failed to legalize operation 'torch.operator' that was explicitly marked illegal: onnx.Unsqueeze

[pdhirajkumarprasad]

For the given IR

module {
  func.func @"torch-jit-export"(%arg0: !torch.vtensor<[2],si64>, %arg1: !torch.vtensor<[1],si64> ) -> (!torch.vtensor<[?,1,?],f32>) attributes {torch.onnx_meta.ir_version = 7 : si64, torch.onnx_meta.opset_version = 21 : si64, torch.onnx_meta.producer_name = "pytorch", torch.onnx_meta.producer_version = "1.11.0"} {
    %1 = torch.operator "onnx.ConstantOfShape"(%arg0)  : (!torch.vtensor<[2],si64>) -> !torch.vtensor<[?,?],f32> 
    %2 = torch.operator "onnx.Unsqueeze"(%1, %arg1) : (!torch.vtensor<[?,?],f32>, !torch.vtensor<[1],si64>) -> !torch.vtensor<[?,1,?],f32> 
    return %2 : !torch.vtensor<[?,1,?],f32>
  }
}

getting error as

t1.mlir:4:10: error: failed to legalize operation 'torch.operator' that was explicitly marked illegal

command:

torch-mlir-opt -split-input-file -verify-diagnostics -convert-torch-onnx-to-torch t1.mlir