do not export compare functions in the wx ABI

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58909 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/fontenum.cpp

@@ -49,7 +49,9 @@
 extern GtkWidget *wxGetRootWindow();
 #endif // __WXGTK20__
 
-extern "C" int wxCMPFUNC_CONV
+extern "C"
+{
+static int wxCMPFUNC_CONV
 wxCompareFamilies (const void *a, const void *b)
 {
   const char *a_name = pango_font_family_get_name (*(PangoFontFamily **)a);
@@ -57,6 +59,7 @@ wxCompareFamilies (const void *a, const void *b)
 
   return g_utf8_collate (a_name, b_name);
 }
+}
 
 bool wxFontEnumerator::EnumerateFacenames(wxFontEncoding encoding,
                                           bool fixedWidthOnly)