Add GCC 12.1 https://gcc.gnu.org/gcc-12/
The following patches from GCC 11.3.0 are no longer needed:
- 0005-arc-Update-ZOL-pattern.patch
- 0006-arc-Update-u-maddhisi4-patterns.patch
- 0007-arc-Fix-maddhisi-patterns.patch
- 0008-Darwin-aarch64-Initial-support-for-the-self-host-dri.patch
- 0009-libstdc-Check-for-TLS-support-on-mingw-cross-compile.patch
One new patch is needed to avoid issues building sh-unknown-elf:
- 0006-sh-Avoid-mb-m1-multilib-combination.patch
It is also necessary to build all-build-libcpp. This target exists as
far back as GCC 6 so has been done unconditionally.
Signed-off-by: Chris Packham <judge.packham@gmail.com>