Enable additional encoding tests in ShadowRealms

[ptomato]

Follow-up to #41968. Enables the rest of the TextEncoder, TextDecoder, TextEncoderStream, and TextDecoderStream test coverage inside ShadowRealm scopes.

[ptomato]

This might look odd at first glance. META: timeout=long was listed twice.

[inexorabletash]

Overall LGTM - and very welcome! I especially appreciate modernizing older tests to be .any.js. A couple things:

• Is the change to give an absolute path for META includes (e.g. resources/encodings.js → /encoding/resources/encodings.js) required? WPTs use a mix; if this is now required for shadowrealm tests then documentation somewhere would be great. (Apologies if this is a well known issue, I haven't kept up with WPT evolution for a bit.)
• Some of the checks are because Chrome and Firefox don't support SABs with the APIs and the tests fail - those are known issues, not a problem. The timeouts because AudioWorklet doesn't support shadow realm are probably new. It would be nice to rework the tests to fail quickly rather than timing out, as timeouts for the CI infrastructure wastes resources.

Apologies for the delay in providing feedback.

[ptomato]

Thanks for the review!

Is the change to give an absolute path for META includes (e.g. resources/encodings.js → /encoding/resources/encodings.js) required? WPTs use a mix; if this is now required for shadowrealm tests then documentation somewhere would be great. (Apologies if this is a well known issue, I haven't kept up with WPT evolution for a bit.)

This is a good question. It does need to be a module specifier, so I believe at least ./ would be required in any case. Currently because of the way I wrote the server and harness code for shadowrealm tests, it will resolve a relative specifier relative to /resources/testharness.js. This might be able to be fixed, which I can look into, and certainly documenting it if not is a good idea. I will probably do that in a separate PR.

Some of the checks are because Chrome and Firefox don't support SABs with the APIs and the tests fail - those are known issues, not a problem. The timeouts because AudioWorklet doesn't support shadow realm are probably new. It would be nice to rework the tests to fail quickly rather than timing out, as timeouts for the CI infrastructure wastes resources.

shadowrealm-in-audioworklet tests timing out instead of failing are probably the fault of my harness code. I'll take a look at this, but I'll probably also do that in a separate PR.

[annevk]

When there's multiple files of the same name, such as with single-byte-decoder, it'd be helpful to have a comment at the top saying how it relates to the other one.

[ptomato]

The relative paths and timeouts are fixed in #49386 and #49387 respectively. I've reverted the relative-to-absolute-path scripts changes in this PR for ease of review, but it'll now need to be applied on top of #49386 for the tests to pass.