Fix slack tracking when instance prototype changes.

src/objects.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 6093 matching lines @@
 
   inline FixedArray* literals();
   inline void set_literals(FixedArray* literals);
 
   inline FixedArray* function_bindings();
   inline void set_function_bindings(FixedArray* bindings);
 
   // The initial map for an object created by this constructor.
   inline Map* initial_map();
   inline void set_initial_map(Map* value);
-  MUST_USE_RESULT inline MaybeObject* set_initial_map_and_cache_transitions(
-      Map* value);
   inline bool has_initial_map();
 
   // Get and set the prototype property on a JSFunction. If the
   // function has an initial map the prototype is set on the initial
   // map. Otherwise, the prototype is put in the initial map field
   // until an initial map is needed.
   inline bool has_prototype();
   inline bool has_instance_prototype();
   inline Object* prototype();
   inline Object* instance_prototype();
@@ skipping 2829 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_