Eager fragment with unsatisfied required token should't throw AssertionError

Due to changes related to NETBEANS-1147, the behaviour of loading module fragments has changed compared to netbeans 9.0.

Before the change eager fragments with unsatisfied token requirements remain disabled without any errors.

Expected behaviour:

• eager: fragment is loaded, if all  requirements  satisfied
• autoload: fragment is only loaded, if a module depends on it. If not all  requirements are satisfied, an error is shown.
• default:  fragment is loaded. If not all  requirements are satisfied, an error is shown.

Broken use case: 
Multiple eager OS specific fragments (Linux, MacOS, Windows) not working any more.