patch 8.1.0610: MS-Windows ctags file list differs from Unix

Problem:    MS-Windows ctags file list differs from Unix.
Solution:   Define TAGS_FILES in the common makefile. (partly by Ken Takata)
diff --git a/src/version.c b/src/version.c
index f44167a..3c194ae 100644
--- a/src/version.c
+++ b/src/version.c
@@ -800,6 +800,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    610,
+/**/
     609,
 /**/
     608,