Fix findoidjoins to recognize oidvector columns.

Tom Lane <tgl@sss.pgh.pa.us>

Commit: 96d175e3e2ea1bbf734f21444126a711da12108b
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: 2020-05-09T20:28:20Z
Releases: 13.0
Fix findoidjoins to recognize oidvector columns.

Somehow we'd never noticed this oversight, even though it means
that such basic columns as pg_proc.proargtypes were not being
validated by the oidjoins test.  Correct the query and update
the test script with the newly-found dependencies.

Files