chore: Add missing headers to sockclient

runtime/tests/sockclient/client.c

@@ -1,10 +1,12 @@
 /* code from http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/socket.html */
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netdb.h>
 #include <string.h>
+#include <unistd.h>
 
 void
 error(char *msg)