Fix speed regression in wxFileHistory::AddFileToHistory().

Avoid full normalization including wxPATH_NORM_LONG when adding files to
wxFileHistory as this can take a very long time when using network paths under
Windows.

Closes #13915.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70503 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/filehistory.h

@@ -23,6 +23,7 @@
 
 class WXDLLIMPEXP_FWD_CORE wxMenu;
 class WXDLLIMPEXP_FWD_BASE wxConfigBase;
+class WXDLLIMPEXP_FWD_BASE wxFileName;
 
 // ----------------------------------------------------------------------------
 // File history management
@@ -79,6 +80,10 @@ private:
     // The ID of the first history menu item (Doesn't have to be wxID_FILE1)
     wxWindowID m_idBase;
 
+    // Normalize a file name to canonical form. We have a special function for
+    // this to ensure the same normalization is used everywhere.
+    static wxString NormalizeFileName(const wxFileName& filename);
+
     wxDECLARE_NO_COPY_CLASS(wxFileHistoryBase);
 };