socket: system getaddrinfo on Windows

* ext/socket/extconf.rb: use system getaddrinfo, getnameinfo, and
  freeaddrinfo on Windows if they are provided.  they conflict
  with addrinfo.h and cannot compile.  conftest.exe linked against
  msvcr90.dll segfaults when invoked in extconf.rb for unknown
  reason, and failed to check them.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59414 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/socket/extconf.rb

@@ -566,6 +566,7 @@ EOS
     getaddr_info_ok = (:wide if getaddr_info_ok.nil?)
     if have_func("getnameinfo", headers) and have_func("getaddrinfo", headers)
       if CROSS_COMPILING ||
+         $mingw || $mswin ||
          checking_for("system getaddrinfo working") {
            try_run(cpp_include(headers) + GETADDRINFO_GETNAMEINFO_TEST)
          }