[css-shapes-2] Maybe add superellipse/squircle etc as basic shapes?

[noamr]

With #10993, we're going to have the generic superellipse() and specifics like squircle as corner shapes.
Perhaps we could have 50%-radius version of them as basic shapes? thinking clip-path: squircle(50%) (similar to circle) is a no brainer.

[tabatkins]

We already have the ability to specify round border-radius on rect https://drafts.csswg.org/css-shapes-1/#funcdef-basic-shape-rect like rect(... round 1em); with corner-shape we should edit the spec to be able to specify rect(... squircle 1em) instead.

(I'm not against a squircle(), just pointing out we have a more straightforward existing way to do it.)\

[noamr]

We already have the ability to specify round border-radius on rect https://drafts.csswg.org/css-shapes-1/#funcdef-basic-shape-rect like rect(... round 1em); with corner-shape we should edit the spec to be able to specify rect(... squircle 1em) instead.

(I'm not against a squircle(), just pointing out we have a more straightforward existing way to do it.)\

Oh yea, I forgot that basic-shapes already have a corner-shape variant (since the old corner-shapes were still on the drawing board)