Make output views accessible to Target during do_relocate().

Make output views accessible to Target during do_relocate().

gold/
	* object.cc (Sized_relobj_file::Sized_relobj_file): Initialize
	output_views_.
	* object.h (Object::get_output_view): New function.
	(Object::do_get_output_view): New function.
	(Sized_relobj_file::do_get_output_view): New function.
	(Sized_relobj_file::output_views_): New data member.
	* reloc.cc: (Sized_relobj_file::do_relocate): Store pointer to
	output views in class object.
	(Sized_relobj_file::do_get_output_view): New function.