[OCaml] fix syntax errors in linker test

[artagnon]

Summary

A couple of loose ends.

[whitequark]

test/Bindings/OCaml/linker.ml

54

This doesn't make sense. The signature of link_modules is:

val link_modules : Llvm.llmodule -> Llvm.llmodule -> Mode.t -> unit

[artagnon]

See d27b926.

-external link_modules : Llvm.llmodule -> Llvm.llmodule -> Mode.t -> unit
+external link_modules : Llvm.llmodule -> Llvm.llmodule -> unit

test/Bindings/OCaml/linker.ml

let make_module name =
     let m = create_module context name in
     let fn = define_function ("fn_" ^ name) fty m in
     ignore (build_ret_void (builder_at_end context (entry_block fn)));
     m
   in
 
   let m1 = make_module "one"
   and m2 = make_module "two" in
-  link_modules m1 m2 Mode.PreserveSource;
+  link_modules m1 m2;
   dispose_module m1;
   dispose_module m2;
 
   let m1 = make_module "one"
   and m2 = make_module "two" in
   link_modules m1 m2;
   dispose_module m1;
 
   let m1 = make_module "one"
   and m2 = make_module "one" in
   try
-    link_modules m1 m2 Mode.PreserveSource;
+    link_modules m1 m2;
     failwith "must raise"
   with Error _ ->
     dispose_module m1;
     dispose_module m2
 
 (*===-- Driver ------------------------------------------------------------===*)
 
 let _ =
   suite "linker" test_linker