[Mesa-stable] 11.1 nomination (Rob H)

[Emil Velikov]

And another commit from Rob H missing the stable tag.

f0f4259324382d3f11131a7acca8c1ca82868f67 virgl: also build vtest for Android
f87330dbce3f67cb531194f63a5db59685dcbbd3 virgl: reuse screen when fd
is already open
2d3301e4d513614873002707d32453f926f63666 virgl: fix reference counting
of prime handles

and maybe everything else from him (yet to be pushed) ? ;-)

-Emil