[DevTools] Restore reconciling Suspense stack after fallback was reconciled

[eps1lon]

When we reconciled the fallback, we popped back up Suspense nodes. We can't pop back up before removedPreviousSuspendedBy.

We immediately push back the stack now. This allows us to unify the measure calls.

[sebmarkbage]

I think this will work since we know the suspense node is local to the scope but this might not work more generally eg for other instances because the thing shadowed isn’t immutable. Sometimes we need to update the thing like the previous sibling and if there’s another concept of that higher up in the stack then that won’t get properly mutated.

So in general this kind of popping up in a deeper stack doesn’t work.