With these changes, the binutils mostly work on the Alpha, except for
objdump -r.
* coffswap.h: Added macros used when accessing several fields;
default is the same as before.
(coff_swap_aouthdr_{in,out}): Handle the Alpha ECOFF fields.
* coff-alpha.c: Defined macros to use the right sizes in
coffswap.h.
* libecoff.h: Backend information is now in target vector, not
BFD. Start of backend information is COFF backend information.
* coff-alpha.c, coff-mips.c: Changed accordingly.
* ecoff.c (ecoff_mkobject): New function.
(ARMAP_START): Changed into backend information, since Alpha uses
a different name.
(ecoff_slurp_armap): Don't overlay archive header.
* bfd.c: Include libcoff.h.