[clang-tools-extra] [llvm] [clang-tidy] Introduced new option --dump-yaml-schema (PR #164412)

[Timur Golubovich via llvm-commits]

tgs-sc wrote:

? This is hard to review in one go and when landing PR all the commits would be squashed. I particularly don't like that all change to yaml traits would land as [clang-tidy] Introduced new option

Well, I agree that this might be a little bit confusing, probably I should rename this PR to something like `[llvm][clang-tidy] New infrastructure for --dump-yaml-schema`

> I can't speak for usefulness of clang-tidy part for now, but to proceed further it should tests at least. For now, I don't understand how it would look like to end-user.

This can be useful for people that use IDE. I attached in RFC topic some screenshots from it. Basically, the only action that is needed to enable this support, is insert schema obtained from the tool to IDE's config file. Probably we can add unittest to compare runtime emitted YAML schema with already obtained one.

https://github.com/llvm/llvm-project/pull/164412