[Bug fortran/30438] Set but never used variable should raise warning

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=30438

--- Comment #9 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
*** Bug 33884 has been marked as a duplicate of this bug. ***