add torch.square (#30719)
Summary:
fixes https://github.com/pytorch/pytorch/issues/30524
This adds an new operator `torch.square` to PyTorch
I think it is ready for the first-time review now albanD
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30719
Differential Revision: D18909268
Pulled By: albanD
fbshipit-source-id: 5626c445d8db20471a56fc1d7a3490e77812662b
