Improve GVN handling of ElementTransitions.

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 4676 matching lines @@
 
   // Computes a hash value for this map, to be used in HashTables and such.
   int Hash();
 
   // Compares this map to another to see if they describe equivalent objects.
   // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
   // it had exactly zero inobject properties.
   // The "shared" flags of both this map and |other| are ignored.
   bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
 
-  // Returns true if this map and |other| describe equivalent objects.
-  // The "shared" flags of both this map and |other| are ignored.
-  bool EquivalentTo(Map* other) {
-    return EquivalentToForNormalization(other, KEEP_INOBJECT_PROPERTIES);
-  }
-
   // Returns the contents of this map's descriptor array for the given string.
   // May return NULL. |safe_to_add_transition| is set to false and NULL
   // is returned if adding transitions is not allowed.
   Object* GetDescriptorContents(String* sentinel_name,
                                 bool* safe_to_add_transitions);
 
   // Returns the map that this map transitions to if its elements_kind
   // is changed to |elements_kind|, or NULL if no such map is cached yet.
   // |safe_to_add_transitions| is set to false if adding transitions is not
   // allowed.
@@ skipping 3530 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_