[clang] [Clang][Driver][AArch64] Add support for aarch64-amazon-linux triple (PR #109263)

[Benjamin Herrenschmidt via cfe-commits]

ozbenh wrote:

So what should we (Amazon Linux) do to help with this ? I'm not the most familiar with autotools and cmake, I know we did some tweaking of triples in the version of llvm/clang we ship as part of the distro and it's very possible that we did something wrong. I would love to help make things work better out of the box.

https://github.com/llvm/llvm-project/pull/109263