Validate VertexBufferLayout::array_stride

[abey79]

Context

The WebGPU spec constraints what the array stride of a VertexBufferLayout might be. In particular, it forbids it to be smaller or equal than the max(offset + size) over all attributes:

One might be tempted to use a stride smaller than the attributes to implement some kind of "sliding window" over a vertex buffer (I certainly was). This is however non-compliant as per above, and may variously lead to at least:

• recent chrome versions to reject your shader
• wgpu 23.0.0+ to emit incorrect metal shader (including out-of-bound array access)
• possibly other phenomenons (I have only tested mac, WebGPU, and WebGL, the latter seemingly being unaffected)

Issue

Currently, wgpu doesn't warn/error on non-compliant stride values. Since 23.0.0, it also silently generate erroneous metal shader when provided with non-compliant stride.

Desired change

wgpu should error (or warn loudly) with a reference to the spec whenever a non-compliant stride is detected.

Reference

• PR which lead to the discovery of the above with my debugging notes, in particular the offending metal shader: Make the line renderer spec compliant abey79/vsvg#160
• PR in which is switch from a sliding window to a compliant, multiple-buffer-binding-with-offset ("zip"): Update egui to 0.30 and wgpu to 23.0.1 abey79/vsvg#159 (This may inspire a work-around to anyone facing this issue.)

[sagudev]

Indeed, we are missing check somewhere around here:

wgpu/wgpu-core/src/device/resource.rs

Lines 2903 to 2909 in 6c9f93b

	for (i, vb_state) in desc.vertex.buffers.iter().enumerate() {
	let mut last_stride = 0;
	for attribute in vb_state.attributes.iter() {
	last_stride = last_stride.max(attribute.offset + attribute.format.size());
	}
	vertex_steps.push(pipeline::VertexStep {
	stride: vb_state.array_stride,

EDIT: We are missing multiple checks.