[clang] [llvm] [ci] New script to generate test reports as Buildkite Annotations (PR #113447)

[Louis Dionne via cfe-commits]

ldionne wrote:

> The script is already written and works, and there still isn't a concrete timeline for when we are going to move things over to Github actions. This solves a valid complaint I hear somewhat often. For libc++ at least, there are definitely platforms that will not be able to move over to Github precommit where something like this might still be useful from what I understand.

True, however for libc++ the benefits are smaller because we run only libc++ specific job in the BuildKite job. I've never had trouble with figuring out what part of a job has caused failures. Either way, like I said I'm fine with the patch, it seems like an improvement.

> Do we make any guarantees about supporting lit flags in the future? It's mostly an internal tool, and I would personally be in support of removing flags that are no longer used in tree, unless there are some extremely compelling downstream use cases and there is an appropriate maintenance story.

No, but someone has to remember and actually take the time to do the cleanup. I also 100% support the removal of unused options and I've done things like that in the past, but it doesn't happen unless someone decides to make it their task.

https://github.com/llvm/llvm-project/pull/113447