Speed-up 'new TypedArray(arrayLike)'.

src/runtime.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 343 matching lines @@
   F(GetObservationState, 0, 1) \
   F(ObservationWeakMapCreate, 0, 1) \
   F(UnwrapGlobalProxy, 1, 1) \
   \
   /* Harmony typed arrays */ \
   F(ArrayBufferInitialize, 2, 1)\
   F(ArrayBufferGetByteLength, 1, 1)\
   F(ArrayBufferSliceImpl, 3, 1) \
   \
   F(TypedArrayInitialize, 5, 1) \
+  F(TypedArrayInitializeFromArrayLike, 4, 1) \
   F(TypedArrayGetBuffer, 1, 1) \
   F(TypedArrayGetByteLength, 1, 1) \
   F(TypedArrayGetByteOffset, 1, 1) \
   F(TypedArrayGetLength, 1, 1) \
   F(TypedArraySetFastCases, 3, 1) \
   \
   F(DataViewInitialize, 4, 1) \
   F(DataViewGetBuffer, 1, 1) \
   F(DataViewGetByteLength, 1, 1) \
   F(DataViewGetByteOffset, 1, 1) \
@@ skipping 403 matching lines @@
 
   static void SetupArrayBuffer(Isolate* isolate,
                                Handle<JSArrayBuffer> array_buffer,
                                bool is_external,
                                void* data,
                                size_t allocated_length);
 
   static bool SetupArrayBufferAllocatingData(
       Isolate* isolate,
       Handle<JSArrayBuffer> array_buffer,
-      size_t allocated_length);
+      size_t allocated_length,
+      bool initialize = true);
 
   static void FreeArrayBuffer(
       Isolate* isolate,
       JSArrayBuffer* phantom_array_buffer);
 
   // Helper functions used stubs.
   static void PerformGC(Object* result);
 
   // Used in runtime.cc and hydrogen's VisitArrayLiteral.
   static Handle<Object> CreateArrayLiteralBoilerplate(
       Isolate* isolate,
       Handle<FixedArray> literals,
       Handle<FixedArray> elements);
 };
 
 
 //---------------------------------------------------------------------------
 // Constants used by interface to runtime functions.
 
 class DeclareGlobalsEvalFlag:     public BitField<bool,         0, 1> {};
 class DeclareGlobalsNativeFlag:   public BitField<bool,         1, 1> {};
 class DeclareGlobalsLanguageMode: public BitField<LanguageMode, 2, 2> {};
 
 } }  // namespace v8::internal
 
 #endif  // V8_RUNTIME_H_