Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/Support/Endian.h b/linux-x64/clang/include/llvm/Support/Endian.h
index f50d9b5..a4d3f4f 100644
--- a/linux-x64/clang/include/llvm/Support/Endian.h
+++ b/linux-x64/clang/include/llvm/Support/Endian.h
@@ -34,7 +34,7 @@
 
 namespace detail {
 
-/// \brief ::value is either alignment, or alignof(T) if alignment is 0.
+/// ::value is either alignment, or alignof(T) if alignment is 0.
 template<class T, int alignment>
 struct PickAlignment {
  enum { value = alignment == 0 ? alignof(T) : alignment };