I don't fully understand the BigInt math here, as the computation for
d1 and d2 don't align with the spec due to BigInt logic. This was
discussed a bit in SerenityOS's Discord some years ago:
https://discord.com/channels/830522505605283862/851522357734408232/978786665306918932
But some new tests in test262 indicate that we need to handle negative
values here, instead of just throwing away the sign.
Our Temporal implementation is woefully out of date. The spec has been
so vastly rewritten that it is unfortunately not practical to update our
implementation in-place. Even just removing Temporal objects that were
removed from the spec, or updating any of the simpler remaining objects,
has proven to be a mess in previous attempts.
So, this removes our Temporal implementation. AOs used by other specs
are left intact.
