LanguageFeatures/Enhanced-Enum/enum_name_A01_t01

[alexmarkov]

This test assumes that default constructor is added automatically into the enum class when there is a user-defined generative constructor:

co19/LanguageFeatures/Enhanced-Enum/enum_name_A01_t01.dart

Lines 30 to 36 in f120c79

	enum E<T extends num> {
	e1,
	e2(),
	e3<int>.named(42);
	const E.named(int x);
	}

However, according to the spec, this is not the case:

https://github.com/dart-lang/language/blob/bdbef03e26047a1f59152f97d23663cf93a7108e/accepted/future-releases/enhanced-enums/feature-specification.md?plain=1#L99-L106

So declarations of elements e1 and e2 in this test are incorrect.

[alexmarkov]

Same problem is in the LanguageFeatures/Enhanced-Enum/grammar_A04_t05 test:

co19/LanguageFeatures/Enhanced-Enum/grammar_A04_t05.dart

Lines 25 to 32 in f120c79

	enum E<T> {
	e1,
	e2(),
	e3<int>.named(42);
	const E.named(int x);
	int foo(covariant int x) => x;
	}