[Bug ada/64866] Lost visibility of package Interfaces after task or PO declaration

[simon at pushface dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64866

--- Comment #1 from simon at pushface dot org ---
This bug appears to be triggered because the RTS contains freertos.ads with

   private with Interfaces;
   package FreeRTOS with Pure is
      ...

s-taprob.ads and s-tposen.ads start with

   private with FreeRTOS.Mutexes;

and

   private with FreeRTOS.Queues;

respectively, so anything to do with protected types (or tasks) is going to
call in FreeRTOS.

If I remove the private, so I just have

   with Interfaces;
   package FreeRTOS with Pure is
      ...

then the bug goes away.

See also PR64548, with a similar problem and a similar workround.

I note that a-cobove.ads has a private with of Ada.Streams; might this lead to
similar problems?