGraph* cfg) const {
+  std::vector<const Type*> argument_types = stack->PopMany(argc);
+  if (argument_types !=
+      LowerParameterTypes(runtime_function->signature().parameter_types,
+                          argc)) {
+    ReportError("wrong argument types");
+  }
+  stack->PushMany(LowerType(runtime_function->signature().return_type));
+}
+
+void BranchInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                        ControlFlowGraph* cfg) const {
+  const Type* condition_type = stack->Pop();
+  if (condition_type != TypeOracle::GetBoolType()) {
+    ReportError("condition has to have type bool");
+  }
+  if_true->SetInputTypes(*stack);
+  if_false->SetInputTypes(*stack);
+}
+
+void ConstexprBranchInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                                 ControlFlowGraph* cfg) const {
+  if_true->SetInputTypes(*stack);
+  if_false->SetInputTypes(*stack);
+}
+
+void GotoInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                      ControlFlowGraph* cfg) const {
+  destination->SetInputTypes(*stack);
+}
+
+void GotoExternalInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                              ControlFlowGraph* cfg) const {
+  if (variable_names.size() != stack->Size()) {
+    ReportError("goto external label with wrong parameter count.");
+  }
+}
+
+void ReturnInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                        ControlFlowGraph* cfg) const {
+  cfg->SetReturnType(stack->Pop());
+}
+
+void PrintConstantStringInstruction::TypeInstruction(
+    Stack<const Type*>* stack, ControlFlowGraph* cfg) const {}
+
+void DebugBreakInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                            ControlFlowGraph* cfg) const {}
+
+void UnsafeCastInstruction::TypeInstruction(Stack<const Type*>* stack,
+                                            ControlFlowGraph* cfg) const {
+  stack->Poke(stack->AboveTop() - 1, destination_type);
+}
+
+}  // namespace torque
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/torque/instructions.h b/deps/v8/src/torque/instructions.h
new file mode 100644
index 0000000000..881074e827
--- /dev/null
+++ b/deps/v8/src/torque/instructions.h
@@ -0,0 +1,354 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TORQUE_INSTRUCTIONS_H_
+#define V8_TORQUE_INSTRUCTIONS_H_
+
+#include <memory>
+
+#include "src/torque/ast.h"
+#include "src/torque/source-positions.h"
+#include "src/torque/types.h"
+#include "src/torque/utils.h"
+
+namespace v8 {
+namespace internal {
+namespace torque {
+
+class Block;
+class Builtin;
+class ControlFlowGraph;
+class Macro;
+class ModuleConstant;
+class RuntimeFunction;
+
+#define TORQUE_INSTRUCTION_LIST(V)    \
+  V(PeekInstruction)                  \
+  V(PokeInstruction)                  \
+  V(DeleteRangeInstruction)           \
+  V(PushUninitializedInstruction)     \
+  V(PushCodePointerInstruction)       \
+  V(CallCsaMacroInstruction)          \
+  V(ModuleConstantInstruction)        \
+  V(CallCsaMacroAndBranchInstruction) \
+  V(CallBuiltinInstruction)           \
+  V(CallRuntimeInstruction)           \
+  V(CallBuiltinPointerInstruction)    \
+  V(BranchInstruction)                \
+  V(ConstexprBranchInstruction)       \
+  V(GotoInstruction)                  \
+  V(GotoExternalInstruction)          \
+  V(ReturnInstruction)                \
+  V(PrintConstantStringInstruction)   \
+  V(DebugBreakInstruction)            \
+  V(UnsafeCastInstruction)
+
+#define TORQUE_INSTRUCTION_BOILERPLATE()                                 \
+  static const InstructionKind kKind;                                    \
+  std::unique_ptr<InstructionBase> Clone() const override;               \
+  void Assign(const InstructionBase& other) override;                    \
+  void TypeInstruction(Stack<const Type*>* stack, ControlFlowGraph* cfg) \
+      const override;
+
+enum class InstructionKind {
+#define ENUM_ITEM(name) k##name,
+  TORQUE_INSTRUCTION_LIST(ENUM_ITEM)
+#undef ENUM_ITEM
+};
+
+struct InstructionBase {
+  InstructionBase() : pos(CurrentSourcePosition::Get()) {}
+  virtual std::unique_ptr<InstructionBase> Clone() const = 0;
+  virtual void Assign(const InstructionBase& other) = 0;
+  virtual ~InstructionBase() = default;
+
+  virtual void TypeInstruction(Stack<const Type*>* stack,
+                               ControlFlowGraph* cfg) const = 0;
+  virtual bool IsBlockTerminator() const { return false; }
+  virtual void AppendSuccessorBlocks(std::vector<Block*>* block_list) const {}
+
+  SourcePosition pos;
+};
+
+class Instruction {
+ public:
+  template <class T>
+  Instruction(T instr)  // NOLINT(runtime/explicit)
+      : kind_(T::kKind), instruction_(new T(std::move(instr))) {}
+
+  template <class T>
+  T& Cast() {
+    DCHECK(Is<T>());
+    return static_cast<T&>(*instruction_);
+  }
+
+  template <class T>
+  const T& Cast() const {
+    DCHECK(Is<T>());
+    return static_cast<const T&>(*instruction_);
+  }
+
+  template <class T>
+  bool Is() const {
+    return kind_ == T::kKind;
+  }
+
+  template <class T>
+  T* DynamicCast() {
+    if (Is<T>()) return &Cast<T>();
+    return nullptr;
+  }
+
+  template <class T>
+  const T* DynamicCast() const {
+    if (Is<T>()) return &Cast<T>();
+    return nullptr;
+  }
+
+  Instruction(const Instruction& other)
+      : kind_(other.kind_), instruction_(other.instruction_->Clone()) {}
+  Instruction& operator=(const Instruction& other) {
+    if (kind_ == other.kind_) {
+      instruction_->Assign(*other.instruction_);
+    } else {
+      kind_ = other.kind_;
+      instruction_ = other.instruction_->Clone();
+    }
+    return *this;
+  }
+
+  InstructionKind kind() const { return kind_; }
+  void TypeInstruction(Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
+    return instruction_->TypeInstruction(stack, cfg);
+  }
+
+  InstructionBase* operator->() { return instruction_.get(); }
+  const InstructionBase* operator->() const { return instruction_.get(); }
+
+ private:
+  InstructionKind kind_;
+  std::unique_ptr<InstructionBase> instruction_;
+};
+
+struct PeekInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+
+  PeekInstruction(BottomOffset slot, base::Optional<const Type*> widened_type)
+      : slot(slot), widened_type(widened_type) {}
+
+  BottomOffset slot;
+  base::Optional<const Type*> widened_type;
+};
+
+struct PokeInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+
+  PokeInstruction(BottomOffset slot, base::Optional<const Type*> widened_type)
+      : slot(slot), widened_type(widened_type) {}
+
+  BottomOffset slot;
+  base::Optional<const Type*> widened_type;
+};
+
+// Preserve the top {preserved_slots} number of slots, and delete
+// {deleted_slots} number or slots below.
+struct DeleteRangeInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  explicit DeleteRangeInstruction(StackRange range) : range(range) {}
+
+  StackRange range;
+};
+
+struct PushUninitializedInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  explicit PushUninitializedInstruction(const Type* type) : type(type) {}
+
+  const Type* type;
+};
+
+struct PushCodePointerInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  PushCodePointerInstruction(std::string external_name, const Type* type)
+      : external_name(std::move(external_name)), type(type) {
+    DCHECK(type->IsFunctionPointerType());
+  }
+
+  std::string external_name;
+  const Type* type;
+};
+
+struct ModuleConstantInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  explicit ModuleConstantInstruction(ModuleConstant* constant)
+      : constant(constant) {}
+
+  ModuleConstant* constant;
+};
+
+struct CallCsaMacroInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  CallCsaMacroInstruction(Macro* macro,
+                          std::vector<std::string> constexpr_arguments)
+      : macro(macro), constexpr_arguments(constexpr_arguments) {}
+
+  Macro* macro;
+  std::vector<std::string> constexpr_arguments;
+};
+
+struct CallCsaMacroAndBranchInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  CallCsaMacroAndBranchInstruction(Macro* macro,
+                                   std::vector<std::string> constexpr_arguments,
+                                   base::Optional<Block*> return_continuation,
+                                   std::vector<Block*> label_blocks)
+      : macro(macro),
+        constexpr_arguments(constexpr_arguments),
+        return_continuation(return_continuation),
+        label_blocks(label_blocks) {}
+  bool IsBlockTerminator() const override { return true; }
+  void AppendSuccessorBlocks(std::vector<Block*>* block_list) const override {
+    if (return_continuation) block_list->push_back(*return_continuation);
+    for (Block* block : label_blocks) block_list->push_back(block);
+  }
+
+  Macro* macro;
+  std::vector<std::string> constexpr_arguments;
+  base::Optional<Block*> return_continuation;
+  std::vector<Block*> label_blocks;
+};
+
+struct CallBuiltinInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return is_tailcall; }
+  CallBuiltinInstruction(bool is_tailcall, Builtin* builtin, size_t argc)
+      : is_tailcall(is_tailcall), builtin(builtin), argc(argc) {}
+
+  bool is_tailcall;
+  Builtin* builtin;
+  size_t argc;
+};
+
+struct CallBuiltinPointerInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return is_tailcall; }
+  CallBuiltinPointerInstruction(bool is_tailcall, Builtin* example_builtin,
+                                size_t argc)
+      : is_tailcall(is_tailcall),
+        example_builtin(example_builtin),
+        argc(argc) {}
+
+  bool is_tailcall;
+  Builtin* example_builtin;
+  size_t argc;
+};
+
+struct CallRuntimeInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return is_tailcall; }
+
+  CallRuntimeInstruction(bool is_tailcall, RuntimeFunction* runtime_function,
+                         size_t argc)
+      : is_tailcall(is_tailcall),
+        runtime_function(runtime_function),
+        argc(argc) {}
+
+  bool is_tailcall;
+  RuntimeFunction* runtime_function;
+  size_t argc;
+};
+
+struct BranchInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return true; }
+  void AppendSuccessorBlocks(std::vector<Block*>* block_list) const override {
+    block_list->push_back(if_true);
+    block_list->push_back(if_false);
+  }
+
+  BranchInstruction(Block* if_true, Block* if_false)
+      : if_true(if_true), if_false(if_false) {}
+
+  Block* if_true;
+  Block* if_false;
+};
+
+struct ConstexprBranchInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return true; }
+  void AppendSuccessorBlocks(std::vector<Block*>* block_list) const override {
+    block_list->push_back(if_true);
+    block_list->push_back(if_false);
+  }
+
+  ConstexprBranchInstruction(std::string condition, Block* if_true,
+                             Block* if_false)
+      : condition(condition), if_true(if_true), if_false(if_false) {}
+
+  std::string condition;
+  Block* if_true;
+  Block* if_false;
+};
+
+struct GotoInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return true; }
+  void AppendSuccessorBlocks(std::vector<Block*>* block_list) const override {
+    block_list->push_back(destination);
+  }
+
+  explicit GotoInstruction(Block* destination) : destination(destination) {}
+
+  Block* destination;
+};
+
+struct GotoExternalInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return true; }
+
+  GotoExternalInstruction(std::string destination,
+                          std::vector<std::string> variable_names)
+      : destination(std::move(destination)),
+        variable_names(std::move(variable_names)) {}
+
+  std::string destination;
+  std::vector<std::string> variable_names;
+};
+
+struct ReturnInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return true; }
+};
+
+struct PrintConstantStringInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  explicit PrintConstantStringInstruction(std::string message) {
+    // The normal way to write this triggers a bug in Clang on Windows.
+    this->message = std::move(message);
+  }
+
+  std::string message;
+};
+
+struct DebugBreakInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  bool IsBlockTerminator() const override { return never_continues; }
+  explicit DebugBreakInstruction(bool never_continues)
+      : never_continues(never_continues) {}
+
+  bool never_continues;
+};
+
+struct UnsafeCastInstruction : InstructionBase {
+  TORQUE_INSTRUCTION_BOILERPLATE()
+  explicit UnsafeCastInstruction(const Type* destination_type)
+      : destination_type(destination_type) {}
+
+  const Type* destination_type;
+};
+
+}  // namespace torque
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TORQUE_INSTRUCTIONS_H_
diff --git a/deps/v8/src/torque/source-positions.h b/deps/v8/src/torque/source-positions.h
index bd5aaa3ec3..ae07ff9bf2 100644
--- a/deps/v8/src/torque/source-positions.h
+++ b/deps/v8/src/torque/source-positions.h
@@ -29,7 +29,7 @@ DECLARE_CONTEXTUAL_VARIABLE(CurrentSourcePosition, SourcePosition)
 
 class SourceFileMap : public ContextualClass<SourceFileMap> {
  public:
-  SourceFileMap() {}
+  SourceFileMap() = default;
   static const std::string& GetSource(SourceId source) {
     return Get().sources_[source.id_];
   }
diff --git a/deps/v8/src/torque/torque-parser.cc b/deps/v8/src/torque/torque-parser.cc
index 92c3fa8815..91f9ef4ed2 100644
--- a/deps/v8/src/torque/torque-parser.cc
+++ b/deps/v8/src/torque/torque-parser.cc
@@ -183,14 +183,68 @@ T* MakeNode(Args... args) {
       new T(CurrentSourcePosition::Get(), std::move(args)...)));
 }
 
+void LintGenericParameters(const GenericParameters& parameters) {
+  for (const std::string& parameter : parameters) {
+    if (!IsUpperCamelCase(parameter)) {
+      NamingConventionError("Generic parameter", parameter, "UpperCamelCase");
+    }
+  }
+}
+
+void CheckNotDeferredStatement(Statement* statement) {
+  if (BlockStatement* block = BlockStatement::DynamicCast(statement)) {
+    if (block->deferred) {
+      LintError(
+          "cannot use deferred with a statement block here, it will have no "
+          "effect");
+    }
+  }
+}
+
+Expression* MakeCall(const std::string& callee, bool is_operator,
+                     const std::vector<TypeExpression*>& generic_arguments,
+                     const std::vector<Expression*>& arguments,
+                     const std::vector<Statement*>& otherwise) {
+  std::vector<std::string> labels;
+
+  // All IdentifierExpressions are treated as label names and can be directly
+  // used as labels identifiers. All other statements in a call's otherwise
+  // must create intermediate Labels for the otherwise's statement code.
+  size_t label_id = 0;
+  std::vector<LabelBlock*> temp_labels;
+  for (auto* statement : otherwise) {
+    if (auto* e = ExpressionStatement::DynamicCast(statement)) {
+      if (auto* id = IdentifierExpression::DynamicCast(e->expression)) {
+        if (id->generic_arguments.size() != 0) {
+          ReportError("An otherwise label cannot have generic parameters");
+        }
+        labels.push_back(id->name);
+        continue;
+      }
+    }
+    auto label_name = std::string("_label") + std::to_string(label_id++);
+    labels.push_back(label_name);
+    auto* label_block =
+        MakeNode<LabelBlock>(label_name, ParameterList::Empty(), statement);
+    temp_labels.push_back(label_block);
+  }
+
+  // Create nested try-label expression for all of the temporary Labels that
+  // were created.
+  Expression* result = MakeNode<CallExpression>(
+      callee, false, generic_arguments, arguments, labels);
+  for (auto* label : temp_labels) {
+    result = MakeNode<TryLabelExpression>(result, label);
+  }
+  return result;
+}
+
 base::Optional<ParseResult> MakeCall(ParseResultIterator* child_results) {
   auto callee = child_results->NextAs<std::string>();
   auto generic_args = child_results->NextAs<TypeList>();
   auto args = child_results->NextAs<std::vector<Expression*>>();
-  auto labels = child_results->NextAs<std::vector<std::string>>();
-  Expression* result =
-      MakeNode<CallExpression>(callee, false, generic_args, args, labels);
-  return ParseResult{result};
+  auto otherwise = child_results->NextAs<std::vector<Statement*>>();
+  return ParseResult{MakeCall(callee, false, generic_args, args, otherwise)};
 }
 
 base::Optional<ParseResult> MakeBinaryOperator(
@@ -198,20 +252,17 @@ base::Optional<ParseResult> MakeBinaryOperator(
   auto left = child_results->NextAs<Expression*>();
   auto op = child_results->NextAs<std::string>();
   auto right = child_results->NextAs<Expression*>();
-  Expression* result = MakeNode<CallExpression>(
-      op, true, TypeList{}, std::vector<Expression*>{left, right},
-      std::vector<std::string>{});
-  return ParseResult{result};
+  return ParseResult{MakeCall(op, true, TypeList{},
+                              std::vector<Expression*>{left, right},
+                              std::vector<Statement*>{})};
 }
 
 base::Optional<ParseResult> MakeUnaryOperator(
     ParseResultIterator* child_results) {
   auto op = child_results->NextAs<std::string>();
   auto e = child_results->NextAs<Expression*>();
-  Expression* result = MakeNode<CallExpression>(op, true, TypeList{},
-                                                std::vector<Expression*>{e},
-                                                std::vector<std::string>{});
-  return ParseResult{result};
+  return ParseResult{MakeCall(op, true, TypeList{}, std::vector<Expression*>{e},
+                              std::vector<Statement*>{})};
 }
 
 template <bool has_varargs>
@@ -233,6 +284,10 @@ base::Optional<ParseResult> MakeParameterListFromNameAndTypeList(
   }
   ParameterList result;
   for (NameAndTypeExpression& pair : params) {
+    if (!IsLowerCamelCase(pair.name)) {
+      NamingConventionError("Parameter", pair.name, "lowerCamelCase");
+    }
+
     result.names.push_back(std::move(pair.name));
     result.types.push_back(pair.type);
   }
@@ -269,6 +324,8 @@ base::Optional<ParseResult> MakeExternalMacro(
   auto operator_name = child_results->NextAs<base::Optional<std::string>>();
   auto name = child_results->NextAs<std::string>();
   auto generic_parameters = child_results->NextAs<GenericParameters>();
+  LintGenericParameters(generic_parameters);
+
   auto args = child_results->NextAs<ParameterList>();
   auto return_type = child_results->NextAs<TypeExpression*>();
   auto labels = child_results->NextAs<LabelAndTypesVector>();
@@ -287,7 +344,13 @@ base::Optional<ParseResult> MakeTorqueMacroDeclaration(
     ParseResultIterator* child_results) {
   auto operator_name = child_results->NextAs<base::Optional<std::string>>();
   auto name = child_results->NextAs<std::string>();
+  if (!IsUpperCamelCase(name)) {
+    NamingConventionError("Macro", name, "UpperCamelCase");
+  }
+
   auto generic_parameters = child_results->NextAs<GenericParameters>();
+  LintGenericParameters(generic_parameters);
+
   auto args = child_results->NextAs<ParameterList>();
   auto return_type = child_results->NextAs<TypeExpression*>();
   auto labels = child_results->NextAs<LabelAndTypesVector>();
@@ -308,7 +371,13 @@ base::Optional<ParseResult> MakeTorqueBuiltinDeclaration(
     ParseResultIterator* child_results) {
   auto javascript_linkage = child_results->NextAs<bool>();
   auto name = child_results->NextAs<std::string>();
+  if (!IsUpperCamelCase(name)) {
+    NamingConventionError("Builtin", name, "UpperCamelCase");
+  }
+
   auto generic_parameters = child_results->NextAs<GenericParameters>();
+  LintGenericParameters(generic_parameters);
+
   auto args = child_results->NextAs<ParameterList>();
   auto return_type = child_results->NextAs<TypeExpression*>();
   auto body = child_results->NextAs<base::Optional<Statement*>>();
@@ -327,6 +396,10 @@ base::Optional<ParseResult> MakeTorqueBuiltinDeclaration(
 base::Optional<ParseResult> MakeConstDeclaration(
     ParseResultIterator* child_results) {
   auto name = child_results->NextAs<std::string>();
+  if (!IsValidModuleConstName(name)) {
+    NamingConventionError("Constant", name, "kUpperCamelCase");
+  }
+
   auto type = child_results->NextAs<TypeExpression*>();
   auto expression = child_results->NextAs<Expression*>();
   Declaration* result =
@@ -355,6 +428,9 @@ base::Optional<ParseResult> MakeTypeAliasDeclaration(
 base::Optional<ParseResult> MakeTypeDeclaration(
     ParseResultIterator* child_results) {
   auto name = child_results->NextAs<std::string>();
+  if (!IsValidTypeName(name)) {
+    NamingConventionError("Type", name, "UpperCamelCase");
+  }
   auto extends = child_results->NextAs<base::Optional<std::string>>();
   auto generates = child_results->NextAs<base::Optional<std::string>>();
   auto constexpr_generates =
@@ -368,6 +444,9 @@ base::Optional<ParseResult> MakeTypeDeclaration(
 base::Optional<ParseResult> MakeExplicitModuleDeclaration(
     ParseResultIterator* child_results) {
   auto name = child_results->NextAs<std::string>();
+  if (!IsSnakeCase(name)) {
+    NamingConventionError("Module", name, "snake_case");
+  }
   auto declarations = child_results->NextAs<std::vector<Declaration*>>();
   Declaration* result = MakeNode<ExplicitModuleDeclaration>(
       std::move(name), std::move(declarations));
@@ -383,6 +462,7 @@ base::Optional<ParseResult> MakeSpecializationDeclaration(
   auto return_type = child_results->NextAs<TypeExpression*>();
   auto labels = child_results->NextAs<LabelAndTypesVector>();
   auto body = child_results->NextAs<Statement*>();
+  CheckNotDeferredStatement(body);
   Declaration* result = MakeNode<SpecializationDeclaration>(
       std::move(name), std::move(generic_parameters), std::move(parameters),
       return_type, std::move(labels), body);
@@ -403,6 +483,8 @@ base::Optional<ParseResult> MakeExternalBuiltin(
   auto js_linkage = child_results->NextAs<bool>();
   auto name = child_results->NextAs<std::string>();
   auto generic_parameters = child_results->NextAs<GenericParameters>();
+  LintGenericParameters(generic_parameters);
+
   auto args = child_results->NextAs<ParameterList>();
   auto return_type = child_results->NextAs<TypeExpression*>();
   BuiltinDeclaration* builtin =
@@ -535,10 +617,11 @@ base::Optional<ParseResult> MakeTypeswitchStatement(
     }
     BlockStatement* case_block;
     if (i < cases.size() - 1) {
-      value = MakeNode<CallExpression>(
-          "cast", false, std::vector<TypeExpression*>{cases[i].type},
-          std::vector<Expression*>{value},
-          std::vector<std::string>{"_NextCase"});
+      value =
+          MakeCall("Cast", false, std::vector<TypeExpression*>{cases[i].type},
+                   std::vector<Expression*>{value},
+                   std::vector<Statement*>{MakeNode<ExpressionStatement>(
+                       MakeNode<IdentifierExpression>("_NextCase"))});
       case_block = MakeNode<BlockStatement>();
     } else {
       case_block = current_block;
@@ -550,9 +633,11 @@ base::Optional<ParseResult> MakeTypeswitchStatement(
     case_block->statements.push_back(cases[i].block);
     if (i < cases.size() - 1) {
       BlockStatement* next_block = MakeNode<BlockStatement>();
-      current_block->statements.push_back(MakeNode<TryLabelStatement>(
-          case_block, std::vector<LabelBlock*>{MakeNode<LabelBlock>(
-                          "_NextCase", ParameterList::Empty(), next_block)}));
+      current_block->statements.push_back(
+          MakeNode<ExpressionStatement>(MakeNode<TryLabelExpression>(
+              MakeNode<StatementExpression>(case_block),
+              MakeNode<LabelBlock>("_NextCase", ParameterList::Empty(),
+                                   next_block))));
       current_block = next_block;
     }
     accumulated_types =
@@ -567,6 +652,7 @@ base::Optional<ParseResult> MakeTypeswitchCase(
   auto name = child_results->NextAs<base::Optional<std::string>>();
   auto type = child_results->NextAs<TypeExpression*>();
   auto block = child_results->NextAs<Statement*>();
+  CheckNotDeferredStatement(block);
   return ParseResult{TypeswitchCase{child_results->matched_input().pos,
                                     std::move(name), type, block}};
 }
@@ -576,6 +662,7 @@ base::Optional<ParseResult> MakeWhileStatement(
   auto condition = child_results->NextAs<Expression*>();
   auto body = child_results->NextAs<Statement*>();
   Statement* result = MakeNode<WhileStatement>(condition, body);
+  CheckNotDeferredStatement(result);
   return ParseResult{result};
 }
 
@@ -599,6 +686,10 @@ base::Optional<ParseResult> MakeVarDeclarationStatement(
   bool const_qualified = kind == "const";
   if (!const_qualified) DCHECK_EQ("let", kind);
   auto name = child_results->NextAs<std::string>();
+  if (!IsLowerCamelCase(name)) {
+    NamingConventionError("Variable", name, "lowerCamelCase");
+  }
+
   auto type = child_results->NextAs<TypeExpression*>();
   base::Optional<Expression*> initializer;
   if (child_results->HasNext())
@@ -637,21 +728,27 @@ base::Optional<ParseResult> MakeBlockStatement(
   return ParseResult{result};
 }
 
-base::Optional<ParseResult> MakeTryLabelStatement(
+base::Optional<ParseResult> MakeTryLabelExpression(
     ParseResultIterator* child_results) {
   auto try_block = child_results->NextAs<Statement*>();
+  CheckNotDeferredStatement(try_block);
+  Statement* result = try_block;
   auto label_blocks = child_results->NextAs<std::vector<LabelBlock*>>();
-  Statement* result =
-      MakeNode<TryLabelStatement>(try_block, std::move(label_blocks));
+  for (auto block : label_blocks) {
+    result = MakeNode<ExpressionStatement>(MakeNode<TryLabelExpression>(
+        MakeNode<StatementExpression>(result), block));
+  }
   return ParseResult{result};
 }
 
 base::Optional<ParseResult> MakeForOfLoopStatement(
     ParseResultIterator* child_results) {
   auto var_decl = child_results->NextAs<Statement*>();
+  CheckNotDeferredStatement(var_decl);
   auto iterable = child_results->NextAs<Expression*>();
   auto range = child_results->NextAs<base::Optional<RangeExpression>>();
   auto body = child_results->NextAs<Statement*>();
+  CheckNotDeferredStatement(body);
   Statement* result =
       MakeNode<ForOfLoopStatement>(var_decl, iterable, range, body);
   return ParseResult{result};
@@ -663,12 +760,16 @@ base::Optional<ParseResult> MakeForLoopStatement(
   auto test = child_results->NextAs<base::Optional<Expression*>>();
   auto action = child_results->NextAs<base::Optional<Expression*>>();
   auto body = child_results->NextAs<Statement*>();
+  CheckNotDeferredStatement(body);
   Statement* result = MakeNode<ForLoopStatement>(var_decl, test, action, body);
   return ParseResult{result};
 }
 
 base::Optional<ParseResult> MakeLabelBlock(ParseResultIterator* child_results) {
   auto label = child_results->NextAs<std::string>();
+  if (!IsUpperCamelCase(label)) {
+    NamingConventionError("Label", label, "UpperCamelCase");
+  }
   auto parameters = child_results->NextAs<ParameterList>();
   auto body = child_results->NextAs<Statement*>();
   LabelBlock* result =
@@ -798,6 +899,9 @@ base::Optional<ParseResult> MakeConditionalExpression(
 base::Optional<ParseResult> MakeLabelAndTypes(
     ParseResultIterator* child_results) {
   auto name = child_results->NextAs<std::string>();
+  if (!IsUpperCamelCase(name)) {
+    NamingConventionError("Label", name, "UpperCamelCase");
+  }
   auto types = child_results->NextAs<std::vector<TypeExpression*>>();
   return ParseResult{LabelAndTypes{std::move(name), std::move(types)}};
 }
@@ -963,10 +1067,10 @@ struct TorqueGrammar : Grammar {
       Sequence({Token("labels"),
                 NonemptyList<LabelAndTypes>(&labelParameter, Token(","))}))};
 
-  // Result: std::vector<std::string>
-  Symbol* optionalOtherwise{TryOrDefault<std::vector<std::string>>(
+  // Result: std::vector<Statement*>
+  Symbol* optionalOtherwise{TryOrDefault<std::vector<Statement*>>(
       Sequence({Token("otherwise"),
-                NonemptyList<std::string>(&identifier, Token(","))}))};
+                NonemptyList<Statement*>(&atomarStatement, Token(","))}))};
 
   // Result: NameAndTypeExpression
   Symbol nameAndType = {
@@ -987,7 +1091,7 @@ struct TorqueGrammar : Grammar {
            MakeParameterListFromNameAndTypeList<true>)};
 
   // Result: std::string
-  Symbol* OneOf(std::vector<std::string> alternatives) {
+  Symbol* OneOf(const std::vector<std::string>& alternatives) {
     Symbol* result = NewSymbol();
     for (const std::string& s : alternatives) {
       result->AddRule(Rule({Token(s)}, YieldMatchedInput));
@@ -1147,28 +1251,27 @@ struct TorqueGrammar : Grammar {
             expression},
            MakeVarDeclarationStatement)};
 
-  // Disallow ambiguous dangling else by only allowing an {atomarStatement} as
-  // a then-clause. Result: Statement*
+  // Result: Statement*
   Symbol atomarStatement = {
-      Rule({&block}),
-      Rule({expression, Token(";")}, MakeExpressionStatement),
-      Rule({Token("return"), Optional<Expression*>(expression), Token(";")},
+      Rule({expression}, MakeExpressionStatement),
+      Rule({Token("return"), Optional<Expression*>(expression)},
            MakeReturnStatement),
-      Rule({Token("tail"), &callExpression, Token(";")}, MakeTailCallStatement),
-      Rule({Token("break"), Token(";")}, MakeBreakStatement),
-      Rule({Token("continue"), Token(";")}, MakeContinueStatement),
+      Rule({Token("tail"), &callExpression}, MakeTailCallStatement),
+      Rule({Token("break")}, MakeBreakStatement),
+      Rule({Token("continue")}, MakeContinueStatement),
       Rule({Token("goto"), &identifier,
-            TryOrDefault<std::vector<Expression*>>(&argumentList), Token(";")},
+            TryOrDefault<std::vector<Expression*>>(&argumentList)},
            MakeGotoStatement),
-      Rule({OneOf({"debug", "unreachable"}), Token(";")}, MakeDebugStatement)};
+      Rule({OneOf({"debug", "unreachable"})}, MakeDebugStatement)};
 
   // Result: Statement*
   Symbol statement = {
-      Rule({&atomarStatement}),
+      Rule({&block}),
+      Rule({&atomarStatement, Token(";")}),
       Rule({&varDeclaration, Token(";")}),
       Rule({&varDeclarationWithInitialization, Token(";")}),
       Rule({Token("if"), CheckIf(Token("constexpr")), Token("("), expression,
-            Token(")"), &atomarStatement,
+            Token(")"), &statement,
             Optional<Statement*>(Sequence({Token("else"), &statement}))},
            MakeIfStatement),
       Rule(
@@ -1179,28 +1282,26 @@ struct TorqueGrammar : Grammar {
           },
           MakeTypeswitchStatement),
       Rule({Token("try"), &block, NonemptyList<LabelBlock*>(&labelBlock)},
-           MakeTryLabelStatement),
+           MakeTryLabelExpression),
       Rule({OneOf({"assert", "check"}), Token("("), &expressionWithSource,
             Token(")"), Token(";")},
            MakeAssertStatement),
-      Rule({Token("while"), Token("("), expression, Token(")"),
-            &atomarStatement},
+      Rule({Token("while"), Token("("), expression, Token(")"), &statement},
            MakeWhileStatement),
       Rule({Token("for"), Token("("), &varDeclaration, Token("of"), expression,
-            Optional<RangeExpression>(&rangeSpecifier), Token(")"),
-            &atomarStatement},
+            Optional<RangeExpression>(&rangeSpecifier), Token(")"), &statement},
            MakeForOfLoopStatement),
       Rule({Token("for"), Token("("),
             Optional<Statement*>(&varDeclarationWithInitialization), Token(";"),
             Optional<Expression*>(expression), Token(";"),
-            Optional<Expression*>(expression), Token(")"), &atomarStatement},
+            Optional<Expression*>(expression), Token(")"), &statement},
            MakeForLoopStatement)};
 
   // Result: TypeswitchCase
   Symbol typeswitchCase = {
       Rule({Token("case"), Token("("),
             Optional<std::string>(Sequence({&identifier, Token(":")})), &type,
-            Token(")"), &block},
+            Token(")"), Token(":"), &block},
            MakeTypeswitchCase)};
 
   // Result: base::Optional<Statement*>
diff --git a/deps/v8/src/torque/torque.cc b/deps/v8/src/torque/torque.cc
index 8fcd0be6eb..fd47251d59 100644
--- a/deps/v8/src/torque/torque.cc
+++ b/deps/v8/src/torque/torque.cc
@@ -26,6 +26,8 @@ int WrappedMain(int argc, const char** argv) {
   CurrentSourceFile::Scope unknown_sourcefile_scope(
       SourceFileMap::AddSource("<unknown>"));
   CurrentAst::Scope ast_scope;
+  LintErrorStatus::Scope lint_error_status_scope;
+
   for (int i = 1; i < argc; ++i) {
     // Check for options
     if (!strcmp("-o", argv[i])) {
@@ -76,6 +78,9 @@ int WrappedMain(int argc, const char** argv) {
       visitor.GenerateImplementation(output_directory, module.second.get());
     }
   }
+
+  if (LintErrorStatus::HasLintErrors()) std::abort();
+
   return 0;
 }
 
diff --git a/deps/v8/src/torque/types.cc b/deps/v8/src/torque/types.cc
index 261f085edb..4f009a8f32 100644
--- a/deps/v8/src/torque/types.cc
+++ b/deps/v8/src/torque/types.cc
@@ -255,7 +255,7 @@ bool Signature::HasSameTypesAs(const Signature& other) const {
     return false;
   }
   size_t i = 0;
-  for (auto l : labels) {
+  for (const auto& l : labels) {
     if (l.types != other.labels[i++].types) {
       return false;
     }
@@ -293,28 +293,66 @@ bool operator<(const Type& a, const Type& b) {
   return a.MangledName() < b.MangledName();
 }
 
-VisitResult::VisitResult(const Type* type, const Value* declarable)
-    : type_(type), value_(), declarable_(declarable) {}
-
-std::string VisitResult::LValue() const {
-  return std::string("*") + (declarable_ ? (*declarable_)->value() : value_);
+VisitResult ProjectStructField(VisitResult structure,
+                               const std::string& fieldname) {
+  DCHECK(structure.IsOnStack());
+  BottomOffset begin = structure.stack_range().begin();
+  const StructType* type = StructType::cast(structure.type());
+  for (auto& field : type->fields()) {
+    BottomOffset end = begin + LoweredSlotCount(field.type);
+    if (field.name == fieldname) {
+      return VisitResult(field.type, StackRange{begin, end});
+    }
+    begin = end;
+  }
+  UNREACHABLE();
 }
 
-std::string VisitResult::RValue() const {
-  std::string result;
-  if (declarable()) {
-    auto value = *declarable();
-    if (value->IsVariable() && !Variable::cast(value)->IsDefined()) {
-      std::stringstream s;
-      s << "\"" << value->name() << "\" is used before it is defined";
-      ReportError(s.str());
+namespace {
+void AppendLoweredTypes(const Type* type, std::vector<const Type*>* result) {
+  DCHECK_NE(type, TypeOracle::GetNeverType());
+  if (type->IsConstexpr()) return;
+  if (type == TypeOracle::GetVoidType()) return;
+  if (auto* s = StructType::DynamicCast(type)) {
+    for (const NameAndType& field : s->fields()) {
+      AppendLoweredTypes(field.type, result);
     }
-    result = value->RValue();
   } else {
-    result = value_;
+    result->push_back(type);
+  }
+}
+}  // namespace
+
+TypeVector LowerType(const Type* type) {
+  TypeVector result;
+  AppendLoweredTypes(type, &result);
+  return result;
+}
+
+size_t LoweredSlotCount(const Type* type) { return LowerType(type).size(); }
+
+TypeVector LowerParameterTypes(const TypeVector& parameters) {
+  std::vector<const Type*> result;
+  for (const Type* t : parameters) {
+    AppendLoweredTypes(t, &result);
+  }
+  return result;
+}
+
+TypeVector LowerParameterTypes(const ParameterTypes& parameter_types,
+                               size_t arg_count) {
+  std::vector<const Type*> result = LowerParameterTypes(parameter_types.types);
+  for (size_t i = parameter_types.types.size(); i < arg_count; ++i) {
+    DCHECK(parameter_types.var_args);
+    AppendLoweredTypes(TypeOracle::GetObjectType(), &result);
   }
-  return "implicit_cast<" + type()->GetGeneratedTypeName() + ">(" + result +
-         ")";
+  return result;
+}
+
+VisitResult VisitResult::NeverResult() {
+  VisitResult result;
+  result.type_ = TypeOracle::GetNeverType();
+  return result;
 }
 
 }  // namespace torque
diff --git a/deps/v8/src/torque/types.h b/deps/v8/src/torque/types.h
index 24acaea5c7..e94413e4c9 100644
--- a/deps/v8/src/torque/types.h
+++ b/deps/v8/src/torque/types.h
@@ -44,7 +44,7 @@ class TypeBase {
     kUnionType,
     kStructType
   };
-  virtual ~TypeBase() {}
+  virtual ~TypeBase() = default;
   bool IsAbstractType() const { return kind() == Kind::kAbstractType; }
   bool IsFunctionPointerType() const {
     return kind() == Kind::kFunctionPointerType;
@@ -344,22 +344,35 @@ inline std::ostream& operator<<(std::ostream& os, const Type& t) {
 
 class VisitResult {
  public:
-  VisitResult() {}
-  VisitResult(const Type* type, const std::string& value)
-      : type_(type), value_(value), declarable_{} {}
-  VisitResult(const Type* type, const Value* declarable);
+  VisitResult() = default;
+  VisitResult(const Type* type, const std::string& constexpr_value)
+      : type_(type), constexpr_value_(constexpr_value) {
+    DCHECK(type->IsConstexpr());
+  }
+  static VisitResult NeverResult();
+  VisitResult(const Type* type, StackRange stack_range)
+      : type_(type), stack_range_(stack_range) {
+    DCHECK(!type->IsConstexpr());
+  }
   const Type* type() const { return type_; }
-  base::Optional<const Value*> declarable() const { return declarable_; }
-  std::string LValue() const;
-  std::string RValue() const;
+  const std::string& constexpr_value() const { return *constexpr_value_; }
+  const StackRange& stack_range() const { return *stack_range_; }
   void SetType(const Type* new_type) { type_ = new_type; }
+  bool IsOnStack() const { return stack_range_ != base::nullopt; }
+  bool operator==(const VisitResult& other) const {
+    return type_ == other.type_ && constexpr_value_ == other.constexpr_value_ &&
+           stack_range_ == other.stack_range_;
+  }
 
  private:
   const Type* type_ = nullptr;
-  std::string value_;
-  base::Optional<const Value*> declarable_;
+  base::Optional<std::string> constexpr_value_;
+  base::Optional<StackRange> stack_range_;
 };
 
+VisitResult ProjectStructField(VisitResult structure,
+                               const std::string& fieldname);
+
 class VisitResultVector : public std::vector<VisitResult> {
  public:
   VisitResultVector() : std::vector<VisitResult>() {}
@@ -420,6 +433,12 @@ bool IsAssignableFrom(const Type* to, const Type* from);
 bool IsCompatibleSignature(const Signature& sig, const TypeVector& types,
                            const std::vector<Label*>& labels);
 
+TypeVector LowerType(const Type* type);
+size_t LoweredSlotCount(const Type* type);
+TypeVector LowerParameterTypes(const TypeVector& parameters);
+TypeVector LowerParameterTypes(const ParameterTypes& parameter_types,
+                               size_t vararg_count = 0);
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/torque/utils.cc b/deps/v8/src/torque/utils.cc
index fb3f66ab02..b39ea288e0 100644
--- a/deps/v8/src/torque/utils.cc
+++ b/deps/v8/src/torque/utils.cc
@@ -7,6 +7,7 @@
 #include <iostream>
 #include <string>
 
+#include "src/base/logging.h"
 #include "src/torque/ast.h"
 #include "src/torque/utils.h"
 
@@ -76,9 +77,89 @@ std::string CurrentPositionAsString() {
   return PositionAsString(CurrentSourcePosition::Get());
 }
 
-[[noreturn]] void ReportError(const std::string& error) {
+DEFINE_CONTEXTUAL_VARIABLE(LintErrorStatus)
+
+[[noreturn]] void ReportErrorString(const std::string& error) {
   std::cerr << CurrentPositionAsString() << ": Torque error: " << error << "\n";
-  std::abort();
+  v8::base::OS::Abort();
+}
+
+void LintError(const std::string& error) {
+  LintErrorStatus::SetLintError();
+  std::cerr << CurrentPositionAsString() << ": Lint error: " << error << "\n";
+}
+
+void NamingConventionError(const std::string& type, const std::string& name,
+                           const std::string& convention) {
+  std::stringstream sstream;
+  sstream << type << " \"" << name << "\" doesn't follow \"" << convention
+          << "\" naming convention.";
+  LintError(sstream.str());
+}
+
+namespace {
+
+bool ContainsUnderscore(const std::string& s) {
+  if (s.empty()) return false;
+  return s.find("_") != std::string::npos;
+}
+
+bool ContainsUpperCase(const std::string& s) {
+  if (s.empty()) return false;
+  return std::any_of(s.begin(), s.end(), [](char c) { return isupper(c); });
+}
+
+// Torque has some module constants that are used like language level
+// keywords, e.g.: 'True', 'Undefined', etc.
+// These do not need to follow the default naming convention for constants.
+bool IsKeywordLikeName(const std::string& s) {
+  static const std::vector<std::string> keyword_like_constants{
+      "True", "False", "Hole", "Null", "Undefined"};
+
+  return std::find(keyword_like_constants.begin(), keyword_like_constants.end(),
+                   s) != keyword_like_constants.end();
+}
+
+// Untagged/MachineTypes like 'int32', 'intptr' etc. follow a 'all-lowercase'
+// naming convention and are those exempt from the normal type convention.
+bool IsMachineType(const std::string& s) {
+  static const std::vector<std::string> machine_types{
+      "void",    "never",   "int32",   "uint32", "int64",  "intptr",
+      "uintptr", "float32", "float64", "bool",   "string", "int31"};
+
+  return std::find(machine_types.begin(), machine_types.end(), s) !=
+         machine_types.end();
+}
+
+}  // namespace
+
+bool IsLowerCamelCase(const std::string& s) {
+  if (s.empty()) return false;
+  return islower(s[0]) && !ContainsUnderscore(s);
+}
+
+bool IsUpperCamelCase(const std::string& s) {
+  if (s.empty()) return false;
+  return isupper(s[0]) && !ContainsUnderscore(s);
+}
+
+bool IsSnakeCase(const std::string& s) {
+  if (s.empty()) return false;
+  return !ContainsUpperCase(s);
+}
+
+bool IsValidModuleConstName(const std::string& s) {
+  if (s.empty()) return false;
+  if (IsKeywordLikeName(s)) return true;
+
+  return s[0] == 'k' && IsUpperCamelCase(s.substr(1));
+}
+
+bool IsValidTypeName(const std::string& s) {
+  if (s.empty()) return false;
+  if (IsMachineType(s)) return true;
+
+  return IsUpperCamelCase(s);
 }
 
 std::string CamelifyString(const std::string& underscore_string) {
diff --git a/deps/v8/src/torque/utils.h b/deps/v8/src/torque/utils.h
index 0612048589..16e3b03ed4 100644
--- a/deps/v8/src/torque/utils.h
+++ b/deps/v8/src/torque/utils.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "src/base/functional.h"
+#include "src/torque/contextual.h"
 
 namespace v8 {
 namespace internal {
@@ -20,7 +21,37 @@ typedef std::vector<std::string> NameVector;
 std::string StringLiteralUnquote(const std::string& s);
 std::string StringLiteralQuote(const std::string& s);
 
-[[noreturn]] void ReportError(const std::string& error);
+class LintErrorStatus : public ContextualClass<LintErrorStatus> {
+ public:
+  LintErrorStatus() : has_lint_errors_(false) {}
+
+  static bool HasLintErrors() { return Get().has_lint_errors_; }
+  static void SetLintError() { Get().has_lint_errors_ = true; }
+
+ private:
+  bool has_lint_errors_;
+};
+
+void LintError(const std::string& error);
+
+// Prints a LintError with the format "{type} '{name}' doesn't follow
+// '{convention}' naming convention".
+void NamingConventionError(const std::string& type, const std::string& name,
+                           const std::string& convention);
+
+bool IsLowerCamelCase(const std::string& s);
+bool IsUpperCamelCase(const std::string& s);
+bool IsSnakeCase(const std::string& s);
+bool IsValidModuleConstName(const std::string& s);
+bool IsValidTypeName(const std::string& s);
+
+[[noreturn]] void ReportErrorString(const std::string& error);
+template <class... Args>
+[[noreturn]] void ReportError(Args&&... args) {
+  std::stringstream s;
+  USE((s << std::forward<Args>(args))...);
+  ReportErrorString(s.str());
+}
 
 std::string CamelifyString(const std::string& underscore_string);
 std::string DashifyString(const std::string& underscore_string);
@@ -82,6 +113,149 @@ void PrintCommaSeparatedList(std::ostream& os, const T& list) {
   }
 }
 
+struct BottomOffset {
+  size_t offset;
+  BottomOffset& operator++() {
+    ++offset;
+    return *this;
+  }
+  BottomOffset operator+(size_t x) const { return BottomOffset{offset + x}; }
+  BottomOffset operator-(size_t x) const {
+    DCHECK_LE(x, offset);
+    return BottomOffset{offset - x};
+  }
+  bool operator<(const BottomOffset& other) const {
+    return offset < other.offset;
+  }
+  bool operator<=(const BottomOffset& other) const {
+    return offset <= other.offset;
+  }
+  bool operator==(const BottomOffset& other) const {
+    return offset == other.offset;
+  }
+  bool operator!=(const BottomOffset& other) const {
+    return offset != other.offset;
+  }
+};
+
+inline std::ostream& operator<<(std::ostream& out, BottomOffset from_bottom) {
+  return out << "BottomOffset{" << from_bottom.offset << "}";
+}
+
+// An iterator-style range of stack slots.
+class StackRange {
+ public:
+  StackRange(BottomOffset begin, BottomOffset end) : begin_(begin), end_(end) {
+    DCHECK_LE(begin_, end_);
+  }
+
+  bool operator==(const StackRange& other) const {
+    return begin_ == other.begin_ && end_ == other.end_;
+  }
+
+  void Extend(StackRange adjacent) {
+    DCHECK_EQ(end_, adjacent.begin_);
+    end_ = adjacent.end_;
+  }
+
+  size_t Size() const { return end_.offset - begin_.offset; }
+  BottomOffset begin() const { return begin_; }
+  BottomOffset end() const { return end_; }
+
+ private:
+  BottomOffset begin_;
+  BottomOffset end_;
+};
+
+template <class T>
+class Stack {
+ public:
+  using value_type = T;
+  Stack() = default;
+  Stack(std::initializer_list<T> initializer)
+      : Stack(std::vector<T>(initializer)) {}
+  explicit Stack(std::vector<T> v) : elements_(std::move(v)) {}
+  size_t Size() const { return elements_.size(); }
+  const T& Peek(BottomOffset from_bottom) const {
+    return elements_.at(from_bottom.offset);
+  }
+  void Poke(BottomOffset from_bottom, T x) {
+    elements_.at(from_bottom.offset) = std::move(x);
+  }
+  void Push(T x) { elements_.push_back(std::move(x)); }
+  StackRange TopRange(size_t slot_count) const {
+    DCHECK_GE(Size(), slot_count);
+    return StackRange{AboveTop() - slot_count, AboveTop()};
+  }
+  StackRange PushMany(const std::vector<T>& v) {
+    for (const T& x : v) {
+      Push(x);
+    }
+    return TopRange(v.size());
+  }
+  const T& Top() const { return Peek(AboveTop() - 1); }
+  T Pop() {
+    T result = std::move(elements_.back());
+    elements_.pop_back();
+    return result;
+  }
+  std::vector<T> PopMany(size_t count) {
+    DCHECK_GE(elements_.size(), count);
+    std::vector<T> result;
+    result.reserve(count);
+    for (auto it = elements_.end() - count; it != elements_.end(); ++it) {
+      result.push_back(std::move(*it));
+    }
+    elements_.resize(elements_.size() - count);
+    return result;
+  }
+  // The invalid offset above the top element. This is useful for StackRange.
+  BottomOffset AboveTop() const { return BottomOffset{Size()}; }
+  // Delete the slots in {range}, moving higher slots to fill the gap.
+  void DeleteRange(StackRange range) {
+    DCHECK_LE(range.end(), AboveTop());
+    for (BottomOffset i = range.begin();
+         i < std::min(range.end(), AboveTop() - range.Size()); ++i) {
+      elements_[i.offset] = std::move(elements_[i.offset + range.Size()]);
+    }
+    elements_.resize(elements_.size() - range.Size());
+  }
+
+  bool operator==(const Stack& other) const {
+    return elements_ == other.elements_;
+  }
+  bool operator!=(const Stack& other) const {
+    return elements_ != other.elements_;
+  }
+
+  T* begin() { return elements_.data(); }
+  T* end() { return begin() + elements_.size(); }
+  const T* begin() const { return elements_.data(); }
+  const T* end() const { return begin() + elements_.size(); }
+
+ private:
+  std::vector<T> elements_;
+};
+
+template <class T>
+T* CheckNotNull(T* x) {
+  CHECK_NOT_NULL(x);
+  return x;
+}
+
+class ToString {
+ public:
+  template <class T>
+  ToString& operator<<(T&& x) {
+    s_ << std::forward<T>(x);
+    return *this;
+  }
+  operator std::string() { return s_.str(); }
+
+ private:
+  std::stringstream s_;
+};
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/tracing/trace-event.h b/deps/v8/src/tracing/trace-event.h
index 52b3bc3461..2f530f9279 100644
--- a/deps/v8/src/tracing/trace-event.h
+++ b/deps/v8/src/tracing/trace-event.h
@@ -50,7 +50,7 @@ enum CategoryGroupEnabledFlags {
   trace_event_internal::TraceID::WithScope(scope, id)
 
