[clang] [clang-format] Add first support for reflection (PR #193794)

[Ryan Keane via cfe-commits]

RyanJK5 wrote:

> Can you elaborate with an example or a GitHub issue?

For the record, I'm running into this issue in my project. I love clang-format but had to disable it on every file because it can't handle the reflection syntax. https://github.com/ryanjk5/rjk-duck

https://github.com/llvm/llvm-project/pull/193794