Create method false-negative trigger

[FMorschel]

Repro:

void f() async {
  int myVar = await g(C.foo); // Try activating it at `foo`
}

Future<T> g<T>(Future<T> Function() foo) => foo();

class C {}

[FMorschel]

Here is the CL https://dart-review.googlesource.com/c/sdk/+/417901