bt-load.c: Use rtx_insn

bt-load.c: Use rtx_insn

gcc/
2014-08-21  David Malcolm  <dmalcolm@redhat.com>

	* bt-load.c (struct btr_user_s): Strengthen field "insn" from rtx
	to rtx_insn *.
	(struct btr_def_s): Likewise.
	(insn_sets_btr_p): Strengthen param "insn" from const_rtx to
	const rtx_insn *.
	(add_btr_def): Likewise.
	(new_btr_user): Likewise.
	(compute_defs_uses_and_gen): Strengthen locals "insn", "last" from
	rtx to rtx_insn *.
	(link_btr_uses): Likewise.
	(move_btr_def): Likewise for locals "insp", "old_insn",
	"new_insn".  Add checked cast to rtx_insn * for now on result of
	gen_move_insn.
	(can_move_up): Strengthen param "insn" from const_rtx to
	const rtx_insn *.

From-SVN: r214287