 #define INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED_FOR_RECORDING_MODE() \
-  *INTERNAL_TRACE_EVENT_UID(category_group_enabled) &                    \
+  TRACE_EVENT_API_LOAD_CATEGORY_GROUP_ENABLED() &                        \
       (kEnabledForRecording_CategoryGroupEnabledFlags |                  \
        kEnabledForEventCallback_CategoryGroupEnabledFlags)
 
@@ -127,6 +127,9 @@ enum CategoryGroupEnabledFlags {
 #define TRACE_EVENT_API_ATOMIC_LOAD(var) v8::base::Relaxed_Load(&(var))
 #define TRACE_EVENT_API_ATOMIC_STORE(var, value) \
   v8::base::Relaxed_Store(&(var), (value))
+#define TRACE_EVENT_API_LOAD_CATEGORY_GROUP_ENABLED()                \
+  v8::base::Relaxed_Load(reinterpret_cast<const v8::base::Atomic8*>( \
+      INTERNAL_TRACE_EVENT_UID(category_group_enabled)))
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -175,7 +178,7 @@ enum CategoryGroupEnabledFlags {
           v8::internal::tracing::kGlobalScope, v8::internal::tracing::kNoId, \
           v8::internal::tracing::kNoId, flags, ##__VA_ARGS__);               \
     }                                                                        \
-  } while (0)
+  } while (false)
 
 // Implementation detail: internal macro to create static category and add begin
 // event if the category is enabled. Also adds the end event when the scope
@@ -227,7 +230,7 @@ enum CategoryGroupEnabledFlags {
           trace_event_trace_id.scope(), trace_event_trace_id.raw_id(),         \
           v8::internal::tracing::kNoId, trace_event_flags, ##__VA_ARGS__);     \
     }                                                                          \
-  } while (0)
+  } while (false)
 
 // Adds a trace event with a given timestamp.
 #define INTERNAL_TRACE_EVENT_ADD_WITH_TIMESTAMP(phase, category_group, name, \
@@ -240,7 +243,7 @@ enum CategoryGroupEnabledFlags {
           v8::internal::tracing::kGlobalScope, v8::internal::tracing::kNoId, \
           v8::internal::tracing::kNoId, flags, timestamp, ##__VA_ARGS__);    \
     }                                                                        \
-  } while (0)
+  } while (false)
 
 // Adds a trace event with a given id and timestamp.
 #define INTERNAL_TRACE_EVENT_ADD_WITH_ID_AND_TIMESTAMP(                        \
@@ -257,7 +260,7 @@ enum CategoryGroupEnabledFlags {
           v8::internal::tracing::kNoId, trace_event_flags, timestamp,          \
           ##__VA_ARGS__);                                                      \
     }                                                                          \
-  } while (0)
+  } while (false)
 
 // Adds a trace event with a given id, thread_id, and timestamp. This redirects
 // to INTERNAL_TRACE_EVENT_ADD_WITH_ID_AND_TIMESTAMP as we presently do not care
diff --git a/deps/v8/src/transitions-inl.h b/deps/v8/src/transitions-inl.h
index 86bcd66128..072e15318b 100644
--- a/deps/v8/src/transitions-inl.h
+++ b/deps/v8/src/transitions-inl.h
@@ -19,7 +19,7 @@ namespace internal {
 
 TransitionArray* TransitionsAccessor::transitions() {
   DCHECK_EQ(kFullTransitionArray, encoding());
-  return TransitionArray::cast(raw_transitions_->ToStrongHeapObject());
+  return TransitionArray::cast(raw_transitions_->GetHeapObjectAssumeStrong());
 }
 
 CAST_ACCESSOR(TransitionArray)
@@ -31,7 +31,7 @@ bool TransitionArray::HasPrototypeTransitions() {
 WeakFixedArray* TransitionArray::GetPrototypeTransitions() {
   DCHECK(HasPrototypeTransitions());  // Callers must check first.
   Object* prototype_transitions =
-      Get(kPrototypeTransitionsIndex)->ToStrongHeapObject();
+      Get(kPrototypeTransitionsIndex)->GetHeapObjectAssumeStrong();
   return WeakFixedArray::cast(prototype_transitions);
 }
 
@@ -52,12 +52,13 @@ int TransitionArray::NumberOfPrototypeTransitions(
   if (proto_transitions->length() == 0) return 0;
   MaybeObject* raw =
       proto_transitions->Get(kProtoTransitionNumberOfEntriesOffset);
-  return Smi::ToInt(raw->ToSmi());
+  return Smi::ToInt(raw->cast<Smi>());
 }
 
 Name* TransitionArray::GetKey(int transition_number) {
   DCHECK(transition_number < number_of_transitions());
-  return Name::cast(Get(ToKeyIndex(transition_number))->ToStrongHeapObject());
+  return Name::cast(
+      Get(ToKeyIndex(transition_number))->GetHeapObjectAssumeStrong());
 }
 
 Name* TransitionsAccessor::GetKey(int transition_number) {
@@ -67,7 +68,7 @@ Name* TransitionsAccessor::GetKey(int transition_number) {
       UNREACHABLE();
       return nullptr;
     case kWeakRef: {
-      Map* map = Map::cast(raw_transitions_->ToWeakHeapObject());
+      Map* map = Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
       return GetSimpleTransitionKey(map);
     }
     case kFullTransitionArray:
@@ -100,7 +101,7 @@ PropertyDetails TransitionsAccessor::GetTargetDetails(Name* name, Map* target) {
 
 // static
 Map* TransitionsAccessor::GetTargetFromRaw(MaybeObject* raw) {
-  return Map::cast(raw->ToWeakHeapObject());
+  return Map::cast(raw->GetHeapObjectAssumeWeak());
 }
 
 MaybeObject* TransitionArray::GetRawTarget(int transition_number) {
@@ -120,7 +121,7 @@ Map* TransitionsAccessor::GetTarget(int transition_number) {
       UNREACHABLE();
       return nullptr;
     case kWeakRef:
-      return Map::cast(raw_transitions_->ToWeakHeapObject());
+      return Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
     case kFullTransitionArray:
       return transitions()->GetTarget(transition_number);
   }
@@ -129,7 +130,8 @@ Map* TransitionsAccessor::GetTarget(int transition_number) {
 
 void TransitionArray::SetRawTarget(int transition_number, MaybeObject* value) {
   DCHECK(transition_number < number_of_transitions());
-  DCHECK(value->IsWeakHeapObject() && value->ToWeakHeapObject()->IsMap());
+  DCHECK(value->IsWeak());
+  DCHECK(value->GetHeapObjectAssumeWeak()->IsMap());
   WeakFixedArray::Set(ToTargetIndex(transition_number), value);
 }
 
@@ -137,7 +139,7 @@ bool TransitionArray::GetTargetIfExists(int transition_number, Isolate* isolate,
                                         Map** target) {
   MaybeObject* raw = GetRawTarget(transition_number);
   HeapObject* heap_object;
-  if (raw->ToStrongHeapObject(&heap_object) &&
+  if (raw->GetHeapObjectIfStrong(&heap_object) &&
       heap_object->IsUndefined(isolate)) {
     return false;
   }
@@ -153,7 +155,7 @@ int TransitionArray::SearchName(Name* name, int* out_insertion_index) {
 
 int TransitionArray::number_of_transitions() const {
   if (length() < kFirstIndex) return 0;
-  return Smi::ToInt(Get(kTransitionLengthIndex)->ToSmi());
+  return Smi::ToInt(Get(kTransitionLengthIndex)->cast<Smi>());
 }
 
 int TransitionArray::CompareKeys(Name* key1, uint32_t hash1, PropertyKind kind1,
diff --git a/deps/v8/src/transitions.cc b/deps/v8/src/transitions.cc
index 2ca28d9321..6c55f53b03 100644
--- a/deps/v8/src/transitions.cc
+++ b/deps/v8/src/transitions.cc
@@ -14,12 +14,11 @@ namespace internal {
 void TransitionsAccessor::Initialize() {
   raw_transitions_ = map_->raw_transitions();
   HeapObject* heap_object;
-  if (raw_transitions_->IsSmi() ||
-      raw_transitions_->IsClearedWeakHeapObject()) {
+  if (raw_transitions_->IsSmi() || raw_transitions_->IsCleared()) {
     encoding_ = kUninitialized;
-  } else if (raw_transitions_->IsWeakHeapObject()) {
+  } else if (raw_transitions_->IsWeak()) {
     encoding_ = kWeakRef;
-  } else if (raw_transitions_->ToStrongHeapObject(&heap_object)) {
+  } else if (raw_transitions_->GetHeapObjectIfStrong(&heap_object)) {
     if (heap_object->IsTransitionArray()) {
       encoding_ = kFullTransitionArray;
     } else {
@@ -37,7 +36,7 @@ void TransitionsAccessor::Initialize() {
 Map* TransitionsAccessor::GetSimpleTransition() {
   switch (encoding()) {
     case kWeakRef:
-      return Map::cast(raw_transitions_->ToWeakHeapObject());
+      return Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
     default:
       return nullptr;
   }
@@ -46,7 +45,7 @@ Map* TransitionsAccessor::GetSimpleTransition() {
 bool TransitionsAccessor::HasSimpleTransitionTo(Map* map) {
   switch (encoding()) {
     case kWeakRef:
-      return raw_transitions_->ToWeakHeapObject() == map;
+      return raw_transitions_->GetHeapObjectAssumeWeak() == map;
     case kPrototypeInfo:
     case kUninitialized:
     case kFullTransitionArray:
@@ -215,7 +214,7 @@ Map* TransitionsAccessor::SearchTransition(Name* name, PropertyKind kind,
     case kUninitialized:
       return nullptr;
     case kWeakRef: {
-      Map* map = Map::cast(raw_transitions_->ToWeakHeapObject());
+      Map* map = Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
       if (!IsMatchingMap(map, name, kind, attributes)) return nullptr;
       return map;
     }
@@ -268,7 +267,7 @@ Handle<String> TransitionsAccessor::ExpectedTransitionKey() {
     case kFullTransitionArray:
       return Handle<String>::null();
     case kWeakRef: {
-      Map* target = Map::cast(raw_transitions_->ToWeakHeapObject());
+      Map* target = Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
       PropertyDetails details = GetSimpleTargetDetails(target);
       if (details.location() != kField) return Handle<String>::null();
       DCHECK_EQ(kData, details.kind());
@@ -318,9 +317,9 @@ bool TransitionArray::CompactPrototypeTransitionArray(Isolate* isolate,
   int new_number_of_transitions = 0;
   for (int i = 0; i < number_of_transitions; i++) {
     MaybeObject* target = array->Get(header + i);
-    DCHECK(target->IsClearedWeakHeapObject() ||
-           (target->IsWeakHeapObject() && target->ToWeakHeapObject()->IsMap()));
-    if (!target->IsClearedWeakHeapObject()) {
+    DCHECK(target->IsCleared() ||
+           (target->IsWeak() && target->GetHeapObject()->IsMap()));
+    if (!target->IsCleared()) {
       if (new_number_of_transitions != i) {
         array->Set(header + new_number_of_transitions, target);
       }
@@ -399,9 +398,10 @@ Handle<Map> TransitionsAccessor::GetPrototypeTransition(
   for (int i = 0; i < length; i++) {
     MaybeObject* target =
         cache->Get(TransitionArray::kProtoTransitionHeaderSize + i);
-    DCHECK(target->IsClearedWeakHeapObject() || target->IsWeakHeapObject());
-    if (!target->IsClearedWeakHeapObject()) {
-      Map* map = Map::cast(target->ToWeakHeapObject());
+    DCHECK(target->IsWeakOrCleared());
+    HeapObject* heap_object;
+    if (target->GetHeapObjectIfWeak(&heap_object)) {
+      Map* map = Map::cast(heap_object);
       if (map->prototype() == *prototype) {
         return handle(map, isolate_);
       }
@@ -452,9 +452,9 @@ void TransitionsAccessor::ReplaceTransitions(MaybeObject* new_transitions) {
   if (encoding() == kFullTransitionArray) {
     TransitionArray* old_transitions = transitions();
 #if DEBUG
-    CheckNewTransitionsAreConsistent(old_transitions,
-                                     new_transitions->ToStrongHeapObject());
-    DCHECK(old_transitions != new_transitions->ToStrongHeapObject());
+    CheckNewTransitionsAreConsistent(
+        old_transitions, new_transitions->GetHeapObjectAssumeStrong());
+    DCHECK(old_transitions != new_transitions->GetHeapObjectAssumeStrong());
 #endif
     // Transition arrays are not shared. When one is replaced, it should not
     // keep referenced objects alive, so we zap it.
@@ -499,7 +499,8 @@ void TransitionsAccessor::TraverseTransitionTreeInternal(
     case kUninitialized:
       break;
     case kWeakRef: {
-      Map* simple_target = Map::cast(raw_transitions_->ToWeakHeapObject());
+      Map* simple_target =
+          Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
       TransitionsAccessor(isolate_, simple_target, no_gc)
           .TraverseTransitionTreeInternal(callback, data, no_gc);
       break;
@@ -511,12 +512,13 @@ void TransitionsAccessor::TraverseTransitionTreeInternal(
         for (int i = 0; i < length; ++i) {
           int index = TransitionArray::kProtoTransitionHeaderSize + i;
           MaybeObject* target = proto_trans->Get(index);
-          DCHECK(target->IsClearedWeakHeapObject() ||
-                 target->IsWeakHeapObject());
-          if (target->IsClearedWeakHeapObject()) continue;
-          TransitionsAccessor(isolate_, Map::cast(target->ToWeakHeapObject()),
-                              no_gc)
-              .TraverseTransitionTreeInternal(callback, data, no_gc);
+          HeapObject* heap_object;
+          if (target->GetHeapObjectIfWeak(&heap_object)) {
+            TransitionsAccessor(isolate_, Map::cast(heap_object), no_gc)
+                .TraverseTransitionTreeInternal(callback, data, no_gc);
+          } else {
+            DCHECK(target->IsCleared());
+          }
         }
       }
       for (int i = 0; i < transitions()->number_of_transitions(); ++i) {
diff --git a/deps/v8/src/trap-handler/trap-handler.h b/deps/v8/src/trap-handler/trap-handler.h
index c25de9c1e9..0e9dbf248c 100644
--- a/deps/v8/src/trap-handler/trap-handler.h
+++ b/deps/v8/src/trap-handler/trap-handler.h
@@ -23,9 +23,9 @@ namespace trap_handler {
 
 // TODO(eholk): Support trap handlers on other platforms.
 #if V8_TARGET_ARCH_X64 && V8_OS_LINUX && !V8_OS_ANDROID
-#define V8_TRAP_HANDLER_SUPPORTED 1
+#define V8_TRAP_HANDLER_SUPPORTED true
 #else
-#define V8_TRAP_HANDLER_SUPPORTED 0
+#define V8_TRAP_HANDLER_SUPPORTED false
 #endif
 
 struct ProtectedInstructionData {
@@ -100,12 +100,6 @@ inline void ClearThreadInWasm() {
   }
 }
 
-class ThreadInWasmScope {
- public:
-  ThreadInWasmScope() { SetThreadInWasm(); }
-  ~ThreadInWasmScope() { ClearThreadInWasm(); }
-};
-
 bool RegisterDefaultTrapHandler();
 V8_EXPORT_PRIVATE void RestoreOriginalSignalHandler();
 
diff --git a/deps/v8/src/turbo-assembler.cc b/deps/v8/src/turbo-assembler.cc
index d6134806fa..4bb09047bb 100644
--- a/deps/v8/src/turbo-assembler.cc
+++ b/deps/v8/src/turbo-assembler.cc
@@ -32,7 +32,7 @@ void TurboAssemblerBase::IndirectLoadConstant(Register destination,
   // check if any of the fast paths can be applied.
 
   int builtin_index;
-  Heap::RootListIndex root_index;
+  RootIndex root_index;
   if (isolate()->heap()->IsRootHandle(object, &root_index)) {
     // Roots are loaded relative to the root register.
     LoadRoot(destination, root_index);
@@ -84,8 +84,9 @@ void TurboAssemblerBase::IndirectLoadExternalReference(
 }
 
 // static
-int32_t TurboAssemblerBase::RootRegisterOffset(Heap::RootListIndex root_index) {
-  return (root_index << kPointerSizeLog2) - kRootRegisterBias;
+int32_t TurboAssemblerBase::RootRegisterOffset(RootIndex root_index) {
+  return (static_cast<int32_t>(root_index) << kPointerSizeLog2) -
+         kRootRegisterBias;
 }
 
 // static
@@ -105,10 +106,8 @@ intptr_t TurboAssemblerBase::RootRegisterOffsetForExternalReference(
 // static
 bool TurboAssemblerBase::IsAddressableThroughRootRegister(
     Isolate* isolate, const ExternalReference& reference) {
-  Address start = reinterpret_cast<Address>(isolate);
-  Address end = isolate->heap()->root_register_addressable_end();
   Address address = reference.address();
-  return start <= address && address < end;
+  return isolate->root_register_addressable_region().contains(address);
 }
 
 // static
diff --git a/deps/v8/src/turbo-assembler.h b/deps/v8/src/turbo-assembler.h
index 44fbbca64c..70048962dd 100644
--- a/deps/v8/src/turbo-assembler.h
+++ b/deps/v8/src/turbo-assembler.h
@@ -16,7 +16,10 @@ namespace internal {
 // platform-independent bits.
 class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
  public:
-  Isolate* isolate() const { return isolate_; }
+  Isolate* isolate() const {
+    DCHECK(!options().v8_agnostic_code);
+    return isolate_;
+  }
 
   Handle<HeapObject> CodeObject() const {
     DCHECK(!code_object_.is_null());
@@ -49,9 +52,9 @@ class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
                                       intptr_t offset) = 0;
   virtual void LoadRootRelative(Register destination, int32_t offset) = 0;
 
-  virtual void LoadRoot(Register destination, Heap::RootListIndex index) = 0;
+  virtual void LoadRoot(Register destination, RootIndex index) = 0;
 
-  static int32_t RootRegisterOffset(Heap::RootListIndex root_index);
+  static int32_t RootRegisterOffset(RootIndex root_index);
   static int32_t RootRegisterOffsetForExternalReferenceIndex(
       int reference_index);
 
@@ -61,11 +64,16 @@ class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
       Isolate* isolate, const ExternalReference& reference);
 
   // An address is addressable through kRootRegister if it is located within
-  // [isolate, roots_ + root_register_addressable_end_offset[.
+  // isolate->root_register_addressable_region().
   static bool IsAddressableThroughRootRegister(
       Isolate* isolate, const ExternalReference& reference);
 
  protected:
+  TurboAssemblerBase(const AssemblerOptions& options, void* buffer,
+                     int buffer_size)
+      : TurboAssemblerBase(nullptr, options.EnableV8AgnosticCode(), buffer,
+                           buffer_size, CodeObjectRequired::kNo) {}
+
   TurboAssemblerBase(Isolate* isolate, const AssemblerOptions& options,
                      void* buffer, int buffer_size,
                      CodeObjectRequired create_code_object);
@@ -97,7 +105,7 @@ class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
 // Avoids emitting calls to the {Builtins::kAbort} builtin when emitting debug
 // code during the lifetime of this scope object. For disabling debug code
 // entirely use the {DontEmitDebugCodeScope} instead.
-class HardAbortScope BASE_EMBEDDED {
+class HardAbortScope {
  public:
   explicit HardAbortScope(TurboAssemblerBase* assembler)
       : assembler_(assembler), old_value_(assembler->should_abort_hard()) {
diff --git a/deps/v8/src/unicode-cache.h b/deps/v8/src/unicode-cache.h
index 8f4badae8f..ddc81b738c 100644
--- a/deps/v8/src/unicode-cache.h
+++ b/deps/v8/src/unicode-cache.h
@@ -16,7 +16,7 @@ namespace internal {
 // Caching predicates used by scanners.
 class UnicodeCache {
  public:
-  UnicodeCache() {}
+  UnicodeCache() = default;
   typedef unibrow::Utf8Decoder<512> Utf8Decoder;
 
   StaticResource<Utf8Decoder>* utf8_decoder() { return &utf8_decoder_; }
diff --git a/deps/v8/src/unicode-decoder.h b/deps/v8/src/unicode-decoder.h
index ab69d0d390..c87e192ad0 100644
--- a/deps/v8/src/unicode-decoder.h
+++ b/deps/v8/src/unicode-decoder.h
@@ -81,7 +81,7 @@ class V8_EXPORT_PRIVATE Utf8DecoderBase {
 template <size_t kBufferSize>
 class Utf8Decoder : public Utf8DecoderBase {
  public:
-  inline Utf8Decoder() {}
+  inline Utf8Decoder() = default;
   explicit inline Utf8Decoder(const v8::internal::Vector<const char>& stream);
   inline void Reset(const v8::internal::Vector<const char>& stream);
   inline size_t WriteUtf16(
diff --git a/deps/v8/src/unicode.h b/deps/v8/src/unicode.h
index dddf22c4c6..68e69324f9 100644
--- a/deps/v8/src/unicode.h
+++ b/deps/v8/src/unicode.h
@@ -28,7 +28,7 @@ const int kMaxMappingSize = 4;
 template <class T, int size = 256>
 class Predicate {
  public:
-  inline Predicate() { }
+  inline Predicate() = default;
   inline bool get(uchar c);
 
  private:
@@ -68,7 +68,7 @@ class Predicate {
 template <class T, int size = 256>
 class Mapping {
  public:
-  inline Mapping() { }
+  inline Mapping() = default;
   inline int get(uchar c, uchar n, uchar* result);
  private:
   friend class Test;
diff --git a/deps/v8/src/utils.cc b/deps/v8/src/utils.cc
index 052664f87f..e799e9ad85 100644
--- a/deps/v8/src/utils.cc
+++ b/deps/v8/src/utils.cc
@@ -345,7 +345,7 @@ static void MemMoveWrapper(void* dest, const void* src, size_t size) {
 static MemMoveFunction memmove_function = &MemMoveWrapper;
 
 // Defined in codegen-ia32.cc.
-MemMoveFunction CreateMemMoveFunction(Isolate* isolate);
+MemMoveFunction CreateMemMoveFunction();
 
 // Copy memory area to disjoint memory area.
 void MemMove(void* dest, const void* src, size_t size) {
@@ -369,46 +369,40 @@ V8_EXPORT_PRIVATE MemCopyUint8Function memcopy_uint8_function =
 MemCopyUint16Uint8Function memcopy_uint16_uint8_function =
     &MemCopyUint16Uint8Wrapper;
 // Defined in codegen-arm.cc.
-MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
-                                                MemCopyUint8Function stub);
+MemCopyUint8Function CreateMemCopyUint8Function(MemCopyUint8Function stub);
 MemCopyUint16Uint8Function CreateMemCopyUint16Uint8Function(
-    Isolate* isolate, MemCopyUint16Uint8Function stub);
+    MemCopyUint16Uint8Function stub);
 
 #elif V8_OS_POSIX && V8_HOST_ARCH_MIPS
 V8_EXPORT_PRIVATE MemCopyUint8Function memcopy_uint8_function =
     &MemCopyUint8Wrapper;
 // Defined in codegen-mips.cc.
-MemCopyUint8Function CreateMemCopyUint8Function(Isolate* isolate,
-                                                MemCopyUint8Function stub);
+MemCopyUint8Function CreateMemCopyUint8Function(MemCopyUint8Function stub);
 #endif
 
 
 static bool g_memcopy_functions_initialized = false;
 
-void init_memcopy_functions(Isolate* isolate) {
+void init_memcopy_functions() {
   if (g_memcopy_functions_initialized) return;
   g_memcopy_functions_initialized = true;
 #if V8_TARGET_ARCH_IA32
-  MemMoveFunction generated_memmove = CreateMemMoveFunction(isolate);
+  MemMoveFunction generated_memmove = CreateMemMoveFunction();
   if (generated_memmove != nullptr) {
     memmove_function = generated_memmove;
   }
 #elif V8_OS_POSIX && V8_HOST_ARCH_ARM
-  memcopy_uint8_function =
-      CreateMemCopyUint8Function(isolate, &MemCopyUint8Wrapper);
+  memcopy_uint8_function = CreateMemCopyUint8Function(&MemCopyUint8Wrapper);
   memcopy_uint16_uint8_function =
-      CreateMemCopyUint16Uint8Function(isolate, &MemCopyUint16Uint8Wrapper);
+      CreateMemCopyUint16Uint8Function(&MemCopyUint16Uint8Wrapper);
 #elif V8_OS_POSIX && V8_HOST_ARCH_MIPS
-  memcopy_uint8_function =
-      CreateMemCopyUint8Function(isolate, &MemCopyUint8Wrapper);
+  memcopy_uint8_function = CreateMemCopyUint8Function(&MemCopyUint8Wrapper);
 #endif
 }
 
-
+// Returns false iff d is NaN, +0, or -0.
 bool DoubleToBoolean(double d) {
-  // NaN, +0, and -0 should return the false object
   IeeeDoubleArchType u;
-
   u.d = d;
   if (u.bits.exp == 2047) {
     // Detect NaN for IEEE double precision floating point.
diff --git a/deps/v8/src/utils.h b/deps/v8/src/utils.h
index f4669524a7..90a1227a2b 100644
--- a/deps/v8/src/utils.h
+++ b/deps/v8/src/utils.h
@@ -1,3 +1,4 @@
+
 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
@@ -56,6 +57,20 @@ inline bool CStringEquals(const char* s1, const char* s2) {
   return (s1 == s2) || (s1 != nullptr && s2 != nullptr && strcmp(s1, s2) == 0);
 }
 
+// Checks if value is in range [lower_limit, higher_limit] using a single
+// branch.
+template <typename T, typename U>
+inline bool IsInRange(T value, U lower_limit, U higher_limit) {
+  DCHECK_LE(lower_limit, higher_limit);
+  STATIC_ASSERT(sizeof(U) <= sizeof(T));
+  typedef typename std::make_unsigned<T>::type unsigned_T;
+  // Use static_cast to support enum classes.
+  return static_cast<unsigned_T>(static_cast<unsigned_T>(value) -
+                                 static_cast<unsigned_T>(lower_limit)) <=
+         static_cast<unsigned_T>(static_cast<unsigned_T>(higher_limit) -
+                                 static_cast<unsigned_T>(lower_limit));
+}
+
 // X must be a power of 2.  Returns the number of trailing zeros.
 template <typename T,
           typename = typename std::enable_if<std::is_integral<T>::value>::type>
@@ -152,13 +167,11 @@ inline bool IsAligned(T value, U alignment) {
   return (value & (alignment - 1)) == 0;
 }
 
-
-// Returns true if (addr + offset) is aligned.
+// Returns true if {addr + offset} is aligned.
 inline bool IsAddressAligned(Address addr,
                              intptr_t alignment,
                              int offset = 0) {
-  intptr_t offs = OffsetFrom(addr + offset);
-  return IsAligned(offs, alignment);
+  return IsAligned(addr + offset, alignment);
 }
 
 
@@ -516,7 +529,7 @@ inline uint32_t ComputeAddressHash(Address address) {
 // Generated memcpy/memmove
 
 // Initializes the codegen support that depends on CPU features.
-void init_memcopy_functions(Isolate* isolate);
+void init_memcopy_functions();
 
 #if defined(V8_TARGET_ARCH_IA32)
 // Limit below which the extra overhead of the MemCopy function is likely
@@ -1609,108 +1622,6 @@ static inline V ByteReverse(V value) {
   }
 }
 
-// Represents a linked list that threads through the nodes in the linked list.
-// Entries in the list are pointers to nodes. The nodes need to have a T**
-// next() method that returns the location where the next value is stored.
-template <typename T>
-class ThreadedList final {
- public:
-  ThreadedList() : head_(nullptr), tail_(&head_) {}
-  void Add(T* v) {
-    DCHECK_NULL(*tail_);
-    DCHECK_NULL(*v->next());
-    *tail_ = v;
-    tail_ = v->next();
-  }
-
-  void Clear() {
-    head_ = nullptr;
-    tail_ = &head_;
-  }
-
-  class Iterator final {
-   public:
-    Iterator& operator++() {
-      entry_ = (*entry_)->next();
-      return *this;
-    }
-    bool operator!=(const Iterator& other) { return entry_ != other.entry_; }
-    T* operator*() { return *entry_; }
-    T* operator->() { return *entry_; }
-    Iterator& operator=(T* entry) {
-      T* next = *(*entry_)->next();
-      *entry->next() = next;
-      *entry_ = entry;
-      return *this;
-    }
-
-   private:
-    explicit Iterator(T** entry) : entry_(entry) {}
-
-    T** entry_;
-
-    friend class ThreadedList;
-  };
-
-  class ConstIterator final {
-   public:
-    ConstIterator& operator++() {
-      entry_ = (*entry_)->next();
-      return *this;
-    }
-    bool operator!=(const ConstIterator& other) {
-      return entry_ != other.entry_;
-    }
-    const T* operator*() const { return *entry_; }
-
-   private:
-    explicit ConstIterator(T* const* entry) : entry_(entry) {}
-
-    T* const* entry_;
-
-    friend class ThreadedList;
-  };
-
-  Iterator begin() { return Iterator(&head_); }
-  Iterator end() { return Iterator(tail_); }
-
-  ConstIterator begin() const { return ConstIterator(&head_); }
-  ConstIterator end() const { return ConstIterator(tail_); }
-
-  void Rewind(Iterator reset_point) {
-    tail_ = reset_point.entry_;
-    *tail_ = nullptr;
-  }
-
-  void MoveTail(ThreadedList<T>* parent, Iterator location) {
-    if (parent->end() != location) {
-      DCHECK_NULL(*tail_);
-      *tail_ = *location;
-      tail_ = parent->tail_;
-      parent->Rewind(location);
-    }
-  }
-
-  bool is_empty() const { return head_ == nullptr; }
-
-  // Slow. For testing purposes.
-  int LengthForTest() {
-    int result = 0;
-    for (Iterator t = begin(); t != end(); ++t) ++result;
-    return result;
-  }
-  T* AtForTest(int i) {
-    Iterator t = begin();
-    while (i-- > 0) ++t;
-    return *t;
-  }
-
- private:
-  T* head_;
-  T** tail_;
-  DISALLOW_COPY_AND_ASSIGN(ThreadedList);
-};
-
 V8_EXPORT_PRIVATE bool PassesFilter(Vector<const char> name,
                                     Vector<const char> filter);
 
diff --git a/deps/v8/src/v8.cc b/deps/v8/src/v8.cc
index 4d152d4d4e..98a807963c 100644
--- a/deps/v8/src/v8.cc
+++ b/deps/v8/src/v8.cc
@@ -4,6 +4,8 @@
 
 #include "src/v8.h"
 
+#include <fstream>
+
 #include "src/api.h"
 #include "src/base/atomicops.h"
 #include "src/base/once.h"
@@ -72,6 +74,12 @@ void V8::InitializeOncePerProcessImpl() {
     FLAG_max_semi_space_size = 1;
   }
 
+  if (FLAG_trace_turbo) {
+    // Create an empty file shared by the process (e.g. the wasm engine).
+    std::ofstream(Isolate::GetTurboCfgFileName(nullptr).c_str(),
+                  std::ios_base::trunc);
+  }
+
   base::OS::Initialize(FLAG_hard_abort, FLAG_gc_fake_mmap);
 
   if (FLAG_random_seed) SetRandomMmapSeed(FLAG_random_seed);
diff --git a/deps/v8/src/v8threads.h b/deps/v8/src/v8threads.h
index 7fde0c9ec4..ac32b7465e 100644
--- a/deps/v8/src/v8threads.h
+++ b/deps/v8/src/v8threads.h
@@ -59,7 +59,7 @@ class ThreadVisitor {
   virtual void VisitThread(Isolate* isolate, ThreadLocalTop* top) = 0;
 
  protected:
-  virtual ~ThreadVisitor() {}
+  virtual ~ThreadVisitor() = default;
 };
 
 class ThreadManager {
diff --git a/deps/v8/src/value-serializer.cc b/deps/v8/src/value-serializer.cc
index 0633d19a2a..3d80634c97 100644
--- a/deps/v8/src/value-serializer.cc
+++ b/deps/v8/src/value-serializer.cc
@@ -517,14 +517,12 @@ Maybe<bool> ValueSerializer::WriteJSReceiver(Handle<JSReceiver> receiver) {
     case JS_TYPED_ARRAY_TYPE:
     case JS_DATA_VIEW_TYPE:
       return WriteJSArrayBufferView(JSArrayBufferView::cast(*receiver));
-    case WASM_MODULE_TYPE: {
-      auto enabled_features = wasm::WasmFeaturesFromIsolate(isolate_);
-      if (!FLAG_wasm_disable_structured_cloning || enabled_features.threads) {
+    case WASM_MODULE_TYPE:
+      if (!FLAG_wasm_disable_structured_cloning) {
         // Only write WebAssembly modules if not disabled by a flag.
         return WriteWasmModule(Handle<WasmModuleObject>::cast(receiver));
       }
       break;
-    }
     case WASM_MEMORY_TYPE: {
       auto enabled_features = wasm::WasmFeaturesFromIsolate(isolate_);
       if (enabled_features.threads) {
@@ -836,7 +834,7 @@ Maybe<bool> ValueSerializer::WriteJSArrayBuffer(
     ThrowDataCloneError(MessageTemplate::kDataCloneErrorNeuteredArrayBuffer);
     return Nothing<bool>();
   }
-  double byte_length = array_buffer->byte_length()->Number();
+  double byte_length = array_buffer->byte_length();
   if (byte_length > std::numeric_limits<uint32_t>::max()) {
     ThrowDataCloneError(MessageTemplate::kDataCloneError, array_buffer);
     return Nothing<bool>();
@@ -867,8 +865,8 @@ Maybe<bool> ValueSerializer::WriteJSArrayBufferView(JSArrayBufferView* view) {
     tag = ArrayBufferViewTag::kDataView;
   }
   WriteVarint(static_cast<uint8_t>(tag));
-  WriteVarint(NumberToUint32(view->byte_offset()));
-  WriteVarint(NumberToUint32(view->byte_length()));
+  WriteVarint(static_cast<uint32_t>(view->byte_offset()));
+  WriteVarint(static_cast<uint32_t>(view->byte_length()));
   return ThrowIfOutOfMemory();
 }
 
@@ -1149,6 +1147,7 @@ void ValueDeserializer::TransferArrayBuffer(
 }
 
 MaybeHandle<Object> ValueDeserializer::ReadObject() {
+  DisallowJavascriptExecution no_js(isolate_);
   MaybeHandle<Object> result = ReadObjectInternal();
 
   // ArrayBufferView is special in that it consumes the value before it, even
@@ -1275,7 +1274,6 @@ MaybeHandle<String> ValueDeserializer::ReadString() {
 }
 
 MaybeHandle<BigInt> ValueDeserializer::ReadBigInt() {
-  if (!FLAG_harmony_bigint) return MaybeHandle<BigInt>();
   uint32_t bitfield;
   if (!ReadVarint<uint32_t>().To(&bitfield)) return MaybeHandle<BigInt>();
   int bytelength = BigInt::DigitsByteLengthForBitfield(bitfield);
@@ -1473,6 +1471,11 @@ MaybeHandle<JSArray> ValueDeserializer::ReadDenseJSArray() {
     // hole. Past version 11, undefined means undefined.
     if (version_ < 11 && element->IsUndefined(isolate_)) continue;
 
+    // Make sure elements is still large enough.
+    if (i >= static_cast<uint32_t>(elements->length())) {
+      return MaybeHandle<JSArray>();
+    }
+
     elements->set(i, *element);
   }
 
@@ -1594,8 +1597,12 @@ MaybeHandle<JSMap> ValueDeserializer::ReadJSMap() {
     }
 
     Handle<Object> argv[2];
-    if (!ReadObject().ToHandle(&argv[0]) || !ReadObject().ToHandle(&argv[1]) ||
-        Execution::Call(isolate_, map_set, map, arraysize(argv), argv)
+    if (!ReadObject().ToHandle(&argv[0]) || !ReadObject().ToHandle(&argv[1])) {
+      return MaybeHandle<JSMap>();
+    }
+
+    AllowJavascriptExecution allow_js(isolate_);
+    if (Execution::Call(isolate_, map_set, map, arraysize(argv), argv)
             .is_null()) {
       return MaybeHandle<JSMap>();
     }
@@ -1630,8 +1637,10 @@ MaybeHandle<JSSet> ValueDeserializer::ReadJSSet() {
     }
 
     Handle<Object> argv[1];
-    if (!ReadObject().ToHandle(&argv[0]) ||
-        Execution::Call(isolate_, set_add, set, arraysize(argv), argv)
+    if (!ReadObject().ToHandle(&argv[0])) return MaybeHandle<JSSet>();
+
+    AllowJavascriptExecution allow_js(isolate_);
+    if (Execution::Call(isolate_, set_add, set, arraysize(argv), argv)
             .is_null()) {
       return MaybeHandle<JSSet>();
     }
@@ -1704,7 +1713,7 @@ MaybeHandle<JSArrayBuffer> ValueDeserializer::ReadTransferredJSArrayBuffer() {
 
 MaybeHandle<JSArrayBufferView> ValueDeserializer::ReadJSArrayBufferView(
     Handle<JSArrayBuffer> buffer) {
-  uint32_t buffer_byte_length = NumberToUint32(buffer->byte_length());
+  uint32_t buffer_byte_length = static_cast<uint32_t>(buffer->byte_length());
   uint8_t tag = 0;
   uint32_t byte_offset = 0;
   uint32_t byte_length = 0;
@@ -1719,15 +1728,6 @@ MaybeHandle<JSArrayBufferView> ValueDeserializer::ReadJSArrayBufferView(
   ExternalArrayType external_array_type = kExternalInt8Array;
   unsigned element_size = 0;
 
-  if (!FLAG_harmony_bigint) {
-    // Refuse to construct BigInt64Arrays unless the flag is on.
-    ArrayBufferViewTag cast_tag = static_cast<ArrayBufferViewTag>(tag);
-    if (cast_tag == ArrayBufferViewTag::kBigInt64Array ||
-        cast_tag == ArrayBufferViewTag::kBigUint64Array) {
-      return MaybeHandle<JSArrayBufferView>();
-    }
-  }
-
   switch (static_cast<ArrayBufferViewTag>(tag)) {
     case ArrayBufferViewTag::kDataView: {
       Handle<JSDataView> data_view =
@@ -1755,9 +1755,7 @@ MaybeHandle<JSArrayBufferView> ValueDeserializer::ReadJSArrayBufferView(
 }
 
 MaybeHandle<JSObject> ValueDeserializer::ReadWasmModuleTransfer() {
-  auto enabled_features = wasm::WasmFeaturesFromIsolate(isolate_);
-  if ((FLAG_wasm_disable_structured_cloning && !enabled_features.threads) ||
-      expect_inline_wasm()) {
+  if (FLAG_wasm_disable_structured_cloning || expect_inline_wasm()) {
     return MaybeHandle<JSObject>();
   }
 
@@ -1779,9 +1777,7 @@ MaybeHandle<JSObject> ValueDeserializer::ReadWasmModuleTransfer() {
 }
 
 MaybeHandle<JSObject> ValueDeserializer::ReadWasmModule() {
-  auto enabled_features = wasm::WasmFeaturesFromIsolate(isolate_);
-  if ((FLAG_wasm_disable_structured_cloning && !enabled_features.threads) ||
-      !expect_inline_wasm()) {
+  if (FLAG_wasm_disable_structured_cloning || !expect_inline_wasm()) {
     return MaybeHandle<JSObject>();
   }
 
@@ -1988,6 +1984,7 @@ Maybe<uint32_t> ValueDeserializer::ReadJSObjectProperties(
       bool success;
       LookupIterator it = LookupIterator::PropertyOrElement(
           isolate_, object, key, &success, LookupIterator::OWN);
+      CHECK_EQ(LookupIterator::NOT_FOUND, it.state());
       if (!success ||
           JSObject::DefineOwnPropertyIgnoreAttributes(&it, value, NONE)
               .is_null()) {
@@ -2022,6 +2019,7 @@ Maybe<uint32_t> ValueDeserializer::ReadJSObjectProperties(
     bool success;
     LookupIterator it = LookupIterator::PropertyOrElement(
         isolate_, object, key, &success, LookupIterator::OWN);
+    CHECK_EQ(LookupIterator::NOT_FOUND, it.state());
     if (!success ||
         JSObject::DefineOwnPropertyIgnoreAttributes(&it, value, NONE)
             .is_null()) {
@@ -2069,6 +2067,7 @@ static Maybe<bool> SetPropertiesFromKeyValuePairs(Isolate* isolate,
     bool success;
     LookupIterator it = LookupIterator::PropertyOrElement(
         isolate, object, key, &success, LookupIterator::OWN);
+    CHECK_EQ(LookupIterator::NOT_FOUND, it.state());
     if (!success ||
         JSObject::DefineOwnPropertyIgnoreAttributes(&it, value, NONE)
             .is_null()) {
diff --git a/deps/v8/src/vector-slot-pair.cc b/deps/v8/src/vector-slot-pair.cc
index e639a9037e..9a1d13c697 100644
--- a/deps/v8/src/vector-slot-pair.cc
+++ b/deps/v8/src/vector-slot-pair.cc
@@ -9,7 +9,7 @@
 namespace v8 {
 namespace internal {
 
-VectorSlotPair::VectorSlotPair() {}
+VectorSlotPair::VectorSlotPair() = default;
 
 int VectorSlotPair::index() const {
   return vector_.is_null() ? -1 : FeedbackVector::GetIndex(slot_);
@@ -17,22 +17,24 @@ int VectorSlotPair::index() const {
 
 bool operator==(VectorSlotPair const& lhs, VectorSlotPair const& rhs) {
   return lhs.slot() == rhs.slot() &&
-         lhs.vector().location() == rhs.vector().location();
+         lhs.vector().location() == rhs.vector().location() &&
+         lhs.ic_state() == rhs.ic_state();
 }
 
 bool operator!=(VectorSlotPair const& lhs, VectorSlotPair const& rhs) {
   return !(lhs == rhs);
 }
 
-std::ostream& operator<<(std::ostream& os, const VectorSlotPair& pair) {
-  if (pair.IsValid()) {
-    return os << "VectorSlotPair(" << pair.slot() << ")";
+std::ostream& operator<<(std::ostream& os, const VectorSlotPair& p) {
+  if (p.IsValid()) {
+    return os << "VectorSlotPair(" << p.slot() << ", "
+              << InlineCacheState2String(p.ic_state()) << ")";
   }
   return os << "VectorSlotPair(INVALID)";
 }
 
 size_t hash_value(VectorSlotPair const& p) {
-  return base::hash_combine(p.slot(), p.vector().location());
+  return base::hash_combine(p.slot(), p.vector().location(), p.ic_state());
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/vector-slot-pair.h b/deps/v8/src/vector-slot-pair.h
index cd9434c630..cb99d06112 100644
--- a/deps/v8/src/vector-slot-pair.h
+++ b/deps/v8/src/vector-slot-pair.h
@@ -19,25 +19,29 @@ class FeedbackVector;
 class V8_EXPORT_PRIVATE VectorSlotPair {
  public:
   VectorSlotPair();
-  VectorSlotPair(Handle<FeedbackVector> vector, FeedbackSlot slot)
-      : vector_(vector), slot_(slot) {}
+  VectorSlotPair(Handle<FeedbackVector> vector, FeedbackSlot slot,
+                 InlineCacheState ic_state)
+      : vector_(vector), slot_(slot), ic_state_(ic_state) {}
 
   bool IsValid() const { return !vector_.is_null() && !slot_.IsInvalid(); }
 
   Handle<FeedbackVector> vector() const { return vector_; }
   FeedbackSlot slot() const { return slot_; }
+  InlineCacheState ic_state() const { return ic_state_; }
 
   int index() const;
 
  private:
   Handle<FeedbackVector> vector_;
   FeedbackSlot slot_;
+  InlineCacheState ic_state_ = UNINITIALIZED;
 };
 
 bool operator==(VectorSlotPair const&, VectorSlotPair const&);
 bool operator!=(VectorSlotPair const&, VectorSlotPair const&);
 
-std::ostream& operator<<(std::ostream& os, const VectorSlotPair& pair);
+V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
+                                           VectorSlotPair const&);
 
 size_t hash_value(VectorSlotPair const&);
 
diff --git a/deps/v8/src/visitors.h b/deps/v8/src/visitors.h
index 9098d8b471..ebe58c3e75 100644
--- a/deps/v8/src/visitors.h
+++ b/deps/v8/src/visitors.h
@@ -54,9 +54,9 @@ enum class Root {
 
 // Abstract base class for visiting, and optionally modifying, the
 // pointers contained in roots. Used in GC and serialization/deserialization.
-class RootVisitor BASE_EMBEDDED {
+class RootVisitor {
  public:
-  virtual ~RootVisitor() {}
+  virtual ~RootVisitor() = default;
 
   // Visits a contiguous arrays of pointers in the half-open range
   // [start, end). Any or all of the values may be modified on return.
@@ -82,9 +82,9 @@ class RelocIterator;
 
 // Abstract base class for visiting, and optionally modifying, the
 // pointers contained in Objects. Used in GC and serialization/deserialization.
-class ObjectVisitor BASE_EMBEDDED {
+class ObjectVisitor {
  public:
-  virtual ~ObjectVisitor() {}
+  virtual ~ObjectVisitor() = default;
 
   // Visits a contiguous arrays of pointers in the half-open range
   // [start, end). Any or all of the values may be modified on return.
@@ -93,6 +93,15 @@ class ObjectVisitor BASE_EMBEDDED {
   virtual void VisitPointers(HeapObject* host, MaybeObject** start,
                              MaybeObject** end) = 0;
 
+  // Custom weak pointers must be ignored by the GC but not other
+  // visitors. They're used for e.g., lists that are recreated after GC. The
+  // default implementation treats them as strong pointers. Visitors who want to
+  // ignore them must override this function with empty.
+  virtual void VisitCustomWeakPointers(HeapObject* host, Object** start,
+                                       Object** end) {
+    VisitPointers(host, start, end);
+  }
+
   // Handy shorthand for visiting a single pointer.
   virtual void VisitPointer(HeapObject* host, Object** p) {
     VisitPointers(host, p, p + 1);
@@ -100,6 +109,9 @@ class ObjectVisitor BASE_EMBEDDED {
   virtual void VisitPointer(HeapObject* host, MaybeObject** p) {
     VisitPointers(host, p, p + 1);
   }
+  virtual void VisitCustomWeakPointer(HeapObject* host, Object** p) {
+    VisitCustomWeakPointers(host, p, p + 1);
+  }
 
