Add file:line:graph to graph printout (#21180)
Summary:
Example:
```
import torch
torch.jit.script
def foo(x):
y = torch.neg(x)
return x - y
print(foo.graph.debug_str())
```
```
graph(%x : Tensor):
%2 : int = prim::Constant[value=1]()
%y : Tensor = aten::neg(%x) # demo.py:5:9
%3 : Tensor = aten::sub(%x, %y, %2) # demo.py:6:12
return (%3)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21180
Differential Revision: D15583548
Pulled By: jamesr66a
fbshipit-source-id: 0c6dc2fb7555c01dde9c563b78422ef234b2681b
