Port inline in-object property stores from ia32 to x64.

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
===================================================================
--- src/ia32/codegen-ia32.cc	(revision 5112)
+++ src/ia32/codegen-ia32.cc	(working copy)
@@ -5339,13 +5339,13 @@
           // Duplicate the object as the IC receiver.
           frame_->Dup();
           Load(property->value());
-          Result dummy = frame_->CallStoreIC(Handle<String>::cast(key), false);
+          Result ignored =
+              frame_->CallStoreIC(Handle<String>::cast(key), false);
           // A test eax instruction following the store IC call would
           // indicate the presence of an inlined version of the
           // store. Add a nop to indicate that there is no such
           // inlined version.
           __ nop();
-          dummy.Unuse();
           break;
         }
         // Fall through