[BINUTILS, AArch64] Enable Transactional Memory Extension

[BINUTILS, AArch64] Enable Transactional Memory Extension

This patch enables the new Transactional Memory Extension added recently
as part of Arm's new architecture technologies.

We introduce a new optional extension "tme" to enable this. The following
instructions are part of the extension:
   * tstart <Xt>
   * ttest <Xt>
   * tcommit
   * tcancel #<imm>
The ISA for the above can be found here:
https://developer.arm.com/docs/ddi0602/latest/base-instructions-alphabetic-order

*** gas/ChangeLog ***

2019-05-01  Sudakshina Das  <sudi.das@arm.com>

	* config/tc-aarch64.c (parse_operands): Add case for
	AARCH64_OPND_TME_UIMM16.
	(aarch64_features): Add "tme".
	* doc/c-aarch64.texi: Document the same.
	* testsuite/gas/aarch64/tme-invalid.d: New test.
	* testsuite/gas/aarch64/tme-invalid.l: New test.
	* testsuite/gas/aarch64/tme-invalid.s: New test.
	* testsuite/gas/aarch64/tme.d: New test.
	* testsuite/gas/aarch64/tme.s: New test.

*** include/ChangeLog ***

2019-05-01  Sudakshina Das  <sudi.das@arm.com>

	* opcode/aarch64.h (AARCH64_FEATURE_TME): New.
	(enum aarch64_opnd): Add AARCH64_OPND_TME_UIMM16.

*** opcodes/ChangeLog ***

2019-05-01  Sudakshina Das  <sudi.das@arm.com>

	* aarch64-asm-2.c: Regenerated.
	* aarch64-dis-2.c: Regenerated.
	* aarch64-opc-2.c: Regenerated.
	* aarch64-opc.c (operand_general_constraint_met_p): Add case for
	AARCH64_OPND_TME_UIMM16.
	(aarch64_print_operand): Likewise.
	* aarch64-tbl.h (QL_IMM_NIL): New.
	(TME): New.
	(_TME_INSN): New.
	(struct aarch64_opcode): Add tstart, tcommit, ttest and tcancel.