Advance to stage 4

[gibson042]

Criteria taken from the TC39 process document minus those from previous stages:

• Test262 acceptance tests have been written for mainline usage scenarios, and merged

TODO

• Two compatible implementations which pass the acceptance tests

TODO: Add #implementations section to README

• Significant in-the-field experience with shipping implementations, such as that provided by two independent VMs

TODO: Add #implementations section to README

Bug tickets to track:

• Chrome/V8: https://bugs.chromium.org/p/v8/issues/detail?id=12955
• Firefox/SpiderMonkey: https://bugzilla.mozilla.org/show_bug.cgi?id=1658310
• Safari/JavaScriptCore: https://bugs.webkit.org/show_bug.cgi?id=248031
• etc.

• A pull request has been sent to https://github.com/tc39/ecma262 with the integrated spec text

TODO

• All ECMAScript editors have signed off on the pull request

TODO

[slavafomin]

Hello!

Thank you for this proposal. The ability to properly parse BigInt values is pretty important for the Web 3.0 developers community. Are there any estimates when this will be implemented?

[gibson042]

@slavafomin I'm planning to unblock implementations by merging #41 soon, and hopefully to advance to Stage 4 in March.

[ljharb]

Webkit PR: WebKit/WebKit#7057

[Constellation]

JSC implementation gets landed now.

[zloirock]

It's supported by all popular engines for a long time.

Usually, proposals moves into stable language earlier. Maybe it's time to advance the proposal forward?