pgsql: Close psql processes gracefully in recovery tests

Close psql processes gracefully in recovery tests

Under windows, psql processes need to be ended explicitly, or the TAP
tests hang. However, the recovery tests were doing this via
IPC::Run::kill_kill(), which causes other major problems on Windows.

We solve this by instead sending '\q' to psql so it quits of its own
accord, and then simply waiting for it. This means we can now run almost
all the recovery tests on all Windows platforms.

Discussion: https://postgr.es/m/20210301200715.tdjpuesfzebpffgn@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d3676a2e9f10a0972c6d6649235c1c7492cd6dea

Modified Files
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src/test/recovery/t/011_crash_recovery.pl | 13 +++----------
src/test/recovery/t/021_row_visibility.pl | 9 ++++++---
2 files changed, 9 insertions(+), 13 deletions(-)