bug in gnatgpl 2015?

[Leo Brewin <leo.brewin@internode.on.net>]

Greetings,

I've run into what I think is a bug in gnatgpl 2015.
I wonder if others could confirm the bug?

I've tried to make the code as short as possible while still
capturing the alleged bug.

Using gnatgpl 2015 from Adacore, I get

   gnatmake crash.adb

      gcc -c crash.adb

      raised CONSTRAINT_ERROR : erroneous memory access
      gnatmake: "crash.adb" compilation error

and on occassions a detailed report (too long to include here but will
be sent to Adacore if need be).

I get no problems when using Simon's gcc-5.1.0 compiler.

I'm using MacOSX 10.10.5 with the command line tools from Xcode 6.4.

Cheers,
Leo

Here are the two packages,
   crash.adb/crash.ads
   simplex.adb/simplex.ads

-- crash.ads --------------------------
   package crash is
      procedure foo;
   end crash;

-- crash.adb --------------------------
   with simplex;

   package body crash is

      package std_lattice is new Simplex (n_head_max => 50);

      use std_lattice;

      procedure foo is
      begin
         null;
      end foo;

   end crash;

-- simplex.ads ------------------------
   generic

      n_head_max : Integer := 5;

   package Simplex is

      procedure deallocate;
      type myArray1dIntg is array (Integer range <>) of Integer;
      type myArray1dIntg_ptr is access myArray1dIntg;

   private

      head_ptr : myArray1dIntg_ptr := new myArray1dIntg (0 .. 1);

      head     : myArray1dIntg renames head_ptr.all;

   end Simplex;

-- simplex.adb ------------------------
   package body Simplex is

      procedure deallocate is
      begin
         null;
      end deallocate;

      procedure clear is
      begin
         head (1) := 1;
      end clear;

      procedure add is
      begin
         head (1) := 1;
      end add;

   end Simplex;