stochastic_depth support (#71536)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71536
as titled
Test Plan: buck test mode/dev-nosan caffe2/test:test_fx_acc_tracer -- test_stochastic_depth
Reviewed By: yinghai
Differential Revision: D33668640
fbshipit-source-id: 3a8e6fc04b5529373d9dc77fef4514e9d01bf088
(cherry picked from commit e346d1d7a306f64334146a1a5c107c3db3ce8cd8)
