Resumable exceptions #2

[Stephen Weeks]

Not long ago, Patrick R. Michaud proclaimed...
> I tried removing the above lines from exceptionhandler.pmc, 
> but even after doing that my test program still gives the same
> results as before:

I looked at it for a bit... the difference between the first and second
throw happens in Parrot_cx_find_handler_local

The second time through, all of the checks for
!PMC_IS_NULL(context->handlers) fail.

It looks like they are actually both getting the same context, but
between the first and second throw, ->handlers is set to PMCNULL.

I'm not sure I'll stay awake long enough to find out why.