Remove cancel and make crash exit with code 253.

sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirrors.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.
 
 library dart2js.mirrors;
 
 import 'dart:collection' show UnmodifiableListView;
 
 import '../elements/elements.dart';
 import '../scanner/scannerlib.dart';
 import '../resolution/resolution.dart' show Scope;
 import '../dart2jslib.dart';
 import '../dart_types.dart';
 import '../tree/tree.dart';
-import '../util/util.dart' show Spannable, Link, LinkBuilder;
+import '../util/util.dart'
+    show Spannable,
+         Link,
+         LinkBuilder,
+         NO_LOCATION_SPANNABLE;
 import '../util/characters.dart' show $CR, $LF;
 
 import 'source_mirrors.dart';
 import 'mirrors_util.dart';
 import 'util.dart';
 
 part 'dart2js_library_mirror.dart';
 part 'dart2js_type_mirrors.dart';
 part 'dart2js_member_mirrors.dart';
 part 'dart2js_instance_mirrors.dart';
@@ skipping 98 matching lines @@
       var members = <Dart2JsMemberMirror>[];
       AbstractFieldElement field = element;
       if (field.getter != null) {
         members.add(new Dart2JsMethodMirror(this, field.getter));
       }
       if (field.setter != null) {
         members.add(new Dart2JsMethodMirror(this, field.setter));
       }
       return members;
     }
-    mirrorSystem.compiler.internalError(
-        "Unexpected member type $element ${element.kind}");
+    mirrorSystem.compiler.internalError(element,
+        "Unexpected member type $element ${element.kind}.");
     return null;
   }
 
 }
 
 abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
   final Dart2JsMirrorSystem mirrorSystem;
   final Element _element;
   List<InstanceMirror> _metadata;
 
@@ skipping 186 matching lines @@
       return new Dart2JsFunctionTypeMirror(this, type, signature);
     } else if (type is VoidType) {
       return new Dart2JsVoidMirror(this, type);
     } else if (type is TypedefType) {
       if (type.typeArguments.isEmpty) {
         return _getTypeDeclarationMirror(type.element);
       } else {
         return new Dart2JsTypedefMirror(this, type);
       }
     }
-    compiler.internalError("Unexpected type $type of kind ${type.kind}");
+    compiler.internalError(type.element,
+        "Unexpected type $type of kind ${type.kind}.");
     return null;
   }
 
   DeclarationMirror _getTypeDeclarationMirror(TypeDeclarationElement element) {
     if (element.isClass()) {
       return new Dart2JsClassDeclarationMirror(this, element.thisType);
     } else if (element.isTypedef()) {
       return new Dart2JsTypedefDeclarationMirror(this, element.thisType);
     }
-    compiler.internalError("Unexpected element $element");
+    compiler.internalError(element, "Unexpected element $element.");
     return null;
   }
 }
 
 abstract class ContainerMixin {
   Map<Symbol, DeclarationMirror> _declarations;
 
   void _ensureDeclarations() {
     if (_declarations == null) {
       _declarations = <Symbol, DeclarationMirror>{};
@@ skipping 90 matching lines @@
  *
  * All API in this class is experimental.
  */
 class BackDoor {
   /// Return the compilation units comprising [library].
   static List<Mirror> compilationUnitsOf(Dart2JsLibraryMirror library) {
     return library._element.compilationUnits.toList().map(
         (cu) => new Dart2JsCompilationUnitMirror(cu, library)).toList();
   }
 }