[PATCH][GAS] aarch64: Add CSR PDEC instruction

[Nick Clifton]

Hi Przemyslaw,

> gas/ChangeLog:
> 2020-10-27  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>
> 
> 	* NEWS: Update docs.
> 	* config/tc-aarch64.c (parse_csr_operand): New operand parser.
> 	(parse_operands): Call to CSR operand parser.
> 	* testsuite/gas/aarch64/csre_csr-invalid.d: New test.
> 	* testsuite/gas/aarch64/csre_csr-invalid.l: New test.
> 	* testsuite/gas/aarch64/csre_csr-invalid.s: New test.
> 	* testsuite/gas/aarch64/csre_csr.d: New test.
> 	* testsuite/gas/aarch64/csre_csr.s: New test.
> 
> include/ChangeLog:
> 2020-10-27  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>
> 
> 	* opcode/aarch64.h (AARCH64_FEATURE_CSRE): New -march feature.
> 	(enum aarch64_opnd): New CSR instruction field AARCH64_OPND_CSRE_CSR.
> 
> opcodes/ChangeLog:
> 2020-10-27  Przemyslaw Wirkus  <przemyslaw.wirkus@arm.com>
> 
> 	* aarch64-opc.c (aarch64_print_operand): CSR PDEC operand print-out.
> 	* aarch64-tbl.h (CSRE): New CSRE feature handler.
> 	(_CSRE_INSN): New CSRE instruction type.
> 	(struct aarch64_opcode): New 'csre' entry for a CSRE CLI feature.
> 	* aarch64-asm-2.c: Regenerate.
> 	* aarch64-dis-2.c: Regenerate.
> 	* aarch64-opc-2.c: Regenerate.

Approved - please apply.

Cheers
  Nick