bpo-33100: Dataclasses now handles __slots__ and default values correctly. (GH-6152) (GH-6153)

If the class has a member that's a MemberDescriptorType, it's not a default value, it's from that member being in __slots__.
(cherry picked from commit 7389fd935c95b4b6f094312294e703ee0de18719)

Co-authored-by: Eric V. Smith <ericvsmith@users.noreply.github.com>
3 files changed