patch 8.0.0190: finding duplicate tags uses a slow linear search

Problem:    Detecting duplicate tags uses a slow linear search.
Solution:   Use a much faster hash table solution. (James McCoy, closes #1046)
            But don't add hi_keylen, it makes hash tables 50% bigger.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    190,
 /**/
     189,
 /**/