re PR tree-optimization/18009 (ICE in vect_transform_stmt, at tree-vectorizer.c:2625 (testcase included))

        PR tree-optimization/18009
        * tree-vectorizer.h (enum dr_alignment_support): New type.
        (MAX_NUMBER_OF_UNALIGNED_DATA_REFS): Removed.
        (LOOP_UNALIGNED_DR): replaced with LOOP_VINFO_UNALIGNED_DR and holds a
        single data_reference (instead of a varray of references).
        * tree-vectorizer.c (new_loop_vec_info): Likewise.
        (vect_gen_niters_for_prolog_loop): Likewise.
        (vect_update_inits_of_drs): Likewise.

        (vect_update_inits_of_drs): Setting of DR_MISALIGNMENT moved to
        vect_enhance_data_refs_alignment.
        (vect_do_peeling_for_alignment): Likewise.
        (vect_enhance_data_refs_alignment): Decide if and by how much to peel;
        this functionality used to be in vect_analyze_data_refs_alignment.
        Also update DR_MISALIGNMENT due to peeling; this functionality used to
        be in vect_update_inits_of_drs and vect_do_peeling_for_alignment).
        (vect_analyze_data_refs_alignment): Decision on whether and by how much
        to peel moved to vect_enhance_data_refs_alignment. Call
        vect_supportable_dr_alignment.

        (vect_compute_data_ref_alignment): Set STMT_VINFO_VECTYPE.
        (vect_compute_data_refs_alignment): Return bool. Consider return value
        of vect_compute_data_ref_alignment and return true/false accordingly.
        (vect_enhance_data_refs_alignment): Consider return value of
        vect_compute_data_refs_alignment and return true/false accordingly.

        (vect_supportable_dr_alignment): New function.
        (vectorizable_store): Call vect_supportable_dr_alignment.
        (vectorizable_load): Call vect_supportable_dr_alignment. Alignment
        support checks moved from here to vect_supportable_dr_alignment.

        (vect_transform_loop): Avoid 80 columns overflow.

From-SVN: r90051