Make it explicit that a few Qt::WindowFlags are overlapping

Change-Id: Ia161fb9b7196d139e22fe7b3b576c5c72ee8a2f1
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

src/corelib/global/qnamespace.h

@@ -294,10 +294,13 @@ public:
         WindowCloseButtonHint = 0x08000000,
         MacWindowToolBarButtonHint = 0x10000000,
         BypassGraphicsProxyWidget = 0x20000000,
-        WindowOkButtonHint = 0x00080000,
-        WindowCancelButtonHint = 0x00100000,
         NoDropShadowWindowHint = 0x40000000,
-        WindowFullscreenButtonHint = 0x80000000
+        WindowFullscreenButtonHint = 0x80000000,
+
+        // The following enums have overlapping values with other enums.
+        // This was not intentional, but it's too late to change now.
+        WindowOkButtonHint = 0x00080000, // WindowTransparentForInput
+        WindowCancelButtonHint = 0x00100000 // WindowOverridesSystemGestures
     };
 
     Q_DECLARE_FLAGS(WindowFlags, WindowType)