Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/CodeGen/CostTable.h b/linux-x64/clang/include/llvm/CodeGen/CostTable.h
index 0fc16d3..48ad769 100644
--- a/linux-x64/clang/include/llvm/CodeGen/CostTable.h
+++ b/linux-x64/clang/include/llvm/CodeGen/CostTable.h
@@ -8,7 +8,7 @@
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// \brief Cost tables and simple lookup functions
+/// Cost tables and simple lookup functions
 ///
 //===----------------------------------------------------------------------===//