dillon1000/react

Dehydrated suspense boundaries in suspense list (#16369)

If we get an insertion after a boundary, that has not yet been hydrated,
we take our best guess at which state the HTML is showing.

isSuspenseInstancePending means that we're still waiting for more server
HTML before we can hydrate. This should mean that we're showing the
fallback state.

isSuspenseInstanceFallback means that we want to client render something.
That most likely means that the server was unable to render and is
displaying a fallback state in this slot.

Adds tests to ensure that dehydrated components don't consider the force
flag.