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diff --git a/deps/v8/src/builtins/constants-table-builder.h b/deps/v8/src/builtins/constants-table-builder.h
new file mode 100644
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+++ b/deps/v8/src/builtins/constants-table-builder.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_BUILTINS_CONSTANTS_TABLE_BUILDER_H_
+#define V8_BUILTINS_CONSTANTS_TABLE_BUILDER_H_
+
+#include "src/allocation.h"
+#include "src/base/macros.h"
+#include "src/handles.h"
+#include "src/identity-map.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+class Object;
+
+// Utility class to build the builtins constants table and store it on the root
+// list. The constants table contains constants used by builtins, and is there
+// to avoid directly embedding them into code objects, which would not be
+// possible for off-heap (and thus immutable) code objects.
+class BuiltinsConstantsTableBuilder final {
+ public:
+  explicit BuiltinsConstantsTableBuilder(Isolate* isolate);
+
+  // Returns the index within the builtins constants list for the given object,
+  // possibly adding the object to the cache. Objects are deduplicated.
+  uint32_t AddObject(Handle<Object> object);
+
+  // Should be called after all affected code (e.g. builtins and bytecode
+  // handlers) has been generated.
+  void Finalize();
+
+ private:
+  Isolate* isolate_;
+
+  // Maps objects to corresponding indices within the constants list.
+  typedef IdentityMap<uint32_t, FreeStoreAllocationPolicy> ConstantsMap;
+  ConstantsMap map_;
+
+  DISALLOW_COPY_AND_ASSIGN(BuiltinsConstantsTableBuilder)
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_BUILTINS_CONSTANTS_TABLE_BUILDER_H_