Rename vshuffle/vec_shuffle to vec_perm.

Rename vshuffle/vec_shuffle to vec_perm.

        * doc/extend.texi (__builtin_shuffle): Improve the description to
        include the modulus of the selector.  Mention OpenCL.
        * doc/md.texi (vec_perm, vec_perm_const): Document named patterns.

        * tree.def (VEC_PERM_EXPR): Rename from VEC_SHUFFLE_EXPR.
        * genopinit.c (optabs): Rename vshuffle to vec_perm.
        * c-typeck.c (c_build_vec_perm_expr): Rename from
        c_build_vec_shuffle_expr.  Update for name changes.
        * optabs.c (expand_vec_perm_expr_p): Rename from
        expand_vec_shuffle_expr_p.
        (expand_vec_perm_expr): Rename from expand_vec_shuffle_expr.
        * optabs.h (OTI_vec_perm): Rename from DOI_vshuffle.
        (vec_perm_optab): Rename from vshuffle_optab.
        * expr.c, gimple-pretty-print.c, gimple.c, gimplify.c,
        c-tree.h, c-parser.c, tree-cfg.c, tree-inline.c, tree-pretty-print.c,
        tree-ssa-operands.c, tree-vect-generic.c: Update for name changes.

        * config/i386/i386.c (ix86_expand_vec_perm): Rename from
        ix86_expand_vshuffle.
        * config/i386/i386-protos.h: Update.
        * config/i386/sse.md (VEC_PERM_AVX2): Rename from VSHUFFLE_AVX2.
        (vec_perm<VEC_PERM_AVX2>): Rename from vshuffle<VSHUFFLE_AVX2>.

From-SVN: r179701