Revert "Better messages for optimized index errors."

sdk/lib/_internal/compiler/js_lib/interceptors.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 _interceptors;
 
 import 'dart:_js_embedded_names' show
     DISPATCH_PROPERTY_NAME,
     TYPE_TO_INTERCEPTOR_MAP;
 
 import 'dart:collection';
 import 'dart:_internal' hide Symbol;
 import "dart:_internal" as _symbol_dev show Symbol;
 import 'dart:_js_helper' show allMatchesInStringUnchecked,
                               Null,
                               JSSyntaxRegExp,
                               Primitives,
                               checkInt,
                               checkNull,
                               checkNum,
                               checkString,
                               defineProperty,
-                              diagnoseIndexError,
                               getRuntimeType,
                               initNativeDispatch,
                               initNativeDispatchFlag,
                               regExpGetNative,
                               regExpCaptureCount,
                               stringContainsUnchecked,
                               stringIndexOfStringUnchecked,
                               stringLastIndexOfUnchecked,
                               stringReplaceAllFuncUnchecked,
                               stringReplaceAllUnchecked,
@@ skipping 367 matching lines @@
  * Interceptor for unclassified JavaScript objects, typically objects with a
  * non-trivial prototype chain.
  *
  * This class also serves as a fallback for unknown JavaScript exceptions.
  */
 class UnknownJavaScriptObject extends JavaScriptObject {
   const UnknownJavaScriptObject();
 
   String toString() => JS('String', 'String(#)', this);
 }