Vulkan's `VK_EXT_memory_budget` extension doesn't cover query sets, so
`wgpu_hal::vulkan::Device::error_if_would_oom_on_resource_allocation`'s
tactic doesn't work to anticipate OOM errors from the Vulkan driver
when creating query sets.
Without these checks, `wgpu_gpu::oom::query_set_oom_test` actually
consumes a significant amount of memory and attracts the attention of
the system's OOM killer. While it does get killed, the situation tends
to adversely affect the stability of the rest of the system, and thus
is not a friendly thing for a test run to do (#7817).
This change can be reverted once a suitable accounting method for
query sets has been implemented on Vulkan.
Adds a new feature flag, `EXTERNAL_TEXTURE`, indicating device support
for our implementation of WebGPU's `GPUExternalTexture` [1] which will
land in upcoming patches. Conceptually this would make more sense as a
downlevel flag, as it is a core part of the WebGPU spec which we do not
yet support. We do not want, however, to cause applications to reject
adapters because we have not finished implementing this, so for now we
are making it an opt-in feature.
As an initial step towards supporting this feature, this patch adds a
new `BindingType` corresponding to WebGPU's
`GPUExternalTextureBindingLayout` [2]. This binding type dictates that
when creating a bind group the corresponding entry must be either an
external texture or a texture view with certain additional requirements
[3].
As of yet wgpu has no concept of an external texture (that will follow
in later patches) but for now this patch ensures that texture views
corresponding to an external texture binding type are validated
correctly. Note that as the feature flag is not yet supported on any
real backends, bind group layout creation will fail before getting the
chance to attempt to create a bind group. But in the added tests using
the noop backend we can see this validation taking place.
[1] https://www.w3.org/TR/webgpu/#gpuexternaltexture
[1] https://www.w3.org/TR/webgpu/#dictdef-gpuexternaltexturebindinglayout
[2] https://gpuweb.github.io/gpuweb/#bind-group-creation
