Missing error for initializing shadowed var in a binding pattern

[JsonFreeman]

These should all be errors, but only the ones where x is initialized directly give errors:

if (true) {
    let x;
    if (true) {
        var x = 0; // Error
        var { x = 0 } = { x: 0 }; // Error
        var { x: x = 0 } = { x: 0 }; // Error
        var { x } = { x: 0 }; // No error, even though the let x is being initialized
        var { x: x } = { x: 0 }; // No error, even though the let x is being initialized
    }
}