* xcofflink.c (XCOFF_DEF_DYNAMIC): Rename from XCOFF_REF_DYNAMIC.

	* xcofflink.c (XCOFF_DEF_DYNAMIC): Rename from XCOFF_REF_DYNAMIC.
	Change all uses.
	(xcoff_swap_ldhdr_in): New static function.
	(xcoff_swap_ldsym_in): New static function.
	(xcoff_link_add_symbols): If we just created a descriptor, pass it
	to _bfd_generic_link_add_one_symbol, to save a hash lookup.
	(xcoff_link_add_dynamic_symbols): Rewrite to read .loader symbols
	rather than normal symbol table.
	(xcoff_mark): When considering called symbols, check whether the
	descriptor is from a dynamic object, rather than the symbol
	itself.
	(xcoff_build_ldsyms): Likewise.