This Pull Request fixes/closes #1180. (I'll open a tracking issue for the progress)
It changes the following:
- Redesigns the internal API of Intl to (hopefully!) make it easier to implement a service.
- Implements the `Intl.Locale` service.
- Implements the `Intl.Collator` service.
- Implements the `Intl.ListFormat` service.
On the subject of the failing tests. Some of them are caused by missing locale data in the `icu_testdata` crate; we would need to regenerate that with the missing locales, or vendor a custom default data.
On the other hand, there are some tests that are bugs from the ICU4X crate. The repo https://github.com/jedel1043/icu4x-test262 currently tracks the found bugs when running test262. I'll sync with the ICU4X team to try to fix those.
cc @sffc
José Julián Espina