ARM: Implement DoMathRound in the lithium code generator.

src/arm/lithium-arm.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 1186 matching lines @@
   LOperand* temp = (op == kMathFloor) ? TempRegister() : NULL;
   LUnaryMathOperation* result = new LUnaryMathOperation(input, temp);
   switch (op) {
     case kMathAbs:
       return AssignEnvironment(AssignPointerMap(DefineSameAsFirst(result)));
     case kMathFloor:
       return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
     case kMathSqrt:
       return DefineSameAsFirst(result);
     case kMathRound:
-      Abort("MathRound LUnaryMathOperation not implemented");
-      return NULL;
+      return AssignEnvironment(DefineAsRegister(result));
     case kMathPowHalf:
       Abort("MathPowHalf LUnaryMathOperation not implemented");
       return NULL;
     case kMathLog:
       Abort("MathLog LUnaryMathOperation not implemented");
       return NULL;
     case kMathCos:
       Abort("MathCos LUnaryMathOperation not implemented");
       return NULL;
     case kMathSin:
@@ skipping 782 matching lines @@
 
 
 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   HEnvironment* outer = current_block_->last_environment()->outer();
   current_block_->UpdateEnvironment(outer);
   return NULL;
 }
 
 
 } }  // namespace v8::internal