Temporal: Tests for week-numbering algorithm

[Aditi-1400]

Adds and updates tests for PR: tc39/proposal-temporal#2756

[ptomato]

Thanks! All these tests look good, with one comment about needing to move a few of them.

However I think we need to cover a few more things in order to make sure that engines implement every aspect of this normative change:

• In test/built-ins/, validation that a custom calendar may return undefined from yearOfWeek and weekOfYear and that a PlainDate/PlainDateTime/ZonedDateTime with this custom calendar will have the yearOfWeek/weekOfYear property with the value of undefined
• In test/intl402/, a sample case where iso8601 and gregory week numbers disagree according to CLDR

I'm happy to merge this after moving those two tests and add the additional coverage in a follow up, or also happy to re-review this with the additional tests added. Let me know what your preference is.

[Aditi-1400]

Thanks! All these tests look good, with one comment about needing to move a few of them.

However I think we need to cover a few more things in order to make sure that engines implement every aspect of this normative change:

• In test/built-ins/, validation that a custom calendar may return undefined from yearOfWeek and weekOfYear and that a PlainDate/PlainDateTime/ZonedDateTime with this custom calendar will have the yearOfWeek/weekOfYear property with the value of undefined
• In test/intl402/, a sample case where iso8601 and gregory week numbers disagree according to CLDR

I'm happy to merge this after moving those two tests and add the additional coverage in a follow up, or also happy to re-review this with the additional tests added. Let me know what your preference is.

I've updated the PR to add the tests you requested.

[ptomato]

Thanks for the update, all looks good!