pgsql: Verify roundtrip dump/restore of regression database

Verify roundtrip dump/restore of regression database

Add a test to pg_upgrade's test suite that verifies that
dump-restore-dump of regression database produces equivalent output to
dumping it directly. This was already being tested by running
pg_upgrade itself, but non-binary-upgrade mode was not being covered.

The regression database has accrued, over time, a sufficient collection
of interesting objects to ensure good coverage, but there hasn't been a
concerted effort to be completely exhaustive, so it is likely still
possible to have more.

This'd belong more naturally in the pg_dump test suite, but we chose to
put it in src/bin/pg_upgrade/t/002_pg_upgrade.pl because we need a run
of the regression tests which is already done here, so this has less
total test runtime impact. Also, experiments have shown that using
parallel dump/restore is slightly faster, so we use --format=directory -j2.

This test has already reported pg_dump bugs, as fixed in fd41ba93e463,
74563f6b9021, d611f8b1587b, 4694aedf63bf.

Author: Ashutosh Bapat <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com>
Reviewed-by: Michael Paquier <michael(at)paquier(dot)xyz>
Reviewed-by: Daniel Gustafsson <daniel(at)yesql(dot)se>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Reviewed-by: Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
Discussion: https://www.postgresql.org/message-id/CAExHW5uF5V=Cjecx3_Z=7xfh4rg2Wf61PT+hfquzjBqouRzQJQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/172259afb563d35001410dc6daad78b250924038

Modified Files
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src/bin/pg_upgrade/t/002_pg_upgrade.pl | 97 ++++++++++++++++-
src/test/perl/Makefile | 2 +
src/test/perl/PostgreSQL/Test/AdjustDump.pm | 157 ++++++++++++++++++++++++++++
src/test/perl/meson.build | 1 +
4 files changed, 254 insertions(+), 3 deletions(-)