   // To allow lazy clearing of inline caches the visitor has
   // a rich interface for iterating over Code objects ...
diff --git a/deps/v8/src/vm-state.h b/deps/v8/src/vm-state.h
index cf74c63870..a9bd08b6cd 100644
--- a/deps/v8/src/vm-state.h
+++ b/deps/v8/src/vm-state.h
@@ -17,7 +17,7 @@ namespace internal {
 // VMState object leaves a state by popping the current state from the
 // stack.
 template <StateTag Tag>
-class VMState BASE_EMBEDDED {
+class VMState {
  public:
   explicit inline VMState(Isolate* isolate);
   inline ~VMState();
@@ -27,8 +27,7 @@ class VMState BASE_EMBEDDED {
   StateTag previous_tag_;
 };
 
-
-class ExternalCallbackScope BASE_EMBEDDED {
+class ExternalCallbackScope {
  public:
   inline ExternalCallbackScope(Isolate* isolate, Address callback);
   inline ~ExternalCallbackScope();
diff --git a/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h b/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
index 725bed590f..24c6d90ec6 100644
--- a/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
+++ b/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
@@ -161,6 +161,7 @@ UNIMPLEMENTED_FP_BINOP(f32_mul)
 UNIMPLEMENTED_FP_BINOP(f32_div)
 UNIMPLEMENTED_FP_BINOP(f32_min)
 UNIMPLEMENTED_FP_BINOP(f32_max)
+UNIMPLEMENTED_FP_BINOP(f32_copysign)
 UNIMPLEMENTED_FP_UNOP(f32_abs)
 UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_UNOP(f32_ceil)
@@ -174,6 +175,7 @@ UNIMPLEMENTED_FP_BINOP(f64_mul)
 UNIMPLEMENTED_FP_BINOP(f64_div)
 UNIMPLEMENTED_FP_BINOP(f64_min)
 UNIMPLEMENTED_FP_BINOP(f64_max)
+UNIMPLEMENTED_FP_BINOP(f64_copysign)
 UNIMPLEMENTED_FP_UNOP(f64_abs)
 UNIMPLEMENTED_FP_UNOP(f64_neg)
 UNIMPLEMENTED_FP_UNOP_RETURN_TRUE(f64_ceil)
@@ -212,6 +214,10 @@ void LiftoffAssembler::emit_i32_remu(Register dst, Register lhs, Register rhs,
   BAILOUT("i32_remu");
 }
 
+void LiftoffAssembler::emit_i32_shr(Register dst, Register lhs, int amount) {
+  BAILOUT("i32_shr");
+}
+
 bool LiftoffAssembler::emit_i64_divs(LiftoffRegister dst, LiftoffRegister lhs,
                                      LiftoffRegister rhs,
                                      Label* trap_div_by_zero,
@@ -237,6 +243,11 @@ bool LiftoffAssembler::emit_i64_remu(LiftoffRegister dst, LiftoffRegister lhs,
   return false;
 }
 
+void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister lhs,
+                                    int amount) {
+  BAILOUT("i64_shr");
+}
+
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
   // This is a nop on arm.
 }
@@ -248,6 +259,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   return true;
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i32");
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }
 
 void LiftoffAssembler::emit_jump(Register target) { BAILOUT("emit_jump"); }
diff --git a/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h b/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
index cdc2dc2a45..c73a60fd7d 100644
--- a/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
+++ b/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
@@ -391,11 +391,24 @@ void LiftoffAssembler::FillI64Half(Register, uint32_t half_index) {
                                      Register amount, LiftoffRegList pinned) { \
     instruction(dst.W(), src.W(), amount.W());                                 \
   }
+#define I32_SHIFTOP_I(name, instruction)                                       \
+  I32_SHIFTOP(name, instruction)                                               \
+  void LiftoffAssembler::emit_##name(Register dst, Register src, int amount) { \
+    DCHECK(is_uint5(amount));                                                  \
+    instruction(dst.W(), src.W(), amount);                                     \
+  }
 #define I64_SHIFTOP(name, instruction)                                         \
   void LiftoffAssembler::emit_##name(LiftoffRegister dst, LiftoffRegister src, \
                                      Register amount, LiftoffRegList pinned) { \
     instruction(dst.gp().X(), src.gp().X(), amount.X());                       \
   }
+#define I64_SHIFTOP_I(name, instruction)                                       \
+  I64_SHIFTOP(name, instruction)                                               \
+  void LiftoffAssembler::emit_##name(LiftoffRegister dst, LiftoffRegister src, \
+                                     int amount) {                             \
+    DCHECK(is_uint6(amount));                                                  \
+    instruction(dst.gp().X(), src.gp().X(), amount);                           \
+  }
 
 I32_BINOP(i32_add, Add)
 I32_BINOP(i32_sub, Sub)
@@ -405,7 +418,7 @@ I32_BINOP(i32_or, Orr)
 I32_BINOP(i32_xor, Eor)
 I32_SHIFTOP(i32_shl, Lsl)
 I32_SHIFTOP(i32_sar, Asr)
-I32_SHIFTOP(i32_shr, Lsr)
+I32_SHIFTOP_I(i32_shr, Lsr)
 I64_BINOP(i64_add, Add)
 I64_BINOP(i64_sub, Sub)
 I64_BINOP(i64_mul, Mul)
@@ -414,7 +427,7 @@ I64_BINOP(i64_or, Orr)
 I64_BINOP(i64_xor, Eor)
 I64_SHIFTOP(i64_shl, Lsl)
 I64_SHIFTOP(i64_sar, Asr)
-I64_SHIFTOP(i64_shr, Lsr)
+I64_SHIFTOP_I(i64_shr, Lsr)
 FP32_BINOP(f32_add, Fadd)
 FP32_BINOP(f32_sub, Fsub)
 FP32_BINOP(f32_mul, Fmul)
@@ -450,7 +463,9 @@ FP64_UNOP(f64_sqrt, Fsqrt)
 #undef FP64_UNOP
 #undef FP64_UNOP_RETURN_TRUE
 #undef I32_SHIFTOP
+#undef I32_SHIFTOP_I
 #undef I64_SHIFTOP
+#undef I64_SHIFTOP_I
 
 bool LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   Clz(dst.W(), src.W());
@@ -611,6 +626,16 @@ void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
   Sxtw(dst, src);
 }
 
+void LiftoffAssembler::emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  BAILOUT("f32_copysign");
+}
+
+void LiftoffAssembler::emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  BAILOUT("f64_copysign");
+}
+
 bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
                                             LiftoffRegister dst,
                                             LiftoffRegister src, Label* trap) {
@@ -749,6 +774,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   }
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  sxtb(dst, src);
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  sxth(dst, src);
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  sxtb(dst.gp(), src.gp());
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  sxth(dst.gp(), src.gp());
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  sxtw(dst.gp(), src.gp());
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { B(label); }
 
 void LiftoffAssembler::emit_jump(Register target) { Br(target); }
diff --git a/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h b/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
index 1fef62542a..3a0ace0d62 100644
--- a/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
+++ b/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
@@ -121,6 +121,11 @@ inline void SpillRegisters(LiftoffAssembler* assm, Regs... regs) {
   }
 }
 
+inline void SignExtendI32ToI64(Assembler* assm, LiftoffRegister reg) {
+  assm->mov(reg.high_gp(), reg.low_gp());
+  assm->sar(reg.high_gp(), 31);
+}
+
 constexpr DoubleRegister kScratchDoubleReg = xmm7;
 
 constexpr int kSubSpSize = 6;  // 6 bytes for "sub esp, <imm32>"
@@ -247,8 +252,7 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
       break;
     case LoadType::kI64Load8S:
       movsx_b(dst.low_gp(), src_op);
-      mov(dst.high_gp(), dst.low_gp());
-      sar(dst.high_gp(), 31);
+      liftoff::SignExtendI32ToI64(this, dst);
       break;
     case LoadType::kI32Load16U:
       movzx_w(dst.gp(), src_op);
@@ -262,8 +266,7 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
       break;
     case LoadType::kI64Load16S:
       movsx_w(dst.low_gp(), src_op);
-      mov(dst.high_gp(), dst.low_gp());
-      sar(dst.high_gp(), 31);
+      liftoff::SignExtendI32ToI64(this, dst);
       break;
     case LoadType::kI32Load:
       mov(dst.gp(), src_op);
@@ -274,8 +277,7 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
       break;
     case LoadType::kI64Load32S:
       mov(dst.low_gp(), src_op);
-      mov(dst.high_gp(), dst.low_gp());
-      sar(dst.high_gp(), 31);
+      liftoff::SignExtendI32ToI64(this, dst);
       break;
     case LoadType::kI64Load: {
       // Compute the operand for the load of the upper half.
@@ -664,6 +666,12 @@ void LiftoffAssembler::emit_i32_shr(Register dst, Register src, Register amount,
                               pinned);
 }
 
+void LiftoffAssembler::emit_i32_shr(Register dst, Register src, int amount) {
+  if (dst != src) mov(dst, src);
+  DCHECK(is_uint5(amount));
+  shr(dst, amount);
+}
+
 bool LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   Label nonzero_input;
   Label continuation;
@@ -879,6 +887,13 @@ void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
                                    &TurboAssembler::ShrPair_cl, pinned);
 }
 
+void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
+                                    int amount) {
+  if (dst != src) Move(dst, src, kWasmI64);
+  DCHECK(is_uint6(amount));
+  ShrPair(dst.high_gp(), dst.low_gp(), amount);
+}
+
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
   // This is a nop on ia32.
 }
@@ -1012,6 +1027,20 @@ void LiftoffAssembler::emit_f32_max(DoubleRegister dst, DoubleRegister lhs,
                                     liftoff::MinOrMax::kMax);
 }
 
+void LiftoffAssembler::emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  static constexpr int kF32SignBit = 1 << 31;
+  Register scratch = GetUnusedRegister(kGpReg).gp();
+  Register scratch2 =
+      GetUnusedRegister(kGpReg, LiftoffRegList::ForRegs(scratch)).gp();
+  Movd(scratch, lhs);                      // move {lhs} into {scratch}.
+  and_(scratch, Immediate(~kF32SignBit));  // clear sign bit in {scratch}.
+  Movd(scratch2, rhs);                     // move {rhs} into {scratch2}.
+  and_(scratch2, Immediate(kF32SignBit));  // isolate sign bit in {scratch2}.
+  or_(scratch, scratch2);                  // combine {scratch2} into {scratch}.
+  Movd(dst, scratch);                      // move result into {dst}.
+}
+
 void LiftoffAssembler::emit_f32_abs(DoubleRegister dst, DoubleRegister src) {
   static constexpr uint32_t kSignBit = uint32_t{1} << 31;
   if (dst == src) {
@@ -1121,6 +1150,24 @@ void LiftoffAssembler::emit_f64_min(DoubleRegister dst, DoubleRegister lhs,
                                      liftoff::MinOrMax::kMin);
 }
 
+void LiftoffAssembler::emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  static constexpr int kF32SignBit = 1 << 31;
+  // On ia32, we cannot hold the whole f64 value in a gp register, so we just
+  // operate on the upper half (UH).
+  Register scratch = GetUnusedRegister(kGpReg).gp();
+  Register scratch2 =
+      GetUnusedRegister(kGpReg, LiftoffRegList::ForRegs(scratch)).gp();
+
+  Pextrd(scratch, lhs, 1);                 // move UH of {lhs} into {scratch}.
+  and_(scratch, Immediate(~kF32SignBit));  // clear sign bit in {scratch}.
+  Pextrd(scratch2, rhs, 1);                // move UH of {rhs} into {scratch2}.
+  and_(scratch2, Immediate(kF32SignBit));  // isolate sign bit in {scratch2}.
+  or_(scratch, scratch2);                  // combine {scratch2} into {scratch}.
+  movsd(dst, lhs);                         // move {lhs} into {dst}.
+  Pinsrd(dst, scratch, 1);                 // insert {scratch} into UH of {dst}.
+}
+
 void LiftoffAssembler::emit_f64_max(DoubleRegister dst, DoubleRegister lhs,
                                     DoubleRegister rhs) {
   liftoff::EmitFloatMinOrMax<double>(this, dst, lhs, rhs,
@@ -1266,7 +1313,7 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
       return true;
     case kExprI64SConvertI32:
       if (dst.low_gp() != src.gp()) mov(dst.low_gp(), src.gp());
-      mov(dst.high_gp(), src.gp());
+      if (dst.high_gp() != src.gp()) mov(dst.high_gp(), src.gp());
       sar(dst.high_gp(), 31);
       return true;
     case kExprI64UConvertI32:
@@ -1318,6 +1365,32 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   }
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  movsx_b(dst, src);
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  movsx_w(dst, src);
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  movsx_b(dst.low_gp(), src.low_gp());
+  liftoff::SignExtendI32ToI64(this, dst);
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  movsx_w(dst.low_gp(), src.low_gp());
+  liftoff::SignExtendI32ToI64(this, dst);
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  if (dst.low_gp() != src.low_gp()) mov(dst.low_gp(), src.low_gp());
+  liftoff::SignExtendI32ToI64(this, dst);
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { jmp(label); }
 
 void LiftoffAssembler::emit_jump(Register target) { jmp(target); }
diff --git a/deps/v8/src/wasm/baseline/liftoff-assembler.cc b/deps/v8/src/wasm/baseline/liftoff-assembler.cc
index 1d604925cc..63cc7344b3 100644
--- a/deps/v8/src/wasm/baseline/liftoff-assembler.cc
+++ b/deps/v8/src/wasm/baseline/liftoff-assembler.cc
@@ -286,7 +286,7 @@ void LiftoffAssembler::CacheState::InitMerge(const CacheState& source,
       auto& dst = stack_state[dst_idx];
       auto& src = source.stack_state[src_idx];
       // Just initialize to any register; will be overwritten before use.
-      LiftoffRegister reg(Register::from_code<0>());
+      LiftoffRegister reg = kGpCacheRegList.GetFirstRegSet();
       RegClass rc = src.is_reg() ? src.reg_class() : reg_class_for(src.type());
       if (src.is_reg() && is_free(src.reg())) {
         reg = src.reg();
diff --git a/deps/v8/src/wasm/baseline/liftoff-assembler.h b/deps/v8/src/wasm/baseline/liftoff-assembler.h
index cfc412d671..673aa4125f 100644
--- a/deps/v8/src/wasm/baseline/liftoff-assembler.h
+++ b/deps/v8/src/wasm/baseline/liftoff-assembler.h
@@ -248,7 +248,7 @@ class LiftoffAssembler : public TurboAssembler {
   };
 
   LiftoffAssembler();
-  ~LiftoffAssembler();
+  ~LiftoffAssembler() override;
 
   LiftoffRegister PopToRegister(LiftoffRegList pinned = {});
 
@@ -399,6 +399,7 @@ class LiftoffAssembler : public TurboAssembler {
                            LiftoffRegList pinned = {});
   inline void emit_i32_shr(Register dst, Register src, Register amount,
                            LiftoffRegList pinned = {});
+  inline void emit_i32_shr(Register dst, Register src, int amount);
 
   // i32 unops.
   inline bool emit_i32_clz(Register dst, Register src);
@@ -433,6 +434,8 @@ class LiftoffAssembler : public TurboAssembler {
                            Register amount, LiftoffRegList pinned = {});
   inline void emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
                            Register amount, LiftoffRegList pinned = {});
+  inline void emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
+                           int amount);
 
   inline void emit_i32_to_intptr(Register dst, Register src);
 
@@ -452,6 +455,21 @@ class LiftoffAssembler : public TurboAssembler {
       emit_i32_sub(dst, lhs, rhs);
     }
   }
+  inline void emit_ptrsize_and(Register dst, Register lhs, Register rhs) {
+    if (kPointerSize == 8) {
+      emit_i64_and(LiftoffRegister(dst), LiftoffRegister(lhs),
+                   LiftoffRegister(rhs));
+    } else {
+      emit_i32_and(dst, lhs, rhs);
+    }
+  }
+  inline void emit_ptrsize_shr(Register dst, Register src, int amount) {
+    if (kPointerSize == 8) {
+      emit_i64_shr(LiftoffRegister(dst), LiftoffRegister(src), amount);
+    } else {
+      emit_i32_shr(dst, src, amount);
+    }
+  }
 
   // f32 binops.
   inline void emit_f32_add(DoubleRegister dst, DoubleRegister lhs,
@@ -466,6 +484,8 @@ class LiftoffAssembler : public TurboAssembler {
                            DoubleRegister rhs);
   inline void emit_f32_max(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
+  inline void emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                DoubleRegister rhs);
 
   // f32 unops.
   inline void emit_f32_abs(DoubleRegister dst, DoubleRegister src);
@@ -489,6 +509,8 @@ class LiftoffAssembler : public TurboAssembler {
                            DoubleRegister rhs);
   inline void emit_f64_max(DoubleRegister dst, DoubleRegister lhs,
                            DoubleRegister rhs);
+  inline void emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                DoubleRegister rhs);
 
   // f64 unops.
   inline void emit_f64_abs(DoubleRegister dst, DoubleRegister src);
@@ -499,10 +521,15 @@ class LiftoffAssembler : public TurboAssembler {
   inline bool emit_f64_nearest_int(DoubleRegister dst, DoubleRegister src);
   inline void emit_f64_sqrt(DoubleRegister dst, DoubleRegister src);
 
-  // type conversions.
   inline bool emit_type_conversion(WasmOpcode opcode, LiftoffRegister dst,
                                    LiftoffRegister src, Label* trap = nullptr);
 
+  inline void emit_i32_signextend_i8(Register dst, Register src);
+  inline void emit_i32_signextend_i16(Register dst, Register src);
+  inline void emit_i64_signextend_i8(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_i64_signextend_i16(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_i64_signextend_i32(LiftoffRegister dst, LiftoffRegister src);
+
   inline void emit_jump(Label*);
   inline void emit_jump(Register);
 
diff --git a/deps/v8/src/wasm/baseline/liftoff-compiler.cc b/deps/v8/src/wasm/baseline/liftoff-compiler.cc
index dbd106d481..d77e7cde4a 100644
--- a/deps/v8/src/wasm/baseline/liftoff-compiler.cc
+++ b/deps/v8/src/wasm/baseline/liftoff-compiler.cc
@@ -16,6 +16,7 @@
 #include "src/wasm/function-body-decoder-impl.h"
 #include "src/wasm/function-compiler.h"
 #include "src/wasm/memory-tracing.h"
+#include "src/wasm/object-access.h"
 #include "src/wasm/wasm-engine.h"
 #include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
@@ -39,11 +40,23 @@ namespace {
   } while (false)
 
 #define WASM_INSTANCE_OBJECT_OFFSET(name) \
-  (WasmInstanceObject::k##name##Offset - kHeapObjectTag)
+  ObjectAccess::ToTagged(WasmInstanceObject::k##name##Offset)
 
-#define LOAD_INSTANCE_FIELD(dst, name, type)                       \
-  __ LoadFromInstance(dst.gp(), WASM_INSTANCE_OBJECT_OFFSET(name), \
-                      LoadType(type).size());
+template <int expected_size, int actual_size>
+struct assert_field_size {
+  static_assert(expected_size == actual_size,
+                "field in WasmInstance does not have the expected size");
+  static constexpr int size = actual_size;
+};
+
+#define WASM_INSTANCE_OBJECT_SIZE(name)     \
+  (WasmInstanceObject::k##name##OffsetEnd - \
+   WasmInstanceObject::k##name##Offset + 1)  // NOLINT(whitespace/indent)
+
+#define LOAD_INSTANCE_FIELD(dst, name, load_size)  \
+  __ LoadFromInstance(                             \
+      dst.gp(), WASM_INSTANCE_OBJECT_OFFSET(name), \
+      assert_field_size<WASM_INSTANCE_OBJECT_SIZE(name), load_size>::size);
 
 #ifdef DEBUG
 #define DEBUG_CODE_COMMENT(str) \
@@ -95,8 +108,6 @@ constexpr Vector<const ValueType> kTypes_ilfd = ArrayVector(kTypesArr_ilfd);
 
 class LiftoffCompiler {
  public:
-  MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(LiftoffCompiler);
-
   // TODO(clemensh): Make this a template parameter.
   static constexpr Decoder::ValidateFlag validate = Decoder::kValidate;
 
@@ -253,14 +264,14 @@ class LiftoffCompiler {
   uint32_t ProcessParameter(ValueType type, uint32_t input_idx) {
     const int num_lowered_params = 1 + needs_reg_pair(type);
     // Initialize to anything, will be set in the loop and used afterwards.
-    LiftoffRegister reg = LiftoffRegister::from_code(kGpReg, 0);
+    LiftoffRegister reg = kGpCacheRegList.GetFirstRegSet();
     RegClass rc = num_lowered_params == 1 ? reg_class_for(type) : kGpReg;
     LiftoffRegList pinned;
     for (int pair_idx = 0; pair_idx < num_lowered_params; ++pair_idx) {
       compiler::LinkageLocation param_loc =
           descriptor_->GetInputLocation(input_idx + pair_idx);
       // Initialize to anything, will be set in both arms of the if.
-      LiftoffRegister in_reg = LiftoffRegister::from_code(kGpReg, 0);
+      LiftoffRegister in_reg = kGpCacheRegList.GetFirstRegSet();
       if (param_loc.IsRegister()) {
         DCHECK(!param_loc.IsAnyRegister());
         int reg_code = param_loc.AsRegister();
@@ -273,7 +284,7 @@ class LiftoffCompiler {
           // Move to a cache register (spill one if necessary).
           // Note that we cannot create a {LiftoffRegister} for reg_code, since
           // {LiftoffRegister} can only store cache regs.
-          LiftoffRegister in_reg = __ GetUnusedRegister(rc, pinned);
+          in_reg = __ GetUnusedRegister(rc, pinned);
           if (rc == kGpReg) {
             __ Move(in_reg.gp(), Register::from_code(reg_code), type);
           } else {
@@ -300,7 +311,7 @@ class LiftoffCompiler {
         OutOfLineCode::StackCheck(position, __ cache_state()->used_registers));
     OutOfLineCode& ool = out_of_line_code_.back();
     LiftoffRegister limit_address = __ GetUnusedRegister(kGpReg);
-    LOAD_INSTANCE_FIELD(limit_address, StackLimitAddress, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(limit_address, StackLimitAddress, kPointerSize);
     __ StackCheck(ool.label.get(), limit_address.gp());
     __ bind(ool.continuation.get());
   }
@@ -344,7 +355,7 @@ class LiftoffCompiler {
     }
     DCHECK_EQ(input_idx, descriptor_->InputCount());
     // Set to a gp register, to mark this uninitialized.
-    LiftoffRegister zero_double_reg(Register::from_code<0>());
+    LiftoffRegister zero_double_reg = kGpCacheRegList.GetFirstRegSet();
     DCHECK(zero_double_reg.is_gp());
     for (uint32_t param_idx = num_params; param_idx < __ num_locals();
          ++param_idx) {
@@ -624,6 +635,20 @@ class LiftoffCompiler {
           __ emit_##fn(dst.gp(), src.gp());             \
         });                                             \
     break;
+#define CASE_I32_SIGN_EXTENSION(opcode, fn)             \
+  case WasmOpcode::kExpr##opcode:                       \
+    EmitUnOp<kWasmI32, kWasmI32>(                       \
+        [=](LiftoffRegister dst, LiftoffRegister src) { \
+          __ emit_##fn(dst.gp(), src.gp());             \
+        });                                             \
+    break;
+#define CASE_I64_SIGN_EXTENSION(opcode, fn)             \
+  case WasmOpcode::kExpr##opcode:                       \
+    EmitUnOp<kWasmI64, kWasmI64>(                       \
+        [=](LiftoffRegister dst, LiftoffRegister src) { \
+          __ emit_##fn(dst, src);                       \
+        });                                             \
+    break;
 #define CASE_FLOAT_UNOP(opcode, type, fn)               \
   case WasmOpcode::kExpr##opcode:                       \
     EmitUnOp<kWasm##type, kWasm##type>(                 \
@@ -692,6 +717,11 @@ class LiftoffCompiler {
                            &ExternalReference::wasm_uint64_to_float64, kNoTrap)
       CASE_TYPE_CONVERSION(F64ConvertF32, F64, F32, nullptr, kNoTrap)
       CASE_TYPE_CONVERSION(F64ReinterpretI64, F64, I64, nullptr, kNoTrap)
+      CASE_I32_SIGN_EXTENSION(I32SExtendI8, i32_signextend_i8)
+      CASE_I32_SIGN_EXTENSION(I32SExtendI16, i32_signextend_i16)
+      CASE_I64_SIGN_EXTENSION(I64SExtendI8, i64_signextend_i8)
+      CASE_I64_SIGN_EXTENSION(I64SExtendI16, i64_signextend_i16)
+      CASE_I64_SIGN_EXTENSION(I64SExtendI32, i64_signextend_i32)
       case kExprI32Popcnt:
         EmitI32UnOpWithCFallback(&LiftoffAssembler::emit_i32_popcnt,
                                  &ExternalReference::wasm_word32_popcnt);
@@ -706,6 +736,8 @@ class LiftoffCompiler {
         return unsupported(decoder, WasmOpcodes::OpcodeName(opcode));
     }
 #undef CASE_I32_UNOP
+#undef CASE_I32_SIGN_EXTENSION
+#undef CASE_I64_SIGN_EXTENSION
 #undef CASE_FLOAT_UNOP
 #undef CASE_FLOAT_UNOP_WITH_CFALLBACK
 #undef CASE_TYPE_CONVERSION
@@ -875,12 +907,14 @@ class LiftoffCompiler {
       CASE_FLOAT_BINOP(F32Div, F32, f32_div)
       CASE_FLOAT_BINOP(F32Min, F32, f32_min)
       CASE_FLOAT_BINOP(F32Max, F32, f32_max)
+      CASE_FLOAT_BINOP(F32CopySign, F32, f32_copysign)
       CASE_FLOAT_BINOP(F64Add, F64, f64_add)
       CASE_FLOAT_BINOP(F64Sub, F64, f64_sub)
       CASE_FLOAT_BINOP(F64Mul, F64, f64_mul)
       CASE_FLOAT_BINOP(F64Div, F64, f64_div)
       CASE_FLOAT_BINOP(F64Min, F64, f64_min)
       CASE_FLOAT_BINOP(F64Max, F64, f64_max)
+      CASE_FLOAT_BINOP(F64CopySign, F64, f64_copysign)
       case WasmOpcode::kExprI32DivS:
         EmitBinOp<kWasmI32, kWasmI32>([this, decoder](LiftoffRegister dst,
                                                       LiftoffRegister lhs,
@@ -1139,12 +1173,12 @@ class LiftoffCompiler {
                                          uint32_t* offset) {
     LiftoffRegister addr = pinned.set(__ GetUnusedRegister(kGpReg));
     if (global->mutability && global->imported) {
-      LOAD_INSTANCE_FIELD(addr, ImportedMutableGlobals, kPointerLoadType);
+      LOAD_INSTANCE_FIELD(addr, ImportedMutableGlobals, kPointerSize);
       __ Load(addr, addr.gp(), no_reg, global->index * sizeof(Address),
               kPointerLoadType, pinned);
       *offset = 0;
     } else {
-      LOAD_INSTANCE_FIELD(addr, GlobalsStart, kPointerLoadType);
+      LOAD_INSTANCE_FIELD(addr, GlobalsStart, kPointerSize);
       *offset = global->offset;
     }
     return addr;
@@ -1161,7 +1195,7 @@ class LiftoffCompiler {
     LiftoffRegister value =
         pinned.set(__ GetUnusedRegister(reg_class_for(global->type), pinned));
     LoadType type = LoadType::ForValueType(global->type);
-    __ Load(value, addr.gp(), no_reg, offset, type, pinned);
+    __ Load(value, addr.gp(), no_reg, offset, type, pinned, nullptr, true);
     __ PushRegister(global->type, value);
   }
 
@@ -1175,7 +1209,7 @@ class LiftoffCompiler {
     LiftoffRegister addr = GetGlobalBaseAndOffset(global, pinned, &offset);
     LiftoffRegister reg = pinned.set(__ PopToRegister(pinned));
     StoreType type = StoreType::ForValueType(global->type);
-    __ Store(addr.gp(), no_reg, offset, reg, type, pinned);
+    __ Store(addr.gp(), no_reg, offset, reg, type, pinned, nullptr, true);
   }
 
   void Unreachable(FullDecoder* decoder) {
@@ -1353,7 +1387,7 @@ class LiftoffCompiler {
     LiftoffRegister end_offset_reg =
         pinned.set(__ GetUnusedRegister(kGpReg, pinned));
     LiftoffRegister mem_size = __ GetUnusedRegister(kGpReg, pinned);
-    LOAD_INSTANCE_FIELD(mem_size, MemorySize, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(mem_size, MemorySize, kPointerSize);
 
     if (kPointerSize == 8) {
       __ LoadConstant(end_offset_reg, WasmValue(end_offset));
@@ -1443,7 +1477,7 @@ class LiftoffCompiler {
     // Set context to zero (Smi::kZero) for the runtime call.
     __ TurboAssembler::Move(kContextRegister, Smi::kZero);
     LiftoffRegister centry(kJavaScriptCallCodeStartRegister);
-    LOAD_INSTANCE_FIELD(centry, CEntryStub, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(centry, CEntryStub, kPointerSize);
     __ CallRuntimeWithCEntry(runtime_function, centry.gp());
     safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kSimple, 0,
                                              Safepoint::kNoLazyDeopt);
@@ -1464,9 +1498,9 @@ class LiftoffCompiler {
     }
     LiftoffRegister tmp = __ GetUnusedRegister(kGpReg, pinned);
     __ LoadConstant(tmp, WasmValue(*offset));
-    __ emit_i32_add(index.gp(), index.gp(), tmp.gp());
-    LOAD_INSTANCE_FIELD(tmp, MemoryMask, LoadType::kI32Load);
-    __ emit_i32_and(index.gp(), index.gp(), tmp.gp());
+    __ emit_ptrsize_add(index.gp(), index.gp(), tmp.gp());
+    LOAD_INSTANCE_FIELD(tmp, MemoryMask, kPointerSize);
+    __ emit_ptrsize_and(index.gp(), index.gp(), tmp.gp());
     *offset = 0;
     return index;
   }
@@ -1485,7 +1519,7 @@ class LiftoffCompiler {
     index = AddMemoryMasking(index, &offset, pinned);
     DEBUG_CODE_COMMENT("Load from memory");
     LiftoffRegister addr = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
-    LOAD_INSTANCE_FIELD(addr, MemoryStart, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(addr, MemoryStart, kPointerSize);
     RegClass rc = reg_class_for(value_type);
     LiftoffRegister value = pinned.set(__ GetUnusedRegister(rc, pinned));
     uint32_t protected_load_pc = 0;
@@ -1498,7 +1532,7 @@ class LiftoffCompiler {
     }
     __ PushRegister(value_type, value);
 
-    if (FLAG_wasm_trace_memory) {
+    if (FLAG_trace_wasm_memory) {
       TraceMemoryOperation(false, type.mem_type().representation(), index.gp(),
                            offset, decoder->position());
     }
@@ -1519,7 +1553,7 @@ class LiftoffCompiler {
     index = AddMemoryMasking(index, &offset, pinned);
     DEBUG_CODE_COMMENT("Store to memory");
     LiftoffRegister addr = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
-    LOAD_INSTANCE_FIELD(addr, MemoryStart, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(addr, MemoryStart, kPointerSize);
     uint32_t protected_store_pc = 0;
     __ Store(addr.gp(), index.gp(), offset, value, type, pinned,
              &protected_store_pc, true);
@@ -1528,22 +1562,16 @@ class LiftoffCompiler {
                        WasmCode::kThrowWasmTrapMemOutOfBounds,
                        protected_store_pc);
     }
-    if (FLAG_wasm_trace_memory) {
+    if (FLAG_trace_wasm_memory) {
       TraceMemoryOperation(true, type.mem_rep(), index.gp(), offset,
                            decoder->position());
     }
   }
 
   void CurrentMemoryPages(FullDecoder* decoder, Value* result) {
-    LiftoffRegList pinned;
-    LiftoffRegister mem_size = pinned.set(__ GetUnusedRegister(kGpReg));
-    LiftoffRegister tmp_const =
-        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
-    LOAD_INSTANCE_FIELD(mem_size, MemorySize, LoadType::kI32Load);
-    // TODO(clemensh): Shift by immediate directly.
-    __ LoadConstant(tmp_const,
-                    WasmValue(int32_t{WhichPowerOf2(kWasmPageSize)}));
-    __ emit_i32_shr(mem_size.gp(), mem_size.gp(), tmp_const.gp(), pinned);
+    LiftoffRegister mem_size = __ GetUnusedRegister(kGpReg);
+    LOAD_INSTANCE_FIELD(mem_size, MemorySize, kPointerSize);
+    __ emit_ptrsize_shr(mem_size.gp(), mem_size.gp(), kWasmPageSizeLog2);
     __ PushRegister(kWasmI32, mem_size);
   }
 
@@ -1602,17 +1630,17 @@ class LiftoffCompiler {
 
       LiftoffRegister imported_targets = tmp;
       LOAD_INSTANCE_FIELD(imported_targets, ImportedFunctionTargets,
-                          kPointerLoadType);
+                          kPointerSize);
       __ Load(target, imported_targets.gp(), no_reg,
               imm.index * sizeof(Address), kPointerLoadType, pinned);
 
       LiftoffRegister imported_instances = tmp;
       LOAD_INSTANCE_FIELD(imported_instances, ImportedFunctionInstances,
-                          kPointerLoadType);
+                          kPointerSize);
       LiftoffRegister target_instance = tmp;
       __ Load(target_instance, imported_instances.gp(), no_reg,
-              compiler::FixedArrayOffsetMinusTag(imm.index), kPointerLoadType,
-              pinned);
+              ObjectAccess::ElementOffsetInTaggedFixedArray(imm.index),
+              kPointerLoadType, pinned);
 
       LiftoffRegister* explicit_instance = &target_instance;
       Register target_reg = target.gp();
@@ -1684,8 +1712,7 @@ class LiftoffCompiler {
 
     // Compare against table size stored in
     // {instance->indirect_function_table_size}.
-    LOAD_INSTANCE_FIELD(tmp_const, IndirectFunctionTableSize,
-                        LoadType::kI32Load);
+    LOAD_INSTANCE_FIELD(tmp_const, IndirectFunctionTableSize, kUInt32Size);
     __ emit_cond_jump(kUnsignedGreaterEqual, invalid_func_label, kWasmI32,
                       index.gp(), tmp_const.gp());
 
@@ -1714,7 +1741,7 @@ class LiftoffCompiler {
 
     DEBUG_CODE_COMMENT("Check indirect call signature");
     // Load the signature from {instance->ift_sig_ids[key]}
-    LOAD_INSTANCE_FIELD(table, IndirectFunctionTableSigIds, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(table, IndirectFunctionTableSigIds, kPointerSize);
     __ LoadConstant(tmp_const,
                     WasmValue(static_cast<uint32_t>(sizeof(uint32_t))));
     // TODO(wasm): use a emit_i32_shli() instead of a multiply.
@@ -1739,14 +1766,13 @@ class LiftoffCompiler {
     }
 
     // Load the target from {instance->ift_targets[key]}
-    LOAD_INSTANCE_FIELD(table, IndirectFunctionTableTargets, kPointerLoadType);
+    LOAD_INSTANCE_FIELD(table, IndirectFunctionTableTargets, kPointerSize);
     __ Load(scratch, table.gp(), index.gp(), 0, kPointerLoadType, pinned);
 
     // Load the instance from {instance->ift_instances[key]}
-    LOAD_INSTANCE_FIELD(table, IndirectFunctionTableInstances,
-                        kPointerLoadType);
+    LOAD_INSTANCE_FIELD(table, IndirectFunctionTableInstances, kPointerSize);
     __ Load(tmp_const, table.gp(), index.gp(),
-            (FixedArray::kHeaderSize - kHeapObjectTag), kPointerLoadType,
+            ObjectAccess::ElementOffsetInTaggedFixedArray(0), kPointerLoadType,
             pinned);
     LiftoffRegister* explicit_instance = &tmp_const;
 
@@ -1835,6 +1861,8 @@ class LiftoffCompiler {
     os << "\n";
 #endif
   }
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(LiftoffCompiler);
 };
 
 }  // namespace
@@ -1903,6 +1931,7 @@ WasmCode* LiftoffCompilationUnit::FinishCompilation(ErrorThrower*) {
 #undef __
 #undef TRACE
 #undef WASM_INSTANCE_OBJECT_OFFSET
+#undef WASM_INSTANCE_OBJECT_SIZE
 #undef LOAD_INSTANCE_FIELD
 #undef DEBUG_CODE_COMMENT
 
diff --git a/deps/v8/src/wasm/baseline/liftoff-register.h b/deps/v8/src/wasm/baseline/liftoff-register.h
index 19bf88948d..c3f89eb506 100644
--- a/deps/v8/src/wasm/baseline/liftoff-register.h
+++ b/deps/v8/src/wasm/baseline/liftoff-register.h
@@ -46,11 +46,11 @@ static inline constexpr RegClass reg_class_for(ValueType type) {
 // Maximum code of a gp cache register.
 static constexpr int kMaxGpRegCode =
     8 * sizeof(kLiftoffAssemblerGpCacheRegs) -
-    base::bits::CountLeadingZeros(kLiftoffAssemblerGpCacheRegs);
+    base::bits::CountLeadingZeros(kLiftoffAssemblerGpCacheRegs) - 1;
 // Maximum code of an fp cache register.
 static constexpr int kMaxFpRegCode =
     8 * sizeof(kLiftoffAssemblerFpCacheRegs) -
-    base::bits::CountLeadingZeros(kLiftoffAssemblerFpCacheRegs);
+    base::bits::CountLeadingZeros(kLiftoffAssemblerFpCacheRegs) - 1;
 // LiftoffRegister encodes both gp and fp in a unified index space.
 // [0 .. kMaxGpRegCode] encodes gp registers,
 // [kMaxGpRegCode+1 .. kMaxGpRegCode + kMaxFpRegCode] encodes fp registers.
@@ -72,16 +72,23 @@ class LiftoffRegister {
   using storage_t = std::conditional<
       needed_bits <= 8, uint8_t,
       std::conditional<needed_bits <= 16, uint16_t, uint32_t>::type>::type;
-  static_assert(8 * sizeof(storage_t) >= needed_bits &&
-                    8 * sizeof(storage_t) < 2 * needed_bits,
-                "right type has been chosen");
+
+  static_assert(8 * sizeof(storage_t) >= needed_bits,
+                "chosen type is big enough");
+  // Check for smallest required data type being chosen.
+  // Special case for uint8_t as there are no smaller types.
+  static_assert((8 * sizeof(storage_t) < 2 * needed_bits) ||
+                    (sizeof(storage_t) == sizeof(uint8_t)),
+                "chosen type is small enough");
 
  public:
   explicit LiftoffRegister(Register reg) : LiftoffRegister(reg.code()) {
+    DCHECK_NE(0, kLiftoffAssemblerGpCacheRegs & reg.bit());
     DCHECK_EQ(reg, gp());
   }
   explicit LiftoffRegister(DoubleRegister reg)
       : LiftoffRegister(kAfterMaxLiftoffGpRegCode + reg.code()) {
+    DCHECK_NE(0, kLiftoffAssemblerFpCacheRegs & reg.bit());
     DCHECK_EQ(reg, fp());
   }
 
diff --git a/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h b/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
index bb18994618..cc8170b499 100644
--- a/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
+++ b/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
@@ -15,6 +15,14 @@ namespace wasm {
 
 namespace liftoff {
 
+#if defined(V8_TARGET_BIG_ENDIAN)
+constexpr int32_t kLowWordOffset = 4;
+constexpr int32_t kHighWordOffset = 0;
+#else
+constexpr int32_t kLowWordOffset = 0;
+constexpr int32_t kHighWordOffset = 4;
+#endif
+
 // fp-4 holds the stack marker, fp-8 is the instance parameter, first stack
 // slot is located at fp-16.
 constexpr int32_t kConstantStackSpace = 8;
@@ -41,8 +49,10 @@ inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Register base,
       assm->lw(dst.gp(), src);
       break;
     case kWasmI64:
-      assm->lw(dst.low_gp(), src);
-      assm->lw(dst.high_gp(), MemOperand(base, offset + 4));
+      assm->lw(dst.low_gp(),
+               MemOperand(base, offset + liftoff::kLowWordOffset));
+      assm->lw(dst.high_gp(),
+               MemOperand(base, offset + liftoff::kHighWordOffset));
       break;
     case kWasmF32:
       assm->lwc1(dst.fp(), src);
@@ -63,8 +73,10 @@ inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
       assm->Usw(src.gp(), dst);
       break;
     case kWasmI64:
-      assm->Usw(src.low_gp(), dst);
-      assm->Usw(src.high_gp(), MemOperand(base, offset + 4));
+      assm->Usw(src.low_gp(),
+                MemOperand(base, offset + liftoff::kLowWordOffset));
+      assm->Usw(src.high_gp(),
+                MemOperand(base, offset + liftoff::kHighWordOffset));
       break;
     case kWasmF32:
       assm->Uswc1(src.fp(), dst, t8);
@@ -106,11 +118,6 @@ inline void ChangeEndiannessLoad(LiftoffAssembler* assm, LiftoffRegister dst,
   switch (type.value()) {
     case LoadType::kI64Load8U:
     case LoadType::kI64Load8S:
-      // Swap low and high registers.
-      assm->TurboAssembler::Move(kScratchReg, tmp.low_gp());
-      assm->TurboAssembler::Move(tmp.low_gp(), tmp.high_gp());
-      assm->TurboAssembler::Move(tmp.high_gp(), kScratchReg);
-      V8_FALLTHROUGH;
     case LoadType::kI32Load8U:
     case LoadType::kI32Load8S:
       // No need to change endianness for byte size.
@@ -140,20 +147,20 @@ inline void ChangeEndiannessLoad(LiftoffAssembler* assm, LiftoffRegister dst,
       assm->TurboAssembler::ByteSwapSigned(tmp.high_gp(), kScratchReg, 4);
       break;
     case LoadType::kI64Load16U:
-      assm->TurboAssembler::ByteSwapUnsigned(tmp.low_gp(), tmp.high_gp(), 2);
+      assm->TurboAssembler::ByteSwapUnsigned(tmp.low_gp(), tmp.low_gp(), 2);
       assm->TurboAssembler::Move(tmp.high_gp(), zero_reg);
       break;
     case LoadType::kI64Load16S:
-      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.high_gp(), 2);
-      assm->sra(tmp.high_gp(), tmp.high_gp(), 31);
+      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.low_gp(), 2);
+      assm->sra(tmp.high_gp(), tmp.low_gp(), 31);
       break;
     case LoadType::kI64Load32U:
-      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.high_gp(), 4);
+      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.low_gp(), 4);
       assm->TurboAssembler::Move(tmp.high_gp(), zero_reg);
       break;
     case LoadType::kI64Load32S:
-      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.high_gp(), 4);
-      assm->sra(tmp.high_gp(), tmp.high_gp(), 31);
+      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.low_gp(), 4);
+      assm->sra(tmp.high_gp(), tmp.low_gp(), 31);
       break;
     default:
       UNREACHABLE();
@@ -179,11 +186,6 @@ inline void ChangeEndiannessStore(LiftoffAssembler* assm, LiftoffRegister src,
   LiftoffRegister tmp = src;
   switch (type.value()) {
     case StoreType::kI64Store8:
-      // Swap low and high registers.
-      assm->TurboAssembler::Move(kScratchReg, tmp.low_gp());
-      assm->TurboAssembler::Move(tmp.low_gp(), tmp.high_gp());
-      assm->TurboAssembler::Move(tmp.high_gp(), kScratchReg);
-      V8_FALLTHROUGH;
     case StoreType::kI32Store8:
       // No need to change endianness for byte size.
       return;
@@ -193,21 +195,27 @@ inline void ChangeEndiannessStore(LiftoffAssembler* assm, LiftoffRegister src,
       assm->emit_type_conversion(kExprI32ReinterpretF32, tmp, src);
       V8_FALLTHROUGH;
     case StoreType::kI32Store:
-    case StoreType::kI32Store16:
       assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 4);
       break;
+    case StoreType::kI32Store16:
+      assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 2);
+      break;
     case StoreType::kF64Store:
       is_float = true;
       tmp = assm->GetUnusedRegister(kGpRegPair, pinned);
       assm->emit_type_conversion(kExprI64ReinterpretF64, tmp, src);
       V8_FALLTHROUGH;
     case StoreType::kI64Store:
-    case StoreType::kI64Store32:
-    case StoreType::kI64Store16:
       assm->TurboAssembler::Move(kScratchReg, tmp.low_gp());
       assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.high_gp(), 4);
       assm->TurboAssembler::ByteSwapSigned(tmp.high_gp(), kScratchReg, 4);
       break;
+    case StoreType::kI64Store32:
+      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.low_gp(), 4);
+      break;
+    case StoreType::kI64Store16:
+      assm->TurboAssembler::ByteSwapSigned(tmp.low_gp(), tmp.low_gp(), 2);
+      break;
     default:
       UNREACHABLE();
   }
@@ -358,11 +366,16 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
       sra(dst.high_gp(), dst.high_gp(), 31);
       break;
     case LoadType::kI64Load: {
-      MemOperand src_op_upper = (offset_reg != no_reg)
-                                    ? MemOperand(src, offset_imm + 4)
-                                    : MemOperand(src_addr, offset_imm + 4);
-      TurboAssembler::Ulw(dst.high_gp(), src_op_upper);
+      MemOperand src_op =
+          (offset_reg != no_reg)
+              ? MemOperand(src, offset_imm + liftoff::kLowWordOffset)
+              : MemOperand(src_addr, offset_imm + liftoff::kLowWordOffset);
+      MemOperand src_op_upper =
+          (offset_reg != no_reg)
+              ? MemOperand(src, offset_imm + liftoff::kHighWordOffset)
+              : MemOperand(src_addr, offset_imm + liftoff::kHighWordOffset);
       TurboAssembler::Ulw(dst.low_gp(), src_op);
+      TurboAssembler::Ulw(dst.high_gp(), src_op_upper);
       break;
     }
     case LoadType::kF32Load:
@@ -377,6 +390,7 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
 
 #if defined(V8_TARGET_BIG_ENDIAN)
   if (is_load_mem) {
+    pinned.set(src_op.rm());
     liftoff::ChangeEndiannessLoad(this, dst, type, pinned);
   }
 #endif
@@ -396,6 +410,7 @@ void LiftoffAssembler::Store(Register dst_addr, Register offset_reg,
 
 #if defined(V8_TARGET_BIG_ENDIAN)
   if (is_store_mem) {
+    pinned.set(dst_op.rm());
     LiftoffRegister tmp = GetUnusedRegister(src.reg_class(), pinned);
     // Save original value.
     Move(tmp, src, type.value_type());
@@ -427,11 +442,16 @@ void LiftoffAssembler::Store(Register dst_addr, Register offset_reg,
       TurboAssembler::Usw(src.gp(), dst_op);
       break;
     case StoreType::kI64Store: {
-      MemOperand dst_op_upper = (offset_reg != no_reg)
-                                    ? MemOperand(dst, offset_imm + 4)
-                                    : MemOperand(dst_addr, offset_imm + 4);
-      TurboAssembler::Usw(src.high_gp(), dst_op_upper);
+      MemOperand dst_op =
+          (offset_reg != no_reg)
+              ? MemOperand(dst, offset_imm + liftoff::kLowWordOffset)
+              : MemOperand(dst_addr, offset_imm + liftoff::kLowWordOffset);
+      MemOperand dst_op_upper =
+          (offset_reg != no_reg)
+              ? MemOperand(dst, offset_imm + liftoff::kHighWordOffset)
+              : MemOperand(dst_addr, offset_imm + liftoff::kHighWordOffset);
       TurboAssembler::Usw(src.low_gp(), dst_op);
+      TurboAssembler::Usw(src.high_gp(), dst_op_upper);
       break;
     }
     case StoreType::kF32Store:
@@ -624,12 +644,20 @@ bool LiftoffAssembler::emit_i32_popcnt(Register dst, Register src) {
       Register dst, Register src, Register amount, LiftoffRegList pinned) { \
     instruction(dst, src, amount);                                          \
   }
+#define I32_SHIFTOP_I(name, instruction)                             \
+  I32_SHIFTOP(name, instruction##v)                                  \
+  void LiftoffAssembler::emit_i32_##name(Register dst, Register src, \
+                                         int amount) {               \
+    DCHECK(is_uint5(amount));                                        \
+    instruction(dst, src, amount);                                   \
+  }
 
