as failing with the new 'entity' key value added to
:attr:`.Query.column_descriptions`, the logic to discover the "from"
clause is again reworked to accommodate columns from aliased classes,
as well as to report the correct value for the "aliased" flag in these
cases.
fixes #3409

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