Go-to-definition doesn't work on path in calls to 'require'

[DanielRosenwasser]

./foo.js:

module.exports = {};

./bar.js:

var x = require(/*$*/"./foo");

1. Go to definition on /*$*/

Expected: Navigate to foo.js.
Actual: Nada.

[mhegazy]

@riknoll has been looking at similar issues with completions in require call. moving to his plate.