Tom Lane). For the moment, only the OID/name variants are provided.
I didn't force initdb, but the additions to the 'privileges' regress
test won't pass until you do one.
for GRANT/REVOKE is now just that, not "CHANGE".
On the way, migrate some of the aclitem internal representation away from
the parser and build a real parse tree instead. Also add some 'const'
qualifiers.