GL lines are nearly X compliant; you just need to fill in the last
pixel when the client hasn't requested CapNotLast.
v2: switch to glamor_make_current
v3: use miPolylines instead of custom glamor fallback path. Wrap
code to 80 columns.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
