Extend objdump's --dwarf=follow-links option so that separate debug info files will also be affected by other dump function, and symbol tables from separate debug info files will be used when disassembling the main file.

	* objdump.c (sym_ok): New function.
	(find_symbol_for_address): Use new function.
	(disassemble_section): Compare sections by name, not pointer.
	(dump_dwarf): Move code to initialise byte_get pointer and iterate
	over separate debug files from here to ...
	(dump_bfd): ... here.  Add parameter indicating that a separate
	debug info file is being dumped.  For main file, pull in the
	symbol tables from all separate debug info files.
	(display_object): Update call to dump_bfd.
	* doc/binutils.texi: Document extened behaviour of the
	--dwarf=follow-links option.
	* NEWS: Mention this new feature.
	* testsuite/binutils-all/objdump.WK2: Update expected output.
	* testsuite/binutils-all/objdump.exp (test_follow_debuglink): Add
	options and dump file parameters.
	Add extra test.
	* testsuite/binutils-all/objdump.WK3: New file.
	* testsuite/binutils-all/readelf.exp: Change expected output for
	readelf -wKis test.
	* testsuite/binutils-all/readelf.wKis: New file.