Revert of Reland: Remove register index/code indirection

src/mips/macro-assembler-mips.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 #define V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
 
 #include "src/assembler.h"
 #include "src/globals.h"
 #include "src/mips/assembler-mips.h"
 
 namespace v8 {
 namespace internal {
 
 // Give alias names to registers for calling conventions.
-const Register kReturnRegister0 = {Register::kCode_v0};
-const Register kReturnRegister1 = {Register::kCode_v1};
-const Register kJSFunctionRegister = {Register::kCode_a1};
+const Register kReturnRegister0 = {kRegister_v0_Code};
+const Register kReturnRegister1 = {kRegister_v1_Code};
+const Register kJSFunctionRegister = {kRegister_a1_Code};
 const Register kContextRegister = {Register::kCpRegister};
-const Register kInterpreterAccumulatorRegister = {Register::kCode_v0};
-const Register kInterpreterRegisterFileRegister = {Register::kCode_t3};
-const Register kInterpreterBytecodeOffsetRegister = {Register::kCode_t4};
-const Register kInterpreterBytecodeArrayRegister = {Register::kCode_t5};
-const Register kInterpreterDispatchTableRegister = {Register::kCode_t6};
-const Register kRuntimeCallFunctionRegister = {Register::kCode_a1};
-const Register kRuntimeCallArgCountRegister = {Register::kCode_a0};
+const Register kInterpreterAccumulatorRegister = {kRegister_v0_Code};
+const Register kInterpreterRegisterFileRegister = {kRegister_t3_Code};
+const Register kInterpreterBytecodeOffsetRegister = {kRegister_t4_Code};
+const Register kInterpreterBytecodeArrayRegister = {kRegister_t5_Code};
+const Register kInterpreterDispatchTableRegister = {kRegister_t6_Code};
+const Register kRuntimeCallFunctionRegister = {kRegister_a1_Code};
+const Register kRuntimeCallArgCountRegister = {kRegister_a0_Code};
 
 // Forward declaration.
 class JumpTarget;
 
 // Reserved Register Usage Summary.
 //
 // Registers t8, t9, and at are reserved for use by the MacroAssembler.
 //
 // The programmer should know that the MacroAssembler may clobber these three,
 // but won't touch other registers except in special cases.
@@ skipping 1704 matching lines @@
 #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 internal
 }  // namespace v8
 
 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_