Optimize %ClassOf() on IA-32 and use it instead of the...

src/x64/codegen-x64.h

 // Copyright 2009 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 511 matching lines @@
   void GenerateIsNonNegativeSmi(ZoneList<Expression*>* args);
   void GenerateIsArray(ZoneList<Expression*>* args);
 
   // Support for construct call checks.
   void GenerateIsConstructCall(ZoneList<Expression*>* args);
 
   // Support for arguments.length and arguments[?].
   void GenerateArgumentsLength(ZoneList<Expression*>* args);
   void GenerateArgumentsAccess(ZoneList<Expression*>* args);
 
-  // Support for accessing the value field of an object (used by Date).
+  // Support for accessing the class and value fields of an object.
+  void GenerateClassOf(ZoneList<Expression*>* args);
   void GenerateValueOf(ZoneList<Expression*>* args);
   void GenerateSetValueOf(ZoneList<Expression*>* args);
 
   // Fast support for charCodeAt(n).
   void GenerateFastCharCodeAt(ZoneList<Expression*>* args);
 
   // Fast support for object equality testing.
   void GenerateObjectEquals(ZoneList<Expression*>* args);
 
   void GenerateLog(ZoneList<Expression*>* args);
@@ skipping 109 matching lines @@
   friend class Reference;
   friend class Result;
 
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_CODEGEN_X64_H_