Migrated test block 29 to Dart 2.0

tests/corelib_strong/symbol_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.
-
-// Basic test of Symbol class.
-
-main() {
-  var x;
-  print(x = const Symbol('fisk'));
-
-  try {
-    print(const Symbol(0)); //# 01: compile-time error
-  } on NoSuchMethodError {
-    print('Caught NoSuchMethodError');
-  } on TypeError {
-    print('Caught TypeError');
-  }
-
-  try {
-    print(const Symbol('0')); //# 02: compile-time error
-  } on ArgumentError catch (e) {
-    print('Caught $e');
-  }
-
-  try {
-    print(const Symbol('_')); //# 03: compile-time error
-  } on ArgumentError catch (e) {
-    print('Caught $e');
-  }
-
-  try {
-    var y = 0;
-    print(new Symbol(y));
-    throw 'Expected a NoSuchMethodError or a TypeError';
-  } on NoSuchMethodError {
-    print('Caught NoSuchMethodError');
-  } on TypeError {
-    print('Caught TypeError');
-  }
-
-  try {
-    print(new Symbol('0'));
-    throw 'Expected an ArgumentError';
-  } on ArgumentError catch (e) {
-    print('Caught $e');
-  }
-
-  try {
-    print(new Symbol('_'));
-    throw 'Expected an ArgumentError';
-  } on ArgumentError catch (e) {
-    print('Caught $e');
-  }
-
-  if (!identical(const Symbol('fisk'), x)) {
-    throw 'Symbol constant is not canonicalized';
-  }
-
-  if (const Symbol('fisk') != x) {
-    throw 'Symbol constant is not equal to itself';
-  }
-
-  if (const Symbol('fisk') != new Symbol('fisk')) {
-    throw 'Symbol constant is not equal to its non-const equivalent';
-  }
-
-  if (new Symbol('fisk') != new Symbol('fisk')) {
-    throw 'new Symbol is not equal to its equivalent';
-  }
-
-  if (new Symbol('fisk') == new Symbol('hest')) {
-    throw 'unrelated Symbols are equal';
-  }
-
-  if (new Symbol('fisk') == new Object()) {
-    throw 'unrelated objects are equal';
-  }
-
-  x.hashCode as int;
-
-  new Symbol('fisk').hashCode as int;
-
-  if (new Symbol('fisk').hashCode != x.hashCode) {
-    throw "non-const Symbol's hashCode not equal to its const equivalent";
-  }
-
-  if (new Symbol('') != const Symbol('')) {
-    throw 'empty Symbol not equals to itself';
-  }
-}