Make empty c10-full (#46092)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46092
Make empty c10-full without using hacky-wrapper, i.e. port the kernel to the new style signature.
This PR also changes the signature of some helpers called by empty to the new style.
ghstack-source-id: 116544203
(Note: this ignores all push blocking failures!)
Test Plan:
vs prev diff (outdated, before c10::optional fix): https://www.internalfb.com/intern/fblearner/details/224735103/
after c10::optional fix:
https://www.internalfb.com/intern/fblearner/details/231391773/
Also, after the c10::optional fix, the instruction counting benchmark shows a 2% regression for calling empty from Python. We decided this is acceptable and decided against landing D24425836 which would fix the regression.
Reviewed By: ezyang
Differential Revision: D24219944
fbshipit-source-id: e554096e90ce438c75b679131c3151ff8e5c5d50
