WebGPU: use wasm-friendly overload of setBindGroup

[kainino0x]

Blocked on Firefox support.
Fixes #20280

[kainino0x]

FYI @jimblandy. Supporting this is not urgent, but it should be more efficient than the old code.

[jimblandy]

@kainino0x Which WebGPU API does this need from Firefox, specifically?

[kainino0x]

Sorry, forgot the detail wasn't here. It's on the linked issue.

This uses the overload of setBindGroup that takes a Uint32Array:

interface mixin GPUBindingCommandsMixin {
    undefined setBindGroup(GPUIndex32 index, GPUBindGroup? bindGroup,
        optional sequence<GPUBufferDynamicOffset> dynamicOffsets = []);

    undefined setBindGroup(GPUIndex32 index, GPUBindGroup? bindGroup,
        Uint32Array dynamicOffsetsData,
        GPUSize64 dynamicOffsetsDataStart,
        GPUSize32 dynamicOffsetsDataLength);
};

Firefox only seems to have the first one:
https://searchfox.org/mozilla-central/source/dom/webidl/WebGPU.webidl#913

[jimblandy]

Firefox work tracked here: https://bugzilla.mozilla.org/show_bug.cgi?id=1878804

This is not an immediate priority for us, but it's in the spec and we will get to it eventually.

[kainino0x]

People are starting to run into some performance bottlenecks with setBindGroup, and this will help a little bit, so let's go ahead and do it.

[kainino0x]

PTAL @lokokung

[kainino0x]

This won't be fixed in Emscripten's current WebGPU bindings, but now that Firefox has been fixed, I'll finally fix this in emdawnwebgpu (see #23432). https://dawn-review.googlesource.com/c/dawn/+/236936