Fix native extension lookup

runtime/bin/utils.h

 // 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.
 
 #ifndef BIN_UTILS_H_
 #define BIN_UTILS_H_
 
 #include <stdlib.h>
 #include <string.h>
 
@@ skipping 66 matching lines @@
   static char* ConsoleStringToUtf8(char* str,
                                    intptr_t len = -1,
                                    intptr_t* result_len = NULL);
   static const char* Utf8ToConsoleString(const char* utf8,
                                          intptr_t len = -1,
                                          intptr_t* result_len = NULL);
   static char* Utf8ToConsoleString(char* utf8,
                                    intptr_t len = -1,
                                    intptr_t* result_len = NULL);
 
+  // Not all platforms support strndup.
+  static char* StrNDup(const char* s, intptr_t n);
+
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(StringUtils);
 };
 
 
 class ShellUtils {
  public:
   // Convert all the arguments to UTF8. On Windows, the arguments are
   // encoded in the current code page and not UTF8.
@@ skipping 17 matching lines @@
 
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(TimerUtils);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_UTILS_H_