A few processor detection/features tweaks (#36831)
* Missing feature from Apple A13
* Enable Cortex-A78 and Cortex-X1 on LLVM 11
llvm/llvm-project@954db63cd149df031d9b660bf68f0fe1de1defb9
https://reviews.llvm.org/D83206
* More relaxed Zen detection: treat all family 23 as Zen* and treat all model >= 0x30 as Zen2.
GCC uses a similar fallback structure albeit based on feature.
This should still generate **correct** code since that is always controlled by
available features. It should be as good a scheduling model estimate as anything else.
Fix #36826
(cherry picked from commit cd3fb4dd10b3556124185a67d35dd4b7c9054484)
