Correctly Handling effects of lambda forward

[feiwang3311]

1. accurate computation of lambda forward latent effect seems overly complex
2. a real stop-of-the-world effect is needed, but how to implement it?
3. temp solution in this PR is to enforce read/write effects to all arguments. I am composing it as a partial step toward a stop-of-the-world effect, and also proves that it fixes my test (and probably some Lantern tests as well).
4. should be able to be precise or conservative or optimistic (be able to choose).