Move JSSyntaxRegExp to core as a private member. This removes the last refrences to dart:coreimpl.

runtime/bin/dartutils.cc

 // 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.
 
 #include "bin/dartutils.h"
 
 #include "bin/extensions.h"
 #include "bin/directory.h"
 #include "bin/file.h"
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/globals.h"
 
 const char* DartUtils::original_working_directory = NULL;
 const char* DartUtils::kDartScheme = "dart:";
 const char* DartUtils::kDartExtensionScheme = "dart-ext:";
 const char* DartUtils::kBuiltinLibURL = "dart:builtin";
 const char* DartUtils::kCoreLibURL = "dart:core";
-const char* DartUtils::kCoreImplLibURL = "dart:coreimpl";
 const char* DartUtils::kCryptoLibURL = "dart:crypto";
 const char* DartUtils::kIOLibURL = "dart:io";
 const char* DartUtils::kIOLibPatchURL = "dart:io-patch";
 const char* DartUtils::kJsonLibURL = "dart:json";
 const char* DartUtils::kUriLibURL = "dart:uri";
 const char* DartUtils::kUtfLibURL = "dart:utf";
 const char* DartUtils::kIsolateLibURL = "dart:isolate";
 
 
 const char* DartUtils::kIdFieldName = "_id";
@@ skipping 628 matching lines @@
 
 CObject* CObject::NewOSError(OSError* os_error) {
   CObject* error_message =
       new CObjectString(CObject::NewString(os_error->message()));
   CObjectArray* result = new CObjectArray(CObject::NewArray(3));
   result->SetAt(0, new CObjectInt32(CObject::NewInt32(kOSError)));
   result->SetAt(1, new CObjectInt32(CObject::NewInt32(os_error->code())));
   result->SetAt(2, error_message);
   return result;
 }