How to tell whether program finalization can be suppressed

[Simon Wright <simon@pushface.org>]

In Cortex GNAT RTS[1] (a Ravenscar RTS), I've wanted to support
finalization (at present, I have the possibly GNAT-specific
restriction No_Finalization).

Unfortunately, as reported in PR66205[2], without No_Finalization and
in the presence of other RTS-limiting features, gnatbind generates
binding code which won't compile.

I need to find a way of determining whether the RTS actually needs
program-level finalization (that is, finalization called on program
exit), because that's where the bad code is generated.

Clearly, if the program never exits, there will be no need for
program-level finalization.

Amongst other things, I can test for specific restrictions, and I'm
wondering whether No_Task_Termination would be appropriate for this?
(I'm assuming that the environment task mustn't terminate, even if the
main program exits; and in this RTS, exceptions can't be propagated).

[1] https://github.com/simonjwright/cortex-gnat-rts
[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66205