patch 8.1.1584: the evalfunc.c file is getting too big

Problem:    The evalfunc.c file is getting too big.
Solution:   Move channel and job related functions to channel.c.
diff --git a/src/version.c b/src/version.c
index 9fec3b8..39884ef 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1584,
+/**/
     1583,
 /**/
     1582,