pgsql: Add opr_sanity queries to inspect commutator/negator links more

Add opr_sanity queries to inspect commutator/negator links more closely.

Make lists of the names of all operators that are claimed to be commutator
pairs or negator pairs. This is analogous to the existing queries that
make lists of all operator names appearing in particular opclass strategy
slots. Unexpected additions to these lists are likely to be mistakes; had
we had these queries in place before, bug #11178 might've been prevented.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/a068b5b65f83660fc99c3faf39ed50493b010fbb

Modified Files
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src/test/regress/expected/opr_sanity.out | 73 ++++++++++++++++++++++++++++--
src/test/regress/sql/opr_sanity.sql | 23 ++++++++--
2 files changed, 90 insertions(+), 6 deletions(-)