pgsql: Tweak new regression test case for more portability.

Tweak new regression test case for more portability.

Ensure that same index gets selected on 32-bit and 64-bit machines.
Per buildfarm results.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/2c30f96103c320d4e3c8cab2807d88476f584278

Modified Files
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src/test/regress/expected/inherit.out | 10 +++++-----
src/test/regress/sql/inherit.sql | 4 ++--
2 files changed, 7 insertions(+), 7 deletions(-)