Fixed comm.cc:644: "address.port() != 0" assertion (#1149)

Fixed comm.cc:644: "address.port() != 0" assertion (#1149)

IPC code creating a TCP socket pair for communication with helpers used
comm_open() to create a _listening_ socket, misleading Comm into
applying IP_BIND_ADDRESS_NO_PORT optimization that delays port
assignment until connect(2) (which is never called for listening
sockets). Listening sockets must be opened using comm_open_listener(),
but the IPC use case was missed in 2009 commit 31be869 that introduced
comm_open_listener(). IP_BIND_ADDRESS_NO_PORT changes in recent commit
74d7d19 hit that bug.

Disclaimer: Windows-specific code adjusted without testing.