Update to GCC 12 for development branch (RTEMS 6)

[Chris Johns]

On 10/5/2022 1:13 am, Sebastian Huber wrote:
> Hello Karel,
> 
> On 09/05/2022 17:09, Karel Gardas wrote:
>> I'm just curious is there any reason to use GCC from git (post release
>> version) and not vanilla 12.1 release tarball from gcc.gnu.org?
> 
> this makes it easier to pick up a GCC 12 release branch which includes fixes
> relevant to RTEMS users.

An area this makes complicated for RTEMS users is how to raise bug reports
against gcc. The gcc bug form lists versions so what do we use?

And thanks for the update to gcc12 all it takes to make it happen :)

Chris