Set the CURL_VERSION_ASYNCHDNS bit if USE_ARES is defined.
diff --git a/lib/version.c b/lib/version.c
index 8191f95..63ed63c 100644
--- a/lib/version.c
+++ b/lib/version.c
@@ -183,6 +183,9 @@
 #ifdef CURLDEBUG
   | CURL_VERSION_DEBUG
 #endif
+#ifdef USE_ARES
+  | CURL_VERSION_ASYNCHDNS
+#endif
   ,
   NULL, /* ssl_version */
   0,    /* ssl_version_num */