Caniuse: Add Webassembly Threads / Threaded Webassembly

[greigs]

I know wasm threads are now supported in chrome but I'd like to know if this is the case for other browsers.
http://webassembly.github.io/spec/core/

(The overall feature rather than wait / notify)

[niklasf]

From my research for stockfish.wasm:

Chromium based (desktop only):

• Since 79: Full support
• Since 74: Support, but without growable shared memory
• 70 to 73: Needs flag chrome://flags/#enable-webassembly-threads or Origin Trial

Firefox:

• Since 79: Full support
• 72 to 78: Structured cloning can no longer be enabled with flags, except on nightlies
• 71: Requires javascript.options.shared_memory and dom.postMessage.sharedArrayBuffer.withCOOP_COEP to be enabled in about:flags
• 68 to 70: Requires javascript.options.shared_memory to be enabled in about:flags

Other browsers: No support.

---

Updated 2020-11-05

[kiding]

Along with SharedArrayBuffer being re-enabled, WebAssembly Threads are also available since Firefox 79.

[wffurr]

Threads in FF 79 (and Chrome Android / M91 desktop) will require the COOP/COEP headers as a mitigation for Spectre-style side-channel attacks: https://web.dev/coop-coep/

NodeJS supports threads as of v12.0.0 but requires the v8 flag --experimental-wasm-threads.