 I32_SHIFTOP(shl, sllv)
 I32_SHIFTOP(sar, srav)
-I32_SHIFTOP(shr, srlv)
+I32_SHIFTOP_I(shr, srl)
 
 #undef I32_SHIFTOP
+#undef I32_SHIFTOP_I
 
 void LiftoffAssembler::emit_i64_mul(LiftoffRegister dst, LiftoffRegister lhs,
                                     LiftoffRegister rhs) {
@@ -745,6 +773,13 @@ void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
                                    &TurboAssembler::ShrPair, pinned);
 }
 
+void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
+                                    int amount) {
+  DCHECK(is_uint6(amount));
+  ShrPair(dst.high_gp(), dst.low_gp(), src.high_gp(), src.low_gp(), amount,
+          kScratchReg);
+}
+
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
   // This is a nop on mips32.
 }
@@ -779,6 +814,11 @@ void LiftoffAssembler::emit_f32_max(DoubleRegister dst, DoubleRegister lhs,
   bind(&done);
 }
 
+void LiftoffAssembler::emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  BAILOUT("f32_copysign");
+}
+
 void LiftoffAssembler::emit_f64_min(DoubleRegister dst, DoubleRegister lhs,
                                     DoubleRegister rhs) {
   Label ool, done;
@@ -801,6 +841,11 @@ void LiftoffAssembler::emit_f64_max(DoubleRegister dst, DoubleRegister lhs,
   bind(&done);
 }
 
+void LiftoffAssembler::emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  BAILOUT("f64_copysign");
+}
+
 #define FP_BINOP(name, instruction)                                          \
   void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
                                      DoubleRegister rhs) {                   \
@@ -1027,6 +1072,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   }
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i32");
+}
+
 void LiftoffAssembler::emit_jump(Label* label) {
   TurboAssembler::Branch(label);
 }
diff --git a/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h b/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
index 4bbfc18251..a2447d8b32 100644
--- a/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
+++ b/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
@@ -72,6 +72,9 @@ inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
 inline void push(LiftoffAssembler* assm, LiftoffRegister reg, ValueType type) {
   switch (type) {
     case kWasmI32:
+      assm->daddiu(sp, sp, -kPointerSize);
+      assm->sw(reg.gp(), MemOperand(sp, 0));
+      break;
     case kWasmI64:
       assm->push(reg.gp());
       break;
@@ -107,22 +110,18 @@ inline void ChangeEndiannessLoad(LiftoffAssembler* assm, LiftoffRegister dst,
       V8_FALLTHROUGH;
     case LoadType::kI64Load32U:
       assm->TurboAssembler::ByteSwapUnsigned(tmp.gp(), tmp.gp(), 4);
-      assm->dsrl32(tmp.gp(), tmp.gp(), 0);
       break;
     case LoadType::kI32Load:
     case LoadType::kI64Load32S:
       assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 4);
-      assm->dsra32(tmp.gp(), tmp.gp(), 0);
       break;
     case LoadType::kI32Load16S:
     case LoadType::kI64Load16S:
       assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 2);
-      assm->dsra32(tmp.gp(), tmp.gp(), 0);
       break;
     case LoadType::kI32Load16U:
     case LoadType::kI64Load16U:
       assm->TurboAssembler::ByteSwapUnsigned(tmp.gp(), tmp.gp(), 2);
-      assm->dsrl32(tmp.gp(), tmp.gp(), 0);
       break;
     case LoadType::kF64Load:
       is_float = true;
@@ -165,18 +164,24 @@ inline void ChangeEndiannessStore(LiftoffAssembler* assm, LiftoffRegister src,
       assm->emit_type_conversion(kExprI32ReinterpretF32, tmp, src);
       V8_FALLTHROUGH;
     case StoreType::kI32Store:
-    case StoreType::kI32Store16:
       assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 4);
       break;
+    case StoreType::kI32Store16:
+      assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 2);
+      break;
     case StoreType::kF64Store:
       is_float = true;
       tmp = assm->GetUnusedRegister(kGpReg, pinned);
       assm->emit_type_conversion(kExprI64ReinterpretF64, tmp, src);
       V8_FALLTHROUGH;
     case StoreType::kI64Store:
+      assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 8);
+      break;
     case StoreType::kI64Store32:
+      assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 4);
+      break;
     case StoreType::kI64Store16:
-      assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 8);
+      assm->TurboAssembler::ByteSwapSigned(tmp.gp(), tmp.gp(), 2);
       break;
     default:
       UNREACHABLE();
@@ -274,12 +279,13 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,
                             uint32_t* protected_load_pc, bool is_load_mem) {
-  MemOperand src_op(src_addr, offset_imm);
+  Register src = no_reg;
   if (offset_reg != no_reg) {
-    Register src = GetUnusedRegister(kGpReg, pinned).gp();
+    src = GetUnusedRegister(kGpReg, pinned).gp();
     emit_ptrsize_add(src, src_addr, offset_reg);
-    src_op = MemOperand(src, offset_imm);
   }
+  MemOperand src_op = (offset_reg != no_reg) ? MemOperand(src, offset_imm)
+                                             : MemOperand(src_addr, offset_imm);
 
   if (protected_load_pc) *protected_load_pc = pc_offset();
   switch (type.value()) {
@@ -321,6 +327,7 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
 
 #if defined(V8_TARGET_BIG_ENDIAN)
   if (is_load_mem) {
+    pinned.set(src_op.rm());
     liftoff::ChangeEndiannessLoad(this, dst, type, pinned);
   }
 #endif
@@ -340,6 +347,7 @@ void LiftoffAssembler::Store(Register dst_addr, Register offset_reg,
 
 #if defined(V8_TARGET_BIG_ENDIAN)
   if (is_store_mem) {
+    pinned.set(dst_op.rm());
     LiftoffRegister tmp = GetUnusedRegister(src.reg_class(), pinned);
     // Save original value.
     Move(tmp, src, type.value_type());
@@ -550,12 +558,20 @@ bool LiftoffAssembler::emit_i32_popcnt(Register dst, Register src) {
       Register dst, Register src, Register amount, LiftoffRegList pinned) { \
     instruction(dst, src, amount);                                          \
   }
+#define I32_SHIFTOP_I(name, instruction)                             \
+  I32_SHIFTOP(name, instruction##v)                                  \
+  void LiftoffAssembler::emit_i32_##name(Register dst, Register src, \
+                                         int amount) {               \
+    DCHECK(is_uint5(amount));                                        \
+    instruction(dst, src, amount);                                   \
+  }
 
 I32_SHIFTOP(shl, sllv)
 I32_SHIFTOP(sar, srav)
-I32_SHIFTOP(shr, srlv)
+I32_SHIFTOP_I(shr, srl)
 
 #undef I32_SHIFTOP
+#undef I32_SHIFTOP_I
 
 void LiftoffAssembler::emit_i64_mul(LiftoffRegister dst, LiftoffRegister lhs,
                                     LiftoffRegister rhs) {
@@ -628,12 +644,20 @@ I64_BINOP(xor, xor_)
                                          LiftoffRegList pinned) {              \
     instruction(dst.gp(), src.gp(), amount);                                   \
   }
+#define I64_SHIFTOP_I(name, instruction)                                    \
+  I64_SHIFTOP(name, instruction##v)                                         \
+  void LiftoffAssembler::emit_i64_##name(LiftoffRegister dst,               \
+                                         LiftoffRegister src, int amount) { \
+    DCHECK(is_uint6(amount));                                               \
+    instruction(dst.gp(), src.gp(), amount);                                \
+  }
 
 I64_SHIFTOP(shl, dsllv)
 I64_SHIFTOP(sar, dsrav)
-I64_SHIFTOP(shr, dsrlv)
+I64_SHIFTOP_I(shr, dsrl)
 
 #undef I64_SHIFTOP
+#undef I64_SHIFTOP_I
 
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
   addu(dst, src, zero_reg);
@@ -669,6 +693,11 @@ void LiftoffAssembler::emit_f32_max(DoubleRegister dst, DoubleRegister lhs,
   bind(&done);
 }
 
+void LiftoffAssembler::emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  BAILOUT("f32_copysign");
+}
+
 void LiftoffAssembler::emit_f64_min(DoubleRegister dst, DoubleRegister lhs,
                                     DoubleRegister rhs) {
   Label ool, done;
@@ -691,6 +720,11 @@ void LiftoffAssembler::emit_f64_max(DoubleRegister dst, DoubleRegister lhs,
   bind(&done);
 }
 
+void LiftoffAssembler::emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  BAILOUT("f64_copysign");
+}
+
 #define FP_BINOP(name, instruction)                                          \
   void LiftoffAssembler::emit_##name(DoubleRegister dst, DoubleRegister lhs, \
                                      DoubleRegister rhs) {                   \
@@ -928,6 +962,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   }
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i32");
+}
+
 void LiftoffAssembler::emit_jump(Label* label) {
   TurboAssembler::Branch(label);
 }
diff --git a/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h b/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
index 9164db2188..e9dcd419ba 100644
--- a/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
+++ b/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
@@ -166,6 +166,7 @@ UNIMPLEMENTED_FP_BINOP(f32_mul)
 UNIMPLEMENTED_FP_BINOP(f32_div)
 UNIMPLEMENTED_FP_BINOP(f32_min)
 UNIMPLEMENTED_FP_BINOP(f32_max)
+UNIMPLEMENTED_FP_BINOP(f32_copysign)
 UNIMPLEMENTED_FP_UNOP(f32_abs)
 UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_UNOP(f32_ceil)
@@ -179,6 +180,7 @@ UNIMPLEMENTED_FP_BINOP(f64_mul)
 UNIMPLEMENTED_FP_BINOP(f64_div)
 UNIMPLEMENTED_FP_BINOP(f64_min)
 UNIMPLEMENTED_FP_BINOP(f64_max)
+UNIMPLEMENTED_FP_BINOP(f64_copysign)
 UNIMPLEMENTED_FP_UNOP(f64_abs)
 UNIMPLEMENTED_FP_UNOP(f64_neg)
 UNIMPLEMENTED_FP_UNOP_RETURN_TRUE(f64_ceil)
@@ -217,6 +219,10 @@ void LiftoffAssembler::emit_i32_remu(Register dst, Register lhs, Register rhs,
   BAILOUT("i32_remu");
 }
 
+void LiftoffAssembler::emit_i32_shr(Register dst, Register lhs, int amount) {
+  BAILOUT("i32_shr");
+}
+
 bool LiftoffAssembler::emit_i64_divs(LiftoffRegister dst, LiftoffRegister lhs,
                                      LiftoffRegister rhs,
                                      Label* trap_div_by_zero,
@@ -246,6 +252,11 @@ bool LiftoffAssembler::emit_i64_remu(LiftoffRegister dst, LiftoffRegister lhs,
   return true;
 }
 
+void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister lhs,
+                                    int amount) {
+  BAILOUT("i64_shr");
+}
+
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
 #ifdef V8_TARGET_ARCH_PPC64
   BAILOUT("emit_i32_to_intptr");
@@ -261,6 +272,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   return true;
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i32");
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }
 
 void LiftoffAssembler::emit_jump(Register target) { BAILOUT("emit_jump"); }
diff --git a/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h b/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
index e39dd90166..970cfe5753 100644
--- a/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
+++ b/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
@@ -166,6 +166,7 @@ UNIMPLEMENTED_FP_BINOP(f32_mul)
 UNIMPLEMENTED_FP_BINOP(f32_div)
 UNIMPLEMENTED_FP_BINOP(f32_min)
 UNIMPLEMENTED_FP_BINOP(f32_max)
+UNIMPLEMENTED_FP_BINOP(f32_copysign)
 UNIMPLEMENTED_FP_UNOP(f32_abs)
 UNIMPLEMENTED_FP_UNOP(f32_neg)
 UNIMPLEMENTED_FP_UNOP(f32_ceil)
@@ -179,6 +180,7 @@ UNIMPLEMENTED_FP_BINOP(f64_mul)
 UNIMPLEMENTED_FP_BINOP(f64_div)
 UNIMPLEMENTED_FP_BINOP(f64_min)
 UNIMPLEMENTED_FP_BINOP(f64_max)
+UNIMPLEMENTED_FP_BINOP(f64_copysign)
 UNIMPLEMENTED_FP_UNOP(f64_abs)
 UNIMPLEMENTED_FP_UNOP(f64_neg)
 UNIMPLEMENTED_FP_UNOP_RETURN_TRUE(f64_ceil)
@@ -217,6 +219,10 @@ void LiftoffAssembler::emit_i32_remu(Register dst, Register lhs, Register rhs,
   BAILOUT("i32_remu");
 }
 
+void LiftoffAssembler::emit_i32_shr(Register dst, Register lhs, int amount) {
+  BAILOUT("i32_shr");
+}
+
 bool LiftoffAssembler::emit_i64_divs(LiftoffRegister dst, LiftoffRegister lhs,
                                      LiftoffRegister rhs,
                                      Label* trap_div_by_zero,
@@ -246,6 +252,11 @@ bool LiftoffAssembler::emit_i64_remu(LiftoffRegister dst, LiftoffRegister lhs,
   return true;
 }
 
+void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister lhs,
+                                    int amount) {
+  BAILOUT("i64_shr");
+}
+
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
 #ifdef V8_TARGET_ARCH_S390X
   BAILOUT("emit_i32_to_intptr");
@@ -261,6 +272,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   return true;
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  BAILOUT("emit_i32_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i8");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i16");
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  BAILOUT("emit_i64_signextend_i32");
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { BAILOUT("emit_jump"); }
 
 void LiftoffAssembler::emit_jump(Register target) { BAILOUT("emit_jump"); }
diff --git a/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h b/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
index f6a8e09b4e..6805e19a76 100644
--- a/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
+++ b/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
@@ -23,9 +23,11 @@ namespace wasm {
 
 namespace liftoff {
 
+constexpr Register kScratchRegister2 = r11;
+static_assert(kScratchRegister != kScratchRegister2, "collision");
 static_assert((kLiftoffAssemblerGpCacheRegs &
-               Register::ListOf<kScratchRegister>()) == 0,
-              "scratch register must not be used as cache registers");
+               Register::ListOf<kScratchRegister, kScratchRegister2>()) == 0,
+              "scratch registers must not be used as cache registers");
 
 constexpr DoubleRegister kScratchDoubleReg2 = xmm14;
 static_assert(kScratchDoubleReg != kScratchDoubleReg2, "collision");
@@ -619,6 +621,12 @@ void LiftoffAssembler::emit_i32_shr(Register dst, Register src, Register amount,
                                         &Assembler::shrl_cl, pinned);
 }
 
+void LiftoffAssembler::emit_i32_shr(Register dst, Register src, int amount) {
+  if (dst != src) movl(dst, src);
+  DCHECK(is_uint5(amount));
+  shrl(dst, Immediate(amount));
+}
+
 bool LiftoffAssembler::emit_i32_clz(Register dst, Register src) {
   Label nonzero_input;
   Label continuation;
@@ -756,6 +764,13 @@ void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
                                         &Assembler::shrq_cl, pinned);
 }
 
+void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
+                                    int amount) {
+  if (dst.gp() != src.gp()) movl(dst.gp(), src.gp());
+  DCHECK(is_uint6(amount));
+  shrq(dst.gp(), Immediate(amount));
+}
+
 void LiftoffAssembler::emit_i32_to_intptr(Register dst, Register src) {
   movsxlq(dst, src);
 }
@@ -885,6 +900,17 @@ void LiftoffAssembler::emit_f32_max(DoubleRegister dst, DoubleRegister lhs,
                                     liftoff::MinOrMax::kMax);
 }
 
+void LiftoffAssembler::emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  static constexpr int kF32SignBit = 1 << 31;
+  Movd(kScratchRegister, lhs);
+  andl(kScratchRegister, Immediate(~kF32SignBit));
+  Movd(liftoff::kScratchRegister2, rhs);
+  andl(liftoff::kScratchRegister2, Immediate(kF32SignBit));
+  orl(kScratchRegister, liftoff::kScratchRegister2);
+  Movd(dst, kScratchRegister);
+}
+
 void LiftoffAssembler::emit_f32_abs(DoubleRegister dst, DoubleRegister src) {
   static constexpr uint32_t kSignBit = uint32_t{1} << 31;
   if (dst == src) {
@@ -994,6 +1020,20 @@ void LiftoffAssembler::emit_f64_min(DoubleRegister dst, DoubleRegister lhs,
                                      liftoff::MinOrMax::kMin);
 }
 
+void LiftoffAssembler::emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
+                                         DoubleRegister rhs) {
+  // Extract sign bit from {rhs} into {kScratchRegister2}.
+  Movq(liftoff::kScratchRegister2, rhs);
+  shrq(liftoff::kScratchRegister2, Immediate(63));
+  shlq(liftoff::kScratchRegister2, Immediate(63));
+  // Reset sign bit of {lhs} (in {kScratchRegister}).
+  Movq(kScratchRegister, lhs);
+  btrq(kScratchRegister, Immediate(63));
+  // Combine both values into {kScratchRegister} and move into {dst}.
+  orq(kScratchRegister, liftoff::kScratchRegister2);
+  Movq(dst, kScratchRegister);
+}
+
 void LiftoffAssembler::emit_f64_max(DoubleRegister dst, DoubleRegister lhs,
                                     DoubleRegister rhs) {
   liftoff::EmitFloatMinOrMax<double>(this, dst, lhs, rhs,
@@ -1213,6 +1253,29 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
   }
 }
 
+void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
+  movsxbl(dst, src);
+}
+
+void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
+  movsxwl(dst, src);
+}
+
+void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
+                                              LiftoffRegister src) {
+  movsxbq(dst.gp(), src.gp());
+}
+
+void LiftoffAssembler::emit_i64_signextend_i16(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  movsxwq(dst.gp(), src.gp());
+}
+
+void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
+                                               LiftoffRegister src) {
+  movsxlq(dst.gp(), src.gp());
+}
+
 void LiftoffAssembler::emit_jump(Label* label) { jmp(label); }
 
 void LiftoffAssembler::emit_jump(Register target) { jmp(target); }
diff --git a/deps/v8/src/wasm/decoder.h b/deps/v8/src/wasm/decoder.h
index 3dd9aff9c6..74955f9ede 100644
--- a/deps/v8/src/wasm/decoder.h
+++ b/deps/v8/src/wasm/decoder.h
@@ -56,7 +56,7 @@ class Decoder {
     DCHECK_EQ(static_cast<uint32_t>(end - start), end - start);
   }
 
-  virtual ~Decoder() {}
+  virtual ~Decoder() = default;
 
   inline bool validate_size(const byte* pc, uint32_t length, const char* msg) {
     DCHECK_LE(start_, pc);
@@ -375,27 +375,6 @@ class Decoder {
   }
 };
 
-// Reference to a string in the wire bytes.
-class WireBytesRef {
- public:
-  WireBytesRef() : WireBytesRef(0, 0) {}
-  WireBytesRef(uint32_t offset, uint32_t length)
-      : offset_(offset), length_(length) {
-    DCHECK_IMPLIES(offset_ == 0, length_ == 0);
-    DCHECK_LE(offset_, offset_ + length_);  // no uint32_t overflow.
-  }
-
-  uint32_t offset() const { return offset_; }
-  uint32_t length() const { return length_; }
-  uint32_t end_offset() const { return offset_ + length_; }
-  bool is_empty() const { return length_ == 0; }
-  bool is_set() const { return offset_ != 0; }
-
- private:
-  uint32_t offset_;
-  uint32_t length_;
-};
-
 #undef TRACE
 }  // namespace wasm
 }  // namespace internal
diff --git a/deps/v8/src/wasm/function-body-decoder-impl.h b/deps/v8/src/wasm/function-body-decoder-impl.h
index 3e0a0da46e..0e49ee7e97 100644
--- a/deps/v8/src/wasm/function-body-decoder-impl.h
+++ b/deps/v8/src/wasm/function-body-decoder-impl.h
@@ -487,7 +487,8 @@ enum ControlKind : uint8_t {
   kControlBlock,
   kControlLoop,
   kControlTry,
-  kControlTryCatch
+  kControlTryCatch,
+  kControlTryCatchAll
 };
 
 enum Reachability : uint8_t {
@@ -534,9 +535,12 @@ struct ControlBase {
   bool is_if_else() const { return kind == kControlIfElse; }
   bool is_block() const { return kind == kControlBlock; }
   bool is_loop() const { return kind == kControlLoop; }
-  bool is_try() const { return is_incomplete_try() || is_try_catch(); }
   bool is_incomplete_try() const { return kind == kControlTry; }
   bool is_try_catch() const { return kind == kControlTryCatch; }
+  bool is_try_catchall() const { return kind == kControlTryCatchAll; }
+  bool is_try() const {
+    return is_incomplete_try() || is_try_catch() || is_try_catchall();
+  }
 
   inline Merge<Value>* br_merge() {
     return is_loop() ? &this->start_merge : &this->end_merge;
@@ -737,6 +741,13 @@ class WasmDecoder : public Decoder {
           }
           decoder->error(decoder->pc() - 1, "invalid local type");
           return false;
+        case kLocalExceptRef:
+          if (enabled.eh) {
+            type = kWasmExceptRef;
+            break;
+          }
+          decoder->error(decoder->pc() - 1, "invalid local type");
+          return false;
         case kLocalS128:
           if (enabled.simd) {
             type = kWasmS128;
@@ -776,7 +787,7 @@ class WasmDecoder : public Decoder {
           break;
         case kExprSetLocal:  // fallthru
         case kExprTeeLocal: {
-          LocalIndexImmediate<Decoder::kValidate> imm(decoder, pc);
+          LocalIndexImmediate<validate> imm(decoder, pc);
           if (assigned->length() > 0 &&
               imm.index < static_cast<uint32_t>(assigned->length())) {
             // Unverified code might have an out-of-bounds index.
@@ -806,8 +817,7 @@ class WasmDecoder : public Decoder {
     return VALIDATE(decoder->ok()) ? assigned : nullptr;
   }
 
-  inline bool Validate(const byte* pc,
-                       LocalIndexImmediate<Decoder::kValidate>& imm) {
+  inline bool Validate(const byte* pc, LocalIndexImmediate<validate>& imm) {
     if (!VALIDATE(imm.index < total_locals())) {
       errorf(pc + 1, "invalid local index: %u", imm.index);
       return false;
@@ -1034,7 +1044,7 @@ class WasmDecoder : public Decoder {
       case kExprSetLocal:
       case kExprTeeLocal:
       case kExprGetLocal: {
-        LocalIndexImmediate<Decoder::kValidate> imm(decoder, pc);
+        LocalIndexImmediate<validate> imm(decoder, pc);
         return 1 + imm.length;
       }
       case kExprBrTable: {
@@ -1466,7 +1476,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           }
           case kExprThrow: {
             CHECK_PROTOTYPE_OPCODE(eh);
-            ExceptionIndexImmediate<Decoder::kValidate> imm(this, this->pc_);
+            ExceptionIndexImmediate<validate> imm(this, this->pc_);
             len = 1 + imm.length;
             if (!this->Validate(this->pc_, imm)) break;
             PopArgs(imm.exception->ToFunctionSig());
@@ -1490,7 +1500,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           case kExprCatch: {
             // TODO(kschimpf): Fix to use type signature of exception.
             CHECK_PROTOTYPE_OPCODE(eh);
-            ExceptionIndexImmediate<Decoder::kValidate> imm(this, this->pc_);
+            ExceptionIndexImmediate<validate> imm(this, this->pc_);
             len = 1 + imm.length;
 
             if (!this->Validate(this->pc_, imm)) break;
@@ -1524,9 +1534,22 @@ class WasmFullDecoder : public WasmDecoder<validate> {
             break;
           }
           case kExprCatchAll: {
-            // TODO(kschimpf): Implement.
             CHECK_PROTOTYPE_OPCODE(eh);
-            OPCODE_ERROR(opcode, "not implemented yet");
+            if (!VALIDATE(!control_.empty())) {
+              this->error("catch-all does not match any try");
+              break;
+            }
+            Control* c = &control_.back();
+            if (!VALIDATE(c->is_try())) {
+              this->error("catch-all does not match any try");
+              break;
+            }
+            if (!VALIDATE(!c->is_try_catchall())) {
+              this->error("catch-all already present for try");
+              break;
+            }
+            c->kind = kControlTryCatchAll;
+            // TODO(mstarzinger): Implement control flow for catch-all.
             break;
           }
           case kExprLoop: {
@@ -1581,7 +1604,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
             }
             Control* c = &control_.back();
             if (!VALIDATE(!c->is_incomplete_try())) {
-              this->error(this->pc_, "missing catch in try");
+              this->error(this->pc_, "missing catch or catch-all in try");
               break;
             }
             if (c->is_onearmed_if()) {
@@ -1742,7 +1765,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
             break;
           }
           case kExprGetLocal: {
-            LocalIndexImmediate<Decoder::kValidate> imm(this, this->pc_);
+            LocalIndexImmediate<validate> imm(this, this->pc_);
             if (!this->Validate(this->pc_, imm)) break;
             auto* value = Push(imm.type);
             CALL_INTERFACE_IF_REACHABLE(GetLocal, value, imm);
@@ -1750,7 +1773,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
             break;
           }
           case kExprSetLocal: {
-            LocalIndexImmediate<Decoder::kValidate> imm(this, this->pc_);
+            LocalIndexImmediate<validate> imm(this, this->pc_);
             if (!this->Validate(this->pc_, imm)) break;
             auto value = Pop(0, local_type_vec_[imm.index]);
             CALL_INTERFACE_IF_REACHABLE(SetLocal, value, imm);
@@ -1758,7 +1781,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
             break;
           }
           case kExprTeeLocal: {
-            LocalIndexImmediate<Decoder::kValidate> imm(this, this->pc_);
+            LocalIndexImmediate<validate> imm(this, this->pc_);
             if (!this->Validate(this->pc_, imm)) break;
             auto value = Pop(0, local_type_vec_[imm.index]);
             auto* result = Push(value.type);
@@ -2445,7 +2468,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return true;
   }
 
-  virtual void onFirstError() {
+  void onFirstError() override {
     this->end_ = this->pc_;  // Terminate decoding loop.
     TRACE(" !%s\n", this->error_msg_.c_str());
     CALL_INTERFACE(OnFirstError);
diff --git a/deps/v8/src/wasm/function-body-decoder.cc b/deps/v8/src/wasm/function-body-decoder.cc
index beb8716d9a..2c5ea465cc 100644
--- a/deps/v8/src/wasm/function-body-decoder.cc
+++ b/deps/v8/src/wasm/function-body-decoder.cc
@@ -37,7 +37,7 @@ struct SsaEnv {
   compiler::WasmInstanceCacheNodes instance_cache;
   TFNode** locals;
 
-  bool go() { return state >= kReached; }
+  bool reached() const { return state >= kReached; }
   void Kill(State new_state = kControlEnd) {
     state = new_state;
     locals = nullptr;
@@ -52,7 +52,7 @@ struct SsaEnv {
 
 #define BUILD(func, ...)                                            \
   ([&] {                                                            \
-    DCHECK(ssa_env_->go());                                         \
+    DCHECK(ssa_env_->reached());                                    \
     DCHECK(decoder->ok());                                          \
     return CheckForException(decoder, builder_->func(__VA_ARGS__)); \
   })()
@@ -99,6 +99,12 @@ class WasmGraphBuildingInterface {
     // instance parameter.
     TFNode* start = builder_->Start(
         static_cast<int>(decoder->sig_->parameter_count() + 1 + 1));
+    ssa_env->effect = start;
+    ssa_env->control = start;
+    // Initialize effect and control before initializing the locals default
+    // values (which might require instance loads) or loading the context.
+    builder_->set_effect_ptr(&ssa_env->effect);
+    builder_->set_control_ptr(&ssa_env->control);
     // Initialize the instance parameter (index 0).
     builder_->set_instance_node(builder_->Param(kWasmInstanceParameterIndex));
     // Initialize local variables. Parameters are shifted by 1 because of the
@@ -115,18 +121,13 @@ class WasmGraphBuildingInterface {
         ssa_env->locals[index++] = node;
       }
     }
-    ssa_env->effect = start;
-    ssa_env->control = start;
-    // Initialize effect and control before loading the context.
-    builder_->set_effect_ptr(&ssa_env->effect);
-    builder_->set_control_ptr(&ssa_env->control);
     LoadContextIntoSsa(ssa_env);
     SetEnv(ssa_env);
   }
 
   // Reload the instance cache entries into the Ssa Environment.
   void LoadContextIntoSsa(SsaEnv* ssa_env) {
-    if (!ssa_env || !ssa_env->go()) return;
+    if (!ssa_env || !ssa_env->reached()) return;
     builder_->InitInstanceCache(&ssa_env->instance_cache);
   }
 
@@ -180,7 +181,9 @@ class WasmGraphBuildingInterface {
   void If(FullDecoder* decoder, const Value& cond, Control* if_block) {
     TFNode* if_true = nullptr;
     TFNode* if_false = nullptr;
-    if (ssa_env_->go()) BUILD(BranchNoHint, cond.node, &if_true, &if_false);
+    if (ssa_env_->reached()) {
+      BUILD(BranchNoHint, cond.node, &if_true, &if_false);
+    }
     SsaEnv* end_env = ssa_env_;
     SsaEnv* false_env = Split(decoder, ssa_env_);
     false_env->control = if_false;
@@ -427,55 +430,46 @@ class WasmGraphBuildingInterface {
                       const ExceptionIndexImmediate<validate>& imm,
                       Control* block, Vector<Value> values) {
     DCHECK(block->is_try_catch());
+    TFNode* exception = block->try_info->exception;
     current_catch_ = block->previous_catch;
     SsaEnv* catch_env = block->try_info->catch_env;
     SetEnv(catch_env);
 
-    TFNode* compare_i32 = nullptr;
-    if (block->try_info->exception == nullptr) {
-      // Catch not applicable, no possible throws in the try
-      // block. Create dummy code so that body of catch still
-      // compiles. Note: This only happens because the current
-      // implementation only builds a landing pad if some node in the
-      // try block can (possibly) throw.
-      //
-      // TODO(kschimpf): Always generate a landing pad for a try block.
-      compare_i32 = BUILD(Int32Constant, 0);
-    } else {
-      // Get the exception and see if wanted exception.
-      TFNode* caught_tag = BUILD(GetExceptionRuntimeId);
-      TFNode* exception_tag = BUILD(ConvertExceptionTagToRuntimeId, imm.index);
-      compare_i32 = BUILD(Binop, kExprI32Eq, caught_tag, exception_tag);
-    }
+    // The catch block is unreachable if no possible throws in the try block
+    // exist. We only build a landing pad if some node in the try block can
+    // (possibly) throw. Otherwise the below catch environments remain empty.
+    DCHECK_EQ(exception != nullptr, ssa_env_->reached());
 
     TFNode* if_catch = nullptr;
     TFNode* if_no_catch = nullptr;
-    BUILD(BranchNoHint, compare_i32, &if_catch, &if_no_catch);
+    if (exception != nullptr) {
+      // Get the exception tag and see if it matches the expected one.
+      TFNode* caught_tag = BUILD(GetExceptionTag, exception);
+      TFNode* exception_tag = BUILD(LoadExceptionTagFromTable, imm.index);
+      TFNode* compare = BUILD(ExceptionTagEqual, caught_tag, exception_tag);
+      BUILD(BranchNoHint, compare, &if_catch, &if_no_catch);
+    }
 
     SsaEnv* if_no_catch_env = Split(decoder, ssa_env_);
     if_no_catch_env->control = if_no_catch;
     SsaEnv* if_catch_env = Steal(decoder->zone(), ssa_env_);
     if_catch_env->control = if_catch;
 
-    // TODO(kschimpf): Generalize to allow more catches. Will force
-    // moving no_catch code to END opcode.
     SetEnv(if_no_catch_env);
-    BUILD(Rethrow);
-    Unreachable(decoder);
-    EndControl(decoder, block);
+    if (exception != nullptr) {
+      // TODO(kschimpf): Generalize to allow more catches. Will force
+      // moving no_catch code to END opcode.
+      BUILD(Rethrow, exception);
+      Unreachable(decoder);
+      EndControl(decoder, block);
+    }
 
     SetEnv(if_catch_env);
-
-    if (block->try_info->exception == nullptr) {
-      // No caught value, make up filler nodes so that catch block still
-      // compiles.
-      for (Value& value : values) {
-        value.node = DefaultValue(value.type);
-      }
-    } else {
+    if (exception != nullptr) {
       // TODO(kschimpf): Can't use BUILD() here, GetExceptionValues() returns
       // TFNode** rather than TFNode*. Fix to add landing pads.
-      TFNode** caught_values = builder_->GetExceptionValues(imm.exception);
+      TFNode** caught_values =
+          builder_->GetExceptionValues(exception, imm.exception);
       for (size_t i = 0, e = values.size(); i < e; ++i) {
         values[i].node = caught_values[i];
       }
@@ -594,6 +588,9 @@ class WasmGraphBuildingInterface {
         return builder_->Float64Constant(0);
       case kWasmS128:
         return builder_->S128Zero();
+      case kWasmAnyRef:
+      case kWasmExceptRef:
+        return builder_->RefNull();
       default:
         UNREACHABLE();
     }
@@ -601,7 +598,7 @@ class WasmGraphBuildingInterface {
 
   void MergeValuesInto(FullDecoder* decoder, Control* c, Merge<Value>* merge) {
     DCHECK(merge == &c->start_merge || merge == &c->end_merge);
-    if (!ssa_env_->go()) return;
+    if (!ssa_env_->reached()) return;
 
     SsaEnv* target = c->end_env;
     const bool first = target->state == SsaEnv::kUnreachable;
@@ -624,7 +621,7 @@ class WasmGraphBuildingInterface {
 
   void Goto(FullDecoder* decoder, SsaEnv* from, SsaEnv* to) {
     DCHECK_NOT_NULL(to);
-    if (!from->go()) return;
+    if (!from->reached()) return;
     switch (to->state) {
       case SsaEnv::kUnreachable: {  // Overwrite destination.
         to->state = SsaEnv::kReached;
@@ -685,7 +682,7 @@ class WasmGraphBuildingInterface {
   }
 
   SsaEnv* PrepareForLoop(FullDecoder* decoder, SsaEnv* env) {
-    if (!env->go()) return Split(decoder, env);
+    if (!env->reached()) return Split(decoder, env);
     env->state = SsaEnv::kMerged;
 
     env->control = builder_->Loop(env->control);
@@ -739,7 +736,7 @@ class WasmGraphBuildingInterface {
     result->control = from->control;
     result->effect = from->effect;
 
-    if (from->go()) {
+    if (from->reached()) {
       result->state = SsaEnv::kReached;
       result->locals =
           size > 0 ? reinterpret_cast<TFNode**>(decoder->zone()->New(size))
@@ -759,7 +756,7 @@ class WasmGraphBuildingInterface {
   // unreachable.
   SsaEnv* Steal(Zone* zone, SsaEnv* from) {
     DCHECK_NOT_NULL(from);
-    if (!from->go()) return UnreachableEnv(zone);
+    if (!from->reached()) return UnreachableEnv(zone);
     SsaEnv* result = reinterpret_cast<SsaEnv*>(zone->New(sizeof(SsaEnv)));
     result->state = SsaEnv::kReached;
     result->locals = from->locals;
@@ -791,11 +788,9 @@ class WasmGraphBuildingInterface {
       arg_nodes[i + 1] = args[i].node;
     }
     if (index_node) {
-      builder_->CallIndirect(index, arg_nodes, &return_nodes,
-                             decoder->position());
+      BUILD(CallIndirect, index, arg_nodes, &return_nodes, decoder->position());
     } else {
-      builder_->CallDirect(index, arg_nodes, &return_nodes,
-                           decoder->position());
+      BUILD(CallDirect, index, arg_nodes, &return_nodes, decoder->position());
     }
     int return_count = static_cast<int>(sig->return_count());
     for (int i = 0; i < return_count; ++i) {
diff --git a/deps/v8/src/wasm/function-compiler.cc b/deps/v8/src/wasm/function-compiler.cc
index c4209d8c9c..4cec770ecc 100644
--- a/deps/v8/src/wasm/function-compiler.cc
+++ b/deps/v8/src/wasm/function-compiler.cc
@@ -45,13 +45,11 @@ ExecutionTier WasmCompilationUnit::GetDefaultExecutionTier() {
 WasmCompilationUnit::WasmCompilationUnit(WasmEngine* wasm_engine,
                                          ModuleEnv* env,
                                          NativeModule* native_module,
-                                         FunctionBody body, WasmName name,
-                                         int index, Counters* counters,
-                                         ExecutionTier mode)
+                                         FunctionBody body, int index,
+                                         Counters* counters, ExecutionTier mode)
     : env_(env),
       wasm_engine_(wasm_engine),
       func_body_(body),
-      func_name_(name),
       counters_(counters),
       func_index_(index),
       native_module_(native_module),
@@ -71,7 +69,7 @@ WasmCompilationUnit::WasmCompilationUnit(WasmEngine* wasm_engine,
 
 // Declared here such that {LiftoffCompilationUnit} and
 // {TurbofanWasmCompilationUnit} can be opaque in the header file.
-WasmCompilationUnit::~WasmCompilationUnit() {}
+WasmCompilationUnit::~WasmCompilationUnit() = default;
 
 void WasmCompilationUnit::ExecuteCompilation(WasmFeatures* detected) {
   auto size_histogram = SELECT_WASM_COUNTER(counters_, env_->module->origin,
@@ -155,7 +153,6 @@ WasmCode* WasmCompilationUnit::CompileWasmFunction(
 
   WasmCompilationUnit unit(isolate->wasm_engine(), env, native_module,
                            function_body,
-                           wire_bytes.GetNameOrNull(function, env->module),
                            function->func_index, isolate->counters(), mode);
   unit.ExecuteCompilation(detected);
   return unit.FinishCompilation(thrower);
diff --git a/deps/v8/src/wasm/function-compiler.h b/deps/v8/src/wasm/function-compiler.h
index 7e19f4d12f..b821f1f64d 100644
--- a/deps/v8/src/wasm/function-compiler.h
+++ b/deps/v8/src/wasm/function-compiler.h
@@ -86,7 +86,7 @@ class WasmCompilationUnit final {
   // If used exclusively from a foreground thread, Isolate::counters() may be
   // used by callers to pass Counters.
   WasmCompilationUnit(WasmEngine* wasm_engine, ModuleEnv*, NativeModule*,
-                      FunctionBody, WasmName, int index, Counters*,
+                      FunctionBody, int index, Counters*,
                       ExecutionTier = GetDefaultExecutionTier());
 
   ~WasmCompilationUnit();
@@ -109,7 +109,6 @@ class WasmCompilationUnit final {
   ModuleEnv* env_;
   WasmEngine* wasm_engine_;
   FunctionBody func_body_;
-  WasmName func_name_;
   Counters* counters_;
   int func_index_;
   NativeModule* native_module_;
diff --git a/deps/v8/src/wasm/module-compiler.cc b/deps/v8/src/wasm/module-compiler.cc
index 892a4e980e..61ec6bc32a 100644
--- a/deps/v8/src/wasm/module-compiler.cc
+++ b/deps/v8/src/wasm/module-compiler.cc
@@ -180,23 +180,15 @@ void UpdateFeatureUseCounts(Isolate* isolate, const WasmFeatures& detected) {
 
 class JSToWasmWrapperCache {
  public:
-  Handle<Code> GetOrCompileJSToWasmWrapper(Isolate* isolate,
-                                           const NativeModule* native_module,
-                                           uint32_t func_index,
-                                           UseTrapHandler use_trap_handler) {
-    const WasmModule* module = native_module->module();
-    const WasmFunction* func = &module->functions[func_index];
-    bool is_import = func_index < module->num_imported_functions;
-    std::pair<bool, FunctionSig> key(is_import, *func->sig);
+  Handle<Code> GetOrCompileJSToWasmWrapper(Isolate* isolate, FunctionSig* sig,
+                                           bool is_import) {
+    std::pair<bool, FunctionSig> key(is_import, *sig);
     Handle<Code>& cached = cache_[key];
-    if (!cached.is_null()) return cached;
-
-    Handle<Code> code =
-        compiler::CompileJSToWasmWrapper(isolate, native_module, func->sig,
-                                         is_import, use_trap_handler)
-            .ToHandleChecked();
-    cached = code;
-    return code;
+    if (cached.is_null()) {
+      cached = compiler::CompileJSToWasmWrapper(isolate, sig, is_import)
+                   .ToHandleChecked();
+    }
+    return cached;
   }
 
  private:
@@ -245,6 +237,7 @@ class InstanceBuilder {
   Handle<JSArrayBuffer> globals_;
   std::vector<TableInstance> table_instances_;
   std::vector<Handle<JSFunction>> js_wrappers_;
+  std::vector<Handle<WasmExceptionObject>> exception_wrappers_;
   Handle<WasmExportedFunction> start_function_;
   JSToWasmWrapperCache js_to_wasm_cache_;
   std::vector<SanitizedImport> sanitized_imports_;
@@ -324,6 +317,10 @@ class InstanceBuilder {
   void InitializeTables(Handle<WasmInstanceObject> instance);
 
   void LoadTableSegments(Handle<WasmInstanceObject> instance);
+
+  // Creates new exception tags for all exceptions. Note that some tags might
+  // already exist if they were imported, those tags will be re-used.
+  void InitializeExceptions(Handle<WasmInstanceObject> instance);
 };
 
 }  // namespace
@@ -337,6 +334,7 @@ MaybeHandle<WasmInstanceObject> InstantiateToInstanceObject(
   if (!instance.is_null() && builder.ExecuteStartFunction()) {
     return instance;
   }
+  DCHECK(isolate->has_pending_exception() || thrower->error());
   return {};
 }
 
@@ -348,18 +346,8 @@ WasmCode* LazyCompileFunction(Isolate* isolate, NativeModule* native_module,
   compilation_timer.Start();
 
   ModuleEnv* module_env = native_module->compilation_state()->module_env();
-  // TODO(wasm): Refactor this to only get the name if it is really needed for
-  // tracing / debugging.
-  WasmName func_name;
-  {
-    ModuleWireBytes wire_bytes(native_module->wire_bytes());
-    WireBytesRef name_ref =
-        module_env->module->LookupFunctionName(wire_bytes, func_index);
-    func_name = wire_bytes.GetName(name_ref);
-  }
 
-  TRACE_LAZY("Compiling function '%.*s' (#%d).\n", func_name.length(),
-             func_name.start(), func_index);
+  TRACE_LAZY("Compiling wasm-function#%d.\n", func_index);
 
   const uint8_t* module_start = native_module->wire_bytes().start();
 
@@ -370,7 +358,7 @@ WasmCode* LazyCompileFunction(Isolate* isolate, NativeModule* native_module,
 
   ErrorThrower thrower(isolate, "WasmLazyCompile");
   WasmCompilationUnit unit(isolate->wasm_engine(), module_env, native_module,
-                           body, func_name, func_index, isolate->counters());
+                           body, func_index, isolate->counters());
   unit.ExecuteCompilation(
       native_module->compilation_state()->detected_features());
   WasmCode* wasm_code = unit.FinishCompilation(&thrower);
@@ -414,42 +402,6 @@ Address CompileLazy(Isolate* isolate, NativeModule* native_module,
   return result->instruction_start();
 }
 
-namespace {
-bool compile_lazy(const WasmModule* module) {
-  return FLAG_wasm_lazy_compilation ||
-         (FLAG_asm_wasm_lazy_compilation && module->origin == kAsmJsOrigin);
-}
-
-byte* raw_buffer_ptr(MaybeHandle<JSArrayBuffer> buffer, int offset) {
-  return static_cast<byte*>(buffer.ToHandleChecked()->backing_store()) + offset;
-}
-
-void RecordStats(const Code* code, Counters* counters) {
-  counters->wasm_generated_code_size()->Increment(code->body_size());
-  counters->wasm_reloc_size()->Increment(code->relocation_info()->length());
-}
-
-bool in_bounds(uint32_t offset, size_t size, size_t upper) {
-  return offset + size <= upper && offset + size >= offset;
-}
-
-using WasmInstanceMap =
-    IdentityMap<Handle<WasmInstanceObject>, FreeStoreAllocationPolicy>;
-
-double MonotonicallyIncreasingTimeInMs() {
-  return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
-         base::Time::kMillisecondsPerSecond;
-}
-
-ModuleEnv CreateDefaultModuleEnv(const WasmModule* module,
-                                 bool allow_trap_handler = true) {
-  UseTrapHandler use_trap_handler =
-      trap_handler::IsTrapHandlerEnabled() && allow_trap_handler
-          ? kUseTrapHandler
-          : kNoTrapHandler;
-  return ModuleEnv(module, use_trap_handler, kRuntimeExceptionSupport);
-}
-
 // The CompilationUnitBuilder builds compilation units and stores them in an
 // internal buffer. The buffer is moved into the working queue of the
 // CompilationState when {Commit} is called.
@@ -460,17 +412,17 @@ class CompilationUnitBuilder {
         compilation_state_(native_module->compilation_state()) {}
 
   void AddUnit(const WasmFunction* function, uint32_t buffer_offset,
-               Vector<const uint8_t> bytes, WasmName name) {
+               Vector<const uint8_t> bytes) {
     switch (compilation_state_->compile_mode()) {
       case CompileMode::kTiering:
-        tiering_units_.emplace_back(CreateUnit(
-            function, buffer_offset, bytes, name, ExecutionTier::kOptimized));
-        baseline_units_.emplace_back(CreateUnit(
-            function, buffer_offset, bytes, name, ExecutionTier::kBaseline));
+        tiering_units_.emplace_back(CreateUnit(function, buffer_offset, bytes,
+                                               ExecutionTier::kOptimized));
+        baseline_units_.emplace_back(CreateUnit(function, buffer_offset, bytes,
+                                                ExecutionTier::kBaseline));
         return;
       case CompileMode::kRegular:
         baseline_units_.emplace_back(
-            CreateUnit(function, buffer_offset, bytes, name,
+            CreateUnit(function, buffer_offset, bytes,
                        WasmCompilationUnit::GetDefaultExecutionTier()));
         return;
     }
@@ -493,13 +445,12 @@ class CompilationUnitBuilder {
   std::unique_ptr<WasmCompilationUnit> CreateUnit(const WasmFunction* function,
                                                   uint32_t buffer_offset,
                                                   Vector<const uint8_t> bytes,
-                                                  WasmName name,
                                                   ExecutionTier mode) {
     return base::make_unique<WasmCompilationUnit>(
         compilation_state_->wasm_engine(), compilation_state_->module_env(),
         native_module_,
         FunctionBody{function->sig, buffer_offset, bytes.begin(), bytes.end()},
-        name, function->func_index,
+        function->func_index,
         compilation_state_->isolate()->async_counters().get(), mode);
   }
 
@@ -509,6 +460,42 @@ class CompilationUnitBuilder {
   std::vector<std::unique_ptr<WasmCompilationUnit>> tiering_units_;
 };
 
+namespace {
+bool compile_lazy(const WasmModule* module) {
+  return FLAG_wasm_lazy_compilation ||
+         (FLAG_asm_wasm_lazy_compilation && module->origin == kAsmJsOrigin);
+}
+
+byte* raw_buffer_ptr(MaybeHandle<JSArrayBuffer> buffer, int offset) {
+  return static_cast<byte*>(buffer.ToHandleChecked()->backing_store()) + offset;
+}
+
+void RecordStats(const Code* code, Counters* counters) {
+  counters->wasm_generated_code_size()->Increment(code->body_size());
+  counters->wasm_reloc_size()->Increment(code->relocation_info()->length());
+}
+
+bool in_bounds(uint32_t offset, size_t size, size_t upper) {
+  return offset + size <= upper && offset + size >= offset;
+}
+
+using WasmInstanceMap =
+    IdentityMap<Handle<WasmInstanceObject>, FreeStoreAllocationPolicy>;
+
+double MonotonicallyIncreasingTimeInMs() {
+  return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
+         base::Time::kMillisecondsPerSecond;
+}
+
+ModuleEnv CreateDefaultModuleEnv(const WasmModule* module,
+                                 bool allow_trap_handler = true) {
+  UseTrapHandler use_trap_handler =
+      trap_handler::IsTrapHandlerEnabled() && allow_trap_handler
+          ? kUseTrapHandler
+          : kNoTrapHandler;
+  return ModuleEnv(module, use_trap_handler, kRuntimeExceptionSupport);
+}
+
 // Run by each compilation task and by the main thread (i.e. in both
 // foreground and background threads). The no_finisher_callback is called
 // within the result_mutex_ lock when no finishing task is running, i.e. when
@@ -545,9 +532,8 @@ void InitializeCompilationUnits(NativeModule* native_module) {
     Vector<const uint8_t> bytes(wire_bytes.start() + func->code.offset(),
                                 func->code.end_offset() - func->code.offset());
 
