[fx] Make NormalizeArgs preserve node type (#85637)

Summary: Make `NormalizeArgs` preserve node types when transforming the graph. This bug is preventing me from scripting a graph that goes through the fx2trt `acc_tracer`.

Test Plan: New unit test

Reviewed By: ipiszy

Differential Revision: D39753021

Pull Request resolved: https://github.com/pytorch/pytorch/pull/85637
Approved by: https://github.com/Chillee

test/test_fx_experimental.py

@@ -1014,6 +1014,19 @@ class {test_classname}(torch.nn.Module):
         else:
             self.fail("Didn't find call_function torch.add")
 
+    def test_normalize_args_perserve_type(self):
+        class MyModule(torch.nn.Module):
+            def forward(self, a: List[torch.Tensor]):
+                return torch.add(a[0], a[1])
+
+        m = MyModule()
+        traced = symbolic_trace(m)
+        traced = NormalizeArgs(traced).transform()
+
+        for node in traced.graph.nodes:
+            if node.op == "placeholder":
+                self.assertEqual(node.type, List[torch.Tensor])
+
     @skipIfNoTorchVision
     def test_annotate_returns_with_schema(self):
         m = resnet18()

torch/fx/experimental/normalize.py

@@ -59,6 +59,7 @@ class NormalizeArgs(Transformer):
         if n.op != "output":
             self.node_map[out] = n
             out.node.meta = n.meta
+            out.node.type = n.type
         return out
 
     def call_function(