Support move semantics for values in EvictingCacheMap::insert,set
Support move semantics for values in EvictingCacheMap::insert,set

Summary: as title

Reviewed By: Gownta

Differential Revision: D40964753

fbshipit-source-id: 590a52d70af2d0987f54b8a0125e841f219135ad

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly