Add script to run ansi-tests
We currently have no easy way to run the ansi-tests locally. You have to know to check out the ansi-test repo, switch to the right branch, and run make in the right way. This is all in .gitlab-ci.yml of course, but it would be nice to have a script to run these locally.
The issue is where to checkout the ansi-test repo. I think it should not be checked out in the cmucl repo. Perhaps ../ansi-tests
.