This is intended to support parallel execution, which is planned for a
future release of Jasmine. Because the execution of unrelated suites will
interleave when run in parallel, reporters will not be able to assume
that the most recent `suiteStarted` event identifies the parent of the
current suite/spec. By adding this feature now, we allow reporters to
support both parallel execution and at least some 4.x versions without
having to implement two different ways of finding the parent suite.