Fix setting clipping region for wxDC with RTL enabled (wxMSW)

It turns out that region being added to DC with enabled RTL layout needs
to be defined using mirrored device x-coordinates.
So if we have DC with RTL layout we need to create a temporary mirrored
region and pass it to the DC instead of the original one.

Closes #19325.

include/wx/msw/dc.h

@@ -281,7 +281,7 @@ protected:
     void DrawAnyText(const wxString& text, wxCoord x, wxCoord y);
 
     // common part of DoSetClippingRegion() and DoSetDeviceClippingRegion()
-    void SetClippingHrgn(WXHRGN hrgn);
+    void SetClippingHrgn(WXHRGN hrgn, bool doRtlOffset = false);
 
     // implementation of DoGetSize() for wxScreen/PrinterDC: this simply
     // returns the size of the entire device this DC is associated with