Mark dubious fallthrough cases as "SAL_FALLTHROUGH; //TODO ???" (in Win-only)

Change-Id: If5ee201aab8c4451971a11ea7d7ff943c9a1a726

vcl/opengl/win/gdiimpl.cxx

@@ -166,6 +166,7 @@ static LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM l
         case VK_SPACE:
             break;
         }
+        SAL_FALLTHROUGH; //TODO ???
     default:
         return DefWindowProc(hwnd, message, wParam, lParam);
     }

winaccessibility/source/service/AccContainerEventListener.cxx

@@ -64,6 +64,7 @@ throw (css::uno::RuntimeException)
         break;
     case AccessibleEventId::TEXT_CHANGED:
         HandleTextChangedEvent(aEvent.OldValue, aEvent.NewValue);
+        SAL_FALLTHROUGH; //TODO ???
     case AccessibleEventId::VISIBLE_DATA_CHANGED:
         HandleVisibleDataChangedEvent();
         break;