Move schema inference to c10 (#18090)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18090
This schema inference is needed by the c10 operator registration mechanism. Move it to c10.
It is going to be used by diffs stacked on top.
Reviewed By: ezyang
Differential Revision: D14491454
fbshipit-source-id: 0f8ddcdbd91467c8347d315dd443a1ca8b216481
