gpuav: Use push constant inside shader

[spencer-lunarg]

So this saves us from currently copying the entire push data/constant range EVERY draw/dispatch to a SSBO buffer... instead since we are in the shader, I just read the actual push constant data!

When the user has a layout(push_constant) already, we can't create our own block and instead use Untyped pointers to do type punning

... only issue (which will probably fail CI) is that you hit this VU in self validation

Validation Error: [ VUID-vkCmdDispatch-None-11376 ] | MessageID = 0xb40dc3ee
[Self Validation] vkCmdDispatch(): shader [VK_SHADER_STAGE_COMPUTE_BIT] uses push-constant statically at range [0, 256), but vkCmdPushDataEXT was never called for range [0, 79).
The Vulkan spec states: If a bound shader was created as a VkShaderEXT with the VK_SHADER_CREATE_DESCRIPTOR_HEAP_BIT_EXT flag or as part of a pipeline with the VK_PIPELINE_CREATE_2_DESCRIPTOR_HEAP_BIT_EXT flag, and that shader statically uses a push constant value, that value must have been set by vkCmdPushDataEXT (https://docs.vulkan.org/spec/latest/chapters/dispatch.html#VUID-vkCmdDispatch-None-11376)

which I think is a bit non-sense so raised https://gitlab.khronos.org/vulkan/vulkan/-/issues/4869 to figure out what is "actually" allowed or not

[ci-tester-lunarg]

CI Vulkan-ValidationLayers build queued with queue ID 5287.

[ci-tester-lunarg]

CI Vulkan-ValidationLayers build # 23620 running.

[ci-tester-lunarg]

CI Vulkan-ValidationLayers build # 23620 failed.

[arno-lunarg]

According to https://registry.khronos.org/OpenGL/extensions/ARB/ARB_gpu_shader_int64.txt
it should be uvec2(low, high), it is reversed here. But then it should have exploded somehow?

[arno-lunarg]

Ah yes looking at:

        const uint32_t indirect_address_hi = GetInternalPushData(block, inst_it, push_offset);
        const uint32_t indirect_address_low = GetInternalPushData(block, inst_it, push_offset + 1);

high and low are inverted

[arno-lunarg]

what a name