Fixed bug 3741 - more compatible initializers for arrays

Ozkan Sezer

An array defined like  int xPositions[] = {-1, 0, 1, w-1, w, w+1 };
errors with Open Watcom: it strictly wants constants.  Small patch
like below makes things more compatible.

test/testmessage.c

@@ -46,12 +46,13 @@ button_messagebox(void *eventNumber)
         "Custom MessageBox",
         "This is a custom messagebox",
         2,
-        buttons,
+        NULL,/* buttons */
         NULL /* Default color scheme */
     };
 
     int button = -1;
     int success = 0;
+    data.buttons = buttons;
     if (eventNumber) {
         data.message = "This is a custom messagebox from a background thread.";
     }