generator: add VPublicNoFish visibility type

Usable to have public functions, i.e. like VPublic, but do not showing
them in guestfish.

generator/actions.ml

@@ -12744,19 +12744,19 @@ let non_daemon_functions, daemon_functions =
 let all_functions = non_daemon_functions @ daemon_functions
 
 let is_external { visibility = v } = match v with
-  | VPublic | VStateTest | VBindTest | VDebug -> true
+  | VPublic | VPublicNoFish | VStateTest | VBindTest | VDebug -> true
   | VInternal -> false
 
 let is_internal f = not (is_external f)
 
 let is_documented { visibility = v } = match v with
-  | VPublic | VStateTest -> true
+  | VPublic | VPublicNoFish | VStateTest -> true
   | VBindTest | VDebug | VInternal -> false
 
 let is_fish { visibility = v; style = (_, args, _) } =
   (* Internal functions are not exported to guestfish. *)
   match v with
-  | VStateTest | VBindTest | VInternal -> false
+  | VPublicNoFish | VStateTest | VBindTest | VInternal -> false
   | VPublic | VDebug ->
     (* Functions that take Pointer parameters cannot be used in
      * guestfish, since there is no way the user could safely

generator/c.ml

@@ -45,7 +45,7 @@ let hash_matches h { name = name } =
 type optarg_proto = Dots | VA | Argv
 
 let is_public { visibility = v } = match v with
-  | VPublic | VStateTest | VDebug -> true
+  | VPublic | VPublicNoFish | VStateTest | VDebug -> true
   | VBindTest | VInternal -> false
 
 let is_private f = not (is_public f)

generator/types.ml

@@ -322,6 +322,8 @@ and cmd = string list
 
 type visibility =
   | VPublic                       (* Part of the public API *)
+  | VPublicNoFish                 (* Like VPublic, but not exported in
+                                     guestfish *)
   | VStateTest                    (* A function which tests the state
                                      of the appliance *)
   | VBindTest                     (* Only used for testing language bindings *)