[Bug libstdc++/127555] filesystem::remove_all fails on targets with neither unlinkat nor dirent::d_type

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127555

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
In fact, EPERM shouldn't be conditional. It's always been present on Windows
and so in MinGW and mingw-w64. I'll remove the conditions from error_constant.h
and code elsewhere that checks whether it's defined.