[jit] fix trace checking reporting divergent names (#37842)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37842
Fixes https://github.com/pytorch/pytorch/issues/23993.
Previously our name lookup function for the tracer was looking in
f.globals for names. For example:
```
sample1 = torch.ones(1)
sample2 = torch.ones(1)
traced = torch.jit.trace(my_mod, ((sample1, sample2,),))
> produces a graph with something like:
> %sample1, %sample2 = prim::TupleUnpack(%input)
```
This is not great if you are, e.g. trace checking, because a non-local
bit of interpreter state is affected the graph produced:
```
traced = torch.jit.trace(my_mod, _clone_inputs((sample, sample,),))
> produces a graph with something like
> %0, %1 = prim::TupleUnpack(%input)
```
I have removed this functionality, as I don't think it provides huge
value. Things that look locally for names will still work, so e.g.
inputs, intermediate variables, and the like will be named correctly.
Test Plan: Imported from OSS
Differential Revision: D21406478
Pulled By: suo
fbshipit-source-id: 3c7066b95d4a6e9b528888309954b02dadbc1a07
