[JS IR BE] Do not create $default stub for external function and any its fake override

js/js.translator/testData/box/jsModule/externalClassWithDefaults.js

@@ -0,0 +1,13 @@
+define("lib", [], function() {
+    function A(ss) {
+        this.s = ss || "A"
+    }
+    A.prototype.foo = function (y) {
+        return y || "K";
+    };
+    A.prototype.bar = function (y) {
+        return y || "O";
+    };
+
+    return A;
+});