[AArch64][SVE 23/32] Add SVE pattern and prfop operands

[AArch64][SVE 23/32] Add SVE pattern and prfop operands

The SVE instructions have two enumerated operands: one to select a
vector pattern and another to select a prefetch operation.  The latter
is a cut-down version of the base AArch64 prefetch operation.

Both types of operand can also be specified as raw enum values such as #31.
Reserved values can only be specified this way.

If it hadn't been for the pattern operand, I would have been tempted
to use the existing parsing for prefetch operations and add extra
checks for SVE.  However, since the patterns needed new enum parsing
code anyway, it seeemed cleaner to reuse it for the prefetches too.

Because of the small number of enum values, I don't think we'd gain
anything by using hash tables.

include/
	* opcode/aarch64.h (AARCH64_OPND_SVE_PATTERN): New aarch64_opnd.
	(AARCH64_OPND_SVE_PRFOP): Likewise.
	(aarch64_sve_pattern_array): Declare.
	(aarch64_sve_prfop_array): Likewise.

opcodes/
	* aarch64-tbl.h (AARCH64_OPERANDS): Add entries for
	AARCH64_OPND_SVE_PATTERN and AARCH64_OPND_SVE_PRFOP.
	* aarch64-opc.h (FLD_SVE_pattern): New aarch64_field_kind.
	(FLD_SVE_prfop): Likewise.
	* aarch64-opc.c: Include libiberty.h.
	(aarch64_sve_pattern_array): New variable.
	(aarch64_sve_prfop_array): Likewise.
	(fields): Add entries for FLD_SVE_pattern and FLD_SVE_prfop.
	(aarch64_print_operand): Handle AARCH64_OPND_SVE_PATTERN and
	AARCH64_OPND_SVE_PRFOP.
	* aarch64-asm-2.c: Regenerate.
	* aarch64-dis-2.c: Likewise.
	* aarch64-opc-2.c: Likewise.

gas/
	* config/tc-aarch64.c (parse_enum_string): New function.
	(po_enum_or_fail): New macro.
	(parse_operands): Handle AARCH64_OPND_SVE_PATTERN and
	AARCH64_OPND_SVE_PRFOP.