dillon1000/react

Add failing event handler test

When we perform an update to the event handler we properly update the
immediate Fiber pointer of a child to be the current. However, when we
bubble events we use the return pointer which is not guaranteed to point
to the current Fiber even if we start from the current.

This manifests itself when we bailout in a parent. So I made the tests
use a PureComponent to illustrate this scenario. There is already a failing
case but I'm adding another one too.