Use LLVM 16

[radekdoulik]

No description provided.

[radekdoulik]

Let see if emscripten still builds with llvm 16

[akoeplinger]

We can certainly try but there's a huge amount of libcxx changes in upstream that were also merged :)
I also wonder if that'd make third-party libraries incompatible if they were built with upstream emsdk instead of our version, even though they use the same version number.

[radekdoulik]

@directhex what was the motivation to use older llvm versions?

[directhex]

@directhex what was the motivation to use older llvm versions?

It's not an arbitrarily old version, it's (in theory!) the LLVM commit matching the binary emsdk release's bundle.

emsdk doesn't really have what you would call "release management" - if you build an old tag from source today, it uses git main HEAD for some components (like LLVM) so a from-source build today of 3.1.34 has entirely different libraries in it vs. the binary download of 3.1.34. It was also kinda synergy that LLVM 16 is also the version we use to build the product on Linux (https://github.com/dotnet/dotnet-buildtools-prereqs-docker/blob/main/src/cbl-mariner/2.0/crossdeps-builder/Dockerfile#L56) but I don't think it hugely matters that those align.

[lewing]

We can do this for the moment but we should also see about standing up a llvm19x build