0001-Revert-r248245-breaks-ROOT.patch

diff --git a/libstdc++-v3/include/bits/refwrap.h b/libstdc++-v3/include/bits/refwrap.h
index c1d4670..4b7d7e0 100644
--- a/libstdc++-v3/include/bits/refwrap.h
+++ b/libstdc++-v3/include/bits/refwrap.h
@@ -98,12 +98,6 @@ _GLIBCXX_MEM_FN_TRAITS( , true_type, true_type)
 _GLIBCXX_MEM_FN_TRAITS(&, true_type, false_type)
 _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
-#if __cplusplus > 201402L
-_GLIBCXX_MEM_FN_TRAITS(noexcept, true_type, true_type)
-_GLIBCXX_MEM_FN_TRAITS(& noexcept, true_type, false_type)
-_GLIBCXX_MEM_FN_TRAITS(&& noexcept, false_type, true_type)
-#endif
-
 #undef _GLIBCXX_MEM_FN_TRAITS
 #undef _GLIBCXX_MEM_FN_TRAITS2
 
diff --git a/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/80478.cc b/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/80478.cc
deleted file mode 100644
index 7f8982d..0000000
--- a/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/80478.cc
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright (C) 2017-2018 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-// { dg-options "-std=gnu++17" }
-// { dg-do compile { target c++17 } }
-
-#include <functional>
-
-struct X {
-  void f() noexcept { }
-};
-
-auto f = std::mem_fn(&X::f);