[patch] Fix BZ#20544 (assert function passed to atexit/on_exit/__cxa_atexit != NULL)

[Florian Weimer]

* Paul Pluzhnikov:

> On Wed, Nov 28, 2018 at 11:07 AM Florian Weimer <fweimer@redhat.com> wrote:
>
>> You can try the patch posted below.  The initial API design was a bit
>> lazy.
>
> Looks good to me. I'll update my patch once you commit this one.

Thanks, committed.

Florian