message: Fix draw call not incremented on each compute shader dispatch
  This is needed for synchronization, to know if image units have been
  used since a memory barrier was last inserted. Probably also useful
  for buffers.
diff: @@ -572,6 +572,8 @@ impl RawProgram {
  fence.insert(&mut ctxt);
  }
  + ctxt.state.next_draw_call_id += 1;
  +
  Ok(())
  }
  @@ -615,6 +617,8 @@ impl RawProgram {
  fence.insert(&mut ctxt);
  }
  + ctxt.state.next_draw_call_id += 1;
  +
  Ok(())
  }
  }
  