Move THCTensor_(cauchy) to ATen (#20622)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20622
ghimport-source-id: b100d6cededf6f2c2020c3d7961271f16497bbdc
Differential Revision: D15454052
Pulled By: ezyang
fbshipit-source-id: 4f4d33ec11cf36b91c67759bd27252d1e457cff1
