AppContext holds strong reference to the context class loader even if it is not needed

The AppContext class holds the strong reference to the context class loader even if it is not needed anymore.
Steps to reproduce:
1. Create custom class loader
2. Set it is as a context loader of the current thread
3. Create a class object from this class loader
4. Call any method that creates an AppContext instance
   For example, java.awt.Window.getWindows()
5. Replace a context loader with another one
6. Ensure that class could not be collected by GC.
See attachement.