pgsql: Always call ExecShutdownNode() if appropriate.

Always call ExecShutdownNode() if appropriate.

Call ExecShutdownNode() after ExecutePlan()'s loop, rather than at each
break.  We had forgotten to do that in one case.  The omission caused
intermittent "temporary file leak" warnings from multi-batch parallel
hash joins with a LIMIT clause.

Back-patch to 11.  Though the problem exists in theory in earlier
parallel query releases, nothing really depended on it.

Author: Kyotaro Horiguchi
Reviewed-by: Thomas Munro, Amit Kapila
Discussion: https://postgr.es/m/20191111.212418.2222262873417235945.horikyota.ntt%40gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/76cbfcdf3a0dff3f029ca079701418b861ce86c8

Modified Files
--------------
src/backend/executor/execMain.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)