(relax_segment): If md_relax_frag is defined, use it to handle a
frag of type rs_machine_dependent rather than looking through
md_relax_table.
* write.c (relax_and_size_seg): Don't set SEC_HAS_CONTENTS for a
bss section. Set SEC_RELOC if there are any relocations, even for
a zero size section.
* write.c (write_relocs): In RELOC_EXPANSION_POSSIBLE case, based
data offset on reloc[0]->address rather than reloc[j]->address, so
that multiple relocs can affect different memory locations.
* write.c (chain_frchains_together, relax_and_size_seg,
adjust_reloc_syms, write_relocs): Make third argument PTR, not
char *, to match definition of bfd_map_over_sections.