Fix/implement new write barrier for x64.

src/codegen.cc

 // Copyright 2010 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 455 matching lines @@
 void ArgumentsAccessStub::Generate(MacroAssembler* masm) {
   switch (type_) {
     case READ_ELEMENT: GenerateReadElement(masm); break;
     case NEW_OBJECT: GenerateNewObject(masm); break;
   }
 }
 
 
 int CEntryStub::MinorKey() {
   int result = (save_doubles_ == kSaveFPRegs) ? 1 : 0;
+  ASSERT(result_size_ == 1 || result_size_ == 2);
 #ifdef _WIN64
-  ASSERT(result_size_ == 1 || result_size_ == 2);
   return result | ((result_size_ == 1) ? 0 : 2);
 #else
-  ASSERT(result_size_ == 1);
   return result;
 #endif
 }
 
 
 } }  // namespace v8::internal