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.
diff --git a/src/version.c b/src/version.c
index 05e8829..88e0791 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1994,
+/**/
     1993,
 /**/
     1992,