Change keyed load IC interface on x64 to pass arguments in registers.

src/ia32/codegen-ia32.cc

 // Copyright 2010 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 8748 matching lines @@
     // Use a fresh temporary to load the elements without destroying
     // the receiver which is needed for the deferred slow case.
     Result elements = allocator()->Allocate();
     ASSERT(elements.is_valid());
 
     Result key = frame_->Pop();
     Result receiver = frame_->Pop();
     key.ToRegister();
     receiver.ToRegister();
 
+    // If key and receiver are shared registers on the frame, their values will
+    // be automatically saved and restored when going to deferred code.
+    // The result is in elements, which is guaranteed non-shared.
     DeferredReferenceGetKeyedValue* deferred =
         new DeferredReferenceGetKeyedValue(elements.reg(),
                                            receiver.reg(),
                                            key.reg());
 
     __ test(receiver.reg(), Immediate(kSmiTagMask));
     deferred->Branch(zero);
 
     // Check that the receiver has the expected map.
     // Initially, use an invalid map. The map is patched in the IC
@@ skipping 4710 matching lines @@
   // tagged as a small integer.
   __ bind(&runtime);
   __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32