Clean up old uses of checkScript (#22002)
Summary:
This cleans up the `checkScript` API and some old tests that were hardcoding outputs. It also now runs the Python function when a string is passed in to verify the outputs.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22002
Differential Revision: D15924485
Pulled By: driazati
fbshipit-source-id: ee870c942d804596913601cb411adc31bd988558
