Make prefix_rules accessible through Super_context

src/super_context.ml

@@ -182,6 +182,9 @@ let create
       | _ -> Chdir (context.build_dir, action))
   }
 
+let prefix_rules t prefix ~f =
+  Build_system.prefix_rules t.build_system prefix ~f
+
 let add_rule t ?sandbox ?mode ?locks ?loc build =
   let build = Build.O.(>>>) build t.chdir in
   Build_system.add_rule t.build_system

src/super_context.mli

@@ -55,6 +55,11 @@ val expand_vars
   -> String_with_vars.t
   -> string
 
+val prefix_rules
+  : t
+  -> (unit, unit) Build.t
+  -> f:(unit -> 'a)
+  -> 'a
 val add_rule
   :  t
   -> ?sandbox:bool