Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/ADT/TinyPtrVector.h b/linux-x64/clang/include/llvm/ADT/TinyPtrVector.h
index 73573d6..1b8e9aa 100644
--- a/linux-x64/clang/include/llvm/ADT/TinyPtrVector.h
+++ b/linux-x64/clang/include/llvm/ADT/TinyPtrVector.h
@@ -108,6 +108,12 @@
     return *this;
   }
 
+  TinyPtrVector(std::initializer_list<EltTy> IL)
+      : Val(IL.size() == 0
+                ? PtrUnion()
+                : IL.size() == 1 ? PtrUnion(*IL.begin())
+                                 : PtrUnion(new VecTy(IL.begin(), IL.end()))) {}
+
   /// Constructor from an ArrayRef.
   ///
   /// This also is a constructor for individual array elements due to the single