Adding the "override" keyword to...

Adding the "override" keyword to Item_char_typecast_func_handler_inet6_to_binary::type_handler_for_create_select()

Clang fails to compile without it.

plugin/type_inet/sql_type_inet.cc

@@ -1230,7 +1230,8 @@ class Item_char_typecast_func_handler_inet6_to_binary:
     return &type_handler_string;
   }
   const Type_handler *
-      type_handler_for_create_select(const Item_handled_func *item) const
+      type_handler_for_create_select(const Item_handled_func *item)
+                                     const override
   {
     if (item->max_length > MAX_FIELD_VARCHARLENGTH)
       return Type_handler::blob_type_handler(item->max_length);