Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/Support/Parallel.h b/linux-x64/clang/include/llvm/Support/Parallel.h
index 01b2bcd..1462265 100644
--- a/linux-x64/clang/include/llvm/Support/Parallel.h
+++ b/linux-x64/clang/include/llvm/Support/Parallel.h
@@ -100,7 +100,7 @@
 #else
 const ptrdiff_t MinParallelSize = 1024;
 
-/// \brief Inclusive median.
+/// Inclusive median.
 template <class RandomAccessIterator, class Comparator>
 RandomAccessIterator medianOf3(RandomAccessIterator Start,
                                RandomAccessIterator End,
@@ -118,7 +118,7 @@
                          const Comparator &Comp, TaskGroup &TG, size_t Depth) {
   // Do a sequential sort for small inputs.
   if (std::distance(Start, End) < detail::MinParallelSize || Depth == 0) {
-    std::sort(Start, End, Comp);
+    llvm::sort(Start, End, Comp);
     return;
   }
 
@@ -200,7 +200,7 @@
           const Comparator &Comp = Comparator()) {
   static_assert(is_execution_policy<Policy>::value,
                 "Invalid execution policy!");
-  std::sort(Start, End, Comp);
+  llvm::sort(Start, End, Comp);
 }
 
 template <class Policy, class IterTy, class FuncTy>