Anyone else seeing this? For the past few days, on the 2.8 builds, when I Open a new scene the default cube is not visible for eevee or workbench. The outline for it is. Curious if it is just me (or anyone with Intel chipset).
Also, clay renderer is gone. 
my favorite!
Note: Yes, I know it’s in active development. I’m not complaining. Thanks!
It looks like same problem than in this thread.
About Clay Engine, if you succeed to make objects visible, you should be able to obtain same result than in Clay engine by using Cavity settings and matcaps available in Shading popover of 3DView’s header.
Advanced settings about SSAO are in Viewport Display panel under Scene Tab of Properties editor.