[dynamo] Expand _nonvar_fields names (#111749)

This should be a small compile time optimization, since we won't need to
walk these fields in apply().

Pull Request resolved: https://github.com/pytorch/pytorch/pull/111749
Approved by: https://github.com/yanboliang

torch/_dynamo/variables/base.py

@@ -107,7 +107,14 @@ class VariableTracker(metaclass=HasPostInit):
     """
 
     # fields to leave unmodified in apply()
-    _nonvar_fields = ["value"]
+    _nonvar_fields = {
+        "value",
+        "guards",
+        "source",
+        "mutable_local",
+        "recursively_contains",
+        "user_code_variable_name",
+    }
 
     @staticmethod
     def propagate(*vars: List[List["VariableTracker"]]):

torch/_dynamo/variables/nn_module.py

@@ -74,7 +74,7 @@ def record_nn_module_stack(module_key: str, source, tx, mod: torch.nn.Module):
 
 
 class NNModuleVariable(VariableTracker):
-    _nonvar_fields = ["module_type", "module_key"]
+    _nonvar_fields = {"module_type", "module_key", *VariableTracker._nonvar_fields}
 
     def __init__(self, module_type: type, module_key: str, **kwargs):
         super().__init__(**kwargs)
@@ -639,7 +639,7 @@ class NNModuleVariable(VariableTracker):
 
 
 class UnspecializedNNModuleVariable(UserDefinedObjectVariable):
-    _nonvar_fields = ["value_type"]
+    _nonvar_fields = {"value_type", *UserDefinedObjectVariable._nonvar_fields}
 
     """
     The above class will specialize on the id() of a module and place