Note that a workaround exists in the specific example given in the ticket description: just reference the ID explicitly. Instead of:

delete from IT i where not exists (select p from PT p where p.it = i)

... write:

delete from IT i where not exists (select p from PT p where p.it.id = i.id)

This will only work in specific cases where the table IT only appears once, though, since the generated statement still won't include the alias.

I'm still working on a fix.