[clang] [clang-format] Fix breaking enum braces when combined with export (PR #189128)

[via cfe-commits]

owenca wrote:

> Also fix (not) breaking variables declared on the same line as the closing brace.
> 
> And adapt whitesmith to that changes.

Better to fix it in a separate patch if it's worth it.

https://github.com/llvm/llvm-project/pull/189128