[Bug libstdc++/97949] Recursive calls of std::call_once together with cout leads to deadlock under mingw64

[fiesh at zefix dot tv via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97949

--- Comment #9 from fiesh at zefix dot tv ---
This test case was meant to be added to 120955

This is a very weird UI bug in Bugzilla.  I tried uploading the attachment, it
complained it was too big, I pressed back or ok or something, added it in
compressed format, but Bugzilla had already jumped to this bug.