and DELETE. If specified, the alias must be used instead of the full
table name. Also, the alias currently cannot be used in the SET clause
of UPDATE.

Patch from Atsushi Ogawa, various editorialization by Neil Conway.
Along the way, make the rowtypes regression test pass if add_missing_from
is enabled, and add a new (skeletal) regression test for DELETE.

now all that is tested is Rod Taylor's recent addition to allow
this syntax:

    UPDATE ... SET <col> = DEFAULT;

If anyone else would like to add more UPDATE tests, go ahead --
I just wanted to write a test for the above functionality, and
couldn't see an existing test that it would be appropriate
to add to.

Neil Conway