Lars Magne Ingebrigtsen <larsi(a)gnus.org> writes in xemacs-beta(a)xemacs.org:
 Under Emacs, these newish functions are called
`line-end-position' and
 `line-beginning-position'.  It would be nice it the same was the case
 under XEmacs. 
They're not `newish' functions.  The first code you sent me was
integrated into XEmacs in December of 1996.
I've made the change, but I wish I had been asked first before the
names were changed. :-(