[NaCl SDK] Add realpath(3) implementation.

native_client_sdk/src/libraries/nacl_io/include/stdlib.h

Index: native_client_sdk/src/libraries/nacl_io/include/stdlib.h
diff --git a/native_client_sdk/src/libraries/nacl_io/include/stdlib.h b/native_client_sdk/src/libraries/nacl_io/include/stdlib.h
new file mode 100644
index 0000000000000000000000000000000000000000..5ffae74d72ebc0668c2fbbc73a207e36b829b729
--- /dev/null
+++ b/native_client_sdk/src/libraries/nacl_io/include/stdlib.h
@@ -0,0 +1,17 @@
+/* Copyright (c) 2014 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file. */
+
+#ifndef LIBRARIES_NACL_IO_INCLUDE_STDLIB_H_
+#define LIBRARIES_NACL_IO_INCLUDE_STDLIB_H_
+
+#include <sys/cdefs.h>
+#include_next <stdlib.h>
+
+__BEGIN_DECLS
+
+char* realpath(const char* path, char* resolved_path);
+
+__END_DECLS
+
+#endif