compile/runtime testing for __cxa_atexit

[Paolo Carlini]

Benjamin Kosnik wrote:

>>your plan makes perfect sense to me. 
>>    
>>
>Ok. It's actually easy to do, just ripping off your namedlocale work
>with a different test case, variables, functions, etc.
>
Sounds like a plan ;)

>>Do you want me to work on this issue or maybe you
>>are going to take care of it together with the mt_allocator testing
>>work? Just let me know...
>>    
>>
>I got it. I was just curious, because this seems pretty basic and I was
>surprised that there wasn't already infrastructure for testing this.
>  
>
Excellent.

Longer term, maybe we can investigate whether we can unify somehow the
different approaches that we have for named locales vs wchar_t/threads.
Probably it's not urgent because the final effect is similar (and
correct) - in some cases, a smaller number of tests actually run - but
maybe the former is a tad more robust?!? I'm not sure. In particular,
I'm not sure which one is more friendly to Mark's ideas about testing
without the build dir.

Paolo.