Hydrogenize (and share) part of StoreTransition handler as a StoreTransitionStub.

src/interface-descriptors.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 56 matching lines @@
 }
 
 
 void StoreDescriptor::Initialize(CallInterfaceDescriptorData* data) {
   Register registers[] = {ContextRegister(), ReceiverRegister(), NameRegister(),
                           ValueRegister()};
   data->Initialize(arraysize(registers), registers, NULL);
 }
 
 
-void ExtendStorageDescriptor::Initialize(CallInterfaceDescriptorData* data) {
+void StoreTransitionDescriptor::Initialize(CallInterfaceDescriptorData* data) {
   Register registers[] = {ContextRegister(), ReceiverRegister(), NameRegister(),
                           ValueRegister(), MapRegister()};
   data->Initialize(arraysize(registers), registers, NULL);
 }
 
 
 void ElementTransitionAndStoreDescriptor::Initialize(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {ContextRegister(), ValueRegister(), MapRegister(),
                           NameRegister(), ReceiverRegister()};
@@ skipping 53 matching lines @@
 }
 
 
 void ContextOnlyDescriptor::Initialize(CallInterfaceDescriptorData* data) {
   Register registers[] = {ContextRegister()};
   data->Initialize(arraysize(registers), registers, NULL);
 }
 
 }
 }  // namespace v8::internal