I saw a problem with built-ins/Temporal/PlainDate/prototype/toPlainDateTime/basic.js

The folllowing should thorw:

const date = new Temporal.PlainDate(2000, 5, 2);
const optionBag = date.toPlainDateTime({ hour: 11, minute: 30, second: 23 });

because

https://tc39.es/proposal-temporal/#sec-temporal.plaindate.prototype.toplaindatetime
3.3.26 Temporal.PlainDate.prototype.toPlainDateTime ( [ temporalTime ] )
4. Set temporalTime to ? ToTemporalTime(temporalTime).

https://tc39.es/proposal-temporal/#sec-temporal-totemporaltime
4.5.2 ToTemporalTime ( item [ , overflow ] )
3-f. Let result be ? ToTemporalTimeRecord(item).

https://tc39.es/proposal-temporal/#sec-temporal-totemporaltimerecord
4.5.9 ToTemporalTimeRecord ( temporalTimeLike )
3. For each row of Table 3, except the header row, in table order, do
a. Let property be the Property value of the current row.
b. Let value be ? Get(temporalTimeLike, property).
c. If value is undefined, then
i. Throw a TypeError exception.

So when 3-a get the second item as "microsecond"
b. Let value be ? Get(temporalTimeLike, "microsecond"). will be undefined and throw.