Add sinc operator (#48740)
Summary:
Implements the sinc operator.
See https://numpy.org/doc/stable/reference/generated/numpy.sinc.html
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48740
Reviewed By: izdeby
Differential Revision: D25564477
Pulled By: soulitzer
fbshipit-source-id: 13f36a2b84dadfb4fd1442a2a40a3a3246cbaecb
