pgsql: Add wait event type "InjectionPoint", a custom type like "Extens

Add wait event type "InjectionPoint", a custom type like "Extension".

Both injection points and customization of type "Extension" are new in
v17, so this just changes a detail of an unreleased feature.

Reported by Robert Haas.  Reviewed by Michael Paquier.

Discussion: https://postgr.es/m/CA+TgmobfMU5pdXP36D5iAwxV5WKE_vuDLtp_1QyH+H5jMMt21g@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/bb93640a681c2cc709e9836e169c8f3eb556df57

Modified Files
--------------
doc/src/sgml/monitoring.sgml                       |  12 +-
doc/src/sgml/xfunc.sgml                            |   4 +
src/backend/storage/ipc/ipci.c                     |   4 +-
.../utils/activity/generate-wait_event_types.pl    |   3 +-
src/backend/utils/activity/wait_event.c            | 243 ++++++++++++---------
src/backend/utils/activity/wait_event_funcs.c      |  31 ++-
src/backend/utils/activity/wait_event_names.txt    |   2 +-
src/include/storage/lwlocklist.h                   |   2 +-
src/include/utils/wait_event.h                     |  27 ++-
.../modules/injection_points/injection_points.c    |   2 +-
src/test/regress/expected/sysviews.out             |   5 +-
src/test/regress/sql/sysviews.sql                  |   5 +-
src/tools/pgindent/typedefs.list                   |   6 +-
13 files changed, 215 insertions(+), 131 deletions(-)