Deflate

* Improved CRC-32 performance on recent x86 CPUs by adding
VPCLMULQDQ-accelerated implementations using 256-bit and 512-bit vectors.

* Improved Adler-32 performance on recent x86 CPUs by adding
VNNI-accelerated implementations using 256-bit and 512-bit vectors.

* Improved CRC-32 and Adler-32 performance on short inputs.

* Optimized the portable implementation of Adler-32.

* Added some basic optimizations for RISC-V.

* Dropped support for gcc versions older than v4.9 (released in 2014)
and clang versions older than v3.9 (released in 2016).

* Dropped support for CRC-32 acceleration on 32-bit ARM using the ARMv8 pmull or
crc32 instructions. This code only worked on CPUs that also have a 64-bit
mode, and it was already disabled on many compiler versions due to compiler
limitations. CRC-32 acceleration remains fully supported on 64-bit ARM.

* Added new functions `libdeflate_alloc_compressor_ex()` and
`libdeflate_alloc_decompressor_ex()`. These functions allow specifying a
custom memory allocator on a per-compressor basis.

* libdeflate now always generates Huffman codes with at least 2 codewords. This
fixes a compatibility issue where Windows Explorer's ZIP unpacker could not
decompress DEFLATE streams created by libdeflate. libdeflate's behavior was
allowed by the DEFLATE RFC, but not all software was okay with it. In rare
cases, compression ratios can be slightly reduced by this change.

* Disabled the use of some compiler intrinsics on MSVC versions where they don't
work correctly.

* libdeflate can now compress up to the exact size of the output buffer.

* Slightly improved compression performance at levels 1-9.

* Improved the compression ratio of very short inputs.

* Fixed a bug where the build type didn't default to "Release" when using
CMake 3.10 or earlier.

* Fixed a bug where some optimized code wasn't used when building with
Clang 15 or later (x86), or with Clang 16 or later (aarch64).

* Fixed build errors with some architecture and compiler combos:
* aarch64 with Clang 16
* armv6kz or armv7e-m with gcc
* armhf with gcc (on Debian only)

(Apologies for another release so soon after v1.16, but the bug fix listed below
needed to go out.)

* Fixed a bug introduced in v1.16 where compression at levels 10-12 would
sometimes produce an output larger than the size that was returned by the
corresponding `libdeflate_*_compress_bound()` function.

* Converted the fuzzing scripts to use LLVM's libFuzzer and added them to the
GitHub Actions workflow. (This would have detected the above bug.)

* Further improved the support for direct compilation without using the official
build system. The top-level source directory no longer needs to be added to
the include path, and building the programs no longer requires that
`_FILE_OFFSET_BITS` and `_POSIX_C_SOURCE` be defined on the command line.

* Improved the compression ratio at levels 10-12 slightly, mainly levels 11-12.
Some inputs (such as certain PNG files) see much improved compression ratios.
As a trade-off, compressing at levels 11-12 is now about 5-20% slower.

* For consistency with zlib, the decompressor now returns an error on some
invalid inputs that were accepted before.

* Fixed a build error on arm64 with gcc with certain target CPUs. (Fixes v1.12)

* Fixed a build error on arm32 with gcc 10.1-10.3 and 11.1-11.2. (Fixes v1.15)

* Fixed a build error on arm32 with gcc in soft float mode. (Fixes v1.15)

* Fixed a build error in programs/gzip.c with uClibc. (Fixes v1.15)

* Fixed the install target on Windows. (Fixes v1.15)

* libdeflate now uses CMake instead of a plain Makefile.

* Improved MSVC support. Enabled most architecture-specific code with MSVC,
fixed building with clang in MSVC compatibility mode, and other improvements.

* When libdeflate is built with MinGW, the static library and import library are
now named using the MinGW convention (`*.a` and `*.dll.a`) instead of the
Visual Studio convention. This affects the official Windows binaries.