struct ira_reg_equiv_s's "init_insns" is an rtx_insn_list

struct ira_reg_equiv_s's "init_insns" is an rtx_insn_list

gcc/ChangeLog:
2014-09-09  David Malcolm  <dmalcolm@redhat.com>

	* ira.c (ira_update_equiv_info_by_shuffle_insn): Use NULL rather
	than NULL_RTX.
	(no_equiv): Likewise.
	(update_equiv_regs): Likewise.
	(setup_reg_equiv): Likewise.  Strengthen locals "elem",
	"prev_elem", "next_elem" from rtx to rtx_insn_list *, and "insn"
	from rtx to rtx_insn *.  Use methods of "elem" for typesafety and
	clarity.
	* ira.h (struct ira_reg_equiv_s): Strengthen field "init_insns"
	from rtx to rtx_insn_list *.
	* lra-assigns.c (spill_for): Strengthen local "x" from rtx to
	rtx_insn_list * and use methods for clarity and typesafety.
	* lra-constraints.c (contains_deleted_insn_p): Likewise for param
	"list".
	(init_insn_rhs_dead_pseudo_p): Likewise for local "insns".  Remove
	redundant check on INSN_P (insns): this cannot hold, as "insns" is
	an INSN_LIST, not an insn.
	(reverse_equiv_p): Strengthen local "insns" from rtx to
	rtx_insn_list * and use methods for clarity and typesafety.
	(contains_reloaded_insn_p): Likewise for local "list".

From-SVN: r215082