Unit tests for the changes in abstract.c version 2.101.  The debug build's "undetected error" problems were originally detected with extension types, but we can whitebox test the same situations with new-style classes.
Unit tests for the changes in abstract.c version 2.101.  The debug
build's "undetected error" problems were originally detected with
extension types, but we can whitebox test the same situations with
new-style classes.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator