message: Mark descriptors as referenced when updated, even if unused
  * Previously we did this because unused descriptors don't have to be
  updated, but for consistency with templated updates we mark them ref'd
  now (although the contents are still not referenced until bound).
diff: @@ -933,13 +933,6 @@ void WrappedVulkan::vkUpdateDescriptorSets(VkDevice device, uint32_t writeCount,
  // handled on queue submission by marking ref'd all the current bindings of the sets referenced
  // by the cmd buffer
  - // as long as descriptor sets are forced to have initial states, we don't have to mark them
  - // ref'd for write here. The reason being that as long as we only mark them as ref'd when
  - // they're actually bound, we can safely skip the ref here and it means any descriptor set
  - // updates of descriptor sets that are never used in the frame can be ignored.
  - // GetResourceManager()->MarkResourceFrameReferenced(GetResID(pDescriptorWrites[i].destSet),
  - // eFrameRef_Write);
  -
  {
  CACHE_THREAD_SERIALISER();
  @@ -950,20 +943,29 @@ void WrappedVulkan::vkUpdateDescriptorSets(VkDevice device, uint32_t writeCount,
  m_FrameCaptureRecord->AddChunk(scope.Get());
  }
  + // previously we would not mark descriptor set destinations as ref'd here. This is because all
  + // descriptor sets are implicitly dirty and they're only actually *needed* when bound - we can
  + // safely skip any updates of unused descriptor sets. However for consistency with template
  + // updates below, we pull them in here even if they won't technically be needed.
  +
  + for(uint32_t i = 0; i < writeCount; i++)
  + {
  + GetResourceManager()->MarkResourceFrameReferenced(GetResID(pDescriptorWrites[i].dstSet),
  + eFrameRef_Write);
  + }
  +
  for(uint32_t i = 0; i < copyCount; i++)
  {
  - // Like writes we don't have to mark the written descriptor set as used because unless it's
  - // bound somewhere we don't need it anyway. However we DO have to mark the source set as used
  - // because it doesn't have to be bound to still be needed (think about if the dest set is
  - // bound somewhere after this copy - what refs the source set?).
  - //
  // At the same time as ref'ing the source set, we must ref all of its resources (via the
  - // bindFrameRefs).
  + // bindFrameRefs). This is because they must be valid even if the source set is not ever bound
  + // (and so its bindings aren't pulled in).
  //
  // We just ref all rather than looking at only the copied sets to keep things simple.
  // This does mean a slightly conservative ref'ing if the dest set doesn't end up getting
  // bound, but we only do this during frame capture so it's not too bad.
  + GetResourceManager()->MarkResourceFrameReferenced(GetResID(pDescriptorCopies[i].dstSet),
  + eFrameRef_Write);
  GetResourceManager()->MarkResourceFrameReferenced(GetResID(pDescriptorCopies[i].srcSet),
  eFrameRef_Read);
  