Reapplying r5147 (caching maps for slow case objects)....

src/ic.h

 // Copyright 2006-2009 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 105 matching lines @@
   bool SlowIsContextual() {
     return ComputeMode() == RelocInfo::CODE_TARGET_CONTEXT;
   }
 
   // Determines which map must be used for keeping the code stub.
   // These methods should not be called with undefined or null.
   static inline InlineCacheHolderFlag GetCodeCacheForObject(Object* object,
                                                             JSObject* holder);
   static inline InlineCacheHolderFlag GetCodeCacheForObject(JSObject* object,
                                                             JSObject* holder);
-  static inline Map* GetCodeCacheMap(Object* object,
-                                     InlineCacheHolderFlag holder);
+  static inline JSObject* GetCodeCacheHolder(Object* object,
+                                             InlineCacheHolderFlag holder);
 
  protected:
   Address fp() const { return fp_; }
   Address pc() const { return *pc_address_; }
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Computes the address in the original code when the code running is
   // containing break points (calls to DebugBreakXXX builtins).
   Address OriginalCodeAddress();
 #endif
@@ skipping 368 matching lines @@
   static const char* GetName(TypeInfo type_info);
 
   static State ToState(TypeInfo type_info);
 
   static TypeInfo GetTypeInfo(Object* left, Object* right);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_IC_H_