Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/ADT/Any.h b/linux-x64/clang/include/llvm/ADT/Any.h
index c64c399..7faa4c9 100644
--- a/linux-x64/clang/include/llvm/ADT/Any.h
+++ b/linux-x64/clang/include/llvm/ADT/Any.h
@@ -65,6 +65,16 @@
       typename std::enable_if<
           llvm::conjunction<
               llvm::negation<std::is_same<typename std::decay<T>::type, Any>>,
+              // We also disable this overload when an `Any` object can be
+              // converted to the parameter type because in that case, this
+              // constructor may combine with that conversion during overload
+              // resolution for determining copy constructibility, and then
+              // when we try to determine copy constructibility below we may
+              // infinitely recurse. This is being evaluated by the standards
+              // committee as a potential DR in `std::any` as well, but we're
+              // going ahead and adopting it to work-around usage of `Any` with
+              // types that need to be implicitly convertible from an `Any`.
+              llvm::negation<std::is_convertible<Any, typename std::decay<T>::type>>,
               std::is_copy_constructible<typename std::decay<T>::type>>::value,
           int>::type = 0>
   Any(T &&Value) {