fix compilation on OpenBSD

compat/clock_nanosleep/clock_nanosleep.c

@@ -19,10 +19,13 @@
  *  http://www.gnu.org/copyleft/gpl.html                               *
  ***********************************************************************/
 
-#include "clock_nanosleep.h"
 #include <errno.h>                           // for errno, EINVAL
 #include <time.h>                            // for nanosleep, NULL
+
+#include "clock_nanosleep.h"
+#ifdef MISSING_GETTIME
 #include "../clock_gettime/clock_gettime.h"  // for clock_gettime
+#endif
 
 int clock_nanosleep(clockid_t id, int flags, const struct timespec *ts,
                     struct timespec *ots) {

compat/clock_nanosleep/clock_nanosleep.h

@@ -1,8 +1,8 @@
 #ifndef CLOCK_NANOSLEEP_H
 #define CLOCK_NANOSLEEP_H
 
-#ifndef CLOCKID_T
-#define CLOCKID_T
+#ifndef _CLOCK_T_DEFINED_
+#define _CLOCK_T_DEFINED_
 typedef enum
 {
     CLOCK_REALTIME,
@@ -10,7 +10,7 @@ typedef enum
     CLOCK_PROCESS_CPUTIME_ID,
     CLOCK_THREAD_CPUTIME_ID
 } clockid_t;
-#endif // CLOCKID_T
+#endif // _CLOCK_T_DEFINED_
 
 #ifndef TIMER_ABSTIME
 #define TIMER_ABSTIME 1