JS backend: fix access to class object members from containing class with implicit receiver.

#KT-4130 Fixed

js/js.translator/testData/closure/cases/closureThisAndClassObject.kt

@@ -0,0 +1,12 @@
+package foo
+
+class A {
+    fun foo() = "O"
+    class object {
+        fun bar() = "K"
+    }
+
+    val f = { foo() + bar() }
+}
+
+fun box(): String = A().f()