RUSTSEC-2020-0081 `mio` invalidly assumes the memory layout of std::net::SocketAddr

The mio crate has assumed std::net::SocketAddrV4 and std::net::SocketAddrV6 have the same memory layout as the system C representation sockaddr. It has simply casted the pointers to convert the socket addresses to the system representation. The standard library does not say anything about the...