aarch64: Normalize and sort feature bit macros

aarch64: Normalize and sort feature bit macros

This patch normalizes and sorts the feature bit macros in
include/opcode/aarch64.h such that it's easy to tell which bits are
allocated and where it's safe to add new feature bits.

Testing:
 * Testsuite run on aarch64-none-elf.

include/ChangeLog:

2020-06-22  Alex Coplan  <alex.coplan@arm.com>

	* opcode/aarch64.h (AARCH64_FEATURE_SHA2): Normalize.
	(AARCH64_FEATURE_AES): Likewise.
	(AARCH64_FEATURE_V8_4): Likewise.
	(AARCH64_FEATURE_SM4): Likewise.
	(AARCH64_FEATURE_SHA3): Likewise.
	(AARCH64_FEATURE_V8): Likewise.
	(AARCH64_FEATURE_V8_2): Likewise.
	(AARCH64_FEATURE_V8_3): Likewise.
	(AARCH64_FEATURE_FP): Likewise.
	(AARCH64_FEATURE_SIMD): Likewise.
	(AARCH64_FEATURE_CRC): Likewise.
	(AARCH64_FEATURE_LSE): Likewise.
	(AARCH64_FEATURE_PAN): Likewise.
	(AARCH64_FEATURE_LOR): Likewise.
	(AARCH64_FEATURE_RDMA): Likewise.
	(AARCH64_FEATURE_V8_1): Likewise.
	(AARCH64_FEATURE_F16): Likewise.
	(AARCH64_FEATURE_RAS): Likewise.
	(AARCH64_FEATURE_PROFILE): Likewise.
	(AARCH64_FEATURE_SVE): Likewise.
	(AARCH64_FEATURE_RCPC): Likewise.
	(AARCH64_FEATURE_COMPNUM): Likewise.
	(AARCH64_FEATURE_DOTPROD): Likewise.
	(AARCH64_FEATURE_F16_FML): Likewise.
	(AARCH64_FEATURE_V8_5): Likewise.
	(AARCH64_FEATURE_V8_6): Likewise.
	(AARCH64_FEATURE_BFLOAT16): Likewise.
	(AARCH64_FEATURE_FLAGMANIP): Likewise.
	(AARCH64_FEATURE_FRINTTS): Likewise.
	(AARCH64_FEATURE_SB): Likewise.
	(AARCH64_FEATURE_PREDRES): Likewise.
	(AARCH64_FEATURE_CVADP): Likewise.
	(AARCH64_FEATURE_RNG): Likewise.
	(AARCH64_FEATURE_BTI): Likewise.
	(AARCH64_FEATURE_SCXTNUM): Likewise.
	(AARCH64_FEATURE_ID_PFR2): Likewise.
	(AARCH64_FEATURE_SSBS): Likewise.
	(AARCH64_FEATURE_MEMTAG): Likewise.
	(AARCH64_FEATURE_TME): Likewise.
	(AARCH64_FEATURE_I8MM): Likewise.
	(AARCH64_FEATURE_F32MM): Likewise.
	(AARCH64_FEATURE_F64MM): Likewise.
	(AARCH64_FEATURE_SVE2): Likewise.
	(AARCH64_FEATURE_SVE2_AES): Likewise.
	(AARCH64_FEATURE_SVE2_BITPERM): Likewise.
	(AARCH64_FEATURE_SVE2_SM4): Likewise.
	(AARCH64_FEATURE_SVE2_SHA3): Likewise.