[llvm] [llvm-readobj] Improve unsupported option messages (PR #216488)

[James Henderson via llvm-commits]

https://github.com/jh7370 approved this pull request.

Per the LLVM GitHub usage guidelines, please avoid force pushes when making edits to a PR. You can push additional commits to the branch containing the changes instead. The LLVM policy of merging always uses "Squash & Merge", which means these additional commits will disappear when merged. If a rebase is necessary, prefer a merge commit from the base branch rather than a rebase + force push.

Aside from that, LGTM. I'll kick off the auto-merge so that this lands if the pre-commit CI passes. Please keep an eye out for build bot failure notifications (I'd be surprised if there were any related failures though, given the nature of the change).

https://github.com/llvm/llvm-project/pull/216488