pthread_cancel and EH: let's try this again

[Alexander Terekhov]

Nathan Sidwell wrote:
[...]
> I suppose it would be possible to determine one was inside a nothrow function
> during the stack scanning phase of exception handling, and then not throw the
> exception if that were the case.  But this relies on 2-phase unwinding and
> restartable exceptions.  

What do you mean by "restartable exceptions"? 2-phase EH exposing 
conditional throw is sufficient. 

http://tinyurl.com/cxdc7

regards,
alexander.