[PATCH] Avoid allocator operator== in _Safe_container

[Jonathan Wakely]

On Mon, 9 Aug 2021 at 11:26, François Dumont via Libstdc++
<libstdc++@gcc.gnu.org> wrote:
>
> Some newly introduced tests in
> 23_containers/unordered_map/cons/default.cc revealed that we are forcing
> the allocator type to have a operator==.

All allocators are required to have operator== so that should not be a
problem. What is the error?