Remove TH/THC link for gesv (#15510)
Summary:
This PR removes the TH/THC binding for gesv.
Changelog:
- Remove TH/THC binding
- Port single matrix case to ATen
- Enable test_gesv for CUDA as well
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15510
Differential Revision: D13559990
Pulled By: soumith
fbshipit-source-id: 9da2825e94d3103627e719709e6b1f8b521a07fb
