Show warning in eager mode for empty containers (#62978)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/54873
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62978
Reviewed By: navahgar
Differential Revision: D30278343
Pulled By: ansley
fbshipit-source-id: ebb19f7b8a10720f2612b99a2668d1ebbc1f2d16
