Commit Briefs
re-add sha script; it's used in the Makefile
While there, use it in the tests too
allow running only specific tests
It's now possible to run only a subset of the tests with: ./runtime test1 test2 ...
rework the regression suite
The tests are still there, the suite is equivalent to the old one, but this one is better structured. The biggest annoyance I had with the old one was that it wasn't straightforward to test only a specific set of tests. It's still impossible, but it's way easier to do it now. This extract all the tests to their own functions. It's overall better in all possible regards.