message: Add an extra test that dict just copies its input for dictionaries
  Summary: It does, but useful to document that to users.
diff: @@ -231,6 +231,7 @@ pub(crate) fn global_functions(builder: &mut GlobalsBuilder) {
  /// # starlark::assert::all_true(r#"
  /// dict() == {}
  /// dict(**{'a': 1}) == {'a': 1}
  + /// dict({'a': 1}) == {'a': 1}
  /// dict([(1, 2), (3, 4)]) == {1: 2, 3: 4}
  /// dict([(1, 2), ['a', 'b']]) == {1: 2, 'a': 'b'}
  /// dict(one=1, two=2) == {'one': 1, 'two': 2}
  