[PATCH][GAS] aarch64: Add DSB instruction Armv8.7-a variant

[Przemyslaw Wirkus]

> > gas/ChangeLog:
> >
> > 2020-10-23  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>
> >
> > 	* NEWS: Docs update.
> > 	* config/tc-aarch64.c (parse_operands): Add
> > 	AARCH64_OPND_BARRIER_DSB_NXS handler.
> > 	(md_begin): Add content of aarch64_barrier_dsb_nxs_options to
> > 	aarch64_barrier_opt_hsh hash.
> > 	* testsuite/gas/aarch64/system-4-invalid.d: New test.
> > 	* testsuite/gas/aarch64/system-4-invalid.l: New test.
> > 	* testsuite/gas/aarch64/system-4-invalid.s: New test.
> > 	* testsuite/gas/aarch64/system-4.d: New test.
> > 	* testsuite/gas/aarch64/system-4.s: New test.
> >
> > include/ChangeLog:
> >
> > 2020-10-23  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>
> >
> > 	* opcode/aarch64.h (enum aarch64_opnd): New operand
> > 	AARCH64_OPND_BARRIER_DSB_NXS.
> > 	(aarch64_barrier_dsb_nxs_options): Declare DSB nXS options.
> >
> > opcodes/ChangeLog:
> >
> > 2020-10-23  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>
> >
> > 	* aarch64-asm.c (aarch64_ins_barrier_dsb_nxs): New inserter.
> > 	* aarch64-asm.h (AARCH64_DECL_OPD_INSERTER): New inserter
> > 	ins_barrier_dsb_nx.
> > 	* aarch64-dis.c (aarch64_ext_barrier_dsb_nxs): New extractor.
> > 	* aarch64-dis.h (AARCH64_DECL_OPD_EXTRACTOR): New extractor
> > 	ext_barrier_dsb_nx.
> > 	* aarch64-opc.c (aarch64_print_operand): New options table
> > 	aarch64_barrier_dsb_nxs_options.
> > 	* aarch64-opc.h (enum aarch64_field_kind): New field name
> FLD_CRm_dsb_nxs.
> > 	* aarch64-tbl.h (struct aarch64_opcode): Define DSB nXS barrier
> > 	Armv8.7-a instruction.
> > 	* aarch64-asm-2.c: Regenerate.
> > 	* aarch64-dis-2.c: Regenerate.
> > 	* aarch64-opc-2.c: Regenerate.
> 
> Approved - please apply.

commit fd195909ce14c7e852319613e7ec6a9a6e7b99ea

> Cheers
>   Nick