[et][dim order] Make edge verifier support empty operator

Differential Revision: [D66801315](https://our.internmc.facebook.com/intern/diff/D66801315/)

ghstack-source-id: 256642462
Pull Request resolved: #7188

---------

Co-authored-by: gasoonjia <[email protected]>

Author: pytorchbot

exir/verification/test/test_verifier.py

@@ -117,8 +117,9 @@ def __init__(self):
 
             def forward(self, x: torch.Tensor) -> torch.Tensor:
                 t1 = x.to(dtype=torch.double, memory_format=torch.channels_last)
-                t2 = t1 + t1
-                return t1 * t2
+                t2 = torch.empty(t1.size(), memory_format=torch.channels_last)
+                t2.copy_(t1)
+                return t2
 
         m = Model().eval()
 

exir/verification/verifier.py

@@ -15,10 +15,12 @@
 from executorch.exir.dialects.edge._ops import EdgeOpOverload
 from executorch.exir.error import ExportError, ExportErrorType
 from executorch.exir.lowered_backend_module import LoweredBackendModule
+from executorch.exir.passes.dim_order_ops_registry import DimOrderOpsMap
 from executorch.exir.verification.arg_validator import (
     EdgeOpArgValidator,
     RunHigherOrderOperatorError,
 )
+
 from torch._dispatch.python import enable_python_dispatcher
 from torch._export.utils import _detect_fake_mode_from_gm
 
@@ -44,7 +46,7 @@ def _check_tensors_are_contiguous(gm: GraphModule) -> None:
 
 def _check_valid_dim_order_ops(op, use_dim_order) -> None:
     if use_dim_order:
-        if op in (torch.ops.aten._to_copy.default,):
+        if op in DimOrderOpsMap:
             raise SpecViolationError(f"{op} should not be used in dim_order mode")
     else:  # not using dim_order
         if op.namespace in ("dim_order_ops",):
@@ -249,7 +251,7 @@ def check_valid_edge_op(self, op):
                     )
                 )
             if isinstance(op, EdgeOpOverload):
-                _check_valid_dim_order_ops(op._op, self.use_dim_order)
+                _check_valid_dim_order_ops(op, self.use_dim_order)
                 self.check_valid_aten_op(op._op)
 
             if isinstance(op, types.FunctionType):