Add support for Intel TDX instructions.

Add support for Intel TDX instructions.

gas/

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

opcodes/

	* i386-dis.c (enum): Add PREFIX_0F01_REG_1_RM_5,
	PREFIX_0F01_REG_1_RM_6, PREFIX_0F01_REG_1_RM_7,
	X86_64_0F01_REG_1_RM_5_P_2, X86_64_0F01_REG_1_RM_6_P_2,
	X86_64_0F01_REG_1_RM_7_P_2.
	(prefix_table): Likewise.
	(x86_64_table): Likewise.
	(rm_table): Likewise.
	* i386-gen.c (cpu_flag_init): Add CPU_TDX_FLAGS
	and CPU_ANY_TDX_FLAGS.
	(cpu_flags): Add CpuTDX.
	* i386-opc.h (enum): Add CpuTDX.
	(i386_cpu_flags): Add cputdx.
	* i386-opc.tbl: Add TDX insns.
	* i386-init.h: Regenerate.
	* i386-tbl.h: Likewise.