Improve runtime and output of tests for replication slots checkpointing.HEADmaster

The TAP tests that verify logical and physical replication slot behavior
during checkpoints (046_checkpoint_logical_slot.pl and
047_checkpoint_physical_slot.pl) inserted two batches of 2 million rows each,
generating approximately 520 MB of WAL.  On slow machines, or when compiled
with '-DRELCACHE_FORCE_RELEASE -DCATCACHE_FORCE_RELEASE', this caused the
tests to run for 8-9 minutes and occasionally time out, as seen on the
buildfarm animal prion.

This commit modifies the mentioned tests to utilize the $node->advance_wal()
function, thereby reducing runtime. Once we do not use the generated data,
the proposed function is a good alternative, which cuts the total wall-clock
run time.

While here, remove superfluous '\n' characters from several note() calls;
these appeared literally in the build-farm logs and looked odd.  Also, remove
excessive 'shared_preload_libraries' GUC from the config and add a check for
'injection_points' extension availability.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Alexander Korotkov <aekorotkov@gmail.com>
Author: Vitaly Davydov <v.davydov@postgrespro.ru>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Discussion: https://postgr.es/m/fbc5d94e-6fbd-4a64-85d4-c9e284a58eb2%40gmail.com
Backpatch-through: 17

0 files changed, 0 insertions, 0 deletions