PR debug/66728
	* dwarf2out.c (get_full_len): Return a value based upon the actual
	precision needed for the value.
	(add_const_value_attribute): Use a maximal wide-int for
	CONST_WIDE_INTs, not VOIDmode.
	(output_die): Don't ever output NULL with printf.

	* rtl.h (get_precision of rtx_mode_t): Ensure we never process
	BLKmode nor VOIDmode values.

From-SVN: r229885