Back out "fix: nn.Module allowing for expected Mixin MRO"
Summary:
Original commit changeset: 54741d983477
Original Phabricator Diff: D34822179
(Note: this ignores all push blocking failures!)
Test Plan: good_testplan
Reviewed By: osalpekar
Differential Revision: D34866030
fbshipit-source-id: 852182b90634873e51634228c33adbb72c5111c7
(cherry picked from commit 28f9a000c06f9c8e6477f369407036c9e54aec27)
