Do not use pthread on mingw

ext/socket/raddrinfo.c

@@ -18,7 +18,7 @@
 #ifndef GETADDRINFO_IMPL
 #  ifdef GETADDRINFO_EMU
 #    define GETADDRINFO_IMPL 0
-#  elif !defined(HAVE_PTHREAD_CREATE) || !defined(HAVE_PTHREAD_DETACH)
+#  elif !defined(HAVE_PTHREAD_CREATE) || !defined(HAVE_PTHREAD_DETACH) || defined(__MINGW32__) || defined(__MINGW64__)
 #    define GETADDRINFO_IMPL 1
 #  else
 #    define GETADDRINFO_IMPL 2