I actually don't agree with this change. __origin__ is not a public API and we should not make internal implementation

(much) more complex to simplify any public use of it. This is precisely the case why `get_origin()` and `get_args()` were just added

to `typing` -- to "decouple" private and public introspection APIs.

Moreover, I think _AnnotatedAlias is much more similar to _GenericAlias than to special forms like ClassVar, so it makes sense

to make it a "thin" subclass of the latter. `get_origin()` and `get_args()` can be adjusted to return `Annotated` and `(int, 'some marker')`.

--

Ivan