pgsql: Avoid permission failure in pg_sequences.last_value

Avoid permission failure in pg_sequences.last_value

Before, reading pg_sequences.last_value would fail unless the user had
appropriate sequence permissions, which would make the pg_sequences view
cumbersome to use. Instead, return null instead of the real value when
there are no permissions.

From: Michael Paquier <michael(dot)paquier(at)gmail(dot)com>
Reported-by: Shinoda, Noriyoshi <noriyoshi(dot)shinoda(at)hpe(dot)com>

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ab82340a43bebe57a3db0e52bb74120b3bb53ae5

Modified Files
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doc/src/sgml/catalogs.sgml | 5 ++++-
src/backend/catalog/system_views.sql | 6 +++++-
src/test/regress/expected/rules.out | 5 ++++-
3 files changed, 13 insertions(+), 3 deletions(-)