Announce 4.166.0

[Atry]

No description provided.

[AndrewDiMola]

@Atry, @Wilfred - Does this change the docs re: expression trees in any significant way?

• Lambdas and calls in Expression Trees are now virtualized:
  - Lambdas are now wrapped in lambdaType(...).
  - Calls are now translated to __unwrap() method instead of direct invoking.

https://docs.hhvm.com/hack/expression-trees/syntax-supported#lambdas

Related... what does it mean for lambdas and calls to be virtualized? Anything to do with runtime visibility?

[Atry]

@AndrewDiMola Yes, I think it is a significant change. See the commit message in facebook/hhvm@e777716

[Atry]

We are making progress in implicit contexts. I did not mention it in the release note because I suppose it is still an unstable feature.