Swift 4.2.1 Release
Merge pull request #30 from cwakamo/prevent-recursive-logging-4.2 [4.2] [PlaygroundLogger] Add checks in the logger entrypoints to prevent recursive logging.
Merge pull request #30 from cwakamo/prevent-recursive-logging-4.2 [4.2] [PlaygroundLogger] Add checks in the logger entrypoints to prevent recursive logging.