message: Ensure even for non-indexed mesh picks we bind dummy buffer
  * The descriptor needs to be valid even if it's not used, when not using
  descriptor indexing rules, so ensure the IB buffer is at least some minimum
  size.
diff: @@ -1319,6 +1319,17 @@ uint32_t VulkanReplay::PickVertex(uint32_t eventId, int32_t width, int32_t heigh
  m_VertexPick.IBUpload.Unmap();
  }
  + else
  + {
  + // ensure IB is non-empty so we have a valid descriptor below
  + if(m_VertexPick.IBSize == 0)
  + {
  + m_VertexPick.IBSize = 1 * sizeof(uint32_t);
  +
  + m_VertexPick.IB.Create(m_pDriver, dev, m_VertexPick.IBSize, 1,
  + GPUBuffer::eGPUBufferGPULocal | GPUBuffer::eGPUBufferSSBO);
  + }
  + }
  // unpack and linearise the data
  {
  @@ -1457,10 +1468,7 @@ uint32_t VulkanReplay::PickVertex(uint32_t eventId, int32_t width, int32_t heigh
  VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, NULL, &ibInfo, NULL},
  };
  - if(!idxs.empty())
  vt->UpdateDescriptorSets(Unwrap(m_Device), 2, writes, 0, NULL);
  - else
  - vt->UpdateDescriptorSets(Unwrap(m_Device), 1, writes, 0, NULL);
  VkCommandBuffer cmd = m_pDriver->GetNextCmd();
  