[Huffman Assembly] Expand supported platforms

The x86-64 Huffman assembly implementation is currently allow-listed to work on:

• Linux: defined(__linux__) || defined(__linux)
• MacOS: defined(__APPLE__)

The macro to check this is HUF_ASM_SUPPORTED defined in huf_decompress.c.

I've selected a very restricted set of platforms because I want to be sure that it is well tested before enabling it. Any platform that shares a calling convention with Linux should just work, but I want to be cautious of details, like working with interrupt handlers & debuggers. It should be easy to add BSD to this list, if someone wants to test that everything works as expected.

The assembly currently doesn't work on Windows because it has a different calling convention. And I had a really hard time getting the detection macros right. So if someone wants to take that on, that would be great.

Tasks:

• Test and enable support for x86-64 assembly on BSD.
• Add support for Windows in the x86-64 assembly & enable assembly in the Visual Studios build.
• Add support for assembly in the amalgamated build (build/single_file_libs). Probably by translating the .S file into inline assembly.
• Add an aarch64 assembly implementation.