ac/nir,radv: add lowering for emulating mesh/task shader queries on GFX10.3
GFX10.3 doesn't support mesh/task queries and they need to be emulated, compared to GFX11 which supports them natively.
This is preliminary work for emulating mesh/task queries on GFX10.3.
I'm passing more than 90% of the CTS on both GFX10.3/GFX11 at the moment, but I found few CTS bugs and probably a spec bug too, so hard to reach 100% for now.
I will submit my other patches once they are finished/cleaned.