MIPS: Removed unused variables.

src/mips/full-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 3732 matching lines @@
   Register separator = a1;
   Register array_length = a2;
   Register result_pos = no_reg;  // Will be a2.
   Register string_length = a3;
   Register string = t0;
   Register element = t1;
   Register elements_end = t2;
   Register scratch1 = t3;
   Register scratch2 = t5;
   Register scratch3 = t4;
-  Register scratch4 = v1;
 
   // Separator operand is on the stack.
   __ pop(separator);
 
   // Check that the array is a JSArray.
   __ JumpIfSmi(array, &bailout);
   __ GetObjectType(array, scratch1, scratch2);
   __ Branch(&bailout, ne, scratch2, Operand(JS_ARRAY_TYPE));
 
   // Check that the array has fast elements.
@@ skipping 907 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS