[clang] [Clang] Add azurelinux to fallback triples (PR #200894)

[Fangrui Song via cfe-commits]

MaskRay wrote:

Rejected. If your GCC installation lives in `lib/gcc/aarch64-azurelinux-linux`, you should ensure your llvm build LLVM_DEFAULT_TARGET_TRIPLE=aarch64-azurelinux-linux, or ensure that you set `--target=aarch64-azurelinux-linux`. It doesn't scale to add every triple variant to this list.

https://github.com/llvm/llvm-project/pull/200894