Mark OCaml values as 'alloc', since references are boxed.
Mark OCaml values as 'alloc', since references are boxed.

In practice, OCaml types can't be used as return types, so it doesn't
much matter whether they're marked as 'alloc'.

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