https://gcc.gnu.org/gcc-12/changes.html

fedora-36 (rawhide) just started to use GCC 12, which we reject. (https://github.com/sagemath/sage/runs/4860062925)

On this ticket we change the spkg-configure.m4 scripts to allow gcc/gfortran 12.
We also add GCC 4.9.x (but not 4.8.x) to the reject list; this compiler was the reason to drop support for debian-jessie in #32947.

Upstream PRs:

• Offsetof needs cstddef in GCC 12 Singular/Singular#1128 (merged)

CC: @culler @dimpase @kiwifb @antonio-rojas

Component: packages: standard

Author: Matthias Koeppe

Branch/Commit: f27ff17

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/33187