[llvm] [GitHub] Add more CODEOWNERS for top level projects (PR #65509)

[Tom Stellard via llvm-commits]

tstellar wrote:

Hi, we are making some changes to the notification system.  I think some of the paths and labels you requested are already in [.github/new-prs-labeler.yml](https://github.com/llvm/llvm-project/blob/main/.github/new-prs-labeler.yml), but if you see something that is missing there could you change this PR to modify that file instead.

Also note that this new file uses [minimatch](https://github.com/isaacs/minimatch) glob parser which is different in some ways from the .gitignore syntax used by the CODEOWNERS file. The main difference is you need to do things like directory/** instead of directory/ to select a directory's contents.

https://github.com/llvm/llvm-project/pull/65509