PATCH: Support Sun symbol versioning in libstdc++-v3

[Paolo Carlini]

Hi,
> * The only symbols missing from the Sun ld created library are those
>   using symbol renaming with gas' .symver directive.  Since this doesn't
>   work with Sun ld, there's a configure test to disable it and the
>   symbols are thus missing.  I don't yet know how to deal with this:
>   having the same version name include different symbols depending on
>   the linker used isn't exactly a brilliant idea.
>
>   I think it's best to disable this wholesale, even with GNU ld.  I've
>   performed the following little experiment that proves that it doesn't
>   work under any circumstances, so it serves no useful purpose, and the
>   Sun linker maintainers have stated they have no intention of
>   supporting this any time soon, neither in ld nor in ld.so.1.  This has
>   the pleasant side effect that there will be no difference in symbol
>   versions irrespective of the linker used.
>   
before anything else, please double check this part with Jakub, he took
care of that fix for a mistake we did with versioning. If you could just
deal with this issue separately, and leave things as they are for
binutils, I think that would speed up the final approval a lot, if you
ask me...

Paolo.