Relocations
===========
BFD maintains relocations in much the same way it maintains symbols:
they are left alone until required, then read in en-masse and
translated into an internal form. A common routine
`bfd_perform_relocation' acts upon the canonical form to do the fixup.
Relocations are maintained on a per section basis, while symbols are
maintained on a per BFD basis.
All that a back end has to do to fit the BFD interface is to create
a `struct reloc_cache_entry' for each relocation in a particular
section, and fill in the right bits of the structures.