Bug 9096 - list::iterator not default constructible

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@124508 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/list b/include/list
index 1779c00..d5c6ca5 100644
--- a/include/list
+++ b/include/list
@@ -237,6 +237,8 @@
     typedef typename pointer_traits<pointer>::difference_type difference_type;
 
     _LIBCPP_INLINE_VISIBILITY
+    __list_iterator() {}
+    _LIBCPP_INLINE_VISIBILITY
     reference operator*() const {return __ptr_->__value_;}
     _LIBCPP_INLINE_VISIBILITY
     pointer operator->() const {return &(operator*());}
@@ -290,6 +292,8 @@
     typedef typename pointer_traits<pointer>::difference_type difference_type;
 
     _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator() {}
+    _LIBCPP_INLINE_VISIBILITY
     __list_const_iterator(__list_iterator<_Tp, _VoidPtr> __p) : __ptr_(__p.__ptr_) {}
 
     _LIBCPP_INLINE_VISIBILITY