Add SQ/CQ overflow tests

Signed-off-by: Jens Axboe <axboe@kernel.dk>

test/sq-full.c

@@ -0,0 +1,41 @@
+/*
+ * Description: test SQ queue full condition
+ *
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include "../src/liburing.h"
+
+int main(int argc, char *argv[])
+{
+	struct io_uring_sqe *sqe;
+	struct io_uring ring;
+	int ret, i;
+
+	ret = io_uring_queue_init(8, &ring, 0);
+	if (ret) {
+		printf("ring setup failed\n");
+		return 1;
+
+	}
+
+	i = 0;
+	while ((sqe = io_uring_get_sqe(&ring)) != NULL)
+		i++;
+
+	if (i != 8) {
+		printf("Got %d SQEs\n", i);
+		goto err;
+	}
+
+	io_uring_queue_exit(&ring);
+	return 0;
+err:
+	io_uring_queue_exit(&ring);
+	return 1;
+}