[clang] [clang-format] Allow breaks before comma-paste operators (PR #214990)

[Matthias Görgens via cfe-commits]

matthiasgoergens wrote:

> I think all these [PR](https://github.com/llvm/llvm-project/issues?q=is%3Apr+author%3Amatthiasgoergens) were generated by LLMs. Please reread [AI Tool Policy](https://llvm.org/docs/AIToolPolicy.html).

Yes, AI tools assisted in making the PRs.  I have added a the disclosure to the PR description.  I hope that's the right format?

https://github.com/llvm/llvm-project/pull/214990