dillon1000/react

Always trigger an update when a callback is enqueued.

enqueueCallbackInternal forgot to schedule an update.

We could rely on the implicit contract of enqueueElement to do it. However,
if we're currently outside a transaction, it'll flush synchronously. Before
we enqueue the callback. We could also enqueueCallback before we
enqueueElement, but that causes a fragile relationship between them. E.g.
enqueueElement should not need to schedule an update if it is the same
element.