add useless, obsolescent function ulimit

src/misc/ulimit.c

+#include <sys/resource.h>
+#include <ulimit.h>
+#include <stdarg.h>
+
+long ulimit(int cmd, ...)
+{
+	struct rlimit rl;
+	getrlimit(RLIMIT_FSIZE, &rl);
+	if (cmd == UL_SETFSIZE) {
+		long val;
+		va_list ap;
+		va_start(ap, cmd);
+		val = va_arg(ap, long);
+		va_end(ap);
+		rl.rlim_cur = 512ULL * val;
+		if (setrlimit(RLIMIT_FSIZE, &rl)) return -1; 
+	}
+	return rl.rlim_cur / 512;
+}