[OCaml] Add missing INPUT, OUTPUT, and INOUT typemaps for primitives

The typemaps are based on PHP's.

Examples/test-suite/ocaml/inout_runme.ml

@@ -0,0 +1,8 @@
+open Swig
+open Inout
+
+let _ =
+  assert (_AddOne1 '(1.) as float = 2.);
+  assert (_AddOne3 '(1, 1, 1) = C_list ['2.;'2.;'2.]);
+  assert (_AddOne1r '(1.) as float = 2.);
+;;