Avoid StackOverflow when comparing unknown foreign objects

[JaroslavTulach]

Pull Request Description

Closes #7677 by eliminating the stackoverflow execption. In general it seems too adventurous to walk members of random foreign objects. There can be anything including cycles. Rather than trying to be too smart in these cases, let's just rely on InteropLibrary.isIdentical message.

Important Notes

Calling sort on the numpy array no longer yields an error, but the array isn't sorted - that needs a fix on the Python side: oracle/graalpython#354 - once it is in, the elements will be treated as numbers and the sorting happens automatically (without any changes in Enso code).

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• All code follows the
  Java,
• All code has been tested:
  • Unit tests have been written where possible.

[radeusgd]

Looks good

[Akirathan]

I understand that a StackOverflow error when comparing numpy arrays is problematic and have to be fixed. But I am not sure I completely agree with this kind of simplification of equalsInteropObjectWithMembers. What about a compromise - keep the old version, but checking of member values would not be implemented with a child equalsNode, but rather with isIdentical interop message?

[JaroslavTulach]

What about a compromise - keep the old version, but checking of member values would not be implemented with a child equalsNode, but rather with isIdentical interop message?

What would be a point of a compromise? How could one explain that to users? Any important use-case that are covered by such a compromise? I could think of JSON, but there is a proper API for JSON in Enso and that one does == right.

[Akirathan]

What about a compromise - keep the old version, but checking of member values would not be implemented with a child equalsNode, but rather with isIdentical interop message?

What would be a point of a compromise? How could one explain that to users? Any important use-case that are covered by such a compromise? I could think of JSON, but there is a proper API for JSON in Enso and that one does == right.

I guess you are right. I cannot think of any important use case for the compromise that I have suggested. Let's just keep it simple and check for isIdenticalObject as you suggest.