pgsql: Tighten pg_upgrade's new check for non-upgradable anyarray usage

Tighten pg_upgrade's new check for non-upgradable anyarray usages.

We only need to reject cases when the aggregate or operator is
itself declared with a polymorphic type. Per buildfarm.

Discussion: /messages/by-id/3383880.QJadu78ljV@vejsadalnx

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/08385ed261965c4e1604e357330ac5bf9755b01a

Modified Files
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src/bin/pg_upgrade/check.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)