We're just creating a unique identifier to match each unique module specifier. Trouble would come when the moduleSpecifiers are unique but somehow map in to non-unique normalized names:
```js
export {foo} from 'traceur/foo';
export {bar} from 'traceur@0/foo';  // same normalized name?
```
Without normalization the temp vars will be different but they will ref the same module. With normalization we'll have two declarations of the same identifier. While not preferred it does not seem horrible.

The inline transformer needs to use normalized names because the declarations are global, not local to the module as in other uses.