ira.c (setup_allocno_and_important_classes): Use ira_class_hard_regs_num to check whether a class has any allocatable registers.

gcc/
	* ira.c (setup_allocno_and_important_classes): Use
	ira_class_hard_regs_num to check whether a class has any
	allocatable registers.
	(ira_init_register_move_cost): Likewise.

From-SVN: r188045