Disable suballocation on Iris(R) Xe gpu

[xiaopengli89]

Checklist

• Run cargo clippy.
• Add change to CHANGELOG.md. See simple instructions inside file.

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Close #3552

[Elabajaba]

This technically invalidates the safety comments for the suballocated path, but I don't think that really matters.

Should probably also not create the allocator (just add an early return to the top of create_allocator_wrapper() in suballocation.rs if suballocation isn't supported).

Also should probably add a comment above each of the if !device.private_caps.suballocation_supported { blocks saying that it's a workaround for Intel Xe drivers.

[xiaopengli89]

Ok.

[Elabajaba]

I'm getting a test failure when I run this on my AMD 6800xt when I force it to use suballocation on the wgpu::wgpu-tests zero_init_texture_after_discard::discarding_depth_target_resets_texture_init_state_check_visible_on_copy_in_same_encoder test. It passes when suballocation is enabled, but it times out if it's disabled.

Does it pass that test on an Xe iGPU?

[xiaopengli89]

I'm getting a test failure when I run this on my AMD 6800xt when I force it to use suballocation on the wgpu::wgpu-tests zero_init_texture_after_discard::discarding_depth_target_resets_texture_init_state_check_visible_on_copy_in_same_encoder test. It passes when suballocation is enabled, but it times out if it's disabled.

Does it pass that test on an Xe iGPU?

I ran the test on AMD Radeon(TM) Graphics with suballoction disabled and it pass wgpu::wgpu-tests zero_init_texture_after_discard::discarding_depth_target_ resets_texture_init_state_check_visible_on_copy_in_same_encoder.

But texture_arrays_non_uniform does not pass, the error is Image data mismatch! Outlier count 768 over limit 0. Max difference 255, even if suballoction is enabled, this should have nothing to do with this PR.

[xiaopengli89]

All tests passed on my Intel(R) Iris(R) Xe Graphics.

[cwfitzgerald]

Thanks so much!