Windows 2000 does not have getaddrinfo in its @file{WS2_32.DLL}.
Thus, if you want to assume Windows XP or later, you can add
-AC_DEFINE(WINVER, 0x0501) to avoid compiling to (partial) getaddrinfo
+AC_DEFINE(WINVER, 0x0501) to avoid compiling the (partial) getaddrinfo
implementation.
If you want to support Windows 2000, don't do anything. The