gnat bug, but which version?

[Nicolas Boulenguez <nicolas@debian.org>]

Dear collective wisdom,
the following source (originating in opentoken-6.0a-1) is
- rejected by gcc-4.9,
- accepted by GNAT-GPL-2014 and GNAT-Pro-7.3.1.
Is it valid Ada 2012?

package P is
   A : access constant Integer;
   procedure P (I : aliased in Integer);
end P;
package body P is
   procedure P (I : aliased in Integer) is
   begin
      A := I'Access;  --  non-local pointer cannot point to local object
   end P;
end P;