Only generate dynamic calls when class has generic params

[jiahaog]

Currently, a dynamic call is generated when a field is a function (previously added back in 2018). Without the dynamic call, this test fails. The error message is:

00:00 +9 -1: GenericFunction can be compared [E]                                                   │
  type '(int) => Null' is not a subtype of type '(dynamic) => dynamic'                             │
  package:end_to_end_test/generics.g.dart 1726:58  _$GenericFunction.==                            │
  test/generics_test.dart 77:63                    main.<fn>.<fn>

In this commit, only use dynamic calls when the enclosing class has generic parameters. This should eliminate a significant number of dynamic call generation in cases that don't need it.

Ideally we would only generate the dynamic call when the field is a function and uses type parameters from the enclosing class, but my understanding is that is much more complex and requires deeper integration with the analyzer.

The *.g.dart files were regenerated by locally modifying the pubspec of end_to_end_test to use dependency_overrides to point to the local repo (not sure if this is the right approach).

Motivation: Dynamic modules do not support dynamic calls and the current generation of dynamic calls makes using built_value in dynamic modules problematic. See b/481568738 for details.

Tested: Running the tests, and also doing an internal global presubmit with this change.

[jiahaog]

@davidmorgan would you be able to take a look if this is right :)

[davidmorgan]

Thanks!

I asked about the cast problem with functions, it's possible to make it work for functions by generating a getter/method that avoids doing the cast

class F<T> {
  void Function(T) function;

  Object _functionAsObject => function;
}

but we would still have the problem of detecting when to do this, as you observed.

Since nobody is actually asking for functions in generic types to work I think this workaround is fine.

Normally I would insist on putting a test of the new functionality in end_to_end_tests, but I don't see a way to check that no dynamic call happens, so the unit test looks fine.

LGTM, thanks! I'll merge + roll into google3.