[Bug fortran/67614] ICE on using arithmetic if with null

[gerhard.steinmetz.fortran@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67614

--- Comment #4 from Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de> ---
In general, a future extension to check pointer status
looks promising (at compile time and runtime).

With a tiny and simple source the problem is clear and
obvious, but for large and complex codes often not.