https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71684
--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> --- Yes but for std::mutex we currently have no user-provided destructor if the INIT macro is supported. If we add a ~__mutex_base() that unconditionally uses __gthread_mutex_destroy that might be an ABI change for some targets. I don't think it matters for the Itanium ABI because std::mutex isn't copyable so can't be passed as an argument anyway.