-    WasmName name = wire_bytes.GetName(func, module);
     DCHECK_NOT_NULL(native_module);
-    builder.AddUnit(func, buffer_offset, bytes, name);
+    builder.AddUnit(func, buffer_offset, bytes);
   }
   builder.Commit();
 }
@@ -680,7 +666,7 @@ void CompileSequentially(Isolate* isolate, NativeModule* native_module,
     WasmCode* code = WasmCompilationUnit::CompileWasmFunction(
         isolate, native_module, &detected, thrower, module_env, &func);
     if (code == nullptr) {
-      TruncatedUserString<> name(wire_bytes.GetName(&func, module));
+      TruncatedUserString<> name(wire_bytes.GetNameOrNull(&func, module));
       thrower->CompileError("Compilation of #%d:%.*s failed.", i, name.length(),
                             name.start());
       break;
@@ -716,7 +702,7 @@ void ValidateSequentially(Isolate* isolate, NativeModule* native_module,
                               &detected, body);
     }
     if (result.failed()) {
-      TruncatedUserString<> name(wire_bytes.GetName(&func, module));
+      TruncatedUserString<> name(wire_bytes.GetNameOrNull(&func, module));
       thrower->CompileError("Compiling function #%d:%.*s failed: %s @+%u", i,
                             name.length(), name.start(),
                             result.error_msg().c_str(), result.error_offset());
@@ -890,7 +876,7 @@ MaybeHandle<WasmModuleObject> CompileToModuleObject(
   Handle<Script> script;
   Handle<ByteArray> asm_js_offset_table;
   if (asm_js_script.is_null()) {
-    script = CreateWasmScript(isolate, wire_bytes);
+    script = CreateWasmScript(isolate, wire_bytes, wasm_module->source_map_url);
   } else {
     script = asm_js_script;
     asm_js_offset_table =
@@ -1001,7 +987,11 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
     // (e.g. https://crbug.com/769637).
     // Allocate memory if the initial size is more than 0 pages.
     memory_ = AllocateMemory(initial_pages);
-    if (memory_.is_null()) return {};  // failed to allocate memory
+    if (memory_.is_null()) {
+      // failed to allocate memory
+      DCHECK(isolate_->has_pending_exception() || thrower_->error());
+      return {};
+    }
   }
 
   //--------------------------------------------------------------------------
@@ -1015,6 +1005,9 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
     if (!memory_tracker->HasFullGuardRegions(
             memory_.ToHandleChecked()->backing_store())) {
       if (!FLAG_wasm_trap_handler_fallback) {
+        thrower_->LinkError(
+            "Provided memory is lacking guard regions but fallback was "
+            "disabled.");
         return {};
       }
 
@@ -1047,7 +1040,6 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   //--------------------------------------------------------------------------
   // Set up the globals for the new instance.
   //--------------------------------------------------------------------------
-  MaybeHandle<JSArrayBuffer> old_globals;
   uint32_t globals_buffer_size = module_->globals_buffer_size;
   if (globals_buffer_size > 0) {
     void* backing_store =
@@ -1085,6 +1077,17 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   }
 
   //--------------------------------------------------------------------------
+  // Set up the exception table used for exception tag checks.
+  //--------------------------------------------------------------------------
+  int exceptions_count = static_cast<int>(module_->exceptions.size());
+  if (exceptions_count > 0) {
+    Handle<FixedArray> exception_table =
+        isolate_->factory()->NewFixedArray(exceptions_count, TENURED);
+    instance->set_exceptions_table(*exception_table);
+    exception_wrappers_.resize(exceptions_count);
+  }
+
+  //--------------------------------------------------------------------------
   // Reserve the metadata for indirect function tables.
   //--------------------------------------------------------------------------
   int table_count = static_cast<int>(module_->tables.size());
@@ -1109,6 +1112,13 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   }
 
   //--------------------------------------------------------------------------
+  // Initialize the exceptions table.
+  //--------------------------------------------------------------------------
+  if (exceptions_count > 0) {
+    InitializeExceptions(instance);
+  }
+
+  //--------------------------------------------------------------------------
   // Create the WebAssembly.Memory object.
   //--------------------------------------------------------------------------
   if (module_->has_memory) {
@@ -1127,7 +1137,7 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
     if (!memory_.is_null()) {
       // Double-check the {memory} array buffer matches the instance.
       Handle<JSArrayBuffer> memory = memory_.ToHandleChecked();
-      CHECK_EQ(instance->memory_size(), memory->byte_length()->Number());
+      CHECK_EQ(instance->memory_size(), memory->byte_length());
       CHECK_EQ(instance->memory_start(), memory->backing_store());
     }
   }
@@ -1177,11 +1187,6 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   }
 
   //--------------------------------------------------------------------------
-  // Install a finalizer on the new instance object.
-  //--------------------------------------------------------------------------
-  WasmInstanceObject::InstallFinalizer(isolate_, instance);
-
-  //--------------------------------------------------------------------------
   // Debugging support.
   //--------------------------------------------------------------------------
   // Set all breakpoints that were set on the shared module.
@@ -1206,14 +1211,14 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   //--------------------------------------------------------------------------
   if (module_->start_function_index >= 0) {
     int start_index = module_->start_function_index;
-    FunctionSig* sig = module_->functions[start_index].sig;
+    auto& function = module_->functions[start_index];
     Handle<Code> wrapper_code = js_to_wasm_cache_.GetOrCompileJSToWasmWrapper(
-        isolate_, native_module, start_index, use_trap_handler());
+        isolate_, function.sig, function.imported);
     // TODO(clemensh): Don't generate an exported function for the start
     // function. Use CWasmEntry instead.
     start_function_ = WasmExportedFunction::New(
         isolate_, instance, MaybeHandle<String>(), start_index,
-        static_cast<int>(sig->parameter_count()), wrapper_code);
+        static_cast<int>(function.sig->parameter_count()), wrapper_code);
   }
 
   DCHECK(!isolate_->has_pending_exception());
@@ -1489,41 +1494,41 @@ int InstanceBuilder::ProcessImports(Handle<WasmInstanceObject> instance) {
         }
         uint32_t func_index = import.index;
         DCHECK_EQ(num_imported_functions, func_index);
+        auto js_receiver = Handle<JSReceiver>::cast(value);
         FunctionSig* expected_sig = module_->functions[func_index].sig;
-        if (WasmExportedFunction::IsWasmExportedFunction(*value)) {
-          // The imported function is a WASM function from another instance.
-          Handle<WasmExportedFunction> imported_function(
-              WasmExportedFunction::cast(*value), isolate_);
-          Handle<WasmInstanceObject> imported_instance(
-              imported_function->instance(), isolate_);
-          FunctionSig* imported_sig =
-              imported_instance->module()
-                  ->functions[imported_function->function_index()]
-                  .sig;
-          if (*imported_sig != *expected_sig) {
+        auto kind = compiler::GetWasmImportCallKind(js_receiver, expected_sig);
+        switch (kind) {
+          case compiler::WasmImportCallKind::kLinkError:
             ReportLinkError(
                 "imported function does not match the expected type", index,
                 module_name, import_name);
             return -1;
+          case compiler::WasmImportCallKind::kWasmToWasm: {
+            // The imported function is a WASM function from another instance.
+            auto imported_function = Handle<WasmExportedFunction>::cast(value);
+            Handle<WasmInstanceObject> imported_instance(
+                imported_function->instance(), isolate_);
+            // The import reference is the instance object itself.
+            Address imported_target = imported_function->GetWasmCallTarget();
+            ImportedFunctionEntry entry(instance, func_index);
+            entry.set_wasm_to_wasm(*imported_instance, imported_target);
+            break;
+          }
+          default: {
+            // The imported function is a callable.
+            Handle<Code> wrapper_code =
+                compiler::CompileWasmImportCallWrapper(
+                    isolate_, kind, expected_sig, func_index, module_->origin,
+                    use_trap_handler())
+                    .ToHandleChecked();
+            RecordStats(*wrapper_code, isolate_->counters());
+
+            WasmCode* wasm_code =
+                native_module->AddImportWrapper(wrapper_code, func_index);
+            ImportedFunctionEntry entry(instance, func_index);
+            entry.set_wasm_to_js(*js_receiver, wasm_code);
+            break;
           }
-          // The import reference is the instance object itself.
-          Address imported_target = imported_function->GetWasmCallTarget();
-          ImportedFunctionEntry entry(instance, func_index);
-          entry.set_wasm_to_wasm(*imported_instance, imported_target);
-        } else {
-          // The imported function is a callable.
-          Handle<JSReceiver> js_receiver(JSReceiver::cast(*value), isolate_);
-          Handle<Code> wrapper_code =
-              compiler::CompileWasmToJSWrapper(
-                  isolate_, js_receiver, expected_sig, func_index,
-                  module_->origin, use_trap_handler())
-                  .ToHandleChecked();
-          RecordStats(*wrapper_code, isolate_->counters());
-
-          WasmCode* wasm_code = native_module->AddCodeCopy(
-              wrapper_code, WasmCode::kWasmToJsWrapper, func_index);
-          ImportedFunctionEntry entry(instance, func_index);
-          entry.set_wasm_to_js(*js_receiver, wasm_code);
         }
         num_imported_functions++;
         break;
@@ -1619,8 +1624,8 @@ int InstanceBuilder::ProcessImports(Handle<WasmInstanceObject> instance) {
         Handle<JSArrayBuffer> buffer(memory->array_buffer(), isolate_);
         // memory_ should have already been assigned in Build().
         DCHECK_EQ(*memory_.ToHandleChecked(), *buffer);
-        uint32_t imported_cur_pages = static_cast<uint32_t>(
-            buffer->byte_length()->Number() / kWasmPageSize);
+        uint32_t imported_cur_pages =
+            static_cast<uint32_t>(buffer->byte_length() / kWasmPageSize);
         if (imported_cur_pages < module_->initial_pages) {
           thrower_->LinkError(
               "memory import %d is smaller than initial %u, got %u", index,
@@ -1740,6 +1745,26 @@ int InstanceBuilder::ProcessImports(Handle<WasmInstanceObject> instance) {
         }
         break;
       }
+      case kExternalException: {
+        if (!value->IsWasmExceptionObject()) {
+          ReportLinkError("exception import requires a WebAssembly.Exception",
+                          index, module_name, import_name);
+          return -1;
+        }
+        Handle<WasmExceptionObject> imported_exception =
+            Handle<WasmExceptionObject>::cast(value);
+        if (!imported_exception->IsSignatureEqual(
+                module_->exceptions[import.index].sig)) {
+          ReportLinkError("imported exception does not match the expected type",
+                          index, module_name, import_name);
+          return -1;
+        }
+        Object* exception_tag = imported_exception->exception_tag();
+        DCHECK(instance->exceptions_table()->get(import.index)->IsUndefined());
+        instance->exceptions_table()->set(import.index, exception_tag);
+        exception_wrappers_[import.index] = imported_exception;
+        break;
+      }
       default:
         UNREACHABLE();
         break;
@@ -1833,7 +1858,7 @@ bool InstanceBuilder::NeedsWrappers() const {
 }
 
 // Process the exports, creating wrappers for functions, tables, memories,
-// and globals.
+// globals, and exceptions.
 void InstanceBuilder::ProcessExports(Handle<WasmInstanceObject> instance) {
   Handle<FixedArray> export_wrappers(module_object_->export_wrappers(),
                                      isolate_);
@@ -1964,9 +1989,7 @@ void InstanceBuilder::ProcessExports(Handle<WasmInstanceObject> instance) {
             Address global_addr =
                 instance->imported_mutable_globals()[global.index];
 
-            uint32_t buffer_size = 0;
-            CHECK(buffer->byte_length()->ToUint32(&buffer_size));
-
+            size_t buffer_size = buffer->byte_length();
             Address backing_store =
                 reinterpret_cast<Address>(buffer->backing_store());
             CHECK(global_addr >= backing_store &&
@@ -2011,6 +2034,20 @@ void InstanceBuilder::ProcessExports(Handle<WasmInstanceObject> instance) {
         }
         break;
       }
+      case kExternalException: {
+        const WasmException& exception = module_->exceptions[exp.index];
+        Handle<WasmExceptionObject> wrapper = exception_wrappers_[exp.index];
+        if (wrapper.is_null()) {
+          Handle<HeapObject> exception_tag(
+              HeapObject::cast(instance->exceptions_table()->get(exp.index)),
+              isolate_);
+          wrapper =
+              WasmExceptionObject::New(isolate_, exception.sig, exception_tag);
+          exception_wrappers_[exp.index] = wrapper;
+        }
+        desc.set_value(wrapper);
+        break;
+      }
       default:
         UNREACHABLE();
         break;
@@ -2090,7 +2127,7 @@ void InstanceBuilder::LoadTableSegments(Handle<WasmInstanceObject> instance) {
 
           Handle<Code> wrapper_code =
               js_to_wasm_cache_.GetOrCompileJSToWasmWrapper(
-                  isolate_, native_module, func_index, use_trap_handler());
+                  isolate_, function->sig, function->imported);
           MaybeHandle<String> func_name;
           if (module_->origin == kAsmJsOrigin) {
             // For modules arising from asm.js, honor the names section.
@@ -2127,6 +2164,20 @@ void InstanceBuilder::LoadTableSegments(Handle<WasmInstanceObject> instance) {
   }
 }
 
+void InstanceBuilder::InitializeExceptions(
+    Handle<WasmInstanceObject> instance) {
+  Handle<FixedArray> exceptions_table(instance->exceptions_table(), isolate_);
+  for (int index = 0; index < exceptions_table->length(); ++index) {
+    if (!exceptions_table->get(index)->IsUndefined(isolate_)) continue;
+    // TODO(mstarzinger): Tags provide an object identity for each exception,
+    // using {JSObject} here is gigantic hack and we should use a dedicated
+    // object with a much lighter footprint for this purpose here.
+    Handle<HeapObject> exception_tag =
+        isolate_->factory()->NewJSObjectWithNullProto();
+    exceptions_table->set(index, *exception_tag);
+  }
+}
+
 AsyncCompileJob::AsyncCompileJob(
     Isolate* isolate, const WasmFeatures& enabled,
     std::unique_ptr<byte[]> bytes_copy, size_t length, Handle<Context> context,
@@ -2218,6 +2269,12 @@ void AsyncCompileJob::FinishCompile() {
   DCHECK_NOT_NULL(isolate_->context());
   // Finish the wasm script now and make it public to the debugger.
   Handle<Script> script(module_object_->script(), isolate_);
+  if (script->type() == Script::TYPE_WASM &&
+      module_object_->module()->source_map_url.size() != 0) {
+    MaybeHandle<String> src_map_str = isolate_->factory()->NewStringFromUtf8(
+        CStrVector(module_object_->module()->source_map_url.c_str()), TENURED);
+    script->set_source_mapping_url(*src_map_str.ToHandleChecked());
+  }
   isolate_->debug()->OnAfterCompile(script);
 
   // Log the code within the generated module for profiling.
@@ -2247,7 +2304,7 @@ void AsyncCompileJob::AsyncCompileSucceeded(Handle<WasmModuleObject> result) {
 // task) and schedule the next step(s), if any.
 class AsyncCompileJob::CompileStep {
  public:
-  virtual ~CompileStep() {}
+  virtual ~CompileStep() = default;
 
   void Run(bool on_foreground) {
     if (on_foreground) {
@@ -2278,7 +2335,7 @@ class AsyncCompileJob::CompileTask : public CancelableTask {
         job_(job),
         on_foreground_(on_foreground) {}
 
-  ~CompileTask() {
+  ~CompileTask() override {
     if (job_ != nullptr && on_foreground_) ResetPendingForegroundTask();
   }
 
@@ -2418,7 +2475,7 @@ class AsyncCompileJob::PrepareAndStartCompile : public CompileStep {
  public:
   PrepareAndStartCompile(std::shared_ptr<const WasmModule> module,
                          bool start_compilation)
-      : module_(module), start_compilation_(start_compilation) {}
+      : module_(std::move(module)), start_compilation_(start_compilation) {}
 
  private:
   std::shared_ptr<const WasmModule> module_;
@@ -2439,10 +2496,11 @@ class AsyncCompileJob::PrepareAndStartCompile : public CompileStep {
 
     // Create heap objects for script and module bytes to be stored in the
     // module object. Asm.js is not compiled asynchronously.
-    Handle<Script> script = CreateWasmScript(job_->isolate_, job_->wire_bytes_);
+    const WasmModule* module = module_.get();
+    Handle<Script> script = CreateWasmScript(job_->isolate_, job_->wire_bytes_,
+                                             module->source_map_url);
     Handle<ByteArray> asm_js_offset_table;
 
-    const WasmModule* module = module_.get();
     ModuleEnv env = CreateDefaultModuleEnv(module);
     // TODO(wasm): Improve efficiency of storing module wire bytes. Only store
     // relevant sections, not function bodies
@@ -2713,13 +2771,12 @@ bool AsyncStreamingProcessor::ProcessFunctionBody(Vector<const uint8_t> bytes,
                                                   uint32_t offset) {
   TRACE_STREAMING("Process function body %d ...\n", next_function_);
 
-    decoder_.DecodeFunctionBody(
-        next_function_, static_cast<uint32_t>(bytes.length()), offset, false);
+  decoder_.DecodeFunctionBody(
+      next_function_, static_cast<uint32_t>(bytes.length()), offset, false);
 
-    uint32_t index = next_function_ + decoder_.module()->num_imported_functions;
-    const WasmFunction* func = &decoder_.module()->functions[index];
-    WasmName name = {nullptr, 0};
-    compilation_unit_builder_->AddUnit(func, offset, bytes, name);
+  uint32_t index = next_function_ + decoder_.module()->num_imported_functions;
+  const WasmFunction* func = &decoder_.module()->functions[index];
+  compilation_unit_builder_->AddUnit(func, offset, bytes);
   ++next_function_;
   // This method always succeeds. The return value is necessary to comply with
   // the StreamingProcessor interface.
@@ -2822,7 +2879,7 @@ void CompilationState::SetNumberOfFunctionsToCompile(size_t num_functions) {
 void CompilationState::SetCallback(
     std::function<void(CompilationEvent, ErrorThrower*)> callback) {
   DCHECK_NULL(callback_);
-  callback_ = callback;
+  callback_ = std::move(callback);
 }
 
 void CompilationState::AddCompilationUnits(
@@ -3014,13 +3071,12 @@ void CompileJsToWasmWrappers(Isolate* isolate,
   int wrapper_index = 0;
   Handle<FixedArray> export_wrappers(module_object->export_wrappers(), isolate);
   NativeModule* native_module = module_object->native_module();
-  UseTrapHandler use_trap_handler =
-      native_module->use_trap_handler() ? kUseTrapHandler : kNoTrapHandler;
   const WasmModule* module = native_module->module();
   for (auto exp : module->export_table) {
     if (exp.kind != kExternalFunction) continue;
+    auto& function = module->functions[exp.index];
     Handle<Code> wrapper_code = js_to_wasm_cache.GetOrCompileJSToWasmWrapper(
-        isolate, native_module, exp.index, use_trap_handler);
+        isolate, function.sig, function.imported);
     export_wrappers->set(wrapper_index, *wrapper_code);
     RecordStats(*wrapper_code, isolate->counters());
     ++wrapper_index;
@@ -3028,7 +3084,8 @@ void CompileJsToWasmWrappers(Isolate* isolate,
 }
 
 Handle<Script> CreateWasmScript(Isolate* isolate,
-                                const ModuleWireBytes& wire_bytes) {
+                                const ModuleWireBytes& wire_bytes,
+                                const std::string& source_map_url) {
   Handle<Script> script =
       isolate->factory()->NewScript(isolate->factory()->empty_string());
   script->set_context_data(isolate->native_context()->debug_context_id());
@@ -3040,12 +3097,6 @@ Handle<Script> CreateWasmScript(Isolate* isolate,
 
   const int kBufferSize = 32;
   char buffer[kBufferSize];
-  int url_chars = SNPrintF(ArrayVector(buffer), "wasm://wasm/%08x", hash);
-  DCHECK(url_chars >= 0 && url_chars < kBufferSize);
-  MaybeHandle<String> url_str = isolate->factory()->NewStringFromOneByte(
-      Vector<const uint8_t>(reinterpret_cast<uint8_t*>(buffer), url_chars),
-      TENURED);
-  script->set_source_url(*url_str.ToHandleChecked());
 
   int name_chars = SNPrintF(ArrayVector(buffer), "wasm-%08x", hash);
   DCHECK(name_chars >= 0 && name_chars < kBufferSize);
@@ -3054,6 +3105,11 @@ Handle<Script> CreateWasmScript(Isolate* isolate,
       TENURED);
   script->set_name(*name_str.ToHandleChecked());
 
+  if (source_map_url.size() != 0) {
+    MaybeHandle<String> src_map_str = isolate->factory()->NewStringFromUtf8(
+        CStrVector(source_map_url.c_str()), TENURED);
+    script->set_source_mapping_url(*src_map_str.ToHandleChecked());
+  }
   return script;
 }
 
diff --git a/deps/v8/src/wasm/module-compiler.h b/deps/v8/src/wasm/module-compiler.h
index 934c978d49..f108a5f939 100644
--- a/deps/v8/src/wasm/module-compiler.h
+++ b/deps/v8/src/wasm/module-compiler.h
@@ -63,7 +63,8 @@ void CompileJsToWasmWrappers(Isolate* isolate,
                              Handle<WasmModuleObject> module_object);
 
 V8_EXPORT_PRIVATE Handle<Script> CreateWasmScript(
-    Isolate* isolate, const ModuleWireBytes& wire_bytes);
+    Isolate* isolate, const ModuleWireBytes& wire_bytes,
+    const std::string& source_map_url);
 
 // Triggered by the WasmCompileLazy builtin.
 // Returns the instruction start of the compiled code object.
diff --git a/deps/v8/src/wasm/module-decoder.cc b/deps/v8/src/wasm/module-decoder.cc
index db9cf45049..6b0a3d6485 100644
--- a/deps/v8/src/wasm/module-decoder.cc
+++ b/deps/v8/src/wasm/module-decoder.cc
@@ -30,6 +30,7 @@ namespace wasm {
 namespace {
 
 constexpr char kNameString[] = "name";
+constexpr char kSourceMappingURLString[] = "sourceMappingURL";
 constexpr char kExceptionString[] = "exception";
 constexpr char kUnknownString[] = "<unknown>";
 
@@ -48,6 +49,8 @@ const char* ExternalKindName(ImportExportKindCode kind) {
       return "memory";
     case kExternalGlobal:
       return "global";
+    case kExternalException:
+      return "exception";
   }
   return "unknown";
 }
@@ -82,6 +85,8 @@ const char* SectionName(SectionCode code) {
       return "Data";
     case kNameSectionCode:
       return kNameString;
+    case kSourceMappingURLSectionCode:
+      return kSourceMappingURLString;
     case kExceptionSectionCode:
       return kExceptionString;
     default:
@@ -219,7 +224,7 @@ class WasmSectionIterator {
     }
 
     if (section_code == kUnknownSectionCode) {
-      // Check for the known "name" section.
+      // Check for the known "name" or "sourceMappingURL" section.
       section_code =
           ModuleDecoder::IdentifyUnknownSection(decoder_, section_end_);
       // As a side effect, the above function will forward the decoder to after
@@ -262,7 +267,7 @@ class ModuleDecoderImpl : public Decoder {
     }
   }
 
-  virtual void onFirstError() {
+  void onFirstError() override {
     pc_ = end_;  // On error, terminate section decoding loop.
   }
 
@@ -337,7 +342,8 @@ class ModuleDecoderImpl : public Decoder {
           static_cast<const void*>(bytes.end()));
 
     // Check if the section is out-of-order.
-    if (section_code < next_section_) {
+    if (section_code < next_ordered_section_ &&
+        section_code < kFirstUnorderedSection) {
       errorf(pc(), "unexpected section: %s", SectionName(section_code));
       return;
     }
@@ -346,19 +352,31 @@ class ModuleDecoderImpl : public Decoder {
       case kUnknownSectionCode:
         break;
       case kExceptionSectionCode:
-        // Note: kExceptionSectionCode > kCodeSectionCode, but must appear
-        // before the code section. Hence, treat it as a special case.
-        if (++number_of_exception_sections > 1) {
+        // Note: kExceptionSectionCode > kExportSectionCode, but must appear
+        // before the export (and code) section, as well as after the import
+        // section. Hence, treat it as a special case.
+        if (seen_unordered_sections_ & (1 << kExceptionSectionCode)) {
           errorf(pc(), "Multiple exception sections not allowed");
           return;
-        } else if (next_section_ >= kCodeSectionCode) {
-          errorf(pc(), "Exception section must appear before the code section");
+        } else if (next_ordered_section_ > kExportSectionCode) {
+          errorf(pc(), "Exception section must appear before export section");
           return;
+        } else if (next_ordered_section_ < kImportSectionCode) {
+          next_ordered_section_ = kImportSectionCode + 1;
         }
+        seen_unordered_sections_ |= 1 << kExceptionSectionCode;
+        break;
+      case kSourceMappingURLSectionCode:
+        // sourceMappingURL is a custom section and currently can occur anywhere
+        // in the module. In case of multiple sourceMappingURL sections, all
+        // except the first occurrence are ignored.
+      case kNameSectionCode:
+        // TODO(titzer): report out of place name section as a warning.
+        // Be lenient with placement of name section. All except first
+        // occurrence are ignored.
         break;
       default:
-        next_section_ = section_code;
-        ++next_section_;
+        next_ordered_section_ = section_code + 1;
         break;
     }
 
@@ -401,6 +419,9 @@ class ModuleDecoderImpl : public Decoder {
       case kNameSectionCode:
         DecodeNameSection();
         break;
+      case kSourceMappingURLSectionCode:
+        DecodeSourceMappingURLSection();
+        break;
       case kExceptionSectionCode:
         if (enabled_features_.eh) {
           DecodeExceptionSection();
@@ -521,6 +542,17 @@ class ModuleDecoderImpl : public Decoder {
           }
           break;
         }
+        case kExternalException: {
+          // ===== Imported exception ======================================
+          if (!enabled_features_.eh) {
+            errorf(pos, "unknown import kind 0x%02x", import->kind);
+            break;
+          }
+          import->index = static_cast<uint32_t>(module_->exceptions.size());
+          module_->exceptions.emplace_back(
+              consume_exception_sig(module_->signature_zone.get()));
+          break;
+        }
         default:
           errorf(pos, "unknown import kind 0x%02x", import->kind);
           break;
@@ -655,6 +687,15 @@ class ModuleDecoderImpl : public Decoder {
           }
           break;
         }
+        case kExternalException: {
+          if (!enabled_features_.eh) {
+            errorf(pos, "invalid export kind 0x%02x", exp->kind);
+            break;
+          }
+          WasmException* exception = nullptr;
+          exp->index = consume_exception_index(module_.get(), &exception);
+          break;
+        }
         default:
           errorf(pos, "invalid export kind 0x%02x", exp->kind);
           break;
@@ -803,30 +844,48 @@ class ModuleDecoderImpl : public Decoder {
 
   void DecodeNameSection() {
     // TODO(titzer): find a way to report name errors as warnings.
-    // Use an inner decoder so that errors don't fail the outer decoder.
-    Decoder inner(start_, pc_, end_, buffer_offset_);
-    // Decode all name subsections.
-    // Be lenient with their order.
-    while (inner.ok() && inner.more()) {
-      uint8_t name_type = inner.consume_u8("name type");
-      if (name_type & 0x80) inner.error("name type if not varuint7");
-
-      uint32_t name_payload_len = inner.consume_u32v("name payload length");
-      if (!inner.checkAvailable(name_payload_len)) break;
-
-      // Decode module name, ignore the rest.
-      // Function and local names will be decoded when needed.
-      if (name_type == NameSectionKindCode::kModule) {
-        WireBytesRef name = consume_string(inner, false, "module name");
-        if (inner.ok() && validate_utf8(&inner, name)) module_->name = name;
-      } else {
-        inner.consume_bytes(name_payload_len, "name subsection payload");
+    // ignore all but the first occurrence of name section.
+    if (!(seen_unordered_sections_ & (1 << kNameSectionCode))) {
+      seen_unordered_sections_ |= 1 << kNameSectionCode;
+      // Use an inner decoder so that errors don't fail the outer decoder.
+      Decoder inner(start_, pc_, end_, buffer_offset_);
+      // Decode all name subsections.
+      // Be lenient with their order.
+      while (inner.ok() && inner.more()) {
+        uint8_t name_type = inner.consume_u8("name type");
+        if (name_type & 0x80) inner.error("name type if not varuint7");
+
+        uint32_t name_payload_len = inner.consume_u32v("name payload length");
+        if (!inner.checkAvailable(name_payload_len)) break;
+
+        // Decode module name, ignore the rest.
+        // Function and local names will be decoded when needed.
+        if (name_type == NameSectionKindCode::kModule) {
+          WireBytesRef name = consume_string(inner, false, "module name");
+          if (inner.ok() && validate_utf8(&inner, name)) module_->name = name;
+        } else {
+          inner.consume_bytes(name_payload_len, "name subsection payload");
+        }
       }
     }
     // Skip the whole names section in the outer decoder.
     consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr);
   }
 
+  void DecodeSourceMappingURLSection() {
+    Decoder inner(start_, pc_, end_, buffer_offset_);
+    WireBytesRef url = wasm::consume_string(inner, true, "module name");
+    if (inner.ok() &&
+        !(seen_unordered_sections_ & (1 << kSourceMappingURLSectionCode))) {
+      const byte* url_start =
+          inner.start() + inner.GetBufferRelativeOffset(url.offset());
+      module_->source_map_url.assign(reinterpret_cast<const char*>(url_start),
+                                     url.length());
+      seen_unordered_sections_ |= 1 << kSourceMappingURLSectionCode;
+    }
+    consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr);
+  }
+
   void DecodeExceptionSection() {
     uint32_t exception_count =
         consume_count("exception count", kV8MaxWasmExceptions);
@@ -935,13 +994,18 @@ class ModuleDecoderImpl : public Decoder {
   std::shared_ptr<WasmModule> module_;
   Counters* counters_ = nullptr;
   // The type section is the first section in a module.
-  uint8_t next_section_ = kFirstSectionInModule;
-  uint32_t number_of_exception_sections = 0;
-  // We store next_section_ as uint8_t instead of SectionCode so that we can
-  // increment it. This static_assert should make sure that SectionCode does not
-  // get bigger than uint8_t accidentially.
-  static_assert(sizeof(ModuleDecoderImpl::next_section_) == sizeof(SectionCode),
+  uint8_t next_ordered_section_ = kFirstSectionInModule;
+  // We store next_ordered_section_ as uint8_t instead of SectionCode so that we
+  // can increment it. This static_assert should make sure that SectionCode does
+  // not get bigger than uint8_t accidentially.
+  static_assert(sizeof(ModuleDecoderImpl::next_ordered_section_) ==
+                    sizeof(SectionCode),
                 "type mismatch");
+  uint32_t seen_unordered_sections_ = 0;
+  static_assert(kBitsPerByte *
+                        sizeof(ModuleDecoderImpl::seen_unordered_sections_) >
+                    kLastKnownModuleSection,
+                "not enough bits");
   Result<bool> intermediate_result_;
   ModuleOrigin origin_;
 
@@ -1108,6 +1172,10 @@ class ModuleDecoderImpl : public Decoder {
     return consume_index("table index", module->tables, table);
   }
 
+  uint32_t consume_exception_index(WasmModule* module, WasmException** except) {
+    return consume_index("exception index", module->exceptions, except);
+  }
+
   template <typename T>
   uint32_t consume_index(const char* name, std::vector<T>& vector, T** ptr) {
     const byte* pos = pc_;
@@ -1482,6 +1550,11 @@ SectionCode ModuleDecoder::IdentifyUnknownSection(Decoder& decoder,
       strncmp(reinterpret_cast<const char*>(section_name_start), kNameString,
               num_chars(kNameString)) == 0) {
     return kNameSectionCode;
+  } else if (string.length() == num_chars(kSourceMappingURLString) &&
+             strncmp(reinterpret_cast<const char*>(section_name_start),
+                     kSourceMappingURLString,
+                     num_chars(kSourceMappingURLString)) == 0) {
+    return kSourceMappingURLSectionCode;
   }
   return kUnknownSectionCode;
 }
@@ -1609,7 +1682,7 @@ std::vector<CustomSectionOffset> DecodeCustomSections(const byte* start,
 
 namespace {
 
-bool FindSection(Decoder& decoder, SectionCode section_code) {
+bool FindNameSection(Decoder& decoder) {
   static constexpr int kModuleHeaderSize = 8;
   decoder.consume_bytes(kModuleHeaderSize, "module header");
 
@@ -1634,7 +1707,7 @@ void DecodeFunctionNames(const byte* module_start, const byte* module_end,
   DCHECK(names->empty());
 
   Decoder decoder(module_start, module_end);
-  if (!FindSection(decoder, kNameSectionCode)) return;
+  if (!FindNameSection(decoder)) return;
 
   while (decoder.ok() && decoder.more()) {
     uint8_t name_type = decoder.consume_u8("name type");
@@ -1669,7 +1742,7 @@ void DecodeLocalNames(const byte* module_start, const byte* module_end,
   DCHECK(result->names.empty());
 
   Decoder decoder(module_start, module_end);
-  if (!FindSection(decoder, kNameSectionCode)) return;
+  if (!FindNameSection(decoder)) return;
 
   while (decoder.ok() && decoder.more()) {
     uint8_t name_type = decoder.consume_u8("name type");
diff --git a/deps/v8/src/wasm/object-access.h b/deps/v8/src/wasm/object-access.h
new file mode 100644
index 0000000000..0f4a4d447d
--- /dev/null
+++ b/deps/v8/src/wasm/object-access.h
@@ -0,0 +1,48 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_WASM_OBJECT_ACCESS_H_
+#define V8_WASM_OBJECT_ACCESS_H_
+
+#include "src/globals.h"
+#include "src/objects/fixed-array.h"
+#include "src/objects/js-objects.h"
+#include "src/objects/shared-function-info.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+class ObjectAccess : public AllStatic {
+ public:
+  // Convert an offset into an object to an offset into a tagged object.
+  static constexpr int ToTagged(int offset) { return offset - kHeapObjectTag; }
+
+  // Get the offset into a fixed array for a given {index}.
+  static constexpr int ElementOffsetInTaggedFixedArray(int index) {
+    return ToTagged(FixedArray::OffsetOfElementAt(index));
+  }
+
+  // Get the offset of the context stored in a {JSFunction} object.
+  static constexpr int ContextOffsetInTaggedJSFunction() {
+    return ToTagged(JSFunction::kContextOffset);
+  }
+
+  // Get the offset of the shared function info in a {JSFunction} object.
+  static constexpr int SharedFunctionInfoOffsetInTaggedJSFunction() {
+    return ToTagged(JSFunction::kSharedFunctionInfoOffset);
+  }
+
+  // Get the offset of the formal parameter count in a {SharedFunctionInfo}
+  // object.
+  static constexpr int FormalParameterCountOffsetInSharedFunctionInfo() {
+    return ToTagged(SharedFunctionInfo::kFormalParameterCountOffset);
+  }
+};
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_OBJECT_ACCESS_H_
diff --git a/deps/v8/src/wasm/value-type.h b/deps/v8/src/wasm/value-type.h
index 8522b3a500..d34bc4bca9 100644
--- a/deps/v8/src/wasm/value-type.h
+++ b/deps/v8/src/wasm/value-type.h
@@ -21,6 +21,7 @@ enum ValueType : uint8_t {
   kWasmS128,
   kWasmAnyRef,
   kWasmAnyFunc,
+  kWasmExceptRef,
   kWasmVar,
 };
 
@@ -220,6 +221,8 @@ class V8_EXPORT_PRIVATE ValueTypes {
         return kLocalS128;
       case kWasmAnyRef:
         return kLocalAnyRef;
+      case kWasmExceptRef:
+        return kLocalExceptRef;
       case kWasmStmt:
         return kLocalVoid;
       default:
diff --git a/deps/v8/src/wasm/wasm-code-manager.cc b/deps/v8/src/wasm/wasm-code-manager.cc
index c2c425a44e..6495421b8f 100644
--- a/deps/v8/src/wasm/wasm-code-manager.cc
+++ b/deps/v8/src/wasm/wasm-code-manager.cc
@@ -7,6 +7,7 @@
 #include <iomanip>
 
 #include "src/assembler-inl.h"
+#include "src/base/adapters.h"
 #include "src/base/macros.h"
 #include "src/base/platform/platform.h"
 #include "src/codegen.h"
@@ -23,7 +24,7 @@
 
 #define TRACE_HEAP(...)                                   \
   do {                                                    \
-    if (FLAG_wasm_trace_native_heap) PrintF(__VA_ARGS__); \
+    if (FLAG_trace_wasm_native_heap) PrintF(__VA_ARGS__); \
   } while (false)
 
 namespace v8 {
@@ -44,53 +45,56 @@ struct WasmCodeUniquePtrComparator {
 
 }  // namespace
 
-void DisjointAllocationPool::Merge(AddressRange range) {
-  auto dest_it = ranges_.begin();
-  auto dest_end = ranges_.end();
+void DisjointAllocationPool::Merge(base::AddressRegion region) {
+  auto dest_it = regions_.begin();
+  auto dest_end = regions_.end();
 
-  // Skip over dest ranges strictly before {range}.
-  while (dest_it != dest_end && dest_it->end < range.start) ++dest_it;
+  // Skip over dest regions strictly before {region}.
+  while (dest_it != dest_end && dest_it->end() < region.begin()) ++dest_it;
 
-  // After last dest range: insert and done.
+  // After last dest region: insert and done.
   if (dest_it == dest_end) {
-    ranges_.push_back(range);
+    regions_.push_back(region);
     return;
   }
 
   // Adjacent (from below) to dest: merge and done.
-  if (dest_it->start == range.end) {
-    dest_it->start = range.start;
+  if (dest_it->begin() == region.end()) {
+    base::AddressRegion merged_region{region.begin(),
+                                      region.size() + dest_it->size()};
+    DCHECK_EQ(merged_region.end(), dest_it->end());
+    *dest_it = merged_region;
     return;
   }
 
   // Before dest: insert and done.
-  if (dest_it->start > range.end) {
-    ranges_.insert(dest_it, range);
+  if (dest_it->begin() > region.end()) {
+    regions_.insert(dest_it, region);
     return;
   }
 
-  // Src is adjacent from above. Merge and check whether the merged range is now
-  // adjacent to the next range.
-  DCHECK_EQ(dest_it->end, range.start);
-  dest_it->end = range.end;
+  // Src is adjacent from above. Merge and check whether the merged region is
+  // now adjacent to the next region.
+  DCHECK_EQ(dest_it->end(), region.begin());
+  dest_it->set_size(dest_it->size() + region.size());
+  DCHECK_EQ(dest_it->end(), region.end());
   auto next_dest = dest_it;
   ++next_dest;
-  if (next_dest != dest_end && dest_it->end == next_dest->start) {
-    dest_it->end = next_dest->end;
-    ranges_.erase(next_dest);
+  if (next_dest != dest_end && dest_it->end() == next_dest->begin()) {
+    dest_it->set_size(dest_it->size() + next_dest->size());
+    DCHECK_EQ(dest_it->end(), next_dest->end());
+    regions_.erase(next_dest);
   }
 }
 
-AddressRange DisjointAllocationPool::Allocate(size_t size) {
-  for (auto it = ranges_.begin(), end = ranges_.end(); it != end; ++it) {
-    size_t range_size = it->size();
-    if (size > range_size) continue;
-    AddressRange ret{it->start, it->start + size};
-    if (size == range_size) {
-      ranges_.erase(it);
+base::AddressRegion DisjointAllocationPool::Allocate(size_t size) {
+  for (auto it = regions_.begin(), end = regions_.end(); it != end; ++it) {
+    if (size > it->size()) continue;
+    base::AddressRegion ret{it->begin(), size};
+    if (size == it->size()) {
+      regions_.erase(it);
     } else {
-      it->start += size;
-      DCHECK_LT(it->start, it->end);
+      *it = base::AddressRegion{it->begin() + size, it->size() - size};
     }
     return ret;
   }
@@ -141,31 +145,53 @@ bool WasmCode::ShouldBeLogged(Isolate* isolate) {
 void WasmCode::LogCode(Isolate* isolate) const {
   DCHECK(ShouldBeLogged(isolate));
   if (IsAnonymous()) return;
+
   ModuleWireBytes wire_bytes(native_module()->wire_bytes());
   // TODO(herhut): Allow to log code without on-heap round-trip of the name.
   ModuleEnv* module_env = GetModuleEnv(native_module()->compilation_state());
   WireBytesRef name_ref =
       module_env->module->LookupFunctionName(wire_bytes, index());
-  WasmName name_vec = wire_bytes.GetName(name_ref);
-  MaybeHandle<String> maybe_name =
-      isolate->factory()->NewStringFromUtf8(Vector<const char>::cast(name_vec));
-  Handle<String> name;
-  if (!maybe_name.ToHandle(&name)) {
-    name = isolate->factory()->NewStringFromAsciiChecked("<name too long>");
+  WasmName name_vec = wire_bytes.GetNameOrNull(name_ref);
+  if (!name_vec.is_empty()) {
+    MaybeHandle<String> maybe_name = isolate->factory()->NewStringFromUtf8(
+        Vector<const char>::cast(name_vec));
+    Handle<String> name;
+    if (!maybe_name.ToHandle(&name)) {
+      name = isolate->factory()->NewStringFromAsciiChecked("<name too long>");
+    }
+    int name_length;
+    auto cname =
+        name->ToCString(AllowNullsFlag::DISALLOW_NULLS,
+                        RobustnessFlag::ROBUST_STRING_TRAVERSAL, &name_length);
+    PROFILE(isolate,
+            CodeCreateEvent(CodeEventListener::FUNCTION_TAG, this,
+                            {cname.get(), static_cast<size_t>(name_length)}));
+  } else {
+    EmbeddedVector<char, 32> generated_name;
+    SNPrintF(generated_name, "wasm-function[%d]", index());
+    PROFILE(isolate, CodeCreateEvent(CodeEventListener::FUNCTION_TAG, this,
+                                     generated_name));
   }
-  int name_length;
-  auto cname =
-      name->ToCString(AllowNullsFlag::DISALLOW_NULLS,
-                      RobustnessFlag::ROBUST_STRING_TRAVERSAL, &name_length);
-  PROFILE(isolate,
-          CodeCreateEvent(CodeEventListener::FUNCTION_TAG, this,
-                          {cname.get(), static_cast<size_t>(name_length)}));
+
   if (!source_positions().is_empty()) {
     LOG_CODE_EVENT(isolate, CodeLinePosInfoRecordEvent(instruction_start(),
                                                        source_positions()));
   }
 }
 
+const char* WasmCode::GetRuntimeStubName() const {
+  DCHECK_EQ(WasmCode::kRuntimeStub, kind());
+#define RETURN_NAME(Name)                                               \
+  if (native_module_->runtime_stub_table_[WasmCode::k##Name] == this) { \
+    return #Name;                                                       \
+  }
+#define RETURN_NAME_TRAP(Name) RETURN_NAME(ThrowWasm##Name)
+  WASM_RUNTIME_STUB_LIST(RETURN_NAME, RETURN_NAME_TRAP)
+#undef RETURN_NAME_TRAP
+#undef RETURN_NAME
+  return "<unknown>";
+}
+
 void WasmCode::Validate() const {
 #ifdef DEBUG
   // We expect certain relocation info modes to never appear in {WasmCode}
@@ -309,22 +335,20 @@ WasmCode::~WasmCode() {
 }
 
 NativeModule::NativeModule(Isolate* isolate, const WasmFeatures& enabled,
-                           bool can_request_more, VirtualMemory* code_space,
+                           bool can_request_more, VirtualMemory code_space,
                            WasmCodeManager* code_manager,
                            std::shared_ptr<const WasmModule> module,
                            const ModuleEnv& env)
     : enabled_features_(enabled),
       module_(std::move(module)),
       compilation_state_(NewCompilationState(isolate, env)),
-      free_code_space_({code_space->address(), code_space->end()}),
+      free_code_space_(code_space.region()),
       wasm_code_manager_(code_manager),
       can_request_more_memory_(can_request_more),
       use_trap_handler_(env.use_trap_handler) {
   DCHECK_EQ(module_.get(), env.module);
   DCHECK_NOT_NULL(module_);
-  VirtualMemory my_mem;
-  owned_code_space_.push_back(my_mem);
-  owned_code_space_.back().TakeControl(code_space);
+  owned_code_space_.emplace_back(std::move(code_space));
   owned_code_.reserve(num_functions());
 
   uint32_t num_wasm_functions = module_->num_declared_functions;
@@ -359,9 +383,9 @@ void NativeModule::LogWasmCodes(Isolate* isolate) {
 }
 
 WasmCode* NativeModule::AddOwnedCode(
-    Maybe<uint32_t> index, Vector<const byte> instructions,
-    uint32_t stack_slots, size_t safepoint_table_offset,
-    size_t handler_table_offset, size_t constant_pool_offset,
+    uint32_t index, Vector<const byte> instructions, uint32_t stack_slots,
+    size_t safepoint_table_offset, size_t handler_table_offset,
+    size_t constant_pool_offset,
     OwnedVector<trap_handler::ProtectedInstructionData> protected_instructions,
     OwnedVector<const byte> reloc_info,
     OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
@@ -371,18 +395,13 @@ WasmCode* NativeModule::AddOwnedCode(
     // Both allocation and insertion in owned_code_ happen in the same critical
     // section, thus ensuring owned_code_'s elements are rarely if ever moved.
     base::LockGuard<base::Mutex> lock(&allocation_mutex_);
-    Address executable_buffer = AllocateForCode(instructions.size());
-    if (executable_buffer == kNullAddress) {
-      V8::FatalProcessOutOfMemory(nullptr, "NativeModule::AddOwnedCode");
-      UNREACHABLE();
-    }
+    Vector<byte> executable_buffer = AllocateForCode(instructions.size());
     // Ownership will be transferred to {owned_code_} below.
-    code = new WasmCode(
-        this, index,
-        {reinterpret_cast<byte*>(executable_buffer), instructions.size()},
-        stack_slots, safepoint_table_offset, handler_table_offset,
-        constant_pool_offset, std::move(protected_instructions),
-        std::move(reloc_info), std::move(source_position_table), kind, tier);
+    code = new WasmCode(this, index, executable_buffer, stack_slots,
+                        safepoint_table_offset, handler_table_offset,
+                        constant_pool_offset, std::move(protected_instructions),
+                        std::move(reloc_info), std::move(source_position_table),
+                        kind, tier);
 
     if (owned_code_.empty() ||
         code->instruction_start() > owned_code_.back()->instruction_start()) {
@@ -405,22 +424,25 @@ WasmCode* NativeModule::AddOwnedCode(
   return code;
 }
 
-WasmCode* NativeModule::AddCodeCopy(Handle<Code> code, WasmCode::Kind kind,
-                                    uint32_t index) {
+WasmCode* NativeModule::AddImportWrapper(Handle<Code> code, uint32_t index) {
   // TODO(wasm): Adding instance-specific wasm-to-js wrappers as owned code to
   // this NativeModule is a memory leak until the whole NativeModule dies.
-  WasmCode* ret = AddAnonymousCode(code, kind);
-  ret->index_ = Just(index);
-  if (index >= module_->num_imported_functions) set_code(index, ret);
+  WasmCode* ret = AddAnonymousCode(code, WasmCode::kWasmToJsWrapper);
+  DCHECK_LT(index, module_->num_imported_functions);
+  ret->index_ = index;
   return ret;
 }
 
