[patch,fortran] Allow namelist with internal file (PR 28224)

[Tobias Burnus]

Hi,

Paul Thomas schrieb:
> Might it not be better to use -std=f95 for this test....
>>     * gfortran.dg/namelist_internal.f90: New namelist test.
>>     * gfortran.dg/namelist_internal2.f90: New namelist test.   
> ...and to drop this latter?
Well, the first test test whether internal file read/write of namelists
works.
The second test tests whether it is still forbidden for -std=f95.

I can drop either test, but I cannot simply change -std=f2003 to
-std=f95 in the first test; doing all the modifications needed, I will
end up with the second test.

That is anyhow the question: How much should one test? Only a minimal
set, which will get easily broken or also more extensively the behaviour
of a function, even if it is unlikely that a regression occurs?
The former prevents bloating, the latter reduces the chance of more
unlikely regressions.

In this regard, shall I check in namelist_internal.f90 or
namelist_internal2.f90 or both?
(If only namelist_internal2.f90, I will rename it to namelist_internal.f90.)

Tobias