add fbgemm fp16 (fbfcpacked) support, add global_init_net in predictor_export_meta (#18257)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18257
support adding op in global_init_net. because pred_init_net is per thread, and just doesn't cut it.
Reviewed By: jspark1105
Differential Revision: D14552695
fbshipit-source-id: 53dd44c84ad019019ab9f35fc04d076b7f941ddc
