Avoid very high screen lines with some fonts

Avoid very high screen lines with some fonts

* src/xdisp.c (get_phys_cursor_geometry): Adjust the height of the
cursor to avoid weird-looking hollow cursor with fonts that have
large ascent values for some glyphs.  This avoids having the
hollow cursor start too low.
(append_space_for_newline): Adjust the ascent value of the newline
glyph, so that the hollow cursor at end of line displays
correctly.
(FONT_TOO_HIGH): New macro.
(x_produce_glyphs): Use it to detect fonts that claim a
preposterously large height, in which case we use per-glyph ascent
and descent values.  (Bug#20628)