Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/CodeGen/GCStrategy.h b/linux-x64/clang/include/llvm/CodeGen/GCStrategy.h
index 16168e7..f835bac 100644
--- a/linux-x64/clang/include/llvm/CodeGen/GCStrategy.h
+++ b/linux-x64/clang/include/llvm/CodeGen/GCStrategy.h
@@ -104,13 +104,13 @@
   const std::string &getName() const { return Name; }
 
   /// By default, write barriers are replaced with simple store
-  /// instructions. If true, you must provide a custom pass to lower 
-  /// calls to @llvm.gcwrite.
+  /// instructions. If true, you must provide a custom pass to lower
+  /// calls to \@llvm.gcwrite.
   bool customWriteBarrier() const { return CustomWriteBarriers; }
 
   /// By default, read barriers are replaced with simple load
-  /// instructions. If true, you must provide a custom pass to lower 
-  /// calls to @llvm.gcread.
+  /// instructions. If true, you must provide a custom pass to lower
+  /// calls to \@llvm.gcread.
   bool customReadBarrier() const { return CustomReadBarriers; }
 
   /// Returns true if this strategy is expecting the use of gc.statepoints,
@@ -146,8 +146,8 @@
   }
 
   /// By default, roots are left for the code generator so it can generate a
-  /// stack map. If true, you must provide a custom pass to lower 
-  /// calls to @llvm.gcroot.
+  /// stack map. If true, you must provide a custom pass to lower
+  /// calls to \@llvm.gcroot.
   bool customRoots() const { return CustomRoots; }
 
   /// If set, gcroot intrinsics should initialize their allocas to null