Implicit dynamic complains about Object-typed generics

[nex3]

If I have the following Dart code:

class Foo {
  final List<Object> values;

  Foo(Iterable<Object> values)
      : values = new List.unmodifiable(values);
}

and I run dartanalyzer --strong --no-implicit-dynamic on it, I get:

[error] Missing type arguments for generic type 'List<dynamic>'. Either add an explicit type like 'dynamic', or enable implicit-dynamic in your Analyzer options.

I'd expect the analyzer to infer List<Object>. If I change <Object> to <String>, inference works as expected.

[jmesserly]

oh shoot. I'll need to check if my current CL makes this better. Yeah, we're not recording type constraints in some cases.

[jmesserly]

(when the constraint is trivial, like top type)

[jmesserly]

related: #27586