cleanup tmp name generation (#25065)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25065
Using global atomic variables is bad because sending the same AST through
the compiler twice will produce different graphs. This makes it a
member of the translation struct.
Test Plan: Imported from OSS
Differential Revision: D16975355
Pulled By: zdevito
fbshipit-source-id: 23e15ffd58937a207898a4c4bed82628237e3c2e
