Extern type not aliased

[kevinresol]

import foo.MyClass;

@:jsRequire('./extern.js', 'MyClass')
extern ExternMyClass {}

trace(MyClass);
trace(ExternMyClass);

will generate something like this:

import {MyClass} from './foo/MyClass'
import {MyClass as MyClass__1} from './extern'

console.log(MyClass)
console.log(MyClass) // but should be MyClass__1

See failing test in 07b3d4d20fb1f2c095cae4b3863662fd32ce75fc