[libclang] Make sure Preprocessor is set in ASTUnit during indexing.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148319 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/IndexingContext.cpp b/tools/libclang/IndexingContext.cpp
index befdce9..1c58d23 100644
--- a/tools/libclang/IndexingContext.cpp
+++ b/tools/libclang/IndexingContext.cpp
@@ -208,6 +208,10 @@
   static_cast<ASTUnit*>(CXTU->TUData)->setASTContext(&ctx);
 }
 
+void IndexingContext::setPreprocessor(Preprocessor &PP) {
+  static_cast<ASTUnit*>(CXTU->TUData)->setPreprocessor(&PP);
+}
+
 bool IndexingContext::shouldAbort() {
   if (!CB.abortQuery)
     return false;