reg-stack.c: Use rtx_insn

reg-stack.c: Use rtx_insn

gcc/
	* reg-stack.c (next_flags_user): Strengthen return type and param
	"insn" from rtx to rtx_insn *.
	(straighten_stack): Likewise for param "insn".
	(check_asm_stack_operands): Likewise.
	(remove_regno_note): Likewise.
	(emit_pop_insn): Likewise for return type, param "insn", local
	"pop_insn".
	(emit_swap_insn):  Strengthen param "insn" and locals "i1", "tmp",
	"limit" from rtx to rtx_insn *.
	(swap_to_top): Likewise for param "insn".
	(move_for_stack_reg): Likewise.
	(move_nan_for_stack_reg): Likewise.
	(swap_rtx_condition): Likewise.
	(compare_for_stack_reg): Likewise.
	(subst_all_stack_regs_in_debug_insn): Likewise.
	(subst_stack_regs_pat): Likewise, and local "insn2".
	(subst_asm_stack_regs): Strengthen param "insn" from rtx to
	rtx_insn *.
	(subst_stack_regs): Likewise.
	(change_stack): Likewise.
	(convert_regs_1): Likewise for locals "insn", "next".

From-SVN: r214365