chore: import upstream snapshot with attribution

tensorflow/compiler/mlir/lite/tests/legalize-tf-assert.mlir

@@ -0,0 +1,25 @@
+// Copyright 2026 The TensorFlow Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ==============================================================================
+// RUN: litert-opt %s -tfl-legalize-tf='preserve-assert-op=true' | FileCheck %s --dump-input=fail
+
+func.func @preserve_assert(%arg0: tensor<1xi32>, %arg1: tensor<1xi32>) -> tensor<1xi1> {
+  %0 = "tf.LessEqual"(%arg0, %arg1) : (tensor<1xi32>, tensor<1xi32>) -> tensor<1xi1>
+  "tf.Assert"(%0, %arg1) {summarize = 3} : (tensor<1xi1>, tensor<1xi32>) -> ()
+  func.return %0 : tensor<1xi1>
+  // CHECK-LABEL: preserve_assert
+  // CHECK: tfl.less_equal
+  // CHECK: Assert
+  // CHECK: return
+}