This is GCC with the patches from CodeSourcery and Sun Microsystems used in the gcc 3.4.3 shipped with Solaris on the codesourcery/* and sun/* branches, and the GCCFSS sources from the git repository in their source tarball in the sun/gccfss* branches.
The il-* branches contain the Solaris patches rebased forward across GCC versions in an attempt to bring them up to date. All stupidity in the merges is mine.