[llvm] [utils][filecheck-lint]: speedup filecheck_lint (PR #94191)

[Benjamin Chetioui via llvm-commits]

bchetioui wrote:

> cc @bchetioui
> 
> Actually, faster way is to use some external package to do fast levenshtein, like jellyfish (which speedup check to few seconds), but this is for separate commit.

That's a good point---there are certainly faster implementations of Levenshtein out there, but I don't think we'll want to add any non-standard third party dependency here. (Which is the reason we implemented a custom one here, even.) If you find one that we can use under these conditions, that'd be awesome!

https://github.com/llvm/llvm-project/pull/94191