Metal: ETC and ASTC are missing on M1 Platform guards are incorrect in mtl_utils.mm. We need to account for macOS post 10.15, which now supports the apple GPU family query. Bug: angleproject:6809 Change-Id: Iae219a11ffe0ef0715681009aa24cbbc6fd2c61e Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3338624 Reviewed-by: Gregg Tavares <gman@chromium.org> Reviewed-by: Alexey Knyazev <lexa.knyazev@gmail.com> Reviewed-by: Kenneth Russell <kbr@chromium.org> Commit-Queue: Kenneth Russell <kbr@chromium.org>