Migrated test block 26 to Dart 2.0.

tests/corelib_2/splay_tree_test.dart

Index: tests/corelib_2/splay_tree_test.dart
diff --git a/tests/corelib/splay_tree_test.dart b/tests/corelib_2/splay_tree_test.dart
similarity index 97%
rename from tests/corelib/splay_tree_test.dart
rename to tests/corelib_2/splay_tree_test.dart
index f1064a3b8679bf6b9f719b5a4a17e92d72fbfdc6..6048410dcb4da8c3d77384e66184974dae4174b2 100644
--- a/tests/corelib/splay_tree_test.dart
+++ b/tests/corelib_2/splay_tree_test.dart
@@ -125,12 +125,8 @@ void regressFromCompare() {
   Expect.equals(null, map[key(5)]);
   Expect.equals(null, map[1]);
   Expect.equals(null, map["string"]);
-  Expect.throws(() {
-    map[1] = 42;
-  });
-  Expect.throws(() {
-    map["string"] = 42;
-  });
+  map[1] = 42; //# 01: compile-time error
+  map["string"] = 42; //# 02: compile-time error
   map[key(5)] = 42;
   Expect.equals(4, map.length);
   Expect.equals(42, map[key(5)]);