Forbid kernels from returning Scalar[] (#19811)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19811
This does not immediately take effect for the custom op API but will break backwards compatibility once we switch to the new operator registration.
Reviewed By: dzhulgakov
Differential Revision: D15101924
fbshipit-source-id: 8890a5a3e163d3263dc1837be0b4851984771917
