Fix DictType isSubtypeOf (#22104)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22104
ghimport-source-id: 9db14020f424cf2e021d63e9c0fe4017ac7cd6c8
Test Plan: Imported from OSS
Differential Revision: D15956726
Pulled By: jamesr66a
fbshipit-source-id: 85448deab70c5e5b7ab1132652836ed575581868
