V3 PATCH to add verbose terminate_handler

[Gabriel Dos Reis]

Jason Merrill <jason@redhat.com> writes:

| As discussed, this patch adds an alternative terminate handler which prints
| information about the offending exception to stderr; it can be installed
| using set_terminate (__gnu_cxx::verbose_terminate_handler).  It also adds a
| new ABI hook to get the type of the currently handled exception, so that
| the handler doesn't need to know about the EH structures.

Hi Jason,

  Apologies for the late comments.

  I think "verbose_terminate_handler" should be named
__verbose_terminate_handler. Yes that is a bit overly anal, but at
least it makes the library less fragile.

Thanks,

-- Gaby