Remove "collect" forms of generic linker add symbols functions

Remove "collect" forms of generic linker add symbols functions

Nothing calls them and they were in the way of a bug fix.

	* linker.c (generic_link_add_symbols): Delete.  Merge into..
	(_bfd_generic_link_add_symbols): ..here.
	(generic_link_check_archive_element_no_collect): Delete.
	(generic_link_check_archive_element_collect): Likewise.
	(generic_link_add_object_symbols): Remove "collect" param.  Update
	callers.
	(generic_link_add_symbol_list): Likewise.
	(generic_link_check_archive_element): Likewise.  Call
	bfd_link_add_symbols rather than generic_link_add_object_symbols.
	* libbfd-in.h (_bfd_generic_link_add_symbols_collect): Delete.
	* libbfd.h: Regenerate.