Modify AArch64 Assembly and disassembly functions to be able to fail and report why.

This patch if the first patch in a series to add the ability to add constraints
to system registers that an instruction must adhere to in order for the register
to be usable with that instruction.

These constraints can also be used to disambiguate between registers with the
same encoding during disassembly.

This patch adds a new flags entry in the sysreg structures and ensures it is
filled in and read out during assembly/disassembly. It also adds the ability for
the assemble and disassemble functions to be able to gracefully fail and re-use
the existing error reporting infrastructure.

The return type of these functions are changed to a boolean to denote success or
failure and the error structure is passed around to them. This requires
aarch64-gen changes so a lot of the changes here are just mechanical.

gas/

	PR binutils/21446
	* config/tc-aarch64.c (parse_sys_reg): Return register flags.
	(parse_operands): Fill in register flags.

gdb/

	PR binutils/21446
	* aarch64-tdep.c (aarch64_analyze_prologue,
	aarch64_software_single_step, aarch64_displaced_step_copy_insn):
	Indicate not interested in errors.

include/

	PR binutils/21446
	* opcode/aarch64.h (aarch64_opnd_info): Change sysreg to struct.
	(aarch64_decode_insn): Accept error struct.

opcodes/

	PR binutils/21446
	* aarch64-asm.h (aarch64_insert_operand, aarch64_##x): Return boolean
	and take error struct.
	* aarch64-asm.c (aarch64_ext_regno, aarch64_ins_reglane,
	aarch64_ins_reglist, aarch64_ins_ldst_reglist,
	aarch64_ins_ldst_reglist_r, aarch64_ins_ldst_elemlist,
	aarch64_ins_advsimd_imm_shift, aarch64_ins_imm, aarch64_ins_imm_half,
	aarch64_ins_advsimd_imm_modified, aarch64_ins_fpimm,
	aarch64_ins_imm_rotate1, aarch64_ins_imm_rotate2, aarch64_ins_fbits,
	aarch64_ins_aimm, aarch64_ins_limm_1, aarch64_ins_limm,
	aarch64_ins_inv_limm, aarch64_ins_ft, aarch64_ins_addr_simple,
	aarch64_ins_addr_regoff, aarch64_ins_addr_offset, aarch64_ins_addr_simm,
	aarch64_ins_addr_simm10, aarch64_ins_addr_uimm12,
	aarch64_ins_simd_addr_post, aarch64_ins_cond, aarch64_ins_sysreg,
	aarch64_ins_pstatefield, aarch64_ins_sysins_op, aarch64_ins_barrier,
	aarch64_ins_prfop, aarch64_ins_hint, aarch64_ins_reg_extended,
	aarch64_ins_reg_shifted, aarch64_ins_sve_addr_ri_s4xvl,
	aarch64_ins_sve_addr_ri_s6xvl, aarch64_ins_sve_addr_ri_s9xvl,
	aarch64_ins_sve_addr_ri_s4, aarch64_ins_sve_addr_ri_u6,
	aarch64_ins_sve_addr_rr_lsl, aarch64_ins_sve_addr_rz_xtw,
	aarch64_ins_sve_addr_zi_u5, aarch64_ext_sve_addr_zz,
	aarch64_ins_sve_addr_zz_lsl, aarch64_ins_sve_addr_zz_sxtw,
	aarch64_ins_sve_addr_zz_uxtw, aarch64_ins_sve_aimm,
	aarch64_ins_sve_asimm, aarch64_ins_sve_index, aarch64_ins_sve_limm_mov,
	aarch64_ins_sve_quad_index, aarch64_ins_sve_reglist,
	aarch64_ins_sve_scale, aarch64_ins_sve_shlimm, aarch64_ins_sve_shrimm,
	aarch64_ins_sve_float_half_one, aarch64_ins_sve_float_half_two,
	aarch64_ins_sve_float_zero_one, aarch64_opcode_encode): Likewise.
