N3644 support for <unordered_set> and <unordered_map>

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@187915 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__hash_table b/include/__hash_table
index 7b0fc41..6157fcd 100644
--- a/include/__hash_table
+++ b/include/__hash_table
@@ -112,6 +112,9 @@
                                                          pointer;
 
     _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __node_(nullptr)
+#endif
     {
 #if _LIBCPP_DEBUG_LEVEL >= 2
         __get_db()->__insert_i(this);
@@ -248,6 +251,9 @@
     typedef __hash_iterator<__non_const_node_pointer> __non_const_iterator;
 
     _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __node_(nullptr)
+#endif
     {
 #if _LIBCPP_DEBUG_LEVEL >= 2
         __get_db()->__insert_i(this);