[PR fortran/71203, patch] - ICE on zero-length arrays or substrings

[Thomas Koenig]

Hi Harald,

> To the reviewer: I am not 100% sure that my solution is correct, but it
> solves the issues reported and regtests cleanly on x86_64-pc-linux-gnu.
> 
> OK for trunk?  Backports?

I don't see how adding the charlen to the current namespace can hurt,
so I think this is OK.

Regarding backports:  I don't think we need to backport every bug fix
if does not fix a regression.  (Officially, we are not even
supposed to fix non-regressions on trunk at this point, but in practice
this means that we should take care not to introduce risky patches.
gfortran is not release critical, so we are free to break our own
compiler without holding up all of gcc).

Regards

	Thomas