[Bug libfortran/80602] Reduce stack usage for blocked matmul

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80602

--- Comment #6 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
I just committed r248074 which I suspect is the same problem
(the fix for PR 80765).

If you could just upgrade to the most recent trunk (only
need to upgrade libgfortran, really) an check if the fix
also works for you, that would be great.