pgsql: Improve objectNamesToOids() comment

Improve objectNamesToOids() comment

Commit d31bbfb6590 removed the comment at objectNamesToOids() that
there is no locking, because that commit added locking. But to fix
all the problems, we'd still need a stronger lock. So put the comment
back with more a detailed explanation.

Co-authored-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: /messages/by-id/bf72b82c-124d-4efa-a484-bb928e9494e4@eisentraut.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/e36fa9319b1366ee0194e130a9a77c4af7ee1853

Modified Files
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src/backend/catalog/aclchk.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)