Attempt to fix endianess issues in new hash partition test.

Attempt to fix endianess issues in new hash partition test.

The tests added as part of 9fdb675fc5 yield differing results
depending on endianess, causing buildfarm failures. As the differences
are expected, split the hash partitioning tests into a different file
and maintain alternative output. The separate file is so the amount of
duplicated output is reduced.

David produced the alternative output without a machine to test on, so
it's possible this'll require a buildfarm cycle or two to get right.

Author: David Rowley
Discussion: https://postgr.es/m/CAKJS1f-6f4c2Qhuipe-GY7BKmFd0FMBobRnLS7hVCoAmTszsBg@mail.gmail.com