[KT-4124] Add test case for nested/inner classes inside native class. Add diagnostic of inner classes inside native classes.

js/js.translator/testData/nestedTypes/cases/outerNative.kt

@@ -0,0 +1,31 @@
+package foo
+
+@native class A(x: Int) {
+    var x: Int
+        get() = noImpl
+        set(value) = noImpl
+
+    fun foo(): Int = noImpl
+
+    class B(val value: Int) {
+        fun bar(): Int = noImpl
+    }
+
+    inner class C(val value: Int) {
+        fun bar(): Int  = noImpl
+        fun dec(): Unit = noImpl
+    }
+}
+
+fun box(): String {
+    var b = A.B(23)
+    if (b.bar() != 10023) return "failed1: ${b.bar()}"
+
+    var c = A(11).C(23)
+    if (c.bar() != 10034) return "failed2: ${c.bar()}"
+    c.dec()
+    if (c.bar() != 10033) return "failed3: ${c.bar()}"
+
+    return "OK"
+}
+

js/js.translator/testData/nestedTypes/native/outerNative.js

@@ -0,0 +1,30 @@
+function A(x) {
+    this.x = x;
+}
+A.prototype = {
+    foo : function() {
+        return this.x;
+    }
+};
+
+A.B = function(value) {
+    this.value = value;
+};
+A.B.prototype = {
+    bar : function() {
+        return 10000 + this.value;
+    }
+};
+
+A.C = function(outer, value) {
+    this.outer = outer;
+    this.value = value;
+};
+A.C.prototype = {
+    bar : function() {
+        return this.outer.foo() + this.value + 10000;
+    },
+    dec : function() {
+        this.outer.x--;
+    }
+};