Before this commit, errors triggered at the level of the fiber (as opposed to at the level
of a component's rendering), were handled as the very top level of the rendering, that is,
in the scheduler.
This was wrong because components below in the rendering tree would not have a chance to handle their
children's or their own errors.
After this commit, error triggered in willPatch, onMounted and onPatched are correctly handled
at the closest component to where they were thrown.
Have a Child Compnent which has one component that succeeds and another
one that fails at its instanciation.
The Child component handles the Errors by rendering itself.
Before this commit, the error handling algorithm made impossible for the scheduler to finish.
This was because the current fiber was still counted as ongoing, when it was actually completed.
After this commit, this use case is handled correctly.
Lucas Perais (lpe)