Add assembler and disassembler support for the new Armv8.4-a instructions for AArch64.

Add assembler and disassembler support for the new Armv8.4-a instructions for AArch64.

Some of these instructions have been back-ported as optional extensions to
Armv8.2-a and higher, but others are only available for Armv8.4-a.

opcodes/

	* aarch64-tbl.h (sha512h, sha512h2, sha512su0, sha512su1, eor3): New.
	(rax1, xar, bcax, sm3ss1, sm3tt1a, sm3tt1b, sm3tt2a, sm3tt2b): New.
	(sm3partw1, sm3partw2, sm4e, sm4ekey, fmlal, fmlsl): New.
	(fmlal2, fmlsl2, cfinv, rmif, setf8, setf16, stlurb): New.
	(ldapurb, ldapursb, stlurh, ldapurh, ldapursh, stlur): New.
	(ldapur, ldapursw, stlur): New.
	* aarch64-dis-2.c: Regenerate.

gas/

	* testsuite/gas/aarch64/armv8_4-a-illegal.d: New.
	* testsuite/gas/aarch64/armv8_4-a-illegal.l: New.
	* testsuite/gas/aarch64/armv8_4-a-illegal.s: New.
	* testsuite/gas/aarch64/armv8_4-a.d: New.
	* testsuite/gas/aarch64/armv8_4-a.s: New.
	* testsuite/gas/aarch64/armv8_2-a-crypto-fp16.s: New.
	* testsuite/gas/aarch64/armv8_2-a-crypto-fp16.d: New.
	* testsuite/gas/aarch64/armv8_3-a-crypto-fp16.d: New.
	* testsuite/gas/aarch64/armv8_4-a-crypto-fp16.d: New.
	* testsuite/gas/aarch64/armv8_2-a-crypto-fp16-illegal.s: New.
	* testsuite/gas/aarch64/armv8_2-a-crypto-fp16-illegal.l: New.
	* testsuite/gas/aarch64/armv8_2-a-crypto-fp16-illegal.d: New.