Moved sourceJava cases to generated test.

compiler/testData/loadJava/sourceJava/ReturnInnerSubclassOfSupersInner.java

@@ -1,6 +1,8 @@
 package test;
 
 //Note: this test could be written in simple load java test, but KT-3128 prevents from writing Kotlin counterpart for it
+//See the same test data in compiledJava test data.
+//Test data is duplicated because Java PSI used to have some differences when loading parallel generic hierarchies from cls and source code.
 public interface ReturnInnerSubclassOfSupersInner {
     class Super<A> {
         class Inner {