add cost_aware_partition (#47673)
Summary:
[WIP]This PR adds cost_aware_partition method in Partitioner class. The method partitions the fx graph module based on the latency of the whole graph.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47673
Reviewed By: gcatron
Differential Revision: D24896685
Pulled By: scottxu0730
fbshipit-source-id: 1b1651fe82ce56554f99d68da116e585c74099ed
