message: Sync to GPU when fence is signalled on a queue
  * Dynamic descriptor writes that happen after a fence sync must be synchronised
  against the work on queues. Since we don't capture CPU-waits on fences we need
  to sync on the signal.
diff: @@ -699,6 +699,7 @@ bool WrappedID3D12CommandQueue::Serialise_Signal(SerialiserType &ser, ID3D12Fenc
  if(IsReplayingAndReading() && pFence)
  {
  m_pReal->Signal(Unwrap(pFence), Value);
  + m_pDevice->GPUSync();
  }
  return true;
  