Make IPv6 definitions comply with RFC 3493:
 - Add some definitions to netinet/in6.h
 - Include netinet/in6.h from netinet/in.h
diff --git a/libc/include/netinet/in6.h b/libc/include/netinet/in6.h
index e645c48..2f5fee1 100644
--- a/libc/include/netinet/in6.h
+++ b/libc/include/netinet/in6.h
@@ -90,4 +90,12 @@
 
 #define INET6_ADDRSTRLEN 46
 
+#define IPV6_JOIN_GROUP IPV6_ADD_MEMBERSHIP
+#define IPV6_LEAVE_GROUP IPV6_DROP_MEMBERSHIP
+
+#define IN6ADDR_ANY_INIT {{{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}}
+
+#define ipv6mr_interface ipv6mr_ifindex
+
+
 #endif /* _NETINET_IN6_H */