Revert of Reland: Remove register index/code indirection

src/arm/simulator-arm.cc

 // 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.
 
 #include <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #if V8_TARGET_ARCH_ARM
 
@@ skipping 280 matching lines @@
         // Leave the debugger shell.
         done = true;
       } else if ((strcmp(cmd, "p") == 0) || (strcmp(cmd, "print") == 0)) {
         if (argc == 2 || (argc == 3 && strcmp(arg2, "fp") == 0)) {
           int32_t value;
           float svalue;
           double dvalue;
           if (strcmp(arg1, "all") == 0) {
             for (int i = 0; i < kNumRegisters; i++) {
               value = GetRegisterValue(i);
-              PrintF("%3s: 0x%08x %10d", Register::from_code(i).ToString(),
-                     value, value);
+              PrintF("%3s: 0x%08x %10d", Registers::Name(i), value, value);
               if ((argc == 3 && strcmp(arg2, "fp") == 0) &&
                   i < 8 &&
                   (i % 2) == 0) {
                 dvalue = GetRegisterPairDoubleValue(i);
                 PrintF(" (%f)\n", dvalue);
               } else {
                 PrintF("\n");
               }
             }
             for (int i = 0; i < DwVfpRegister::NumRegisters(); i++) {
@@ skipping 3845 matching lines @@
   set_register(sp, current_sp + sizeof(uintptr_t));
   return address;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_ARM