pgsql: Fix bugs in comparison functions for multirange_bsearch_match()

Fix bugs in comparison functions for multirange_bsearch_match()

Two functions multirange_range_overlaps_bsearch_comparison() and
multirange_range_contains_bsearch_comparison() contain bugs of returning -1
instead of 1.  This commit fixes these bugs and adds corresponding regression
tests.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a5b81b6f0006ea0b502780ce7f73d295a225842c

Modified Files
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src/backend/utils/adt/multirangetypes.c       |  4 ++--
src/test/regress/expected/multirangetypes.out | 12 ++++++++++++
src/test/regress/sql/multirangetypes.sql      |  2 ++
3 files changed, 16 insertions(+), 2 deletions(-)