Needed for #88061.

Describe the problem

PostgreSQL and CockroachDB differ on the following:

create table mytable(mycolumn int);
create index myidx on mytable(mycolumn);
select oid, pg_table_is_visible(oid) from pg_class where relname = 'myidx';

In PostgreSQL, this returns properly true for the visibility.
In CockroachDB, we get NULL.

cc @rafiss for triage.

Jira issue: CRDB-19683

Epic: CRDB-23454