daemon, generator: Use power of 2 for initial size of Hashtbl.create

Before 2011 it was recommended to use a prime number for the initial
size.  In 2011 the OCaml hash table was reimplemented using a hash
function based on Murmur 3.  Hashtbl.create now adjusts the initial
size to the next power of 2 (minimum 16).  So replace obsolete
'Hashtbl.create 13' with 'Hashtbl.create 16'.

generator/memoized_cache.ml

@@ -44,7 +44,7 @@ let create ?(version = 1) ?(batch_size = 100) name lookup_fn =
   let filename = sprintf "generator/.%s.data.version.%d" name version in
   let memo =
     try with_open_in filename input_value
-    with _ -> Hashtbl.create 13 in
+    with _ -> Hashtbl.create 16 in
   {
     memo; filename; lookup_fn; batch_size; unsaved_count = 0;
   }

generator/optgroups.ml

@@ -34,7 +34,7 @@ let optgroups_retired = [
 
 (* Create list of optional groups. *)
 let optgroups =
-  let h = Hashtbl.create 13 in
+  let h = Hashtbl.create 16 in
   List.iter (
     function
     | { optional = Some group } as fn ->

generator/pr.ml

@@ -32,7 +32,7 @@ let lines = ref 0
 
 (* Name of each file generated. *)
 let files = ref []
-let fileshash = Hashtbl.create 13
+let fileshash = Hashtbl.create 16
 
 (* Print-to-current-output function, used everywhere.  It has
  * printf-like semantics.

generator/tests_c_api.ml

@@ -64,7 +64,7 @@ let rec generate_c_api_tests () =
   pr "  size_t i;\n";
   pr "  const char *no_tests[] = {\n";
 
-  let hash : (string, bool) Hashtbl.t = Hashtbl.create 13 in
+  let hash : (string, bool) Hashtbl.t = Hashtbl.create 16 in
   List.iter (
     fun { tests } ->
       let seqs = List.filter_map (

generator/utils.ml

@@ -109,7 +109,7 @@ let rstructs_used_by functions =
     | RStructListOnly, RStructListOnly -> RStructListOnly
   in
 
-  let h = Hashtbl.create 13 in
+  let h = Hashtbl.create 16 in
 
   (* if elem->oldv exists, update entry using ||| operator,
    * else just add elem->newv to the hash