Planning failure with update subquery compensation with agg comparision

An update of the form:

delete from pm3.g1 where e1 = (SELECT MAX(e1) FROM pm3.g1 as z where e2 = pm3.g1.e2)

Such that the subquery cannot be pushed will result in the unaliased max being known by two different names which results in an AssertionError in the SortNode initialization.