patch 7.4.1978

Problem:    Large file test does not delete its output.
Solution:   Delete the output. Check size properly when possible. (Ken Takata)

src/version.c

@@ -758,6 +758,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1978,
 /**/
     1977,
 /**/