Added more regression test for groupconv w/o bias. (#18519)
Summary:
Follow-up of https://github.com/pytorch/pytorch/issues/18218, which was fixed by https://github.com/pytorch/pytorch/pull/18463 with mkl-dnn upgraded to v0.18.1.
Covering special case when group > 1, input-channel / group < 16 and output-channel is multiple of 16.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18519
Differential Revision: D14643071
Pulled By: soumith
fbshipit-source-id: d0ebed59326c67089e042b50583b87ed2c3ccc2f
