[libclang] Don't bind a StringRef to a temporary std::string object.
It may end up pointing at garbage.

Fixes the MSVC debug build. rdar://11703319

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159377 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/Indexing.cpp b/tools/libclang/Indexing.cpp
index e660c4d..6b68134 100644
--- a/tools/libclang/Indexing.cpp
+++ b/tools/libclang/Indexing.cpp
@@ -369,7 +369,6 @@
     IndexActionCleanup(IndexAction.get());
 
   bool Persistent = requestedToGetTU;
-  StringRef ResourceFilesPath = CXXIdx->getClangResourcesPath();
   bool OnlyLocalDecls = false;
   bool PrecompilePreamble = false;
   bool CacheCodeCompletionResults = false;
@@ -393,7 +392,7 @@
                                                        IndexAction.get(),
                                                        Unit,
                                                        Persistent,
-                                                       ResourceFilesPath,
+                                                CXXIdx->getClangResourcesPath(),
                                                        OnlyLocalDecls,
                                                     /*CaptureDiagnostics=*/true,
                                                        PrecompilePreamble,