gcc got rid of this target macro in 2003, so it seems safe to assume the
alternate path works fine on all targets.

libobjc/ChangeLog:

2015-11-03  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	PR libobjc/24775
	* encoding.c (objc_layout_finish_structure): Remove usage of
	ROUND_TYPE_SIZE.

From-SVN: r229727