message: Add tests that equality works after freezing
  Summary: I was investigating something, and thought this might be wrong. It isn't, but useful tests even so.
diff: @@ -1031,6 +1031,18 @@ x = repr; y = repr; x == y
  );
  }
  +#[test]
  +fn test_frozen_equality() {
  + let program = "(str, (), 1, range(4), True, None, [8], {'test':3})";
  + let a = assert::pass(program);
  + let b = assert::pass(program);
  + assert_eq!(a.value(), b.value());
  +
  + let mut a = Assert::new();
  + a.module("saved", &format!("val = {}", program));
  + a.is_true(&format!("load('saved', 'val'); val == {}", program));
  +}
  +
  #[test]
  fn test_comparison() {
  assert::all_true(
  