options/posix: Define UIO_MAXIOV
#include <bits/ssize_t.h>
#include <bits/off_t.h>
#include <bits/size_t.h>
+#include <limits.h>
#ifdef __cplusplus
extern "C" {
#endif
+#define UIO_MAXIOV IOV_MAX
+
ssize_t readv(int fd, const struct iovec *iov, int iovcnt);
ssize_t writev(int fd, const struct iovec *iov, int iovcnt);
