Add fusion support of aten::to (#48976)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/48976
Test Plan: Imported from OSS
Reviewed By: ZolotukhinM
Differential Revision: D25413164
Pulled By: eellison
fbshipit-source-id: 0c31787e8b5e1368b0cba6e23660799b652389cd
