Enable global observers API (#37195)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37195
After adding c10::DispatchKey::Profiler the behavior of RecordFunction
observers is also controlled by the dispatch key,
this PR moves the logic outside of the profiler into the record function
Reviewed By: ngimel
Differential Revision: D21213786
fbshipit-source-id: e618254da74a4f1ce16c51a3869bbd75a4f561ad
