Additional loadJava/loadKotlin tests for nested classes

#KT-1174 Fixed

compiler/testData/loadJava/NestedClass.java

@@ -0,0 +1,6 @@
+package test;
+
+public class NestedClass {
+    public static class Nested {
+    }
+}

compiler/testData/loadJava/NestedClass.kt

@@ -0,0 +1,5 @@
+package test
+
+public open class NestedClass() : java.lang.Object() {
+    public open class Nested() : java.lang.Object()
+}

compiler/testData/loadJava/NestedClass.txt

@@ -0,0 +1,9 @@
+package test
+
+public open class NestedClass : java.lang.Object {
+    public constructor NestedClass()
+    
+    public open class Nested : java.lang.Object {
+        public constructor Nested()
+    }
+}