Add None return type to init -- functorch and torchgen (#132351)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/132351
Approved by: https://github.com/jamesjwu
ghstack dependencies: #132335

functorch/dim/reference.py

@@ -383,7 +383,7 @@ _orig_getitem = torch.Tensor.__getitem__
 
 
 class dim_tracker:
-    def __init__(self):
+    def __init__(self) -> None:
         self.dims = llist()
         self.count = []
 

functorch/examples/compilation/fuse_module.py

@@ -23,7 +23,7 @@ def run(mod, input):
 
 
 class Foo(nn.Module):
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self.param = nn.Parameter(torch.randn(1))
         self.register_buffer("buf", torch.randn(1))

functorch/examples/maml_regression/evjang_transforms_module.py

@@ -18,7 +18,7 @@ mpl.use("Agg")
 
 
 class ThreeLayerNet(nn.Module):
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self.fc1 = nn.Linear(1, 40)
         self.relu1 = nn.ReLU()

torchgen/_autoheuristic/pad_mm/train_pad_mm.py

@@ -11,7 +11,7 @@ from torch._inductor.fx_passes.pad_mm import pad_mm_operations
 
 
 class AHTrainPadMM(AHTrain):
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
 
     def add_new_features(self, results):

torchgen/_autoheuristic/train.py

@@ -33,7 +33,7 @@ class AHTrain:
     torch/_inductor/autoheuristic/artifacts/ directory.
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         self.parser = argparse.ArgumentParser()
         self.add_base_arguments()
         self.args = None