Implementation status tracking

[mathiasbynens]

Might be good to add a list of implementations/tracking bugs to the README. I’ll start by linking to the V8 tracking bug: https://bugs.chromium.org/p/v8/issues/detail?id=9547

[rkirsling]

JSC patch: https://bugs.webkit.org/show_bug.cgi?id=200072

[MatthiasKunnen]

TypeScript: microsoft/TypeScript#26578

[jridgewell]

Babel is done, but we're updating to forbid mixing logical operators .

[rkirsling]

Landed in JSC (behind feature flag) in WebKit/WebKit@b4b72e9 (https://trac.webkit.org/r247819). 🎊

[rkirsling]

SM tracking bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1566141

[mathiasbynens]

Landed in JSC (behind feature flag) in WebKit/webkit@b4b72e9 (https://trac.webkit.org/r247819). 🎊

…and shipping in Safari TP Release 89: https://developer.apple.com/safari/technology-preview/release-notes/#release-89

[devsnek]

landed in engine262 behind --features=NullishCoalescing (engine262/engine262@7121727)

[MatthiasKunnen]

Landed in TypeScript 3.7

• https://devblogs.microsoft.com/typescript/announcing-typescript-3-7/
• https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html

[chicoxyzzy]

landed in Firefox 72 without a flag

[rkirsling]

This is now on by default in JSC (will likely be available in STP 97).

[robpalme]

V8 unflagged this feature on master on 2019-11-01 which makes it available in Chrome 80.

[avp]

Landed in Hermes: facebook/hermes@6f44f28

[ljharb]

Closing, since this proposal is at stage 4.