Add support for OCaml 4.13 (#250)

Add support for OCaml 4.13

ast/supported_version/supported_version.ml

@@ -12,6 +12,7 @@ let all =
   ; 4, 10
   ; 4, 11
   ; 4, 12
+  ; 4, 13
   ]
 
 let to_string (a, b) = Printf.sprintf "%d.%02d" a b

ast/versions.ml

@@ -485,6 +485,13 @@ module OCaml_412 = struct
   let string_version = "4.12"
 end
 let ocaml_412 : OCaml_412.types ocaml_version = (module OCaml_412)
+module OCaml_413 = struct
+  module Ast = Astlib.Ast_413
+  include Make_witness(Astlib.Ast_413)
+  let version = 413
+  let string_version = "4.13"
+end
+let ocaml_413 : OCaml_413.types ocaml_version = (module OCaml_413)
 (*$*)
 
 let all_versions : (module OCaml_version) list = [
@@ -501,6 +508,7 @@ let all_versions : (module OCaml_version) list = [
 (module OCaml_410 : OCaml_version);
 (module OCaml_411 : OCaml_version);
 (module OCaml_412 : OCaml_version);
+(module OCaml_413 : OCaml_version);
 (*$*)
 ]
 
@@ -529,6 +537,8 @@ include Register_migration(OCaml_410)(OCaml_411)
     (Astlib.Migrate_410_411)(Astlib.Migrate_411_410)
 include Register_migration(OCaml_411)(OCaml_412)
     (Astlib.Migrate_411_412)(Astlib.Migrate_412_411)
+include Register_migration(OCaml_412)(OCaml_413)
+    (Astlib.Migrate_412_413)(Astlib.Migrate_413_412)
 (*$*)
 
 module OCaml_current = OCaml_OCAML_VERSION

ast/versions.mli

@@ -126,6 +126,7 @@ module OCaml_409 : OCaml_version with module Ast = Astlib.Ast_409
 module OCaml_410 : OCaml_version with module Ast = Astlib.Ast_410
 module OCaml_411 : OCaml_version with module Ast = Astlib.Ast_411
 module OCaml_412 : OCaml_version with module Ast = Astlib.Ast_412
+module OCaml_413 : OCaml_version with module Ast = Astlib.Ast_413
 (*$*)
 
 (* An alias to the current compiler version *)