I don't see a clean way to address this problem. We don't know the
section is going to be discarded in check_relocs, where we initially
collect the information. In size_dynamic_sections, we can't get to
the local symbol/section table of the bfd to tell whether the section
was discarded either. Then, in relocate_section, the relocation was
already modified and we can't get back the information we need to tell
which entry we should get the information from. So I'm just punting
at it and disabling the warning at this point. If it turns out that
we emit a different number of dynamic relocations than initially
estimated, we'll still get a warning.
Anyhow... Here's the patch. Ok?