[libc] Use correct header file for newlib.
#ifndef LIBC_FCNTL_H__
#define LIBC_FCNTL_H__
+#ifdef RT_USING_NEWLIB
+#include <fcntl.h>
+
+#ifndef O_NONBLOCK
+#define O_NONBLOCK 04000
+#endif
+
+#else
#define O_RDONLY 00
#define O_WRONLY 01
#define O_RDWR 02
#define F_GETOWN_EX 16
#define F_GETOWNER_UIDS 17
+#endif
#endif
+
