pgsql: Fix order of shutdown processing when CTEs contain inter-referen

Fix order of shutdown processing when CTEs contain inter-references.

We need ExecutorEnd to run the ModifyTable nodes to completion in
reverse order of initialization, not forward order. Easily done
by constructing the list back-to-front.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/000128bc7f591025d0c1ce539bb53c6ad00ab69c

Modified Files
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src/backend/executor/nodeModifyTable.c | 9 +++-
src/test/regress/expected/with.out | 76 ++++++++++++++++++++++++++++++++
src/test/regress/sql/with.sql | 26 +++++++++++
3 files changed, 108 insertions(+), 3 deletions(-)