pgsql: pg_stat_statements: Add TAP test for testing restarts

pg_stat_statements: Add TAP test for testing restarts

This tests that pg_stat_statement contents are successfully kept
across restart.  (This similar to
src/test/recovery/t/029_stats_restart.pl for the stats collector.)

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/4710b67d4d35832223dc49ccc2ccc043dff53793

Modified Files
--------------
contrib/pg_stat_statements/Makefile         |  2 ++
contrib/pg_stat_statements/meson.build      |  5 +++
contrib/pg_stat_statements/t/010_restart.pl | 53 +++++++++++++++++++++++++++++
3 files changed, 60 insertions(+)