	* aarch64-dis.h (aarch64_extract_operand, aarch64_##x): Likewise.
	* aarch64-dis.c (aarch64_ext_regno, aarch64_ext_reglane,
	aarch64_ext_reglist, aarch64_ext_ldst_reglist,
	aarch64_ext_ldst_reglist_r, aarch64_ext_ldst_elemlist,
	aarch64_ext_advsimd_imm_shift, aarch64_ext_imm, aarch64_ext_imm_half,
	aarch64_ext_advsimd_imm_modified, aarch64_ext_fpimm,
	aarch64_ext_imm_rotate1, aarch64_ext_imm_rotate2, aarch64_ext_fbits,
	aarch64_ext_aimm, aarch64_ext_limm_1, aarch64_ext_limm, decode_limm,
	aarch64_ext_inv_limm, aarch64_ext_ft, aarch64_ext_addr_simple,
	aarch64_ext_addr_regoff, aarch64_ext_addr_offset, aarch64_ext_addr_simm,
	aarch64_ext_addr_simm10, aarch64_ext_addr_uimm12,
	aarch64_ext_simd_addr_post, aarch64_ext_cond, aarch64_ext_sysreg,
	aarch64_ext_pstatefield, aarch64_ext_sysins_op, aarch64_ext_barrier,
	aarch64_ext_prfop, aarch64_ext_hint, aarch64_ext_reg_extended,
	aarch64_ext_reg_shifted, aarch64_ext_sve_addr_ri_s4xvl,
	aarch64_ext_sve_addr_ri_s6xvl, aarch64_ext_sve_addr_ri_s9xvl,
	aarch64_ext_sve_addr_ri_s4, aarch64_ext_sve_addr_ri_u6,
	aarch64_ext_sve_addr_rr_lsl, aarch64_ext_sve_addr_rz_xtw,
	aarch64_ext_sve_addr_zi_u5, aarch64_ext_sve_addr_zz,
	aarch64_ext_sve_addr_zz_lsl, aarch64_ext_sve_addr_zz_sxtw,
	aarch64_ext_sve_addr_zz_uxtw, aarch64_ext_sve_aimm,
	aarch64_ext_sve_asimm, aarch64_ext_sve_index, aarch64_ext_sve_limm_mov,
	aarch64_ext_sve_quad_index, aarch64_ext_sve_reglist,
	aarch64_ext_sve_scale, aarch64_ext_sve_shlimm, aarch64_ext_sve_shrimm,
	aarch64_ext_sve_float_half_one, aarch64_ext_sve_float_half_two,
	aarch64_ext_sve_float_zero_one, aarch64_opcode_decode): Likewise.
	(determine_disassembling_preference, aarch64_decode_insn,
	print_insn_aarch64_word, print_insn_data): Take errors struct.
	(print_insn_aarch64): Use errors.
	* aarch64-asm-2.c: Regenerate.
	* aarch64-dis-2.c: Regenerate.
	* aarch64-gen.c (print_operand_inserter): Use errors and change type to
	boolean in aarch64_insert_operan.
	(print_operand_extractor): Likewise.
	* aarch64-opc.c (aarch64_print_operand): Use sysreg struct.

include/opcode/aarch64.h

@@ -957,9 +957,17 @@ struct aarch64_opnd_info
 	  unsigned preind : 1;		/* Pre-indexed.  */
 	  unsigned postind : 1;		/* Post-indexed.  */
 	} addr;
+
+      struct
+	{
+	  /* The encoding of the system register.  */
+	  aarch64_insn value;
+
+	  /* The system register flags.  */
+	  uint32_t flags;
+	} sysreg;
+
       const aarch64_cond *cond;
-      /* The encoding of the system register.  */
-      aarch64_insn sysreg;
       /* The encoding of the PSTATE field.  */
       aarch64_insn pstatefield;
       const aarch64_sys_ins_reg *sysins_op;
@@ -1138,7 +1146,8 @@ extern int
 aarch64_zero_register_p (const aarch64_opnd_info *);
 
 extern int
-aarch64_decode_insn (aarch64_insn, aarch64_inst *, bfd_boolean);
+aarch64_decode_insn (aarch64_insn, aarch64_inst *, bfd_boolean,
+		     aarch64_operand_error *errors);
 
 /* Given an operand qualifier, return the expected data element size
    of a qualified operand.  */