objc modern rewriter: Define __OBJC2__ in written file.
// rdar://11024543

llvm-svn: 152496
diff --git a/clang/lib/Rewrite/RewriteModernObjC.cpp b/clang/lib/Rewrite/RewriteModernObjC.cpp
index 3099499..87d49fd 100644
--- a/clang/lib/Rewrite/RewriteModernObjC.cpp
+++ b/clang/lib/Rewrite/RewriteModernObjC.cpp
@@ -5146,6 +5146,10 @@
 void RewriteModernObjC::Initialize(ASTContext &context) {
   InitializeCommon(context);
   
+  Preamble += "#ifndef __OBJC2__\n";
+  Preamble += "#define __OBJC2__\n";
+  Preamble += "#endif\n";
+
   // declaring objc_selector outside the parameter list removes a silly
   // scope related warning...
   if (IsHeader)