empty_meta: Add functions that don't depend on Tensor (#70615)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70615
This adds `at::detail::empty_meta` and
`at::detail::empty_strided_meta` to complement the cpu API.
Test Plan: Imported from OSS
Reviewed By: samdow
Differential Revision: D33623678
Pulled By: ngimel
fbshipit-source-id: 59e003116361fb547ec2c633bbc15a7973e21d0e
(cherry picked from commit b4f5836fa106418755381abedf327125bde744ef)
