[Reland] Implement cusparse Descriptor class and clean up cusparse code (#37533)
Summary:
Reland of https://github.com/pytorch/pytorch/issues/37389. Fix for the cuda 10.1 CI failure.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37533
Differential Revision: D21326386
Pulled By: ezyang
fbshipit-source-id: f34875865c8bad76163995c18d88b0e76656bb22
