Remove scratch register requirement from LoadInstanceDescriptors on arm and mips.

src/arm/lithium-codegen-arm.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 5603 matching lines @@
   __ LoadRoot(ip, Heap::kMetaMapRootIndex);
   __ cmp(r1, ip);
   DeoptimizeIf(ne, instr->environment());
   __ bind(&use_cache);
 }
 
 
 void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
   Register map = ToRegister(instr->map());
   Register result = ToRegister(instr->result());
-  Register scratch = ToRegister(instr->scratch());
   Label load_cache, done;
   __ EnumLength(result, map);
   __ cmp(result, Operand(Smi::FromInt(0)));
   __ b(ne, &load_cache);
   __ mov(result, Operand(isolate()->factory()->empty_fixed_array()));
   __ jmp(&done);
 
   __ bind(&load_cache);
-  __ LoadInstanceDescriptors(map, result, scratch);
+  __ LoadInstanceDescriptors(map, result);
   __ ldr(result,
          FieldMemOperand(result, DescriptorArray::kEnumCacheOffset));
   __ ldr(result,
          FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
   __ cmp(result, Operand(0));
   DeoptimizeIf(eq, instr->environment());
 
   __ bind(&done);
 }
 
@@ skipping 29 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal