* config/avr/avr.c (out_shift_with_cnt): Genetare a more optimal
	shift cycle for unknown shift count. Also generates dec + brpl.
	(ashlqi3_out): Don't generate dec + brpl which now generates by
	`out_shift_with_cnt'.
	(ashlhi3_out): Likewise.
	(ashlsi3_out): Likewise.
	(ashrqi3_out): Likewise.
	(ashrhi3_out): Likewise.
	(ashrsi3_out): Likewise.
	(lshrqi3_out): Likewise.
	(lshrhi3_out): Likewise.
	(lshrsi3_out): Likewise.

From-SVN: r33700