[llvm] [clang] [AArch64] Add support for Cortex-A520, Cortex-A720 and Cortex-X4 CPUs (PR #72395)

[Lucas Duarte Prates via cfe-commits]

https://github.com/pratlucas approved this pull request.

Thanks for the updates! LGTM.

https://github.com/llvm/llvm-project/pull/72395