task model: F bounded quantification bug

[vsmenon]

From f_bounded_quantification2_test.dart:

class Entities<T extends ConceptEntity<T>> implements EntitiesApi<T> { }

class ConceptEntity<T extends ConceptEntity<T>> implements EntityApi { }

abstract class EntityApi<T extends EntityApi<T>> { }

abstract class EntitiesApi<T extends EntityApi<T>> { }

class Concept extends ConceptEntity<Concept> { }

main() {
  new ConceptEntity<Concept>();
  new ConceptEntity<ConceptEntity>();
}

is triggering the following errors - newly in the task model strong mode:

severe: [AnalyzerMessage] 'T' does not extend 'EntityApi<T>' (test/codegen/language/f_bounded_quantification2_test.dart, line 7, col 67)
severe: [AnalyzerMessage] 'ConceptEntity' does not extend 'ConceptEntity<ConceptEntity>' (test/codegen/language/f_bounded_quantification2_test.dart, line 19, col 21)

This particular test isn't strictly blocking - we don't support this pattern yet in codegen, but it is a regression.

[vsmenon]

We're now supporting codegen for this, but those errors are still there.

[jmesserly]

moved to dart-lang/sdk#25530