Implement basic array prefetching hints in Hydrogen.

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 1422 matching lines @@
     inputs_[0] = object;
   }
 
   LOperand* object() { return inputs_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(LoadExternalArrayPointer,
                                "load-external-array-pointer")
 };
 
 
-class LLoadKeyed: public LTemplateInstruction<1, 2, 0> {
+class LLoadKeyed: public LTemplateInstruction<1, 3, 1> {
  public:
-  LLoadKeyed(LOperand* elements, LOperand* key) {
+  LLoadKeyed(LOperand* elements, LOperand* key, LOperand* prefetch_distance,
+             LOperand* temp) {
     inputs_[0] = elements;
     inputs_[1] = key;
+    inputs_[2] = prefetch_distance;
+    temps_[0] = temp;
   }
   LOperand* elements() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }
+  LOperand* prefetch_distance() { return inputs_[2]; }
+  LOperand* temp() { return temps_[0]; }
   ElementsKind elements_kind() const {
     return hydrogen()->elements_kind();
   }
   bool is_external() const {
     return hydrogen()->is_external();
   }
 
   virtual bool ClobbersDoubleRegisters() const {
     return !IsDoubleOrFloatElementsKind(hydrogen()->elements_kind());
   }
@@ skipping 1260 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_LITHIUM_IA32_H_