Add option to ar's 't' command to display the offset of elements within the archive.

Add option to ar's 't' command to display the offset of elements within the archive.

	PR 23107
	* ar.c (display_offsets): New variable.
	(usage): Add description of 'O' operator.
	(decode_option): Handle 'O' operator.
	(print_descr): Pass display_offsets to print_arelt_descr.
	* arsup.c: Update call to printy_arelt_descr.
	* objdump.c: Likewise.
	* bucomm.c (print_arelt_descr): If offsets parameter is true then
	display offset of archive element within the archive.
	* bucomm.h: Update prototype for print_arelt_descr.
	* doc/binutils.texi: Update description of ar command.
	* NEWS: Mention the new feature.
	* testsuite/binutils-all/ar.exp: Add text of new feature.