[clang-tools-extra] [clang-tidy] Added check 'bugprone-function-visibility-change' (PR #140086)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat approved this pull request.

LGTM if you implement the changes suggested by EugeneZelenko.

https://github.com/llvm/llvm-project/pull/140086