Update loongson vector reductions.

Update loongson vector reductions.

2015-11-06  Simon Dardis  <simon.dardis@imgtec.com>

        * config/mips/loongson.md (vec_loongson_extract_lo_<mode>): New, extract
        low part to scalar.
        (reduc_uplus_<mode>): Remove.
        (reduc_plus_scal_<mode>): Rename from reduc_splus_<mode>, Use vec
        loongson_extract_lo_<mode>.
        (reduc_smax_scal_<mode>, reduc_smin_scal_<mode>): Rename from
        reduc_smax_<mode>, reduc_smax_<mode>, use vec
        loongson_extract_lo_<mode>.
        (reduc_umax_scal_<mode>, reduc_umin_scal_<mode>): Rename.

From-SVN: r229844