Remove cancel and make crash exit with code 253.

sdk/lib/_internal/compiler/implementation/ir/ir_pickler.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.
 
 library dart2js.ir_pickler;
 
 import 'ir_nodes.dart' as ir;
 import '../dart2jslib.dart' show
     Constant, FalseConstant, TrueConstant, IntConstant, DoubleConstant,
     StringConstant, NullConstant, ListConstant, MapConstant,
     InterceptorConstant, DummyConstant, FunctionConstant, TypeConstant,
     ConstructedConstant,
     ConstantVisitor, ConstantSystem,
-    Compiler;
+    Compiler, NO_LOCATION_SPANNABLE;
 import 'dart:typed_data' show ByteData, Endianness, Uint8List;
 import 'dart:convert' show UTF8;
 import '../tree/tree.dart' as ast show
     DartString, LiteralDartString, RawSourceDartString, EscapedSourceDartString,
     ConsDartString;
 import '../elements/elements.dart' show
     Element, LibraryElement, FunctionElement;
 import '../universe/universe.dart' show Selector, TypedSelector, SelectorKind;
 
 part 'ir_unpickler.dart';
@@ skipping 423 matching lines @@
   void visitList(ListConstant constant) => abort(constant);
   void visitMap(MapConstant constant) => abort(constant);
   void visitInterceptor(InterceptorConstant constant) => abort(constant);
   void visitDummy(DummyConstant constant) => abort(constant);
   void visitFunction(FunctionConstant constant) => abort(constant);
   void visitType(TypeConstant constant) => abort(constant);
   void visitConstructed(ConstructedConstant constant) => abort(constant);
 
   void abort(Constant value) => throw "Can not pickle constant $value";
 }