Register class names for NSKeyedArchiver and NSKeyedUnarchiver based on the @NSKeyedArchiveLegacy and @_staticInitializeObjCMetadata class attributes.
@NSKeyedArchiveLegacy registers a class name translation.
@_staticInitializeObjCMetadata just makes sure that the metadata of a class is instantiated.
This registration code is executed as a static initializer, like a C++ global constructor.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
Generate global symbols which are function pointers to the actual implementations of runtime entry points.
This is done only for entry points using the new calling convention or for those entry points which explicitly require it.
