Serialization methods for SourceRange and Source (#22178)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22178
ghimport-source-id: 85ca4d4454c6d4b57a82f211004c4bb712d1c980
Test Plan: Imported from OSS
Differential Revision: D15981426
Pulled By: jamesr66a
fbshipit-source-id: f81f5ee3b66fc4a0d4a708b8109712b5df9f241a
