[TySan] Add skeleton for adding interface functions (#170859)

This pr has the more straightforward changes from the initial interfaces
pr (https://github.com/llvm/llvm-project/pull/169023). By supporting
interfaces, it also will help me fix [this
issue](https://github.com/llvm/llvm-project/issues/169024) where we
don't test tysan with the sanitizer_common codebase

GitOrigin-RevId: c9753859d19b07315c5a9a493efaa4df18db84ab