MIPS: Fix test262 regression.

src/mips/lithium-codegen-mips.cc

 // 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 1250 matching lines @@
         uint32_t constant_abs = (constant + mask) ^ mask;
 
         if (IsPowerOf2(constant_abs) ||
             IsPowerOf2(constant_abs - 1) ||
             IsPowerOf2(constant_abs + 1)) {
           if (IsPowerOf2(constant_abs)) {
             int32_t shift = WhichPowerOf2(constant_abs);
             __ sll(result, left, shift);
           } else if (IsPowerOf2(constant_abs - 1)) {
             int32_t shift = WhichPowerOf2(constant_abs - 1);
-            __ sll(result, left, shift);
-            __ Addu(result, result, left);
+            __ sll(scratch, left, shift);
+            __ Addu(result, scratch, left);
           } else if (IsPowerOf2(constant_abs + 1)) {
             int32_t shift = WhichPowerOf2(constant_abs + 1);
-            __ sll(result, left, shift);
-            __ Subu(result, result, left);
+            __ sll(scratch, left, shift);
+            __ Subu(result, scratch, left);
           }
 
           // Correct the sign of the result is the constant is negative.
           if (constant < 0)  {
             __ Subu(result, zero_reg, result);
           }
 
         } else {
           // Generate standard code.
           __ li(at, constant);
@@ skipping 4815 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal