message: Add a timer to measure op enqueue overhead for XLA GPU
diff: @@ -303,6 +303,8 @@ StatusOr<ExecutionOutput> GpuExecutable::ExecuteAsyncOnStream(
  const ServiceExecutableRunOptions* run_options,
  std::vector<ShapeTree<MaybeOwningDeviceMemory>> arguments,
  HloExecutionProfile* hlo_execution_profile) {
  + XLA_SCOPED_LOGGING_TIMER(absl::StrCat("GpuExecutable::ExecuteAsyncOnStream(",
  + module().name(), ")"));
  se::DeviceMemoryAllocator* const memory_allocator = run_options->allocator();
  // Force synchronous execution if the allocator requires it.
  const bool block_host_until_done =
  