fix for invalid dynamic_cast

after my loplugin-cstylecast commits.
this is a follow on to the bug reported in fdo#84608

Change-Id: Icc4f4baf3690e939c07a71a949200270bf1f4614

toolkit/source/awt/vclxtopwindow.cxx

@@ -147,15 +147,16 @@ void VCLXTopWindow_Base::setMenuBar( const ::com::sun::star::uno::Reference< ::c
 {
     SolarMutexGuard aGuard;
 
-    SystemWindow* pWindow = dynamic_cast<SystemWindow*>( GetWindowImpl() );
+    vcl::Window* pWindow = GetWindowImpl();
     if ( pWindow )
     {
-        pWindow->SetMenuBar( NULL );
+        SystemWindow* pSystemWindow = static_cast<SystemWindow*>( pWindow );
+        pSystemWindow->SetMenuBar( NULL );
         if ( rxMenu.is() )
         {
             VCLXMenu* pMenu = VCLXMenu::GetImplementation( rxMenu );
             if ( pMenu && !pMenu->IsPopupMenu() )
-                pWindow->SetMenuBar( static_cast<MenuBar*>( pMenu->GetMenu() ));
+                pSystemWindow->SetMenuBar( static_cast<MenuBar*>( pMenu->GetMenu() ));
         }
     }
     mxMenuBar = rxMenu;

vcl/source/window/menufloatingwindow.cxx

@@ -80,7 +80,7 @@ void MenuFloatingWindow::doShutdown()
             }
             if( i < nCount )
             {
-                MenuFloatingWindow* pPWin = dynamic_cast<MenuFloatingWindow*>(pMenu->pStartedFrom->ImplGetWindow());
+                MenuFloatingWindow* pPWin = static_cast<MenuFloatingWindow*>(pMenu->pStartedFrom->ImplGetWindow());
                 if( pPWin )
                     pPWin->HighlightItem( i, false );
             }
@@ -682,7 +682,7 @@ void MenuFloatingWindow::ChangeHighlightItem( sal_uInt16 n, bool bStartPopupTime
             }
             if( i < nCount )
             {
-                MenuFloatingWindow* pPWin = dynamic_cast<MenuFloatingWindow*>(pMenu->pStartedFrom->ImplGetWindow());
+                MenuFloatingWindow* pPWin = static_cast<MenuFloatingWindow*>(pMenu->pStartedFrom->ImplGetWindow());
                 if( pPWin && pPWin->nHighlightedItem != i )
                 {
                     pPWin->HighlightItem( i, true );