Use isl_schedule_node instead of isl_band_list for isl-0.15.
Passes regtest and bootstrap for isl-0.15 and isl-0.12.2 on x86_64-linux.

gcc/ChangeLog:

        * graphite-optimize-isl.c (get_schedule_for_node_st): New callback
          function to schedule based on isl_schedule_node.
        (get_schedule_map_st): New schedule optimizer based on isl_schedule_node.
        (scop_get_domains): New. Return the isl_union_set containing the domains of all the pbbs.
        (optimize_isl): Call the new function get_schedule_map_st for isl-0.15

gcc/testsuite/ChangeLog:

        * gcc.dg/graphite/block-0.c: Changed to match pattern.
        * gcc.dg/graphite/interchange-1.c: Same.
        * gcc.dg/graphite/interchange-10.c: Same.
        * gcc.dg/graphite/interchange-11.c: Same.
        * gcc.dg/graphite/interchange-13.c: Same.
        * gcc.dg/graphite/interchange-3.c: Same.
        * gcc.dg/graphite/interchange-4.c: Same.
        * gcc.dg/graphite/interchange-7.c: Same.
        * gcc.dg/graphite/interchange-9.c: Same.
        * gcc.dg/graphite/uns-interchange-9.c: Same.
        * gfortran.dg/graphite/interchange-3.f90: Same.

Co-Authored-By: Aditya Kumar <aditya.k7@samsung.com>

From-SVN: r229445