12.7.11.7 No specification of Equals and GetHashCode?

While we certainly don't want to pin down a single implementation of Equals and GetHashCode, I think it would be worth setting expectations around the results of:

``` csharp
var x = new { Name = "Jon" };
var y = new { Name = "Jon" };
var z = new { Name = "Mads" };
Console.WriteLine(x.Equals(y));
Console.WriteLine(x.Equals(z));
```

I think we'd want to mention:
- Use of `IEquatable` for property values, if indeed that's used
- null handling