Consider outer classes when topsorting hierarchy

- when building a topsorted hierarchy, consider not only edges to the class'
  superclasses, but also from inner/nested classes to their container. This
  effectively means that a class cannot inherit from its nested class. Similar
  cases (see the tests) are disallowed in Java.
- filter classes by their presence in TopDownAnalysisContext, not by being a
  MutableClassDescriptor (otherwise analysis for local classes ends up trying
  to do something with outer superclasses)
- delete outdated comment: topsort is needed not only for better diagnostics,
  but also for correct order of fake overrides construction

compiler/testData/diagnostics/tests/cyclicHierarchy/kotlinJavaNestedCycle.kt

@@ -0,0 +1,21 @@
+// FILE: ExceptionTracker.kt
+
+trait ExceptionTracker : <!CYCLIC_INHERITANCE_HIERARCHY!>LockBasedStorageManager.ExceptionHandlingStrategy<!> {
+}
+
+// FILE: StorageManager.kt
+
+trait StorageManager : <!CYCLIC_INHERITANCE_HIERARCHY!>ExceptionTracker<!> {
+    fun foo()
+}
+
+// FILE: LockBasedStorageManager.java
+
+class LockBasedStorageManager extends StorageManager {
+    interface ExceptionHandlingStrategy {
+        void bar();
+    }
+
+    @Override
+    void foo() {}
+}