There was an opengl library at one point, I'm not sure of the state of it now though. I think it still works.
It looks like glut and opengl are included with the standard libraries. Unfortunately I can't find any building information so I can't do anything with it.
What build information is missing? The README.txt describes how to build the compiler; it's a fairly typical cmake setup.
Yep, I'm an idiot. I grabbed the binaries from the official site instead of from the repo.