message: Add more details in the tfl.pack error string.
diff: @@ -720,7 +720,8 @@ static LogicalResult Verify(PackOp op) {
  for (Value *operand : op.getOperands()) {
  auto other_type = operand->getType().cast<ShapedType>();
  if (input_type != other_type)
  - return op.emitOpError("operands should be of the same type");
  + return op.emitOpError("operands should be of the same type. got ")
  + << input_type << ", " << other_type;
  }
  return success();
  