Add sparc vec_perm patterns when VIS2.

	* config/sparc/sparc.md (vec_perm_constv8qi, vec_perm<mode>): New
	patterns.
	* config/sparc/sparc.c (sparc_expand_vec_perm_bmask): New function.
	* config/sparc/sparc-protos.h (sparc_expand_vec_perm_bmask): Declare.

From-SVN: r180119