[AOTInductor] Remove call to aot_autograd when receiving ExportedProgram (#105977)
https://github.com/pytorch/pytorch/issues/105555
Existing flow first exports and then calls torch._inductor.aot_compile. However, export calls aot_autograd with the core aten decomposition table, and then torch._inductor.aot_compile calls aot_autograd again with the inductor decomposition table. The 2nd calling of aot_autograd is supposedly causing some problems, and seems excessive, so instead we will create a new function, torch._export.aot_compiler which will export using the inductor decomposition table, pass it to inductor's compile_fx_aot, and because it has already been exported, avoid recalling aot_autograd.
```
def aot_compile(
f: Callable,
args: Tuple[Any],
kwargs: Optional[Dict[str, Any]] = None,
constraints: Optional[List[Constraint]] = None,
) -> Tuple[str, ExportedProgram]:
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/105977
Approved by: https://github.com/desertfire, https://github.com/zhxchen17, https://github.com/eellison
