LanguageFeatures/Constructor-tear-offs/tearing_off_from_typedef_A07_t01.dart can be stronger

[eernstg]

Said test has Expect.equals(A<int, String>.testme, AAlias1.testme) plus several other similar cases. We would indeed expect that. But in this case the type arguments are provided for every tearoff of a type alias, and this means that both operands are constant expressions in all cases, and hence we'd expect identical as well.

Whenever identical(o1, o2) holds we would also expect o1 == o2 to hold. So we might consider the Expect.equals cases to be redundant when we have the corresponding Expect.identical cases. Nevertheless, I think it makes sense to test for both identical and equals at least now and then, just to make sure that we don't have any weird bugs that make them !=.