Naga generates invalid SPIR-V in a shader with a unused acceleration structure

[Vecvec]

Description
When converting a shader with one acceleration structure that is never used using Naga to SPIR-V and using it (using #3631) the vulkan validation layers give

Validation Error: [ VUID-VkShaderModuleCreateInfo-pCode-08737 ] | MessageID = 0xa5625282 | vkCreateShaderModule(): pCreateInfo->pCode (spirv-val produced an error):
    1st operand of Capability: operand RayQueryKHR(4472) requires one of these extensions: SPV_KHR_ray_query
      OpCapability RayQueryKHR
    . The Vulkan spec states: If pCode is a pointer to SPIR-V code, pCode must adhere to the validation rules described by the Validation Rules within a Module section of the SPIR-V Environment appendix (https://vulkan.lunarg.com/doc/view/1.3.275.0/windows/1.3-extensions/vkspec.html#VUID-VkShaderModuleCreateInfo-pCode-08737)

while this is a fork of #3631, no naga changes are in either.

Repro steps

@group(0) @binding(0)
var acc_struct: acceleration_structure;

@workgroup_size(1)
@compute
fn comp_main() {}

gives this error, while changing comp_main to

fn comp_main() {
    var rq: ray_query;
    rayQueryInitialize(&rq, acc_struct, RayDesc(0u, 0xFFu, 0.001, 100000.0, vec3f(0.0, 0.0, 0.0), vec3f(0.0, 0.0, 1.0)));
    rayQueryProceed(&rq);
    let intersection = rayQueryGetCommittedIntersection(&rq);
}

fixes the issue

Expected vs observed behavior
Expected: No validation error
Observed: Validation error

Extra materials
test log (just this test, I don't think the other tests would help):
failed test.txt

Platform
This is a fork of #3631.

[teoxoy]

There is probably some validation missing. The fix should be part of #3631.

[Vecvec]

I think this might be the cause

wgpu/naga/src/back/spv/writer.rs

Lines 1861 to 1862 in 0f4839c

	let has_ray_query = ir_module.special_types.ray_desc.is_some()
	| ir_module.special_types.ray_intersection.is_some();

this only puts the extension in if there is a ray desc or a ray intersection used, should there be a bool that is set somewhere (maybe in the shader module?) to tell the writer that this feature is enabled if any ray-tracing type is used?

[teoxoy]

Ah, I misunderstood what the issue was.

The backend should loop over all types and set the has_ray_query var if it sees TypeInner::AccelerationStructure or TypeInner::RayQuery in addition to the special types.