 WasmCode* NativeModule::AddInterpreterEntry(Handle<Code> code, uint32_t index) {
   WasmCode* ret = AddAnonymousCode(code, WasmCode::kInterpreterEntry);
-  ret->index_ = Just(index);
+  ret->index_ = index;
   base::LockGuard<base::Mutex> lock(&allocation_mutex_);
-  PatchJumpTable(index, ret->instruction_start(), WasmCode::kFlushICache);
-  set_code(index, ret);
+  InstallCode(ret);
+  return ret;
+}
+
+WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
+  WasmCode* ret = AddAnonymousCode(code, WasmCode::kFunction);
   return ret;
 }
 
@@ -445,15 +467,15 @@ void NativeModule::SetRuntimeStubs(Isolate* isolate) {
 #define COPY_BUILTIN(Name)                                                     \
   runtime_stub_table_[WasmCode::k##Name] =                                     \
       AddAnonymousCode(isolate->builtins()->builtin_handle(Builtins::k##Name), \
-                       WasmCode::kRuntimeStub);
+                       WasmCode::kRuntimeStub, #Name);
 #define COPY_BUILTIN_TRAP(Name) COPY_BUILTIN(ThrowWasm##Name)
-  WASM_RUNTIME_STUB_LIST(COPY_BUILTIN, COPY_BUILTIN_TRAP);
+  WASM_RUNTIME_STUB_LIST(COPY_BUILTIN, COPY_BUILTIN_TRAP)
 #undef COPY_BUILTIN_TRAP
 #undef COPY_BUILTIN
 }
 
-WasmCode* NativeModule::AddAnonymousCode(Handle<Code> code,
-                                         WasmCode::Kind kind) {
+WasmCode* NativeModule::AddAnonymousCode(Handle<Code> code, WasmCode::Kind kind,
+                                         const char* name) {
   // For off-heap builtins, we create a copy of the off-heap instruction stream
   // instead of the on-heap code object containing the trampoline. Ensure that
   // we do not apply the on-heap reloc info to the off-heap instructions.
@@ -473,17 +495,17 @@ WasmCode* NativeModule::AddAnonymousCode(Handle<Code> code,
   int safepoint_table_offset =
       code->has_safepoint_info() ? code->safepoint_table_offset() : 0;
   WasmCode* ret =
-      AddOwnedCode(Nothing<uint32_t>(),           // index
-                   instructions,                  // instructions
-                   stack_slots,                   // stack_slots
-                   safepoint_table_offset,        // safepoint_table_offset
-                   code->handler_table_offset(),  // handler_table_offset
-                   code->constant_pool_offset(),  // constant_pool_offset
-                   {},                            // protected_instructions
-                   std::move(reloc_info),         // reloc_info
-                   std::move(source_pos),         // source positions
-                   kind,                          // kind
-                   WasmCode::kOther);             // tier
+      AddOwnedCode(WasmCode::kAnonymousFuncIndex,  // index
+                   instructions,                   // instructions
+                   stack_slots,                    // stack_slots
+                   safepoint_table_offset,         // safepoint_table_offset
+                   code->handler_table_offset(),   // handler_table_offset
+                   code->constant_pool_offset(),   // constant_pool_offset
+                   {},                             // protected_instructions
+                   std::move(reloc_info),          // reloc_info
+                   std::move(source_pos),          // source positions
+                   kind,                           // kind
+                   WasmCode::kOther);              // tier
 
   // Apply the relocation delta by iterating over the RelocInfo.
   intptr_t delta = ret->instruction_start() - code->InstructionStart();
@@ -510,7 +532,7 @@ WasmCode* NativeModule::AddAnonymousCode(Handle<Code> code,
   // made while iterating over the RelocInfo above.
   Assembler::FlushICache(ret->instructions().start(),
                          ret->instructions().size());
-  if (FLAG_print_code || FLAG_print_wasm_code) ret->Print();
+  if (FLAG_print_code || FLAG_print_wasm_code) ret->Print(name);
   ret->Validate();
   return ret;
 }
@@ -523,12 +545,12 @@ WasmCode* NativeModule::AddCode(
   OwnedVector<byte> reloc_info = OwnedVector<byte>::New(desc.reloc_size);
   memcpy(reloc_info.start(), desc.buffer + desc.buffer_size - desc.reloc_size,
          desc.reloc_size);
-  WasmCode* ret = AddOwnedCode(
-      Just(index), {desc.buffer, static_cast<size_t>(desc.instr_size)},
-      stack_slots, safepoint_table_offset, handler_table_offset,
-      desc.instr_size - desc.constant_pool_size,
-      std::move(protected_instructions), std::move(reloc_info),
-      std::move(source_pos_table), WasmCode::kFunction, tier);
+  WasmCode* ret =
+      AddOwnedCode(index, {desc.buffer, static_cast<size_t>(desc.instr_size)},
+                   stack_slots, safepoint_table_offset, handler_table_offset,
+                   desc.instr_size - desc.constant_pool_size,
+                   std::move(protected_instructions), std::move(reloc_info),
+                   std::move(source_pos_table), WasmCode::kFunction, tier);
 
   // Apply the relocation delta by iterating over the RelocInfo.
   intptr_t delta = ret->instructions().start() - desc.buffer;
@@ -571,17 +593,17 @@ WasmCode* NativeModule::AddDeserializedCode(
     OwnedVector<trap_handler::ProtectedInstructionData> protected_instructions,
     OwnedVector<const byte> reloc_info,
     OwnedVector<const byte> source_position_table, WasmCode::Tier tier) {
-  WasmCode* code = AddOwnedCode(
-      Just(index), instructions, stack_slots, safepoint_table_offset,
-      handler_table_offset, constant_pool_offset,
-      std::move(protected_instructions), std::move(reloc_info),
-      std::move(source_position_table), WasmCode::kFunction, tier);
+  WasmCode* code =
+      AddOwnedCode(index, instructions, stack_slots, safepoint_table_offset,
+                   handler_table_offset, constant_pool_offset,
+                   std::move(protected_instructions), std::move(reloc_info),
+                   std::move(source_position_table), WasmCode::kFunction, tier);
 
   if (!code->protected_instructions_.is_empty()) {
     code->RegisterTrapHandlerData();
   }
-  set_code(index, code);
-  PatchJumpTable(index, code->instruction_start(), WasmCode::kFlushICache);
+  base::LockGuard<base::Mutex> lock(&allocation_mutex_);
+  InstallCode(code);
   // Note: we do not flush the i-cache here, since the code needs to be
   // relocated anyway. The caller is responsible for flushing the i-cache later.
   return code;
@@ -598,10 +620,7 @@ void NativeModule::PublishCode(WasmCode* code) {
   if (!code->protected_instructions_.is_empty()) {
     code->RegisterTrapHandlerData();
   }
-  DCHECK(!code->IsAnonymous());
-  set_code(code->index(), code);
-  PatchJumpTable(code->index(), code->instruction_start(),
-                 WasmCode::kFlushICache);
+  InstallCode(code);
 }
 
 std::vector<WasmCode*> NativeModule::SnapshotCodeTable() const {
@@ -618,52 +637,66 @@ WasmCode* NativeModule::CreateEmptyJumpTable(uint32_t num_wasm_functions) {
   OwnedVector<byte> instructions = OwnedVector<byte>::New(
       JumpTableAssembler::SizeForNumberOfSlots(num_wasm_functions));
   memset(instructions.start(), 0, instructions.size());
-  return AddOwnedCode(Nothing<uint32_t>(),       // index
-                      instructions.as_vector(),  // instructions
-                      0,                         // stack_slots
-                      0,                         // safepoint_table_offset
-                      0,                         // handler_table_offset
-                      0,                         // constant_pool_offset
-                      {},                        // protected_instructions
-                      {},                        // reloc_info
-                      {},                        // source_pos
-                      WasmCode::kJumpTable,      // kind
-                      WasmCode::kOther);         // tier
+  return AddOwnedCode(WasmCode::kAnonymousFuncIndex,  // index
+                      instructions.as_vector(),       // instructions
+                      0,                              // stack_slots
+                      0,                              // safepoint_table_offset
+                      0,                              // handler_table_offset
+                      0,                              // constant_pool_offset
+                      {},                             // protected_instructions
+                      {},                             // reloc_info
+                      {},                             // source_pos
+                      WasmCode::kJumpTable,           // kind
+                      WasmCode::kOther);              // tier
 }
 
-void NativeModule::PatchJumpTable(uint32_t func_index, Address target,
-                                  WasmCode::FlushICache flush_icache) {
-  DCHECK_LE(module_->num_imported_functions, func_index);
-  uint32_t slot_idx = func_index - module_->num_imported_functions;
+void NativeModule::InstallCode(WasmCode* code) {
+  DCHECK_LT(code->index(), num_functions());
+  DCHECK_LE(module_->num_imported_functions, code->index());
+
+  // Update code table.
+  code_table_[code->index() - module_->num_imported_functions] = code;
+
+  // Patch jump table.
+  uint32_t slot_idx = code->index() - module_->num_imported_functions;
   JumpTableAssembler::PatchJumpTableSlot(jump_table_->instruction_start(),
-                                         slot_idx, target, flush_icache);
+                                         slot_idx, code->instruction_start(),
+                                         WasmCode::kFlushICache);
 }
 
-Address NativeModule::AllocateForCode(size_t size) {
+Vector<byte> NativeModule::AllocateForCode(size_t size) {
+  DCHECK_LT(0, size);
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   // This happens under a lock assumed by the caller.
   size = RoundUp(size, kCodeAlignment);
-  AddressRange mem = free_code_space_.Allocate(size);
+  base::AddressRegion mem = free_code_space_.Allocate(size);
   if (mem.is_empty()) {
-    if (!can_request_more_memory_) return kNullAddress;
+    if (!can_request_more_memory_) {
+      V8::FatalProcessOutOfMemory(nullptr,
+                                  "NativeModule::AllocateForCode reservation");
+      UNREACHABLE();
+    }
 
     Address hint = owned_code_space_.empty() ? kNullAddress
                                              : owned_code_space_.back().end();
-    VirtualMemory empty_mem;
-    owned_code_space_.push_back(empty_mem);
-    VirtualMemory& new_mem = owned_code_space_.back();
-    wasm_code_manager_->TryAllocate(size, &new_mem,
-                                    reinterpret_cast<void*>(hint));
-    if (!new_mem.IsReserved()) return kNullAddress;
-    base::LockGuard<base::Mutex> lock(
-        &wasm_code_manager_->native_modules_mutex_);
+
+    VirtualMemory new_mem =
+        wasm_code_manager_->TryAllocate(size, reinterpret_cast<void*>(hint));
+    if (!new_mem.IsReserved()) {
+      V8::FatalProcessOutOfMemory(nullptr,
+                                  "NativeModule::AllocateForCode reservation");
+      UNREACHABLE();
+    }
     wasm_code_manager_->AssignRanges(new_mem.address(), new_mem.end(), this);
 
-    free_code_space_.Merge({new_mem.address(), new_mem.end()});
+    free_code_space_.Merge(new_mem.region());
+    owned_code_space_.emplace_back(std::move(new_mem));
     mem = free_code_space_.Allocate(size);
-    if (mem.is_empty()) return kNullAddress;
+    DCHECK(!mem.is_empty());
   }
-  Address commit_start = RoundUp(mem.start, AllocatePageSize());
-  Address commit_end = RoundUp(mem.end, AllocatePageSize());
+  const Address page_size = page_allocator->AllocatePageSize();
+  Address commit_start = RoundUp(mem.begin(), page_size);
+  Address commit_end = RoundUp(mem.end(), page_size);
   // {commit_start} will be either mem.start or the start of the next page.
   // {commit_end} will be the start of the page after the one in which
   // the allocation ends.
@@ -673,38 +706,43 @@ Address NativeModule::AllocateForCode(size_t size) {
   // start is already committed (or we start at the beginning of a page).
   // The end needs to be committed all through the end of the page.
   if (commit_start < commit_end) {
+    committed_code_space_.fetch_add(commit_end - commit_start);
+    // Committed code cannot grow bigger than maximum code space size.
+    DCHECK_LE(committed_code_space_.load(), kMaxWasmCodeMemory);
 #if V8_OS_WIN
-    // On Windows, we cannot commit a range that straddles different
+    // On Windows, we cannot commit a region that straddles different
     // reservations of virtual memory. Because we bump-allocate, and because, if
     // we need more memory, we append that memory at the end of the
     // owned_code_space_ list, we traverse that list in reverse order to find
     // the reservation(s) that guide how to chunk the region to commit.
-    for (auto it = owned_code_space_.crbegin(),
-              rend = owned_code_space_.crend();
-         it != rend && commit_start < commit_end; ++it) {
-      if (commit_end > it->end() || it->address() >= commit_end) continue;
-      Address start = std::max(commit_start, it->address());
-      size_t commit_size = static_cast<size_t>(commit_end - start);
-      DCHECK(IsAligned(commit_size, AllocatePageSize()));
+    for (auto& vmem : base::Reversed(owned_code_space_)) {
+      if (commit_end <= vmem.address() || vmem.end() <= commit_start) continue;
+      Address start = std::max(commit_start, vmem.address());
+      Address end = std::min(commit_end, vmem.end());
+      size_t commit_size = static_cast<size_t>(end - start);
       if (!wasm_code_manager_->Commit(start, commit_size)) {
-        return kNullAddress;
+        V8::FatalProcessOutOfMemory(nullptr,
+                                    "NativeModule::AllocateForCode commit");
+        UNREACHABLE();
       }
-      committed_code_space_.fetch_add(commit_size);
-      commit_end = start;
+      // Opportunistically reduce the commit range. This might terminate the
+      // loop early.
+      if (commit_start == start) commit_start = end;
+      if (commit_end == end) commit_end = start;
+      if (commit_start >= commit_end) break;
     }
 #else
-    size_t commit_size = static_cast<size_t>(commit_end - commit_start);
-    DCHECK(IsAligned(commit_size, AllocatePageSize()));
-    if (!wasm_code_manager_->Commit(commit_start, commit_size)) {
-      return kNullAddress;
+    if (!wasm_code_manager_->Commit(commit_start, commit_end - commit_start)) {
+      V8::FatalProcessOutOfMemory(nullptr,
+                                  "NativeModule::AllocateForCode commit");
+      UNREACHABLE();
     }
-    committed_code_space_.fetch_add(commit_size);
 #endif
   }
-  DCHECK(IsAligned(mem.start, kCodeAlignment));
-  allocated_code_space_.Merge(std::move(mem));
-  TRACE_HEAP("Code alloc for %p: %" PRIuPTR ",+%zu\n", this, mem.start, size);
-  return mem.start;
+  DCHECK(IsAligned(mem.begin(), kCodeAlignment));
+  allocated_code_space_.Merge(mem);
+  TRACE_HEAP("Code alloc for %p: %" PRIxPTR ",+%zu\n", this, mem.begin(), size);
+  return {reinterpret_cast<byte*>(mem.begin()), mem.size()};
 }
 
 WasmCode* NativeModule::Lookup(Address pc) const {
@@ -787,7 +825,8 @@ bool WasmCodeManager::Commit(Address start, size_t size) {
                                              ? PageAllocator::kReadWrite
                                              : PageAllocator::kReadWriteExecute;
 
-  bool ret = SetPermissions(start, size, permission);
+  bool ret =
+      SetPermissions(GetPlatformPageAllocator(), start, size, permission);
   TRACE_HEAP("Setting rw permissions for %p:%p\n",
              reinterpret_cast<void*>(start),
              reinterpret_cast<void*>(start + size));
@@ -802,24 +841,37 @@ bool WasmCodeManager::Commit(Address start, size_t size) {
 
 void WasmCodeManager::AssignRanges(Address start, Address end,
                                    NativeModule* native_module) {
+  base::LockGuard<base::Mutex> lock(&native_modules_mutex_);
+  lookup_map_.insert(std::make_pair(start, std::make_pair(end, native_module)));
+}
+
+void WasmCodeManager::AssignRangesAndAddModule(Address start, Address end,
+                                               NativeModule* native_module) {
+  base::LockGuard<base::Mutex> lock(&native_modules_mutex_);
   lookup_map_.insert(std::make_pair(start, std::make_pair(end, native_module)));
+  native_modules_.emplace(native_module);
 }
 
-void WasmCodeManager::TryAllocate(size_t size, VirtualMemory* ret, void* hint) {
+VirtualMemory WasmCodeManager::TryAllocate(size_t size, void* hint) {
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   DCHECK_GT(size, 0);
-  size = RoundUp(size, AllocatePageSize());
-  DCHECK(!ret->IsReserved());
-  if (!memory_tracker_->ReserveAddressSpace(size)) return;
-  if (hint == nullptr) hint = GetRandomMmapAddr();
-
-  if (!AlignedAllocVirtualMemory(size, static_cast<size_t>(AllocatePageSize()),
-                                 hint, ret)) {
-    DCHECK(!ret->IsReserved());
+  size = RoundUp(size, page_allocator->AllocatePageSize());
+  if (!memory_tracker_->ReserveAddressSpace(size,
+                                            WasmMemoryTracker::kHardLimit)) {
+    return {};
+  }
+  if (hint == nullptr) hint = page_allocator->GetRandomMmapAddr();
+
+  VirtualMemory mem(page_allocator, size, hint,
+                    page_allocator->AllocatePageSize());
+  if (!mem.IsReserved()) {
     memory_tracker_->ReleaseReservation(size);
+    return {};
   }
   TRACE_HEAP("VMem alloc: %p:%p (%zu)\n",
-             reinterpret_cast<void*>(ret->address()),
-             reinterpret_cast<void*>(ret->end()), ret->size());
+             reinterpret_cast<void*>(mem.address()),
+             reinterpret_cast<void*>(mem.end()), mem.size());
+  return mem;
 }
 
 void WasmCodeManager::SampleModuleSizes(Isolate* isolate) const {
@@ -897,7 +949,7 @@ std::unique_ptr<NativeModule> WasmCodeManager::NewNativeModule(
   static constexpr int kAllocationRetries = 2;
   VirtualMemory mem;
   for (int retries = 0;; ++retries) {
-    TryAllocate(vmem_size, &mem);
+    mem = TryAllocate(vmem_size);
     if (mem.IsReserved()) break;
     if (retries == kAllocationRetries) {
       V8::FatalProcessOutOfMemory(isolate, "WasmCodeManager::NewNativeModule");
@@ -911,13 +963,12 @@ std::unique_ptr<NativeModule> WasmCodeManager::NewNativeModule(
   Address start = mem.address();
   size_t size = mem.size();
   Address end = mem.end();
-  std::unique_ptr<NativeModule> ret(new NativeModule(
-      isolate, enabled, can_request_more, &mem, this, std::move(module), env));
+  std::unique_ptr<NativeModule> ret(
+      new NativeModule(isolate, enabled, can_request_more, std::move(mem), this,
+                       std::move(module), env));
   TRACE_HEAP("New NativeModule %p: Mem: %" PRIuPTR ",+%zu\n", this, start,
              size);
-  base::LockGuard<base::Mutex> lock(&native_modules_mutex_);
-  AssignRanges(start, end, ret.get());
-  native_modules_.emplace(ret.get());
+  AssignRangesAndAddModule(start, end, ret.get());
   return ret;
 }
 
@@ -925,6 +976,8 @@ bool NativeModule::SetExecutable(bool executable) {
   if (is_executable_ == executable) return true;
   TRACE_HEAP("Setting module %p as executable: %d.\n", this, executable);
 
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
+
   if (FLAG_wasm_write_protect_code_memory) {
     PageAllocator::Permission permission =
         executable ? PageAllocator::kReadExecute : PageAllocator::kReadWrite;
@@ -939,7 +992,8 @@ bool NativeModule::SetExecutable(bool executable) {
     // committed or not.
     if (can_request_more_memory_) {
       for (auto& vmem : owned_code_space_) {
-        if (!SetPermissions(vmem.address(), vmem.size(), permission)) {
+        if (!SetPermissions(page_allocator, vmem.address(), vmem.size(),
+                            permission)) {
           return false;
         }
         TRACE_HEAP("Set %p:%p to executable:%d\n", vmem.address(), vmem.end(),
@@ -949,16 +1003,18 @@ bool NativeModule::SetExecutable(bool executable) {
       return true;
     }
 #endif
-    for (auto& range : allocated_code_space_.ranges()) {
+    for (auto& region : allocated_code_space_.regions()) {
       // allocated_code_space_ is fine-grained, so we need to
       // page-align it.
-      size_t range_size = RoundUp(range.size(), AllocatePageSize());
-      if (!SetPermissions(range.start, range_size, permission)) {
+      size_t region_size =
+          RoundUp(region.size(), page_allocator->AllocatePageSize());
+      if (!SetPermissions(page_allocator, region.begin(), region_size,
+                          permission)) {
         return false;
       }
       TRACE_HEAP("Set %p:%p to executable:%d\n",
-                 reinterpret_cast<void*>(range.start),
-                 reinterpret_cast<void*>(range.end), executable);
+                 reinterpret_cast<void*>(region.begin()),
+                 reinterpret_cast<void*>(region.end()), executable);
     }
   }
   is_executable_ = executable;
@@ -970,29 +1026,22 @@ void WasmCodeManager::FreeNativeModule(NativeModule* native_module) {
   DCHECK_EQ(1, native_modules_.count(native_module));
   native_modules_.erase(native_module);
   TRACE_HEAP("Freeing NativeModule %p\n", this);
-  for (auto& vmem : native_module->owned_code_space_) {
-    lookup_map_.erase(vmem.address());
-    Free(&vmem);
-    DCHECK(!vmem.IsReserved());
+  for (auto& mem : native_module->owned_code_space_) {
+    DCHECK(mem.IsReserved());
+    TRACE_HEAP("VMem Release: %" PRIxPTR ":%" PRIxPTR " (%zu)\n", mem.address(),
+               mem.end(), mem.size());
+    lookup_map_.erase(mem.address());
+    memory_tracker_->ReleaseReservation(mem.size());
+    mem.Free();
+    DCHECK(!mem.IsReserved());
   }
   native_module->owned_code_space_.clear();
 
   size_t code_size = native_module->committed_code_space_.load();
   DCHECK(IsAligned(code_size, AllocatePageSize()));
   remaining_uncommitted_code_space_.fetch_add(code_size);
-}
-
-// TODO(wasm): We can make this more efficient if needed. For
-// example, we can preface the first instruction with a pointer to
-// the WasmCode. In the meantime, we have a separate API so we can
-// easily identify those places where we know we have the first
-// instruction PC.
-WasmCode* WasmCodeManager::GetCodeFromStartAddress(Address pc) const {
-  WasmCode* code = LookupCode(pc);
-  // This method can only be called for valid instruction start addresses.
-  DCHECK_NOT_NULL(code);
-  DCHECK_EQ(pc, code->instruction_start());
-  return code;
+  // Remaining code space cannot grow bigger than maximum code space size.
+  DCHECK_LE(remaining_uncommitted_code_space_.load(), kMaxWasmCodeMemory);
 }
 
 NativeModule* WasmCodeManager::LookupNativeModule(Address pc) const {
@@ -1002,12 +1051,12 @@ NativeModule* WasmCodeManager::LookupNativeModule(Address pc) const {
   auto iter = lookup_map_.upper_bound(pc);
   if (iter == lookup_map_.begin()) return nullptr;
   --iter;
-  Address range_start = iter->first;
-  Address range_end = iter->second.first;
+  Address region_start = iter->first;
+  Address region_end = iter->second.first;
   NativeModule* candidate = iter->second.second;
 
   DCHECK_NOT_NULL(candidate);
-  return range_start <= pc && pc < range_end ? candidate : nullptr;
+  return region_start <= pc && pc < region_end ? candidate : nullptr;
 }
 
 WasmCode* WasmCodeManager::LookupCode(Address pc) const {
@@ -1015,16 +1064,6 @@ WasmCode* WasmCodeManager::LookupCode(Address pc) const {
   return candidate ? candidate->Lookup(pc) : nullptr;
 }
 
-void WasmCodeManager::Free(VirtualMemory* mem) {
-  DCHECK(mem->IsReserved());
-  void* start = reinterpret_cast<void*>(mem->address());
-  void* end = reinterpret_cast<void*>(mem->end());
-  size_t size = mem->size();
-  mem->Free();
-  memory_tracker_->ReleaseReservation(size);
-  TRACE_HEAP("VMem Release: %p:%p (%zu)\n", start, end, size);
-}
-
 size_t WasmCodeManager::remaining_uncommitted_code_space() const {
   return remaining_uncommitted_code_space_.load();
 }
diff --git a/deps/v8/src/wasm/wasm-code-manager.h b/deps/v8/src/wasm/wasm-code-manager.h
index ffcc05fbcd..65156b7457 100644
--- a/deps/v8/src/wasm/wasm-code-manager.h
+++ b/deps/v8/src/wasm/wasm-code-manager.h
@@ -18,6 +18,7 @@
 #include "src/vector.h"
 #include "src/wasm/module-compiler.h"
 #include "src/wasm/wasm-features.h"
+#include "src/wasm/wasm-limits.h"
 
 namespace v8 {
 namespace internal {
@@ -32,47 +33,34 @@ class WasmCodeManager;
 class WasmMemoryTracker;
 struct WasmModule;
 
-struct AddressRange {
-  Address start;
-  Address end;
-
-  AddressRange(Address s, Address e) : start(s), end(e) {
-    DCHECK_LE(start, end);
-    DCHECK_IMPLIES(start == kNullAddress, end == kNullAddress);
-  }
-  AddressRange() : AddressRange(kNullAddress, kNullAddress) {}
-
-  size_t size() const { return static_cast<size_t>(end - start); }
-  bool is_empty() const { return start == end; }
-  operator bool() const { return start == kNullAddress; }
-};
-
-// Sorted, disjoint and non-overlapping memory ranges. A range is of the
+// Sorted, disjoint and non-overlapping memory regions. A region is of the
 // form [start, end). So there's no [start, end), [end, other_end),
 // because that should have been reduced to [start, other_end).
 class V8_EXPORT_PRIVATE DisjointAllocationPool final {
  public:
   DisjointAllocationPool() = default;
 
-  explicit DisjointAllocationPool(AddressRange range) : ranges_({range}) {}
+  explicit DisjointAllocationPool(base::AddressRegion region)
+      : regions_({region}) {}
 
   DisjointAllocationPool(DisjointAllocationPool&& other) = default;
   DisjointAllocationPool& operator=(DisjointAllocationPool&& other) = default;
 
-  // Merge the parameter range into this object while preserving ordering of the
-  // ranges. The assumption is that the passed parameter is not intersecting
-  // this object - for example, it was obtained from a previous Allocate.
-  void Merge(AddressRange);
+  // Merge the parameter region into this object while preserving ordering of
+  // the regions. The assumption is that the passed parameter is not
+  // intersecting this object - for example, it was obtained from a previous
+  // Allocate.
+  void Merge(base::AddressRegion);
 
-  // Allocate a contiguous range of size {size}. Return an empty pool on
+  // Allocate a contiguous region of size {size}. Return an empty pool on
   // failure.
-  AddressRange Allocate(size_t size);
+  base::AddressRegion Allocate(size_t size);
 
-  bool IsEmpty() const { return ranges_.empty(); }
-  const std::list<AddressRange>& ranges() const { return ranges_; }
+  bool IsEmpty() const { return regions_.empty(); }
+  const std::list<base::AddressRegion>& regions() const { return regions_; }
 
  private:
-  std::list<AddressRange> ranges_;
+  std::list<base::AddressRegion> regions_;
 
   DISALLOW_COPY_AND_ASSIGN(DisjointAllocationPool)
 };
@@ -113,9 +101,12 @@ class V8_EXPORT_PRIVATE WasmCode final {
     return source_position_table_.as_vector();
   }
 
-  uint32_t index() const { return index_.ToChecked(); }
+  uint32_t index() const {
+    DCHECK(!IsAnonymous());
+    return index_;
+  }
   // Anonymous functions are functions that don't carry an index.
-  bool IsAnonymous() const { return index_.IsNothing(); }
+  bool IsAnonymous() const { return index_ == kAnonymousFuncIndex; }
   Kind kind() const { return kind_; }
   NativeModule* native_module() const { return native_module_; }
   Tier tier() const { return tier_; }
@@ -135,6 +126,8 @@ class V8_EXPORT_PRIVATE WasmCode final {
     return protected_instructions_.as_vector();
   }
 
+  const char* GetRuntimeStubName() const;
+
   void Validate() const;
   void Print(const char* name = nullptr) const;
   void Disassemble(const char* name, std::ostream& os,
@@ -150,7 +143,7 @@ class V8_EXPORT_PRIVATE WasmCode final {
  private:
   friend class NativeModule;
 
-  WasmCode(NativeModule* native_module, Maybe<uint32_t> index,
+  WasmCode(NativeModule* native_module, uint32_t index,
            Vector<byte> instructions, uint32_t stack_slots,
            size_t safepoint_table_offset, size_t handler_table_offset,
            size_t constant_pool_offset,
@@ -185,11 +178,14 @@ class V8_EXPORT_PRIVATE WasmCode final {
   // trap_handler_index.
   void RegisterTrapHandlerData();
 
+  static constexpr uint32_t kAnonymousFuncIndex = 0xffffffff;
+  STATIC_ASSERT(kAnonymousFuncIndex > kV8MaxWasmFunctions);
+
   Vector<byte> instructions_;
   OwnedVector<const byte> reloc_info_;
   OwnedVector<const byte> source_position_table_;
   NativeModule* native_module_ = nullptr;
-  Maybe<uint32_t> index_;
+  uint32_t index_;
   Kind kind_;
   size_t constant_pool_offset_ = 0;
   uint32_t stack_slots_ = 0;
@@ -216,8 +212,8 @@ class V8_EXPORT_PRIVATE NativeModule final {
   static constexpr bool kCanAllocateMoreMemory = true;
 #endif
 
-  // {AddCode} is thread safe w.r.t. other calls to {AddCode} or {AddCodeCopy},
-  // i.e. it can be called concurrently from background threads.
+  // {AddCode} is thread safe w.r.t. other calls to {AddCode} or methods adding
+  // code below, i.e. it can be called concurrently from background threads.
   WasmCode* AddCode(uint32_t index, const CodeDesc& desc, uint32_t stack_slots,
                     size_t safepoint_table_offset, size_t handler_table_offset,
                     OwnedVector<trap_handler::ProtectedInstructionData>
@@ -234,16 +230,19 @@ class V8_EXPORT_PRIVATE NativeModule final {
       OwnedVector<const byte> reloc_info,
       OwnedVector<const byte> source_position_table, WasmCode::Tier tier);
 
-  // A way to copy over JS-allocated code. This is because we compile
-  // certain wrappers using a different pipeline.
-  WasmCode* AddCodeCopy(Handle<Code> code, WasmCode::Kind kind, uint32_t index);
+  // Add an import wrapper for wasm-to-JS transitions. This method copies over
+  // JS-allocated code, because we compile wrappers using a different pipeline.
+  WasmCode* AddImportWrapper(Handle<Code> code, uint32_t index);
 
-  // Add an interpreter entry. For the same reason as AddCodeCopy, we
+  // Add an interpreter entry. For the same reason as AddImportWrapper, we
   // currently compile these using a different pipeline and we can't get a
   // CodeDesc here. When adding interpreter wrappers, we do not insert them in
   // the code_table, however, we let them self-identify as the {index} function.
   WasmCode* AddInterpreterEntry(Handle<Code> code, uint32_t index);
 
+  // Adds anonymous code for testing purposes.
+  WasmCode* AddCodeForTesting(Handle<Code> code);
+
   // When starting lazy compilation, provide the WasmLazyCompile builtin by
   // calling SetLazyBuiltin. It will be copied into this NativeModule and the
   // jump table will be populated with that copy.
@@ -346,18 +345,20 @@ class V8_EXPORT_PRIVATE NativeModule final {
   friend class NativeModuleModificationScope;
 
   NativeModule(Isolate* isolate, const WasmFeatures& enabled_features,
-               bool can_request_more, VirtualMemory* code_space,
+               bool can_request_more, VirtualMemory code_space,
                WasmCodeManager* code_manager,
                std::shared_ptr<const WasmModule> module, const ModuleEnv& env);
 
-  WasmCode* AddAnonymousCode(Handle<Code>, WasmCode::Kind kind);
-  Address AllocateForCode(size_t size);
+  WasmCode* AddAnonymousCode(Handle<Code>, WasmCode::Kind kind,
+                             const char* name = nullptr);
+  // Allocate code space. Returns a valid buffer or fails with OOM (crash).
+  Vector<byte> AllocateForCode(size_t size);
 
   // Primitive for adding code to the native module. All code added to a native
   // module is owned by that module. Various callers get to decide on how the
   // code is obtained (CodeDesc vs, as a point in time, Code*), the kind,
   // whether it has an index or is anonymous, etc.
-  WasmCode* AddOwnedCode(Maybe<uint32_t> index, Vector<const byte> instructions,
+  WasmCode* AddOwnedCode(uint32_t index, Vector<const byte> instructions,
                          uint32_t stack_slots, size_t safepoint_table_offset,
                          size_t handler_table_offset,
                          size_t constant_pool_offset,
@@ -368,18 +369,12 @@ class V8_EXPORT_PRIVATE NativeModule final {
 
   WasmCode* CreateEmptyJumpTable(uint32_t num_wasm_functions);
 
-  void PatchJumpTable(uint32_t func_index, Address target,
-                      WasmCode::FlushICache);
+  // Hold the {allocation_mutex_} when calling this method.
+  void InstallCode(WasmCode* code);
 
   Vector<WasmCode*> code_table() const {
     return {code_table_.get(), module_->num_declared_functions};
   }
-  void set_code(uint32_t index, WasmCode* code) {
-    DCHECK_LT(index, num_functions());
-    DCHECK_LE(module_->num_imported_functions, index);
-    DCHECK_EQ(code->index(), index);
-    code_table_[index - module_->num_imported_functions] = code;
-  }
 
   // Features enabled for this module. We keep a copy of the features that
   // were enabled at the time of the creation of this native module,
@@ -390,12 +385,6 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // AsyncCompileJob).
   std::shared_ptr<const WasmModule> module_;
 
-  // Holds all allocated code objects, is maintained to be in ascending order
-  // according to the codes instruction start address to allow lookups.
-  std::vector<std::unique_ptr<WasmCode>> owned_code_;
-
-  std::unique_ptr<WasmCode* []> code_table_;
-
   OwnedVector<const byte> wire_bytes_;
 
   WasmCode* runtime_stub_table_[WasmCode::kRuntimeStubCount] = {nullptr};
@@ -408,13 +397,25 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // hence needs to be destructed first when this native module dies.
   std::unique_ptr<CompilationState, CompilationStateDeleter> compilation_state_;
 
-  // This mutex protects concurrent calls to {AddCode} and {AddCodeCopy}.
+  // This mutex protects concurrent calls to {AddCode} and friends.
   mutable base::Mutex allocation_mutex_;
 
+  //////////////////////////////////////////////////////////////////////////////
+  // Protected by {allocation_mutex_}:
+
+  // Holds all allocated code objects, is maintained to be in ascending order
+  // according to the codes instruction start address to allow lookups.
+  std::vector<std::unique_ptr<WasmCode>> owned_code_;
+
+  std::unique_ptr<WasmCode* []> code_table_;
+
   DisjointAllocationPool free_code_space_;
   DisjointAllocationPool allocated_code_space_;
   std::list<VirtualMemory> owned_code_space_;
 
+  // End of fields protected by {allocation_mutex_}.
+  //////////////////////////////////////////////////////////////////////////////
+
   WasmCodeManager* wasm_code_manager_;
   std::atomic<size_t> committed_code_space_{0};
   int modification_scope_depth_ = 0;
@@ -443,7 +444,6 @@ class V8_EXPORT_PRIVATE WasmCodeManager final {
 
   NativeModule* LookupNativeModule(Address pc) const;
   WasmCode* LookupCode(Address pc) const;
-  WasmCode* GetCodeFromStartAddress(Address pc) const;
   size_t remaining_uncommitted_code_space() const;
 
   // Add a sample of all module sizes.
@@ -459,22 +459,30 @@ class V8_EXPORT_PRIVATE WasmCodeManager final {
  private:
   friend class NativeModule;
 
-  void TryAllocate(size_t size, VirtualMemory*, void* hint = nullptr);
+  V8_WARN_UNUSED_RESULT VirtualMemory TryAllocate(size_t size,
+                                                  void* hint = nullptr);
   bool Commit(Address, size_t);
   // Currently, we uncommit a whole module, so all we need is account
   // for the freed memory size. We do that in FreeNativeModule.
   // There's no separate Uncommit.
 
   void FreeNativeModule(NativeModule*);
-  void Free(VirtualMemory* mem);
   void AssignRanges(Address start, Address end, NativeModule*);
+  void AssignRangesAndAddModule(Address start, Address end, NativeModule*);
   bool ShouldForceCriticalMemoryPressureNotification();
 
   WasmMemoryTracker* const memory_tracker_;
+  std::atomic<size_t> remaining_uncommitted_code_space_;
   mutable base::Mutex native_modules_mutex_;
+
+  //////////////////////////////////////////////////////////////////////////////
+  // Protected by {native_modules_mutex_}:
+
   std::map<Address, std::pair<Address, NativeModule*>> lookup_map_;
   std::unordered_set<NativeModule*> native_modules_;
-  std::atomic<size_t> remaining_uncommitted_code_space_;
+
+  // End of fields protected by {native_modules_mutex_}.
+  //////////////////////////////////////////////////////////////////////////////
 
   DISALLOW_COPY_AND_ASSIGN(WasmCodeManager);
 };
diff --git a/deps/v8/src/wasm/wasm-constants.h b/deps/v8/src/wasm/wasm-constants.h
index 70794fc7ab..8e1f508979 100644
--- a/deps/v8/src/wasm/wasm-constants.h
+++ b/deps/v8/src/wasm/wasm-constants.h
@@ -25,7 +25,8 @@ enum ValueTypeCode : uint8_t {
   kLocalF64 = 0x7c,
   kLocalS128 = 0x7b,
   kLocalAnyFunc = 0x70,
-  kLocalAnyRef = 0x6f
+  kLocalAnyRef = 0x6f,
+  kLocalExceptRef = 0x68,
 };
 // Binary encoding of other types.
 constexpr uint8_t kWasmFunctionTypeCode = 0x60;
@@ -35,7 +36,8 @@ enum ImportExportKindCode : uint8_t {
   kExternalFunction = 0,
   kExternalTable = 1,
   kExternalMemory = 2,
-  kExternalGlobal = 3
+  kExternalGlobal = 3,
+  kExternalException = 4
 };
 
 // Binary encoding of maximum and shared flags for memories.
@@ -64,10 +66,12 @@ enum SectionCode : int8_t {
   kDataSectionCode = 11,       // Data segments
   kNameSectionCode = 12,       // Name section (encoded as a string)
   kExceptionSectionCode = 13,  // Exception section
+  kSourceMappingURLSectionCode = 14,  // Source Map URL section
 
   // Helper values
   kFirstSectionInModule = kTypeSectionCode,
-  kLastKnownModuleSection = kExceptionSectionCode,
+  kLastKnownModuleSection = kSourceMappingURLSectionCode,
+  kFirstUnorderedSection = kNameSectionCode,
 };
 
 // Binary encoding of name section kinds.
@@ -75,7 +79,7 @@ enum NameSectionKindCode : uint8_t { kModule = 0, kFunction = 1, kLocal = 2 };
 
 constexpr size_t kWasmPageSize = 0x10000;
 constexpr uint32_t kWasmPageSizeLog2 = 16;
-constexpr int kInvalidExceptionTag = -1;
+static_assert(kWasmPageSize == size_t{1} << kWasmPageSizeLog2, "consistency");
 
 // TODO(wasm): Wrap WasmCodePosition in a struct.
 using WasmCodePosition = int;
diff --git a/deps/v8/src/wasm/wasm-debug.cc b/deps/v8/src/wasm/wasm-debug.cc
index 0d8b1f18aa..425681a5e1 100644
--- a/deps/v8/src/wasm/wasm-debug.cc
+++ b/deps/v8/src/wasm/wasm-debug.cc
@@ -138,11 +138,10 @@ class InterpreterHandle {
   }
 
  public:
-  // TODO(wasm): properly handlify this constructor.
-  InterpreterHandle(Isolate* isolate, WasmDebugInfo* debug_info)
+  InterpreterHandle(Isolate* isolate, Handle<WasmDebugInfo> debug_info)
       : isolate_(isolate),
         module_(debug_info->wasm_instance()->module_object()->module()),
-        interpreter_(isolate, module_, GetBytes(debug_info),
+        interpreter_(isolate, module_, GetBytes(*debug_info),
                      handle(debug_info->wasm_instance(), isolate)) {}
 
   ~InterpreterHandle() { DCHECK_EQ(0, activations_.size()); }
@@ -416,10 +415,8 @@ class InterpreterHandle {
           STATIC_CHAR_VECTOR("memory"));
       Handle<JSArrayBuffer> memory_buffer(
           instance->memory_object()->array_buffer(), isolate_);
-      uint32_t byte_length;
-      CHECK(memory_buffer->byte_length()->ToUint32(&byte_length));
       Handle<JSTypedArray> uint8_array = isolate_->factory()->NewJSTypedArray(
-          kExternalUint8Array, memory_buffer, 0, byte_length);
+          kExternalUint8Array, memory_buffer, 0, memory_buffer->byte_length());
       JSObject::SetOwnPropertyIgnoreAttributes(global_scope_object, name,
                                                uint8_array, NONE)
           .Assert();
@@ -535,7 +532,7 @@ wasm::InterpreterHandle* GetOrCreateInterpreterHandle(
     // of the stack.
     size_t interpreter_size = FLAG_stack_size * KB * 2;
     handle = Managed<wasm::InterpreterHandle>::Allocate(
-        isolate, interpreter_size, isolate, *debug_info);
+        isolate, interpreter_size, isolate, debug_info);
     debug_info->set_interpreter_handle(*handle);
   }
 
@@ -556,16 +553,17 @@ wasm::InterpreterHandle* GetInterpreterHandleOrNull(WasmDebugInfo* debug_info) {
 
 Handle<FixedArray> GetOrCreateInterpretedFunctions(
     Isolate* isolate, Handle<WasmDebugInfo> debug_info) {
-  Handle<Object> obj(debug_info->interpreted_functions(), isolate);
-  if (!obj->IsUndefined(isolate)) return Handle<FixedArray>::cast(obj);
-
+  Handle<FixedArray> arr(debug_info->interpreted_functions(), isolate);
   int num_functions = debug_info->wasm_instance()
                           ->module_object()
                           ->native_module()
                           ->num_functions();
-  Handle<FixedArray> new_arr = isolate->factory()->NewFixedArray(num_functions);
-  debug_info->set_interpreted_functions(*new_arr);
-  return new_arr;
+  if (arr->length() == 0 && num_functions > 0) {
+    arr = isolate->factory()->NewFixedArray(num_functions);
+    debug_info->set_interpreted_functions(*arr);
+  }
+  DCHECK_EQ(num_functions, arr->length());
+  return arr;
 }
 
 }  // namespace
@@ -576,6 +574,7 @@ Handle<WasmDebugInfo> WasmDebugInfo::New(Handle<WasmInstanceObject> instance) {
   Handle<WasmDebugInfo> debug_info = Handle<WasmDebugInfo>::cast(
       factory->NewStruct(WASM_DEBUG_INFO_TYPE, TENURED));
   debug_info->set_wasm_instance(*instance);
+  debug_info->set_interpreted_functions(*factory->empty_fixed_array());
   instance->set_debug_info(*debug_info);
   return debug_info;
 }
@@ -590,7 +589,7 @@ wasm::WasmInterpreter* WasmDebugInfo::SetupForTesting(
   // account for the growing strategy for the backing store of the stack.
   size_t interpreter_size = FLAG_stack_size * KB * 2;
   auto interp_handle = Managed<wasm::InterpreterHandle>::Allocate(
-      isolate, interpreter_size, isolate, *debug_info);
+      isolate, interpreter_size, isolate, debug_info);
   debug_info->set_interpreter_handle(*interp_handle);
   auto ret = interp_handle->raw()->interpreter();
   ret->SetCallIndirectTestMode();
diff --git a/deps/v8/src/wasm/wasm-engine.cc b/deps/v8/src/wasm/wasm-engine.cc
index 4f772d9bdd..dc78797365 100644
--- a/deps/v8/src/wasm/wasm-engine.cc
+++ b/deps/v8/src/wasm/wasm-engine.cc
@@ -24,6 +24,8 @@ WasmEngine::WasmEngine()
 WasmEngine::~WasmEngine() {
   // All AsyncCompileJobs have been canceled.
   DCHECK(jobs_.empty());
+  // All Isolates have been deregistered.
+  DCHECK(isolates_.empty());
 }
 
 bool WasmEngine::SyncValidate(Isolate* isolate, const WasmFeatures& enabled,
@@ -189,9 +191,11 @@ Handle<WasmModuleObject> WasmEngine::ImportNativeModule(
     Isolate* isolate, std::shared_ptr<NativeModule> shared_module) {
   CHECK_EQ(code_manager(), shared_module->code_manager());
   Vector<const byte> wire_bytes = shared_module->wire_bytes();
-  Handle<Script> script = CreateWasmScript(isolate, wire_bytes);
+  const WasmModule* module = shared_module->module();
+  Handle<Script> script =
+      CreateWasmScript(isolate, wire_bytes, module->source_map_url);
   Handle<WasmModuleObject> module_object =
-      WasmModuleObject::New(isolate, shared_module, script);
+      WasmModuleObject::New(isolate, std::move(shared_module), script);
 
   // TODO(6792): Wrappers below might be cloned using {Factory::CopyCode}.
   // This requires unlocking the code space here. This should eventually be
@@ -249,6 +253,7 @@ std::unique_ptr<AsyncCompileJob> WasmEngine::RemoveCompileJob(
 
 bool WasmEngine::HasRunningCompileJob(Isolate* isolate) {
   base::LockGuard<base::Mutex> guard(&mutex_);
+  DCHECK_EQ(1, isolates_.count(isolate));
   for (auto& entry : jobs_) {
     if (entry.first->isolate() == isolate) return true;
   }
@@ -257,6 +262,7 @@ bool WasmEngine::HasRunningCompileJob(Isolate* isolate) {
 
 void WasmEngine::DeleteCompileJobsOnIsolate(Isolate* isolate) {
   base::LockGuard<base::Mutex> guard(&mutex_);
+  DCHECK_EQ(1, isolates_.count(isolate));
   for (auto it = jobs_.begin(); it != jobs_.end();) {
     if (it->first->isolate() == isolate) {
       it = jobs_.erase(it);
@@ -266,6 +272,18 @@ void WasmEngine::DeleteCompileJobsOnIsolate(Isolate* isolate) {
   }
 }
 
+void WasmEngine::AddIsolate(Isolate* isolate) {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+  DCHECK_EQ(0, isolates_.count(isolate));
+  isolates_.insert(isolate);
+}
+
+void WasmEngine::RemoveIsolate(Isolate* isolate) {
+  base::LockGuard<base::Mutex> guard(&mutex_);
+  DCHECK_EQ(1, isolates_.count(isolate));
+  isolates_.erase(isolate);
+}
+
 namespace {
 
 struct WasmEnginePointerConstructTrait final {
@@ -284,16 +302,19 @@ base::LazyStaticInstance<std::shared_ptr<WasmEngine>,
 
 }  // namespace
 
+// static
 void WasmEngine::InitializeOncePerProcess() {
   if (!FLAG_wasm_shared_engine) return;
   global_wasm_engine.Pointer()->reset(new WasmEngine());
 }
 
+// static
 void WasmEngine::GlobalTearDown() {
   if (!FLAG_wasm_shared_engine) return;
   global_wasm_engine.Pointer()->reset();
 }
 
+// static
 std::shared_ptr<WasmEngine> WasmEngine::GetWasmEngine() {
   if (FLAG_wasm_shared_engine) return global_wasm_engine.Get();
   return std::shared_ptr<WasmEngine>(new WasmEngine());
diff --git a/deps/v8/src/wasm/wasm-engine.h b/deps/v8/src/wasm/wasm-engine.h
index 66c12404b7..4f4cddb550 100644
--- a/deps/v8/src/wasm/wasm-engine.h
+++ b/deps/v8/src/wasm/wasm-engine.h
@@ -6,6 +6,7 @@
 #define V8_WASM_WASM_ENGINE_H_
 
