Add bounds check tests.
Add bounds check tests.

whitequark/ocaml-ctypes,whitequark/ocaml-ctypes,dsheets/ocaml-ctypes,whitequark/ocaml-ctypes,yallop/ocaml-ctypes,yallop/ocaml-ctypes,ocamllabs/ocaml-ctypes,dsheets/ocaml-ctypes,ocamllabs/ocaml-ctypes,dsheets/ocaml-ctypes