gir2pas: Added code to disable warning about non ascending enumeration values.

FPC does warn about non strictly ascending enumeration values.
Unfortunately, some GTK enum identifiers share the same value and this
warning can safely be ignored. We shut it up.

girpascalwritertypes.pas

@@ -2639,6 +2639,7 @@ begin
     for i := 0 to Libs.Count-1 do
       Str.WriteString(IndentText('{$LINKLIB '+Libs.Strings[i]+'}',0,1));
     Str.WriteString(IndentText('{$endif}',0,1));
+	Str.WriteString(IndentText('{$WARN 3031 off : Values in enumeration types have to be ascending}', 0, 1));
    end;
 
   Libs.Free;