Remove scratch register requirement from LoadInstanceDescriptors on arm and mips.

src/mips/macro-assembler-mips.h

 // 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 1380 matching lines @@
                                            Register scratch2,
                                            Label* failure);
 
   void ClampUint8(Register output_reg, Register input_reg);
 
   void ClampDoubleToUint8(Register result_reg,
                           DoubleRegister input_reg,
                           DoubleRegister temp_double_reg);
 
 
-  void LoadInstanceDescriptors(Register map,
-                               Register descriptors,
-                               Register scratch);
+  void LoadInstanceDescriptors(Register map, Register descriptors);
   void EnumLength(Register dst, Register map);
   void NumberOfOwnDescriptors(Register dst, Register map);
 
   template<typename Field>
   void DecodeField(Register reg) {
     static const int shift = Field::kShift;
     static const int mask = (Field::kMask >> shift) << kSmiTagSize;
     srl(reg, reg, shift);
     And(reg, reg, Operand(mask));
   }
@@ skipping 132 matching lines @@
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_