The object-set-name-string function of eieio has changed to eieio-object-set-name-string, at one point my code (ergoemacs-mode) depended on that function, so I had to use a macro to pick the right version for different versions of emacs.
You may keep it or change it as you wish. Today ergoemacs-mode no longer uses this function.
Just an FYI, prompted by Stefan.
Matt