[PATCH v2][PR libgfortran/78314] Fix ieee_support_halting

[FX]

Dear Nagy,

> it seems this broke ieee_8.f90 which tests compile time vs runtime value of ieee_support_halting
> if fortran needs this, then support_halting should be always false on arm and aarch64.
> but i'm not familiar enough with fortran to tell if there is some better workaround.

Can you XFAIL the test on your platform, open a PR and assign it to me?
This is a corner of the Fortran standard that is not entirely clear, and there have been some corrigenda on the topic, so I need to review it.

Thanks,
FX