Add planner support function for starts_with()

When Who What
2021-11-17 22:07:10 Tom Lane (tgl) Closed in commitfest 2021-11 with status: Committed
2021-11-17 22:07:10 Tom Lane (tgl) Changed committer to tgl
2021-11-17 19:00:27 Nathan Bossart (bossartn) New status: Ready for Committer
2021-11-17 19:00:21 Nathan Bossart (bossartn) Added bossartn as reviewer
2021-11-17 19:00:20 Nathan Bossart (bossartn) Removed bossartn from reviewers
2021-11-17 19:00:19 Nathan Bossart (bossartn) Added bossartn as reviewer
2021-10-09 17:25:51 Tom Lane (tgl) Changed authors to Tom Lane (tgl)
2021-10-09 17:25:34 Tom Lane (tgl) Attached mail thread 232599.1633800229@sss.pgh.pa.us
2021-10-09 17:25:34 Tom Lane (tgl) Created patch record