Remove support for smi-based keyed accesses on 64bit.

src/hydrogen-instructions.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 5867 matching lines @@
 class ArrayInstructionInterface {
  public:
   virtual HValue* GetKey() = 0;
   virtual void SetKey(HValue* key) = 0;
   virtual void SetIndexOffset(uint32_t index_offset) = 0;
   virtual bool IsDehoisted() = 0;
   virtual void SetDehoisted(bool is_dehoisted) = 0;
   virtual ~ArrayInstructionInterface() { };
 
   static Representation KeyedAccessIndexRequirement(Representation r) {
-    return r.IsInteger32() ? Representation::Integer32()
-                           : Representation::Smi();
+    return r.IsInteger32() || kSmiValueSize != 31
+        ? Representation::Integer32() : Representation::Smi();
   }
 };
 
 
 enum LoadKeyedHoleMode {
   NEVER_RETURN_HOLE,
   ALLOW_RETURN_HOLE
 };
 
 
@@ skipping 1047 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_