pytorch

8f8524a4 - Expose is_metal_available in header (#68942)

Expose is_metal_available in header (#68942) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/68942 Currently, `at::native::is_metal_available()` is implemented, but it's not exposed in the header, so nobody can use it. It's a useful function and I want to use it, so exposing it in the header. Test Plan: CI Reviewed By: sodastsai, xta0 Differential Revision: D32675236 fbshipit-source-id: b4e692db7d171dfb872d5c2233cc808d7131f2e9