Redecode the filenames of:
- all modules: __file__ and __path__ attributes
- all code objects: co_filename attribute
- sys.path
- sys.meta_path
- sys.executable
- sys.path_importer_cache (keys)
Keep weak references to all code objects until initfsencoding() is called, to
be able to redecode co_filename attribute of all code objects.
c39211f51e