Clean up wxMSW tooltip window on library shutdown

Not doing this prevented the tooltips from working correctly if the library
was shut down and reinitialized again, so add a module ensuring this is done.

Closes #17360.

src/msw/tooltip.cpp

@@ -134,6 +134,30 @@ public:
     }
 };
 
+// Takes care of deleting ToolTip control window when shutting down the library.
+class wxToolTipModule : public wxModule
+{
+public:
+    wxToolTipModule()
+    {
+    }
+
+    virtual bool OnInit() wxOVERRIDE
+    {
+        return true;
+    }
+
+    virtual void OnExit() wxOVERRIDE
+    {
+        wxToolTip::DeleteToolTipCtrl();
+    }
+
+private:
+    wxDECLARE_DYNAMIC_CLASS(wxToolTipModule);
+};
+
+wxIMPLEMENT_DYNAMIC_CLASS(wxToolTipModule, wxModule);
+
 #ifdef __VISUALC__
     #pragma warning( default : 4097 )
 #endif
@@ -253,6 +277,15 @@ void wxToolTip::SetMaxWidth(int width)
     ms_maxWidth = width;
 }
 
+void wxToolTip::DeleteToolTipCtrl()
+{
+    if ( ms_hwndTT )
+    {
+        ::DestroyWindow((HWND)ms_hwndTT);
+        ms_hwndTT = (WXHWND)NULL;
+    }
+}
+
 // ---------------------------------------------------------------------------
 // implementation helpers
 // ---------------------------------------------------------------------------