Alias for logsumexp to special namespace (#58838)
Summary:
See https://github.com/pytorch/pytorch/issues/50345
cc: kshitij12345 Lezcano mruberry
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58838
Reviewed By: malfet
Differential Revision: D29565033
Pulled By: mruberry
fbshipit-source-id: 9b715ea00c78f47b6f183357ee3c7d4c3abe4d01
