Switch pg_test_fsync to use binary mode on Windows

When Who What
2020-07-17 05:04:16 Michael Paquier (michael-kun) Closed in commitfest 2020-09 with status: Committed
2020-07-17 05:04:16 Michael Paquier (michael-kun) Changed committer to michael-kun
2020-07-10 01:52:52 Michael Paquier (michael-kun) Changed authors to Michael Paquier (michael-kun)
2020-07-10 01:52:52 Michael Paquier (michael-kun) Changed targetversion to stable
2020-07-10 01:52:19 Michael Paquier (michael-kun) Attached mail thread 16526-279ded30a230d275@postgresql.org
2020-07-10 01:52:19 Michael Paquier (michael-kun) Created patch record