 #include <memory>
+#include <unordered_set>
 
 #include "src/wasm/wasm-code-manager.h"
 #include "src/wasm/wasm-memory.h"
@@ -30,14 +31,14 @@ class V8_EXPORT_PRIVATE CompilationResultResolver {
  public:
   virtual void OnCompilationSucceeded(Handle<WasmModuleObject> result) = 0;
   virtual void OnCompilationFailed(Handle<Object> error_reason) = 0;
-  virtual ~CompilationResultResolver() {}
+  virtual ~CompilationResultResolver() = default;
 };
 
 class V8_EXPORT_PRIVATE InstantiationResultResolver {
  public:
   virtual void OnInstantiationSucceeded(Handle<WasmInstanceObject> result) = 0;
   virtual void OnInstantiationFailed(Handle<Object> error_reason) = 0;
-  virtual ~InstantiationResultResolver() {}
+  virtual ~InstantiationResultResolver() = default;
 };
 
 // The central data structure that represents an engine instance capable of
@@ -135,6 +136,10 @@ class V8_EXPORT_PRIVATE WasmEngine {
   // for tearing down an isolate, or to clean it up to be reused.
   void DeleteCompileJobsOnIsolate(Isolate* isolate);
 
+  // Manage the set of Isolates that use this WasmEngine.
+  void AddIsolate(Isolate* isolate);
+  void RemoveIsolate(Isolate* isolate);
+
   // Call on process start and exit.
   static void InitializeOncePerProcess();
   static void GlobalTearDown();
@@ -168,6 +173,9 @@ class V8_EXPORT_PRIVATE WasmEngine {
   std::unique_ptr<CompilationStatistics> compilation_stats_;
   std::unique_ptr<CodeTracer> code_tracer_;
 
+  // Set of isolates which use this WasmEngine. Used for cross-isolate GCs.
+  std::unordered_set<Isolate*> isolates_;
+
   // End of fields protected by {mutex_}.
   //////////////////////////////////////////////////////////////////////////////
 
diff --git a/deps/v8/src/wasm/wasm-interpreter.cc b/deps/v8/src/wasm/wasm-interpreter.cc
index 0c7fb25b67..e724e73078 100644
--- a/deps/v8/src/wasm/wasm-interpreter.cc
+++ b/deps/v8/src/wasm/wasm-interpreter.cc
@@ -641,6 +641,8 @@ const char* OpcodeName(uint32_t val) {
   return WasmOpcodes::OpcodeName(static_cast<WasmOpcode>(val));
 }
 
+}  // namespace
+
 class SideTable;
 
 // Code and metadata needed to execute a function.
@@ -902,32 +904,6 @@ class SideTable : public ZoneObject {
   }
 };
 
-struct ExternalCallResult {
-  enum Type {
-    // The function should be executed inside this interpreter.
-    INTERNAL,
-    // For indirect calls: Table or function does not exist.
-    INVALID_FUNC,
-    // For indirect calls: Signature does not match expected signature.
-    SIGNATURE_MISMATCH,
-    // The function was executed and returned normally.
-    EXTERNAL_RETURNED,
-    // The function was executed, threw an exception, and the stack was unwound.
-    EXTERNAL_UNWOUND
-  };
-  Type type;
-  // If type is INTERNAL, this field holds the function to call internally.
-  InterpreterCode* interpreter_code;
-
-  ExternalCallResult(Type type) : type(type) {  // NOLINT
-    DCHECK_NE(INTERNAL, type);
-  }
-  ExternalCallResult(Type type, InterpreterCode* code)
-      : type(type), interpreter_code(code) {
-    DCHECK_EQ(INTERNAL, type);
-  }
-};
-
 // The main storage for interpreter code. It maps {WasmFunction} to the
 // metadata needed to execute each function.
 class CodeMap {
@@ -1037,6 +1013,34 @@ class CodeMap {
   }
 };
 
+namespace {
+
+struct ExternalCallResult {
+  enum Type {
+    // The function should be executed inside this interpreter.
+    INTERNAL,
+    // For indirect calls: Table or function does not exist.
+    INVALID_FUNC,
+    // For indirect calls: Signature does not match expected signature.
+    SIGNATURE_MISMATCH,
+    // The function was executed and returned normally.
+    EXTERNAL_RETURNED,
+    // The function was executed, threw an exception, and the stack was unwound.
+    EXTERNAL_UNWOUND
+  };
+  Type type;
+  // If type is INTERNAL, this field holds the function to call internally.
+  InterpreterCode* interpreter_code;
+
+  ExternalCallResult(Type type) : type(type) {  // NOLINT
+    DCHECK_NE(INTERNAL, type);
+  }
+  ExternalCallResult(Type type, InterpreterCode* code)
+      : type(type), interpreter_code(code) {
+    DCHECK_EQ(INTERNAL, type);
+  }
+};
+
 // Like a static_cast from src to dst, but specialized for boxed floats.
 template <typename dst, typename src>
 struct converter {
@@ -1073,6 +1077,8 @@ V8_INLINE bool has_nondeterminism<double>(double val) {
   return std::isnan(val);
 }
 
+}  // namespace
+
 // Responsible for executing code directly.
 class ThreadImpl {
   struct Activation {
@@ -1426,7 +1432,7 @@ class ThreadImpl {
     Push(result);
     len = 1 + imm.length;
 
-    if (FLAG_wasm_trace_memory) {
+    if (FLAG_trace_wasm_memory) {
       MemoryTracingInfo info(imm.offset + index, false, rep);
       TraceMemoryOperation(ExecutionTier::kInterpreter, &info,
                            code->function->func_index, static_cast<int>(pc),
@@ -1452,7 +1458,7 @@ class ThreadImpl {
     WriteLittleEndianValue<mtype>(addr, converter<mtype, ctype>{}(val));
     len = 1 + imm.length;
 
-    if (FLAG_wasm_trace_memory) {
+    if (FLAG_trace_wasm_memory) {
       MemoryTracingInfo info(imm.offset + index, true, rep);
       TraceMemoryOperation(ExecutionTier::kInterpreter, &info,
                            code->function->func_index, static_cast<int>(pc),
@@ -2762,17 +2768,19 @@ class ThreadImpl {
       arg_buffer.resize(return_size);
     }
 
-    // Wrap the arg_buffer data pointer in a handle. As
-    // this is an aligned pointer, to the GC it will look like a Smi.
+    // Wrap the arg_buffer and the code target data pointers in handles. As
+    // these are aligned pointers, to the GC it will look like Smis.
     Handle<Object> arg_buffer_obj(reinterpret_cast<Object*>(arg_buffer.data()),
                                   isolate);
     DCHECK(!arg_buffer_obj->IsHeapObject());
+    Handle<Object> code_entry_obj(
+        reinterpret_cast<Object*>(code->instruction_start()), isolate);
+    DCHECK(!code_entry_obj->IsHeapObject());
 
     static_assert(compiler::CWasmEntryParameters::kNumParameters == 3,
                   "code below needs adaption");
     Handle<Object> args[compiler::CWasmEntryParameters::kNumParameters];
-    args[compiler::CWasmEntryParameters::kCodeObject] = Handle<Object>::cast(
-        isolate->factory()->NewForeign(code->instruction_start(), TENURED));
+    args[compiler::CWasmEntryParameters::kCodeEntry] = code_entry_obj;
     args[compiler::CWasmEntryParameters::kWasmInstance] = instance;
     args[compiler::CWasmEntryParameters::kArgumentsBuffer] = arg_buffer_obj;
 
@@ -2983,6 +2991,8 @@ class InterpretedFrameImpl {
   }
 };
 
+namespace {
+
 // Converters between WasmInterpreter::Thread and WasmInterpreter::ThreadImpl.
 // Thread* is the public interface, without knowledge of the object layout.
 // This cast is potentially risky, but as long as we always cast it back before
@@ -3090,20 +3100,21 @@ class WasmInterpreterInternals : public ZoneObject {
 };
 
 namespace {
-// TODO(wasm): a finalizer is only required to delete the global handle.
-void GlobalHandleDeleter(const v8::WeakCallbackInfo<void>& data) {
-  GlobalHandles::Destroy(reinterpret_cast<Object**>(
-      reinterpret_cast<JSObject**>(data.GetParameter())));
+void NopFinalizer(const v8::WeakCallbackInfo<void>& data) {
+  Object** global_handle_location =
+      reinterpret_cast<Object**>(data.GetParameter());
+  GlobalHandles::Destroy(global_handle_location);
 }
 
 Handle<WasmInstanceObject> MakeWeak(
     Isolate* isolate, Handle<WasmInstanceObject> instance_object) {
-  Handle<Object> handle = isolate->global_handles()->Create(*instance_object);
-  // TODO(wasm): use a phantom handle in the WasmInterpreter.
-  GlobalHandles::MakeWeak(handle.location(), handle.location(),
-                          &GlobalHandleDeleter,
-                          v8::WeakCallbackType::kFinalizer);
-  return Handle<WasmInstanceObject>::cast(handle);
+  Handle<WasmInstanceObject> weak_instance =
+      isolate->global_handles()->Create<WasmInstanceObject>(*instance_object);
+  Object** global_handle_location =
+      Handle<Object>::cast(weak_instance).location();
+  GlobalHandles::MakeWeak(global_handle_location, global_handle_location,
+                          &NopFinalizer, v8::WeakCallbackType::kParameter);
+  return weak_instance;
 }
 }  // namespace
 
diff --git a/deps/v8/src/wasm/wasm-interpreter.h b/deps/v8/src/wasm/wasm-interpreter.h
index 896196ef67..31021a5d4e 100644
--- a/deps/v8/src/wasm/wasm-interpreter.h
+++ b/deps/v8/src/wasm/wasm-interpreter.h
@@ -208,7 +208,7 @@ class V8_EXPORT_PRIVATE WasmInterpreter {
 
  private:
   Zone zone_;
-  WasmInterpreterInternals* const internals_;
+  WasmInterpreterInternals* internals_;
 };
 
 }  // namespace wasm
diff --git a/deps/v8/src/wasm/wasm-js.cc b/deps/v8/src/wasm/wasm-js.cc
index 1a20b88f10..314db914ed 100644
--- a/deps/v8/src/wasm/wasm-js.cc
+++ b/deps/v8/src/wasm/wasm-js.cc
@@ -212,7 +212,7 @@ class AsyncCompilationResolver : public i::wasm::CompilationResultResolver {
   AsyncCompilationResolver(i::Isolate* isolate, i::Handle<i::JSPromise> promise)
       : promise_(isolate->global_handles()->Create(*promise)) {}
 
-  ~AsyncCompilationResolver() {
+  ~AsyncCompilationResolver() override {
     i::GlobalHandles::Destroy(i::Handle<i::Object>::cast(promise_).location());
   }
 
@@ -248,7 +248,7 @@ class InstantiateModuleResultResolver
                                   i::Handle<i::JSPromise> promise)
       : promise_(isolate->global_handles()->Create(*promise)) {}
 
-  ~InstantiateModuleResultResolver() {
+  ~InstantiateModuleResultResolver() override {
     i::GlobalHandles::Destroy(i::Handle<i::Object>::cast(promise_).location());
   }
 
@@ -284,7 +284,7 @@ class InstantiateBytesResultResolver
         promise_(isolate_->global_handles()->Create(*promise)),
         module_(isolate_->global_handles()->Create(*module)) {}
 
-  ~InstantiateBytesResultResolver() {
+  ~InstantiateBytesResultResolver() override {
     i::GlobalHandles::Destroy(i::Handle<i::Object>::cast(promise_).location());
     i::GlobalHandles::Destroy(i::Handle<i::Object>::cast(module_).location());
   }
@@ -349,7 +349,7 @@ class AsyncInstantiateCompileResultResolver
                            : isolate_->global_handles()->Create(
                                  *maybe_imports.ToHandleChecked())) {}
 
-  ~AsyncInstantiateCompileResultResolver() {
+  ~AsyncInstantiateCompileResultResolver() override {
     i::GlobalHandles::Destroy(i::Handle<i::Object>::cast(promise_).location());
     if (!maybe_imports_.is_null()) {
       i::GlobalHandles::Destroy(
@@ -956,7 +956,7 @@ void WebAssemblyMemory(const v8::FunctionCallbackInfo<v8::Value>& args) {
       v8::MaybeLocal<v8::Value> maybe = descriptor->Get(context, shared_key);
       v8::Local<v8::Value> value;
       if (maybe.ToLocal(&value)) {
-        if (!value->BooleanValue(context).To(&is_shared_memory)) return;
+        is_shared_memory = value->BooleanValue(isolate);
       }
     }
     // Throw TypeError if shared is true, and the descriptor has no "maximum"
@@ -1012,7 +1012,7 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
     v8::MaybeLocal<v8::Value> maybe = descriptor->Get(context, mutable_key);
     v8::Local<v8::Value> value;
     if (maybe.ToLocal(&value)) {
-      if (!value->BooleanValue(context).To(&is_mutable)) return;
+      is_mutable = value->BooleanValue(isolate);
     }
   }
 
@@ -1095,6 +1095,15 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
   args.GetReturnValue().Set(Utils::ToLocal(global_js_object));
 }
 
+// WebAssembly.Exception
+void WebAssemblyException(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  v8::Isolate* isolate = args.GetIsolate();
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  HandleScope scope(isolate);
+  ScheduledErrorThrower thrower(i_isolate, "WebAssembly.Excepion()");
+  thrower.TypeError("WebAssembly.Exception cannot be called");
+}
+
 constexpr const char* kName_WasmGlobalObject = "WebAssembly.Global";
 constexpr const char* kName_WasmMemoryObject = "WebAssembly.Memory";
 constexpr const char* kName_WasmInstanceObject = "WebAssembly.Instance";
@@ -1250,8 +1259,7 @@ void WebAssemblyMemoryGrow(const v8::FunctionCallbackInfo<v8::Value>& args) {
     thrower.RangeError("This memory cannot be grown");
     return;
   }
-  uint32_t old_size =
-      old_buffer->byte_length()->Number() / i::wasm::kWasmPageSize;
+  int64_t old_size = old_buffer->byte_length() / i::wasm::kWasmPageSize;
   int64_t new_size64 = old_size + delta_size;
   if (delta_size < 0 || max_size64 < new_size64 || new_size64 < old_size) {
     thrower.RangeError(new_size64 < old_size ? "trying to shrink memory"
@@ -1580,11 +1588,11 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
   JSObject::AddProperty(isolate, memory_proto, factory->to_string_tag_symbol(),
                         v8_str(isolate, "WebAssembly.Memory"), ro_attributes);
 
-  // Setup Global
-
   // The context is not set up completely yet. That's why we cannot use
   // {WasmFeaturesFromIsolate} and have to use {WasmFeaturesFromFlags} instead.
   auto enabled_features = i::wasm::WasmFeaturesFromFlags();
+
+  // Setup Global
   if (enabled_features.mut_global) {
     Handle<JSFunction> global_constructor =
         InstallFunc(isolate, webassembly, "Global", WebAssemblyGlobal, 1);
@@ -1604,6 +1612,21 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
                           v8_str(isolate, "WebAssembly.Global"), ro_attributes);
   }
 
+  // Setup Exception
+  if (enabled_features.eh) {
+    Handle<JSFunction> exception_constructor =
+        InstallFunc(isolate, webassembly, "Exception", WebAssemblyException, 1);
+    context->set_wasm_exception_constructor(*exception_constructor);
+    SetDummyInstanceTemplate(isolate, exception_constructor);
+    JSFunction::EnsureHasInitialMap(exception_constructor);
+    Handle<JSObject> exception_proto(
+        JSObject::cast(exception_constructor->instance_prototype()), isolate);
+    i::Handle<i::Map> exception_map = isolate->factory()->NewMap(
+        i::WASM_EXCEPTION_TYPE, WasmExceptionObject::kSize);
+    JSFunction::SetInitialMap(exception_constructor, exception_map,
+                              exception_proto);
+  }
+
   // Setup errors
   attributes = static_cast<PropertyAttributes>(DONT_ENUM);
   Handle<JSFunction> compile_error(
diff --git a/deps/v8/src/wasm/wasm-linkage.h b/deps/v8/src/wasm/wasm-linkage.h
index 92390cc556..6f022207bf 100644
--- a/deps/v8/src/wasm/wasm-linkage.h
+++ b/deps/v8/src/wasm/wasm-linkage.h
@@ -40,6 +40,7 @@ constexpr DoubleRegister kFpReturnRegisters[] = {xmm1, xmm2};
 // ===========================================================================
 constexpr Register kGpParamRegisters[] = {r3, r0, r1, r2};
 constexpr Register kGpReturnRegisters[] = {r0, r1};
+// ARM d-registers must be in ascending order for correct allocation.
 constexpr DoubleRegister kFpParamRegisters[] = {d0, d1, d2, d3, d4, d5, d6, d7};
 constexpr DoubleRegister kFpReturnRegisters[] = {d0, d1};
 
@@ -129,9 +130,11 @@ class LinkageAllocator {
 #if V8_TARGET_ARCH_ARM
     switch (rep) {
       case MachineRepresentation::kFloat32:
-        return extra_float_reg >= 0 || fp_offset_ < fp_count_;
+        return extra_float_reg_ >= 0 ||
+               (extra_double_reg_ >= 0 && extra_double_reg_ < 16) ||
+               (fp_offset_ < fp_count_ && fp_regs_[fp_offset_].code() < 16);
       case MachineRepresentation::kFloat64:
-        return extra_double_reg >= 0 || fp_offset_ < fp_count_;
+        return extra_double_reg_ >= 0 || fp_offset_ < fp_count_;
       case MachineRepresentation::kSimd128:
         return ((fp_offset_ + 1) & ~1) + 1 < fp_count_;
       default:
@@ -151,10 +154,10 @@ class LinkageAllocator {
 #if V8_TARGET_ARCH_ARM
     switch (rep) {
       case MachineRepresentation::kFloat32: {
-        // Use the extra S-register if we can.
-        if (extra_float_reg >= 0) {
-          int reg_code = extra_float_reg;
-          extra_float_reg = -1;
+        // Use the extra S-register if there is one.
+        if (extra_float_reg_ >= 0) {
+          int reg_code = extra_float_reg_;
+          extra_float_reg_ = -1;
           return reg_code;
         }
         // Allocate a D-register and split into 2 float registers.
@@ -162,15 +165,15 @@ class LinkageAllocator {
         DCHECK_GT(16, d_reg_code);  // D-registers 16 - 31 can't split.
         int reg_code = d_reg_code * 2;
         // Save the extra S-register.
-        DCHECK_EQ(-1, extra_float_reg);
-        extra_float_reg = reg_code + 1;
+        DCHECK_EQ(-1, extra_float_reg_);
+        extra_float_reg_ = reg_code + 1;
         return reg_code;
       }
       case MachineRepresentation::kFloat64: {
-        // Use an extra D-register if we can.
-        if (extra_double_reg >= 0) {
-          int reg_code = extra_double_reg;
-          extra_double_reg = -1;
+        // Use the extra D-register if there is one.
+        if (extra_double_reg_ >= 0) {
+          int reg_code = extra_double_reg_;
+          extra_double_reg_ = -1;
           return reg_code;
         }
         DCHECK_LT(fp_offset_, fp_count_);
@@ -178,16 +181,16 @@ class LinkageAllocator {
       }
       case MachineRepresentation::kSimd128: {
         // Q-register must be an even-odd pair, so we must try to allocate at
-        // the end, not using extra_double_reg. If we are at an odd D-register,
-        // skip past it (saving it to extra_double_reg).
+        // the end, not using extra_double_reg_. If we are at an odd D-register,
+        // skip past it (saving it to extra_double_reg_).
         DCHECK_LT(((fp_offset_ + 1) & ~1) + 1, fp_count_);
         int d_reg1_code = fp_regs_[fp_offset_++].code();
         if (d_reg1_code % 2 != 0) {
-          // If we're misaligned then extra_double_reg must have been consumed.
-          DCHECK_EQ(-1, extra_double_reg);
+          // If we're misaligned then extra_double_reg_ must have been consumed.
+          DCHECK_EQ(-1, extra_double_reg_);
           int odd_double_reg = d_reg1_code;
           d_reg1_code = fp_regs_[fp_offset_++].code();
-          extra_double_reg = odd_double_reg;
+          extra_double_reg_ = odd_double_reg;
         }
         // Combine the current D-register with the next to form a Q-register.
         int d_reg2_code = fp_regs_[fp_offset_++].code();
@@ -244,8 +247,8 @@ class LinkageAllocator {
   // ARM FP register aliasing may require splitting or merging double registers.
   // Track fragments of registers below fp_offset_ here. There can only be one
   // extra float and double register.
-  int extra_float_reg = -1;
-  int extra_double_reg = -1;
+  int extra_float_reg_ = -1;
+  int extra_double_reg_ = -1;
 #endif
 
   int stack_offset_ = 0;
diff --git a/deps/v8/src/wasm/wasm-memory.cc b/deps/v8/src/wasm/wasm-memory.cc
index f7cc70a9e7..cf18817bb1 100644
--- a/deps/v8/src/wasm/wasm-memory.cc
+++ b/deps/v8/src/wasm/wasm-memory.cc
@@ -27,28 +27,14 @@ void AddAllocationStatusSample(Isolate* isolate,
 }
 
 void* TryAllocateBackingStore(WasmMemoryTracker* memory_tracker, Heap* heap,
-                              size_t size, bool require_full_guard_regions,
-                              void** allocation_base,
+                              size_t size, void** allocation_base,
                               size_t* allocation_length) {
   using AllocationStatus = WasmMemoryTracker::AllocationStatus;
-#if V8_TARGET_ARCH_32_BIT
-  DCHECK(!require_full_guard_regions);
+#if V8_TARGET_ARCH_64_BIT
+  bool require_full_guard_regions = true;
+#else
+  bool require_full_guard_regions = false;
 #endif
-  // We always allocate the largest possible offset into the heap, so the
-  // addressable memory after the guard page can be made inaccessible.
-  //
-  // To protect against 32-bit integer overflow issues, we also protect the 2GiB
-  // before the valid part of the memory buffer.
-  // TODO(7881): do not use static_cast<uint32_t>() here
-  *allocation_length =
-      require_full_guard_regions
-          ? RoundUp(kWasmMaxHeapOffset + kNegativeGuardSize, CommitPageSize())
-          : RoundUp(
-                base::bits::RoundUpToPowerOfTwo32(static_cast<uint32_t>(size)),
-                kWasmPageSize);
-  DCHECK_GE(*allocation_length, size);
-  DCHECK_GE(*allocation_length, kWasmPageSize);
-
   // Let the WasmMemoryTracker know we are going to reserve a bunch of
   // address space.
   // Try up to three times; getting rid of dead JSArrayBuffer allocations might
@@ -57,16 +43,43 @@ void* TryAllocateBackingStore(WasmMemoryTracker* memory_tracker, Heap* heap,
   static constexpr int kAllocationRetries = 2;
   bool did_retry = false;
   for (int trial = 0;; ++trial) {
-    if (memory_tracker->ReserveAddressSpace(*allocation_length)) break;
+    // For guard regions, we always allocate the largest possible offset into
+    // the heap, so the addressable memory after the guard page can be made
+    // inaccessible.
+    //
+    // To protect against 32-bit integer overflow issues, we also protect the
+    // 2GiB before the valid part of the memory buffer.
+    // TODO(7881): do not use static_cast<uint32_t>() here
+    *allocation_length =
+        require_full_guard_regions
+            ? RoundUp(kWasmMaxHeapOffset + kNegativeGuardSize, CommitPageSize())
+            : RoundUp(base::bits::RoundUpToPowerOfTwo32(
+                          static_cast<uint32_t>(size)),
+                      kWasmPageSize);
+    DCHECK_GE(*allocation_length, size);
+    DCHECK_GE(*allocation_length, kWasmPageSize);
+
+    auto limit = require_full_guard_regions ? WasmMemoryTracker::kSoftLimit
+                                            : WasmMemoryTracker::kHardLimit;
+    if (memory_tracker->ReserveAddressSpace(*allocation_length, limit)) break;
+
     did_retry = true;
     // After first and second GC: retry.
     if (trial == kAllocationRetries) {
+      // If we fail to allocate guard regions and the fallback is enabled, then
+      // retry without full guard regions.
+      if (require_full_guard_regions && FLAG_wasm_trap_handler_fallback) {
+        require_full_guard_regions = false;
+        --trial;  // one more try.
+        continue;
+      }
+
       // We are over the address space limit. Fail.
       //
       // When running under the correctness fuzzer (i.e.
-      // --abort-on-stack-or-string-length-overflow is preset), we crash instead
-      // so it is not incorrectly reported as a correctness violation. See
-      // https://crbug.com/828293#c4
+      // --abort-on-stack-or-string-length-overflow is preset), we crash
+      // instead so it is not incorrectly reported as a correctness
+      // violation. See https://crbug.com/828293#c4
       if (FLAG_abort_on_stack_or_string_length_overflow) {
         FATAL("could not allocate wasm memory");
       }
@@ -81,8 +94,9 @@ void* TryAllocateBackingStore(WasmMemoryTracker* memory_tracker, Heap* heap,
   // The Reserve makes the whole region inaccessible by default.
   DCHECK_NULL(*allocation_base);
   for (int trial = 0;; ++trial) {
-    *allocation_base = AllocatePages(nullptr, *allocation_length, kWasmPageSize,
-                                     PageAllocator::kNoAccess);
+    *allocation_base =
+        AllocatePages(GetPlatformPageAllocator(), nullptr, *allocation_length,
+                      kWasmPageSize, PageAllocator::kNoAccess);
     if (*allocation_base != nullptr) break;
     if (trial == kAllocationRetries) {
       memory_tracker->ReleaseReservation(*allocation_length);
@@ -99,8 +113,9 @@ void* TryAllocateBackingStore(WasmMemoryTracker* memory_tracker, Heap* heap,
 
   // Make the part we care about accessible.
   if (size > 0) {
-    bool result = SetPermissions(memory, RoundUp(size, kWasmPageSize),
-                                 PageAllocator::kReadWrite);
+    bool result =
+        SetPermissions(GetPlatformPageAllocator(), memory,
+                       RoundUp(size, kWasmPageSize), PageAllocator::kReadWrite);
     // SetPermissions commits the extra memory, which may put us over the
     // process memory limit. If so, report this as an OOM.
     if (!result) {
@@ -115,6 +130,20 @@ void* TryAllocateBackingStore(WasmMemoryTracker* memory_tracker, Heap* heap,
                                       : AllocationStatus::kSuccess);
   return memory;
 }
+
+#if V8_TARGET_ARCH_MIPS64
+// MIPS64 has a user space of 2^40 bytes on most processors,
+// address space limits needs to be smaller.
+constexpr size_t kAddressSpaceSoftLimit = 0x2100000000L;  // 132 GiB
+constexpr size_t kAddressSpaceHardLimit = 0x4000000000L;  // 256 GiB
+#elif V8_TARGET_ARCH_64_BIT
+constexpr size_t kAddressSpaceSoftLimit = 0x6000000000L;   // 384 GiB
+constexpr size_t kAddressSpaceHardLimit = 0x10100000000L;  // 1 TiB + 4 GiB
+#else
+constexpr size_t kAddressSpaceSoftLimit = 0x90000000;  // 2 GiB + 256 MiB
+constexpr size_t kAddressSpaceHardLimit = 0xC0000000;  // 3 GiB
+#endif
+
 }  // namespace
 
 WasmMemoryTracker::~WasmMemoryTracker() {
@@ -124,33 +153,19 @@ WasmMemoryTracker::~WasmMemoryTracker() {
   DCHECK_EQ(allocated_address_space_, 0u);
 }
 
-bool WasmMemoryTracker::ReserveAddressSpace(size_t num_bytes) {
-// Address space reservations are currently only meaningful using guard
-// regions, which is currently only supported on 64-bit systems. On other
-// platforms, we always fall back on bounds checks.
-#if V8_TARGET_ARCH_MIPS64
-  // MIPS64 has a user space of 2^40 bytes on most processors,
-  // address space limits needs to be smaller.
-  constexpr size_t kAddressSpaceLimit = 0x2100000000L;  // 132 GiB
-#elif V8_TARGET_ARCH_64_BIT
-  // We set the limit to 1 TiB + 4 GiB so that there is room for mini-guards
-  // once we fill everything up with full-sized guard regions.
-  constexpr size_t kAddressSpaceLimit = 0x10100000000L;  // 1 TiB + 4 GiB
-#else
-  constexpr size_t kAddressSpaceLimit = 0x90000000;  // 2 GiB + 256 MiB
-#endif
-
-  int retries = 5;  // cmpxchng can fail, retry some number of times.
-  do {
-    size_t old_count = reserved_address_space_;
-    if ((kAddressSpaceLimit - old_count) < num_bytes) return false;
+bool WasmMemoryTracker::ReserveAddressSpace(size_t num_bytes,
+                                            ReservationLimit limit) {
+  size_t reservation_limit =
+      limit == kSoftLimit ? kAddressSpaceSoftLimit : kAddressSpaceHardLimit;
+  while (true) {
+    size_t old_count = reserved_address_space_.load();
+    if (old_count > reservation_limit) return false;
+    if (reservation_limit - old_count < num_bytes) return false;
     if (reserved_address_space_.compare_exchange_weak(old_count,
                                                       old_count + num_bytes)) {
       return true;
     }
-  } while (retries-- > 0);
-
-  return false;
+  }
 }
 
 void WasmMemoryTracker::ReleaseReservation(size_t num_bytes) {
@@ -233,7 +248,8 @@ bool WasmMemoryTracker::FreeMemoryIfIsWasmMemory(Isolate* isolate,
                                                  const void* buffer_start) {
   if (IsWasmMemory(buffer_start)) {
     const AllocationData allocation = ReleaseAllocation(isolate, buffer_start);
-    CHECK(FreePages(allocation.allocation_base, allocation.allocation_length));
+    CHECK(FreePages(GetPlatformPageAllocator(), allocation.allocation_base,
+                    allocation.allocation_length));
     return true;
   }
   return false;
@@ -272,25 +288,9 @@ MaybeHandle<JSArrayBuffer> NewArrayBuffer(Isolate* isolate, size_t size,
   void* allocation_base = nullptr;
   size_t allocation_length = 0;
 
-#if V8_TARGET_ARCH_64_BIT
-  bool require_full_guard_regions = true;
-#else
-  bool require_full_guard_regions = false;
-#endif
   void* memory = TryAllocateBackingStore(memory_tracker, isolate->heap(), size,
-                                         require_full_guard_regions,
                                          &allocation_base, &allocation_length);
-  if (memory == nullptr && FLAG_wasm_trap_handler_fallback) {
-    // If we failed to allocate with full guard regions, fall back on
-    // mini-guards.
-    require_full_guard_regions = false;
-    memory = TryAllocateBackingStore(memory_tracker, isolate->heap(), size,
-                                     require_full_guard_regions,
-                                     &allocation_base, &allocation_length);
-  }
-  if (memory == nullptr) {
-    return {};
-  }
+  if (memory == nullptr) return {};
 
 #if DEBUG
   // Double check the API allocator actually zero-initialized the memory.
diff --git a/deps/v8/src/wasm/wasm-memory.h b/deps/v8/src/wasm/wasm-memory.h
index d95f7a88c8..5a919fe71c 100644
--- a/deps/v8/src/wasm/wasm-memory.h
+++ b/deps/v8/src/wasm/wasm-memory.h
@@ -24,13 +24,16 @@ namespace wasm {
 // that buffer.
 class WasmMemoryTracker {
  public:
-  WasmMemoryTracker() {}
+  WasmMemoryTracker() = default;
   V8_EXPORT_PRIVATE ~WasmMemoryTracker();
 
   // ReserveAddressSpace attempts to increase the reserved address space counter
   // by {num_bytes}. Returns true if successful (meaning it is okay to go ahead
   // and reserve {num_bytes} bytes), false otherwise.
-  bool ReserveAddressSpace(size_t num_bytes);
+  // Use {kSoftLimit} if you can implement a fallback which needs less reserved
+  // memory.
+  enum ReservationLimit { kSoftLimit, kHardLimit };
+  bool ReserveAddressSpace(size_t num_bytes, ReservationLimit limit);
 
   void RegisterAllocation(Isolate* isolate, void* allocation_base,
                           size_t allocation_length, void* buffer_start,
diff --git a/deps/v8/src/wasm/wasm-module.cc b/deps/v8/src/wasm/wasm-module.cc
index ab603bfb3a..7e4621571a 100644
--- a/deps/v8/src/wasm/wasm-module.cc
+++ b/deps/v8/src/wasm/wasm-module.cc
@@ -27,15 +27,6 @@ namespace v8 {
 namespace internal {
 namespace wasm {
 
-// static
-const WasmExceptionSig WasmException::empty_sig_(0, 0, nullptr);
-
-// static
-constexpr const char* WasmException::kRuntimeIdStr;
-
-// static
-constexpr const char* WasmException::kRuntimeValuesStr;
-
 WireBytesRef WasmModule::LookupFunctionName(const ModuleWireBytes& wire_bytes,
                                             uint32_t function_index) const {
   if (!function_names) {
@@ -57,20 +48,6 @@ void WasmModule::AddFunctionNameForTesting(int function_index,
 }
 
 // Get a string stored in the module bytes representing a name.
-WasmName ModuleWireBytes::GetName(WireBytesRef ref) const {
-  if (ref.is_empty()) return {"<?>", 3};  // no name.
-  CHECK(BoundsCheck(ref.offset(), ref.length()));
-  return WasmName::cast(
-      module_bytes_.SubVector(ref.offset(), ref.end_offset()));
-}
-
-// Get a string stored in the module bytes representing a function name.
-WasmName ModuleWireBytes::GetName(const WasmFunction* function,
-                                  const WasmModule* module) const {
-  return GetName(module->LookupFunctionName(*this, function->func_index));
-}
-
-// Get a string stored in the module bytes representing a name.
 WasmName ModuleWireBytes::GetNameOrNull(WireBytesRef ref) const {
   if (!ref.is_set()) return {nullptr, 0};  // no name.
   CHECK(BoundsCheck(ref.offset(), ref.length()));
@@ -129,6 +106,7 @@ Handle<JSArray> GetImports(Isolate* isolate,
   Handle<String> table_string = factory->InternalizeUtf8String("table");
   Handle<String> memory_string = factory->InternalizeUtf8String("memory");
   Handle<String> global_string = factory->InternalizeUtf8String("global");
+  Handle<String> exception_string = factory->InternalizeUtf8String("exception");
 
   // Create the result array.
   const WasmModule* module = module_object->module();
@@ -161,6 +139,9 @@ Handle<JSArray> GetImports(Isolate* isolate,
       case kExternalGlobal:
         import_kind = global_string;
         break;
+      case kExternalException:
+        import_kind = exception_string;
+        break;
       default:
         UNREACHABLE();
     }
@@ -196,6 +177,7 @@ Handle<JSArray> GetExports(Isolate* isolate,
   Handle<String> table_string = factory->InternalizeUtf8String("table");
   Handle<String> memory_string = factory->InternalizeUtf8String("memory");
   Handle<String> global_string = factory->InternalizeUtf8String("global");
+  Handle<String> exception_string = factory->InternalizeUtf8String("exception");
 
   // Create the result array.
   const WasmModule* module = module_object->module();
@@ -226,6 +208,9 @@ Handle<JSArray> GetExports(Isolate* isolate,
       case kExternalGlobal:
         export_kind = global_string;
         break;
+      case kExternalException:
+        export_kind = exception_string;
+        break;
       default:
         UNREACHABLE();
     }
diff --git a/deps/v8/src/wasm/wasm-module.h b/deps/v8/src/wasm/wasm-module.h
index b1020661ab..d188cf59e1 100644
--- a/deps/v8/src/wasm/wasm-module.h
+++ b/deps/v8/src/wasm/wasm-module.h
@@ -9,7 +9,7 @@
 
 #include "src/globals.h"
 #include "src/handles.h"
-#include "src/wasm/decoder.h"
+#include "src/vector.h"
 #include "src/wasm/signature-map.h"
 #include "src/wasm/wasm-constants.h"
 #include "src/wasm/wasm-opcodes.h"
@@ -22,8 +22,31 @@ class WasmModuleObject;
 
 namespace wasm {
 
+using WasmName = Vector<const char>;
+
 class ErrorThrower;
 
+// Reference to a string in the wire bytes.
+class WireBytesRef {
+ public:
+  WireBytesRef() : WireBytesRef(0, 0) {}
+  WireBytesRef(uint32_t offset, uint32_t length)
+      : offset_(offset), length_(length) {
+    DCHECK_IMPLIES(offset_ == 0, length_ == 0);
+    DCHECK_LE(offset_, offset_ + length_);  // no uint32_t overflow.
+  }
+
+  uint32_t offset() const { return offset_; }
+  uint32_t length() const { return length_; }
+  uint32_t end_offset() const { return offset_ + length_; }
+  bool is_empty() const { return length_ == 0; }
+  bool is_set() const { return offset_ != 0; }
+
+ private:
+  uint32_t offset_;
+  uint32_t length_;
+};
+
 // Static representation of a wasm function.
 struct WasmFunction {
   FunctionSig* sig;      // signature of the function.
@@ -51,19 +74,12 @@ struct WasmGlobal {
 // function signature.
 typedef FunctionSig WasmExceptionSig;
 
+// Static representation of a wasm exception type.
 struct WasmException {
-  explicit WasmException(const WasmExceptionSig* sig = &empty_sig_)
-      : sig(sig) {}
+  explicit WasmException(const WasmExceptionSig* sig) : sig(sig) {}
   FunctionSig* ToFunctionSig() const { return const_cast<FunctionSig*>(sig); }
 
   const WasmExceptionSig* sig;  // type signature of the exception.
-
-  // Used to hold data on runtime exceptions.
-  static constexpr const char* kRuntimeIdStr = "WasmExceptionRuntimeId";
-  static constexpr const char* kRuntimeValuesStr = "WasmExceptionValues";
-
- private:
-  static const WasmExceptionSig empty_sig_;
 };
 
 // Static representation of a wasm data segment.
@@ -156,6 +172,7 @@ struct V8_EXPORT_PRIVATE WasmModule {
   ModuleOrigin origin = kWasmOrigin;  // origin of the module
   mutable std::unique_ptr<std::unordered_map<uint32_t, WireBytesRef>>
       function_names;
+  std::string source_map_url;
 
   explicit WasmModule(std::unique_ptr<Zone> owned = nullptr);
 
@@ -179,13 +196,6 @@ struct V8_EXPORT_PRIVATE ModuleWireBytes {
   }
 
   // Get a string stored in the module bytes representing a name.
-  WasmName GetName(WireBytesRef ref) const;
-
-  // Get a string stored in the module bytes representing a function name.
-  WasmName GetName(const WasmFunction* function,
-                   const WasmModule* module) const;
-
-  // Get a string stored in the module bytes representing a name.
   WasmName GetNameOrNull(WireBytesRef ref) const;
 
   // Get a string stored in the module bytes representing a function name.
diff --git a/deps/v8/src/wasm/wasm-objects-inl.h b/deps/v8/src/wasm/wasm-objects-inl.h
index 481d2274bf..0144b8af5b 100644
--- a/deps/v8/src/wasm/wasm-objects-inl.h
+++ b/deps/v8/src/wasm/wasm-objects-inl.h
@@ -22,6 +22,7 @@ namespace v8 {
 namespace internal {
 
 CAST_ACCESSOR(WasmDebugInfo)
+CAST_ACCESSOR(WasmExceptionObject)
 CAST_ACCESSOR(WasmExportedFunctionData)
 CAST_ACCESSOR(WasmGlobalObject)
 CAST_ACCESSOR(WasmInstanceObject)
@@ -101,10 +102,7 @@ int WasmGlobalObject::type_size() const {
 }
 
 Address WasmGlobalObject::address() const {
-  uint32_t buffer_size = 0;
-  DCHECK(array_buffer()->byte_length()->ToUint32(&buffer_size));
-  DCHECK_LE(offset() + type_size(), buffer_size);
-  USE(buffer_size);
+  DCHECK_LE(offset() + type_size(), array_buffer()->byte_length());
   return Address(array_buffer()->backing_store()) + offset();
 }
 
@@ -187,6 +185,8 @@ OPTIONAL_ACCESSORS(WasmInstanceObject, indirect_function_table_instances,
                    FixedArray, kIndirectFunctionTableInstancesOffset)
 OPTIONAL_ACCESSORS(WasmInstanceObject, managed_native_allocations, Foreign,
                    kManagedNativeAllocationsOffset)
+OPTIONAL_ACCESSORS(WasmInstanceObject, exceptions_table, FixedArray,
+                   kExceptionsTableOffset)
 ACCESSORS(WasmInstanceObject, undefined_value, Oddball, kUndefinedValueOffset)
 ACCESSORS(WasmInstanceObject, null_value, Oddball, kNullValueOffset)
 ACCESSORS(WasmInstanceObject, centry_stub, Code, kCEntryStubOffset)
@@ -209,6 +209,11 @@ ImportedFunctionEntry::ImportedFunctionEntry(
   DCHECK_LT(index, instance->module()->num_imported_functions);
 }
 
+// WasmExceptionObject
+ACCESSORS(WasmExceptionObject, serialized_signature, PodArray<wasm::ValueType>,
+          kSerializedSignatureOffset)
+ACCESSORS(WasmExceptionObject, exception_tag, HeapObject, kExceptionTagOffset)
+
 // WasmExportedFunctionData
 ACCESSORS(WasmExportedFunctionData, wrapper_code, Code, kWrapperCodeOffset)
 ACCESSORS(WasmExportedFunctionData, instance, WasmInstanceObject,
@@ -220,7 +225,7 @@ SMI_ACCESSORS(WasmExportedFunctionData, function_index, kFunctionIndexOffset)
 // WasmDebugInfo
 ACCESSORS(WasmDebugInfo, wasm_instance, WasmInstanceObject, kInstanceOffset)
 ACCESSORS(WasmDebugInfo, interpreter_handle, Object, kInterpreterHandleOffset)
-ACCESSORS(WasmDebugInfo, interpreted_functions, Object,
+ACCESSORS(WasmDebugInfo, interpreted_functions, FixedArray,
           kInterpretedFunctionsOffset)
 OPTIONAL_ACCESSORS(WasmDebugInfo, locals_names, FixedArray, kLocalsNamesOffset)
 OPTIONAL_ACCESSORS(WasmDebugInfo, c_wasm_entries, FixedArray,
diff --git a/deps/v8/src/wasm/wasm-objects.cc b/deps/v8/src/wasm/wasm-objects.cc
index 4cd66a81c5..9d0e20ab2b 100644
--- a/deps/v8/src/wasm/wasm-objects.cc
+++ b/deps/v8/src/wasm/wasm-objects.cc
@@ -72,16 +72,14 @@ class WasmInstanceNativeAllocations {
         reinterpret_cast<Address*>(
             calloc(num_imported_mutable_globals, sizeof(Address))));
   }
-  ~WasmInstanceNativeAllocations() { free(); }
-  // Frees natively-allocated storage.
-  void free() {
+  ~WasmInstanceNativeAllocations() {
     ::free(indirect_function_table_sig_ids_);
-    ::free(indirect_function_table_targets_);
-    ::free(imported_function_targets_);
-    ::free(imported_mutable_globals_);
     indirect_function_table_sig_ids_ = nullptr;
+    ::free(indirect_function_table_targets_);
     indirect_function_table_targets_ = nullptr;
+    ::free(imported_function_targets_);
     imported_function_targets_ = nullptr;
+    ::free(imported_mutable_globals_);
     imported_mutable_globals_ = nullptr;
   }
   // Resizes the indirect function table.
@@ -262,9 +260,9 @@ bool WasmModuleObject::SetBreakPoint(Handle<WasmModuleObject> module_object,
                                            isolate);
   for (int i = 0; i < weak_instance_list->length(); ++i) {
     MaybeObject* maybe_instance = weak_instance_list->Get(i);
-    if (maybe_instance->IsWeakHeapObject()) {
+    if (maybe_instance->IsWeak()) {
       Handle<WasmInstanceObject> instance(
-          WasmInstanceObject::cast(maybe_instance->ToWeakHeapObject()),
+          WasmInstanceObject::cast(maybe_instance->GetHeapObjectAssumeWeak()),
           isolate);
       Handle<WasmDebugInfo> debug_info =
           WasmInstanceObject::GetOrCreateDebugInfo(instance);
@@ -690,7 +688,7 @@ Vector<const uint8_t> WasmModuleObject::GetRawFunctionName(
   wasm::ModuleWireBytes wire_bytes(native_module()->wire_bytes());
   wasm::WireBytesRef name_ref =
       module()->LookupFunctionName(wire_bytes, func_index);
-  wasm::WasmName name = wire_bytes.GetName(name_ref);
+  wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
   return Vector<const uint8_t>::cast(name);
 }
 
@@ -728,6 +726,14 @@ int WasmModuleObject::GetContainingFunction(uint32_t byte_offset) {
 
 bool WasmModuleObject::GetPositionInfo(uint32_t position,
                                        Script::PositionInfo* info) {
+  if (script()->source_mapping_url()->IsString()) {
+    if (module()->functions.size() == 0) return false;
+    info->line = 0;
+    info->column = position;
+    info->line_start = module()->functions[0].code.offset();
+    info->line_end = module()->functions.back().code.end_offset();
+    return true;
+  }
   int func_index = GetContainingFunction(position);
   if (func_index < 0) return false;
 
@@ -881,7 +887,7 @@ MaybeHandle<JSArrayBuffer> GrowMemoryBuffer(Isolate* isolate,
                                             uint32_t maximum_pages) {
   if (!old_buffer->is_growable()) return {};
   void* old_mem_start = old_buffer->backing_store();
-  size_t old_size = old_buffer->byte_length()->Number();
+  size_t old_size = old_buffer->byte_length();
   CHECK_GE(wasm::kV8MaxWasmMemoryBytes, old_size);
   CHECK_EQ(0, old_size % wasm::kWasmPageSize);
   size_t old_pages = old_size / wasm::kWasmPageSize;
@@ -904,8 +910,8 @@ MaybeHandle<JSArrayBuffer> GrowMemoryBuffer(Isolate* isolate,
       DCHECK_NOT_NULL(old_buffer->backing_store());
       // If adjusting permissions fails, propagate error back to return
       // failure to grow.
-      if (!i::SetPermissions(old_mem_start, new_size,
-                             PageAllocator::kReadWrite)) {
+      if (!i::SetPermissions(GetPlatformPageAllocator(), old_mem_start,
+                             new_size, PageAllocator::kReadWrite)) {
         return {};
       }
       reinterpret_cast<v8::Isolate*>(isolate)
@@ -949,7 +955,7 @@ MaybeHandle<JSArrayBuffer> GrowMemoryBuffer(Isolate* isolate,
 void SetInstanceMemory(Handle<WasmInstanceObject> instance,
                        Handle<JSArrayBuffer> buffer) {
   instance->SetRawMemory(reinterpret_cast<byte*>(buffer->backing_store()),
-                         buffer->byte_length()->Number());
+                         buffer->byte_length());
 #if DEBUG
   if (!FLAG_mock_arraybuffer_allocator) {
     // To flush out bugs earlier, in DEBUG mode, check that all pages of the
@@ -992,9 +998,8 @@ Handle<WasmMemoryObject> WasmMemoryObject::New(
 }
 
 uint32_t WasmMemoryObject::current_pages() {
-  uint32_t byte_length;
-  CHECK(array_buffer()->byte_length()->ToUint32(&byte_length));
-  return byte_length / wasm::kWasmPageSize;
+  return static_cast<uint32_t>(array_buffer()->byte_length() /
+                               wasm::kWasmPageSize);
 }
 
 bool WasmMemoryObject::has_full_guard_region(Isolate* isolate) {
@@ -1049,8 +1054,7 @@ int32_t WasmMemoryObject::Grow(Isolate* isolate,
                                uint32_t pages) {
   Handle<JSArrayBuffer> old_buffer(memory_object->array_buffer(), isolate);
   if (!old_buffer->is_growable()) return -1;
-  uint32_t old_size = 0;
-  CHECK(old_buffer->byte_length()->ToUint32(&old_size));
+  size_t old_size = old_buffer->byte_length();
   DCHECK_EQ(0, old_size % wasm::kWasmPageSize);
   Handle<JSArrayBuffer> new_buffer;
 
