Revert of Remove register index/code indirection

src/arm/disasm-arm.cc

 // Copyright 2011 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.
 
 // A Disassembler object is used to disassemble a block of code instruction by
 // instruction. The default implementation of the NameConverter object can be
 // overriden to modify register names or to do symbol lookup on addresses.
 //
 // The example below will disassemble a block of code and print it to stdout.
 //
@@ skipping 1905 matching lines @@
   return tmp_buffer_.start();
 }
 
 
 const char* NameConverter::NameOfConstant(byte* addr) const {
   return NameOfAddress(addr);
 }
 
 
 const char* NameConverter::NameOfCPURegister(int reg) const {
-  return v8::internal::Register::from_code(reg).ToString();
+  return v8::internal::Registers::Name(reg);
 }
 
 
 const char* NameConverter::NameOfByteCPURegister(int reg) const {
   UNREACHABLE();  // ARM does not have the concept of a byte register
   return "nobytereg";
 }
 
 
 const char* NameConverter::NameOfXMMRegister(int reg) const {
@@ skipping 41 matching lines @@
     v8::internal::PrintF(
         f, "%p    %08x      %s\n",
         prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
   }
 }
 
 
 }  // namespace disasm
 
 #endif  // V8_TARGET_ARCH_ARM