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

[Ramon de C Valle via cfe-commits]

rcvalle wrote:

Sorry, what I meant was we should be looking only at the number of return (with void being zero, and everything else being one) and parameters from the function declaration/definition and shouldn't be looking at the parameters' type layout (i.e., size), and how and what registers are used to pass them (i.e., we shouldn't mention or reference registers or assembly code at all in the implementation and documentation). The implementation should be completely ABI and architecture agnostic. Does it make sense?

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