[AArch64] Add ARMv8.3 PACGA instruction

[AArch64] Add ARMv8.3 PACGA instruction

Add support for the ARMv8.3 PACGA instruction.

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

	* opcode/aarch64.h (enum aarch64_opnd): Add AARCH64_OPND_Rm_SP.

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

	* aarch64-tbl.h (arch64_opcode_table): Add pacga.
	(AARCH64_OPERANDS): Add Rm_SP.
	* aarch64-opc.c (aarch64_print_operand): Handle AARCH64_OPND_Rm_SP.
	* aarch64-asm-2.c: Regenerate.
	* aarch64-dis-2.c: Regenerate.
	* aarch64-opc-2.c: Regenerate.

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

	* config/tc-aarch64.c (process_omitted_operand): Handle AARCH64_OPND_Rm_SP.
	(parse_operands): Likewise.
	* testsuite/gas/aarch64/pac.s: Add pacga.
	* testsuite/gas/aarch64/pac.d: Add pacga.