* ext/socket/extconf.rb: test struct sockaddr_un and its member,
  sun_len.

* ext/socket/sockport.h (INIT_SOCKADDR_UN): new macro defined.

* ext/socket/socket.c (sock_s_pack_sockaddr_un): use INIT_SOCKADDR_UN.

* ext/socket/unixsocket.c (rsock_init_unixsock): ditto.

* ext/socket/raddrinfo.c (init_unix_addrinfo): ditto.
  (addrinfo_mload): ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39260 b2dd03c8-39d4-4d8f-98ff-823fe69b080e