[clang-tools-extra] [clangd] Add code action to suppress clang-tidy diagnostics (PR #188796)

[Sirui Mu via cfe-commits]

Lancern wrote:

> > The issue is that ParsedAST::build has a non-trivial amount of code building a ClangTidy context for identifying and processing ClangTidy diagnostics, which is not accessible in a feature module.
> 
> Would it make sense to move all of clang-tidy into a feature module? And make the ClangTidy context an implementation detail of that Then you could add the "suppress diagnostic" as part of that clang-tidy feature module. Since you would be inside that module, you would have access to the module-private ClangTidy context.
> 
> (That being said, I know next to nothing about feature modules, and hence don't know how much work that refactoring would be or if it's even doable)

This sounds like a good idea to me. I'm willing to take some time to investigate into this and I think I would hold this PR on for a while until that approach is attempted.

https://github.com/llvm/llvm-project/pull/188796