- Fix the external_test.dart as it was relying on outdated

tests/language/external_test.dart

 // Copyright (c) 2012, 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.
 
 class Foo {
   var x;
   f() {}
 
+  Foo() : x = 0;
+
   external var x01;  /// 01: compile-time error
   external int x02;  /// 02: compile-time error
 
   external f10();   /// 10: runtime error
   external f11() { }  /// 11: compile-time error
   external f12() => 1;  /// 12: compile-time error
   external static f13();  /// 13: runtime error
   static external f14();  /// 14: compile-time error
   int external f16();  /// 16: compile-time error
 
   external Foo.n20();  /// 20: runtime error
-  external Foo.n21() : x(1);  /// 21: compile-time error
+  external Foo.n21() : x = 1;  /// 21: compile-time error
   external Foo.n22() { x = 1; }  /// 22: compile-time error
   external factory Foo.n23() => new Foo();  /// 23: compile-time error
+  external factory Foo.n24(this.x);  /// 24: compile-time error
 }
 
 external int t06(int i) { }  /// 30: compile-time error
 external int t07(int i) => i + 1;  /// 31: compile-time error
 
 main() {
 
+  // Ensure Foo class is compiled.
+  var foo = new Foo();
+
   // Try calling an unpatched external function.
-  var foo = new Foo();
-  try {                                               /// 10: continued
-    foo.f05();                                        /// 10: continued
-  } on String catch (exc) {                           /// 10: continued
-    if (exc == "External implementation missing.") {  /// 10: continued
-      throw exc;                                      /// 10: continued
-    }                                                 /// 10: continued
-  }                                                   /// 10: continued
-
-  new Foo().f11();                                    /// 11: continued
+  new Foo().f10();                                    /// 10: continued
   new Foo().f12();                                    /// 12: continued
-
-  try {                                               /// 13: continued
-    Foo.f13();                                        /// 13: continued
-  } on String catch (exc) {                           /// 13: continued
-    if (exc == "External implementation missing.") {  /// 13: continued
-      throw exc;                                      /// 13: continued
-    }                                                 /// 13: continued
-  }                                                   /// 13: continued
+  Foo.f13();                                          /// 13: continued
 
   // Try calling an unpatched external constructor.
-  try {                                               /// 20: continued
-    var foo = new Foo.n09();                          /// 20: continued
-  } on String catch (exc) {                           /// 20: continued
-    if (exc == "External implementation missing.") {  /// 20: continued
-      throw exc;                                      /// 20: continued
-    }                                                 /// 20: continued
-  }                                                   /// 20: continued
-
+  new Foo.n20();                                      /// 20: continued
   new Foo.n21();                                      /// 21: continued
   new Foo.n22();                                      /// 22: continued
   new Foo.n23();                                      /// 23: continued
+  new Foo.n24();                                      /// 24: continued
 
   t06(1);                                             /// 30: continued
   t07(1);                                             /// 31: continued
 }