Change ASTUnit to only initialize the predefines buffer to the suggested predefines.
 - It isn't really clear what to do with the preprocessor here, but this is more sensible.

llvm-svn: 82431
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 1e2ad46..d3475b5 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -126,7 +126,7 @@
                                  AST->getSourceManager(), HeaderInfo));
   Preprocessor &PP = *AST->PP.get();
 
-  PP.setPredefines(Predefines);
+  PP.setPredefines(Reader->getSuggestedPredefines());
   PP.setCounterValue(Counter);
   Reader->setPreprocessor(PP);