pgsql: Track block level checksum failures in pg_stat_database

Track block level checksum failures in pg_stat_database

This adds a column that counts how many checksum failures have occurred
on files belonging to a specific database. Both checksum failures
during normal backend processing and those created when a base backup
detects a checksum failure are counted.

Author: Magnus Hagander
Reviewed by: Julien Rouhaud

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6b9e875f7286d8535bff7955e5aa3602e188e436

Modified Files
--------------
doc/src/sgml/monitoring.sgml | 5 ++++
src/backend/catalog/system_views.sql | 1 +
src/backend/postmaster/pgstat.c | 56 ++++++++++++++++++++++++++++++++++++
src/backend/replication/basebackup.c | 16 +++++++----
src/backend/storage/page/bufpage.c | 3 ++
src/backend/utils/adt/pgstatfuncs.c | 15 ++++++++++
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_proc.dat | 4 +++
src/include/pgstat.h | 18 +++++++++++-
src/test/regress/expected/rules.out | 1 +
10 files changed, 114 insertions(+), 7 deletions(-)