bug: Exception raised by ClassTypingContext#isOverriding ("Cannot adapt type parameters of non type scope")

[monperrus]

In some cases, ClassTypingContext#isOverriding crasheswith an exception:

spoon.SpoonException: Cannot adapt type parameters of non type scope

	at spoon.support.visitor.ClassTypingContext.resolveTypeParameters(ClassTypingContext.java:473)
	at spoon.support.visitor.ClassTypingContext.access$000(ClassTypingContext.java:62)
	at spoon.support.visitor.ClassTypingContext$1.accept(ClassTypingContext.java:234)
	at spoon.support.visitor.ClassTypingContext$1.accept(ClassTypingContext.java:203)
	at spoon.reflect.visitor.chain.CtQueryImpl$OutputFunctionWrapper._accept(CtQueryImpl.java:471)
	at spoon.reflect.visitor.chain.CtQueryImpl$AbstractStep.accept(CtQueryImpl.java:319)
	at spoon.reflect.visitor.filter.SuperInheritanceHierarchyFunction.sendResult(SuperInheritanceHierarchyFunction.java:347)
	at spoon.reflect.visitor.filter.SuperInheritanceHierarchyFunction.visitSuperClasses(SuperInheritanceHierarchyFunction.java:281)
	at spoon.reflect.visitor.filter.SuperInheritanceHierarchyFunction.apply(SuperInheritanceHierarchyFunction.java:248)
	at spoon.reflect.visitor.filter.SuperInheritanceHierarchyFunction.apply(SuperInheritanceHierarchyFunction.java:51)
	at spoon.reflect.visitor.chain.CtQueryImpl$LazyFunctionWrapper._accept(CtQueryImpl.java:505)
	at spoon.reflect.visitor.chain.CtQueryImpl$AbstractStep.accept(CtQueryImpl.java:319)
	at spoon.reflect.visitor.chain.CtQueryImpl.forEach(CtQueryImpl.java:105)
	at spoon.support.visitor.ClassTypingContext.resolveActualTypeArgumentsOf(ClassTypingContext.java:203)
	at spoon.support.visitor.ClassTypingContext.isSubtypeOf(ClassTypingContext.java:133)
	at spoon.support.visitor.ClassTypingContext.isOverriding(ClassTypingContext.java:274)

One can reproduce the problem with

		Launcher spoon = new Launcher();
		spoon.getEnvironment().setCommentEnabled(true);
		spoon.addInputResource("src/main/java/");
		spoon.buildModel();
		List<String> notDocumented = new ArrayList<>();
		List<CtMethod> list = spoon.getFactory().Package().getRootPackage().filterChildren(x -> x instanceof CtMethod).list(CtMethod.class);
		for (CtMethod m1 : list) {
			// going directly to the case the reproduces the bug
			if (!(
					m1.getDeclaringType().getQualifiedName().equals("spoon.reflect.meta.impl.ListHandler$1")
					&& m1.getSignature().equals("iterator()"))
				) {
				continue;
			}

			Collection<CtMethod<?>> allMethods = m1.getDeclaringType().map(new AllTypeMembersFunction(CtMethod.class)).list();
			for (CtMethod m2 : allMethods) {
				ClassTypingContext c = new ClassTypingContext(m1.getDeclaringType());
				System.out.println("trying isOverriding("+m1.getSignature()+", "+m2.getSignature()+")");
				// triggerring the exception
				c.isOverriding(m1, m2);
			}
		}

@pvojtechovsky could you have look at this? Thanks!