[Bug ada/83027] Hang when attaching a SIGINT handler

[porton at narod dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83027

--- Comment #4 from Victor Porton <porton at narod dot ru> ---
If I remove `with "ahven";` from spawn_tests.gpr the bug disappears.

Seems to do something with elaboration order.

I also deleted `with "anet";` from spawn_common.gpr without any effect on the
bug.

I will attach bug2.zip without `with "anet";` (but with `with "ahven";`).