contrib modules and relkind check

Some contrib functions fail to fail sooner when relations of unsupported
relkinds are passed, resulting in error message like one below:

create table foo (a int);
create view foov as select * from foo;
select pg_visibility('foov', 0);
ERROR: could not open file "base/13123/16488": No such file or directory

Attached patch fixes that for all such functions I could find in contrib.

It also installs RELKIND_PARTITIONED_TABLE as unsupported in a couple of
places (in pageinspect and pgstattuple).

Thanks,
Amit