We picked those up from Polari, which had those for

 - object arrays:
    let foo = [
        { bar: 42,
          quz: true },
        { bar: 23,
          quz: false }
    ];

 - "enums":

    let Options = {
        ONE:   0,
        TWO:   1,
        THREE: 2
    };

We don't have either of those, so drop the rules to minimise divergence
with gjs.

!57