Adjust types in SplayTree implementation and some strong tests to

tests/corelib_strong/sort_test.dart

Index: tests/corelib_strong/sort_test.dart
diff --git a/tests/corelib_strong/sort_test.dart b/tests/corelib_strong/sort_test.dart
index 3c1181892d7a83658eb447737a5fa4361e87ac7b..541b258d83be08df491eb26597cf32f420fa425f 100644
--- a/tests/corelib_strong/sort_test.dart
+++ b/tests/corelib_strong/sort_test.dart
@@ -9,11 +9,11 @@ import "package:expect/expect.dart";
 import 'sort_helper.dart';
 
 main() {
-  var compare = (a, b) => a.compareTo(b);
-  var sort = (list) => list.sort(compare);
+  var compare = (num a, num b) => a.compareTo(b);
+  var sort = (List<num> list) => list.sort(compare);
   new SortHelper(sort, compare).run();
 
-  compare = (a, b) => -a.compareTo(b);
+  compare = (num a, num b) => -a.compareTo(b);
   new SortHelper(sort, compare).run();
 
   var intCompare = (int a, int b) => a.compareTo(b);
@@ -68,7 +68,7 @@ main() {
     2
   ];
   list.sort(intCompare);
-  Expect.listEquals(list, [
+  Expect.listEquals(list, <int>[
     0,
     0,
     0,
@@ -164,7 +164,7 @@ main() {
     2
   ];
   list.sort(intCompare);
-  Expect.listEquals(list, [
+  Expect.listEquals(list, <int>[
     0,
     0,
     0,
@@ -263,7 +263,7 @@ main() {
     8
   ];
   list.sort(intCompare);
-  Expect.listEquals(list, [
+  Expect.listEquals(list, <int>[
     0,
     0,
     0,