Several tests in staging use the Pacific/Apia IANA time zone to test the
behaviour of various algorithms for the case where Samoa skipped the
entire day of Dec. 30, 2011, when they switched from one side of the
International Date Line to the other. Since implementations are not
technically required to support IANA time zones, add a fake Samoa time
zone to TemporalHelpers that has the same transition, and use it in those
tests.
(The time zone isn't exactly the same as Pacific/Apia, since Samoa also
observes DST and this time zone doesn't. It's only the same for this one
transition.)
See: #3649
Philip Chimento