(reassert_line_highlight_hook, change_line_highlight_hook): Variables removed.

(reassert_line_highlight_hook, change_line_highlight_hook): Variables removed.
(reassert_line_highlight, change_line_highlight): Functions removed.
(standout_requested): Variable removed.
(update_end, highlight_if_desired): Don't use it.
(chars_wasted, copybuf): Variables removed.
(write_standout_marker): Function removed.
(cursor_to, clear_to_end, clear_frame, clear_end_of_line_raw)
(clear_end_of_line_raw, write_glyphs, ins_del_lines):
Don't use `chars_wasted' or `copybuf'.
(calculate_costs): Don't allocate `chars_wasted' or `copybuf'.
Set `costs_set' to true.
(cursor_to, clear_end_of_line): Test `costs_set' instead of `chars_wasted'.
(clear_end_of_line): Function removed.
(clear_end_of_line_raw): Renamed to `clear_end_of_line'.
(clear_to_end): Call `clear_end_of_line' instead of `clear_end_of_line_raw'.