Add `torch.compile` implementation (#89607)
`torch.compile` can be used either as decorator or to optimize model directly, for example:
```
@torch.compile
def foo(x):
return torch.sin(x) + x.max()
```
or
```
mod = torch.nn.ReLU()
optimized_mod = torch.compile(mod, mode="max-autotune")
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89607
Approved by: https://github.com/soumith
