Analyzer: If type is used as a generic argument to a new constrain RUC on default .ctor should be reported

```C#
void Test ()
{
// IL2026 Foo
Method();
}

class ResultType {
[RequiresUnreferencedCode("Foo")]
public ResultType() { }
}

static void Method () where T : new() { }
```

If a type is used in a generic parameter which has the new constraint, then trimmer must assume its default .ctor is going to be called. If that .ctor has a RUC annotation a warning should be reported.