patch 8.2.4911: the mode #defines are not clearly named

Problem:    The mode #defines are not clearly named.
Solution:   Prepend MODE_.  Renumber them to put the mapped modes first.
diff --git a/src/autocmd.c b/src/autocmd.c
index 223f92c..4b30c1f 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -1758,7 +1758,7 @@
     static int
 has_cursorhold(void)
 {
-    return (first_autopat[(int)(get_real_state() == NORMAL_BUSY
+    return (first_autopat[(int)(get_real_state() == MODE_NORMAL_BUSY
 			    ? EVENT_CURSORHOLD : EVENT_CURSORHOLDI)] != NULL);
 }
 
@@ -1777,7 +1777,7 @@
 	    && !ins_compl_active())
     {
 	state = get_real_state();
-	if (state == NORMAL_BUSY || (state & INSERT) != 0)
+	if (state == MODE_NORMAL_BUSY || (state & MODE_INSERT) != 0)
 	    return TRUE;
     }
     return FALSE;