Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/CodeGen/PBQPRAConstraint.h b/linux-x64/clang/include/llvm/CodeGen/PBQPRAConstraint.h
index 269b7a7..995467d 100644
--- a/linux-x64/clang/include/llvm/CodeGen/PBQPRAConstraint.h
+++ b/linux-x64/clang/include/llvm/CodeGen/PBQPRAConstraint.h
@@ -33,7 +33,7 @@
 
 using PBQPRAGraph = PBQP::RegAlloc::PBQPRAGraph;
 
-/// @brief Abstract base for classes implementing PBQP register allocation
+/// Abstract base for classes implementing PBQP register allocation
 ///        constraints (e.g. Spill-costs, interference, coalescing).
 class PBQPRAConstraint {
 public:
@@ -44,7 +44,7 @@
   virtual void anchor();
 };
 
-/// @brief PBQP register allocation constraint composer.
+/// PBQP register allocation constraint composer.
 ///
 ///   Constraints added to this list will be applied, in the order that they are
 /// added, to the PBQP graph.