[lld] [lld][GNU Properties] Refactor storage of PAuth ABI core info (PR #141920)

[Oliver Stannard via llvm-commits]

https://github.com/ostannard commented:

This isn't NFC, because it changes the error messages, but I think it's fine to do that since the new errors are more useful.

https://github.com/llvm/llvm-project/pull/141920