If you want to see the patches go into the Debian/Ubuntu packages, run apt-get source php5 and look at the php5-$version/debian/patches directory. The build process uses a quilt wrapper (dh_quilt_patch) to apply them in the correct order. There are patches for building (in general or for a specific architecture), segmentation faults, security issues, manual pages and very few configuration changes (mostly just FHS compliance).
Fedora users have it easy, the packages there are mere days behind: https://admin.fedoraproject.org/updates/php
With a bit of experimenting you can easily do a network install of a headless Fedora/SL/CentOS in KVM using virt-install and a kickstart file. Use filesystem passthrough to access your source files, run php-fpm and configure its address as a backend in your web server. Keep SELinux enabled, but adjust it to your needs using setsebool if necessary.
I've tried Fedora in the past. I found it unstable and broken and I don't like RPM very much. It's undoubtedly improved since I last tried it (c. 2005-2006) but I don't miss RPM at all.