h8300.c (output_logical_op): Use extu.w if we are clearing the most significant byte.

	* config/h8300/h8300.c (output_logical_op): Use extu.w if we
	are clearing the most significant byte.
	(compute_logical_op_length): Update to reflect the change in
	output_logical_op.
	(compute_logical_op_cc): Likewise.

From-SVN: r60632