Fix @providesModule not being ignored properly

Summary:
There's quite a bit of code scattered around the packager regarding ignoring the `providesModule` Haste pragma in any file that isn't in `react-native`, `react-tools` or `parse`. There is even a (passing) test case.

However, there's an edge case.

Take, for example, `fbjs`. It has a module inside of it called `ErrorUtils`. `react-relay` requires this file normally, in Common.JS style, by doing `require('fbjs/libs/ErrorUtils')`. But when `react-native` attempts to require `ErrorUtils` using the HasteModule format (in it's JavaScript initialization), it resolves the `fbjs` `ErrorUtils` module, instead of RN's `ErrorUtils`.

This happens, it turns out, because when a module is read (in `Module._read`), it's not caring about whether or not it should pay attention to `providesModule`, and is just assigning the `providesModule` value as the id of the module no matter what. Then when `Module.getName` is called, it will always use that `data.id` that was set, thus creating the wrong dependency tree.

This
Closes https://github.com/facebook/react-native/pull/3625

Reviewed By: svcscm

Differential Revision: D2632317

Pulled By: vjeux

fb-gh-sync-id: efd8066eaf6f18fcf79698beab36cab90bf5cd6d

packager/react-packager/src/DependencyResolver/AssetModule.js

@@ -25,7 +25,7 @@ class AssetModule extends Module {
     return Promise.resolve([]);
   }
 
-  _read() {
+  read() {
     return Promise.resolve({});
   }