S/390: Add vector pack/unpack patterns.

S/390: Add vector pack/unpack patterns.

gcc/ChangeLog:

2016-12-02  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* config/s390/vector.md (vec_halfhalf): New mode iterator.
	("vec_pack_trunc_<mode>", "vec_pack_ssat_<mode>")
	("vec_pack_usat_<mode>", "vec_unpacks_hi_v16qi")
	("vec_unpacks_low_v16qi", "vec_unpacku_hi_v16qi")
	("vec_unpacku_low_v16qi", "vec_unpacks_hi_v8hi")
	("vec_unpacks_lo_v8hi", "vec_unpacku_hi_v8hi")
	("vec_unpacku_lo_v8hi", "vec_unpacks_hi_v4si")
	("vec_unpacks_lo_v4si", "vec_unpacku_hi_v4si")
	("vec_unpacku_lo_v4si"): New pattern definitions.
	* config/s390/vx-builtins.md: Move VI_HW_HSD mode iterator to
	vector.md.

From-SVN: r243157