Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/MC/MCStreamer.h b/linux-x64/clang/include/llvm/MC/MCStreamer.h
index e4d0dc0..91fb4e5 100644
--- a/linux-x64/clang/include/llvm/MC/MCStreamer.h
+++ b/linux-x64/clang/include/llvm/MC/MCStreamer.h
@@ -231,6 +231,9 @@
 
   virtual void EmitRawTextImpl(StringRef String);
 
+  /// Returns true if the the .cv_loc directive is in the right section.
+  bool checkCVLocSection(unsigned FuncId, unsigned FileNo, SMLoc Loc);
+
 public:
   MCStreamer(const MCStreamer &) = delete;
   MCStreamer &operator=(const MCStreamer &) = delete;