patch 8.2.2807: build fails with tiny features

Problem:    Build fails with tiny features.
Solution:   Use a dummy function for ex_incdec().

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2807,
 /**/
     2806,
 /**/