more consistent fix for #40655 (thanks to Max)

Author: slowphil

src/Plugins/Qt/qt_widget.cpp

@@ -27,7 +27,7 @@
  * qt_widget_rep: the base widget for the Qt port.
  ******************************************************************************/
 
-void qt_widget::tm_delete (qt_widget_rep* ptr) {
+void tm_delete (qt_widget_rep* ptr) {
   void *mem= ptr->derived_this ();
   ptr -> ~qt_widget_rep ();
   fast_delete (mem);

src/Plugins/Qt/qt_widget.hpp

@@ -201,9 +201,6 @@ class qt_widget_rep : public widget_rep {
 */
 class qt_widget {
 public:
-
-  void tm_delete (qt_widget_rep* ptr);
-
   ABSTRACT_NULL(qt_widget); // Automagically declared constructor, methods, etc.
 
   inline bool operator == (qt_widget w) { return rep == w.rep; }

src/System/Misc/fast_alloc.hpp

@@ -69,6 +69,9 @@ inline void* operator new[] (size_t s, void* loc) { return loc; }
 class widget_rep;
 void tm_delete (widget_rep* ptr);
 
+class qt_widget_rep;
+void tm_delete (qt_widget_rep* ptr);
+
 class editor_rep;
 void tm_delete (editor_rep* ptr);