DDC fix for foreign futures

pkg/dev_compiler/test/codegen_expected/varargs.js

 define(['dart_sdk'], function(dart_sdk) {
   'use strict';
   const core = dart_sdk.core;
   const dart = dart_sdk.dart;
   const dartx = dart_sdk.dartx;
   const varargs = Object.create(null);
   const src__varargs = Object.create(null);
   let dynamicAnddynamicTodynamic = () => (dynamicAnddynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
   let dynamicTodynamic = () => (dynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic])))();
   varargs.varargsTest = function(x, ...others) {
@@ skipping 12 matching lines @@
   };
   dart.defineLazy(src__varargs, {
     get rest() {
       return dart.const(new src__varargs._Rest());
     }
   });
   src__varargs.spread = function(args) {
     dart.throw(new core.StateError('The spread function cannot be called, ' + 'it should be compiled away.'));
   };
   dart.fn(src__varargs.spread, dynamicTodynamic());
-  dart.trackLibraries("varargs", {"varargs.dart": varargs, "package:js/src/varargs.dart": src__varargs}, null);
+  dart.trackLibraries("varargs", {
+    "varargs.dart": varargs,
+    "package:js/src/varargs.dart": src__varargs
+  }, null);
   // Exports:
   return {
     varargs: varargs,
     src__varargs: src__varargs
   };
 });