S/390: arch12: New vector popcount variants

S/390: arch12: New vector popcount variants

arch12 provides pop count vector instructions for bigger elements than
just chars.

gcc/testsuite/ChangeLog:

2017-03-24  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* gcc.target/s390/vxe/popcount-1.c: New test.

gcc/ChangeLog:

2017-03-24  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>

	* config/s390/vector.md ("popcountv16qi2", "popcountv8hi2")
	("popcountv4si2", "popcountv2di2"): Rename to ...
	("popcount<mode>2", "popcountv8hi2_vx", "popcountv4si2_vx")
	("popcountv2di2_vx"): ... these and add !TARGET_VXE to the
	condition.
	("popcount<mode>2_vxe"): New pattern.

From-SVN: r246454