Ensure that all descriptors have a valid enumeration index, and replace NextEnumIndex with LastAdde…

src/transitions-inl.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 159 matching lines @@
     }
     return Map::cast(accessors->setter());
   }
   return Map::cast(value);
 }
 
 
 PropertyDetails TransitionArray::GetTargetDetails(int transition_number) {
   Map* map = GetTargetMap(transition_number);
   DescriptorArray* descriptors = map->instance_descriptors();
-  String* key = GetKey(transition_number);
-  int descriptor = descriptors->SearchWithCache(key);
+  int descriptor = descriptors->LastAdded();
   ASSERT(descriptor != DescriptorArray::kNotFound);
   return descriptors->GetDetails(descriptor);
 }
 
 
 Object** TransitionArray::GetElementsTransitionSlot() {
   return HeapObject::RawField(reinterpret_cast<HeapObject*>(this),
                               kElementsTransitionOffset);
 }
 
@@ skipping 17 matching lines @@
 
 
 #undef FIELD_ADDR
 #undef WRITE_FIELD
 #undef CONDITIONAL_WRITE_BARRIER
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TRANSITIONS_INL_H_