Even if I bootstrap gcc with --disable-tls to work around PR gold/12990, A large majority of them seems to be 64-bit EH-related. I haven't yet investigated in detail what's going on there, but there are some possible candidates, e.g. PR ld/12253 or the use of SHT_PROGBITS, not SHT_AMD64_UNWIND/SHT_X86_64_UNWIND for .eh_frame/.eh_frame_hdr.
@ian: If you still need access to a Solaris system just let me know: http://www.opencsw.org/extend-it/signup/to-upstream-maintainers/