Fix use of int instead of EMACS_INT in editfns.c.

Fix use of int instead of EMACS_INT in editfns.c.

 editfns.c (transpose_markers, update_buffer_properties)
 (buildmark, clip_to_bounds, Fgoto_char, overlays_around)
 (get_pos_property, Fconstrain_to_field)
 (Fline_beginning_position, Fline_end_position, Fprevious_char)
 (Fchar_after, Fchar_before, Finsert_char)
 (Finsert_buffer_substring, Fcompare_buffer_substrings)
 (Fsubst_char_in_region, Fformat, Ftranspose_regions): Use
 EMACS_INT for buffer and string position variables.
 lisp.h (clip_to_bounds): Adjust prototype.