swift234

Runtime: Provide ARC methods for the root metaclass.

In ObjC, RootClass's metaclass isa RootClass, which is bad for SwiftObject, because its applying instance retain/release operations ends up clobbering internal state of the class. Add class method versions of 'retain' and 'release' that are no-ops, like +[NSObject retain/release] are. Fixes rdar://problem/18625294.

Swift SVN r22703