empty_strided: Factor out generic implementation (#70614)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70614
This creates an `empty_strided_generic` function which, similar to
`empty_generic`, is a device-independent tensor constructor. This also
adds `at::detail::empty_strided_cpu` to complement
`at::detail::empty_cpu`.
Test Plan: Imported from OSS
Reviewed By: samdow
Differential Revision: D33623679
Pulled By: ngimel
fbshipit-source-id: 85994e88d664870bf425f398dfcdfc467885c694
(cherry picked from commit 2ff2a89df5752cfad667463aa3c3bffe8479ec9a)
