graph_for based on last_optimized_executed_graph (#19142)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19142
ghimport-source-id: 822013fb7e93032c74867fc77c6774c680aef6d1
Differential Revision: D14888703
Pulled By: zdevito
fbshipit-source-id: a2ad65a042d08b1adef965c2cceef37bb5d26ba9
