patch 8.0.1004: matchstrpos() without a match returns too many items

Problem:    Matchstrpos() without a match returns too many items.
Solution:   Also remove the second item when the position is beyond the end of
            the string. (Hirohito Higashi)  Use an enum for the type.

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1004,
 /**/
     1003,
 /**/