This commit implements automatic verification of implement ARM/AArch64
intrinsics. Or it's at least a start! This downloads a snapshot of ARM's
[online documentation][docs] and implements necessary logic to parse
that and use it to verify all the intrinsics. Almost everything
checked out A-OK but a few minor tweaks were needed to the neon
intrinsics and the crc ones needed some renaming.
[docs]: https://developer.arm.com/technologies/neon/intrinsics