[numpy] torch.exp: promote integer inputs to float (#50093)
Summary:
Reference: https://github.com/pytorch/pytorch/issues/42515
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50093
Reviewed By: H-Huang
Differential Revision: D25803549
Pulled By: mruberry
fbshipit-source-id: e6f245b5e728f2dca6072f8c359f03dff63aa14d
