[Bug libstdc++/51008] GTHR - extend interface with __gthread_recursive_mutex_destroy

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51008

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-11-07 14:24:43 UTC ---
Created attachment 25735
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25735
use __GTHREAD_RECURSIVE_MUTEX_DESTROY_FUNCTION if defined

here's a proof of concept, that would allow your private gthr to define the
macro and work.

we could then gradually transition Win32 and other gthr impls to use that and
remove the sfinae hacks