[Bug fortran/56226] Add support for DEC UNION and MAP extensions

[joel.matz at horizonbtc dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56226

--- Comment #12 from Joel Matz <joel.matz at horizonbtc dot com> ---
I'll see if I can put together some unit tests. Thanks for the effort,