Fix bug in X64 Math.abs optimization

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 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 2664 matching lines @@
     __ subsd(scratch, input_reg);
     __ andpd(input_reg, scratch);
   } else if (r.IsInteger32()) {
     EmitIntegerMathAbs(instr);
   } else {  // Tagged case.
     DeferredMathAbsTaggedHeapNumber* deferred =
         new DeferredMathAbsTaggedHeapNumber(this, instr);
     Register input_reg = ToRegister(instr->InputAt(0));
     // Smi check.
     __ JumpIfNotSmi(input_reg, deferred->entry());
+    __ SmiToInteger32(input_reg, input_reg);
     EmitIntegerMathAbs(instr);
+    __ Integer32ToSmi(input_reg, input_reg);
     __ bind(deferred->exit());
   }
 }
 
 
 void LCodeGen::DoMathFloor(LUnaryMathOperation* instr) {
   XMMRegister xmm_scratch = xmm0;
   Register output_reg = ToRegister(instr->result());
   XMMRegister input_reg = ToDoubleRegister(instr->InputAt(0));
 
@@ skipping 1318 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64