Should assumeIsolated adopt sending?

[xwu (Xiaodi Wu)]

Have you seen this other thread?

Why does assumeIsolated() now require T: Sendable?

I believe that's still correct and that a sending result would be okay here. We do need to have some restrictions so that you can't merge the isolated region with the enclosing non-isolated region, though. For MainActor.assumeIsolated, this should be taken care of by the fact that the function is @Sendable; we need to check if those restrictions are in place for the general function.