* Add NodePath to artifact graph
Since this is cached, this should make PathToNode computation correct
even when code is formatted, whitespace changes, and source ranges
are different.
* Remove dead code
* Add unit tests
* Add tests for PathToNode conversion
* Remove unused parameter
* Add missing PathToNode cases
* Fix to handle unlabeled arg
* Cherry pick unlabeled arg fix
* Change PathToNode comment to match TS implementation
819ee23565