x-graphics/draw-arc broken for a while now?

[Matt Birkholz]

I don't see an arc in the x11 plugin's
test graphic, using master, also using
10.1.11, probably also release-11 (but
I can't see any points either given that
the 300x300px graphic is very, very tiny
on a HiDPI screen).  If a broken X11
draw-arc op is a release breaker, I'll
try to get it fixed sooner.