Add test for decompiled text

idea/testData/libraries/decompiledText/NestedClasses/NestedClasses.kt

@@ -0,0 +1,31 @@
+package test
+
+class NestedClasses {
+    fun f() {
+    }
+
+    private class Nested {
+        fun f() {
+        }
+
+        public class NN {
+            fun f() {
+            }
+        }
+
+        inner class NI {
+            fun f() {
+            }
+        }
+    }
+
+    public inner class Inner {
+        fun f() {
+        }
+
+        private inner class II {
+            fun f() {
+            }
+        }
+    }
+}