Polyfill: Hour cycle not correctly set when defaults are used

[anba]

Test case:

console.log(new Temporal.PlainDateTime(2020, 1, 1).toLocaleString("en", {hour12: false}));
console.log(new Temporal.PlainDateTime(2020, 1, 1).toLocaleString("en", {hour12: true}));

console.log(new Temporal.PlainDateTime(2020, 1, 1).toLocaleString("en", {hourCycle: "h23"}));
console.log(new Temporal.PlainDateTime(2020, 1, 1).toLocaleString("en", {hourCycle: "h24"}));
console.log(new Temporal.PlainDateTime(2020, 1, 1).toLocaleString("en", {hourCycle: "h11"}));
console.log(new Temporal.PlainDateTime(2020, 1, 1).toLocaleString("en", {hourCycle: "h12"}));

Actual:

1/1/2020, 12:00:00 AM
1/1/2020, 12:00:00 AM
1/1/2020, 12:00:00 AM
1/1/2020, 12:00:00 AM
1/1/2020, 12:00:00 AM
1/1/2020, 12:00:00 AM

Expected:

1/1/2020, 00:00:00
1/1/2020, 12:00:00 AM
1/1/2020, 00:00:00
1/1/2020, 24:00:00
1/1/2020, 0:00:00 AM
1/1/2020, 12:00:00 AM