Add logging import and failing MLP (#20115)
Summary:
Add logging import and a failed MLP model that confirms that we don't fail `add_graph` when graph optimization fails.
This addresses part of https://github.com/pytorch/pytorch/issues/18903
cc lanpa ezyang natalialunova
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20115
Reviewed By: natalialunova
Differential Revision: D15206765
Pulled By: orionr
fbshipit-source-id: c40b7e2671ef845a1529a2910ba030159f53f393
