pgsql: Improve portability of test with oid8 comparison function

Improve portability of test with oid8 comparison function

Oversight in b139bd3b6ef0, per reports from buildfarm members longfin
and prion, that use -DSTRESS_SORT_INT_MIN. Thanks to Tom Lane for the
poke.

Discussion: /messages/by-id/1656709.1767754981@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a2e632ece1691be18771644182f769b525991f97

Modified Files
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src/test/regress/expected/oid8.out | 20 ++++++++++----------
src/test/regress/sql/oid8.sql | 6 +++---
2 files changed, 13 insertions(+), 13 deletions(-)