Create build structure for X64.

src/globals.h

 // Copyright 2006-2008 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 55 matching lines @@
 #define bool __my_bool__  // use 'indirection' to avoid name clashes
 #endif
 
 typedef uint8_t byte;
 typedef byte* Address;
 
 // Code-point values in Unicode 4.0 are 21 bits wide.
 typedef uint16_t uc16;
 typedef signed int uc32;
 
-#ifndef ARM
+#if defined(V8_ARCH_IA32) || defined(V8_ARCH_X64)
 #define CAN_READ_UNALIGNED 1
 #endif
 
 // -----------------------------------------------------------------------------
 // Constants
 
 const int KB = 1024;
 const int MB = KB * KB;
 const int GB = KB * KB * KB;
 const int kMaxInt = 0x7FFFFFFF;
@@ skipping 418 matching lines @@
 
   Dest dest;
   memcpy(&dest, &source, sizeof(dest));
   return dest;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBALS_H_