Re: Keeping track of rs6000-coff archive element pointers

Re: Keeping track of rs6000-coff archive element pointers

Commit de7b90610e9e left a hole in the element checking, explained by
the comment added to _bfd_xcoff_openr_next_archived_file.  While
fixing this, tidy some types used to hold unsigned values so that
casts are not needed to avoid signed/unsigned comparison warnings.
Also tidy a few things in xcoff.h.

bfd/
	* coff-rs6000.c (_bfd_xcoff_openr_next_archived_file): Check
	that we aren't pointing back at the last element.  Make
	filestart a ufile_ptr.  Update for xcoff_artdata change.
	(_bfd_strntol, _bfd_strntoll): Return unsigned values.
	(_bfd_xcoff_slurp_armap): Make off a ufile_ptr.
	(add_ranges): Update for xcoff_artdata change.
	* libbfd-in.h (struct artdata): Make first_file_filepos a
	ufile_ptr.
	* libbfd.h: Regenerate.
include/
	* coff/xcoff.h (struct xcoff_artdata): Replace min_elt with
	ar_hdr_size.
	(xcoff_big_format_p): In the !SMALL_ARCHIVE case return true
	for anything but a small archive.