Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/Support/FileCheck.h b/linux-x64/clang/include/llvm/Support/FileCheck.h
index e68acca..de8d46b 100644
--- a/linux-x64/clang/include/llvm/Support/FileCheck.h
+++ b/linux-x64/clang/include/llvm/Support/FileCheck.h
@@ -80,7 +80,7 @@
   std::vector<std::pair<StringRef, unsigned>> VariableUses;
 
   /// Maps definitions of variables to their parenthesized capture numbers.
-  /// 
+  ///
   /// E.g. for the pattern "foo[[bar:.*]]baz", VariableDefs will map "bar" to
   /// 1.
   std::map<StringRef, unsigned> VariableDefs;