Add sysctls for divert socket send and receive buffers.
This introduces two new sysctls, net.inet.divert.recvspace and net.inet.divert.sendspace, which respectively affects the divert socket receive and send buffers. The default value for both should remain the same at 65536.
Submitted by: Neel Chauhan <neel at neelc.org>
@Neel Can this go back to stable/11 ? If not, set mfc-stable11 to -