generator: Add 'added' (version when added) field.

generator/actions.ml

@@ -24,7 +24,9 @@ open Utils
 (* Default settings for all action fields.  So we copy and override
  * this struct by writing '{ defaults with name = &c }'
  *)
-let defaults = { name = ""; style = RErr, [], []; proc_nr = None;
+let defaults = { name = "";
+                 added = (-1,-1,-1);
+                 style = RErr, [], []; proc_nr = None;
                  tests = []; test_excuse = "";
                  shortdesc = ""; longdesc = "";
                  protocol_limit_warning = false; fish_alias = [];

generator/types.ml

@@ -330,9 +330,12 @@ type visibility =
   | VDebug                        (* Exported everywhere, but not documented *)
   | VInternal                     (* Not exported *)
 
+type version = int * int * int
+
 (* Type of an action as declared in Actions module. *)
 type action = {
   name : string;                  (* name, not including "guestfs_" *)
+  added : version;                (* which version was the API first added *)
   style : style;                  (* args and return value *)
   proc_nr : int option;           (* proc number, None for non-daemon *)
   tests : c_api_tests;            (* C API tests *)