test(ctypes): ensure all .h are present and used

Author: Khady

test/blackbox-tests/test-cases/ctypes/deps-full-spec.t/bar.h

@@ -0,0 +1 @@
+#define BAR_VERSION 1

test/blackbox-tests/test-cases/ctypes/deps-full-spec.t/baz.h

@@ -0,0 +1 @@
+#define BAZ_VERSION 1

test/blackbox-tests/test-cases/ctypes/deps-full-spec.t/example.ml

@@ -1,2 +1,6 @@
 let () =
-  Printf.printf "%d\n" (C.Functions.add2 2)
+  Printf.printf "%d\n" (C.Functions.add2 C.Types.foo_version);
+  Printf.printf "%d\n" (C.Functions.add2 C.Types.bar_version);
+  Printf.printf "%d\n" (C.Functions.add2 C.Types.baz_version);
+  Printf.printf "%d\n" (C.Functions.add2 C.Types.qux_version);
+  ()

test/blackbox-tests/test-cases/ctypes/deps-full-spec.t/foo.h

@@ -0,0 +1 @@
+#define FOO_VERSION 1

test/blackbox-tests/test-cases/ctypes/deps-full-spec.t/type_description.ml

@@ -1,6 +1,9 @@
 module Types (F : Ctypes.TYPE) = struct
   open F
 
+  let foo_version = constant "FOO_VERSION" int
+  let bar_version = constant "BAR_VERSION" int
+  let baz_version = constant "BAZ_VERSION" int
   let qux_version = constant "QUX_VERSION" int
 
 end