pgsql: Fix FOR PORTION OF with non-updatable view columns

Fix FOR PORTION OF with non-updatable view columns

Both UPDATE and DELETE were failing to test that the application-time
column was updatable. The column is not part of
perminfo->updatedCols, because it should not be checked for
permissions. And it needs to be checked in the DELETE case as well,
since we might insert leftovers with a value for that column.

Author: Paul A. Jungwirth <pj(at)illuminatedcomputing(dot)com>
Co-authored-by: jian he <jian(dot)universality(at)gmail(dot)com>
Discussion: https://www.postgresql.org/message-id/CACJufxFRqg8%3DgbZ-Q6ZS_UQ%2BYdwfZpk%2B9rf7jgWrk8m4RMUm%3DA%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7ca8c9429675b34600e679525da6b5280c1cafa5

Modified Files
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src/backend/rewrite/rewriteHandler.c | 47 +++++++++++++++++++++++++++
src/test/regress/expected/updatable_views.out | 14 ++++++++
src/test/regress/sql/updatable_views.sql | 11 +++++++
3 files changed, 72 insertions(+)