Fix for OCaml bindings

The OCaml bindings have been broken in trunk for a while. I chased it
down to the addition of the Half type (rev 146786) not being reflected
in the OCaml enums, causing mysterious type checking to break in the
middle of the LLVM stack when using code generated from OCaml.

The fix was trivial:

fix-ocaml-binding.patch (1.18 KB)

Thanks! Patch applied in svn r147314