ocamltest: add the afl-support test

ocamltest/Makefile

@@ -175,6 +175,7 @@ ocamltest.opt$(EXE): $(native_modules)
 
 ocamltest_config.ml: ocamltest_config.ml.in
 	sed \
+	  -e 's|@@AFL_SUPPORT@@|$(AFL_INSTRUMENT)|' \
 	  -e 's|@@ARCH@@|$(ARCH)|' \
 	  -e 's|@@SHARED_LIBRARIES@@|$(SUPPORTS_SHARED_LIBRARIES)|' \
 	  -e 's|@@UNIX@@|$(unix)|' \

ocamltest/ocaml_actions.ml

@@ -625,6 +625,12 @@ let native_compiler = Actions.make
     "native compiler available"
     "native compiler not available")
 
+let afl_support = Actions.make
+  "afl-support"
+  (Actions_helpers.pass_or_skip Ocamltest_config.afl_support
+    "support for AFL instrumentation enabled"
+    "support for AFL instrumentation disabled")
+
 let _ =
   Environments.register_initializer "find_source_modules" find_source_modules;
   Environments.register_initializer "config_variables" config_variables;
@@ -655,4 +661,5 @@ let _ =
     no_flat_float_array;
     shared_libraries;
     native_compiler;
+    afl_support;
   ]

ocamltest/ocaml_actions.mli

@@ -43,3 +43,5 @@ val no_flat_float_array : Actions.t
 val shared_libraries : Actions.t
 
 val native_compiler : Actions.t
+
+val afl_support : Actions.t

ocamltest/ocamltest_config.ml.in

@@ -17,6 +17,8 @@
 
 let arch = "@@ARCH@@"
 
+let afl_support = @@AFL_SUPPORT@@
+
 let shared_libraries = @@SHARED_LIBRARIES@@
 
 let libunix = @@UNIX@@

ocamltest/ocamltest_config.mli

@@ -18,6 +18,9 @@
 val arch : string
 (** Architecture for the native compiler, "none" if it is disabled *)
 
+val afl_support : bool
+(** Whether AFL support has been enabled in the compiler *)
+
 val shared_libraries : bool
 (** [true] if shared libraries are supported, [false] otherwise *)