Add FileSystemEntity.identical, to test if two file system objects are the same.

runtime/bin/builtin_natives.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/builtin.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include "bin/dartutils.h"
@@ skipping 31 matching lines @@
   V(File_Flush, 1)                                                             \
   V(File_Create, 1)                                                            \
   V(File_CreateLink, 2)                                                        \
   V(File_LinkTarget, 1)                                                        \
   V(File_Delete, 1)                                                            \
   V(File_Directory, 1)                                                         \
   V(File_FullPath, 1)                                                          \
   V(File_OpenStdio, 1)                                                         \
   V(File_GetStdioHandleType, 1)                                                \
   V(File_GetType, 2)                                                           \
+  V(File_AreIdentical, 2)                                                      \
   V(File_NewServicePort, 0)                                                    \
   V(Logger_PrintString, 1)
 
 BUILTIN_NATIVE_LIST(DECLARE_FUNCTION);
 
 static struct NativeEntries {
   const char* name_;
   Dart_NativeFunction function_;
   int argument_count_;
 } BuiltinEntries[] = {
@@ skipping 38 matching lines @@
   fputc('\n', out);
   fflush(out);
 }
 
 
 void FUNCTION_NAME(Logger_PrintString)(Dart_NativeArguments args) {
   Dart_EnterScope();
   Builtin::PrintString(stdout, Dart_GetNativeArgument(args, 0));
   Dart_ExitScope();
 }