[Bug fortran/78659] [F03] Spurious "requires DTIO" reported against namelist statement

[jvdelisle at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78659

--- Comment #4 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
I have the ICE resolved, but also note that the Fortran 95 standard has the
constraint on namelist statements and F2003 does not.

Constraint - namelist-group-object shall not be an array dummy argument with a
nonconstant bound, a variable with nonconstant character length, an automatic
object, a pointer, a variable of a type that has an ultimate component that is
a pointer, or an allocatable array.

We can got two ways here, forget about the F95 standard and accept it, or give
an error with -std=f95. This is sort of troublsome because we have to maintain
two or more behaviors if a user wants to check against F95.  I wonder if we
should get rid of the -std=f95 altogether and just keep -std=F2003 or similar.

Any opinions?