fix: Wrap import of ConstantFold utilities (#2312)

Author: gs-olive

py/torch_tensorrt/dynamo/backend/backends.py

@@ -7,16 +7,27 @@
 import torch
 import torch._dynamo as td
 import torch.utils._pytree as pytree
+import torch_tensorrt
 from torch._dynamo.utils import detect_fake_mode
 from torch._functorch.aot_autograd import _aot_export_function
-from torch._inductor.constant_folding import ConstantFolder, replace_node_with_constant
 from torch._ops import OpOverload
 from torch_tensorrt.dynamo import CompilationSettings
 from torch_tensorrt.dynamo.compile import compile_module
 from torch_tensorrt.dynamo.lowering._decompositions import get_decompositions
 from torch_tensorrt.dynamo.lowering._pre_aot_lowering import pre_aot_substitutions
 from torch_tensorrt.dynamo.utils import parse_dynamo_kwargs
 
+from packaging import version
+
+# Modify import location of utilities based on Torch version
+if version.parse(torch_tensorrt.sanitized_torch_version()) <= version.parse("2.1.0"):
+    from torch._inductor.freezing import ConstantFolder, replace_node_with_constant
+else:
+    from torch._inductor.constant_folding import (
+        ConstantFolder,
+        replace_node_with_constant,
+    )
+
 logger = logging.getLogger(__name__)