updated for version 7.4.177
Problem:    Compiler warning for unused variable. (Tony Mechelynck)
Solution:   Add #ifdef.
diff --git a/src/move.c b/src/move.c
index 3a75ce3..67e214b 100644
--- a/src/move.c
+++ b/src/move.c
@@ -2101,7 +2101,9 @@
     int		used;
     lineoff_T	loff;
     lineoff_T	boff;
+#ifdef FEAT_DIFF
     linenr_T	old_topline = curwin->w_topline;
+#endif
 
     loff.lnum = boff.lnum = curwin->w_cursor.lnum;
 #ifdef FEAT_FOLDING