[clang] [clang-tools-extra] [clang-tidy] Avoid matching nodes in system headers (PR #151035)

[Balazs Benics via cfe-commits]

https://github.com/steakhal commented:

The patch looks good. I had a couple of remarks though.
Thank you for working on this.

https://github.com/llvm/llvm-project/pull/151035