Fix load elimination: can only .Equals() GVN-able instructions.

src/hydrogen-load-elimination.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 331 matching lines @@
           continue;
         }
       }
       prev = approx;
       approx = approx->next_;
     }
   }
 
   bool Equal(HValue* a, HValue* b) {
     if (a == b) return true;
-    if (a != NULL && b != NULL) return a->Equals(b);
+    if (a != NULL && b != NULL && a->CheckFlag(HValue::kUseGVN)) {
+      return a->Equals(b);
+    }
     return false;
   }
 
   // Remove the last approximation for a field so that it can be reused.
   // We reuse the last entry because it was the first inserted and is thus
   // farthest away from the current instruction.
   HFieldApproximation* ReuseLastApproximation(int field) {
     HFieldApproximation* approx = fields_[field];
     ASSERT(approx != NULL);
 
@@ skipping 136 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