[Morello] Add Morello system registers

[Morello] Add Morello system registers

Implement MRS/MSR for capability registers.

gas/ChangeLog:

2020-10-20  Siddhesh Poyarekar  <siddesh.poyarekar@arm.com>

	* config/tc-aarch64.c (parse_sys_reg): New opcode argument.
	(parse_operands): Adjust callers.
	* testsuite/gas/aarch64/morello_insn-c64.d: Add tests.
	* testsuite/gas/aarch64/morello_insn.d: Likewise.
	* testsuite/gas/aarch64/morello_insn.s: Likewise.

include/ChangeLog:

2020-10-20  Siddhesh Poyarekar  <siddesh.poyarekar@arm.com>

	* include/opcode/aarch64.h
	(aarch64_sys_reg_capreg_supported_p): New function.

opcodes/ChangeLog:

2020-10-20  Siddhesh Poyarekar  <siddesh.poyarekar@arm.com>

	* aarch64-asm.c (aarch64_ins_sysreg): Adjust for morello
	MRS/MSR.
	* aarch64-dis.c (aarch64_ext_sysreg): Likewise.
	* aarch64-opc.c (fields): New field a64c_op0.
	(operand_general_constraint_met_p): Add SYSREG operand
	validation.
	(aarch64_print_operand): Print Morello MRS/MSR operands
	correctly.
	(SR_MORELLO): New macro.
	(aarch64_sys_regs): Use it.  Add Morello system registers.
	(aarch64_sys_reg_capreg_supported_p): New function.
	* aarch64-opc.h (aarch64_field_kind): New field FLD_a64c_op0.
	* aarch64-tbl.h (QL2_SRC_CA, QL2_DST_CA): New macros.
	(aarch64_opcode_table): New instructions.
	* aarch64-asm-2.c: Regenerate.
	* aarch64-dis-2.c: Regenerate.
	* aarch64-opc-2.c: Regenerate.