In killop.js, we check that a find is running, and then kill the operation. We then check that the operation is set as killPending. This assumes that the operation had already yielded before we kill it, so that it gets marked as killPending instead of being killed immediately. We should verify here that the operation has numYields > 0.

While we are modifying this test, we could also add a filter to the currentOp in the error output, to make debugging easier.