reduce inline autodiff threshold so we can caputre smaller fusions (#57062)
Summary:
This should let us fuse simpler expressions like
```cpp
torch.jit.script
def foo(x):
return torch.sigmoid(torch.sigmoid(x))
```
RUN_TORCHBENCH: alexnet attention_is_all_you_need_pytorch Background_Matting BERT_pytorch demucs densenet121 dlrm fastNLP gen_torchvision_benchmarks.py LearningToPaint maml mnasnet1_0 mobilenet_v2 mobilenet_v2_quantized_qat moco pyhpc_equation_of_state pyhpc_isoneutral_mixing pytorch_CycleGAN_and_pix2pix pytorch_mobilenet_v3 pytorch_stargan pytorch_struct resnet18 resnet50 resnext50_32x4d shufflenet_v2_x1_0 squeezenet1_1 Super_SloMo tacotron2 vgg16 yolov3
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57062
Reviewed By: zou3519
Differential Revision: D28053608
Pulled By: Krovatkin
fbshipit-source-id: 6871c3d2a81dd326a481e7ecfaf2ffefffce4a89
