[K/N] Supported outer this references from cached inline bodies

kotlin-native/backend.native/tests/codegen/innerClass/inheritance2_linkTest_lib.kt

@@ -0,0 +1,13 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+open class Outer(val x: Int) {
+    open inner class Inner1
+    inner class Middle(x: Int) : Outer(x) {
+        inner class Inner2 : Inner1() {
+            fun foo() = this@Outer.x + this@Middle.x
+        }
+    }
+}