Fix for bug #2310-2

In this email
http://archives.postgresql.org/pgsql-bugs/2006-03/msg00076.php
belonging to bug #2310, Tom says

> I wrote:
> > The relevant owner field for a composite type is pg_type.typowner.
> > We don't bother to maintain pg_class.relowner for the subsidiary
> > pg_class entry.
>
> Actually, now that I look at it, there is a non-cosmetic issue here:
> we seem to be creating a dependency link for the pg_class owner field.
> We have to either not do that, or be willing to fix it during ALTER TYPE
> OWNER.

This patch fixes this problem, by inhibiting the recording of the owner
in pg_shdepend for a RELKIND_COMPOSITE_TYPE relation (i.e. the first
solution proposed above). I intend to apply it to 8.1 and current
trunk, later today.

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support