@@ -1069,17 +1073,17 @@ int32_t WasmMemoryObject::Grow(Isolate* isolate,
     for (int i = 0; i < instances->length(); i++) {
       MaybeObject* elem = instances->Get(i);
       HeapObject* heap_object;
-      if (elem->ToWeakHeapObject(&heap_object)) {
+      if (elem->GetHeapObjectIfWeak(&heap_object)) {
         Handle<WasmInstanceObject> instance(
             WasmInstanceObject::cast(heap_object), isolate);
         SetInstanceMemory(instance, new_buffer);
       } else {
-        DCHECK(elem->IsClearedWeakHeapObject());
+        DCHECK(elem->IsCleared());
       }
     }
   }
   memory_object->set_array_buffer(*new_buffer);
-  return old_size / wasm::kWasmPageSize;
+  return static_cast<uint32_t>(old_size / wasm::kWasmPageSize);
 }
 
 // static
@@ -1107,9 +1111,7 @@ MaybeHandle<WasmGlobalObject> WasmGlobalObject::New(
   }
 
   // Check that the offset is in bounds.
-  uint32_t buffer_size = 0;
-  CHECK(buffer->byte_length()->ToUint32(&buffer_size));
-  CHECK(offset + type_size <= buffer_size);
+  CHECK_LE(offset + type_size, buffer->byte_length());
 
   global_obj->set_array_buffer(*buffer);
   global_obj->set_flags(0);
@@ -1297,50 +1299,52 @@ Handle<WasmInstanceObject> WasmInstanceObject::New(
   return instance;
 }
 
-namespace {
-void InstanceFinalizer(const v8::WeakCallbackInfo<void>& data) {
-  DisallowHeapAllocation no_gc;
-  JSObject** p = reinterpret_cast<JSObject**>(data.GetParameter());
-  WasmInstanceObject* instance = reinterpret_cast<WasmInstanceObject*>(*p);
-  Isolate* isolate = reinterpret_cast<Isolate*>(data.GetIsolate());
-  // If a link to shared memory instances exists, update the list of memory
-  // instances before the instance is destroyed.
-  TRACE("Finalizing instance of %p {\n",
-        instance->module_object()->native_module());
-
-  // Since the order of finalizers is not guaranteed, it can be the case
-  // that {instance->compiled_module()->module()}, which is a
-  // {Managed<WasmModule>} has been collected earlier in this GC cycle.
-  // Weak references to this instance won't be cleared until
-  // the next GC cycle, so we need to manually break some links (such as
-  // the weak references from {WasmMemoryObject::instances}.
-  if (instance->has_memory_object()) {
-    WasmMemoryObject::RemoveInstance(handle(instance->memory_object(), isolate),
-                                     handle(instance, isolate));
+Address WasmInstanceObject::GetCallTarget(uint32_t func_index) {
+  wasm::NativeModule* native_module = module_object()->native_module();
+  if (func_index < native_module->num_imported_functions()) {
+    return imported_function_targets()[func_index];
   }
-
-  // Free raw C++ memory associated with the instance.
-  GetNativeAllocations(instance)->free();
-
-  GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
-  TRACE("}\n");
+  return native_module->GetCallTargetForFunction(func_index);
 }
 
-}  // namespace
+// static
+Handle<WasmExceptionObject> WasmExceptionObject::New(
+    Isolate* isolate, const wasm::FunctionSig* sig,
+    Handle<HeapObject> exception_tag) {
+  Handle<JSFunction> exception_cons(
+      isolate->native_context()->wasm_exception_constructor(), isolate);
+  Handle<JSObject> exception_object =
+      isolate->factory()->NewJSObject(exception_cons, TENURED);
+  Handle<WasmExceptionObject> exception =
+      Handle<WasmExceptionObject>::cast(exception_object);
+
+  // Serialize the signature.
+  DCHECK_EQ(0, sig->return_count());
+  DCHECK_LE(sig->parameter_count(), std::numeric_limits<int>::max());
+  int sig_size = static_cast<int>(sig->parameter_count());
+  Handle<PodArray<wasm::ValueType>> serialized_sig =
+      PodArray<wasm::ValueType>::New(isolate, sig_size, TENURED);
+  int index = 0;  // Index into the {PodArray} above.
+  for (wasm::ValueType param : sig->parameters()) {
+    serialized_sig->set(index++, param);
+  }
+  exception->set_serialized_signature(*serialized_sig);
+  exception->set_exception_tag(*exception_tag);
 
-void WasmInstanceObject::InstallFinalizer(Isolate* isolate,
-                                          Handle<WasmInstanceObject> instance) {
-  Handle<Object> global_handle = isolate->global_handles()->Create(*instance);
-  GlobalHandles::MakeWeak(global_handle.location(), global_handle.location(),
-                          InstanceFinalizer, v8::WeakCallbackType::kFinalizer);
+  return exception;
 }
 
-Address WasmInstanceObject::GetCallTarget(uint32_t func_index) {
-  wasm::NativeModule* native_module = module_object()->native_module();
-  if (func_index < native_module->num_imported_functions()) {
-    return imported_function_targets()[func_index];
+bool WasmExceptionObject::IsSignatureEqual(const wasm::FunctionSig* sig) {
+  DCHECK_EQ(0, sig->return_count());
+  DCHECK_LE(sig->parameter_count(), std::numeric_limits<int>::max());
+  int sig_size = static_cast<int>(sig->parameter_count());
+  if (sig_size != serialized_signature()->length()) return false;
+  for (int index = 0; index < sig_size; ++index) {
+    if (sig->GetParam(index) != serialized_signature()->get(index)) {
+      return false;
+    }
   }
-  return native_module->GetCallTargetForFunction(func_index);
+  return true;
 }
 
 bool WasmExportedFunction::IsWasmExportedFunction(Object* object) {
diff --git a/deps/v8/src/wasm/wasm-objects.h b/deps/v8/src/wasm/wasm-objects.h
index a493f97e95..084b70489c 100644
--- a/deps/v8/src/wasm/wasm-objects.h
+++ b/deps/v8/src/wasm/wasm-objects.h
@@ -387,6 +387,7 @@ class WasmInstanceObject : public JSObject {
   DECL_ACCESSORS(imported_function_callables, FixedArray)
   DECL_OPTIONAL_ACCESSORS(indirect_function_table_instances, FixedArray)
   DECL_OPTIONAL_ACCESSORS(managed_native_allocations, Foreign)
+  DECL_OPTIONAL_ACCESSORS(exceptions_table, FixedArray)
   DECL_ACCESSORS(undefined_value, Oddball)
   DECL_ACCESSORS(null_value, Oddball)
   DECL_ACCESSORS(centry_stub, Code)
@@ -422,6 +423,7 @@ class WasmInstanceObject : public JSObject {
   V(kImportedFunctionCallablesOffset, kPointerSize)                     \
   V(kIndirectFunctionTableInstancesOffset, kPointerSize)                \
   V(kManagedNativeAllocationsOffset, kPointerSize)                      \
+  V(kExceptionsTableOffset, kPointerSize)                               \
   V(kUndefinedValueOffset, kPointerSize)                                \
   V(kNullValueOffset, kPointerSize)                                     \
   V(kCEntryStubOffset, kPointerSize)                                    \
@@ -461,15 +463,37 @@ class WasmInstanceObject : public JSObject {
 
   static Handle<WasmInstanceObject> New(Isolate*, Handle<WasmModuleObject>);
 
-  static void InstallFinalizer(Isolate* isolate,
-                               Handle<WasmInstanceObject> instance);
-
   Address GetCallTarget(uint32_t func_index);
 
   // Iterates all fields in the object except the untagged fields.
   class BodyDescriptor;
-  // No weak fields.
-  typedef BodyDescriptor BodyDescriptorWeak;
+};
+
+// Representation of WebAssembly.Exception JavaScript-level object.
+class WasmExceptionObject : public JSObject {
+ public:
+  DECL_CAST(WasmExceptionObject)
+
+  DECL_ACCESSORS(serialized_signature, PodArray<wasm::ValueType>)
+  DECL_ACCESSORS(exception_tag, HeapObject)
+
+// Layout description.
+#define WASM_EXCEPTION_OBJECT_FIELDS(V)       \
+  V(kSerializedSignatureOffset, kPointerSize) \
+  V(kExceptionTagOffset, kPointerSize)        \
+  V(kSize, 0)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
+                                WASM_EXCEPTION_OBJECT_FIELDS)
+#undef WASM_EXCEPTION_OBJECT_FIELDS
+
+  // Checks whether the given {sig} has the same parameter types as the
+  // serialized signature stored within this exception object.
+  bool IsSignatureEqual(const wasm::FunctionSig* sig);
+
+  static Handle<WasmExceptionObject> New(Isolate* isolate,
+                                         const wasm::FunctionSig* sig,
+                                         Handle<HeapObject> exception_tag);
 };
 
 // A WASM function that is wrapped and exported to JavaScript.
@@ -521,12 +545,9 @@ class WasmExportedFunctionData : public Struct {
 
 class WasmDebugInfo : public Struct, public NeverReadOnlySpaceObject {
  public:
-  using NeverReadOnlySpaceObject::GetHeap;
-  using NeverReadOnlySpaceObject::GetIsolate;
-
   DECL_ACCESSORS(wasm_instance, WasmInstanceObject)
-  DECL_ACCESSORS(interpreter_handle, Object);
-  DECL_ACCESSORS(interpreted_functions, Object);
+  DECL_ACCESSORS(interpreter_handle, Object);  // Foreign or undefined
+  DECL_ACCESSORS(interpreted_functions, FixedArray);
   DECL_OPTIONAL_ACCESSORS(locals_names, FixedArray)
   DECL_OPTIONAL_ACCESSORS(c_wasm_entries, FixedArray)
   DECL_OPTIONAL_ACCESSORS(c_wasm_entry_map, Managed<wasm::SignatureMap>)
diff --git a/deps/v8/src/wasm/wasm-opcodes.h b/deps/v8/src/wasm/wasm-opcodes.h
index dff02f8147..238873228f 100644
--- a/deps/v8/src/wasm/wasm-opcodes.h
+++ b/deps/v8/src/wasm/wasm-opcodes.h
@@ -6,7 +6,6 @@
 #define V8_WASM_WASM_OPCODES_H_
 
 #include "src/globals.h"
-#include "src/vector.h"
 #include "src/wasm/value-type.h"
 #include "src/wasm/wasm-constants.h"
 
@@ -22,8 +21,6 @@ using FunctionSig = Signature<ValueType>;
 std::ostream& operator<<(std::ostream& os, const FunctionSig& function);
 bool IsJSCompatibleSignature(const FunctionSig* sig);
 
-using WasmName = Vector<const char>;
-
 // Control expressions and blocks.
 #define FOREACH_CONTROL_OPCODE(V)         \
   V(Unreachable, 0x00, _)                 \
diff --git a/deps/v8/src/wasm/wasm-result.cc b/deps/v8/src/wasm/wasm-result.cc
index 314f320752..1bcad13030 100644
--- a/deps/v8/src/wasm/wasm-result.cc
+++ b/deps/v8/src/wasm/wasm-result.cc
@@ -149,7 +149,7 @@ ErrorThrower::ErrorThrower(ErrorThrower&& other) V8_NOEXCEPT
     : isolate_(other.isolate_),
       context_(other.context_),
       error_type_(other.error_type_),
-      error_msg_(other.error_msg_) {
+      error_msg_(std::move(other.error_msg_)) {
   other.error_type_ = kNone;
 }
 
diff --git a/deps/v8/src/wasm/wasm-serialization.cc b/deps/v8/src/wasm/wasm-serialization.cc
index 2edc412afa..b676a5b61b 100644
--- a/deps/v8/src/wasm/wasm-serialization.cc
+++ b/deps/v8/src/wasm/wasm-serialization.cc
@@ -46,9 +46,9 @@ class Writer {
     DCHECK_GE(current_size(), sizeof(T));
     WriteUnalignedValue(reinterpret_cast<Address>(current_location()), value);
     pos_ += sizeof(T);
-    if (FLAG_wasm_trace_serialization) {
-      StdoutStream{} << "wrote: " << (size_t)value << " sized: " << sizeof(T)
-                     << std::endl;
+    if (FLAG_trace_wasm_serialization) {
+      StdoutStream{} << "wrote: " << static_cast<size_t>(value)
+                     << " sized: " << sizeof(T) << std::endl;
     }
   }
 
@@ -58,7 +58,7 @@ class Writer {
       memcpy(current_location(), v.start(), v.size());
       pos_ += v.size();
     }
-    if (FLAG_wasm_trace_serialization) {
+    if (FLAG_trace_wasm_serialization) {
       StdoutStream{} << "wrote vector of " << v.size() << " elements"
                      << std::endl;
     }
@@ -90,9 +90,9 @@ class Reader {
     T value =
         ReadUnalignedValue<T>(reinterpret_cast<Address>(current_location()));
     pos_ += sizeof(T);
-    if (FLAG_wasm_trace_serialization) {
-      StdoutStream{} << "read: " << (size_t)value << " sized: " << sizeof(T)
-                     << std::endl;
+    if (FLAG_trace_wasm_serialization) {
+      StdoutStream{} << "read: " << static_cast<size_t>(value)
+                     << " sized: " << sizeof(T) << std::endl;
     }
     return value;
   }
@@ -103,7 +103,7 @@ class Reader {
       memcpy(v.start(), current_location(), v.size());
       pos_ += v.size();
     }
-    if (FLAG_wasm_trace_serialization) {
+    if (FLAG_trace_wasm_serialization) {
       StdoutStream{} << "read vector of " << v.size() << " elements"
                      << std::endl;
     }
@@ -127,14 +127,6 @@ void WriteVersion(Isolate* isolate, Writer* writer) {
   writer->Write(FlagList::Hash());
 }
 
-bool IsSupportedVersion(Isolate* isolate, const Vector<const byte> version) {
-  if (version.size() < kVersionSize) return false;
-  byte current_version[kVersionSize];
-  Writer writer({current_version, kVersionSize});
-  WriteVersion(isolate, &writer);
-  return memcmp(version.start(), current_version, kVersionSize) == 0;
-}
-
 // On Intel, call sites are encoded as a displacement. For linking and for
 // serialization/deserialization, we want to store/retrieve a tag (the function
 // index). On Intel, that means accessing the raw displacement.
@@ -537,6 +529,14 @@ bool NativeModuleDeserializer::ReadCode(uint32_t fn_index, Reader* reader) {
   return true;
 }
 
+bool IsSupportedVersion(Isolate* isolate, Vector<const byte> version) {
+  if (version.size() < kVersionSize) return false;
+  byte current_version[kVersionSize];
+  Writer writer({current_version, kVersionSize});
+  WriteVersion(isolate, &writer);
+  return memcmp(version.start(), current_version, kVersionSize) == 0;
+}
+
 MaybeHandle<WasmModuleObject> DeserializeNativeModule(
     Isolate* isolate, Vector<const byte> data, Vector<const byte> wire_bytes) {
   if (!IsWasmCodegenAllowed(isolate, isolate->native_context())) {
@@ -553,7 +553,8 @@ MaybeHandle<WasmModuleObject> DeserializeNativeModule(
   if (!decode_result.ok()) return {};
   CHECK_NOT_NULL(decode_result.val);
   WasmModule* module = decode_result.val.get();
-  Handle<Script> script = CreateWasmScript(isolate, wire_bytes);
+  Handle<Script> script =
+      CreateWasmScript(isolate, wire_bytes, module->source_map_url);
 
   // TODO(eholk): We need to properly preserve the flag whether the trap
   // handler was used or not when serializing.
diff --git a/deps/v8/src/wasm/wasm-serialization.h b/deps/v8/src/wasm/wasm-serialization.h
index 436a369fb6..93f79a59de 100644
--- a/deps/v8/src/wasm/wasm-serialization.h
+++ b/deps/v8/src/wasm/wasm-serialization.h
@@ -11,9 +11,9 @@ namespace v8 {
 namespace internal {
 namespace wasm {
 
-// Support to serialize WebAssembly {NativeModule} objects. This class intends
-// to be thread-safe in that it takes a consistent snapshot of the module state
-// at instantiation, allowing other threads to mutate the module concurrently.
+// Support for serializing WebAssembly {NativeModule} objects. This class takes
+// a snapshot of the module state at instantiation, and other code that modifies
+// the module after that won't affect the serialized result.
 class WasmSerializer {
  public:
   WasmSerializer(Isolate* isolate, NativeModule* native_module);
@@ -31,7 +31,11 @@ class WasmSerializer {
   std::vector<WasmCode*> code_table_;
 };
 
-// Support to deserialize WebAssembly {NativeModule} objects.
+// Support for deserializing WebAssembly {NativeModule} objects.
+// Checks the version header of the data against the current version.
+bool IsSupportedVersion(Isolate* isolate, Vector<const byte> data);
+
+// Deserializes the given data to create a compiled Wasm module.
 MaybeHandle<WasmModuleObject> DeserializeNativeModule(
     Isolate* isolate, Vector<const byte> data, Vector<const byte> wire_bytes);
 
diff --git a/deps/v8/src/x64/assembler-x64.cc b/deps/v8/src/x64/assembler-x64.cc
index 27120e2d15..e52c35a532 100644
--- a/deps/v8/src/x64/assembler-x64.cc
+++ b/deps/v8/src/x64/assembler-x64.cc
@@ -21,6 +21,7 @@
 #include "src/code-stubs.h"
 #include "src/deoptimizer.h"
 #include "src/macro-assembler.h"
+#include "src/string-constants.h"
 #include "src/v8.h"
 
 namespace v8 {
@@ -82,7 +83,10 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
   // Only use statically determined features for cross compile (snapshot).
   if (cross_compile) return;
 
-  if (cpu.has_sse41() && FLAG_enable_sse4_1) supported_ |= 1u << SSE4_1;
+  if (cpu.has_sse41() && FLAG_enable_sse4_1) {
+    supported_ |= 1u << SSE4_1;
+    supported_ |= 1u << SSSE3;
+  }
   if (cpu.has_ssse3() && FLAG_enable_ssse3) supported_ |= 1u << SSSE3;
   if (cpu.has_sse3() && FLAG_enable_sse3) supported_ |= 1u << SSE3;
   // SAHF is not generally available in long mode.
@@ -335,6 +339,7 @@ bool Operand::AddressUsesRegister(Register reg) const {
 }
 
 void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
+  DCHECK_IMPLIES(isolate == nullptr, heap_object_requests_.empty());
   for (auto& request : heap_object_requests_) {
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     switch (request.kind()) {
@@ -349,6 +354,13 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         UpdateCodeTarget(Memory<int32_t>(pc), request.code_stub()->GetCode());
         break;
       }
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        Handle<String> allocated = str->AllocateStringConstant(isolate);
+        Memory<Handle<Object>>(pc) = allocated;
+        break;
+      }
     }
   }
 }
@@ -449,6 +461,9 @@ Assembler::Assembler(const AssemblerOptions& options, void* buffer,
 
   ReserveCodeTargetSpace(100);
   reloc_info_writer.Reposition(buffer_ + buffer_size_, pc_);
+  if (CpuFeatures::IsSupported(SSE4_1)) {
+    EnableCpuFeature(SSSE3);
+  }
 }
 
 void Assembler::GetCode(Isolate* isolate, CodeDesc* desc) {
@@ -943,7 +958,7 @@ void Assembler::bswapq(Register dst) {
   emit(0xC8 + dst.low_bits());
 }
 
-void Assembler::bt(Operand dst, Register src) {
+void Assembler::btq(Operand dst, Register src) {
   EnsureSpace ensure_space(this);
   emit_rex_64(src, dst);
   emit(0x0F);
@@ -951,7 +966,7 @@ void Assembler::bt(Operand dst, Register src) {
   emit_operand(src, dst);
 }
 
-void Assembler::bts(Operand dst, Register src) {
+void Assembler::btsq(Operand dst, Register src) {
   EnsureSpace ensure_space(this);
   emit_rex_64(src, dst);
   emit(0x0F);
@@ -959,6 +974,23 @@ void Assembler::bts(Operand dst, Register src) {
   emit_operand(src, dst);
 }
 
+void Assembler::btsq(Register dst, Immediate imm8) {
+  EnsureSpace ensure_space(this);
+  emit_rex_64(dst);
+  emit(0x0F);
+  emit(0xBA);
+  emit_modrm(0x5, dst);
+  emit(imm8.value_);
+}
+
+void Assembler::btrq(Register dst, Immediate imm8) {
+  EnsureSpace ensure_space(this);
+  emit_rex_64(dst);
+  emit(0x0F);
+  emit(0xBA);
+  emit_modrm(0x6, dst);
+  emit(imm8.value_);
+}
 
 void Assembler::bsrl(Register dst, Register src) {
   EnsureSpace ensure_space(this);
@@ -1818,6 +1850,14 @@ void Assembler::movp_heap_number(Register dst, double value) {
   emitp(0, RelocInfo::EMBEDDED_OBJECT);
 }
 
+void Assembler::movp_string(Register dst, const StringConstantBase* str) {
+  EnsureSpace ensure_space(this);
+  emit_rex(dst, kPointerSize);
+  emit(0xB8 | dst.low_bits());
+  RequestHeapObject(HeapObjectRequest(str));
+  emitp(0, RelocInfo::EMBEDDED_OBJECT);
+}
+
 void Assembler::movq(Register dst, int64_t value, RelocInfo::Mode rmode) {
   if (constpool_.TryRecordEntry(value, rmode)) {
     // Emit rip-relative move with offset = 0
@@ -4962,12 +5002,7 @@ void Assembler::dq(Label* label) {
 // Relocation information implementations.
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
-  DCHECK(!RelocInfo::IsNone(rmode));
-  if (options().disable_reloc_info_for_patching) return;
-  if (RelocInfo::IsOnlyForSerializer(rmode) &&
-      !options().record_reloc_info_for_serialization && !emit_debug_code()) {
-    return;
-  }
+  if (!ShouldRecordRelocInfo(rmode)) return;
   RelocInfo rinfo(reinterpret_cast<Address>(pc_), rmode, data, nullptr);
   reloc_info_writer.Write(&rinfo);
 }
diff --git a/deps/v8/src/x64/assembler-x64.h b/deps/v8/src/x64/assembler-x64.h
index 8823334a46..a0af3a3509 100644
--- a/deps/v8/src/x64/assembler-x64.h
+++ b/deps/v8/src/x64/assembler-x64.h
@@ -219,7 +219,6 @@ typedef XMMRegister Simd128Register;
   constexpr DoubleRegister R = DoubleRegister::from_code<kDoubleCode_##R>();
 DOUBLE_REGISTERS(DECLARE_REGISTER)
 #undef DECLARE_REGISTER
-constexpr DoubleRegister no_double_reg = DoubleRegister::no_reg();
 constexpr DoubleRegister no_dreg = DoubleRegister::no_reg();
 
 enum Condition {
@@ -488,7 +487,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // buffer is too small, a fatal error occurs. No deallocation of the buffer is
   // done upon destruction of the assembler.
   Assembler(const AssemblerOptions& options, void* buffer, int buffer_size);
-  virtual ~Assembler() {}
+  ~Assembler() override = default;
 
   // GetCode emits any pending (non-emitted) code and fills the descriptor
   // desc. GetCode() is idempotent; it returns the same result if no other
@@ -689,6 +688,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // move.
   void movp_heap_number(Register dst, double value);
 
+  void movp_string(Register dst, const StringConstantBase* str);
+
   // Loads a 64-bit immediate into a register.
   void movq(Register dst, int64_t value,
             RelocInfo::Mode rmode = RelocInfo::NONE);
@@ -856,8 +857,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Bit operations.
   void bswapl(Register dst);
   void bswapq(Register dst);
-  void bt(Operand dst, Register src);
-  void bts(Operand dst, Register src);
+  void btq(Operand dst, Register src);
+  void btsq(Operand dst, Register src);
+  void btsq(Register dst, Immediate imm8);
+  void btrq(Register dst, Immediate imm8);
   void bsrq(Register dst, Register src);
   void bsrq(Register dst, Operand src);
   void bsrl(Register dst, Register src);
@@ -2433,7 +2436,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 // instructions and relocation information.  The constructor makes
 // sure that there is enough space and (in debug mode) the destructor
 // checks that we did not generate too much.
-class EnsureSpace BASE_EMBEDDED {
+class EnsureSpace {
  public:
   explicit EnsureSpace(Assembler* assembler) : assembler_(assembler) {
     if (assembler_->buffer_overflow()) assembler_->GrowBuffer();
diff --git a/deps/v8/src/x64/code-stubs-x64.cc b/deps/v8/src/x64/code-stubs-x64.cc
index 5310a64714..d13181eea3 100644
--- a/deps/v8/src/x64/code-stubs-x64.cc
+++ b/deps/v8/src/x64/code-stubs-x64.cc
@@ -107,7 +107,7 @@ void JSEntryStub::Generate(MacroAssembler* masm) {
   ExternalReference pending_exception = ExternalReference::Create(
       IsolateAddressId::kPendingExceptionAddress, isolate());
   __ Store(pending_exception, rax);
-  __ LoadRoot(rax, Heap::kExceptionRootIndex);
+  __ LoadRoot(rax, RootIndex::kException);
   __ jmp(&exit);
 
   // Invoke: Link this frame into the handler chain.
@@ -352,19 +352,19 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ CmpInstanceType(map, FIRST_JS_RECEIVER_TYPE);
   __ j(above_equal, &ok, Label::kNear);
 
-  __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
+  __ CompareRoot(map, RootIndex::kHeapNumberMap);
   __ j(equal, &ok, Label::kNear);
 
-  __ CompareRoot(return_value, Heap::kUndefinedValueRootIndex);
+  __ CompareRoot(return_value, RootIndex::kUndefinedValue);
   __ j(equal, &ok, Label::kNear);
 
-  __ CompareRoot(return_value, Heap::kTrueValueRootIndex);
+  __ CompareRoot(return_value, RootIndex::kTrueValue);
   __ j(equal, &ok, Label::kNear);
 
-  __ CompareRoot(return_value, Heap::kFalseValueRootIndex);
+  __ CompareRoot(return_value, RootIndex::kFalseValue);
   __ j(equal, &ok, Label::kNear);
 
-  __ CompareRoot(return_value, Heap::kNullValueRootIndex);
+  __ CompareRoot(return_value, RootIndex::kNullValue);
   __ j(equal, &ok, Label::kNear);
 
   __ Abort(AbortReason::kAPICallReturnedInvalidObject);
@@ -428,15 +428,15 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   __ PopReturnAddressTo(return_address);
 
   // new target
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
 
   // call data
   __ Push(call_data);
 
   // return value
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
   // return value default
-  __ PushRoot(Heap::kUndefinedValueRootIndex);
+  __ PushRoot(RootIndex::kUndefinedValue);
   // isolate
   Register scratch = call_data;
   __ Move(scratch, ExternalReference::isolate_address(masm->isolate()));
@@ -526,7 +526,7 @@ void CallApiGetterStub::Generate(MacroAssembler* masm) {
   __ PopReturnAddressTo(scratch);
   __ Push(receiver);
   __ Push(FieldOperand(callback, AccessorInfo::kDataOffset));
-  __ LoadRoot(kScratchRegister, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
   __ Push(kScratchRegister);  // return value
   __ Push(kScratchRegister);  // return value default
   __ PushAddress(ExternalReference::isolate_address(isolate()));
diff --git a/deps/v8/src/x64/codegen-x64.cc b/deps/v8/src/x64/codegen-x64.cc
index 41fe3dc363..bced4a0fd3 100644
--- a/deps/v8/src/x64/codegen-x64.cc
+++ b/deps/v8/src/x64/codegen-x64.cc
@@ -5,7 +5,6 @@
 #if V8_TARGET_ARCH_X64
 
 #include "src/codegen.h"
-#include "src/isolate.h"
 #include "src/macro-assembler.h"
 #include "src/x64/assembler-x64-inl.h"
 
@@ -14,13 +13,14 @@ namespace internal {
 
 #define __ masm.
 
-UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
+UnaryMathFunction CreateSqrtFunction() {
+  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   size_t allocated = 0;
-  byte* buffer = AllocatePage(isolate->heap()->GetRandomMmapAddr(), &allocated);
+  byte* buffer = AllocatePage(page_allocator,
+                              page_allocator->GetRandomMmapAddr(), &allocated);
   if (buffer == nullptr) return nullptr;
 
-  MacroAssembler masm(isolate, buffer, static_cast<int>(allocated),
-                      CodeObjectRequired::kNo);
+  MacroAssembler masm(AssemblerOptions{}, buffer, static_cast<int>(allocated));
 
   // xmm0: raw double input.
   // Move double input into registers.
@@ -28,12 +28,13 @@ UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   __ Ret();
 
   CodeDesc desc;
-  masm.GetCode(isolate, &desc);
+  masm.GetCode(nullptr, &desc);
   DCHECK(!RelocInfo::RequiresRelocationAfterCodegen(desc));
 
   Assembler::FlushICache(buffer, allocated);
-  CHECK(SetPermissions(buffer, allocated, PageAllocator::kReadExecute));
-  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+  CHECK(SetPermissions(page_allocator, buffer, allocated,
+                       PageAllocator::kReadExecute));
+  return FUNCTION_CAST<UnaryMathFunction>(buffer);
 }
 
 #undef __
diff --git a/deps/v8/src/x64/disasm-x64.cc b/deps/v8/src/x64/disasm-x64.cc
index 371735590c..4b57221571 100644
--- a/deps/v8/src/x64/disasm-x64.cc
+++ b/deps/v8/src/x64/disasm-x64.cc
@@ -1816,7 +1816,7 @@ int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
         AppendToBuffer(",0x%x", (*current) & 7);
         current += 1;
       } else {
-        const char* mnemonic = "?";
+        const char* mnemonic;
         if (opcode == 0x54) {
           mnemonic = "andpd";
         } else  if (opcode == 0x56) {
@@ -2166,7 +2166,6 @@ int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
   } else if (opcode == 0xA2) {
     // CPUID
     AppendToBuffer("%s", mnemonic);
-
   } else if ((opcode & 0xF0) == 0x40) {
     // CMOVcc: conditional move.
     int condition = opcode & 0x0F;
@@ -2229,13 +2228,13 @@ int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
              opcode == 0xB7 || opcode == 0xAF) {
     // Size-extending moves, IMUL.
     current += PrintOperands(mnemonic, REG_OPER_OP_ORDER, current);
-
   } else if ((opcode & 0xF0) == 0x90) {
     // SETcc: Set byte on condition. Needs pointer to beginning of instruction.
     current = data + SetCC(data);
-
-  } else if (opcode == 0xAB || opcode == 0xA5 || opcode == 0xAD) {
-    // SHLD, SHRD (double-precision shift), BTS (bit set).
+  } else if (opcode == 0xA3 || opcode == 0xA5 || opcode == 0xAB ||
+             opcode == 0xAD) {
+    // BT (bit test), SHLD, BTS (bit test and set),
+    // SHRD (double-precision shift)
     AppendToBuffer("%s ", mnemonic);
     int mod, regop, rm;
     get_modrm(*current, &mod, &regop, &rm);
@@ -2245,6 +2244,14 @@ int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
     } else {
       AppendToBuffer(",%s,cl", NameOfCPURegister(regop));
     }
+  } else if (opcode == 0xBA) {
+    // BTS / BTR (bit test and set/reset) with immediate
+    int mod, regop, rm;
+    get_modrm(*current, &mod, &regop, &rm);
+    mnemonic = regop == 5 ? "bts" : regop == 6 ? "btr" : "?";
+    AppendToBuffer("%s ", mnemonic);
+    current += PrintRightOperand(current);
+    AppendToBuffer(",%d", *current++);
   } else if (opcode == 0xB8 || opcode == 0xBC || opcode == 0xBD) {
     // POPCNT, CTZ, CLZ.
     AppendToBuffer("%s%c ", mnemonic, operand_size_code());
@@ -2297,6 +2304,8 @@ const char* DisassemblerX64::TwoByteMnemonic(byte opcode) {
       return (group_1_prefix_ == 0xF2) ? "maxsd" : "maxss";
     case 0xA2:
       return "cpuid";
+    case 0xA3:
+      return "bt";
     case 0xA5:
       return "shld";
     case 0xAB:
diff --git a/deps/v8/src/x64/interface-descriptors-x64.cc b/deps/v8/src/x64/interface-descriptors-x64.cc
index 65c708024d..0115fcf75d 100644
--- a/deps/v8/src/x64/interface-descriptors-x64.cc
+++ b/deps/v8/src/x64/interface-descriptors-x64.cc
@@ -90,9 +90,9 @@ void CallVarargsDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   // rax : number of arguments (on the stack, not including receiver)
   // rdi : the target to call
-  // rbx : arguments list (FixedArray)
   // rcx : arguments list length (untagged)
-  Register registers[] = {rdi, rax, rbx, rcx};
+  // rbx : arguments list (FixedArray)
+  Register registers[] = {rdi, rax, rcx, rbx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -127,9 +127,9 @@ void ConstructVarargsDescriptor::InitializePlatformSpecific(
   // rax : number of arguments (on the stack, not including receiver)
   // rdi : the target to call
   // rdx : the new target
-  // rbx : arguments list (FixedArray)
   // rcx : arguments list length (untagged)
-  Register registers[] = {rdi, rdx, rax, rbx, rcx};
+  // rbx : arguments list (FixedArray)
+  Register registers[] = {rdi, rdx, rax, rcx, rbx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -195,7 +195,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       rdi,  // JSFunction
@@ -239,10 +239,10 @@ void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       rax,  // argument count (not including receiver)
+      rcx,  // address of first argument
+      rdi,  // constructor to call
       rdx,  // new target
-      rdi,  // constructor
       rbx,  // allocation site feedback if available, undefined otherwise
-      rcx,  // address of first argument
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
diff --git a/deps/v8/src/x64/macro-assembler-x64.cc b/deps/v8/src/x64/macro-assembler-x64.cc
index adb52afac9..16dc893ab7 100644
--- a/deps/v8/src/x64/macro-assembler-x64.cc
+++ b/deps/v8/src/x64/macro-assembler-x64.cc
@@ -21,6 +21,7 @@
 #include "src/objects-inl.h"
 #include "src/register-configuration.h"
 #include "src/snapshot/snapshot.h"
+#include "src/string-constants.h"
 #include "src/x64/assembler-x64.h"
 
 #include "src/x64/macro-assembler-x64.h"  // Cannot be the first include.
@@ -135,8 +136,8 @@ void MacroAssembler::Store(ExternalReference destination, Register source) {
 void TurboAssembler::LoadFromConstantsTable(Register destination,
                                             int constant_index) {
   DCHECK(isolate()->heap()->RootCanBeTreatedAsConstant(
-      Heap::kBuiltinsConstantsTableRootIndex));
-  LoadRoot(destination, Heap::kBuiltinsConstantsTableRootIndex);
+      RootIndex::kBuiltinsConstantsTable));
+  LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
   movp(destination,
        FieldOperand(destination,
                     FixedArray::kHeaderSize + constant_index * kPointerSize));
@@ -192,22 +193,22 @@ void MacroAssembler::PushAddress(ExternalReference source) {
   Push(kScratchRegister);
 }
 
-void TurboAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
+void TurboAssembler::LoadRoot(Register destination, RootIndex index) {
   DCHECK(root_array_available_);
   movp(destination, Operand(kRootRegister, RootRegisterOffset(index)));
 }
 
-void MacroAssembler::PushRoot(Heap::RootListIndex index) {
+void MacroAssembler::PushRoot(RootIndex index) {
   DCHECK(root_array_available_);
   Push(Operand(kRootRegister, RootRegisterOffset(index)));
 }
 
-void TurboAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
+void TurboAssembler::CompareRoot(Register with, RootIndex index) {
   DCHECK(root_array_available_);
   cmpp(with, Operand(kRootRegister, RootRegisterOffset(index)));
 }
 
-void TurboAssembler::CompareRoot(Operand with, Heap::RootListIndex index) {
+void TurboAssembler::CompareRoot(Operand with, RootIndex index) {
   DCHECK(root_array_available_);
   DCHECK(!with.AddressUsesRegister(kScratchRegister));
   LoadRoot(kScratchRegister, index);
@@ -285,8 +286,6 @@ void TurboAssembler::CallRecordWriteStub(
       RecordWriteDescriptor::kObject));
   Register slot_parameter(
       callable.descriptor().GetRegisterParameter(RecordWriteDescriptor::kSlot));
-  Register isolate_parameter(callable.descriptor().GetRegisterParameter(
-      RecordWriteDescriptor::kIsolate));
   Register remembered_set_parameter(callable.descriptor().GetRegisterParameter(
       RecordWriteDescriptor::kRememberedSet));
   Register fp_mode_parameter(callable.descriptor().GetRegisterParameter(
@@ -311,8 +310,6 @@ void TurboAssembler::CallRecordWriteStub(
     xchgq(slot_parameter, object_parameter);
   }
 
-  LoadAddress(isolate_parameter, ExternalReference::isolate_address(isolate()));
-
   Smi* smi_rsa = Smi::FromEnum(remembered_set_action);
   Smi* smi_fm = Smi::FromEnum(fp_mode);
   Move(remembered_set_parameter, smi_rsa);
@@ -1343,6 +1340,12 @@ void TurboAssembler::Move(Operand dst, Handle<HeapObject> object,
   movp(dst, kScratchRegister);
 }
 
+void TurboAssembler::MoveStringConstant(Register result,
+                                        const StringConstantBase* string,
+                                        RelocInfo::Mode rmode) {
+  movp_string(result, string);
+}
+
 void MacroAssembler::Drop(int stack_elements) {
   if (stack_elements > 0) {
     addp(rsp, Immediate(stack_elements * kPointerSize));
@@ -2173,7 +2176,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
   // Clear the new.target register if not given.
   if (!new_target.is_valid()) {
-    LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
+    LoadRoot(rdx, RootIndex::kUndefinedValue);
   }
 
   Label done;
diff --git a/deps/v8/src/x64/macro-assembler-x64.h b/deps/v8/src/x64/macro-assembler-x64.h
index 6b96c3dcb3..25c488ad35 100644
--- a/deps/v8/src/x64/macro-assembler-x64.h
+++ b/deps/v8/src/x64/macro-assembler-x64.h
@@ -50,6 +50,8 @@ constexpr Register kOffHeapTrampolineRegister = kScratchRegister;
 // Convenience for platform-independent signatures.
 typedef Operand MemOperand;
 
+class StringConstantBase;
+
 enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
 enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 
@@ -66,7 +68,7 @@ enum StackArgumentsAccessorReceiverMode {
   ARGUMENTS_DONT_CONTAIN_RECEIVER
 };
 
-class StackArgumentsAccessor BASE_EMBEDDED {
+class StackArgumentsAccessor {
  public:
   StackArgumentsAccessor(Register base_reg, int argument_count_immediate,
                          StackArgumentsAccessorReceiverMode receiver_mode =
@@ -114,6 +116,9 @@ class StackArgumentsAccessor BASE_EMBEDDED {
 
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
+  TurboAssembler(const AssemblerOptions& options, void* buffer, int buffer_size)
+      : TurboAssemblerBase(options, buffer, buffer_size) {}
+
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
                  CodeObjectRequired create_code_object)
@@ -215,8 +220,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Set(Operand dst, intptr_t x);
 
   // Operations on roots in the root-array.
-  void LoadRoot(Register destination, Heap::RootListIndex index) override;
-  void LoadRoot(Operand destination, Heap::RootListIndex index) {
+  void LoadRoot(Register destination, RootIndex index) override;
+  void LoadRoot(Operand destination, RootIndex index) {
     LoadRoot(kScratchRegister, index);
     movp(destination, kScratchRegister);
   }
@@ -350,6 +355,9 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
     movp(dst, ptr, rmode);
   }
 
+  void MoveStringConstant(Register result, const StringConstantBase* string,
+                          RelocInfo::Mode rmode = RelocInfo::EMBEDDED_OBJECT);
+
   // Convert smi to word-size sign-extended value.
   void SmiUntag(Register dst, Register src);
   void SmiUntag(Register dst, Operand src);
@@ -401,8 +409,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Pinsrd(XMMRegister dst, Register src, int8_t imm8);
   void Pinsrd(XMMRegister dst, Operand src, int8_t imm8);
 
-  void CompareRoot(Register with, Heap::RootListIndex index);
-  void CompareRoot(Operand with, Heap::RootListIndex index);
+  void CompareRoot(Register with, RootIndex index);
+  void CompareRoot(Operand with, RootIndex index);
 
   // Generates function and stub prologue code.
   void StubPrologue(StackFrame::Type type);
@@ -517,11 +525,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler : public TurboAssembler {
  public:
-  // TODO(titzer): inline this utility constructor.
+  MacroAssembler(const AssemblerOptions& options, void* buffer, int size)
+      : TurboAssembler(options, buffer, size) {}
+
   MacroAssembler(Isolate* isolate, void* buffer, int size,
                  CodeObjectRequired create_code_object)
       : MacroAssembler(isolate, AssemblerOptions::Default(isolate), buffer,
                        size, create_code_object) {}
+
   MacroAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int size, CodeObjectRequired create_code_object);
 
@@ -541,29 +552,27 @@ class MacroAssembler : public TurboAssembler {
   // Load a root value where the index (or part of it) is variable.
   // The variable_offset register is added to the fixed_offset value
   // to get the index into the root-array.
-  void PushRoot(Heap::RootListIndex index);
+  void PushRoot(RootIndex index);
 
   // Compare the object in a register to a value and jump if they are equal.
-  void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal,
+  void JumpIfRoot(Register with, RootIndex index, Label* if_equal,
                   Label::Distance if_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(equal, if_equal, if_equal_distance);
   }
-  void JumpIfRoot(Operand with, Heap::RootListIndex index, Label* if_equal,
+  void JumpIfRoot(Operand with, RootIndex index, Label* if_equal,
                   Label::Distance if_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(equal, if_equal, if_equal_distance);
   }
 
   // Compare the object in a register to a value and jump if they are not equal.
-  void JumpIfNotRoot(Register with, Heap::RootListIndex index,
-                     Label* if_not_equal,
+  void JumpIfNotRoot(Register with, RootIndex index, Label* if_not_equal,
                      Label::Distance if_not_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(not_equal, if_not_equal, if_not_equal_distance);
   }
-  void JumpIfNotRoot(Operand with, Heap::RootListIndex index,
-                     Label* if_not_equal,
+  void JumpIfNotRoot(Operand with, RootIndex index, Label* if_not_equal,
                      Label::Distance if_not_equal_distance = Label::kFar) {
     CompareRoot(with, index);
     j(not_equal, if_not_equal, if_not_equal_distance);
diff --git a/deps/v8/src/zone/zone-allocator.h b/deps/v8/src/zone/zone-allocator.h
index 3914241e04..b3ce2473b6 100644
--- a/deps/v8/src/zone/zone-allocator.h
+++ b/deps/v8/src/zone/zone-allocator.h
@@ -42,7 +42,7 @@ class ZoneAllocator {
   T* address(T& x) const { return &x; }
   const T* address(const T& x) const { return &x; }
 
-  T* allocate(size_t n, const void* hint = 0) {
+  T* allocate(size_t n, const void* hint = nullptr) {
     return static_cast<T*>(zone_->NewArray<T>(static_cast<int>(n)));
   }
   void deallocate(T* p, size_t) { /* noop for Zones */
@@ -103,7 +103,7 @@ class RecyclingZoneAllocator : public ZoneAllocator<T> {
   template <typename U>
   friend class RecyclingZoneAllocator;
 
-  T* allocate(size_t n, const void* hint = 0) {
+  T* allocate(size_t n, const void* hint = nullptr) {
     // Only check top block in free list, since this will be equal to or larger
     // than the other blocks in the free list.
     if (free_list_ && free_list_->size >= n) {
diff --git a/deps/v8/src/zone/zone-chunk-list.h b/deps/v8/src/zone/zone-chunk-list.h
index 9c0c073a81..049e8f52a9 100644
--- a/deps/v8/src/zone/zone-chunk-list.h
+++ b/deps/v8/src/zone/zone-chunk-list.h
@@ -155,8 +155,8 @@ class ZoneChunkListIterator
   using ChunkList = maybe_const<ZoneChunkList<T>>;
 
  public:
-  maybe_const<T>& operator*() { return current_->items()[position_]; }
-  maybe_const<T>* operator->() { return &current_->items()[position_]; }
+  maybe_const<T>& operator*() const { return current_->items()[position_]; }
+  maybe_const<T>* operator->() const { return &current_->items()[position_]; }
   bool operator==(const ZoneChunkListIterator& other) const {
     return other.current_ == current_ && other.position_ == position_;
   }
diff --git a/deps/v8/src/zone/zone-containers.h b/deps/v8/src/zone/zone-containers.h
index 1988826779..86c4bd0702 100644
--- a/deps/v8/src/zone/zone-containers.h
+++ b/deps/v8/src/zone/zone-containers.h
@@ -161,10 +161,10 @@ class ZoneUnorderedMap
                                 ZoneAllocator<std::pair<const K, V>>> {
  public:
   // Constructs an empty map.
-  explicit ZoneUnorderedMap(Zone* zone)
+  explicit ZoneUnorderedMap(Zone* zone, size_t bucket_count = 100)
       : std::unordered_map<K, V, Hash, KeyEqual,
                            ZoneAllocator<std::pair<const K, V>>>(
-            100, Hash(), KeyEqual(),
+            bucket_count, Hash(), KeyEqual(),
             ZoneAllocator<std::pair<const K, V>>(zone)) {}
 };
 
diff --git a/deps/v8/src/zone/zone.cc b/deps/v8/src/zone/zone.cc
index 295d7815cb..a851f6797a 100644
--- a/deps/v8/src/zone/zone.cc
+++ b/deps/v8/src/zone/zone.cc
@@ -43,7 +43,6 @@ Zone::Zone(AccountingAllocator* allocator, const char* name,
 
 Zone::~Zone() {
   allocator_->ZoneDestruction(this);
-
   DeleteAll();
 
   DCHECK_EQ(segment_bytes_allocated_, 0);
@@ -77,6 +76,12 @@ void* Zone::New(size_t size) {
   return reinterpret_cast<void*>(result);
 }
 
+void Zone::ReleaseMemory() {
+  allocator_->ZoneDestruction(this);
+  DeleteAll();
+  allocator_->ZoneCreation(this);
+}
+
 void Zone::DeleteAll() {
   // Traverse the chained list of segments and return them all to the allocator.
   for (Segment* current = segment_head_; current;) {
diff --git a/deps/v8/src/zone/zone.h b/deps/v8/src/zone/zone.h
index 6f863f27fd..5fcc25b350 100644
--- a/deps/v8/src/zone/zone.h
+++ b/deps/v8/src/zone/zone.h
@@ -9,8 +9,10 @@
 
 #include "src/base/hashmap.h"
 #include "src/base/logging.h"
+#include "src/base/threaded-list.h"
 #include "src/globals.h"
 #include "src/splay-tree.h"
+#include "src/utils.h"
 #include "src/zone/accounting-allocator.h"
 
 #ifndef ZONE_NAME
@@ -56,6 +58,10 @@ class V8_EXPORT_PRIVATE Zone final {
   // Seals the zone to prevent any further allocation.
   void Seal() { sealed_ = true; }
 
+  // Allows the zone to be safely reused. Releases the memory and fires zone
+  // destruction and creation events for the accounting allocator.
+  void ReleaseMemory();
+
   // Returns true if more memory has been allocated in zones than
   // the limit allows.
   bool excess_allocation() const {
@@ -69,6 +75,9 @@ class V8_EXPORT_PRIVATE Zone final {
   AccountingAllocator* allocator() const { return allocator_; }
 
  private:
+  // Deletes all objects and free all memory allocated in the Zone.
+  void DeleteAll();
+
   // All pointers returned from New() are 8-byte aligned.
   static const size_t kAlignmentInBytes = 8;
 
@@ -81,9 +90,6 @@ class V8_EXPORT_PRIVATE Zone final {
   // Report zone excess when allocation exceeds this limit.
   static const size_t kExcessLimit = 256 * MB;
 
-  // Deletes all objects and free all memory allocated in the Zone.
-  void DeleteAll();
-
   // The number of bytes allocated in this zone so far.
   size_t allocation_size_;
 
@@ -295,6 +301,11 @@ class ZoneList final {
 template <typename T>
 using ZonePtrList = ZoneList<T*>;
 
+// ZoneThreadedList is a special variant of the ThreadedList that can be put
+// into a Zone.
+template <typename T, typename TLTraits = base::ThreadedListTraits<T>>
+using ZoneThreadedList = base::ThreadedListBase<T, ZoneObject, TLTraits>;
+
 // A zone splay tree.  The config type parameter encapsulates the
 // different configurations of a concrete splay tree (see splay-tree.h).
 // The tree itself and all its elements are allocated in the Zone.