Replace tagged keys for fast access by smi, and use smi in boundscheck.

src/ia32/lithium-ia32.h

 // Copyright 2012 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 1578 matching lines @@
   }
 };
 
 
 inline static bool ExternalArrayOpRequiresTemp(
     Representation key_representation,
     ElementsKind elements_kind) {
   // Operations that require the key to be divided by two to be converted into
   // an index cannot fold the scale operation into a load and need an extra
   // temp register to do the work.
-  return key_representation.IsTagged() &&
+  return key_representation.IsSmi() &&
       (elements_kind == EXTERNAL_BYTE_ELEMENTS ||
        elements_kind == EXTERNAL_UNSIGNED_BYTE_ELEMENTS ||
        elements_kind == EXTERNAL_PIXEL_ELEMENTS);
 }
 
 
 class LLoadKeyedGeneric: public LTemplateInstruction<1, 3, 0> {
  public:
   LLoadKeyedGeneric(LOperand* context, LOperand* obj, LOperand* key) {
     inputs_[0] = context;
@@ skipping 1377 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_LITHIUM_IA32_H_