[clang] [llvm] [X86] Enhance kCFI type IDs with a 3-bit arity indicator. (PR #117121)

[Sami Tolvanen via cfe-commits]

samitolvanen wrote:

While this overall looks like a nice improvement to me, changing the hashing scheme is going to break compatibility with Rust. I would suggest moving this change behind a command line flag, so the kernel can choose to enable it only if Rust support isn't enabled, or if we have a rustc that also supports this hashing scheme.

https://github.com/llvm/llvm-project/pull/117121