AviSynth+ 3.7.4 with unofficial additional builds, "filesonly" edition.
Surely, we don't want to officially support so many different kind of compiler sugar.
I provide there builds as-is (and is good for a reference build for myself for developing and benchmarking).
LLVM is not magic, they are not necessarily quicker than MSVC builds, sometimes are slower.
This is true for these AVX2 vs SSE4.2 builds, where sometimes the SSE4.2 version provides 25% quicker code from unoptimized C source than the AVX2 counterpart. But in other use cases AVX2 is much faster.
So it depends; evaluate for your favourite script and decide. If you cannot decide, stuck with the official files at https://github.com/AviSynth/AviSynthPlus/releases/tag/v3.7.4
Added:
Intel C++ Compiler 2025 (ICX - LLVM based) Windows x64 builds with two compiler options: SSE4.2, AVX2.
Note, that as an extra, only avisynth.dll is provided.