It is called cavity map in blender.
I found out a cavity map is an AO map with short rays. Problem with baking an AO map with short rays in blender, is the rays don't reach far enough. But I am will try something and see if it works.
Textools has the cavity map option. But the image seems too dark. Maybe it's correct?
I tested the short rays by baking an AO map without cage, and using short ray of 0.0001. I then put the caged AO map in krita, and put the short ao map ontop of it in krita. I then selected the black part with krita's magic select tool and pressed delete. I ended up with the exact same results as the caged AO map.
It didn't work in blender. I will look and try something.