bpo-33018 (GH-5944) fixed bpo-32999 too. So fc7df0e6 is not required
anymore. Revert it except test case.
(cherry picked from commit f757b72b25)
Co-authored-by: INADA Naoki <methane@users.noreply.github.com>
This improves error message for situations when a non-class is
checked w.r.t. an abstract base class.
(cherry picked from commit 40472dd42d)
Co-authored-by: jab <jab@users.noreply.github.com>