dart2js: Allow 'throw' when inlining

tests/compiler/dart2js/mock_compiler.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 mock_compiler;
 
 import "package:expect/expect.dart";
 import 'dart:collection';
 import 'dart:uri';
 
@@ skipping 21 matching lines @@
 
 class WarningMessage {
   Node node;
   Message message;
   WarningMessage(this.node, this.message);
 
   toString() => message.toString();
 }
 
 const String DEFAULT_HELPERLIB = r'''
-  $throw(x) { return x; }
+  wrapException(x) { return x; }
   iae(x) { throw x; } ioore(x) { throw x; }
   guard$array(x) { return x; }
   guard$num(x) { return x; }
   guard$string(x) { return x; }
   guard$stringOrArray(x) { return x; }
   makeLiteralMap(List keyValuePairs) {}
   setRuntimeTypeInfo(a, b) {}
   getRuntimeTypeInfo(a) {}
   stringTypeCheck(x) {}
   boolConversionCheck(x) {}
@@ skipping 335 matching lines @@
   }
 }
 
 class MockDeferredLoadTask extends DeferredLoadTask {
   MockDeferredLoadTask(Compiler compiler) : super(compiler);
 
   void registerMainApp(LibraryElement mainApp) {
     // Do nothing.
   }
 }