[Patterns] Angular compiler implementation

[itsjustkevin]

[grouma]

Please provide more details

[srawlins]

We missed a milestone on this one, but I think it should have "Dart 3 stable."

[srawlins]

The general idea for tickets like this is to ensure that the Angular compiler won't crash or misbehave when interacting with new language features.

So for patterns, which are a language feature that only exist at the statement/expression level, I don't think there is anything to do:

• A pattern cannot appear in an annotation.
• This introduces no new syntax for declaring a class, or declaring fields, or methods.

I think this can probably be closed.

[grouma]

cc @leonsenft

[grouma]

Internal tracking id: b/279910583