[Bug libstdc++/108861] notify_all_at_thread_exit() should notify on cond while lock is held to avoid a race

[vini.ipsmaker at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108861

--- Comment #5 from Vinícius dos Santos Oliveira <vini.ipsmaker at gmail dot 
com> ---
> Because there is an open defect report against the C++ standard about this. 
> Basically until that is resolved, GCC's behavior is considered correct.

How clueless of me to miss such obvious fact. So it turns out that
notify_all_at_thread_exit() does *not* have any bugs and can be used safely? I
reverted the GCC workaround I had in my codebase. We can close the issue
already. It was dumb of me to even assume that GCC could have bugs.