PR 33385 vms archives

PR 33385 vms archives

Commit 5c4ce239a3ab "Tidy bfdio to consistenly use containing archive"
broke vms archive handling, which has some horrible hacks involving
use of a special iovec for archive elements.  Modify the generic
archive handling code to not use the archive iovec when it differs
from the element iovec.

Also, various commits involving seek optimisation broke the vms
archive handling, which needs to see a rewind on an archive element.

	* bfdio.c (bfd_read, bfd_write, bfd_tell, bfd_flush),
	(bfd_stat, bfd_seek, bfd_mmap): Do not use the archive
	bfd for IO when the archive and element iovec differ.
	* plugin.c (bfd_plugin_open_input),
	(bfd_plugin_close_file_descriptor): Likewise.
	* vms-lib.c (vms_lib_bopen): Force bfd_seek to call iovec seek.