add torch.tensor requires grad (#19445)
Summary:
Add setting requires_grad = True within torchscript to torch.Tensor
Within constant propagation, we can't insert any constants that require grad.
Also added shape analysis and requires grad analysis to torch.tensor
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19445
Differential Revision: D15039713
Pulled By: eellison
fbshipit-source-id: 47f1931b6fc4a1137c13d80110cc404465bfdf06
