pgsql: Fix add_rte_to_flat_rtable() for recent feature additions.

Fix add_rte_to_flat_rtable() for recent feature additions.

The TABLESAMPLE and row security patches each overlooked this function,
though their errors of omission were opposite: RLS failed to zero out the
securityQuals field, leading to wasteful copying of useless expression
trees in finished plans, while TABLESAMPLE neglected to add a comment
saying that it intentionally *isn't* deleting the tablesample subtree.
There probably should be a similar comment about ctename, too.

Back-patch as appropriate.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/46d0a9bfac3d5221702318cc1cf119221d729c84

Modified Files
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src/backend/optimizer/plan/setrefs.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)