patch 9.0.2138: Overflow logic requires long long

Problem:  Overflow logic requires long long
Solution: Define vimlong_T data type to make life easier
          for porters

closes: #13598

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2138,
 /**/
     2137,
 /**/