Experimental: fix debug test failure caused by r1160.

src/codegen-ia32.cc

 // Copyright 2006-2008 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 1148 matching lines @@
         ASSERT(kSmiTag == 0);  // adjust code if not the case
         if (shift_value == 0) {
           __ sar(answer.reg(), kSmiTagSize);
         } else if (shift_value > 1) {
           __ shl(answer.reg(), shift_value - 1);
         }  // We do no shifts, only the Smi conversion, if shift_value is 1.
         // Convert int result to Smi, checking that it is in int range.
         ASSERT(kSmiTagSize == times_2);  // adjust code if not the case
         __ add(answer.reg(), Operand(answer.reg()));
         deferred->enter()->Branch(overflow, &operand, not_taken);
+        operand.Unuse();
         deferred->exit()->Bind(&answer);
         frame_->Push(&answer);
       }
       break;
     }
 
     case Token::BIT_OR:
     case Token::BIT_XOR:
     case Token::BIT_AND: {
       DeferredCode* deferred = NULL;
@@ skipping 5022 matching lines @@
 
   // Slow-case: Go through the JavaScript implementation.
   __ bind(&slow);
   __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_FUNCTION);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal