Enable IPv6 in Windows libdnet build

libdnet-stripped/CMakeLists.txt

@@ -40,6 +40,7 @@ if (MSVC)
     add_definitions(-DWIN32_LEAN_AND_MEAN)
     check_include_file(winsock2.h HAVE_WINSOCK2_H)
     if(HAVE_WINSOCK2_H)
+        set(HAVE_SOCKADDR_IN6 TRUE)
         set(HAVE_LIBWS2_32 TRUE)
         set(DNET_LINK_LIBS ws2_32 ${DNET_LINK_LIBS})
     endif()

libdnet-stripped/include/dnet_winconfig.h

@@ -134,7 +134,7 @@
 /* #undef HAVE_ROUTE_RT_MSGHDR */
 
 /* Define if <netinet/in.h> has sockaddr_in6 struct. */
-/* #undef HAVE_SOCKADDR_IN6 */
+#define HAVE_SOCKADDR_IN6
 
 /* Define if sockaddr struct has sa_len. */
 /* #undef HAVE_SOCKADDR_SA_LEN */
@@ -274,6 +274,7 @@
 
 #ifdef HAVE_WINSOCK2_H
 # include <winsock2.h>
+# include <ws2tcpip.h>
 # include <windows.h>
 #endif