updated for version 7.4.498
Problem:    Typo in DOS makefile.
Solution:   Change exists to exist. (Ken Takata)
diff --git a/src/testdir/Make_dos.mak b/src/testdir/Make_dos.mak
index 07c6831..7fd2763 100644
--- a/src/testdir/Make_dos.mak
+++ b/src/testdir/Make_dos.mak
@@ -87,7 +87,7 @@
 	-if exist Xfind rd /s /q Xfind
 	-if exist viminfo del viminfo
 	-del test.log
-	-if exists benchmark.out del benchmark.out
+	-if exist benchmark.out del benchmark.out
 
 .in.out:
 	-if exist $*.failed del $*.failed