[JIT] Fix torch.tensor for empty multidimensional-typed lists (#44652)
Summary:
We were hitting an assert error when you passed in an empty `List[List[int]]` - this fixes that error by not recursing into 0-element tensors.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44652
Reviewed By: ZolotukhinM
Differential Revision: D23688247
Pulled By: eellison
fbshipit-source-id: d48ea24893044fae96bc39f76c0f1f9726eaf4c7
