[llvm] [llvm-cxxfilt] Add --quote option to quote demangled function names (PR #111871)

[James Henderson via llvm-commits]

https://github.com/jh7370 requested changes to this pull request.

Thanks for this: the core of it looks fine. Just some testing could be simplified and improved, in my opinion, and there are a few other minor bits and pieces.

https://github.com/llvm/llvm-project/pull/111871