Use a wrapper for copying object.

src/heap.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 2092 matching lines @@
   MUST_USE_RESULT MaybeObject* AllocateEmptyFixedArray();
 
   // Allocate empty external array of given type.
   MUST_USE_RESULT MaybeObject* AllocateEmptyExternalArray(
       ExternalArrayType array_type);
 
   // Allocate empty fixed typed array of given type.
   MUST_USE_RESULT MaybeObject* AllocateEmptyFixedTypedArray(
       ExternalArrayType array_type);
 
-  // Allocate empty fixed double array.
-  MUST_USE_RESULT MaybeObject* AllocateEmptyFixedDoubleArray();
-
   // Allocate empty constant pool array.
   MUST_USE_RESULT MaybeObject* AllocateEmptyConstantPoolArray();
 
   // Allocate a tenured simple cell.
   MUST_USE_RESULT MaybeObject* AllocateCell(Object* value);
 
   // Allocate a tenured JS global property cell initialized with the hole.
   MUST_USE_RESULT MaybeObject* AllocatePropertyCell();
 
   // Performs a minor collection in new generation.
@@ skipping 875 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_