Change dart2js_foreign suite to use metadata.

dart/tests/compiler/dart2js_foreign/native_call_arity2_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // This is a similar test to NativeCallArity1FrogTest, but makes sure
 // that subclasses also get the right number of arguments.
 
-class A native "*A" {
-  int foo([x, y]) native;
+@native("*A")
+class A  {
+  @native int foo([x, y]);
 }
 
-class B extends A native "*B" {
-  int foo([x, y]) native;
+@native("*B")
+class B extends A  {
+  @native int foo([x, y]);
 }
 
-A makeA() native { return new A(); }
-B makeB() native { return new B(); }
+@native A makeA() { return new A(); }
+@native B makeB() { return new B(); }
 
-void setup() native """
+@native("""
 function inherits(child, parent) {
   if (child.prototype.__proto__) {
     child.prototype.__proto__ = parent.prototype;
   } else {
     function tmp() {};
     tmp.prototype = parent.prototype;
     child.prototype = new tmp();
     child.prototype.constructor = child;
   }
 }
 function A() {}
 A.prototype.foo = function () { return arguments.length; };
 
 function B() {}
 B.prototype.foo = function () { return arguments.length; };
 inherits(B, A);
 
 makeA = function(){return new A;};
 makeB = function(){return new B;};
-""";
+""")
+void setup();
 
 
 testDynamicContext() {
   var things = [makeA(), makeB()];
   var a = things[0];
   var b = things[1];
 
   Expect.equals(0, a.foo());
   Expect.equals(1, a.foo(10));
   Expect.equals(2, a.foo(10, 20));
@@ skipping 34 matching lines @@
   Expect.equals(1, b.foo(x: 10));   // 1 = x
   Expect.equals(2, b.foo(y: 20));   // 2 = x, y
   Expect.throws(() => b.foo(10, 20, 30));
 }
 
 main() {
   setup();
   testDynamicContext();
   testStaticContext();
 }