batch size 0 tests for element-wise DNNLOWP ops (#26870)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26870
Add batch_size == 0 testings of element-wise DNNLOWP operators.
Test Plan: CI
Reviewed By: jianyuh
Differential Revision: D17595162
fbshipit-source-id: f358748b56b236cce8736bac16054ea84541bf7f
