[llvm] Support target names with dots in more utilities (PR #65812)

[James Henderson via llvm-commits]

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

Force pushing (and therefore rebasing) is [supposed to be avoided](https://llvm.org/docs/GitHub.html#rebasing-pull-requests-and-force-pushes) unless it's absolutely necessary. Was a rebase actually required for this change? One of the motivations to avoid force pushes is that I can no longer see what changed versus my previous review, which is a fairly major usability issue for reviewing. Fortunately, this is a small review...

By the way, did you mean to have two commits in your PR?

LGTM, aside from a comment on the TODO.

https://github.com/llvm/llvm-project/pull/65812