Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/CodeGen/RegAllocPBQP.h b/linux-x64/clang/include/llvm/CodeGen/RegAllocPBQP.h
index 5b34286..ba97630 100644
--- a/linux-x64/clang/include/llvm/CodeGen/RegAllocPBQP.h
+++ b/linux-x64/clang/include/llvm/CodeGen/RegAllocPBQP.h
@@ -43,10 +43,10 @@
 namespace PBQP {
 namespace RegAlloc {
 
-/// @brief Spill option index.
+/// Spill option index.
 inline unsigned getSpillOptionIdx() { return 0; }
 
-/// \brief Metadata to speed allocatability test.
+/// Metadata to speed allocatability test.
 ///
 /// Keeps track of the number of infinities in each row and column.
 class MatrixMetadata {
@@ -89,7 +89,7 @@
   std::unique_ptr<bool[]> UnsafeCols;
 };
 
-/// \brief Holds a vector of the allowed physical regs for a vreg.
+/// Holds a vector of the allowed physical regs for a vreg.
 class AllowedRegVector {
   friend hash_code hash_value(const AllowedRegVector &);
 
@@ -127,7 +127,7 @@
                       hash_combine_range(OStart, OEnd));
 }
 
-/// \brief Holds graph-level metadata relevant to PBQP RA problems.
+/// Holds graph-level metadata relevant to PBQP RA problems.
 class GraphMetadata {
 private:
   using AllowedRegVecPool = ValuePool<AllowedRegVector>;
@@ -164,7 +164,7 @@
   AllowedRegVecPool AllowedRegVecs;
 };
 
-/// \brief Holds solver state and other metadata relevant to each PBQP RA node.
+/// Holds solver state and other metadata relevant to each PBQP RA node.
 class NodeMetadata {
 public:
   using AllowedRegVector = RegAlloc::AllowedRegVector;
@@ -505,14 +505,14 @@
 public:
   PBQPRAGraph(GraphMetadata Metadata) : BaseT(std::move(Metadata)) {}
 
-  /// @brief Dump this graph to dbgs().
+  /// Dump this graph to dbgs().
   void dump() const;
 
-  /// @brief Dump this graph to an output stream.
+  /// Dump this graph to an output stream.
   /// @param OS Output stream to print on.
   void dump(raw_ostream &OS) const;
 
-  /// @brief Print a representation of this graph in DOT format.
+  /// Print a representation of this graph in DOT format.
   /// @param OS Output stream to print on.
   void printDot(raw_ostream &OS) const;
 };
@@ -527,7 +527,7 @@
 } // end namespace RegAlloc
 } // end namespace PBQP
 
-/// @brief Create a PBQP register allocator instance.
+/// Create a PBQP register allocator instance.
 FunctionPass *
 createPBQPRegisterAllocator(char *customPassID = nullptr);