Don't register precompiled scripts that are missing

When a bundle provides resource type capabilities for scripts that turn out to be missing an executable from the bundle (or can't be loaded) there is a case where if the resource type extends another resource type it is possible that a parent script is found.

When the resource type wasn't based on a script in the bundle, then this should cause a registration of the parent script (and it does) - however, when it was based on a script in the bundle, it shouldn't be registered (but it is).