* win32/win32.c, include/ruby/win32.h (getipaddrs): [experimental]
  emulate getipaddrs(3) on Unix.

* win32/Makefile.sub, configure.in (LIBS): need iphlpapi.lib for above
  function.

* include/ruby/win32.h (socketpair): rb_w32_socketpair() doesn't
  substitute for any function, so use non-prefixed name.

* ext/socket/extconf.rb (socketpair); follow above change.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40693 b2dd03c8-39d4-4d8f-98ff-823fe69b080e