Using #ifdef to selectively register runtimeclasses from the public IDLs isn't going to work out, this implements explicit class registration instead.
For now we are missing a possible useful check in widl to make sure the referenced class is defined, this will be added later on after all modules are made explicit.
-- v2: include: Remove now unnecessary registration ifdefs. wintypes: Register runtimeclasses explicitly. windows.storage: Register runtimeclasses explicitly. windows.storage.applicationdata: Register runtimeclasses explicitly. widl: Allow explicit registration by referencing runtimeclasses. widl: Keep track of statements source locations.