Revert "Refactor transitioning stores."

src/hydrogen-load-elimination.cc

 // Copyright 2013 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 "hydrogen-alias-analysis.h"
 #include "hydrogen-load-elimination.h"
 #include "hydrogen-instructions.h"
 #include "hydrogen-flow-engine.h"
 
 namespace v8 {
@@ skipping 222 matching lines @@
       TRACE(("  skipping non existing property initialization store\n"));
       return instr;
     }
 
     int field = FieldOf(instr->access());
     if (field < 0) return KillIfMisaligned(instr);
 
     HValue* object = instr->object()->ActualValue();
     HValue* value = instr->value();
 
-    if (instr->store_mode() == STORE_TO_INITIALIZED_ENTRY) {
+    if (instr->has_transition()) {
+      // A transition introduces a new field and alters the map of the object.
+      // Since the field in the object is new, it cannot alias existing entries.
+      // TODO(titzer): introduce a constant for the new map and remember it.
+      KillFieldInternal(object, FieldOf(JSObject::kMapOffset), NULL);
+    } else {
       // Kill non-equivalent may-alias entries.
       KillFieldInternal(object, field, value);
     }
     HFieldApproximation* approx = FindOrCreate(object, field);
 
     if (Equal(approx->last_value_, value)) {
       // The store is redundant because the field already has this value.
       return NULL;
     } else {
       // The store is not redundant. Update the entry.
@@ skipping 244 matching lines @@
   } else {
     // Perform only local analysis.
     for (int i = 0; i < graph()->blocks()->length(); i++) {
       table->Kill();
       engine.AnalyzeOneBlock(graph()->blocks()->at(i), table);
     }
   }
 }
 
 } }  // namespace v8::internal