loadChildren on modules that are outside src fails #6755

Bug Report or Feature Request (mark with an x)

- [ X ] bug report 

Explanation

I've seen multiple people on gitter and on stackoverflow being confused by this, including me. When the router uses lazy loading with a module that is outside the src folder (in node_modules for instance) the build will fail giving the error: ERROR in ./src/$$_gendir async

Related to this and this

If you can provide a simple repro we can investigate.

Repro steps.

git clone https://github.com/cedvdb/test-aot-bug.git && cd test-aot-bug && npm install && ng serve --aot

The error will appear in the console at the end. I cannot make a plnkr for this.

The log given by the failure.

ERROR in ./src/$$_gendir async
Module not found: Error: Can't resolve '/home/ced/Documents/angular/aot-bug/s
rc/node_modules/test-aot-bug/test.module.ngfactory.ts' in '/home/ced/Documents/angular/aot-bug/src/$$_gendir'
 @ ./src/$$_gendir async
 @ ./~/@angular/core/@angular/core.es5.js
 @ ./src/main.ts
 @ multi webpack-dev-server/client?http://localhost:4200 ./src/main.ts

notice it tries to find node_modules in the src folder.

Desired functionality.

It would be nice if loadChildren worked with ngModules that are outside the src folder. Mainly the node_modules folder

Versions.

@angular/cli: 1.1.2
node: 8.0.0
os: linux x64