GDB `cannotfix' pr state, require PR with xfail `moving forward'.

[Michael Elizabeth Chastain]

Daniel J writes:
> In that case I'd want "broken in all GCC's" to be open rather than
> suspended.  Does this bother anyone?

If "external" is a class, it's okay with me if some of them
are "open" and some of them are "suspended".

I wish the state was an indicator of who we are waiting for:

  open      -> waiting for gdb investigator
  analyzed  -> waiting for gdb patch-writer
  external  -> waiting for external issue to be fixed
  suspended -> waiting for some miscellaneous condition
  feedback  -> waiting for original user
  closed    -> not waiting

But since we're headed for 'external' as a class rather than a state,
this isn't going to happen.

Michael C