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

[Balázs Kéri via cfe-commits]

balazske wrote:

The current code is not finished. I want to check for false positives and probably add options to disable check at destructors and operators.

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