add newlib directory

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@594 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/libc/newlib/syscalls.c

+#include <reent.h>
+
+int _fork_r (struct _reent *ptr)
+{
+	/* return "not supported" */
+	ptr->errno = ENOTSUP;
+	return -1;
+}