* combine.c: Include obstack.h.

	* combine.c: Include obstack.h.
	(struct insn_link): Define.
	(uid_log_links): Adjust type.
	(FOR_EACH_LOG_LINK): New macro.
	(insn_link_obstack): Declare.
	(alloc_insn_link): Define.
	(create_log_links): Call it.  Use FOR_EACH_LOG_LINK and adjust
	type of link variables.
	(find_single_use, insn_a_feeds_b, combine_instructions): Likewise.
	(try_combine, record_promoted_values, distribute_notes): Likewise.
	(distribute_links): Likewise.  Tweak prototype.
	(clear_log_links): Delete.
	(adjust_for_new_dest): Call alloc_insn_link.
	* Makefile.in (combine.o): Depend on $(OBSTACK_H).

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@171993 138bc75d-0d04-0410-961f-82ee72b054a4