Adding sys/stat.h to src/platform/posix/posix_aio.h for building with musl
#include "posix_pollq.h"
#include <sys/types.h> // needed for mode_t
+#include <sys/stat.h> // needed for musl build
typedef struct nni_posix_pipedesc nni_posix_pipedesc;
typedef struct nni_posix_epdesc nni_posix_epdesc;
