Handle the list of code-stub types using macro expansion

src/x64/regexp-macro-assembler-x64.cc

 // 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 1269 matching lines @@
       __ movl(current_character(),
               Operand(rsi, rdi, times_1, cp_offset * sizeof(uc16)));
     } else {
       ASSERT(characters == 1);
       __ movzxwl(current_character(),
                  Operand(rsi, rdi, times_1, cp_offset * sizeof(uc16)));
     }
   }
 }
 
-
-void RegExpCEntryStub::Generate(MacroAssembler* masm_) {
-  __ int3();  // Unused on x64.
-}
-
 #undef __
 
 #endif  // V8_NATIVE_REGEXP
 
 }}  // namespace v8::internal