Pass non-primitive types by const reference instead of value.

No real changes, just avoid the unnecessary copying and also make the
signatures more consistent by adding the apparently forgotten "&" in a couple
of places.

See #15893.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75657 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/richtext/richtextctrl.h

@@ -903,7 +903,7 @@ public:
     /**
         Finds the container at the given point, which is in screen coordinates.
     */
-    wxRichTextParagraphLayoutBox* FindContainerAtPoint(const wxPoint pt, long& position, int& hit, wxRichTextObject* hitObj, int flags = 0);
+    wxRichTextParagraphLayoutBox* FindContainerAtPoint(const wxPoint& pt, long& position, int& hit, wxRichTextObject* hitObj, int flags = 0);
     //@}
 
 #if wxUSE_DRAG_AND_DROP