Fixes T4570. When a test case doesn't make any assertions, fail it:
- A tiny fraction of tests pass by not throwing. These tests can easily make a trivial assertion. It took about 5 minutes to fix them all (D8435, D8436).
- In other cases, no assertions means a test construction problem, as with T4570. In these cases, failing loudly catches a severe error.
- Fixes the no-assertion test cases in arcanist/
- Makes the PHP 5.4 test pass for the moment, see discussion in T4334.