Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/ADT/DepthFirstIterator.h b/linux-x64/clang/include/llvm/ADT/DepthFirstIterator.h
index e964d7f..1f3766d 100644
--- a/linux-x64/clang/include/llvm/ADT/DepthFirstIterator.h
+++ b/linux-x64/clang/include/llvm/ADT/DepthFirstIterator.h
@@ -177,7 +177,7 @@
     return *this;
   }
 
-  /// \brief Skips all children of the current node and traverses to next node
+  /// Skips all children of the current node and traverses to next node
   ///
   /// Note: This function takes care of incrementing the iterator. If you
   /// always increment and call this function, you risk walking off the end.