Serve URL.prototype.toJSON to Safari <12 and Edge <18.17134

[romainmenke]

URL polyfill is loaded in Safari <12 and Edge <18.17134.
This erases native support for URL.prototype.toJSON.

Matching config for should resolve this.

https://mrhenry.github.io/web-tests/#59933cd3-48cc-4f36-9c52-9ac7b46e5329

[romainmenke]

iOS also has unexpected results.
I haven't had the time yet to look into it.

[romainmenke]

@JakeChampion Manually verified that iOS 12 and 13 would work after the config change.
These now also receive the URL polyfill, but not URL.prototype.toJSON

If I am not mistaken they receive the polyfill even when config says <12 because of the user agent parser.

[romainmenke]

Flaky test run in Edge I think.

[romainmenke]

@JakeChampion could you rerun CI on this one?
It should be ready to ship :)

Thank you

[JakeChampion]

@romainmenke running it now 👍

[JakeChampion]

@romainmenke I'm not sure it is a flaky test, I've rerun it several times now and it is always the same browser version and test which fails

[romainmenke]

I think I know why it's failing.
The tests run against Edge 18 based on test/polyfills/browserstackBrowsers.toml

[[browsers]]
os = "Windows"
os_version = "10"
browser = "edge"
browser_version = "18.0"

But the polyfill config has edge = "<18.17134".
The browser from browserstack has a version higher than 18.17134.

This is causing issues.

Thank you for running those tests. I assumed it was flaky because it was a seemingly unrelated polyfill.

I'll get back to you with a fix.

[romainmenke]

That should do it.

If the combination of the test UA and the feature query params results in an empty list we now fallback to the full list for the current UA.

It is never wrong to run the full list for a UA as running a subset is just an optimization to make CI faster.

This PR will run all tests anyway now because test/polyfills/server.js was changed.
You can test this locally with http://bs-local.com:9876/?includePolyfills=yes&always=no&feature=URL.prototype.toJSON against Edge 18 in browserstack.

[JakeChampion]

@romainmenke running on ci now 👍

[romainmenke]

All green now :)

[romainmenke]

Thank you @JakeChampion! 🎉

I noticed that the last version wasn't released yet on npm.
Maybe these latest changes can be released as well?