I booted my M1 Mac into macOS rather than Asahi for the first time in
a while, and discovered that an OS update seems to have added some
sysctl flags indicating the presence of the CPU extensions that I
previously knew of no way to check for! Added them checks to
arm_arch_queries.c, though I've also retained backwards compat with
the previous OS version which didn't have them at all.
fd840f0dfe