[AArch64] Add ARMv8.3 instructions which are in the NOP space

[AArch64] Add ARMv8.3 instructions which are in the NOP space

This patch adds support for a subset of the ARMv8.3 pointer authentication
instructions: XPACLRI, PACIA1716, PACIB1716, AUTIA1716, AUTIA1716, PACIAZ,
PACIASP, PACIBZ, PACISP, AUTIAZ, AUTIASP, AUTIBZ, AUTIBSP.

These are aliases to HINT #0x7, HINT #0x8, HINT #0xa, HINT #0xc, HINT #0xe,
HINT #0x18, HINT #0x19, ..., HINT #0x1f respectively.

For more details about pointer authentication in ARMv8.3 see
https://community.arm.com/groups/processors/blog/2016/10/27/armv8-a-architecture-2016-additions

opcodes/
2016-11-11  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* aarch64-tbl.h (aarch64_feature_v8_3, ARMV8_3, V8_3_INSN): New.
	(arch64_opcode_table): Add xpaclri, pacia1716, pacib1716, autia1716,
	autib1716, paciaz, paciasp, pacibz, pacibsp, autiaz, autiasp, autibz,
	autibsp.
	* aarch64-asm-2.c: Regenerate.
	* aarch64-dis-2.c: Regenerate.

gas/
2016-11-11  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* testsuite/gas/aarch64/system-3.s: New.
	* testsuite/gas/aarch64/system-3.d: New.
	* testsuite/gas/aarch64/system.d: Update expected output.