[Bug libstdc++/90454] filesystem::path template constructor void* overload interference

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90454

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
C++20 fixes this by iterator_traits<T*> requires is_object_v<T>.

I think I have a patch implementing that for C++11 upwards...