Strengthen invalid_value lint to forbid uninit primitives, adjust docs to say that's UB For context: https://github.com/rust-lang/rust/issues/66151#issuecomment-1174477404= This does not make it a FCW, but it does explicitly state in the docs that uninit integers are UB. This also doesn't affect any runtime behavior, uninit u32's will still successfully be created through mem::uninitialized.