create //c10/cuda library (#70863)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70863
ghstack-source-id: 148159368
Test Plan: Ought to be a no-op: rely on CI to validate.
Reviewed By: malfet
Differential Revision: D33367290
fbshipit-source-id: cb550538b9eafaa0117f94077ebd4cb920688881
(cherry picked from commit 077d9578bcbf5e41e806c6acb7a8f7c622f66fe9)
