pg_upgrade: Ignore TOAST for partitioned tables
Since partitioned tables in pg12 do not have toast tables, trying to set
the toast OID confuses pg_upgrade. Have pg_dump omit those values to
avoid the problem.
Per Andres Freund and buildfarm members crake and snapper
Discussion: https://postgr.es/m/
20190306204104.yle5jfbnqkcwykni@alap3.anarazel.de