[static runtime] Minimum fusion group size (#50217)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50217
If we fuse small groups, things are slow
Test Plan: buck test //caffe2/test:static_runtime
Reviewed By: bertmaher
Differential Revision: D25643460
fbshipit-source-id: d2f39a4d612df3e1e29362abb23c2d997202f6ea
