pgsql: Ignore partitioned tables when processing ON COMMIT DELETE ROWS

Ignore partitioned tables when processing ON COMMIT DELETE ROWS

Those tables have no physical storage, making this option unusable with
partition trees as at commit time an actual truncation was attempted.
There are still issues with the way ON COMMIT actions are done when
mixing several action types, however this impacts as well inheritance
trees, so this issue will be dealt with later.

Reported-by: Rajkumar Raghuwanshi
Author: Amit Langote
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/CAKcux6mhgcjSiB_egqEAEFgX462QZtncU8QCAJ2HZwM-wWGVew@mail.gmail.com

Branch
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REL_10_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/70c38e7080128e27cb6b9e20237f2c36807b0000

Modified Files
--------------
src/backend/catalog/heap.c         |  7 +++++++
src/test/regress/expected/temp.out | 17 +++++++++++++++++
src/test/regress/sql/temp.sql      | 14 ++++++++++++++
3 files changed, 38 insertions(+)