RawSockaddr allows structs to be used with [Bind] and [ConnectEx]. The struct must meet the Win32 sockaddr requirements specified here: https://docs.microsoft.com/en-us/windows/win32/winsock/sockaddr-2
Specifically, the struct size must be least larger than an int16 (unsigned short) for the address family.
type RawSockaddr interface {
// Sockaddr returns a pointer to the RawSockaddr and its struct size, allowing
// for the RawSockaddr's data to be overwritten by syscalls (if necessary).
//
// It is the callers responsibility to validate that the values are valid; invalid
// pointers or size can cause a panic.
Sockaddr() (unsafe.Pointer, int32, error)
}