add test cases

test/840/C840T05.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <errno.h>
+
+int
+main(int argc, char **argv)
+{
+	int pfd[2];
+	char c;
+
+	pipe(pfd);
+	read(pfd[0], &c, 1);
+	exit(0);
+}