[clang] [clang][AArch64] Add getHostCPUFeatures to query for enabled features in cpu info (PR #97749)

[David Spickett via cfe-commits]

DavidSpickett wrote:

Looks ok to me, X86 and ARM already do this.

> One point we noticed is that it could end up turning "aes+sha2" into "crypto" and "crypto" back into "sha2+aes+sha3+sm4", as it uses the old meaning of "crypto"

Then this needs to be fixed before this PR can go in, we don't want to be making binaries folks can't run. @davemgreen do we have a way that @neildhickey can reproduce that easily?


https://github.com/llvm/llvm-project/pull/97749