The existing tests would fail after making the normative change from
tc39/proposal-temporal#2265 because they rely on the getter directly
returning whatever value the calendar method returned. This is no longer
the case, because the value returned by the calendar is validated, so
adjust the assertions in these tests.
Also, no longer any need to return a value from the calendar method that
needs to be converted; we'll add separate tests for that.
Expand these tests to cover all of the PlainDate, PlainDateTime,
PlainMonthDay, PlainYearMonth, and ZonedDateTime property getters that
delegate to the calendar methods.
b83af50771