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

[tkoenig at gcc dot gnu.org]

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

--- Comment #12 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Created attachment 64573
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64573&action=edit
Incomplete first draft