KJS: don't copy members from native interfaces

js/js.translator/testData/box/inheritance/fromNativeInterface.kt

@@ -0,0 +1,15 @@
+package foo
+
+@native
+interface A {
+    val bar: Int get() = noImpl
+    fun foo(): String = noImpl
+}
+
+class C : A
+
+fun box(): String {
+    val c = C()
+
+    return "OK"
+}