Listen returns TCP listener with SO_REUSEPORT option set.

The returned listener tries enabling the following TCP options, which usually have positive impact on performance:

- TCP_DEFER_ACCEPT. This option expects that the server reads from accepted

connections before writing to them.

- TCP_FASTOPEN. See for details.

Use if you want customizing these options.

Only tcp4 and tcp6 networks are supported.

ErrNoReusePort error is returned if the system doesn't support SO_REUSEPORT.