Put back __OBJC2__ definition.

llvm-svn: 67802

clang/lib/Lex/Preprocessor.cpp

@@ -497,12 +497,8 @@ static void InitializePredefinedMacros(Preprocessor &PP,
   
   if (PP.getLangOptions().ObjC1) {
     DefineBuiltinMacro(Buf, "__OBJC__=1");
-#if 0
-// FIXME. This flag controls declaration of ivars which is
-// needed since we do not support synthesize ivars yet.
     if (PP.getLangOptions().ObjCNonFragileABI)
       DefineBuiltinMacro(Buf, "__OBJC2__=1");
-#endif
 
     if (PP.getLangOptions().getGCMode() == LangOptions::NonGC) {
       DefineBuiltinMacro(Buf, "__weak=");