MINOR: connection: Add a CTL flag to notify mux it should wait for reads again

MUX_SUBS_RECV ctl flag is added to instruct the mux it should wait for read
events. This flag will be pretty useful to handle abortonclose option.

(cherry picked from commit e5cffa8ace3b9a3d6a634d8754380e699909ad3a)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit fb79f968bfb24d20be583f8a8c447afe6f890609)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 2398c781dc4ce5f41afd70590caba80128bbac8c)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 530a06377af9b616db9842d0dba8aa0deaa5bcbd)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/include/haproxy/connection-t.h b/include/haproxy/connection-t.h
index 7ad89e6..e45a70b 100644
--- a/include/haproxy/connection-t.h
+++ b/include/haproxy/connection-t.h
@@ -324,6 +324,7 @@
 enum mux_ctl_type {
 	MUX_STATUS, /* Expects an int as output, sets it to a combinaison of MUX_STATUS flags */
 	MUX_EXIT_STATUS, /* Expects an int as output, sets the mux exist/error/http status, if known or 0 */
+	MUX_SUBS_RECV, /* Notify the mux it must wait for read events again  */
 };
 
 /* response for ctl MUX_STATUS */