Listing deprecated targets in changes.html

[Eric Gallager]

Hi, I see that a number of targets are going to be deprecated for GCC 12:
- m32r{,le}-linux:
https://gcc.gnu.org/pipermail/gcc-patches/2021-September/579265.html
- cr16: https://gcc.gnu.org/pipermail/gcc-patches/2021-September/579280.html
- m68k-openbsd:
https://gcc.gnu.org/pipermail/gcc-patches/2021-September/579298.html
- vax-openbsd: https://gcc.gnu.org/pipermail/gcc-patches/2021-September/579299.html
However, none of these targets are listed in the changes page for GCC 12 yet:
https://gcc.gnu.org/gcc-12/changes.html
I would encourage people involved with these patches to list these
deprecations on the changes page ASAP, so that people can have time to
prepare for the impending deprecations.
Thanks,
Eric Gallager