patch 8.0.0391: arabic support is verbose and not well tested

Problem:    Arabic support is verbose and not well tested.
Solution:   Simplify the code.  Add more tests.
diff --git a/src/version.c b/src/version.c
index 63eda8b..d4d27ec 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    391,
+/**/
     390,
 /**/
     389,