[Bug libstdc++/58142] _pthread_tsd_cleanup called before destructors are called

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58142

--- Comment #7 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Iain Sandoe from comment #6)
> I'd need to see what dyld is actually implementing for
> tlv_atexit.

Seems to be layered on top of pthread_get/set_specific - so, in principle, we
could do something similar for earlier systems.

However, not high on (my) priority list at present.