The current implementation of glibc_have_ssp() on amd64 is borked. It seems to be only a typo. Patch attached that solves compilation problems with CFLAGS containing "-fstack-protector" for me. BTW: Can't that conditional construct for amd64 inside this subroutine be wiped out ? libc.so.6 resides in /lib/ on amd64 as well because /lib is a symlink to /lib64 on amd64...
Created attachment 28624 [details, diff] Patch for sys-devel/gcc-3.3.3.ebuild to allow proper check whether __guard and __stack_smash_handler reside in libc.so.6
Killed that construct, thanks.