Dedupe regression with browserify v8

I'm logging the issue here, but the error is due to changes in browserify 8.0.0.

This might be best explained with an example:
- Module `A` depends on module `B`
- Other modules depend on module `B'`, which is identical to `B` but a separate copy exists for whatever reason
- `B` is deduped by browserify and points to `B'`
- `B` gets routed to the `A` bundle, assigned ID of `200`
- `B'` gets routed to the common bundle, assigned ID of `100`
- Page includes common bundle then `A` bundle

`A` bundle in browserify v7:

``` js
200:[function(require,module,exports){
module.exports=require(100)
},{"dup":100}]}
```

`A` bundle in browserify v8:

``` js
200:[function(require,module,exports){
arguments[4][100][0].apply(exports,arguments)
},{"dup":100}]}
```

This results in an exception `Uncaught TypeError: Cannot read property '0' of undefined` because ID `100` is not defined in the current bundle.

This worked in v7 because it used `require`, which tries to resolve the module with previously defined `require`s from other bundles.

I realize this is an edge case and that if `npm` is correctly deduping dependencies, this situation should not occur. And the v8 behaviour is more correct in theory because `B` may have different dependencies from `B'`. However, assuming that any module is defined in the current bundle is dangerous when factor-bundle is involved.

Riproduci lo scenario di deduplicazione con factor-bundle e browserify 8.0.0, confrontando il bundle A generato con l'output di browserify v7 mostrato qui. Traccia il modo in cui il bundle comune e il bundle A fanno riferimento agli ID dei moduli 100 e 200. Il lavoro è completato quando il modulo deduplicato viene caricato senza il TypeError riportato, preservando al contempo il caso con dipendenze distinte.

Scritto dal modello di indicizzazione a partire dal testo della issue.