I recently updated a plugin to use the file descriptor directly. This 
worked fine in gold, but had two issues using bfd (nm and ar):

*) The filesize was not being set.
*) The code expected the claim_file callback to not seek.

That is not my understanding from reading the api documentation in 
http://gcc.gnu.org/wiki/whopr/driver, so the attached patch fixes both 
issues.

2010-02-08  Rafael Ávila de Espíndola <respindola@mozilla.com>

	* plugin.c (bfd_plugin_object_p): Correctly set the filesize
	and handle claim_file seeking.

Cheers,
Rafael