message: Add subgraph device into the dumped partitioned graph name for easier debugging.
diff: @@ -707,7 +707,8 @@ Status ProcessFunctionLibraryRuntime::InstantiateMultiDevice(
  if (VLOG_IS_ON(1)) {
  DumpGraphDefToFile(
  strings::StrCat("pflr_after_all_optimization_passes_",
  - reinterpret_cast<uintptr_t>(optimized_subgraph)),
  + reinterpret_cast<uintptr_t>(optimized_subgraph), "_",
  + pair.first),
  optimized_subgraph->ToGraphDefDebug());
  }
  }
  