* configure.ac: Add check for new options in isl-0.15.
	* config.in, configure: Rebuilt.
	* graphite-blocking.c: Include <isl/constraint.h>
	* graphite-interchange.c,  graphite-poly.c: Likewise.
	* graphhite-scop-detection.c, graphite-sese-to-poly.c: Likewise.
	* graphite.c: Likewise.
	* graphite-isl-ast-to-gimple.c: Include <isl/constraint.h> and
	<isl/union_set.h>.
	* graphite-dependences.c: Include <isl/constraint.h>.
	(max_number_of_out_dimensions): Returns isl_stat.
	(extend_schedule_1): Likewise
	(extend_schedule): Corresponding changes.
	* graphite-optimize-isl.c: Include <isl/constraint.h> and
	<isl/union_set.h>.
	(getSingleMap): Change return type of isl_stat.
	(optimize_isl): Conditionally use
	isl_options_set_schedule_serialize_sccs.
	* graphite-poly.h (isl_stat, isl_stat_ok): Define fallbacks
	if not HAVE_ISL_OPTIONS_SET_SCHEDULE_SERIALIZE_SCCS.

Co-Authored-By: Bernhard Reutner-Fischer <aldot@gcc.gnu.org>

From-SVN: r226050