SERVER-26879 proposes getting rid of LockerNoop and de-virtualizing the Locker class.
SERVER-35970 proposes a similar task to this ticket in the comments; and in the description it proposes a 3rd Locker implementation for startup.
OperationContextNoop should be looked into as well. The only place it appears to be used in production is the StorageEngineImpl constructor, otherwise just testing.
SERVER-35970 alludes to the lock manager needing to be initialized earlier during startup in order for the storage engine initialization to use LockerImpls. I have not investigated whether this would be difficult, but there is no known impediment.