Make corelib_strong tests strong-mode compliant

tests/corelib_strong/splay_tree_from_iterable_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.
 
 import "package:expect/expect.dart";
 import 'dart:collection';
 
 main() {
   defaultFunctionValuesTest();
   defaultKeyFunctionTest();
@@ skipping 99 matching lines @@
 
 void genericTypeTest() {
   var map = new SplayTreeMap<int, String>.fromIterable([1, 2, 3], value: (x) => '$x');
   Expect.isTrue(map is Map<int, String>);
   Expect.isTrue(map is SplayTreeMap<int, String>);
 
   // Make sure it is not just SplayTreeMap<dynamic, dynamic>.
   Expect.isFalse(map is SplayTreeMap<String, dynamic>);
   Expect.isFalse(map is SplayTreeMap<dynamic, int>);
 }
+typedef String intToString(int v);
+typedef bool intToBool(int v);
 
 // Test in checked mode with explicitly given types.
 void typedTest() {
   bool isCheckedMode = false;
   assert((isCheckedMode = true));
   if (!isCheckedMode) return;
 
-  // Assign functions to untyped function variables.
-  Function key = (int v) => "$v";
-  Function value = (int v) => v.isOdd;
+  // Assign functions to typed function variables.
+  intToString key = (int v) => "$v";
+  intToBool value = (int v) => v.isOdd;
   Function id = (int i) => i;
-
+  
   Expect.throws(() {
     new SplayTreeMap<String,bool>.fromIterable(<int>[1, 2, 3],
       key: key
       // No "value" map, defaults to identity, which returns int, not bool.
     );
   });
 
   Expect.throws(() {
     new SplayTreeMap<String,bool>.fromIterable(<int>[1, 2, 3],
       // No "key" map, defaults to identity, which returns int, not String.
       value: value
     );
   });
 
   Expect.throws(() {
     new SplayTreeMap<String,bool>.fromIterable(<int>[1, 2, 3],
-      key: id,     // wrong type.
+      key: id as dynamic,     // wrong type.
       value: value
     );
   });
 
   Expect.throws(() {
     new SplayTreeMap<String,bool>.fromIterable(<int>[1, 2, 3],
       key: key,
-      value: id    // wrong type.
+      value: id as dynamic   // wrong type.
     );
   });
 
   // But it works with explicit types when used correctly.
   SplayTreeMap<String, bool> map =
       new SplayTreeMap<String, bool>.fromIterable(<int>[1, 2, 3],
                                                   key: key,
                                                   value: value);
   Iterable<String> keys = map.keys;
   Iterable<bool> values = map.values;
   List<String> keyList = keys.toList();
   List<bool> valueList = values.toList();
   Expect.equals(3, keyList.length);
   Expect.equals(3, valueList.length);
   Expect.equals(keys.first, map.firstKey());
   Expect.equals(keys.last, map.lastKey());
 }