Make linker scripts and section ordering via --section-ordering-file or

Make linker scripts and section ordering via --section-ordering-file or
linker plugins work. This patch lets linker scripts take precedence.

2013-01-09  Sriraman Tallam  <tmsriram@google.com>

	* output.h (sort_attached_input_sections): Change to be public.
	* script-sections.cc
	(Output_section_definition::set_section_addresses): Sort
	attached input sections according to section order before linker
	script assigns section addresses.
	(Orphan_output_section::set_section_addresses): Sort
	attached input sections according to section order before linker
	script assigns section addresses.
	* Makefile.am (final_layout.sh): Use a simple linker script to
	check if section ordering still works.
	* Makefile.in: Regenerate.