When re-raising an exception after a cleanup, we need to call _Unwind_Resume_or_Rethrow

instead of _Unwind_Resume.  With SJLJ exceptions, this is spelled
"_Unwind_SjLj_Resume_or_Rethrow", not "_Unwind_SjLj_Resume", which has
significantly different semantics.

We should actually never be generating a call to _Unwind_SjLj_Resume directly;
even if we were generating true cleanups (which we aren't because of the
horrible hack), we should be calling __cxa_end_cleanup() on ARM.  I
haven't implemented this because there's little point as long as the HH is
present.

I believe this fixes <rdar://problem/8281377>.

llvm-svn: 110851