message: Improve diagnostic when a mutable global tensor is found
diff: @@ -66,7 +66,9 @@ void FreezeGlobalTensorsPass::runOnOperation() {
  // previous optimize global tensors pass). If not, this pass has to fail
  // since it cannot perform one of its goals.
  if (global_tensor.is_mutable()) {
  - global_tensor.emitError() << "is not immutable";
  + global_tensor.emitError() << "is not immutable, try running "
  + "tf-saved-model-optimize-global-tensors "
  + "to prove tensors are immutable";
  return signalPassFailure();
  }
  