pgsql: Band-aid fix for incorrect use of view options as StdRdOptions.

Band-aid fix for incorrect use of view options as StdRdOptions.

We really ought to make StdRdOptions and the other decoded forms of
reloptions self-identifying, but for the moment, assume that only plain
relations could possibly be user_catalog_tables. Fixes problem with bogus
"ON CONFLICT is not supported on table ... used as a catalog table" error
when target is a view with cascade option.

Discussion: <26681(dot)1477940227(at)sss(dot)pgh(dot)pa(dot)us>

Branch
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REL9_6_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/5ee3a7453a428890ed4c0a1061c367e510b8253b

Modified Files
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src/include/utils/rel.h | 3 ++-
src/test/regress/expected/insert_conflict.out | 24 ++++++++++++++++++++++++
src/test/regress/sql/insert_conflict.sql | 18 ++++++++++++++++++
3 files changed, 44 insertions(+), 1 deletion(-)