Clean up final compilation warnings.

src/implementation/yaml-events-queue.adb

@@ -80,7 +80,7 @@ package body Yaml.Events.Queue is
      ((Data => Object.Data));
 
    function New_Queue return Reference is
-      Ptr : constant not null access Instance := new Instance;
+      Ptr : constant not null Instance_Access := new Instance;
    begin
       return Reference'(Ada.Finalization.Controlled with Data => Ptr);
    end New_Queue;
@@ -96,7 +96,7 @@ package body Yaml.Events.Queue is
    end Element;
 
    function As_Stream (Object : Reference'Class) return Stream_Reference is
-      Ptr : constant not null access Stream_Instance :=
+      Ptr : constant not null Stream_Instance_Access :=
         new Stream_Instance'(Refcount_Base with Buffer => Reference (Object),
                              Offset => 0);
    begin

src/implementation/yaml-events-store.adb

@@ -3,7 +3,7 @@
 
 package body Yaml.Events.Store is
    function New_Store return Reference is
-      Ptr : constant not null access Instance := new Instance;
+      Ptr : constant not null Instance_Access := new Instance;
    begin
       return (Ada.Finalization.Controlled with Data => Ptr);
    end New_Store;
@@ -208,7 +208,7 @@ package body Yaml.Events.Store is
 
    function Retrieve (Object : Reference'Class; Position : Anchor_Cursor)
                          return Stream_Reference is
-      Ptr : constant not null access Stream_Instance :=
+      Ptr : constant not null Stream_Instance_Access :=
         new Stream_Instance'(Refcount_Base with Object => Reference (Object),
                              Depth => 0, Current => Anchor_To_Index.Element
                                (Anchor_To_Index.Cursor (Position)).Position);
@@ -219,7 +219,7 @@ package body Yaml.Events.Store is
 
    function Retrieve (Object : Reference'Class; Position : Element_Cursor)
                       return Stream_Reference is
-      Ptr : constant not null access Stream_Instance :=
+      Ptr : constant not null Stream_Instance_Access :=
         new Stream_Instance'(Refcount_Base with Object => Reference (Object),
                              Depth => 0, Current => Positive (Position));
    begin

src/interface/yaml-events-queue.ads

@@ -5,6 +5,7 @@ private with Ada.Finalization;
 
 package Yaml.Events.Queue is
    type Instance is limited new Refcount_Base with private;
+   type Instance_Access is access all Instance'Class;
    type Reference is tagged private;
    type Accessor (Data : not null access Instance) is limited null record with
      Implicit_Dereference => Data;
@@ -27,6 +28,7 @@ package Yaml.Events.Queue is
                      return Element_Accessor;
 
    type Stream_Instance is new Refcount_Base with private;
+   type Stream_Instance_Access is access all Stream_Instance'Class;
    type Stream_Reference is tagged private;
    type Stream_Accessor (Data : not null access Stream_Instance) is limited
      null record with Implicit_Dereference => Data;

src/interface/yaml-events-store.ads

@@ -5,6 +5,7 @@ private with Ada.Containers.Hashed_Maps;
 
 package Yaml.Events.Store is
    type Instance is limited new Refcount_Base with private;
+   type Instance_Access is access all Instance'Class;
    type Reference is tagged private;
    type Optional_Reference is tagged private;
 
@@ -45,6 +46,8 @@ package Yaml.Events.Store is
    procedure Copy (Source : in Instance; Target : in out Instance);
 
    type Stream_Instance is limited new Refcount_Base with private;
+   type Stream_Instance_Access is access all Stream_Instance 'Class;
+
    type Stream_Reference is tagged private;
    type Optional_Stream_Reference is tagged private;
    type Stream_Accessor (Data : not null access Stream_Instance) is limited