Enable Intel WBNOINVD instruction.

Enable Intel WBNOINVD instruction.

Intel has disclosed a set of new instructions for Icelake processor.
The spec is
https://software.intel.com/sites/default/files/managed/c5/15/architecture-instruction-set-extensions-programming-reference.pdf

This patch enables Intel WBNOINVD instruction.

gas/
	* config/tc-i386.c (cpu_arch): Add .wbnoinvd.
	* doc/c-i386.texi: Document .wbnoinvd.
	* testsuite/gas/i386/i386.exp: Add WBNOINVD tests.
	* testsuite/gas/i386/wbnoinvd-intel.d: New test.
	* testsuite/gas/i386/wbnoinvd.d: Likewise.
	* testsuite/gas/i386/wbnoinvd.s: Likewise.
	* testsuite/gas/i386/x86-64-wbnoinvd-intel.d: Likewise.
	* testsuite/gas/i386/x86-64-wbnoinvd.d: Likewise.
	* testsuite/gas/i386/x86-64-wbnoinvd.s: Likewise.
opcodes/
	* i386-dis.c (enum): Add PREFIX_0F09.
	* i386-gen.c (cpu_flag_init): Add CPU_WBNOINVD_FLAGS.
	(cpu_flags): Add CpuWBNOINVD.
	* i386-opc.h (enum): Add CpuWBNOINVD.
	(i386_cpu_flags): Add cpuwbnoinvd.
	* i386-opc.tbl: Add WBNOINVD instruction.
	* i386-init.h: Regenerate.
	* i386-tbl.h: Likewise.