ReadKotlinBinaryClassTest: inner class extend inner class

compiler/testData/readKotlinBinaryClass/class/InnerClassExtendInnerClass.kt

+package test
+
+class Outer() {
+    open class Inner1()
+    
+    class Inner2() : Inner1()
+}

compiler/testData/readKotlinBinaryClass/class/InnerClassExtendInnerClass.txt

+namespace test
+
+final class test.Outer : jet.Any {
+    final /*constructor*/ fun <init>(): test.Outer
+    open class test.Outer.Inner1 : jet.Any {
+        final /*constructor*/ fun <init>(): test.Outer.Inner1
+    }
+    final class test.Outer.Inner2 : test.Outer.Inner1 {
+        final /*constructor*/ fun <init>(): test.Outer.Inner2
+    }
+}