Debug assertion fail on DX12 due to miscalculated indirect draw arg stride

[Noxime]

In (at least) [edit] multi_draw_indirect the stride is calculated wrong for Dx12 backend.

wgpu/wgpu-core/src/command/render.rs

Lines 2758 to 2761 in 49b773f

	debug_assert_eq!(
	draw_data.offset,
	current_draw_data.offset + stride * current_draw_data.count as u64
	);

The draw_data.offset is calculated to be 28 in DrawBatcher::add, due to "space for D3D12 special constants". I am not familiar with DX12 backend enough to know what these are, but it seems right. However, the right hand of this assert is calculated by

wgpu/wgpu-core/src/command/render.rs

Lines 3605 to 3610 in 49b773f

	pub(crate) const fn get_stride_of_indirect_args(indexed: bool) -> u64 {
	match indexed {
	false => size_of::<wgt::DrawIndirectArgs>() as u64,
	true => size_of::<wgt::DrawIndexedIndirectArgs>() as u64,
	}
	}

which does not account for those extra constants and returns 16 bytes.

wgpu 26.0.1

[teoxoy]

This makes sense, I forgot to update the debug assert in #7535.
Would you be able to put up a PR for this? Adding a small testcase would be great as well.