Continue working on set_cursor_from_row.
Cleanup of resolved_level and bidi_type members of struct glyph.
xdisp.c (set_cursor_from_row): Fix off-by-one error when
skipping over non-character glyphs at end of a reversed row.
dispextern.h (struct glyph): The `resolved_level' member needs
only 5 bits, not 6. The `bidi_type' member needs only 3 bits.
(bidi_type_t): Rearrange so that types that can appear in the
resolved type are at the beginning and have values less than 8.