As a first step towards implementing thumb2, add code for...

src/arm/constants-arm.h

 // Copyright 2009 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 293 matching lines @@
   // reference to an instruction is to convert a pointer. There is no way
   // to allocate or create instances of class Instr.
   // Use the At(pc) function to create references to Instr.
   static Instr* At(byte* pc) { return reinterpret_cast<Instr*>(pc); }
 
  private:
   // We need to prevent the creation of instances of class Instr.
   DISALLOW_IMPLICIT_CONSTRUCTORS(Instr);
 };
 
+class ThumbInstr {
+};
 
 // Helper functions for converting between register numbers and names.
 class Registers {
  public:
   // Return the name of the register.
   static const char* Name(int reg);
 
   // Lookup the register number for the name provided.
   static int Number(const char* name);
 
@@ skipping 14 matching lines @@
   static const char* Name(int reg);
 
  private:
   static const char* names_[kNumVFPRegisters];
 };
 
 
 } }  // namespace assembler::arm
 
 #endif  // V8_ARM_CONSTANTS_ARM_H_