Summary: public
This adds the following subtyping rules:
- methods that are not annotated with Expensive cannot be overwritten by a method annotated with Expensive
- methods annotated with PerformanceCritical must be overwitten by method annotated with PerformanceCritical
Reviewed By: cristianoc
Differential Revision: D2636076
fb-gh-sync-id: eb616c9
jrm