pgsql: Fix refreshing physical relfilenumber on shared index

Fix refreshing physical relfilenumber on shared index

Buildfarm member 'prion', which is configured with
-DRELCACHE_FORCE_RELEASE -DCATCACHE_FORCE_RELEASE, failed with errors
like this:

    ERROR:  could not read blocks 0..0 in file "global/2672": read only 0 of 8192 bytes

while running a parallel test group that includes VACUUM FULL on some
catalog tables among other things. I was not able to reproduce that
just by running the tests with -DRELCACHE_FORCE_RELEASE
-DCATCACHE_FORCE_RELEASE, even though 'prion' hit it on first run
after commit 2b9b8ebbf8, so there might be something else that makes
it more susceptible to the race. However, I was able to reproduce it
by adding another test to the same test group that runs "vacuum full
pg_database" repeatedly.

The problem is that RelationReloadIndexInfo() no longer calls
RelationInitPhysicalAddr() on a nailed, shared index, when an
invalidation happens early during backend startup, before the critical
relcaches have been built. Before commit 2b9b8ebbf8, that was done by
RelationReloadNailed(), but it went missing from that path. Add it
back as an explicit step.

Broken by commit 2b9b8ebbf8, which refactored these functions.

Discussion: https://www.postgresql.org/message-id/db876575-8f5b-4193-a538-df7e1f92d47a%40iki.fi

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b82c877e76e2398409e823773413079668cf1881

Modified Files
--------------
src/backend/utils/cache/relcache.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)