bpo-33029: Fix signatures of getter and setter functions. (GH-10746)


Fix also return type for few other functions (clear, releasebuffer).
(cherry picked from commit d4f9cf5545d6d8844e0726552ef2e366f5cc3abd)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
25 files changed