changes made to the :class:`.Query` object's collection of entities
to load within the event would render in the SQL, but would not
be reflected during the loading process.
fixes #3387

and ``__declare_last__`` accessors where these would no longer be
called on the superclass of the declarative base.
fixes #3383

the string label placed in the order_by() or group_by() of a statement
would place higher priority on the name as found
inside the FROM clause instead of a more locally available name
inside the columns clause.
fixes #3335

out.
- add __backend__ to the dialect suite so that it runs on CI.
- will be 1.0.0b3