add handle to run all jit tests (#21161)
Summary:
Now you can run `python test/run_tests --jit` to run all jit tests
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21161
Differential Revision: D15563912
Pulled By: eellison
fbshipit-source-id: 4bb0285cda4168b72a3dc4bba471485566a59873
