[clang-tools-extra] [clang-reorder-fields] Prevent rewriting unsupported cases (PR #142149)

[Clement Courbet via cfe-commits]

legrosbuffle wrote:

Not  a big deal, but note for next time: we don't do force push to avoid losing context (https://llvm.org/docs/GitHub.html#rebasing-pull-requests-and-force-pushes)

https://github.com/llvm/llvm-project/pull/142149