message: Ruy: Guard an include, fixing MacOS build.
diff: @@ -15,14 +15,13 @@ limitations under the License.
  #include "tensorflow/lite/experimental/ruy/pmu.h"
  -#include <syscall.h>
  -
  #include "tensorflow/lite/experimental/ruy/check_macros.h"
  #ifdef __linux__
  #include <asm/unistd.h>
  #include <linux/perf_event.h>
  #include <sys/ioctl.h>
  +#include <syscall.h>
  #include <unistd.h>
  #include <cstdio>
  