Cyclic containment of feature groups not detected

[lwrage]

Summary
A feature group may not contain itself.

Expected behavior
Validation should detect if a feature group contains itself either directly or indirectly.

Actual behavior
The validator does not detect this.

Steps To Reproduce

1. Paste model below into AADL text editor in OSATE.
2. See that there is no error marker.

package P
public
	feature group FG
		features
			-- there should be an error on the next line
			fg: feature group FG;
	end FG;
end P;

Desktop (please complete the following information):

• OSATE Version: 2.11
• Operating System: Linux

Additional context
A similar validation is implemented for component implementations.