add test coverage for make_np (#20317)
Summary:
addresses https://github.com/pytorch/pytorch/pull/16196#discussion_r276381946
cc orionr
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20317
Differential Revision: D15289400
Pulled By: orionr
fbshipit-source-id: 914416a8c1369d95656f556c6e05348957789466
