Add support for intel SERIALIZE instruction

Add support for intel SERIALIZE instruction

gas/

	* config/tc-i386.c (cpu_arch): Add .serialize.
	(cpu_noarch): Likewise.
	* doc/c-i386.texi: Document serialize.
	* testsuite/gas/i386/i386.exp: Run serialize tests
	* testsuite/gas/i386/serialize.d: Likewise.
	* testsuite/gas/i386/x86-64-serialize.d: Likewise.
	* testsuite/gas/i386/serialize.s: Likewise.

opcodes/

	* i386-dis.c (prefix_table): New instructions serialize.
	* i386-gen.c (cpu_flag_init): Add CPU_SERIALIZE_FLAGS,
	CPU_ANY_SERIALIZE_FLAGS.
	(cpu_flags): Add CpuSERIALIZE.
	* i386-opc.h (enum): Add CpuSERIALIZE.
	(i386_cpu_flags): Add cpuserialize.
	* i386-opc.tbl: Add SERIALIZE insns.
	* i386-init.h: Regenerate.
	* i386-tbl.h: Likewise.