feat(systime): gettimeofday/itimer/utimes

include/sys/select.h

@@ -86,12 +86,20 @@ typedef struct
 typedef unsigned long sigset_t;
 #endif
 
-/* Elapsed time in seconds and microseconds (see select()'s timeout). */
+/*
+ * Elapsed time in seconds and microseconds (see select()'s timeout).
+ * Shared guard with <sys/time.h>, the canonical POSIX home of struct
+ * timeval: both headers define the same layout under
+ * VLIBC_TIMEVAL_DEFINED, so either may be included first at any level.
+ */
+#ifndef VLIBC_TIMEVAL_DEFINED
+#define VLIBC_TIMEVAL_DEFINED
 struct timeval
 {
     time_t tv_sec;
     suseconds_t tv_usec;
 };
+#endif
 
 /*
  * Wait for readiness on the descriptors marked in readfds, writefds and