Fix test_data_parallel name errors and add to run_test.py (#32428)
Summary:
While working on https://github.com/pytorch/pytorch/issues/31768 and trying to add tests for `DataParallel`, I discovered that:
- `test_data_parallel.py` can't be run through `run_test.py`
- running it with `pytest` fails with many name errors
`test_data_parallel.py` seems to have been split from `test_nn.py` in https://github.com/pytorch/pytorch/issues/28297 but not in a state where it can actually be run. Presumably `DataParallel` hasn't been tested by CI in the time since.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32428
Differential Revision: D19499345
Pulled By: ezyang
fbshipit-source-id: f9b748a99a5c85fc6675c22506cf10bbfd9c8a4d
