message: Add TODO for defining parallel_execute op via tablegen.
diff: @@ -42,6 +42,9 @@ class TensorFlowDeviceDialect : public Dialect {
  #define GET_OP_CLASSES
  #include "tensorflow/compiler/mlir/tensorflow/ir/tf_device.h.inc"
  +// TODO(b/148642767): Use tablegen to define tf_device.parallel_execute op once
  +// variadic regions can be expressed in tablegen.
  +//
  // ParallelExecute op concurrently executes variadic number of regions. Regions
  // must represent separate sets of instructions to execute concurrently. In
  // order to represent concurrently executed regions with dependencies, multiple
  