Platform integration work

[bakkot]

This needs integration with a couple of bits of the web platform:

• Web IDL's ArrayBufferView, BufferRelatedType, etc need to be updated to list Float16Array done in Add Float16Array whatwg/webidl#1398
• WebGL's texImage2D needs to be updated so Float16Array is accepted as a source for HALF_FLOAT

As far as I am aware these are the only places which need updating currently (updating Web IDL will flow to a number of places, including WebGPU). WebNN and float-backed canvases are in progress features, and I've informed people working on both about Float16Array.

[bathos]

I opened an issue for this on the Web IDL repo, whatwg/webidl#1310. I didn’t see this issue first, but it probably doesn’t hurt to track it there too.

[petamoriken]

I opended an issue for DOMMatrix: w3c/fxtf-drafts#546

[bakkot]

Opened whatwg/webidl#1398 adding Float16Array to WebIDL.

Edit: also w3c/webidl2.js#777 and web-platform-tests/wpt#45483.