[PATCH, BINUTILS, AARCH64, 7/9] Add BTI instruction

[PATCH, BINUTILS, AARCH64, 7/9] Add BTI instruction

This patch is part of the patch series to add support for ARMv8.5-A
extensions.
(https://developer.arm.com/products/architecture/cpu-architecture/a-profile/docs/ddi0596/a/a64-base-instructions-alphabetic-order/bti-branch-target-identification)

The Branch Target Identification instructions (BTI) are allocated to
existing HINT space, using HINT numbers 32, 34, 36, 38, such that
bits[7:6] of the instruction identify the compatibility of the BTI
instruction to different branches.

	BTI {<targets>}

where <targets> one of the following, specifying which type of
indirection is allowed:

	j : Can be a target of any BR Xn isntruction.
	c : Can be a target of any BLR Xn and BR {X16|X17}.
	jc: Can be a target of any free branch.

A BTI instruction without any <targets> is the strictest of all and
can not be a target of nay free branch.

*** include/ChangeLog ***

2018-10-09  Sudakshina Das  <sudi.das@arm.com>

	* opcode/aarch64.h (AARCH64_FEATURE_BTI): New.
	(AARCH64_ARCH_V8_5): Add AARCH64_FEATURE_BTI by default.
	(aarch64_opnd): Add AARCH64_OPND_BTI_TARGET.
	(HINT_OPD_CSYNC, HINT_OPD_C, HINT_OPD_J): New macros to
	define HINT #imm values.
	(HINT_OPD_JC, HINT_OPD_NULL): Likewise.

*** opcodes/ChangeLog ***

2018-10-09  Sudakshina Das  <sudi.das@arm.com>

	* aarch64-opc.h (HINT_OPD_NOPRINT, HINT_ENCODE): New.
	(HINT_FLAG, HINT_VALUE): New macros to encode NO_PRINT flag
	with the hint immediate.
	* aarch64-opc.c (aarch64_hint_options): New entries for
	c, j, jc and default (with HINT_OPD_F_NOPRINT flag) for BTI.
	(aarch64_print_operand): Add case for AARCH64_OPND_BTI_TARGET
	while checking for HINT_OPD_F_NOPRINT flag.
	* aarch64-dis.c (aarch64_ext_hint): Use new HINT_VALUE to
	extract value.
	* aarch64-tbl.h (aarch64_feature_bti, BTI, BTI_INSN): New.
	(aarch64_opcode_table): Add entry for BTI.
	(AARCH64_OPERANDS): Add new description for BTI targets.
	* aarch64-asm-2.c: Regenerate.
	* aarch64-dis-2.c: Regenerate.
	* aarch64-opc-2.c: Regenerate.

*** gas/ChangeLog ***

2018-10-09  Sudakshina Das  <sudi.das@arm.com>

	* config/tc-aarch64.c (parse_bti_operand): New.
	(process_omitted_operand): Add case for AARCH64_OPND_BTI_TARGET.
	(parse_operands): Likewise.
	* testsuite/gas/aarch64/system.d: Update for BTI.
	* testsuite/gas/aarch64/bti.s: New.
	* testsuite/gas/aarch64/bti.d: New.
	* testsuite/gas/aarch64/illegal-bti.d: New.
	* testsuite/gas/aarch64/illegal-bti.l: New.