Update host CPU detection for Apple M2 and Apple M3

[madsmtm]

CPUFAMILY_ARM_BLIZZARD_AVALANCHE and CPUFAMILY_ARM_EVEREST_SAWTOOTH are taken from <mach/machine.h> in Kernel.framework.

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[lattner]

Is there any concern landing this? This would be helpful to get in for us M3 users! :)

[jroelofs]

I forgot about this PR, and should have offered to merge it for @madsmtm, if they need me to.

[lattner]

I'm happy to merge this, just don't want to overstep :) lemme know, it seems "obvious" to me.

[lattner]

Cool, I'll merge it now, thanks for the feedback Jon

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[lattner]

Also thank you @madsmtm for implementing this!