Generate light classes for Kotlin inner classes

#KT-6237 Fixed

idea/testData/findUsages/kotlin/findClassUsages/kotlinNestedClassAllUsages.2.java

@@ -0,0 +1,7 @@
+package b;
+
+import a.Outer;
+
+public class X extends Outer.A {
+    Outer.A next = new Outer.A();
+}