Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/Analysis/PHITransAddr.h b/linux-x64/clang/include/llvm/Analysis/PHITransAddr.h
index f0f34f3..0a335b6 100644
--- a/linux-x64/clang/include/llvm/Analysis/PHITransAddr.h
+++ b/linux-x64/clang/include/llvm/Analysis/PHITransAddr.h
@@ -43,7 +43,7 @@
   /// TLI - The target library info if known, otherwise null.
   const TargetLibraryInfo *TLI;
 
-  /// A cache of @llvm.assume calls used by SimplifyInstruction.
+  /// A cache of \@llvm.assume calls used by SimplifyInstruction.
   AssumptionCache *AC;
 
   /// InstInputs - The inputs for our symbolic address.