Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/Support/BinaryStreamWriter.h b/linux-x64/clang/include/llvm/Support/BinaryStreamWriter.h
index f31db87..6e8a68a 100644
--- a/linux-x64/clang/include/llvm/Support/BinaryStreamWriter.h
+++ b/linux-x64/clang/include/llvm/Support/BinaryStreamWriter.h
@@ -24,7 +24,7 @@
 
 namespace llvm {
 
-/// \brief Provides write only access to a subclass of `WritableBinaryStream`.
+/// Provides write only access to a subclass of `WritableBinaryStream`.
 /// Provides bounds checking and helpers for writing certain common data types
 /// such as null-terminated strings, integers in various flavors of endianness,
 /// etc.  Can be subclassed to provide reading and writing of custom datatypes,