Vulkan on asahi fails `wgpu_gpu::multiview::draw_multiview_noncontiguous`

[cwfitzgerald]

Discovered in #8610 (comment)

This feels like a driver bug, especially as there's a note in the test code that metal pre-initializes things to 255 sometimes, and that's the result we got.

wgpu/tests/tests/wgpu-gpu/multiview/mod.rs

Lines 186 to 191 in ae90040

	// Some metal devices automatically initialize stuff to 255, so I decided to use 128 instead of that
	let failed_value = data[each_texture_size * view_idx..each_texture_size * (view_idx + 1)]
	.iter()
	.copied()
	.find(|b| b.abs_diff(target_value) > 1);
	assert_eq!(failed_value, None, "Expected {target_value}");

        FAIL [   0.045s] ( 752/1314) wgpu-test::wgpu-gpu [Executed] [Vulkan/Apple M1 Pro (G13S C0)/0] wgpu_gpu::multiview::draw_multiview_noncontiguous
  stdout ───

    running 1 test
    test [Executed] [Vulkan/Apple M1 Pro (G13S C0)/0] wgpu_gpu::multiview::draw_multiview_noncontiguous ... FAILED

    failures:

    ---- [Executed] [Vulkan/Apple M1 Pro (G13S C0)/0] wgpu_gpu::multiview::draw_multiview_noncontiguous ----
    test panicked: tests/tests/wgpu-gpu/multiview/mod.rs:39:61: test "wgpu_gpu::multiview::draw_multiview_noncontiguous" did not behave as expected


    failures:
        [Executed] [Vulkan/Apple M1 Pro (G13S C0)/0] wgpu_gpu::multiview::draw_multiview_noncontiguous

    test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 767 filtered out; finished in 0.04s

  stderr ───

    thread '<unnamed>' panicked at tests/tests/wgpu-gpu/multiview/mod.rs:191:9:
    assertion `left == right` failed: Expected 0
      left: Some(255)
     right: None
    note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
    [2025-12-02T22:04:56Z ERROR wgpu_test::expectations] Panic: assertion `left == right` failed: Expected 0
          left: Some(255)
         right: None

    thread '<unnamed>' panicked at tests/src/run.rs:121:9:
    tests/tests/wgpu-gpu/multiview/mod.rs:39:61: test "wgpu_gpu::multiview::draw_multiview_noncontiguous" did not behave as expected