pgsql: For inplace update durability, make heap_update() callers wait.

For inplace update durability, make heap_update() callers wait.

The previous commit fixed some ways of losing an inplace update.  It
remained possible to lose one when a backend working toward a
heap_update() copied a tuple into memory just before inplace update of
that tuple.  In catalogs eligible for inplace update, use LOCKTAG_TUPLE
to govern admission to the steps of copying an old tuple, modifying it,
and issuing heap_update().  This includes MERGE commands.  To avoid
changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when
holding a relation lock sufficient to exclude inplace updaters.
Back-patch to v12 (all supported versions).  In v13 and v12, "UPDATE
pg_class" or "UPDATE pg_database" can still lose an inplace update.  The
v14+ UPDATE fix needs commit 86dc90056dfdbd9d1b891718d2e5614e3e432f35,
and it wasn't worth reimplementing that fix without such infrastructure.

Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas.

Discussion: https://postgr.es/m/20231027214946.79.nmisch@google.com

Branch
------
REL_17_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/3b7a689e1a805c4dac2f35ff14fd5c9fdbddf150

Modified Files
--------------
src/backend/access/heap/README.tuplock             |  42 ++++++
src/backend/access/heap/heapam.c                   | 150 ++++++++++++++++++++-
src/backend/access/index/genam.c                   |   4 +-
src/backend/catalog/aclchk.c                       |   9 +-
src/backend/catalog/catalog.c                      |   9 ++
src/backend/commands/dbcommands.c                  |  25 +++-
src/backend/commands/event_trigger.c               |   7 +-
src/backend/commands/indexcmds.c                   |   7 +-
src/backend/commands/tablecmds.c                   |  28 +++-
src/backend/executor/execMain.c                    |   6 +
src/backend/executor/execReplication.c             |   6 +-
src/backend/executor/nodeModifyTable.c             |  98 +++++++++++---
src/backend/utils/cache/relcache.c                 |   9 +-
src/backend/utils/cache/syscache.c                 | 117 ++++++++++++++++
src/include/nodes/execnodes.h                      |   3 +
src/include/storage/lockdefs.h                     |   2 +
src/include/utils/syscache.h                       |   5 +
.../isolation/expected/intra-grant-inplace.out     |  14 +-
src/test/isolation/specs/eval-plan-qual.spec       |   2 +-
src/test/isolation/specs/intra-grant-inplace.spec  |  12 +-
20 files changed, 498 insertions(+), 57 deletions(-)