pgsql: Fix portability issues in new amcheck test.

Fix portability issues in new amcheck test.

The tests added by commit 866e24d47 failed on big-endian machines
due to lack of attention to endianness considerations. Fix that.

While here, improve a few small cosmetic things, such as running
it through perltidy.

Mark Dilger

Discussion: /messages/by-id/30B8E99A-2D9C-48D4-A55C-741C9D5F1563@enterprisedb.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/860593ec3bd15e8969effdfcb5cbd98c561dd722

Modified Files
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contrib/amcheck/t/001_verify_heapam.pl | 148 ++++++++++-----------------------
1 file changed, 46 insertions(+), 102 deletions(-)