This is a PARTIAL reland of 8d094249
Only land the newly added tests files

Original change's description:
> [Intl] Validate u extension type
>
> Fix intl402/*/ignore-invalid-unicode-ext-values
> Add tests for other valid/invalid -u- ext values.
>
> Bug: v8:7481
> Change-Id: I429effd071bb03599a1e767bb2a9e9918a91b850
> Reviewed-on: https://chromium-review.googlesource.com/c/1351307
> Commit-Queue: Frank Tang <ftang@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58173}

Bug: v8:7481
Change-Id: I0a1c5701ade330026e2cf7eb554c6390b048a68d
Reviewed-on: https://chromium-review.googlesource.com/c/1396737Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58604}