Support arbitrary length fill patterns.

	Support arbitrary length fill patterns.
	* linker.c (bfd_new_link_order): Zero all fields with bfd_zalloc.
	(_bfd_default_link_order): Remove bfd_fill_link_order code.
	Call default_data_link_order.
	(default_fill_link_order): Delete.
	(default_data_link_order): New function.
	* elf32-mips.c (_bfd_mips_elf_final_link): Replace occurrences
	of bfd_fill_link_order with bfd_data_link_order.
	* elf64-alpha.c (elf64_alpha_final_link): Likewise.
	* elf64-mips.c (mips_elf64_final_link): Likewise.