[Bug c++/98386] C++20 module: file exists failure and success happen alternatively for windows.

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98386

--- Comment #3 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
Hm does rename(2) fail on windows if the new name exists?  (in posix it
replaces, otherwise there's gonna be a race condition)