Fix PR #504.
Fix PR #504.

byterun/afl.c should include signal.h so that the kill function is
declared.

yunxing/ocaml,msprotz/ocaml,msprotz/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,yunxing/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,yunxing/ocaml