Make corelib_strong tests strong-mode compliant

tests/corelib_strong/apply3_test.dart

 // Copyright (c) 2013, 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.
 
 // Test [Function.apply] on user-defined classes that implement [noSuchMethod].
 
 import "package:expect/expect.dart";
 import 'dart:mirrors';
 
 class F {
@@ skipping 11 matching lines @@
 }
 
 main() {
   Expect.equals('call', Function.apply(new F(), []));
   Expect.equals('call', Function.apply(new F(), [1]));
   Expect.equals('NSM', Function.apply(new F(), [1, 2]));
   Expect.equals('NSM', Function.apply(new F(), [1, 2, 3]));
 
   var symbol = const Symbol('a');
   var requiredParameters = [1];
-  var optionalParameters = new Map()..[symbol] = 42;
+  var optionalParameters = new Map<Symbol, int>()..[symbol] = 42;
   Invocation i = Function.apply(
       new G(), requiredParameters, optionalParameters);
 
   Expect.equals(const Symbol('call'), i.memberName);
   Expect.listEquals(requiredParameters, i.positionalArguments);
   Expect.mapEquals(optionalParameters, i.namedArguments);
   Expect.isTrue(i.isMethod);
   Expect.isFalse(i.isGetter);
   Expect.isFalse(i.isSetter);
   Expect.isFalse(i.isAccessor);
@@ skipping 17 matching lines @@
   Expect.equals(i.isSetter, other.isSetter);
   Expect.equals(i.isAccessor, other.isAccessor);
 
   // Test that [i] can be used to hit an existing method.
   Expect.equals(43, new H().call(1, a: 42));
   Expect.equals(43, Function.apply(new H(), [1], new Map()..[symbol] = 42));
   mirror = reflect(new H());
   Expect.equals(43, mirror.delegate(i));
   Expect.equals(43, mirror.delegate(other));
 }