aarch64: [SME] Add ZERO instruction

aarch64: [SME] Add ZERO instruction

This patch is adding ZERO (a list of 64-bit element ZA tiles)
instruction.

gas/ChangeLog:

	* config/tc-aarch64.c (parse_sme_list_of_64bit_tiles):
	New parser.
	(parse_operands): Handle OPND_SME_list_of_64bit_tiles.
	* testsuite/gas/aarch64/sme-4-illegal.d: New test.
	* testsuite/gas/aarch64/sme-4-illegal.l: New test.
	* testsuite/gas/aarch64/sme-4-illegal.s: New test.
	* testsuite/gas/aarch64/sme-4.d: New test.
	* testsuite/gas/aarch64/sme-4.s: New test.

include/ChangeLog:

	* opcode/aarch64.h (enum aarch64_opnd): New operand
	AARCH64_OPND_SME_list_of_64bit_tiles.

opcodes/ChangeLog:

	* aarch64-opc.c (print_sme_za_list): New printing function.
	(aarch64_print_operand): Handle OPND_SME_list_of_64bit_tiles.
	* aarch64-opc.h (enum aarch64_field_kind): New bitfield
	FLD_SME_zero_mask.
	* aarch64-tbl.h (struct aarch64_opcode): New ZERO instruction.
	aarch64-asm-2.c: Regenerate.
	aarch64-dis-2.c: Regenerate.
	aarch64-opc-2.c: Regenerate.