[Bug libgcc/82635] std::thread's join broken on FreeBSD with all GCCs >= 5

[andreast at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82635

--- Comment #12 from Andreas Tobler <andreast at gcc dot gnu.org> ---
Will soon commit a fix, for gcc6/7/8 on FreeBSD > 9.3. Older gcc's and OS
releases will not be supported by this fix.