ld -z combreloc elf_link_sort_relocs

A linker script may put .rela.plt in with other .rela.dyn relocs.
The change to elf_reloc_type_class puts any PLT relocs last.  This
patch makes the input section layout better match the sorted relocs.

	* elflink.c (elf_link_sort_relocs): Wrap overlong lines.  Fix
	octets_per_byte.  Put dynamic .rela.plt last in link orders.
	Assign output_offset for reloc sections rather than writing
	sorted relocs from block corresponding to output_offset.