[Mask R-CNN]Add Int8 AABB Generate proposals Op (#49574)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49574
Adds support for additional Eigen Utils for custom type defs.
Reviewed By: linbinyu
Differential Revision: D25624556
fbshipit-source-id: 0ffa90aaf8cbf1d08825e95156fb40d966ca7042
