Add initial prototype.

3-mid/opengl/source/platform/egl/opengl-screen.adb

@@ -0,0 +1,21 @@
+package body openGL.Screen
+is
+
+--     function Thin (Self : in Item) return xcb.xcb_screen_t.Pointer
+--     is
+--     begin
+--        return Self.Thin;
+--     end Thin;
+
+
+--     procedure Thin_is (Self : in out Item;   Now : in xcb.xcb_screen_t.Pointer)
+--     is
+--     begin
+--        Self.Thin := Now;
+--     end Thin_is;
+
+
+   procedure dummy is begin null; end dummy;
+
+
+end openGL.Screen;