patch 8.1.1994: MS-Windows: cannot build with eval but without cscope

Problem:    MS-Windows: cannot build with eval but without cscope
Solution:   Adjust the makefiles to always build if_cscope.obj.

src/version.c

@@ -757,6 +757,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1994,
 /**/
     1993,
 /**/