dart2js cps: Direct access on JS arrays.

pkg/compiler/lib/src/js_backend/backend.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.
 
 part of js_backend;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 1719 matching lines @@
       cachedCheckConcurrentModificationError =
           findHelper('checkConcurrentModificationError');
     }
     return cachedCheckConcurrentModificationError;
   }
 
   Element getThrowConcurrentModificationError() {
     return findHelper('throwConcurrentModificationError');
   }
 
+  Element getThrowIndexOutOfBoundsError() {
+    return findHelper('ioore');
+  }
+
   Element getStringInterpolationHelper() {
     return findHelper('S');
   }
 
   Element getWrapExceptionHelper() {
     return findHelper(r'wrapException');
   }
 
   Element getThrowExpressionHelper() {
     return findHelper('throwExpression');
@@ skipping 1255 matching lines @@
   }
 }
 
 /// Records that [constant] is used by the element behind [registry].
 class Dependency {
   final ConstantValue constant;
   final Element annotatedElement;
 
   const Dependency(this.constant, this.annotatedElement);
 }