Use Argument Buffers on Metal

[cwfitzgerald]

This is a major change for our binding model on Mac, but would allow us to support bindless in it's true form by letting us bind up to a million textures and buffers on modern chips.

Argument buffers are unconditionally supported for our target, so we can just universally change the API usage.

This isn't true, it requires Mac 10.13 and WebGPU is minimum 10.12. There are also issues with write resources on tier 1 hardware. I suspect we should just use argument buffer for bindless arrays.

[kanerogers]

According to @cwfitzgerald WebGPU minimum is now 10.13, which should ameliorate the compatibility issues.

[kanerogers]

I've made some progress on this issue, which I've documented on the corresponding naga issue.