Include "font.h".

Include "font.h".
(set_lface_from_font_name)
(set_font_frame_param, free_realized_face)
(prepare_face_for_display, clear_face_gcs)
(Finternal_set_font_selection_order, realize_x_face)
[USE_FONT_BACKEND]: If enable_font_backend is nonzero, use
font-backend mechanism.
(clear_face_cache) [USE_FONT_BACKEND]: Don't call
clear_font_table.
(load_face_font) [USE_FONT_BACKEND]: Abort.
(face_symbolic_value, face_symbolic_weight, face_symbolic_slant)
(face_symbolic_swidth, face_for_font) [USE_FONT_BACKEND]: New
functions.