Please add a gold USE flag to enable the experimental gold linker and allow it to be tested more easily. All that's needed is to add --enable-gold to $myconf in toolchain-binutils_src_compile(). Since it's experimental it would be a good idea to add a note saying it's unsupported, and it should also be disabled by default (i.e. IUSE="-gold"). BTW, other distributions offer gold (e.g. debian offers binutils-gold in experimental), so it's not unheard of :)
in the mean time, you can use EXTRA_ECONF
added to the binutils eclass
As of binutils-2.20.51.3, gold is still filtered.
toolchain-binutils.eclass needs to be changed to search in configure script not "enable-gold=both/ld" and "enable-gold=both/bfd", but just "enable-gold"
new issue -> new bug