Fix postgres_fdw's ORDER BY pushdown handling

When Who What
2022-03-31 18:51:04 Tom Lane (tgl) Closed in commitfest 2022-03 with status: Committed
2022-03-31 00:05:33 Tom Lane (tgl) Added tgl as committer
2022-03-30 23:42:51 Tom Lane (tgl) New status: Ready for Committer
2022-03-30 20:46:27 Tom Lane (tgl) Added tgl as reviewer
2022-02-02 16:18:48 Julien Rouhaud (rjuju) Closed in commitfest 2022-01 with status: Moved to next CF
2021-12-02 13:36:39 Daniel Gustafsson (d_gustafsson) Closed in commitfest 2021-11 with status: Moved to next CF
2021-10-04 07:30:47 Jaime Casanova (jcasanov) Closed in commitfest 2021-09 with status: Moved to next CF
2021-09-03 20:54:25 David Zhang (david.z) Posted review with messageid <163070246538.1167.10966495665230293888.pgcf@coridan.postgresql.org>
2021-09-03 20:24:44 David Zhang (david.z) Added david.z as reviewer
2021-07-22 07:15:48 Ronan Dunklau (rdunklau) Changed authors to Ronan Dunklau (rdunklau)
2021-07-22 07:15:31 Ronan Dunklau (rdunklau) Attached mail thread CAApHDvr4OeC2DBVY--zVP83-K=bYrTD7F8SZDhN4g+pj2f2S-A@mail.gmail.com
2021-07-22 07:15:31 Ronan Dunklau (rdunklau) Created patch record