Split the ARM Crypto ISA extensions for AES and SHA1+2 into their own options (+aes and +sha2). The reason for the split is because with the introduction of Armv8.4-a the implementation of AES has explicitly been made independent of the implementation of the other crypto extensions.
gas * config/tc-aarch64.c (aarch64_arch_option_table): Add armv8.4-a.
(aarch64_features): Added SM4 and SHA3.
include * opcode/aarch64.h:
(AARCH64_FEATURE_V8_4, AARCH64_FEATURE_SM4): New.
(AARCH64_ARCH_V8_4, AARCH64_FEATURE_SHA3): New.