bfd_read and bfd_write

[Alan Modra]

I have a (rather large) patch to clean up a few things in bfd that I'd
like to apply in the next day or so, but first thought I'd better give
people fair warning and a chance to object.

One of the changes I've made is to bfd_read, and similarly bfd_write.

 bfd_size_type
-bfd_read (ptr, size, nitems, abfd)
+bfd_read (ptr, size, abfd)
      PTR ptr;
      bfd_size_type size;
-     bfd_size_type nitems;
      bfd *abfd;

Why the change?  Well, in having both "size" and "nitems", you'd expect
bfd_read to behave like fread, but it doesn't.  bfd_read returns
"size * nitems" on success, whereas fread returns "nitems".  Additionally,
many places in bfd swap the "size" and "nitems" args, and technically
we should always have size == 1 since we are operating on files of bytes.
This doesn't really matter as bfd_read does the multiplication and
passes size == 1 down to fread, but we're breaking the fread abstraction.

This change will of course break gdb, for which I have patches, and
any uncontributed ports.

Comments/flames?

Alan