Add test for trace (#47125)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47125
We didn't actually have any tests for torch.trace. The tests expose a
discrepancy between the behavior of torch.trace on CPU and CUDA that
I'll file an issue for.
Test Plan: Imported from OSS
Reviewed By: mruberry
Differential Revision: D24683260
Pulled By: zou3519
fbshipit-source-id: 71dd3af62bc98c6b9b0ba2bf2923cb6d44daa640
