Expand AclMode to 64 bits

Expand AclMode to 64 bits

We're running out of bits for new permissions. This change doubles the
number of permissions we can accomodate from 16 to 32, so the
forthcoming new ones for vacuum/analyze don't exhaust the pool.

Nathan Bossart

Reviewed by: Bharath Rupireddy, Kyotaro Horiguchi, Stephen Frost, Robert
Haas, Mark Dilger, Tom Lane, Corey Huinker, David G. Johnston, Michael
Paquier.

Discussion: https://postgr.es/m/20220722203735.GB3996698@nathanxps13