Simplify and compact transitions storage

src/hydrogen.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_H_
 #define V8_HYDROGEN_H_
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 2535 matching lines @@
 
     void LookupDescriptor(Map* map, Name* name) {
       DescriptorArray* descriptors = map->instance_descriptors();
       int number = descriptors->SearchWithCache(name, map);
       if (number == DescriptorArray::kNotFound) return NotFound();
       lookup_type_ = DESCRIPTOR_TYPE;
       details_ = descriptors->GetDetails(number);
       number_ = number;
     }
     void LookupTransition(Map* map, Name* name, PropertyAttributes attributes) {
-      int transition_index = map->SearchTransition(kData, name, attributes);
-      if (transition_index == TransitionArray::kNotFound) return NotFound();
+      Map* target =
+          TransitionArray::SearchTransition(map, kData, name, attributes);
+      if (target == NULL) return NotFound();
       lookup_type_ = TRANSITION_TYPE;
-      transition_ = handle(map->GetTransition(transition_index));
+      transition_ = handle(target);
       number_ = transition_->LastAdded();
       details_ = transition_->instance_descriptors()->GetDetails(number_);
     }
     void NotFound() {
       lookup_type_ = NOT_FOUND;
       details_ = PropertyDetails(NONE, DATA, 0);
     }
     Representation representation() const {
       DCHECK(IsFound());
       return details_.representation();
@@ skipping 393 matching lines @@
   }
 
  private:
   HGraphBuilder* builder_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_