Bug introduced by recent ALTER OWNER permissions check change

postgres=# create user u1;
CREATE ROLE
postgres=# create schema s1;
CREATE SCHEMA
postgres=# create table s1.t1(f1 int);
CREATE TABLE
postgres=# alter table s1.t1 owner to u1;
ERROR:  permission denied for schema s1
postgres=#

Considering I am superuser, it should darn well allow this.

The problem of course is the test that u1 would have the rights to
create t1 in s1, which he doesn't.  I think we have to skip that
test if superuser.  As long as we need an explicit test on
superuserness, we may as well skip *all* the added code.

Comments?
        regards, tom lane