Register extern links for new es6 types (Generator, Iterator, Map, Promise, Set, Symbol, WeakMap, & WeakSet).
Register extern links for new es6 types (Generator, Iterator, Map, Promise, Set,
Symbol, WeakMap, & WeakSet).

Fixes #45

jleyba/js-dossier,jleyba/js-dossier,jleyba/js-dossier,jleyba/js-dossier,jleyba/js-dossier