move ImplWindowAutoMnemonic into DoInitialLayout

so Floating windows get automnemonics as well, e.g.
the Floating Sort floating window of reportdesign

Change-Id: I0805840f7b0b2329e210c77e32c5eabfdac387fb

vcl/source/window/dialog.cxx

@@ -618,9 +618,6 @@ void Dialog::StateChanged( StateChangedType nType )
 {
     if (nType == STATE_CHANGE_INITSHOW)
     {
-        if ( GetSettings().GetStyleSettings().GetAutoMnemonic() )
-            ImplWindowAutoMnemonic( this );
-
         DoInitialLayout();
 
         if ( !HasChildPathFocus() || HasFocus() )

vcl/source/window/syswin.cxx

@@ -24,6 +24,7 @@
 #include <tools/debug.hxx>
 
 #include <vcl/layout.hxx>
+#include <vcl/settings.hxx>
 #include <vcl/svapp.hxx>
 #include <vcl/menu.hxx>
 #include <vcl/event.hxx>
@@ -1089,8 +1090,13 @@ void SystemWindow::setOptimalLayoutSize()
     setPosSizeOnContainee(aSize, *pBox);
 }
 
+extern void ImplWindowAutoMnemonic(Window* pWindow);
+
 void SystemWindow::DoInitialLayout()
 {
+    if ( GetSettings().GetStyleSettings().GetAutoMnemonic() )
+       ImplWindowAutoMnemonic( this );
+
     if (isLayoutEnabled())
     {
         mbIsCalculatingInitialLayoutSize = true;