message: Update TFLite TensorList lowering pass unit tests
  Updated the existing WhileOp test to also include an op operating on TensorList to make sure that the op is lowered even though it won't have variant operand or result type once the function signature is updated.
diff: @@ -175,17 +175,17 @@ func @tensorlistWhileLoop(%arg0: tensor<2x3xf32>) -> tensor<*xf32> {
  }
  func @tensorlistWhileBody(%arg0: tensor<*xi32>, %arg1: tensor<!tf.variant>) -> (tensor<*xi32>, tensor<!tf.variant>) {
  - %cst = constant dense<1> : tensor<i32>
  - %0 = "tf.Add"(%arg0, %cst) : (tensor<*xi32>, tensor<i32>) -> tensor<*xi32>
  + %0 = "tf.TensorListLength"(%arg1) : (tensor<!tf.variant>) -> tensor<*xi32>
  %1 = "tf.Identity"(%arg1) : (tensor<!tf.variant>) -> tensor<!tf.variant>
  return %0, %1 : tensor<*xi32>, tensor<!tf.variant>
  // verify `body` function's signature.
  -// CHECK: func @tensorlistWhileBody(%arg0: tensor<*xi32>, %arg1: tensor<*xf32>) -> (tensor<*xi32>, tensor<*xf32>)
  -// CHECK: %0 = "tf.Add"(%arg0, %cst) : (tensor<*xi32>, tensor<i32>) -> tensor<*xi32>
  +// CHECK: func @tensorlistWhileBody(%[[ARG0:.*]]: tensor<*xi32>, %[[ARG:.*]]: tensor<*xf32>) -> (tensor<*xi32>, tensor<*xf32>)
  // CHECK-NOT: tensor<!tf.variant>
  -// CHECK: %1 = "tf.Identity"(%arg1) : (tensor<*xf32>) -> tensor<*xf32>
  -// CHECK: return %0, %1 : tensor<*xi32>, tensor<*xf32>
  +// CHECK: %[[LEN:.*]] = "tf.Gather"
  +// CHECK-NOT: tensor<!tf.variant>
  +// CHECK: %[[LIST:.*]] = "tf.Identity"(%arg1) : (tensor<*xf32>) -> tensor<*xf32>
  +// CHECK: return %[[LEN]], %[[LIST]] : tensor<*xi32>, tensor<*xf32>
  }
  func @tensorlistWhileCond(%arg0: tensor<*xi32>, %arg1: tensor<!tf.variant>) -> tensor<*xi1> {
  @@ -194,7 +194,7 @@ func @tensorlistWhileCond(%arg0: tensor<*xi32>, %arg1: tensor<!tf.variant>) -> t
  return %0 : tensor<*xi1>
  // verify `cond` function's signature.
  -// CHECK: func @tensorlistWhileCond(%arg0: tensor<*xi32>, %arg1: tensor<*xf32>) -> tensor<*xi1>
  -// CHECK: %0 = "tf.Less"(%arg0, %cst) : (tensor<*xi32>, tensor<i32>) -> tensor<*xi1>
  -// CHECK: return %0 : tensor<*xi1>
  +// CHECK: func @tensorlistWhileCond(%[[ARG0:.*]]: tensor<*xi32>, %[[ARG1:.*]]: tensor<*xf32>) -> tensor<*xi1>
  +// CHECK: %[[RESULT:.*]] = "tf.Less"(%[[ARG0]], {{.*}}) : (tensor<*xi32>, tensor<i32>) -> tensor<*xi1>
  +// CHECK: return %[[RESULT]] : tensor<*xi1>
  }
  