deps: cherry-pick 6803eef from V8 upstream

Original commit message:
  Allow embedder to set promise internal field count

  Asynchronous context tracking mechanisms in Node.js need to store some
  state on all promise objects. This change will allow embedders to
  configure the number of internal fields on promises as is already done
  for ArrayBuffers.

  BUG=v8:6435

  Review-Url: https://codereview.chromium.org/2889863002
  Cr-Commit-Position: refs/heads/master@{#45496}

PR-URL: https://github.com/nodejs/node/pull/13175
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/deps/v8/src/builtins/builtins-promise.cc b/deps/v8/src/builtins/builtins-promise.cc
index 0d0238d267..6d9fed83a9 100644
--- a/deps/v8/src/builtins/builtins-promise.cc
+++ b/deps/v8/src/builtins/builtins-promise.cc
@@ -31,6 +31,10 @@ void PromiseBuiltinsAssembler::PromiseInit(Node* promise) {
   StoreObjectField(promise, JSPromise::kStatusOffset,
                    SmiConstant(v8::Promise::kPending));
   StoreObjectField(promise, JSPromise::kFlagsOffset, SmiConstant(0));
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    int offset = JSPromise::kSize + i * kPointerSize;
+    StoreObjectFieldNoWriteBarrier(promise, offset, SmiConstant(Smi::kZero));
+  }
 }
 
 Node* PromiseBuiltinsAssembler::AllocateAndInitJSPromise(Node* context) {
@@ -62,6 +66,10 @@ Node* PromiseBuiltinsAssembler::AllocateAndSetJSPromise(Node* context,
   StoreObjectFieldNoWriteBarrier(instance, JSPromise::kResultOffset, result);
   StoreObjectFieldNoWriteBarrier(instance, JSPromise::kFlagsOffset,
                                  SmiConstant(0));
+  for (int i = 0; i < v8::Promise::kEmbedderFieldCount; i++) {
+    int offset = JSPromise::kSize + i * kPointerSize;
+    StoreObjectFieldNoWriteBarrier(instance, offset, SmiConstant(Smi::kZero));
+  }
 
   Label out(this);
   GotoIfNot(IsPromiseHookEnabledOrDebugIsActive(), &out);