pgsql: Replace literal 0 with InvalidXLogRecPtr for XLogRecPtr assignme

Replace literal 0 with InvalidXLogRecPtr for XLogRecPtr assignments

Use the proper constant InvalidXLogRecPtr instead of literal 0 when
assigning XLogRecPtr variables and struct fields.

This improves code clarity by making it explicit that these are
invalid LSN values rather than ambiguous zero literals.

Author: Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com>
Discussion: https://postgr.es/m/aRtd2dw8FO1nNX7k@ip-10-97-1-34.eu-west-3.compute.internal

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ec317440716487753bafa4c0f8adae53e2c32446

Modified Files
--------------
src/backend/access/gist/gist.c | 4 ++--
src/backend/access/transam/parallel.c | 4 ++--
src/backend/access/transam/xlog.c | 6 +++---
src/backend/access/transam/xlogprefetcher.c | 2 +-
src/backend/access/transam/xlogrecovery.c | 6 +++---
src/backend/replication/syncrep.c | 4 ++--
src/backend/replication/walreceiver.c | 4 ++--
src/backend/storage/lmgr/proc.c | 2 +-
src/bin/pg_resetwal/pg_resetwal.c | 8 ++++----
src/bin/pg_rewind/pg_rewind.c | 2 +-
10 files changed, 21 insertions(+), 21 deletions(-)