pgsql: Add support for runtime arguments in injection points

Add support for runtime arguments in injection points

The macros INJECTION_POINT() and INJECTION_POINT_CACHED() are extended
with an optional argument that can be passed down to the callback
attached when an injection point is run, giving to callbacks the
possibility to manipulate a stack state given by the caller. The
existing callbacks in modules injection_points and test_aio have their
declarations adjusted based on that.

da7226993fd4 (core AIO infrastructure) and 93bc3d75d8e1 (test_aio) and
been relying on a set of workarounds where a static variable called
pgaio_inj_cur_handle is used as runtime argument in the injection point
callbacks used by the AIO tests, in combination with a TRY/CATCH block
to reset the argument value. The infrastructure introduced in this
commit will be reused for the AIO tests, simplifying them.

Reviewed-by: Greg Burd <greg(at)burd(dot)me>
Discussion: https://postgr.es/m/Z_y9TtnXubvYAApS@paquier.xyz

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/371f2db8b05e4d46cbf489f05cbfc4d6ed6976d4

Modified Files
--------------
doc/src/sgml/xfunc.sgml | 16 ++++++++++------
src/backend/access/gin/ginbtree.c | 6 +++---
src/backend/access/heap/heapam.c | 2 +-
src/backend/access/index/genam.c | 2 +-
src/backend/access/transam/multixact.c | 4 ++--
src/backend/access/transam/xlog.c | 2 +-
src/backend/commands/indexcmds.c | 4 ++--
src/backend/executor/nodeAgg.c | 10 +++++-----
src/backend/libpq/be-secure-gssapi.c | 2 +-
src/backend/libpq/be-secure.c | 2 +-
src/backend/postmaster/autovacuum.c | 2 +-
src/backend/storage/aio/aio.c | 2 +-
src/backend/tcop/backend_startup.c | 2 +-
src/backend/tcop/postgres.c | 6 +++---
src/backend/utils/cache/catcache.c | 2 +-
src/backend/utils/cache/inval.c | 2 +-
src/backend/utils/cache/typcache.c | 2 +-
src/backend/utils/init/postinit.c | 2 +-
src/backend/utils/misc/injection_point.c | 8 ++++----
src/include/utils/injection_point.h | 15 ++++++++-------
src/test/modules/injection_points/injection_points.c | 19 +++++++++++--------
src/test/modules/test_aio/test_aio.c | 12 ++++++++----
src/test/modules/test_slru/test_multixact.c | 2 +-
23 files changed, 69 insertions(+), 57 deletions(-)