[OCaml] Bump ctypes dependency to 0.4.

ctypes 0.3 and earlier contains an interface-definig bug:
its ptr_of_raw_address accepts Int64 and not Nativeint. ctypes 0.4
was not released during the 3.6 cycle, and because of that, LLVM 3.6
was released with ctypes 0.3 as a dependency, which now breaks
the build on modern ctypes.

Unbreak.

llvm-svn: 240882

llvm/bindings/ocaml/executionengine/llvm_executionengine.ml

@@ -43,11 +43,11 @@ external run_static_dtors : llexecutionengine -> unit
   = "llvm_ee_run_static_dtors"
 external data_layout : llexecutionengine -> Llvm_target.DataLayout.t
   = "llvm_ee_get_data_layout"
-external add_global_mapping_ : Llvm.llvalue -> int64 -> llexecutionengine -> unit
+external add_global_mapping_ : Llvm.llvalue -> nativeint -> llexecutionengine -> unit
   = "llvm_ee_add_global_mapping"
-external get_global_value_address_ : string -> llexecutionengine -> int64
+external get_global_value_address_ : string -> llexecutionengine -> nativeint
   = "llvm_ee_get_global_value_address"
-external get_function_address_ : string -> llexecutionengine -> int64
+external get_function_address_ : string -> llexecutionengine -> nativeint
   = "llvm_ee_get_function_address"
 
 let add_global_mapping llval ptr ee =
@@ -55,14 +55,14 @@ let add_global_mapping llval ptr ee =
 
 let get_global_value_address name typ ee =
   let vptr = get_global_value_address_ name ee in
-  if Int64.to_int vptr <> 0 then
+  if Nativeint.to_int vptr <> 0 then
     let open Ctypes in !@ (coerce (ptr void) (ptr typ) (ptr_of_raw_address vptr))
   else
     raise (Error ("Value " ^ name ^ " not found"))
 
 let get_function_address name typ ee =
   let fptr = get_function_address_ name ee in
-  if Int64.to_int fptr <> 0 then
+  if Nativeint.to_int fptr <> 0 then
     let open Ctypes in coerce (ptr void) typ (ptr_of_raw_address fptr)
   else
     raise (Error ("Function " ^ name ^ " not found"))

llvm/cmake/config-ix.cmake

@@ -546,13 +546,13 @@ else()
     if( OCAML_VERSION VERSION_LESS "4.00.0" )
       message(STATUS "OCaml bindings disabled, need OCaml >=4.00.0.")
     else()
-      find_ocamlfind_package(ctypes VERSION 0.3 OPTIONAL)
+      find_ocamlfind_package(ctypes VERSION 0.4 OPTIONAL)
       if( HAVE_OCAML_CTYPES )
         message(STATUS "OCaml bindings enabled.")
         find_ocamlfind_package(oUnit VERSION 2 OPTIONAL)
         set(LLVM_BINDINGS "${LLVM_BINDINGS} ocaml")
       else()
-        message(STATUS "OCaml bindings disabled, need ctypes >=0.3.")
+        message(STATUS "OCaml bindings disabled, need ctypes >=0.4.")
       endif()
     endif()
   endif()