Implement IDL Float16Array

[annevk]

As per whatwg/webidl#1398.

[targos]

Does it mean it's not going to be implemented by the JS engine?

[annevk]

Bindings are typically not implemented in the JS engine I think? Otherwise it would not make a whole lot of sense for Node to ask for implementer bugs to be filed when Web IDL gets changed.

[aduh95]

If/when https://github.com/tc39/proposal-float16array is implemented by V8, it will be available for Node.js without any effort (expect upgrading the vendored V8 version) from us.

EDIT: V8 has already started implementation work: https://chromium-review.googlesource.com/c/v8/v8/+/5082566

[bakkot]

There's various places in Node which do something for every typed array, like the isXArray methods and napi_create_typedarray, and those will need to be updated. The WebIDL changes probably don't require anything because in practice those aren't implemented by listing every TA type, despite that being how they're specified.