[OCaml] Runtime tests for abstract_access, abstract_typedef and some others

Add runtime tests for abstract_access, abstract_typedef,
abstract_typedef2, abstract_virtual, aggregate, cast_operator, and
constover. The aggregate and cast_operator tests are based on the
corresponding ruby tests, and the rest are based on python tests.

Examples/test-suite/ocaml/aggregate_runme.ml

@@ -0,0 +1,15 @@
+open Swig
+open Aggregate
+
+let _ =
+  assert((_move (_UP '()) as int) = (_UP '() as int));
+  assert((_move (_DOWN '()) as int) = (_DOWN '() as int));
+  assert((_move (_LEFT '()) as int) = (_LEFT '() as int));
+  assert((_move (_RIGHT '()) as int) = (_RIGHT '() as int));
+;;
+
+let _ =
+  try
+    _move(0 to int)
+  with Failure _ -> exit 0
+let _ = raise (Failure "0 test failed")