I have a production server based on 12.04 LTS and I need to somehow install a newer gcc version -- specifically 5.3.1 -- alongside the existing gcc (4.6.3). Is there a repository containing these packages already somewhere?

I was looking here: https://launchpad.net/~ubuntu-toolch...filter=precise but I see only 4.x and 5.4.

Also, I could try to compile it by hand following the LFS guide but then I have no multilib support which I need.

Thank you,