Fix MoveOnlyAddressChecker to handle value deinits.

[atrick]

Track liveness of self so we don't accidentally think that such types can be memberwise reinitialized.

Fixes rdar://110232973 ([move-only] Checker should distinguish in between field of single field struct vs parent field itself (was: mutation of field in noncopyable struct should not trigger deinit))

struct HighScore: ~Copyable {
    var value = 0

    consuming func finalize() {
        print("Saving score to disk…")
        discard self
    }

    deinit {
        print("Deinit is saving score to disk…")
    }
}

func createHighScore() {
    var highScore = HighScore()
    highScore.value = 20 // should not trigger deinit, but does.
    highScore.finalize()
}

createHighScore()

[atrick]

@swift-ci test

[atrick]

This passed full testing.

[atrick]

@swift-ci test source compatibility

[atrick]

@swift-ci smoke test

[atrick]

The SCK failure is the same on main

[gottesmm]

I am fine with this as is... but I would like a larger comment here that doesn't just say 'self' has its own liveness. I wish it had the larger explanation or a reference back to the earlier explanation.

[atrick]

Good point. although I need to merge this now to put up a 5.9 PR