Limit initial size of hidden properties and store identity hashes inline.

src/factory.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 279 matching lines @@
                                 Handle<FixedArrayBase> elements,
                                 uint32_t length,
                                 EnsureElementsMode mode);
 
   Handle<JSProxy> NewJSProxy(Handle<Object> handler, Handle<Object> prototype);
 
   // Change the type of the argument into a JS object/function and reinitialize.
   void BecomeJSObject(Handle<JSReceiver> object);
   void BecomeJSFunction(Handle<JSReceiver> object);
 
-  void SetIdentityHash(Handle<JSObject> object, Object* hash);
+  void SetIdentityHash(Handle<JSObject> object, Smi* hash);
 
   Handle<JSFunction> NewFunction(Handle<String> name,
                                  Handle<Object> prototype);
 
   Handle<JSFunction> NewFunctionWithoutPrototype(
       Handle<String> name,
       LanguageMode language_mode);
 
   Handle<JSFunction> NewFunction(Handle<Object> super, bool is_global);
 
@@ skipping 191 matching lines @@
   // Update the map cache in the global context with (keys, map)
   Handle<MapCache> AddToMapCache(Handle<Context> context,
                                  Handle<FixedArray> keys,
                                  Handle<Map> map);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_