arm: Implement vec_perm and vec_perm_const for NEON.

	* config/arm/arm.c (arm_vectorize_vec_perm_const_ok,
	TARGET_VECTORIZE_VEC_PERM_CONST_OK, neon_split_vcombine, MAX_VECT_LEN,
	struct expand_vec_perm_d, arm_expand_vec_perm_1, arm_expand_vec_perm,
	arm_evpc_neon_vuzp, arm_evpc_neon_vzip, arm_evpc_neon_vrev,
	arm_evpc_neon_vtrn, arm_evpc_neon_vtbl, arm_expand_vec_perm_const_1,
	arm_expand_vec_perm_const): New.
	* config/arm/arm-protos.h: Update.
	* config/arm/neon.md (UNSPEC_VCONCAT): New.
	(*neon_vswp<VDQX>): New.
	(neon_vcombine<VDX>): Use neon_split_vcombine.
	(neon_vtbl1v16qi, neon_vtbl2v16qi, neon_vcombinev16qi): New.
	* config/arm/vec-common.md (vec_perm_const<VALL>): New.
	(vec_perm<VE>): New.

testsuite/
	* lib/target-supports.exp (check_effective_target_vect_perm,
	check_effective_target_vect_perm_byte,
	check_effective_target_vect_perm_short): Enable for arm neon.

From-SVN: r183051