nettle: Update to version 3.8.1

nettle: Update to version 3.8.1

- Update from version 3.7.3 to 3.8.1
- Update of rootfile
- Changelog
   3.8.1 release
	This is a bugfix release, fixing a few portability issues
	reported for Nettle-3.8.
	Bug fixes:
	* Avoid non-posix m4 argument references in the chacha
	  implementation for arm64, powerpc64 and s390x. Reported by
	  Christian Weisgerber, fix contributed by Mamone Tarsha.
	* Use explicit .machine pseudo-ops where needed in s390x
	  assembly files. Bug report by Andreas K. Huettel, fix
	  contributed by Mamone Tarsha.
	Optimizations:
	* Implemented runtime detection of cpu features for OpenBSD on
	  arm64. Contributed by Christian Weisgerber.
	The new version is intended to be fully source and binary
	compatible with Nettle-3.6. The shared library names are
	libnettle.so.8.6 and libhogweed.so.6.6, with sonames
	libnettle.so.8 and libhogweed.so.6.
   3.8 release
	This release includes a couple of new features, and many
	performance improvements. It adds assembly code for two more
	architectures: ARM64 and S390x.
	The new version is intended to be fully source and binary
	compatible with Nettle-3.6. The shared library names are
	libnettle.so.8.5 and libhogweed.so.6.5, with sonames
	libnettle.so.8 and libhogweed.so.6.
	New features:
	* AES keywrap (RFC 3394), contributed by Nicolas Mora.
	* SM3 hash function, contributed by Tianjia Zhang.
	* New functions cbc_aes128_encrypt, cbc_aes192_encrypt,
	  cbc_aes256_encrypt.
	  On processors where AES is fast enough, e.g., x86_64 with
	  aesni instructions, the overhead of using Nettle's general
	  cbc_encrypt can be significant. The new functions can be
	  implemented in assembly, to do multiple blocks with reduced
	  per-block overhead.
	  Note that there's no corresponding new decrypt functions,
	  since the general cbc_decrypt doesn't suffer from the same
	  performance problem.
	Bug fixes:
	* Fix fat builds for x86_64 windows, these appear to never
          have worked.
	Optimizations:
	* New ARM64 implementation of AES, GCM, Chacha, SHA1 and
	  SHA256, for processors supporting crypto extensions. Great
	  speedups, and fat builds are supported. Contributed by
	  Mamone Tarsha.
	* New s390x implementation of AES, GCM, Chacha, memxor, SHA1,
	  SHA256, SHA512 and SHA3. Great speedups, and fat builds are
	  supported. Contributed by Mamone Tarsha.
	* New PPC64 assembly for ecc modulo/redc operations,
	  contributed by Amitay Isaacs, Martin Schwenke and Alastair
	  D´Silva.
	* The x86_64 AES implementation using aesni instructions has
	  been reorganized with one separate function per key size,
	  each interleaving the processing of two blocks at a time
	  (when the caller processes multiple blocks with each call).
	  This gives a modest performance improvement on some
	  processors.
	* Rewritten and faster x86_64 poly1305 assembly.
	Known issues:
	* Nettle's testsuite doesn't work out-of-the-box on recent
	  MacOS, due to /bin/sh discarding the DYLD_LIBRARY_PATH
	  environment variable. Nettle's test scripts handle this in
	  some cases, but currently fails the test cases that are
	  themselves written as /bin/sh scripts. As a workaround, use
	  make check EMULATOR='env DYLD_LIBRARY_PATH=$(TEST_SHLIB_DIR)'
	Miscellaneous:
	* Updated manual to current makeinfo conventions, with no
	  explicit node pointers. Generate pdf version with texi2pdf,
	  to get working hyper links.
	* Added square root functions for NIST ecc curves, as a
	  preparation for supporting compact point representation.
	* Reworked internal GCM/ghash interfaces, simplifying assembly
	  implementations. Deleted unused GCM C implementation
	  variants with less than 8-bit lookup table.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>