such as :meth:`.Query.union` now handle the case where the embedded
SELECT statements need to be parenthesized due to the fact that they
include LIMIT, OFFSET and/or ORDER BY.   These queries **do not work
on SQLite**, and will fail on that backend as they did before, but
should now work on all other backends.
fixes #2528

- test for .cast() method has no good place now except for
test_cast in test_compiler.py

(hence becoming two regressions); reports that
SELECT statements would GROUP BY a label name and fail was misconstrued
that certain backends such as SQL Server should not be emitting
ORDER BY or GROUP BY on a simple label name at all; when in fact,
we had forgotten that 0.9 was already emitting ORDER BY on a simple
label name for all backends, as described in :ref:`migration_1068`,
as 1.0 had rewritten this logic as part of :ticket:`2992`.

In 1.0.2, the bug is fixed both that SQL Server, Firebird and others
will again emit ORDER BY on a simple label name when passed a
:class:`.Label` construct that is expressed in the columns clause,
and no backend will emit GROUP BY on a simple label name in this case,
as even Postgresql can't reliably do GROUP BY on a simple name
in every case.
fixes #3338, fixes #3385

with Firebird, so that the values are again rendered inline when
this is selected.  Related to :ticket:`3034`.
fixes #3381

assign the proper result type of Boolean to the result mapping, and
instead would leak column types from within the query into the
result map.  This issue exists in 0.9 and earlier as well, however
has less of an impact in those versions.  In 1.0, due to #918
this becomes a regression in that we now rely upon the result mapping
to be very accurate, else we can assign result-type processors to
the wrong column.   In all versions, this issue also has the effect
that a simple EXISTS will not apply the Boolean type handler, leading
to simple 1/0 values for backends without native boolean instead of
True/False.   The fix includes that an EXISTS columns argument
will be anon-labeled like other column expressions; a similar fix is
implemented for pure-boolean expressions like ``not_(True())``.
fixes #3372

- replace force_result_map with a mini-API for nested result sets, add
coverage

that quoting should be applied in %(name)s under with_hint.

INSERT, either through the values clause or as a "from select",
would pollute the column types used in the result set produced by
the RETURNING clause when columns from both statements shared the
same name, leading to potential errors or mis-adaptation when
retrieving the returning rows.
fixes #3248