patch 8.2.0894: :mkspell can take very long if the word count is high

Problem:    :mkspell can take very long if the word count is high.
Solution:   Use long to avoid negative numbers.  Increase the limits by 20% if
            the compression did not have effect.

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    894,
 /**/
     893,
 /**/