pgsql: Fix partitioning crashes during error reporting.

Fix partitioning crashes during error reporting.

In various places where we reverse-map a tuple before calling
ExecBuildSlotValueDescription, we neglected to ensure that the
slot descriptor matched the tuple stored in it.

Amit Langote and Amit Khandekar, reviewed by Etsuro Fujita

Discussion: http://postgr.es/m/CAJ3gD9cqpP=WvJj=dv1ONkPWjy8ZuUaOM4_x86i3uQPas=0_jg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4132dbec69dd4d437e132e57a74a98a40cdcf776

Modified Files
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src/backend/executor/execMain.c | 4 ++++
src/test/regress/expected/insert.out | 15 +++++++++++++++
src/test/regress/expected/updatable_views.out | 15 ++++++++-------
src/test/regress/sql/insert.sql | 12 ++++++++++++
src/test/regress/sql/updatable_views.sql | 4 ++--
5 files changed, 41 insertions(+), 9 deletions(-)