pg_upgrade and reg* system oid user types

Hi,

I think it might be worth mentioning in the release notes (unless I've
missed it, of course) that, with the addition of
check_for_reg_data_type_usage(), pg_upgrade will error if it finds, for
example, tsearch data from pre-8.3 in user tables.

Otherwise, pg_upgrade has worked wonderfully for me - thanks again for
bringing it into contrib.

Best regards,

--
Glen Barber