bpo-42972: Fully implement GC protocol for xxlimited (GH-26451) (GH-26460)

(cherry picked from commit 4b20f2574d412f4c4a5b1ab799d8e71a5dd3b766)

Co-authored-by: Hai Shi <shihai1992@gmail.com>

Co-authored-by: Hai Shi <shihai1992@gmail.com>
2 files changed