alpha: Cleaup builtins and folding

alpha: Cleaup builtins and folding

        * config/alpha/alpha.c (alpha_dimode_u): New.
        (alpha_init_builtins): Initialize it, and use it.
        (alpha_fold_builtin_cmpbge): Use alpha_dimode_u.
        (alpha_fold_builtin_zapnot, alpha_fold_builtin_insxx): Likewise.
        (alpha_fold_vector_minmax, alpha_fold_builtin_perr): Likewise.
        (alpha_fold_builtin_pklb, alpha_fold_builtin_pkwb): Likewise.
        (alpha_fold_builtin_unpkbl, alpha_fold_builtin_unpkbw): Likewise.
        (alpha_fold_builtin_cttz, alpha_fold_builtin_ctlz): Likewise.
        (alpha_fold_builtin_ctpop): Likewise.
        (alpha_fold_builtin_umulh): Remove.
        (alpha_fold_builtin): Use MULT_HIGHPART_EXPR for UMULH; fix
        typo in MAX_ARGS check.

From-SVN: r189028