Equality of Sets should be fixed.

[efortuna]

With the following code:

  var a = new Set.from(['emily', 'm', 'fortuna']);
  var b = new Set.from(['emily', 'm', 'fortuna']);
  print(a == b);

"false" gets printed.

These are both Hash sets whose containing objects implement equality based on content, so we should actually inspect the hash set contents to see if the elements in the set are the same and return true, rather than just checking if a and b are the same Set object.

[lrhn]

Removed Type-Defect label.
Added Type-Enhancement, Duplicate labels.
Marked as being merged into #2217.

[floitschG]

Issue #14638 has been merged into this issue.