[iOS GPU] Add Metal API availability check (#57663)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57663
Detail error messages when shader compilation fails.
ghstack-source-id: 128206967
Test Plan: CI
Reviewed By: linbinyu
Differential Revision: D28177176
fbshipit-source-id: b5913e5ed75df96fda770c3f1a893f9bfd781ec0
