[clang] [clang][Driver] Add a custom error option in multilib.yaml. (PR #105684)

[Simon Tatham via cfe-commits]

statham-arm wrote:

To be clear, are you asking _me_ to make a followup PR to change that identifier in this already-landed patch, or are you going to do it?

(Just to avoid the situation where both of us do it, or both of us think the other is going to)

https://github.com/llvm/llvm-project/pull/105684