pgsql: Rename debug_invalidate_system_caches_always to debug_discard_ca

Rename debug_invalidate_system_caches_always to debug_discard_caches.

The name introduced by commit 4656e3d66 was agreed to be unreasonably
long. To match this change, rename initdb's recently-added
--clobber-cache option to --discard-caches.

Discussion: https://postgr.es/m/1374320.1625430433@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d68a00391214be2020e49be4b55f761d47a5c229

Modified Files
--------------
contrib/postgres_fdw/expected/postgres_fdw.out | 6 +++---
contrib/postgres_fdw/sql/postgres_fdw.sql | 6 +++---
doc/src/sgml/config.sgml | 8 ++++----
doc/src/sgml/ref/initdb.sgml | 22 ++++++++++-----------
doc/src/sgml/regress.sgml | 2 +-
src/backend/utils/adt/lockfuncs.c | 8 ++++----
src/backend/utils/cache/inval.c | 16 +++++++--------
src/backend/utils/cache/plancache.c | 5 ++---
src/backend/utils/cache/relcache.c | 17 ++++++++--------
src/backend/utils/misc/guc.c | 12 ++++++------
src/bin/initdb/initdb.c | 6 +++---
src/include/pg_config_manual.h | 26 ++++++++++++-------------
src/include/utils/inval.h | 2 +-
src/pl/plpgsql/src/expected/plpgsql_cache.out | 12 ++++++------
src/pl/plpgsql/src/expected/plpgsql_cache_1.out | 12 ++++++------
src/pl/plpgsql/src/expected/plpgsql_record.out | 8 ++++----
src/pl/plpgsql/src/sql/plpgsql_cache.sql | 12 ++++++------
src/pl/plpgsql/src/sql/plpgsql_record.sql | 8 ++++----
src/test/isolation/specs/deadlock-soft-2.spec | 2 +-
19 files changed, 94 insertions(+), 96 deletions(-)