The hoursInDay could be fractional number on the date of changng
daylight saving time for time zone in half hours or some historical time
zone.
Ex: Australia/Lord_Howe on Sunday, April 3, 2022, 2:00:00 am clocks were
turned backward 0:30 hours to Sunday, April 3, 2022, 1:30:00 am local
standard time instead. so that day will have 24.5 hours.
On Sunday, October 2, 2022, 2:00:00 am clocks are turned forward 0:30
hours to Sunday, October 2, 2022, 2:30:00 am local daylight time
instead. So the hoursInDay for that day is only 23.5 hours.

Historically, Singapore from 1933 to 1941 moved clocks forward 20 minutes for daylight savings, resulting the day in 24.33333 and
23.66667 hours.

Test covered in https://github.com/tc39/test262/blob/main/test/staging/Temporal/ZonedDateTime/old/dst-properties.js

Change the return type from MaybeHandle<Smi> to MaybeHandle<Object> so
we can return non integer value. Also change the method of division by
first convert the value to second in BigInt, then divid 3600 (number of
seconds in a hour) in double.

Bug: v8:11544
Change-Id: Ia69d2606cd832e51f415a00440fb9cbc236883e4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3901619Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83311}