Extends true_divide to be a method (#34794)
Summary:
Per title. See related https://github.com/pytorch/pytorch/pull/34570.
In PyTorch 1.7 the plan is for torch.div and Python's division operator to perform "true" division, like Python 3, JAX, and NumPy. To facilitate this change, this PR expands true_divide to be a method so it can cover all of torch.div's use cases.
New true_divide tests are added to test_torch.py, test_type_promotion.py, and test_sparse.py.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34794
Differential Revision: D20545507
Pulled By: mruberry
fbshipit-source-id: 55286f819716c8823d1930441a69008560ac2bd5
