Allow pregenerating most HW intrinsics in CoreLib (#24917)

Allow pregenerating most HW intrinsics in CoreLib (#24917)

* Allow pregenerating all HW intrinsics in CoreLib

This is a follow up to #24689 that lets us pregenerate all hardware intrinsics in CoreLib.

We ensures the potentially unsupported code will never be reachable at runtime on CPUs that don't support it by not reporting the `IsSupported` property as intrinsic in crossgen. This ensures the support checks are always JITted. JITting the support checks is very cheap.

There is cost in the form of an extra call and failure to do constant propagation of the return value, but the cost is negligible in practice and gets eliminated once the tiered JIT tiers the method up.

We only do this in CoreLib because user code could technically not guard intrinsic use in `IsSupported` checks and pregenerating the code could lead to illegal instruction traps at runtime (instead of `PlatformNotSupportedException` throws) - it's a bad user experience.