Update echo (#82)

vendor/golang.org/x/sys/unix/syscall_openbsd.go

@@ -89,9 +89,30 @@ func Pipe(p []int) (err error) {
 	return
 }
 
-//sys getdents(fd int, buf []byte) (n int, err error)
+//sys Getdents(fd int, buf []byte) (n int, err error)
 func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {
-	return getdents(fd, buf)
+	n, err = Getdents(fd, buf)
+	if err != nil || basep == nil {
+		return
+	}
+
+	var off int64
+	off, err = Seek(fd, 0, 1 /* SEEK_CUR */)
+	if err != nil {
+		*basep = ^uintptr(0)
+		return
+	}
+	*basep = uintptr(off)
+	if unsafe.Sizeof(*basep) == 8 {
+		return
+	}
+	if off>>32 != 0 {
+		// We can't stuff the offset back into a uintptr, so any
+		// future calls would be suspect. Generate an error.
+		// EIO was allowed by getdirentries.
+		err = EIO
+	}
+	return
 }
 
 const ImplementsGetwd = true