JS: fix serialization of fileId in case of incremental compilation

js/js.translator/testData/box/incremental/jsModule.js

@@ -0,0 +1,14 @@
+define("foo", [], function() {
+    return {
+        "fooF": function() {
+            return "foo";
+        }
+    };
+});
+define("bar", [], function() {
+    return {
+        "barF": function() {
+            return "bar";
+        }
+    };
+});