Introduce processor detection in globals.h, instead of from the build system.

src/jsregexp.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 19 matching lines @@
 
 namespace v8 { namespace internal {
 
 
 class RegExpMacroAssembler;
 
 
 class RegExpImpl {
  public:
   static inline bool UseNativeRegexp() {
-#ifdef V8_ARCH_ARM
-    return false;
-#endif
-#ifdef V8_ARCH_X64
-    return false;
-#endif
-#ifdef V8_ARCH_IA32
+#ifdef V8_TARGET_ARCH_IA32
     return FLAG_regexp_native;
+#else
+  return false;
 #endif
   }
   // Creates a regular expression literal in the old space.
   // This function calls the garbage collector if necessary.
   static Handle<Object> CreateRegExpLiteral(Handle<JSFunction> constructor,
                                             Handle<String> pattern,
                                             Handle<String> flags,
                                             bool* has_pending_exception);
 
   // Returns a string representation of a regular expression.
@@ skipping 1309 matching lines @@
                                    Handle<String> pattern,
                                    bool is_ascii);
 
   static void DotPrint(const char* label, RegExpNode* node, bool ignore_case);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSREGEXP_H_