vsx.md (vsx_concat_<mode>): Add support for the ISA 3.0 MTVSRDD instruction.

vsx.md (vsx_concat_<mode>): Add support for the ISA 3.0 MTVSRDD instruction.

[gcc]
2016-08-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config/rs6000/vsx.md (vsx_concat_<mode>): Add support for the
	ISA 3.0 MTVSRDD instruction.
	(vsx_splat_<mode>): Change cpu type of MTVSRDD instruction to
	vecperm.

[gcc/testsuite]
2016-08-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* gcc.target/powerpc/vec-init-1.c: New tests to test various
	vector initialization options.
	* gcc.target/powerpc/vec-init-2.c: Likewise.
	* gcc.target/powerpc/vec-init-3.c: New test to make sure MTVSRDD
	is generated on ISA 3.0.

From-SVN: r239428