Replace mapcheck dependency on HStoreNamedField with object.

src/hydrogen.cc

 // Copyright 2013 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 4477 matching lines @@
     if (transition_to_field) {
       // The store requires a mutable HeapNumber to be allocated.
       NoObservableSideEffectsScope no_side_effects(this);
       HInstruction* heap_number_size = Add<HConstant>(HeapNumber::kSize);
       HInstruction* heap_number = Add<HAllocate>(heap_number_size,
           HType::HeapNumber(), isolate()->heap()->GetPretenureMode(),
           HEAP_NUMBER_TYPE);
       AddStoreMapConstant(heap_number, isolate()->factory()->heap_number_map());
       Add<HStoreNamedField>(heap_number, HObjectAccess::ForHeapNumberValue(),
                             value);
-      instr = New<HStoreNamedField>(checked_object,
+      instr = New<HStoreNamedField>(checked_object->ActualValue(),
                                     heap_number_access,
                                     heap_number);
     } else {
       // Already holds a HeapNumber; load the box and write its value field.
       HInstruction* heap_number = Add<HLoadNamedField>(checked_object,
                                                        heap_number_access);
       heap_number->set_type(HType::HeapNumber());
       instr = New<HStoreNamedField>(heap_number,
                                     HObjectAccess::ForHeapNumberValue(),
                                     value);
     }
   } else {
     // This is a normal store.
-    instr = New<HStoreNamedField>(checked_object, field_access, value);
+    instr = New<HStoreNamedField>(checked_object->ActualValue(),
+                                  field_access,
+                                  value);
   }
 
   if (transition_to_field) {
     Handle<Map> transition(lookup->GetTransitionMapFromMap(*map));
     HConstant* transition_constant = Add<HConstant>(transition);
     instr->SetTransition(transition_constant, top_info());
     // TODO(fschneider): Record the new map type of the object in the IR to
     // enable elimination of redundant checks after the transition store.
     instr->SetGVNFlag(kChangesMaps);
   }
@@ skipping 5341 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal