[special] erfcx cuda support (#60519)
Summary:
Reference: https://github.com/pytorch/pytorch/issues/50345
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60519
Reviewed By: ngimel
Differential Revision: D29353105
Pulled By: mruberry
fbshipit-source-id: 2f525a347a22f96411739a16e354c7291e863f95
