CONF_LD_LINKER_OPTS_STAGE* are unused?

It seems the CONF_LD_LINKER_OPTS_STAGE0 variables are unused. We use $CC to link and the right option to pass linker options is CONF_GCC_LINKER_OPTS_STAGE0which ends up in the --info file as ("C compiler link flags","")`.

There is logic in hadrian for linking things with Ld directly but I couldn't find any direct rules which used this builder.

It would be good to remove these flags from the configure script as they probably just add confusion.