rs6000.h: Add conditional preprocessing directives to disable Power9-specific compiler...

gcc/ChangeLog:

2016-06-21  Kelvin Nilsen  <kelvin@gcc.gnu.org>

	* config/rs6000/rs6000.h: Add conditional preprocessing directives
	to disable Power9-specific compiler features if HAVE_AS_POWER9 is
	not defined.

gcc/testsuite/ChangeLog:

2016-06-21  Kelvin Nilsen  <kelvin@gcc.gnu.org>

	* gcc.target/powerpc/darn-0.c: Add dejagnu directives to disable
	test if effective-target is not powerpc_p9vector_ok, or if a -mcpu
	override other than -mcpu=power9 command-line option is specified,
	or if the target operating system is aix.
	* gcc.target/powerpc/darn-1.c: Likewise.
	* gcc.target/powerpc/darn-2.c: Likewise.
	* gcc.target/powerpc/vslv-0.c: Add dejagnu directives to disable
	test if effective-target is not powerpc_p9vector_ok or if the
	target operating system is not defined.
	* gcc.target/powerpc/vslv-1.c: Likewise.
	* gcc.target/powerpc/vsrv-0.c: Likewise.
	* gcc.target/powerpc/vsrv-1.c: Likewise.

From-SVN: r237659