move dr->alias_set to a helper structure

move dr->alias_set to a helper structure

2015-10-06  Aditya Kumar  <aditya.k7@samsung.com>
                Sebastian Pop  <s.pop@samsung.com>

                * graphite-poly.c (new_scop): Initialize drs.
                * graphite-poly.h (struct dr_info): New.
                (struct scop): Add drs.
                * graphite-sese-to-poly.c (pdr_add_alias_set): Use dr_info.
                (pdr_add_memory_accesses): Same.
                (build_poly_dr): Same.
                (build_alias_set): Same.
                (build_scop_drs): Same.
                (build_pbb_drs): Remove.
                * tree-data-ref.c (create_data_ref): Do not initialize alias_set.
                * tree-data-ref.h (data_reference): Remove alias_set.

Co-Authored-By: Sebastian Pop <s.pop@samsung.com>
From-SVN: r228545