* elf32-mips.c: Extensive changes for a start at dynamic linking

	* elf32-mips.c: Extensive changes for a start at dynamic linking
	support, from Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.

	* elf-bfd.h (struct elf_backend_data): Add type_change_ok field.
	(struct elf_backend_data): Remove
	elf_backend_create_program_headers field.  Add
	elf_backend_additional_program_headers and
	elf_backend_modify_segment_map fields.
	* elfxx-target.h (elf_backend_type_change_ok): Define if not
	defined.
	(elf_backend_additional_program_headers): Likewise.
	(elf_backend_modify_segment_map): Likewise.
	(elf_backend_create_program_headers): Don't define.
	(elfNN_bed): Change to account for field changes.
	* elf.c (assign_file_positions_for_segments): Call new
	modify_segment_map backend function.  Don't call old
	create_program_headers backend function.
	(get_program_header_size): Call additional_program_headers rather
	than create_program_headers.
	* elflink.h (elf_link_add_object_symbols): Initialize
	type_change_ok from new backend field.
	(elf_link_output_extsym): Don't warn if _rld_new_interface is
	defined.
	(elf_reloc_link_order): Treat a reloc against a defined symbol as
	a reloc against the appropriate section.