Fix broken emitter test (#1892)

Summary:
Pull Request resolved: #1892

Been broken for a while I imagine off of some symint checks. This adds the info needed

Reviewed By: tarun292

Differential Revision: D53581212

fbshipit-source-id: 015ef44862189d389b030d927dd858bd4d24984a

Author: JacobSzwejbka

exir/emit/test/test_emit.py

@@ -35,6 +35,7 @@
     KernelTypes,
     MoveCall,
     Null,
+    OptionalTensorList,
     Program,
     String,
     Tensor,
@@ -538,12 +539,12 @@ def test_optional_tensor_list(self) -> None:
         class Foo(torch.nn.Module):
             def forward(self, x: torch.Tensor) -> torch.Tensor:
                 a = torch.nonzero(x)
+                torch._constrain_as_size(a.shape[0], min=1)
                 b = torch.ops.aten.index.Tensor(x, [a])
                 return b
 
         f = Foo()
-
-        x = (torch.randn(3, 2),)
+        x = (torch.triu(torch.ones(2, 2)),)
         program = (
             to_edge(
                 export(f, x),
@@ -552,6 +553,9 @@ def forward(self, x: torch.Tensor) -> torch.Tensor:
             .to_executorch()
             .executorch_program
         )
+        self.assertTrue(
+            isinstance(program.execution_plan[0].values[3].val, OptionalTensorList)
+        )
         self._assertCallLength(program, 0, 3)
         self._assertCallLength(program, 1, 4)