[OCaml] Runtime tests for template_opaque, using_extend and some others

Add runtime tests for namespace_virtual_method, template_opaque,
using_extend, using_inherit, using_pointers, using_private, and
varargs_overload.

Examples/test-suite/ocaml/using_inherit_runme.ml

@@ -0,0 +1,24 @@
+open Swig
+open Using_inherit
+
+let _ =
+  let b = new_Bar '() in
+  assert (b -> test (3) as int = 3);
+  assert (b -> test (3.5) as float = 3.5);
+  let b = new_Bar2 '() in
+  assert (b -> test (3) as int = 6);
+  assert (b -> test (3.5) as float = 7.0);
+  let b = new_Bar3 '() in
+  assert (b -> test (3) as int = 6);
+  assert (b -> test (3.5) as float = 7.0);
+  let b = new_Bar4 '() in
+  assert (b -> test (3) as int = 6);
+  assert (b -> test (3.5) as float = 7.0);
+
+  let f = new_Fred1 '() in
+  assert (f -> test (3) as int = 3);
+  assert (f -> test (3.5) as float = 7.0);
+  let f = new_Fred2 '() in
+  assert (f -> test (3) as int = 3);
+  assert (f -> test (3.5) as float = 7.0)
+;;