Fix remaining failing tests caused by test block 29 migration to Dart 2.0.

tests/corelib_2/symbol_test.dart

Index: tests/corelib_2/symbol_test.dart
diff --git a/tests/corelib_2/symbol_test.dart b/tests/corelib_2/symbol_test.dart
index 088443cbebdea93f6c868a508c18b022092c0bb5..93e59ab6cfcc1951bc39c06f89a2b5e7393625d8 100644
--- a/tests/corelib_2/symbol_test.dart
+++ b/tests/corelib_2/symbol_test.dart
@@ -7,7 +7,6 @@
 main() {
   var x;
   print(x = const Symbol('fisk'));
-
   try {
     print(const Symbol(0)); //# 01: compile-time error
   } on NoSuchMethodError {
@@ -31,7 +30,7 @@ main() {
   try {
     var y = 0;
     print(new Symbol(y)); //# 04: compile-time error
-    throw 'Expected a NoSuchMethodError or a TypeError';
+    throw 'Expected a NoSuchMethodError or a TypeError'; //# 04: ok
   } on NoSuchMethodError {
     print('Caught NoSuchMethodError');
   } on TypeError {