* lisp/emacs-lisp/bytecomp.el: Remember location of unresolved calls

* lisp/emacs-lisp/bytecomp.el: Remember location of unresolved calls

I've gotten tired of seeing the "function foo not known to be defined"
warning without any line number information.  So this patch adds as
line number the position of the first use of that function in the file
(well, approximately, as usual).

(byte-compile-unresolved-functions): Add POSITIONs in the alist.
(byte-compile-function-warn): Store the current position in
`byte-compile-unresolved-functions`.
(byte-compile-arglist-warn): Adjust accordingly.
(byte-compile-print-syms): Delete unused function.
(byte-compile-warn-about-unresolved-functions): Use the stored position
to give more precise warnings.