Fixed apparently very old issue where the
:paramref:`_postgresql.ENUM.create_type` parameter, when set to its
non-default of ``False``, would not be propagated when the
:class:`_schema.Column` which it's a part of were copied, as is common when
using ORM Declarative mixins.

Fixes: #9773
Change-Id: I79a7c6f052ec39b42400d92bf591c791feca573b

fix a handful of warnings that were emitting but not raising,
usually because they were inside an "expect_warnings" block.

modify "expect_warnings" to always use "raise_on_any_unexpected"
behavior; remove this parameter.

Fixed issue in semi-private ``await_only()`` and ``await_fallback()``
concurrency functions where the given awaitable would remain un-awaited if
the function threw a ``GreenletError``, which could cause "was not awaited"
warnings later on if the program continued. In this case, the given
awaitable is now cancelled before the exception is thrown.

Change-Id: I33668c5e8c670454a3d879e559096fb873b57244

Fixed the base class for dialect-specific float/double types; Oracle
:class:`_oracle.BINARY_DOUBLE` now subclasses :class:`_sqltypes.Double`,
and internal types for :class:`_sqltypes.Float` for asyncpg and pg8000 now
correctly subclass :class:`_sqltypes.Float`.

Added suite tests to ensure that floating point types, such as
class:`_types.Float` and :class:`_types.Double` are not resolved as
class:`_types.Numeric` in the dialect, since it may not compatible in
all cases, such as when casting a value.

Change-Id: I20b814e8e029d57921d9728a55f2570f74c35c87

Fixed another regression due to the "insertmanyvalues" change in 2.0.10 as
part of :ticket:`9618`, in a similar way as regression :ticket:`9701`, where
:class:`.LargeBinary` datatypes also need additional casts on when using the
asyncpg driver specifically in order to work with the new bulk INSERT
format.

Fixes: #9739
Change-Id: I57370d269ea757f263c1f3a16c324ceae76fd4e8

Fixed regression caused by the fix for :ticket:`9618` where floating point
values would lose precision being inserted in bulk, using either the
psycopg2 or psycopg drivers.

Implemented the :class:`_sqltypes.Double` type for SQL Server, having it
resolve to ``REAL``, or :class:`_mssql.REAL`, at DDL rendering time.

Fixed issue in Oracle dialects where ``Decimal`` returning types such as
:class:`_sqltypes.Numeric` would return floating point values, rather than
``Decimal`` objects, when these columns were used in the
:meth:`_dml.Insert.returning` clause to return INSERTed values.

Fixes: #9701
Change-Id: I8865496a6ccac6d44c19d0ca2a642b63c6172da9