There is now a NO_BINUTILS221 option, added by Sascha Wildner, that will keep your system from building binutils 2.21 during a buildworld.  The system will still build binutils 2.22, so there will still be a functioning ld on the system.  Use this along with NO_GCC41 (so only gcc 4.4 gets built) to speed up your buildworlds, if you like.