Add (Un)Fold modules to standard library (#14759)
Summary:
Depends on #14597 for the corresponding aten ops.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14759
Differential Revision: D13325356
Pulled By: driazati
fbshipit-source-id: 99e39449c1ccfa293de05672c31a11e580bdd11f
