Add nan_to_num plugin (#72144)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72144
As title
Test Plan: buck test mode/opt //caffe2/torch/fb/fx2trt:test_nan2num
Reviewed By: yinghai
Differential Revision: D33851283
fbshipit-source-id: 582029c57d2189d727e55d1cbd099dc02b787b75
(cherry picked from commit ee940681761d7f42f21e1e35914b1e0825eee8e9)
