[binutils][aarch64] New SVE_Zm4_11_INDEX operand.

[binutils][aarch64] New SVE_Zm4_11_INDEX operand.

This includes defining a new single bit field SVE_i2h at position 20.
SVE_Zm4_11_INDEX handles indexed Zn registers where the index is encoded
in bits 20:11 and the register is chosed from range z0-z15 in bits 19-16.

gas/ChangeLog:

2019-05-09  Matthew Malcomson  <matthew.malcomson@arm.com>

	* config/tc-aarch64.c (parse_operands): Handle new SVE_Zm4_11_INDEX
	operand.

include/ChangeLog:

2019-05-09  Matthew Malcomson  <matthew.malcomson@arm.com>

	* opcode/aarch64.h (enum aarch64_opnd): New SVE_Zm4_11_INDEX operand.

opcodes/ChangeLog:

2019-05-09  Matthew Malcomson  <matthew.malcomson@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): Constraint checking
	for SVE_Zm4_11_INDEX.
	(aarch64_print_operand): Add printing for SVE_Zm4_11_INDEX.
	(fields): Handle SVE_i2h field.
	* aarch64-opc.h (enum aarch64_field_kind): New SVE_i2h field.
	* aarch64-tbl.h (AARCH64_OPERANDS): Use new SVE_Zm4_11_INDEX operand.