That's possible, since any comparison to `:unbounded` could just as easily be against `Float::INFINITY`.

On the flip side, though, using the symbol has caught a couple of bugs for us. When the height is unbounded, basically it's an error to ever try to use that height as if it's an explicit value. The fact that it's not a number at all means we get a crash saying `:unbounded` if the height tries to get misused.

With `Float::INFINITY` arithmetic would pass through, but I'm betting some code (like setting a height on the underlying SWT elements?) might either fail or behave weirdly.