Remove scratch register requirement from LoadInstanceDescriptors on arm and mips.

src/mips/macro-assembler-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
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@@ skipping 5284 matching lines @@
   And(bitmap_scratch, bitmap_scratch, Operand(~Page::kPageAlignmentMask));
   lw(t8, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
   Addu(t8, t8, Operand(length));
   sw(t8, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
 
   bind(&done);
 }
 
 
 void MacroAssembler::LoadInstanceDescriptors(Register map,
-                                             Register descriptors,
-                                             Register scratch) {
+                                             Register descriptors) {
   lw(descriptors, FieldMemOperand(map, Map::kDescriptorsOffset));
 }
 
 
 void MacroAssembler::NumberOfOwnDescriptors(Register dst, Register map) {
   lw(dst, FieldMemOperand(map, Map::kBitField3Offset));
   DecodeField<Map::NumberOfOwnDescriptorsBits>(dst);
 }
 
 
@@ skipping 142 matching lines @@
        opcode == BGTZL);
   opcode = (cond == eq) ? BEQ : BNE;
   instr = (instr & ~kOpcodeMask) | opcode;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS