Enable ALTER TABLE ADD PRIMARY KEY for pg_dump, for performance reasons

so index is not on table during COPY.

> > AFAICT, the patch I posted to -patches a little while to enable the
> > usage of ALTER TABLE ADD PRIMARY KEY by pg_dump hasn't been applied, nor
> > is it in the unapplied patches list. I was under the impression that
> > this was in the queue for application -- did it just get lost?

Neil Conway <neilconway@rogers.com>