message: Remove special handling for tf.Identity op in side-effect analysis
diff: @@ -219,12 +219,6 @@ llvm::Optional<ResourceIdsByValue> GetResourceIdsByValue(
  // Returns true if `op` is known to not have any side effect.
  bool OpIsKnownToHaveNoSideEffect(Operation* op) {
  - // Note: Identity op is really side-effect free, but it is not marked as such
  - // in the TF dialect (see comments in definition of Identity op in tf_ops.td)
  - // However, for adding control dependencies, its safe to assume
  - // that the Identity op is side-effect free.
  - if (isa<IdentityOp>(op)) return true;
  -
  // For op's in the Tensorflow dialect, query the dialect.
  if (isa_and_nonnull<TF::TensorFlowDialect>(op->getDialect()))
  return !TensorFlowDialect::CanHaveSideEffects(op);
  