Fixed wxMSW compilation with wxUSE_POPUPWIN = 0.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@24577 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/popupwin.cpp

@@ -29,8 +29,11 @@
 #endif
 
 #ifndef WX_PRECOMP
+#include "wx/wx.h"
 #endif //WX_PRECOMP
 
+#if wxUSE_POPUPWIN
+
 #include "wx/popupwin.h"
 
 #include "wx/msw/private.h"     // for GetDesktopWindow()
@@ -85,3 +88,5 @@ WXHWND wxPopupWindow::MSWGetParent() const
     return (WXHWND)::GetDesktopWindow();
 }
 
+#endif // #if wxUSE_POPUPWIN
+