Node.js' internal scripts should be hidden in the inspector.

Node.js' internal scripts are not distinguished from user scripts. So when debugging a user script, the inspector is polluted with these internal scripts.

This could be solved either by blackboxing internal scripts by default, or setting a different script kind in V8 internally for these scripts. The latter probably requires an API change in V8.

@ak239 @ofrobots

screenshot from 2017-03-17 09 02 09