[patch] Add tests for atexit/on_exit firing order

[Joseph Myers]

On Mon, 10 Jul 2017, Paul Pluzhnikov wrote:

> Greetings,
> 
> While working a on patch for bz14333, I discovered that there are no
> tests for ordering of functions registered with atexit/on_exit, and in
> particular the case where such function itself registers new exit
> handlers.
> 
> This patch adds such test. I am using on_exit here because it
> conveniently allows passing an argument.

I'd think that it would make sense to test all of atexit, on_exit, 
at_quick_exit this way.

-- 
Joseph S. Myers
joseph@codesourcery.com