Move TorchDynamo into PyTorch core (#86461)

Context:
https://github.com/pytorch/torchdynamo/issues/1588

This PR moves [TorchDynamo](https://github.com/pytorch/torchdynamo) and TorchInductor into PyTorch core.
- `torchdynamo` becomes `torch._dynamo`
- `torchinductor` becomes `torch._inductor`

This PR was generated by running `copy_to_core.sh` in https://github.com/pytorch/torchdynamo/pull/1538

Pull Request resolved: https://github.com/pytorch/pytorch/pull/86461
Approved by: https://github.com/voznesenskym

setup.py

@@ -968,6 +968,8 @@ def main():
     # the list of runtime dependencies required by this built package
     install_requires = [
         'typing_extensions',
+        'sympy',
+        'networkx',
     ]
 
     extras_require = {