[clang] [clang-tools-extra] Add function check for windows platform (PR #106581)

[Balazs Benics via cfe-commits]

https://github.com/steakhal requested changes to this pull request.

Looks good overall. I have mixed feelings about combining semantic changes across semi-subprojects like builtins, clang-tidy and the clang static analyzer.
Could you please demonstrate the improvements on tests?

https://github.com/llvm/llvm-project/pull/106581