The check for internalized strings relied on the fact that we had less

src/ia32/macro-assembler-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 866 matching lines @@
                                               Label* on_not_flat_ascii_string);
 
   // Checks if both objects are sequential ASCII strings, and jumps to label
   // if either is not.
   void JumpIfNotBothSequentialAsciiStrings(Register object1,
                                            Register object2,
                                            Register scratch1,
                                            Register scratch2,
                                            Label* on_not_flat_ascii_strings);
 
+  // Checks if the given register or operand is a unique name
+  void JumpIfNotUniqueName(Register reg, Label* not_unique_name,
+                           Label::Distance distance = Label::kFar) {
+    JumpIfNotUniqueName(Operand(reg), not_unique_name, distance);
+  }
+
+  void JumpIfNotUniqueName(Operand operand, Label* not_unique_name,
+                           Label::Distance distance = Label::kFar);
+
   static int SafepointRegisterStackIndex(Register reg) {
     return SafepointRegisterStackIndex(reg.code());
   }
 
   // Activation support.
   void EnterFrame(StackFrame::Type type);
   void LeaveFrame(StackFrame::Type type);
 
   // Expects object in eax and returns map with validated enum cache
   // in eax.  Assumes that any other register can be used as a scratch.
@@ skipping 147 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_H_